Risk of no-reflow in culprit lesion versus culprit vessel PCI in acute STEMI.

PubMed

Arslan, Uğur; Yaman, Mehmet; Kocaoğlu, İbrahim; Turan, Oğuzhan Ekrem; Yücel, Huriye; Aksakal, Aytekin; Günaydin, İlksen Atasoy; Hakan Ateş, Ahmet

2015-09-01

The present report describes patients with acute ST-elevation myocardial infarction who had at least two lesions in the culprit vessel (CV) during primary percutaneous coronary intervention (PCI). Here, we aimed to examine two different strategies, namely, PCI of only culprit lesion (CL) versus PCI of all lesions in the CV in the setting of acute ST-elevation myocardial infarction. Patients who underwent primary PCI were examined for the presence of an additional lesion in the infarct-related artery and divided into two groups according to the PCI strategy: CV versus CL groups. Coronary angiograms were examined for coronary thrombolysis in myocardial infarction (TIMI) flow and major clinical outcomes were determined. Of 637 patients, 472 (74.1%) underwent primary PCI for the CV (CV group) and 165 (25.9%) underwent primary PCI only for CL (CL group). TIMI flow before primary PCI and after stenting of the CL was similar; however, TIMI flow after completion of the procedure was significantly better in the CL group (P=0.022). The composite of death, nonfatal myocardial infarction and repeat revascularization was significantly better in the CL group (P=0.041) and early stent thrombosis was observed more commonly in the CV group [14 (3.0%) patients vs. 1 (0.6%) patient, P=0.09]. In the presence of an additional lesion in the CV during primary PCI, deferring stenting for the non-CL in the culprit artery after stenting the CL may be considered to prevent the development of no-reflow or slow-reflow, and thus major clinical adverse events may be reduced.

Myonecrosis following stent placement: association between impaired TIMI myocardial perfusion grade and MRI visualization of microinfarction.

PubMed

Choi, James W; Gibson, C Michael; Murphy, Sabina A; Davidson, Charles J; Kim, Raymond J; Ricciardi, Mark J

2004-04-01

Contrast-enhanced cardiac MRI (ceMRI) and TIMI myocardial perfusion grade analysis (TMPG) are proven methods for visualization of microinfarction and assessment of microvascular perfusion, respectively. To determine whether microvascular obstruction accounts for procedure-related myonecrosis, 14 poststent patients, 9 with procedural CK-MB elevation and 5 controls, underwent ceMRI and TMPG. All had TIMI 3 flow pre- and poststent. TMPG was normal in 12/14 pre- and 7/14 poststent. Those with poststent decline in TMPG had higher CK-MB (median, 41.0 vs. 7.4 ng/mL; P = 0.01) and larger infarct mass (median, 3.1 vs. 0.89 g; P = 0.04). More extensive myonecrosis (CK-MB > 3 x normal; infarct mass > 3 g) was observed more frequently if there was a poststent decline in TMPG (3/3, 100%, vs. 2/11, 18.2%; P = 0.03). These data support the theory that distal embolization and microvascular obstruction are associated with myonecrosis following otherwise successful coronary stent placement and provide further insight into its pathophysiology. Copyright 2004 Wiley-Liss, Inc.

Thrombus aspiration and prehospital ticagrelor administration in ST-elevation myocardial infarction: Findings from the ATLANTIC trial.

PubMed

Kilic, Sinem; Fabris, Enrico; Van't Hof, Arnoud W J; Hamm, Christian W; Lapostolle, Frédéric; Lassen, Jens Flensted; Tsatsaris, Anne; Diallo, Abdourahmane; Vicaut, Eric; Montalescot, Gilles

2018-02-01

The potential interactions between prehospital (pre-H) ticagrelor administration and thrombus aspiration (TA) in patients with ST-elevation myocardial infarction (STEMI) treated with primary percutaneous coronary intervention (PCI) have never been studied. Therefore, we evaluated the potential benefit of TA and pre-H ticagrelor treatment in patients enrolled in the ATLANTIC trial (NCT01347580). This analysis included 1,630 patients who underwent primary PCI. Multivariate analysis was used to explore the potential association of TA and pre-H treatment to clinical outcomes. Potential interactions between TA and pre-H ticagrelor were also explored. A total of 941 (57.7%) patients underwent TA. In adjusted multivariate logistic model, pre-H ticagrelor treatment was significantly associated with less frequent new MI or definite stent *thrombosis (ST) (odds ratio [OR] 0.43, 95% CI 0.20-0.92, P=.031), or definite ST (OR 0.26, 95% CI 0.07-0.91, P=.036) at 30 days. Patients treated with TA had higher frequency of Thrombolysis in Myocardial Infarction (TIMI) flow 0-1 compared with no-TA group (80.7% vs 51.9%, P<.0001). TA when also adjusted for TIMI flow 0-1 showed significant association only for higher bailout use of glycoprotein IIb/IIIa inhibitors (OR 1.72, 95% CI 1.18-2.50, P=.004) and more frequent 30-day TIMI major bleeding (OR 2.92, 95% CI 1.10-7.76, P=.032). No significant interactions between TA and pre-H ticagrelor were present for the explored end points. TA when left to physicians' discretion was used in high-risk patients, was associated with bailout use of glycoprotein IIb/IIIa inhibitors and TIMI major bleeding, and had no impact on 30-day clinical outcomes. Conversely, pre-H ticagrelor treatment predicted lower 30-day rates of ST or new MI without interaction with TA. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Gender, TIMI risk score and in-hospital mortality in STEMI patients undergoing primary PCI: results from the Belgian STEMI registry.

PubMed

Gevaert, Sofie A; De Bacquer, Dirk; Evrard, Patrick; Convens, Carl; Dubois, Philippe; Boland, Jean; Renard, Marc; Beauloye, Christophe; Coussement, Patrick; De Raedt, Herbert; de Meester, Antoine; Vandecasteele, Els; Vranckx, Pascal; Sinnaeve, Peter R; Claeys, Marc J

2014-01-22

The relationship between the predictive performance of the TIMI risk score for STEMI and gender has not been evaluated in the setting of primary PCI (pPCI). Here, we compared in-hospital mortality and predictive performance of the TIMI risk score between Belgian women and men undergoing pPCI. In-hospital mortality was analysed in 8,073 (1,920 [23.8%] female and 6,153 [76.2%] male patients) consecutive pPCI-treated STEMI patients, included in the prospective, observational Belgian STEMI registry (January 2007 to February 2011). A multivariable logistic regression model, including TIMI risk score variables and gender, evaluated differences in in-hospital mortality between men and women. The predictive performance of the TIMI risk score according to gender was evaluated in terms of discrimination and calibration. Mortality rates for TIMI scores in women and men were compared. Female patients were older, had more comorbidities and longer ischaemic times. Crude in-hospital mortality was 10.1% in women vs. 4.9% in men (OR 2.2; 95% CI: 1.82-2.66, p<0.001). When adjusting for TIMI risk score variables, mortality remained higher in women (OR 1.47, 95% CI: 1.15-1.87, p=0.002). The TIMI risk score provided a good predictive discrimination and calibration in women as well as in men (c-statistic=0.84 [95% CI: 0.809-0.866], goodness-of-fit p=0.53 and c-statistic=0.89 [95% CI: 0.873-0.907], goodness-of-fit p=0.13, respectively), but mortality prediction for TIMI scores was better in men (p=0.02 for TIMI score x gender interaction). In the Belgian STEMI registry, pPCI-treated women had a higher in-hospital mortality rate even after correcting for TIMI risk score variables. The TIMI risk score was effective in predicting in-hospital mortality but performed slightly better in men. The database was registered with clinicaltrials.gov (NCT00727623).

Coronary artery ectasia, an independent predictor of no-reflow after primary PCI for ST-elevation myocardial infarction.

PubMed

Schram, H C F; Hemradj, V V; Hermanides, R S; Kedhi, E; Ottervanger, J P

2018-04-25

The no-reflow phenomenon is a serious complication after primary percutaneous coronary intervention (PCI) for ST-elevation Myocardial Infarction (STEMI). Coronary artery ectasia (CAE) may increase the risk of no-reflow, however, only limited data is available on the potential impact of CAE. The aim of this study was to determine the potential association between CAE and no-reflow after primary PCI. A case control study was performed based on a prospective cohort of STEMI patients from January 2000 to December 2011. All patients with TIMI 0-1 flow post primary PCI, in the absence of dissection, thrombus, spasm or high-grade residual stenosis, were considered as no-reflow case. Control subjects were two consecutive STEMI patients after each case, with TIMI flow ≥2 after primary PCI. CAE was defined as dilatation of an arterial segment to a diameter at least 1.5 times that of the adjacent normal coronary artery. In the no-reflow group, frequency of CAE was significantly higher (33.8% vs 3.9%, p < 0.001) compared to the control group. Baseline variables were comparable between patients with and without CAE. Patients with CAE had more often TIMI 0-1 flow pre-PCI (91% vs 71% p = 0.03), less often anterior STEMI (3% vs 37%, p < 0.001) and underwent significantly less often a PCI with stenting (47% vs 74%, p = 0.003). After multivariate analysis, CAE remained a strong and independent predictor of no-reflow (OR 13.9, CI 4.7-41.2, p < 0.001). CAE is a strong and independent predictor of no-reflow after primary PCI for STEMI. Future studies should assess optimal treatment. Copyright © 2017 Elsevier B.V. All rights reserved.

Distal embolization during native vessel and vein graft coronary intervention with a vascular protection device: predictors of high-risk lesions.

PubMed

El-Jack, Seif S; Suwatchai, Pornratanarangsi; Stewart, James T; Ruygrok, Peter N; Ormiston, John A; West, Teena; Webster, Mark W I

2007-12-01

We sought to define clinical and angiographic variables that may predict patients and lesions at increased risk for distal embolism during percutaneous intervention (PCI), as assessed by debris retrieval from a distal-protection filter device. Distal thrombo- and atheroembolism may contribute to periprocedural myocardial necrosis during PCI, which may in turn affect long-term outcomes. Distal protection devices have been used to reduce this occurrence with variable outcomes depending on lesion and patient subsets. 194 consecutive patients in whom the FilterWire(R) device (FW) [Boston Scientific Corp., Natick, MA] was used for native coronary vessel (n =129) or vein graft (n = 65) PCI were studied. FW debris was visually analyzed using a semi-quantitative grading score. Patients with "significant" debris (particles > or = 1 mm diameter) were compared with those with "nonsignificant" debris (no debris or particles <1 mm) with respect to clinical (age, gender, coronary disease risk factors, clinical presentation, periprocedural medications), and angiographic (vessel treated, vessel size, lesion length, lesion characteristics, angiographic thrombus and TIMI flow before and after PCI) variables. Significant debris was retrieved in 55% of patients, more frequently from vein graft (69%) than native vessel lesions (48%, p = 0.006). No clinical characteristics predicted significant debris retrieval. Angiographic predictors of significant debris by multivariate analysis were longer stent length and final TIMI flow <3 (p = 0.009 and 0.007, respectively). Longer stent length, likely reflecting increased lesion length and plaque burden, predicted significant distal embolism during PCI in native vessel and vein graft lesions, as assessed by debris collected in a distal vascular protection device. This suggests that use of vascular protection devices should be considered during PCI of long lesions.

The relationship between neutrophil to lymphocyte ratio, platelet to lymphocyte ratio and thrombolysis in myocardial infarction risk score in patients with ST elevation acute myocardial infarction before primary coronary intervention

PubMed Central

Ertaş, Faruk; Bilik, Mehmet Zihni; Akıl, Mehmet Ata; Özyurtlu, Ferhat; Aydın, Mesut; Oylumlu, Mustafa; Polat, Nihat; Yüksel, Murat; Yıldız, Abdulkadir; Kaya, Hasan; Akyüz, Abdurrahman; Ayçiçek, Hilal; Özbek, Mehmet; Toprak, Nizamettin

2015-01-01

Introduction The thrombolysis in myocardial infarction (TIMI) risk score is calculated as the sum of independent predictors of mortality and ischemic events in ST elevation acute myocardial infarction (STEMI). Several studies show that the neutrophil to lymphocyte ratio (NLR) is a prognostic inflammatory marker. In preliminary studies, platelet to lymphocyte ratio (PLR) has been proposed as a pro-thrombotic marker. The relationship between NLR, PLR and TIMI risk score for STEMI has never been studied. Aim To evaluate the association between TIMI-STEMI risk score and NLR, PLR and other biochemical indices in STEMI. Material and methods In this retrospective study, we evaluated 390 patients who presented with STEMI within 12 h of symptom onset. Patients were grouped according to low and high TIMI risk scores. Results We enrolled 390 patients (mean age 61.9 ±13.6 years; 73% were men). The NLR, platelet distribution width (PDW) and uric acid level (UA) were significantly associated with a high TIMI-STEMI risk score (p = 0.016, p = 0.008, p = 0.030, respectively), but PLR was not associated with a high TIMI-STEMI risk score. Left ventricular ejection fraction was an independent predictor of TIMI-STEMI risk score. A cut-off point of TIMI-STEMI score of > 4 predicted in-hospital mortality (sensitivity 75%, specificity 70%, p < 0.001). We found that NLR, PDW, and UA level were associated with TIMI-STEMI risk score. Conclusions Neutrophil to lymphocyte ratio, PDW and UA level are convenient, inexpensive and reproducible biomarkers for STEMI prognosis before primary angioplasty when these indicators are combined with the TIMI-STEMI risk score. We believe that these significant findings can guide further clinical practice. PMID:26161105

Effect of intracoronary nitroprusside injection on flow recovery during primary PCI in acute STEMI patients.

