Terbutaline pump maintenance therapy after threatened preterm labour for reducing adverse neonatal outcomes.

PubMed

Chawanpaiboon, Saifon; Laopaiboon, Malinee; Lumbiganon, Pisake; Sangkomkamhang, Ussanee S; Dowswell, Therese

2014-03-23

After successful inhibition of threatened preterm labour women are at high risk of recurrent preterm labour. Terbutaline pump maintenance therapy has been used to reduce adverse neonatal outcomes. This review replaces an earlier Cochrane review, published in 2002, which is no longer being updated by the team. To determine the effectiveness of terbutaline pump maintenance therapy after threatened preterm labour in reducing adverse neonatal outcomes. We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (31 January 2014) and reference lists of retrieved studies. Randomised controlled trials comparing terbutaline pump therapy with alternative therapy, placebo, or no therapy after arrest of threatened preterm labour. Two review authors independently assessed the studies for inclusion and then extracted data as eligible for inclusion in qualitative and quantitative synthesis (meta-analysis). Four studies were included with a total of 234 women randomised. The overall methodological quality of the included studies was mixed; two studies provided very little information on study methods, there was high sample attrition in one study and in three studies the risk of performance bias was high. We found no strong evidence that terbutaline maintenance therapy offered any advantages over saline placebo or oral terbutaline maintenance therapy in reducing adverse neonatal outcomes by prolonging pregnancy among women with arrested preterm labour. The mean difference (MD) for gestational age at birth was -0.14 weeks (95% confidence interval (CI) -1.66 to 1.38) for terbutaline pump therapy compared with saline placebo pump for two trials combined. One trial reported a risk ratio (RR) of 1.17 (95% CI 0.79 to 1.73) for preterm birth (less than 37 completed weeks) and a RR of 0.97 (95% CI 0.51 to 1.84) of very preterm birth (less than 34 completed weeks) for terbutaline pump compared with saline placebo pump. We found no evidence that terbutaline pump therapy was associated with statistically significant reductions in infant respiratory distress syndrome, or neonatal intensive care unit admission compared with placebo. Compared with oral terbutaline, we found no evidence that pump therapy increased the rate of therapy continuation, or reduced the rate of infant complications or maternal hospital re-admissions. One study suggested that pump therapy resulted in significantly increased weekly cost/woman, $580 versus $12.50 (P < 0.01). No data were reported on long-term infant outcomes. We found no evidence that terbutaline pump maintenance therapy decreased adverse neonatal outcomes. Taken together with the lack of evidence of benefit, its substantial expense and the lack of information on the safety of the therapy do not support its use in the management of arrested preterm labour. Future use should only be in the context of well-conducted, adequately powered randomised controlled trials.

Myocardial revascularization with miniaturized extracorporeal circulation versus off pump: Evaluation of systemic and myocardial inflammatory response in a prospective randomized study.

PubMed

Formica, Francesco; Broccolo, Francesco; Martino, Antonello; Sciucchetti, Jennifer; Giordano, Vincenzo; Avalli, Leonello; Radaelli, Gianluigi; Ferro, Orazio; Corti, Fabrizio; Cocuzza, Clementina; Paolini, Giovanni

2009-05-01

This prospective randomized study sought to verify the systemic inflammatory response, inflammatory myocardial damage, and early clinical outcome in coronary surgery with the miniaturized extracorporeal circulation system or on the beating heart. Sixty consecutive patients were randomized to miniaturized extracorporeal circulation (n = 30) or off-pump coronary revascularization (off-pump coronary artery bypass grafting, n = 30). Intraoperative and postoperative data were recorded. Plasma levels of interleukin-6 and tumor necrosis factor-alpha were measured from systemic blood intraoperatively, at the end of operation, and 24 and 48 hours thereafter. Levels of the same markers and blood lactate were measured from coronary sinus blood intraoperatively to evaluate myocardial inflammation. Markers of myocardial damage were also analyzed. One patient died in the off-pump coronary artery bypass grafting group. There was no statistical difference in early clinical outcome in both groups. Release of interleukin-6 was higher in the off-pump coronary artery bypass grafting group 24 hours after the operation (P = .03), whereas levels of tumor necrosis factor-alpha were not different in both groups. Cardiac release of interleukin-6, tumor necrosis factor-alpha, and blood lactate were not different in both groups. Release of troponin T was not significantly different in both groups. Levels of creatine kinase mass were statistically higher in the miniaturized extracorporeal circulation group than in the off-pump coronary artery bypass grafting group, but only at the end of the operation (P < .0001). Hemoglobin levels were significantly higher in the miniaturized extracorporeal circulation group than in the off-pump coronary artery bypass grafting group after 24 hours (P = .01). Miniaturized extracorporeal circulation can be considered similar to off-pump surgery in terms of systemic inflammatory response, myocardial inflammation and damage, and early outcome.

Current outcomes of off-pump coronary artery bypass grafting: evidence from real world practice

PubMed Central

2016-01-01

Coronary artery bypass grafting (CABG) can be performed conventionally using cardiopulmonary bypass (CPB) and aortic clamping or on a beating heart (BH) without the use of CPB, the so-called off-pump CABG. Some surgeons, who are proponents of off-pump CABG, preferentially use this technique for the majority of operations, whereas others use it only in certain situations which warrant avoidance of CPB. Ever since the conception of off-pump CABG, the never-ending debate about which technique of CABG is safe and efficacious continues to date. Several randomized controlled trials (RCTs) have been conducted that have either favored on-pump CABG or have failed to show a significant difference in outcomes between the two techniques. However, these RCTs have been fraught with claims that they do not represent the majority of patients undergoing CABG in real world practice. Therefore, assessment of the benefits and drawbacks of each technique through observational and registry studies would be more representative of patients encountered in daily practice. The present review examines various retrospective studies and meta-analyses of observational studies that compare the early and long-term outcomes of off- and on-pump CABG, which assesses their safety and efficacy. Additionally, their outcomes in older patients, females, and those with diabetes mellitus, renal dysfunction, presence of ascending aortic disease, and/or acute coronary syndrome (ACS) have also been discussed separately. The general consensus is that early results of off-pump CABG are comparable to or in some cases better than on-pump CABG. However, on-pump CABG provides a survival benefit in the long term according to a majority of publications in literature. PMID:27942395

Assessing the effectiveness of a 3-month day-and-night home closed-loop control combined with pump suspend feature compared with sensor-augmented pump therapy in youths and adults with suboptimally controlled type 1 diabetes: a randomised parallel study protocol.

PubMed

Bally, Lia; Thabit, Hood; Tauschmann, Martin; Allen, Janet M; Hartnell, Sara; Wilinska, Malgorzata E; Exall, Jane; Huegel, Viki; Sibayan, Judy; Borgman, Sarah; Cheng, Peiyao; Blackburn, Maxine; Lawton, Julia; Elleri, Daniela; Leelarathna, Lalantha; Acerini, Carlo L; Campbell, Fiona; Shah, Viral N; Criego, Amy; Evans, Mark L; Dunger, David B; Kollman, Craig; Bergenstal, Richard M; Hovorka, Roman

2017-07-13

Despite therapeutic advances, many individuals with type 1 diabetes are unable to achieve tight glycaemic target without increasing the risk of hypoglycaemia. The objective of this study is to determine the effectiveness of a 3-month day-and-night home closed-loop glucose control combined with a pump suspend feature, compared with sensor-augmented insulin pump therapy in youths and adults with suboptimally controlled type 1 diabetes. The study adopts an open-label, multi-centre, multi-national (UK and USA), randomised, single-period, parallel design and aims for 84 randomised patients. Participants are youths (6-21 years) or adults (>21 years) with type 1 diabetes treated with insulin pump therapy and suboptimal glycaemic control (glycated haemoglobin (HbA1c) ≥7.5% (58 mmol/mol) and ≤10% (86 mmol/mol)). Following a 4-week run-in period, eligible participants will be randomised to a 3-month use of automated closed-loop insulin delivery combined with pump suspend feature or to sensor-augmented insulin pump therapy. Analyses will be conducted on an intention-to-treat basis. The primary outcome is the time spent in the target glucose range from 3.9 to 10.0 mmol/L based on continuous glucose monitoring levels during the 3-month free-living phase. Secondary outcomes include HbA1c at 3 months, mean glucose, time spent below and above target; time with glucose levels <3.5 and <2.8 mmol/L; area under the curve when sensor glucose is <3.5 mmol/L, time with glucose levels >16.7 mmol/L, glucose variability; total, basal and bolus insulin dose and change in body weight. Participants' and their families' perception in terms of lifestyle change, daily diabetes management and fear of hypoglycaemia will be evaluated. Ethics/institutional review board approval has been obtained. Before screening, all participants/guardians will be provided with oral and written information about the trial. The study will be disseminated by peer-reviewed publications and conference presentations. NCT02523131; Pre-results. © 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.

Does off-pump coronary surgery reduce morbidity and mortality?

PubMed

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

2002-10-01

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

Short-term clinical outcomes after off-pump coronary artery bypass grafting at a single Veterans Affairs Medical Center.

PubMed

Lushaj, Entela B; Schreiner, Athanasia; Jonuzi, Besa; Badami, Abbasali; DeOliveira, Nilto; Lozonschi, Lucian

2016-05-17

We retrospectively assessed the outcomes after coronary revascularization at a single Veterans Affairs Medical Center when a strategy of assigning higher risk patients to off-pump coronary artery bypass grafting (CABG) was employed. Over a 5 year period all consecutive patients that underwent CABG at our VA Medical Center were assigned to a surgeon who either performs the CABG exclusively off-pump or to one who performed the CABG on-pump. The higher risk patients were assigned preferentially for off-pump revascularization. VASQIP (VA Hospitals Surgical Quality Improvement Program) data between 10/2007 and 12/2012 were retrospectively reviewed at our VA Medical Center and the short term outcomes were assessed. A total of 252 consecutive patients underwent off-pump CABG (n = 170) and on-pump CABG (n = 82). There were significantly more patients with low LVEF (<45 %; p = 0.008) and cerebrovascular disease in the off-pump group (p = 0.024). The number of patients smoking at the time of surgery was significantly higher in the off-pump group (p = 0.002) as well. The 30-day composite morbidity and mortality was 6 % for all CABG patients and significantly lower with off-pump vs. on-pump CABG (3.5 % vs. 11 %; p = 0.019). There were no conversions from off-pump to on-pump surgery. A selective strategy to direct higher risk patients towards an off-pump revascularization yielded favorable outcomes in an unselected veteran population treated at a single VA Medical Center over a 5 year period.

TOPPITS: Trial Of Proton Pump Inhibitors in Throat Symptoms. Study protocol for a randomised controlled trial.

PubMed

Watson, Gillian; O'Hara, James; Carding, Paul; Lecouturier, Jan; Stocken, Deborah; Fouweather, Tony; Wilson, Janet

2016-04-01

Persistent throat symptoms and Extra Oesophageal Reflux (EOR) are among the commonest reasons for attendance at a secondary care throat or voice clinic. There is a growing trend to treat throat symptom patients with proton pump inhibitors (PPIs) to suppress stomach acid, but most controlled studies fail to demonstrate a significant benefit of PPI over placebo. In addition, patient views on PPI use vary widely. A UK multi-centre, randomised, controlled trial for adults with persistent throat symptoms to compare the effectiveness of treatment with the proton pump inhibitor (PPI) lansoprazole versus placebo. The trial includes a six-month internal pilot, during which three sites will recruit 30 participants in total, to assess the practicality of the trial and assess the study procedures and willingness of the patient population to participate. If the pilot is successful, three additional sites will be opened to recruitment, and a further 302 participants recruited across the six main trial sites. Further trial sites may be opened, as necessary. The main trial will continue for a further 18 months. Participants will be followed up for 12 months from randomisation, throughout which both primary and secondary outcome data will be collected. The primary outcome is change in Reflux Symptom Index (RSI) score, the 'area standard' for this type of assessment, after 16 weeks (four months) of treatment. Secondary outcomes are RSI changes at 12 months after randomisation, Quality of Life assessment at four and 12 months, laryngeal mucosal changes, assessments of compliance and side effects, and patient-reported satisfaction. TOPPITS is designed to evaluate the relative effectiveness of treatment with a proton pump inhibitor versus placebo in patients with persistent throat symptoms. This will provide valuable information to clinicians and GPs regarding the treatment and management of care for these patients, on changes in symptoms, and in Quality of Life, over time. ISRCTN38578686 . Registered 17 April 2014.

On pump versus off pump coronary artery bypass grafting in patients with end-stage renal disease and coronary artery disease - A nation-wide, propensity score matched database analyses.

PubMed

Chen, Jien-Jiun; Lin, Lian-Yu; Yang, Yao-Hsu; Hwang, Juey-Jen; Chen, Pau-Chung; Lin, Jiunn-Lee; Chi, Nai-Hsin

2017-01-15

The usage of on or off cardiopulmonary bypass in patients with coronary artery disease receiving coronary artery bypass grafting (CABG) surgery had been debated and had not yet been investigated thoroughly in patients with end-stage renal disease (ESRD). We aimed to study cardiovascular outcomes and total mortality in these patients by using our National Health Insurance (NHI) database. By using our NHI ESRD claim database, we searched ESRD patients aged more than 18years, who received CABG and divided them into on pump and off pump groups. Baseline characteristics and underlying comorbidities were identified from the database. Propensity score (PS) method was used to match all the potential confounders between patients. Outcomes including mortality, myocardial infarction, stroke and repeat revascularization within 30days, 1year and whole follow-up period were also obtained. A total of 134,410 ESRD patients were identified in the database. We included 341 patients and 543 patients who received off pump and on pump CABG respectively. The hazard ratios of different outcomes at 30days, 1year and a median of 745days after CABG did not show significant different between on, or off pump groups before and after PS match. ESRD patients with CAD undergoing either on pump or off pump CABG surgery showed similar outcomes in 30days, 1year and whole follow-up period. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

On- vs. off-pump coronary artery bypass grafting: A systematic review and meta-analysis.

PubMed

Dieberg, Gudrun; Smart, Neil A; King, Nicola

2016-11-15

To reduce complications during coronary artery bypass grafting (CABG) off-pump CABG was introduced; however, results have been mixed. The aim of this work was to conduct a systematic review and meta-analysis of off-pump vs. on-pump CABG. To identify potential studies systematic searches were carried out using various databases. The search strategy included the key concepts of "cardiopulmonary bypass" AND "coronary artery bypass grafting" AND "off pump". This was followed by a meta-analysis investigating post-operative atrial fibrillation, myocardial infarction, ≤30day mortality, stroke, ventilation time, intensive care unit (ICU) stay and hospital stay. Fifty four studies (59 intervention groups), totalling 16,261 participants were analysed. Off pump CABG led to a significantly lower incidence of post-operative atrial fibrillation odds ratio (OR) 0.87 (95% confidence interval [CI] 0.78 to 0.97, p=0.01), but no differences in either myocardial infarction OR 0.98 (95% CI 0.82 to 1.15, p=0.77) or ≤30day mortality OR 0.85 (95% CI 0.68 to 1.06, p=0.16). There was a strong trend towards a reduced incidence of stroke OR 0.77 (95% CI 0.59 to 1.00, p=0.05); however this did not quite reach significance. Ventilation time mean difference (MD) -3.78h (95% CI -4.75 to -2.82, p<0.00001); ICU stay MD -0.34days (95% CI -0.50 to -0.17, p<0.0001); and hospital stay MD -0.9days (95% CI -1.25 to -0.56, p<0.00001) were all significantly shorter in the off-pump group. Off-pump CABG has some benefits over on-pump CABG, particularly in relation to post-operative atrial fibrillation. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

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

PubMed

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

2010-07-01

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

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

PubMed

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.

Randomised trial comparing hand expression with breast pumping for mothers of term newborns feeding poorly.

PubMed

Flaherman, Valerie J; Gay, Barbara; Scott, Cheryl; Avins, Andrew; Lee, Kathryn A; Newman, Thomas B

2012-01-01

Breast pumping or hand expression may be recommended when newborns latch or suck poorly. A recent trial found worse outcomes among mothers who used a breast pump in the early postpartum period. The objective of this study was to compare bilateral electric breast pumping to hand expression among mothers of healthy term infants feeding poorly at 12-36 h after birth. Randomised controlled trial. Well-baby nursery and postpartum unit. 68 mothers of newborns 12-36 h old who were latching or sucking poorly were randomly assigned to either 15 min of bilateral electric pumping or 15 min of hand expression. Milk transfer, maternal pain, breastfeeding confidence and breast milk expression experience (BMEE) immediately after the intervention, and breastfeeding rates at 2 months after birth. The median volume of expressed milk (range) was 0.5 (0-5) ml for hand expressing mothers and 1 (0-40) ml for pumping mothers (p=0.07). Maternal pain, breastfeeding confidence and BMEE did not differ by intervention. At 2 months, mothers assigned to hand expression were more likely to be breastfeeding (96.1%) than mothers assigned to breast pumping (72.7%) (p=0.02). Hand expression in the early postpartum period appears to improve eventual breastfeeding rates at 2 months after birth compared with breast pumping, but further research is needed to confirm this. However, in circumstances where either pumping or hand expression would be appropriate for healthy term infants 12-36 h old feeding poorly, providers should consider recommending hand expression.

Anaortic off-pump versus clampless off-pump using the PAS-Port device versus conventional coronary artery bypass grafting: mid-term results from a matched propensity score analysis of 5422 unselected patients.

PubMed

Furukawa, Nobuyuki; Kuss, Oliver; Preindl, Konstantin; Renner, André; Aboud, Anas; Hakim-Meibodi, Kavous; Benzinger, Michael; Pühler, Thomas; Ensminger, Stephan; Fujita, Buntaro; Becker, Tobias; Gummert, Jan F; Börgermann, Jochen

2017-10-01

Meta-analyses from observational and randomized studies have demonstrated benefits of off-pump surgery for hard and surrogate endpoints. In some of them, increased re-revascularization was noted in the off-pump groups, which could impact their long-term survival. Therefore, we analyzed the course of all patients undergoing isolated coronary surgery regarding the major cardiac and cerebrovascular event (MACCE) criteria. A prospective register was taken from a high-volume off-pump center recording all anaortic off-pump (ANA), clampless off-pump (PAS-Port) and conventional (CONV) coronary artery bypass operations between July 2009 and June 2015. Propensity Score Matching was performed based on 28 preoperative risk variables. We identified 935 triplets (N = 2805). Compared with CONV, in-hospital mortality of both the ANA group (OR for ANA [95% CI] 0.25 [0.06; 0.83], P = 0.021), and the PAS-Port group was lower (OR for PAS-Port [95% CI] 0.50 [0.17; 1.32], P = 0.17). In the mid-term follow-up there were no significant differences between the groups regarding mortality (HR for ANA [95%-CI] 0.83 [0.55-1.26], P = 0.38; HR for PAS-Port [95%-CI] 1.06 [0.70-1.59], P = 0.79), incidence of stroke (HR for ANA 0.81 [0.43-1.53], P = 0.52; HR for PAS-Port 0.78 [0.41-1.50], P = 0.46), myocardial infarction (HR for ANA 0.53 [0.22-1.31], P = 0.17; HR for PAS-Port 0.78 [0.37-1.66], P = 0.52) or re-revascularization rate (HR for ANA 0.99 [0.67-1.44], P = 0.94; HR for PAS-Port 0.95 [0.65-1.38], P = 0.77). Both off-pump clampless techniques were associated with lower in-hospital mortality compared with conventional CABG. The mid-term course showed no difference with regard to the MACCE criteria between anaortic off-pump, clampless off-pump using PAS-Port and conventional CABG. © The Author 2017. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

On- or off-pump coronary artery bypass grafting for octogenarians: A meta-analysis of comparative studies involving 27,623 patients.

PubMed

Khan, Habib; Uzzaman, Mohsin; Benedetto, Umberto; Butt, Salman; Raja, Shahzad G

2017-11-01

Coronary artery bypass grafting (CABG) is being increasingly offered to octogenarians. Both on- and off-pump CABG are reported as effective surgical revascularization strategies for octogenarians by single institution studies. However, the issue of superiority of one strategy over the other for octogenarians remains unresolved due to limited sample size of these studies. A meta-analysis of studies comparing outcomes of on- and off-pump CABG in octogenarians was undertaken to address the issue. A literature search was conducted from 1966 through September 2016 using MEDLINE, EMBASE, Scopus and Web of Science to identify relevant articles. Primary outcomes of interest included in-hospital mortality and stroke. Secondary outcomes of interest were atrial fibrillation, acute renal failure, reoperation for bleeding, deep sternal wound infection, myocardial infarction, intensive therapy unit (ITU) stay and hospital stay. The random effects model was used to calculate the outcomes of both binary and continuous data to control any heterogeneity between the studies. Heterogeneity amongst the trials was determined by means of the Cochran Q value and quantified using the I 2 inconsistency test. All p-values were 2-sided and a 5% level was considered significant. Sixteen retrospective studies (18,685 on-pump patients and 8938 off-pump patients) were included in the systematic review. In-hospital mortality (pooled OR = 0.64, 95% CI = 0.44 to 0.93; p = 0.02), stroke rate (pooled OR = 0.61, 95% CI = 0.48 to 0.76; p < 0.001) and length of hospital stay (pooled WMD = +0.29, 95% CI = +0.02 to +0.56; p = 0.04) were significantly lower in the off-pump patients. Atrial fibrillation (p = 0.36), acute renal failure (p = 0.47), reoperation for bleeding (p = 0.99), deep sternal wound infection (p = 0.59), myocardial infarction (p = 0.93), and length of ITU stay (p = 0.27) were comparable. Off-pump compared to on-pump CABG offers surgical myocardial revascularization to octogenarians with lower in-hospital mortality, stroke rate and length of hospital stay with similar incidence of other adverse outcomes. Preferentially offering off-pump CABG to octogenarians could translate into reduced economic burden on the healthcare providers. Copyright © 2017 IJS Publishing Group Ltd. Published by Elsevier Ltd. All rights reserved.

The Relative Effectiveness of Pumps Over MDI and Structured Education (REPOSE): study protocol for a cluster randomised controlled trial.

PubMed

White, David; Waugh, Norman; Elliott, Jackie; Lawton, Julia; Barnard, Katharine; Campbell, Michael J; Dixon, Simon; Heller, Simon

2014-09-03

People with type 1 diabetes (T1DM) require insulin therapy to sustain life, and need optimal glycaemic control to prevent diabetic ketoacidosis and serious long-term complications. Insulin is generally administered using multiple daily injections but can also be delivered using an infusion pump (continuous subcutaneous insulin infusion), a more costly option with benefits for some patients. The UK National Institute for Health and Care Excellence (NICE) recommend the use of pumps for patients with the greatest need, citing insufficient evidence to approve extension to a wider population. Far fewer UK adults use pumps than in comparable countries. Previous trials of pump therapy have been small and of short duration and failed to control for training in insulin adjustment. This paper describes the protocol for a large randomised controlled trial comparing pump therapy with multiple daily injections, where both groups are provided with high-quality structured education. A multicentre, parallel group, cluster randomised controlled trial among 280 adults with T1DM. All participants attended the week-long dose adjustment for normal eating (DAFNE) structured education course, and receive either multiple daily injections or pump therapy for 2 years. The trial incorporates a detailed mixed-methods psychosocial evaluation and cost-effectiveness analysis. The primary outcome will be the change in glycosylated haemoglobin (HbA1c) at 24 months in those participants whose baseline HbA1c is at or above 7.5% (58 mmol/mol). The key secondary outcome will be the proportion of participants reaching the NICE target of an HbA1c of 7.5% (58 mmol/mol) or less at 24 months. The protocol was approved by the Research Ethics Committee North West, Liverpool East and received Medicines and Healthcare products Regulatory Agency (MHRA) clinical trials authorisation. Each participating centre gave National Health Service R&D approval. We shall disseminate study findings to study participants and through peer reviewed publications and conference presentations, including lay user groups. ISRCTN 61215213. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Use of cardiopulmonary pump support during coronary artery bypass grafting in the high-risk: a meta-analysis.

PubMed

Yousif, A; Addison, D; Lakkis, N; Rosengart, T; Virani, S S; Birnbaum, Y; Alam, M

2018-05-01

Data from randomized trials evaluating the efficacy of on- versus off-pump coronary artery bypass grafting remain inconclusive, particularly in high-risk populations. The aim of this study is to compare the outcomes associated with on- versus off-pump coronary artery bypass grafting among high-risk patients. We performed a meta-analysis of randomized control trials comparing on- versus off-pump coronary artery bypass grafting, focusing on high-risk populations. Studies focusing on "high-risk" features: European System of Cardiac Operative Risk Evaluation (EuroSCORE) ≥ 5, age > 70 years, preexisting renal insufficiency, history of stroke(s), and the presence of left ventricular dysfunction were included. MEDLINE, Scopus, and Embase were searched for all publications between January 1, 2000 and August 1, 2016, using the following terms: on-pump, off-pump, coronary artery bypass, high-risk, left ventricular dysfunction, elderly, aged, and renal insufficiency. Endpoints included cardiovascular and all-cause mortality, non-fatal myocardial infarction, stroke, need for revascularization, renal failure, and length of hospital stay. Nine studies incorporating 11,374 patients with a mean age of 70 years were selected. There was no statistical difference in cardiovascular mortality, all-cause mortality, non-fatal myocardial infarction, and renal failure between the two groups. There was a decrease in further revascularization at 1 year with on-pump (OR 0.67 (0.50-0.89)). However, there was an increase in length of hospital stay by 2.24 days (p = 0.03) among the on-pump group with no difference in stroke (OR 1.34 (1.00-1.80)). On-pump is associated with a decreased risk of additional revascularization by 1 year. However, this appears to be a cost of longer hospitalization.

Uptake of Workplace HIV Counselling and Testing: A Cluster-Randomised Trial in Zimbabwe

PubMed Central

Corbett, Elizabeth L; Dauya, Ethel; Matambo, Ronnie; Cheung, Yin Bun; Makamure, Beauty; Bassett, Mary T; Chandiwana, Steven; Munyati, Shungu; Mason, Peter R; Butterworth, Anthony E; Godfrey-Faussett, Peter; Hayes, Richard J

2006-01-01

Background HIV counselling and testing is a key component of both HIV care and HIV prevention, but uptake is currently low. We investigated the impact of rapid HIV testing at the workplace on uptake of voluntary counselling and testing (VCT). Methods and Findings The study was a cluster-randomised trial of two VCT strategies, with business occupational health clinics as the unit of randomisation. VCT was directly offered to all employees, followed by 2 y of open access to VCT and basic HIV care. Businesses were randomised to either on-site rapid HIV testing at their occupational clinic (11 businesses) or to vouchers for off-site VCT at a chain of free-standing centres also using rapid tests (11 businesses). Baseline anonymised HIV serology was requested from all employees. HIV prevalence was 19.8% and 18.4%, respectively, at businesses randomised to on-site and off-site VCT. In total, 1,957 of 3,950 employees at clinics randomised to on-site testing had VCT (mean uptake by site 51.1%) compared to 586 of 3,532 employees taking vouchers at clinics randomised to off-site testing (mean uptake by site 19.2%). The risk ratio for on-site VCT compared to voucher uptake was 2.8 (95% confidence interval 1.8 to 3.8) after adjustment for potential confounders. Only 125 employees (mean uptake by site 4.3%) reported using their voucher, so that the true adjusted risk ratio for on-site compared to off-site VCT may have been as high as 12.5 (95% confidence interval 8.2 to 16.8). Conclusions High-impact VCT strategies are urgently needed to maximise HIV prevention and access to care in Africa. VCT at the workplace offers the potential for high uptake when offered on-site and linked to basic HIV care. Convenience and accessibility appear to have critical roles in the acceptability of community-based VCT. PMID:16796402

Off-pump versus on-pump coronary artery bypass surgery in patients with actively treated diabetes and multivessel coronary disease.

PubMed

Benedetto, Umberto; Caputo, Massimo; Vohra, Hunaid; Davies, Alan; Hillier, James; Bryan, Alan; Angelini, Gianni D

2016-11-01

We conducted a single-center analysis on short-term outcomes and long-term survival in actively treated diabetic patients undergoing off-pump coronary artery bypass versus on-pump coronary artery bypass surgery. The final population consisted of 2450 patients with actively treated diabetes (mean age, 66 ± 9 years; female/male 545/1905, 22%). Of those, 1493 subjects were orally treated and 1011 subjects were taking insulin. Off-pump coronary artery bypass and on-pump coronary artery bypass were performed in 1253 and 1197 patients, respectively. Propensity score matching was used to compare the 2 matched groups. When compared with on-pump coronary artery bypass, off-pump coronary artery bypass was associated with a significant risk reduction for postoperative cerebrovascular accident (odds ratio, 0.49; 95% confidence interval [CI], 0.25-0.99; P = .04), need for postoperative intra-aortic balloon pump (odds ratio, 0.48; 95% CI, 0.30-0.77; P = .002), and reexploration for bleeding (odds ratio, 0.55; 95% CI, 0.33-0.94; P = .02). Off-pump coronary artery bypass did not significantly affect early (hazard ratio [HR], 1.32; 95% CI, 0.73-2.40; P = .36) and late (HR, 1.08; 95% CI, 0.92-1.28; P = .32) mortality. However, off-pump coronary artery bypass with incomplete revascularization was associated with reduced survival when compared with off-pump coronary artery bypass with complete revascularization (HR, 1.82; 95% CI, 1.34-2.46; P = .0002) and on-pump coronary artery bypass with complete revascularization (HR, 1.83; 95% CI, 1.36-2.47; P < .0001). Off-pump coronary artery bypass is a safe and feasible option for diabetic patients with multivessel disease, reduces the incidence of early complications including postoperative cerebrovascular events, and provides excellent long-term survival similar to on-pump coronary artery bypass surgery in case of complete revascularization. Crown Copyright © 2016. Published by Elsevier Inc. All rights reserved.

Chronic Obstructive Pulmonary Disease and Off-Pump Coronary Surgery.

PubMed

Ovalı, Cengiz; Şahin, Aykut

2018-05-18

To determine to what extent chronic obstructive pulmonary disease (COPD) affects mortality and morbidity rates in patients treated with off-pump coronary artery bypass graft (CABG). A total of 321 patients treated with off-pump CABG were included in the present study. Of the 321 patients, 46 patients had COPD and they were designated as Group 1 and the remaining 275 patients did not have COPD and they were considered as Group 2. We compared the data obtained from the patients in both groups. While preoperative spirometry values and arterial blood gas oxygen saturation levels were significantly lower, the partial values of carbon dioxide were higher in Group 1. Likewise, extubation time, the amount of drainage and blood transfusion, inotropic support, prolonged intubation, pulmonary complications, the use of bronchodilators, and steroids were statistically higher in Group 1 when compared with Group 2. Overall, there was no marked difference between the two groups in terms of mortality incidence. We found similar morbidity and mortality rates among the patients with COPD and without COPD when they were treated with off-pump CABG. Therefore, the present results indicate that the presence of COPD is not associated with in-hospital mortality or severe morbidity post-CABG by off-pump approach.

Diamorphine for pain relief in labour : a randomised controlled trial comparing intramuscular injection and patient-controlled analgesia.

PubMed

McInnes, Rhona J; Hillan, Edith; Clark, Diana; Gilmour, Harper

2004-10-01

To compare the efficacy of diamorphine administered by a patient-controlled pump (patient-controlled analgesia) with intramuscular administration for pain relief in labour. Randomised controlled trial. The South Glasgow University Hospitals NHS Trust. Primigravidae and multigravidae in labour at term (37-42 weeks). Women were randomised in labour to the study (patient-controlled analgesia) or control group (intramuscular). Randomisation was achieved through a random permuted block design stratified by parity. Study group women were given a loading dose of 1.2 mg diamorphine intravenously and then attached to the pump. Control group women received intramuscular diamorphine as per hospital protocol. Participants were also given 3 mg of buccal Stemetil. Data were collected throughout labour and at six postnatal weeks. Analgesia requirements during labour and women's satisfaction with the method of pain relief. Women in the study group (patient-controlled analgesia) used significantly less diamorphine than women in the control group (intramuscular) but were significantly more likely to state that they were very dissatisfied with their use of diamorphine and were significantly more likely to opt out of the trial before the birth of the baby. The majority of women in both groups used other analgesia concurrent with diamorphine such as Entonox, aromatherapy or TENS. Patient-controlled analgesia administration of diamorphine for the relief of pain in labour offers no significant advantages over intramuscular administration. The results also suggest that diamorphine is a poor analgesic for labour pain irrespective of the mode of administration.

In-hospital outcomes of a minimally invasive off-pump left thoracotomy approach using a centrifugal continuous-flow left ventricular assist device.

PubMed

Sileshi, Bantayehu; Haglund, Nicholas A; Davis, Mary E; Tricarico, Nicole M; Stulak, John M; Khalpey, Zain; Danter, Matthew R; Deegan, Robert; Kennedy, Jason; Keebler, Mary E; Maltais, Simon

2015-01-01

Minimally invasive left thoracotomy (MILT) and off-pump implantation strategies have been anecdotally reported for implantation of the HeartWare ventricular assist device (HVAD). We analyzed our experience with off-pump MILT implantation techniques and compared early in-hospital outcomes with conventional on-pump sternotomy (CS) implantation strategy. Between January 2013 and February 2014, 51 patients underwent HVAD implantation and were included in this study. Thirty-three patients had CS, whereas 18 patients underwent off-pump MILT. To compare outcomes of these techniques, a multivariate analysis using propensity score modeling was performed after adjusting for age, INTERMACS, Kormos and Leitz-Miller (LM) scores. Mean age at implant was 57 (range 18 to 69) years, and overall in-hospital mortality was 8%. Univariate analysis revealed a statistically significant reduction in days on inotropes (p = 0.04), and a trend toward reduced intra-operative blood product administration (p = 0.08) in the MILT group. There was no difference in intensive-care-unit length of stay (p = 0.5), total length of stay (p = 0.76), post-operative blood product administration (p = 0.34) and total time on mechanical ventilation (p = 0.32). After adjusting for age, INTERMACS profile and Kormos and LM scores, no statistically significant differences were observed between the MILT and CS groups. An off-pump MILT implantation strategy can be utilized as a safe surgical approach for patients undergoing HVAD implantation. Further large collaborative studies are needed to identify advantages of the MILT approach. Published by Elsevier Inc.

Off-pump versus On-pump Coronary Artery Bypass Grafting in Frail Patients: Study Protocol for the FRAGILE Multicenter Randomized Controlled Trial.

PubMed

Mejía, Omar Asdrúbal Vilca; Sá, Michel Pompeu Barros Oliveira; Deininger, Maurilio Onofre; Dallan, Luís Roberto Palma; Segalote, Rodrigo Coelho; Oliveira, Marco Antonio Praça de; Atik, Fernando Antibas; Santos, Magaly Arrais Dos; Silva, Pedro Gabriel Melo de Barros E; Milani, Rodrigo Mussi; Hueb, Alexandre Ciappina; Monteiro, Rosangela; Lima, Ricardo Carvalho; Lisboa, Luiz Augusto Ferreira; Dallan, Luís Alberto Oliveira; Puskas, John; Jatene, Fabio Biscegli

2017-01-01

Advances in modern medicine have led to people living longer and healthier lives. Frailty is an emerging concept in medicine yet to be explored as a risk factor in cardiac surgery. When it comes to CABG surgery, randomized controlled clinical trials have primarily focused on low-risk (ROOBY, CORONARY), elevated-risk (GOPCABE) or high-risk patients (BBS), but not on frail patients. Therefore, we believe that off-pump CABG could be an important technique in patients with limited functional capacity to respond to surgical stress. In this study, the authors introduce the new national, multicenter, randomized, controlled trial "FRAGILE", to be developed in the main cardiac surgery centers of Brazil, to clarify the potential benefit of off-pump CABG in frail patients. FRAGILE is a two-arm, parallel-group, multicentre, individually randomized (1:1) controlled trial which will enroll 630 patients with blinded outcome assessment (at 30 days, 6 months, 1 year, 2 years and 3 years), which aims to compare adverse cardiac and cerebrovascular events after off-pump versus on-pump CABG in pre-frail and frail patients. Primary outcomes will be all-cause mortality, acute myocardial infarction, cardiac arrest with successful resuscitation, low cardiac output syndrome/cardiogenic shock, stroke, and coronary reintervention. Secondary outcomes will be major adverse cardiac and cerebrovascular events, operative time, mechanical ventilation time, hyperdynamic shock, new onset of atrial fibrillation, renal replacement therapy, reoperation for bleeding, pneumonia, length of stay in intensive care unit, length of stay in hospital, number of units of blood transfused, graft patency, rate of complete revascularization, neurobehavioral outcomes after cardiac surgery, quality of life after cardiac surgery and costs. FRAGILE trial will determine whether off-pump CABG is superior to conventional on-pump CABG in the surgical treatment of pre-frail and frail patients. ClinicalTrials.gov, ID: NCT02338947. Registered on August 29th 2014; last updated on March 21st 2016.

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

PubMed

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 < or = 30% (group 1) and 562 had ejection 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 < or = 30% was found to be an independent risk factor for postoperative complications and hospital mortality. The subgroup of patients undergoing off-pump surgery in both groups had a significantly lower rate of total complications than those undergoing conventional on-pump 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.

Rationale and design of the coronary artery bypass grafting surgery off or on pump revascularization study: a large international randomized trial in cardiac surgery.

PubMed

Lamy, Andre; Devereaux, Philip J; Prabhakaran, Dorairaj; Hu, Shengshou; Piegas, Leopoldo S; Straka, Zbynek; Paolasso, Ernesto; Taggart, David; Lanas, Fernando; Akar, A Ruchan; Jain, Anil; Noiseux, Nicolas; Ou, Yongning; Chrolavicius, Susan; Ng, Jennifer; Yusuf, Salim

2012-01-01

Uncertainty remains regarding the benefits and risks of the technique of operating on a beating heart (off pump) for coronary artery bypass grafting (CABG) surgery versus on-pump CABG. Prior trials had few events and relatively short follow-up. There is a need for a large randomized, controlled trial with long-term follow-up to inform both the short- and long-term impact of the 2 approaches to CABG. We plan to randomize 4,700 patients in whom CABG is planned to undergo the procedure on pump or off pump. The coprimary outcomes are a composite of total mortality, myocardial infarction (MI), stroke, and renal failure at 30 days and a composite of total mortality, MI, stroke, renal failure, and repeat revascularization at 5 years. We will also undertake a cost-effectiveness analysis at 30 days and 5 years after CABG surgery. Other outcomes include neurocognitive dysfunction, recurrence of angina, cardiovascular mortality, blood transfusions, and quality of life. As of May 3, 2011, CORONARY has recruited >3,884 patients from 79 centers in 19 countries. Currently, patient's mean age is 67.6 years, 80.7% are men, 47.0% have a history of diabetes, 51.4% have a history of smoking, and 34.4% had a previous MI. In addition, 20.9% of patients have a left main disease, and 96.6% have double or triple vessel disease. CORONARY is the largest trial yet conducted comparing off-pump CABG to on-pump CABG. Its results will lead to a better understanding of the safety and efficacy of off-pump CABG. Copyright © 2012 Mosby, Inc. All rights reserved.

Evaluation of a Novel Laser-assisted Coronary Anastomotic Connector - the Trinity Clip - in a Porcine Off-pump Bypass Model

PubMed Central

Stecher, David; Bronkers, Glenn; Noest, Jappe O.T.; Tulleken, Cornelis A.F.; Hoefer, Imo E.; van Herwerden, Lex A.; Pasterkamp, Gerard; Buijsrogge, Marc P.

2014-01-01

To simplify and facilitate beating heart (i.e., off-pump), minimally invasive coronary artery bypass surgery, a new coronary anastomotic connector, the Trinity Clip, is developed based on the excimer laser-assisted nonocclusive anastomosis technique. The Trinity Clip connector enables simplified, sutureless, and nonocclusive connection of the graft to the coronary artery, and an excimer laser catheter laser-punches the opening of the anastomosis. Consequently, owing to the complete nonocclusive anastomosis construction, coronary conditioning (i.e., occluding or shunting) is not necessary, in contrast to the conventional anastomotic technique, hence simplifying the off-pump bypass procedure. Prior to clinical application in coronary artery bypass grafting, the safety and quality of this novel connector will be evaluated in a long-term experimental porcine off-pump coronary artery bypass (OPCAB) study. In this paper, we describe how to evaluate the coronary anastomosis in the porcine OPCAB model using various techniques to assess its quality. Representative results are summarized and visually demonstrated. PMID:25490000

Pump efficiency in solar-energy systems

NASA Technical Reports Server (NTRS)

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.

Numerical and In Vitro Experimental Investigation of the Hemolytic Performance at the Off-Design Point of an Axial Ventricular Assist Pump.

PubMed

Liu, Guang-Mao; Jin, Dong-Hai; Jiang, Xi-Hang; Zhou, Jian-Ye; Zhang, Yan; Chen, Hai-Bo; Hu, Sheng-Shou; Gui, Xing-Min

The ventricular assist pumps do not always function at the design point; instead, these pumps may operate at unfavorable off-design points. For example, the axial ventricular assist pump FW-2, in which the design point is 5 L/min flow rate against 100 mm Hg pressure increase at 8,000 rpm, sometimes works at off-design flow rates of 1 to 4 L/min. The hemolytic performance of the FW-2 at both the design point and at off-design points was estimated numerically and tested in vitro. Flow characteristics in the pump were numerically simulated and analyzed with special attention paid to the scalar sheer stress and exposure time. An in vitro hemolysis test was conducted to verify the numerical results. The simulation results showed that the scalar shear stress in the rotor region at the 1 L/min off-design point was 70% greater than at the 5 L/min design point. The hemolysis index at the 1 L/min off-design point was 3.6 times greater than at the 5 L/min design point. The in vitro results showed that the normalized index of hemolysis increased from 0.017 g/100 L at the 5 L/min design point to 0.162 g/100 L at the 1 L/min off-design point. The hemolysis comparison between the different blood pump flow rates will be helpful for future pump design point selection and will guide the usage of ventricular assist pumps. The hemolytic performance of the blood pump at the working point in the clinic should receive more focus.

Partially anaortic clampless off-pump coronary artery bypass prevents neurologic injury compared to on-pump coronary surgery: a propensity score-matched study on 286 patients.

PubMed

Bassano, Carlo; Bovio, Emanuele; Uva, Floriano; Iacobelli, Simona; Iasevoli, Nicola; Farinaccio, Andrea; Ruvolo, Giovanni

2016-09-01

Anaortic coronary artery bypass proved to prevent early neurologic injury compared to on-pump CABG. The Cardica PAS-Port(®) is a fully automated device that might be able to perform proximal aorto-venous anastomoses without an increased embolic risk. We evaluated early post-operative neurologic outcome in a matched population following clampless OPCAB (CCAB: either "all-arterial" or with automatically anastomosed venous grafts) or on-pump CABG. 366 consecutive patients were submitted to isolated coronary bypass by a single surgeon experienced in both off and on-pump procedures between January 2009 and December 2013. Of these patients, 223 underwent a clampless off-pump revascularization. After propensity score matching, 143 pairs were selected, who received either off-pump or on-pump surgery. In the off-pump group, CCAB was performed with an all-arterial approach (n = 33) or with automated proximal anastomosis of the venous graft(s) by means of the Cardica PAS-Port(®) connector (n = 110). Neurologic injury was defined as non-reversible (NRNI: lethal coma or stroke) or reversible (RNI: TIA or delirium). Operative mortality was 2.4 % (CCAB 1.4 %; CABG 3.5 %; p = 0.14). The global rate of early neurologic injury was 5.6 % (CCAB 2.1 vs. CABG 9.1 %; p = 0.006). Incidence was 1.4 % for NRNI (CCAB 0 vs. CABG 2.8 %; p = 0.04) and 4.2 % for RNI (CCAB 2.1 vs. CABG 6.3 %; p = 0.06). No differences were found among other major perioperative outcomes. CCAB prevents both early post-operative RNI and NRNI. This result can be achieved with a totally anaortic strategy and also with the aid of a fully automated device for proximal aorto-venous anastomoses.

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

PubMed

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.

Numerical investigation of output beam quality in efficient broadband optical parametric chirped pulse amplification

NASA Astrophysics Data System (ADS)

Liu, Xiao-Di; Xu, Lu; Liang, Xiao-Yan

2017-01-01

We theoretically analyzed output beam quality of broad bandwidth non-collinear optical parametric chirped pulse amplification (NOPCPA) in LiB3O5 (LBO) centered at 800 nm. With a three-dimensional numerical model, the influence of the pump intensity, pump and signal spatial modulations, and the walk-off effect on the OPCPA output beam quality are presented, together with conversion efficiency and the gain spectrum. The pump modulation is a dominant factor that affects the output beam quality. Comparatively, the influence of signal modulation is insignificant. For a low-energy system with small beam sizes, walk-off effect has to be considered. Pump modulation and walk-off effect lead to asymmetric output beam profile with increased modulation. A special pump modulation type is found to optimize output beam quality and efficiency. For a high-energy system with large beam sizes, the walk-off effect can be neglected, certain back conversion is beneficial to reduce the output modulation. A trade-off must be made between the output beam quality and the conversion efficiency, especially when the pump modulation is large since. A relatively high conversion efficiency and a low output modulation are both achievable by controlling the pump modulation and intensity.

Does an intensive self-management structured education course improve outcomes for children and young people with type 1 diabetes? The Kids In Control OF Food (KICk-OFF) cluster-randomised controlled trial protocol

PubMed Central

Price, Katherine J; Wales, Jerry; Eiser, Christine; Knowles, Julie; Heller, Simon; Freeman, Jenny; Brennan, Alan; McPherson, Amy; Wellington, Jerry

2013-01-01

Introduction The Kids In Control OF Food (KICk-OFF) is a cluster-randomised controlled trial, which aims to determine the efficacy of a 5 day structured education course for 11-year-olds to 16-year-olds with type 1 diabetes (T1DM) when compared with standard care, and its cost effectiveness. Less than 15% of children and young people with T1DM in the UK meet the recommended glycaemic target. Self-management education programmes for adults with T1DM improve clinical and psychological outcomes, but none have been evaluated in the paediatric population. KICk-OFF is a 5-day structured education course for 11-year-olds to 16- year-olds with T1DM. It was developed with input from young people, parents, teachers and educationalists. Methods and analysis 36 paediatric diabetes centres across the UK randomised into intervention and control arms. Up to 560 participants were recruited prior to centre randomisation. KICk-OFF courses are delivered in the intervention centres, with standard care continued in the control arm. Primary outcomes are change in glycaemic control (HbA1c) and quality of life between baseline and 6 months postintervention, and the incidence of severe hypoglycaemia. Sustained change in self-management behaviour is assessed by follow-up at 12 and 24 months. Health economic analysis will be undertaken. Data will be reported according to the CONSORT statement for cluster-randomised clinical trials. All analyses will be by intention-to-treat with a two-sided p value of <0.05 being regarded as statistically significant. The study commenced in 2008. Data collection from participants is ongoing and the study will be completed in 2013. Ethics The study has been approved by the Sheffield Research Ethics Committee. Dissemination Results will be reported in peer reviewed journals and conferences. Trial registration Current Controlled Trials ISRCTN37042683. PMID:23355675

Centrifugal and Axial Pump Design and Off-Design Performance Prediction

NASA Technical Reports Server (NTRS)

Veres, Joseph P.

1995-01-01

A meanline pump-flow modeling method has been developed to provide a fast capability for modeling pumps of cryogenic rocket engines. Based on this method, a meanline pump-flow code PUMPA was written that can predict the performance of pumps at off-design operating conditions, given the loss of the diffusion system at the design point. The design-point rotor efficiency and slip factors are obtained from empirical correlations to rotor-specific speed and geometry. The pump code can model axial, inducer, mixed-flow, and centrifugal pumps and can model multistage pumps in series. The rapid input setup and computer run time for this meanline pump flow code make it an effective analysis and conceptual design tool. The map-generation capabilities of the code provide the information needed for interfacing with a rocket engine system modeling code. The off-design and multistage modeling capabilities of PUMPA permit the user to do parametric design space exploration of candidate pump configurations and to provide head-flow maps for engine system evaluation.

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

PubMed

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.

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.

PubMed

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.

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

NASA Astrophysics Data System (ADS)

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.

Aircraft Alerting Systems Standardization Study. Volume I. Candidate System Validation and Time-Critical Display Evaluation.

DTIC Science & Technology

1981-01-01

SELCAL FLT ALT ATNI AUO ALT BRK CANSELCAL OVSO CALL CONTRL ALRT _ I7CT be SPLR b 0 11CALL Figure 5.4.4-1 Pilot’s Response Panel Figure 5.4.4-2 Flight...Galley bus off 27 GLY BUS OFF A RP ELEC CYCLE SWITCH Utility bus off 28 UTIL BUS OFF A RP ELEC CYCLE SWITCH Right engine 29 R ENG HYD PUMP A RP HYD...CYCLE SWITCH hydraulic pump Left engine 30 L ENG FIRE DET A RP FIRE RP FIRE fire detector Left brake overheat 31 L BRAKE OVHT A RP BRK RP BRK Right

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

PubMed

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

2016-03-12

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

28. PUMP/ENGINE ROOM OFF THE BASEMENT OF MILL NO. 1. ...

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

28. PUMP/ENGINE ROOM OFF THE BASEMENT OF MILL NO. 1. ENGINE PLATFORM IS SEEN BEHIND PUMP. THIS AMERICAN MOISTURE CO. PUMP WAS USED TO HUMIDIFY UPPER FLOORS OF MILL. NOTE TANK TO LEFT, UNKNOWN USE. NOTHING IN THIS ROOM HAS BEEN USED SINCE 1945. - Prattville Manufacturing Company, Number One, 242 South Court Street, Prattville, Autauga County, AL

Current evidence of coronary artery bypass grafting off-pump versus on-pump: a systematic review with meta-analysis of over 16,900 patients investigated in randomized controlled trials†.

PubMed

Deppe, Antje-Christin; Arbash, Wasim; Kuhn, Elmar W; Slottosch, Ingo; Scherner, Maximilian; Liakopoulos, Oliver J; Choi, Yeong-Hoon; Wahlers, Thorsten

2016-04-01

In the present systematic review with meta-analysis, we sought to determine the current strength of evidence for or against off-pump and on-pump coronary artery bypass grafting (CABG) with regard to hard clinical end-points, graft patency and cost-effectiveness. We performed a meta-analysis of only randomized controlled trials (RCT) which reported at least one of the desired end-points including: (i) major adverse cardiac and cerebrovascular events (MACCE), (ii) all-cause mortality, (iii) myocardial infarction, (iv) cerebrovascular accident, (v) repeat revascularization, (vi) graft patency and (vii) cost-effectiveness. The pooled treatment effects [odds ratio (OR) or weighted mean difference, 95% confidence intervals (95% CIs)] were assessed using a fixed or random effects model. A total of 16 904 patients from 51 studies were identified after literature search of the major databases using a predefined keyword list. The incidence of MACCE did not differ between the groups, neither during the first 30 days (OR: 0.93; 95% CI: 0.82-1.04) nor for the longest available follow-up (OR: 1.01; 95% CI: 0.92-1.12). While the incidence of mid-term graft failure (OR: 1.37; 95% CI: 1.09-1.72) and the need for repeat revascularization (OR: 1.55; 95% CI: 1.33-1.80) was increased after off-pump surgery, on-pump surgery was associated with an increased occurrence of stroke (OR: 0.74; 95% CI: 0.58-0.95), renal impairment (OR: 0.79; 95% CI: 0.71-0.89) and mediastinitis (OR: 0.44; 95% CI: 0.31-0.62). There was no difference with regard to hard clinical end-points between on- or off-pump surgery, including myocardial infarction or mortality. The present systematic review emphasizes that both off- and on-pump surgery provide excellent and comparable results in patients requiring surgical revascularization. The choice for either strategy should take into account the individual patient profile (comorbidities, life expectancy, etc.) and importantly, the surgeon's experience in performing on- or off-pump CABG in their routine practice. © The Author 2015. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

Off-pump supra-arterial myotomy for myocardial bridging.

PubMed

Crespo, Alejandro; Aramendi, José I; Hamzeh, Gadah; Voces, Roberto

2008-09-01

We report the results of surgery and midterm outcome in two patients with symptomatic myocardial bridging who underwent off-pump supra-arterial myotomy. Both patients were operated upon through a median sternotomy. The anterior wall of the heart was exposed in the same manner as in off-pump CABG. The left anterior descending coronary artery is unroofed from its myocardial bridge with the aid of a heart stabilizer and a blower. Neither heparin nor blood transfusion was required. Both patients survived the operation and are asymptomatic. Postoperative coronary angiogram showed good resolution of the muscle bridge in one patient. We conclude that in symptomatic patients with myocardial bridging despite medical therapy, surgical myotomy can be considered an adequate therapy. It can be safely done off-pump.

Effectiveness of Additives in Improving Fuel Lubricity and Preventing Pump Failure at High Temperature

DTIC Science & Technology

2013-01-01

after pump calibrations , transfer pump blade measurements, injector nozzle tests, pump parts evaluation, and parts conditions photographs are also... Injectors –0 0.53 5,500 0.257 1 2-15293089 DF2 As Purchased 105 (40) 1,000 1,000 Calibration off spec areas–4 Pump Rating–1.04 Failed Injectors –0 0.53...5,500 0.257 2 1-15382732 DF2 As Purchased 135 (57) 1,000 1,000 Calibration off spec areas–4 Pump Rating–1.13 Failed Injectors –0 0.55

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

PubMed

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

2014-06-04

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

Off-pump surgery: a choice in unstable angina.

PubMed

Kohli, Vijay; Goel, Mukesh; Sharma, Vijay Kumar; Mishra, Yugal; Malhotra, Rajneesh; Mehta, Yatin; Trehan, Naresh

2003-12-01

The benefit and safety of off-pump coronary artery bypass surgery in patients with unstable angina was assessed retrospectively. From February 1996 to October 2001, 5,306 patients underwent multivessel off-pump coronary artery bypass, of whom 920 (17%) had unstable angina. In these 920 patients, ejection fractions ranged from 15% to 70%, 203 (22%) had an ejection fraction of 20%-35%, and 11 (1%) had an ejection fraction < 20%. Triple-vessel disease was present in 625 patients. Preoperative intraaortic balloon pump support was used in 28 patients. Operative approaches included mid sternotomy (86%), lower partial sternotomy (9%), and left anterior thoracotomy (2%). The number of grafts ranged from 1 to 5 with a mean of 2.43 +/- 0.86, and 92.3% of patients received a left internal mammary artery graft. Twenty-two patients need intraoperative intraaortic balloon pumping. Ten patients (1%) suffered perioperative myocardial infarction. The mean hospital stay was 7.8 +/- 4.3 days. Hospital mortality was 2/920 (0.22%). Intraaortic balloon pumping was helpful in these cases of unstable angina refractory to medical therapy. Off-pump coronary artery surgery was found to be safe and beneficial in these patients.

Does off-pump coronary artery bypass graft surgery have a beneficial effect on long-term mortality and morbidity compared with on-pump coronary artery bypass graft surgery?

PubMed

Chaudhry, Umar A R; Rao, Christopher; Harling, Leanne; Athanasiou, Thanos

2014-07-01

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was whether off-pump coronary artery bypass grafting (CABG) surgery offered superior long-term outcomes compared with on-pump CABG surgery. Best evidence papers were considered to be those that had a follow-up period of ≥5 years, had >50 patients in either cohort, did not utilize concomitant interventions nor comprised low-risk, high-risk or sub-population groups. Where potential duplicate data sets from the same institution were likely, the more credible and recently published study was included. Two hundred and fifty-six papers were found as a result of the reported search, of which 16 represented the best evidence to answer the clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. The 16 studies comprised 4 prospective randomized controlled trials (RCTs), with the remaining 12 retrospective, of which 8 were propensity-score matched. All 4 RCTs contained fewer than 450 participants. Two studies concluded with a survival advantage towards on-pump CABG: one, a large registry-based study, the Veterans Affairs, with >25 000 patients, and another, a propensity-matched retrospective study involving almost 8000 patients. The remaining 14 studies all provided evidence to suggest comparable long-term survival. In addition, all other long-term outcomes mentioned within these studies including angina recurrence, myocardial infarction heart failure, need for revascularization, stroke, graft patency, cognitive and quality of life showed similar results between the two groups. We conclude that off-pump CABG surgery may have similar or slightly reduced long-term survival compared with on-pump CABG surgery. Other long-term indicators such as cardiovascular or cerebrovascular events or neuro-psychological outcomes were similar between the two groups. Despite these conclusions, the evidence is limited by substantial variability in patient selection and study methods. The CORONARY (coronary artery bypass surgery off- or on-pump revascularization study) trial recently presented results, which showed no significant differences in composite outcomes at 1 year; it will be interesting to observe whether these comparable outcomes are maintained for a much longer time frame. © The Author 2014. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

Off-pump grafting does not reduce postoperative pulmonary dysfunction.

PubMed

Izzat, Mohammad Bashar; Almohammad, Farouk; Raslan, Ahmad Fahed

2017-02-01

Objectives Pulmonary dysfunction is a recognized postoperative complication that may be linked to use of cardiopulmonary bypass. The off-pump technique of coronary artery bypass aims to avoid some of the complications that may be related to cardiopulmonary bypass. In this study, we compared the influence of on-pump or off-pump coronary artery bypass on pulmonary gas exchange following routine surgery. Methods Fifty patients (mean age 60.4 ± 8.4 years) with no preexisting lung disease and good left ventricular function undergoing primary coronary artery bypass grafting were prospectively randomized to undergo surgery with or without cardiopulmonary bypass. Alveolar/arterial oxygen pressure gradients were calculated prior to induction of anesthesia while the patients were breathing room air, and repeated postoperatively during mechanical ventilation and after extubation while inspiring 3 specific fractions of oxygen. Results Baseline preoperative arterial blood gases and alveolar/arterial oxygen pressure gradients were similar in both groups. At both postoperative stages, the partial pressure of arterial oxygen and alveolar/arterial oxygen pressure gradients increased with increasing fraction of inspired oxygen, but there were no statistically significant differences between patients who underwent surgery with or without cardiopulmonary bypass, either during ventilation or after extubation. Conclusions Off-pump surgery is not associated with superior pulmonary gas exchange in the early postoperative period following routine coronary artery bypass grafting in patients with good left ventricular function and no preexisting lung disease.

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

PubMed

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.

Early and mid-term results of off-pump endarterectomy of the left anterior descending artery

PubMed Central

Takahashi, Mitsuko; Gohil, Sunir; Tong, Bonnie; Lento, Patrick; Filsoufi, Farzan; Reddy, Ramachandra C.

2013-01-01

OBJECTIVES Many patients referred for coronary artery bypass surgery (CABG) today have diffusely diseased coronary vessels, and some of them may require coronary endarterectomy to provide adequate revascularization. Most reports of coronary endarterectomy describe an on-pump procedure. As off-pump coronary artery bypass graft has become safer and more routine, there is renewed interest in off-pump coronary endarterectomy. We report on our series of patients who underwent off-pump coronary endarterectomy of the left anterior descending (LAD) artery using an open endarterectomy technique. METHODS All patients undergoing open heart surgery at The Mount Sinai Medical Center are entered into a state-mandated, audited database. A retrospective review of this database revealed 12 patients between January 2008 and June 2012 who underwent off-pump endarterectomy of the LAD as part of their coronary revascularization. Additional data were collected from a review of the patients' charts. RESULTS There were a total of 12 patients, with a mean age of 72 ± 4 years. Nine (75%) were male and 3 (25%) were female. Comorbidities included hypertension in 11 (92%) patients, dyslipidaemia in 10 (83%), diabetes in 8 (67%), renal failure in 6 (50%) and stroke in 1 (8%). The mean number of diseased coronary territories was 3 ± 0.4 (range 2–3), and the mean number of coronary bypass grafts performed was 4 ± 0.8 (range 2–5). Eight patients required transfusion with packed red blood cells (67%). One (8%) patient was converted from off-pump to on-pump. The mean intensive care unit stay was 3 ± 2.8 (range 1–8 days), and the mean hospital length of stay was 15 ± 13 (range 4–54 days). Postoperative follow-up (mean 24 ± 19 months, range 1–53) is complete, and no ischaemic events have occurred in the early and mid-term follow-up period. CONCLUSIONS We conclude that off-pump endarterectomy of the LAD is a viable option for patients with diffuse LAD disease. PMID:23190620

A novel coronary active perfusion system using a conventional intra-aortic balloon pump for off-pump coronary artery bypass grafting.

PubMed

Kiuchi, Ryuta; Tomita, Shigeyuki; Yamaguchi, Shojiro; Nishida, Yuji; Ohtake, Hiroshi; Nakamura, Hiroyuki; Watanabe, Go

2014-07-01

It is important for coronary active perfusion systems to avoid myocardial ischemia during off-pump coronary artery bypass grafting. We have developed a new concept for a perfusion system to pump blood based on changes in helium gas volume. This system uses a conventional intra-aortic balloon pump to activate the perfusion pump. Our study used basic and animal experiments to investigate the most suitable system for coronary perfusion using this new concept. A conventional intra-aortic balloon pump was used to supply power. A device for perfusion was developed with a balloon placed inside a stiff syringe barrel. The device was connected to the helium gas line of the intra-aortic balloon pump. Changes in flow with changes in augmentation level were noted when volumes outside and within the balloon were changed. Six pigs with occlusion of the left anterior descending artery were used for system validation, with monitoring to identify changes in hemodynamics and cardiac enzyme levels. In the basic experiment, an 80-mL outside volume and 3.0-mL inner volume resulted in the greatest percentage change in flow rate with respect to changes in augmentation. In the animal experiment, the new coronary active perfusion system prevented myocardial ischemia during coronary occlusion. We clarified the most suitable method for our new coronary active perfusion system. Using this system, safe anastomosis was consistently performed in animal experiments. Clinically, off-pump coronary artery bypass may potentially be performed more safely and easily using this new system. Copyright © 2014 The American Association for Thoracic Surgery. Published by Mosby, Inc. All rights reserved.

Mechanical performance comparison between RotaFlow and CentriMag centrifugal blood pumps in an adult ECLS model.

PubMed

Yulong Guan; Xiaowei Su; McCoach, Robert; Kunselman, Allen; El-Banayosy, Aly; Undar, Akif

2010-03-01

Centrifugal blood pumps have been widely adopted in conventional adult cardiopulmonary bypass and circulatory assist procedures. Different brands of centrifugal blood pumps incorporate distinct designs which affect pump performance. In this adult extracorporeal life support (ECLS) model, the performances of two brands of centrifugal blood pump (RotaFlow blood pump and CentriMag blood pump) were compared. The simulated adult ECLS circuit used in this study included a centrifugal blood pump, Quadrox D membrane oxygenator and Sorin adult ECLS tubing package. A Sorin Cardiovascular(R) VVR(R) 4000i venous reservoir (Sorin S.p.A., Milan, Italy) with a Hoffman clamp served as a pseudo-patient. The circuit was primed with 900ml heparinized human packed red blood cells and 300ml lactated Ringer's solution (total volume 1200 ml, corrected hematocrit 40%). Trials were conducted at normothermia (36 degrees C). Performance, including circuit pressure and flow rate, was measured for every setting analyzed. The shut-off pressure of the RotaFlow was higher than the CentriMag at all measurement points given the same rotation speed (p < 0.0001). The shut-off pressure differential between the two centrifugal blood pumps was significant and increased given higher rotation speeds (p < 0.0001). The RotaFlow blood pump has higher maximal flow rate (9.08 +/- 0.01L/min) compared with the CentriMag blood pump (8.37 +/- 0.02L/min) (p < 0.0001). The blood flow rate differential between the two pumps when measured at the same revolutions per minute (RPM) ranged from 1.64L/min to 1.73L/min. The results obtained in this experiment demonstrate that the RotaFlow has a higher shut-off pressure (less retrograde flow) and maximal blood flow rate than the CentriMag blood pump. Findings support the conclusion that the RotaFlow disposable pump head has a better mechanical performance than the CentriMag. In addition, the RotaFlow disposable pump is 20-30 times less expensive than the CentriMag.

Circulating and Urinary miR-210 and miR-16 Increase during Cardiac Surgery Using Cardiopulmonary Bypass - A Pilot Study.

PubMed

Mazzone, Annette L; Baker, Robert A; McNicholas, Kym; Woodman, Richard J; Michael, Michael Z; Gleadle, Jonathan M

2018-03-01

A pilot study to measure and compare blood and urine microRNAs miR-210 and miR-16 in patients undergoing cardiac surgery with cardiopulmonary bypass (CPB) and off-pump coronary artery bypass grafting surgery. Frequent serial blood and urine samples were taken from patients undergoing cardiac surgery with CPB (n = 10) and undergoing off-pump cardiac surgery (n = 5) before, during, and after surgery. Circulating miR-210 and miR-16 levels were determined by relative quantification real-time polymerase chain reaction. Levels of plasma-free haemoglobin (fHb), troponin-T, creatine kinase, and creatinine were measured. Perioperative serum miR-210 and miR-16 were elevated significantly compared to preoperative levels in patients undergoing cardiac surgery with CPB (CPB vs. Pre Op and Rewarm vs. Pre Op; p < .05 for both). There were increases of greater than 200% in miR-210 levels during rewarming and immediately postoperatively and a 3,000% increase in miR-16 levels immediately postoperatively in urine normalized to urinary creatinine concentration. Serum levels of miR-16 were relatively constant during off-pump surgery. miR-210 levels increased significantly in off-pump patients perioperatively ( p < .05 Octopus on vs. Pre Op); however, the release was less marked when compared to cardiac surgery with CPB. A significant association was observed between both miR-16 and miR-210 and plasma fHb when CPB was used ( r = -.549, p < .0001 and r = -.463, p < .0001 respectively). Serum and urine concentrations of hypoxically regulated miR-210 and hemolysis-associated miR-16 increased in cardiac surgery using CPB compared to off-pump surgery. These molecules may have utility in indicating severity of cardiac, red cell, and renal injury during cardiac surgery.

Long pulse pumping behavior of a cryopump for the neutral beam injector

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

Chakrapani, Ch.; Sharma, S. K.; Chakraborty, A. K.

2007-01-15

This article presents studies on the long term pumping behavior of a cryopump. It is shown that the pumping speed does not deteriorate on a time scale of 4200 s for a gas load of 2.4x10{sup 5} torr l, corresponding to {approx}10{sup 6} ML of hydrogen. It has also been observed that the need for regeneration of the pump is dictated by the safety limits of operation rather than its pumping capability. No sudden boil off of the cryogen takes place during the regeneration phase.

RESPIRE 2: a phase III placebo-controlled randomised trial of ciprofloxacin dry powder for inhalation in non-cystic fibrosis bronchiectasis.

PubMed

Aksamit, Timothy; De Soyza, Anthony; Bandel, Tiemo-Joerg; Criollo, Margarita; Elborn, J Stuart; Operschall, Elisabeth; Polverino, Eva; Roth, Katrin; Winthrop, Kevin L; Wilson, Robert

2018-01-01

We evaluated the efficacy and safety of ciprofloxacin dry powder for inhalation (DPI) in patients with non-cystic fibrosis bronchiectasis, two or more exacerbations in the previous year and predefined sputum bacteria.Patients were randomised 2:1 to twice-daily ciprofloxacin DPI 32.5 mg or placebo in 14- or 28-day on/off treatment cycles for 48 weeks. Primary end-points were time to first exacerbation and frequency of exacerbations. Enrolling countries and α level split (0.049 and 0.001 for 14- and 28-day cycles, respectively) differed from RESPIRE 1.Patients were randomised to ciprofloxacin DPI (14 days on/off (n=176) or 28 days on/off (n=171)) or placebo (14 days on/off (n=88) or 28 days on/off (n=86)). The exacerbation rate was low across treatment arms (mean±sd 0.6±0.9). Active treatment showed trends to prolonged time to first exacerbation (ciprofloxacin DPI 14 days on/off: hazard ratio 0.87, 95.1% CI 0.62-1.21; p=0.3965; ciprofloxacin DPI 28 days on/off: hazard ratio 0.71, 99.9% CI 0.39-1.27; p=0.0511) and reduced frequency of exacerbations (ciprofloxacin DPI 14 days on/off: incidence rate ratio 0.83, 95.1% CI 0.59-1.17; p=0.2862; ciprofloxacin DPI 28 days on/off: incidence rate ratio 0.55, 99.9% CI 0.30-1.02; p=0.0014), although neither achieved statistical significance. Ciprofloxacin DPI was well tolerated.Trends towards clinical benefit were seen with ciprofloxacin DPI, but primary end-points were not met. Copyright ©ERS 2018.

Comparison of dual-hormone artificial pancreas, single-hormone artificial pancreas, and conventional insulin pump therapy for glycaemic control in patients with type 1 diabetes: an open-label randomised controlled crossover trial.

PubMed

Haidar, Ahmad; Legault, Laurent; Messier, Virginie; Mitre, Tina Maria; Leroux, Catherine; Rabasa-Lhoret, Rémi

2015-01-01

The artificial pancreas is an emerging technology for the treatment of type 1 diabetes and two configurations have been proposed: single-hormone (insulin alone) and dual-hormone (insulin and glucagon). We aimed to delineate the usefulness of glucagon in the artificial pancreas system. We did a randomised crossover trial of dual-hormone artificial pancreas, single-hormone artificial pancreas, and conventional insulin pump therapy (continuous subcutaneous insulin infusion) in participants aged 12 years or older with type 1 diabetes. Participants were assigned in a 1:1:1:1:1:1 ratio with blocked randomisation to the three interventions and attended a research facility for three 24-h study visits. During visits when the patient used the single-hormone artificial pancreas, insulin was delivered based on glucose sensor readings and a predictive dosing algorithm. During dual-hormone artificial pancreas visits, glucagon was also delivered during low or falling glucose. During conventional insulin pump therapy visits, patients received continuous subcutaneous insulin infusion. The study was not masked. The primary outcome was the time for which plasma glucose concentrations were in the target range (4·0-10·0 mmol/L for 2 h postprandially and 4·0-8·0 mmol/L otherwise). Hypoglycaemic events were defined as plasma glucose concentration of less than 3·3 mmol/L with symptoms or less than 3·0 mmol/L irrespective of symptoms. Analysis was by modified intention to treat, in which we included data for all patients who completed at least two visits. A p value of less than 0·0167 (0·05/3) was regarded as significant. This trial is registered with ClinicalTrials.gov, number NCT01754337. The mean proportion of time spent in the plasma glucose target range over 24 h was 62% (SD 18), 63% (18), and 51% (19) with single-hormone artificial pancreas, dual-hormone artificial pancreas, and conventional insulin pump therapy, respectively. The mean difference in time spent in the target range between single-hormone artificial pancreas and conventional insulin pump therapy was 11% (17; p=0·002) and between dual-hormone artificial pancreas and conventional insulin pump therapy was 12% (21; p=0·00011). There was no difference (15; p=0·75) in the proportion of time spent in the target range between the single-hormone and dual-hormone artificial pancreas systems. There were 52 hypoglycaemic events with conventional insulin pump therapy (12 of which were symptomatic), 13 with the single-hormone artificial pancreas (five of which were symptomatic), and nine with the dual-hormone artificial pancreas (0 of which were symptomatic); the number of nocturnal hypoglycaemic events was 13 (0 symptomatic), 0, and 0, respectively. Single-hormone and dual-hormone artificial pancreas systems both provided better glycaemic control than did conventional insulin pump therapy. The single-hormone artificial pancreas might be sufficient for hypoglycaemia-free overnight glycaemic control. Canadian Diabetes Association; Fondation J A De Sève; Juvenile Diabetes Research Foundation; and Medtronic. Copyright © 2015 Elsevier Ltd. All rights reserved.

Series-parallel solar-augmented rock-bed heat pump. Final report

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

Sowell, E.F.; Othmer, P.W.

1979-12-31

This report deals with a system representing an alternate arrangement of the components in an air-type, heat pump augmented solar heating system. In this system, referred to as Series-Parallel, the heat pump coils are at opposite ends of the rock bed, allowing heating and cooling of the air entering and leaving the bed. This allows a number of unique modes of operation, some of which allow off-peak use of the necessary utility power. Cooling modes are also available, including off-peak cooling-effect storage, night cooling, and free cooling (economizing). The system finds applications principally in single-family residences. The study examined themore » performance of this system at three locations (Sacramento, Albuquerque, and New York) by means of a simulation model. Seasonal heating and cooling performance factors of about 3 were obtained for Albuquerque for the system integrated into a 200 m/sup 2/ residence. Design integration studies suggest an installed cost of approximately $28,000 above a conventional heat pump system using commercially available components. This high cost is largely due to solar hardware, although system complexity also adds. Availability of low-cost air type collectors may make the system attractive. The study also addresses the general problem of predictive control necessary whenever off-peak storage is employed. An algorithm is presented, along with results.« less

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

PubMed Central

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

2008-01-01

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

Selective suppression of CARS signal with three-beam competing stimulated Raman scattering processes.

PubMed

Choi, Dae Sik; Rao, B Jayachander; Kim, Doyeon; Shim, Sang-Hee; Rhee, Hanju; Cho, Minhaeng

2018-06-14

Coherent Raman scattering spectroscopy and microscopy are useful methods for studying the chemical and biological structures of molecules with Raman-active modes. In particular, coherent anti-Stokes Raman scattering (CARS) microscopy, which is a label-free method capable of imaging structures by displaying the vibrational contrast of the molecules, has been widely used. However, the lack of a technique for switching-off the CARS signal has prevented the development of the super-resolution Raman imaging method. Here, we demonstrate that a selective suppression of the CARS signal is possible by using a three-beam double stimulated Raman scattering (SRS) scheme; the three beams are the pump, Stokes, and depletion lights in order of frequency. Both pump-Stokes and pump-depletion beam pairs can generate SRS processes by tuning their beat frequencies to match two different vibrational modes, then two CARS signals induced by pump-Stokes-pump and pump-depletion-pump interactions can be generated, where the two CARS signals are coupled with each other because they both involve interactions with the common pump beam. Herein, we show that as the intensity of the depletion beam is increased, one can selectively suppress the pump-Stokes-pump CARS signal because the pump-depletion SRS depletes the pump photons. A detailed theoretical description of the coupled differential equations for the three incident fields and the generated CARS signal fields is presented. Taking benzene as a molecular system, we obtained a maximum CARS suppression efficiency of about 97% with our experimental scheme, where the ring breathing mode of the benzene is associated with pump-Stokes-pump CARS, while the C-H stretching mode is associated with the competing pump-depletion SRS process. We anticipate that this selective switching-off scheme will be of use in developing super-resolution label-free CARS microscopy.

Intermediate coronary revascularization using the Deltastream blood pump: results from an experimental study.

PubMed

Litmathe, J; Hansen, E; Feindt, P; Kurt, M; Boeken, U; Gams, E

2009-01-01

Myocardial revascularization using a complete heart-lung machine may involve many problems, as do complete off-pump attempts. Thus, it was the aim of this study to evaluate the effects of intermediate on-pump/off-pump myocardial revascularization using the miniaturized Deltastream blood pump, on ischemia and hemolysis, in comparison with standard myocardial revascularization. In a group of 8 mini-pigs, combined on-pump/off-pump myocardial revascularization was performed using the Deltastream blood pump as beating-heart support for the on-pump part of the operation (group A). Seven other animals served as controls and underwent standard myocardial revascularization with the same device as integrated pump of a complete heart-lung machine (group B). Blood samples for blood gas metabolism, creatine kinase (CK), troponin I, lactate dehydrogenase (LDH), and hydroxybutyrate dehydrogenase (HBDH) were taken before and after the entire operation. Comparing the baseline values, the increase of CK was more pronounced in group B than in group A (176.4-/+41.2 to 279.7-/+29 U/L vs. 274-/+142.7 to 288.1-/+118.6 U/L, respectively; p=0.0006). Increase of troponin I was significantly higher in group B than in group A (1-/+0.3 to 2.9-/+1 ng/mL vs. 1.1-/+0.9 to 3-/+3.8 ng/mL, respectively; p=0.002). LDH increase was also more pronounced in group B (231.7-/+54.3 to 299.9-/+39.8 U/L vs. 274.9-/+59.7 to 263.8-/+57.9 U/L, respectively; p=0.01). HBDH values increased significantly in group B after the operation (group A: 215.9-/+34.7 to 200-/+39.2 U/L vs. group B: 195.4-/+41.7 to 274.9-/+51.6 U/L; p=0.02). Hemodynamic measures and LDH values under luxation (group A: 1.9-/+0.6 U/L; B: 3.5-/+1 U/L,p=0.001) were also superior in the study group. The current set-up might be superior to conventional extracorporeal circulation and thus be an alternative for high-risk candidates to avoid the adverse events of a complete heart-lung machine, when they are scheduled for complete myocardial revascularization.