PubMed

Yang, Lixia; Mu, Lihua; Sun, Linhui; Qi, Feng; Guo, Ruiwei

2017-04-01

The no/slow reflow phenomenon during primary percutaneous coronary intervention (PPCI) causes the destruction of the coronary microcirculation and further myocardial damage. Some studies have shown that intracoronary nitroprusside infusion is a safe and effective method for managing the no/slow reflow phenomenon. However, it is uncertain whether the injection of nitroprusside at a specific time point during PPCI can most effectively prevent no-reflow. In this study, we investigated the effect of the timing of an intracoronary nitroprusside injection on flow recovery during PPCI in patients with ST elevation acute myocardial infarction (STEMI). One hundred twenty consecutive patients with STEMI who underwent PPCI were enrolled in the study. Patients who fulfilled the eligibility criteria were randomly allocated to three groups: control group (N.=40) received no nitroprusside before they completed PCI; the second group (N.=40) received nitroprusside before balloon dilatation; and the third group (N.=40) received nitroprusside after each balloon dilatation and before contrast agent refilling. The baseline clinical variables and the details of the PCI procedure were collected. The thrombolysis in myocardial infarction (TIMI) flow grades and the corrected TIMI frame count (cTFC) were evaluated immediately after stent implantation was completed. There were no significant differences in the baseline characteristics, antithrombotic drugs given before PCI, and details of the PCI procedure among the three groups (P>0.05). The incidence of TIMI grade 3 after PCI was significantly higher in the nitroprusside group than in the control group (P=0.025), whereas cTFC was significantly lower in the nitroprusside group (26.6±15.2) than in the control group (38.1±21.3, P=0.001). The incidence of TIMI grade 3 after PCI was significantly higher in the third group than in the second group (P=0.045), and cTFC was significantly lower in the third group (21.5±9.5) than in the second group (31.2±18.3, P=0.002). Multivariable linear regression analyses showed that the intracoronary nitroprusside injection time was a significant predictor of cTFC after PCI. These data suggest that the intracoronary injection of nitroprusside significantly reduced the incidence of no/slow reflow during PPCI. The intracoronary injection of nitroprusside most effectively prevented the no/slow reflow phenomenon when administered between balloon dilatation and contrast agent refilling during PPCI.

Comparison of primary coronary percutaneous coronary intervention between Diabetic Men and Women with acute myocardial infarction.

PubMed

Liu, Heng-Liang; Liu, Yang; Hao, Zhen-Xuan; Geng, Guo-Ying; Zhang, Zhi-Fang; Jing, Song-Bin; Ba, Ning; Guo, Wei

2015-01-01

This study aimed to explore the short-term efficacy and safety of primary percutaneous coronary intervention (PCI) in female diabetic patients complicated with acute myocardial infarction (AMI). A total of 169 diabetic patients with AMI who underwent primary PCI were selected and divided into group A (52 females) and group B (117 males). The clinical data, characteristics of coronary artery lesions, lengths of hospital stay, and incidences of complications were then compared between two groups. The average age, history of hyperlipidemia, double branch lesions, triple branch lesions, and left main lesions were significantly higher in group A than in group B (P < 0.05). Smoking history, PCI history, and pre-infarction angina were distinctly lower in group A than in group B (P < 0.05). Thrombolysis in myocardial infarction 3 (TIMI3) flow and TIMI myocardial perfusion grade 3 (TMPG3) after PCI were markedly lower in group A than in group B (P < 0.001). Group A had a higher incidence of complications, such as severe arrhythmia, cardiac function Killip III/IV, cardiogenic shock, major, moderate and mild bleed event, as well as a 30-day mortality rate, compared with group B (P < 0.05). In summary, our study demonstrated that female diabetic patients with AMI had lower TIMI3 flow and TMPG3 following PCI than male patients, while there was higher incidence of complications and 30-day mortality rate. Therefore, more attention should be paid to the therapy of diabetic women with acute myocardial infarction as well as the control of risk factors.

Comparison of the HEART and TIMI Risk Scores for Suspected Acute Coronary Syndrome in the Emergency Department.

PubMed

Sun, Benjamin C; Laurie, Amber; Fu, Rongwei; Ferencik, Maros; Shapiro, Michael; Lindsell, Christopher J; Diercks, Deborah; Hoekstra, James W; Hollander, Judd E; Kirk, J Douglas; Peacock, W Frank; Anantharaman, Venkataraman; Pollack, Charles V

2016-03-01

The emergency department evaluation for suspected acute coronary syndrome (ACS) is common, costly, and challenging. Risk scores may help standardize clinical care and screening for research studies. The Thrombolysis in Myocardial Infarction (TIMI) and HEART are two commonly cited risk scores. We tested the null hypothesis that the TIMI and HEART risk scores have equivalent test characteristics. We analyzed data from the Internet Tracking Registry of Acute Coronary Syndromes (i*trACS) from 9 EDs on patients with suspected ACS, 1999-2001. We excluded patients with an emergency department diagnosis consistent with ACS, or without sufficient data to calculate TIMI and HEART scores. The primary outcome was 30-day major adverse cardiovascular events, including all-cause death, acute myocardial infarction, and urgent revascularization. We describe test characteristics of the TIMI and HEART risk scores. The study cohort included 8255 patients with 508 (6.2%) 30-day major adverse cardiovascular events. Receiver operating curve and reclassification analyses favored HEART [c statistic: 0.753, 95% confidence interval (CI): 0.733-0.773; continuous net reclassification improvement: 0.608, 95% CI: 0.527-0.689] over TIMI (c statistic: 0.678, 95% CI: 0.655-0.702). A HEART score 0-3 [negative predictive value (NPV) 0.982, 95% CI: 0.978-0.986; positive predictive value (PPV) 0.103, 95% CI: 0.094-0.113; likelihood ratio (LR) positive 1.76; LR negative 0.28] demonstrates similar or superior NPV/PPV/LR compared with TIMI = 0 (NPV 0.978, 95% CI: 0.971-0.983; PPV 0.077, 95% CI: 0.071-0.084; LR positive 1.28; LR negative 0.35) and TIMI = 0-1 (NPV 0.963, 95% CI: 0.958-0.968; PPV 0.102, 95% CI: 0.092-0.113; LR positive 1.73; LR negative 0.58). The HEART score has better discrimination than TIMI and outperforms TIMI within previously published "low-risk" categories.

Prognostic Value of Real Time Myocardial Contrast Echocardiography after Percutaneous Coronary Intervention.

PubMed

Yang, Lixia; Xia, Chunmei; Mu, Yuming; Guan, Lina; Wang, Chunmei; Tang, Qi; Verocai, Flavia Gomes; Fonseca, Lea Mirian Barbosa da; Shih, Ming Chi

2016-03-01

Real time myocardial contrast echocardiography (RTMCE) is a cost-effective and simple method to quantify coronary flow reserve (CFR). We aimed to determine the value of RTMCE to predict cardiac events after percutaneous coronary intervention (PCI). We have studied myocardial blood volume (A), velocity (β), flow indexes (MBF, A × β), and vasodilator reserve (stress-to-rest ratios) in 36 patients with acute coronary syndrome (ACS) who underwent PCI. CFR (MBF at stress/MBF at rest) was calculated for each patient. Perfusion scores were used for visual interpretation by MCE and correlation with TIMI flow grade. In qualitative RTMCE assessment, post-PCI visual perfusion scores were higher than pre-PCI (Z = -7.26, P < 0.01). Among 271 arteries with TIMI flow grade 3 post-PCI, 72 (36%) did not reach visual perfusion score 1. The β- and A × β-reserve of the abnormal segments supplied by obstructed arteries increased after PCI comparing to pre-PCI values (P < 0.01). Patients with adverse cardiac events had significantly lower β- and lower A × β-reserve than patients without adverse cardiac events. In the former group, the CFR was ≥ 1.5 both pre- and post-PCI. CFR estimation by RTMCE can quantify myocardial perfusion in patients with ACS who underwent PCI. The parameters β-reserve and CFR combined might predict cardiac events on the follow-up. © 2015, Wiley Periodicals, Inc.

Clinical Trial Updates and Hotline Sessions presented at the European Society of Cardiology Congress 2007: (FINESSE, CARESS, OASIS 5, PRAGUE-8, OPTIMIST, GRACE, STEEPLE, SCAAR, STRATEGY, DANAMI-2, ExTRACT-TIMI-25, ISAR-REACT 2, ACUITY, ALOFT, 3CPO, PROSPECT, EVEREST, COACH, BENEFiT, MERLIN-TIMI 36, SEARCH-MI, ADVANCE, WENBIT, EUROASPIRE I-III, ARISE, getABI, RIO).

PubMed

Kindermann, Michael; Adam, Oliver; Werner, Nikos; Böhm, Michael

2007-11-01

This article provides information and commentaries on trials which were presented at the Hotline and Clinical Trial Update Sessions at the European Society of Cardiology Congress 2007 in Vienna. The key presentations were performed by leading experts in the field with relevant positions in the trials or registries. It is important to note that unpublished reports should be considered as preliminary data, as the analysis may change in the final publications. The comprehensive summaries have been generated from the oral presentation and the webcasts of the European Society of Cardiology and should provide the readers with the most comprehensive information of relevant publications.

Plasminogen activator inhibitor-1 5G/5G genotype is associated with early spontaneous recanalization of the infarct-related artery in patients presenting with acute ST-elevation myocardial infarction.

PubMed

Cagliyan, Caglar E; Yuregir, Ozge O; Balli, Mehmet; Tekin, Kamuran; Akilli, Rabia E; Bozdogan, Sevcan T; Turkmen, Serdar; Deniz, Ali; Baykan, Oytun A; Aslan, Huseyin; Cayli, Murat

2013-05-01

We aimed to examine the association between plasminogen activator inhibitor-1 (PAI-1) genetic polymorphism and early spontaneous recanalization in patients presenting with acute ST-elevation myocardial infarction. Patients admitted to our emergency department with ST-elevation myocardial infarction in the first 6 h of symptom onset were included. An immediate primary percutaneous coronary intervention was performed. Patients were grouped according to the initial patency of the infarct-related artery (IRA) as follows: total occlusion (TO) group [Thrombolysis in Myocardial Infarction (TIMI) 0-1 flow in the IRA], partial recanalization group (TIMI 2 flow in the IRA), and complete recanalization (CR) group (TIMI 3 flow in the IRA). PAI-1 4G/5G polymorphism was detected using the real-time PCR method. There were 107 patients in the TO group, 30 patients in the partial recanalization group, and 45 patients in the CR group. When we evaluated degrees of patency according to the PAI-1 genotype, TO of the IRA was the highest in patients with the PAI 4G/4G genotype (PAI-1 4G/4G: 66.7%, PAI-1 4G/5G: 65.9%, PAI-1 5G/5G: 40.4%) and CR of the IRA was the highest in patients with the PAI 5G/5G genotype (PAI-1 5G/5G: 38.5%, PAI-1 4G/5G: 19.8%, PAI-1 4G/4G: 17.9%). The distribution of genotypes in different degrees of patency of IRA was statistically significant (P=0.029). In logistic regression analysis, the PAI-1 5G/5G genotype was associated independently with the spontaneous CR of the IRA (odds ratio: 2.875, 95% confidence interval [1.059-7.086], P=0.038). Patients with the PAI-1 5G/5G genotype seem to be luckier than others in terms of early spontaneous recanalization of the IRA. Further prospective studies with large patient populations are required for more precise results.

Unanswered questions for management of acute coronary syndrome: risk stratification of patients with minimal disease or normal findings on coronary angiography.

PubMed

Bugiardini, Raffaele; Manfrini, Olivia; De Ferrari, Gaetano M

2006-07-10

The prognostic implication of chest pain associated with normal or near-normal findings on angiography is still unknown. We explored outcomes and methods of risk stratification in patients with nonobstructive coronary artery disease in the setting of non-ST-segment elevation acute coronary syndromes. Data were pooled from 3 Thrombolysis in Myocardial Infarction (TIMI) trials (TIMI 11B, TIMI 16, and TIMI 22). Angiographic data were available on 7656 patients with non-ST-segment elevation acute coronary syndromes. The primary end point of this analysis was the composite of the rates of death, myocardial infarction, unstable angina requiring rehospitalization, revascularization, and stroke at 1-year follow-up. Outcomes were evaluated by mean of the TIMI risk score for developing at least 1 component of the primary end point. Angiographic findings showed that 710 (9.1%) of 7656 patients had nonobstructive coronary artery disease; 48.7% of these had normal coronary arteries (0% stenosis), and 51.3% had mild coronary artery disease (>0% to <50% stenosis). A primary end-point event occurred in 101 patients (12.1%). It is noteworthy that a 2% event rate of deaths and myocardial infarctions had occurred in these patients at the 1-year follow-up. Event rates of death and myocardial infarction increased significantly as the TIMI risk score increased from 0.6% for a score of 1 to 4.0% for a score greater than 4. Patients with non-ST-segment elevation acute coronary syndromes with nonobstructive coronary artery disease detected by angiography have a substantial risk of subsequent coronary events within 1 year. The risk is not univariately high, and the TIMI risk score helps to reveal patients at high risk.

Efficacy and safety of different doses of tirofiban combined with ticagrelor on diabetic patients with AMI receiving in emergency percutaneous coronary intervention (PCI)

PubMed Central

Liu, Yang; Liu, Hengliang; Hao, Zhenxuan; Geng, Guoying; Chen, Qi; Han, Wenjie; Jia, Kailong; Zhou, Yuxin

2015-01-01

Objective: The aim of this study was to investigate the efficacy and safety of dual antiplatelet drugs combined with different doses of tirofiban on diabetic patients with acute myocardial infarction (AMI) receiving emergency percutaneous coronary intervention (PCI). Methods: 158 diabetic patients with AMI undergone emergency PCI were randomly divided into three groups: Group A (53 cases) as the control group-dual anti-platelet agents (aspirin + ticagrelor); Group B (52 cases)-dual anti-platelet agents + conventional dose of tirofiban [10 μg/kg by PCI and 0.15 μg/(kg·min) by continue venous pump for 24 h]; Group C (53 cases)-dual antiplatelet agents + half-dose tirofiban [10 μg/kg by PCI and 0.075 μg/(kg·min) by continue venous pump for 24 h]. Results: Compared with group A, thrombolysis in myocardial infarction 3 (TIMI3) blood flow and TIMI myocardial perfusion grade 3 (TMPG3) myocardial perfusion of patients in group B and group C after PCI was significantly higher (P < 0.05), the average day of hospitalization was significantly shorter (P < 0.05), reinfarction during hospitalization, post-infarction angina, severe arrhythmia, the incidence of cardiac function above KillipIII level was significantly lower (P < 0.05). And the differences between group B and C was not statistically significant (P > 0.05). Severe bleeding and moderate incidence of bleeding in group B was significantly higher than that in group A and group C (P < 0.05). Conclusions: Based on combination of dual the anti-platelet agents and ticagrelor for diabetic patients with AMI receiving PCI, the combination of half-dose tirofiban can effectively improve TIMI flow and TMPG myocardial tissue perfusion, and reduce the incidence of major adverse cardiac events (MACE) and severe bleeding. PMID:26379951

Primary percutaneous coronary intervention for acute ST elevation myocardial infarction: Outcomes and determinants of outcomes: A tertiary care center study from North India.

PubMed

Dubey, Gajendra; Verma, Sunil Kumar; Bahl, Vinay Kumar

Primary percutaneous coronary intervention (PCI) is the current standard of care for acute ST elevation myocardial infarction (STEMI). Most of the data on primary PCI in acute STEMI is from western countries. We studied the outcomes of primary PCI for acute STEMI at a tertiary care center in North India. Consecutive patients undergoing primary PCI for STEMI were prospectively studied during the period from February 2103 to May 2015. The outcomes assessed were all cause in hospital mortality, factors associated with mortality, major adverse cardiac and cerebrovascular event rate (composite of all cause in hospital mortality, non-fatal re infarction and stroke) and procedural complications. 371 patients underwent primary PCI during the study period. The mean age was 54 years and 82.7% were males. The mean total ischemia time and door to balloon times were 6.8h and 51min respectively. 96.4% patients underwent successful primary PCI. The total in hospital mortality was 12.9%. Mortality with cardiogenic shock at presentation was 66.7% while non-shock mortality was 2.6%. In hospital MACCE rate was 13.5%. Factors significantly associated with mortality were KILLIP class (OR: 8.4), door to balloon time (OR 1.02), final TIMI flow (OR 0.44) and severe LV dysfunction (OR 22.0). Procedure related adverse events were rare and there was no non-CABG associated major TIMI bleeding. Primary PCI for acute STEMI is feasible in our setup and associated with high success rate, low mortality in non-shock patients and low complication rates. Copyright © 2016. Published by Elsevier B.V.

Prognostic Value of the Thrombolysis in Myocardial Infarction Risk Score in ST-Elevation Myocardial Infarction Patients With Left Ventricular Dysfunction (from the EPHESUS Trial).

PubMed

Popovic, Batric; Girerd, Nicolas; Rossignol, Patrick; Agrinier, Nelly; Camenzind, Edoardo; Fay, Renaud; Pitt, Bertram; Zannad, Faiez

2016-11-15

The Thrombolysis in Myocardial Infarction (TIMI) risk score remains a robust prediction tool for short-term and midterm outcome in the patients with ST-elevation myocardial infarction (STEMI). However, the validity of this risk score in patients with STEMI with reduced left ventricular ejection fraction (LVEF) remains unclear. A total of 2,854 patients with STEMI with early coronary revascularization participating in the randomized EPHESUS (Epleronone Post-Acute Myocardial Infarction Heart Failure Efficacy and Survival Study) trial were analyzed. TIMI risk score was calculated at baseline, and its predictive value was evaluated using C-indexes from Cox models. The increase in reclassification of other variables in addition to TIMI score was assessed using the net reclassification index. TIMI risk score had a poor predictive accuracy for all-cause mortality (C-index values at 30 days and 1 year ≤0.67) and recurrent myocardial infarction (MI; C-index values ≤0.60). Among TIMI score items, diabetes/hypertension/angina, heart rate >100 beats/min, and systolic blood pressure <100 mm Hg were inconsistently associated with survival, whereas none of the TIMI score items, aside from age, were significantly associated with MI recurrence. Using a constructed predictive model, lower LVEF, lower estimated glomerular filtration rate (eGFR), and previous MI were significantly associated with all-cause mortality. The predictive accuracy of this model, which included LVEF and eGFR, was fair for both 30-day and 1-year all-cause mortality (C-index values ranging from 0.71 to 0.75). In conclusion, TIMI risk score demonstrates poor discrimination in predicting mortality or recurrent MI in patients with STEMI with reduced LVEF. LVEF and eGFR are major factors that should not be ignored by predictive risk scores in this population. Copyright © 2016 Elsevier Inc. All rights reserved.

Predictive values of D-dimer assay, GRACE scores and TIMI scores for adverse outcome in patients with non-ST-segment elevation myocardial infarction

PubMed Central

Satilmisoglu, Muhammet Hulusi; Ozyilmaz, Sinem Ozbay; Gul, Mehmet; Ak Yildirim, Hayriye; Kayapinar, Osman; Gokturk, Kadir; Aksu, Huseyin; Erkanli, Korhan; Eksik, Abdurrahman

2017-01-01

Purpose To determine the predictive values of D-dimer assay, Global Registry of Acute Coronary Events (GRACE) and Thrombolysis in Myocardial Infarction (TIMI) risk scores for adverse outcome in patients with non-ST-segment elevation myocardial infarction (NSTEMI). Patients and methods A total of 234 patients (mean age: 57.2±11.7 years, 75.2% were males) hospitalized with NSTEMI were included. Data on D-dimer assay, GRACE and TIMI risk scores were recorded. Logistic regression analysis was conducted to determine the risk factors predicting increased mortality. Results Median D-dimer levels were 349.5 (48.0–7,210.0) ng/mL, the average TIMI score was 3.2±1.2 and the GRACE score was 90.4±27.6 with high GRACE scores (>118) in 17.5% of patients. The GRACE score was correlated positively with both the D-dimer assay (r=0.215, P=0.01) and TIMI scores (r=0.504, P=0.000). Multivariate logistic regression analysis revealed that higher creatinine levels (odds ratio =18.465, 95% confidence interval: 1.059–322.084, P=0.046) constituted the only significant predictor of increased mortality risk with no predictive values for age, D-dimer assay, ejection fraction, glucose, hemoglobin A1c, sodium, albumin or total cholesterol levels for mortality. Conclusion Serum creatinine levels constituted the sole independent determinant of mortality risk, with no significant values for D-dimer assay, GRACE or TIMI scores for predicting the risk of mortality in NSTEMI patients. PMID:28408834

An Asian validation of the TIMI risk score for ST-segment elevation myocardial infarction.

PubMed

Selvarajah, Sharmini; Fong, Alan Yean Yip; Selvaraj, Gunavathy; Haniff, Jamaiyah; Uiterwaal, Cuno S P M; Bots, Michiel L

2012-01-01

Risk stratification in ST-elevation myocardial infarction (STEMI) is important, such that the most resource intensive strategy is used to achieve the greatest clinical benefit. This is essential in developing countries with wide variation in health care facilities, scarce resources and increasing burden of cardiovascular diseases. This study sought to validate the Thrombolysis In Myocardial Infarction (TIMI) risk score for STEMI in a multi-ethnic developing country. Data from a national, prospective, observational registry of acute coronary syndromes was used. The TIMI risk score was evaluated in 4701 patients who presented with STEMI. Model discrimination and calibration was tested in the overall population and in subgroups of patients that were at higher risk of mortality; i.e., diabetics and those with renal impairment. Compared to the TIMI population, this study population was younger, had more chronic conditions, more severe index events and received treatment later. The TIMI risk score was strongly associated with 30-day mortality. Discrimination was good for the overall study population (c statistic 0.785) and in the high risk subgroups; diabetics (c statistic 0.764) and renal impairment (c statistic 0.761). Calibration was good for the overall study population and diabetics, with χ2 goodness of fit test p value of 0.936 and 0.983 respectively, but poor for those with renal impairment, χ2 goodness of fit test p value of 0.006. The TIMI risk score is valid and can be used for risk stratification of STEMI patients for better targeted treatment.

Immediate- and short-term outcome following recanalization of long chronic total occlusions (> 50 mm) of native coronary arteries with the Frontrunner catheter.

PubMed

Loli, Akil; Liu, Rex; Pershad, Ashish

2006-06-01

Thirty percent of diagnostic angiograms have at least 1 chronic total occlusion (CTO). The 10-year survival of patients with a CTO is improved if they have the CTO successfully recanalized. The success of recanalization with conventional wires is 50% and the impact of new technology on recanalization is unknown. This abstract reports a single center experience with one such new device, the Lumend Frontrunner catheter in revascularization of this difficult lesion subset. A consecutive series of 18 patients with CTO's of native coronary arteries were enrolled in this single center, single operator series. The mean age of the CTO was 5.3 years. The indication for attempt at recanalization was ischemia in the territory of the CTO on SPECT imaging. Success was defined as TIMI flow restoration and < 40% residual stenosis. Primary success (defined as TIMI 3 Flow restoration and < 40% residual stenosis) was achieved in 77% of patients. At 30 days and out to 6 months, clinical TVR was 11% (2/18) in this difficult lesion subset. Conventional predictors of failure to recanalize CTOs do not appear to hold true with the use of the Frontrunner catheter. In this small series, dual cusp injections and use of the Microglide catheter appears to correlate with favorable outcomes. Fluoroscopy times and contrast use are high when attempting recanalization of CTOs with this technology.

At least seven days delayed stenting using minimalist immediate mechanical intervention (MIMI) in ST-segment elevation myocardial infarction: the SUPER-MIMI study.

PubMed

Mester, Petru; Bouvaist, Helene; Delarche, Nicolas; Bouisset, Frédéric; Abdellaoui, Mohamed; Petiteau, Pierre-Yves; Dubreuil, Olivier; Boueri, Ziad; Chettibi, Mohamed; Souteyrand, Géraud; Madiot, Hend; Belle, Loic

2017-07-20

The aim of this study was to ascertain whether a minimalist immediate mechanical intervention (MIMI) aiming to restore an optimal Thrombolysis In Myocardial Infarction (TIMI) flow in the culprit artery, followed ≥7 days later by a second percutaneous coronary intervention with intentional stenting, is safe in patients with ST-segment elevation myocardial infarction and large thrombotic burden. SUPER-MIMI was a prospective, observational trial conducted between January 2014 and April 2015 in 14 French centres. A total of 155 patients were enrolled. The pharmacological therapy was left to the operator's discretion. Eighty-one patients (52.3%) had glycoprotein IIb/IIIa inhibitors (GPI) initiated before the end of the first procedure. The median (interquartile range [IQR]) delay between the two procedures was eight (seven to 12) days. Infarct-related artery reocclusion between the two procedures (primary endpoint) occurred in two patients (1.3%), neither of whom received GPI treatment. TIMI flow was maintained or improved between the end of the first procedure and the beginning of the second procedure in all patients. Thrombotic burden and stenosis severity diminished significantly between the two procedures. Stents were ultimately implanted in 97 patients (62.6%). Deferred stenting (≥7 days) in patients with a high thrombus burden was safe on a background of GPI therapy.