Design trade-offs among shunt current, pumping loss and compactness in the piping system of a multi-stack vanadium flow battery

NASA Astrophysics Data System (ADS)

Ye, Qiang; Hu, Jing; Cheng, Ping; Ma, Zhiqi

2015-11-01

Trade-off between shunt current loss and pumping loss is a major challenge in the design of the electrolyte piping network in a flow battery system. It is generally recognized that longer and thinner ducts are beneficial to reduce shunt current but detrimental to minimize pumping power. Base on the developed analog circuit model and the flow network model, we make case studies of multi-stack vanadium flow battery piping systems and demonstrate that both shunt current and electrolyte flow resistance can be simultaneously minimized by using longer and thicker ducts in the piping network. However, extremely long and/or thick ducts lead to a bulky system and may be prohibited by the stack structure. Accordingly, the intrinsic design trade-off is between system efficiency and compactness. Since multi-stack configurations bring both flexibility and complexity to the design process, we perform systematic comparisons among representative piping system designs to illustrate the complicated trade-offs among numerous parameters including stack number, intra-stack channel resistance and inter-stack pipe resistance. As the final design depends on various technical and economical requirements, this paper aims to provide guidelines rather than solutions for designers to locate the optimal trade-off points according to their specific cases.

Investigation of an ejector heat pump by analytical methods

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

Hsu, C.T.

1984-07-01

Using existing theories of ejector design, the optimum geometry of a high-efficiency ejector - including mixing section cross-sectional area, mass flow entrainment rate, ejector efficiency, and overall COP - for a heat pump cycle was determined. A parametric study was performed to evaluate the COP values for different operating conditions. A sensitivity study determined th effects of nozzle efficiency and diffuser efficiency on the overall ejector heat pump COP. The off-design study estimated the COP for an ejector heat pump operating at off-design conditions. Refrigerants 11, 113, and 114 are three of the halocarbons which best satisfy the criteria formore » an ejector heat pump system. The estimated COPs were 0.3 for the cooling mode and 1.3 for the heating mode at standard operating conditions: a boiler temperature of 93.3/sup 0/C (200/sup 0/F), a condenser temperature of 43.3/sup 0/C (110/sup 0/F), and an evaporator temperature of 10/sup 0/C (50/sup 0/F). Based on the same operating conditions, an optimum ejector geometry was estimated for each of the refrigerants R-11 and R-113. Since the COP values for heating obtained in this analysis are greater than unity, the performance of an ejector heat pump operating in the heating mode should be competitive with that of oil- or gas-fired furnaces or electrical resistance heaters.« less

Off-pump repair of a post-infarct ventricular septal defect: the 'Hamburger procedure'

PubMed Central

Barker, Thomas A; Ng, Alexander; Morgan, Ian S

2006-01-01

We report a novel off-pump technique for the surgical closure of post-infarct ventricular septal defects (VSDs). The case report describes the peri-operative management of a 76 year old lady who underwent the 'Hamburger procedure' for closure of her apical VSD. Refractory cardiogenic shock meant that traditional patch repairs requiring cardiopulmonary bypass would be poorly tolerated. We show that echocardiography guided off-pump posterior-anterior septal plication is a safe, effective method for closing post-infarct VSDs in unstable patients. More experience is required to ascertain whether this technique will become an accepted alternative to patch repairs. PMID:16722552

Right pleuropericardial release: a useful technique in off-pump coronary surgery.

PubMed

Velissaris, Theodore; Stuklis, Robert G; Hett, David A; Ohri, Sunil K

2003-06-01

We describe the use of right pleurotomy combined with right pericardial release during off-pump coronary surgery. The maneuver releases the compression exerted on the right cardiac chambers during cardiac verticalization and improves hemodynamic stability during exposure of the posterior or lateral coronary vessels.

RESONATORS. MODES: Modes of a plano - spherical laser resonator with the Gaussian gain distribution of the active medium

NASA Astrophysics Data System (ADS)

Malyutin, A. A.

2007-03-01

Modes of a laser with plano-spherical degenerate and nondegenerate resonators are calculated upon diode pumping producing the Gaussian gain distribution in the active medium. Axially symmetric and off-axis pumpings are considered. It is shown that in the first case the lowest Hermite-Gaussian mode is excited with the largest weight both in the degenerate and nondegenerate resonator if the pump level is sufficiently high or the characteristic size wg of the amplifying region greatly exceeds the mode radius w0. The high-order Ince-Gaussian modes are excited upon weak off-axis pumping in the nondegenerate resonator both in the absence and presence of the symmetry of the gain distribution with respect to the resonator axis. It is found that when the level of off-axis symmetric pumping of the resonator is high enough, modes with the parameters of the TEM00 mode periodically propagating over a closed path in the resonator can exist. The explanation of this effect is given.

Modeling and design of a high efficiency hybrid heat pump clothes dryer

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

TeGrotenhuis, Ward; Butterfield, Andrew; Caldwell, Dustin

Computational modeling is used to design a hybrid heat pump clothes dryer capable of saving 50% of the energy used by residential clothes dryers with comparable drying times. The model represents the various stages of a drying cycle from warm-up through constant drying rate and falling drying rate phases and finishing with a cooldown phase. The model is fit to data acquired from a U.S. commercial standard vented electric dryer, and when a hybrid heat pump system is added, the energy factor increases from 3.0 lbs/kWh to 5.7-6.0 lbs/kWh, depending on the increase in blower motor power. The hybrid heatmore » pump system is designed from off-the-shelf components and includes a recuperative heat exchanger, an electric element, and an R-134a vapor compression heat pump. Parametric studies of element power and heating element use show a trade-off between energy savings and cycle time. Results show a step-change in energy savings from heat pump dryers currently marketed in the U.S. based on performance represented by Enery Star from standardized DOE testing.« less

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

USDA-ARS?s Scientific Manuscript database

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...

Should I change to OPCAB?

PubMed

Swart, Marius J; Joubert, Gina

2005-01-01

Much is written about the benefits of off-pump coronary artery bypass surgery (OPCAB). Is it applicable to all practices? Does that mean we all need to change to OPCAB? The surgical literature appears to have flaws with regard to providing answers. In striving for evidence-based medicine, one could integrate clinical data with external best evidence or do proper power calculations to determine study sizes. In a local, retrospective, observational study, 535 patients had a CABG done with the aid of cardiopulmonary bypass and cardiac arrest. Five hundred and seven patients were considered appropriate for analysis. Mortality was seven (1.4%), the prevalence of myocardial infarction four (0.8%), renal dialysis was four (0.8%) and stroke six (1.2%). Eighty (16%) patients required homologous blood transfusions. The median length of hospital stay was five days. If a local, randomised, controlled study was to be conducted to confirm an improvement with OPCAB, a large number of patients would be needed. For a 12.5% reduction in an event rate presently at 0.8%, 262,000 patients would be necessary. For a 50% reduction in an event rate presently at .0%, 2300 patients should be recruited. The local prevalence rate is very low and the number of patients required for a series is too high. The supremacy of OPCAB for this practice is therefore not established.

Current Status of Off-pump Coronary Artery Bypass Grafting in Patients with Multiple Coronary Artery Disease Compared with On-pump Coronary Artery Bypass Grafting: The Korean National Cohort Study.

PubMed

Kim, Hee Jung; Chung, Jae Eun; Jung, Jae Seung; Kim, In Seup; Son, Ho Sung

2018-05-31

 Despite advance in off-pump coronary artery bypass (OPCAB) grafting, there are large debating issues regarding survival benefit between OPCAB and on-pump coronary artery bypass grafting (CABG). The aim of this study is to address appropriateness of OPCAB approach in patients with ischemic heart disease having multiple vessels using South Korea national cohort data.  To evaluate the safety and efficacy of OPCAB, we accessed all causes of death, late repeat revascularization, hospitalization for cerebrovascular accident (CVA), and new renal replacement therapy in patients who underwent isolated CABG with multiple grafting (≥2 grafts) and who were registered in the Korean Health Insurance Review and Assessment Service Database between April 2011 and September 2014.  OPCAB was performed in 4,692 patients and on-pump CABG in 2,999 patients from 82 hospitals in South Korea. On multivariable analysis, on-pump CABG was associated with a significantly higher adjusted risk of overall all-cause death (hazard ratio [HR]: 1.876, 95% confidence interval [CI]: 1.587-2.216, p  < 0.001) and initiation of new renal replacement therapy (HR: 1.618, 95% CI: 1.124-2.331, p  = 0.009). However, we observed no significant difference in repeat revascularization and hospitalization for CVA between the two groups. In propensity score matching, matched patients (2,940 pairs) showed results similar to multivariable analysis that on-pump CABG was associated with a higher overall mortality and initiation of new renal replacement therapy ( p  < 0.001).  In this study, we found that OPCAB was associated with better survival rates and renal preservation compared with on-pump CABG. Georg Thieme Verlag KG Stuttgart · New York.

Mold Heating and Cooling Pump Package Operator Interface Controls Upgrade

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

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 lowmore » residual stresses. The products fabricated are used on multiple programs.« less

A cluster randomised trial, cost-effectiveness analysis and psychosocial evaluation of insulin pump therapy compared with multiple injections during flexible intensive insulin therapy for type 1 diabetes: the REPOSE Trial.

PubMed

Heller, Simon; White, David; Lee, Ellen; Lawton, Julia; Pollard, Daniel; Waugh, Norman; Amiel, Stephanie; Barnard, Katharine; Beckwith, Anita; Brennan, Alan; Campbell, Michael; Cooper, Cindy; Dimairo, Munyaradzi; Dixon, Simon; Elliott, Jackie; Evans, Mark; Green, Fiona; Hackney, Gemma; Hammond, Peter; Hallowell, Nina; Jaap, Alan; Kennon, Brian; Kirkham, Jackie; Lindsay, Robert; Mansell, Peter; Papaioannou, Diana; Rankin, David; Royle, Pamela; Smithson, W Henry; Taylor, Carolin

2017-04-01

Insulin is generally administered to people with type 1 diabetes mellitus (T1DM) using multiple daily injections (MDIs), but can also be delivered using infusion pumps. In the UK, pumps are recommended for patients with the greatest need and adult use is less than in comparable countries. Previous trials have been small, of short duration and have failed to control for training in insulin adjustment. To assess the clinical effectiveness and cost-effectiveness of pump therapy compared with MDI for adults with T1DM, with both groups receiving equivalent structured training in flexible insulin therapy. Pragmatic, multicentre, open-label, parallel-group cluster randomised controlled trial, including economic and psychosocial evaluations. After participants were assigned a group training course, courses were randomly allocated in pairs to either pump or MDI. Eight secondary care diabetes centres in the UK. Adults with T1DM for > 12 months, willing to undertake intensive insulin therapy, with no preference for pump or MDI, or a clinical indication for pumps. Pump or MDI structured training in flexible insulin therapy, followed up for 2 years. MDI participants used insulin analogues. Pump participants used a Medtronic Paradigm ® Veo TM (Medtronic, Watford, UK) with insulin aspart (NovoRapid, Novo Nordisk, Gatwick, UK). Primary outcome - change in glycated haemoglobin (HbA 1c ) at 2 years in participants whose baseline HbA 1c was ≥ 7.5% (58 mmol/mol). Key secondary outcome - proportion of participants with HbA 1c ≤ 7.5% at 2 years. Other outcomes at 6, 12 and 24 months - moderate and severe hypoglycaemia; insulin dose; body weight; proteinuria; diabetic ketoacidosis; quality of life (QoL); fear of hypoglycaemia; treatment satisfaction; emotional well-being; qualitative interviews with participants and staff (2 weeks), and participants (6 months); and ICERs in trial and modelled estimates of cost-effectiveness. We randomised 46 courses comprising 317 participants: 267 attended a Dose Adjustment For Normal Eating course (132 pump; 135 MDI); 260 were included in the intention-to-treat analysis, of which 235 (119 pump; 116 MDI) had baseline HbA 1c of ≥ 7.5%. HbA 1c and severe hypoglycaemia improved in both groups. The drop in HbA 1c % at 2 years was 0.85 on pump and 0.42 on MDI. The mean difference (MD) in HbA 1c change at 2 years, at which the baseline HbA 1c was ≥ 7.5%, was -0.24% [95% confidence interval (CI) -0.53% to 0.05%] in favour of the pump ( p  = 0.098). The per-protocol analysis showed a MD in change of -0.36% (95% CI -0.64% to -0.07%) favouring pumps ( p  = 0.015). Pumps were not cost-effective in the base case and all of the sensitivity analyses. The pump group had greater improvement in diabetes-specific QoL diet restrictions, daily hassle plus treatment satisfaction, statistically significant at 12 and 24 months and supported by qualitative interviews. Blinding of pump therapy was not possible, although an objective primary outcome was used. Adding pump therapy to structured training in flexible insulin therapy did not significantly enhance glycaemic control or psychosocial outcomes in adults with T1DM. To understand why few patients achieve a HbA 1c of < 7.5%, particularly as glycaemic control is worse in the UK than in other European countries. Current Controlled Trials ISRCTN61215213. This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment ; Vol. 21, No. 20. See the NIHR Journals Library website for further project information.

Relative effectiveness of insulin pump treatment over multiple daily injections and structured education during flexible intensive insulin treatment for type 1 diabetes: cluster randomised trial (REPOSE).

PubMed

2017-03-30

Objective  To compare the effectiveness of insulin pumps with multiple daily injections for adults with type 1 diabetes, with both groups receiving equivalent training in flexible insulin treatment. Design  Pragmatic, multicentre, open label, parallel group, cluster randomised controlled trial (Relative Effectiveness of Pumps Over MDI and Structured Education (REPOSE) trial). Setting  Eight secondary care centres in England and Scotland. Participants  Adults with type 1 diabetes who were willing to undertake intensive insulin treatment, with no preference for pumps or multiple daily injections. Participants were allocated a place on established group training courses that taught flexible intensive insulin treatment ("dose adjustment for normal eating," DAFNE). The course groups (the clusters) were then randomly allocated in pairs to either pump or multiple daily injections. Interventions  Participants attended training in flexible insulin treatment (using insulin analogues) structured around the use of pump or injections, followed for two years. Main outcome measures  The primary outcomes were a change in glycated haemoglobin (HbA1c) values (%) at two years in participants with baseline HbA1c value of ≥7.5% (58 mmol/mol), and the proportion of participants achieving an HbA1c value of <7.5%. Secondary outcomes included body weight, insulin dose, and episodes of moderate and severe hypoglycaemia. Ancillary outcomes included quality of life and treatment satisfaction. Results  317 participants (46 courses) were randomised (156 pump and 161 injections). 267 attended courses and 260 were included in the intention to treat analysis, of which 235 (119 pump and 116 injection) had baseline HbA1c values of ≥7.5%. Glycaemic control and rates of severe hypoglycaemia improved in both groups. The mean change in HbA1c at two years was -0.85% with pump treatment and -0.42% with multiple daily injections. Adjusting for course, centre, age, sex, and accounting for missing values, the difference was -0.24% (-2.7 mmol/mol) in favour of pump users (95% confidence interval -0.53 to 0.05, P=0.10). Most psychosocial measures showed no difference, but pump users showed greater improvement in treatment satisfaction and some quality of life domains (dietary freedom and daily hassle) at 12 and 24 months. Conclusions  Both groups showed clinically relevant and long lasting decreases in HbA1c, rates of severe hypoglycaemia, and improved psychological measures, although few participants achieved glucose levels currently recommended by national and international guidelines. Adding pump treatment to structured training in flexible intensive insulin treatment did not substantially enhance educational benefits on glycaemic control, hypoglycaemia, or psychosocial outcomes in adults with type 1 diabetes. These results do not support a policy of providing insulin pumps to adults with poor glycaemic control until the effects of training on participants' level of engagement in intensive self management have been determined. Trial registration  Current Controlled Trials ISRCTN61215213. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Classroom attention in children with type 1 diabetes mellitus: the effect of stabilizing serum glucose.

PubMed

Daley, Kelly B; Wodrich, David L; Hasan, Khalid

2006-02-01

To determine whether stabilizing serum glucose, via introduction of an insulin pump, improves classroom attention among children with type-1 diabetes mellitus. Four boys having type-1 diabetes mellitus with unstable serum glucose were observed in their classroom for 10 baseline days. An insulin pump was placed and serum glucose stabilized, and they were then observed again for 10 days. A modified multiple baseline design was used to determine if improved on-task and off-task behavior was associated with better glycemic control. Rating scales and a laboratory measure of attention, measures of secondary interest, were also administered before and after pump introduction, and potential improvement in individuals' scores was evaluated. All boys had apparent improvement in on-task and off-task behavior as observed in their classrooms. Improvements were substantial, averaging 20% in on-task behavior and 34% in off-task behavior. However, no changes were detected on rating scales or laboratory measures. This study offers preliminary evidence that stabilizing serum glucose improves classroom attention, although the effect was detected only by observation of classroom behavior using highly structured techniques. Consequently, use of direct observation techniques may be important in studying the effects of chronic illness on classroom functioning.

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

NASA Astrophysics Data System (ADS)

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.

Risk Factors of On-Pump Conversion during Off-Pump Coronary Artery Bypass Graft

PubMed Central

Yoon, Sung Sil; Bang, Jung Hee; Jeong, Sang Seok; Jeong, Jae Hwa; Woo, Jong Soo

2017-01-01

Background Off-pump coronary artery bypass grafting (OPCABG) procedures can avoid the complications of an on-pump bypass. However, some cases unexpectedly require conversion to cardiopulmonary bypass during OPCABG. The risk factors associated with a sudden need for cardiopulmonary bypass were analyzed. Methods This retrospective study included 283 subjects scheduled for OPCABG from 2001 to 2010. These were divided into an OPCABG group and an on-pump conversion group. Preoperative, operative, and postoperative variables were compared between the 2 groups. Results Of the 283 patients scheduled for OPCABG, 47 (16%) were switched to on-pump coronary artery bypass grafting (CABG). The mortality of the both the OPCABG and on-pump conversion groups was not significantly different. The major risk factors for conversion to on-pump CABG were congestive heart failure (CHF) (odds ratio [OR], 3.5; p=0.029), ejection fraction (EF) <35% (OR, 4.4; p=0.012), and preoperative beta-blocker (BB) administration (OR, 0.3; p=0.007). The use of intraoperative (p=0.007) and postoperative (p=0.021) inotropics was significantly higher in the conversion group. The amount of postoperative drainage (p<0.001) and transfusion (p<0.001) also was significantly higher in the conversion group. There were no significant differences in stroke or cardiovascular complications between the groups over the course of short-term and long-term follow-up. Conclusion Patients who undergo OPCABG and have CHF or a lower EF (<35%) are more likely to undergo on-pump conversion, while preoperative BB administration could help prevent conversions from OPCABG to on-pump CABG. PMID:29124027

Off-pump compared to minimal extracorporeal circulation surgery in coronary artery bypass grafting.

PubMed

Reuthebuch, Oliver; Koechlin, Luca; Gahl, Brigitta; Matt, Peter; Schurr, Ulrich; Grapow, Martin; Eckstein, Friedrich

2014-01-01

Coronary artery bypass grafting (CABG) using extracorporeal circulation (ECC) is still the gold standard. However, alternative techniques have been developed to avoid ECC and its potential adverse effects. These encompass minimal extracorporeal circulation (MECC) or off-pump coronary artery bypass grafting (OPCAB). However, the prevailing potential benefits when comparing MECC and OPCABG are not yet clearly established. In this retrospective study we investigated the potential benefits of MECC and OPCABG in 697 patients undergoing CABG. Of these, 555 patients had been operated with MECC and 142 off-pump. The primary endpoint was Troponin T level as an indicator for myocardial damage. Study groups were not significantly different in general. However, patients undergoing OPCABG were significantly older (65.01 years ± 9.5 vs. 69.39 years ± 9.5; p value <0.001) with a higher Logistic EuroSCORE I (4.92% ± 6.5 vs. 5.88% ± 6.8; p value = 0.017). Operating off pump significantly reduced the need for intra-operative blood products (0.7% vs. 8.6%; p-value <0.001) and the length of stay in the intensive care unit (ICU) (2.04 days ± 2.63 vs. 2.76 days ± 2.79; p value <0.001). Regarding other blood values a significant difference could not be found in the adjusted calculations. The combined secondary endpoint, major cardiac or cerebrovascular events (MACCE), was equal in both groups as well. Coronary artery bypass grafting using MECC or OPCABG are two comparable techniques with advantages for OPCABG regarding the reduced need for intra-operative blood products and shorter length of stay in the ICU. However serological values and combined endpoint MACCE did not differ significantly in both groups.

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

PubMed Central

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

Mean Line Pump Flow Model in Rocket Engine System Simulation

NASA Technical Reports Server (NTRS)

Veres, Joseph P.; Lavelle, Thomas M.

2000-01-01

A mean line pump flow modeling method has been developed to provide a fast capability for modeling turbopumps of rocket engines. Based on this method, a mean line pump flow code PUMPA has been written that can predict the performance of pumps at off-design operating conditions, given the loss of the diffusion system at the design point. The pump code can model axial flow inducers, mixed-flow and centrifugal pumps. The code can model multistage pumps in series. The code features rapid input setup and computer run time, and is an effective analysis and conceptual design tool. The map generation capability of the code provides the map information needed for interfacing with a rocket engine system modeling code. The off-design and multistage modeling capabilities of the code permit parametric design space exploration of candidate pump configurations and provide pump performance data for engine system evaluation. The PUMPA code has been integrated with the Numerical Propulsion System Simulation (NPSS) code and an expander rocket engine system has been simulated. The mean line pump flow code runs as an integral part of the NPSS rocket engine system simulation and provides key pump performance information directly to the system model at all operating conditions.

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

PubMed

Chakravarthy, Murali; Prabhakumar, Dattatreya; Thimmannagowda, Patil; Krishnamoorthy, Jayaprakash; George, Antony; Jawali, Vivek

2017-01-01

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. 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. 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. 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 blood loss (1906.29 ± 611.87 ml vs 1793.65 ± 663.54 ml , p value 0.49) were similar among the groups [Table 4]. The incidence of ECG changes of ischemia, arrhythmias, conversion to CPB, or need for intra-aortic balloon counter pulsation were not different. Use of either 2 or 3 mg/kg heparin for systemic heparinization in patients undergoing OPCAB did not affect the outcome.

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

PubMed

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

2017-01-01

The 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). Forty 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 CO 2 , 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. The value of IPI registered during respiratory support correlated weakly with cardiac index (rho = 0.4; p  = 0.04) and ScvO 2 (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. In off-pump coronary surgery, the IPI decreases significantly after tracheal extubation and may predict postoperative complications.

Safety and efficacy of the predictive low glucose management system in the prevention of hypoglycaemia: protocol for randomised controlled home trial to evaluate the Suspend before low function

PubMed Central

Abraham, M B; Nicholas, J A; Ly, T T; Roby, H C; Paramalingam, N; Fairchild, J; King, B R; Ambler, G R; Cameron, F; Davis, E A; Jones, T W

2016-01-01

Introduction Innovations with sensor-augmented pump therapy (SAPT) to reduce hypoglycaemia in patients with type 1 diabetes are an ongoing area of research. The predictive low glucose management (PLGM) system incorporates continuous glucose sensor data into an algorithm and suspends basal insulin before the occurrence of hypoglycaemia. The system was evaluated in in-clinic studies, and has informed the parameters of a larger home trial to study its efficacy and safety in real life. Methods and analysis The aim of this report is to describe the study design and outcome measures for the trial. This is a 6-month, multicentre, randomised controlled home trial to test the PLGM system in children and adolescents with type 1 diabetes. The system is available in the Medtronic MiniMed 640G pump as the ‘Suspend before low’ feature. Following a run-in period, participants are randomised to either the control arm with SAPT alone or the intervention arm with SAPT and Suspend before low. The primary aim of this study is to evaluate the time spent hypoglycaemic (sensor glucose <3.5 mmol/L) with and without the system. The secondary aims are to determine the number of hypoglycaemic events, the time spent hyperglycaemic, and to evaluate safety with ketosis and changes in glycated haemoglobin. The study also aims to assess the changes in counter-regulatory hormone responses to hypoglycaemia evaluated by a hyperinsulinaemic hypoglycaemic clamp in a subgroup of patients with impaired awareness. Validated questionnaires are used to measure the fear of hypoglycaemia and the impact on the quality of life to assess burden of the disease. Ethics and dissemination Ethics committee permissions were gained from respective Institutional Review boards. The findings of the study will provide high quality evidence of the ability of the system in the prevention of hypoglycaemia in real life. Trial registration number ACTRN12614000510640, Pre-results. PMID:27084290

Tricuspid valve excision using off-pump inflow occlusion technique: role of intra-operative trans-esophageal echocardiography.

PubMed

Gadhinglajkar, Shrinivas; Sreedhar, Rupa; Karunakaran, Jayakumar; Misra, Manoranjan; Somasundaram, Ganesh; Mathew, Thomas

2010-01-01

A pacing system infection may lead to infective endocarditis and systemic sepsis. Tricuspid valve surgery may be required if the valve is severely damaged in the process of endocarditis. Although, cardiopulmonary bypass is the safe choice for performing right-heart procedures, it may carry risk of inducing systemic inflammatory response and multi-organ dysfunction. Some studies have advocated TV surgery without institution of CPB. We report tricuspid valve excision using the off-pump inflow occlusion technique in a 68-year-old man. We also describe role of intra-operative TEE as a monitoring tool at different stages of the surgical procedure.

Day-and-night glycaemic control with closed-loop insulin delivery versus conventional insulin pump therapy in free-living adults with well controlled type 1 diabetes: an open-label, randomised, crossover study.

PubMed

Bally, Lia; Thabit, Hood; Kojzar, Harald; Mader, Julia K; Qerimi-Hyseni, Jehona; Hartnell, Sara; Tauschmann, Martin; Allen, Janet M; Wilinska, Malgorzata E; Pieber, Thomas R; Evans, Mark L; Hovorka, Roman

2017-04-01

Tight control of blood glucose concentration in people with type 1 diabetes predisposes to hypoglycaemia. We aimed to investigate whether day-and-night hybrid closed-loop insulin delivery can improve glucose control while alleviating the risk of hypoglycaemia in adults with HbA 1c below 7·5% (58 mmol/mol). In this open-label, randomised, crossover study, we recruited adults (aged ≥18 years) with type 1 diabetes and HbA 1c below 7·5% from Addenbrooke's Hospital (Cambridge, UK) and Medical University of Graz (Graz, Austria). After a 2-4 week run-in period, participants were randomly assigned (1:1), using web-based randomly permuted blocks of four, to receive insulin via the day-and-night hybrid closed-loop system or usual pump therapy for 4 weeks, followed by a 2-4 week washout period and then the other intervention for 4 weeks. Treatment interventions were unsupervised and done under free-living conditions. During the closed-loop period, a model-predictive control algorithm directed insulin delivery, and prandial insulin delivery was calculated with a standard bolus wizard. The primary outcome was the proportion of time when sensor glucose concentration was in target range (3·9-10·0 mmol/L) over the 4 week study period. Analyses were by intention to treat. This study is registered with ClinicalTrials.gov, number NCT02727231, and is completed. Between March 21 and June 24, 2016, we recruited 31 participants, of whom 29 were randomised. One participant withdrew during the first closed-loop period because of dissatisfaction with study devices and glucose control. The proportion of time when sensor glucose concentration was in target range was 10·5 percentage points higher (95% CI 7·6-13·4; p<0·0001) during closed-loop delivery compared with usual pump therapy (65·6% [SD 8·1] when participants used usual pump therapy vs 76·2% [6·4] when they used closed-loop). Compared with usual pump therapy, closed-loop delivery also reduced the proportion of time spent in hypoglycaemia: the proportion of time with glucose concentration below 3·5 mmol/L was reduced by 65% (53-74, p<0·0001) and below 2·8 mmol/L by 76% (59-86, p<0·0001). No episodes of serious hypoglycaemia or other serious adverse events occurred. Use of day-and-night hybrid closed-loop insulin delivery under unsupervised, free-living conditions for 4 weeks in adults with type 1 diabetes and HbA 1c below 7·5% is safe and well tolerated, improves glucose control, and reduces hypoglycaemia burden. Larger and longer studies are warranted. Swiss National Science Foundation (P1BEP3_165297), JDRF, UK National Institute for Health Research Cambridge Biomedical Research Centre, and Wellcome Strategic Award (100574/Z/12/Z). Copyright © 2017 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY license. Published by Elsevier Ltd.. All rights reserved.

Generation of vortex array laser beams with Dove prism embedded unbalanced Mach-Zehnder interferometer

NASA Astrophysics Data System (ADS)

Chu, Shu-Chun

2009-02-01

This paper introduces a scheme for generation of vortex laser beams from a solid-state laser with off-axis laser-diode pumping. The proposed system consists of a Dove prism embedded in an unbalanced Mach-Zehnder interferometer configuration. This configuration allows controlled construction of p × p vortex array beams from Ince-Gaussian modes, IGep,p modes. An incident IGe p,p laser beam of variety order p can easily be generated from an end-pumped solid-state laser with an off-axis pumping mechanism. This study simulates this type of vortex array laser beam generation and discusses beam propagation effects. The formation of ordered transverse emission patterns have applications in a variety of areas such as optical data storage, distribution, and processing that exploit the robustness of soliton and vortex fields and optical manipulations of small particles and atoms in the featured intensity distribution.

RESPIRE 1: a phase III placebo-controlled randomised trial of ciprofloxacin dry powder for inhalation in non-cystic fibrosis bronchiectasis.

PubMed

De Soyza, Anthony; Aksamit, Timothy; Bandel, Tiemo-Joerg; Criollo, Margarita; Elborn, J Stuart; Operschall, Elisabeth; Polverino, Eva; Roth, Katrin; Winthrop, Kevin L; Wilson, Robert

2018-01-01

We evaluated the efficacy and safety of ciprofloxacin dry powder for inhalation (DPI) in patients with non-cystic fibrosis bronchiectasis, two or more exacerbations in the previous year and pre-defined bacteria in sputum.In this phase III, double-blind, placebo-controlled trial, patients were randomised 2:1 to twice-daily ciprofloxacin DPI 32.5 mg or placebo in two treatment regimens consisting of on/off treatment cycles of 14 or 28 days for 48 weeks. The primary end-points were time to first exacerbation and frequency of exacerbations.A total of 416 patients were randomised to the 14-day on/off regimen (ciprofloxacin DPI (n=137) and placebo (n=68)) or the 28-day on/off regimen (ciprofloxacin DPI (n=141) and placebo (n=70)). Ciprofloxacin DPI 14 days on/off significantly prolonged time to first exacerbation versus pooled placebo (median time >336 versus 186 days; hazard ratio 0.53, 97.5% CI 0.36-0.80; p=0.0005) and reduced the frequency of exacerbations compared with matching placebo by 39% (mean number of exacerbations 0.6 versus 1.0; incidence rate ratio 0.61, 97.5% CI 0.40-0.91; p=0.0061). Outcomes for ciprofloxacin DPI 28 days on/off were not statistically significantly different from placebo. The safety profile of ciprofloxacin DPI was favourable.Ciprofloxacin DPI was well tolerated and has the potential to be an effective treatment option in non-cystic fibrosis bronchiectasis. Copyright ©ERS 2018.

The optimal operation of cooling tower systems with variable-frequency control

NASA Astrophysics Data System (ADS)

Cao, Yong; Huang, Liqing; Cui, Zhiguo; Liu, Jing

2018-02-01

This study investigates the energy performance of chiller and cooling tower systems integrated with variable-frequency control for cooling tower fans and condenser water pumps. With regard to an example chiller system serving an office building, Chiller and cooling towers models were developed to assess how different variable-frequency control methods of cooling towers fans and condenser water pumps influence the trade-off between the chiller power, pump power and fan power under various operating conditions. The matching relationship between the cooling tower fans frequency and condenser water pumps frequency at optimal energy consumption of the system is introduced to achieve optimum system performance.

B-1 Systems Approach to Training. Task Analysis Listings

DTIC Science & Technology

1975-07-01

OFF FUEL VALVES AND PUMPS PHR-OFF FUEL VALVES AND PUMPS = AUTO ^FT TFR MODE LAND SELECTOR SWITCHES TQ *QFF...TFR MODE SWITCH-RIGHT «JFT L TFR MODE SELECT SWITCH TQ * TF1 CHECKLIST TFR MODE SWITCH-LEFT TFR MODE SWITCH-LEFT...DOOR HANDLE ENTRY LADDER CONTROL SWITCH ENTRY LADDER CONTROL SWITCH = DN* 16.1.1.001.OC* SET TANK FILL VALVE SWS ON

Experimental Study of Unshrouded Impeller Pump Stage Sensitivity to Tip Clearance

NASA Technical Reports Server (NTRS)

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.

Methods of weaning preterm babies <30 weeks gestation off CPAP: a multicentre randomised controlled trial.

PubMed

Todd, David A; Wright, A; Broom, M; Chauhan, M; Meskell, S; Cameron, C; Perdomi, A M; Rochefort, M; Jardine, L; Stewart, A; Shadbolt, B

2012-07-01

Controversy exists whether different continuous positive airway pressure (CPAP) weaning methods influence time to wean off CPAP, CPAP duration, oxygen duration, Bronchopulmonary Dysplasia (BPD) or length of admission. In a multicentre randomised controlled trial, the authors have primarily compared CPAP weaning methods impact on time to wean off CPAP and CPAP duration and secondarily their effect on oxygen duration, BPD and time of admission. Between April 2006 and October 2009, 177 infants <30 weeks gestational age (GA) who fulfilled stability criteria on CPAP were randomised to one of the three CPAP weaning methods (M). M1: Taken 'OFF' CPAP with the view to stay 'OFF'. M2: Cycled on and off CPAP with incremental time 'OFF'. M3: As with m(2), cycled on and off CPAP but during 'OFF' periods were supported by 2 mm nasal cannula at a flow of 0.5 l/min. Based on intention to treat analysis, there was no significant difference in mean GA or birthweight between the groups (27.1 ± 1.4, 26.9 ± 1.6 and 27.3 ± 1.5 (weeks ± 1SD) and 988 ± 247, 987 ± 249 and 1015 ± 257 (grams ± 1SD), respectively). Primary outcomes showed M1 produced a significantly shorter time to wean from CPAP (11.3 ± 0.8, 16.8 ± 1.0, 19.4 ± 1.3 (days ± 1SE) p<0.0001, respectively) and CPAP duration (24.4 ± 0.1, 38.6 ± 0.1, 30.5 ± 0.1 (days ± 1SE) p<0.0001, respectively). All the secondary outcomes were significantly shorter with M1, (oxygen duration: 24.1 ± 1.5, 45.8 ± 2.2, 34.1 ± 2.0 (days ± 1SE) p<0.0001, BPD: 7/56 (12.5%), 29/69 (42%), 10/52 (19%) p=0.011 and length of admission: 58.5 ± 0.1, 73.8 ± 0.1 69.5 ± 0.1 (days ± 1SE) p<0.0001, respectively). Method 1 significantly shortens CPAP weaning time, CPAP duration, oxygen duration, BPD and admission time.

Method, system and computer program product for monitoring and optimizing fluid extraction from geologic strata

DOEpatents

Medizade, Masoud [San Luis Obispo, CA; Ridgely, John Robert [Los Osos, CA

2009-12-15

An arrangement which utilizes an inexpensive flap valve/flow transducer combination and a simple local supervisory control system to monitor and/or control the operation of a positive displacement pump used to extract petroleum from geologic strata. The local supervisory control system controls the operation of an electric motor which drives a reciprocating positive displacement pump so as to maximize the volume of petroleum extracted from the well per pump stroke while minimizing electricity usage and pump-off situations. By reducing the electrical demand and pump-off (i.e., "pounding" or "fluid pound") occurrences, operating and maintenance costs should be reduced sufficiently to allow petroleum recovery from marginally productive petroleum fields. The local supervisory control system includes one or more applications to at least collect flow signal data generated during operation of the positive displacement pump. No flow, low flow and flow duration are easily evaluated using the flap valve/flow transducer arrangement.

Evaluation of mitral valve replacement anchoring in a phantom

NASA Astrophysics Data System (ADS)

McLeod, A. Jonathan; Moore, John; Lang, Pencilla; Bainbridge, Dan; Campbell, Gordon; Jones, Doug L.; Guiraudon, Gerard M.; Peters, Terry M.

2012-02-01

Conventional mitral valve replacement requires a median sternotomy and cardio-pulmonary bypass with aortic crossclamping and is associated with significant mortality and morbidity which could be reduced by performing the procedure off-pump. Replacing the mitral valve in the closed, off-pump, beating heart requires extensive development and validation of surgical and imaging techniques. Image guidance systems and surgical access for off-pump mitral valve replacement have been previously developed, allowing the prosthetic valve to be safely introduced into the left atrium and inserted into the mitral annulus. The major remaining challenge is to design a method of securely anchoring the prosthetic valve inside the beating heart. The development of anchoring techniques has been hampered by the expense and difficulty in conducting large animal studies. In this paper, we demonstrate how prosthetic valve anchoring may be evaluated in a dynamic phantom. The phantom provides a consistent testing environment where pressure measurements and Doppler ultrasound can be used to monitor and assess the valve anchoring procedures, detecting pararvalvular leak when valve anchoring is inadequate. Minimally invasive anchoring techniques may be directly compared to the current gold standard of valves sutured under direct vision, providing a useful tool for the validation of new surgical instruments.

Generation of high-order Hermite-Gaussian modes in end-pumped solid-state lasers for square vortex array laser beam generation.

PubMed

Chu, Shu-Chun; Chen, Yun-Ting; Tsai, Ko-Fan; Otsuka, Kenju

2012-03-26

This study reports the first systematic approach to the excitation of all high-order Hermite-Gaussian modes (HGMs) in end-pumped solid-state lasers. This study uses a metal-wire-inserted laser resonator accompanied with the "off axis pumping" approach. This study presents numerical analysis of the excitation of HGMs in end-pumped solid-state lasers and experimentally generated HGM patterns. This study also experimentally demonstrates the generation of an square vortex array laser beams by passing specific high-order HGMs (HGn,n + 1 or HGn + 1,n modes) through a Dove prism-embedded unbalanced Mach-Zehnder interferometer [Optics Express 16, 19934-19949]. The resulting square vortex array laser beams with embedded vortexes aligned in a square array can be applied to multi-spot dark optical traps in the future.

Hydraulic and Thermal Response to Intermittent Pumping in Unconfined Alluvial Aquifers along a Regulated Stream

NASA Astrophysics Data System (ADS)

Maharjan, Madan

Groundwater response to stream stage fluctuations was studied using a year-long time series of stream stage and well heads in Glen Dale and New Martinsville, WV. Stream stage fluctuations exerted primary control over groundwater levels, especially during high flows. The location and operation of river pools created by dams alter groundwater flow paths and velocities. Aquifers are more prone to surface water infiltration in the upper reaches of pools than in lower reaches. Aquifer diffusivity is heterogeneous within and between the two sites. Temperature fluctuations were observed for 2.5 years in 14 wells in three alluvial aquifers. Temperature signals have 2 components corresponding to pump-on and pump-off periods. Both components vary seasonality at different magnitudes. While pump-off temperatures fluctuated up to 3.8o C seasonally, short-term temperature shifts induced by turning the pump on were 0.2 to 2.5o C. Pumping-induced temperature shifts were highest in magnitude in summer and winter. Groundwater temperature lagged behind that of surface water by approximately six months. Pumping induced and seasonal temperature shifts were spatially and temporally complex but indicate stream exfiltration is a major driver for a number of these wells. Numerical simulation of aquifer response to pumping show different conditions before and after well-field development. During pre-development, the stream was losing at high flow and gaining at low flow. During post-development, however, the stream was losing at high flow and spatially variable at low flow. While bank storage gained only during high stage, stream exfiltration occurred year-round. Pumping induced stream exfiltration by creating an extensive cone of depression beneath the stream in both upstream and downstream directions. Spatially and temporally variable groundwater-surface water interaction next to a regulated stream were studied using analytical and numerical models, based on field observations. Seasonality plays an important role in these interactions, but human activity may also alter its intensity.

Investigation of lunar base thermal control system options

NASA Technical Reports Server (NTRS)

Ewart, Michael K.

1993-01-01

Long duration human exploration missions to the Moon will require active thermal control systems which have not previously been used in space. The two technologies which are most promising for long term lunar base thermal control are heat pumps and radiator shades. Recent trade-off studies at the Johnson Space Center have focused development efforts on the most promising heat pump and radiator shade technologies. Since these technologies are in the early stages of development and many parameters used in the study are not well defined, a parametric study was done to test the sensitivity to each assumption. The primary comparison factor in these studies was the total mass system, with power requirements included in the form of a mass penalty for power. Heat pump technologies considered were thermally driven heat pumps such as metal hydride, complex compound, absorption and zeolite. Also considered were electrically driven Stirling and vapor compression heat pumps. Radiator shade concepts considered included step shaped, V-shaped and parabolic (or catenary) shades and ground covers. A further trade study compared the masses of heat pump and radiator shade systems.

A cluster randomised trial, cost-effectiveness analysis and psychosocial evaluation of insulin pump therapy compared with multiple injections during flexible intensive insulin therapy for type 1 diabetes: the REPOSE Trial.

PubMed Central

Heller, Simon; White, David; Lee, Ellen; Lawton, Julia; Pollard, Daniel; Waugh, Norman; Amiel, Stephanie; Barnard, Katharine; Beckwith, Anita; Brennan, Alan; Campbell, Michael; Cooper, Cindy; Dimairo, Munyaradzi; Dixon, Simon; Elliott, Jackie; Evans, Mark; Green, Fiona; Hackney, Gemma; Hammond, Peter; Hallowell, Nina; Jaap, Alan; Kennon, Brian; Kirkham, Jackie; Lindsay, Robert; Mansell, Peter; Papaioannou, Diana; Rankin, David; Royle, Pamela; Smithson, W Henry; Taylor, Carolin

2017-01-01

BACKGROUND Insulin is generally administered to people with type 1 diabetes mellitus (T1DM) using multiple daily injections (MDIs), but can also be delivered using infusion pumps. In the UK, pumps are recommended for patients with the greatest need and adult use is less than in comparable countries. Previous trials have been small, of short duration and have failed to control for training in insulin adjustment. OBJECTIVE To assess the clinical effectiveness and cost-effectiveness of pump therapy compared with MDI for adults with T1DM, with both groups receiving equivalent structured training in flexible insulin therapy. DESIGN Pragmatic, multicentre, open-label, parallel-group cluster randomised controlled trial, including economic and psychosocial evaluations. After participants were assigned a group training course, courses were randomly allocated in pairs to either pump or MDI. SETTING Eight secondary care diabetes centres in the UK. PARTICIPANTS Adults with T1DM for > 12 months, willing to undertake intensive insulin therapy, with no preference for pump or MDI, or a clinical indication for pumps. INTERVENTIONS Pump or MDI structured training in flexible insulin therapy, followed up for 2 years. MDI participants used insulin analogues. Pump participants used a Medtronic Paradigm(®) Veo(TM) (Medtronic, Watford, UK) with insulin aspart (NovoRapid, Novo Nordisk, Gatwick, UK). MAIN OUTCOME MEASURES Primary outcome - change in glycated haemoglobin (HbA1c) at 2 years in participants whose baseline HbA1c was ≥ 7.5% (58 mmol/mol). Key secondary outcome - proportion of participants with HbA1c ≤ 7.5% at 2 years. Other outcomes at 6, 12 and 24 months - moderate and severe hypoglycaemia; insulin dose; body weight; proteinuria; diabetic ketoacidosis; quality of life (QoL); fear of hypoglycaemia; treatment satisfaction; emotional well-being; qualitative interviews with participants and staff (2 weeks), and participants (6 months); and ICERs in trial and modelled estimates of cost-effectiveness. RESULTS We randomised 46 courses comprising 317 participants: 267 attended a Dose Adjustment For Normal Eating course (132 pump; 135 MDI); 260 were included in the intention-to-treat analysis, of which 235 (119 pump; 116 MDI) had baseline HbA1c of ≥ 7.5%. HbA1c and severe hypoglycaemia improved in both groups. The drop in HbA1c% at 2 years was 0.85 on pump and 0.42 on MDI. The mean difference (MD) in HbA1c change at 2 years, at which the baseline HbA1c was ≥ 7.5%, was -0.24% [95% confidence interval (CI) -0.53% to 0.05%] in favour of the pump (p = 0.098). The per-protocol analysis showed a MD in change of -0.36% (95% CI -0.64% to -0.07%) favouring pumps (p = 0.015). Pumps were not cost-effective in the base case and all of the sensitivity analyses. The pump group had greater improvement in diabetes-specific QoL diet restrictions, daily hassle plus treatment satisfaction, statistically significant at 12 and 24 months and supported by qualitative interviews. LIMITATION Blinding of pump therapy was not possible, although an objective primary outcome was used. CONCLUSION Adding pump therapy to structured training in flexible insulin therapy did not significantly enhance glycaemic control or psychosocial outcomes in adults with T1DM. RESEARCH PRIORITY To understand why few patients achieve a HbA1c of < 7.5%, particularly as glycaemic control is worse in the UK than in other European countries. TRIAL REGISTRATION Current Controlled Trials ISRCTN61215213. FUNDING This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 21, No. 20. See the NIHR Journals Library website for further project information. PMID:28440211

Perioperative Outcomes, Transfusion Requirements, and Inflammatory Response After Coronary Artery Bypass Grafting With Off-Pump, Mini-Extracorporeal, and On-Pump Circulation Techniques.

PubMed

Brinkman, William T; Squiers, John J; Filardo, Giovanni; Arsalan, Mani; Smith, Robert L; Moore, David; Mack, Michael J; DiMaio, J Michael

2015-12-01

Mini-extracorporeal circulation (MECC) units were developed to reduce postoperative morbidity, transfusion requirements, and inflammation associated with conventional on-pump coronary artery bypass (ONCAB) surgery without the technical demands of the off-pump (OPCAB) technique. We compared perioperative outcomes and inflammatory mediation among OPCAB, MECC, and ONCAB techniques. We prospectively enrolled 102 patients undergoing elective isolated coronary bypass grafting. Perfusion methods were OPCAB (n = 34), MECC (n = 34), and ONCAB (n = 34). Serial blood samples were collected to measure serum inflammatory markers. There were no operative deaths or strokes. Total red blood cell (RBC) products used in OPCAB, MECC, and ONCAB patients were 0.676, 1.000, and 1.235 units, respectively. Adjusted (by splined Society of Thoracic Surgeons operative risk score) analysis showed no statistically significant differences in mean RBC product use among the different operative systems (OPCAB vs MECC, P = 0.580; OPCAB vs ONCAB, P = 0.311; MECC vs ONCAB, P = 0.633). Adjusted (by Society of Thoracic Surgeons risk score and baseline level) mean plasma level differences (24 hours postoperative - baseline) of C-reactive protein for OPCAB (117.89; 95% confidence interval [95% CI], 106.23-129.54) and for MECC (124.88; 95% CI, 113.45-136.32) were significantly higher than for ONCAB (98.82; 95% CI, 86.40-111.24). No significant adjusted differences (P = 0.304) in interleukin-6 level changes were observed. Off-pump coronary artery bypass and MECC did not significantly reduce mean total RBC transfusion requirements. Off-pump coronary artery bypass and MECC were associated with greater C-reactive protein elevation than ONCAB, suggestive of an increased inflammatory response to each of these techniques.

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

NASA Astrophysics Data System (ADS)

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.

Stress ulcer prophylaxis with a proton pump inhibitor versus placebo in critically ill patients (SUP-ICU trial): study protocol for a randomised controlled trial.

PubMed

Krag, Mette; Perner, Anders; Wetterslev, Jørn; Wise, Matt P; Borthwick, Mark; Bendel, Stepani; Pelosi, Paolo; Keus, Frederik; Guttormsen, Anne Berit; Schefold, Joerg C; Møller, Morten Hylander

2016-04-19

Critically ill patients in the intensive care unit (ICU) are at risk of clinically important gastrointestinal bleeding, and acid suppressants are frequently used prophylactically. However, stress ulcer prophylaxis may increase the risk of serious adverse events and, additionally, the quantity and quality of evidence supporting the use of stress ulcer prophylaxis is low. The aim of the SUP-ICU trial is to assess the benefits and harms of stress ulcer prophylaxis with a proton pump inhibitor in adult patients in the ICU. We hypothesise that stress ulcer prophylaxis reduces the rate of gastrointestinal bleeding, but increases rates of nosocomial infections and myocardial ischaemia. The overall effect on mortality is unpredictable. The SUP-ICU trial is an investigator-initiated, pragmatic, international, multicentre, randomised, blinded, parallel-group trial of stress ulcer prophylaxis with a proton pump inhibitor versus placebo (saline) in 3350 acutely ill ICU patients at risk of gastrointestinal bleeding. The primary outcome measure is 90-day mortality. Secondary outcomes include the proportion of patients with clinically important gastrointestinal bleeding, pneumonia, Clostridium difficile infection or myocardial ischaemia, days alive without life support in the 90-day period, serious adverse reactions, 1-year mortality, and health economic analyses. The sample size will enable us to detect a 20 % relative risk difference (5 % absolute risk difference) in 90-day mortality assuming a 25 % event rate with a risk of type I error of 5 % and power of 90 %. The trial will be externally monitored according to Good Clinical Practice standards. Interim analyses will be performed after 1650 and 2500 patients. The SUP-ICU trial will provide high-quality data on the benefits and harms of stress ulcer prophylaxis with a proton pump inhibitor in critically ill adult patients admitted in the ICU. ClinicalTrials.gov Identifier: NCT02467621 .

Individualized strategy for clopidogrel suspension in patients undergoing off-pump coronary surgery for acute coronary syndrome: a case-control study.

PubMed

Mannacio, Vito; Meier, Pascal; Antignano, Anita; Di Tommaso, Luigi; De Amicis, Vincenzo; Vosa, Carlo

2014-10-01

An increasing number of patients presenting for urgent coronary surgery have been exposed to clopidogrel, which constitutes a risk of bleeding and related events. Based on the wide variability in clopidogrel response and platelet function recovery after cessation, we evaluated the role of point-of-care platelet function testing to define the optimal time for off-pump coronary artery bypass graft (CABG) surgery in a case-control study. Three equally matched groups (300 patients in total) undergoing isolated off-pump CABG for acute coronary syndrome were compared. Group A were treated with clopidogrel and prospectively underwent a strategy guided by platelet function testing. Outcomes were compared with 2 propensity score matched groups: group B underwent CABG after the currently recommended 5 days without clopidogrel; group C were never exposed to clopidogrel. Patients in group A had reduced postoperative bleeding compared with those in group B (523±202 mL vs 851±605 mL; P<.001) and a lower number of units packed red blood cells (PRBCs) transfused during the postoperative hospital stay (1.2±1.6 units vs 1.9±1.8 units; P=.004). Postoperative bleeding and the number of units of PRBCs transfused were similar in group A and group C. There was no difference in blood-derived products and platelet consumption, mortality, or the need for reoperation among the groups. Patients in group A waited 3.6±1.7 days for surgery. The strategy used for group A saved 280 days of hospital stay in total. The strategy guided by platelet function testing for off-pump CABG offers improved guidance for optimal timing of CABG in patients treated with clopidogrel. This strategy significantly reduces postoperative bleeding and blood consumption, and has a shorter waiting time for surgery than current clinical practice. Copyright © 2014 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.

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

PubMed

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.

Measuring axial pump thrust

DOEpatents

Suchoza, Bernard P.; Becse, Imre

1988-01-01

An apparatus for measuring the hydraulic axial thrust of a pump under operation conditions is disclosed. The axial thrust is determined by forcing the rotating impeller off of an associated thrust bearing by use of an elongate rod extending coaxially with the pump shaft. The elongate rod contacts an impeller retainer bolt where a bearing is provided. Suitable measuring devices measure when the rod moves to force the impeller off of the associated thrust bearing and the axial force exerted on the rod at that time. The elongate rod is preferably provided in a housing with a heat dissipation mechanism whereby the hot fluid does not affect the measuring devices.

Measuring axial pump thrust

DOEpatents

Suchoza, B.P.; Becse, I.

1988-11-08

An apparatus for measuring the hydraulic axial thrust of a pump under operation conditions is disclosed. The axial thrust is determined by forcing the rotating impeller off of an associated thrust bearing by use of an elongate rod extending coaxially with the pump shaft. The elongate rod contacts an impeller retainer bolt where a bearing is provided. Suitable measuring devices measure when the rod moves to force the impeller off of the associated thrust bearing and the axial force exerted on the rod at that time. The elongate rod is preferably provided in a housing with a heat dissipation mechanism whereby the hot fluid does not affect the measuring devices. 1 fig.

Perineal techniques during the second stage of labour for reducing perineal trauma.

PubMed

Aasheim, Vigdis; Nilsen, Anne Britt Vika; Lukasse, Mirjam; Reinar, Liv Merete

2011-12-07

Most vaginal births are associated with some form of trauma to the genital tract. The morbidity associated with perineal trauma is significant, especially when it comes to third- and fourth-degree tears. Different perineal techniques and interventions are being used to prevent perineal trauma. These interventions include perineal massage, warm compresses and perineal management techniques. The objective of this review was to assess the effect of perineal techniques during the second stage of labour on the incidence of perineal trauma. We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (20 May 2011), the Cochrane Central Register of ControlledTrials (The Cochrane Library 2011, Issue 2 of 4), MEDLINE (January 1966 to 20 May 2011) and CINAHL (January 1983 to 20 May 2011). Published and unpublished randomised and quasi-randomised controlled trials evaluating any described perineal techniques during the second stage. Three review authors independently assessed trails for inclusion, extracted data and evaluated methodological quality. Data were checked for accuracy. We included eight trials involving 11,651 randomised women. There was a significant effect of warm compresses on reduction of third- and fourth-degree tears (risk ratio (RR) 0.48, 95% confidence interval (CI) 0.28 to 0.84 (two studies, 1525 women)). There was also a significant effect towards favouring massage versus hands off to reduce third- and fourth-degree tears (RR 0.52, 95% CI 0.29 to 0.94 (two studies, 2147 women)). Hands off (or poised) versus hand on showed no effect on third- and fourth-degree tears, but we observed a significant effect of hands off on reduced rate of episiotomy (RR 0.69, 95% CI 0.50 to 0.96 (two studies, 6547 women)). The use of warm compresses on the perineum is associated with a decreased occurrence of perineal trauma. The procedure has shown to be acceptable to women and midwives. This procedure may therefore be offered to women.

Three-dimensional analysis for liquid hydrogen in a cryogenic storage tank with heat pipe pump system

NASA Astrophysics Data System (ADS)

Ho, Son H.; Rahman, Muhammad M.

2008-01-01

This paper presents a study on fluid flow and heat transfer of liquid hydrogen in a zero boil-off cryogenic storage tank in a microgravity environment. The storage tank is equipped with an active cooling system consisting of a heat pipe and a pump-nozzle unit. The pump collects cryogen at its inlet and discharges it through its nozzle onto the evaporator section of the heat pipe in order to prevent the cryogen from boiling off due to the heat leaking through the tank wall from the surroundings. A three-dimensional (3-D) finite element model is employed in a set of numerical simulations to solve for velocity and temperature fields of liquid hydrogen in steady state. Complex structures of 3-D velocity and temperature distributions determined from the model are presented. Simulations with an axisymmetric model were also performed for comparison. Parametric study results from both models predict that as the speed of the cryogenic fluid discharged from the nozzle increases, the mean or bulk cryogenic fluid speed increases linearly and the maximum temperature within the cryogenic fluid decreases.

Magnetized Target Fusion - Field Reversed Configuration Formation and Injection (MTF-FRC)

DTIC Science & Technology

2009-11-06

from accidental breakage and personnel from injury in that event. The pumps for the vacuum system included a Varian dry scroll pump that was...a dry scroll (oil-free) mechanical pump could be used, as mTorr pressures would be sufficient for the vacuum switch voltage hold-off and operation...56 FIGURE 46. ROUGHING PUMP AND VACUUM -GAUGE CONTROLLERS BENEATH THETA COIL CABLE HEADER

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

PubMed

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.

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

NASA Astrophysics Data System (ADS)

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.

Wavelength-tunable Hermite-Gaussian modes and an orbital-angular-momentum-tunable vortex beam in a dual-off-axis pumped Yb:CALGO laser.

PubMed

Shen, Yijie; Meng, Yuan; Fu, Xing; Gong, Mali

2018-01-15

A dual-off-axis pumping scheme is presented to generate wavelength-tunable high-order Hermite-Gaussian (HG) modes in Yb:CaGdAlO 4 lasers. The mode and wavelength can be actively controlled by the off-axis displacements and pump power. The purities of the output HG modes are quantified by intensity distributions and the measured M 2 values. The highest order reaches m=15 for stable HG m,0 mode, and wavelength-tunable width is about 10 nm. Moreover, through externally converting the HG m,0 modes, the vortex beams carrying orbital angular momentum (OAM) with a large OAM-tunable range from ±1ℏ to ±15ℏ are produced. This work is effective for largely scaling the spectral and OAM tunable ranges of optical vortex beams.

Safety and efficacy of the predictive low glucose management system in the prevention of hypoglycaemia: protocol for randomised controlled home trial to evaluate the Suspend before low function.

PubMed

Abraham, M B; Nicholas, J A; Ly, T T; Roby, H C; Paramalingam, N; Fairchild, J; King, B R; Ambler, G R; Cameron, F; Davis, E A; Jones, T W

2016-04-15

Innovations with sensor-augmented pump therapy (SAPT) to reduce hypoglycaemia in patients with type 1 diabetes are an ongoing area of research. The predictive low glucose management (PLGM) system incorporates continuous glucose sensor data into an algorithm and suspends basal insulin before the occurrence of hypoglycaemia. The system was evaluated in in-clinic studies, and has informed the parameters of a larger home trial to study its efficacy and safety in real life. The aim of this report is to describe the study design and outcome measures for the trial. This is a 6-month, multicentre, randomised controlled home trial to test the PLGM system in children and adolescents with type 1 diabetes. The system is available in the Medtronic MiniMed 640G pump as the 'Suspend before low' feature. Following a run-in period, participants are randomised to either the control arm with SAPT alone or the intervention arm with SAPT and Suspend before low. The primary aim of this study is to evaluate the time spent hypoglycaemic (sensor glucose <3.5 mmol/L) with and without the system. The secondary aims are to determine the number of hypoglycaemic events, the time spent hyperglycaemic, and to evaluate safety with ketosis and changes in glycated haemoglobin. The study also aims to assess the changes in counter-regulatory hormone responses to hypoglycaemia evaluated by a hyperinsulinaemic hypoglycaemic clamp in a subgroup of patients with impaired awareness. Validated questionnaires are used to measure the fear of hypoglycaemia and the impact on the quality of life to assess burden of the disease. Ethics committee permissions were gained from respective Institutional Review boards. The findings of the study will provide high quality evidence of the ability of the system in the prevention of hypoglycaemia in real life. ACTRN12614000510640, Pre-results. 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/

77 FR 54793 - Airworthiness Directives; the Boeing Company Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2012-09-06

... was prompted by fuel system reviews conducted by the manufacturer. This AD requires adding design... system must shut off each pump no later than 60 seconds after the fuel tank is emptied. Noting that the... paragraph (g)(2): ``The pump shutoff system design must preclude undetected running of a fuel pump in an...

[Coronary revascularization in patients with preoperative electrical storm].

PubMed

Kawashima, Toshiya; Naraoka, S

2007-03-01

We report 5 cases who underwent surgical coronary revascularization for subacute myocardial ischemia with preoperative electrical storm. All patients showed severe left ventricular dysfunction. Mean ejection fraction was 24.4 +/- 7.6%. Three patients had already had implantable cardioverter-defibrillator (ICD) therapy. Procedures were on-pump coronary artery bypass grafting (CABG) and mitral valvuloplasty (MVP) [case 1], on-pump CABG, MVP, left ventricular restoration (LVR) and cryoablation (case 2), and off-pump CABG (case 3-5). Case 5 necessitated conversion to on-pump for electrical storm during left circumflex artery (LCx) anastomosis. Case 3 suddenly died on the 2nd postoperative day due to electrical storm. Case 1 had recurrent attack of electrical storm postoperatively, treated by ICD, overdrive pacing, repeated intraaortic balloon pumping (IABP), deep sedation with endotracheal intubation, and finally catheter ablation. Four patients have survived 2 years (mean) postoperatively without any arrhythmia, and are all in good condition [New York Heart Association (NYHA) I] now. It was concluded that off-pump procedure was not suitable for subacute myocardial ischemia with electrical storm and that LVR with surgical cryoablation would be effective if indicated.

Fuel Delivery System.

DTIC Science & Technology

1996-07-24

to fuel tank 27 aboard 23 test torpedo 26. Pressure switch 19B operates to close solenoid 24 valve 22A and concurrently open solenoid valve 22D...leading to a pump explosion. The boost pump 4 is driven by its 11 motor 14B and positive displacement pump 1 by its respective 12 motor 14A. Pressure ... switch 19A monitors the head pressure 13 created by the boost pump 4 and it will shut off the motor 14A of 14 the positive displacement pump 1 if

Hemodynamic changes during displacement of the beating heart using epicardial stabilization for off-pump coronary artery bypass graft surgery.

PubMed

Mishra, Manisha; Malhotra, Rajneesh; Mishra, Anil; Meharwal, Zile Singh; Trehan, Naresh

2002-12-01

To evaluate the hemodynamic alterations during off-pump coronary artery bypass graft surgery to determine the degree of impairment caused and the techniques to rectify them. Prospective, observational cohort study performed from January 2000 through September 2000. Patients (n = 500) with coronary artery disease undergoing multivessel off-pump coronary artery bypass graft surgery using the Octopus tissue stabilizer (Medtronic, Inc, Minneapolis, MN). Unstable patients with ongoing ischemia were excluded from the study. All patients were monitored with radial artery and pulmonary artery catheters and continuous transesophageal echocardiography monitoring with a multiplane transducer. The perioperative requirement of an intracoronary shunt, inotropes, or an intra-aortic balloon pump was noted. The effect of the Trendelenburg position and fluids on hemodynamics was observed. The need for defibrillation and institution of emergency cardiopulmonary bypass were major endpoints to determine the inability of the patient to tolerate displacement of the heart. Mean patient age was 59.3 +/- 11.6 years. There were 204 (40%) patients in the high-risk category; 54 (10.8%) patients had left ventricular ejection fraction <25%. The mean number of grafts was 2.7 +/- 0.8. Vertical displacement of the heart to access the lateral and inferior walls decreased the mean arterial pressure by 18 +/- 4% (p < 0.01), with a concomitant increase in central venous pressure of 66 +/- 18% (p < 0.001). The stroke volume and the cardiac index were reduced by 35.7 +/- 11% (p < 0.001) and 45 +/- 13% (p < 0.001). On transesophageal echocardiography, there was development of new regional wall motion abnormalities in 59.2% and a decrease in global left ventricular functions in 61.2%. The use of inotropes was highest during anastomosis on the posterior wall-78.4% compared with 21.9% for the anterior wall. An intra-aortic balloon pump was used in 55 (11.2%) patients, and 7 (0.71 %) patients had to be put on emergency CPB. The in-hospital mortality was 1.2%. Most patients had hemodynamic changes easily correctable by fluids and inotropes. Monitoring of left ventricular and right ventricular function by transesophageal echocardiography enhances safety of the procedure and is recommended. The use of the Octopus II tissue stabilizer proved to be a safe and versatile means to stabilize the heart during off-pump coronary artery bypass procedures, especially in high-risk patients. Copyright 2002, Elsevier Science (USA). All rights reserved.

LASER APPLICATIONS AND OTHER TOPICS IN QUANTUM ELECTRONICS: Study of thermooptic distortions of a Nd:YVO4 active element at different methods of its mounting

NASA Astrophysics Data System (ADS)

Kijko, V. V.; Ofitserov, Evgenii N.

2006-05-01

Thermooptic distortions of the active element of an axially diode-pumped Nd:YVO4 solid-state laser are studied at different methods of its mounting. The study was performed by the Hartmann method. A mathematical model for calculating the optical power of a thermal lens produced in the crystal upon pumping is developed and verified experimentally. It is shown that the optical power of a thermal lens produced upon axial pumping of the convectively cooled active element sealed off in a copper heat sink is half the optical power observed upon convective cooling of the active element without heat sink. The experimental and theoretical results are in good agreement.

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

PubMed

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.

Methods of milk expression for lactating women.

PubMed

Becker, Genevieve E; Smith, Hazel A; Cooney, Fionnuala

2016-09-29

Breastfeeding is important, however not all infants can feed at the breast and methods of expressing milk need evaluation. To assess acceptability, effectiveness, safety, effect on milk composition, contamination and costs of methods of milk expression. We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (21 March 2016), handsearched relevant journals and conference proceedings, and contacted experts in the field to seek additional published or unpublished studies. We also examined reference lists of all relevant retrieved papers. Randomised and quasi-randomised trials comparing methods at any time after birth. Three review authors independently assessed trials for inclusion and risk of bias, extracted data and checked them for accuracy. This updated review includes 41 trials involving 2293 participants, with 22 trials involving 1339 participants contributing data for analysis. Twenty-six of the trials referred to mothers of infants in neonatal units (n = 1547) and 14 to mothers of healthy infants at home (n = 730), with one trial containing mothers of both neonatal and healthy older infants (n = 16). Eleven trials compared one or more types of pump versus hand expression and 14 studies compared one type of pump versus another type of pump, with three of these studies comparing both hand expression and pump types. Twenty studies compared a specific protocol or adjunct behaviour including sequential versus simultaneous pumping protocols, pumping frequency, provision of an education and support intervention, relaxation, breast massage, combining hand expression with pumping and a breast cleansing protocol.Due to heterogeneity in participants, interventions, and outcomes measured or reported, we were unable to pool findings for most of the specified outcomes. It was not possible therefore to produce a 'Summary of findings' table in this update. Most of the included results were derived from single studies. Trials took place in 14 countries under a variety of circumstances and were published from 1982 to 2015. Sixteen of the 30 trials that evaluated pumps or products had support from the manufacturers. The risk of bias of the included studies was variable. Primary outcomesOnly one of the 17 studies examining maternal satisfaction/acceptability with the method or adjunct behaviour provided data suitable for analysis. In this study, self-efficacy was assessed by asking mothers if they agreed or disagreed with the following statement: 'I don't want anyone to see me (hand expressing/pumping)'. The study found that mothers who were using the electric pump were more likely to agree with the statement compared to mothers hand expressing, (mean difference (MD) 0.70, 95% confidence interval (CI) 0.15 to 1.25; P = 0.01, participants = 68). Mothers who were hand expressing reported that the instructions for expression were clearer compared to the electric pump, (MD -0.40, 95% CI -0.75 to -0.05; P = 0.02, participants = 68). Descriptive reporting of satisfaction in the other studies varied in the measures used, did not indicate a clear preference for one pump type, although there was satisfaction with some relaxation and support interventions.We found no clinically significant differences between methods related to contamination of the milk that compared any type of pump to hand expression (risk ratio (RR) 1.13, 95% CI 0.79 to 1.61; P = 0.51, participants = 28), manual pump compared to hand expression, (MD 0.20, 95% CI -0.18 to 0.58; P = 0.30, participants = 142) a large electric pump compared to hand expression (MD 0.10, 95% CI -0.29 to 0.49; P = 0.61, participants = 123), or a large electric pump compared to a manual pump (MD -0.10, 95% CI -0.46 to 0.26; P = 0.59, participants = 141).The level of maternal breast or nipple pain or damage was similar in comparisons of a large electric pump to hand expression (MD 0.02, 95% CI -0.67 to 0.71; P = 0.96, participants = 68). A study comparing a manual and large electric pump, reported sore nipples in 7% for both groups and engorgement in 4% using a manual pump versus 6% using an electric pump; and in one study no nipple damage was reported in the hand-expression group, and one case of nipple damage in each of the manual pump and the large electric pump groups.One study examined adverse effects on infants, however as the infants did not all receive their mothers' expressed milk, we have not included the results. Secondary outcomesThe quantity of expressed milk obtained was increased, in some studies by a clinically significant amount, in interventions involving relaxation, music, warmth, massage, initiation of pumping, increased frequency of pumping and suitable breast shield size. Support programmes and simultaneous compared to sequential pumping did not show a difference in milk obtained. No pump consistently increased the milk volume obtained significantly.In relation to nutrient quality, hand expression or a large electric pump were found to provide higher protein than a manual pump, and hand expression provided higher sodium and lower potassium compared to a large electric pump or a manual pump. Fat content was higher with breast massage when pumping; no evidence of difference was found for energy content between methods.No consistent effect was found related to prolactin change or effect on oxytocin release with pump type or method. Economic aspects were not reported. The most suitable method for milk expression may depend on the time since birth, purpose of expression and the individual mother and infant. Low-cost interventions including initiation of milk expression sooner after birth when not feeding at the breast, relaxation, massage, warming the breasts, hand expression and lower cost pumps may be as effective, or more effective, than large electric pumps for some outcomes. Variation in nutrient content across methods may be relevant to some infants. Small sample sizes, large standard deviations, and the diversity of the interventions argue caution in applying these results beyond the specific method tested in the specific settings. Independently funded research is needed for more trials on hand expression, relaxation and other techniques that do not have a commercial potential.

Factors associated with postoperative requirement of renal replacement therapy following off-pump coronary bypass surgery.

PubMed

Kato, Tomoko S; Machida, Yoichiro; Kuwaki, Kenji; Yamamoto, Taira; Amano, Atsushi

2017-02-01

Cardiopulmonary bypass usage provokes a systemic inflammatory response resulting in deterioration of renal function. However, risk factors for requiring renal replacement therapy (RRT) following off-pump coronary artery bypass graft surgery (CABG) have not yet been fully elucidated. We reviewed 718 consecutive patients undergoing elective off-pump CABG at our institution, excluding patients on chronic hemodialysis preoperatively. Sub-analysis of patients with preserved renal function, defined as a creatinine level below a cut-off value of 1.12 mg/dL (obtained by receiver operating characteristic curve), was also performed. Of the 718 patients, 41 (5.7 %) required RRT. There were 556 patients (77.4 %) with preserved renal function preoperatively, and 13 (2.4 %) of these required postoperative RRT. Multivariate analysis revealed that age (years) and preoperative serum creatinine (mg/dL) and brain natriuretic peptide (BNP) levels (pg/dL) were associated with RRT [odds ratios (OR) 1.052, 95 % confidence interval (CI) 9.064 and 1.001, respectively, all p < 0.05] in the total population, whereas low albumin concentration was the only independent predictor for RRT in patients with preserved renal function (OR 0.062, p < 0.0001). When creatinine levels were below 1.5 mg/dL, the predictive power of hypoalbuminemia for RRT requirement overwhelmed that of creatinine or BNP levels. Older age, preoperative elevated creatinine and BNP levels were associated with a requirement for RRT following off-pump CABG. In patients with preserved renal function, hypoalbuminemia was most significantly related to the RRT requirement.

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

PubMed

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 compared to the control group as well as reduces the need for anesthetic compounds. The present study has been registered at the Iranian Registry of Clinical Trials (www.IRCT.IR) with a code of IRCT2016072413159N9 before starting the study. This study was fully sponsored by the Research Deputy at Mashhad University of Medical Sciences, Iran (grant number 941413).

Thermo-wrap technology preserves normothermia better than routine thermal care in patients undergoing off-pump coronary artery bypass and is associated with lower immune response and lesser myocardial damage.

PubMed

Nesher, Nahum; Uretzky, Gideon; Insler, Steven; Nataf, Patrick; Frolkis, Inna; Pineau, Emmanuelle; Cantoni, Emmanuel; Bolotin, Gil; Vardi, Moshe; Pevni, Dimitry; Lev-Ran, Oren; Sharony, Ram; Weinbroum, Avi A

2005-06-01

Perioperative hypothermia might be detrimental to the patient undergoing off-pump coronary artery bypass surgery. We assessed the efficacy of the Allon thermoregulation system (MTRE Advanced Technologies Ltd, Or-Akiva, Israel) compared with that of routine thermal care in maintaining normothermia during and after off-pump coronary artery bypass surgery. Patients undergoing off-pump coronary artery bypass surgery were perioperatively and randomly warmed with the 2 techniques (n = 45 per group). Core temperature, hemodynamics, and troponin I, interleukin 6, interleukin 8, and interleukin 10 blood levels were assessed. The mean temperature of the patients in the Allon thermoregulation system group (AT group) was significantly ( P < .005) higher than that of the patients receiving routine thermal care (the RTC group); less than 40% of the latter reached 36 degrees C compared with 100% of the former. The cardiac index was higher and the systemic vascular resistance was lower ( P < .05) by 16% and 25%, respectively, in the individuals in the AT group compared with in the individuals in the RTC group during the 4 postoperative hours. End-of-surgery interleukin 6 levels and 24-hour postoperative troponin I levels were significantly ( P < .01) lower in the patients in the AT group than in the RTC group. The RTC group's troponin levels closely correlated with their interleukin 6 levels at the end of the operation ( R = 0.51, P = .002). Unlike routine thermal care, the Allon thermoregulation system maintains core normothermia in more than 80% of patients undergoing off-pump coronary artery bypass surgery. Normothermia is associated with better cardiac and vascular conditions, a lower cardiac injury rate, and a lower inflammatory response. The close correlation between the increased interleukin 6 and troponin I levels in the routine thermal care group indicates a potential deleterious effect of lowered temperature on the patient's outcome.

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

PubMed Central

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

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

PubMed Central

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%) had

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

PubMed

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

2016-02-01

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. 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). A total of 1069 (86%) had

Vitamin K for upper gastrointestinal bleeding in people with acute or chronic liver diseases.

PubMed

Martí-Carvajal, Arturo J; Solà, Ivan

2015-06-09

Upper gastrointestinal bleeding is one of the most frequent causes of morbidity and mortality in the course of liver cirrhosis. Several treatments are used for upper gastrointestinal bleeding in people with liver diseases. One of them is vitamin K administration, but it is not known whether it benefits or harms people with acute or chronic liver disease and upper gastrointestinal bleeding. This is an update of this Cochrane review. To assess the beneficial and harmful effects of vitamin K for people with acute or chronic liver disease and upper gastrointestinal bleeding. We searched The Cochrane Hepato-Biliary Controlled Trials Register (February 2015), the Cochrane Central Register of Controlled Trials (CENTRAL) (Issue 2 of 12, 2015), MEDLINE (Ovid SP) (1946 to February 2015), EMBASE (Ovid SP) (1974 to February 2015), Science Citation Index EXPANDED (1900 to February 2015), and LILACS (1982 to 25 February 2015). We sought additional randomised trials from two registries of clinical trials: the World Health Organization Clinical Trials Search Portal and the metaRegister of Controlled Trials. We looked through the reference lists of the retrieved publications and review articles. Randomised clinical trials irrespective of blinding, language, or publication status for assessment of benefits and harms. We considered observational studies for assessment of harms only. \\We aimed to summarise data from randomised clinical trials using Standard Cochrane methodology and assess them according to the GRADE approach. We found no randomised trials on vitamin K for upper gastrointestinal bleeding in people with liver diseases assessing benefits and harms of the intervention. We identified no quasi-randomised studies, historically controlled studies, or observational studies assessing harms. This updated review found no randomised clinical trials of vitamin K for upper gastrointestinal bleeding in people with liver diseases. The benefits and harms of vitamin K need to be tested in randomised clinical trials. Until randomised clinical trials are conducted to assess the trade-off between benefits and harms, we cannot recommend or refute the use of vitamin K for upper gastrointestinal bleeding in people with liver diseases.

Time-resolved orbital angular momentum spectroscopy

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

Noyan, Mehmet A.; Kikkawa, James M.