Water Wells Monitoring Using SCADA System for Water Supply Network, Case Study: Water Treatment Plant Urseni, Timis County, Romania

NASA Astrophysics Data System (ADS)

Adrian-Lucian, Cococeanu; Ioana-Alina, Cretan; Ivona, Cojocinescu Mihaela; Teodor Eugen, Man; Narcis, Pelea George

2017-10-01

The water supply system in Timisoara Municipality is insured with about 25-30 % of the water demand from wells. The underground water headed to the water treatment plant in order to ensure equal distribution and pressure to consumers. The treatment plants used are Urseni and Ronaţ, near Timisoara, in Timis County. In Timisoara groundwater represents an alternative source for water supply and complementary to the surface water source. The present paper presents a case study with proposal and solutions for rehabilitation /equipment /modernization/ automation of water drilling in order to ensure that the entire system can be monitored and controlled remotely through SCADA (Supervisory control and data acquisition) system. The data collected from the field are designed for online efficiency monitoring regarding the energy consumption and water flow intake, performance indicators such as specific energy consumption KW/m3 and also in order to create a hydraulically system of the operating area to track the behavior of aquifers in time regarding the quality and quantity aspects.

The value of novel invasive hemodynamic parameters added to the TIMI risk score for short-term prognosis assessment in patients with ST segment elevation myocardial infarction.

PubMed

Tesak, Martin; Kala, Petr; Jarkovsky, Jiri; Poloczek, Martin; Bocek, Otakar; Jerabek, Petr; Kubková, Lenka; Manousek, Jan; Spinar, Jindrich; Mebazaa, Alexandre; Parenica, Jiri; Cohen-Solal, Alain

2016-07-01

We compared the prognostic capacity of conventional and novel invasive parameters derived from the slope of the preload recruitable stroke work relationship (PRSW) in STEMI patients and assessed their contribution to the TIMI risk score. Left ventricular end-diastolic pressure (EDP), ejection fraction (EF), pressure adjusted maximum rate of pressure change in the left ventricle (dP/dt/P), aortic systolic pressure to EDP ratio (SBP/EDP) and end-diastolic volume adjusted stroke work (EW), derived from the slope of the PRSW relationship, were obtained during the emergency cardiac catheterization in 523 STEMI patients. The predictive power of the analyzed parameters for 30-day and 1-year mortality was evaluated using C-statistics and reclassification analysis was adopted to assess the improvement in TIMI score. The highest area under the curve (AUC) values for 30-day mortality were observed for EW (0.872(95% confidence interval 0.801-0.943)), SBP/EDP (0.843(0.758-0.928)) and EF (0.833(0.735-0.931)); p<0.001 for all values. For 1-year mortality the best predictive value was found for EW (0.806(0.724-0.887) and EF (0.793(0.703-0.883)); p<0.001 for both. The addition of EDP, SBP/EDP ratio and EW to TIMI score significantly increased the AUC according to De Long's test. For 30-day mortality, increased discriminative power following addition to the TIMI score was observed for EW and SBP/EDP (Integrated Discrimination Improvement was 0.086(0.033-0.140), p=0.002 and 0.078(0.028-0.128), p=0.002, respectively). EW and SBP/EDP are prognostic markers with high predictive value for 30-day and 1-year mortality. Both parameters, easily obtained during emergency catheterization, improve the discriminatory capacity of the TIMI score for 30-day mortality. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Effects of nebivolol on endothelial function and exercise parameters in patients with slow coronary flow.

PubMed

Tiryakioglu, Selma; Tiryakioglu, Osman; Ari, Hasan; Basel, Mehmet C; Bozat, Tahsin

2009-11-03

Earlier studies have reported that a decrease in exercise capacity might indicate endothelial dysfunction. However, the effects of improvement of endothelial functions on exercise capacity have not been evaluated. The aim of the present study is to investigate the effects of nebivolol on flow-mediated dilatation (FMD), and on the exercise capacities of the patients with slow coronary flow (SCF). The study population included 25 subjects with SCF (Group 1) documented by the thrombolysis in myocardial infarction (TIMI) frame count, and 25 control group (Group 2) subjects with normal coronary angiography, for a total of 50 subjects who underwent coronary angiography due to several indications and had no coronary lesion. The TIMI frame count (TFC) values of the subjects in Group I for left anterior descending artery, right coronary, and circumflex coronary artery were 61.8 +/- 30.6, 37.2 +/- 17.4, and 34.6 +/- 17.4, respectively. All the subjects received nebivolol 5 mg/day. At the end of the first month of FMD, the mean exercise duration (MED) and the Duke Scores of the patients with SCF were significantly higher than the baseline values. However, the values by the sixth month did not differ from that at the first month. Although a numerical improvement compared to the baseline values was observed for the subjects in Group 2 by the measurements at the end of the first and the sixth month, this difference was not statistically significant. Nebivolol treatment increases FMD in the subjects with SCF. The difference in the exercise parameters of these subjects is particularly dramatic, and such an outcome may indirectly indicate long-term improvement in endothelial function.

Assessment of the 2016 National Institute for Health and Care Excellence high-sensitivity troponin rule-out strategy

PubMed Central

Greenslade, Jaimi; Cullen, Louise; Than, Martin; Kendall, Jason; Body, Richard; Parsonage, William A; Khattab, Ahmed

2018-01-01

Objective We aimed to evaluate the limit of detection of high-sensitivity troponin (hs-cTn) and Thrombolysis In Myocardial Infarction (TIMI) score combination rule-out strategy suggested within the 2016 National Institute for Health and Care Excellence (NICE) Chest Pain of Recent Onset guidelines and establish the optimal TIMI score threshold for clinical use. Methods A pooled analysis of adult patients presenting to the emergency department with chest pain and a non-ischaemic ECG, recruited into six prospective studies, from Australia, New Zealand and the UK. We evaluated the sensitivity of TIMI score thresholds from 0 to 2 alongside hs-cTnT or hs-cTnI for the primary outcome of major adverse cardiac events within 30 days. Results Data were available for 3159 patients for hs-cTnT and 4532 for hs-cTnI, of these 376 (11.9%) and 445 (9.8%) had major adverse cardiac events, respectively. Using a TIMI score of 0, the sensitivity for the primary outcome was 99.5% (95% CI 98.1% to 99.9%) alongside hs-cTnT and 98.9% (97.4% to 99.6%)%) alongside hs-cTnI, identifying 17.9% and 21.0% of patients as low risk, respectively. For a TIMI score ≤1 sensitivity was 98.9% (97.3% to 99.7%)%) alongside hs-cTnT and 98.4% (96.8% to 99.4%)%) alongside hs-cTnI, identifying 28.1% and 35.7% as low risk, respectively. For TIMI≤2, meta-sensitivity was <98% with either assay. Conclusions Our findings support the rule-out strategy suggested by NICE. The TIMI score threshold suggested for clinical use is 0. The proportion of patients identified as low risk (18%–21%) and suitable for early discharge using this threshold may be sufficient to encourage change of practice. Trial registration numbers ADAPT observational study/IMPACT intervention trial ACTRN12611001069943. ADAPT-ADP randomised controlled trial ACTRN12610000766011. EDACS-ADP randomised controlled trial ACTRN12613000745741. TRUST observational study ISRCTN no. 21109279. PMID:28864718

Relationship between platelet-to-lymphocyte ratio and coronary slow flow.

PubMed

Oylumlu, Muhammed; Doğan, Adnan; Oylumlu, Mustafa; Yıldız, Abdülkadir; Yüksel, Murat; Kayan, Fethullah; Kilit, Celal; Amasyalı, Basri

2015-05-01

The coronary slow flow phenomenon (CSFP), which is characterized by delayed distal vessel opacification in the absence of significant epicardial coronary disease, is an angiographic finding. The aim of this study is to investigate the association between platelet-to-lymphocyte ratio (PLR) and coronary blood flow rate. This is a retrospective observational study. It was based on two medical centers. A total of 197 patients undergoing coronary angiography were included in the study, 95 of whom were patients with coronary slow flow without stenosis in coronary angiography and 102 of whom had normal coronary arteries and normal flow. The PLR was higher in the coronary slow flow group compared with the control groups (p=0.001). In the correlation analysis, PLR showed a significant correlation with left anterior descending (LAD) artery thrombolysis in myocardial infarction (TIMI) frame count. After multiple logistic regression, high levels of PLR were independently associated with coronary slow flow, together with hemoglobin. PLR was higher in patients with CSFP, and we also showed that PLR was significantly and independently associated with CSFP.

Scores for post-myocardial infarction risk stratification in the community.

PubMed

Singh, Mandeep; Reeder, Guy S; Jacobsen, Steven J; Weston, Susan; Killian, Jill; Roger, Véronique L

2002-10-29

Several scores, most of which were derived from clinical trials, have been proposed for stratifying risk after myocardial infarctions (MIs). Little is known about their generalizability to the community, their respective advantages, and whether the ejection fraction (EF) adds prognostic information to the scores. The purpose of this study is to evaluate the Thrombolysis in Myocardial Infarction (TIMI) and Predicting Risk of Death in Cardiac Disease Tool (PREDICT) scores in a geographically defined MI cohort and determine the incremental value of EF for risk stratification. MIs occurring in Olmsted County were validated with the use of standardized criteria and stratified with the ECG into ST-segment elevation (STEMI) and non-ST-segment elevation (NSTEMI) MI. Logistic regression examined the discriminant accuracy of the TIMI and PREDICT scores to predict death and recurrent MI and assessed the incremental value of the EF. After 6.3+/-4.7 years, survival was similar for the 562 STEMIs and 717 NSTEMIs. The discriminant accuracy of the TIMI score was good in STEMI but only fair in NSTEMI. Across time and end points, irrespective of reperfusion therapy, the discriminant accuracy of the PREDICT score was consistently superior to that of the TIMI scores, largely because PREDICT includes comorbidity; EF provided incremental information over that provided by the scores and comorbidity. In the community, comorbidity and EF convey important prognostic information and should be included in approaches for stratifying risk after MI.

The cost of developing a computerized tailored interactive multimedia intervention vs. a print based Photonovella intervention for HPV vaccine education.

PubMed

Karanth, Siddharth S; Lairson, David R; Savas, Lara S; Vernon, Sally W; Fernández, María E

2017-08-01

Mobile technology is opening new avenues for healthcare providers to create and implement tailored and personalized health education programs. We estimate and compare the cost of developing an i-Pad based tailored interactive multimedia intervention (TIMI) and a print based (Photonovella) intervention to increase human papillomavirus (HPV) immunization. The development costs of the interventions were calculated using a societal perspective. Direct cost included the cost of planning the study, conducting focus groups, and developing the intervention materials by the research staff. Costs also included the amount paid to the vendors who produced the TIMI and Photonovella. Micro cost data on the staff time and materials were recorded in logs for tracking personnel time, meeting time, supplies and software purchases. The costs were adjusted for inflation and reported in 2015 USD. The total cost of developing the Photonovella was $66,468 and the cost of developing the TIMI was $135,978. The amortized annual cost for the interventions calculated at a 3% discount rate and over a 7-year period was $10,669 per year for the Photonovella and $21,825 per year for the TIMI intervention. The results would inform decision makers when planning and investing in the development of interactive multimedia health interventions. Copyright © 2017 Elsevier Ltd. All rights reserved.

Infarct size in primary angioplasty without on-site cardiac surgical backup versus transferal to a tertiary center: a single photon emission computed tomography study.

PubMed

Knaapen, Paul; de Mulder, Maarten; van der Zant, Friso M; Peels, Hans O; Twisk, Jos W R; van Rossum, Albert C; Cornel, Jan H; Umans, Victor A W M

2009-02-01

Primary percutaneous coronary intervention (PCI) performed in large community hospitals without cardiac surgery back-up facilities (off-site) reduces door-to-balloon time compared with emergency transferal to tertiary interventional centers (on-site). The present study was performed to explore whether off-site PCI for acute myocardial infarction results in reduced infarct size. One hundred twenty-eight patients with acute ST-segment elevation myocardial infarction were randomly assigned to undergo primary PCI at the off-site center (n = 68) or to transferal to an on-site center (n = 60). Three days after PCI, (99m)Tc-sestamibi SPECT was performed to estimate infarct size. Off-site PCI significantly reduced door-to-balloon time compared with on-site PCI (94 +/- 54 versus 125 +/- 59 min, respectively, p < 0.01), although symptoms-to-treatment time was only insignificantly reduced (257 +/- 211 versus 286 +/- 146 min, respectively, p = 0.39). Infarct size was comparable between treatment centers (16 +/- 15 versus 14 +/- 12%, respectively p = 0.35). Multivariate analysis revealed that TIMI 0/1 flow grade at initial coronary angiography (OR 3.125, 95% CI 1.17-8.33, p = 0.023), anterior wall localization of the myocardial infarction (OR 3.44, 95% CI 1.38-8.55, p < 0.01), and development of pathological Q-waves (OR 5.07, 95% CI 2.10-12.25, p < 0.01) were independent predictors of an infarct size > 12%. Off-site PCI reduces door-to-balloon time compared with transferal to a remote on-site interventional center but does not reduce infarct size. Instead, pre-PCI TIMI 0/1 flow, anterior wall infarct localization, and development of Q-waves are more important predictors of infarct size.

Pre-hospital ticagrelor in patients with ST-segment elevation myocardial infarction with long transport time to primary PCI facility.

PubMed

Lupi, Alessandro; Schaffer, Alon; Lazzero, Maurizio; Tessitori, Massimo; De Martino, Leonardo; Rognoni, Andrea; Bongo, Angelo S; Porto, Italo

2016-12-01

Pre-hospital ticagrelor, given less than 1h before coronary intervention (PCI), failed to improve coronary reperfusion in ST-segment elevation myocardial infarction (STEMI) patients undergoing primary PCI. It is unknown whether a longer interval from ticagrelor administration to primary PCI might reveal any improvement of coronary reperfusion. We retrospectively compared 143 patients, pre-treated in spoke centers or ambulance with ticagrelor at least 1.5h before PCI (Pre-treatment Group), with 143 propensity score-matched controls treated with ticagrelor in the hub before primary PCI (Control Group) extracted from RENOVAMI, a large observational Italian registry of more than 1400 STEMI patients enrolled from Jan. 2012 to Oct. 2015 (ClinicalTrials.gov id: NCT01347580). The median time from ticagrelor administration and PCI was 2.08h (95% CI 1.66-2.84) in the Pre-treatment Group and 0.56h (95% CI 0.33-0.76) in the Control Group. TIMI flow grade before primary PCI in the infarct related artery was the primary endpoint. The primary endpoint, baseline TIMI flow grade, was significantly higher in Pre-treatment Group (0.88±1.14 vs 0.53±0.86, P=0.02). However in-hospital mortality, in-hospital stent thrombosis, bleeding rates and other clinical and angiographic outcomes were similar in the two groups. In a real world STEMI network, pre-treatment with ticagrelor in spoke hospitals or in ambulance loading at least 1.5h before primary PCI is safe and might improve pre-PCI coronary reperfusion, in comparison with ticagrelor administration immediately before PCI. Copyright © 2016 Elsevier Inc. All rights reserved.

Global outcomes of ST-elevation myocardial infarction: comparisons of the Enoxaparin and Thrombolysis Reperfusion for Acute Myocardial Infarction Treatment-Thrombolysis In Myocardial Infarction study 25 (ExTRACT-TIMI 25) registry and trial.

PubMed

Steinberg, Benjamin A; Moghbeli, Nazanin; Buros, Jacqueline; Ruda, Mikhail; Parkhomenko, Alexander; Raju, B Soma; García-Castillo, Armando; Janion, Marianna; Nicolau, José C; Fox, Keith A A; Morrow, David A; Gibson, C Michael; Antman, Elliott M

2007-07-01

Outcomes in patients with ST-elevation myocardial infarction (STEMI) differ between those in clinical trials and those in routine practice, as well as across different regions. We hypothesized that adjustment for baseline risk would minimize such variations. The Enoxaparin and Thrombolysis Reperfusion for Acute Myocardial Infarction Treatment-Thrombolysis In Myocardial Infarction (ExTRACT-TIMI) 25 registry was an observational study of patients with STEMI presenting to hospitals participating in the ExTRACT-TIMI 25 randomized clinical trial. Consecutive patients with STEMI who were not enrolled in the trial were entered into the registry. Demographics, in-hospital therapies, and in-hospital events were collected. Baseline risk was assessed using the TIMI Risk Index for STEMI. To adjust for differences among the countries from which the patients presented, the gross national income per annum per capita (GNI) was used. A total of 3726 patients were registered from 109 sites in 25 countries. Patients in the registry had a higher baseline risk than those in the trial; they had more extensive prior cardiac histories and more comorbidities. Unadjusted in-hospital mortality was higher in the registry (8.3%) than in the trial (6.6%) (hazard ratio, 1.30; P < .001); however, after adjusting for TIMI Risk Index, mortality was similar (hazard ratio(adj), 1.00; P = .97). The GNI was not significantly predictive of in-hospital mortality in the multivariable model of the registry. Patients in the registry had higher mortality than those in the trial. This difference could be explained by the higher baseline risk of patients in the registry. After adjusting for baseline risk, the GNI of the country in which the patient presented did not contribute to predicting in-hospital mortality.

External validation of the TIMI risk score for secondary cardiovascular events among patients with recent myocardial infarction.

PubMed

Williams, Brent A; Chagin, Kevin M; Bash, Lori D; Boden, William E; Duval, Sue; Fowkes, F Gerry R; Mahaffey, Kenneth W; Patel, Mehul D; D'Agostino, Ralph B; Peterson, Eric D; Kattan, Michael W; Bhatt, Deepak L; Bonaca, Marc P

2018-05-01

Risk stratification of patients with recent myocardial infarction (MI) for subsequent cardiovascular (CV) events helps identify patients most likely to benefit from secondary prevention therapies. This study externally validated a new risk score (TRS2˚P) for secondary events derived from the TRA2°P-TIMI 50 trial among post-MI patients from two large health care systems. This retrospective cohort study included 9618 patients treated for acute MI at either the Cleveland Clinic (CC) or Geisinger Health System (GHS) between 2008 and 2013. Patients with a clinic visit within 2-52 weeks of MI were included and followed for CV death, repeat MI, and ischemic stroke through electronic medical records (EMR). The TRS2˚P is based on nine factors determined through EMR documentation. Discrimination and calibration of the TRS2˚P were quantified in both patient populations. MI patients at CC and GHS were older, had more comorbidities, received fewer medications, and had higher 3-year event rates compared to subjects in the TRA2°P trial: 31% (CC), 33% (GHS), and 10% (TRA2°P-TIMI 50). The proposed risk score had similar discrimination across the three cohorts with c-statistics of 0.66 (CC), 0.66 (GHS), and 0.67 (TRA2°P-TIMI 50). A strong graded relationship between the risk score and event rates was observed in all cohorts, though 3-year event rates were consistently higher within TRS2°P strata in the CC and GHS cohorts relative to TRA2˚P-TIMI 50. The TRS2˚P demonstrated consistent risk discrimination across trial and non-trial patients with recent MI, but event rates were consistently higher in the non-trial cohorts. Copyright © 2018. Published by Elsevier B.V.

Predictors of bleeding in patients with acute coronary syndromes treated with prasugrel.

PubMed

Widimsky, Petr; Motovska, Zuzana; Bolognese, Leonardo; Dudek, Dariusz; Hamm, Christian; Tanguay, Jean-Francois; Ten Berg, Jurrien; Brown, Eileen; LeNarz, LeRoy; Miller, Debra L; Montalescot, Gilles

2015-08-01

When considering antiplatelet therapy for acute coronary syndrome (ACS), it is essential to balance benefits (less thrombotic/ischaemic events) versus bleeding risks related to intense platelet inhibition via antagonism of P2Y12 receptors. This analysis aimed to identify predictors of bleeding events among A Comparison of Prasugrel at the Time of PCI or as Pretreatment at the Time of Diagnosis in Patients with NSTEACS (ACCOAST) study population. The ACCOAST study randomised 4033 patients with non-ST-segment elevation myocardial infarction (NSTEMI) to (A) a 30 mg prasugrel loading dose (LD) followed by coronary angiography with an additional 30 mg prasugrel at the time of percutaneous coronary intervention (PCI) or (B) a placebo LD followed by a 60 mg prasugrel at the time of PCI. Patients received standard of care, including use of aspirin. Independent predictors of Thrombolysis in Myocardial Infarction (TIMI) major bleeding not related to coronary artery bypass grafting (CABG) within 7 days were assessed using stepwise Cox proportional model for time to first occurrence of the event. Non-CABG-related TIMI major or minor bleeding was similarly analysed. Non-CABG-related TIMI major bleeding occurred in 36 (0.9%) patients, and TIMI major or minor bleeding occurred in 81 (2.0%) patients. Independent predictors for TIMI major bleeding alone were pretreatment with prasugrel LD (HR 3.02; 95% CI 1.42 to 6.43), femoral access (HR 2.45; 95% CI 1.11 to 5.38), female sex (HR 2.57; 95% CI 1.32 to 5.00), placement of >1 stent (HR 2.50; 95% CI 1.26 to 4.95) and age (HR 1.05; 95% CI 1.02 to 1.09). Pretreatment with prasugrel LD (HR 3.05; 95% CI 1.84 to 5.07), femoral access (HR 3.06; 95% CI 1.74 to 5.38), female sex (HR 2.62; 95% CI 1.67 to 4.12), performed PCI (HR 2.21; 95% CI 1.23 to 3.99), therapy with glycoprotein IIb/IIIa inhibitors (HR 1.88; 95% CI 1.06 to 3.33) and age (increased bleed per year of age HR 1.04; 95% CI 1.02 to 1.06) were independent predictors of TIMI major or minor bleeding through 7 days. Pretreatment, age, gender and procedural variables predicted bleeding risk in patients with NSTEMI. NCT01015287. 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.

Pregnant women in Timis County, Romania are exposed primarily to low-level (<10 μg/L) arsenic through residential drinking water consumption

PubMed Central

Neamtiu, Iulia; Bloom, Michael S.; Gati, Gabriel; Goessler, Walter; Surdu, Simona; Pop, Cristian; Braeuer, Simone; Fitzgerald, Edward F.; Baciu, Calin; Lupsa, Ioana Rodica; Anastasiu, Doru; Gurzau, Eugen

2015-01-01

Excessive arsenic content in drinking water poses health risks to millions of people worldwide. Inorganic arsenic (iAs) in groundwater exceeding the 10 μg/l maximum contaminant level (MCL) set by the World Health Organization (WHO) is characteristic for intermediate-depth aquifers over large areas of the Pannonian Basin in Central Europe. In western Romania, near the border with Hungary, Arad, Bihor, and Timis counties use drinking water coming partially or entirely from iAs contaminated aquifers. In nearby Arad and Bihor counties, more than 45,000 people are exposed to iAs over 10 μg/l via public drinking water sources. However, comparable data are unavailable for Timis County. To begin to address this data gap, we determined iAs in 124 public and private Timis County drinking water sources, including wells and taps, used by pregnant women participating in a case-control study of spontaneous loss. Levels in water sources were low overall (median = 3.0; range = < 0.5–175 μg/l), although higher in wells (median = 3.1, range = < 0.5–175) than in community taps (median = 2.7, range = < 0.5–36.4). In a subsample of 20 control women we measured urine biomarkers of iAs exposure, including iAs (arsenite and arsenate), dimethylarsinic acid (DMA), and methylarsonic acid (MMA). Median values were higher among 10 women using iAs contaminated drinking water sources compared to 10 women using uncontaminated sources for urine total iAs (6.6 vs. 5.0 μg/l, P = 0.24) and DMA (5.5 vs. 4.2 μg/l, P = 0.31). The results suggested that the origin of urine total iAs (r = 0.35, P = 0.13) and DMA (r = 0.31, P = 0.18) must have been not only iAs in drinking-water but also some other source. Exposure of pregnant women to arsenic via drinking water in Timis County appears to be lower than for surrounding counties; however, it deserves a more definitive investigation as to its origin and the regional distribution of its risk potential. PMID:25697081

Acute coronary syndrome: Relationship between genetic variants and TIMI risk.

PubMed

de Carvalho, Viviane do Carmo Vasconcelos; Silva, Lílian Caroliny Amorim; Araújo, Romário Martins; da Silva Soares, Fábia Carla; Bezerra, Maria José Ribeiro; de Oliveira, Sávio Augusto Vieira; de Melo Silva, Alex José; Montenegro, Sérgio Tavares; Werkhauser, Roberto Pereira; da Silva, Carlos Gustavo Régis; Gomes, Adriana Vieira; de Morais, Clarice Neuenschwander Lins; Montenegro, Silvia Maria Lucena

2018-04-11

Acute Coronary Syndrome (ACS) is a multifactorial disease, including the genetic factor, caused by coronary artery obstruction by atheroma. Some genetic variants have been described as risk factors for this disease. Its early diagnosis and stratification of risk of death by Thrombolysis in Myocardial Infarction (TIMI) are important. Therefore, we evaluated variants in the IL6R (c950-1722C>T), TNFa (c.-488G>A), LEPR (c.2673+1118C>T) and IL1b (c.-598T>C) genes in relation to TIMI risk, cytokine serum levels, and risk factors for ACS. We selected 200 patients with ACS, 50 without ACS from the Real Hospital Português, Recife - PE, and 295 blood donors at the Fundação de Hematologia e Hemoterapia de Pernambuco (Hemope). Variants were determined by DNA sequencing or enzymatic cleavage. Cytokine levels were measured by ELISA. The most frequent risk factors found in the patients were dyslipidemia and hypertension, this latter associated with high TIMI risk (p = 0.003). Genotype frequencies of IL6R and TNFa differed between patients with ACS and the blood donors (p = 0.0002 and p = 0.01, respectively), and TNF-α levels differed between genotypes. The TT genotype of the IL6R gene is as a possible protective factor for ACS because it was significantly more present in blood donors (32.2%) than in patients with ACS (18.0%), and was more frequent in low TIMI risk (22.9%) than in the intermediate (20.2%) or high (4.9%). In patients with ACS, the TT genotype in IL6R was related to a lower concentration of c-reactive protein (p = 0.03) and troponin (p = 0.02), showing a less inflammatory reaction and tissue damage. The differences in the frequencies of variants in genes of medical interest among the groups show the importance of studies in specific populations groups to establish the relationship between genes and diseases. Copyright © 2018. Published by Elsevier Ltd.