We introduce pump-probe magneto-orbital spectroscopy, wherein Laguerre-Gauss optical pump pulses impart orbital angular momentum to the electronic states of a material and subsequent dynamics are studied with 100 fs time resolution. The excitation uses vortex modes that distribute angular momentum over a macroscopic area determined by the spot size, and the optical probe studies the chiral imbalance of vortex modes reflected off the sample. First observations in bulk GaAs yield transients that evolve on time scales distinctly different from population and spin relaxation, as expected, but with surprisingly large lifetimes.

Assessment of cardiac autonomic regulation and ventricular repolarization after off-pump coronary artery bypass grafting.

PubMed

Kalisnik, Jurij M; Avbelj, Viktor; Trobec, Roman; Ivaskovic, Daroslav; Vidmar, Gaj; Troise, Giovanni; Gersak, Borut

2006-01-01

Altered autonomic regulation precipitates cardiac arrhythmias and increases the risk of sudden cardiac death. This risk is further increased by changes in ventricular repolarization. Autonomic regulation is deranged in patients after myocardial on-pump revascularization. We aimed to clarify how off-pump coronary artery bypass grafting (CABG) affects postoperative cardiac autonomic regulation and ventricular repolarization within 4 weeks after CABG. Forty-two patients (mean age, 61.9 +/- 9.3 years; mean EURO score 2.6 +/- 1.9) were electively admitted for off-pump CABG. The electrocardiographic and respiratory waveform recordings were performed in the afternoon in the supine position for 10 minutes. Autonomic modulation was assessed using heart rate variability analysis. Power spectra were computed from 5-minute stable RR intervals using Fourier Transform analysis. Total power of spectra was defined in the range of 0.01 to 0.40 Hz, high-frequency power within 0.15 to 0.40 Hz, and low-frequency power within 0.04 to 0.15 Hz. Normalized power was defined as a ratio of power in each band/total power. The high- and low-frequency power as well as their normalized values indicated cardiac vagal and sympathetic modulation, respectively. Ventricular repolarization was assessed using QT interval, QT interval variability, and QT-RR interdependence analysis. QT intervals were determined from the beginning of the 5-minute segments. QT interval variability was evaluated by a T-wave template-matching algorithm. Pearson correlation between length of RR and QT interval was applied to study QT-RR characteristics. The results were tested for significance using the Fisher exact test, nonpaired t test, and analysis of variance; a P <.05 was considered significant. The frequency of arrhythmic events and heart rate increased from the fourth to the seventh postoperative day and returned to preoperative levels 4 weeks after CABG. Heart rate variability measures indicating autonomic modulation remained depressed even 4 weeks after the procedure. QT variability index increased from -1.2 +/- 0.5 to -0.8 +/- 0.4 on the fourth day after the operation (P <.05) and returned to -1.0 +/- 0.5 4 weeks after CABG (P = not significant). QT-RR correlation decreased from 0.41 to 0.23 (P <.05) and remained significantly impaired as long as 4 weeks after CABG. Observed faster heart rates until 1 week after off-pump CABG imply excessive adrenergic activation, which is comparable to on-pump CABG procedure rates. The results indicate profound autonomic derangement and loss of rate-dependent regulation after off-pump CABG even 4 weeks after operation. Restituted repolarization as assessed by QT variability index 4 weeks postoperatively corresponded with decreased frequency of rhythm disturbances 4 weeks after CABG. The loss of coupling between QT and RR intervals shows increased electrical instability postoperatively, which may serve as an additional promoter for postoperative arrhythmias, especially at higher heart rates.

Adiabatic quantum pump in a zigzag graphene nanoribbon junction

NASA Astrophysics Data System (ADS)

Zhang, Lin

2015-11-01

The adiabatic electron transport is theoretically studied in a zigzag graphene nanoribbon (ZGNR) junction with two time-dependent pumping electric fields. By modeling a ZGNR p-n junction and applying the Keldysh Green’s function method, we find that a pumped charge current is flowing in the device at a zero external bias, which mainly comes from the photon-assisted tunneling process and the valley selection rule in an even-chain ZGNR junction. The pumped charge current and its ON and OFF states can be efficiently modulated by changing the system parameters such as the pumping frequency, the pumping phase difference, and the Fermi level. A ferromagnetic ZGNR device is also studied to generate a pure spin current and a fully polarized spin current due to the combined spin pump effect and the valley valve effect. Our finding might pave the way to manipulate the degree of freedom of electrons in a graphene-based electronic device. Project supported by the National Natural Science Foundation of China (Grant No. 110704033), the Natural Science Foundation of Jiangsu Province, China (Grant No. BK2010416), and the Natural Science Foundation for Colleges and Universities in Jiangsu Province, China (Grant No. 13KJB140005).

Experimental demonstration of localized Brillouin gratings with low off-peak reflectivity established by perfect Golomb codes.

PubMed

Antman, Yair; Yaron, Lior; Langer, Tomi; Tur, Moshe; Levanon, Nadav; Zadok, Avi

2013-11-15

Dynamic Brillouin gratings (DBGs), inscribed by comodulating two writing pump waves with a perfect Golomb code, are demonstrated and characterized experimentally. Compared with pseudo-random bit sequence (PRBS) modulation of the pump waves, the Golomb code provides lower off-peak reflectivity due to the unique properties of its cyclic autocorrelation function. Golomb-coded DBGs allow the long variable delay of one-time probe waveforms with higher signal-to-noise ratios, and without averaging. As an example, the variable delay of return-to-zero, on-off keyed data at a 1 Gbit/s rate, by as much as 10 ns, is demonstrated successfully. The eye diagram of the reflected waveform remains open, whereas PRBS modulation of the pump waves results in a closed eye. The variable delay of data at 2.5 Gbit/s is reported as well, with a marginally open eye diagram. The experimental results are in good agreement with simulations.

The oesophagus and cough: laryngo-pharyngeal reflux, microaspiration and vagal reflexes

PubMed Central

2013-01-01

Gastro-oesophageal reflux disease is generally considered to be one of the commonest causes of chronic cough, however randomised controlled trials of proton pump inhibitors have often failed to support this notion. This article reviews the most recent studies investigating the mechanisms thought to link reflux and cough, namely laryngo-pharyngeal reflux, micro-aspiration and neuronal cross-organ sensitisation. How recent evidence might shed light on the failure of acid suppressing therapies and suggest new approaches to treating reflux related cough are also discussed. PMID:23590893

Intra-aortic balloon pump counterpulsation (IABP) for myocardial infarction complicated by cardiogenic shock.

PubMed

Unverzagt, Susanne; Buerke, Michael; de Waha, Antoinette; Haerting, Johannes; Pietzner, Diana; Seyfarth, Melchior; Thiele, Holger; Werdan, Karl; Zeymer, Uwe; Prondzinsky, Roland

2015-03-27

Intra-aortic balloon pump counterpulsation (IABP) is currently the most commonly used mechanical assist device for patients with cardiogenic shock due to acute myocardial infarction. Although there has been only limited evidence from randomised controlled trials, the previous guidelines of the American Heart Association/American College of Cardiology (AHA/ACC) and the European Society of Cardiology (ESC) strongly recommended the use of the IABP in patients with infarction-related cardiogenic shock on the basis of pathophysiological considerations, non-randomised trials and registry data. The recent guidelines downgraded the recommendation based on a meta-analysis which could only include non-randomised trials showing conflicting results. Up to now, there have been no guideline recommendations and no actual meta-analysis including the results of the large randomised multicentre IABP-SHOCK II Trial which showed no survival benefit with IABP support. This systematic review is an update of the review published in 2011. To evaluate, in terms of efficacy and safety, the effect of IABP versus non-IABP or other assist devices guideline compliant standard therapy on mortality and morbidity in patients with acute myocardial infarction complicated by cardiogenic shock. Searches of CENTRAL, MEDLINE (Ovid) and EMBASE (Ovid), LILACS, IndMed and KoreaMed, registers of ongoing trials and proceedings of conferences were updated in October 2013. Reference lists were scanned and experts in the field contacted to obtain further information. No language restrictions were applied. Randomised controlled trials on patients with acute myocardial infarction complicated by cardiogenic shock. Data collection and analysis were performed according to the published protocol. Individual patient data were provided for six trials and merged with aggregate data. Summary statistics for the primary endpoints were hazard ratios (HRs) and odds ratios (ORs) with 95% confidence intervals (CIs). Seven eligible studies were identified from a total of 2314 references. One new study with 600 patients was added to the original review. Four trials compared IABP to standard treatment and three to other percutaneous left assist devices (LVAD). Data from a total of 790 patients with acute myocardial infarction and cardiogenic shock were included in the updated meta-analysis: 406 patients were treated with IABP and 384 patients served as controls; 339 patients were treated without assisting devices and 45 patients with other LVAD. The HR for all-cause 30-day mortality of 0.95 (95% CI 0.76 to 1.19) provided no evidence for a survival benefit. Different non-fatal cardiovascular events were reported in five trials. During hospitalisation, 11 and 4 out of 364 patients from the intervention groups suffered from reinfarction or stroke, respectively. Altogether 5 out of 363 patients from the control group suffered from reinfarction or stroke. Reocclusion was treated with subsequent re-revascularization in 6 out of 352 patients from the intervention group and 13 out of 353 patients of the control group. The high incidence of complications such as moderate and severe bleeding or infection in the control groups has to be attributed to interventions with other LVAD. Possible reasons for bias were more frequent in small studies with high cross-over rates, early stopping and the inclusion of patients with IABP at randomisation. Available evidence suggests that IABP may have a beneficial effect on some haemodynamic parameters. However, this did not result in survival benefits so there is no convincing randomised data to support the use of IABP in infarct-related cardiogenic shock.

A randomised controlled trial comparing three analgesia regimens following total knee joint replacement: continuous femoral nerve block, intrathecal morphine or both.

PubMed

Olive, D J; Barrington, M J; Simone, S A; Kluger, R

2015-07-01

This randomised controlled trial compared three analgesia regimens following primary unilateral total knee joint replacement: continuous femoral nerve block (CFNB), intrathecal morphine (ITM), and both. The primary outcome was pain ratings over the first 24 hours. Secondary outcomes included morphine consumption, nausea, pruritus and sedation ratings, oxygen saturation (SpO2) ratings, and ability to mobilise postoperatively. All patients received a spinal anaesthetic and a postoperative patient-controlled morphine pump. Patients were randomised to receive CFNB, ITM, or both. In patients with no CFNB, the use of ITM was blinded. Eighty-one patients were randomised and there were no withdrawals. At 24 hours, the ITM-only group had higher pain ratings than either of the other groups (P=0.04 versus CFNB, P=0.01 versus combination). In the 18 to 24 hour period, the ITM group used more morphine than either of the other groups. There were no statistically significant differences in pain ratings or morphine consumption at earlier time intervals. The ITM group were less likely to be able to sit out of bed on day one. Patients who received ITM were more likely to have pruritus. There were no statistically significant differences in nausea, SpO₂or sedation ratings. This study showed that a CFNB resulted in reduced pain and was also associated with less morphine consumption and improved mobilisation at 24 hours compared to ITM. This study did not show any statistically significant differences between CFNB alone and CFNB+ITM.

Stable donutlike vortex beam generation from lasers with controlled Ince-Gaussian modes

NASA Astrophysics Data System (ADS)

Chu, Shu-Chun; Otsuka, Kenju

2007-11-01

This study proposes a three-lens configuration for generating a stable donutlike vortex laser beam with controlled Ince-Gaussian mode (IGM) operation in the model of laser-diode (LD)-pumped solid-state lasers. Simply controlling the lateral off-axis position of the pump beam's focus on the laser crystal can generate a desired donutlike vortex beam from the proposed simple and easily made three-lens configuration, a proposed astigmatic mode converter assembled into one body with a concave-convex laser cavity.

Variational and WKB Descriptions of Laterally Localized Eigenmodes in Non-Collinear Optical Parametric Amplifiers

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

Afeyan, Bedros; Charbonneau-Lefort, Mathieu; Fejer, Martin

With a finite lateral width pump, non-collinear interactions result in metastable or stable laterally localized bound states. The physical processes involved are group velocity walk-off, diffraction, chirped QPM gratings and different pump shapes.

Hourly simulation of a Ground-Coupled Heat Pump system

NASA Astrophysics Data System (ADS)

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.

Long-term proton pump induced hypergastrinaemia does induce lineage-specific restitution but not clonal expansion in benign Barrett's oesophagus in vivo.

PubMed

Obszynska, Jolanta A; Atherfold, Paul A; Nanji, Manoj; Glancy, Deborah; Santander, Sonia; Graham, Trevor A; Otto, William R; West, Kevin; Harrison, Rebecca F; Jankowski, Janusz A Z

2010-02-01

Barrett's oesophagus is a common premalignant lesion caused partly by acid reflux. Although the requisite therapy, proton pump inhibitors (PPIs), have been implicated in the progression of Barrett's oesophagus in animal models, harmful effects of prolonged PPI therapy in Barrett's oesophagus is both inconclusive and controversial. We therefore aimed to test the role of PPI-induced hypergastrinaemia in vitro and see whether any biological parameters were useful surrogates of long-term therapy in man. We undertook detailed serological and tissue assessment of gastrin and CCK(2) receptors in 90 patients randomised to different doses of PPI therapy during a detailed 2-year follow-up. We also undertook a comprehensive study of cell models to study the consequential biological effects of gastrin on the mucosa. Gastrin and its cognate receptor CCK(2)R were expressed highest in the stomach, then less in Barrett's oesophagus and least in squamous oesophagus (SqE) (n=20 paired t-test, p<0.01). Analysis of the change in Barrett's oesophagus segment length change in 70 patients who were randomised to high or low PPI dose showed no difference over 2 years (n=70 t-test, p=0.8). Prolonged PPI use did, however, increase the serum gastrin, (36 pg/ml+/-57 pg/ml to 103 pg/ml+/-94 pg/ml (paired t test, p<0.05)). In vitro gastrin also induced changes in OE33(E)(cckr) Barrett's oesophagus cells, but not OE21(E)(cckr) squamous cells, transfected with CCK(2)R; migration was induced by 1 ng/ml of gastrin but proliferation only increased with 100 ng/ml (paired t-test, p<0.01) and both were abolished by antagonists. While the short-term effects of gastrin enhance epithelial restitution in Barrett's oesophagus (but not squamous mucosa) there is no clinical evidence that Barrett's oesophagus length expands over time. This study, which is the largest and longest term randomised controlled trial of gastrin biology in Barrett's oesophagus, is further proof of the clinical safety of PPI therapy.

Self-regenerating Nanotips: Indestructable Field-emission Cathodes for Low-power Electric Propulsion

DTIC Science & Technology

2010-09-27

Field Emission Scanning Electron Microscope. The chamber was evacuated using a series of three ion pumps and vacuum pressure of 10-7 Torr was...backed by a 110-L/min dry scroll pump . The chamber is also equipped with a 300-L/s combination ion/sublimation pump that can maintain pressure of...Torr for 2 to 24 hours and then the ion pump was turned off to let the vacuum pressure slowly increase while observing the electron emission

Metabolic control after years of completing a clinical trial on sensor-augmented pump therapy.

PubMed

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.

Remotely Adjustable Hydraulic Pump

NASA Technical Reports Server (NTRS)

Kouns, H. H.; Gardner, L. D.

1987-01-01

Outlet pressure adjusted to match varying loads. Electrohydraulic servo has positioned sleeve in leftmost position, adjusting outlet pressure to maximum value. Sleeve in equilibrium position, with control land covering control port. For lowest pressure setting, sleeve shifted toward right by increased pressure on sleeve shoulder from servovalve. Pump used in aircraft and robots, where hydraulic actuators repeatedly turned on and off, changing pump load frequently and over wide range.

Randomised clinical trial: alginate (Gaviscon Advance) vs. placebo as add-on therapy in reflux patients with inadequate response to a once daily proton pump inhibitor.

PubMed

Reimer, C; Lødrup, A B; Smith, G; Wilkinson, J; Bytzer, P

2016-04-01

Many reflux patients remain symptomatic on a standard dose of proton pump inhibitor (PPI). Alginates decrease the number of reflux events by forming a raft on top of the stomach content and thus offer a supplemental mechanism of action to acid suppression. To assess the efficacy of an alginate (Gaviscon Advance, Reckitt Benckiser, Slough, UK) on reflux symptoms in patients with persistent symptoms despite once daily PPI. This was a multicentre, randomised, placebo-controlled, 7-day double-blind trial preceded by a 7-day run-in period. Reflux symptoms were assessed using the Heartburn Reflux Dyspepsia Questionnaire (HRDQ). Based on symptom score during run-in, eligible patients were randomised to Gaviscon Advance 10 mL four times a day or placebo in addition to a once daily PPI. The primary endpoint was change in HRDQ score post-treatment compared to baseline. One hundred and thirty-six patients were randomised. Change in HRDQ reflux score was significantly greater for Gaviscon Advance (mean: -5.0, s.d.: 4.7) than for placebo (mean: -3.5, s.d.: 5.5) with an LS mean difference of 1.6 [95% CI -3.1 to -0.1], P = 0.03. A decrease in the mean (s.d.) number of nights with symptoms was observed from 3.6 (2.8) to 3.0 (3.0) in the placebo group and from 3.9 (2.8) to 2.2 (2.7) for the Gaviscon Advance group. This reduction was significantly greater in the Gaviscon Advance group than in the placebo group [LS mean difference = -0.9, 95% CI (-1.6 to -0.2), P < 0.01]. In patients with residual reflux symptoms despite PPI treatment, adding an alginate offers additional decrease in the burden of reflux symptoms (EudraCT/IND Number: 2011-005486-21). © 2016 John Wiley & Sons Ltd.

In reply to: "Intra-aortic balloon pump protects against hydrostatic pulmonary oedema during peripheral venoarterial-extracorporeal membrane oxygenation".

PubMed

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.

CeasIng Cpap At standarD criteriA (CICADA): impact on weight gain, time to full feeds and caffeine use.

PubMed

Broom, Margaret; Ying, Lei; Wright, Audrey; Stewart, Alice; Abdel-Latif, Mohamed E; Shadbolt, Bruce; Todd, David A

2014-09-01

In our previous randomised controlled trial (RCT), we have shown in preterm babies (PBs) <30 weeks gestation that CeasIng Cpap At standarD criteriA (CICADA (method 1)) compared with cycling off continuous positive airway pressure (CPAP) gradually (method 2) or cycling off CPAP gradually with low flow air/oxygen during periods off CPAP (method 3) reduces CPAP cessation time in PBs <30 weeks gestation. This retrospective study reviewed weight gain, time to reach full feeds and time to cease caffeine in PBs previously enrolled in the RCT. Data were collected from 162 of the 177 PBs, and there was no significant difference in the projected weight gain between the three methods. Based on intention to treat, the time taken to reach full feeds for all three methods showed no significant difference. However, post hoc analysis showed the CICADA method compared with cycling off gradually just failed significance (30.3±1.6 vs 31.1±2.4 (weeks corrected gestational age (Wks CGA±SD)), p=0.077). Analysis of time to cease caffeine showed there was a significant difference between the methods with PBs randomised to the CICADA method compared with the cycling off method ceasing caffeine almost a week earlier (33.6±2.4 vs 34.5±2.8 (Wks CGA±SD), p=0.02). This retrospective study provides evidence to substantiate the optimum method of ceasing CPAP; the CICADA method, does not adversely affect weight gain, time to reach full feeds and may reduce time to cease caffeine in PBs <30 weeks gestation. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Quantum theory of the far-off-resonance continuous-wave Raman laser: Heisenberg-Langevin approach

NASA Astrophysics Data System (ADS)

Roos, P. A.; Murphy, S. K.; Meng, L. S.; Carlsten, J. L.; Ralph, T. C.; White, A. G.; Brasseur, J. K.

2003-07-01

We present the quantum theory of the far-off-resonance continuous-wave Raman laser using the Heisenberg-Langevin approach. We show that the simplified quantum Langevin equations for this system are mathematically identical to those of the nondegenerate optical parametric oscillator in the time domain with the following associations: pump ↔ pump, Stokes ↔ signal, and Raman coherence ↔ idler. We derive analytical results for both the steady-state behavior and the time-dependent noise spectra, using standard linearization procedures. In the semiclassical limit, these results match with previous purely semiclassical treatments, which yield excellent agreement with experimental observations. The analytical time-dependent results predict perfect photon statistics conversion from the pump to the Stokes and nonclassical behavior under certain operational conditions.

Oxygen uptake on-kinetics during six-minute walk test predicts short-term outcomes after off-pump coronary artery bypass surgery.

PubMed

Rocco, Isadora Salvador; Viceconte, Marcela; Pauletti, Hayanne Osiro; Matos-Garcia, Bruna Caroline; Marcondi, Natasha Oliveira; Bublitz, Caroline; Bolzan, Douglas William; Moreira, Rita Simone Lopes; Reis, Michel Silva; Hossne, Nelson Américo; Gomes, Walter José; Arena, Ross; Guizilini, Solange

2017-12-26

We aimed to investigate the ability of oxygen uptake kinetics to predict short-term outcomes after off-pump coronary artery bypass grafting. Fifty-two patients aged 60.9 ± 7.8 years waiting for off-pump coronary artery bypass surgery were evaluated. The 6-min walk test distance was performed pre-operatively, while simultaneously using a portable cardiopulmonary testing device. The transition of oxygen uptake kinetics from rest to exercise was recorded to calculate oxygen uptake kinetics fitting a monoexponential regression model. Oxygen uptake at steady state, constant time, and mean response time corrected by work rate were analysed. Short-term clinical outcomes were evaluated during the early post-operative of off-pump coronary artery bypass surgery. Multivariate analysis showed body mass index, surgery time, and mean response time corrected by work rate as independent predictors for short-term outcomes. The optimal mean response time corrected by work rate cut-off to estimate short-term clinical outcomes was 1.51 × 10 -3  min 2 /ml. Patients with slower mean response time corrected by work rate demonstrated higher rates of hypertension, diabetes, EuroSCOREII, left ventricular dysfunction, and impaired 6-min walk test parameters. The per cent-predicted distance threshold of 66% in the pre-operative was associated with delayed oxygen uptake kinetics. Pre-operative oxygen uptake kinetics during 6-min walk test predicts short-term clinical outcomes after off-pump coronary artery bypass surgery. From a clinically applicable perspective, a threshold of 66% of pre-operative predicted 6-min walk test distance indicated slower kinetics, which leads to longer intensive care unit and post-surgery hospital length of stay. Implications for rehabilitation Coronary artery bypass grafting is a treatment aimed to improve expectancy of life and prevent disability due to the disease progression; The use of pre-operative submaximal functional capacity test enabled the identification of patients with high risk of complications, where patients with delayed oxygen uptake kinetics exhibited worse short-term outcomes; Our findings suggest the importance of the rehabilitation in the pre-operative in order to "pre-habilitate" the patients to the surgical procedure; Faster oxygen uptake on-kinetics could be achieved by improving the oxidative capacity of muscles and cardiovascular conditioning through rehabilitation, adding better results following cardiac surgery.

Method to improve optical parametric oscillator beam quality

DOEpatents

Smith, Arlee V.; Alford, William J.; Bowers, Mark S.

2003-11-11

A method to improving optical parametric oscillator (OPO) beam quality having an optical pump, which generates a pump beam at a pump frequency greater than a desired signal frequency, a nonlinear optical medium oriented so that a signal wave at the desired signal frequency and a corresponding idler wave are produced when the pump beam (wave) propagates through the nonlinear optical medium, resulting in beam walk off of the signal and idler waves, and an optical cavity which directs the signal wave to repeatedly pass through the nonlinear optical medium, said optical cavity comprising an equivalently even number of non-planar mirrors that produce image rotation on each pass through the nonlinear optical medium. Utilizing beam walk off where the signal wave and said idler wave have nonparallel Poynting vectors in the nonlinear medium and image rotation, a correlation zone of distance equal to approximately .rho.L.sub.crystal is created which, through multiple passes through the nonlinear medium, improves the beam quality of the OPO output.

Optical parametric osicllators with improved beam quality

DOEpatents

Smith, Arlee V.; Alford, William J.

2003-11-11

An optical parametric oscillator (OPO) having an optical pump, which generates a pump beam at a pump frequency greater than a desired signal frequency, a nonlinear optical medium oriented so that a signal wave at the desired signal frequency and a corresponding idler wave are produced when the pump beam (wave) propagates through the nonlinear optical medium, resulting in beam walk off of the signal and idler waves, and an optical cavity which directs the signal wave to repeatedly pass through the nonlinear optical medium, said optical cavity comprising an equivalently even number of non-planar mirrors that produce image rotation on each pass through the nonlinear optical medium. Utilizing beam walk off where the signal wave and said idler wave have nonparallel Poynting vectors in the nonlinear medium and image rotation, a correlation zone of distance equal to approximately .rho.L.sub.crystal is created which, through multiple passes through the nonlinear medium, improves the beam quality of the OPO output.

The off-pump technique in redo coronary artery bypass grafting reduces mortality and major morbidities: propensity score analysis of data from the Japan Cardiovascular Surgery Database†.

PubMed

Dohi, Masahiro; Miyata, Hiroaki; Doi, Kiyoshi; Okawa, Kazunari; Motomura, Noboru; Takamoto, Shinichi; Yaku, Hitoshi

2015-02-01

The benefits of off-pump coronary artery grafting (OPCAB) have been demonstrated. Especially in patients with a high number of comorbidities, redo coronary artery bypass grafting (CABG) remains a difficult entity of CABG, because patients are likely to have multiple risk factors and often have diseased patent grafts with adhesions. The aim of the present study was to evaluate the effects of the OPCAB technique in redo CABG on mortality and morbidity using data from the Japan Cardiovascular Surgery Database (JCVSD). We analysed 34 980 patients who underwent isolated CABG between 2008 and 2011, as reported in the JCVSD. Of these, 1.8% of patients (n = 617/34980) had undergone redo CABG, including those who underwent OPCAB (n = 364; 69%) and on-pump CABG (n = 253; 41%). We used propensity score (PS) matching with 13 preoperative risk factors to adjust for differences in baseline characteristics between the redo OPCAB and on-pump redo CABG groups. By one-to-one PS matching, we selected 200 pairs from each group. There were no significant differences in patient background between the redo OPCAB and on-pump redo CABG groups after PS matching. There was no significant difference in the mean number of distal anastomoses after matching (2.41 ± 1.00 vs 2.21 ± 1.04, P = 0.074); nevertheless, the mean operation time was significantly shorter in the redo OPCAB than the on-pump redo CABG group (353.7 vs 441.3 min, P < 0.00010). Patients in the redo OPCAB group had a lower 30-day mortality rate (3.5 vs 7.0%, P = 0.18), a significantly lower rate of composite mortality or major morbidities (11.0 vs 21.5%, P = 0.0060), a significantly lower rate of prolonged ventilation (>24 h) (7.0 vs 15.0%, P = 0.016), a significantly shorter duration of intensive care unit (ICU) stay (ICU stay ≥ 8 days) (7.0 vs 14.5%, P = 0.023) and a significantly decreased need for blood transfusions (71.5 vs 94.0%, P < 0.00010) than patients in the on-pump redo CABG group. The off-pump technique reduced early operative mortality and the incidences of major complications in redo CABG. © The Author 2014. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

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

PubMed Central

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

2017-01-01

Background 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. Objective 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. Methods 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. Results 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). Conclusion 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 compared to the control group as well as reduces the need for anesthetic compounds. Trial Registration The present study has been registered at the Iranian Registry of Clinical Trials (www.IRCT.IR) with a code of IRCT2016072413159N9 before starting the study. Founding This study was fully sponsored by the Research Deputy at Mashhad University of Medical Sciences, Iran (grant number 941413). PMID:29238500

Systematic off-pump coronary artery revascularization in multivessel disease: experience of three hundred cases.

PubMed

Cartier, R; Brann, S; Dagenais, F; Martineau, R; Couturier, A

2000-02-01

We sought to report our recent experience with off-pump coronary artery revascularization in multivessel disease. Between October 1996 and December 1998, 300 off-pump beating heart operations were performed at the Montreal Heart Institute by a single surgeon, representing 94% of all procedures undertaken during this same time frame (97% for 1998). This cohort of patients was compared with 1870 patients operated on with cardiopulmonary bypass from 1995 to 1996. Mean age, sex distribution, and preoperative risk factors were comparable for the two groups. On average, 2.92 +/- 0.8 and 2.84 +/- 0.6 grafts per patient were completed in the beating heart and cardiopulmonary bypass groups, respectively. A majority of patients (70%) had either a triple or quadruple bypass. Coronary anastomoses were achieved with myocardial mechanical stabilization and heart "verticalization." Ischemic time was shorter in the beating heart group (29.8 +/- 0.9 vs 45 +/- 0.4 minutes, P <.05). Similarly, the need for transfusion was significantly less in the beating heart group (beating heart operations, 34%; cardiopulmonary bypass, 66%; P <.005). Reduced use of postoperative intra-aortic counterpulsation, as well as a lower rise in creatine kinase MB isoenzyme, was observed in the beating heart group. Operative mortality rates (beating heart operations, 1. 3%; cardiopulmonary bypass, 2%) and perioperative myocardial infarction (beating heart operations, 3.6%; cardiopulmonary bypass, 4.2%) were comparable for the two groups. In a majority of patients, off-pump complete coronary artery revascularization is an acceptable alternative to conventional operations, yielding good results given progressive experience, rigorous technique, and adequate coronary artery stabilization.

Hybrid coronary revascularization in the era of drug-eluting stents.

PubMed

Murphy, Gavin J; Bryan, Alan J; Angelini, Gianni D

2004-11-01

Left internal mammary artery to left anterior descending coronary artery bypass grafting integrated with percutaneous coronary angioplasty (hybrid procedure) offers multivessel revascularization with minimal morbidity in high-risk patients. This is caused in part by the avoidance of cardiopulmonary bypass-related morbidity and manipulation of the aorta coupled with minimally invasive techniques. Hybrid revascularization is currently reserved for particularly high-risk patients or those with favorable anatomic variants however, largely because of the emergence of off-pump coronary artery bypass grafting, which permits more complete multivessel revascularization, with low morbidity in high-risk groups. The wider introduction of hybrid revascularization is limited chiefly by the high number of repeat interventions compared with off-pump coronary artery bypass grafting, which occurs because of the target vessel failure rate of percutaneous coronary intervention. Other demerits are the costs and logistic problems associated with performing two procedures with differing periprocedural management protocols. Recently, drug-eluting stents have reduced the need for repeat intervention after percutaneous coronary intervention, and this has raised the possibility that the results of hybrid revascularization may now equal or even better those of off-pump coronary artery bypass grafting. Although undoubtedly effective at reducing in-stent restenosis, drug-eluting stents will not address the issues of incomplete revascularization or the logistic problems associated with hybrid. Uncertainty regarding the long-term effectiveness of drug-eluting stents in many patients, as well as their high cost when compared with those of off-pump coronary artery bypass grafting surgery, also militates against the wider introduction of hybrid revascularization.

Off-pump versus on-pump revascularization in females: a meta-analysis of observational studies.

PubMed

Attaran, S; Harling, L; Ashrafian, H; Moscarelli, M; Casula, R; Anderson, J; Punjabi, P; Athanasiou, T

2014-09-01

Coronary revascularization in female patients presents several challenges, including smaller target vessels and smaller conduits. Furthermore, late presentation and more co-morbidities than males may increase complication rates. The aim of this study was to assess whether off-pump coronary artery bypass (OPCAB) improves outcomes when compared to on-pump coronary artery bypass (ONCAB) in the female population. A systematic literature review identified six observational studies, incorporating 23313 patients (n=9596 OPCAB, 13717 ONCAB). These were meta-analyzed using random effects modeling. Heterogeneity, subgroup analysis, quality scoring and publication bias were assessed. The primary endpoints were 30-day mortality and major cardiac, respiratory and renal complications. Secondary endpoints were the number of grafts per patient. No statistically significant difference was observed in 30-day mortality between the OPCAB and ONCAB groups (4.8% vs. 0.7%; OR 0.96; 95% CI [0.41, 2.24], p=0.92). Significant inter-study heterogeneity was also present (I2=94%) and was not explained by study size or quality. Peri-operative myocardial infarction (OR 0.65; 95% CI [0.51, 0.84], p=0.0009) was significantly lower with OPCAB without significant heterogeneity; however, OPCAB did not significantly alter other morbidity outcomes. OPCAB was associated with a trend towards fewer grafts per patient than ONCAB. OPCAB is a safe alternative to ONCAB in the surgical revascularisation of female patients and may reduce post-operative myocardial infarction (MI). However, this does not translate into a reduction in 30-day mortality and OPCAB does not significantly improve other cardiovascular, renal or neurological outcomes. Late outcome data remains lacking and a well-structured, randomized trial is required to answer vital questions regarding the effect of OPCAB on women in the long-term. © The Author(s) 2014.

In vitro and in vivo evaluation of drug-drug interaction between dabigatran and proton pump inhibitors.

PubMed

Ollier, Edouard; Hodin, Sophie; Basset, Thierry; Accassat, Sandrine; Bertoletti, Laurent; Mismetti, Patrick; Delavenne, Xavier

2015-12-01

To quantify the drug-drug interactions between dabigatran etexilate (DE) and proton pump inhibitors (PPI) and in particular the role of P-gp activity modulation. In the first part of the study, efflux ratios of DE were evaluated using the caco-2 cell line in the presence of pantoprazole, omeprazole, rabeprazole, lansoprazole and ciclosporin A (positive control). The two PPI that reduced the efflux ratio of dabigatran to the greatest and least extent, respectively, were used during the second part of the study, comprising a single-centre, randomised, open-label study with an incomplete Latin square design. Nine healthy volunteers received DE (150 mg) alone, DE (150 mg) with the first PPI and DE (150 mg) with the second PPI in randomised sequence. Dabigatran plasma concentration and thrombin time were measured in blood samples withdrawn at 11 time points after each treatment. Models were built using a nonlinear mixed-effect modelling approach. Omeprazole and rabeprazole were the two PPI that reduced the efflux ratio of DE least and most, respectively. The PK model was based on an inverse Gaussian absorption process with one compartment. The relationship between dabigatran concentration and thrombin time was considered linear. Some PK profiles had dramatically low concentration values due to poor absorption. These profiles were clustered using a between subject model mixture with interoccasion variability. The concomitant administration of PPI did not significantly change dabigatran pharmacokinetics. DE is subject to high absorption variability, precluding evaluation of the effect of PPI on its pharmacokinetics. © 2015 Société Française de Pharmacologie et de Thérapeutique.

Ethical implications of excessive cluster sizes in cluster randomised trials.

PubMed

Hemming, Karla; Taljaard, Monica; Forbes, Gordon; Eldridge, Sandra M; Weijer, Charles

2018-02-20

The cluster randomised trial (CRT) is commonly used in healthcare research. It is the gold-standard study design for evaluating healthcare policy interventions. A key characteristic of this design is that as more participants are included, in a fixed number of clusters, the increase in achievable power will level off. CRTs with cluster sizes that exceed the point of levelling-off will have excessive numbers of participants, even if they do not achieve nominal levels of power. Excessively large cluster sizes may have ethical implications due to exposing trial participants unnecessarily to the burdens of both participating in the trial and the potential risks of harm associated with the intervention. We explore these issues through the use of two case studies. Where data are routinely collected, available at minimum cost and the intervention poses low risk, the ethical implications of excessively large cluster sizes are likely to be low (case study 1). However, to maximise the social benefit of the study, identification of excessive cluster sizes can allow for prespecified and fully powered secondary analyses. In the second case study, while there is no burden through trial participation (because the outcome data are routinely collected and non-identifiable), the intervention might be considered to pose some indirect risk to patients and risks to the healthcare workers. In this case study it is therefore important that the inclusion of excessively large cluster sizes is justifiable on other grounds (perhaps to show sustainability). In any randomised controlled trial, including evaluations of health policy interventions, it is important to minimise the burdens and risks to participants. Funders, researchers and research ethics committees should be aware of the ethical issues of excessively large cluster sizes in cluster trials. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Details of the Construction and Production of Fuel Pumps and Fuel Nozzles for the Airplane Diesel Engine

NASA Technical Reports Server (NTRS)

Lubenetsky, W S

1936-01-01

This report presents investigations into the design and construction of fuel pumps for diesel engines. The results of the pump tests on the engines showed that, with a good cut-off, accurate injection, assured by the proper adjustment of the pump elements, there is a decrease in the consumption of fuel and hence an increase in the rated power of the engine. Some of the aspects investigated include: cam profile, coefficient of discharge, and characteristics of the injection system.

Preoperative intra-aortic balloon pump improves the clinical outcomes of off-pump coronary artery bypass grafting in left ventricular dysfunction patients

PubMed Central

Yang, Feng; Wang, Jinhong; Hou, Dengbang; Xing, Jialin; Liu, Feng; Xing, Zhi chen; Jiang, Chunjing; Hao, Xing; Du, Zhongtao; Yang, Xiaofang; Zhao, Yanyan; Miao, Na; Jiang, Yu; Dong, Ran; Gu, Chengxiong; Sun, Lizhong; Wang, Hong; Hou, Xiaotong

2016-01-01

Severe left ventricular (LV) dysfunction patients undergoing off-pump coronary artery bypass grafting (OPCAB) are often associated with a higher mortality. The efficacy and safety of the preoperative prophylactic intra-aortic balloon pump (IABP) insertion is not well established. 416 consecutive patients with severe LV dysfunction (ejection fraction ≤35%) undergoing isolated OPCAB were enrolled in a retrospective observational study. 191 patients was enrolled in the IABP group; the remaining 225 patients was in control group. A total of 129 pairs of patients were propensity-score matched. No significant differences in demographic and preoperative risk factors were found between the two groups. The postoperative 30-day mortality occurred more frequently in the control group compared with the IABP group (8.5% vs. 1.6%, p = 0.02). There was a significant reduction of low cardiac output syndrome in the IABP group compared with the control group (14% vs. 6.2%, p = 0.04). Prolonged mechanical ventilation (≥48 h) occurred more frequently in the control group (34.9% vs. 20.9%, p = 0.02). IABP also decreased the postoperative length of stay. Preoperative IABP was associated with a lower 30-day mortality, suggesting that it is effective in patients with severe LV dysfunction undergoing OPCAB. PMID:27279591

Systematic Review of Integrative Health Care Research: Randomized Control Trials, Clinical Controlled Trials, and Meta-Analysis

DTIC Science & Technology

2010-01-01

to usual care (control). Also, in the pilot study of the 4 individual Noetic therapies, off-site prayer was associated with the lowest absolute...mortality in-hospital and at 6 months [16]. The parallel randomization to 4 different Noetic therapies across 5 study arms limited the assessment of...interventional cardiac care: the Monitoring and Actualisation of Noetic Trainings (MANTRA) II randomised study ,” Lancet, vol. 366, no. 9481, pp. 211–217, 2005. [18

Generation of Multiple Vortex Beams with Specified Vortex Number from Lasers with Controlled Ince-Gaussian Modes

NASA Astrophysics Data System (ADS)

Chu, Shu-Chun

2008-07-01

This study proposes a systematic method of selecting excitations of part of Ince-Gaussian modes (IGMs) and a three-lens configuration for generating multiple vortex beams with forced IGMs in the model of laser-diode (LD)-pumped solid-state lasers. Simply changing the lateral off-axis position of the tight pump beam focus on the laser crystal can produce the desired multiple optical vortex beam from the laser in a well-controlled manner using a proposed astigmatic mode converter assembled into one body with the laser cavity.

Transapical aortic valve implantation and minimally invasive off-pump bypass surgery

PubMed Central

Ahad, Samir; Baumbach, Hardy; Hill, Stephan; Franke, Ulrich F. W.

2014-01-01

Transcatheter aortic valve implantation (TAVI) has gained increasing popularity for high-risk patients with symptomatic aortic valve stenosis. A concomitant coronary artery disease leads to a complicated management and an increased perioperative risk. This case report describes the successful total arterial coronary revascularization of the left anterior descending and the left marginal branch of the circumflex artery utilizing the left internal mammary artery (LIMA) and left radial artery in off-pump technique in combination with the transapical transcatheter aortic valve implantation via minimally invasive anterolateral access in the fifth intercostal space. PMID:24221960

Current status of cardiovascular surgery in Japan, 2013 and 2014: A report based on the Japan Cardiovascular Surgery Database 3. Coronary artery bypass surgery.

PubMed

Saito, Aya; Hirahara, Norimichi; Motomura, Noboru; Miyata, Hiroaki; Takamoto, Shinichi

2018-01-01

Data on isolated coronary artery bypass grafting (CABG) performed in 2013 and 2014, and registered in the Japan Cardiovascular Surgery Database were reviewed for preoperative characteristics, postoperative outcomes, and choice of graft material for the left anterior descending artery (LAD). Isolated CABG was performed off-pump in 54.7% of cases, and graft material for the LAD was left internal thoracic artery in 74.3% and right internal thoracic artery in 15.6%. Operative mortality was 2.0% in elective cases, 8.2% in emergency cases, and 3.0% overall. In elective cases, operative mortality was 1.1% for off-pump CABG compared with 3.0% for on-pump CABG. Clinical results of our isolated CABG were reasonable and acceptable.

Minimally Invasive Extracorporeal Circulation Circuit Is Not Inferior to Off-Pump Coronary Artery Bypass Grafting: Meta-Analysis Using the Bayesian Method.

PubMed

Winkler, Bernhard; Heinisch, Paul P; Gahl, Brigitta; Aghlmandi, Soheila; Jenni, Hans Jörg; Carrel, Thierry P

2017-01-01

The pathophysiologic side effects of cardiopulmonary bypass have already been identified. Minimally invasive extracorporeal circulation technologies (MiECT) and off-pump coronary artery bypass graft surgery (OPCABG) aim to reduce these problems. This meta-analysis provides a comparison of MiECT and OPCABG in randomized and observational studies. A fully probabilistic, Bayesian approach of primary and secondary endpoints was conducted. MiECT does not give inferior results when compared with OPCABG. However, there is a trend to borderline significantly higher blood loss in this group in randomized controlled trials. The question whether MiECT is equivalent to OPCABG can be answered with the affirmative, but long-term follow-up data are needed to detect any advantage over time. Copyright © 2017 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

Characterization of light-control-light system using graphene oxide coated optical waveguide

NASA Astrophysics Data System (ADS)

Ahmad, Harith; Soltani, Soroush; Faizal Ismail, Mohammad; Thambiratnam, Kavintheran; Yi, Chong Wu; Yasin, Moh

2018-07-01

An optical waveguide was coated with graphene oxide (GO) using the drop-casting technique to increase the interaction between the waveguide’s evanescent field and the GO layer. Subsequently, a 1550 nm tunable laser source and 980 nm pump laser is used to study the potential of the GO-film to control the flow of light through the waveguide by altering the state of the waveguide between transparent (ON) and opaque (OFF). The GO layer has a thickness of 0.40 µm and allows a 1550 nm signal with a peak power of  ‑7.0 dBm and average output power of 0 dBm to pass through at a maximum pump power of 60 mW. The waveguide has a responsivity of ~0.1 dB mW‑1, with the time to switch between the ON and OFF states being about 3 ms.

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

PubMed

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 (<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.

Representations and evolutionary operators for the scheduling of pump operations in water distribution networks.

PubMed

López-Ibáñez, Manuel; Prasad, T Devi; Paechter, Ben

2011-01-01

Reducing the energy consumption of water distribution networks has never had more significance. The greatest energy savings can be obtained by carefully scheduling the operations of pumps. Schedules can be defined either implicitly, in terms of other elements of the network such as tank levels; or explicitly, by specifying the time during which each pump is on/off. The traditional representation of explicit schedules is a string of binary values with each bit representing pump on/off status during a particular time interval. In this paper, we formally define and analyze two new explicit representations based on time-controlled triggers, where the maximum number of pump switches is established beforehand and the schedule may contain fewer than the maximum number of switches. In these representations, a pump schedule is divided into a series of integers with each integer representing the number of hours for which a pump is active/inactive. This reduces the number of potential schedules compared to the binary representation, and allows the algorithm to operate on the feasible region of the search space. We propose evolutionary operators for these two new representations. The new representations and their corresponding operations are compared with the two most-used representations in pump scheduling, namely, binary representation and level-controlled triggers. A detailed statistical analysis of the results indicates which parameters have the greatest effect on the performance of evolutionary algorithms. The empirical results show that an evolutionary algorithm using the proposed representations is an improvement over the results obtained by a recent state of the art hybrid genetic algorithm for pump scheduling using level-controlled triggers.

Randomised, prospective, medico-economic nationwide French study of islet transplantation in patients with severely unstable type 1 diabetes: the STABILOT study protocol.

PubMed

Lablanche, Sandrine; David-Tchouda, Sandra; Margier, Jennifer; Schir, Edith; Wojtusciszyn, Anne; Borot, Sophie; Kessler, Laurence; Morelon, Emmanuel; Thivolet, Charles; Pattou, François; Vantyghem, Marie Christine; Berney, Thierry; Benhamou, Pierre-Yves

2017-02-20

Islet transplantation may be an appropriate treatment option for patients with severely unstable type 1 diabetes experiencing major glucose variability with severe hypoglycaemia despite intensive insulin therapy. Few data are available on the costs associated with islet transplantation in relation to its benefits. The STABILOT study proposes to assess the economic impact of islet transplantation in comparison with the current best medical treatment defined as sensor-augmented pump (SAP) therapy. The trial will adopt an open-label, randomised, multicentred design. The study will include 30 patients with severely unstable type 1 diabetes. Eligible participants will be 18-65 years old, with type 1 diabetes duration >5 years, a negative basal or stimulated C-peptide, and severe instability defined by persistent, recurrent and disabling severe hypoglycaemia, despite optimised medical treatment. Participants will be randomised into two groups: one group with immediate registration for islet transplantation, and one group with delayed registration for 1 year while patients receive SAP therapy. The primary endpoint will be the incremental cost-utility ratio at 1 year between islet transplantation and SAP therapy. Perspectives of both the French Health Insurance System and the hospitals will be retained. Ethical approval has been obtained at all sites. The trial has been approved by ClinicalTrials.gov (Trial registration ID NCT02854696). All participants will sign a free and informed consent form before randomisation. Results of the study will be communicated during national and international meetings in the field of diabetes and transplantation. A publication will be sought in journals usually read by physicians involved in diabetes care, transplantation and internal medicine. NCT02854696; Pre-results. 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/.

Effects of 12 weeks' treatment with a proton pump inhibitor on insulin secretion, glucose metabolism and markers of cardiovascular risk in patients with type 2 diabetes: a randomised double-blind prospective placebo-controlled study.

PubMed

Hove, K D; Brøns, C; Færch, K; Lund, S S; Petersen, J S; Karlsen, A E; Rossing, P; Rehfeld, J F; Vaag, A

2013-01-01

Recent studies suggest that proton pump inhibitor treatment may increase insulin secretion and improve glucose metabolism in type 2 diabetes. In a randomised double-blind prospective placebo-controlled 2 × 2 factorial study, we examined the effect of esomeprazole on insulin secretion, HbA(1c) and cardiovascular risk factors in type 2 diabetes. Forty-one patients with type 2 diabetes using dietary control or oral glucose-lowering treatment were randomised to receive add-on esomeprazole 40 mg (n = 20) or placebo (n = 21) for 12 weeks. Randomisation was carried out prior to inclusion on the basis of a computer-generated random-number list. The allocation sequence was concealed in sealed envelopes from the researcher enrolling and assessing participants. The study was undertaken at Steno Diabetes Center, Gentofte, Denmark. The primary outcome was change in AUC for insulin levels during a meal test. Secondary outcomes were the levels of HbA(1c) and biochemical markers of cardiovascular risk, including lipids, coagulation factors, inflammation markers, markers of endothelial function and 24 h ambulatory BP measurements. Forty-one participants were analysed. In the esomeprazole-treated group the AUC for insulin did not change (before vs after treatment: 28,049 ± 17,659 vs 27,270 ± 32,004 pmol/l × min (p = 0.838). In the placebo group AUC for insulin decreased from 27,392 ± 14,348 pmol/l × min to 22,938 ± 11,936 pmol/l × min (p = 0.002). Esomeprazole treatment (n = 20) caused a ninefold increase in the AUC for gastrin. HbA(1c) increased from 7.0 ± 0.6% (53 ± 5 mmol/mol) to 7.3 ± 0.8% (56 ± 6 mmol/mol) in the esomeprazole-treated group and from 7.0 ± 0.6% (53 ± 5 mmol/mol) to 7.4 ± 0.8% (57 ± 6 mmol/mol) in the placebo group (n = 21) (p for difference in change >0.05). Except for BP, there were no differences between the groups in the markers of cardiovascular risk (p > 0.05). Monitoring of 24 h ambulatory BP showed a significant decrease in daytime systolic BP, daytime diastolic BP and 24 h diastolic BP in the placebo group (p < 0.05). No change in BP was seen in the patients treated with esomeprazole. Treatment with esomeprazole over 12 weeks did not improve insulin secretion, glycaemic control or cardiovascular disease biomarkers in patients with type 2 diabetes.

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

PubMed

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 <35%; and (v) reoperation or emergency. Patients were evenly randomized to receive either sodium bicarbonate (0.5 mmol kg -1 for 1 h upon induction of anaesthesia followed by 0.15 mmol kg -1 h -1 for 23 h) or 0.9% saline. Acute kidney injury within 48 h after surgery was assessed using the Acute Kidney Injury Network criteria. The incidences of AKI were 21 and 26% in the bicarbonate and control groups, respectively (P=0.458). Serially measured serum creatinine concentrations and perioperative fluid balance were also comparable between the groups. The length of postoperative hospitalization and incidence of morbidity end points were similar between the groups, whereas significantly more patients in the bicarbonate group required prolonged mechanical ventilation (>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.

Lift-Off Performance in Flexure Pivot Pad and Hybrid Bearings

DTIC Science & Technology

2008-12-01

and Dawson, M. P., 1998, "Experience in the Use of Flexure Pivot Tilt Pad Bearings in Boiler Feed Water Pumps ," Proc. of the 15th International...freely. Test Procedure 1) Turn on the pump to buffer water to the test bearing. 2) Turn on air to the air seal that prevents water flowing... Pump Users Symposium, Turbomachinery Laboratory, College Station, Texas, pp. 77-84. [6] Rodriguez, L., 2004, “Experimental Frequency-Dependent

Internet trials: participant experiences and perspectives.

PubMed

Mathieu, Erin; Barratt, Alexandra; Carter, Stacy M; Jamtvedt, Gro

2012-10-23

Use of the Internet to conduct randomised controlled trials is increasing, and provides potential to increase equity of access to medical research, increase the generalisability of trial results and decrease the costs involved in conducting large scale trials. Several studies have compared response rates, completeness of data, and reliability of surveys using the Internet and traditional methods, but very little is known about participants' attitudes towards Internet-based randomised trials or their experience of participating in an Internet-based trial. To obtain insights into the experiences and perspectives of participants in an Internet-based randomised controlled trial, their attitudes to the use of the Internet to conduct medical research, and their intentions regarding future participation in Internet research. All English speaking participants in a recently completed Internet randomised controlled trial were invited to participate in an online survey. 1246 invitations were emailed. 416 participants completed the survey between May and October 2009 (33% response rate). Reasons given for participating in the Internet RCT fell into 4 main areas: personal interest in the research question and outcome, ease of participation, an appreciation of the importance of research and altruistic reasons. Participants' comments and reflections on their experience of participating in a fully online trial were positive and less than half of participants would have participated in the trial had it been conducted using other means of data collection. However participants identified trade-offs between the benefits and downsides of participating in Internet-based trials. The main trade-off was between flexibility and convenience - a perceived benefit - and a lack connectedness and understanding - a perceived disadvantage. The other tradeoffs were in the areas of: ease or difficulty in use of the Internet; security, privacy and confidentiality issues; perceived benefits and disadvantages for researchers; technical aspects of using the Internet; and the impact of Internet data collection on information quality. Overall, more advantages were noted by participants, consistent with their preference for this mode of research over others. The majority of participants (69%) would prefer to participate in Internet-based research compared to other modes of data collection in the future. Participants in our survey would prefer to participate in Internet-based trials in the future compared to other ways of conducting trials. From the participants' perspective, participating in Internet-based trials involves trade-offs. The central trade-off is between flexibility and convenience - a perceived benefit - and lack of connectedness and understanding - a perceived disadvantage. Strategies to maintain the convenience of the Internet while increasing opportunities for participants to feel supported, well-informed and well-understood would seem likely to increase the acceptability of Internet-based trials.

Internet trials: participant experiences and perspectives

PubMed Central

2012-01-01

Background Use of the Internet to conduct randomised controlled trials is increasing, and provides potential to increase equity of access to medical research, increase the generalisability of trial results and decrease the costs involved in conducting large scale trials. Several studies have compared response rates, completeness of data, and reliability of surveys using the Internet and traditional methods, but very little is known about participants’ attitudes towards Internet-based randomised trials or their experience of participating in an Internet-based trial. Objective To obtain insights into the experiences and perspectives of participants in an Internet-based randomised controlled trial, their attitudes to the use of the Internet to conduct medical research, and their intentions regarding future participation in Internet research. Methods All English speaking participants in a recently completed Internet randomised controlled trial were invited to participate in an online survey. Results 1246 invitations were emailed. 416 participants completed the survey between May and October 2009 (33% response rate). Reasons given for participating in the Internet RCT fell into 4 main areas: personal interest in the research question and outcome, ease of participation, an appreciation of the importance of research and altruistic reasons. Participants’ comments and reflections on their experience of participating in a fully online trial were positive and less than half of participants would have participated in the trial had it been conducted using other means of data collection. However participants identified trade-offs between the benefits and downsides of participating in Internet-based trials. The main trade-off was between flexibility and convenience – a perceived benefit – and a lack connectedness and understanding – a perceived disadvantage. The other tradeoffs were in the areas of: ease or difficulty in use of the Internet; security, privacy and confidentiality issues; perceived benefits and disadvantages for researchers; technical aspects of using the Internet; and the impact of Internet data collection on information quality. Overall, more advantages were noted by participants, consistent with their preference for this mode of research over others. The majority of participants (69%) would prefer to participate in Internet-based research compared to other modes of data collection in the future. Conclusion Participants in our survey would prefer to participate in Internet-based trials in the future compared to other ways of conducting trials. From the participants’ perspective, participating in Internet-based trials involves trade-offs. The central trade-off is between flexibility and convenience – a perceived benefit – and lack of connectedness and understanding – a perceived disadvantage. Strategies to maintain the convenience of the Internet while increasing opportunities for participants to feel supported, well-informed and well-understood would seem likely to increase the acceptability of Internet-based trials. PMID:23092116

Clinical outcome and quality of life after reoperative CABG: off-pump versus on-pump – observational pilot study

PubMed Central

2013-01-01

Background Coronary artery bypass grafting (CABG) on cardiopulmonary bypass (CBP) is associated with significant morbidity and mortality. In high-risk patients, doomed for reoperation the adverse effects of CBP may be more striking. We evaluated the results of reoperative CABG (redo-CABG) by either off-pump (OPCAB) or on-pump (ONCAB). Clinical endpoints were perioperative myocardial infarction, mortality, survival and as the most striking difference between prior studies the quality of life (QoL). Methods We performed a prospective, non-randomized assessment for patients who underwent redo-CABG by redo-OPCAB (n = 40) or redo-ONCAB (n = 40) at our institution between January 2007 and December 2010. For evaluation of QoL the SF-36 health survey was used with self-administered assessment. Results During follow-up 37 of 40 patients were alive in the redo-OPCAB group versus 32 of 40 patients in the redo-ONCAB group (p < 0.05). The shorter operation time, less blood loss, fewer perioperative myocardial infarctions, the higher rate of totally arterial revascularisation and shorter intensive care stay were the significantly beneficial differences for patients in the redo-OPCAB group (p < 0.05). The 3-year survival rate was higher in the redo-OPCAB group with 81 ± 12% versus 63 ± 9%in the redo-ONCAB group. The quality of life survey did not reveal any significant differences between both groups. Conclusion In conclusion, with our present retrospective study, we could demonstrate the safety and efficacy of the redo-OPCAB technique with even higher 3-year survival rate. Both techniques seem to have similar impact on the outcome of patients. PMID:23561396

Microchip solid-state cylindrical vector lasers with orthogonally polarized dual laser-diode end pumping.

PubMed

Otsuka, Kenju; Chu, Shu-Chun

2013-05-01

We report a simple method for generating cylindrical vector beams directly from laser-diode (LD)-pumped microchip solid-state lasers by using dual end-pumping beams. Radially as well as azimuthally polarized vector field emissions have been generated from the common c-cut Nd:GdVO4 laser cavity merely by controlling the focus positions of orthogonally polarized LD off-axis pump beams. Hyperbolically polarized vector fields have also been observed, in which the cylindrical symmetry of vector fields is broken. Experimental results have been well reproduced by numerical simulations.

A stable submillimeter laser local oscillator for heterodyne radiometry and spectroscopy

NASA Technical Reports Server (NTRS)

Koepf, G. A.; Fetterman, H. R.; Mcavoy, N.

1980-01-01

A submillimeter laser with off-axis pump beam injection is described. This design concept achieves complete isolation of the pump laser with respect to the pump radiation reflected from the submillimeter resonator. Active line independent stabilization of the pump laser is obtained by the use of an external tunable etalon as a frequency reference. The submillimeter output power is constant to within 4% over periods of hours. Mean frequency drifts of less than 2 parts in 100 million per minute were measured by mixing with very high harmonics of an X-band synthesizer in a planar Schottky diode.

Erbium Doped GaN Lasers by Optical Pumping

DTIC Science & Technology

2016-07-13

obtained via growth by hydride vapor phase epitaxy (HVPE) in conjunction with a laser-lift-off (LLO) process. An Er doping level of 1.4 × 10^20 atoms/cm3... conjunction with a laser-lift-off (LLO) 2 process. An Er doping level

Controlling signal transport in a carbon nanotube opto-transistor

NASA Astrophysics Data System (ADS)

Li, Jinjin; Chu, Yanhui; Zhu, Ka-Di

2016-11-01

With the highly competitive development of communication technologies, modern information manufactures place high importance on the ability to control the transmitted signal using easy miniaturization materials. A controlled and miniaturized optical information device is, therefore, vital for researchers in information and communication fields. Here we propose a controlled signal transport in a doubly clamped carbon nanotube system, where the transmitted signal can be controlled by another pump beam. Pump off results in the transmitted signal off, while pump on results in the transmitted signal on. The more pump, the more amplified output signal transmission. Analogous with traditional cavity optomechanical system, the role of optical cavity is played by a localized exciton in carbon nanotube while the role of the mechanical element is played by the nanotube vibrations, which enables the realization of an opto-transistor based on carbon nanotube. Since the signal amplification and attenuation have been observed in traditional optomechanical system, and the nanotube optomechanical system has been realized in laboratory, the proposed carbon nanotube opto-transistor could be implemented in current experiments and open the door to potential applications in modern optical networks and future quantum networks.

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

PubMed

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.

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

NASA Astrophysics Data System (ADS)

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.

A study with pharyngeal and esophageal 24-hour pH-impedance monitoring in patients with laryngopharyngeal symptoms refractory to proton pump inhibitors.

PubMed

Dulery, C; Lechot, A; Roman, S; Bastier, P-L; Stoll, D; de Gabory, L; Zerbib, F

2017-01-01

The role of gastroesophageal reflux in chronic laryngeal symptoms is difficult to establish. The aim of this study was to characterize pharyngeal and esophageal pH-impedance reflux patterns in a group of patients with suspected laryngopharyngeal reflux and to determine predictive factors of response to proton pump inhibitors. Patients with chronic pharyngolaryngeal symptoms were evaluated with a symptom score questionnaire, laryngoscopy, and 24-hour pharyngeal and esophageal pH-impedance monitoring at baseline and after 8-week treatment with esomeprazole 40 mg b.i.d. Response to treatment was defined by a diminution of more than 50% of the score for the primary symptom. Reflux patterns and baseline impedance values were compared to those obtained in 46 healthy subjects. Twenty-four patients were included (17 women, median age 54 years), all previously refractory to antisecretory therapy. Symptom scores were 46 (32-62) and 40 (27-76) off and on therapy, respectively (P=.1). There was no significant difference between patients and controls for pH-impedance reflux parameters and baseline values off and on therapy in distal and proximal esophagus and in the pharynx. Median numbers of pharyngeal reflux were 0 and 0 off and on therapy, respectively. Only two patients were responders to treatment, both with excessive distal reflux but no pharyngeal reflux. Only one patient had abnormal pharyngeal reflux but did not respond to proton pump inhibitors. Patients with suspected laryngopharyngeal reflux refractory to therapy do not exhibit abnormal pharyngeal or esophageal pH-impedance reflux. In these patients, laryngopharyngeal reflux is unlikely. © 2016 John Wiley & Sons Ltd.

Suggested techniques, equipment, and standards for the testing of hand insecticide-spraying equipment

PubMed Central

Hall, Lawrence B.

1955-01-01

The new demands placed upon application equipment by the introduction of modern insecticides have revealed the deficiencies of this equipment when required for continuous use on a large scale. If adequate equipment is to be produced, specifications must be based not only on basic materials tests but also on “use” tests, in which the conditions of field use are simulated. The author outlines suggested techniques to be followed and standards to be adopted in testing the performance of compression sprayers and allied equipment, with reference to the following features: compression-sprayer tank fatigue; tank impact; pump resistance to bursting; pump resistance to collapse; pump friction; cut-off valve durability; constant-pressure valves; cut-off valve actuation; hose flexure; hose tension and bursting-pressure; hose friction; gaskets, valve faces, and similar non-metallic parts; nozzle-orifice erosion; and nozzle pattern. ImagesFIG. 1FIG. 14FIG. 20 PMID:14364189

Analysis of Dual-Order Backward Pumping Schemes in Distributed Raman Amplification System

NASA Astrophysics Data System (ADS)

Singh, Kulwinder; Patterh, Manjeet Singh; Bhamrah, Manjit Singh

2018-04-01

Backward pumping in fiber Raman amplifiers has been investigated in this paper in terms of on-off Raman gain, noise figure and optical signal-to-noise ratio. The results exhibit that with four first-order pumps and one second-order pump scheme can be employed to achieve 8.2 dB noise figure in 64 channel fiber optic communication system. It has also been reported that 2.65 dB gain ripple, 0.87 dB noise figure tilt and 2.02 dB OSNR tilt can be attained with the second-order pumping in fiber Raman amplifiers. The main advantage of the scheme is that only 50 mW second-order pump shows appreciable improvement in the system performance. It shows that further increase in first-order and second-order pump powers increase system noise implications.

Zero Gravity Cryogenic Vent System Concepts for Upper Stages

NASA Technical Reports Server (NTRS)

Flachbart, Robin H.; Holt, James B.; Hastings, Leon J.

1999-01-01

The capability to vent in zero gravity without resettling is a technology need that involves practically all uses of sub-critical cryogenics in space. Venting without resettling would extend cryogenic orbital transfer vehicle capabilities. However, the lack of definition regarding liquid/ullage orientation coupled with the somewhat random nature of the thermal stratification and resulting pressure rise rates, lead to significant technical challenges. Typically a zero gravity vent concept, termed a thermodynamic vent system (TVS), consists of a tank mixer to destratify the propellant, combined with a Joule-Thomson (J-T) valve to extract thermal energy from the propellant. Marshall Space Flight Center's (MSFC's) Multipurpose Hydrogen Test Bed (MHTB) was used to test both spray bar and axial jet TVS concepts. The axial jet system consists of a recirculation pump heat exchanger unit. The spray bar system consists of a recirculation pump, a parallel flow concentric tube, heat exchanger, and a spray bar positioned close to the longitudinal axis of the tank. The operation of both concepts is similar. In the mixing mode, the recirculation pump withdraws liquid from the tank and sprays it into the tank liquid, ullage, and exposed tank surfaces. When energy is required. a small portion of the recirculated liquid is passed sequentially through the J-T expansion valve, the heat exchanger, and is vented overboard. The vented vapor cools the circulated bulk fluid, thereby removing thermal energy and reducing tank pressure. The pump operates alone, cycling on and off, to destratify the tank liquid and ullage until the liquid vapor pressure reaches the lower set point. At that point. the J-T valve begins to cycle on and off with the pump. Thus, for short duration missions, only the mixer may operate, thus minimizing or even eliminating, boil-off losses.

Zero Gravity Cryogenic Vent System Concepts for Upper Stages

NASA Technical Reports Server (NTRS)

Flachbart, Robin H.; Holt, James B.; Hastings, Leon J.

2001-01-01

The capability to vent in zero gravity without resettling is a technology need that involves practically all uses of sub-critical cryogenics in space, and would extend cryogenic orbital transfer vehicle capabilities. However, the lack of definition regarding liquid/ullage orientation coupled with the somewhat random nature of the thermal stratification and resulting pressure rise rates, lead to significant technical challenges. Typically a zero gravity vent concept, termed a thermodynamic vent system (TVS), consists of a tank mixer to destratify the propellant, combined with a Joule-Thomson (J-T) valve to extract thermal energy from the propellant. Marshall Space Flight Center's (MSFC's) Multipurpose Hydrogen Test Bed (MHTB) was used to test both spray-bar and axial jet TVS concepts. The axial jet system consists of a recirculation pump heat exchanger unit. The spray-bar system consists of a recirculation pump, a parallel flow concentric tube heat exchanger, and a spray-bar positioned close to the longitudinal axis of the tank. The operation of both concepts is similar. In the mixing mode, the recirculation pump withdraws liquid from the tank and sprays it into the tank liquid, ullage, and exposed tank surfaces. When energy extraction is required, a small portion of the recirculated liquid is passed sequentially through the J-T expansion valve, the heat exchanger, and is vented overboard. The vented vapor cools the circulated bulk fluid, thereby removing thermal energy and reducing tank pressure. The pump operates alone, cycling on and off, to destratify the tank liquid and ullage until the liquid vapor pressure reaches the lower set point. At that point, the J-T valve begins to cycle on and off with the pump. Thus, for short duration missions, only the mixer may operate, thus minimizing or even eliminating boil-off losses.

Two-color pump-probe laser spectroscopy instrument with picosecond time-resolved electronic delay and extended scan range

NASA Astrophysics Data System (ADS)

Yu, Anchi; Ye, Xiong; Ionascu, Dan; Cao, Wenxiang; Champion, Paul M.

2005-11-01

An electronically delayed two-color pump-probe instrument was developed using two synchronized laser systems. The instrument has picosecond time resolution and can perform scans over hundreds of nanoseconds without the beam divergence and walk-off effects that occur using standard spatial delay systems. A unique picosecond Ti :sapphire regenerative amplifier was also constructed without the need for pulse stretching and compressing optics. The picosecond regenerative amplifier has a broad wavelength tuning range, which suggests that it will make a significant contribution to two-color pump-probe experiments. To test this instrument we studied the rotational correlation relaxation of myoglobin (τr=8.2±0.5ns) in water as well as the geminate rebinding kinetics of oxygen to myoglobin (kg1=1.7×1011s-1, kg2=3.4×107s-1). The results are consistent with, and improve upon, previous studies.

Antifibrinolytic amino acids for upper gastrointestinal bleeding in people with acute or chronic liver disease.

PubMed

Martí-Carvajal, Arturo J; Solà, Ivan

2015-06-09

Upper gastrointestinal bleeding is one of the most frequent causes of morbidity and mortality in the course of liver cirrhosis. People with liver disease frequently have haemostatic abnormalities such as hyperfibrinolysis. Therefore, antifibrinolytic amino acids have been proposed to be used as supplementary interventions alongside any of the primary treatments for upper gastrointestinal bleeding in people with liver diseases. This is an update of this Cochrane review. To assess the beneficial and harmful effects of antifibrinolytic amino acids for upper gastrointestinal bleeding in people with acute or chronic liver disease. We searched The Cochrane Hepato-Biliary Controlled Trials Register (February 2015), Cochrane Central Register of Controlled Trials (CENTRAL) (Issue 2 of 12, 2015), MEDLINE (Ovid SP) (1946 to February 2015), EMBASE (Ovid SP) (1974 to February 2015), Science Citation Index EXPANDED (1900 to February 2015), LILACS (1982 to February 2015), World Health Organization Clinical Trials Search Portal (accessed 26 February 2015), and the metaRegister of Controlled Trials (accessed 26 February 2015). We scrutinised the reference lists of the retrieved publications. Randomised clinical trials irrespective of blinding, language, or publication status for assessment of benefits and harms. Observational studies for assessment of harms. We planned to summarise data from randomised clinical trials using standard Cochrane methodologies and assessed according to the GRADE approach. We found no randomised clinical trials assessing antifibrinolytic amino acids for treating upper gastrointestinal bleeding in people with acute or chronic liver disease. We did not identify quasi-randomised, historically controlled, or observational studies in which we could assess harms. This updated Cochrane review identified no randomised clinical trials assessing the benefits and harms of antifibrinolytic amino acids for upper gastrointestinal bleeding in people with acute or chronic liver disease. The benefits and harms of antifibrinolytic amino acids need to be tested in randomised clinical trials. Unless randomised clinical trials are conducted to assess the trade-off between benefits and harms, we cannot recommend or refute antifibrinolytic amino acids for upper gastrointestinal bleeding in people with acute or chronic liver diseases.

Effect of intra-aortic balloon pump on coronary blood flow during different balloon cycles support: A computer study.

PubMed

Aye, Thin Pa Pa; Htet, Zwe Lin; Singhavilai, Thamvarit; Naiyanetr, Phornphop

2015-01-01

Intra-aortic balloon pump (IABP) has been used in clinical treatment as a mechanical circulatory support device for patients with heart failure. A computer model is used to study the effect on coronary blood flow (CBF) with different balloon cycles under both normal and pathological conditions. The model of cardiovascular and IABP is developed by using MATLAB SIMULINK. The effect on coronary blood flow has been studied under both normal and pathological conditions using different balloon cycles (balloon off; 1:4; 1:2; 1:1). A pathological heart is implemented by reducing the left ventricular contractility. The result of this study shows that the rate of balloon cycles is related to the level of coronary blood flow.

Wide sternal retraction may impede internal mammary artery graft flow and reduce myocardial function during off-pump coronary artery bypass grafting: presentation of two cases

PubMed Central

Espinoza, Andreas; Bergsland, Jacob; Lundblad, Runar; Fosse, Erik

2012-01-01

The internal mammary artery (IMA) is routinely used for grafting of the left anterior descending coronary artery (LAD), providing good flow to the anterior left ventricle (LV) wall. Impeded IMA-to-LAD flow may result in myocardial ischaemia and haemodynamic deterioration. From a study population, we describe two incidents where myocardial ischaemia was observed during off-pump coronary artery bypass surgery (CABG), with a confirmed reduction in the IMA-to-LAD flow in one patient. In patient no. 1, normal IMA flow was assessed by transit-time flow measurement after a complete IMA-to-LAD anastomosis. The anterior LV wall thickening was monitored continuously by epicardial ultrasonic transducers. Normal wall thickening was confirmed after IMA grafting. During a wide sternal opening for circumflex grafting the anterior wall motion displayed an ischaemic pattern, with reduced systolic and increased post-systolic wall thickening. IMA flow was reduced simultaneously. When easing the sternal opening, IMA flow normalized, as did the motion pattern in the anterior LV wall. In patient no. 2, similar changes in wall thickening occurred during a wide sternal opening after IMA-to-LAD grafting. When easing the retractor, the wall thickening normalized. It is important for the surgeon to be aware of this possible cause of myocardial ischaemia, with a risk of subsequent haemodynamic deterioration. This may not only be of great importance during off-pump CABG, but can also be significant for successful weaning from the cardiopulmonary bypass machine. PMID:22499803

Fluid sample collection and distribution system. [qualitative analysis of aqueous samples from several points

NASA Technical Reports Server (NTRS)

Brooks, R. L. (Inventor)

1979-01-01

A multipoint fluid sample collection and distribution system is provided wherein the sample inputs are made through one or more of a number of sampling valves to a progressive cavity pump which is not susceptible to damage by large unfiltered particles. The pump output is through a filter unit that can provide a filtered multipoint sample. An unfiltered multipoint sample is also provided. An effluent sample can be taken and applied to a second progressive cavity pump for pumping to a filter unit that can provide one or more filtered effluent samples. The second pump can also provide an unfiltered effluent sample. Means are provided to periodically back flush each filter unit without shutting off the whole system.

Quantitative analysis of backflow of reversible pump-turbine in generating mode

NASA Astrophysics Data System (ADS)

Liu, K. H.; Zhang, Y. N.; Li, J. W.; Xian, H. Z.

2016-05-01

Significant vibration and pressure fluctuations are usually observed when pump- turbine is operated during the off-design conditions, especially turbine brake and runaway. The root cause of these instability phenomena is the abnormal unsteady flow (especially the backflow) inside the pump-turbine. In the present paper, numerical simulation method is adopted to investigate the characteristics of the flow inside the whole passage of pump-turbine with two guide vane openings (6° and 21° respectively) and three kinds of operating conditions (turbine, runaway and turbine braking respectively). A quantitative analysis of backflow is performed in both the axial and radial directions and the generation and development of backflow in the pump turbine are revealed with great details.

Femtosecond Nonlinearities in Indium Gallium Arsenic Phosphide Diode Lasers

NASA Astrophysics Data System (ADS)

Hall, Katherine Lavin

Semiconductor optical amplifiers are receiving increasing attention for possible applications to broadband optical communication and switching systems. In this thesis we report the results of an extensive experimental study of the ultrafast gain and refractive index nonlinearities in 1.5 μm InGaAsP laser diode amplifiers. The temporal resolution afforded by the femtosecond optical pulses used in these experiments allows us to study carrier interactions with other carriers as well as carrier interactions with the lattice. The 100-200 fs optical pulses used in the pump -probe experiments are generated by an Additive Pulse Modelocked color center laser. The measured group velocity dispersion in the diodes ranged from -0.6 to -0.95 mu m^{-1 }. Differences in the group velocity for TE - and TM-polarized pulses suggested that cross-polarized pump-probe pulses walk off from each other in the diode. This walk-off can diminish the time resolution of some experiments. A novel heterodyne pump-probe technique was developed to distinguish collinear, copolarized, pump and probe pulses that were nominally at the same wavelength. Comparing cross-polarized and copolarized pump-probe results yielded new information about the physical mechanisms responsible for nonlinear gain in the diodes. We observed a gain compression across the entire bandwidth of the diode, associated with carrier heating. The hot carrier distribution cooled back to the lattice temperature with a 0.6 to 1.0 ps time constant, depending on the device structure. In addition, we observed a 0.1 to 0.25 ps delay in onset of carrier heating. Large gain compression due to two photon absorption was also observed. A small portion of the nonlinear gain is attributed to spectral hole burning. Pulsewidth-dependent output saturation energies were explained by a rate equation model that included the effect of carrier heating. Measurements of pump-induced probe phase changes revealed index nonlinearities due to delayed carrier heating and an instantaneous electronic, or virtual process. (Copies available exclusively from MIT Libraries, Rm. 14-0551, Cambridge, MA 02139-4307. Ph. 617 -253-5668; Fax 617-253-1690.).