Prasugrel compared with clopidogrel in patients undergoing percutaneous coronary intervention for ST-elevation myocardial infarction (TRITON-TIMI 38): double-blind, randomised controlled trial.

PubMed

Montalescot, Gilles; Wiviott, Stephen D; Braunwald, Eugene; Murphy, Sabina A; Gibson, C Michael; McCabe, Carolyn H; Antman, Elliott M

2009-02-28

Mechanical reperfusion with stenting for ST-elevation myocardial infarction (STEMI) is supported by dual antiplatelet treatment with aspirin and clopidogrel. Prasugrel, a potent and rapid-acting thienopyridine, is a potential alternative to clopidogrel. We aimed to assess prasugrel versus clopidogrel in patients undergoing percutaneous coronary intervention (PCI) for STEMI. We undertook a double-blind, randomised controlled trial in 707 sites in 30 countries. 3534 participants presenting with STEMI were randomly assigned by interactive voice response system either prasugrel (60 mg loading, 10 mg maintenance [n=1769]) or clopidogrel (300 mg loading, 75 mg maintenance [n=1765]) and were unaware of the allocation. The primary endpoint was cardiovascular death, non-fatal myocardial infarction, or non-fatal stroke. Efficacy analyses were by intention to treat. Follow-up was to 15 months, with secondary analyses at 30 days. This trial is registered with ClinicalTrials.gov, number NCT00097591. At 30 days, 115 (6.5%) individuals assigned prasugrel had met the primary endpoint compared with 166 (9.5%) allocated clopidogrel (hazard ratio 0.68 [95% CI 0.54-0.87]; p=0.0017). This effect continued to 15 months (174 [10.0%] vs 216 [12.4%]; 0.79 [0.65-0.97]; p=0.0221). The key secondary endpoint of cardiovascular death, myocardial infarction, or urgent target vessel revascularisation was also significantly reduced with prasugrel at 30 days (0.75 [0.59-0.96]; p=0.0205) and 15 months (0.79 [0.65-0.97]; p=0.0250), as was stent thrombosis. Treatments did not differ with respect to thrombolysis in myocardial infarction (TIMI) major bleeding unrelated to coronary-artery bypass graft (CABG) surgery at 30 days (p=0.3359) and 15 months (p=0.6451). TIMI life-threatening bleeding and TIMI major or minor bleeding were also similar with the two treatments, and only TIMI major bleeding after CABG surgery was significantly increased with prasugrel (p=0.0033). In patients with STEMI undergoing PCI, prasugrel is more effective than clopidogrel for prevention of ischaemic events, without an apparent excess in bleeding.

Additive prognostic value of the SYNTAX score over GRACE, TIMI, ZWOLLE, CADILLAC and PAMI risk scores in patients with acute ST-segment elevation myocardial infarction treated by primary percutaneous coronary intervention.

PubMed

Brkovic, Voin; Dobric, Milan; Beleslin, Branko; Giga, Vojislav; Vukcevic, Vladan; Stojkovic, Sinisa; Stankovic, Goran; Nedeljkovic, Milan A; Orlic, Dejan; Tomasevic, Miloje; Stepanovic, Jelena; Ostojic, Miodrag

2013-08-01

This study evaluated additive prognostic value of the SYNTAX score over GRACE, TIMI, ZWOLLE, CADILLAC and PAMI risk scores in patients with ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (pPCI). All six scores were calculated in 209 consecutive STEMI patients undergoing pPCI. Primary end-point was the major adverse cardiovascular event (MACE--composite of cardiovascular mortality, non-fatal myocardial infarction and stroke); secondary end point was cardiovascular mortality. Patients were stratified according to the SYNTAX score tertiles (≤12; between 12 and 19.5; >19.5). The median follow-up was 20 months. Rates of MACE and cardiovascular mortality were highest in the upper tertile of the SYNTAX score (p < 0.001 and p = 0.003, respectively). SYNTAX score was independent multivariable predictor of MACE and cardiovascular mortality when added to GRACE, TIMI, ZWOLLE, and PAMI risk scores. However, the SYNTAX score did not improve the Cox regression models of MACE and cardiovascular mortality when added to the CADILLAC score. The SYNTAX score has predictive value for MACE and cardiovascular mortality in patients with STEMI undergoing primary PCI. Furthermore, SYNTAX score improves prognostic performance of well-established GRACE, TIMI, ZWOLLE and PAMI clinical scores, but not the CADILLAC risk score. Therefore, long-term survival in patients after STEMI depends less on detailed angiographical characterization of coronary lesions, but more on clinical characteristics, myocardial function and basic angiographic findings as provided by the CADILLAC score.

Platelet counts on admission affect coronary flow, myocardial perfusion and left ventricular systolic function after primary percutaneous coronary intervention.

PubMed

Sharif, Dawod; Abu-Salem, Mira; Sharif-Rasslan, Amal; Rosenschein, Uri

2017-10-01

Patients with acute ST-elevation myocardial infarction (STEMI) and increased platelet count treated by fibrinolysis have worse outcomes. The aim of this study was to test the hypothesis that platelet blood count at admission in patients with acute STEMI treated by primary percutaneous coronary intervention affects coronary flow, myocardial perfusion and recovery of left ventricular systolic function. A total of 174 patients presenting with acute anterior STEMI and treated with primary percutaneous coronary intervention were included and divided into subgroups of admission platelet blood count of <200 K, 200-300 K, 300-400 K and >400 K. Evaluation of coronary artery flow and myocardial blush grade was performed according to the TIMI criteria. Electrocardiographic ST elevation resolution post-primary percutaneous coronary intervention was evaluated. Doppler echocardiographic evaluation of left anterior descending coronary artery velocities early and late after primary percutaneous coronary intervention and assessment of left ventricular ejection fraction and wall motion score index (WMSI) of left ventricular and left anterior descending coronary artery territory were performed. Post-primary percutaneous coronary intervention TIMI, myocardial blush grade and ST elevation resolution were similar in all groups. Patients with platelet counts <200 K had higher peak diastolic left anterior descending coronary artery velocity both early and late after primary percutaneous coronary intervention, and higher prevalence of left anterior descending coronary artery velocity deceleration time exceeding 600 ms, (45.5% vs. 40%, P<0.05). Patients with platelet counts >400 K presented with worse left ventricular ejection fraction, left ventricular WMSI and left anterior descending coronary artery WMSI, and before discharge this subgroup had worse left ventricular WMSI and left anterior descending coronary artery WMSI, P<0.01. Patients with anterior STEMI treated by primary percutaneous coronary intervention with lower admission platelet count had higher left anterior descending coronary artery diastolic velocities, better myocardial perfusion with more patients having left anterior descending coronary artery-descending coronary artery velocity deceleration time >600 ms. Patients with higher platelet counts had lower left ventricular systolic function both at admission and before discharge.

Side-Branch and Coaxial Intravascular Ultrasound Guided Wire Re-Entry after Failed Retrograde Approach of Chronic Total Occlusion Intervention.

PubMed

Chou, Ruey-Hsing; Lai, Chih-Hung; Lu, Tse-Min

2016-05-01

Intravascular ultrasound (IVUS) can provide valuable information during the intervention of difficult chronic total occlusion (CTO) lesion. Stumpless CTO lesions with an adjacent side branch are associated with a significantly lower success rate because the proper entry point is not always clearly identified and the guidewires easily slip into the side branch. Herein we presented a case of a stumpless middle left circumflex (LCX) artery CTO lesion with auto-collateral from obtuse marginal branch. Initially, we positioned the IVUS into the side-branch to find the entry point of LCX-CTO lesion. However, the punctured wire went into the false lumen. A retrograde approach was tried but later failed. Therefore, we used IVUS to find the entry point where the true lumen transited to the false lumen, and used a stiff guidewire to puncture the entry point. After we confirmed with IVUS that the whole guidewire was in the true lumen, we deployed 3 drug-eluting stents. The final angiogram showed TIMI 3 flow with preservation of all side branches. The patient was angina-free during the 6-month follow-up. By presenting this case, we have demonstrated the application of both side-branch and coaxial IVUS-guided recanalization technique in the stumpless CTO lesion.

Short- and Long-Term Prognostic Utility of the HEART Score in Patients Evaluated in the Emergency Department for Possible Acute Coronary Syndrome.

PubMed

Jain, Tarun; Nowak, Richard; Hudson, Michael; Frisoli, Tiberio; Jacobsen, Gordon; McCord, James

2016-06-01

The HEART score is a risk-stratification tool that was developed and validated for patients evaluated for possible acute coronary syndrome (ACS) in the emergency department (ED). We sought to determine the short-term and long-term prognostic utility of the HEART score. A retrospective single-center analysis of 947 patients evaluated for possible ACS in the ED in 1999 was conducted. Patients were followed for major adverse cardiac events (MACEs) at 30 days: death, acute myocardial infarction, or revascularization procedure. All-cause mortality was assessed at 5 years. The HEART score was compared with the Thrombolysis in Myocardial Infarction (TIMI) score. At 30 days, 14% (135/947) of patients had an MACE: 48 deaths (5%), 84 acute myocardial infarctions (9%), and 48 (5%) revascularization procedures. The MACE rate in patients with HEART score ≤3 was 0.6% (1/175) involving a revascularization procedure, 9.5% (53/557) in patients with HEART score between 4 and 6, and 38% (81/215) with HEART score ≥7. The C-statistic for the HEART score was 0.82 and 0.68 for the TIMI score for predicting 30-day MACE (P < 0.05). Patients with HEART score ≤3 had lower 5-year mortality rate compared with those with TIMI score of 0 (10.6% vs. 20.5%, P = 0.02). The HEART score is a valuable risk-stratification tool in predicting not only short-term MACE but also long-term mortality in patients evaluated for possible ACS in the ED. The HEART score had a superior prognostic value compared with the TIMI score.

Pregnant women in Timis County, Romania are exposed primarily to low-level (<10μg/l) arsenic through residential drinking water consumption.

PubMed

Neamtiu, Iulia; Bloom, Michael S; Gati, Gabriel; Goessler, Walter; Surdu, Simona; Pop, Cristian; Braeuer, Simone; Fitzgerald, Edward F; Baciu, Calin; Lupsa, Ioana Rodica; Anastasiu, Doru; Gurzau, Eugen

2015-06-01

Excessive arsenic content in drinking water poses health risks to millions of people worldwide. Inorganic arsenic (iAs) in groundwater exceeding the 10μg/l maximum contaminant level (MCL) set by the World Health Organization (WHO) is characteristic for intermediate-depth aquifers over large areas of the Pannonian Basin in Central Europe. In western Romania, near the border with Hungary, Arad, Bihor, and Timis counties use drinking water coming partially or entirely from iAs contaminated aquifers. In nearby Arad and Bihor counties, more than 45,000 people are exposed to iAs over 10μg/l via public drinking water sources. However, comparable data are unavailable for Timis County. To begin to address this data gap, we determined iAs in 124 public and private Timis County drinking water sources, including wells and taps, used by pregnant women participating in a case-control study of spontaneous loss. Levels in water sources were low overall (median=3.0; range=<0.5-175μg/l), although higher in wells (median=3.1, range=<0.5-1.75) than in community taps (median=2.7, range=<0.5-36.4). In a subsample of 20 control women we measured urine biomarkers of iAs exposure, including iAs (arsenite and arsenate), dimethylarsinic acid (DMA), and methylarsonic acid (MMA). Median values were higher among 10 women using iAs contaminated drinking water sources compared to 10 women using uncontaminated sources for urine total iAs (6.6 vs. 5.0μg/l, P=0.24) and DMA (5.5 vs. 4.2μg/l, P=0.31). The results suggested that the origin of urine total iAs (r=0.35, P=0.13) and DMA (r=0.31, P=0.18) must have been not only iAs in drinking-water but also some other source. Exposure of pregnant women to arsenic via drinking water in Timis County appears to be lower than for surrounding counties; however, it deserves a more definitive investigation as to its origin and the regional distribution of its risk potential. Copyright © 2015 Elsevier GmbH. All rights reserved.

The effect of blood cell count on coronary flow in patients with coronary slow flow phenomenon.

PubMed

Soylu, Korhan; Gulel, Okan; Yucel, Huriye; Yuksel, Serkan; Aksan, Gokhan; Soylu, Ayşegül İdil; Demircan, Sabri; Yılmaz, Ozcan; Sahin, Mahmut

2014-09-01

The coronary slow flow phenomenon (CSFP) is a coronary artery disease with a benign course, but its pathological mechanisms are not yet fully understood.The purpose of this controlled study was to investigate the cellular content of blood in patients diagnosed with CSFP and the relationship of this with coronary flow rates. Selective coronary angiographies of 3368 patients were analyzed to assess Thrombolysis in Myocardial Infarction (TIMI) frame count (TFC) values. Seventy eight of them had CSFP, and their demographic and laboratory findings were compared with 61 patients with normal coronary flow. Patients' demographic characteristics were similar in both groups. Mean corrected TFC (cTFC) values were significantly elevated in CSFP patients (p<0.001). Furthermore, hematocrit and hemoglobin values, and eosinophil and basophil counts of the CSFP patients were significantly elevated compared to the values obtained in the control group (p=0.005, p=0.047, p=0.001 and p=0.002, respectively). The increase observed in hematocrit and eosinophil levels showed significant correlations with increased TFC values (r=0.288 and r=0.217, respectively). Significant changes have been observed in the cellular composition of blood in patients diagnosed with CSFP as compared to the patients with normal coronary blood flow. The increases in hematocrit levels and in the eosinophil and basophil counts may have direct or indirect effects on the rate of coronary blood flow.