Optimization and Performance Study of Select Heating Ventilation and Air Conditioning Technologies for Commercial Buildings

NASA Astrophysics Data System (ADS)

Kamal, Rajeev

Buildings contribute a significant part to the electricity demand profile and peak demand for the electrical utilities. The addition of renewable energy generation adds additional variability and uncertainty to the power system. Demand side management in the buildings can help improve the demand profile for the utilities by shifting some of the demand from peak to off-peak times. Heating, ventilation and air-conditioning contribute around 45% to the overall demand of a building. This research studies two strategies for reducing the peak as well as shifting some demand from peak to off-peak periods in commercial buildings: 1. Use of gas heat pumps in place of electric heat pumps, and 2. Shifting demand for air conditioning from peak to off-peak by thermal energy storage in chilled water and ice. The first part of this study evaluates the field performance of gas engine-driven heat pumps (GEHP) tested in a commercial building in Florida. Four GEHP units of 8 Tons of Refrigeration (TR) capacity each providing air-conditioning to seven thermal zones in a commercial building, were instrumented for measuring their performance. The operation of these GEHPs was recorded for ten months, analyzed and compared with prior results reported in the literature. The instantaneous COPunit of these systems varied from 0.1 to 1.4 during typical summer week operation. The COP was low because the gas engines for the heat pumps were being used for loads that were much lower than design capacity which resulted in much lower efficiencies than expected. The performance of equivalent electric heat pump was simulated from a building energy model developed to mimic the measured building loads. An economic comparison of GEHPs and conventional electrical heat pumps was done based on the measured and simulated results. The average performance of the GEHP units was estimated to lie between those of EER-9.2 and EER-11.8 systems. The performance of GEHP systems suffers due to lower efficiency at part load operation. The study highlighted the need for optimum system sizing for GEHP/HVAC systems to meet the building load to obtain better performance in buildings. The second part of this study focusses on using chilled water or ice as thermal energy storage for shifting the air conditioning load from peak to off-peak in a commercial building. Thermal energy storage can play a very important role in providing demand-side management for diversifying the utility demand from buildings. Model of a large commercial office building is developed with thermal storage for cooling for peak power shifting. Three variations of the model were developed and analyzed for their performance with 1) ice storage, 2) chilled water storage with mixed storage tank and 3) chilled water storage with stratified tank, using EnergyPlus 8.5 software developed by the US Department of Energy. Operation strategy with tactical control to incorporate peak power schedule was developed using energy management system (EMS). The modeled HVAC system was optimized for minimum cost with the optimal storage capacity and chiller size using JEPlus. Based on the simulation, an optimal storage capacity of 40-45 GJ was estimated for the large office building model along with 40% smaller chiller capacity resulting in higher chiller part-load performance. Additionally, the auxiliary system like pump and condenser were also optimized to smaller capacities and thus resulting in less power demand during operation. The overall annual saving potential was found in the range of 7-10% for cooling electricity use resulting in 10-17% reduction in costs to the consumer. A possible annual peak shifting of 25-78% was found from the simulation results after comparing with the reference models. Adopting TES in commercial buildings and achieving 25% peak shifting could result in a reduction in peak summer demand of 1398 MW in Tampa.

Sutureless Technique to Fix the Great Saphenous Vein along the Atrioventricular Groove Using Fibrin Glue in Off-Pump Coronary Artery Bypass Grafting.

PubMed

Ohira, Suguru; Doi, Kiyoshi; Yaku, Hitoshi

2016-04-05

We describe a simple method to fix the great saphenous vein graft (SVG) to the right coronary artery along the atrioventricular groove using fibrin glue in off-pump coronary artery bypass grafting (OPCAB). After completion of the proximal anastomosis, the SVG was placed along the atrioventricular groove to the acute margin. Fibrin glue was sprayed using pressurized carbon dioxide gas. A distal anastomosis was subsequently performed after rotating the heart to expose the posterior descending artery. It is a straightforward and reproducible technique to determine the optimal length of the SVG and prevent kinking or stretching of the graft, especially in OPCAB.

FMR-driven spin pumping in Y3Fe5O12-based structures

NASA Astrophysics Data System (ADS)

Yang, Fengyuan; Hammel, P. Chris

2018-06-01

Ferromagnetic resonance driven spin pumping, a topic of steadily increasing interest since its emergence over two decades ago, remains one of the most exciting research fields in condensed matter physics. Among the many materials that have been explored for spin pumping, yttrium iron garnet (YIG) is one of the most extensively studied because of its exceptionally low magnetic damping and insulating nature. There is a great amount of literature in the spin pumping and related research fields, too broad for this review to cover. In this Topical Review, we focus on the YIG-based spin pumping results carried out by our groups, including: the mechanism and technical details of our off-axis sputtering technique for the growth of single-crystalline YIG epitaxial films with a high degree ordering, experimental evidence for the high quality of the YIG films, spin pumping results from YIG into various transition metals and their heterostructures, dynamic spin transport in YIG/antiferromagnet hybrid structures, intralayer spin pumping by localized spin wave modes confined by a micromagnetic probe, dynamic spin coupling between YIG and nitrogen-vacancy centers in diamond, parametric spin pumping from high-wavevector spin waves in YIG, and localized spin wave mode behavior in broadly tunable spatially complex magnetic configurations. These results build on the power and versatility of YIG spin pumping to improve our understanding of spin dynamics, spin currents, spin Hall physics, spin–orbit coupling, dynamic magnetic coupling, and the relationship between these phenomena in a broad range of materials, geometries, and settings.

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

PubMed

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 < 0.001) and remained elevated up to 6 hours after surgery. It rapidly declined again by 18 hours postoperatively. The observed increase in the pulmonary lactate release (PLR) from a baseline value of 0.022 [range -0.074 to 0.066] to 0.089 [range 0.016 to 0.209] mmol/min/m2 at six hours postoperatively did not reach statistical significance (P = 0.105). The systemic arterial lactate (Ls) concentration increased from 0.94 [range 0.78 to 1.06] to 1.39 [range 0.97 to 2.81] mmol/L (P < 0.001). The venoarterial pCO2 difference showed no significant change in comparison to baseline values. The mortality in the studied group was 2.5% (1/40). The pulmonary lactate production showed a statistically significant correlation with the systemic lactate concentration (R = 0.46; P = 0.003). Pulmonary injury following off 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.

Effect of Impeller Geometry on Lift-Off Characteristics and Rotational Attitude in a Monopivot Centrifugal Blood Pump.

PubMed

Nishida, Masahiro; Nakayama, Kento; Sakota, Daisuke; Kosaka, Ryo; Maruyama, Osamu; Kawaguchi, Yasuo; Kuwana, Katsuyuki; Yamane, Takashi

2016-06-01

The effect of the flow path geometry of the impeller on the lift-off and tilt of the rotational axis of the impeller against the hydrodynamic force was investigated in a centrifugal blood pump with an impeller supported by a single-contact pivot bearing. Four types of impeller were compared: the FR model with the flow path having both front and rear cutouts on the tip, the F model with the flow path having only a front cutout, the R model with only a rear cutout, and the N model with a straight flow path. First, the axial thrust and the movement about the pivot point, which was loaded on the surface of the impeller, were calculated using computational fluid dynamics (CFD) analysis. Next, the lift-off point and the tilt of the rotational axis of the impeller were measured experimentally. The CFD analysis showed that the axial thrust increased gently in the FR and R models as the flow rate increased, whereas it increased drastically in the F and N models. This difference in axial thrust was likely from the higher pressure caused by the smaller circumferential velocity in the gap between the top surface of the impeller and the casing in the FR and R models than in the F and N models, which was caused by the rear cutout. These results corresponded with the experimental results showing that the impellers lifted off in the F and N models as the flow rate increased, whereas it did not in the FR and R models. Conversely, the movement about the pivot point increased in the direction opposite the side with the pump outlet as the flow rate increased. However, the tilt of the rotational axis of the impeller, which oriented away from the pump outlet, was less than 0.8° in any model under any conditions, and was considered to negligibly affect the rotational attitude of the impeller. These results confirm that a rear cutout prevents lift-off of the impeller caused by a decrease in the axial thrust. © 2016 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

Spill-Detector-and-Shutoff Device

NASA Technical Reports Server (NTRS)

Jarvis, M. R.; Fulton, D. S.

1985-01-01

Overflow in liquid chromatography systems rapidly detected and stopped. Spill-detector-and-shutoff device incorporated into liquid-chromatography system. When liquid from output nozzle spills on liquid sensor, device automatically shuts off pump and releases solenoid to pinch off flow in tube. Device uses common type of alarm circuit reset manually before normal operation resumes.

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

NASA Astrophysics Data System (ADS)

Greenberg, Joel A.; Gauthier, Daniel J.

2012-07-01

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

Theoretical and experimental study of a laser-diode-pumped actively Q-switched Yb:NaY(WO4)2 laser with acoustic-optic modulator

NASA Astrophysics Data System (ADS)

Zhang, Haikun; Xia, Wei; Song, Peng; Wang, Jing; Li, Xin

2018-03-01

A laser-diode-pumped actively Q-switched Yb:NaY(WO4)2 laser operating at around 1040 nm is presented for the first time with acoustic-optic modulator. The dependence of pulse width on incident pump power for different pulse repetition rates is measured. By considering the Guassian spatial distribution of the intracavity photon density and the initial population-inversion density as well as the longitudinal distribution of the photon density along the cavity axis and the turn off time of the acoustic-optic Q-switch, the coupled equations of the actively Q-switched Yb:NaY(WO4)2 laser are given. The coupled rate equations are used to simulate the Q-switched process of laser, and the numerical solutions agree with the experimental results.

Pulsed and cw laser oscillations in LiF:F-2 color center crystal under laser diode pumping.

PubMed

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 systemic factor: the comparative roles of cardiopulmonary bypass and off-pump surgery in the genesis of patient injury during and following cardiac surgery.

PubMed

Menasché, P

2001-12-01

There is compelling evidence that off-pump coronary artery bypass operations are associated with reduced circulating levels of inflammatory mediators. Whereas complement activation and release of acute-phase reactants such as interleukin-6 are still expected to occur as consequences of a nonbypass-related general surgical trauma, a major feature of off-pump surgery seems to be a decreased production of interleukin-8, which may have important practical implications because of the participation of this cytokine in neutrophil trafficking and myocardial injury. The scarcity of carefully controlled, randomized trials precludes firm conclusions regarding the extent to which these biological changes translate into meaningful improvements in clinical outcomes. The problem is further complicated by the fact that the adverse effects of cardiopulmonary bypass largely depend on a genetically controlled balance between proinflammatory and antiinflammatory mediators. Currently, it is still impossible to predict, in a given patient, the side toward which this balance will be shifted. Nevertheless, accumulating experience identifies patient subgroups who may greatly benefit from avoiding extracorporeal circulation. These subsets include patients with severe extracardiac comorbidities (in particular, renal failure) and, possibly, patients with advanced left ventricular dysfunction, who may poorly tolerate superimposed, bypass-related, inflammatory tissue injuries.

Off-pump coronary artery bypass grafting. The 1st Medical Faculty of Charles University study.

PubMed

Semrád, M; Bodlák, P; Stríteský, M; Kristof, J; Lindner, J; Urban, T; Vondrácek, V; Vanĕk, I

2002-01-01

To explore the surgical technique, anaesthesiological management, immediate and mid-term results, graft patency and effectiveness of less invasive coronary artery bypass grafting through a median sternotomy. From January 1998 through December 1999, 144 patients had coronary artery bypass grafting (CABG) without cardiopulmonary bypass (CPB) done by one surgeon through a median sternotomy. The cohort of 107 men and 37 women averaged 60.8 years, mean ejection fraction (EF) was 51.8%. An average of 2.7 (range 1 to 5) grafts/patients was achieved. Results are compared with a CPB subgroup of patients operated on through a median sternotomy in the same time (N = 234). In a random subgroup of 100 patients (50 per group) an angiographic control of graft patency was done. A non-CPB group showed less postoperative acute myocardial infarction (0.7% vs. 3.8%, p < 0.05) and atrial fibrillation (14.6% vs. 26%, p < 0.05), lower incidence of renal (2.8% vs. 5.1%, p < 0.05) and respiratory complications (2.0% vs. 3.8%, NS). We observed lower operative mortality (0.7% vs. 3.4%, p < 0.05), as well as the occurrence of low cardiac output syndrome (0.7% vs. 5.6%, p < 0.05) in the off-pump group. The follow-up is 36 +/- 12 months and the number of patients with recurrent angina, late AMI and late death is acceptable. We did not find an inordinate number of vein grafts occlusions (0.7% vs. 1.8%, NS) and stenoses (6.6% vs. 6.7%, NS) at anastomotic sites. None of the arterial grafts in both groups were occluded. There was little known about the efficacy of the less invasive coronary artery bypass grafting at the beginning of our study. Starting with pioneering the operative technique, we have discovered and proposed three types of a heart verticalization and a reusable stabilizing device. We detected lower incidence of postoperative complications and decreased operative mortality in a non-CPB group. Angiographic assessment displayed an excellent run-off in both groups of patients. Off-pump coronary bypass grafting is associated with sufficient short-term graft patency and mid-term clinical outcomes.

Off-Pump Versus On-Pump Coronary Artery Bypass Grafting-A Systematic Review and Analysis of Clinical Outcomes.

PubMed

Shaefi, Shahzad; Mittel, Aaron; Loberman, Dan; Ramakrishna, Harish

2018-04-04

Surgical coronary artery bypass grafting (CABG) is the standard of care for revascularization of left main or three-vessel coronary artery disease. The off-pump coronary artery bypass graft (OPCAB) procedure avoids the use of cardiopulmonary bypass. Theoretically, OPCAB may improve long-term outcomes by reducing the rates of perioperative myocardial injury, stroke, neurocognitive impairment, and cardiac-related mortality. Several high-quality clinical trials have been conducted since OPCAB became popular in the 1990s and have demonstrated no benefit of OPCAB over traditional CABG with respect to these outcomes despite favorable short-term reductions in transfusion requirements and other postoperative complications. Ultimately, OPCAB is associated with less effective myocardial revascularization and does not entirely prevent complications traditionally associated with cardiopulmonary bypass. This article reviews major high-quality trials of OPCAB versus traditional CABG with respect to both short- and long-term clinical outcomes. Copyright © 2018 Elsevier Inc. All rights reserved.

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

PubMed

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.

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

NASA Astrophysics Data System (ADS)

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

2012-11-01

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.

Physiological uncoupling of mitochondrial oxidative phosphorylation. Studies in different yeast species.

PubMed

Guerrero-Castillo, Sergio; Araiza-Olivera, Daniela; Cabrera-Orefice, Alfredo; Espinasa-Jaramillo, Juan; Gutiérrez-Aguilar, Manuel; Luévano-Martínez, Luís A; Zepeda-Bastida, Armando; Uribe-Carvajal, Salvador

2011-06-01

Under non-phosphorylating conditions a high proton transmembrane gradient inhibits the rate of oxygen consumption mediated by the mitochondrial respiratory chain (state IV). Slow electron transit leads to production of reactive oxygen species (ROS) capable of participating in deleterious side reactions. In order to avoid overproducing ROS, mitochondria maintain a high rate of O(2) consumption by activating different exquisitely controlled uncoupling pathways. Different yeast species possess one or more uncoupling systems that work through one of two possible mechanisms: i) Proton sinks and ii) Non-pumping redox enzymes. Proton sinks are exemplified by mitochondrial unspecific channels (MUC) and by uncoupling proteins (UCP). Saccharomyces. cerevisiae and Debaryomyces hansenii express highly regulated MUCs. Also, a UCP was described in Yarrowia lipolytica which promotes uncoupled O(2) consumption. Non-pumping alternative oxido-reductases may substitute for a pump, as in S. cerevisiae or may coexist with a complete set of pumps as in the branched respiratory chains from Y. lipolytica or D. hansenii. In addition, pumps may suffer intrinsic uncoupling (slipping). Promising models for study are unicellular parasites which can turn off their aerobic metabolism completely. The variety of energy dissipating systems in eukaryote species is probably designed to control ROS production in the different environments where each species lives.

Engineering microbial biofuel tolerance and export using efflux pumps

PubMed Central

Dunlop, Mary J; Dossani, Zain Y; Szmidt, Heather L; Chu, Hou Cheng; Lee, Taek Soon; Keasling, Jay D; Hadi, Masood Z; Mukhopadhyay, Aindrila

2011-01-01

Many compounds being considered as candidates for advanced biofuels are toxic to microorganisms. This introduces an undesirable trade-off when engineering metabolic pathways for biofuel production because the engineered microbes must balance production against survival. Cellular export systems, such as efflux pumps, provide a direct mechanism for reducing biofuel toxicity. To identify novel biofuel pumps, we used bioinformatics to generate a list of all efflux pumps from sequenced bacterial genomes and prioritized a subset of targets for cloning. The resulting library of 43 pumps was heterologously expressed in Escherichia coli, where we tested it against seven representative biofuels. By using a competitive growth assay, we efficiently distinguished pumps that improved survival. For two of the fuels (n-butanol and isopentanol), none of the pumps improved tolerance. For all other fuels, we identified pumps that restored growth in the presence of biofuel. We then tested a beneficial pump directly in a production strain and demonstrated that it improved biofuel yields. Our findings introduce new tools for engineering production strains and utilize the increasingly large database of sequenced genomes. PMID:21556065

Effectiveness of an influenza vaccine used in Poland in the 1998-1999 influenza season.

PubMed

Banzhoff, A; Kaniok, W; Muszer, A

2001-05-01

The aim of this study was to evaluate the effectiveness of the influenza vaccine used at the Proelmed Medical Center, Poland during the influenza season 1998-1999. The study randomised patients attending the Proelmed Medical Center, Poland to receive influenza vaccination or not. Volunteers were monitored for the following 6 months by interviews at which systemic and local symptoms were recorded. 193 volunteers were randomised to receive influenza vaccine and 206 to the control group. In the vaccinated group, 7 cases (3.7%) of influenza were recorded, compared to 59 cases (28.6%) in the unvaccinated group. Respiratory disease other than influenza occurred in 29.5% of the vaccinated group and 34.5% of the unvaccinated group. Vaccinated patients had a total of 62 days off sick due to influenza, compared to 467 days for the unvaccinated patients. No unexpected adverse events were reported. The influenza vaccine used is highly efficacious in protecting against influenza infection leading to absenteeism from work, and has a good safety profile.

Mechanical ventilation and thoracic artificial lung assistance during mechanical circulatory support with PUCA pump: in silico study.

PubMed

De Lazzari, Claudio; Genuini, Igino; Quatember, Bernhard; Fedele, Francesco

2014-02-01

Patients assisted with left ventricular assist device (LVAD) may require prolonged mechanical ventilatory assistance secondary to postoperative respiratory failure. The goal of this work is the study of the interdependent effects LVAD like pulsatile catheter (PUCA) pump and mechanical ventilatory support or thoracic artificial lung (TAL), by the hemodynamic point of view, using a numerical simulator of the human cardiovascular system. In the simulator, different circulatory sections are described using lumped parameter models. Lumped parameter models have been designed to describe the hydrodynamic behavior of both PUCA pump and thoracic artificial lung. Ventricular behavior atrial and septum functions were reproduced using variable elastance model. Starting from simulated pathological conditions we studied the effects produced on some hemodynamic variables by simultaneous PUCA pump, thoracic artificial lung or mechanical ventilation assistance. Thoracic artificial lung was applied in parallel or in hybrid mode. The effects of mechanical ventilation have been simulated by changing mean intrathoracic pressure value from -4 mmHg to +5 mmHg. The hemodynamic variables observed during the simulations, in different assisted conditions, were: left and right ventricular end systolic (diastolic) volume, systolic/diastolic aortic pressure, mean pulmonary arterial pressure, left and right mean atrial pressure, mean systemic venous pressure and the total blood flow. Results show that the application of PUCA (without mechanical ventilatory assistance) increases the total blood flow, reduces the left ventricular end systolic volume and increases the diastolic aortic pressure. Parallel TAL assistance increases the right ventricular end diastolic (systolic) volume reduction both when PUCA is switched "ON" and both when PUCA is switched "OFF". By switching "OFF" the PUCA pump, it seems that parallel thoracic artificial lung assistance produces a greater cardiac output (respect to hybrid TAL assistance). Results concerning PUCA and TAL interaction produced by simulations cannot be compared with "in vivo" results since they are not presented in literature. But results concerning the effects produced by LVAD and mechanical ventilation have a trend consistent with those presented in literature. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Disposable magnetically levitated centrifugal blood pump: design and in vitro performance.

PubMed

Hoshi, Hideo; Asama, Junichi; Shinshi, Tadahiko; Ohuchi, Katsuhiro; Nakamura, Makoto; Mizuno, Tomohiro; Arai, Hirokuni; Shimokohbe, Akira; Takatani, Setsuo

2005-07-01

A magnetically levitated (MagLev) centrifugal blood pump (CBP) with a disposable pump head has been designed to realize a safe, easy-to-handle, reliable, and low-cost extracorporeal blood pump system. It consisted of a radial magnetic-coupled driver with a magnetic bearing having a two-degree freedom control and a disposable pump head unit with a priming volume of 24 mL. The easy on-off disposable pump head unit was made into a three-piece system consisting of the top and bottom housings, and the impeller-rotor assembly. The size and weight of the disposable pump unit were 75 mm x 45 mm and 100 g, respectively. Because the structure of the pump head unit is easily attachable and removable, the gap between the electromagnets of the stator and the target material in the rotor increased to 1.8 mm in comparison to the original integrated bearing system of 1.0 mm. The pump performance, power requirements, and controllability of the magnetic bearing revealed that from 1400 to 2400 rpm, the pump performance remained fairly unchanged. The amplitudes of the X- and Y-axis rotor oscillation increased to +/- 24 microm. The axial displacement of the rotor, 0.4 mm, toward the top housing was also observed at the pump rpm between 1400 and 2400. The axial and rotational stiffness of the bearing were 15.9 N/mm and 4.4 Nm/rad, respectively. The MagLev power was within 0.7 Watts. This study demonstrated the feasibility of a disposable, magnetically suspended CBP as the safe, reliable, easy-to-handle, low-cost extracorporeal circulation support device.

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.

PubMed

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.

A randomized controlled trial of the Arctic Sun Temperature Management System versus conventional methods for preventing hypothermia during off-pump cardiac surgery.

PubMed

Grocott, Hilary P; Mathew, Joseph P; Carver, Elizabeth H; Phillips-Bute, Barbara; Landolfo, Kevin P; Newman, Mark F

2004-02-01

In this trial we compared the hypothermia avoidance abilities of the Arctic Sun Temperature Management System (a servo-regulated system that circulates temperature-controlled water through unique energy transfer pads adherent to the patient's body) with conventional temperature control methods. Patients undergoing off-pump coronary artery bypass (OPCAB) surgery were randomized to either the Arctic Sun System alone (AS group) or conventional methods (control group; increased room temperature, heated IV fluids, convective forced air warming system) for the prevention of hypothermia (defined by a temperature <36 degrees C). The AS group had nasopharyngeal temperature servo-regulated to a target of 36.8 degrees C. Temperature was recorded throughout the operative period and comparisons were made between groups for both the time and area under the curve (AUC) for a temperature <36 degrees C (AUC<36 degrees C). Twenty-nine patients (AS group = 14, control group = 15) were studied. The AS group had significantly less hypothermia than the control group, both for duration of time <36 degrees C (2.5 [0-22] min, median [interquartile range] AS group versus 118 [49-192] min, control group; P = 0.0008) as well as for AUC<36 degrees C (0.3 [0-2.2] degrees C x min, AS group versus 17.1 [3.6-173.4] degrees C x min, control group; P = 0.002). The Arctic Sun Temperature Management System significantly reduced intraoperative hypothermia during OPCAB surgery. Importantly, this was achieved in the absence of any other temperature modulating techniques, including the use of IV fluid warming or increases in the ambient operating room temperature. The Arctic Sun Temperature Management System was more effective than conventional methods in preventing hypothermia during off-pump coronary artery bypass graft surgery.

Lubricating Oil Burn-Off in Coast Guard Power Plants

DTIC Science & Technology

1975-02-01

of the in-line fuel filters and wear of the fuel pumps . The overwhelming majority of tests performed by others in L• lube oil burn-off programs...February 1975 IAJBRICATING OIL BURN-OFF IN 6. perfarming Organization Code COAST GUARD POWER PLANTS ___________A. Performing Organization Report No. 7...Authorls) J.R. Hobbs and R. A. WalterDOTC-JC76 9. Performing Organization Name and Address 10. Work Unit No. (TRAIS) U.S. Department of Transportation

Representing pump-capacity relations in groundwater simulation models

USGS Publications Warehouse

Konikow, Leonard F.

2010-01-01

The yield (or discharge) of constant-speed pumps varies with the total dynamic head (or lift) against which the pump is discharging. The variation in yield over the operating range of the pump may be substantial. In groundwater simulations that are used for management evaluations or other purposes, where predictive accuracy depends on the reliability of future discharge estimates, model reliability may be enhanced by including the effects of head-capacity (or pump-capacity) relations on the discharge from the well. A relatively simple algorithm has been incorporated into the widely used MODFLOW groundwater flow model that allows a model user to specify head-capacity curves. The algorithm causes the model to automatically adjust the pumping rate each time step to account for the effect of drawdown in the cell and changing lift, and will shut the pump off if lift exceeds a critical value. The algorithm is available as part of a new multinode well package (MNW2) for MODFLOW.

Representing pump-capacity relations in groundwater simulati on models

USGS Publications Warehouse

Konikow, Leonard F.

2010-01-01

The yield (or discharge) of constant-speed pumps varies with the total dynamic head (or lift) against which the pump is discharging. The variation in yield over the operating range of the pump may be substantial. In groundwater simulations that are used for management evaluations or other purposes, where predictive accuracy depends on the reliability of future discharge estimates, model reliability may be enhanced by including the effects of head-capacity (or pump-capacity) relations on the discharge from the well. A relatively simple algorithm has been incorporated into the widely used MODFLOW groundwater flow model that allows a model user to specify head-capacity curves. The algorithm causes the model to automatically adjust the pumping rate each time step to account for the effect of drawdown in the cell and changing lift, and will shut the pump off if lift exceeds a critical value. The algorithm is available as part of a new multinode well package (MNW2) for MODFLOW. ?? 2009 National Ground Water Association.

Theoretical and experimental analysis of a multiphase screw pump, handling gas-liquid mixtures with very high gas volume fractions

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

Raebiger, K.; Faculty of Advanced Technology, University of Glamorgan, Pontypridd, Wales; Maksoud, T.M.A.

In the investigation of the pumping behaviour of multiphase screw pumps, handling gas-liquid mixtures with very high gas volume fractions, theoretical and experimental analyses were performed. A new theoretical screw pump model was developed, which calculates the time-dependent conditions inside the several chambers of a screw pump as well as the exchange of mass and energy between these chambers. By means of the performed experimental analysis, the screw pump model was verified, especially at very high gas volume fractions from 90% to 99%. The experiments, which were conducted with the reference fluids water and air, can be divided mainly intomore » the determination of the steady state pumping behaviour on the one hand and into the analysis of selected transient operating conditions on the other hand, whereas the visualisation of the leakage flows through the circumferential gaps was rounded off the experimental analysis. (author)« less

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

NASA Astrophysics Data System (ADS)

Zhang, L.

2017-02-01

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

Simulation of the ground-water flow system at Naval Submarine Base Bangor and vicinity, Kitsap County, Washington

USGS Publications Warehouse

Heeswijk, Marijke van; Smith, Daniel T.

2002-01-01

An evaluation of the interaction between ground-water flow on Naval Submarine Base Bangor and the regional-flow system shows that for selected alternatives of future ground-water pumping on and near the base, the risk is low that significant concentrations of on-base ground-water contamination will reach off-base public-supply wells and hypothetical wells southwest of the base. The risk is low even if worst-case conditions are considered ? no containment and remediation of on-base contamination. The evaluation also shows that future saltwater encroachment of aquifers below sea level may be possible, but this determination has considerable uncertainty associated with it. The potential effects on the ground-water flow system resulting from four hypothetical ground-water pumping alternatives were considered, including no change in 1995 pumping rates, doubling the rates, and 2020 rates estimated from population projections with two different pumping distributions. All but a continuation of 1995 pumping rates demonstrate the possibility of future saltwater encroachment in the Sea-level aquifer on Naval Submarine Base Bangor. The amount of time it would take for encroachment to occur is unknown. For all pumping alternatives, future saltwater encroachment in the Sea-level aquifer also may be possible along Puget Sound east and southeast of the base. Future saltwater encroachment in the Deep aquifer also may be possible throughout large parts of the study area. Projections of saltwater encroachment are least certain outside the boundaries of Naval Submarine Base Bangor. The potential effects of the ground-water pumping alternatives were evaluated by simulating the ground-water flow system with a three-dimensional uniform-density ground-water flow model. The model was calibrated by trial-and-error by minimizing differences between simulated and measured or estimated variables. These included water levels from prior to January 17, 1977 (termed 'predevelopment'), water-level drawdowns since predevelopment until April 15, 1995, ground-water discharge to streams in water year 1995, and residence times of ground water in different parts of the flow system that were estimated in a separate but related study. Large amounts of ground water were pumped from 1977 through 1980 from the Sea-level aquifer on Naval Submarine Base Bangor to enable the construction of an off-shore drydock. Records of the flow-system responses to the applied stresses were used to help calibrate the model. Errors in the calibrated model were significant. The poor agreement between simulated and measured values could be improved by making many local changes to hydraulic parameters but these changes were not supported by other data. Model errors may have resulted in errors in the simulated effects of ground-water pumping alternatives.

Impact of Spatial Pumping Patterns on Groundwater Management

NASA Astrophysics Data System (ADS)

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.

Ring-Down Spectroscopy for Characterizing a CW Raman Laser

NASA Technical Reports Server (NTRS)

Matsko, Andrey; Savchenkov, Anatoliy; Maleki, Lute

2007-01-01

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

Biventricular support with the Jarvik 2000 axial flow pump: a feasibility study.

PubMed

Radovancevic, Branislav; Gregoric, Igor D; Tamez, Daniel; Vrtovec, Bojan; Tuzun, Egemen; Chee, Hyun Keun; Moore, Sheila; Jarvik, Robert K; Frazier, O H

2003-01-01

Patients with congestive heart failure who are supported with a left ventricular assist device (LVAD) may experience right ventricular dysfunction or failure that requires support with a right ventricular assist device (RVAD). To determine the feasibility of using a clinically available axial flow ventricular assist device as an RVAD, we implanted Jarvik 2000 pumps in the left ventricle and right atrium of two Corriente crossbred calves (approximately 100 kg each) by way of a left thoracotomy and then analyzed the hemodynamic effects in the mechanically fibrillated heart at various LVAD and RVAD speeds. Right atrial implantation of the device required no modification of either the device or the surgical technique used for left ventricular implantation. Satisfactory biventricular support was achieved during fibrillation as evidenced by an increase in mean aortic pressure from 34 mm Hg with the pumps off to 78 mm Hg with the pumps generating a flow rate of 4.8 L/min. These results indicate that the Jarvik 2000 pump, which can provide chronic circulatory support and can be powered by external batteries, is a feasible option for right ventricular support after LVAD implantation and is capable of completely supporting the circulation in patients with global heart failure.

Phase analysis of coherent radial-breathing-mode phonons in carbon nanotubes: Implications for generation and detection processes

NASA Astrophysics Data System (ADS)

Shimura, Akihiko; Yanagi, Kazuhiro; Yoshizawa, Masayuki

2018-01-01

In time-resolved pump-probe spectroscopy of carbon nanotubes, the fundamental understanding of the optical generation and detection processes of radial-breathing-mode (RBM) phonons has been inconsistent among the previous reports. In this study, the tunable-pumping/broadband-probing scheme was used to fully reveal the amplitude and phase of the phonon-modulated signals. We observed that signals detected off resonantly to excitonic transitions are delayed by π /2 radians with respect to resonantly detected signals, which demonstrates that RBM phonons are detected through dynamically modulating the linear response, not through adiabatically modulating the light absorption. Furthermore, we found that the initial phases are independent of the pump detuning across the first (E11) and the second (E22) excitonic resonances, evidencing that the RBM phonons are generated by the displacive excitation rather than stimulated Raman process.

User oriented end-station on VUV pump-probe magneto-optical ellipsometry at ELI beamlines

NASA Astrophysics Data System (ADS)

Espinoza, Shirly; Neuber, Gerd; Brooks, Christopher D.; Besner, Bastian; Hashemi, Maryam; Rübhausen, Michael; Andreasson, Jakob

2017-11-01

A state of the art ellipsometer for user operations is being implemented at ELI Beamlines in Prague, Czech Republic. It combines three of the most promising and exotic forms of ellipsometry: VUV, pump-probe and magneto-optical ellipsometry. This new ellipsometer covers a spectral operational range from the NIR up to the VUV, with high through-put between 1 and 40 eV. The ellipsometer also allows measurements of magneto-optical spectra with a 1 kHz switchable magnetic field of up to 1.5 T across the sample combining ellipsometry and Kerr spectroscopy measurements in an unprecedented spectral range. This form of generalized ellipsometry enables users to address diagonal and off-diagonal components of the dielectric tensor within one measurement. Pump-probe measurements enable users to study the dynamic behaviour of the dielectric tensor in order to resolve the time-domain phenomena in the femto to 100 ns range.

A Secure and High-Fidelity Live Animal Model for Off-Pump Coronary Bypass Surgery Training.

PubMed

Liu, Xiaopeng; Yang, Yan; Meng, Qiang; Sun, Jiakang; Luo, Fuliang; Cui, Yongchun; Zhang, Hong; Zhang, Dong; Tang, Yue

2016-01-01

Existing simulators for off-pump coronary artery (CA) bypass grafting training are unable to provide cardiac surgery residents all necessary skills they need entering the operation room. In this study, we introduced a secure and high-fidelity live animal model to supplement the in vitro simulators for off-pump CA bypass grafting training. The left internal thoracic artery (ITA) of 3 Chinese miniature pigs was grafted to the left anterior descending CA using an end-to-side anastomosis. The free segment of the ITA was fixed on the ventricle surface, making it a simulative CA beating in synchrony with the heart. A total of 6 to 8 training anastomoses were made on each ITA. Animal Experiment Center in Fuwai Hospital. In total, 19 resident surgeons with at least 3 years of cardiac surgery work experience were trained using the new model. Their performances were recorded and reviewed. Simulative coronary arteries were successfully constructed in all 3 animals with no adverse event observed. A total of 19 anastomoses were then completed, 1 pig of 7 anastomoses and the other 2 animals of 6 anastomoses. Time consumption for the anastomosis was 782 ± 107 seconds. Anastomotic leakage was observed in 10/19 procedures. The most frequency site (7/10) was at the toe of the anastomosis. Further, the most common cause was uneven spacing or small margin of the stitches or both. Emergencies occurred during the training process included hypotension (7 procedures), tachyarrhythmia (4 procedures), and low blood oxygen saturation (1 procedure). This study demonstrated the safety and feasibility of our new live pig model in training resident surgeons. The simulative arteries can be easily accomplished and were long enough to place at least 6 anastomoses. Both on lumen diameter and motion status, they were proven to be a good substitution of the CA. Copyright © 2016. Published by Elsevier Inc.

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

PubMed

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.

Less invasive coronary artery revascularization with a minimized extracorporeal circulation system: preliminary results of a comparative study with off-pump-procedures

PubMed Central

2013-01-01

Background Coronary-artery-bypass-grafting (CABG) with conventional extracorporeal circulation (CECC) is associated with adverse effects such as systemic inflammatory response leading to a decrease in systemic vascular resistance and hemodynamic instability. Modern "less invasive" procedures have been established recently which potentially avoid negative side effects of CECC. The aim of this study was to compare perioperative outcome following coronary revascularization using either a minimized extracorporeal circuit (Mini-HLM) or off-pump technique (OPCAB). Methods In this prospective ethics-approved trial, 120 patients referred for CABG were randomly assigned either to off-pump coronary artery bypass (OPCAB) or to a Mini-HLM procedure. Patient demographics, preoperative characteristics and extensive postoperative outcome were analyzed for both groups. Hemodynamic data were measured at seven time points perioperatively. Results Operation-time was longer in the Mini-HLM group (178,3 ± 32,9 min) compared to OPCAB (133,2 ± 32,7 min, p < 0,001) with higher graft numbers in Mini-HLM group (3,11 ± 0,7 vs. 1,78 ± 0,7, p < 0.001). There were no significant differences in perioperative hemodynamic criteria, catecholaminergic support, hospital (p = 0,534) and intensive care unit stay (p = 0,880), ventilation time (p = 0,113), blood loss (p = 0,570), transfusion requirements, postoperative atrial fibrillation rate (p = 0,706) and neurocognitive disturbance (p = 0,297). No deaths and no myocardial infarctions were observed. Conclusions Coronary revascularisation with Mini-HLM represents a suitable and "less invasive" procedure which achieves all benefits of OPCAB but may allow for less demanding revascularisation than OPCAB in special patients with complex coronary anatomy and can therefore be used both on a routine basis and in all "conversion" cases of OPCAB. PMID:23577663

Hydrogen-Fuel Engine Component Tests Near Completion

NASA Technical Reports Server (NTRS)

2003-01-01

Gaseous hydrogen is burned off at the E1 Test Stand the night of Oct. 7 during a cold-flow test of the fuel turbopump of the Integrated Powerhead Demonstrator (IPD) at NASA Stennis Space Center (SSC). The gaseous hydrogen spins the pump's turbine during the test, which was conducted to verify the pump's performance. Engineers plan one more test before sending the pump to The Boeing Co. for inspection. It will then be returned to SSC for engine system assembly. The IPD is the first reusable hydrogen-fueled advanced engine in development since the Space Shuttle Main Engine.

Hydrogen-Fuel Engine Component Tests Near Completion

NASA Image and Video Library

2003-11-05

Gaseous hydrogen is burned off at the E1 Test Stand the night of Oct. 7 during a cold-flow test of the fuel turbopump of the Integrated Powerhead Demonstrator (IPD) at NASA Stennis Space Center (SSC). The gaseous hydrogen spins the pump's turbine during the test, which was conducted to verify the pump's performance. Engineers plan one more test before sending the pump to The Boeing Co. for inspection. It will then be returned to SSC for engine system assembly. The IPD is the first reusable hydrogen-fueled advanced engine in development since the Space Shuttle Main Engine.

Laser Diode Pumped Solid State Lasers

DTIC Science & Technology

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

Heart bypass surgery

MedlinePlus

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

Effects of glargine insulin on glycemic control in patients with diabetes mellitus type II undergoing off-pump coronary artery bypass graft.

PubMed

Gandhi, Hemang; Sarvaia, Alpesh; Malhotra, Amber; Acharya, Himanshu; Shah, Komal; Rajavat, Jeevraj

2018-01-01

The prevalence of diabetes mellitus in patients requiring coronary artery bypass grafting (CABG) is noticeably high (20%-30%). These patients have inferior perioperative outcome, reduced long-term survival, and high risk of recurrent episodes of angina. To improve perioperative outcome surgical unit defined satisfactory glycemic control is desired during this period. Hence, the aim of our study is to compare the efficacy of glargine insulin combination with continuous human insulin infusion for perioperative glycemic control in patients with diabetes undergoing CABG. Fifty Patients, who were posted for off-pump CABG with diabetes mellitus type II, were randomized in two group, Group I normal saline + human insulin infusion during the perioperative period, Group II (glargine group): Glargine + human insulin infusion during perioperative period. During surgery and in the postoperative period, random blood sugar and human insulin requirement are significantly higher in control group than glargine group. Other infection, step-up antibiotics, intensive care unit (ICU) stay, and hospital stay were significantly higher in control groups in postoperative period. Our study results suggest that glargine effectively manages blood glucose level with significantly greater control over postoperative morbidity.

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

NASA Astrophysics Data System (ADS)

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.

Development of stable, narrow spectral line-width, fiber delivered laser source for spin exchange optical pumping

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

Liu, Bo; Tong, Xin; Jiang, Chenyang

2015-06-05

In this study, we developed a stable, narrow spectral line-width, fiber delivered laser source for spin exchange optical pumping. An optimized external cavity equipped with an off-the-shelf volume holographic grating narrowed the spectral line-width of a 100 W high-power diode laser and stabilized the laser spectrum. The laser spectrum showed a high side mode suppression ratio of >30 dB and good long-term stability (center wavelength drifting within ±0.002 nm during 220 h of operation). Finally, our laser is delivered by a multimode fiber with power ~70 W, center wavelength of 794.77 nm, and spectral bandwidth of ~0.12 nm.

Reduction in duration of hypoglycemia by automatic suspension of insulin delivery: the in-clinic ASPIRE study.

PubMed

Garg, Satish; Brazg, Ronald L; Bailey, Timothy S; Buckingham, Bruce A; Slover, Robert H; Klonoff, David C; Shin, John; Welsh, John B; Kaufman, Francine R

2012-03-01

The efficacy of automatic suspension of insulin delivery in induced hypoglycemia among subjects with type 1 diabetes was evaluated. In this randomized crossover study, subjects used a sensor-augmented insulin pump system with a low glucose suspend (LGS) feature that automatically stops insulin delivery for 2 h following a sensor glucose (SG) value ≤70 mg/dL. Subjects fasted overnight and exercised until their plasma glucose (measured with the YSI 2300 STAT Plus™ glucose and lactate analyzer [YSI Life Sciences, Yellow Springs, OH]) value reached ≤85 mg/dL on different occasions separated by washout periods lasting 3-10 days. Exercise sessions were done with the LGS feature turned on (LGS-On) or with continued insulin delivery regardless of SG value (LGS-Off). The order of LGS-On and LGS-Off sessions was randomly assigned. YSI glucose data were used to compare the duration and severity of hypoglycemia from successful LGS-On and LGS-Off sessions and to estimate the risk of rebound hyperglycemia after pump suspension. Fifty subjects attempted 134 sessions, 98 of which were successful. The mean±SD hypoglycemia duration was less during LGS-On than during LGS-Off sessions (138.5±76.68 vs. 170.7±75.91 min, P=0.006). During LGS-On compared with LGS-Off sessions, mean nadir YSI glucose was higher (59.5±5.72 vs. 57.6±5.69 mg/dL, P=0.015), as was mean end-observation YSI glucose (91.4±41.84 vs. 66.2±13.48 mg/dL, P<0.001). Most (53.2%) end-observation YSI glucose values in LGS-On sessions were in the 70-180 mg/dL range, and none was >250 mg/dL. Automatic suspension of insulin delivery significantly reduced the duration and severity of induced hypoglycemia without causing rebound hyperglycemia.

Impact of Prostatic-specific Antigen Threshold and Screening Interval in Prostate Cancer Screening Outcomes: Comparing the Swedish and Finnish European Randomised Study of Screening for Prostate Cancer Centres.

PubMed

Saarimäki, Lasse; Hugosson, Jonas; Tammela, Teuvo L; Carlsson, Sigrid; Talala, Kirsi; Auvinen, Anssi

2017-08-10

The European Randomised Study of Screening for Prostate Cancer trial has shown a 21% reduction in prostate cancer (PC) mortality with prostate-specific antigen (PSA)-based screening. Sweden used a 2-yr screening interval and showed a larger mortality reduction than Finland with a 4-yr interval and higher PSA cut-off. To evaluate the impact of screening interval and PSA cut-off on PC detection and mortality. We analysed the core age groups (55-69 yr at entry) of the Finnish (N=31 866) and Swedish (N=5901) screening arms at 13 yr and 16 yr of follow-up. Sweden used a screening interval of 2 yr and a PSA cut-off of 3.0ng/ml, while in Finland the screening interval was 4 yr and the PSA cut-off 4.0ng/ml (or PSA 3.0-3.9ng/ml with free PSA<16%). We compared PC detection rate and PC mortality between the Finnish and Swedish centres and estimated the impact of different screening protocols. If the Swedish screening protocol had been followed in Finland, 122 additional PC cases would have been diagnosed at screening, 84% of which would have been low-risk cancers, and four leading to PC death. In contrast, if a lower PSA threshold had been applied in Finland, at least 127 additional PC would have been found, with 19 PC deaths. The small number of deaths among cases that would have been potentially detectable in Finland with the Swedish protocol (or those that would have been missed in Sweden with the Finnish approach) is unlikely to explain the differences in mortality in this long of a follow-up. A prostate-specific antigen threshold of 3ng/ml versus 4ng/ml or a screening interval of 2 yr instead of 4 yr is unlikely to explain the larger mortality reduction achieved in Sweden compared with Finland. Copyright © 2017 European Association of Urology. Published by Elsevier B.V. All rights reserved.

A phase III, multi-centre, double-masked randomised controlled trial of adjunctive intraocular and peri-ocular steroid (triamcinolone acetonide) versus standard treatment in eyes undergoing vitreoretinal surgery for open globe trauma (ASCOT): statistical analysis plan.

PubMed

Lo, Jessica W; Bunce, Catey; Charteris, David; Banerjee, Philip; Phillips, Rachel; Cornelius, Victoria R

2016-08-02

Open globe ocular trauma complicated by intraocular scarring (proliferative vitreoretinopathy) is a relatively rare, blinding, but potentially treatable condition for which, at present, surgery is often unsatisfactory and visual results frequently poor. To date, no pharmacological adjuncts to surgery have been proven to be effective. The aim of the Adjunctive Steroid Combination in Ocular Trauma (ASCOT) randomised controlled trial is to determine whether adjunctive steroid (triamcinolone acetonide), given at the time of surgery, can improve the outcome of vitreoretinal surgery in patients with open globe ocular trauma. This article presents the statistical analysis plan for the main publication as approved and signed off by the Trial Steering Committee prior to the first data extraction for the Data Monitoring Committee meeting report. ASCOT is a pragmatic, multi-centre, parallel-group, double-masked randomised controlled trial. The aim of the study is to recruit from 20-25 centres in the United Kingdom and randomise 300 eyes (from 300 patients) into two treatment arms. Both groups will receive standard surgical treatment and care; the intervention arm will additionally receive a pre-operative steroid combination (triamcinolone acetonide) into the vitreous cavity consisting of 4 mg/0.1 ml and 40 mg/1 ml sub-Tenon's. Participants will be followed for 6 months post-surgery. The primary outcome is the proportion of patients achieving a clinically meaning improvement in visual acuity in the study eye at 6 months after initial surgery, defined as a 10 letter score improvement in the ETDRS (the standard scale to test visual acuity). ISRCTN30012492 . Registered on 5 September 2014. EudraCT2014-002193-37 . Registered on 5 September 2014.

A pilot effectiveness study of the Enhancing Parenting Skills (EPaS) 2014 programme for parents of children with behaviour problems: study protocol for a randomised controlled trial.

PubMed

Williams, Margiad Elen; Hutchings, Judy

2015-05-20

The Enhancing Parenting Skills (EPaS) 2014 programme is a home-based, health visitor-delivered parenting support programme for parents of children with identified behaviour problems. This trial aims to evaluate the effectiveness of the EPaS 2014 programme compared to a waiting-list treatment as usual control group. This is a pragmatic, multicentre randomised controlled trial. Sixty health visitors will each be asked to identify two families that have a child scoring above the clinical cut-off for behaviour problems using the Eyberg Child Behaviour Inventory (ECBI). Families recruited to the trial will be randomised in a 1:1 ratio into an intervention or waiting-list control group. Randomisation will occur within health visitor to ensure that each health visitor has one intervention family and one control family. The primary outcome is change in child behaviour problems as measured by the parent-reported ECBI. Secondary outcomes include other measures of child behaviour, parent behaviour, and parental depression as measured by parent-reports and an independent observation of parent and child behaviour. Follow-up measures will be collected 6-months after the collection of baseline measures. This is the first rigorous evaluation of the EPaS 2014 programme. The trial will provide important information on the effectiveness of a one-to-one home-based intervention, delivered by health visitors, for pre-school children with behaviour problems. It will also examine potential mediating (improved parent behaviour and/or improved parental depression) and moderating (single parent, teenage parent, poverty, low education level) factors. Current Controlled Trials ISRCTN06867279 (18 June 2014).

Brightness enhancement limits in pulsed cladding-pumped fiber Raman amplifiers

NASA Astrophysics Data System (ADS)

Ji, Junhua; Codemard, Christophe A.; Nilsson, Johan

2010-02-01

We analyze theoretically limitations on brightness enhancement of a multimode pump beam into a diffraction-limited Stokes beam in efficient cladding-pumped fiber Raman amplifiers. Firstly, the power-scaling of the 1st Stokes (hence the brightness enhancement) is limited by the generation of the 2nd order Stokes. Thus using a spectral waveguide filter such as a W-type fiber core, it is possible to improve this limit to nearly five times that of a normal fiber without spectral filter. Secondly, we analyze limits set by glass damage, propagation loss, and pump-signal pulse walk-off in the multimode fiber. We show that a well-designed fiber with a propagation loss of 3.5 dB/km allows for a pump-to-signal brightness improvement of over 1000 times for pulses longer than 40 ns and up to 3500 times in the cw regime.

76 FR 12634 - Airworthiness Directives; The Boeing Company Model 737-600, -700, -700C, -800, and -900 Series...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-03-08

... left-hand fuel pump of the center wing tank (CWT) to shut off after being selected ``OFF'' by the... original NPRM will not be extended to the main wing tanks, as discussed in meetings between Boeing and the... wing tanks on Model 737-600, -700, -700C, -800, and -900 series airplanes to support the proposed AD...

Two-stage optical parametric chirped-pulse amplifier using sub-nanosecond pump pulse generated by stimulated Brillouin scattering compression

NASA Astrophysics Data System (ADS)

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.

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

PubMed

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 < 0.01). The operative time and the number of distal anastomosis of off-pump group were less than MECC and cECC groups (P < 0.05), while no difference between MECC group and cECC group. Intrinsic coagulation (activated partial thromboplastin time) were much more prolonged early postoperatively in cECC group, and higher than in MECC group and off-pump group at 2 h, 6 h and 12 h postoperatively (P < 0.05), but no difference in extrinsic coagulation (prothrombin time) among three group. Adjusted by hematocrit of the same sample, free hemoglobin level rose up during the ECC procedure and reached the maximum at the end of ECC in cECC group and MECC group, but the levels were more higher in cECC group than in MECC group (P < 0.05). The draining volume during the first 24 h after operation of cECC group was larger than MECC group and off-pump group (P < 0.05). Although the decreased platelet count perioperatively and more consumed of the 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.

Effects of mobile phone use on specific intensive care unit devices.

PubMed

Hans, Nidhi; Kapadia, Farhad N

2008-10-01

To observe the effects of mobile phone use in the vicinity of medical devices used in a critical care setting. Electromagnetic interference (EMI) was tested by using two types of mobile phones - GSM and CDMA. Mobile phones were placed at a distance of one foot from three medical devices - syringe pump, mechanical ventilator, and the bedside monitor - in switch off, standby, and talking modes of the phone. Medical devices were observed for any interference caused by the electromagnetic radiations (EMR) from the mobile phones. Out of the three medical devices that were tested, EMI occurred while using the mobile phone in the vicinity of the syringe pump, in the 'talk mode.' The mean variation observed in the calculated and delivered volume of the syringe pump was 2.66 ml. Mechanical ventilator did not show any specific adverse effects with mobile phone use in the one-foot vicinity. No other adverse effects or unexplained malfunctions or shutdown of the syringe pump, mechanical ventilator, or the bedside monitor was noted during the study period of 36 hours. EMI from mobile phones have an adverse effect on the medical devices used in critical care setup. They should be used at least one foot away from the diameter of the syringe pump.

Preoperative intra-aortic counterpulsation in high-risk patients undergoing cardiac surgery: a meta-analysis of randomized controlled trials†.

PubMed

Pilarczyk, Kevin; Boening, Andreas; Jakob, Heinz; Langebartels, Georg; Markewitz, Andreas; Haake, Nils; Heringlake, Matthias; Trummer, Georg

2016-01-01

In contrast to the results of previous studies, recent randomized controlled trials (RCTs) failed to show a benefit of prophylactic aortic counterpulsation in high-risk patients undergoing cardiac surgery. The present analysis aims to redefine the effects of this treatment modality in the light of this new evidence. MEDLINE, EMBASE, CENTRAL/CCTR, Google Scholar and reference lists of relevant articles were searched for full-text articles of RCTs in English or German. Assessments for eligibility, relevance, study validity and data extraction were performed by two reviewers independently using prespecified criteria. The primary outcome was hospital mortality. A total of nine eligible RCTs with 1171 patients were identified: 577 patients were treated preoperatively with intra-aortic balloon pump (IABP) and 594 patients served as controls. The pooled odds ratio (OR) for hospital mortality (22 hospital deaths in the intervention arm, 54 in the control group) was 0.381 (95% CI 0.230-0.629; P < 0.001). The pooled analyses of five RCTs including only patients undergoing isolated on-pump coronary artery bypass grafting (n[IABP] = 348, n[control] = 347) also showed a statistically significant improvement in mortality for preoperative IABP implantation (fixed-effects model: OR 0.267, 95% CI 0.129-0.552, P < 0.001). The pooled OR for hospital mortality from two randomized off-pump trials was 0.556 (fixed-effects model, 95% CI 0.207-1.493, P = 0.226). Preoperative aortic counterpulsation was associated with a significant reduction in low cardiac output syndrome (LCOS) in the total population (fixed-effects model: OR 0.330, 95% CI 0.214-0.508, P < 0.001) as well as in the subgroup of CAGB patients (fixed-effects model: OR 0.113, 95% CI 0.056-0.226, P < 0.001), whereas there was no benefit in the off-pump population (fixed-effects model: OR 0.555, 95% CI 0.209-1.474, P = 0.238). Preoperative IABP implantation was associated with a reduction of intensive care unit (ICU) stay in all investigated populations with a greater effect in the total population [fixed-effects model: standard mean difference (SMD) -0.931 ± 0.198, P < 0.001] as well as in the subgroup of CAGB patients (fixed-effects model: SMD -1.240 ± 0.156, P < 0.001), compared with the off-pump group (fixed-effects model: SMD -0.723 ± 0.128, P < 0.001). Despite contradictory results from recent trials, the present study confirms the findings of previous meta-analyses that prophylactic aortic counterpulsation reduces hospital mortality, incidence of LCOS and ICU requirement in high-risk patients undergoing on-pump cardiac surgery. However, owing to small sample sizes and the lack of a clear-cut definition of high-risk patients, an adequately powered, prospective RCT is necessary to find a definite answer to the question, if certain groups of patients undergoing cardiac surgery benefit from a prophylactic IABP insertion. © The Author 2015. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

Inadequate safety reporting in pre-eclampsia trials: a systematic evaluation.

PubMed

Duffy, Jmn; Hirsch, M; Pealing, L; Showell, M; Khan, K S; Ziebland, S; McManus, R J

2018-06-01

Randomised trials and their syntheses in meta-analyses offer a unique opportunity to assess the frequency and severity of adverse reactions. To assess safety reporting in pre-eclampsia trials. Systematic search using bibliographic databases, including Cochrane Central Register of Controlled Trials, Embase, and MEDLINE, from inception to August 2017. Randomised trials evaluating anticonvulsant or antihypertensive medication for pre-eclampsia. Descriptive statistics appraising the adequacy of adverse reaction and toxicity reporting. We included 60 randomised trials. Six trials (10%) were registered with the International Clinical Trials Registry Platform, two registry records referred to adverse reactions, stating 'safety and toleration' and 'possible side effects' would be collected. Twenty-six trials (43%) stated the frequency of withdrawals within each study arm, and five trials (8%) adequately reported these withdrawals. Adverse reactions were inconsistently reported across eligible trials: 24 (40%) reported no serious adverse reactions and 36 (60%) reported no mild adverse reactions. The methods of definition or measurement of adverse reactions were infrequently reported within published trial reports. Pre-eclampsia trials regularly omit critical information related to safety. Despite the paucity of reporting, randomised trials collect an enormous amount of safety data. Developing and implementing a minimum data set could help to improve safety reporting, permitting a more balanced assessment of interventions by considering the trade-off between the benefits and harms. National Institute for Health Research (DRF-2014-07-051), UK; Maternity Forum, Royal Society of Medicine, UK. Developing @coreoutcomes could help to improve safety reporting in #preeclampsia trials. @NIHR_DC. © 2017 Royal College of Obstetricians and Gynaecologists.

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

PubMed

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.

Process Options for Nominal 2-K Helium Refrigeration System Designs

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

Peter Knudsen, Venkatarao Ganni

Nominal 2-K helium refrigeration systems are frequently used for superconducting radio frequency and magnet string technologies used in accelerators. This paper examines the trade-offs and approximate performance of four basic types of processes used for the refrigeration of these technologies; direct vacuum pumping on a helium bath, direct vacuum pumping using full or partial refrigeration recovery, cold compression, and hybrid compression (i.e., a blend of cold and warm sub-atmospheric compression).

Should we consider off-pump coronary artery bypass grafting in patients with acute coronary syndrome?

PubMed

Moscarelli, Marco; Harling, Leanne; Ashrafian, Hutan; Athanasiou, Thanos

2013-03-01

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was whether off-pump coronary artery bypass (OPCAB) grafting should be considered as an alternative to the conventional on-pump surgery (ONCAB) in patients presenting with acute coronary syndrome (ACS) requiring emergency revascularization. Eighty-two papers were identified by a systematic search, of which nine were judged to best answer the clinical question. Of these, one was a randomized controlled trial and the remaining eight were retrospective observational studies. The author, journal, date, patient group, country of publication, relevant outcomes, results and study weaknesses were tabulated. In total, these nine studies included 3001 patients (n = 817 OPCAB, 2184 ONCAB) undergoing emergency revascularization in the setting of ACS. The timing between the onset of ACS and operative intervention ranged from 6 to 72 h. All cases were categorized as urgent/emergent according to the National confidential enquiry into patient outcome and death classification of intervention. Six studies included patients with preoperative cardiogenic shock; however the majority of patients were haemodynamically stable at the time of surgery. Three out of nine studies showed an improvement in 30-day mortality with OPCAB although the remaining six reveal no significant mortality benefit. No difference in long-term mortality was observed between the two techniques. OPCAB was associated with significantly fewer grafts per patient (six studies) and less complete revascularization (two studies). We conclude that whilst OPCAB may have a beneficial effect on 30-day mortality in haemodynamically stable patients undergoing emergency revascularization, there is a lack of high-quality data with clearly defined patient demographics. Future studies must ensure adequate preoperative matching between OPCAB and ONCAB groups and clearly categorize haemodynamic status, disease pattern and time to surgery in order to determine the patients in whom OPCAB may confer the greatest benefit.

Hydraulic Fracture Growth in a Layered Formation based on Fracturing Experiments and Discrete Element Modeling

NASA Astrophysics Data System (ADS)

Yushi, Zou; Xinfang, Ma; Tong, Zhou; Ning, Li; Ming, Chen; Sihai, Li; Yinuo, Zhang; Han, Li

2017-09-01

Hydraulic fracture (HF) height containment tends to occur in layered formations, and it significantly influences the entire HF geometry or the stimulated reservoir volume. This study aims to explore the influence of preexisting bedding planes (BPs) on the HF height growth in layered formations. Laboratory fracturing experiments were performed to confirm the occurrence of HF height containment in natural shale that contains multiple weak and high-permeability BPs under triaxial stresses. Numerical simulations were then conducted to further illustrate the manner in which vertical stress, BP permeability, BP density(or spacing), pump rate, and fluid viscosity control HF height growth using a 3D discrete element method-based fracturing model. In this model, the rock matrix was considered transversely isotropic and multiple BPs can be explicitly represented. Experimental and numerical results show that the vertically growing HF tends to be limited by multi-high-permeability BPs, even under higher vertical stress. When the vertically growing HF intersects with the multi-high-permeability BPs, the injection pressure will be sharply reduced. If a low pumping rate or a low-viscosity fluid is used, the excess fracturing fluid leak-off into the BPs obviously decreases the rate of pressure build up, which will then limit the growth of HF. Otherwise, a higher pumping rate and/or a higher viscosity will reduce the leak-off time and fluid volume, but increase the injection pressure to drive the HF to grow and to penetrate through the BPs.

Drug utilization and off-label drug use in Spanish pediatric gastroenterology outpatients.

PubMed

Ruíz-Antorán, Belén; Piñeiro, Roi; Avendaño, Cristina; Román, Enriqueta; Cilleruelo, María Luz; Gutiérrez-Junquera, Carolina; Centeno, Gustavo; Cilleruelo, María José

2013-02-01

The clinical use of medicines outside the conditions authorized in their Summary of Product Characteristics (SPC) (off-label use) is a common practice in pediatrics. The aim of the present study was to describe and quantify the medicines received by children attended in the pediatric gastroenterology department, their off-label use, and compliance with accepted rules for said use. A retrospective observational study was performed on all of the patients who had their first consultation in pediatric gastroenterology between January 1 and October 31, 2010. All of the clinical information and medicines prescribed were analyzed. Off-label use was defined as the use of medicines in indications not included in the officially approved SPC or in ages not included or recommended in the SPC as well as the use of doses, intervals, or administration routes different from those considered in the SPC. A total of 695 patients (52.8% male) were included, 48.2% younger than 2 years. Two-hundred seven patients (29.8%) received 331 prescriptions. The most commonly used medicines were anti-H2 and proton pump inhibitors. Of all the prescriptions, 33.2% were considered off-label, and up to 47.3% of the prescribed patients had at least 1 medicine under off-label conditions. The medical records contained no documentation on information given to the parents regarding off-label use. The study found a high percentage of off-label use of medicines in the Pediatric Gastroenterology outpatient setting, especially in children younger than 2 years. Several initiatives were derived from the present study and implemented in our hospital.

Micro-osmotic pumps for continuous release of the tyrosine kinase inhibitor bosutinib in juvenile rats and its impact on bone growth.

PubMed

Tauer, Josephine Tabea; Hofbauer, Lorenz C; Jung, Rolang; Erben, Reinhold G; Suttorp, Meinolf

2013-11-04

Bosutinib is a third-generation dual tyrosine kinase inhibitor (TKI) inhibiting Abl and Src kinases. It was developed to act on up-regulated tyrosine kinases (TKs) like BCR-ABL in Philadelphia chromosome positive (Ph+) chronic myeloid leukemia (CML) when resistance to first- and second-generation TKIs developed. However, first- and second-generation TKIs show off-target effects on bone metabolism, whereas studies on skeletal adverse effects of bosutinib are still lacking. Therefore, it was the aim of this study to continuously expose juvenile rats to bosutinib and to analyze its influence on the growing bone. Starting after weaning, 4-week-old Wistar rats were chronically exposed over a 28-day period to varying concentrations of bosutinib, which were continuously administered subcutaneously via implanted Alzet® micro-osmotic pumps. After necropsy, the length of the femora and tibiae were analyzed. Continuous administration of bosutinib by micro-osmotic pumps led to serum drug levels in the lower therapeutic range, was well tolerated, and exhibited only minor adverse effects on the growing skeleton. Micro-osmotic pumps represent a convenient system for continuous TKI release in young growing rats. Compared to first- and second-generation TKIs, bosutinib seems to exert fewer adverse effects on the growing bone.

Cost-effectiveness of insulin pumps compared with multiple daily injections both provided with structured education for adults with type 1 diabetes: a health economic analysis of the Relative Effectiveness of Pumps over Structured Education (REPOSE) randomised controlled trial.

PubMed

Pollard, Daniel John; Brennan, Alan; Dixon, Simon; Waugh, Norman; Elliott, Jackie; Heller, Simon; Lee, Ellen; Campbell, Michael; Basarir, Hasan; White, David

2018-04-07

To assess the long-term cost-effectiveness of insulin pumps and Dose Adjustment for Normal Eating (pumps+DAFNE) compared with multiple daily insulin injections and DAFNE (MDI+DAFNE) for adults with type 1 diabetes mellitus (T1DM) in the UK. We undertook a cost-utility analysis using the Sheffield Type 1 Diabetes Policy Model and data from the Relative Effectiveness of Pumps over Structured Education (REPOSE) trial to estimate the lifetime incidence of diabetic complications, intervention-based resource use and associated effects on costs and quality-adjusted life years (QALYs). All economic analyses took a National Health Service and personal social services perspective and discounted costs and QALYs at 3.5% per annum. A probabilistic sensitivity analysis was performed on the base case. Further uncertainties in the cost of pumps and the evidence used to inform the model were explored using scenario analyses. Eight diabetes centres in England and Scotland. Adults with T1DM who were eligible to receive a structured education course and did not have a strong clinical indication or a preference for a pump. Pumps+DAFNE. MDI+DAFNE. Incremental costs, incremental QALYs gained and incremental cost-effectiveness ratios (ICERs). Compared with MDI+DAFNE, pumps+DAFNE was associated with an incremental discounted lifetime cost of +£18 853 (95% CI £6175 to £31 645) and a gain in discounted lifetime QALYs of +0.13 (95% CI -0.70 to +0.96). The base case mean ICER was £142 195 per QALY gained. The probability of pump+DAFNE being cost-effective using a cost-effectiveness threshold of £20 000 per QALY gained was 14.0%. All scenario and subgroup analyses examined indicated that the ICER was unlikely to fall below £30 000 per QALY gained. Our analysis of the REPOSE data suggests that routine use of pumps in adults without an immediate clinical need for a pump, as identified by National Institute for Health and Care Excellence, would not be cost-effective. ISRCTN61215213. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Remediation System Evaluation, Raymark Superfund Site (PDF)

EPA Pesticide Factsheets

The Raymark site occupies 7 acres off Jacksonville Road in an industrial part of Hatboro, Pennsylvania.The pump-and-treat system addresses groundwater contamination, primarily trichloroethylene (TCE),associated with the operations of various ...

[Systemic coronary surgery in the beating heart. Experience in 250 cases].

PubMed

Cartier, R; Bouchard, D; Martineau, R; Couturier, A

1999-01-01

To report our recent experience with off-pump coronary artery revascularization in multi-vessel disease. Between October 1996 and August 1998, 250 off-pump (OP) procedures were completed at the Montreal Heart Institute, representing more than 90% of all procedures done during the same time frame (97% for 1998). These patients have been compared to 1870 patients operated upon under cardiopulmonary bypass during the years 1995-1996 (CPB). Mean age, sexe distribution, and preoperative risk factors were comparable for both groups. On average 2.89 +/- 0.8 and 2.84 +/- 0.6 grafts/patient were completed in OP and CPB groups respectively. A majority (70%) of patients had either a triple or quadruple bypass. Coronary anastomoses were achieved with myocardial mechanical stabilization and heart "verticalization". Ischemic time was shorter in the OP group (29.8 +/- 0.9 vs 45 +/- 0.4 min, p < 0.05). Similarly, need for transfusion was significantly less (OP: 34 vs CPB: 66%, p < 0.005). Use of postoperative intra-aortic counterpulsation as well as the raise of CK-MB were lesser in the OP group. Operative mortality (OP: 1.6%, vs CPB: 2%, p = ns) and perioperative myocardial infarction rate (OP: 3.6% vs CPB: 4.2) were comparable for both groups. Off-pump complete coronary artery revascularization is an acceptable alternative to conventional surgery in a majority of patients with good results given progressive experience, rigorous technique, and adequate coronary artery stabilization.

Transapical off-pump mitral valve repair. First experience with the NeoChord system in Poland (report of two cases).

PubMed

Wróbel, Krzysztof; Kurnicka, Katarzyna; Zygier, Marcin; Dyk, Wojciech; Wojdyga, Ryszard; Zieliński, Dariusz; Jarzębska, Małgorzata; Juraszyński, Zbigniew; Lichodziejewska, Barbara; Pruszczyk, Piotr; Biederman, Andrzej; Speziali, Giovanni; Kasten, Uwe

2017-01-01

Artificial chord implantation to repair a flail or prolapsing mitral valve leaflet requires open heart surgery and cardiopulmonary bypass. Transapical off-pump artificial chordae implantation is a new surgical technique proposed to treat degenerative mitral valve regurgitation. The procedure is performed using the NeoChord DS1000 system (NeoChord, Inc., St. Louis Park, MN, USA), which facilitates both implantation and lenght adjustment of the artificial chordae under two (2D)- and three (3D)-dimensional transoesophageal echocardiographic (TEE) guidance on a beating heart. Two male patients aged 60 and 55 years with severe mitral regurgitation due to posterior leaflet prolapse underwent transapical off-pump artificial chordae implantation on September 3, 2015. The procedure was performed by left minithoracotomy under general anaesthesia in a cardiac surgical theatre, using 2D and 3D TEE guidance. Early procedural success as confirmed by 3D TEE was achieved in both patients, with implantation of 6 artificial chordae in the first patient and 3 artificial chordae in the second patient. Both procedures were uneventful, and no postoperative complications were noted. The patients were discharged home on the 8th and 6th postoperative day, respectively. The NeoChord DS1000 system allows both implantation and lenght adjustment of artificial chordae under 2D and 3D TEE guidance on a beating heart. Our initial experience in 2 patients with posterior mitral leaflet prolapse indicates that the procedure is feasible and safe.

Comparison of energy expenditure and heart rate responses between three commercial group fitness classes.

PubMed

Wickham, James B; Mullen, Nicholas J; Whyte, Douglas G; Cannon, Jack

2017-07-01

The objectives of this study were to compare the energy expenditure and heart rate responses between three commercial group fitness classes (group resistance exercise [PUMP]; indoor stationary cycling [RIDE]; and step aerobics [STEP]). One-Way Repeated Measures incorporating a Latin Square Design for class randomisation. Ten participants (5 males and 5 females) completed each group fitness class in random order with energy expenditure and heart rate determined using an Actiheart monitor. STEP and RIDE produced significantly (p<0.05) higher average heart rates (HR avg ) (85.8±5.1% and 86.4±4.3% of HR max , respectively) compared to PUMP (73.7±7% of HR max ). HR peak was also significantly (p<0.05) higher in STEP and RIDE (97.1±4.7% and 95.6±4.5% of HR max, respectively) when compared with the PUMP class (90±5.9% of HR max ). Total energy expenditure (TEE), both absolute and relative, were significantly (p<0.05) higher for STEP (2101.7±560.2kJ and 0.59±0.07kJkg -1 min -1 ) and RIDE (1880.4±420kJ and 0.58±0.03kJkg -1 min -1 ) when compared with the PUMP class (1385.1±504kJ and 0.36±0.07kJkg -1 min -1 ). These data suggest that overall exercise intensity and energy expenditure was highly comparable between RIDE and STEP, which suggests these group fitness classes are more effective for developing cardiovascular fitness and assisting with weight management compared with group resistance exercise classes when performed on a regular basis. Copyright © 2017 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

Numerical Simulation of Tubular Pumping Systems with Different Regulation Methods

NASA Astrophysics Data System (ADS)

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.

The dependency of expiratory airway collapse on pump system and flow rate in liquid ventilated rabbits.

PubMed

Meinhardt, J P; Ashton, B A; Annich, G M; Quintel, M; Hirschl, R B

2003-05-30

To evaluate the influence of pump system and flow pattern on expiratory airway collapse (EAC) in total perfluorocarbon ventilation. - Prospective, controlled, randomized animal trial for determination of (1) post-mortem changes by repeated expiration procedures (EP) with a constant flow piston pump (PP) before and after sacrifice (n = 8 rabbits), (2) differences between pump systems by subjecting animals to both PP and roller pump (RP) circuits for expiration (n = 16 rabbits). EP were performed using a servo-controlled shut-off at airway pressures < 25 cm H subset 2O randomly with either pump at different flows. - Expired volumes before and after sacrifice were not significantly different. PP and RP revealed identical mean flows, while significantly more liquid was drained using PP (p<0.05). Increasing differences towards higher flow rates indicated profound flow pulsatility in RP. - (1) post-mortem changes in expired volumes are not significant, (2) EAC is related to flow rate and pump system; (3) relationship between expiratory flow rate and drainable liquid volume is linear inverse; (4) PP provides higher drainage than RP. - Expiratory airway collapse is related to flow rate and pump system, post mortem changes in expirable volumes are not significant. Relationship between expiratory flow rate and drainable liquid volume is linear inverse, piston pump expiration provides higher drainage volumes than roller pump expiration.

Sustained multi-kHz flamefront and 3-component velocity-field measurements for the study of turbulent flames

NASA Astrophysics Data System (ADS)

Boxx, I.; Stöhr, M.; Carter, C.; Meier, W.

2009-04-01

We describe an approach of imaging the dynamic interaction of the flamefront and flowfield. Here, a diode-pumped Nd:YLF laser operating at 5 kHz is used to pump a dye laser, which is then frequency doubled to 283 nm to probe flamefront OH, while a dual cavity diode-pumped Nd:YAG system produces pulse-pairs for particle image velocimetry (PIV). CMOS digital cameras are used to detect both planar laser-induced fluorescence (PLIF) and particle scattering (in a stereo arrangement) such that a 5 kHz measurement frequency is attained. This diagnostic is demonstrated in lifted-jet and swirl-stabilized flames, wherein the dynamics of the flame stabilization processes are seen. Nonperiodic effects such as local ignition and/or extinction, lift-off and flashback events, and their histories can be captured by this technique. As such, this system has the potential to significantly extend our understanding of nonstationary combustion processes relevant to industrial and technical applications.

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

NASA Astrophysics Data System (ADS)

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.

Controllable optical bistability in a three-mode optomechanical system with atom-cavity-mirror couplings

NASA Astrophysics Data System (ADS)

Chen, Bin; Wang, Xiao-Fang; Yan, Jia-Kai; Zhu, Xiao-Fei; Jiang, Cheng

2018-01-01

We theoretically investigate the optical bistable behavior in a three-mode optomechanical system with atom-cavity-mirror couplings. The effects of the cavity-pump detuning and the pump power on the bistable behavior are discussed detailedly, the impacts of the atom-pump detuning and the atom-cavity coupling strength on the bistability of the system are also explored, and the influences of the cavity-resonator coupling strength and the cavity decay rate are also taken into consideration. The numerical results demonstrate that by tuning these parameters the bistable behavior of the system can be freely switched on or off, and the threshold of the pump power for the bistability as well as the bistable region width can also be effectively controlled. These results can find potential applications in optical bistable switch in the quantum information processing.

Architecture and Bloch-Maxwell modelling of multi-mJ 100 fs fully-coherent soft X-ray laser based on X-ray CPA

NASA Astrophysics Data System (ADS)

Zeitoun, Ph.; Oliva, E.; Fajardo, M.; Cheriaux, G.; Le, T. T. T.; Li, L.; Pitman, M.; Ros, D.; Sebban, S.; Velarde, P.

2012-07-01

By seeding amplifying plasmas pumped with the so-called Transient collisionnal excitation scheme, the amplified pulse seems to be limited to an energy of several 10's of μJ. Aiming to attain several mJ, we study the seeding of plasma pumped by long laser pulse. Thanks to our time-dependent Maxwell-Bloch code, we demonstrate that direct seeding with femtosecond pulse is inefficient. We also study the amplification of pulse train with the drawback of re-synchronizing the pulses. We proposed and studied the amplification of high harmonic seed stretched by a grating pair, amplified finally compressed. We consider off-axis diffraction on the gratings for maximizing their efficiency. Considering the phase deformation induced by the amplification and the spectral narrowing the final pulse is 230 fs in duration and 5 mJ.

Architecture and Bloch-Maxwell modelling of multi-mJ 100 fs fully-coherent soft X-ray laser based on X-ray CPA

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

Zeitoun, Ph.; Oliva, E.; Fajardo, M.

2012-07-09

By seeding amplifying plasmas pumped with the so-called Transient collisionnal excitation scheme, the amplified pulse seems to be limited to an energy of several 10's of {mu}J. Aiming to attain several mJ, we study the seeding of plasma pumped by long laser pulse. Thanks to our time-dependent Maxwell-Bloch code, we demonstrate that direct seeding with femtosecond pulse is inefficient. We also study the amplification of pulse train with the drawback of re-synchronizing the pulses. We proposed and studied the amplification of high harmonic seed stretched by a grating pair, amplified finally compressed. We consider off-axis diffraction on the gratings formore » maximizing their efficiency. Considering the phase deformation induced by the amplification and the spectral narrowing the final pulse is 230 fs in duration and 5 mJ.« less

An advanced molecule-surface scattering instrument for study of vibrational energy transfer in gas-solid collisions.

PubMed

Ran, Qin; Matsiev, Daniel; Wodtke, Alec M; Auerbach, Daniel J

2007-10-01

We describe an advanced and highly sensitive instrument for quantum state-resolved molecule-surface energy transfer studies under ultrahigh vacuum (UHV) conditions. The apparatus includes a beam source chamber, two differential pumping chambers, and a UHV chamber for surface preparation, surface characterization, and molecular beam scattering. Pulsed and collimated supersonic molecular beams are generated by expanding target molecule mixtures through a home-built pulsed nozzle, and excited quantum state-selected molecules were prepared via tunable, narrow-band laser overtone pumping. Detection systems have been designed to measure specific vibrational-rotational state, time-of-flight, angular and velocity distributions of molecular beams coming to and scattered off the surface. Facilities are provided to clean and characterize the surface under UHV conditions. Initial experiments on the scattering of HCl(v = 0) from Au(111) show many advantages of this new instrument for fundamental studies of the energy transfer at the gas-surface interface.

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

PubMed

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 in a novel surgical technique.

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

PubMed

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 <0.05). 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 <0.05), lower pain scores (P <0.0001), and shorter orotracheal intubation and hospitalization lengths (P <0.001). Sub-xyphoid pleural drain determined better functional 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.

The efficacy and safety of extended-release methylphenidate following traumatic brain injury: a randomised controlled pilot study.