Clinical characteristics and thrombolysis in myocardial infarction frame counts in women with transient left ventricular apical ballooning syndrome.

PubMed

Bybee, Kevin A; Prasad, Abhiram; Barsness, Greg W; Lerman, Amir; Jaffe, Allan S; Murphy, Joseph G; Wright, R Scott; Rihal, Charanjit S

2004-08-01

The characteristics of 16 women with transient left ventricular (LV) apical ballooning syndrome in a United States population are presented. Additionally, Thrombolysis In Myocardial Infarction (TIMI) frame counts were evaluated during the acute period. Patients generally presented with anterior ST-elevation acute coronary syndrome in the absence of obstructive coronary disease. All patients had LV apical wall motion abnormalities. An acute emotional or physiologic stressor preceded most cases. TIMI frame counts were abnormal in all patients and often abnormal in all 3 major coronary vessels, suggesting that the diffuse impairment of coronary microcirculatory function may play a role in the pathogenesis of the syndrome.

Angiographic core laboratory reproducibility analyses: implications for planning clinical trials using coronary angiography and left ventriculography end-points.

PubMed

Steigen, Terje K; Claudio, Cheryl; Abbott, David; Schulzer, Michael; Burton, Jeff; Tymchak, Wayne; Buller, Christopher E; John Mancini, G B

2008-06-01

To assess reproducibility of core laboratory performance and impact on sample size calculations. Little information exists about overall reproducibility of core laboratories in contradistinction to performance of individual technicians. Also, qualitative parameters are being adjudicated increasingly as either primary or secondary end-points. The comparative impact of using diverse indexes on sample sizes has not been previously reported. We compared initial and repeat assessments of five quantitative parameters [e.g., minimum lumen diameter (MLD), ejection fraction (EF), etc.] and six qualitative parameters [e.g., TIMI myocardial perfusion grade (TMPG) or thrombus grade (TTG), etc.], as performed by differing technicians and separated by a year or more. Sample sizes were calculated from these results. TMPG and TTG were also adjudicated by a second core laboratory. MLD and EF were the most reproducible, yielding the smallest sample size calculations, whereas percent diameter stenosis and centerline wall motion require substantially larger trials. Of the qualitative parameters, all except TIMI flow grade gave reproducibility characteristics yielding sample sizes of many 100's of patients. Reproducibility of TMPG and TTG was only moderately good both within and between core laboratories, underscoring an intrinsic difficulty in assessing these. Core laboratories can be shown to provide reproducibility performance that is comparable to performance commonly ascribed to individual technicians. The differences in reproducibility yield huge differences in sample size when comparing quantitative and qualitative parameters. TMPG and TTG are intrinsically difficult to assess and conclusions based on these parameters should arise only from very large trials.

Plasma Chemerin Levels Are Increased in ST Elevation Myocardial Infarction Patients with High Thrombus Burden.

PubMed

Ateş, Ahmet Hakan; Arslan, Uğur; Aksakal, Aytekin; Yanık, Ahmet; Özdemir, Metin; Kul, Selim

2018-01-01

To investigate plasma chemerin levels in ST elevation myocardial infarction (STEMI) patients and find out possible relationships between plasma chemerin levels and angiographic characteristics. Ninety-seven consecutive patients who presented with STEMI and underwent primary percutaneous coronary intervention (PCI) with coronary stents were enrolled, and 30 age- and sex-matched patients with stable angina pectoris who underwent coronary angiography formed the control group. Angiographic characteristics of the patients including thrombolysis in myocardial infarction (TIMI) thrombus and Gensini scores were noted. Blood samples were taken to detect several biochemical markers including plasma chemerin levels at the admission to hospital. Serum chemerin and C-reactive protein (CRP) levels were significantly increased in patients with STEMI. Among STEMI patients, serum chemerin levels were significantly higher in patients with high thrombus burden (581.5 ± 173.7 versus 451.3 ± 101.2 mg/dL, p < 0.001). CRP levels and peak creatine kinase-MB (CK-MB) levels were higher, and left ventricular ejection fraction and post-PCI TIMI flow were lower in patients with high thrombus burden. After multivariate analysis, serum chemerin levels were also higher in patients with high thrombus grade (odds ratio: 1.009 (1.005-1.014), p < 0.001). Besides, serum chemerin levels were also found to be significantly correlated with CRP ( r =0.47, p < 0.001) and peak CK-MB ( r =0.376, p < 0.001) levels. Results from our study have demonstrated for the first time that chemerin levels were higher in STEMI patients with greater thrombus burden and higher level of inflammation.

Evaluation of a novel antiplatelet agent for secondary prevention in patients with a history of atherosclerotic disease: design and rationale for the Thrombin-Receptor Antagonist in Secondary Prevention of Atherothrombotic Ischemic Events (TRA 2 degrees P)-TIMI 50 trial.

PubMed

Morrow, David A; Scirica, Benjamin M; Fox, Keith A A; Berman, Gail; Strony, John; Veltri, Enrico; Bonaca, Marc P; Fish, Polly; McCabe, Carolyn H; Braunwald, Eugene

2009-09-01

Thrombin potently activates platelets via interaction with the protease-activated receptor 1. SCH 530348 is a novel antiplatelet agent that selectively inhibits the cellular actions of thrombin via antagonism of the protease-activated receptor 1. Because SCH 530348 does not interfere with other pathways for hemostasis, it is possible that SCH 530348 reduces thrombosis with less increase in bleeding than do other potent antiplatelet agents. TRA 2 degrees P-TIMI 50 is a phase III, randomized, double-blind, placebo-controlled, multinational clinical trial designed to evaluate the efficacy and safety of SCH 530348 during long-term treatment of patients with established atherosclerotic disease receiving standard therapy (up to 27,000). Eligible patients with a history of myocardial infarction, ischemic stroke, or peripheral arterial disease are randomized 1:1 to SCH 530348 2.5 mg daily or matched placebo until the end of study. Randomization is stratified by the qualifying disease and planned use of a thienopyridine. The primary end point is the composite of cardiovascular death, myocardial infarction, stroke, or urgent coronary revascularization. The major secondary end point is the composite of cardiovascular death, myocardial infarction, or stroke. The evaluation of long-term safety includes bleeding defined by the GUSTO and TIMI criteria. Recruitment began in September 2007. The trial will continue until 2,279 primary end points and 1,400 secondary end points are recorded with expected completion in 36 to 44 months from first enrollment. TRA 2 degrees P-TIMI 50 is evaluating whether a new approach to platelet inhibition via interruption of thrombin-mediated platelet activation reduces major cardiovascular events with a favorable safety profile in patients with established atherosclerosis.

Comparison of RISK-PCI, GRACE, TIMI risk scores for prediction of major adverse cardiac events in patients with acute coronary syndrome.

PubMed

Jakimov, Tamara; Mrdović, Igor; Filipović, Branka; Zdravković, Marija; Djoković, Aleksandra; Hinić, Saša; Milić, Nataša; Filipović, Branislav

2017-12-31

To compare the prognostic performance of three major risk scoring systems including global registry for acute coronary events (GRACE), thrombolysis in myocardial infarction (TIMI), and prediction of 30-day major adverse cardiovascular events after primary percutaneous coronary intervention (RISK-PCI). This single-center retrospective study involved 200 patients with acute coronary syndrome (ACS) who underwent invasive diagnostic approach, ie, coronary angiography and myocardial revascularization if appropriate, in the period from January 2014 to July 2014. The GRACE, TIMI, and RISK-PCI risk scores were compared for their predictive ability. The primary endpoint was a composite 30-day major adverse cardiovascular event (MACE), which included death, urgent target-vessel revascularization (TVR), stroke, and non-fatal recurrent myocardial infarction (REMI). The c-statistics of the tested scores for 30-day MACE or area under the receiver operating characteristic curve (AUC) with confidence intervals (CI) were as follows: RISK-PCI (AUC=0.94; 95% CI 1.790-4.353), the GRACE score on admission (AUC=0.73; 95% CI 1.013-1.045), the GRACE score on discharge (AUC=0.65; 95% CI 0.999-1.033). The RISK-PCI score was the only score that could predict TVR (AUC=0.91; 95% CI 1.392-2.882). The RISK-PCI scoring system showed an excellent discriminative potential for 30-day death (AUC=0.96; 95% CI 1.339-3.548) in comparison with the GRACE scores on admission (AUC=0.88; 95% CI 1.018-1.072) and on discharge (AUC=0.78; 95% CI 1.000-1.058). In comparison with the GRACE and TIMI scores, RISK-PCI score showed a non-inferior ability to predict 30-day MACE and death in ACS patients. Moreover, RISK-PCI was the only scoring system that could predict recurrent ischemia requiring TVR.

Comparison of RISK-PCI, GRACE, TIMI risk scores for prediction of major adverse cardiac events in patients with acute coronary syndrome

PubMed Central

Jakimov, Tamara; Mrdović, Igor; Filipović, Branka; Zdravković, Marija; Djoković, Aleksandra; Hinić, Saša; Milić, Nataša; Filipović, Branislav

2017-01-01

Aim To compare the prognostic performance of three major risk scoring systems including global registry for acute coronary events (GRACE), thrombolysis in myocardial infarction (TIMI), and prediction of 30-day major adverse cardiovascular events after primary percutaneous coronary intervention (RISK-PCI). Methods This single-center retrospective study involved 200 patients with acute coronary syndrome (ACS) who underwent invasive diagnostic approach, ie, coronary angiography and myocardial revascularization if appropriate, in the period from January 2014 to July 2014. The GRACE, TIMI, and RISK-PCI risk scores were compared for their predictive ability. The primary endpoint was a composite 30-day major adverse cardiovascular event (MACE), which included death, urgent target-vessel revascularization (TVR), stroke, and non-fatal recurrent myocardial infarction (REMI). Results The c-statistics of the tested scores for 30-day MACE or area under the receiver operating characteristic curve (AUC) with confidence intervals (CI) were as follows: RISK-PCI (AUC = 0.94; 95% CI 1.790-4.353), the GRACE score on admission (AUC = 0.73; 95% CI 1.013-1.045), the GRACE score on discharge (AUC = 0.65; 95% CI 0.999-1.033). The RISK-PCI score was the only score that could predict TVR (AUC = 0.91; 95% CI 1.392-2.882). The RISK-PCI scoring system showed an excellent discriminative potential for 30-day death (AUC = 0.96; 95% CI 1.339-3.548) in comparison with the GRACE scores on admission (AUC = 0.88; 95% CI 1.018-1.072) and on discharge (AUC = 0.78; 95% CI 1.000-1.058). Conclusions In comparison with the GRACE and TIMI scores, RISK-PCI score showed a non-inferior ability to predict 30-day MACE and death in ACS patients. Moreover, RISK-PCI was the only scoring system that could predict recurrent ischemia requiring TVR. PMID:29308832

Reduction in recurrent cardiovascular events with prasugrel compared with clopidogrel in patients with acute coronary syndromes from the TRITON-TIMI 38 trial

PubMed Central

Murphy, Sabina A.; Antman, Elliott M.; Wiviott, Stephen D.; Weerakkody, Govinda; Morocutti, Giorgio; Huber, Kurt; Lopez-Sendon, Jose; McCabe, Carolyn H.; Braunwald, Eugene

2008-01-01

Aims In the TRITON-TIMI 38 trial, greater platelet inhibition with prasugrel reduced the first occurrence of the primary endpoint (cardiovascular death, MI, or stroke) compared with clopidogrel in patients with an acute coronary syndrome (ACS) undergoing planned percutaneous coronary intervention. We hypothesized that prasugrel would reduce not only first events but also recurrent primary endpoint events and therefore total events compared with clopidogrel. Methods and results Poisson regression analysis was performed to compare the number of occurrences of the primary endpoint between prasugrel and clopidogrel in TRITON-TIMI 38. Landmark analytic methods were used to evaluate the risk of a recurrent primary endpoint event following an initial non-fatal endpoint event. Among patients with an initial non-fatal event, second events were significantly reduced with prasugrel compared to clopidogrel (10.8 vs. 15.4%, HR 0.65, 95% CI 0.46–0.92; P = 0.016), as was CV death following the non-fatal event (3.7 vs. 7.1%, HR 0.46, 95% CI 0.25–0.82; P = 0.008). Overall there was a reduction of 195 total primary efficacy events with prasugrel vs. clopidogrel (rate ratio 0.79, 95% CI 0.71–0.87; P < 0.001). Recurrent bleeding events occurred infrequently (TIMI major non-CABG bleeds: four with prasugrel and two with clopidogrel). Study drug discontinuation was frequent following the initial major bleeding event (42% of patients discontinued study drug). Conclusion While standard statistical analytic techniques for clinical trials censor patients who experience a component of the primary composite endpoint, total cardiovascular events remain important to both patients and clinicians. Prasugrel, a more potent anti-platelet agent, reduced both first and subsequent cardiovascular events compared with clopidogrel in patients with ACS. PMID:18682445

Impact of initial platelet count on baseline angiographic finding and end-points in ST-elevation myocardial infarction referred for primary percutaneous coronary intervention.