PubMed

Dymowski, Alicia R; Ponsford, Jennie L; Owens, Jacqueline A; Olver, John H; Ponsford, Michael; Willmott, Catherine

2017-06-01

To investigate the feasibility, safety and efficacy of extended-release methylphenidate in enhancing processing speed, complex attentional functioning and everyday attentional behaviour after traumatic brain injury. Seven week randomised, placebo-controlled, double-blind, parallel pilot study. Inpatient and outpatient Acquired Brain Injury Rehabilitation Program. Eleven individuals with reduced processing speed and/or attention deficits following complicated mild to severe traumatic brain injury. Participants were allocated using a blocked randomisation schedule to receive daily extended-release methylphenidate (Ritalin ® LA at a dose of 0.6 mg/kg) or placebo (lactose) in identical capsules. Tests of processing speed and complex attention, and ratings of everyday attentional behaviour were completed at baseline, week 7 (on-drug), week 8 (off-drug) and 9 months follow-up. Vital signs and side effects were monitored from baseline to week 8. Three percent ( n = 11) of individuals screened participated (mean post-traumatic amnesia duration = 63.80 days, SD = 45.15). Results were analysed for six and four individuals on methylphenidate and placebo, respectively. Groups did not differ on attentional test performance or relative/therapist ratings of everyday attentional behaviour. One methylphenidate participant withdrew due to difficulty sleeping. Methylphenidate was associated with trends towards increased blood pressure and reported anxiety. Methylphenidate was not associated with enhanced processing speed, attentional functioning or everyday attentional behaviour after traumatic brain injury. Alternative treatments for attention deficits after traumatic brain injury should be explored given the limited feasibility of methylphenidate in this population.

Release of serum S-100β protein and neuron-specific enolase after off-pump coronary artery bypass grafting with and without intracranial and cervical artery stenosis.

PubMed

Tamura, Atsushi; Imamaki, Mizuho; Shimura, Hitoshi; Niitsuma, Yuriko; Miyazaki, Masaru

2011-01-01

The aim of this study was to quantify the amount of brain damage suffered by patients who underwent off-pump coronary artery bypass grafting (OPCAB) in which S-100β protein and neuron-specific enolase were used. Thirty-four patients undergoing scheduled OPCAB were enrolled in the study. The patients were divided into two groups according to the results of their magnetic resonance angiography (MRA) and cervical ultrasonography: 13 patients had cervical or intracranial arterial stenosis (Group A), and 21 patients did not (Group B). Blood samples were collected from the arterial catheters immediately before surgery, upon arrival to the intensive care unit, and 6 and 24 hours after surgery. In blood samples collected from patients upon arrival to the intensive care unit, the maximum concentration of serum s-100β protein in Group A was significantly higher than that of Group B (p = 0.029). Though patients in Group A tended to have higher maximum neuron-specific enolase (NSE) concentrations, there were no significant differences in NSE concentrations at any point between the two groups. Our findings show a correlation between the stenosis detected by MRA or cervical ultrasonography and brain damage after OPCAB.

Advantages of autologous blood transfusion in off-pump coronary artery bypass.

PubMed

Ela, Yuksel; Emmiler, Mustafa; Kocogullari, Cevdet Ugur; Terzi, Yuksel; Sivaci, Remziye Gul; Cekirdekci, Ahmet

2009-10-01

In this randomized controlled study, we investigated the effects of autologous Hemobag blood transfusion (AHBT) and allogenic blood transfusion (ABT) in off-pump coronary artery bypass (OPCAB) surgery. Sixty patients who underwent surgery between February 2008 and August 2008 were randomized into 2 groups. The AHBT group (n = 30) consisted of patients who received autologous Hemobag blood transfusion, and the ABT group (n = 30) consisted of patients who received allogenic blood transfusion. All patients underwent OPCAB via sternotomy. The time to extubation, chest tube drainage volume, postoperative white blood cell counts, amount of blood transfusion, sedimentation rate, C-reactive protein concentration, postoperative temperature, and the presence of atelectasis were recorded in the intensive care unit. Intraoperative bleeding and fluid resuscitation were similar in the 2 groups (P > .05); however, there were significant decreases in postoperative blood loss, extubation period, postoperative white cell counts, sedimentation rate, incidence of atelectasis, C-reactive protein, and fever in the AHBT group compared with the ABT group (P < .05). The rate of atrial fibrillation in the AHBT group tended to be lower than in the ABT group. Autologous blood transfusion in OPCAB may be beneficial in certain cardiac surgery patients; however, these beneficial effects require further study to be proved.

Efficacy, safety, and tolerance of the non-ergoline dopamine agonist pramipexole in the treatment of advanced Parkinson's disease: a double blind, placebo controlled, randomised, multicentre study.

PubMed

Pinter, M M; Pogarell, O; Oertel, W H

1999-04-01

Pramipexole, a non-ergot dopamine D2/D3 receptor agonist, was investigated as an add on drug in advanced parkinsonian patients with motor fluctuations to assess efficacy, safety, and tolerance. Seventy eight patients of either sex with advanced Parkinson's disease and treatment complications such as motor fluctuations were enrolled into a double blind, placebo controlled, randomised, multicentre study (phase II) and assigned to add on treatment with pramipexole (n=34) versus placebo (n=44) to a previously stabilised antiparkinsonian medication (7 week dose titration interval, 4 week maintenance period). The primary end point of efficacy was the change from baseline in the total score of the unified Parkinson's disease rating scale (UPDRS) in the on "period" (2 hours after intake of study medication). Safety and tolerability were assessed on the basis of adverse events, vital signs, laboratory measurements, and ECG recordings. There was a significant improvement of the pramipexole group in UPDRS total scores, subscores part II, III (activities of daily living and motor examination), and IV (complications of therapy). Mean UPDRS total score decreased by 37.3% under pramipexole compared with 12.2% under placebo (p<0.001). Patients under pramipexole reported an overall reduction in "off" periods of 12%--resulting in 1.7 more hours "on" time a day--compared with an increase in "off" periods of 2% under placebo. There were no unexpected safety results. The adverse event profile disclosed a high tolerability. The most important adverse events under pramipexole were fatigue, dyskinesia, and vivid dreams. Pramipexole administration is an efficacious and well tolerated add on therapy in patients with advanced Parkinson's disease with an improvement in activities of daily living, motor function, and treatment associated complications.

Simulation-based team training for multi-professional obstetric care teams to improve patient outcome: a multicentre, cluster randomised controlled trial.

PubMed

Fransen, A F; van de Ven, J; Schuit, E; van Tetering, Aac; Mol, B W; Oei, S G

2017-03-01

To investigate whether simulation-based obstetric team training in a simulation centre improves patient outcome. Multicentre, open, cluster randomised controlled trial. Obstetric units in the Netherlands. Women with a singleton pregnancy beyond 24 weeks of gestation. Random allocation of obstetric units to a 1-day, multi-professional, simulation-based team training focusing on crew resource management (CRM) in a simulation centre or to no such team training. Intention-to-treat analyses were performed at the cluster level, including a measurement 1 year prior to the intervention. Primary outcome was a composite outcome of obstetric complications during the first year post-intervention, including low Apgar score, severe postpartum haemorrhage, trauma due to shoulder dystocia, eclampsia and hypoxic-ischaemic encephalopathy. Maternal and perinatal mortality were also registered. Each study group included 12 units with a median unit size of 1224 women, combining for a total of 28 657 women. In total, 471 medical professionals received the training course. The composite outcome of obstetric complications did not differ between study groups [odds ratio (OR) 1.0, 95% confidence interval (CI) 0.80-1.3]. Team training reduced trauma due to shoulder dystocia (OR 0.50, 95% CI 0.25-0.99) and increased invasive treatment for severe postpartum haemorrhage (OR 2.2, 95% CI 1.2-3.9) compared with no intervention. Other outcomes did not differ between study groups. A 1-day, off-site, simulation-based team training, focusing on teamwork skills, did not reduce a composite of obstetric complications. 1-day, off-site, simulation-based team training did not reduce a composite of obstetric complications. © 2016 Royal College of Obstetricians and Gynaecologists.

Comprehensive experimental and numerical analysis of instability phenomena in pump turbines

NASA Astrophysics Data System (ADS)

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

2014-03-01

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). For several wicket gate positions, the flow fields in the vane-less space at runner inlet observed in the experiment are compared with the results of unsteady CFD flow simulations. Physical phenomena are visualized and insight to flow phenomena is given. Analyses using both results of simulation and measurement allow deriving a consistent explanation of the fluid mechanical mechanisms leading to the S-shaped instability of pump turbines.

Stress Introduction Rate Alters the Benefit of AcrAB-TolC Efflux Pumps.

PubMed

Langevin, Ariel M; Dunlop, Mary J

2018-01-01

Stress tolerance studies are typically conducted in an all-or-none fashion. However, in realistic settings-such as in clinical or metabolic engineering applications-cells may encounter stresses at different rates. Therefore, how cells tolerate stress may depend on its rate of appearance. To address this, we studied how the rate of stress introduction affects bacterial stress tolerance by focusing on a key stress response mechanism. Efflux pumps, such as AcrAB-TolC of Escherichia coli , are membrane transporters well known for the ability to export a wide variety of substrates, including antibiotics, signaling molecules, and biofuels. Although efflux pumps improve stress tolerance, pump overexpression can result in a substantial fitness cost to the cells. We hypothesized that the ideal pump expression level would involve a rate-dependent trade-off between the benefit of pumps and the cost of their expression. To test this, we evaluated the benefit of the AcrAB-TolC pump under different rates of stress introduction, including a step, a fast ramp, and a gradual ramp. Using two chemically diverse stresses, the antibiotic chloramphenicol and the jet biofuel precursor pinene, we assessed the benefit provided by the pumps. A mathematical model describing these effects predicted the benefit as a function of the rate of stress introduction. Our findings demonstrate that as the rate of introduction is lowered, stress response mechanisms provide a disproportionate benefit to pump-containing strains, allowing cells to survive beyond the original inhibitory concentrations. IMPORTANCE Efflux pumps are ubiquitous in nature and provide stress tolerance in the cells of species ranging from bacteria to mammals. Understanding how pumps provide tolerance has far-reaching implications for diverse fields, from medicine to biotechnology. Here, we investigated how the rate of stressor appearance impacts tolerance. We focused on two distinct substrates of AcrAB-TolC efflux pumps, the antibiotic chloramphenicol and the biofuel precursor pinene. Interestingly, tolerance is highly dependent on the rate of stress introduction. Therefore, it is important to consider not only the total quantity of a stressor but also the rate at which it is applied. The implications of this work are significant because environments are rarely static; antibiotic concentrations change during dosing, and metabolic engineering processes change with time. Copyright © 2017 American Society for Microbiology.

Effect of artificial pancreas systems on glycaemic control in patients with type 1 diabetes: a systematic review and meta-analysis of outpatient randomised controlled trials.

PubMed

Weisman, Alanna; Bai, Johnny-Wei; Cardinez, Marina; Kramer, Caroline K; Perkins, Bruce A

2017-07-01

Closed-loop artificial pancreas systems have been in development for several years, including assessment in numerous varied outpatient clinical trials. We aimed to summarise the efficacy and safety of artificial pancreas systems in outpatient settings and explore the clinical and technical factors that can affect their performance. We did a systematic review and meta-analysis of randomised controlled trials comparing artificial pancreas systems (insulin only or insulin plus glucagon) with conventional pump therapy (continuous subcutaneous insulin infusion [CSII] with blinded continuous glucose monitoring [CGM] or unblinded sensor-augmented pump [SAP] therapy) in adults and children with type 1 diabetes. We searched Medline, Embase, and the Cochrane Central Register of Controlled Trials for studies published from 1946, to Jan 1, 2017. We excluded studies not published in English, those involving pregnant women or participants who were in hospital, and those testing adjunct medications other than glucagon. The primary outcome was the mean difference in percentage of time blood glucose concentration remained in target range (3·9-10 mmol/L or 3·9-8 mmol/L, depending on the study), assessed by random-effects meta-analysis. This study is registered with PROSPERO, number 2015:CRD42015026854. We identified 984 reports; after exclusions, 27 comparisons from 24 studies (23 crossover and one parallel design) including a total of 585 participants (219 in adult studies, 265 in paediatric studies, and 101 in combined studies) were eligible for analysis. Five comparisons assessed dual-hormone (insulin and glucagon), two comparisons assessed both dual-hormone and single-hormone (insulin only), and 20 comparisons assessed single-hormone artificial pancreas systems. Time in target was 12·59% higher with artificial pancreas systems (95% CI 9·02-16·16; p<0·0001), from a weighted mean of 58·21% for conventional pump therapy (I 2 =84%). Dual-hormone artificial pancreas systems were associated with a greater improvement in time in target range compared with single-hormone systems (19·52% [95% CI 15·12-23·91] vs 11·06% [6·94 to 15·18]; p=0·006), although six of seven comparisons compared dual-hormone systems to CSII with blinded CGM, whereas 21 of 22 single-hormone comparisons had SAP as the comparator. Single-hormone studies had higher heterogeneity than dual-hormone studies (I 2 79% vs 66%). Bias assessment characteristics were incompletely reported in 12 of 24 studies, no studies masked participants to the intervention assignment, and masking of outcome assessment was not done in 12 studies and was unclear in 12 studies. Artificial pancreas systems uniformly improved glucose control in outpatient settings, despite heterogeneous clinical and technical factors. None. Copyright © 2017 Elsevier Ltd. All rights reserved.

Nonlinear Optics Technology, Area 1: FWM (Four Wave Mixing) Technology

DTIC Science & Technology

1986-09-22

41 0 u Q)Co o 0 0. >1- o 0 41 -A $4 P4 38 paths to insure a high degree of copolarization at the Na cell. Turning mirrors (M) were visible dielectric...or MAXBRIte coated Zerodur substrate optics with twentieth wave or better surface figures. A 50-50 beamsplitter (BSl) served to generate the two pump...retroreflecting mirror . The signal beam, which essentially constituted a very bright glint, was split off of the pump leg by a beamsplitter and directed to a

AAFES Gas Station at Creech Air Force Base Environmental Assessment

DTIC Science & Technology

2009-07-01

Creech AFB with modern fuel refilling services. The AAFES Gas Station would include a one pump two hose filling station, a concrete slab, a 12,000...at both end of each hose , a shear valve at the base of the pump, and an electronic sensor in the dispenser to detect fuel leakage. In order to add...designed and built with leak prevention safety equipment. Shut- off valves would be installed at both ends of each hose . A shear valve would be

Development of a system for off-peak electrical energy use by air conditioners and heat pumps

NASA Astrophysics Data System (ADS)

Russell, L. D.

1980-05-01

Investigation and evaluation of several alternatives for load management for the TVA system are described. Specific data for the TVA system load characteristics were studied to determine the typical peak and off peak periods for the system. The alternative systems investigated for load management included gaseous energy storage, phase change materials energy storage, zeolite energy storage, variable speed controllers for compressors, and weather sensitive controllers. After investigating these alternatives, system design criteria were established; then, the gaseous and PCM energy storage systems were analyzed. The system design criteria include economic assessment of all alternatives. Handbook data were developed for economic assessment. A liquid/PCM energy storage system was judged feasible.

[Critical infusion incident caused by incorrect use of a patient-controlled analgesia pump].

PubMed

Steffen, M; von Hintzenstern, U; Obermayer, A

2002-01-01

We report on the case of a 17-year-old male patient who received a PCA pump after nephrectomy for postoperative analgesia. The syringe of the PCA pump was filled with 50 mg morphine and positioned about 25 cm above the heart. Since the piston of the syringe was not bolted while the pump was switched off, an unnoticed accidental evacuation of the whole content of the syringe into the intravenous line of the patient occurred because of gravity. This problem exists not only with PCA pumps, but can happen with syringe pumps in general. The incident, which can only be explained by strongly reduced venous pressure, was detected by chance. No harm resulted for the patient, but under different conditions it could have been lethal. This critical incident was caused by various factors: incorrect application in combination with insufficient experience or training, stress, inadequate handing-over of the patient and a lack of arrangements and instructions for procedures in routine situations. Suggestions for preventing such dangerous critical incidents are made and discussed. In particular, an algorithm for the correct procedure when inserting or changing the syringe of a syringe pump is presented.

Comparison of continuous subcutaneous and intravenous hydromorphone infusions for management of cancer pain.

PubMed

Moulin, D E; Kreeft, J H; Murray-Parsons, N; Bouquillon, A I

1991-02-23

To compare the safety and efficacy of subcutaneous and intravenous infusion of opioid analgesics, a randomised, double-blind, crossover trial was carried out in inpatients. 15 patients with severe cancer pain received two 48 h infusions of hydromorphone--one subcutaneously and one intravenously in randomly allocated order. The study was made double-blind by the use of two infusion pumps throughout; during the active subcutaneous infusion the intravenous pump delivered saline and vice versa. Serial measurements of pain intensity, pain relief, mood, and sedation by means of visual analogue scales showed no clinically or statistically significant difference between the two infusion routes. Side-effects were slight, and the mean number of morphine injections for breakthrough pain did not differ significantly between the routes (4.8 [SD 4.5] for intravenous vs 5.3 [5.6] for subcutaneous). Plasma hydromorphone concentrations measured at 24 h and 48 h of infusion showed stable steady-state pharmacokinetics; the mean bioavailability from subcutaneous infusion was 78% of that with intravenous infusion. Because of the simplicity, technical advantages, and cost-effectiveness of continuous subcutaneous opioid infusion into the chest wall or trunk, intravenous opioid infusion for the management of severe cancer pain should be abandoned.

Treatment of Parkinson's disease could be regulated by movement sensors: subcutaneous infusion of varying apomorphine doses according to the intensity of motor activity.

PubMed

Rodríguez-Molinero, Alejandro; Pérez-Martínez, David A; Català, Andreu; Cabestany, Joan; Yuste, Antonio

2009-04-01

Most recent therapeutic solutions to treat Parkinson's disease seek continuous administration of dopaminergic agonists, as for example rigotine patches or apomorphine infusion pumps. Such drug-delivery devices are aimed at preventing fluctuations in drug plasma levels, which could cause certain symptoms such as wearing-off periods or dyskinesia. However, we postulate that drug plasma levels should not keep constant, but rather adjust to the varying intensity of the different user's activities. The rationale behind this is that the drug amount appropriate to treat a patient at rest is lower than that required to treat the same patient when engaged in physical activity. We propose dynamic real-time dose adjustment, so that the doses increase as the patient starts performing physical activity, thus preventing off periods such as "freeze" phenomenon, and the doses reduce during the resting periods, thus preventing adverse effects. Small portable movement sensors are currently available, which detect the amount and type of activity in a continuous way. Combining such technology with infusion pumps to produce modified pumps capable of adjusting the infusion rate to the user's activity, seems to be feasible in the short-term.

Modeling and design of light powered biomimicry micropump utilizing transporter proteins

NASA Astrophysics Data System (ADS)

Liu, Jin; Sze, Tsun-Kay Jackie; Dutta, Prashanta

2014-11-01

The creation of compact micropumps to provide steady flow has been an on-going challenge in the field of microfluidics. We present a mathematical model for a micropump utilizing Bacteriorhodopsin and sugar transporter proteins. This micropump utilizes transporter proteins as method to drive fluid flow by converting light energy into chemical potential. The fluid flow through a microchannel is simulated using the Nernst-Planck, Navier-Stokes, and continuity equations. Numerical results show that the micropump is capable of generating usable pressure. Designing parameters influencing the performance of the micropump are investigated including membrane fraction, lipid proton permeability, illumination, and channel height. The results show that there is a substantial membrane fraction region at which fluid flow is maximized. The use of lipids with low membrane proton permeability allows illumination to be used as a method to turn the pump on and off. This capability allows the micropump to be activated and shut off remotely without bulky support equipment. This modeling work provides new insights on mechanisms potentially useful for fluidic pumping in self-sustained bio-mimic microfluidic pumps. This work is supported in part by the National Science Fundation Grant CBET-1250107.

Fluid dynamic characteristics of the VentrAssist rotary blood pump.

PubMed

Tansley, G; Vidakovic, S; Reizes, J

2000-06-01

The VentrAssist pump has no shaft or seal, and the device is unique in design because the rotor is suspended passively by hydrodynamic forces, and urging is accomplished by an integrated direct current motor rotor that also acts as the pump impeller. This device has led to many challenges in its fluidic design, namely large flow-blockage from impeller blades, low stiffness of bearings with concomitant impeller displacement under pulsatile load conditions, and very small running clearances. Low specific speed and radial blade off-flow were selected in order to minimize the hemolysis. Pulsatile and steady-flow tests show the impeller is stable under normal operating conditions. Computational fluid dynamics (CFD) has been used to optimize flow paths and reduce net axial force imbalance to acceptably small values. The latest design of the pump achieved a system efficiency of 18% (in 30% hematocrit of red blood cells suspended in phosphate-buffered saline), and efficiency was optimized over the range of operating conditions. Parameters critical to improving pump efficiency were investigated.

Oilwell Power Controller (OPC)

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

Not Available

1993-08-01

The Oil Well Power Controller (OPC) prototype units is nearing completion. This device is an oilwell beam pump controller and data logger. Applications for this device have been for an electrical power saving device, pump off control, parafffin detection, demand power load control, chemical treatment data, dynamometer and pump efficiency data. Preliminary results appear vary promising. A total of ten OPC rod pump controllers were assembled and installed on oilwells in several areas of Central and Western United States. Data was analyzed on these wells and forwarded to the participating oil companies. Cost savings on each individual oil well participatingmore » in the OPC testing vary considerably, savings on some situations have been outstanding. In situations where the pump efficiency was determined to be low, the cost savings have been considerable. Cost savings due to preventive maintenance are also present, but are difficult to pin point an exact dollar amount at the present time. A break out of actual cost data obtained on some of the oilwells controlled and monitored with the oilwell power controller.« less

Electron particle transport and turbulence studies in the T-10 tokamak

NASA Astrophysics Data System (ADS)

Vershkov, V. A.; Borisov, M. A.; Subbotin, G. F.; Shelukhin, D. A.; Dnestrovskii, Yu. N.; Danilov, A. V.; Cherkasov, S. V.; Gorbunov, E. P.; Sergeev, D. S.; Grashin, S. A.; Krylov, S. V.; Kuleshin, E. O.; Myalton, T. B.; Skosyrev, Yu. V.; Chistiakov, V. V.

2013-08-01

The goals of this paper are to compare the results of electron particle transport measurements in ohmic (OH) plasmas by means of a small perturbation technique, high-level gas puff and gas switch off, investigate the phenomenon of ‘density pump out’ during electron cyclotron resonance heating (ECRH) and to correlate density behaviour with turbulence. Two approaches for plasma particle transport studies were compared: the low perturbation technique of periodic puff (δn/ne = 0.3%) and strong density variations (δn/ne < 50%), including density ramp-up by gas puff and ramp-down with gas switch off. The model with constant in time diffusion coefficients and pinch velocities could describe the core density perturbations but failed at the edge. In the case of strong puff three stages were distinguished. Degraded energy confinement and, respectively, low turbulence frequencies were observed during density ramp-up and ramp-down, while enhanced confinement and higher turbulence frequencies were typical for the intermediate stage. Density profile variation during this intermediate phase could be described in the framework of the transport model with constant in time coefficients. The application of ECRH at the density ramp-up phase provided the possibility of postponing the ‘density pump out’. The increase in the low-frequency modes in turbulence spectra was observed at the ‘density pump out’ phase during central ECRH. Although the high- and low-frequency bands of turbulence spectra behaved as trapped electron mode and ion temperature gradient, respectively, they both rotated at the same angular velocity as a rigid body together with magnetohydrodynamic mode m/n = 2/1 and [E × B] plasma rotation.

Acute uncomplicated appendicitis study: rationale and protocol for a multicentre, prospective randomised controlled non-inferiority study to evaluate the safety and effectiveness of non-operative management in children with acute uncomplicated appendicitis.

PubMed

Xu, Jane; Liu, Yingrui Cyril; Adams, Susan; Karpelowsky, Jonathan

2016-12-21

This article presents an overview of a prospective randomised controlled non-inferiority study designed to evaluate the safety and effectiveness of non-operative management (NOM) with operative management in children with acute uncomplicated appendicitis (AUA). Here, we present the study protocol for this APRES study, a multicentre Australian study. The rationale and details of future analysis, in particular, non-inferiority calculations, cost-effectiveness, feasibility and acceptability of each intervention. A multicentre, prospective randomised controlled clinical trial, conducted in 2 Australian tertiary paediatric hospitals. Children who meet the inclusion criteria of an age between 5 and 15 years and a clinical diagnosis of AUA will be invited to participate, and after consent will be randomised via a computer-based program into treatment groups. The study started in June 2016, and the target recruitment is 220 patients. Children in the control group will be treated with prophylactic antibiotics and appendicectomy, and those in the intervention group will be treated with antibiotic therapy alone. Primary outcome measures include unplanned or unnecessary operation and complications at 30 days. Secondary outcomes include longer term complications within 1 year, length of stay, time off work and school analgesic requirements and cost. Data analyses will be on the intention-to-treat principle using non-inferiority analysis. Analysis will include the Pearson χ 2 test for categorical variables and independent sample t-test or Mann-Whitney test for continuous variables. Non-inferiority for NOM will be tested using 1-sided Wald tests with an α level of 0.05. The research has been approved by the Human Research Ethics Committee of the Sydney Children's Hospital Network. In addition, results will be reported through academic journals, seminars and conference presentations. NCT02795793; ACTRN12616000788471. 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/.

Assessment of the effect of off-pump coronary artery bypass (OPCAB) surgery on right ventricle function using strain and strain rate imaging.

PubMed

Khani, Mohammad; Hosseintash, Mahsa; Foroughi, Mahnoosh; Naderian, Mohammadreza; Khaheshi, Isa

2016-04-01

Right ventricle function significantly decreases after coronary artery bypass surgery; as one of the likely causes, such a condition is attributed to the use of cardiopulmonary pump (CPB). Because nowadays there is a tendency toward increasing use of off-pump coronary artery bypass (OPCAB) surgery, this study was conducted to evaluate the right ventricle function after this type of surgery using strain and strain rate imaging (SRI) echocardiography. This study was conducted on 30 patients, candidate for elective OPCAB surgery, between 2011 and 2012. Standard echocardiography was performed before the surgery and the right ventricle function was examined using strain and SRI echocardiography. Then patient underwent surgery, 6 days and 3 months after surgery they underwent echocardiography again and the results obtained from the three stages were compared with each other. Participants included 30 patients (23 males and 7 females) with a mean age of 66±11 years. Compared to the prior of the surgery, 6 days and 3 months after the surgery there was a significant decrease in tricuspid annular plane systolic excursion (TAPSE), tissue Doppler imaging (TDI) at the lateral annulus of tricuspid valve, and strain and SRI of right ventricle. However, the values obtained 3 months after surgery were significantly higher than those obtained after 6 days. In other words, the right ventricle function 6 days after the surgery had dropped, however some of the values recovered 3 months after the surgery. The findings of this study are consistent with other studies in this field and showed that after coronary artery surgery a decline occurs in right ventricular function. However, more detailed quantitative strain and SRI parameters which were measured in our study showed that at the early days after the OPCAB surgery there is a decline in the right ventricle function which is relatively reversible at longer intervals (3 months after surgery).

Procedure Training Aid for the SH-3D/H Normal Start Checklist.

DTIC Science & Technology

1982-02-01

1 Engine .... START Pupoe: To make a Normal Start of No. 1 engine. :4 14. Action Pilot/Copilot verify lite -off by noting rapid rise in T5 and Nq and...Nf increasinq 15. Note Normal starts are characterized by 7 0-75D0 T5 in I seconds after lite -off 16. If T5 is incrasinn too rapidlyv or appears to...Pumps 206 NORMAL START CHECKLIST ITEM NO. 23. No. I Ergine ... TART 14. Action Pilot/Copilot verify lite -off by noting ra ’pid rise in and Ng and Nf

Experimental analysis of the flow pattern of a pump turbine model in pump mode

NASA Astrophysics Data System (ADS)

Guggenberger, Mark; Senn, Florian; Jaberg, Helmut; Gehrer, Arno; Sallaberger, Manfred; Widmer, Christian

2016-11-01

Reversible pump turbines are the only means to store primary energy in an highly efficient way. Within a short time their operation can be switched between the different operational regimes thus enhancing the stabilization of the electric grid. These qualities in combination with the operation even at off-design conditions offer a high flexibility to the energy market. However, pump turbines pass through operational regimes where their behaviour becomes unstable. One of these effects occurs when the flowrate is decreased continuously down to a minimum. This point is the physical limitation of the pump operation and is very difficult to predict properly by numerical design without a model test. The purpose of the present study is to identify the fluid mechanical phenomena leading to the occurrence of instabilities of pump turbines in pump mode. A reduced scale model of a ANDRITZ pump turbine was installed on a 4-quadrant test rig for the experimental investigation of unstable conditions in pump mode. The performed measurements are based on the IEC60193-standard. Characteristic measurements at a single guide vane opening were carried out to get a detailed insight into the instabilities in pump mode. The interaction between runner and guide vane was analysed by Particle Image Velocimetry. Furthermore, high-speed visualizations of the suction side part load flow and the suction recirculation were performed. Like never before the flow pattern in the draft tube cone became visible with the help of a high-speed camera by intentionally caused cavitation effects which allow a qualitative view on the flow pattern in the draft tube cone. Suction recirculation is observed in form of single vortices separating from each runner blade and stretching into the draft tube against the main flow direction. To find an explanation for the flow phenomena responsible for the appearance of the unstable head curve also characteristic velocity distributions on the pressure side were combined with high-speed visualizations on the suction side of the pump turbine model. The results enhance the comprehension of the physical background leading to the instability and improve the numerical predictability of the instability in pump mode.

Performance of a solar augmented heat pump

NASA Astrophysics Data System (ADS)

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.

Role of phase matching in pulsed second-harmonic generation: Walk-off and phase-locked twin pulses in negative-index media

NASA Astrophysics Data System (ADS)

Roppo, Vito; Centini, Marco; Sibilia, Concita; Bertolotti, Mario; de Ceglia, Domenico; Scalora, Michael; Akozbek, Neset; Bloemer, Mark J.; Haus, Joseph W.; Kosareva, Olga G.; Kandidov, Valery P.

2007-09-01

The present investigation is concerned with the study of pulsed second-harmonic generation under conditions of phase and group velocity mismatch, and generally low conversion efficiencies and pump intensities. In positive-index, nonmetallic materials, we generally find qualitative agreement with previous reports regarding the presence of a double-peaked second harmonic signal, which comprises a pulse that walks off and propagates at the nominal group velocity one expects at the second-harmonic frequency, and a second pulse that is “captured” and propagates under the pump pulse. We find that the origin of the double-peaked structure resides in a phase-locking mechanism that characterizes not only second-harmonic generation, but also χ(3) processes and third-harmonic generation. The phase-locking mechanism that we describe occurs for arbitrarily small pump intensities, and so it is not a soliton effect, which usually relies on a threshold mechanism, although multicolor solitons display similar phase locking characteristics. Thus, in second harmonic generation a phase-matched component is always generated, even under conditions of material phase mismatch: This component is anomalous, because the material does not allow energy exchange between the pump and the second-harmonic beam. On the other hand, if the material is phase matched, phase locking and phase matching are indistinguishable, and the conversion process becomes efficient. We also report a similar phase-locking phenomenon in negative index materials. A spectral analysis of the pump and the generated signals reveals that the phase-locking phenomenon causes the forward moving, phase-locked second-harmonic pulse to experience the same negative index as the pump pulse, even though the index of refraction at the second-harmonic frequency is positive. Our analysis further shows that the reflected second-harmonic pulse generated at the interface and the forward-moving, phase-locked pulse appear to be part of the same pulse initially generated at the surface, part of which is immediately back-reflected, while the rest becomes trapped and dragged along by the pump pulse. These pulses thus constitute twin pulses generated at the interface, having the same negative wave vector, but propagating in opposite directions. Almost any break of the longitudinal symmetry, even an exceedingly small χ(2) discontinuity, releases the trapped pulse which then propagates in the backward direction. These dynamics are indicative of very rich and intricate interactions that characterize ultrashort pulse propagation phenomena.

Role of phase matching in pulsed second-harmonic generation: Walk-off and phase-locked twin pulses in negative-index media

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

Roppo, Vito; Centini, Marco; Sibilia, Concita

The present investigation is concerned with the study of pulsed second-harmonic generation under conditions of phase and group velocity mismatch, and generally low conversion efficiencies and pump intensities. In positive-index, nonmetallic materials, we generally find qualitative agreement with previous reports regarding the presence of a double-peaked second harmonic signal, which comprises a pulse that walks off and propagates at the nominal group velocity one expects at the second-harmonic frequency, and a second pulse that is 'captured' and propagates under the pump pulse. We find that the origin of the double-peaked structure resides in a phase-locking mechanism that characterizes not onlymore » second-harmonic generation, but also {chi}{sup (3)} processes and third-harmonic generation. The phase-locking mechanism that we describe occurs for arbitrarily small pump intensities, and so it is not a soliton effect, which usually relies on a threshold mechanism, although multicolor solitons display similar phase locking characteristics. Thus, in second harmonic generation a phase-matched component is always generated, even under conditions of material phase mismatch: This component is anomalous, because the material does not allow energy exchange between the pump and the second-harmonic beam. On the other hand, if the material is phase matched, phase locking and phase matching are indistinguishable, and the conversion process becomes efficient. We also report a similar phase-locking phenomenon in negative index materials. A spectral analysis of the pump and the generated signals reveals that the phase-locking phenomenon causes the forward moving, phase-locked second-harmonic pulse to experience the same negative index as the pump pulse, even though the index of refraction at the second-harmonic frequency is positive. Our analysis further shows that the reflected second-harmonic pulse generated at the interface and the forward-moving, phase-locked pulse appear to be part of the same pulse initially generated at the surface, part of which is immediately back-reflected, while the rest becomes trapped and dragged along by the pump pulse. These pulses thus constitute twin pulses generated at the interface, having the same negative wave vector, but propagating in opposite directions. Almost any break of the longitudinal symmetry, even an exceedingly small {chi}{sup (2)} discontinuity, releases the trapped pulse which then propagates in the backward direction. These dynamics are indicative of very rich and intricate interactions that characterize ultrashort pulse propagation phenomena.« less

Randomised clinical trial: the efficacy of a 10-day sequential therapy vs. a 14-day standard proton pump inhibitor-based triple therapy for Helicobacter pylori in Korea.

PubMed

Kim, Y S; Kim, S J; Yoon, J H; Suk, K T; Kim, J B; Kim, D J; Kim, D Y; Min, H J; Park, S H; Shin, W G; Kim, K H; Kim, H Y; Baik, G H

2011-11-01

The eradication rates of Helicobacter pylori (H. pylori) using a proton pump inhibitor (PPI)-based triple therapy have declined due to antibiotic resistance worldwide. To compare the eradication rate of the 10-day sequential therapy for H. pylori infection with that of the 14-day standard PPI-based triple therapy. This was a prospective, randomised, controlled study. A total of 409 patients with H. pylori infection were randomly assigned to receive either the 10-day sequential therapy regimen, which consisted of pantoprazole (40 mg) plus amoxicillin (1000 mg) twice a day for 5 days, then pantoprazole (40 mg) with clarithromycin (500 mg) and metronidazole (500 mg) twice a day for another five consecutive days or the 14-day PPI-based triple therapy regimen, which consisted of pantoprazole (40 mg) with amoxicillin (1000 mg) and clarithromycin (500 mg) twice a day for 14 days. The pre- and post-treatment H. pylori status were assessed by rapid urease test, urea breath test, or histology. Successful eradication was confirmed at least 4 weeks after finishing the treatment. In the intention-to-treat analysis, the eradication rates of the 10-day sequential therapy and of the 14-day PPI-based triple therapy were 85.9% (176/205) and 75.0% (153/205), respectively (P = 0.006). In the per-protocol analysis, the eradication rates were 92.6% (175/205) and 85% (153/204), respectively (P = 0.019). There was no statistically significant difference between the two investigated groups regarding the occurrence of adverse event rates (18.9% vs. 13.3%, P = 0.143). The 10-day sequential therapy achieved significantly higher eradication rates than the 14-day standard PPI-based triple therapy in Korea. © 2011 Blackwell Publishing Ltd.

Assessing the potential for using wetlands as intermediary storages to conjunctively maintain ecological values and support agricultural demands.

PubMed

Ning, Nathan S P; Watkins, Susanne C; Gawne, Ben; Nielsen, Daryl L

2012-09-30

Water sharing to meet both agricultural and environmental demands is a critical issue affecting the health of many floodplain river systems around the world. This study explored the potential for using wetlands as temporary off-river storages to conjunctively maintain ecological values and support agricultural demands by assessing the effects of artificial drawdown on wetland aquatic plant communities. An initial experiment was undertaken in outdoor mesocosms in which four different treatments were compared over a 131 day duration: (1) natural drawdown where the water was left to drawdown naturally via evaporation; (2) partial drawdown where approximately half of the volume of water was pumped out after 42 days; (3) stepped drawdown where approximately half of the volume of water pumped out after 42 days, and then the remaining volume of water was pumped out after 117 days; and (4) total drawdown where all of the of water was pumped out after 117 days. A complementary field study was subsequently undertaken where two wetlands were left to drawdown naturally and two were partially drawn down artificially (i.e. had approximately half of their volume removed by pumping). Results from both of these studies indicated that neither aquatic plant abundance nor taxon richness were adversely affected by partial drawdown. Rather, both studies showed that aquatic plant communities subjected to a partial drawdown treatment became more species rich and diverse than communities subjected to a natural drawdown treatment. This suggests that it may be possible to use wetlands as intermediary storages for the dual purposes of maintaining ecological values and supporting agricultural demands. Crown Copyright © 2012. Published by Elsevier Ltd. All rights reserved.

Q-switched oscillation in thulium-doped fiber lasers using preloaded dynamic microbending technique

NASA Astrophysics Data System (ADS)

Sakata, H.; Takahashi, N.; Ushiro, Y.

2018-01-01

We demonstrate Q-switched pulse generation in thulium-doped fiber lasers by introducing piezoelectric-driven microbend with preloaded stress. We employed a pair of corrugated chips each attached on piezoelectric actuators (PAs) to clamp the fiber in a ring laser resonator. The thulium-doped fiber is pumped by a laser diode emitting at 1.63 μm and generates the Q-switched laser pulses at around 1.9 μm by switching off the PAs. The laser pulse performance is improved by optimizing the preload and switch-off period for the PAs. The Q-switched pulses with a peak power of 2.8 W and a pulsewidth of 900 ns are observed for a launched pump power of 161 mW. We expect that the in-fiber Q-switching technique will provide efficient laser systems for environmental sensing and medical applications.

Enhanced broadband near-IR luminescence and gain spectra of bismuth/erbium co-doped fiber by 830 and 980 nm dual pumping

NASA Astrophysics Data System (ADS)

Zhao, Qiancheng; Luo, Yanhua; Wang, Wenyu; Canning, John; Peng, Gang-Ding

2017-04-01

A dual 830 and 980 nm pumping scheme is proposed aiming at broadening and flattening the spectral performance of bismuth/erbium codoped multicomponent fiber (BEDF). The spectral properties of distinct Bi active centers (BACs) associated with germanium (BAC-Ge), aluminium (BAC-Al), phosphorus (BAC-P) and silicon (BAC-Si) are characterized under single pumping of 830 and 980 nm, respectively. Based on the emission slope efficiencies of BAC-Al (˜1100 nm) and BAC-Si (˜1430 nm) under single pumping of 830 and 980 nm, the dual pumping scheme with the optimal pump power ratio of 25 (980 nm VS 830 nm) is determined to achieve flat, ultrabroadband luminescence spectra covering the wavelength range 950-1600 nm. The dual pumping scheme is further demonstrated on the on-off gain performance of BEDF. It is found under the pump power ratio of ˜8 (980 VS 830 nm), The gain spectrum has been flattened and broadened over 300 nm (1300-1600 nm) with an average gain coefficient of ˜1.5 dBm-1. The spectral coverage is approximately 1.5 and 3 times wider compared to single pumping of 830 and 980 nm pumping, respectively. The energy level diagrams of 830 and 980 nm are also constructed separately in view of the optical characteristic, which further clarifies the advantage for dual pumping. The proposed dual 830 and 980 nm pumping scheme with the multicomponent BEDF shows great potential in various broadband optical applications such as uniform ASE source, broadband amplifier and tuneable laser in NIR band.

Zero Gravity Cryogenic Vent System Concepts for Upper Stages

NASA Astrophysics Data System (ADS)

Ravex, Alain; Flachbart, Robin; Holt, Barney

The capability to vent in zero gravity without resettling is a technology need that involves practically all uses of sub-critical cryogenics in space. Venting without resettling would extend cryogenic orbital transfer vehicle capabilities. However, the lack of definition regarding liquid/ullage orientation coupled with the somewhat random nature of the thermal stratification and resulting pressure rise rates, lead to significant technical challenges. Typically a zero gravity vent concept, termed a thermodynamic vent system (TVS), consists of a tank mixer to destratify the propellant, combined with a Joule-Thomson (J-T) valve to extract thermal energy from the propellant. Marshall Space Flight Center's (MSFC's) Multipurpose Hydrogen Test Bed (MHTB) was used to test both spray bar and axial jet TVS concepts. The axial jet system consists of a recirculation pump heat exchanger unit. The spray bar system consists of a recirculation pump, a parallel flow concentric tube, heat exchanger, and a spray bar positioned close to the longitudinal axis of the tank. The operation of both concepts is similar. In the mixing mode, the recirculation pump withdraws liquid from the tank and sprays it into the tank liquid, ullage, and exposed tank surfaces. When energy extraction is required, a small portion of the recirculated liquid is passed sequentially through the J-T expansion valve, the heat exchanger, and is vented overboard. The vented vapor cools the circulated bulk fluid, thereby removing thermal energy and reducing tank pressure. The pump operates alone, cycling on and off, to destratify the tank liquid and ullage until the liquid vapor pressure reaches the lower set point. At that point, the J-T valve begins to cycle on and off with the pump. Thus, for short duration missions, only the mixer may operate, thus minimizing or even eliminating boil-off losses. TVS performance testing demonstrated that the spray bar was effective in providing tank pressure control within a 6.89 kPa (1psi) band for fill levels of 90%, 50%, and 25%. Complete destratification of the liquid and ullage was achieved at these fill levels. The axial jet was effective in providing tank pressure control within the same pressure control band at the 90% fill level. However, at the 50% level, the system reached a point at which it was unable to extract enough energy to keep up with the heat leak into the tank. Due to a hardware problem, the recirculation pump operated well below the axial jet design flow rate. Therefore, it is likely that the performance of the axial jet would have improved had the pump operated at the proper flow rate. A CFD model is being used to determine if the desired axial jet performance would be achieved if a higher pump flow rate were available. Testing conducted thus far has demonstrated that both TVS concepts can be effective in destratifying a propellant tank, rejecting stored heat energy, and thus, controlling tank pressure.

Design and modeling of a light powered biomimicry micropump

NASA Astrophysics Data System (ADS)

Sze, Tsun-kay Jackie; Liu, Jin; Dutta, Prashanta

2015-06-01

The design of compact micropumps to provide steady flow has been an on-going challenge in the field of microfluidics. In this work, a novel micropump concept is introduced utilizing bacteriorhodopsin and sugar transporter proteins. The micropump utilizes light energy to activate the transporter proteins, which create an osmotic pressure gradient and drive the fluid flow. The capability of the bio inspired micropump is demonstrated using a quasi 1D numerical model, where the contributions of bacteriorhodopsin and sugar transporter proteins are taken care of by appropriate flux boundary conditions in the flow channel. Proton flux created by the bacteriorhodopsin proteins is compared with experimental results to obtain the appropriate working conditions of the proteins. To identify the pumping capability, we also investigate the influences of several key parameters, such as the membrane fraction of transporter proteins, membrane proton permeability and the presence of light. Our results show that there is a wide bacteriorhodopsin membrane fraction range (from 0.2 to 10%) at which fluid flow stays nearly at its maximum value. Numerical results also indicate that lipid membranes with low proton permeability can effectively control the light source as a method to turn on/off fluid flow. This capability allows the micropump to be activated and shut off remotely without bulky support equipment. In comparison with existing micropumps, this pump generates higher pressures than mechanical pumps. It can produce peak fluid flow and shutoff head comparable to other non-mechanical pumps.

Building America Case Study: Impact of Improved Duct Insulation on Fixed-Capacity (SEER 13) and Variable-Capacity (SEER 22) Heat Pumps, Cocoa, Florida

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

C. Withers, J. Cummings, B. Nigusse, E. Martin

A new generation of central, ducted variable-capacity heat pump systems has come on the market, promising very high cooling and heating efficiency. Instead of cycling on at full capacity and then cycling off when the thermostat is satisfied, they vary their cooling and heating output over a wide range (approximately 40 to 118% of nominal full capacity); thus, staying 'on' for 60% to 100% more hours per day compared to fixed-capacity systems. Current Phase 4 experiments in an instrumented lab home with simulated occupancy evaluate the impact of duct R-value enhancement on the overall operating efficiency of the variable-capacity systemmore » compared to the fixed-capacity system.« less

Broadband and tunable optical parametric generator for remote detection of gas molecules in the short and mid-infrared.

PubMed

Lambert-Girard, Simon; Allard, Martin; Piché, Michel; Babin, François

2015-04-01

The development of a novel broadband and tunable optical parametric generator (OPG) is presented. The OPG properties are studied numerically and experimentally in order to optimize the generator's use in a broadband spectroscopic LIDAR operating in the short and mid-infrared. This paper discusses trade-offs to be made on the properties of the pump, crystal, and seeding signal in order to optimize the pulse spectral density and divergence while enabling energy scaling. A seed with a large spectral bandwidth is shown to enhance the pulse-to-pulse stability and optimize the pulse spectral density. A numerical model shows excellent agreement with output power measurements; the model predicts that a pump having a large number of longitudinal modes improves conversion efficiency and pulse stability.

Highly nonlinear organic crystal OHQ-T for efficient ultra-broadband terahertz wave generation beyond 10 THz.

PubMed

Kang, Bong Joo; Baek, In Hyung; Lee, Seung-Heon; Kim, Won Tae; Lee, Seung-Jun; Jeong, Young Uk; Kwon, O-Pil; Rotermund, Fabian

2016-05-16

We report on efficient generation of ultra-broadband terahertz (THz) waves via optical rectification in a novel nonlinear organic crystal with acentric core structure, i.e. 2-(4-hydroxystyryl)-1-methylquinolinium 4-methylbenzenesulfonate (OHQ-T), which possesses an ideal molecular structure leading to a maximized nonlinear optical response for near-infrared-pumped THz wave generation. By systematic studies on wavelength-dependent phase-matching conditions in OHQ-T crystals of different thicknesses we are able to generate coherent THz waves with a high peak-to-peak electric field amplitude of up to 650 kV/cm and an upper cut-off frequency beyond 10 THz. High optical-to-THz conversion efficiency of 0.31% is achieved by efficient index matching with a selective pumping at 1300 nm.

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

PubMed

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.

Far infrared maser communications technology

NASA Technical Reports Server (NTRS)

Claspy, P. C.; Pao, Y. H.

1975-01-01

An optically pumped FIR laser was constructed and tested. Optimum operating conditions were determined with CH3OH as the lasing medium. The laser was found to operate equally well with flowing gas or in a sealed off configuration. The FIR cavity stability and pump laser stability were found to have significant problems. The absorption coefficient per unit pressure of 1-1 difluoroethylene at the P(22) and P(24) lines of the 10.4 micron CO2 band was measured. The FIR line pumped by P(22) occurs at approximately 890 microns, which may be in an atmospheric transmission window. It was found that significant Stark tuning of absorption lines of methanol and 1-1 difluoroethylene can be accomplished, even at the usual 100 to 300 mTorr operating pressures of FIR lasers. This means that the use of Stark tuning may enable more effective use of pump laser output.

Five-order SRSs and supercontinuum generation from a tapered tellurite microstructured fiber with longitudinally varying dispersion.

PubMed

Liao, Meisong; Yan, Xin; Gao, Weiqing; Duan, Zhongchao; Qin, Guanshi; Suzuki, Takenobu; Ohishi, Yasutake

2011-08-01

We try to obtain stable supercontinuum (SC) generation with broad bandwidth under relative simple pump conditions. We use a 1.3-m-long highly nonlinear tellurite microstructured fiber and pump it by a 15 ps 1064 nm fiber laser. One segment of the fiber is tapered from a core diameter of 3.4 μm to 1.3 μm. For the first time five-order stimulated Raman scatterings (SRSs) are observed for soft glass fibers. SC covering 730-1700 nm is demonstrated with the pump-pulse-energy of several nJ. The mechanisms of SC broadening are mainly SRS, self-phase modulation (SPM) and cross phase modulation (XPM). The tapered segment has two advantages. Firstly it increases the nonlinearity of fiber by several times. Secondly, it acts as a compensation for the dispersion of the untapered segment, and mitigates the walk-off between pump pulse and SRS peaks.

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

PubMed

Seifried, Bernhard; Temelli, Feral

2009-07-01

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

The feasibility and safety of off-pump coronary bypass surgery in emergency revascularization

PubMed Central

Joo, Hyun-Chel; Youn, Young-Nam; Chang, Byung-Chul

2018-01-01

Background The efficacy and safety of off-pump coronary artery bypass grafting (OPCAB) in emergency revascularization remains controversial despite its widespread use. The aim of our study was to examine the applicability and safety of OPCAB in patients who were indicated for emergency surgery. Methods This single-center study reviewed the indication, operative data, and early and long-term outcomes of 113 patients (mean age, 67.2±9.0 years; logistic EuroSCORE, 14.3±13.5) who underwent emergency OPCAB from January 2003 to December 2014 and were followed up (94.6% completion rate) for a mean 51.1±40.3 (range, 1–135) months. Results Emergency OPCAB was associated with favorable surgical outcomes (number of distal anastomoses per patient, 3.04±0.87; internal thoracic artery (IMA) use, 98.2%; complete revascularization, 79.6%) and in-hospital outcomes (mortality, 5.3%; low cardiac output syndrome, 5.3%; stroke, 2.7%; pulmonary complications, 8.8%; renal failure, 11.5%). Only five patients (4.4%) required on-pump conversion. The 10-year outcomes were also acceptable (survival, 75.4%±5.6%; major cerebral and cardiovascular events, 52.1%±1.8%). The multivariate risk factors for late mortality were peripheral vascular disease (HR 2.95, 95% CI: 1.11–11.83), cardiogenic shock (HR 3.67, 95% CI: 1.35–9.96), and incomplete revascularization (HR 3.41, 95% CI: 1.06–14.26). When patients were separated by whether the procedure was performed early (<2010) or late (≥2010) in the study period, the late period cohort had better outcomes despite containing higher-risk patients. Conclusions Our study suggests that emergency OPCAB can be performed safely and effectively with good hospital outcomes and adequate long-term results. OPCAB strategy can be considered as a good option in emergency revascularization. PMID:29850131

Efficacy and safety of lesogaberan in gastro-oesophageal reflux disease: a randomised controlled trial.

PubMed

Shaheen, Nicholas J; Denison, Hans; Björck, Karin; Karlsson, Maria; Silberg, Debra G

2013-09-01

Lesogaberan (AZD3355) is a novel γ-aminobutyric acid B-type receptor agonist designed to treat gastro-oesophageal reflux disease (GERD) by inhibiting transient lower oesophageal sphincter relaxations. A randomised, double-blind, placebo-controlled, multi-centre phase IIb study was performed to assess the efficacy and safety of lesogaberan as an add-on to proton pump inhibitor (PPI) therapy in patients with GERD who are partially responsive to PPI therapy (ClinicalTrials.gov reference: NCT01005251). In total, 661 patients were randomised to receive 4 weeks of placebo or 60, 120, 180 or 240 mg of lesogaberan twice daily, in addition to ongoing PPI therapy. Symptoms were measured using the Reflux Symptom Questionnaire electronic Diary. Response to treatment was defined as having an average of ≥ 3 additional days per week of not more than mild GERD symptoms during treatment compared with baseline. In the primary analysis, 20.9%, 25.6%, 23.5% and 26.2% of patients responded to the 60, 120, 180 and 240 mg twice daily lesogaberan doses, respectively, and 17.9% responded to placebo. The response to the 240 mg twice daily dose was statistically significantly greater than the response to placebo using a one-sided test at the predefined significance level of p < 0.1. However, the absolute increases in the proportions of patients who responded to lesogaberan compared with placebo were low. Lesogaberan was generally well tolerated, although six patients receiving lesogaberan developed reversible elevated alanine transaminase levels. In patients with GERD symptoms partially responsive to PPI therapy, lesogaberan was only marginally superior to placebo in achieving an improvement in symptoms.

Stress ulcer prophylaxis versus placebo or no prophylaxis in critically ill patients. A systematic review of randomised clinical trials with meta-analysis and trial sequential analysis.

PubMed

Krag, Mette; Perner, Anders; Wetterslev, Jørn; Wise, Matt P; Hylander Møller, Morten

2014-01-01

To assess the effects of stress ulcer prophylaxis (SUP) versus placebo or no prophylaxis on all-cause mortality, gastrointestinal (GI) bleeding and hospital-acquired pneumonia in adult critically ill patients in the intensive care unit (ICU). We performed a systematic review using meta-analysis and trial sequential analysis (TSA). Eligible trials were randomised clinical trials comparing proton pump inhibitors or histamine 2 receptor antagonists with either placebo or no prophylaxis. Two reviewers independently assessed studies for inclusion and extracted data. The Cochrane Collaboration methodology was used. Risk ratios/relative risks (RR) with 95% confidence intervals (CI) were estimated. The predefined outcome measures were all-cause mortality, GI bleeding, and hospital-acquired pneumonia. Twenty trials (n = 1,971) were included; all were judged as having a high risk of bias. There was no statistically significant difference in mortality (fixed effect: RR 1.00, 95% CI 0.84-1.20; P = 0.87; I(2) = 0%) or hospital-acquired pneumonia (random effects: RR 1.23, 95% CI 0.86-1.78; P = 0.28; I(2) = 19%) between SUP patients and the no prophylaxis/placebo patients. These findings were confirmed in the TSA. With respect to GI bleeding, a statistically significant difference was found in the conventional meta-analysis (random effects: RR 0.44, 95% CI 0.28-0.68; P = 0.01; I(2) = 48%); however, TSA (TSA adjusted 95% CI 0.18-1.11) and subgroup analyses could not confirm this finding. This systematic review using meta-analysis and TSA demonstrated that both the quality and the quantity of evidence supporting the use of SUP in adult ICU patients is low. Consequently, large randomised clinical trials are warranted.

Understanding the C-pulse device and its potential to treat heart failure.

PubMed

Sales, Virna L; McCarthy, Patrick M

2010-03-01

The Sunshine Heart C-Pulse (C-Pulse; Sunshine Heart Inc., Tustin, CA) device is an extra-aortic implantable counterpulsation pump designed as a non-blood contacting ambulatory heart assist device, which may provide relief from symptoms for class II-III congestive heart failure patients. It has a comparable hemodynamic augmentation to intra-aortic balloon counterpulsation devices. The C-Pulse cuff is implanted through a median sternotomy, secured around the ascending aorta, and pneumatically driven by an external system controller. Pre-clinical studies in the acute pig model, and initial temporary clinical studies in patients undergoing off-pump coronary bypass surgery have shown substantial increase in diastolic perfusion of the coronary vessels, which translated to a favorable improvement in ventricular function. A U.S. prospective multi-center trial to evaluate the safety and efficacy of the C-Pulse in class III patients with moderate heart failure is now in progress.

The Effects of On-Pump and Off-Pump Coronary Artery Bypass Surgery on Respiratory Function in the Early Postoperative Period.

PubMed

Chiarenza, Federica; Tsoutsouras, Theodoros; Cassisi, Cesare; Santonocito, Cristina; Gerry, Stephen; Astuto, Marinella; George, Shane; Sanfilippo, Filippo

2017-01-01

Respiratory complications are common after cardiac surgery and the use of extracorporeal circulation is one of the main causes of lung injury. We hypothesized a better postoperative respiratory function in off-pump coronary artery bypass grafting (OPCABG) as compared with "on-pump coronary artery bypass grafting" (ONCABG). This is a retrospective, single-center study at a cardiothoracic intensive care unit (ICU) in a tertiary university hospital. Consecutive data on 339 patients undergoing elective CABG (n = 215 ONCABG, n = 124 OPCABG) were collected for 1 year from the ICU electronic medical records. We compared respiratory variables (Pao 2 , Pao 2 /Fio 2 ratio, Sao 2 , and Paco 2 ) at 7 predefined time points (ICU admission, postoperative hours 1, 3, 6, 12, 18, and 24). We also evaluated time to extubation, rates of reintubation, and use of noninvasive ventilation (NIV). We used mixed-effects linear regression models (with time as random effect for clustering of repeated measures) adjusted for a predetermined set of covariates. The values of Pao 2 and Pao 2 /Fio 2 were significantly higher in the OPCABG group only at ICU admission (mean differences: 9.7 mm Hg, 95% confidence interval [CI] 3.1-16.2; and 27, 95% CI 6.1-47.7, respectively). The OPCABG group showed higher Paco 2 , overall ( P = .02) and at ICU admission (mean difference 1.8 mm Hg, 95% CI: 0.6-3), although mean values were always within normal range in both groups. No differences were seen in Sao 2 values, time to extubation, rate of reintubation rate, and use of postoperative NIV. Extubation rate was higher in OPCABG only at postoperative hour 12 (92% vs ONCABG 82%, P = .02). The OPCABG showed only marginal improvements of unlikely clinical meaning in oxygenation as compared to ONCABG in elective low-risk patients.

Evaluation of CGP 39393 as the anticoagulant in cardiopulmonary bypass operation in a dog model.

PubMed

Walenga, J M; Koza, M J; Park, S J; Terrell, M R; Pifarré, R

1994-12-01

Recombinant desulphatohirudin HV1 (CGP 39393), a specific and potent peptidic inhibitor of thrombin, was evaluated as the sole anticoagulant in a dog model of cardiopulmonary bypass. CGP 39393 was administered as a bolus plus infusion for a 1-hour pump period at doses of 1.0 mg/kg + 0.75 mg.kg-1.h-1, 1.0 mg/kg + 1.50 mg.kg-1.h-1, 1.0 mg/kg + 2.25 mg.kg-1.h-1, or 1.0 mg/kg + 3.0 mg.kg-1.h-1 (n = 5 per group). The lowest dose was ineffective, as a high degree of clot formation (314 +/- 160 mg) occurred as determined by quantitation of protein deposits in the pump line filter. The three higher doses inhibited clot formation (35 to 44 mg) but did not reveal a dose-dependent effect (p = 0.308 between groups). All four doses produced the same amount of postoperative blood loss (6.5 to 10 g/kg over 2 hours; p = 0.215 between groups) and no oozing of blood from cut tissues (sternum, muscle, skin) during or after operation. No adverse hemodynamic or hematologic effects were observed. Animals were physiologically stable coming off pump, requiring minimal fluid replacement or other cardiovascular supportive measures. The chromogenic anti-IIa assay could be used to monitor CGP 39393. Some activated partial thromboplastin time and all activated clotting time values were off scale on pump, but they fell immediately after cardiopulmonary bypass, typically reaching near-normal levels within 30 to 60 minutes. No reversal of CGP 39393 was used, as blood levels declined rapidly after cessation of the infusion. This study in a dog model shows that CGP 39393 administered as a bolus plus infusion (minimum dose, 1.0 mg/kg + 1.50 mg.kg-1.h-1) can be used safely and effectively during cardiopulmonary bypass for cardiac operation.

Magnetic heat pumping near room temperature

NASA Technical Reports Server (NTRS)

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

Pumping Performance or RBCC Engine under Sea Level Static Condition

NASA Astrophysics Data System (ADS)

Kouchi, Toshinori; Tomioka, Sadatake; Kanda, Takeshi

Numerical simulations were conducted to predict the ejector pumping performance of a rocket-ramjet combined-cycle engine under a take-off condition. The numerical simulations revealed that the suction airflow was chocked at the exit of the engine throat when the ejector rocket was driven by cold N2 gas at the chamber pressure of 3MPa. When the ejector-driving gas was changed from cold N2 gas to hot combustion gas, the suction performance decreased remarkably. Mach contours in the engine revealed that the rocket plume constricted when the driving gas was the hot combustion gas. The change of the area of the stream tube area seemed to induce the pressure rise in the duct and decreasing in the pumping performance.

Affordable Hybrid Heat Pump Clothes Dryer

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

TeGrotenhuis, Ward E.; Butterfield, Andrew; Caldwell, Dustin D.

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 overmore » heat pump dryers recently introduced to the U.S. market, with 30% improvement in energy efficiency at comparable drying times.« less

The CLOSED trial; CLOnidine compared with midazolam for SEDation of paediatric patients in the intensive care unit: study protocol for a multicentre randomised controlled trial

PubMed Central

Neubert, Antje; Baarslag, Manuel Alberto; van Dijk, Monique; van Rosmalen, Joost; Standing, Joseph F; Sheng, Yucheng; Rascher, Wolfgang; Roberts, Deborah; Winslade, Jackie; Rawcliffe, Louise; Hanning, Sara M; Metsvaht, Tuuli; Giannuzzi, Viviana; Larsson, Peter; Pokorná, Pavla; Simonetti, Alessandra; Tibboel, Dick

2017-01-01

Introduction Sedation is an essential part of paediatric critical care. Midazolam, often in combination with opioids, is the current gold standard drug. However, as it is a far-from-ideal agent, clonidine is increasingly being used in children. This drug is prescribed off-label for this indication, as many drugs in paediatrics are. Therefore, the CLOSED trial aims to provide data on the pharmacokinetics, safety and efficacy of clonidine for the sedation of mechanically ventilated patients in order to obtain a paediatric-use marketing authorisation. Methods and analysis The CLOSED study is a multicentre, double-blind, randomised, active-controlled non-inferiority trial with a 1:1 randomisation between clonidine and midazolam. Both treatment groups are stratified according to age in three groups with the same size: <28 days (n=100), 28 days to <2 years (n=100) and 2–18 years (n=100). The primary end point is defined as the occurrence of sedation failure within the study period. Secondary end points include a pharmacokinetic/pharmacodynamic relationship, pharmacogenetics, occurrence of delirium and withdrawal syndrome, opioid consumption and neurodevelopment in the neonatal age group. Logistic regression will be used for the primary end point, appropriate statistics will be used for the secondary end points. Ethics Written informed consent will be obtained from the parents/caregivers. Verbal or deferred consent will be used in the sites where national legislation allows. The study has institutional review board approval at recruiting sites. The results will be published in a peer-reviewed journal and shared with the worldwide medical community. Trial Registration EudraCT: 2014-003582-24; Clinicaltrials.gov: NCT02509273; pre-results. PMID:28637741

The effectiveness of a stratified care model for non-specific low back pain in Danish primary care compared to current practice: study protocol of a randomised controlled trial.

PubMed

Morso, Lars; Schiøttz-Christensen, Berit; Søndergaard, Jens; Andersen, Nils-Bo de Vos; Pedersen, Flemming; Olsen, Kim Rose; Jensen, Morten Sall; Hill, Jonathan; Christiansen, David Høyrup

2018-06-08

Prior studies indicate that stratified care for low back pain results in better clinical outcome and reduced costs in healthcare compared to current practice. Stratified care may be associated with clinical benefits for patients with low back pain at a lower cost, but evidence is sparse. Hence this study aims to evaluate the clinical effects and cost-effectiveness of stratified care in patients with non-specific low back pain compared to current practice. The study is a two-armed randomised controlled trial in primary care in the Regions of Southern and Central Denmark (2.5 million citizens). Patients with non-specific low back will be recruited by paticpating GPs. Patients are randomised to either (1) stratified care or (2) current practice at participating physiotherapy clinics. In the stratified care arm, the intervention is based on the patient's STarT Back Tool classification and trained accordingly, whereas physiotherapists in the current pratice arm are blinded to the STarT score. Primary outcomes in the trial will be group differences in time off work, improvement in LBP disability measured by the Roland Morris Disability Questionnaire (RMDQ) and patient-reported global change. Secondary measures will be pain intensity, patient satisfaction, data on patient healthcare resource utilisation and quality-adjusted life year based on the EQ-5D-5L. Stratified care that effectively targets treatment to relevant sub-groups of patients has potentially great impact on the treatment pathways of low back pain. Thus, if effective, this could result in better patient outcomes and at the same time reduce the costs for treatment of low back pain. ClinicalTrials.gov , NCT02612467 . Registered on 16 November 2015.

Effects of improved home heating on asthma in community dwelling children: randomised controlled trial.

PubMed

Howden-Chapman, Philippa; Pierse, Nevil; Nicholls, Sarah; Gillespie-Bennett, Julie; Viggers, Helen; Cunningham, Malcolm; Phipps, Robyn; Boulic, Mikael; Fjällström, Pär; Free, Sarah; Chapman, Ralph; Lloyd, Bob; Wickens, Kristin; Shields, David; Baker, Michael; Cunningham, Chris; Woodward, Alistair; Bullen, Chris; Crane, Julian

2008-09-23

To assess whether non-polluting, more effective home heating (heat pump, wood pellet burner, flued gas) has a positive effect on the health of children with asthma. Randomised controlled trial. Households in five communities in New Zealand. 409 children aged 6-12 years with doctor diagnosed asthma. Installation of a non-polluting, more effective home heater before winter. The control group received a replacement heater at the end of the trial. The primary outcome was change in lung function (peak expiratory flow rate and forced expiratory volume in one second, FEV(1)). Secondary outcomes were child reported respiratory tract symptoms and daily use of preventer and reliever drugs. At the end of winter 2005 (baseline) and winter 2006 (follow-up) parents reported their child's general health, use of health services, overall respiratory health, and housing conditions. Nitrogen dioxide levels were measured monthly for four months and temperatures in the living room and child's bedroom were recorded hourly. Improvements in lung function were not significant (difference in mean FEV(1) 130.7 ml, 95% confidence interval -20.3 to 281.7). Compared with children in the control group, however, children in the intervention group had 1.80 fewer days off school (95% confidence interval 0.11 to 3.13), 0.40 fewer visits to a doctor for asthma (0.11 to 0.62), and 0.25 fewer visits to a pharmacist for asthma (0.09 to 0.32). Children in the intervention group also had fewer reports of poor health (adjusted odds ratio 0.48, 95% confidence interval 0.31 to 0.74), less sleep disturbed by wheezing (0.55, 0.35 to 0.85), less dry cough at night (0.52, 0.32 to 0.83), and reduced scores for lower respiratory tract symptoms (0.77, 0.73 to 0.81) than children in the control group. The intervention was associated with a mean temperature rise in the living room of 1.10 degrees C (95% confidence interval 0.54 degrees C to 1.64 degrees C) and in the child's bedroom of 0.57 degrees C (0.05 degrees C to 1.08 degrees C). Lower levels of nitrogen dioxide were measured in the living rooms of the intervention households than in those of the control households (geometric mean 8.5 microg/m(3) v 15.7 microg/m(3), P<0.001). A similar effect was found in the children's bedrooms (7.3 microg/m(3) v 10.9 microg/m(3), P<0.001). Installing non-polluting, more effective heating in the homes of children with asthma did not significantly improve lung function but did significantly reduce symptoms of asthma, days off school, healthcare utilisation, and visits to a pharmacist. Clinical Trials NCT00489762.

Catheter-based renal denervation in patients with uncontrolled hypertension in the absence of antihypertensive medications (SPYRAL HTN-OFF MED): a randomised, sham-controlled, proof-of-concept trial.

PubMed

Townsend, Raymond R; Mahfoud, Felix; Kandzari, David E; Kario, Kazuomi; Pocock, Stuart; Weber, Michael A; Ewen, Sebastian; Tsioufis, Konstantinos; Tousoulis, Dimitrios; Sharp, Andrew S P; Watkinson, Anthony F; Schmieder, Roland E; Schmid, Axel; Choi, James W; East, Cara; Walton, Anthony; Hopper, Ingrid; Cohen, Debbie L; Wilensky, Robert; Lee, David P; Ma, Adrian; Devireddy, Chandan M; Lea, Janice P; Lurz, Philipp C; Fengler, Karl; Davies, Justin; Chapman, Neil; Cohen, Sidney A; DeBruin, Vanessa; Fahy, Martin; Jones, Denise E; Rothman, Martin; Böhm, Michael

2017-11-11

Previous randomised renal denervation studies did not show consistent efficacy in reducing blood pressure. The objective of our study was to evaluate the effect of renal denervation on blood pressure in the absence of antihypertensive medications. SPYRAL HTN-OFF MED was a multicentre, international, single-blind, randomised, sham-controlled, proof-of-concept trial. Patients were enrolled at 21 centres in the USA, Europe, Japan, and Australia. Eligible patients were drug-naive or discontinued their antihypertensive medications. Patients with an office systolic blood pressure (SBP) of 150 mm Hg or greater and less than 180 mm Hg, office diastolic blood pressure (DBP) of 90 mm Hg or greater, and a mean 24-h ambulatory SBP of 140 mm Hg or greater and less than 170 mm Hg at second screening underwent renal angiography and were randomly assigned to renal denervation or sham control. Patients, caregivers, and those assessing blood pressure were blinded to randomisation assignments. The primary endpoint, change in 24-h blood pressure at 3 months, was compared between groups. Drug surveillance was done to ensure patient compliance with absence of antihypertensive medication. The primary analysis was done in the intention-to-treat population. Safety events were assessed at 3 months. This study is registered with ClinicalTrials.gov, number NCT02439749. Between June 25, 2015, and Jan 30, 2017, 353 patients were screened. 80 patients were randomly assigned to renal denervation (n=38) or sham control (n=42) and followed up for 3 months. Office and 24-h ambulatory blood pressure decreased significantly from baseline to 3 months in the renal denervation group: 24-h SBP -5·5 mm Hg (95% CI -9·1 to -2·0; p=0·0031), 24-h DBP -4·8 mm Hg (-7·0 to -2·6; p<0·0001), office SBP -10·0 mm Hg (-15·1 to -4·9; p=0·0004), and office DBP -5·3 mm Hg (-7·8 to -2·7; p=0·0002). No significant changes were seen in the sham-control group: 24-h SBP -0·5 mm Hg (95% CI -3·9 to 2·9; p=0·7644), 24-h DBP -0·4 mm Hg (-2·2 to 1·4; p=0·6448), office SBP -2·3 mm Hg (-6·1 to 1·6; p=0·2381), and office DBP -0·3 mm Hg (-2·9 to 2·2; p=0·8052). The mean difference between the groups favoured renal denervation for 3-month change in both office and 24-h blood pressure from baseline: 24-h SBP -5·0 mm Hg (95% CI -9·9 to -0·2; p=0·0414), 24-h DBP -4·4 mm Hg (-7·2 to -1·6; p=0·0024), office SBP -7·7 mm Hg (-14·0 to -1·5; p=0·0155), and office DBP -4·9 mm Hg (-8·5 to -1·4; p=0·0077). Baseline-adjusted analyses showed similar findings. There were no major adverse events in either group. Results from SPYRAL HTN-OFF MED provide biological proof of principle for the blood-pressure-lowering efficacy of renal denervation. Medtronic. Copyright © 2017 Elsevier Ltd. All rights reserved.

Miniaturised medium pressure capillary liquid chromatography system with flexible open platform design using off-the-shelf microfluidic components.

PubMed

Li, Yan; Dvořák, Miloš; Nesterenko, Pavel N; Stanley, Roger; Nuchtavorn, Nantana; Krčmová, Lenka Kujovská; Aufartová, Jana; Macka, Mirek

2015-10-08

Trends towards portable analytical instrumentation of the last decades have not been equally reflected in developments of portable liquid chromatography (LC) instrumentation for rapid on-site measurements. A miniaturised medium pressure capillary LC (MPLC) system with gradient elution capability has been designed based on a flexible modular microfluidic system using primarily off-the-shelf low cost components to ensure wide accessibility to other analysts. The microfluidic platform was assembled on a breadboard and contained microsyringe pumps and switch valves, complemented with an injection valve and on-capillary detectors, all controlled by a PC. Four miniaturised microsyringe pumps, with 5, 20 and 100 μL syringe volume options, formed the basis of the pumping system. Two pairs of pumps were used for each mobile phase to create gradient elution capability. The two microsyringe pumps in each pairs were linked by two electrically operated microfluidic switching valves and both pairs of pumps were connected through a zero void volume cross-connector, thus providing a low hold-up volume for gradient formation. Sample was injected by a 20 nL nano-LC sampling valve, directly connected to a 18 cm long 100 μm i.d. Chromolith CapRod RP-18 monolithic capillary column. On-capillary LED-based UV-vis photometric detection was conducted through a piece of equal diameter fused silica capillary connected after the column. The performance of the portable LC system was evaluated theoretically and experimentally, including the maximum operating pressure, gradient mixing performance, and the performance of the detectors. The 5 μL microsyringe pump offered the best performance, with typical maximum operating pressures up to 11.4 ± 0.4 MPa (water) and gradient pumping repeatability of between 4 and 9% for gradients between 0.10% s(-1) and 0.33% s(-1). Test analytes of charged and uncharged dyes and pharmaceuticals of varying hydrophobicity showed typical RSD values of 0.7-1.4% and 3.3-4.8% in isocratic mode and 1.2-4.6% and 3.2-6.4% in gradient mode, respectively for retention time and peak area repeatability. Crown Copyright © 2015. Published by Elsevier B.V. All rights reserved.

Ultra-fast all-optical plasmonic switching in near infra-red spectrum using a Kerr nonlinear ring resonator

NASA Astrophysics Data System (ADS)

Nurmohammadi, Tofiq; Abbasian, Karim; Yadipour, Reza

2018-03-01

In this paper, an all-optical plasmonic switch based on metal-insulator-metal (MIM) nanoplasmonic waveguide with a Kerr nonlinear ring resonator is introduced and studied. Two-dimensional simulations utilizing the finite-difference time-domain algorithm are used to demonstrate an apparent optical bistability and significant switching mechanisms (in enabled-low condition: T(ON/OFF) =21.9 and in enabled-high condition: T(ON/OFF) =24.9) of the signal light arisen by altering the pump-light intensity. The proposed all-optical switching demonstrates femtosecond-scale feedback time (90 fs) and then ultra-fast switching can be achieved. The offered all-optical switch may recognize potential significant applications in integrated optical circuits.

Two-photon Anderson localization in a disordered quadratic waveguide array

NASA Astrophysics Data System (ADS)

Bai, Y. F.; Xu, P.; Lu, L. L.; Zhong, M. L.; Zhu, S. N.

2016-05-01

We theoretically investigate two-photon Anderson localization in a χ (2) waveguide array with off-diagonal disorder. The nonlinear parametric down-conversion process would enhance both the single-photon and the two-photon Anderson localization. In the strong disorder regime, the two-photon position correlation exhibits a bunching distribution around the pumped waveguides, which is independent of pumping conditions and geometrical structures of waveguide arrays. Quadratic nonlinearity can be supplied as a new ingredient for Anderson localization. Also, our results pave the way for engineering quantum states through nonlinear quantum walks.

New concepts and new design of permanent maglev rotary artificial heart blood pumps.

PubMed

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.

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

PubMed

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%, p<0.001). The hospital OPCAB volume is associated with efficient resource use. The findings of the present study indicate the need to focus on hospital elective OPCAB volume in Japan in order to improve cost 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/

78 FR 23546 - Proposed Extension of Approval of Information Collection; Comment Request: Virginia Graeme Baker...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-04-19

..., 2011. In addition to the anti-entrapment devices or systems, each public pool and spa in the United... release system; suction-limiting vent system; gravity drainage system; automatic pump shut-off system or...

Randomised controlled trial of a brief intervention targeting predominantly non-verbal communication in general practice consultations.

PubMed

Little, Paul; White, Peter; Kelly, Joanne; Everitt, Hazel; Mercer, Stewart

2015-06-01

The impact of changing non-verbal consultation behaviours is unknown. To assess brief physician training on improving predominantly non-verbal communication. Cluster randomised parallel group trial among adults aged ≥16 years attending general practices close to the study coordinating centres in Southampton. Sixteen GPs were randomised to no training, or training consisting of a brief presentation of behaviours identified from a prior study (acronym KEPe Warm: demonstrating Knowledge of the patient; Encouraging [back-channelling by saying 'hmm', for example]; Physically engaging [touch, gestures, slight lean]; Warm-up: cool/professional initially, warming up, avoiding distancing or non-verbal cut-offs at the end of the consultation); and encouragement to reflect on videos of their consultation. Outcomes were the Medical Interview Satisfaction Scale (MISS) mean item score (1-7) and patients' perceptions of other domains of communication. Intervention participants scored higher MISS overall (0.23, 95% confidence interval [CI] = 0.06 to 0.41), with the largest changes in the distress-relief and perceived relationship subscales. Significant improvement occurred in perceived communication/partnership (0.29, 95% CI = 0.09 to 0.49) and health promotion (0.26, 95% CI = 0.05 to 0.46). Non-significant improvements occurred in perceptions of a personal relationship, a positive approach, and understanding the effects of the illness on life. Brief training of GPs in predominantly non-verbal communication in the consultation and reflection on consultation videotapes improves patients' perceptions of satisfaction, distress, a partnership approach, and health promotion. © British Journal of General Practice 2015.

Energo- and exergo-technical assessment of ground-source heat pump systems for geothermal energy production from underground mines.

PubMed

Amiri, Leyla; Madadian, Edris; Hassani, Ferri P

2018-06-08

The objective of this study is to perform the energy and exergy analysis of an integrated ground-source heat pump (GSHP) system, along with technical assessment, for geothermal energy production by deployment of Engineering Equation Solver (EES). The system comprises heat pump cycle and ground heat exchanger for extracting geothermal energy from underground mine water. A simultaneous energy and exergy analysis of the system is brought off. These analyses provided persuasive outcomes due to the use of an economic and green source of energy. The energetic coefficient of performance (COP) of the entire system is 2.33 and the exergy efficiency of the system is 28.6%. The exergetic efficiencies of the compressor, ground heat exchanger, evaporator, expansion valve, condenser and fan are computed to be 38%, 42%, 53%, 55%, 60% and 64%, respectively. In the numerical investigation, different alteration such as changing the temperature and pressure of the condenser show promising potential for further application of GSHPs. The outcomes of this research can be used for developing and designing novel coupled heat and power systems.

Temporal patterns of physical activity in Olympic dinghy racing.

PubMed

Legg, S; Mackie, H; Smith, P

1999-12-01

The objective of the present study was to determine the temporal patterns of physical activity in four classes of Olympic racing dinghy. Descriptive. A field (on-water) study. Nineteen elite New Zealand sailors (fifteen male and four female). Not applicable. The temporal pattern (duration and frequency) and nature of the physical activities of each sailor during each leg of simulated races were recorded on video tape and subsequently systematically quantified and categorised using notational analysis. The accumulated percentage of total leg time spent sitting (upright or leaning backwards), hiking (upright or fully extended) whilst trimming and whilst pumping the mainsheet and for the time spent on rig adjustments, tacking and gybing were calculated for both up-wind and off-wind sailing. When sailing up-wind, the most time was spent hiking upright (average 29-66% of total leg time) while trimming the mainsheet. During off-wind sailing, sailors spent the most time sitting upright while trimming the mainsheet (average 29-55% total leg time). Hiking upright while trimming the mainsheet was executed the greatest number of times (average 15.8-23.9) when sailing up-wind and sitting upright while trimming was executed the most times (average 3.5-7.4) when sailing off-wind. The most lengthy continuous activity was hiking upright while trimming the mainsheet when sailing up-wind (9-18 seconds) and sitting upright while trimming the mainsheet when sailing off-wind (17-34 seconds). The most physically demanding aspect of Olympic yacht racing is hiking. It occurs for the majority of up-wind legs when the wind starts to exceed approximately 8 knots. The only respite that the sailor gets from hiking is during tacking, rig adjustments or sitting in-board for brief periods when the wind is low. Sustained hiking tends to last for no more than approximately 20 seconds before the sailor changes to either a more extended or more upright hiking posture. The physical demands during off-wind sailing are generally less, except for a greater requirement for power in the arms and shoulders to pump the mainsheet in order to assist the dinghy in accelerating down waves. The findings of the present study are directly applicable to the design of sailing specific physical conditioning programmes for Olympic class sailors.

Low amplified spontaneous emission threshold and suppression of electroluminescence efficiency roll-off in layers doped with ter(9,9'-spirobifluorene)

NASA Astrophysics Data System (ADS)

Inoue, Munetomo; Matsushima, Toshinori; Adachi, Chihaya

2016-03-01

We demonstrate that ter(9,9'-spirobifluorene) (TSBF) doped in a host matrix layer of 4,4'-bis(carbazol-9-yl)biphenyl (CBP) shows a low amplified spontaneous emission (ASE) threshold (Eth = 1.0 μJ cm-2) and suppressed electroluminescence efficiency roll-off at high current densities (no roll-off up to 100 mA cm-2). One origin of the low ASE threshold is that the TSBF-doped CBP layer possesses a very large radiative decay constant (kr = 1.1 × 109 s-1). Singlet-triplet annihilation is almost suppressed in the TSBF-doped CBP layer, which can be ascribed to the small overlap between the emission and triplet absorption of TSBF. Also, the small energy level difference between TSBF and CBP minimizes carrier trapping in TSBF, leading to the suppression of singlet-polaron annihilation. TSBF showed one of the lowest Eth and the most suppressed efficiency roll-off among organic laser dyes investigated in this study and, therefore, is believed to be a promising candidate to realize electrically pumped organic semiconductor laser diodes in the future.

Significance of off-pump coronary artery bypass grafting compared with percutaneous coronary intervention: a propensity score analysis.

PubMed

Marui, Akira; Kimura, Takeshi; Tanaka, Shiro; Furukawa, Yutaka; Kita, Toru; Sakata, Ryuzo

2012-01-01

Although there have been several studies that compared the efficacy of percutaneous coronary intervention (PCI) and coronary artery bypass grafting (CABG), the impact of off-pump CABG (OPCAB) has not been well elucidated. The objective of the present study was to compare the outcomes after PCI, on-pump CABG (ONCAB), and OPCAB in patients with multivessel and/or left main disease. Among the 9877 patients undergoing first PCI using bare-metal stents or CABG who were enrolled in the CREDO-Kyoto Registry, 6327 patients with multivessel and/or left main disease were enrolled into the present study (67.9±9.8 years old). Among them, 3877 patients received PCI, 1388 ONCAB, and 1069 OPCAB. Median follow-up was 3.5 years. Comparing PCI with all CABG (ONCAB and OPCAB), propensity-score-adjusted all-cause mortality after PCI was higher than that CABG (hazard ratio (95% confidence interval): 1.37 (1.15-1.63), p<0.01). The incidence of stroke was lower after PCI than that after CABG (0.75 (0.59-0.96), p=0.02). CABG was associated with better survival outcomes than PCI in the elderly (interaction p=0.04). Comparing OPCAB with PCI or ONCAB, propensity-score-adjusted all-cause mortality after PCI was higher than that after OPCAB (1.50 (1.20-1.86), p<0.01). Adjusted mortality was similar between ONCAB and OPCAB (1.18 (0.93-1.51), p=0.33). The incidence of stroke after OPCAB was similar to that after PCI (0.98 (0.71-1.34), p>0.99), but incidence of stroke after ONCAB was higher than that after OPCAB (1.59 (1.16-2.18), p<0.01). In patients with multivessel and/or left main disease, CABG, particularly OPCAB, is associated with better survival outcomes than PCI using bare-metal stents. Survival outcomes are similar between ONCAB and OPCAB.

The Effects of Clinical Hypnosis versus Neurolinguistic Programming (NLP) before External Cephalic Version (ECV): A Prospective Off-Centre Randomised, Double-Blind, Controlled Trial

PubMed Central

Reinhard, Joscha; Peiffer, Swati; Sänger, Nicole; Herrmann, Eva; Yuan, Juping; Louwen, Frank

2012-01-01

Objective. To examine the effects of clinical hypnosis versus NLP intervention on the success rate of ECV procedures in comparison to a control group. Methods. A prospective off-centre randomised trial of a clinical hypnosis intervention against NLP of women with a singleton breech fetus at or after 370/7 (259 days) weeks of gestation and normal amniotic fluid index. All 80 participants heard a 20-minute recorded intervention via head phones. Main outcome assessed was success rate of ECV. The intervention groups were compared with a control group with standard medical care alone (n = 122). Results. A total of 42 women, who received a hypnosis intervention prior to ECV, had a 40.5% (n = 17), successful ECV, whereas 38 women, who received NLP, had a 44.7% (n = 17) successful ECV (P > 0.05). The control group had similar patient characteristics compared to the intervention groups (P > 0.05). In the control group (n = 122) 27.3% (n = 33) had a statistically significant lower successful ECV procedure than NLP (P = 0.05) and hypnosis and NLP (P = 0.03). Conclusions. These findings suggest that prior clinical hypnosis and NLP have similar success rates of ECV procedures and are both superior to standard medical care alone. PMID:22778774

The Effects of Clinical Hypnosis versus Neurolinguistic Programming (NLP) before External Cephalic Version (ECV): A Prospective Off-Centre Randomised, Double-Blind, Controlled Trial.

PubMed

Reinhard, Joscha; Peiffer, Swati; Sänger, Nicole; Herrmann, Eva; Yuan, Juping; Louwen, Frank

2012-01-01

Objective. To examine the effects of clinical hypnosis versus NLP intervention on the success rate of ECV procedures in comparison to a control group. Methods. A prospective off-centre randomised trial of a clinical hypnosis intervention against NLP of women with a singleton breech fetus at or after 37(0/7) (259 days) weeks of gestation and normal amniotic fluid index. All 80 participants heard a 20-minute recorded intervention via head phones. Main outcome assessed was success rate of ECV. The intervention groups were compared with a control group with standard medical care alone (n = 122). Results. A total of 42 women, who received a hypnosis intervention prior to ECV, had a 40.5% (n = 17), successful ECV, whereas 38 women, who received NLP, had a 44.7% (n = 17) successful ECV (P > 0.05). The control group had similar patient characteristics compared to the intervention groups (P > 0.05). In the control group (n = 122) 27.3% (n = 33) had a statistically significant lower successful ECV procedure than NLP (P = 0.05) and hypnosis and NLP (P = 0.03). Conclusions. These findings suggest that prior clinical hypnosis and NLP have similar success rates of ECV procedures and are both superior to standard medical care alone.

Manual perineal support at the time of childbirth: a systematic review and meta-analysis.

PubMed

Bulchandani, S; Watts, E; Sucharitha, A; Yates, D; Ismail, K M

2015-08-01

Genital tract trauma is common with vaginal births and is associated with significant morbidity, particularly with obstetric anal sphincter injuries (OASIS). Debate continues regarding the effectiveness of perineal support during childbirth in reducing the risk of trauma. This review aimed to assess the effect of routine 'hands on'/manual perineal support (MPS) during childbirth, versus ad hoc/no perineal support ('hands off/poised'), on the risk and degree of perineal trauma. This review is registered on PROSPERO (http://www.crd.york.ac.uk/PROSPERO/display_record.asp?ID=CRD42014007058). We searched the CENTRAL, Embase, Medline, CINAHL, and OVIDs midwifery and infant care databases (from inception to December 2014). Published randomised controlled trials (RCTs) and non-randomised studies (NRSs) evaluating any 'hands on' perineal support technique during childbirth. Two reviewers independently assessed trials for inclusion, data extraction, and methodological quality. Discrepancies were resolved by discussion with a third reviewer. We included five RCTs and seven NRSs in the review. Meta-analysis of RCTs did not demonstrate a statistically significant protective effect of MPS on the risk of OASIS (three studies, 6647 women; relative risk, RR 1.03; 95% confidence interval, 95% CI 0.32-3.36; statistical test for heterogeneity I(2) = 71%). Meta-analysis of NRSs showed a significant reduction in the risk of OASIS with MPS (three studies, 74,744 women; RR 0.45; 95% CI 0.40-0.50; I(2) = 32%). Current evidence is insufficient to drive change in practice. An adequately powered randomised trial with an efficient design to evaluate the complex interventions adopted as part of MPS policies, ensuring controlled childbirth, is urgently needed. © 2015 Royal College of Obstetricians and Gynaecologists.

View from southeast to northwest of administration building. Community center ...

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

View from southeast to northwest of administration building. Community center can be seen in far left background - Stanley R. Mickelsen Safeguard Complex, Administrative Headquarters Building, In Controlled Area just off Avenue A & East of Pump House, Nekoma, Cavalier County, ND

Ultra-long fiber Raman lasers: design considerations

NASA Astrophysics Data System (ADS)

Koltchanov, I.; Kroushkov, D. I.; Richter, A.

2015-03-01

In frame of the European Marie Currie project GRIFFON [http://astonishgriffon.net/] the usage of a green approach in terms of reduced power consumption and maintenance costs is envisioned for long-span fiber networks. This shall be accomplished by coherent transmission in unrepeatered links (100 km - 350 km) utilizing ultra-long Raman fiber laser (URFL)-based distributed amplification, multi-level modulation formats, and adapted Digital Signal Processing (DSP) algorithms. The URFL uses a cascaded 2-order pumping scheme where two (co- and counter-) ˜ 1365 nm pumps illuminate the fiber. The URFL oscillates at ˜ 1450 nm whereas amplification is provided by stimulated Raman scattering (SRS) of the ˜ 1365 nm pumps and the optical feedback is realized by two Fiber Bragg gratings (FBGs) at the fiber ends reflecting at 1450 nm. The light field at 1450 nm provides amplification for signal waves in the 1550 nm range due to SRS. In this work we present URFL design studies intended to characterize and optimize the power and noise characteristics of the fiber links. We use a bidirectional fiber model describing propagation of the signal, pump and noise powers along the fiber length. From the numerical solution we evaluate the on/off Raman gain and its bandwidth, the signal excursion over the fiber length, OSNR spectra, and the accumulated nonlinearities. To achieve best performance for these characteristics the laser design is optimized with respect to the forward/backward pump powers and wavelengths, input/output signal powers, reflectivity profile of the FBGs and other parameters.

Electrochemical oxidation coupled with liquid chromatography and mass spectrometry to study the oxidative stability of active pharmaceutical ingredients in solution: A comparison of off-line and on-line approaches.

PubMed

Torres, Susana; Brown, Roland; Zelesky, Todd; Scrivens, Garry; Szucs, Roman; Hawkins, Joel M; Taylor, Mark R

2016-11-30

Stability studies of pharmaceutical drug products and pharmaceutical active substances are important to research and development in order to fully understand and maintain product quality and safety throughout its shelf-life. Oxidative forced degradation studies are among the different types of stability studies performed by the pharmaceutical industry in order to understand the intrinsic stability of drug molecules. We have been comparing the use of electrochemistry as an alternative oxidative forced degradation method to traditional forced degradation and accelerated stability studies. Using the electrochemical degradation approach the substrate oxidation takes place in a commercially available electrochemical cell and the effluent of the cell can be either a) directly infused into the mass spectrometer or b) injected in a chromatographic column for separation of the different products formed prior to the mass spectrometry analysis. To enable the study of large numbers of different experimental conditions and molecules we developed a new dual pump automated electrochemical screening platform. This system used a HPLC pump and autosampler to load and wash the electrochemical cell and deliver the oxidized sample plug to a second injection loop. This system enabled the automatic sequential analyses of large numbers of different solutions under varied experimental conditions without need for operator intervention during the run sequence. Here we describe the system and evaluate its performance using a test molecule with well characterized stability and compare results to those obtained using an off-line electrochemistry approach. Copyright © 2016 Elsevier B.V. All rights reserved.

Stimulated Raman scattering of sub-millimeter waves in bismuth

NASA Astrophysics Data System (ADS)

Kumar, Pawan; Tripathi, V. K.

2007-12-01

A high-power sub-millimeter wave propagating through bismuth, a semimetal with non-spherical energy surfaces, parametrically excites a space-charge mode and a back-scattered electromagnetic wave. The free carrier density perturbation associated with the space-charge wave couples with the oscillatory velocity due to the pump to derive the scattered wave. The scattered and pump waves exert a pondermotive force on electrons and holes, driving the space-charge wave. The collisional damping of the decay waves determines the threshold for the parametric instability. The threshold intensity for 20 μm wavelength pump turns out to be ˜2×1012 W/cm2. Above the threshold, the growth rate scales increase with ωo, attain a maximum around ωo=6.5ωp, and, after this, falls off.

Saturation of low-threshold two-plasmon parametric decay leading to excitation of one localized upper hybrid wave

NASA Astrophysics Data System (ADS)

Gusakov, E. Z.; Popov, A. Yu.; Saveliev, A. N.

2018-06-01

We analyze the saturation of the low-threshold absolute parametric decay instability of an extraordinary pump wave leading to the excitation of two upper hybrid (UH) waves, only one of which is trapped in the vicinity of a local maximum of the plasma density profile. The pump depletion and the secondary decay of the localized daughter UH wave are treated as the most likely moderators of a primary two-plasmon decay instability. The reduced equations describing the nonlinear saturation phenomena are derived. The general analytical consideration is accompanied by the numerical analysis performed under the experimental conditions typical of the off-axis X2-mode ECRH experiments at TEXTOR. The possibility of substantial (up to 20%) anomalous absorption of the pump wave is predicted.

Real-time Control of sewer pumps by using ControlNEXT to smooth inflow at Waste Water Treatment Plant Garmerwolde

NASA Astrophysics Data System (ADS)

van Heeringen, Klaas-Jan; van Nooijen, Ronald; Kooij, Kees; Postma, Bokke

2016-04-01

The Garmerwolde waste water treatment plant (WWTP) in the Groningen area of the Netherlands, receives waste water from a large area. That waste water is collected from many sewer systems and transported to the WWTP through pressurized pipes. The supply of waste water to the WWTP is relatively low and very irregular during dry-weather conditions, resulting in a random pattern of flows. This irregularity is the effect of the local control of the pumps, where the pumps are individually operated as an on/off control based on the water levels in the connected sewer system. The influent may change from zero to high values in a few minutes. The treatment processes at the WWTP are negatively influenced by this irregularity, which ends in high costs for energy and use of chemicals. The ControlNEXT central control system is used to control the 5 largest pump stations, such that the total inflow at the WWTP becomes much smoother. This results in a reduction of operational costs of about 10%. The control algorithm determines whether the actual condition is dry or wet, based on real-time radar precipitation images and the rainfall forecast product HiRLAM. All actual data is also collected and validated, like water levels, pump operations and pump availability. This data management is done using Delft-FEWS. If the situation is identified as "wet", the sewer systems are emptied as far as possible to create maximum storage. If the situation is "dry" (and of course there is a dead band between dry and wet), the pumps are operated such that the total inflow into the WWTP is smoothed. This is done with a Greedy algorithm, developed by Delft University of Technology. The algorithm makes a plan for the next 24 hours (as the daily inflow has a typical daily pattern) and generally stores some water volume in the sewer systems during the day to be able to continue operations during the night. The pumps are controlled with a time step of 5 minutes, where ControlNEXT manages the communication of pump operation setpoints to the SCADA system. In case of failing communication, backup procedures are programmed in the PLC of the pump stations. In that case the old on/off operation based on local water levels will be used. The system has been operational since January 2016 and has been monitored since then. In addition to monitoring the positive effect on the inflow at the WWTP, an important issue is the possible sedimentation in the sewer systems. This will be monitored too.

Testing of a Spray-Bar Zero Gravity Cryogenic Vent System for Upper Stages

NASA Technical Reports Server (NTRS)

Lak, Tibor; Flachbart, Robin; Nguyen, Han; Martin, James

1999-01-01

The capability to vent in zero gravity without resettling is a fundamental technology need that involves practically all uses of subcritical cryogenics in space. Venting without resettling would extend cryogenic orbital transfer vehicle capabilities. However, the lack of definition regarding liquid/ullage orientation coupled with the somewhat random nature of the thermal stratification and resulting pressure rise rates, lead to significant technical challenges. Typically a zero gravity vent concept, termed a thermodynamic vent system (TVS), consists of a tank mixer to destratify the propellant, combined with a Joule- Thomson (J-T) valve to extract then-nal energy from the propellant. In a cooperative effort, Marshall Space Flight Center's (MSFC's) Multipurpose Hydrogen Test Bed (N4HTB) was used to test a unique "spray bar" TVS system developed by Boeing. A schematic of this system is included in Figure 1. The system consists of a recirculation pump, a parallel flow concentric tube, heat exchanger, and a spray bar positioned close to the longitudinal axis of the tank. In the mixing mode, the recirculation pump withdraws liquid from the tank and sprays it radially into the tank liquid, ullage, and exposed tank surfaces. When energy extraction is required, a small portion of the recirculated liquid is passed sequentially through the J-T expansion valve, the spray bar heat exchanger element, and is vented overboard. The vented vapor cools the circulated bulk fluid, thereby removing thermal energy and reducing tank pressure. Figure 2 is a plot of ullage pressure (P4) and liquid vapor pressure (PSAI) versus time. The pump operates alone, cycling on and off, to destratify the tank liquid and ullage until the liquid vapor pressure reaches the lower set point. At that point, the J-T valve begins to cycle on and off with the pump. Thus, for short duration missions, only the mixer may operate, thus minimizing or even eliminating boil-off losses. The primary advantage of the spray bar configuration is that pressure reduction is achieved independent of liquid and vapor location, thereby enhancing the applicability of normal gravity test data to zero gravity conditions. The in-tank components are minimized with the proposed TVS design. Because the recirculation pump is external to the tank, no electrical power penetration of the tank is required for pump or valve operation. This is especially desirable for L02 tanks since the presence of an electrical ignition source in oxygen represents a critical failure mode. Also, since the critical components (pump, motor, valve, orifice) are external to the tank, system checkout and ground servicing/replacement are easier. For zero-g operation, component replacement external to the tank may be a significant benefit. In addition to satisfying the zero g TVS design objectives, the TVS concept tested offers additional benefits to the integrated subcritical cryogenic storage and launch system.

Giant pseudoaneurysm from Vieussens' arterial ring.

PubMed

Kocica, Mladen J; Vranes, Mile R; Djukic, Petar L; Mikic, Aleksandar Dj; Velinovic, Milos M; Havelka, Marija; Kanjuh, Vladimir I

2004-11-01

A giant coronary pseudoaneurysm of uncertain cause, arising from Vieussens' arterial ring, was preoperatively diagnosed in an oligosymptomatic female patient. Successful off-pump surgical excision without additional bypass grafting was performed. Difficulties in diagnostic algorithm, as well as possible cause and extremely rare localization were discussed.

Effects of omeprazole or anti-reflux surgery on lower oesophageal sphincter characteristics and oesophageal acid exposure over 10 years.

PubMed

Emken, Birgitte-Elise G; Lundell, Lars R; Wallin, Lene; Myrvold, Helge E; Engström, Cecilia; Montgomery, Madeleine; Malm, Anders R; Lind, Tore; Hatlebakk, Jan G

2017-01-01

To compare the effect of anti-reflux surgery (ARS) versus proton pump inhibitor therapy on lower oesophageal sphincter (LOS) function and oesophageal acid exposure in patients with chronic gastro-oesophageal reflux disease (GORD) over a decade of follow-up. In this randomised, prospective, multicentre study we compared LOS pressure profiles, as well as oesophageal exposure to acid, at baseline and at 1 and 10 years after randomisation to either open ARS (n = 137) or long-term treatment with omeprazole (OME) 20-60 mg daily (n = 108). Median LOS resting pressure and abdominal length increased significantly and remained elevated in patients operated on with ARS, as opposed to those on OME. The proportion of total time (%) with oesophageal pH <4.0 decreased significantly in both the surgical and medical groups, and was significantly lower after 1 year in patients treated with ARS versus OME. After 10 years, oesophageal acid exposure was normalised in both groups, with no significant differences, and bilirubin exposure was within normal limits. After 10 years, patients with or without Barrett's oesophagus did not differ in acid reflux control between the two treatment options. Open ARS and OME were both effective in normalising acid reflux into the oesophagus even when studied over a period of 10 years. Anatomically and functionally the LOS was repaired durably by surgery, with increased resting pressure and abdominal length.

Clinical and economic evaluation of laparoscopic surgery compared with medical management for gastro-oesophageal reflux disease: 5-year follow-up of multicentre randomised trial (the REFLUX trial).

PubMed

Grant, A M; Boachie, C; Cotton, S C; Faria, R; Bojke, L; Epstein, D M; Ramsay, C R; Corbacho, B; Sculpher, M; Krukowski, Z H; Heading, R C; Campbell, M K

2013-06-01

Despite promising evidence that laparoscopic fundoplication provides better short-term relief of gastro-oesophageal reflux disease (GORD) than continued medical management, uncertainty remains about whether benefits are sustained and outweigh risks. To evaluate the long-term clinical effectiveness, cost-effectiveness and safety of laparoscopic surgery among people with GORD requiring long-term medication and suitable for both surgical and medical management. Five-year follow-up of a randomised trial (with parallel non-randomised preference groups) comparing a laparoscopic surgery-based policy with a continued medical management policy. Cost-effectiveness was assessed alongside the trial using a NHS perspective for costs and expressing health outcomes in terms of quality-adjusted life-years (QALYs). Follow-up was by annual postal questionnaire and selective hospital case notes review; initial recruitment in 21 UK hospitals. Questionnaire responders among the 810 original participants. At entry, all had documented evidence of GORD and symptoms for > 12 months. Questionnaire response rates (years 1-5) were from 89.5% to 68.9%. Three hundred and fifty-seven participants were recruited to the randomised comparison (178 randomised to surgical management and 179 randomised to continued medical management) and 453 to the preference groups (261 surgical management and 192 medical management). The surgeon chose the type of fundoplication. Primary: disease-specific outcome measure (the REFLUX questionnaire); secondary: Short Form questionnaire-36 items (SF-36), European Quality of Life-5 Dimensions (EQ-5D), NHS resource use, reflux medication, complications. The randomised groups were well balanced. By 5 years, 63% in the randomised surgical group and 13% in the randomised medical management group had received a total or partial wrap fundoplication (85% and 3% in the preference groups), with few perioperative complications and no associated deaths. At 1 year (and 5 years) after surgery, 36% (41%) in the randomised surgical group - 15% (26%) of those who had surgery - were taking proton pump inhibitor medication compared with 87% (82%) in the randomised medical group. At each year, differences in the REFLUX score significantly favoured the randomised surgical group (a third of a SD; p< 0.01 at 5 years). SF-36 and EQ-5D scores also favoured surgery, but differences attenuated over time and were generally not statistically significant at 5 years. The worse the symptoms at trial entry, the larger the benefit observed after surgery. Those randomised to medical management who subsequently had surgery had low baseline scores that markedly improved after surgery. Following fundoplication, 3% had surgical treatment for a complication and 4% had subsequent reflux-related operations - most often revision of the wrap. Dysphagia, flatulence and inability to vomit were similar in the two randomised groups. The economic analysis indicated that surgery was the more cost-effective option for this patient group. The incremental cost-effectiveness ratio for surgery in the base case was £7028 per additional QALY; these findings were robust to changes in approaches and assumptions. The probability of surgery being cost-effective at a threshold of £20,000 per additional QALY was > 0.80 for all analyses. After 5 years, laparoscopic fundoplication continues to provide better relief of GORD symptoms with associated improved health-related quality of life. Complications of surgery were uncommon. Despite being initially more costly, a surgical policy is highly likely to be cost-effective. Current Controlled Trials ISRCTN15517081. This project was funded by the NIHR Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 17, No. 22. See the HTA programme website for further project information.

Cerebral hemodynamics with intra-aortic balloon pump: business as usual?

PubMed

Caldas, J R; Panerai, R B; Bor-Seng-Shu, E; Almeida, J P; Ferreira, G S R; Camara, L; Nogueira, R C; Oliveira, M L; Jatene, F B; Robinson, T G; Hajjar, L A

2017-06-22

Intra-aortic balloon pump (IABP) is commonly used as mechanical support after cardiac surgery or cardiac shock. Although its benefits for cardiac function have been well documented, its effects on cerebral circulation are still controversial. We hypothesized that transfer function analysis (TFA) and continuous estimates of dynamic cerebral autoregulation (CA) provide consistent results in the assessment of cerebral autoregulation in patients with IABP. Continuous recordings of blood pressure (BP, intra-arterial line), end-tidal CO 2 , heart rate and cerebral blood flow velocity (CBFV, transcranial Doppler) were obtained (i) 5 min with IABP ratio 1:3, (ii) 5 min, starting 1 min with the IABP-ON, and continuing for another 4 min without pump assistance (IABP-OFF). Autoregulation index (ARI) was estimated from the CBFV response to a step change in BP derived by TFA and as a function of time using an autoregressive moving-average model during removal of the device (ARI t ). Critical closing pressure and resistance area-product were also obtained. ARI with IABP-ON (4.3  ±  1.2) were not different from corresponding values at IABP-OFF (4.7  ±  1.4, p  =  0.42). Removal of the balloon had no effect on ARI t , CBFV, BP, cerebral critical closing pressure or resistance area-product. IABP does not disturb cerebral hemodynamics. TFA and continuous estimates of dynamic CA can be used to assess cerebral hemodynamics in patients with IABP. These findings have important implications for the design of studies of critically ill patients requiring the use of different invasive support devices.

Long-term Effects of Off-Pump Coronary Bypass Versus Conventional Coronary Bypass Grafting on Renal Function.

PubMed

Hynes, Conor F; Colo, Sanchez; Amdur, Richard L; Chawla, Lakhmir S; Greenberg, Michael D; Trachiotis, Gregory D

2016-01-01

This study aimed to evaluate the short- and long-term effects of conventional on-pump coronary bypass grafting (cCABG) compared with off-pump coronary artery bypass (OPCAB) on renal function. A retrospective review of patients undergoing coronary bypass grafting from 2004 through 2013 at a single center was conducted. Preoperative renal function, perioperative acute kidney injury, and long-term glomerular filtration were evaluated. Multivariable analyses were used to determine factors contributing to short- and long-term renal impairment. A total of 234 patients underwent cCABG, and 582 underwent OPCAB. Patients undergoing OPCAB were significantly older, had greater preoperative renal dysfunction, had greater functional dependence, and took more hypertension medications. Multivariable analyses found that 30-day acute kidney injury was an independent risk factor for a 10% decline in glomerular filtration rate at 1 and 5 years (P < 0.0001 and 0.002, respectively). However, the use of cardiopulmonary bypass was not found to influence long-term renal function (P = 0.78 at 1 year, P = 0.76 at 5 years). The percentage of patients experiencing a 10% drop in renal function from baseline at 1 year (33% OPCAB, 35% cCABG; P = 0.73) and 5 years (16% OPCAB, 16% cCABG; P = 0.93) were not significantly different. Independent predictors of acute kidney injury included baseline kidney function (P = 0.04) and age (P < 0.0001), whereas cardiopulmonary bypass did not affect the incidence (P = 0.17). A propensity-matched analysis confirmed these findings. Acute kidney injury is a risk factor for long-term renal dysfunction after either bypass method and was not greater after cCABG compared with OPCAB. Patients undergoing OPCAB did not experience greater decrease in long-term kidney function despite having worse baseline kidney function.

Benefits of off-pump coronary artery bypass grafting in high-risk patients.

PubMed

Marui, Akira; Okabayashi, Hitoshi; Komiya, Tatsuhiko; Tanaka, Shiro; Furukawa, Yutaka; Kita, Toru; Kimura, Takeshi; Sakata, Ryuzo

2012-09-11

The benefits of off-pump coronary artery bypass graft (OPCAB) compared with conventional on-pump coronary artery bypass graft (CCAB) remain controversial. Thus, it is important to investigate which patient subgroups may benefit the most from OPCAB rather than CCAB. Among the patients undergoing first coronary revascularization enrolled in the CREDO-Kyoto Registry (a registry of first-time percutaneous coronary intervention and coronary artery bypass graft patients in Japan), 2468 patients undergoing coronary artery bypass graft were entered into the study (mean age, 67 ± 9 years). Predicted risk of operative mortality (PROM) of each patient was calculated by logistic EuroSCORE. Patients were divided into tertile based on their PROM. Mortality rates and the incidences of cardiovascular events were compared between CCAB and OPCAB within each PROM tertile using propensity score analysis. A total of 1377 patients received CCAB whereas 1091 received OPCAB. Adjusted 30-day mortality was not significantly different between CCAB and OPCAB patients regardless of their PROM range. However, the odds ratio of 30-day stroke in CCAB compared with OPCAB in the high-risk tertile was 8.30 (95% confidence interval, 2.25-30.7; P<0.01). Regarding long-term outcomes, hazard ratio of stroke in CCAB compared with OPCAB in the high-risk tertile was 1.80 (95% confidence interval, 1.07-3.02; P=0.03). Nevertheless, hazard ratio of overall mortality in the high-risk tertile was 1.44 (95% confidence interval, 0.98-2.11; P=0.06), indicating no statistically significant difference between the 2 procedures. OPCAB as opposed to CCAB is associated with short-term and long-term benefits in stroke prevention in patients at higher risk as estimated by EuroSCORE. No survival benefit of OPCAB was shown regardless of preoperative risk level.

Successful resuscitation of cardiac arrest caused by CO2 embolism with intra-aortic injection of epinephrine during off-pump coronary bypass surgery -a case report-.

PubMed

Lee, Choon Soo; Yoon, Yeo Sam; Shim, Jae-Kwang; Lim, Hyun Kyoung

2013-12-01

Although compressed gas (CO2) blowers have been used safely to aid accurate grafting during off-pump coronary bypass surgery, hemodynamic collapse due to gas embolism into the right coronary artery may occur. Supportive measures to facilitate gas clearance by increasing the coronary perfusion pressure have been reported to be successful in restoring hemodynamic stability. However, right ventricular dysfunction and atrioventricular nodal ischemia may hinder effective systemic delivery of the vasoactive medications, even when performing resuscitative measures such as direct cardiac massage. We herein report a case of cardiac arrest that was caused by a right coronary gas embolism and that could not be restored by cardiac resuscitation. When supportive measures fail, direct aortic injection of epinephrine to increase the coronary perfusion pressure can be attempted before initiating cardiopulmonary bypass, and this approach may be life-saving in situations that limit systemic drug delivery from the venous side despite the performance of direct cardiac massage.

Successful resuscitation of cardiac arrest caused by CO2 embolism with intra-aortic injection of epinephrine during off-pump coronary bypass surgery -a case report-

PubMed Central

Lee, Choon Soo; Yoon, Yeo Sam; Shim, Jae-Kwang

2013-01-01

Although compressed gas (CO2) blowers have been used safely to aid accurate grafting during off-pump coronary bypass surgery, hemodynamic collapse due to gas embolism into the right coronary artery may occur. Supportive measures to facilitate gas clearance by increasing the coronary perfusion pressure have been reported to be successful in restoring hemodynamic stability. However, right ventricular dysfunction and atrioventricular nodal ischemia may hinder effective systemic delivery of the vasoactive medications, even when performing resuscitative measures such as direct cardiac massage. We herein report a case of cardiac arrest that was caused by a right coronary gas embolism and that could not be restored by cardiac resuscitation. When supportive measures fail, direct aortic injection of epinephrine to increase the coronary perfusion pressure can be attempted before initiating cardiopulmonary bypass, and this approach may be life-saving in situations that limit systemic drug delivery from the venous side despite the performance of direct cardiac massage. PMID:24427464

Controlled in-situ dissolution of an alkali metal

DOEpatents

Jones, Jeffrey Donald; Dooley, Kirk John; Tolman, David Donald

2012-09-11

A method for the controllable dissolution of one or more alkali metals from a vessel containing a one or more alkali metals and/or one or more partially passivated alkali metals. The vessel preferably comprising a sodium, NaK or other alkali metal-cooled nuclear reactor that has been used. The alkali metal, preferably sodium, potassium or a combination thereof, in the vessel is exposed to a treatment liquid, preferably an acidic liquid, more preferably citric acid. Preferably, the treatment liquid is maintained in continuous motion relative to any surface of unreacted alkali metal with which the treatment liquid is in contact. The treatment liquid is preferably pumped into the vessel containing the one or more alkali metals and the resulting fluid is extracted and optionally further processed. Preferably, the resulting off-gases are processed by an off-gas treatment system and the resulting liquids are processed by a liquid disposal system. In one preferred embodiment, an inert gas is pumped into the vessel along with the treatment liquid.

Integration of InGaAs MOSFETs and GaAs/ AlGaAs lasers on Si Substrate for advanced opto-electronic integrated circuits (OEICs).

PubMed

Kumar, Annie; Lee, Shuh-Ying; Yadav, Sachin; Tan, Kian Hua; Loke, Wan Khai; Dong, Yuan; Lee, Kwang Hong; Wicaksono, Satrio; Liang, Gengchiau; Yoon, Soon-Fatt; Antoniadis, Dimitri; Yeo, Yee-Chia; Gong, Xiao

2017-12-11

Lasers monolithically integrated with high speed MOSFETs on the silicon (Si) substrate could be a key to realize low cost, low power, and high speed opto-electronic integrated circuits (OEICs). In this paper, we report the monolithic integration of InGaAs channel transistors with electrically pumped GaAs/AlGaAs lasers on the Si substrate for future advanced OEICs. The laser and transistor layers were grown on the Si substrate by molecular beam epitaxy (MBE) using direct epitaxial growth. InGaAs n-FETs with an I ON /I OFF ratio of more than 10 6 with very low off-state leakage and a low subthreshold swing with a minimum of 82 mV/decade were realized. Electrically pumped GaAs/AlGaAs quantum well (QW) lasers with a lasing wavelength of 795 nm at room temperature were demonstrated. The overall fabrication process has a low thermal budget of no more than 400 °C.

Observer-based perturbation extremum seeking control with input constraints for direct-contact membrane distillation process

NASA Astrophysics Data System (ADS)

Eleiwi, Fadi; Laleg-Kirati, Taous Meriem

2018-06-01

An observer-based perturbation extremum seeking control is proposed for a direct-contact membrane distillation (DCMD) process. The process is described with a dynamic model that is based on a 2D advection-diffusion equation model which has pump flow rates as process inputs. The objective of the controller is to optimise the trade-off between the permeate mass flux and the energy consumption by the pumps inside the process. Cases of single and multiple control inputs are considered through the use of only the feed pump flow rate or both the feed and the permeate pump flow rates. A nonlinear Lyapunov-based observer is designed to provide an estimation for the temperature distribution all over the designated domain of the DCMD process. Moreover, control inputs are constrained with an anti-windup technique to be within feasible and physical ranges. Performance of the proposed structure is analysed, and simulations based on real DCMD process parameters for each control input are provided.

The assessment of energy demand in the new Olympic windsurf board: Neilpryde RS:X.

PubMed

Castagna, O; Vaz Pardal, C; Brisswalter, J

2007-05-01

The aim of this study was to evaluate the energy demands of sailing the new Neilpryde RS:X Olympic windsurf board. Ten skilled male subjects performed an exhaustive incremental treadmill test to determine their maximal physiological parameters. Thereafter, four tests were performed in a randomised order using two wind conditions, light [2-4 ms(-1) (4-8 knots)] and strong: [9-11 ms(-1)(16-22 knots)]. Oxygen consumption (VO2, ml min(-1) kg(-1)), blood lactate concentration ([la](b), mmol l(-1)), and time spent pumping (% total time) were recorded during 10 min of up-wind leg and during 6 min of down-wind leg. The results indicate that sailing on RS:X is associated with a high level of energy demand using both aerobic and anaerobic pathways whatever the wind conditions. During the down-wind leg, VO2, (ml min(-1) kg(-1)), [la](b) (mmol l(-1)), and time spent pumping (% total time) values for the light and strong wind conditions were 56.5 +/- 5.9 versus 55.5 +/- 3.6; 10.2 +/- 1.5 versus 9.6 +/- 2.3, and 69 +/- 5 versus 64 +/- 2%, respectively. In contrast, during up-wind leg the same parameters for light and strong wind were 53.9 +/- 4.5 versus 40.4 +/- 7.2; 9.7 +/- 2.8 versus 5.0 +/- 2.7 and 66 +/- 3 versus 37 +/- 8%, respectively. During the up-wind leg with strong wind conditions, less time was spent pumping (p < 0.05), mean oxygen consumption values were close to 60% VO2max and post-exercise blood lactate was less than 50% maximal lactate concentration. These results could be related to the time spent in pumping action, involving whole body activity. When sailing with the RS:X board, the physiological demand seems to be higher than with the previous official Olympic windsurf board [Mistral One Design (MOD)]. This difference could be mainly attributed to the specific biomechanical constraints induced by each board characteristic.

Continued advances in high brightness fiber-coupled laser modules for efficient pumping of fiber and solid-state lasers

NASA Astrophysics Data System (ADS)

Hemenway, M.; Chen, Z.; Urbanek, W.; Dawson, D.; Bao, L.; Kanskar, M.; DeVito, M.; Martinsen, R.

2018-02-01

Both the fibber laser and diode-pumped solid-state laser market continue to drive advances in pump diode module brightness. We report on the continued progress by nLIGHT to develop and deliver the highest brightness diode-laser pumps using single-emitter technology. Continued advances in multimode laser diode technology [13] and fiber-coupling techniques have enabled higher emitter counts in the element packages, enabling us to demonstrate 305 W into 105 μm - 0.16 NA. This brightness improvement is achieved by leveraging our prior-reported package re-optimization, allowing an increase in the emitter count from two rows of nine emitters to two rows of twelve emitters. Leveraging the two rows off twelve emitter architecture,, product development has commenced on a 400 W into 200 μm - 00.16 NA package. Additionally, the advances in pump technology intended for CW Yb-doped fiber laser pumping has been leveraged to develop the highest brightness 793 nm pump modules for 2 μm Thulium fiber laser pumping, generating 150 W into 200 μm - 0.18 NA and 100 W into 105 μm - 0.15 NA. Lastly, renewed interest in direct diode materials processing led us to experiment with wavelength multiplexing our existing state of the art 200 W, 105 μm - 00.15 NA package into a combined output of 395 WW into 105 μm - 0.16 NA.

Single-Centre Experience of Off-Pump Multi-Vessel Coronary Artery Bypass Grafting Using Proximal Suture Device.

PubMed

Ohira, Suguru; Doi, Kiyoshi; Numata, Satoshi; Yamazaki, Sachiko; Itatani, Keiichi; Kawajiri, Hidetake; Morimoto, Kazuki; Yaku, Hitoshi

2017-10-01

To investigate the results of off-pump coronary artery grafting (OPCAB) with the proximal suture device (PSD) regarding postoperative stroke and graft patency. The PSD was used in 376 patients (32.0%), aorta-no-touch OPCAB was performed in 523 patients (45.2%), on-pump beating coronary artery bypass surgery (CABG) (on-beat group) in 125 patients (10.6%) including 51 conversions (conversion rate: 5.4%), and CABG with aortic clamp use (clamp group) in 152 patients. In the PSD group, Enclose II was used in 267 patients (71.0%). The hospital mortality rate was 1.95%. There was no early stroke in the OPCAB group, whereas the early-stroke rate was 0.8% in the on-beat group and 2.6% in the clamp group. The incidences of stroke at one month were: PSD group, 1.6%; no-touch group, 1.1%; on-beat group, 1.6%; and clamp group, 4.6% (p=0.014). The rates of complete revascularisation were higher in the PSD and clamp groups (94.7 and 94.0%, respectively) compared with the no-touch and on-beat groups (81.5 and 84.9%, respectively; p<0.001). The vein graft patency rates were comparable between the PSD and clamp groups. In multiple logistic regression analysis, OPCAB using the PSD did not increase the risk of stroke compared with the no-touch group (adjusted odds ratio [AOR]: 1.40; p=0.594) or on-beat group (AOR: 0.99; p=0.206), but reduced the risk of stroke compared with the clamp group (AOR: 0.19; p=0.005). Off-pump coronary artery grafting using the PSD was a safe and effective procedure. It led to lower incidences of postoperative stroke and excellent rates of graft patency and complete revascularisation compared with conventional CABG. Copyright © 2016 Australian and New Zealand Society of Cardiac and Thoracic Surgeons (ANZSCTS) and the Cardiac Society of Australia and New Zealand (CSANZ). Published by Elsevier B.V. All rights reserved.

Experimental and numerical investigation of centrifugal pumps with asymmetric inflow conditions

NASA Astrophysics Data System (ADS)

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.

Coronagraphic Notch Filter for Raman Spectroscopy

NASA Technical Reports Server (NTRS)

Cohen, David; Stirbl, Robert

2004-01-01

A modified coronagraph has been proposed as a prototype of improved notch filters in Raman spectrometers. Coronagraphic notch filters could offer alternatives to both (1) the large and expensive double or triple monochromators in older Raman spectrometers and (2) holographic notch filters, which are less expensive but are subject to environmental degradation as well as to limitations of geometry and spectral range. Measurement of a Raman spectrum is an exercise in measuring and resolving faint spectral lines close to a bright peak: In Raman spectroscopy, a monochromatic beam of light (the pump beam) excites a sample of material that one seeks to analyze. The pump beam generates a small flux of scattered light at wavelengths slightly greater than that of the pump beam. The shift in wavelength of the scattered light from the pump wavelength is known in the art as the Stokes shift. Typically, the flux of scattered light is of the order of 10 7 that of the pump beam and the Stokes shift lies in the wave-number range of 100 to 3,000 cm 1. A notch filter can be used to suppress the pump-beam spectral peak while passing the nearby faint Raman spectral lines. The basic principles of design and operation of a coronagraph offer an opportunity for engineering the spectral transmittance of the optics in a Raman spectrometer. A classical coronagraph may be understood as two imaging systems placed end to end, such that the first system forms an intermediate real image of a nominally infinitely distant object and the second system forms a final real image of the intermediate real image. If the light incident on the first telescope is collimated, then the intermediate image is a point-spread function (PSF). If an appropriately tailored occulting spot (e.g., a Gaussian-apodized spot with maximum absorption on axis) is placed on the intermediate image plane, then the instrument inhibits transmission of light from an on-axis source. However, the PSFs of off-axis light sources are formed off axis - that is, away from the occulting spot - so that they become refocused onto the final image plane.

TISU: Extracorporeal shockwave lithotripsy, as first treatment option, compared with direct progression to ureteroscopic treatment, for ureteric stones: study protocol for a randomised controlled trial.

PubMed

McClinton, Samuel; Cameron, Sarah; Starr, Kathryn; Thomas, Ruth; MacLennan, Graeme; McDonald, Alison; Lam, Thomas; N'Dow, James; Kilonzo, Mary; Pickard, Robert; Anson, Ken; Keeley, Frank; Burgess, Neil; Clark, Charles Terry; MacLennan, Sara; Norrie, John

2018-05-22

Urinary stone disease is very common with an estimated prevalence among the general population of 2-3%. Ureteric stones are associated with severe pain as they pass through the urinary tract and have significant impact on patients' quality of life due to the detrimental effect on their ability to work and need for hospitalisation. Most ureteric stones can be expected to pass spontaneously with supportive care. However, between one-fifth and one-third of cases require an intervention. The two standard active intervention options are extracorporeal shockwave lithotripsy (ESWL) and ureteroscopic stone retrieval. ESWL and ureteroscopy are effective in terms of stone clearance; however, they differ in terms of invasiveness, anaesthetic requirement, treatment setting, complications, patient-reported outcomes (e.g. pain after intervention, time off work) and cost. There is uncertainty around which is the most clinically effective in terms of stone clearance and the true cost to the NHS and to society (in terms of impact on patient-reported health and economic burden). The aim of this trial is to determine whether, in adults with ureteric stones, judged to require active intervention, ESWL is not inferior and is more cost-effective compared to ureteroscopic treatment as the initial management option. The TISU study is a pragmatic multicentre non-inferiority randomised controlled trial of ESWL as the first treatment option compared with direct progression to ureteroscopic treatment for ureteric stones. Patients aged over 16 years with a ureteric stone confirmed by non-contrast computed tomography of the kidney, ureter and bladder (CTKUB) will be randomised to either ESWL or ureteroscopy. The primary clinical outcome is resolution of the stone episode (no further intervention required to facilitate stone clearance) up to six months from randomisation. The primary economic outcome is the incremental cost per quality-adjusted life years (QALYs) gained at six months from randomisation. Determining whether ESWL is not inferior clinically and is cost-effective compared to ureteroscopic treatment as the initial management in adults with ureteric stones who are judged to require active treatment is relevant not only to patients and clinicians but also to healthcare providers, both in the UK and globally. ISRCTN registry, ISRCTN92289221 . Registered on 21 February 2013.

Astigmatism transfer phenomena in the optical parametric amplification process

NASA Astrophysics Data System (ADS)

Li, Wenkai; Chen, Yun; Li, Yanyan; Xu, Yi; Guo, Xiaoyang; Lu, Jun; Leng, Yuxin

2017-01-01

We numerically and experimentally investigate the astigmatism transfer phenomena in femtosecond optical parametric amplification (OPA). We model the OPA process based on the coupled second-order three-wave nonlinear propagation equations. The numerical and experimental results support that the input pump pulse astigmatism can be transferred into the idler pulse but not the signal pulse, and the idler pulse astigmatism originating from spatial walk-off is less than the idler pulse astigmatism received from the pump. Thus, we can provide a clear understanding of astigmatism transfer mechanisms in the OPA process, and make better use of broadband tunable OPA sources.

Efficient, high power, Q-switched Nd:YLF slab laser end-pumped by diode stack

NASA Astrophysics Data System (ADS)

Zhang, Hengli; Li, Daijun; Shi, Peng; Diart, Rober; Shell, Alexander; Haas, Claus R.; Du, Keming

2005-06-01

A high power diode stack end-pumped electro-optically Q-switched Nd:YLF slab laser with a stable and off-axis negative-branch confocal unstable hybrid resonator was demonstrated. By using a cylindrical lens in the stable direction the thermal lens effect was compensated. Pulse energy of 25 mJ was obtained with a pulse width of 22.4 ns at repetition rates of 500 Hz and a conversion efficiency of 22%. The stability was better than 0.8% and the beam propagation M2 factor was about 1.2.

Practical and efficient magnetic heat pump

NASA Technical Reports Server (NTRS)

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.

Hydrologic trade-offs in conjunctive use management.

PubMed

Bredehoeft, John

2011-01-01

An aquifer, in a stream/aquifer system, acts as a storage reservoir for groundwater. Groundwater pumping creates stream depletion that recharges the aquifer. As wells in the aquifer are moved away from the stream, the aquifer acts to filter out annual fluctuations in pumping; with distance the stream depletion tends to become equal to the total pumping averaged as an annual rate, with only a small fluctuation. This is true for both a single well and an ensemble of wells. A typical growing season in much of the western United States is 3 to 4 months. An ensemble of irrigation wells spread more or less uniformly across an aquifer several miles wide, pumping during the growing season, will deplete the stream by approximately one-third of the total amount of water pumped during the growing season. The remaining two-thirds of stream depletion occurs outside the growing season. Furthermore, it takes more than a decade of pumping for an ensemble of wells to reach a steady-state condition in which the impact on the stream is the same in succeeding years. After a decade or more of pumping, the depletion is nearly constant through the year, with only a small seasonal fluctuation: ±10%. Conversely, stream depletion following shutting down the pumping from an ensemble of wells takes more than a decade to fully recover from the prior pumping. Effectively managing a conjunctive groundwater and surface water system requires integrating the entire system into a single management institution with a long-term outlook. Copyright © 2010 The Author(s). Journal compilation © 2010 National Ground Water Association.

Research on the performance of low-lift diving tubular pumping system by CFD and Test

NASA Astrophysics Data System (ADS)

Xia, Chenzhi; Cheng, Li; Liu, Chao; Zhou, Jiren; Tang, Fangping; Jin, Yan

2016-11-01

Post-diving tubular pump is always used in large-discharge & low-head irrigation or storm drainage pumping station, its impeller and motor share the same shaft. Considering diving tubular pump system's excellent hydraulic performance, compact structure, good noise resistance and low operating cost, it is used in Chinese pump stations. To study the hydraulic performance and pressure fluctuation of inlet and outlet passage in diving tubular pump system, both of steady and unsteady full flow fields are numerically simulated at three flow rate conditions by using CFD commercial software. The asymmetry of the longitudinal structure of inlet passage affects the flow pattern on outlet. Especially at small flow rate condition, structural asymmetry will result in the uneven velocity distribution on the outlet of passage inlet. The axial velocity distribution uniformity increases as the flow rate increases on the inlet of passage inlet, and there is a positive correlation between hydraulic loss in the passage inlet and flow rate's quadratic. The axial velocity distribution uniformity on the outlet of passage inlet is 90% at design flow rate condition. The predicted result shows the same trend with test result, and the range of high efficiency area between predicted result and test result is almost identical. The dominant frequency of pressure pulsation is low frequency in inlet passage at design condition. The dominant frequency is high frequency in inlet passage at small and large flow rate condition. At large flow rate condition, the flow pattern is significantly affected by the rotation of impeller in inlet passage. At off-design condition, the pressure pulsation is strong at outlet passage. At design condition, the dominant frequency is 35.57Hz, which is double rotation frequency.

Initial in vitro testing of a paediatric continuous-flow total artificial heart.

PubMed

Fukamachi, Kiyotaka; Karimov, Jamshid H; Horvath, David J; Sunagawa, Gengo; Byram, Nicole A; Kuban, Barry D; Moazami, Nader

2018-06-01

Mechanical circulatory support has become standard therapy for adult patients with end-stage heart failure; however, in paediatric patients with congenital heart disease, the options for chronic mechanical circulatory support are limited to paracorporeal devices or off-label use of devices intended for implantation in adults. Congenital heart disease and cardiomyopathy often involve both the left and right ventricles; in such cases, heart transplantation, a biventricular assist device or a total artificial heart is needed to adequately sustain both pulmonary and systemic circulations. We aimed to evaluate the in vitro performance of the initial prototype of our paediatric continuous-flow total artificial heart. The paediatric continuous-flow total artificial heart pump was downsized from the adult continuous-flow total artificial heart configuration by a scale factor of 0.70 (1/3 of total volume) to enable implantation in infants. System performance of this prototype was evaluated using the continuous-flow total artificial heart mock loop set to mimic paediatric circulation. We generated maps of pump performance and atrial pressure differences over a wide range of systemic vascular resistance/pulmonary vascular resistance and pump speeds. Performance data indicated left pump flow range of 0.4-4.7 l/min at 100 mmHg delta pressure. The left/right atrial pressure difference was maintained within ±5 mmHg with systemic vascular resistance/pulmonary vascular resistance ratios between 1.4 and 35, with/without pump speed modulation, verifying expected passive self-regulation of atrial pressure balance. The paediatric continuous-flow total artificial heart prototype met design requirements for self-regulation and performance; in vivo pump performance studies are ongoing.

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

PubMed

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  < 0.01). The average time until tracheal extubation did not differ in the automated weaning and the protocolized weaning groups: 193 (115-309) and 197 (158-253) min, respectively, but increased to 290 (210-411) min in the standard weaning group. The automated weaning system after off-pump coronary surgery might provide postoperative ventilation in a more protective way, reduces the workload on medical staff, and does not prolong the duration of weaning from ventilator. The use of automated or protocolized weaning can reduce the duration of postoperative mechanical ventilation in comparison with non-protocolized weaning based on the physician's decision.

Study for every other day administration of vonoprazan in maintenance treatment of erosive GERD: study protocol for a multicentre randomised cross-over study.

PubMed

Kato, Mototsugu; Ito, Noriko; Demura, Mamiko; Kubo, Kimitoshi; Mabe, Katsuhiro; Harada, Naohiko

2018-01-01

The first drug selected for treatment of gastro-oesophageal reflux disease (GERD) and prevention of the recurrence is a proton pump inhibitor (PPI), but recently, a potassium-competitive acid blocker (P-CAB) was put on the market in Japan. Its onset of effect is faster than PPI, and it takes more than 2 days to recover acid secretion after the withdrawal period. Therefore, unlike PPI, the usefulness of every other day administration or discontinuous administration is expected. This study is a prospective, multicentre, open-label, two-period randomised cross-over study to compare the efficacy and safety of PPI every other day administration and P-CAB every other day administration in 120 patients who receive erosive GERD maintenance therapy with PPI. Patients will be randomly allocated to receive 4 weeks P-CAB or PPI followed by 4 weeks cross over, where those on P-CAB will receive PPI and vice versa. The primary endpoint is proportion of asymptomatic patients. Secondary endpoints are suppressive effect of GERD symptoms, proportion of asymptomatic patients at each time point, safety and cost-saving effect of P-CAB every other day administration, compliance with every other day administration, and proportion of asymptomatic patients at the first month of study drug administration. This study was approved by the National Hospital Organization Central Review Board for Clinical Trials (5 December 2017). If P-CAB every other day administration is established as one of GERD maintenance therapies, there is merit in both medical cost reduction and the safety to alleviate elevation in serum gastrin. UMIN000034701.

Study for every other day administration of vonoprazan in maintenance treatment of erosive GERD: study protocol for a multicentre randomised cross-over study

PubMed Central

Kato, Mototsugu; Ito, Noriko; Demura, Mamiko; Kubo, Kimitoshi; Mabe, Katsuhiro; Harada, Naohiko

2018-01-01

Introduction The first drug selected for treatment of gastro-oesophageal reflux disease (GERD) and prevention of the recurrence is a proton pump inhibitor (PPI), but recently, a potassium-competitive acid blocker (P-CAB) was put on the market in Japan. Its onset of effect is faster than PPI, and it takes more than 2 days to recover acid secretion after the withdrawal period. Therefore, unlike PPI, the usefulness of every other day administration or discontinuous administration is expected. Methods and analysis This study is a prospective, multicentre, open-label, two-period randomised cross-over study to compare the efficacy and safety of PPI every other day administration and P-CAB every other day administration in 120 patients who receive erosive GERD maintenance therapy with PPI. Patients will be randomly allocated to receive 4 weeks P-CAB or PPI followed by 4 weeks cross over, where those on P-CAB will receive PPI and vice versa. The primary endpoint is proportion of asymptomatic patients. Secondary endpoints are suppressive effect of GERD symptoms, proportion of asymptomatic patients at each time point, safety and cost-saving effect of P-CAB every other day administration, compliance with every other day administration, and proportion of asymptomatic patients at the first month of study drug administration. Ethics and dissemination This study was approved by the National Hospital Organization Central Review Board for Clinical Trials (5 December 2017). Discussion If P-CAB every other day administration is established as one of GERD maintenance therapies, there is merit in both medical cost reduction and the safety to alleviate elevation in serum gastrin. Trial registration number UMIN000034701. PMID:29527318

Competing power-generating technologies for the 21st century

NASA Astrophysics Data System (ADS)

Troost, G. K.

1994-04-01

Several new and advanced power-generating systems are presently being developed, e.g., fuel cells, advanced heat pumps, high-performance gas turbines. An analysis of these systems is presented and is based on projections of comparative studies and relevant trends. For advanced systems, a trade-off between efficiency gain and projected development cost is crucial. Projections for market conditions in the 21st century and, in particular, environmental issues are made in order to assess market-entry opportunities. Results from various case studies indicate challenging opportunities in process and metallurgical industries; several process-integrated configurations are being studied.

[Pre-randomisation in study designs: getting past the taboo].

PubMed

Schellings, R; Kessels, A G; Sturmans, F

2008-09-20

In October 2006 the Dutch Ministry of Health, Welfare and Sport announced that the use of pre-randomisation in study designs is admissible and not in conflict with the Dutch Medical Research in Human Subjects Act. With pre-randomisation, the conventional sequence of obtaining informed consent followed by randomisation is reversed. According to the original pre-randomisation design (Zelen design), participants are randomised before they are asked to consent; after randomisation, only participants in the experimental group are asked to consent to treatment and effect measurement. In the past, pre-randomisation has seldom been used, and when it was, it was often under the wrong circumstances. Awareness regarding the ethical, legal and methodological objections to pre-randomisation is increasing. About a decade ago, we illustrated the applicability and acceptability of pre-randomisation by means of a fictitious heroin provision trial. In general, pre-randomisation is justified if valid evaluation of the effects of an intervention is impossible using a conventional randomised design, e.g., if knowledge of the intervention may lead to non-compliance or drop-out in the control group, or when the intervention is an educational programme. Other requirements for pre-randomisation include the following: the study has a clinically relevant objective, it is likely that the study will lead to important new insights, the informed consent procedure bears no potential harm to participants, at least standard care is offered to participants in the control group, and the approval of an independent research ethics committee is obtained.

78 FR 60275 - Alternative Method for Calculating Off-Cycle Credits for Mercedes-Benz Vehicles Under the Light...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-10-01

...., small/mid-size/large cars and light-duty trucks) (See Section II-III of Mercedes-Benz Application...-start effectiveness unless the vehicle possesses an electric heater circulation pump, or equivalent...-start system includes an electric [[Page 60278

Gastrointestinal safety of celecoxib versus naproxen in patients with cardiothrombotic diseases and arthritis after upper gastrointestinal bleeding (CONCERN): an industry-independent, double-blind, double-dummy, randomised trial.

PubMed

Chan, Francis K L; Ching, Jessica Y L; Tse, Yee Kit; Lam, Kelvin; Wong, Grace L H; Ng, Siew C; Lee, Vivian; Au, Kim W L; Cheong, Pui Kuan; Suen, Bing Y; Chan, Heyson; Kee, Ka Man; Lo, Angeline; Wong, Vincent W S; Wu, Justin C Y; Kyaw, Moe H

2017-06-17

Present guidelines are conflicting for patients at high risk of both cardiovascular and gastrointestinal events who continue to require non-steroidal anti-inflammatory drugs (NSAIDs). We hypothesised that a cyclooxygenase-2-selective NSAID plus proton-pump inhibitor is superior to a non-selective NSAID plus proton-pump inhibitor for prevention of recurrent ulcer bleeding in concomitant users of aspirin with previous ulcer bleeding. For this industry-independent, double-blind, double-dummy, randomised trial done in one academic hospital in Hong Kong, we screened patients with arthritis and cardiothrombotic diseases who were presenting with upper gastrointestinal bleeding, were on NSAIDs, and require concomitant aspirin. After ulcer healing, an independent staff member randomly assigned (1:1) patients who were negative for Helicobacter pylori with a computer-generated list of random numbers to receive oral administrations of either celecoxib 100 mg twice per day plus esomeprazole 20 mg once per day or naproxen 500 mg twice per day plus esomeprazole 20 mg once per day for 18 months. All patients resumed aspirin 80 mg once per day. Both patients and investigators were masked to their treatments. The primary endpoint was recurrent upper gastrointestinal bleeding within 18 months. The primary endpoint and secondary safety endpoints were analysed in the modified intention-to-treat population. This study was registered with ClinicalTrials.gov, number NCT00153660. Between May 24, 2005, and Nov 28, 2012, we enrolled 514 patients, assigning 257 patients to each study group, all of whom were included in the intention-to-treat population. Recurrent upper gastrointestinal bleeding occurred in 14 patients in the celecoxib group (nine gastric ulcers and five duodenal ulcers) and 31 patients in the naproxen group (25 gastric ulcers, three duodenal ulcers, one gastric ulcer and duodenal ulcer, and two bleeding erosions). The cumulative incidence of recurrent bleeding in 18 months was 5·6% (95% CI 3·3-9·2) in the celecoxib group and 12·3% (8·8-17·1) in the naproxen group (p=0·008; crude hazard ratio 0·44, 95% CI 0·23-0·82; p=0·010). Excluding patients who reached study endpoints, 21 (8%) patients in the celecoxib group and 17 (7%) patients in the naproxen group had adverse events leading to discontinuation of treatment. No treatment-related deaths occurred during the study. In patients at high risk of both cardiovascular and gastrointestinal events who require concomitant aspirin and NSAID, celecoxib plus proton-pump inhibitor is the preferred treatment to reduce the risk of recurrent upper gastrointestinal bleeding. Naproxen should be avoided despite its perceived cardiovascular safety. The Research Grant Council of Hong Kong. Copyright © 2017 Elsevier Ltd. All rights reserved.

Properties of excited states in organic light emitting diodes and lasers

NASA Astrophysics Data System (ADS)

Giebink, Noel C.

The field of organic semiconductors has grown rapidly over the past decade with the development of light emitting diodes, solar cells, and lasers that promise a new generation of low-cost, flexible optoelectronic devices. In each case, the behavior of molecular excited states, or excitons, is of fundamental importance. The present study explores the nature and interactions of such excited states in the attempt to develop an electrically pumped organic semiconductor laser, and to improve the performance and operational stability of organic light emitting diodes. We begin by investigating intrinsic loss processes in optically pumped organic semiconductor lasers and demonstrate that exciton annihilation implies a fundamental limit that will prevent lasing by electrical injection in currently known materials. Searching for an alternative approach to reach threshold leads us to study metastable geminate charge pairs, where we find that optically generated excitons can be accumulated over time in an external electric field via these intermediate states. Upon field turn-off, the excitons are immediately restored, leading to a sudden burst of excitation density over 30 times higher than that generated by the pump alone. Unfortunately, we identify limitations that have thus far prevented reaching laser threshold with this technique. In a parallel push toward high power density, we investigate the origins of quantum efficiency roll-off in organic light emitting diodes (OLEDs) and find that it is dominated by loss of charge balance in the majority of fluorescent and phosphorescent devices. The second major theme of this work involves understanding the intrinsic modes of OLED operational degradation. Based on extensive modeling and supported directly by experimental evidence, we identify exciton-charge carrier annihilation reactions as a principle degradation pathway. Exploiting the diffusion of triplet excitons, we show that fluorescence and phosphorescence can be combined to increase the operational lifetime of white OLEDs and still retain the potential for unity internal quantum efficiency.

All-optical switching in GaAs microdisk resonators by a femtosecond pump-probe technique through tapered-fiber coupling.

PubMed

Lin, Yen-Chih; Mao, Ming-Hua; Lin, You-Ru; Lin, Hao-Hsiung; Lin, Che-An; Wang, Lon A

2014-09-01

We demonstrate ultrafast all-optical switching in GaAs microdisk resonators using a femtosecond pump-probe technique through tapered-fiber coupling. The temporal tuning of the resonant modes resulted from the refractive index change due to photoexcited carrier density variation inside the GaAs microdisk resonator. Transmission through the GaAs microdisk resonator can be modulated by more than 10 dB with a switching time window of 8 ps in the switch-off operation using pumping pulses with energies as low as 17.5 pJ. The carrier lifetime was fitted to be 42 ps, much shorter than that of the bulk GaAs, typically of the order of nanoseconds. The above observation indicates that the surface recombination plays an important role in increasing the switching speed.

Large-Scale Coherent Vortex Formation in Two-Dimensional Turbulence

NASA Astrophysics Data System (ADS)

Orlov, A. V.; Brazhnikov, M. Yu.; Levchenko, A. A.

2018-04-01

The evolution of a vortex flow excited by an electromagnetic technique in a thin layer of a conducting liquid was studied experimentally. Small-scale vortices, excited at the pumping scale, merge with time due to the nonlinear interaction and produce large-scale structures—the inverse energy cascade is formed. The dependence of the energy spectrum in the developed inverse cascade is well described by the Kraichnan law k -5/3. At large scales, the inverse cascade is limited by cell sizes, and a large-scale coherent vortex flow is formed, which occupies almost the entire area of the experimental cell. The radial profile of the azimuthal velocity of the coherent vortex immediately after the pumping was switched off has been established for the first time. Inside the vortex core, the azimuthal velocity grows linearly along a radius and reaches a constant value outside the core, which agrees well with the theoretical prediction.

Design of simulation-based medical education and advantages and disadvantages of in situ simulation versus off-site simulation.

PubMed

Sørensen, Jette Led; Østergaard, Doris; LeBlanc, Vicki; Ottesen, Bent; Konge, Lars; Dieckmann, Peter; Van der Vleuten, Cees

2017-01-21

Simulation-based medical education (SBME) has traditionally been conducted as off-site simulation in simulation centres. Some hospital departments also provide off-site simulation using in-house training room(s) set up for simulation away from the clinical setting, and these activities are called in-house training. In-house training facilities can be part of hospital departments and resemble to some extent simulation centres but often have less technical equipment. In situ simulation, introduced over the past decade, mainly comprises of team-based activities and occurs in patient care units with healthcare professionals in their own working environment. Thus, this intentional blend of simulation and real working environments means that in situ simulation brings simulation to the real working environment and provides training where people work. In situ simulation can be either announced or unannounced, the latter also known as a drill. This article presents and discusses the design of SBME and the advantage and disadvantage of the different simulation settings, such as training in simulation-centres, in-house simulations in hospital departments, announced or unannounced in situ simulations. Non-randomised studies argue that in situ simulation is more effective for educational purposes than other types of simulation settings. Conversely, the few comparison studies that exist, either randomised or retrospective, show that choice of setting does not seem to influence individual or team learning. However, hospital department-based simulations, such as in-house simulation and in situ simulation, lead to a gain in organisational learning. To our knowledge no studies have compared announced and unannounced in situ simulation. The literature suggests some improved organisational learning from unannounced in situ simulation; however, unannounced in situ simulation was also found to be challenging to plan and conduct, and more stressful among participants. The importance of setting, context and fidelity are discussed. Based on the current limited research we suggest that choice of setting for simulations does not seem to influence individual and team learning. Department-based local simulation, such as simulation in-house and especially in situ simulation, leads to gains in organisational learning. The overall objectives of simulation-based education and factors such as feasibility can help determine choice of simulation setting.

Aerodynamics of electrically driven freight pipeline system

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

Lundgren, T.S.; Zhao, Y.

2000-06-01

This paper examines the aerodynamic characteristics of a freight pipeline system in which freight capsules are individually propelled by electrical motors. The fundamental difference between this system and the more extensively studied pneumatic capsule pipeline is the different role played by aerodynamic forces. In a driven system the propelled capsules are resisted by aerodynamic forces and, in reaction, pump air through the tube. In contrast, in a pneumatically propelled system external blowers pump air through the tubes, and this provides the thrust for the capsules. An incompressible transient analysis is developed to study the aerodynamics of multiple capsules in amore » cross-linked two-bore pipeline. An aerodynamic friction coefficient is used as a cost parameter to compare the effects of capsule blockage and headway and to assess the merits of adits and vents. The authors conclude that optimum efficiency for off-design operation is obtained with long platoons of capsules in vented or adit connected tubes.« less

The role of drug efflux pumps in Malassezia pachydermatis and Malassezia furfur defence against azoles.

PubMed

Iatta, Roberta; Puttilli, Maria Rita; Immediato, Davide; Otranto, Domenico; Cafarchia, Claudia

2017-03-01

This study aims to evaluate the effect of efflux pump modulators (EPMs) on the minimal inhibitory concentration (MIC) of fluconazole (FLZ) and voriconazole (VOR) in Malassezia furfur and Malassezia pachydermatis. The in vitro efficacy of azoles, in combination with EPMs (ie haloperidol-HAL, promethazine-PTZ and cyclosporine A-CYS), against 21 M. furfur from bloodstream infection patients and 14 M. pachydermatis from the skin of dogs with dermatitis, was assessed using a broth microdilution chequerboard analysis. Data were analysed using the model-fractional inhibitory concentration index (FICI) method. The MIC of FLZ and VOR of Malassezia spp. decreased in the presence of sub-inhibitory concentrations of HAL and/or PTZ. The synergic effect was observed only in strains with FLZ MIC≥128 μg/mL for M. furfur, FLZ MIC≥64 μg/mL for M. pachydermatis and VOR MIC≥4 μg/mL in both Malassezia spp. These results suggest that the drug efflux pumps are involved as defence mechanisms to azole drugs in Malassezia yeast. The synergism might be related to an increased expression of efflux pump genes, eventually resulting in azole resistance phenomena. Finally, the above FLZ and VOR MIC values might be considered the cut-off to discriminate susceptible and resistant strains. © 2016 Blackwell Verlag GmbH.

Shamba Maisha: A pilot study assessing impacts of a micro-irrigation intervention on the health and economic wellbeing of HIV patients

PubMed Central

2010-01-01

Background HIV/AIDS negatively impacts poverty alleviation and food security, which reciprocally hinder the rapid scale up and effectiveness of HIV care programs. Nyanza province has the highest HIV prevalence (15.3%), and is the third highest contributor (2.4 million people) to rural poverty in Kenya. Thus, we tested the feasibility of providing a micro-irrigation pump to HIV-positive farmers in order to evaluate its impact on health and economic advancement among HIV-positive patients and their families. Methods Thirty HIV-positive patients enrolled in the Family AIDS Care and Education Services (FACES) program in Kisumu, Kenya were provided a micro-financed loan to receive an irrigation pump and farming guidance from KickStart, the developer of the pump. Economic data, CD4 counts, household health and loan repayment history were collected 12 months after the pumps were distributed. Results Mean annual family income increased by $1,332 over baseline. CD4 counts did not change significantly. Though income increased, only three (10%) participants had paid off more than a quarter of the loan. Conclusions We demonstrated the feasibility of an income-generating micro-irrigation intervention among HIV-positive patients and the collection of health and economic data. While family income improved significantly, loan repayment rates were low- likely complicated by the drought that occurred in Kenya during the intervention period. PMID:20459841

Shamba Maisha: a pilot study assessing impacts of a micro-irrigation intervention on the health and economic wellbeing of HIV patients.

PubMed

Pandit, Jay A; Sirotin, Nicole; Tittle, Robin; Onjolo, Elijah; Bukusi, Elizabeth A; Cohen, Craig R

2010-05-11

HIV/AIDS negatively impacts poverty alleviation and food security, which reciprocally hinder the rapid scale up and effectiveness of HIV care programs. Nyanza province has the highest HIV prevalence (15.3%), and is the third highest contributor (2.4 million people) to rural poverty in Kenya. Thus, we tested the feasibility of providing a micro-irrigation pump to HIV-positive farmers in order to evaluate its impact on health and economic advancement among HIV-positive patients and their families. Thirty HIV-positive patients enrolled in the Family AIDS Care and Education Services (FACES) program in Kisumu, Kenya were provided a micro-financed loan to receive an irrigation pump and farming guidance from KickStart, the developer of the pump. Economic data, CD4 counts, household health and loan repayment history were collected 12 months after the pumps were distributed. Mean annual family income increased by $1,332 over baseline. CD4 counts did not change significantly. Though income increased, only three (10%) participants had paid off more than a quarter of the loan. We demonstrated the feasibility of an income-generating micro-irrigation intervention among HIV-positive patients and the collection of health and economic data. While family income improved significantly, loan repayment rates were low- likely complicated by the drought that occurred in Kenya during the intervention period.

Evaluation of the horizontal-to-vertical spectral ratio (HVSR) seismic method to determine sediment thickness in the vicinity of the South Well Field, Franklin County, OH

USGS Publications Warehouse

Haefner, Ralph J.; Sheets, Rodney A.; Andrews, Robert E.

2011-01-01

The horizontal-to-vertical spectral ratio (HVSR) seismic method involves analyzing measurements of ambient seismic noise in three dimensions to determine the fundamental site resonance frequency. Resonance is excited by the interaction of surface waves (Rayleigh and Love) and body waves (vertically incident shear) with the high-contrast aconstic impedance boundary at the bedrock-sediment interface. Measurements were made to determine the method's utility for estimating thickness of unconsolidated glacial sediments at 18 locations at the South Well Field, Franklin County, OH, and at six locations in Pickaway County where sediment thickness was already known. Measurements also were made near a high-capacity production well (with pumping on and off) and near a highway and a limestone quarry to examine changes in resonance frequencies over a 20-hour period. Although the regression relation for resonance frequency and sediment thickness had a relatively low [r.sup.2] (0.322), estimates of sediment thickness were, on average, within 14 percent of known thicknesses. Resonance frequencies for pumping on and pumping off were identical, although the amplitude of the peak was nearly double under pumping conditions. Resonance frequency for the 20-hour period did not change, but the amplitude of the peak changed considerably, with a maximum amplitude in the early afternoon and minimum in the very early morning hours. Clay layers within unconsolidated sediments may influence resonance frequency and the resulting regression equation, resulting in underestimation of sediment thickness; however, despite this and other complicating factors, hydrogeologists should consider this method when thickness data are needed for unconsolidated sediments.

Evaluation of the horizontal-to-vertical spectral ratio (HVSR) seismic method to determine sediment thickness in the vicinity of the south well field, Franklin county, OH

USGS Publications Warehouse

Haefner, R.J.; Sheets, R.A.; Andrews, R.E.

2010-01-01

The horizontal-to-vertical spectral ratio (HVSR) seismic method involves analyzing measurements of ambient seismic noise in three dimensions to determine the fundamental site resonance frequency. Resonance is excited by the interaction of surface waves (Rayleigh and Love) and body waves (vertically incident shear) with the high-contrast acoustic impedance boundary at the bedrock-sediment interface. Measurements were made to determine the method's utility for estimating thickness of unconsolidated glacial sediments at 18 locations at the South Well Field, Franklin County, OH, and at six locations in Pickaway County where sediment thickness was already known. Measurements also were made near a high-capacity production well (with pumping on and off ) and near a highway and a limestone quarry to examine changes in resonance frequencies over a 20-hour period. Although the regression relation for resonance frequency and sediment thickness had a relatively low r 2(0.322), estimates of sediment thickness were, on average, within 14 percent of known thicknesses. Resonance frequencies for pumping on and pumping off were identical, although the amplitude of the peak was nearly double under pumping conditions. Resonance frequency for the 20-hour period did not change, but the amplitude of the peak changed considerably, with a maximum amplitude in the early afternoon and minimum in the very early morning hours. Clay layers within unconsolidated sediments may influence resonance frequency and the resulting regression equation, resulting in underestimation of sediment thickness; however, despite this and other complicating factors, hydrogeologists should consider this method when thickness data are needed for unconsolidated sediments. ?? 2011 by The Ohio Academy of Science. All Rights Reserved.

A Modular Control Platform for a Diode Pumped Alkali Laser

NASA Astrophysics Data System (ADS)

Shapiro, J.; Teare, S.

Many of the difficulties of creating compact, high power laser systems can be overcome if the heat dissipating properties of chemical lasers can be combined with the efficiency of diode lasers. Recently, the novel idea of using solid state diode lasers to pump gaseous gain media, such as is done in diode pumped alkali lasers (DPALs), has been proposed and early experiments have shown promising results. However, a number of technical issues need to be overcome to realize high output power from these lasers. In order to achieve higher power, the efficiency of coupling between pump laser energy and the chemical cell must be increased, and eventually multiple high power diode pumps must be combined and synchronized so that their energy can pump the chemical cell. Additionally, an inter-cavity adaptive optics system may be a requirement to be able to propagate these lasers with high efficiency. DPAL systems are complex and require a significant amount of data fusion and active feedback to control and optimize their performance. There are a wide range of components including pump lasers, gain cells and monitoring points needed to study and refine the overall laser system. In support of this dynamic development environment, we have developed a hardware framework using commercial off the shelf (COTS) components which supports the rapid assembly of functional system blocks into a cohesive integrated system. Critical to this system are a simple communication protocol, industry standard communication pipes (USB, Bluetooth, etc), and flexible high level scripting. Simplifying the integration process has the benefit of allowing flexible "on the fly" modifications to adapt the system as needed and enhance available functionality. The modular nature of the architecture allows scalability and adaptability as more pieces are added to the system. Key components of this system are demonstrated for selected portions of a DPAL system using a USB backbone.

Changing eating behaviours to treat childhood obesity in the community using Mandolean: the Community Mandolean randomised controlled trial (ComMando)--a pilot study.

PubMed

Hamilton-Shield, Julian; Goodred, Joanna; Powell, Lesley; Thorn, Joanna; Banks, Jon; Hollinghurst, Sandra; Montgomery, Alan; Turner, Katrina; Sharp, Debbie

2014-07-01

Around one in five children in England is obese when they leave primary school. Thus far, it has not been demonstrated that primary care interventions to manage childhood obesity can achieve significant weight reduction. Training obese children to eat more slowly as an adjunct to other healthy lifestyle behaviour change has been shown to increase weight reduction in a hospital setting. This pilot study aimed to test recruitment strategies, treatment adherence, clinic attendance and participants' experiences of using a device [Mandolean® (previously Mandometer®, Mikrodidakt AB, Lund, Sweden)] to slow down speed of eating as an adjunct to dietary and activity advice in treating obesity in primary school-aged children. A two-arm, parallel, randomised controlled trial with a qualitative study embedded within the pilot. Randomisation occurred after informed consent and baseline measures were collected. Participants were randomised by the Bristol Randomised Trials Collaboration randomisation service with allocation stratified by hub and minimised by age of the child, gender, and baseline body mass index (BMI) standard deviation score (BMI z-value) of the child, and by BMI of the study parent (obese/not obese). General practices across Bristol, North Somerset and South Gloucestershire primary care trusts. Children (BMI ≥ 95th percentile) aged 5-11 years and their families. Standard care comprised dietary and activity advice by trained practice nurses. Adjunctive Mandolean training (the intervention) educated participants to eat meals more slowly and to rate levels of fullness (satiety). Mandolean is a small computer device attached to a weighing scale that provides visual and oral feedback during meals while generating a visual representation of levels of satiety during the meal. Participants were encouraged to eat their main meal each day from the Mandolean. One parent was also given a Mandolean to use when eating with the child. Outcomes for the pilot were recruitment of 36 families to the trial in the 9-month pilot phase, that meals would be eaten at least five times a week off a Mandolean by 90% of patients randomised to the intervention arm, that 80% of patients in both arms would attend the weight management clinic appointment 3 months post randomisation and that > 60% of children using Mandolean would demonstrate a reduction in speed of eating from baseline within 3 months of randomisation. None of the criteria for progression to the main trial were reached. Despite numerous pathways being available for referral, only 21 (13 to standard care, eight to intervention arm; 58%) of the target 36 families were recruited in the pilot phase. Less than 20% of those randomised to Mandolean used the device at least five times a week. The > 60% target for slowing down of eating speed by 3 months was unmet. Attendance at the weight management clinic in general practice hubs for both arms of the study at 3 months was 44% against a target of 80%. This pilot trial failed to meet its objectives in terms of recruitment, treatment adherence, demonstration of a reduction in speed of eating in sufficient numbers of children, and attendance at follow-up appointments. Despite a high prevalence of childhood obesity in the geographical area and practices signing up for the trial, this study, like many others, demonstrates a failure of families to engage with and respond to primary care weight management interventions. We need to understand why the target population seems inured to the health message that childhood obesity is a significant health-care issue and identify the barriers to seeking help and then acting on positive health behaviour retraining. Only when we have fully understood the general public's perceptions of childhood obesity and have identified ways of engaging target populations can we hope to develop interventions that can work in a primary or community-based setting. Current Controlled Trials ISRCTN90561114. This project was funded by the NIHR Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 18, No. 47. See the NIHR Journals Library website for further project information.

77 FR 29861 - Airworthiness Directives; Fokker Services B.V. Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2012-05-21

... an in-flight failure of the hydraulic control panel, which resulted in the absence of pressure and... absence of pressure and quantity indication of the hydraulic system and accompanying alerts for... shut-off of the engine driven hydraulic pumps, resulting in complete absence of hydraulic pressure...

Pump RIN-induced impairments in unrepeatered transmission systems using distributed Raman amplifier.

PubMed

Cheng, Jingchi; Tang, Ming; Lau, Alan Pak Tao; Lu, Chao; Wang, Liang; Dong, Zhenhua; Bilal, Syed Muhammad; Fu, Songnian; Shum, Perry Ping; Liu, Deming

2015-05-04

High spectral efficiency modulation format based unrepeatered transmission systems using distributed Raman amplifier (DRA) have attracted much attention recently. To enhance the reach and optimize system performance, careful design of DRA is required based on the analysis of various types of impairments and their balance. In this paper, we study various pump RIN induced distortions on high spectral efficiency modulation formats. The vector theory of both 1st and higher-order stimulated Raman scattering (SRS) effect using Jones-matrix formalism is presented. The pump RIN will induce three types of distortion on high spectral efficiency signals: intensity noise stemming from SRS, phase noise stemming from cross phase modulation (XPM), and polarization crosstalk stemming from cross polarization modulation (XPolM). An analytical model for the statistical property of relative phase noise (RPN) in higher order DRA without dealing with complex vector theory is derived. The impact of pump RIN induced impairments are analyzed in polarization-multiplexed (PM)-QPSK and PM-16QAM-based unrepeatered systems simulations using 1st, 2nd and 3rd-order forward pumped Raman amplifier. It is shown that at realistic RIN levels, negligible impairments will be induced to PM-QPSK signals in 1st and 2nd order DRA, while non-negligible impairments will occur in 3rd order case. PM-16QAM signals suffer more penalties compared to PM-QPSK with the same on-off gain where both 2nd and 3rd order DRA will cause non-negligible performance degradations. We also investigate the performance of digital signal processing (DSP) algorithms to mitigate such impairments.

Serum uric acid levels and multiple health outcomes: umbrella review of evidence from observational studies, randomised controlled trials, and Mendelian randomisation studies.

PubMed

Li, Xue; Meng, Xiangrui; Timofeeva, Maria; Tzoulaki, Ioanna; Tsilidis, Konstantinos K; Ioannidis, John PA; Campbell, Harry; Theodoratou, Evropi

2017-06-07

Objective  To map the diverse health outcomes associated with serum uric acid (SUA) levels. Design  Umbrella review. Data sources  Medline, Embase, Cochrane Database of Systematic Reviews, and screening of citations and references. Eligibility criteria  Systematic reviews and meta-analyses of observational studies that examined associations between SUA level and health outcomes, meta-analyses of randomised controlled trials that investigated health outcomes related to SUA lowering treatment, and Mendelian randomisation studies that explored the causal associations of SUA level with health outcomes. Results  57 articles reporting 15 systematic reviews and144 meta-analyses of observational studies (76 unique outcomes), 8 articles reporting 31 meta-analyses of randomised controlled trials (20 unique outcomes), and 36 articles reporting 107 Mendelian randomisation studies (56 unique outcomes) met the eligibility criteria. Across all three study types, 136 unique health outcomes were reported. 16 unique outcomes in meta-analyses of observational studies had P<10 -6 , 8 unique outcomes in meta-analyses of randomised controlled trials had P<0.001, and 4 unique outcomes in Mendelian randomisation studies had P<0.01. Large between study heterogeneity was common (80% and 45% in meta-analyses of observational studies and of randomised controlled trials, respectively). 42 (55%) meta-analyses of observational studies and 7 (35%) meta-analyses of randomised controlled trials showed evidence of small study effects or excess significance bias. No associations from meta-analyses of observational studies were classified as convincing; five associations were classified as highly suggestive (increased risk of heart failure, hypertension, impaired fasting glucose or diabetes, chronic kidney disease, coronary heart disease mortality with high SUA levels). Only one outcome from randomised controlled trials (decreased risk of nephrolithiasis recurrence with SUA lowering treatment) had P<0.001, a 95% prediction interval excluding the null, and no large heterogeneity or bias. Only one outcome from Mendelian randomisation studies (increased risk of gout with high SUA levels) presented convincing evidence. Hypertension and chronic kidney disease showed concordant evidence in meta-analyses of observational studies, and in some (but not all) meta-analyses of randomised controlled trials with respective intermediate or surrogate outcomes, but they were not statistically significant in Mendelian randomisation studies. Conclusion  Despite a few hundred systematic reviews, meta-analyses, and Mendelian randomisation studies exploring 136 unique health outcomes, convincing evidence of a clear role of SUA level only exists for gout and nephrolithiasis. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Fiber Raman laser and amplifier pumped by Nd3+:YVO4 solid state laser

NASA Astrophysics Data System (ADS)

Liu, Deming; Zhang, Minming; Liu, Shuang; Nie, Mingju; Wang, Ying

2005-04-01

Pumping source is the key technology of fiber Raman amplifiers (FRA) which are important for ultra long haul and high bit rate dense wavelength division multiplexing (DWDM) systems. In this paper the research work of the project, "Fiber Raman Laser and Amplifier pumped by Nd3+:YVO4 Solid State Laser", supported by the National High-tech Program (863-program) of China is introduced, in which a novel 14xx nm pump module with fine characteristics of high efficiency, simplicity, compactness and low cost is researched and developed. A compact 1342 nm Nd3+:YVO4 diode pumped solid state laser (DPSSL) module is developed with the total laser power of 655mW and the slope efficiency of 42.6% pumped by a 2W 808nm laser diode (LD). A special C-lens fiber collimator is designed to couple the 1342nm laser beam into a piece of single mode fiber (SMF) and the coupling efficiency of 80% is reached. The specific 14xx nm output laser is generated from a single stage Raman resonator which includes a pair of fiber Bragg gratings and a piece of Germanic-silicate or Phospho-silicate fiber pumped by such DPSSL module. The slope efficiency for conversion from 1342 to 14xx nm radiation is 75% and the laser power is more than 300mW each. Finally, Raman gain experiments are carried out with 100km SMF. 100 nm bandwidth with 10dB on-off Raman gain and 1.1dB gain flatness is achieved by pumped at 1425, 1438, 1455 and 1490nm.

Formation of the stimulated electromagnetic emission spectra near gyroharmonics for quasi-stationary and decaying striations

NASA Astrophysics Data System (ADS)

Grach, Savely; Norin, Lars; Sergeev, Evgeny; Thide, Bo; Leyser, Thomas

We present new results of the analysis of the stimulated electromagnetic emission (SEE) measurements performed with special diagnostic HF-pumping scheme, for pump wave frequencies f0 close to a multiple of the electron gyroharmonic nfce , n = 4, 5. The pumping scheme used was an alternation of quasi-continuous pumping (˜ 100-200 ms on, ˜ 20-30 ms off) during a few tens of seconds, and low duty cycle radiation (pulse duration 20-500 ms with 1-3 s interpulse period). The main attention is paid to the following: (i) The development of some spectral features of the SEE, such as the downshifted maximum (DM), the second downshifted maximum (2DM), the upshifted maximum (UM) and the broad upshifted maximum (BUM) in a preconditioned ionosphere such that stationary small-scale magnetic field-aligned irregularities (striations) are already present. In particular, we characterize a fast (3-15 ms) overshoot in the DM, 2DM and UM, and we study the properties of a transient BUM with a maximum intensity for 18 kHz < f - f0 < 25 kHz and the same lower cutoff at f - f0 ≈ 14 kHz as the stationary BUM. The transient BUM vanishes after 5 to 10 ms of the pump turn-on and does not reappear. (ii) The formation of SEE features caused by the pump wave after the transition to low duty cycle pumping (i.e. on the background of decaying striations). In particular we note, that the BUM growths exponentially with a characteristic time ˜ 15 ms while the DM grows much faster and later exhibits slower dynamics. (iii) A slow (from pulse to pulse) temporal evolution of the SEE after the changing the pump scheme to a low duty cycle pulse mode. We note a disappearance of the transient BUM 1-2 s after the change of pump scheme and we observe an overshoot of the DM and (part of) the BUM. Higher frequency components of the BUM decays much faster than its lower frequencies. The results allow us to investigate ponderomotive processes responsible for the formation of upper hybrid turbulence in the HP-pumped ionosphere and the comparative contribution of the striations with different scales to the generation of different SEE spectral components. The work was supported by the RFBR (grants No. 06-02-17334, 07-02-00464).

DPSSL pumped 20-TW Ti:sapphire laser system for DD fusion experiment

NASA Astrophysics Data System (ADS)

Sekine, T.; Hatano, Y.; Takeuchi, Y.; Kawashima, T.

2016-03-01

A diode-pumped solid-state laser (DPSSL) pumped 20-TW output Ti:sapphire laser system has been developed. A diode-pumped Nd:glass laser with output energy of 12.7 J in 527 nm was used as a pump source for a 20-TW Ti:sapphire amplifier. A CeLiB6O10 nonlinear optical crystal was used as a frequency doubler of the Nd:glass DPSSL[1]. Figure 1 shows typical output pulse energy of the 20-TW amplifier as a function of pumping energy and a near field pattern. A 1.65 J pulse energy was obtained by 4.5 J pump energy. The amplified seed pulse is compressed to typically 60 fs as shown in Fig. 1 by a vacuumed pulse compressor with 80% of transmissivity. Encircled energy ratio, into a circled with 8 μm diameter area, of far field pattern focused by off-axis parabolic mirror with F# of 3 is numerically evaluated to 40% at TW class output condition. Then focal intensity would reach to 1018W/cm2. This all- DPSSL system contributes for stable and continual investigation of laser induced plasma experiment. We have succeeded continual and high efficient generation of DD fusion neutron from CD nano-particles by cluster fusion scheme using the 20-TW laser. A yield of ∼105 neutrons per shot was stably observed during continuous 100 shots with repetition rate of 0.1Hz.

Simulation-based multiprofessional obstetric anaesthesia training conducted in situ versus off-site leads to similar individual and team outcomes: a randomised educational trial

PubMed Central

Sørensen, Jette Led; van der Vleuten, Cees; Rosthøj, Susanne; Østergaard, Doris; LeBlanc, Vicki; Johansen, Marianne; Ekelund, Kim; Starkopf, Liis; Lindschou, Jane; Gluud, Christian; Weikop, Pia; Ottesen, Bent

2015-01-01

Objective To investigate the effect of in situ simulation (ISS) versus off-site simulation (OSS) on knowledge, patient safety attitude, stress, motivation, perceptions of simulation, team performance and organisational impact. Design Investigator-initiated single-centre randomised superiority educational trial. Setting Obstetrics and anaesthesiology departments, Rigshospitalet, University of Copenhagen, Denmark. Participants 100 participants in teams of 10, comprising midwives, specialised midwives, auxiliary nurses, nurse anaesthetists, operating theatre nurses, and consultant doctors and trainees in obstetrics and anaesthesiology. Interventions Two multiprofessional simulations (clinical management of an emergency caesarean section and a postpartum haemorrhage scenario) were conducted in teams of 10 in the ISS versus the OSS setting. Primary outcome Knowledge assessed by a multiple choice question test. Exploratory outcomes Individual outcomes: scores on the Safety Attitudes Questionnaire, stress measurements (State-Trait Anxiety Inventory, cognitive appraisal and salivary cortisol), Intrinsic Motivation Inventory and perceptions of simulations. Team outcome: video assessment of team performance. Organisational impact: suggestions for organisational changes. Results The trial was conducted from April to June 2013. No differences between the two groups were found for the multiple choice question test, patient safety attitude, stress measurements, motivation or the evaluation of the simulations. The participants in the ISS group scored the authenticity of the simulation significantly higher than did the participants in the OSS group. Expert video assessment of team performance showed no differences between the ISS versus the OSS group. The ISS group provided more ideas and suggestions for changes at the organisational level. Conclusions In this randomised trial, no significant differences were found regarding knowledge, patient safety attitude, motivation or stress measurements when comparing ISS versus OSS. Although participant perception of the authenticity of ISS versus OSS differed significantly, there were no differences in other outcomes between the groups except that the ISS group generated more suggestions for organisational changes. Trial registration number NCT01792674. PMID:26443654

Effectiveness of sequential automatic-manual home respiratory polygraphy scoring.

PubMed

Masa, Juan F; Corral, Jaime; Pereira, Ricardo; Duran-Cantolla, Joaquin; Cabello, Marta; Hernández-Blasco, Luis; Monasterio, Carmen; Alonso-Fernandez, Alberto; Chiner, Eusebi; Vázquez-Polo, Francisco-José; Montserrat, Jose M

2013-04-01

Automatic home respiratory polygraphy (HRP) scoring functions can potentially confirm the diagnosis of sleep apnoea-hypopnoea syndrome (SAHS) (obviating technician scoring) in a substantial number of patients. The result would have important management and cost implications. The aim of this study was to determine the diagnostic cost-effectiveness of a sequential HRP scoring protocol (automatic and then manual for residual cases) compared with manual HRP scoring, and with in-hospital polysomnography. We included suspected SAHS patients in a multicentre study and assigned them to home and hospital protocols at random. We constructed receiver operating characteristic (ROC) curves for manual and automatic scoring. Diagnostic agreement for several cut-off points was explored and costs for two equally effective alternatives were calculated. Of 366 randomised patients, 348 completed the protocol. Manual scoring produced better ROC curves than automatic scoring. There was no sensitive automatic or subsequent manual HRP apnoea-hypopnoea index (AHI) cut-off point. The specific cut-off points for automatic and subsequent manual HRP scorings (AHI >25 and >20, respectively) had a specificity of 93% for automatic and 94% for manual scorings. The costs of manual protocol were 9% higher than sequential HRP protocol; these were 69% and 64%, respectively, of the cost of the polysomnography. A sequential HRP scoring protocol is a cost-effective alternative to polysomnography, although with limited cost savings compared to HRP manual scoring.

Pathways of proton transfer in the light-driven pump bacteriorhodopsin

NASA Technical Reports Server (NTRS)

Lanyi, J. K.

1993-01-01

The mechanism of proton transport in the light-driven pump bacteriorhodopsin is beginning to be understood. Light causes the all-trans to 13-cis isomerization of the retinal chromophore. This sets off a sequential and directed series of transient decreases in the pKa's of a) the retinal Schiff base, b) an extracellular proton release complex which includes asp-85, and c) a cytoplasmic proton uptake complex which includes asp-96. The timing of these pKa changes during the photoreaction cycle causes sequential proton transfers which result in the net movement of a proton across the protein, from the cytoplasmic to the extracellular surface.

Low-noise delays from dynamic Brillouin gratings based on perfect Golomb coding of pump waves.

PubMed

Antman, Yair; Levanon, Nadav; Zadok, Avi

2012-12-15

A method for long variable all-optical delay is proposed and simulated, based on reflections from localized and stationary dynamic Brillouin gratings (DBGs). Inspired by radar methods, the DBGs are inscribed by two pumps that are comodulated by perfect Golomb codes, which reduce the off-peak reflectivity. Compared with random bit sequence coding, Golomb codes improve the optical signal-to-noise ratio (OSNR) of delayed waveforms by an order of magnitude. Simulations suggest a delay of 5  Gb/s data by 9 ns, or 45 bit durations, with an OSNR of 13 dB.

Oil/gas separator for installation at burning wells

DOEpatents

Alonso, C.T.; Bender, D.A.; Bowman, B.R.; Burnham, A.K.; Chesnut, D.A.; Comfort, W.J. III; Guymon, L.G.; Henning, C.D.; Pedersen, K.B.; Sefcik, J.A.; Smith, J.A.; Strauch, M.S.

1993-03-09

An oil/gas separator is disclosed that can be utilized to return the burning wells in Kuwait to production. Advantageously, a crane is used to install the separator at a safe distance from the well. The gas from the well is burned off at the site, and the oil is immediately pumped into Kuwait's oil gathering system. Diverters inside the separator prevent the oil jet coming out of the well from reaching the top vents where the gas is burned. The oil falls back down, and is pumped from an annular oil catcher at the bottom of the separator, or from the concrete cellar surrounding the well.

Oil/gas separator for installation at burning wells

DOEpatents

Alonso, Carol T.; Bender, Donald A.; Bowman, Barry R.; Burnham, Alan K.; Chesnut, Dwayne A.; Comfort, III, William J.; Guymon, Lloyd G.; Henning, Carl D.; Pedersen, Knud B.; Sefcik, Joseph A.; Smith, Joseph A.; Strauch, Mark S.

1993-01-01

An oil/gas separator is disclosed that can be utilized to return the burning wells in Kuwait to production. Advantageously, a crane is used to install the separator at a safe distance from the well. The gas from the well is burned off at the site, and the oil is immediately pumped into Kuwait's oil gathering system. Diverters inside the separator prevent the oil jet coming out of the well from reaching the top vents where the gas is burned. The oil falls back down, and is pumped from an annular oil catcher at the bottom of the separator, or from the concrete cellar surrounding the well.

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

PubMed

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

2007-05-18

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

All-optical switching application based on optical nonlinearity of Yb(3+) doped aluminosilicate glass fiber with a long-period fiber gratings pair.

PubMed

Kim, Yune; Kim, Nam; Chung, Youngjoo; Paek, Un-Chul; Han, Won-Taek

2004-02-23

We propose a new fiber-type all-optical switching device based on the optical nonlinearity of Yb(3+) doped fiber and a long-period fiber gratings(LPG) pair. The all-optical ON-OFF switching with the continuous wave laser signal at ~1556nm in the LPG pair including the 25.5cm long Yb(3+) doped fiber was demonstrated up to ~200Hz upon pumping with the modulated square wave pulses at 976nm, where a full optical switching with the ~18dB extinction ratio was obtained at the launched pump power of ~35mW.

Effects of improved home heating on asthma in community dwelling children: randomised controlled trial

PubMed Central

Pierse, Nevil; Nicholls, Sarah; Gillespie-Bennett, Julie; Viggers, Helen; Cunningham, Malcolm; Phipps, Robyn; Boulic, Mikael; Fjällström, Pär; Free, Sarah; Lloyd, Bob; Wickens, Kristin; Shields, David; Baker, Michael; Cunningham, Chris; Woodward, Alistair; Bullen, Chris; Crane, Julian

2008-01-01

Objective To assess whether non-polluting, more effective home heating (heat pump, wood pellet burner, flued gas) has a positive effect on the health of children with asthma. Design Randomised controlled trial. Setting Households in five communities in New Zealand. Participants 409 children aged 6-12 years with doctor diagnosed asthma. Interventions Installation of a non-polluting, more effective home heater before winter. The control group received a replacement heater at the end of the trial. Main outcome measures The primary outcome was change in lung function (peak expiratory flow rate and forced expiratory volume in one second, FEV1). Secondary outcomes were child reported respiratory tract symptoms and daily use of preventer and reliever drugs. At the end of winter 2005 (baseline) and winter 2006 (follow-up) parents reported their child’s general health, use of health services, overall respiratory health, and housing conditions. Nitrogen dioxide levels were measured monthly for four months and temperatures in the living room and child’s bedroom were recorded hourly. Results Improvements in lung function were not significant (difference in mean FEV1 130.7 ml, 95% confidence interval −20.3 to 281.7). Compared with children in the control group, however, children in the intervention group had 1.80 fewer days off school (95% confidence interval 0.11 to 3.13), 0.40 fewer visits to a doctor for asthma (0.11 to 0.62), and 0.25 fewer visits to a pharmacist for asthma (0.09 to 0.32). Children in the intervention group also had fewer reports of poor health (adjusted odds ratio 0.48, 95% confidence interval 0.31 to 0.74), less sleep disturbed by wheezing (0.55, 0.35 to 0.85), less dry cough at night (0.52, 0.32 to 0.83), and reduced scores for lower respiratory tract symptoms (0.77, 0.73 to 0.81) than children in the control group. The intervention was associated with a mean temperature rise in the living room of 1.10°C (95% confidence interval 0.54°C to 1.64°C) and in the child’s bedroom of 0.57°C (0.05°C to 1.08°C). Lower levels of nitrogen dioxide were measured in the living rooms of the intervention households than in those of the control households (geometric mean 8.5 μg/m3 v 15.7 μg/m3, P<0.001). A similar effect was found in the children’s bedrooms (7.3 μg/m3 v 10.9 μg/m3, P<0.001). Conclusion Installing non-polluting, more effective heating in the homes of children with asthma did not significantly improve lung function but did significantly reduce symptoms of asthma, days off school, healthcare utilisation, and visits to a pharmacist. Trial registration Clinical Trials NCT00489762. PMID:18812366

The CLOSED trial; CLOnidine compared with midazolam for SEDation of paediatric patients in the intensive care unit: study protocol for a multicentre randomised controlled trial.

PubMed

Neubert, Antje; Baarslag, Manuel Alberto; Dijk, Monique van; Rosmalen, Joost van; Standing, Joseph F; Sheng, Yucheng; Rascher, Wolfgang; Roberts, Deborah; Winslade, Jackie; Rawcliffe, Louise; Hanning, Sara M; Metsvaht, Tuuli; Giannuzzi, Viviana; Larsson, Peter; Pokorná, Pavla; Simonetti, Alessandra; Tibboel, Dick

2017-06-21

Sedation is an essential part of paediatric critical care. Midazolam, often in combination with opioids, is the current gold standard drug. However, as it is a far-from-ideal agent, clonidine is increasingly being used in children. This drug is prescribed off-label for this indication, as many drugs in paediatrics are. Therefore, the CLOSED trial aims to provide data on the pharmacokinetics, safety and efficacy of clonidine for the sedation of mechanically ventilated patients in order to obtain a paediatric-use marketing authorisation. The CLOSED study is a multicentre, double-blind, randomised, active-controlled non-inferiority trial with a 1:1 randomisation between clonidine and midazolam. Both treatment groups are stratified according to age in three groups with the same size: <28 days (n=100), 28 days to <2 years (n=100) and 2-18 years (n=100). The primary end point is defined as the occurrence of sedation failure within the study period. Secondary end points include a pharmacokinetic/pharmacodynamic relationship, pharmacogenetics, occurrence of delirium and withdrawal syndrome, opioid consumption and neurodevelopment in the neonatal age group. Logistic regression will be used for the primary end point, appropriate statistics will be used for the secondary end points. Written informed consent will be obtained from the parents/caregivers. Verbal or deferred consent will be used in the sites where national legislation allows. The study has institutional review board approval at recruiting sites. The results will be published in a peer-reviewed journal and shared with the worldwide medical community. EudraCT: 2014-003582-24; Clinicaltrials.gov: NCT02509273; pre-results. © 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.

Rapid Speed Modulation of a Rotary Total Artificial Heart Impeller.

PubMed

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

2016-09-01

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

Distinguishing the impact of dexlansoprazole on heartburn vs. regurgitation in patients with gastro-oesophageal reflux disease.

PubMed

Peura, D A; Pilmer, B; Hunt, B; Mody, R; Perez, M C

2013-11-01

Gastro-oesophageal reflux disease (GERD) is characterised by symptomatic heartburn and regurgitation. Treatment with proton pump inhibitors (PPI) effectively decreases heartburn symptoms, but their effects on symptomatic regurgitation are less clear. To determine the impact of PPI therapy on heartburn and regurgitation severity in patients with either non-erosive GERD (NERD) or erosive oesophagitis (EE). Endoscopically-confirmed NERD patients received dexlansoprazole 30 or 60 mg or placebo in a randomised, blinded, 4-week study. Endoscopically-confirmed EE patients received dexlansoprazole 60 mg or lansoprazole 30 mg in two 8-week, randomised, blinded healing studies. The Patient Assessment of Upper Gastrointestinal Symptom Severity questionnaire, which includes a heartburn/regurgitation subscale, was administered to assess symptom severity at baseline, and at weeks 2 and 4 of the NERD study and at weeks 4 and 8 during the EE trials. We defined separate subscales for heartburn and regurgitation for this post-hoc analysis. Among patients with both symptoms at baseline, improvements in individual heartburn and regurgitation subscales along with the original combined heartburn/regurgitation subscale were determined. In the NERD and EE studies, 661 and 1909 patients, respectively, had both heartburn and regurgitation at baseline. NERD patients receiving dexlansoprazole 30 and 60 mg experienced significantly greater improvements in symptom severity for both heartburn and regurgitation compared with placebo. EE patients receiving dexlansoprazole 60 mg had significantly greater improvements in heartburn/regurgitation and heartburn-only subscales at week 4 compared with those receiving lansoprazole. Dexlansoprazole appears to be effective in improving both heartburn and regurgitation, and this improvement is maintained for the duration of treatment. © 2013 John Wiley & Sons Ltd.

Preliminary Design of the Vacuum System for FAIR Super FRS Quadrupole Magnet Cryostat

NASA Astrophysics Data System (ADS)

Akhter, J.; Pal, G.; Datta, A.; Sarma, P. R.; Bhunia, U.; Roy, S.; Bhattacharyya, S.; Nandi, C.; Mallik, C.; Bhandari, R. K.

2012-11-01

The Super-Conducting Fragment Separator (Super FRS) of the Facility for Antiproton and Ion Research (FAIR) at GSI Darmstadt is a large-acceptance superonducting fragment separator. The separator consists of large dipole, quadrupole and hexapole superconducting magnets. The long quadrupole magnet cryostat houses the helium chamber, which has the magnet iron and NbTi superconducting coil. The magnet weighs about 30 tons. The helium chamber is enclosed in vacuum inside the magnet cryostat. Multilayer Insulation (MLI) will be wrapped around the thermal shield to reduce radiation loss. Polyster of MLI comprises the major component responsible for outgassing. In order to reduce outgassing, pumping at elevated temperatures has to be carried out. In view of the large size and weight of the magnet, a seal off approach might not be operationally feasible. Continuous pumping of the cryostat has also been examined. Pump has been kept at a distance from the magnet considering the effect of stray magnetic fields. Oil free turbo molecular pump and scroll pump combination will be used to pump down the cryostat. The ultimate heat load of the cryostat will be highly dependent on the pressure attained. Radiation and conduction plays an important role in the heat transfer at low temperatures. This paper presents the vacuum design of the long quadrupole magnet cryostat and estimates the heat load of the cryostat.

Direct emission of chirality controllable femtosecond LG01 vortex beam

NASA Astrophysics Data System (ADS)

Wang, S.; Zhang, S.; Yang, H.; Xie, J.; Jiang, S.; Feng, G.; Zhou, S.

2018-05-01

Direct emission of a chirality controllable ultrafast LG01 mode vortex optical beam from a conventional z-type cavity design SESAM (SEmiconductor Saturable Absorber Mirror) mode locked LD pumped Yb:Phosphate laser has been demonstrated. A clean 360 fs vortex beam of ˜45.7 mW output power has been achieved. A radial shear interferometer has been built to determine the phase singularity and the wavefront helicity of the ultrafast output laser. Theoretically, it is found that the LG01 vortex beam is obtained via the combination effect of diagonal HG10 mode generation by off-axis pumping and the controllable Gouy phase difference between HG10 and HG01 modes in the sagittal and tangential planes. The chirality of the LG01 mode can be manipulated by the pump position to the original point of the laser cavity optical axis.

Relative phase noise induced impairment in CO-OFDM optical communication system with distributed fiber Raman amplifier.

PubMed

Wu, Jiadi; Cheng, Jingchi; Tang, Ming; Deng, Lei; Songnian, Fu; Shum, Perry Ping; Liu, Deming

2014-05-15

In this Letter, we demonstrate that the interplay between Raman pump relative intensity noise and cross-phase modulation leads to a relative phase noise (RPN) that brings non-negligible performance degradation to coherent optical orthogonal frequency-division multiplexing (CO-OFDM) transmission systems with co-pumped Raman amplification. By theoretical analysis and numerical simulation, we proved that RPN brings more system impairment in terms of Q-factor penalty than the single carrier system, and relatively larger walk-off between pump and signal helps to suppress the RPN induced impairment. A higher-order modulated signal is less tolerant to RPN than a lower-order signal. With the same spectral efficiency, the quadrature-amplitude modulation format shows better tolerance to RPN than phase-shift keying. The reported findings will be useful for the design and optimization of Raman amplified CO-OFDM multi-carrier transmission systems.

Device and method to relieve cordelle action in a chain driven pump

DOEpatents

Dysarz, Edward D.

1994-01-01

A cordelle action relief apparatus or device for use in sucker rod pumps in a petroleum or water well. The device is incorporated in a chain driven pump to prevent the chain from forming a bow or archlike configuration as the chain rolls off of the sprocket and down into the well. When the chain is allowed to form this bow or arch it could damage the well and well casing. The device includes a first rod on the side of the chain and a second rod on the second side of the chain that will allow the rollers of the chain to roll on the rod and further prevent the chain from bowing or arching and will further allow the rollers on the chain to roll on the rods which will further prevent damage to the well casing, the well, and the chain.

Application of fuzzy adaptive control to a MIMO nonlinear time-delay pump-valve system.

PubMed

Lai, Zhounian; Wu, Peng; Wu, Dazhuan

2015-07-01

In this paper, a control strategy to balance the reliability against efficiency is introduced to overcome the common off-design operation problem in pump-valve systems. The pump-valve system is a nonlinear multi-input-multi-output (MIMO) system with time delays which cannot be accurately measured but can be approximately modeled using Bernoulli Principle. A fuzzy adaptive controller is applied to approximate system parameters and achieve the control of delay-free model since the system model is inaccurate and the direct feedback linearization method cannot be applied. An extended Smith predictor is introduced to compensate time delays of the system using the inaccurate system model. The experiment is carried out to verify the effectiveness of the control strategy whose results show that the control performance is well achieved. Copyright © 2015 ISA. Published by Elsevier Ltd. All rights reserved.

Dual-wavelength vortex beam with high stability in a diode-pumped Yb:CaGdAlO4 laser

NASA Astrophysics Data System (ADS)

Shen, Yijie; Meng, Yuan; Fu, Xing; Gong, Mali

2018-05-01

We present a stable dual-wavelength vortex beam carrying orbital angular momentum (OAM) with two spectral peaks separated by a few terahertz in a diode-pumped Yb:CaGdAlO4 (CALGO) laser. The dual-wavelength spectrum is controlled by the pump power and off-axis loss in a laser resonator, arising from the broad emission bandwidth of Yb:CALGO. The OAM beam is obtained by a pair of cylindrical lenses serving as a π/2 convertor for high-order Hermite–Gaussian modes. The stability is verified by the fact that a 1\\hbar OAM beam with two spectral peaks at 1046.1 nm and 1057.2 nm (3.01 THz interval) can steadily operate for more than 3 h. It has great potential for scaling the application of OAM beams in terahertz spectroscopy, high-resolution interferometry, and so on.

Insulin pump therapy with automated insulin suspension in response to hypoglycemia: reduction in nocturnal hypoglycemia in those at greatest risk.

PubMed

Choudhary, Pratik; Shin, John; Wang, Yongyin; Evans, Mark L; Hammond, Peter J; Kerr, David; Shaw, James A M; Pickup, John C; Amiel, Stephanie A

2011-09-01

To evaluate a sensor-augmented insulin pump with a low glucose suspend (LGS) feature that automatically suspends basal insulin delivery for up to 2 h in response to sensor-detected hypoglycemia. The LGS feature of the Paradigm Veo insulin pump (Medtronic, Inc., Northridge, CA) was tested for 3 weeks in 31 adults with type 1 diabetes. There were 166 episodes of LGS: 66% of daytime LGS episodes were terminated within 10 min, and 20 episodes lasted the maximum 2 h. LGS use was associated with reduced nocturnal duration ≤2.2 mmol/L in those in the highest quartile of nocturnal hypoglycemia at baseline (median 46.2 vs. 1.8 min/day, P = 0.02 [LGS-OFF vs. LGS-ON]). Median sensor glucose was 3.9 mmol/L after 2-h LGS and 8.2 mmol/L at 2 h after basal restart. Use of an insulin pump with LGS was associated with reduced nocturnal hypoglycemia in those at greatest risk and was well accepted by patients.

Circulatory support for OPCAB procedures.

PubMed

Mueller, Xavier M; von Segesser, Ludwig K

2002-07-01

During off-pump coronary artery bypass grafting (OPCAB) which allows complete revascularization through a median sternotomy, revascularization of the lateral and posterior walls requires the verticalization of the heart, which may cause haemodynamic disturbance. This concern has stimulated the development of circulatory support with mini-pumps. Initially, these pumps were designed for the right side of the heart, which was found to be the main contributor to haemodynamic instability under experimental conditions. The three types of mini-pumps that have been developed so far - two for the right side of the heart and one for both sides - are reviewed as well as a new concept of integrated cardiopulmonary bypass (CPB) circuit with reduced surface and priming volume. However, with increasing experience and improved methods of exposition, OPCAB has become a procedure that can be performed without support in the majority of the cases. Nevertheless, the concept of miniaturization and the possibility to insert these devices through a peripheral access has opened the way to new indications, mainly short-term circulatory support for acute heart failure. This development is welcome in a field where available devices are invasive and plagued with a heavy morbidity.

Distributed parametric amplifier for RZ-DPSK signal transmission system.

PubMed

Xu, Xing; Zhang, Chi; Yuk, T I; Wong, Kenneth K Y

2012-08-13

We have experimentally demonstrated a single pump distributed parametric amplification (DPA) system for differential phase shift keying (DPSK) signal in a spool of dispersion-shifted fiber (DSF). The gain spectrum of single pump DPA is thoroughly investigated by both simulation and experiment, and a possible reference for optimal input pump power and fiber length relationship is provided to DPA based applications. Furthermore, DPSK format is compared with on-off keying (OOK) within DPA scheme. Eight WDM signal channels at 10-Gb/s are utilized, and approximately 0.5-dB power penalties at the bit-error rate (BER) of 10(-9) are achieved for return-to-zero DPSK (RZ-DPSK), comparing to larger than 1.5-dB with OOK format. In order to improve the system power efficiency, at the receiver, the pump is recycled by a photovoltaic cell and the converted energy can be used by potential low-power-consuming devices, i.e sensors or small-scale electronic circuits. Additionally, with suitable components, the whole DPA concept could be directly applied to the 1.3-μm telecommunication window along the most commonly used single-mode fiber (SMF).

Steroids In caRdiac Surgery (SIRS) trial: acute kidney injury substudy protocol of an international randomised controlled trial.

PubMed

Garg, Amit X; Vincent, Jessica; Cuerden, Meaghan; Parikh, Chirag; Devereaux, P J; Teoh, Kevin; Yusuf, Salim; Hildebrand, Ainslie; Lamy, Andre; Zuo, Yunxia; Sessler, Daniel I; Shah, Pallav; Abbasi, Seyed Hesameddin; Quantz, Mackenzie; Yared, Jean-Pierre; Noiseux, Nicolas; Tagarakis, Georgios; Rochon, Antoine; Pogue, Janice; Walsh, Michael; Chan, Matthew T V; Lamontagne, Francois; Salehiomran, Abbas; Whitlock, Richard

2014-03-05

Steroids In caRdiac Surgery trial (SIRS) is a large international randomised controlled trial of methylprednisolone or placebo in patients undergoing cardiac surgery with the use of a cardiopulmonary bypass pump. At the time of surgery, compared with placebo, methylprednisolone divided into two intravenous doses of 250 mg each may reduce the risk of postoperative acute kidney injury (AKI). With respect to the study schedule, over 7000 substudy eligible patients from 81 centres in 18 countries were randomised in December 2013. The authors will use a logistic regression to estimate the adjusted OR of methylprednisolone versus placebo on the primary outcome of AKI in the 14 days following surgery (a postoperative increase in serum creatinine of ≥50%, or ≥26.5 μmol/L, from the preoperative value). The stage of AKI will also be considered, as will the outcome of AKI in those with and without preoperative chronic kidney disease. After receipt of grant funding, the authors began to record additional perioperative serum creatinine measurements in consecutive patients enrolled at substudy participating centres, and patients were invited to enroll in a 6-month serum creatinine collection. In these trial subpopulations, the authors will consider the outcome of AKI defined in alternate ways, and the outcome of a 6-month change in kidney function from the preoperative value. The authors were competitively awarded a grant from the Canadian Institutes of Health Research for this SIRS AKI substudy. Ethics approval was obtained for additional serum creatinine recordings in consecutive patients enrolled at participating centres. The additional kidney data collection first began for patients enrolled after 1 March 2012. In patients who provided consent, the last 6-month kidney outcome data will be collected in 2014. The results will be reported no later than 2015. Number NCT00427388.

Local versus general anaesthesia in carotid endarterectomy: a systematic review of the evidence.

PubMed

Tangkanakul, C; Counsell, C E; Warlow, C P

1997-05-01

To determine whether carotid endarterectomy under local anaesthesia is safer and as effective as under general anaesthesia. Systematic review of the randomised and non-randomised studies. Studies were identified from the Cochrane Stroke Group's database plus additional handsearching and electronic searching. Two authors independently selected studies for inclusion and extracted details of trial quality and data on death, any stroke, myocardial infarction and other operative complications. Meta-analysis was performed using the Peto method. There were 17 non-randomised studies (about 5970 patients) and only three randomised studies (143 patients). The non-randomised studies suggested that the use of local anaesthesia may be associated with clinically important reductions (approximately 50%) in the odds of stroke, stroke or death, myocardial infarction and pulmonary complications during the perioperative period, and with reductions in hospital stay. There were far too little data from the randomised trials to confirm or refute these findings: only one death and seven strokes were reported. Non-randomised studies suggest potentially important benefits from performing carotid endarterectomy under local anaesthesia. However, these studies were seriously flawed and can only be hypothesis generating. The results must be confirmed in large well-designed randomised trials before any recommendations on the use of local anaesthetic can be made.

Vehicle fuel system

DOEpatents

Risse, John T.; Taggart, James C.

1976-01-01

A vehicle fuel system comprising a plurality of tanks, each tank having a feed and a return conduit extending into a lower portion thereof, the several feed conduits joined to form one supply conduit feeding fuel to a supply pump and using means, unused fuel being returned via a return conduit which branches off to the several return conduits.

Biological Aerosol Test Method and Personal Protective Equipment (PPE) Decon

DTIC Science & Technology

2011-05-01

supply to the porous tube diluter. This stops all air into the LSAT. 6. Power off the vacuum pump and the compressed air supply. 22 Distribution...Experiment from Template from the menu. 10. Scroll down the template list until you find APHL Flu Assay 04272009. 11. Highlight the test, then click

Warfighting and Logistic Support of Joint Forces from the Joint Sea Base

DTIC Science & Technology

2007-01-01

Intel- ligence Community. For more information on RAND’s Acquisition and Technology Policy Center, contact the Director, Philip Antón. He can be reached...This is similar to ships such as the 225-meter MV American Cor- morant , a float-on/float-off heavy lift semisubmersible vessel, and the pumping

76 FR 18105 - Energy Conservation Program for Consumer Products: Test Procedures for Residential Central Air...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-04-01

... the low-voltage transformer used when testing coil-only residential central air conditioners and heat... the Low-Voltage Transformer Used When Testing Coil- Only Central Air Conditioners and Heat Pumps and... metric, estimating off-mode energy consumption, and selecting the low- voltage transformer in the test...

Generation and detection of 80-Gbit/s return-to-zero differential phase-shift keying signals

NASA Astrophysics Data System (ADS)

Möller, Lothar; Su, Yikai; Xie, Chongjin; Liu, Xiang; Leuthold, Juerg; Gill, Douglas; Wei, Xing

2003-12-01

Nonlinear polarization rotation between a pump and a probe signal in a highly nonlinear fiber is used as a modulation process to generate 80-Gbit/s return-to-zero differential phase-shift keying signals. Its performance is analyzed and compared with a conventional on-off keying modulated signal.

78 FR 4160 - Federal Property Suitable as Facilities To Assist the Homeless

Federal Register 2010, 2011, 2012, 2013, 2014

2013-01-18

... use to assist the homeless. The properties were reviewed using information provided to HUD by Federal...-0801 Directions: fuel pump bldg.: 220 sf.; vehicle maint. bldg.: 1,526 sf. Comments: off-site removal only; vacant for 180 mons. or 15 yrs.; conditions unknown South Carolina Former US Vegetable Lab 2875...

A proteinuria cut-off level of 0.7 g/day after 12 months of treatment best predicts long-term renal outcome in lupus nephritis: data from the MAINTAIN Nephritis Trial

PubMed Central

Tamirou, Farah; Lauwerys, Bernard R; Dall'Era, Maria; Mackay, Meggan; Rovin, Brad; Cervera, Ricard; Houssiau, Frédéric A

2015-01-01

Background Although an early decrease in proteinuria has been correlated with good long-term renal outcome in lupus nephritis (LN), studies aimed at defining a cut-off proteinuria value are missing, except a recent analysis performed on patients randomised in the Euro-Lupus Nephritis Trial, demonstrating that a target value of 0.8 g/day at month 12 optimised sensitivity and specificity for the prediction of good renal outcome. The objective of the current work is to validate this target in another LN study, namely the MAINTAIN Nephritis Trial (MNT). Methods Long-term (at least 7 years) renal function data were available for 90 patients randomised in the MNT. Receiver operating characteristic curves were built to test the performance of proteinuria measured within the 1st year as short-term predictor of long-term renal outcome. We calculated the positive and negative predictive values (PPV, NPV). Results After 12 months of treatment, achievement of a proteinuria <0.7 g/day best predicted good renal outcome, with a sensitivity and a specificity of 71% and 75%, respectively. The PPV was high (94%) but the NPV low (29%). Addition of the requirement of urine red blood cells ≤5/hpf as response criteria at month 12 reduced sensitivity from 71% to 41%. Conclusions In this cohort of mainly Caucasian patients suffering from a first episode of LN in most cases, achievement of a proteinuria <0.7 g/day at month 12 best predicts good outcome at 7 years and inclusion of haematuria in the set of criteria at month 12 undermines the sensitivity of early proteinuria decrease for the prediction of good outcome. The robustness of these conclusions stems from the very similar results obtained in two distinct LN cohorts. Trial registration number: NCT00204022. PMID:26629352

Validation of the AUDIT-C in adults seeking help with their drinking online.

PubMed

Khadjesari, Zarnie; White, Ian R; McCambridge, Jim; Marston, Louise; Wallace, Paul; Godfrey, Christine; Murray, Elizabeth

2017-01-04

The abbreviated Alcohol Use Disorder Identification Test for Consumption (AUDIT-C) is rapidly becoming the alcohol screening tool of choice for busy practitioners in clinical settings and by researchers keen to limit assessment burden and reactivity. Cut-off scores for detecting drinking above recommended limits vary by population, setting, country and potentially format. This validation study aimed to determine AUDIT-C thresholds that indicated risky drinking among a population of people seeking help over the Internet. The data in this study were collected in the pilot phase of the Down Your Drink trial, which recruited people seeking help over the Internet and randomised them to a web-based intervention or an information-only website. Sensitivity, specificity, and positive and negative likelihood ratios were calculated for AUDIT-C scores, relative to weekly consumption that indicated drinking above limits and higher risk drinking. Receiver-operating characteristic (ROC) curves were created to assess the performance of different cut-off scores on the AUDIT-C for men and women. Past week alcohol consumption was used as the reference-standard and was collected via the TOT-AL, a validated online measure of past week drinking. AUDIT-C scores were obtained from 3720 adults (2053 female and 1667 male) searching the internet for help with drinking, mostly from the UK. The area under the ROC curve for risky drinking was 0.84 (95% CI 0.80, 0.87) (female) and 0.80 (95% CI 0.76, 0.84) (male). AUDIT-C cut-off scores for detecting risky drinking that maximise the sum of sensitivity and specificity were ≥8 for women and ≥8 for men; whereas those identifying the highest proportion of correctly classified individuals were ≥4 for women and ≥5 for men. AUDIT-C cut-off scores for detecting higher risk drinking were also calculated. AUDIT-C cut-off scores for identifying alcohol consumption above weekly limits in this largely UK based study population were substantially higher than those reported in other validation studies. Researchers and practitioners should select AUDIT-C cut-off scores according to the purpose of identifying risky drinkers and hence the relative importance of sensitivity and/or specificity.

Significance of off-pump coronary artery bypass grafting compared with percutaneous coronary intervention: a propensity score analysis

PubMed Central

Marui, Akira; Kimura, Takeshi; Tanaka, Shiro; Furukawa, Yutaka; Kita, Toru; Sakata, Ryuzo

2012-01-01

OBJECTIVE Although there have been several studies that compared the efficacy of percutaneous coronary intervention (PCI) and coronary artery bypass grafting (CABG), the impact of off-pump CABG (OPCAB) has not been well elucidated. The objective of the present study was to compare the outcomes after PCI, on-pump CABG (ONCAB), and OPCAB in patients with multivessel and/or left main disease. METHODS Among the 9877 patients undergoing first PCI using bare-metal stents or CABG who were enrolled in the CREDO-Kyoto Registry, 6327 patients with multivessel and/or left main disease were enrolled into the present study (67.9 ± 9.8 years old). Among them, 3877 patients received PCI, 1388 ONCAB, and 1069 OPCAB. Median follow-up was 3.5 years. RESULTS Comparing PCI with all CABG (ONCAB and OPCAB), propensity-score-adjusted all-cause mortality after PCI was higher than that CABG (hazard ratio (95% confidence interval): 1.37 (1.15–1.63), p < 0.01). The incidence of stroke was lower after PCI than that after CABG (0.75 (0.59–0.96), p = 0.02). CABG was associated with better survival outcomes than PCI in the elderly (interaction p = 0.04). Comparing OPCAB with PCI or ONCAB, propensity-score-adjusted all-cause mortality after PCI was higher than that after OPCAB (1.50 (1.20–1.86), p < 0.01). Adjusted mortality was similar between ONCAB and OPCAB (1.18 (0.93–1.51), p = 0.33). The incidence of stroke after OPCAB was similar to that after PCI (0.98 (0.71–1.34), p > 0.99), but incidence of stroke after ONCAB was higher than that after OPCAB (1.59 (1.16–2.18), p < 0.01). CONCLUSIONS In patients with multivessel and/or left main disease, CABG, particularly OPCAB, is associated with better survival outcomes than PCI using bare-metal stents. Survival outcomes are similar between ONCAB and OPCAB. PMID:21676626

Open urethroplasty versus endoscopic urethrotomy--clarifying the management of men with recurrent urethral stricture (the OPEN trial): study protocol for a randomised controlled trial.

PubMed

Stephenson, Rachel; Carnell, Sonya; Johnson, Nicola; Brown, Robbie; Wilkinson, Jennifer; Mundy, Anthony; Payne, Steven; Watkin, Nick; N'Dow, James; Sinclair, Andrew; Rees, Rowland; Barclay, Stewart; Cook, Jonathan A; Goulao, Beatriz; MacLennan, Graeme; McPherson, Gladys; Jackson, Matthew; Rapley, Tim; Shen, Jing; Vale, Luke; Norrie, John; McColl, Elaine; Pickard, Robert

2015-12-30

Urethral stricture is a common cause of difficulty passing urine in men with prevalence of 0.5 %; about 62,000 men in the UK. The stricture is usually sited in the bulbar part of the urethra causing symptoms such as reduced urine flow. Initial treatment is typically by endoscopic urethrotomy but recurrence occurs in about 60% of men within 2 years. The best treatment for men with recurrent bulbar stricture is uncertain. Repeat endoscopic urethrotomy opens the narrowing but it usually scars up again within 2 years requiring repeated procedures. The alternative of open urethroplasty involves surgically reconstructing the urethra, which may need an oral mucosal graft. It is a specialist procedure with a longer recovery period but may give lower risk of recurrence. In the absence of firm evidence as to which is best, individual men have to trade off the invasiveness and possible benefit of each option. Their preference will be influenced by individual social circumstances, availability of local expertise and clinician guidance. The open urethroplasty versus endoscopic urethrotomy (OPEN) trial aims to better guide the choice of treatment for men with recurrent urethral strictures by comparing benefit over 2 years in terms of symptom control and need for further treatment. OPEN is a pragmatic, UK multicentre, randomised trial. Men with recurrent bulbar urethral strictures (at least one previous treatment) will be randomised to undergo endoscopic urethrotomy or open urethroplasty. Participants will be followed for 24 months after randomisation, measuring symptoms, flow rate, the need for re-intervention, health-related quality of life, and costs. The primary clinical outcome is the difference in symptom control over 24 months measured by the area under the curve (AUC) of a validated score. The trial has been powered at 90% with a type I error rate of 5% to detect a 0.1 difference in AUC measured on a 0-1 scale. The analysis will be based on all participants as randomised (intention-to-treat). The primary economic outcome is the incremental cost per quality-adjusted life year. A qualitative study will assess willingness to be randomised and hence ability to recruit to the trial. The OPEN Trial seeks to clarify relative benefit of the current options for surgical treatment of recurrent bulbar urethral stricture which differ in their invasiveness and resources required. Our feasibility study identified that participation would be limited by patient preference and differing recruitment styles of general and specialist urologists. We formulated and implemented effective strategies to address these issues in particular by inviting participation as close as possible to diagnosis. In addition re-calculation of sample size as recruitment progressed allowed more efficient design given the limited target population and funding constraints. Recruitment is now to target. ISRCTN98009168 Date of registration: 29 November 2012.

Bias in reporting of randomised clinical trials in oncology.

PubMed

Vera-Badillo, Francisco E; Napoleone, Marc; Krzyzanowska, Monika K; Alibhai, Shabbir M H; Chan, An-Wen; Ocana, Alberto; Seruga, Bostjan; Templeton, Arnoud J; Amir, Eitan; Tannock, Ian F

2016-07-01

Bias in reporting efficacy and toxicity in clinical trials may impact treatment decisions. Here, we report quality of reporting of efficacy and of toxicity in articles describing randomised controlled trials (RCTs) of cancer therapy and the association between biased reporting and study results, funding and financial relationships of the authors with the sponsor. We reviewed articles published from July 2010 to December 2012 in six high-impact journals reporting RCTs of systemic treatment for cancer. Bias in reporting of the primary end-point and toxicity were assessed. Associations between biased reporting and study results, funding source and financial ties of the author with the funding source were evaluated using logistic regression. Two hundred articles were identified. Among 107 RCTs where there was no statistically significant difference in the primary end-point between the two arms, 50 (47%) reports used biased reporting in the abstract of the paper to imply benefit of the experimental treatment. Toxicity was not reported in the abstract in 18.5% of the studies and this was associated with a positive primary end-point. Source of funding and financial ties were not associated with biased reporting. Bias in reporting of efficacy outcomes is common for studies with a negative primary end-point and can lead to off-label misuse of experimental therapies, if they are approved for other indications. Toxicity is under-reported, especially for studies with a positive primary end-point, leading to a biased view of the safety of new treatments. Copyright © 2016 Elsevier Ltd. All rights reserved.

The ASPIRE study: design and methods of an in-clinic crossover trial on the efficacy of automatic insulin pump suspension in exercise-induced hypoglycemia.

PubMed

Brazg, Ronald L; Bailey, Timothy S; Garg, Satish; Buckingham, Bruce A; Slover, Robert H; Klonoff, David C; Nguyen, Xuan; Shin, John; Welsh, John B; Lee, Scott W

2011-11-01

The Paradigm®Veo™ System includes a low glucose suspend (LGS) feature which suspends insulin delivery when a prespecified glucose threshold setting is reached by the associated continuous glucose monitoring (CGM) sensor. The ASPIRE (Automation to Simulate Pancreatic Insulin REsponse) study is a multicenter, in-clinic, randomized, crossover study to examine the efficacy of LGS in exercise-induced hypoglycemia. Insulin-pump users underwent two separate exercise sessions, one with the LGS feature set to suspend insulin (LGS-on) when the CGM-detected glucose concentration was ≤ 70 mg/dl and one with the LGS feature off. Exercise sessions were conducted after an overnight fast and with initial plasma glucose level as measured by the YSI 2300 STAT Plus glucose analyzer (YSI) of 100-140 mg/dl. Subjects exercised until their YSI value fell to ≤ 85 mg/dl; subsequent YSI values <70 mg/dl were recorded for up to 4 h to measure the duration and nadir of hypoglycemia. The protocol required that subjects with YSI values <50 or >300 mg/dl were rescued with carbohydrates or insulin, respectively, based on the provider's recommendation. The primary end point was comparison of duration and severity of hypoglycemia between LGS-on and LGS-off sessions. Secondary end points included areas under the glucose concentration curve, CGM sensor accuracy, and last YSI glucose. Device- and procedure-related adverse events and serious adverse events were recorded. Fifty adults and teenagers (17-58 years) with type 1 diabetes were randomized. Study completion is expected in November 2011. © 2011 Diabetes Technology Society.

Impacts of mesoscale eddies on biogeochemical cycles in the South China Sea

NASA Astrophysics Data System (ADS)

Xiu, P.; Chai, F.; Guo, M.

2016-02-01

Biogeochemical cycles associated with mesoscale eddies in the South China Sea (SCS) are investigated by using satellite surface chlorophyll concentration, altimeter data, satellite sea surface temperature, and a coupled physical-biogeochemical Pacific Ocean model (ROMS-CoSiNE) simulation for the period from 1991 to 2007. Considering the annual mean, composite analysis reveals that cyclonic eddies are associated with higher concentrations of nutrients, phytoplankton and zooplankton while the anticyclonic eddies are with lower concentrations compared with surrounding waters, which is generally controlled by the eddy pumping mechanism. Dipole structures of vertical fluxes with net upward motion in cyclonic eddies and net downward motion in anticyclonic eddies are also revealed. During the lifetime of an eddy, the evolutions of physical, biological, and chemical structures are not linearly coupled at the eddy core where plankton grow and composition of the community depend not only on the physical and chemical processes but also on the adjustments by the predator-prey relationship. Considering the seasonal variability, we find eddy pumping mechanisms are generally dominant in winter and eddy advection effects are dominant in summer. Over the space, variability of chlorophyll to the west of Luzon Strait and off northwest of Luzon Island are mainly controlled by eddy pumping mechanism. In regions off the Vietnam coast, chlorophyll distributions are generally associated with horizontal eddy advection. This research highlights different mesoscale mechanisms affecting biological structures that can potentially disturb ocean biogeochemical cycling processes in the South China Sea.

Predicting performance of axial pump inducer of LOX booster turbo-pump of staged combustion cycle based rocket engine using CFD

NASA Astrophysics Data System (ADS)

Mishra, Arpit; Ghosh, Parthasarathi

2015-12-01

For low cost, high thrust, space missions with high specific impulse and high reliability, inert weight needs to be minimized and thereby increasing the delivered payload. Turbopump feed system for a liquid propellant rocket engine (LPRE) has the highest power to weight ratio. Turbopumps are primarily equipped with an axial flow inducer to achieve the high angular velocity and low suction pressure in combination with increased system reliability. Performance of the turbopump strongly depends on the performance of the inducer. Thus, for designing a LPRE turbopump, demands optimization of the inducer geometry based on the performance of different off-design operating regimes. In this paper, steady-state CFD analysis of the inducer of a liquid oxygen (LOX) axial pump used as a booster pump for an oxygen rich staged combustion cycle rocket engine has been presented using ANSYS® CFX. Attempts have been made to obtain the performance characteristic curves for the LOX pump inducer. The formalism has been used to predict the performance of the inducer for the throttling range varying from 80% to 113% of nominal thrust and for the different rotational velocities from 4500 to 7500 rpm. The results have been analysed to determine the region of cavitation inception for different inlet pressure.

A protocol for a systematic review of non-randomised evaluations of strategies to improve participant recruitment to randomised controlled trials.

PubMed

Gardner, Heidi R; Fraser, Cynthia; MacLennan, Graeme; Treweek, Shaun

2016-08-02

Randomised controlled trials guard against selection bias and therefore offer the fairest way of evaluating healthcare interventions such as medicinal products, devices and services. Recruitment to trials can be extremely difficult, and poor recruitment can lead to extensions to both time and budget and may result in an underpowered study which does not satisfactorily answer the original research question. In the worst cases, a trial may be abandoned, causing huge waste. The evidence to support the choice of recruitment interventions is currently weak. Non-randomised evaluations of recruitment interventions are currently rejected on grounds of poor methodological quality, but systematic evaluation and assessment of this substantial body of work (using Grading of Recommendations Assessment, Development and Evaluation (GRADE) where possible) may provide useful information to support and inform the recruitment decisions of trialists and the research priorities of methodology researchers. The following databases will be searched for relevant studies: Cochrane Methodology Register, MEDLINE, EMBASE, CINAHL and PsycINFO. Any non-randomised study that includes a comparison of two or more interventions to improve recruitment to randomised controlled trials will be included. We will not apply any restrictions on publication date, language or journal. The primary outcome will be the number of individuals or centres recruited into a randomised controlled trial. The secondary outcome will be cost per recruit. Two reviewers will independently screen abstracts for eligible studies, and then, full texts of potentially relevant records will be reviewed. Disagreements will be resolved through discussion. The methodological quality of studies will be assessed using the Cochrane risk of bias tool for non-randomised studies, and the GRADE system will be used if studies are pooled. This review aims to summarise the evidence on methods used to improve recruitment to randomised controlled trials. Carrying out a systematic review including only data from non-randomised studies is a novel approach, and one which some may argue is futile. However, we believe that the systematic evaluation of what is likely to be a substantial amount of research activity is necessary, worthwhile, and will yield valuable results for the clinical trials community regardless of whether the outcomes find in favour of one or more interventions. Should the results of this review suggest that non-randomised evaluations do have something to offer trialists planning their recruitment strategies, the review may be combined in the future with the Cochrane review of randomised evaluations to produce a full review of recruitment strategies encompassing both randomised and non-randomised evaluation methods. PROSPERO CRD42016037718.

Sustainable Improvement of Urban River Network Water Quality and Flood Control Capacity by a Hydrodynamic Control Approach-Case Study of Changshu City

NASA Astrophysics Data System (ADS)

Xie, Chen; Yang, Fan; Liu, Guoqing; Liu, Yang; Wang, Long; Fan, Ziwu

2017-01-01

Water environment of urban rivers suffers degradation with the impacts of urban expansion, especially in Yangtze River Delta. The water area in cites decreased sharply, and some rivers were cut off because of estate development, which brings the problems of urban flooding, flow stagnation and water deterioration. The approach aims to enhance flood control capability and improve the urban river water quality by planning gate-pump stations surrounding the cities and optimizing the locations and functions of the pumps, sluice gates, weirs in the urban river network. These gate-pump stations together with the sluice gates and weirs guarantee the ability to control the water level in the rivers and creating hydraulic gradient artificially according to mathematical model. Therefore the flow velocity increases, which increases the rate of water exchange, the DO concentration and water body self-purification ability. By site survey and prototype measurement, the river problems are evaluated and basic data are collected. The hydrodynamic model of the river network is established and calibrated to simulate the scenarios. The schemes of water quality improvement, including optimizing layout of the water distribution projects, improvement of the flow discharge in the river network and planning the drainage capacity are decided by comprehensive Analysis. Finally the paper introduces the case study of the approach in Changshu City, where the approach is successfully implemented.

Novel pump head design for high energy 1064 nm oscillator amplifier system for lidar applications

NASA Astrophysics Data System (ADS)

Willis, Christina C. C.; Witt, Greg; Martin, Nigel; Albert, Michael; Culpepper, Charles; Burnham, Ralph

2017-02-01

Many scientific endeavors are benefitted by the development of increasingly high energy laser sources for lidar applications. Space-based applications for lidar require compact, efficient and high energy sources, and we have designed a novel gain head that is compatible with these requirements. The gain medium for the novel design consists of a composite Nd:YAG/Sm:YAG slab, wherein the Sm:YAG portion absorbs any parasitic 1064 nm oscillations that might occur in the main pump axis. A pump cavity is built around the slab, consisting of angled gold-coated reflectors which allow for five pump passes from each of the four pumping locations around the slab. Pumping is performed with off-axis diode bars, allowing for highly compact conductively cooled design. Optical and thermal modeling of this design was done to verify and predict its performance. In order to ultimately achieve 50 W average power at a repetition rate of 500 Hz, three heads of this design will be used in a MOPA configuration with two stages of amplification. To demonstrate the pump head we built it into a 1064 nm laser cavity and performed initial amplification experiments. Modeling and design of the system is presented along with the initial oscillator and amplifier results. The greatest pulse energy produced from the seeded q-switched linear oscillator was an output of 25 mJ at 500 Hz. With an input of 25 mJ and two planned stages of amplification, we expect to readily reach 100 mJ or more per pulse.

Prescribed computer games in addition to occlusion versus standard occlusion treatment for childhood amblyopia: a pilot randomised controlled trial.

PubMed

Tailor, Vijay K; Glaze, Selina; Khandelwal, Payal; Davis, Alison; Adams, Gillian G W; Xing, Wen; Bunce, Catey; Dahlmann-Noor, Annegret

2015-01-01

Amblyopia ("lazy eye") is the commonest vision deficit in children. If not fully corrected by glasses, amblyopia is treated by patching or blurring the better-seeing eye. Compliance with patching is often poor. Computer-based activities are increasingly topical, both as an adjunct to standard treatment and as a platform for novel treatments. Acceptability by families has not been explored, and feasibility of a randomised controlled trial (RCT) using computer games in terms of recruitment and treatment acceptability is uncertain. We carried out a pilot RCT to test whether computer-based activities are acceptable and accessible to families and to test trial methods such as recruitment and retention rates, randomisation, trial-specific data collection tools and analysis. The trial had three arms: standard near activity advice, Eye Five, a package developed for children with amblyopia, and an off-the-shelf handheld games console with pre-installed games. We enrolled 60 children age 3-8 years with moderate or severe amblyopia after completion of optical treatment. This trial was registered as UKCRN-ID 11074. Pre-screening of 3600 medical notes identified 189 potentially eligible children, of whom 60 remained eligible after optical treatment, and were enrolled between April 2012 and March 2013. One participant was randomised twice and withdrawn from the study. Of the 58 remaining, 37 were boys. The mean (SD) age was 4.6 (1.7) years. Thirty-seven had moderate and 21 severe amblyopia. Three participants were withdrawn at week 6, and in total, four were lost to follow-up at week 12. Most children and parents/carers found the study procedures, i.e. occlusion treatment, usage of the allocated near activity and completion of a study diary, easy. The prescribed cumulative dose of near activity was 84 h at 12 weeks. Reported near activity usage numbers were close to prescribed numbers in moderate amblyopes (94 % of prescribed) but markedly less in severe amblyopes (64 %). Reported occlusion usage at 12 weeks was 90 % of prescribed dose for moderate and 33 % for severe amblyopes. Computer-based games and activities appear acceptable to families as part of their child's amblyopia treatment. Trial methods were appropriate and accepted by families.

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

PubMed

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.

Thermal nonlinear optical response of meso-tetraphenylporphyrin under aggregation conditions versus that in the absence of aggregation

NASA Astrophysics Data System (ADS)

Rasouli, Saifollah; Sakha, Fereshteh; Mojarrad, Aida G.; Zakavi, Saeed

2018-05-01

In this work, measurement of thermally induced nonlinear refractive index of meso-tetraphenylporphyrin (H2TPP) at different concentrations in 1,2-dicoloroethane using a double-grating interferometer set-up in a pump-probe configuration is reported. The formation of aggregates of H2TPP at concentrations greater than ca. 5 × 10-5 M was evident by deviation from Beer's law. An almost focused pump beam passes through the solution. A part of the pump beam energy is absorbed by the sample and therefore a thermal lens is generated in the sample. An expanded probe beam propagates through the sample and indicates the sample refractive index changes. Just after the sample a band-pass filter cuts off the pump beam from the path but the distorted probe beam passes through a double-grating interferometer consisting of two similar diffraction gratings with a few centimetres distance. A CCD camera is installed after the interferometer in which on its sensitive area two diffraction orders of the gratings are overlying and producing interference pattern. The refractive index changes of the sample are obtained from the phase distribution of the successive interference patterns recorded at different times after turning on of the pump beam using Fourier transform method. In this study, for different concentrations of H2TPP in 1,2-dichloroethane solution the thermal nonlinear refractive index is determined. Also, we present the measurement of the temperature changes induced by the pump beam in the solution. We found that value of nonlinear refractive index increased by increasing the concentration up to a concentration of 5 × 10-4 M and then decreased at higher concentrations. In addition, we have investigated the stability of the observed thermal nonlinearity after a period of two weeks from the sample preparation.

Insights in nutrient sources and transport from high-frequency monitoring at the outlet pumping station of an agricultural lowland polder catchment

NASA Astrophysics Data System (ADS)

Rozemeijer, J.; Van der Grift, B.; Broers, H. P.; Berendrecht, W.; Oste, L.; Griffioen, J.

2015-12-01

In this study, we present new insights in nutrient sources and transport processes in an agricultural-dominated lowland water system based on high-frequency monitoring technology. Starting in October 2014, we have collected semi-continuous measurements of the TP and NO3 concentrations, conductivity and water temperature at a large scale pumping station at the outlet of a 576 km2 polder catchment. The semi-continuous measurements complement a water quality monitoring program at six locations within the drainage area based on conventional monthly or biweekly grab sampling. The NO3 and TP concentrations at the pumping station varied between 0.5 and 10 mgN/L and 0.1 and 0.5 mgP/L. The seasonal trends and short scale concentration dynamics clearly indicated that most of the NO3 loads at the pumping station originated from subsurface drain tubes that were active after intensive rainfall events during the winter months. A transfer function-noise model of hourly NO3 concentrations reveals that a large part of the dynamics in NO3 concentrations during the winter months can be predicted using rainfall data. In February however, NO3 concentrations were higher than predicted due to direct losses after the first manure application. The TP concentration almost doubled during operation of the pumping station. This highlights resuspension of particulate P from channel bed sediments induced by the higher flow velocities during pumping. Rainfall events that caused peaks in NO3 concentrations did not result in TP concentration peaks. Direct effects of run-off, with an association increase in the TP concentration and decrease of the NO3concentration, was only observed during rainfall event at the end of a freeze-thaw cycle. The high-frequency monitoring at the outlet of an agricultural-dominated lowland water system in combination with low-frequency monitoring within the area provided insight in nutrient sources and transport processes that are highly relevant for water quality management.

Optical gain measurements in porous silicon planar waveguides codoped by erbium and ytterbium ions at 1.53 μm

NASA Astrophysics Data System (ADS)

Najar, Adel; Charrier, Joël; Lorrain, Nathalie; Haji, Lazhar; Oueslati, Mehrezi

2007-09-01

The on-off optical gain measurements as a function of the pump power were performed on porous silicon planar waveguides codoped by erbium and ytterbium ions. These measurements were obtained for different ratios of Yb concentration to Er concentration. The highest value of the gain was reached when the Yb concentration is three times higher than that of Er at a moderate 980nm pump power value equal to 70mW. Optical losses measurements have been performed on these waveguides and were equal to 2.1dB/cm and an internal gain of about 6.4dB/cm was obtained.

Apparatus and method for generating continuous wave 16. mu. m laser radiation using gaseous CF/sub 4/

DOEpatents

Telle, J.M.

1984-05-01

Apparatus and method for generating continuous wave 16 ..mu..m laser radiation using gaseous CF/sub 4/. Laser radiation at 16 ..mu..m has been observed in a cooled static cell containing low pressure CF/sub 4/ optically pumped by an approximately 3 W output power c-w CO/sub 2/ laser. The laser cavity employed was a multiple-pass off-axis-path two spherical mirror ring resonator. Unidirectional CF/sub 4/ laser output power at 615 cm/sup -1/ exceeded 2 mW. Computer calculations indicate that for modest pump powers of about 40 W, approximately 1 W of emitted laser radiation at 16 ..mu..m might be obtained.

Apparatus and method for generating continuous wave 16 .mu.m laser radiation using gaseous CF.sub.4

DOEpatents

Telle, John M.

1986-01-01

Apparatus and method for generating continuous wave 16 .mu.m laser radiation using gaseous CF.sub.4. Laser radiation at 16 .mu.m has been observed in a cooled static cell containing low pressure CF.sub.4 optically pumped by an approximately 3 W output power cw CO.sub.2 laser. The laser cavity employed was a multiple-pass off-axis-path two spherical mirror ring resonator. Unidirectional CF.sub.4 laser output power at 615 cm.sup.-1 exceeded 2 mW. Computer calculations indicate that for modest pump powers of about 40 W, approximately 1 W of emitted laser radiation at 16 .mu.m might be obtained.

Monolithic microfabricated valves and pumps by multilayer soft lithography.

PubMed

Unger, M A; Chou, H P; Thorsen, T; Scherer, A; Quake, S R

2000-04-07

Soft lithography is an alternative to silicon-based micromachining that uses replica molding of nontraditional elastomeric materials to fabricate stamps and microfluidic channels. We describe here an extension to the soft lithography paradigm, multilayer soft lithography, with which devices consisting of multiple layers may be fabricated from soft materials. We used this technique to build active microfluidic systems containing on-off valves, switching valves, and pumps entirely out of elastomer. The softness of these materials allows the device areas to be reduced by more than two orders of magnitude compared with silicon-based devices. The other advantages of soft lithography, such as rapid prototyping, ease of fabrication, and biocompatibility, are retained.

Impact of intra-aortic balloon pump on long-term mortality of unselected patients with ST-segment elevation myocardial infarction complicated by cardiogenic shock

PubMed Central

Dziewierz, Artur; Siudak, Zbigniew; Rakowski, Tomasz; Kleczyński, Paweł; Zasada, Wojciech

2014-01-01

Introduction A large, randomised trial (IABP-SHOCK II) confirmed no benefit of intra-aortic balloon pump (IABP) on clinical outcomes of patients with ST-segment elevation myocardial infarction (STEMI) complicated by cardiogenic shock. However, the ‘sickest’ patients are often excluded from randomised clinical trials, so it is difficult to generalise expected outcomes from randomized clinical trials to the real life setting. Aim We sought to evaluate the impact of IABP on 1-year mortality of unselected patients with STEMI presenting in cardiogenic shock. Material and methods Data were gathered for 1,650 consecutive patients with STEMI transferred for primary angioplasty from hospital networks in 7 countries in Europe from November 2005 to January 2007 (the EUROTRANSFER registry population). Of them, 51 patients with cardiogenic shock on admission were identified and stratified based on the use of IABP. Outcome results were adjusted for age and sex, to control possible selection bias. Results At the discretion of the operators, IABP was applied in 30 patients (58.8%, IABP group). The remaining 21 patients were treated without IABP (no-IABP group). The use of IABP was more frequent among males, younger patients, and patients with STEMI of the anterior wall. There was no difference in 30-day mortality in patients with and without IABP (no-IABP vs. IABP: 38.1% vs. 33.3%; adjusted OR 1.79 (95% CI 0.43–7.52); p = 0.43). Similarly, IABP had no impact on 1-year mortality (42.9% vs. 33.3%; adjusted OR 1.27 (95% CI 0.32–5.09); p = 0.74). One-year mortality was comparable among patients who survived hospitalisation (14.3% vs. 13%; p = 0.64). Conclusions We observed no benefit of IABP on short – and long-term mortality of unselected patients with STEMI complicated by cardiogenic shock. PMID:25489303

Parametric study of ion heating in a burnout device (HIP-1)

NASA Technical Reports Server (NTRS)

Sigman, D. R.; Reinmann, J. J.; Lauver, M. R.

1974-01-01

Results of further studies on the Lewis Research Center hot-ion plasma source (HIP-1) are reported. Changes have been made in both the electrode geometry and materials to produce higher ion temperatures. Ion temperature increased significantly with increased vacuum pumping speed. The best ion temperatures achieved, so far, for H(+), D(+), and He(+) plasmas are estimated to be equal to, or greater than 0.6, equal to, or greater than 0.9, and equal to, greater than 2.0 keV, respectively. Electrode pairs produced high ion temperatures whether on the magnetic axis or off it by 5.5 cm. Multiple sources, one on-axis and one off-axis, were run simultaneously from a single power supply by using independent gas feed rates. A momentum analyzer has been added to the charge-exchange neutral particle analyzer to identify particles according to mass, as well as energy. Under any given plasma condition, the higher mass ions have higher average energies but not by as much as the ratio of their respective masses.

75 FR 29520 - Agency Information Collection Activities; Submission for Office of Management and Budget Review...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-26

... section 1404(b) of the Act (``Drain Cover Standard''). In addition to the anti-entrapment devices or... system; gravity drainage system; automatic pump shut-off system or drain disablement. The Pool and Spa... the drain covers, anti-entrapment device/systems, sump or equalizer lines at the site; and report on...

Prospective randomized comparison of coronary bypass grafting with minimal extracorporeal circulation system (MECC) versus off-pump coronary surgery.

PubMed

Mazzei, Valerio; Nasso, Giuseppe; Salamone, Giovanni; Castorino, Filippo; Tommasini, Antonello; Anselmi, Amedeo

2007-10-16

We aimed to evaluate the clinical results and biocompatibility of the minimal extracorporeal circulation system (MECC) compared with off-pump coronary revascularization (OPCABG). In a prospective randomized study, 150 patients underwent coronary surgery with the use of MECC and 150 underwent OPCABG. End points were (1) circulating markers of inflammation and organ injury, (2) operative results, and (3) outcome at 1-year follow-up. Operative mortality and morbidity were comparable between the groups. Release of inflammatory markers was similar between groups at all time points (peak interleukin-6 167.2+/-13.5 versus 181+/-6.5 pg/mL, P=0.14, OPCABG versus MECC group, respectively). Peak creatine kinase was 419.3+/-103.5 versus 326+/-84.2 mg/dL (P=0.28), and peak S-100 protein was 0.13+/-0.08 versus 0.29+/-0.1 pg/mL (P=0.058, OPCABG versus MECC group, respectively). Length of hospital stay and use of blood products were similar between groups. Two cases of angina recurrence at 1 year in the MECC group were observed versus 5 cases observed in the OPCABG group (P=0.44). A residual perfusion defect at myocardial nuclear scan was less frequent among patients in the MECC group (3 versus 9 cases, P=0.14; odds ratio 0.32, 95% confidence interval 0.07 to 1.32). Six (OPCABG group) versus 3 (MECC group) coronary grafts were occluded or severely stenotic at 1 year (P=0.33, odds ratio 0.47, 95% confidence interval 0.09 to 2.14). Clinical results of coronary revascularization with MECC are optimal when this procedure is performed by experienced teams. Postoperative morbidity is comparable to that with OPCABG. MECC is associated with little pump-related systemic and organ injury. It may achieve the benefits of OPCABG (less morbidity in high-risk patients) while facilitating complete revascularization in the case of complex lesions unsuitable for OPCABG.

Predictors of new malignant ventricular arrhythmias after coronary surgery: a case-control study.

PubMed

Ascione, Raimondo; Reeves, Barnaby C; Santo, Kirkpatrick; Khan, Nouman; Angelini, Gianni D

2004-05-05

We sought to investigate the relationship between perioperative factors and the occurrence of ventricular tachycardia (VT) and ventricular fibrillation (VF), as well as the impact of VT/VF on early and late mortality. Both VT and VF are rare but serious complications after coronary artery bypass graft surgery (CABG), and their etiology and implications remain uncertain. Data on 4,411 consecutive patients undergoing CABG (1,154 [25.8%] had off-pump surgery) between April 1996 and September 2001 were extracted from a prospective database and analyzed. Odds ratios (ORs) describing associations between possible risk factors and VT/VF were estimated separately. Factors observed to be significantly associated with VT/VF were further investigated using multivariate logistic regression. Sixty-nine patients suffered VT/VF (1.6%). There were 61 (1.4%) in-hospital/30-day deaths, 15 among patients who had postoperative VT/VF (21.7%). Patient factors independently associated with an increase in the odds of VT/VF included age <65 years, female gender, body mass index <25 kg/m(2), unstable angina, moderate or poor ejection fraction, and the need for inotropes and an intra-aortic balloon pump (OR 1.72 to 4.47, p < 0.05). After adjustment, off-pump surgery was associated with a substantial but nonsignificant protective effect against VT/VF (OR 0.53, 95% confidence interval [CI] 0.25 to 1.13; p = 0.10). Actuarial survival at two years was 98.2% among patients who had VT/VF and who survived to discharge/30 days, compared with 97.0% for the control group (adjusted hazard ratio 0.96 (95% CI 0.40 to 2.31, p = 0.92). The incidence of VT/VF is low in patients undergoing coronary surgery but is associated with high in-hospital mortality. The late survival of the discharged VT/VF patients compares favorably with that of controls.

Kinetics of plasma heat shock protein HSP-70 release in coronary artery surgery: on-pump versus off-pump.

PubMed

Pizon, M T; Gburek, T; Pizon, M; Sztefko, K

2006-12-01

Heat shock protein HSP-70 is known as protective chaperone molecule synthetized in response following ischemia and stress agents. It is detected in the myocardium and endothelium as well as in the circulation. Damaged as well as viable but exposed to stress cells contribute to the release of HSP-70 into the circulation. The aim of the study was to investigate if cardiopulmonary bypss (CPB) leads to more circulating HSP-70, on the basis of comparison dynamics of plasma concentration HSP-70 in 8 men undergoing procedures with the use of CPB (coronary artery bypass grafting, CABG group) and 8 men undergoing off-pump surgery (OPCAB group). Blood samples were taken preoperatively, twice intraoperatively, immediately after surgical procedure (1 h) and 24-hours thereafter. The concentration of plasma HSP-70 was measured by means of immunoassay. The derived results were compared statistically with the frequency of incidence postoperative atrial fibrillation (AF). In CABG group was observed continuous gradual increase of plasma HSP-70 concentration during the operation with the peak 1 h after surgery (P<0.01), in striking contrast to OPCAB group, in which was detected small, but non statistically significant increase of HSP-70 1 h after operation. Significantly more of circulating HSP-70 it was detected in CABG group during the operation and 1 h after surgery (CABG vs OPCAB, respectively P<0.015 and P<0.028). In both groups among patients witch AF it was found higher postoperative values of circulating HSP-70 compared with the non-AF group (P=0.0415). The use of CPB leads to significant more release of HSP-70 into the circulation. According to our findings high plasma concentration of HSP-70 may be the measure of operative cellular stress, ischemia or injury and may be related with greater onset of postoperative AF. High circulating HSP-70 levels is connected with higher incidence of postoperative AF after open heart surgery.

Low amplified spontaneous emission threshold and suppression of electroluminescence efficiency roll-off in layers doped with ter(9,9′-spirobifluorene)

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

Inoue, Munetomo; Center for Organic Photonics and Electronics Research, Kyushu University, 744 Motooka, Nishi, Fukuoka 819-0395; Matsushima, Toshinori

2016-03-28

We demonstrate that ter(9,9′-spirobifluorene) (TSBF) doped in a host matrix layer of 4,4′-bis(carbazol-9-yl)biphenyl (CBP) shows a low amplified spontaneous emission (ASE) threshold (E{sub th} = 1.0 μJ cm{sup −2}) and suppressed electroluminescence efficiency roll-off at high current densities (no roll-off up to 100 mA cm{sup −2}). One origin of the low ASE threshold is that the TSBF-doped CBP layer possesses a very large radiative decay constant (k{sub r} = 1.1 × 10{sup 9 }s{sup −1}). Singlet–triplet annihilation is almost suppressed in the TSBF-doped CBP layer, which can be ascribed to the small overlap between the emission and triplet absorption of TSBF. Also, the small energy level difference between TSBF and CBPmore » minimizes carrier trapping in TSBF, leading to the suppression of singlet–polaron annihilation. TSBF showed one of the lowest E{sub th} and the most suppressed efficiency roll-off among organic laser dyes investigated in this study and, therefore, is believed to be a promising candidate to realize electrically pumped organic semiconductor laser diodes in the future.« less

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

PubMed

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.

[Potential analysis for research on physiotherapy-led treadmill training in Parkinson's disease].

PubMed

Lohkamp, Monika; Braun, Cordula; Wasner, Mieke; Voigt-Radloff, Sebastian

2014-01-01

Parkinson's disease is one of the major neurodegenerative disorders with prevalence rates between 0.1 and 0.2 % in the global population and 1.8 % in people aged 64 years and over. Future incidence rates are estimated to increase within aging societies. The progressive course of Parkinson's disease is clinically characterised by bradykinesia, rigidity and tremor. These limitations in motor functioning reduce the capacity to work, social participation and the clients' quality of life. Parkinson's disease causes incapacity to work and a large number of days off from work. The benefits clients expect from physiotherapy-led treatment include an improvement of gait, a better speed of motion and the decrease of fatigue and rigidity. A recent Cochrane review (Mehrholz et al., 2010) analysed seven randomised comparisons with 153 participants and found that treadmill training compared with no treatment improved gait speed (SMD 0.50; 95 % confidence interval [0.17 to 0.84]). A lack of evidence exists on how to reduce fatigue and rigidity. There is also need to evaluate long-term effects and cost-effectiveness. Furthermore, an updated meta-analysis should include eleven new randomised trials on treadmill training after 2009. Physiotherapy-led treadmill training can easily be transferred into the German healthcare context since the environmental and educational preconditions are met by German physiotherapeutic care. Within the German context, there is need to prepare a randomised clinical trial evaluating the impact of physiotherapy-led treadmill training on motor functioning, quality of life, costs, adverse events und long-term effects. Prior to this, a feasibility study should explore the acceptance and intensity of treadmill training as well as the access of private physiotherapy practices to people suffering from early- to mid-stage Parkinson's disease. Copyright © 2014. Published by Elsevier GmbH.

A versatile design for resonant guided-wave parametric down-conversion sources for quantum repeaters

NASA Astrophysics Data System (ADS)

Brecht, Benjamin; Luo, Kai-Hong; Herrmann, Harald; Silberhorn, Christine

2016-05-01

Quantum repeaters—fundamental building blocks for long-distance quantum communication—are based on the interaction between photons and quantum memories. The photons must fulfil stringent requirements on central frequency, spectral bandwidth and purity in order for this interaction to be efficient. We present a design scheme for monolithically integrated resonant photon-pair sources based on parametric down-conversion in nonlinear waveguides, which facilitate the generation of such photons. We investigate the impact of different design parameters on the performance of our source. The generated photon spectral bandwidths can be varied between several tens of MHz up to around 1 GHz, facilitating an efficient coupling to different memories. The central frequency of the generated photons can be coarsely tuned by adjusting the pump frequency, poling period and sample temperature, and we identify stability requirements on the pump laser and sample temperature that can be readily fulfilled with off-the-shelf components. We find that our source is capable of generating high-purity photons over a wide range of photon bandwidths. Finally, the PDC emission can be frequency fine-tuned over several GHz by simultaneously adjusting the sample temperature and pump frequency. We conclude our study with demonstrating the adaptability of our source to different quantum memories.

Critical surface roughness for wall bounded flow of viscous fluids in an electric submersible pump

NASA Astrophysics Data System (ADS)

Deshmukh, Dhairyasheel; Siddique, Md Hamid; Kenyery, Frank; Samad, Abdus

2017-11-01

Surface roughness plays a vital role in the performance of an electric submersible pump (ESP). A 3-D numerical analysis has been carried out to find the roughness effect on ESP. The performance of pump for steady wall bounded turbulent flows is evaluated at different roughness values and compared with smooth surface considering a non-dimensional roughness factor K. The k- ω SST turbulence model with fine mesh at near wall region captures the rough wall effects accurately. Computational results are validated with experimental results of water (1 cP), at a design speed (3000 RPM). Maximum head is observed for a hydraulically smooth surface (K=0). When roughness factor is increased, the head decreases till critical roughness factor (K=0.1) due to frictional loss. Further increase in roughness factor (K>0.1) increases the head due to near wall turbulence. The performance of ESP is analyzed for turbulent kinetic energy and eddy viscosity at different roughness values. The wall disturbance over the rough surface affects the pressure distribution and velocity field. The roughness effect is predominant for high viscosity oil (43cP) as compared to water. Moreover, the study at off-design conditions showed that Reynolds number influences the overall roughness effect.

Ultrafast dynamics of an unoccupied surface resonance state in B i2T e2Se

NASA Astrophysics Data System (ADS)

Munisa, Nurmamat; Krasovskii, E. E.; Ishida, Y.; Sumida, K.; Chen, Jiahua; Yoshikawa, T.; Chulkov, E. V.; Kokh, K. A.; Tereshchenko, O. E.; Shin, S.; Kimura, Akio

2018-03-01

Electronic structure and electron dynamics in the ternary topological insulator B i2T e2Se are studied with time- and angle-resolved photoemission spectroscopy using optical pumping. An unoccupied surface resonance split off from the bulk conduction band previously indirectly observed in scanning tunneling measurements is spectroscopically identified. Furthermore, an unoccupied topological surface state (TSS) is found, which is serendipitously located at about 1.5 eV above the occupied TSS, thereby facilitating direct optical transitions between the two surface states at ℏ ω =1.5 eV in an n -type topological insulator. An appreciable nonequilibrium population of the bottom of the bulk conduction band is observed for longer than 15 ps after the pump pulse. This leads to a long recovery time of the lower TSS, which is constantly populated by the electrons coming from the bulk conduction band. Our results demonstrate B i2T e2Se to be an ideal platform for designing future optoelectronic devices based on topological insulators.

Volume, distribution and acidity of gastric secretion on and off proton pump inhibitor treatment: a randomized double-blind controlled study in patients with gastro-esophageal reflux disease (GERD) and healthy subjects.

PubMed

Steingoetter, Andreas; Sauter, Matthias; Curcic, Jelena; Liu, Dian; Menne, Dieter; Fried, Michael; Fox, Mark; Schwizer, Werner

2015-09-02

Postprandial accumulation of gastric secretions in the proximal stomach above the meal adjacent to the esophagogastric junction (EGJ), referred to as the 'acid pocket', has been proposed as a pathophysiological factor in gastro-esophageal reflux disease (GERD) and as a target for GERD treatment. This study assessed the effect of proton pump inhibitor (PPI) therapy on the volume, distribution and acidity of gastric secretions in GERD and healthy subjects (HS). A randomized, double blind, cross-over study in 12 HS and 12 GERD patients pre-treated with 40 mg pantoprazole (PPI) or placebo b.i.d. was performed. Postprandial secretion volume (SV), formation of a secretion layer and contact between the layer and the EGJ were quantified by Magnetic Resonance Imaging (MRI). Multi-channel pH-monitoring assessed intragastric pH. A distinct layer of undiluted acid secretion was present on top of gastric contents in almost all participants on and off high-dose acid suppression. PPI reduced SV (193 ml to 100 ml, in HS, 227 ml to 94 ml in GERD; p < 0.01) and thickness of the acid layer (26 mm to 7 mm, 36 mm to 9 mm respectively, p < 0.01). No differences in secretion volume or layer thickness were observed between groups; however, off treatment, contact time between the secretion layer and EGJ was 2.6 times longer in GERD compared to HS (p = 0.012). This was not the case on PPI. MRI can visualize and quantify the volume and distribution dynamics of gastric secretions that form a layer in the proximal stomach after ingestion of a liquid meal. The secretion volume and the secretion layer on top of gastric contents is similar in GERD patients and HS; however contact between the layer of undiluted secretion and the EGJ is prolonged in patients. High dose PPI reduced secretion volume by about 50% and reduced contact time between secretion and EGJ towards normal levels. NCT01212614.

Monolithic Teflon membrane valves and pumps for harsh chemical and low-temperature use.

PubMed

Willis, Peter A; Hunt, Brian D; White, Victor E; Lee, Michael C; Ikeda, Michael; Bae, Sam; Pelletier, Michael J; Grunthaner, Frank J

2007-11-01

Microfluidic diaphragm valves and pumps capable of surviving conditions required for unmanned spaceflight applications have been developed. The Pasteur payload of the European ExoMars Rover is expected to experience temperatures ranging between -100 degrees C and +50 degrees C during its transit to Mars and on the Martian surface. As such, the Urey instrument package, which contains at its core a lab-on-a-chip capillary electrophoresis analysis system first demonstrated by Mathies et al., requires valving and pumping systems that are robust under these conditions before and after exposure to liquid samples, which are to be analyzed for chemical signatures of past or present living processes. The microfluidic system developed to meet this requirement uses membranes consisting of Teflon and Teflon AF as a deformable material in the valve seat region between etched Borofloat glass wafers. Pneumatic pressure and vacuum, delivered via off-chip solenoid valves, are used to actuate individual on-chip valves. Valve sealing properties of Teflon diaphragm valves, as well as pumping properties from collections of valves, are characterized. Secondary processing for embossing the membrane against the valve seats after fabrication is performed to optimize single valve sealing characteristics. A variety of different material solutions are found to produce robust devices. The optimal valve system utilizes a membrane of mechanically cut Teflon sandwiched between two thin spun films of Teflon AF-1600 as a composite "laminated" diaphragm. Pump rates up to 1600 nL s(-1) are achieved with pumps of this kind. These high pumping rates are possible because of the very fast response of the membranes to applied pressure, enabling extremely fast pump cycling with relatively small liquid volumes, compared to analogous diaphragm pumps. The developed technologies are robust over extremes of temperature cycling and are applicable in a wide range of chemical environments.

[Dexpanthenol nasal spray in comparison to dexpanthenol nasal ointment. A prospective, randomised, open, cross-over study to compare nasal mucociliary clearance].

PubMed

Verse, T; Klöcker, N; Riedel, F; Pirsig, W; Scheithauer, M O

2004-07-01

Recent technical developments in metered pump systems allow the production and use of preservative-free nasal products. The aim of the current study is to compare the tolerability of a preservative-free dexpanthenol (5%) nasal spray with that of the established dexpanthenol (5%) nasal ointment, also without preservatives. The main outcome measure was in vivo mucociliary clearance. Mucociliary clearance was assessed by saccharin migration time in 20 volunteers. Wash-out phases were 7 days and the spray or ointment was always applied 20 min before the saccharin test. The study was designed to test for non-inferiority. Saccharin migration time was slightly longer after ointment administration, however, these were not significantly different to nasal spray. The saccharin migration time showed a significant correlation with the age of the volunteers. The upper confidence limit of dexpanthenol nasal spray was markedly less than that of the ointment. Therefore, dexpanthenol nasal spray is at least equal to if not better than dexpanthenol nasal ointment. Due to its ease of administration, preservative-free dexpanthenol nasal spray offers a valuable therapeutic alternative.

Assessment of deformation of the mitral valve complex during off-pump coronary artery bypass surgery using three-dimensional echocardiography in a porcine model.

PubMed

Igarashi, Takashi; Iwai-Takano, Masumi; Wakamatsu, Hiroki; Haruta, Mineyuki; Omata, Sadao; Yokoyama, Hitoshi

2018-01-01

This study aimed to assess the deformation of the mitral valve complex during the displacement of the beating heart by using three-dimensional echocardiography in a porcine off-pump coronary artery bypass grafting (OPCAB) model. In nine healthy swine, we positioned the beating heart as an OPCAB model, i.e. control, left anterior descending artery (LAD), right coronary artery (RCA), and left circumflex artery (LCX) positions. In each position, three-dimensional echocardiography was performed to assess the mitral valve complex with hemodynamic parameters. We analyzed the deformation of the mitral valve and the three-dimensional coordinates of the papillary muscles. There was a significant increase in maximum tenting length and tenting volume (control 0.70±0.30, LAD 0.65±0.27, RCA 0.79±0.23, LCX 0.95±0.34cm 3 , p<0.05) in the LCX position compared with the other positions. The posterior papillary muscle (PPM) angle had a significant relationship with the tenting volume (r=-0.643, p<0.001). The PPM was displaced to the medial side in the LAD and LCX positions (p<0.01). The prime cause of the deformation of the mitral leaflets is suggested to be the displacement of the PPM associated with the change in geometry of the left ventricle in a porcine model. Copyright © 2017 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.

Systemic and myocardial inflammatory response in coronary artery bypass graft surgery with miniaturized extracorporeal circulation: differences with a standard circuit and off-pump technique in a randomized clinical trial.

PubMed

Formica, Francesco; Mariani, Silvia; Broccolo, Francesco; Caruso, Rosa; Corti, Fabrizio; D'Alessandro, Stefano; Amigoni, Pietro; Sangalli, Fabio; Paolini, Giovanni

2013-01-01

Inflammatory response and hemodilution are the main drawbacks of extracorporeal circulation. We hypothesize that the use of miniaturized extracorporeal circulation (MECC) might lower the systemic and myocardial inflammatory patterns compared with a standard system (SECC) and off-pump coronary artery bypass grafting (OPCABG). Sixty-one patients undergoing isolated coronary artery bypass graft were prospectively randomized to MECC (n = 19), SECC (n = 20), or OPCABG (n = 22). Blood samples were collected from radial artery and coronary sinus to analyze blood lactate, hemodilution, and markers for inflammation and endothelial activation such as tumor necrosis factor (TNF)-α, interleukin-6, monocyte chemotactic protein-1, and E-selectin. No differences were observed in early clinical outcome. Interleukin -6 levels increased in every group during and after cardiac surgery, whereas TNF-α values grew in the SECC group (p = 0.05). E-selectin systemic values decreased during and after operation (p = 0.001) in every group. Monocyte chemotactic protein-1 systemic and cardiac levels raised only in SECC group (p = 0.014). In conclusion, MECC is comparable to SECC and OPCABG in the clinical outcome of low-risk patients, and it might be extensively used with no additional intraoperative risk. The analysis of the inflammatory patterns of endothelial activation shows MECC as effective as OPCABG, suggesting further studies to clarify MECC recommendation in high-risk patients.

Glad you brought it up: a patient-centred programme to reduce proton-pump inhibitor prescribing in general medical practice.

PubMed

Murie, Jill; Allen, Jane; Simmonds, Ray; de Wet, Carl

2012-01-01

Many patients unnecessarily receive proton-pump inhibitor (PPI) drugs long term with significant financial and safety implications. Educating, empowering and supporting patients to self-manage their symptoms can lead to significant and sustained reductions in PPI prescribing. We aimed to implement a programme to reduce inappropriate PPI prescribing. Eligible patients in one general medical practice in rural Scotland were invited for participation between November 2008 and February 2010. Patients attended special nurse advisor clinics, completed dyspepsia questionnaires, received information, formulated self-management plans and were offered flexible support. Of the study population, 437/2883 (15%) were prescribed PPIs. Of these, 166 (38%) were judged eligible for participation. After 12 months, 138/157 (83%) had reduced or stopped their PPIs, while 19/157 (11%) had reverted. The estimated annual net saving in the prescribing budget was ?3180.67. Self-reported understanding of symptom self-management increased from 6/20 (30%) to 18/20 (90%) patients after participation in the programme. A patient-centred programme delivered by a specialist nurse significantly reduced PPI prescribing with financial and potential therapeutic benefits. The vast majority of eligible patients were able to 'step down and off' or 'step off' PPI use after 12 months without any complications or deteriorating symptom control. Further research with larger cohorts of practices and patients is needed to develop a feasible, acceptable and effective programme if similar benefits are to be achieved for primary care in general.

Coupled two-dimensional edge plasma and neutral gas modeling of tokamak scrape-off-layers

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

Maingi, Rajesh

1992-08-01

The objective of this study is to devise a detailed description of the tokamak scrape-off-layer (SOL), which includes the best available models of both the plasma and neutral species and the strong coupling between the two in many SOL regimes. A good estimate of both particle flux and heat flux profiles at the limiter/divertor target plates is desired. Peak heat flux is one of the limiting factors in determining the survival probability of plasma-facing-components at high power levels. Plate particle flux affects the neutral flux to the pump, which determines the particle exhaust rate. A technique which couples a two-dimensionalmore » (2-D) plasma and a 2-D neutral transport code has been developed (coupled code technique), but this procedure requires large amounts of computer time. Relevant physics has been added to an existing two-neutral-species model which takes the SOL plasma/neutral coupling into account in a simple manner (molecular physics model), and this model is compared with the coupled code technique mentioned above. The molecular physics model is benchmarked against experimental data from a divertor tokamak (DIII-D), and a similar model (single-species model) is benchmarked against data from a pump-limiter tokamak (Tore Supra). The models are then used to examine two key issues: free-streaming-limits (ion energy conduction and momentum flux) and the effects of the non-orthogonal geometry of magnetic flux surfaces and target plates on edge plasma parameter profiles.« less

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

PubMed

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.

Transient Flows in a Pipe System with Pump Shut-Down and the Simultaneous Closing of a Spherical Valve

NASA Astrophysics Data System (ADS)

Zhang, Zh.

2016-11-01

Because of the limited value of the wave propagation speed in water the propagation of a pressure surge in transient flows can be tracked in the time series. This enables both the pressure head and the flow velocity in pipe flows to be determined as a function of both the coordinate along the pipe and the time. The propagation of the pressure surge includes both wave transmission and reflection. The latter occurs where the flow section is changed. The wave tracking method has been demonstrated as highly accurate and subsequently was applied to much more complex hydraulic systems, in which the pump is shut off and the spherical valve is simultaneously progressively closed. A combined four-quadrant characteristic of the pump and a spherical valve has been worked out, with which the computational procedure for the transient flow in the complex system could be significantly simplified. It has been demonstrated that not only the pressure surge in the hydraulic system but also the rotational speed of the pump could be satisfactorily computed. The computational algorithm has been demonstrated as quite simple, so that all calculations could be performed simply by means of the Microsoft Excel module.

Analysis of pumping tests: Significance of well diameter, partial penetration, and noise

USGS Publications Warehouse

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 confined and unconfined aquifers with finite diameter and partially penetrating piezometers and observation wells. Noiseless and moderately noisy drawdown data from observation points located less than two saturated thicknesses of the aquifer from the pumping well produced a set of parameters that agrees very well with piezometer test data when the diameter of the pumping well was included in the analysis. The accuracy of the estimated parameters decreased with increasing noise level.

Ultra-fast movies of thin-film laser ablation

NASA Astrophysics Data System (ADS)

Domke, Matthias; Rapp, Stephan; Schmidt, Michael; Huber, Heinz P.

2012-11-01

Ultra-short-pulse laser irradiation of thin molybdenum films from the glass substrate side initiates an intact Mo disk lift off free from thermal effects. For the investigation of the underlying physical effects, ultra-fast pump-probe microscopy is used to produce stop-motion movies of the single-pulse ablation process, initiated by a 660-fs laser pulse. The ultra-fast dynamics in the femtosecond and picosecond ranges are captured by stroboscopic illumination of the sample with an optically delayed probe pulse of 510-fs duration. The nanosecond and microsecond delay ranges of the probe pulse are covered by an electronically triggered 600-ps laser. Thus, the setup enables an observation of general laser ablation processes from the femtosecond delay range up to the final state. A comparison of time- and space-resolved observations of film and glass substrate side irradiation of a 470-nm molybdenum layer reveals the driving mechanisms of the Mo disk lift off initiated by glass-side irradiation. Observations suggest that a phase explosion generates a liquid-gas mixture in the molybdenum/glass interface about 10 ps after the impact of the pump laser pulse. Then, a shock wave and gas expansion cause the molybdenum layer to bulge, while the enclosed liquid-gas mixture cools and condenses at delay times in the 100-ps range. The bulging continues for approximately 20 ns, when an intact Mo disk shears and lifts off at a velocity of above 70 m/s. As a result, the remaining hole is free from thermal effects.

Observation of sub-100-fs optical response from spin-coated films of squarylium dye J aggregates

NASA Astrophysics Data System (ADS)

Furuki, Makoto; Tian, Minquan; Sato, Yasuhiro; Pu, Lyong Sun; Kawashima, Hitoshi; Tatsuura, Satoshi; Wada, Osamu

2001-04-01

For spin-coated films of squarylium dye J aggregates, ultrafast nonlinear optical responses were investigated by pump-probe measurements. By using a broadband mode-locked titanium:sapphire laser, we succeeded in observing the optical response with a time resolution of better than 60 fs. Time-resolved transmission data are shown for different excitation wavelengths, resonant to the excitonic absorption band and off-resonant. Relaxation times of the absorption saturation were evaluated to be 140 fs (fast component) and 950 fs (slow component) in the case of resonant excitation and 98 fs in the case of off-resonant excitation.

Modelling and simulation of thermal behaviour of vanadium redox flow battery

NASA Astrophysics Data System (ADS)

Yan, Yitao; Li, Yifeng; Skyllas-Kazacos, Maria; Bao, Jie

2016-08-01

This paper extends previous thermal models of the vanadium redox flow battery to predict temperature profiles within multi-cell stacks. This involves modelling the thermal characteristics of the stack as a whole to modelling each individual cell. The study investigates the thermal behaviour for two different scenarios: during standby periods when the pumps are turned off, and in a residential power arbitrage scenario for two types of membranes. It was found that the temperature gradient across the cells is most significant during the standby case, with the simulation results showing completely different thermal behaviours between the two systems.

Time matters--realism in resuscitation training.

PubMed

Krogh, Kristian B; Høyer, Christian B; Ostergaard, Doris; Eika, Berit

2014-08-01

The advanced life support guidelines recommend 2min of cardiopulmonary resuscitation (CPR) and minimal hands-off time to ensure sufficient cardiac and cerebral perfusion. We have observed doctors who shorten the CPR intervals during resuscitation attempts. During simulation-based resuscitation training, the recommended 2-min CPR cycles are often deliberately decreased in order to increase the number of scenarios. The aim of this study was to test if keeping 2-min CPR cycles during resuscitation training ensures better adherence to time during resuscitation in a simulated setting. This study was designed as a randomised control trial. Fifty-four 4th-year medical students with no prior advanced resuscitation training participated in an extra-curricular one-day advanced life support course. Participants were either randomised to simulation-based training using real-time (120s) or shortened CPR cycles (30-45s instead of 120s) in the scenarios. Adherence to time was measured using the European Resuscitation Council's Cardiac Arrest Simulation Test (CASTest) in retention tests conducted one and 12 weeks after the course. The real-time group adhered significantly better to the recommended 2-min CPR cycles (time-120s) (mean 13; standard derivation (SD) 8) than the shortened CPR cycle group (mean 45; SD 19) when tested (p<0.001.) This study indicates that time is an important part of fidelity. Variables critical for performance, like adherence to time in resuscitation, should therefore be kept realistic during training to optimise outcome. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Parental depression and child conduct problems: evaluation of parental service use and associated costs after attending the Incredible Years Basic Parenting Programme.

PubMed

Charles, Joanna M; Bywater, Tracey J; Edwards, Rhiannon Tudor; Hutchings, Judy; Zou, Lu

2013-12-18

There is co-morbidity between parental depression and childhood conduct disorder. The Incredible Years (IY) parenting programmes reduce both conduct disorder in children and depression in their parents. Recent U.K. and Ireland trials of the effectiveness and cost-effectiveness of IY parenting programmes have assessed children's health and social care service use, but little is known about the programme's impact on parental service use. This paper explores whether an above clinical cut-off score on the Beck Depression Inventory II (BDI II) is associated with high or low parental health and social care service use in high-risk families receiving the IY Basic Programme. This is a secondary analysis of a subsample (N = 119) from the first U.K. community-based randomised controlled trial of the 12-week IY Basic Programme (N = 153). Parents with children at risk of developing conduct disorder were randomised to receive the programme or to a waiting-list control group. BDI II total and BDI II clinical depression cut-off scores were compared to frequencies and costs of parents' service use, at baseline, six, twelve and eighteen months post-baseline for the intervention group and at baseline and six months post-baseline for the control group. Intervention group parents who scored above the clinical cut-off on the BDI II at baseline used more health and social care services than those who scored below at baseline, six and eighteen months. Significant reductions in service use frequencies were found for the intervention group only. Parents with higher levels or depression used more health and social care service and parenting programmes have been shown to reduce parental depression and also health and social service use. However, further exploration of depressed parents' service use and the cost implications for publically funded health and social care services is needed.

Modeling and performance improvement of the constant power regulator systems in variable displacement axial piston pump.

PubMed

Park, Sung Hwan; Lee, Ji Min; Kim, Jong Shik

2013-01-01

An irregular performance of a mechanical-type constant power regulator is considered. In order to find the cause of an irregular discharge flow at the cut-off pressure area, modeling and numerical simulations are performed to observe dynamic behavior of internal parts of the constant power regulator system for a swashplate-type axial piston pump. The commercial numerical simulation software AMESim is applied to model the mechanical-type regulator with hydraulic pump and simulate the performance of it. The validity of the simulation model of the constant power regulator system is verified by comparing simulation results with experiments. In order to find the cause of the irregular performance of the mechanical-type constant power regulator system, the behavior of main components such as the spool, sleeve, and counterbalance piston is investigated using computer simulation. The shape modification of the counterbalance piston is proposed to improve the undesirable performance of the mechanical-type constant power regulator. The performance improvement is verified by computer simulation using AMESim software.

Air source integrated heat pump simulation model for EnergyPlus

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

Shen, Bo; New, Joshua; Baxter, Van

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 savingmore » 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.« less

Influence of chirp on laser-pulse amplification in Brillouin backscattering schemes

NASA Astrophysics Data System (ADS)

Lehmann, Goetz; Schluck, Friedrich; Spatschek, Karl-Heinz

2015-11-01

Plasma-based amplification of laser pulses is currently discussed as a key component for the next generation of high-intensity laser systems, possibly enabling the generation of ultra-short pulses in the exawatt-zetawatt regime. In these scenarios the energy of a long pump pulse (several ps to ns of duration) is transferred to a short seed pulse via a plasma oscillation. Weakly- and strongly-coupled (sc) Brillouin backscattering have been identified as potential candidates for robust amplification scenarios. With the help of three-wave interaction models, we investigate the influence of a chirp of the pump beam on the seed amplification. We show that chirp can mitigate deleterious spontaneous Raman backscattering of the pump off noise and that at the same time the amplification dynamics due to Brillouin scattering is still intact. For the experimentally very interesting case of sc-Brillouin we find a dependence of the efficiency on the sign of the chirp. Funding provided by project B10 of SFB TR18 of the Deutsche Forschungsgemeinschaft (DFG).

Flow rate logging seepage meter

NASA Technical Reports Server (NTRS)

Reay, William G. (Inventor); Walthall, Harry G. (Inventor)

1996-01-01

An apparatus for remotely measuring and logging the flow rate of groundwater seepage into surface water bodies. As groundwater seeps into a cavity created by a bottomless housing, it displaces water through an inlet and into a waterproof sealed upper compartment, at which point, the water is collected by a collection bag, which is contained in a bag chamber. A magnet on the collection bag approaches a proximity switch as the collection bag fills, and eventually enables the proximity switch to activate a control circuit. The control circuit then rotates a three-way valve from the collection path to a discharge path, enables a data logger to record the time, and enables a pump, which discharges the water from the collection bag, through the three-way valve and pump, and into the sea. As the collection bag empties, the magnet leaves the proximity of the proximity switch, and the control circuit turns off the pump, resets the valve to provide a collection path, and restarts the collection cycle.

Vacuum delivery at The Maternity Hospital Kuala Lumpur: a comparison of metal and silicone cups.

PubMed

Lee, H Y; Subramaniam, N; Nordin, M M

1996-02-01

To compare the advantages and disadvantages of the New Bird metal cups and silicone cups in terms of maternal and foetal outcome. To study the adverse effects and factors associated with failed vacuum deliveries. A prospective randomised study of all vacuum deliveries from 1 December 1991 to 31 April 1992. The Hanshin electrical vacuum pump was used. A large obstetric unit-The Maternity Hospital Kuala Lumpur (MHKL). Seventy-two consecutive patients where vacuum deliveries were indicated. Forty had metal and 32 had silicone cups. Another 7 vacuum deliveries using the manual vacuum pump were excluded. Success rate of vaginal delivery, birth canal injuries, post-partum haemorrhage, duration of hospital stay, Apgar score, foetal injuries (scalp-ecchymosis, haematomas) neonatal jaundice, the rate of special care nursery (SCN) admission and neonatal mortality rate. Failure to deliver with silicone cups alone was 21.9% compared to 10% for metal cups alone. Material morbidities and serious foetal scalp injuries were almost the same in both cups. However, minor foetal scalp injuries were significantly lower with silicone cups. Maternal height and baby's weight had no independent predictive values for successful vacuum delivery. When the foetal head was palpable per abdomen, the failure rate was 54.5% compared to 8.2% when it was not. Failed vacuum deliveries were associated with increased maternal and foetal morbidities. Silicone cups and metal cups can be equally dangerous to the baby. Although our sample size was small, we recommend that vacuum delivery be avoided if the foetal head is palpable per abdomen.

Ten-watt level picosecond parametric mid-IR source broadly tunable in wavelength

NASA Astrophysics Data System (ADS)

Vyvlečka, Michal; Novák, Ondřej; Roškot, Lukáscaron; Smrž, Martin; Mužík, Jiří; Endo, Akira; Mocek, Tomáš

2018-02-01

Mid-IR wavelength range (between 2 and 8 μm) offers perspective applications, such as minimally-invasive neurosurgery, gas sensing, or plastic and polymer processing. Maturity of high average power near-IR lasers is beneficial for powerful mid-IR generation by optical parametric conversion. We utilize in-house developed Yb:YAG thin-disk laser of 100 W average power at 77 kHz repetition rate, wavelength of 1030 nm, and about 2 ps pulse width for pumping of a ten-watt level picosecond mid-IR source. Seed beam is obtained by optical parametric generation in a double-pass 10 mm long PPLN crystal pumped by a part of the fundamental near-IR beam. Tunability of the signal wavelength between 1.46 μm and 1.95 μm was achieved with power of several tens of miliwatts. Main part of the fundamental beam pumps an optical parametric amplification stage, which includes a walk-off compensating pair of 10 mm long KTP crystals. We already demonstrated the OPA output signal and idler beam tunability between 1.70-1.95 μm and 2.18-2.62 μm, respectively. The signal and idler beams were amplified up to 8.5 W and 5 W, respectively, at 42 W pump without evidence of strong saturation. Thus, increase in signal and idler output power is expected for pump power increase.

Integrable optical-fiber source of polarization-entangled photon pairs in the telecom band

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

Li Xiaoying; Liang Chuang; Fook Lee, Kim

We demonstrate an optical-fiber-based source of polarization-entangled photon pairs with improved quality and efficiency, which has been integrated with off-the-shelf telecom components and is, therefore, well suited for quantum communication applications in the 1550-nm telecom band. Polarization entanglement is produced by simultaneously pumping a loop of standard dispersion-shifted fiber with two orthogonally polarized pump pulses, one propagating in the clockwise and the other in the counterclockwise direction. We characterize this source by investigating two-photon interference between the generated signal-idler photon pairs under various conditions. The experimental parameters are carefully optimized to maximize the generated photon-pair correlation and to minimize contaminationmore » of the entangled photon pairs from extraneously scattered background photons that are produced by the pump pulses for two reasons: (i) spontaneous Raman scattering causes uncorrelated photons to be emitted in the signal and idler bands and (ii) broadening of the pump-pulse spectrum due to self-phase modulation causes pump photons to leak into the signal and idler bands. We obtain two-photon interference with visibility >90% without subtracting counts caused by the background photons (only dark counts of the detectors are subtracted), when the mean photon number in the signal (idler) channel is about 0.02/pulse, while no interference is observed in direct detection of either the signal or idler photons.« less

Transient dynamics of secondary radiation from an HF pumped magnetized space plasma

NASA Astrophysics Data System (ADS)

Norin, L.; Grach, S. M.; Thidé, B.; Sergeev, E. N.; Leyser, T. B.

2007-09-01

In order to systematically analyze the transient wave and radiation processes that are excited when a high-frequency (HF) radio wave is injected into a magnetized space plasma, we have measured the secondary radiation, or stimulated electromagnetic emission (SEE), from the ionosphere, preconditioned such that geomagnetic field-aligned plasma irregularities are already present. The transient dynamics experiments were made using a duty cycle of the HF radio wave of 200 ms (180 ms on and 20 ms off) and 100 ms (80 ms on and 20 ms off) for various frequencies near the fifth harmonic of the local ionospheric electron cyclotron frequency. Within the first 10 ms after the radio pulse turn-on, frequency downshifted structures of the SEE exhibit an overshoot with a maximum at 3 ms < t < 8 ms, whereas the upshifted spectral components do not exhibit this feature. The relative magnitude of the overshoot is strongly dependent on the frequency offset of the pump from the harmonic of the electron cyclotron frequency. A transient blue-shifted frequency component is identified. This component is upshifted from the pump by 14 kHz < Δ f < 55 kHz and exists only within the first 10 ms after the radio pulse turn-on. On a longer time scale we analyze the amplitude modulation, or ``ringing,'' of the reflected radio wave, (also known as ``quasi-periodic oscillations'' or ``spikes''). The ringing has a frequency of the order 15-20 Hz and we show that this phenomenon is also present in the SEE sidebands and is synchronized with the ringing of the reflected HF wave itself.

Reduced mortality in high-risk coronary patients operated off pump with preoperative intraaortic balloon counterpulsation.

PubMed

Etienne, Pierre Yves; Papadatos, Spiridon; Glineur, David; Mairy, Yves; El Khoury, Elie; Noirhomme, Philippe; El Khoury, Gebrine

2007-08-01

Preoperative intraaortic balloon pump (IABP) counterpulsation has better outcomes compared with perioperative or postoperative insertion in critical patients, and off-pump surgical procedures have been advocated to reduce mortality in high-risk patients. However, some surgeons are reluctant to perform beating heart operations in specific patient subgroups, including those with unstable angina or patients with low ejection fraction, because of their possible perioperative hemodynamic instability. We evaluated combined beating heart procedures and preoperative IABP in selected high-risk patients and compared our results with the predictive European System for Cardiac Operative Risk Evaluation (EuroSCORE) model. Fifty-five high-risk patients with a mean logistic EuroSCORE of 24 were prospectively enrolled and then divided into emergency (group 1, n = 25) and nonemergency (group 2, n = 30) groups. IABP was inserted immediately before operation in group 1 and the day before the procedure in group 2. Compared with the EuroSCORE predictive model, a dramatic decrease in mortality occurred in both groups. Group I predicted mortality was 36.8%, and observed was 20%; and group 2 predicted mortality was 15.2% and observed was 0%. No specific complications from the use of IABP were encountered. During mid-term (2 years) follow-up, no patient died from a cardiac cause or required percutaneous coronary intervention or subsequent reoperation due to incomplete revascularization. The combined use of preoperative intraaortic counterpulsation and beating heart intervention allows complete revascularization in high-risk patients with a important reduction in operative mortality and excellent mid-term results.

A remotely operated drug delivery system with an electrolytic pump and a thermo-responsive valve

PubMed Central

Yi, Ying; Zaher, Amir; Yassine, Omar; Kosel, Jurgen; Foulds, Ian G.

2015-01-01

Implantable drug delivery devices are becoming attractive due to their abilities of targeted and controlled dose release. Currently, two important issues are functional lifetime and non-controlled drug diffusion. In this work, we present a drug delivery device combining an electrolytic pump and a thermo-responsive valve, which are both remotely controlled by an electromagnetic field (40.5 mT and 450 kHz). Our proposed device exhibits a novel operation mechanism for long-term therapeutic treatments using a solid drug in reservoir approach. Our device also prevents undesired drug liquid diffusions. When the electromagnetic field is on, the electrolysis-induced bubble drives the drug liquid towards the Poly (N-Isopropylacrylamide) (PNIPAM) valve that consists of PNIPAM and iron micro-particles. The heat generated by the iron micro-particles causes the PNIPAM to shrink, resulting in an open valve. When the electromagnetic field is turned off, the PNIPAM starts to swell. In the meantime, the bubbles are catalytically recombined into water, reducing the pressure inside the pumping chamber, which leads to the refilling of the fresh liquid from outside the device. A catalytic reformer is included, allowing more liquid refilling during the limited valve's closing time. The amount of body liquid that refills the drug reservoir can further dissolve the solid drug, forming a reproducible drug solution for the next dose. By repeatedly turning on and off the electromagnetic field, the drug dose can be cyclically released, and the exit port of the device is effectively controlled. PMID:26339328

All-optical 40Gbit/s format conversion from NRZ to RZ based on SFG in a PPLN waveguide

NASA Astrophysics Data System (ADS)

Wang, Jian; Sun, Junqiang

2006-01-01

A novel all-optical 40Gbit/s NRZ-to-RZ data format conversion scheme based on sum-frequency generation (SFG) interaction in a periodically poled LiNbO 3 (PPLN) waveguide is presented for the first time, using a Mach-Zehnder interferometer (MZI). The conversion mechanism relies on the combination of attenuation and nonlinear phase shift Φ NL induced on the signal field. The performance of the conversion is numerically evaluated, with the result showing that it is more effective to yield Φ NL when appropriately phase mismatched for SFG process but Φ NL~0 when quasi-phase-matching (QPM). Compared with the cascaded second-order nonlinear interactions (SHG+DFG) with the influence of walk-off effect, a high conversion efficiency and good performance are achieved with peak power 500mw and width 2ps of the pump, which can be used in super high-speed situation (40Gbit/s and above). Finally, the inverse process of SFG and corresponding walk-off effect are analyzed and the optimum arrangement of power is proposed, showing that proper power, pump width, and waveguide length are necessary for achieving a satisfied conversion effect.

KSC-2011-5302

NASA Image and Video Library

2011-07-08

CAPE CANAVERAL, Fla. -- In Firing Room 4 of the Launch Control Center at NASA's Kennedy Space Center in Florida, Shuttle Launch Director Mike Leinbach, and Payloads Launch Manager and Deputy Director of ISS and Spacecraft Processing at Kennedy, Bill Dowdell along with the launch control members, watch intently as space shuttle Atlantis lifts off on its STS-135 mission to the International Space Station. Atlantis with its crew of four; Commander Chris Ferguson, Pilot Doug Hurley, Mission Specialists Sandy Magnus and Rex Walheim, lifted off at 11:29 a.m. EDT on July 8, 2011 to deliver the Raffaello multi-purpose logistics module packed with supplies and spare parts for the station. Atlantis also will fly the Robotic Refueling Mission experiment that will investigate the potential for robotically refueling existing satellites in orbit. In addition, Atlantis will return with a failed ammonia pump module to help NASA better understand the failure mechanism and improve pump designs for future systems. STS-135 will be the 33rd flight of Atlantis, the 37th shuttle mission to the space station, and the 135th and final mission of NASA's Space Shuttle Program. For more information, visit www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts135/index.html. Photo credit: NASA/Kim Shiflett

Magnetic microscopic imaging with an optically pumped magnetometer and flux guides

DOE PAGES

Kim, Young Jin; Savukov, Igor Mykhaylovich; Huang, Jen -Huang; ...

2017-01-23

Here, by combining an optically pumped magnetometer (OPM) with flux guides (FGs) and by installing a sample platform on automated translation stages, we have implemented an ultra-sensitive FG-OPM scanning magnetic imaging system that is capable of detecting magnetic fields of ~20 pT with spatial resolution better than 300 μm (expected to reach ~10 pT sensitivity and ~100 μm spatial resolution with optimized FGs). As a demonstration of one possible application of the FG-OPM device, we conducted magnetic imaging of micron-size magnetic particles. Magnetic imaging of such particles, including nano-particles and clusters, is very important for many fields, especially for medicalmore » cancer diagnostics and biophysics applications. For rapid, precise magnetic imaging, we constructed an automatic scanning system, which holds and moves a target sample containing magnetic particles at a given stand-off distance from the FG tips. We show that the device was able to produce clear microscopic magnetic images of 10 μm-size magnetic particles. In addition, we also numerically investigated how the magnetic flux from a target sample at a given stand-off distance is transmitted to the OPM vapor cell.« less

Polarization-insensitive all-optical dual pump-phase transmultiplexing from 2 x 10-GBd OOKs to 10-GBd RZ-QPSK using cross-phase modulation in a passive nonlinear birefringent photonic crystal fiber

NASA Astrophysics Data System (ADS)

Mahmood, Tanvir

Considering the network size, bit rate, spectral and channel capacity limitations, different modulation formats may be selectively used in future optical networks. Although the traditional metropolitan area networks (MANs) still uses the non-return-to-zero on-off keying (NRZ-OOK) modulation format due to its technical simplicity and therefore low cost, QPSK format is more advantageous in spectrally efficient long-haul fiber optic transmission systems because of its constant power envelope, and robustness to various transmission impairments. Consequently, an important problem may arise, in particular how to route the OOK-data streams from MANs to long-haul backbone networks when the state of polarization (SOP) of the remotely generated OOK is unpredictable. Hence, the focus of this dissertation was to investigate a polarization insensitive (PI) all-optical nonlinear optical signal processing (NOSP) method that can be implemented at the network cross-connect (X-connect) to transfer data from a remotely and a locally generated OOK data simultaneously to more effectual QPSK format for long-haul transmission. By utilizing cross-phase modulation (XPM) and inherent birefringence of the device, the work demonstrated, for the first time, PI all-optical data transfer utilizing dual pump-phase transmultiplexing (DPTM) from 2 x 10-GBd OOKs to 10-GBd RZ-QPSK in a passive nonlinear birefringent photonic crystal fiber (PCF). Polarization insensitivity was achieved by scrambling the SOP of the remotely generated OOK pump and launching the locally generated OOK pump and the probe off-axis. To mitigate polarization induced power fluctuations and detrimental effects due to nearby partially degenerate and non-degenerate four wave mixings, an optimum pump-probe detuning was also utilized. The PI DPTM RZ-QPSK demonstrated a pre-amplified receiver sensitivity penalty < 5.5 dB at 10--9 bit-error-rate (BER), relative to relative to the FPGA-precoded RZ-DQPSK baseline in ASE-limited transmission system. The effect of the remotely generated OOK pump OSNR degradation on PI DPTM RZ-QPSK was also investigated and it was established that 10 -9 BER metric was attainable till the remotely generated OOK pump reached the threshold OSNR limit of 34 dB/0.1nm. Finally, DWDM transmission performance of the PI DPTM RZ-QPSK signal was evaluated using 138-km long recirculating loop and it was demonstrated that the PI DPTM RZ-QPSK can be transmitted over 1,500 km before it reached ITU-T G.709 7% HD-FEC overhead limit. This propagation distance was well beyond the transmission requisites of any typical metro network (≈ 600 km). Furthermore, it was demonstrated that, within the threshold limit, OSNR degradation of the remotely generated OOK pump had minimal impact on the transmission distance of the PI DPTM RZ-QPSK before it reached 7% HD-FEC overhead limit.

Practicalities of Using a Modified Version of the Cochrane Collaboration Risk of Bias Tool for Randomised and Non-Randomised Study Designs Applied in a Health Technology Assessment Setting

ERIC Educational Resources Information Center

Robertson, Clare; Ramsay, Craig; Gurung, Tara; Mowatt, Graham; Pickard, Robert; Sharma, Pawana

2014-01-01

We describe our experience of using a modified version of the Cochrane risk of bias (RoB) tool for randomised and non-randomised comparative studies. Objectives: (1) To assess time to complete RoB assessment; (2) To assess inter-rater agreement; and (3) To explore the association between RoB and treatment effect size. Methods: Cochrane risk of…

Multi-model groundwater-management optimization: reconciling disparate conceptual models

NASA Astrophysics Data System (ADS)

Timani, Bassel; Peralta, Richard

2015-09-01

Disagreement among policymakers often involves policy issues and differences between the decision makers' implicit utility functions. Significant disagreement can also exist concerning conceptual models of the physical system. Disagreement on the validity of a single simulation model delays discussion on policy issues and prevents the adoption of consensus management strategies. For such a contentious situation, the proposed multi-conceptual model optimization (MCMO) can help stakeholders reach a compromise strategy. MCMO computes mathematically optimal strategies that simultaneously satisfy analogous constraints and bounds in multiple numerical models that differ in boundary conditions, hydrogeologic stratigraphy, and discretization. Shadow prices and trade-offs guide the process of refining the first MCMO-developed `multi-model strategy into a realistic compromise management strategy. By employing automated cycling, MCMO is practical for linear and nonlinear aquifer systems. In this reconnaissance study, MCMO application to the multilayer Cache Valley (Utah and Idaho, USA) river-aquifer system employs two simulation models with analogous background conditions but different vertical discretization and boundary conditions. The objective is to maximize additional safe pumping (beyond current pumping), subject to constraints on groundwater head and seepage from the aquifer to surface waters. MCMO application reveals that in order to protect the local ecosystem, increased groundwater pumping can satisfy only 40 % of projected water demand increase. To explore the possibility of increasing that pumping while protecting the ecosystem, MCMO clearly identifies localities requiring additional field data. MCMO is applicable to other areas and optimization problems than used here. Steps to prepare comparable sub-models for MCMO use are area-dependent.

Development of picosecond time-resolved X-ray absorption spectroscopy by high-repetition-rate laser pump/X-ray probe at Beijing Synchrotron Radiation Facility.

PubMed

Wang, Hao; Yu, Can; Wei, Xu; Gao, Zhenhua; Xu, Guang Lei; Sun, Da Rui; Li, Zhenjie; Zhou, Yangfan; Li, Qiu Ju; Zhang, Bing Bing; Xu, Jin Qiang; Wang, Lin; Zhang, Yan; Tan, Ying Lei; Tao, Ye

2017-05-01

A new setup and commissioning of transient X-ray absorption spectroscopy are described, based on the high-repetition-rate laser pump/X-ray probe method, at the 1W2B wiggler beamline at the Beijing Synchrotron Radiation Facility. A high-repetition-rate and high-power laser is incorporated into the setup with in-house-built avalanche photodiodes as detectors. A simple acquisition scheme was applied to obtain laser-on and laser-off signals simultaneously. The capability of picosecond transient X-ray absorption spectroscopy measurement was demonstrated for a photo-induced spin-crossover iron complex in 6 mM solution with 155 kHz repetition rate.

Simulation-based multiprofessional obstetric anaesthesia training conducted in situ versus off-site leads to similar individual and team outcomes: a randomised educational trial.

PubMed

Sørensen, Jette Led; van der Vleuten, Cees; Rosthøj, Susanne; Østergaard, Doris; LeBlanc, Vicki; Johansen, Marianne; Ekelund, Kim; Starkopf, Liis; Lindschou, Jane; Gluud, Christian; Weikop, Pia; Ottesen, Bent

2015-10-06

To investigate the effect of in situ simulation (ISS) versus off-site simulation (OSS) on knowledge, patient safety attitude, stress, motivation, perceptions of simulation, team performance and organisational impact. Investigator-initiated single-centre randomised superiority educational trial. Obstetrics and anaesthesiology departments, Rigshospitalet, University of Copenhagen, Denmark. 100 participants in teams of 10, comprising midwives, specialised midwives, auxiliary nurses, nurse anaesthetists, operating theatre nurses, and consultant doctors and trainees in obstetrics and anaesthesiology. Two multiprofessional simulations (clinical management of an emergency caesarean section and a postpartum haemorrhage scenario) were conducted in teams of 10 in the ISS versus the OSS setting. Knowledge assessed by a multiple choice question test. Individual outcomes: scores on the Safety Attitudes Questionnaire, stress measurements (State-Trait Anxiety Inventory, cognitive appraisal and salivary cortisol), Intrinsic Motivation Inventory and perceptions of simulations. Team outcome: video assessment of team performance. Organisational impact: suggestions for organisational changes. The trial was conducted from April to June 2013. No differences between the two groups were found for the multiple choice question test, patient safety attitude, stress measurements, motivation or the evaluation of the simulations. The participants in the ISS group scored the authenticity of the simulation significantly higher than did the participants in the OSS group. Expert video assessment of team performance showed no differences between the ISS versus the OSS group. The ISS group provided more ideas and suggestions for changes at the organisational level. In this randomised trial, no significant differences were found regarding knowledge, patient safety attitude, motivation or stress measurements when comparing ISS versus OSS. Although participant perception of the authenticity of ISS versus OSS differed significantly, there were no differences in other outcomes between the groups except that the ISS group generated more suggestions for organisational changes. NCT01792674. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

[Control of postoperative hemorrhage in isolated coronary bypass surgery: comparison of tranexamic acid effects in off-pump surgery with aprotinin effects in conventional surgery].

PubMed

Bordalo, Alvaro D B; Nobre, Angelo L; Silva, Fernanda; Serpa, Carlos; Cravino, João

2011-01-01

In spite of the strong criticism elicited thereafter, the results of a multicentric study on the consequences of several perioperative anti-hemorrhagic strategies in cardiac surgery, published five years ago, led to the aprotinin (Aprot) withdrawal from the market and its progressive replacement by tranexamic acid (TrAc) in many surgical departments. To evaluate the hemostatic effects and clinical consequences of TrAc use or non-use in off-pump coronary bypass surgery (CABG) and compare them with those of Aprot use or non-use in conventional (conv) CABG. Retrospective analysis of 2 groups (Gr) of patients (pts): GrA - 252 pts undergoing isolated conv CABG (GrA1 - 185 pts submitted to an intra-operative full-dose Aprot protocol; GrA2 - 67 pts operated without Aprot); GrB - 383 pts undergoing isolated off-pump CABG (GrB1 - 136 pts submitted to an intra-operative low-dose TrAc protocol; GrB2 - 247 pts operated in absence of TrAc). Pre-operative clinical characteristics (GrA1 vs GrA2, GrB1 vs GrB2): mean age (years) - 65 vs 64 (NS), 64 vs 64; female gender - 20% vs 21% (NS), 23% vs 20% (NS); logistic Euroscore - 5.1% vs 6.2% (NS), 6.3% vs 5.5% (NS); chronic renal failure - 21% vs 27% (NS), 27% vs 25% (NS); diffuse coronary artery disease - 34% vs 42% (NS), 36% vs 30% (NS); pre-operative betablocker treatment - 64% vs 55% (NS), 74% vs 71% (NS); statin therapy for > 3 months - 78% vs 82% (NS), 81% vs 85% (NS). Pts have been operated by 4 surgeons largely experienced in both CABG modalities. Antiplatelet therapy was stopped => 4 days prior to surgery (but aspirin was maintained in high-risk pts). Results (GrA1 vs GrA2, GrB1 vs GrB2): 1) Bleeding (mL/pt - mean): 783 vs 1375 (p < 0.001), 1061 vs 1368 (p < 0.001); blood loss > 1500 mL (%pts) - 5.4% vs 34% (p < 0.0001), 12% vs 28% (p < 0.001); surgical re-exploration for bleeding - 1.1% vs 3.0% (NS), 2.2% vs 2.0% (NS). 2) Transfusion of blood products (U/pt - mean): plasma - 0.56 vs 2.19 (p < 0.001), 1.45 vs 1.03 (p < 0.05); platelets - 0.09 vs 0.22 (p < 0.02), 0.24 vs 0.15 (NS). 3) Renal function (%pts): increased serum cre- atinine - 56% vs 56%, 55% vs 38% (p < 0.001); hemofiltration use - 1.1% vs 1.5% (NS), 1.5% vs 0.4% (NS). 4) Perioperative myocardial infarction - 21.6% vs 17.9% (NS), 17.6% vs 14.6% (NS); other ischemic events - 3.2% vs 3.0% (NS), 1.5% vs 1.2% (NS). 5) Hospital mortality: 4.8% vs 4.5% (NS), 4.4% vs 1.6% (NS). 1) TrAc does not reduce the risk of surgical re-exploration for bleeding. 2) Taking into account the differences between conv CABG and off-pump CABG, TrAc hemostatic effect seems to be inferior to that of Aprot, without offering a better safety profile in terms of lesser renal or ischemic risk as a counterpart.

Qubit-qubit entanglement dynamics control via external classical pumping and Kerr nonlinearity mediated by a single detuned cavity field powered by two-photon processes

NASA Astrophysics Data System (ADS)

Ateto, M. S.

2017-11-01

The nonlinear time-dependent two-photon Hamiltonian of a couple of classically pumped independent qubits is analytically solved, and the corresponding time evolution unitary operator, in an exact form, is derived. Using the concurrence, entanglement dynamics between the qubits under the influence of a wide range of effective parameters are examined and, in detail, analyzed. Observations analysis is documented with aid of the field phase-space distribution Wigner function. A couple of initial qubit states is considered, namely similar excited states and a Bell-like pure state. It is demonstrated that an initial Bell-like pure state is as well typical initial qubits setting for robust, regular and a high degree of entanglement. Moreover, it is established that high-constant Kerr media represent an effective tool for generating periodical entanglement at fixed time cycles of maxima reach unity forever when qubits are initially in a Bell-like pure state. Further, it is showed that the medium strength of the classical pumping stimulates efficiently qubits entanglement, specially, when the interaction occurs off resonantly. However, the high-intensity pumping thermalizes the coherent distribution of photons, thus, the least photons number is used and, hence, the least minimum degree of qubits entanglement could be created. Furthermore, when the cavity field and external pumping are detuned, the external pumping acts like an auxiliary effective frequency for the cavity, as a result, the field Gaussian distribution acquires linear chirps, and consequently, more entanglement revivals appear in the same cycle during timescale.

Analysis of the pump-turbine S characteristics using the detached eddy simulation method

NASA Astrophysics Data System (ADS)

Sun, Hui; Xiao, Ruofu; Wang, Fujun; Xiao, Yexiang; Liu, Weichao

2015-01-01

Current research on pump-turbine units is focused on the unstable operation at off-design conditions, with the characteristic curves in generating mode being S-shaped. Unlike in the traditional water turbines, pump-turbine operation along the S-shaped curve can lead to difficulties during load rejection with unusual increases in the water pressure, which leads to machine vibrations. This paper describes both model tests and numerical simulations. A reduced scale model of a low specific speed pump-turbine was used for the performance tests, with comparisons to computational fluid dynamics(CFD) results. Predictions using the detached eddy simulation(DES) turbulence model, which is a combined Reynolds averaged Naviers-Stokes(RANS) and large eddy simulation(LES) model, are compared with the two-equation turbulence mode results. The external characteristics as well as the internal flow are for various guide vane openings to understand the unsteady flow along the so called S characteristics of a pump-turbine. Comparison of the experimental data with the CFD results for various conditions and times shows that DES model gives better agreement with experimental data than the two-equation turbulence model. For low flow conditions, the centrifugal forces and the large incident angle create large vortices between the guide vanes and the runner inlet in the runner passage, which is the main factor leading to the S-shaped characteristics. The turbulence model used here gives more accurate simulations of the internal flow characteristics of the pump-turbine and a more detailed force analysis which shows the mechanisms controlling of the S characteristics.

Simulation of deleterious processes in a static-cell diode pumped alkali laser

NASA Astrophysics Data System (ADS)

Oliker, Benjamin Q.; Haiducek, John D.; Hostutler, David A.; Pitz, Greg A.; Rudolph, Wolfgang; Madden, Timothy J.

2014-02-01

The complex interactions in a diode pumped alkali laser (DPAL) gain cell provide opportunities for multiple deleterious processes to occur. Effects that may be attributable to deleterious processes have been observed experimentally in a cesium static-cell DPAL at the United States Air Force Academy [B.V. Zhdanov, J. Sell, R.J. Knize, "Multiple laser diode array pumped Cs laser with 48 W output power," Electronics Letters, 44, 9 (2008)]. The power output in the experiment was seen to go through a "roll-over"; the maximum power output was obtained with about 70 W of pump power, then power output decreased as the pump power was increased beyond this point. Research to determine the deleterious processes that caused this result has been done at the Air Force Research Laboratory utilizing physically detailed simulation. The simulations utilized coupled computational fluid dynamics (CFD) and optics solvers, which were three-dimensional and time-dependent. The CFD code used a cell-centered, conservative, finite-volume discretization of the integral form of the Navier-Stokes equations. It included thermal energy transport and mass conservation, which accounted for chemical reactions and state kinetics. Optical models included pumping, lasing, and fluorescence. The deleterious effects investigated were: alkali number density decrease in high temperature regions, convective flow, pressure broadening and shifting of the absorption lineshape including hyperfine structure, radiative decay, quenching, energy pooling, off-resonant absorption, Penning ionization, photoionization, radiative recombination, three-body recombination due to free electron and buffer gas collisions, ambipolar diffusion, thermal aberration, dissociative recombination, multi-photon ionization, alkali-hydrocarbon reactions, and electron impact ionization.

Effect of Perioperative Pregabalin on Postoperative Quality of Recovery in Patients Undergoing Off-Pump Coronary Artery Bypass Grafting (OPCABG): A Prospective, Randomized, Double-Blind Trial.

PubMed

Borde, Deepak Prakash; Futane, Savani Sameer; Asegaonkar, Balaji; Apsingekar, Pramod; Khade, Sujeet; Khodve, Bapu; Puranik, Manish; George, Antony; Joshi, Shreedhar

2017-08-01

Use of pregabalin is increasing in cardiac surgical patients. However, studies using comprehensive scoring systems are lacking on the drug's impact on postoperative recovery. The authors tested the hypothesis that perioperative oral pregabalin improves the postoperative quality of recovery as assessed using the Quality of Recovery (QoR-40) questionnaire in patients undergoing off-pump coronary artery bypass grafting (OPCABG). This was a randomized, double-blind, placebo-controlled study. Tertiary-care hospital. Patients undergoing OPCABG. Patients were assigned randomly to the following 2 groups: the pregabalin group (those who received pregabalin, 150 mg capsule orally, 1 hour before surgery and 2 days postoperatively [75 mg twice a day] starting after extubation; n = 37); and the control group (those who received 2 similar-looking multivitamin capsules at similar times; n = 34). The QoR-40 scores were noted preoperatively and 24 hours after extubation. Both groups were comparable in terms of preoperative patient characteristics and baseline QoR-40 scores. Global scores were significantly improved in the pregabalin group compared with the control group in the postoperative period (177±9 v 170±9; p = 0.002). QoR-40 values in the dimensions of emotional state (p = 0.005), physical comfort (p = 0.04), and pain (p = 0.02) were improved in the pregabalin group. Perioperative pregabalin improved postoperative quality of recovery as assessed using the QoR-40 questionnaire in patients undergoing OPCABG. Perioperative pregabalin offered advantages beyond better pain control, such as improved physical comfort and better emotional state; therefore, the drug's use in the perioperative period is recommended. Copyright © 2017 Elsevier Inc. All rights reserved.

Double-blinded, randomized controlled trial of N-acetylcysteine for prevention of acute kidney injury in high risk patients undergoing off-pump coronary artery bypass.

PubMed

Song, Jong Wook; Shim, Jae Kwang; Soh, Sarah; Jang, Jaewon; Kwak, Young Lan

2015-02-01

The aim of this study was to investigate the influence of perioperative N-acetylcysteine (NAC) administration, a known antioxidant, on the incidence of acute kidney injury (AKI) after off-pump coronary bypass surgery (OPCAB) in patients with known risk factors of AKI. One hundred and seventeen patients with ≥1 of the following risk factors of AKI were randomized into either the control (n = 57) or the NAC (n = 60) group; (i) preoperative serum creatinine >1.4 mg/dL; (ii) left ventricular ejection fraction <35% or congestive heart failure (iii) age >70 years (iv) diabetes or (v) re-operation. Patients in the NAC group received 150 mg/kg of NAC IV bolus at anaesthetic induction followed by a continuous infusion at 150 mg/kg per day for 24 h. AKI was diagnosed based on Acute Kidney Injury Network criteria during 48 h postoperatively. The incidence of AKI was 32% (19/60) and 35% (20/57) in the control and the NAC group, respectively (P = 0.695). The serum concentrations of creatinine and cystatin C were similar between the groups throughout the study period. Fluid balance including the amount of blood loss and transfusion requirement were similar between the groups except the amount of postoperative urine output, which was higher in the control group compared with the NAC group (5528 ± 1247 mL vs. 4982 ± 1185 mL, control vs. NAC, P = 0.017). Perioperative administration of NAC did not prevent the development of postoperative AKI after OPCAB in highly susceptible patients to AKI. © 2014 Asian Pacific Society of Nephrology.

Prevention of Hypoglycemia With Predictive Low Glucose Insulin Suspension in Children With Type 1 Diabetes: A Randomized Controlled Trial.

PubMed

Battelino, Tadej; Nimri, Revital; Dovc, Klemen; Phillip, Moshe; Bratina, Natasa

2017-06-01

To investigate whether predictive low glucose management (PLGM) of the MiniMed 640G system significantly reduces the rate of hypoglycemia compared with the sensor-augmented insulin pump in children with type 1 diabetes. This randomized, two-arm, parallel, controlled, two-center open-label study included 100 children and adolescents with type 1 diabetes and glycated hemoglobin A 1c ≤10% (≤86 mmol/mol) and using continuous subcutaneous insulin infusion. Patients were randomly assigned to either an intervention group with PLGM features enabled (PLGM ON) or a control group (PLGM OFF), in a 1:1 ratio, all using the same type of sensor-augmented insulin pump. The primary end point was the number of hypoglycemic events below 65 mg/dL (3.6 mmol/L), based on sensor glucose readings, during a 14-day study treatment. The analysis was performed by intention to treat for all randomized patients. The number of hypoglycemic events below 65 mg/dL (3.6 mmol/L) was significantly smaller in the PLGM ON compared with the PLGM OFF group (mean ± SD 4.4 ± 4.5 and 7.4 ± 6.3, respectively; P = 0.008). This was also true when calculated separately for night ( P = 0.025) and day ( P = 0.022). No severe hypoglycemic events occurred; however, there was a significant increase in time spent above 140 mg/dL (7.8 mmol/L) in the PLGM ON group ( P = 0.0165). The PLGM insulin suspension was associated with a significantly reduced number of hypoglycemic events. Although this was achieved at the expense of increased time in moderate hyperglycemia, there were no serious adverse effects in young patients with type 1 diabetes. © 2017 by the American Diabetes Association.

Effects of preoperative aspirin on perioperative platelet activation and dysfunction in patients undergoing off-pump coronary artery bypass graft surgery: A prospective randomized study.

PubMed

Lee, Jiwon; Jung, Chul-Woo; Jeon, Yunseok; Kim, Tae Kyong; Cho, Youn Joung; Koo, Chang-Hoon; Choi, Yoon Hyeong; Kim, Ki-Bong; Hwang, Ho Young; Kim, Hang-Rae; Park, Ji-Young

2017-01-01

The benefit of aspirin use after coronary artery bypass graft surgery has been well proven. However, the effect of preoperative aspirin use in patients undergoing off-pump coronary artery bypass graft surgery (OPCAB) has not been evaluated sufficiently. To evaluate platelet function changes during OPCAB due to preoperative aspirin use, we conducted a randomized controlled trial using flow cytometry and the Multiplate® analyzer. Forty-eight patients scheduled for elective OPCAB were randomized to the aspirin continuation (100 mg/day until operative day) and discontinuation (4 days before the operative day) groups. Platelet function was measured using the platelet activation markers CD62P, CD63, and PAC-1 by flow cytometry, and platelet aggregation was measured using the Multiplate® analyzer, after the induction of anesthesia (baseline), at the end of the operation, and 24 and 48 h postoperatively. Findings of conventional coagulation assays, thromboelastography by ROTEM® assays, and postoperative bleeding-related clinical outcomes were compared between groups. No significant change in CD62P, CD63, or PAC-1 was observed at the end of the operation or 24 or 48 h postoperatively compared with baseline in either group. The area under the curve for arachidonic acid-stimulated platelet aggregation, measured by the Multiplate® analyzer, was significantly smaller in the aspirin continuation group (P < 0.01). However, chest tube drainage and intraoperative and postoperative transfusion requirements did not differ between groups. Our study showed that preoperative use of aspirin for OPCAB did not affect perioperative platelet activation, but it impaired platelet aggregation, which did not affect postoperative bleeding, by arachidonic acid.

Effect of questionnaire length, personalisation and reminder type on response rate to a complex postal survey: randomised controlled trial

PubMed Central

2011-01-01

Background Minimising participant non-response in postal surveys helps to maximise the generalisability of the inferences made from the data collected. The aim of this study was to examine the effect of questionnaire length, personalisation and reminder type on postal survey response rate and quality and to compare the cost-effectiveness of the alternative survey strategies. Methods In a pilot study for a population study of travel behaviour, physical activity and the environment, 1000 participants sampled from the UK edited electoral register were randomly allocated using a 2 × 2 factorial design to receive one of four survey packs: a personally addressed long (24 page) questionnaire pack, a personally addressed short (15 page) questionnaire pack, a non-personally addressed long questionnaire pack or a non-personally addressed short questionnaire pack. Those who did not return a questionnaire were stratified by initial randomisation group and further randomised to receive either a full reminder pack or a reminder postcard. The effects of the survey design factors on response were examined using multivariate logistic regression. Results An overall response rate of 17% was achieved. Participants who received the short version of the questionnaire were more likely to respond (OR = 1.48, 95% CI 1.06 to 2.07). In those participants who received a reminder, personalisation of the survey pack and reminder also increased the odds of response (OR = 1.44, 95% CI 1.01 to 1.95). Item non-response was relatively low, but was significantly higher in the long questionnaire than the short (9.8% vs 5.8%; p = .04). The cost per additional usable questionnaire returned of issuing the reminder packs was £23.1 compared with £11.3 for the reminder postcards. Conclusions In contrast to some previous studies of shorter questionnaires, this trial found that shortening a relatively lengthy questionnaire significantly increased the response. Researchers should consider the trade off between the value of additional questions and a larger sample. If low response rates are expected, personalisation may be an important strategy to apply. Sending a full reminder pack to non-respondents appears a worthwhile, albeit more costly, strategy. PMID:21548947

Is the Stretta procedure as effective as the best medical and surgical treatments for gastro-oesophageal reflux disease? A best evidence topic.

PubMed

Das, Bibek; Reddy, Marcus; Khan, Omar A

2016-06-01

A best evidence topic in surgery was written according to a structured protocol. The question addressed whether the Stretta(®) procedure is as effective as the best medical and surgical treatments for patients with symptoms of gastro-oesophageal reflux disease (GORD). One hundred and forty Stretta-related papers were identified using the reported search, of which five represented the best evidence to answer the clinical question. The authors, journal, date and country of publication, patient group, study type, relevant outcomes and results of these papers are tabulated. One study was a randomised controlled trial comparing Stretta with proton pump inhibitors (PPIs), and four were prospective observational studies that compared Stretta with laparoscopic fundoplication. These studies provide limited evidence that Stretta is as effective as medical therapy at controlling symptoms of GORD and may allow some patients to reduce their PPI use, but laparoscopic fundoplication appears to be more effective than Stretta though with a higher rate of adverse events. Further studies are required to determine the long-term efficacy of Stretta compared to the current best medical and surgical treatments. Copyright © 2016. Published by Elsevier Ltd.