PubMed

Kaplan, Sahin; Kaplan, Safiye Tuba; Kiris, Abdulkadir; Gedikli, Omer

2014-01-01

The baseline platelet count (BPC) in patients with acute ST elevation myocardial infarction (STEMI) may reflect the baseline anjiografic finding and may also predic long-term outcomes after primary percutaneous coronary intervention (PPCI). Available data for the value of BPC in patients with STEMI treated with PPCI are still questionable. Therefore, we sought to determine the prognostic value of BPC for baseline angiographic finding and the impact of BPC on clinical outcomes of patients treating with PPCI. Blood sample for BPC was obtained on admission in 140 consecutive patients undergoing PPCI. Patients were divided 2 groups that group-1 (104 patients): TIMI flow-grade 0 and group-2 (36 patients): TIMI flow-grade 1-3. Follow-up was performed at 1-9 months. Baseline demographics were comparable, but, BPC was significantly higher in group-1 comparing 2 (293.7±59.8x10(9)/L vs. 237.7±50.9x10(9)/L, p<0.0001), pre-procedural lesion length longer in group-1 comparing 2 (13.6±3.6 mm vs. 11.4±3.9 mm, p:0.003). Distal embolization (19.0% vs. 0.0%, p:0.001), slow-flow (15.2% vs. 2.9%, p:0.033) were more common in group-1 and mean maximum troponin-I level (9.1±4.2 μg/L vs. 5.1±3.9 μg/L, p<0.0001) and mean maximum creatinin kinase (2077.6±1378.4 U/L vs. 1163.4±869.7 U/L, p:<0.0001) were higher in group-1. In-hospital and 30-days major cardiac adverse events (MACEs) (16.5% vs. 5.7%), p:0.14) were similarly in both groups, but, at 6-months target vessel revascularization (13.9% vs. 0.0%, p:0.017) and MACEs significantly higher in the group-1 (24.1% vs. 2.9%, p:0.013). A higher BPC without any antithrombotic agent is a strongly predictor of total occlusion of IRA in STEMI treated with PPCI. And a higher BPC associated with poor clinical outcomes at 9-months. Apart from prognostic value, measuring of a BPC on admission may also provide further practical and therapeutic profits.

Impact of initial platelet count on baseline angiographic finding and end-points in ST-elevation myocardial infarction referred for primary percutaneous coronary intervention

PubMed Central

Kaplan, Sahin; Kaplan, Safiye Tuba; Kiris, Abdulkadir; Gedikli, Omer

2014-01-01

The baseline platelet count (BPC) in patients with acute ST elevation myocardial infarction (STEMI) may reflect the baseline anjiografic finding and may also predic long-term outcomes after primary percutaneous coronary intervention (PPCI). Available data for the value of BPC in patients with STEMI treated with PPCI are still questionable. Therefore, we sought to determine the prognostic value of BPC for baseline angiographic finding and the impact of BPC on clinical outcomes of patients treating with PPCI. Blood sample for BPC was obtained on admission in 140 consecutive patients undergoing PPCI. Patients were divided 2 groups that group-1 (104 patients): TIMI flow-grade 0 and group-2 (36 patients): TIMI flow-grade 1-3. Follow-up was performed at 1-9 months. Baseline demographics were comparable, but, BPC was significantly higher in group-1 comparing 2 (293.7±59.8x109/L vs. 237.7±50.9x109/L, p<0.0001), pre-procedural lesion length longer in group-1 comparing 2 (13.6±3.6 mm vs. 11.4±3.9 mm, p:0.003). Distal embolization (19.0% vs. 0.0%, p:0.001), slow-flow (15.2% vs. 2.9%, p:0.033) were more common in group-1 and mean maximum troponin-I level (9.1±4.2 μg/L vs. 5.1±3.9 μg/L, p<0.0001) and mean maximum creatinin kinase (2077.6±1378.4 U/L vs. 1163.4±869.7 U/L, p:<0.0001) were higher in group-1. In-hospital and 30-days major cardiac adverse events (MACEs) (16.5% vs. 5.7%), p:0.14) were similarly in both groups, but, at 6-months target vessel revascularization (13.9% vs. 0.0%, p:0.017) and MACEs significantly higher in the group-1 (24.1% vs. 2.9%, p:0.013). Conclusion: A higher BPC without any antithrombotic agent is a strongly predictor of total occlusion of IRA in STEMI treated with PPCI. And a higher BPC associated with poor clinical outcomes at 9-months. Apart from prognostic value, measuring of a BPC on admission may also provide further practical and therapeutic profits. PMID:24955183

Relationship between serum visfatin levels and coronary slow-flow phenomenon.

PubMed

Cakmak, Huseyin Altug; Aslan, Serkan; Yalcin, Ahmet Arif; Akturk, Ibrahim Faruk; Yalcin, Burce; Uzun, Fatih; Ozturk, Derya; Erturk, Mehmet; Gul, Mehmet

2015-09-01

Increased levels of visfatin, a novel adipocytokine, are reported in atherosclerosis, obesity, and type 2 diabetes. The aim of the present study was to investigate the relationship between coronary slow flow (CSF) and visfatin in patients undergoing elective coronary angiography for suspected coronary artery disease. A total of 140 recruited participants (90 patients with CSF and 50 controls) were divided into two groups according to their coronary flow rates. Coronary flow was quantified by thrombolysis in myocardial infarction (TIMI) frame count (TFC). Serum visfatin levels were higher in the CSF group than in the control group (3.29 ± 1.11 vs. 2.70 ± 1.08 ng/ml, p = 0.003). A significant correlation was found between TFC and visfatin (r = 0.535, p < 0.001). The area under the receiver operating characteristic curve was 0.720 (95 % confidence interval, 0.622-0.817, p < 0.001) for visfatin in the diagnosis of CSF. If a cut-off value of 2.59 ng/ml was used, higher levels of visfatin could predict the presence of CSF with 78.9 % sensitivity and 64.0 % specificity. Visfatin levels might be a useful biomarker for predicting CSF in patients undergoing diagnostic coronary angiography.

The effect of blood cell count on coronary flow in patients with coronary slow flow phenomenon

PubMed Central

Soylu, Korhan; Gulel, Okan; Yucel, Huriye; Yuksel, Serkan; Aksan, Gokhan; Soylu, Ayşegül İdil; Demircan, Sabri; Yılmaz, Özcan; Sahin, Mahmut

2014-01-01

Background and Objective: The coronary slow flow phenomenon (CSFP) is a coronary artery disease with a benign course, but its pathological mechanisms are not yet fully understood.The purpose of this controlled study was to investigate the cellular content of blood in patients diagnosed with CSFP and the relationship of this with coronary flow rates. Methods: Selective coronary angiographies of 3368 patients were analyzed to assess Thrombolysis in Myocardial Infarction (TIMI) frame count (TFC) values. Seventy eight of them had CSFP, and their demographic and laboratory findings were compared with 61 patients with normal coronary flow. Results: Patients’ demographic characteristics were similar in both groups. Mean corrected TFC (cTFC) values were significantly elevated in CSFP patients (p<0.001). Furthermore, hematocrit and hemoglobin values, and eosinophil and basophil counts of the CSFP patients were significantly elevated compared to the values obtained in the control group (p=0.005, p=0.047, p=0.001 and p=0.002, respectively). The increase observed in hematocrit and eosinophil levels showed significant correlations with increased TFC values (r=0.288 and r=0.217, respectively). Conclusion: Significant changes have been observed in the cellular composition of blood in patients diagnosed with CSFP as compared to the patients with normal coronary blood flow. The increases in hematocrit levels and in the eosinophil and basophil counts may have direct or indirect effects on the rate of coronary blood flow. PMID:25225502

Left ventricular ejection fraction to predict early mortality in patients with non-ST-segment elevation acute coronary syndromes.

PubMed

Bosch, Xavier; Théroux, Pierre

2005-08-01

Improvement in risk stratification of patients with non-ST-segment elevation acute coronary syndrome (ACS) is a gateway to a more judicious treatment. This study examines whether the routine determination of left ventricular ejection fraction (EF) adds significant prognostic information to currently recommended stratifiers. Several predictors of inhospital mortality were prospectively characterized in a registry study of 1104 consecutive patients, for whom an EF was determined, who were admitted for an ACS. Multiple regression models were constructed using currently recommended clinical, electrocardiographic, and blood marker stratifiers, and values of EF were incorporated into the models. Age, ST-segment shifts, elevation of cardiac markers, and the Thrombolysis in Myocardial Infarction (TIMI) risk score all predicted mortality (P < .0001). Adding EF into the model improved the prediction of mortality (C statistic 0.73 vs 0.67). The odds of death increased by a factor of 1.042 for each 1% decrement in EF. By receiver operating curves, an EF cutoff of 48% provided the best predictive value. Mortality rates were 3.3 times higher within each TIMI risk score stratum in patients with an EF of 48% or lower as compared with those with higher. The TIMI risk score predicts inhospital mortality in a broad population of patients with ACS. The further consideration of EF adds significant prognostic information.

Correlation of ABO blood groups with spontaneous recanalization in acute myocardial infarction.

PubMed

Lin, Xian-Liang; Zhou, Bing-Yang; Li, Sha; Li, Xiao-Lin; Luo, Zhu-Rong; Li, Jian-Jun

2017-08-01

Although previous studies have demonstrated the relationship between ABO blood groups and cardiovascular disease, the association of ABO blood type with spontaneous recanalization (SR) in patients with acute myocardial infarction (AMI) has not been previously investigated. We performed an initial exploratory study on the association of ABO blood groups with the presence of SR in 1209 patients with AMI. They were divided into two groups according to the thrombolysis in myocardial infarction (TIMI) grades: no-SR group (TIMI 0-1, n = 442) and SR group (TIMI 2-3, n = 767). To confirm our primary findings, data from a second AMI population (n = 200) was analyzed. In the initial data, SR group had a significantly higher percentage of blood type O and a lower percentage of blood type A compared to the no-SR group. Multivariate logistic regression analysis showed that blood type O was positively associated with SR (odds ratio: 1.40, 95% confidence interval: 1.05-1.87, p = .02), and this finding was confirmed in our second population. The present study demonstrates that blood type O was independently and positively associated with an open culprit artery in patients with AMI, suggesting that the ABO blood type is not only associated with the susceptibility to coronary artery disease but also to spontaneous reperfusion in AMI patients.

Search and rescue helicopter-assisted transfer of ST-elevation myocardial infarction patients from an island in the Baltic Sea: results from over 100 rescue missions.

PubMed

Schoos, Mikkel Malby; Kelbæk, Henning; Pedersen, Frants; Kjærgaard, Benedict; Trautner, Sven; Holmvang, Lene; Jørgensen, Erik; Helqvist, Steffen; Saunamäki, Kari; Engstrøm, Thomas; Clemmensen, Peter

2014-11-01

Since 2005, ST-elevation myocardial infarction (STEMI) patients from the island of Bornholm in the Baltic Sea have been transferred for primary percutaneous coronary intervention (pPCI) by an airborne service. We describe the result of pPCI as part of the Danish national reperfusion strategy offered to a remote island population. In this observational study, patients from Bornholm (n=101) were compared with patients from the mainland (Zealand) (n=2495), who were grouped according to time intervals (<120, 121-180, >180 min). The primary endpoint was all-cause 30-day mortality. Individual-level data from the Central Population Registry provided outcome that was linked to our inhospital PCI database. Treatment delay was longer in patients from Bornholm (349 min (IQR 267-446)) vs Zealand (211 (IQR 150-315)) (p<0.001). In patients from Zealand, 30-day mortality did not increase with time intervals (p=0.176), whereas, long-term mortality did (∼3 years) (p=0.007). Thirty-day mortality was similar for Bornholm and the overall Zealand group (5.9% vs 6.2% p=0.955). Early presenters (<180 min) from Zealand (37%) had similar 30-day (5.3% vs 5.9% p=0.789), but numerically reduced long-term mortality compared with Bornholm (12.8% vs 15.8% p=0.387). Age, female gender, diabetes, Killipclass >2 and preprocedural thrombolysis in myocardial infarction (TIMI) flow 0/1 independently predicted 30-day mortality, however, treatment delay did not. Postprocedural TIMI flow 3 predicted improved survival. In this small population of STEMI patients from a remote island, airborne transfer appears feasible and safe, and their 30-day mortality after pPCI comparable with that of the mainland population despite inherent reperfusion delay exceeding guidelines. 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.

Association of admission testosterone level with ST-segment resolution in male patients with ST-segment elevation myocardial infarction undergoing primary percutaneous coronary intervention.

PubMed

Separham, Ahmad; Ghaffari, Samad; Sohrabi, Bahram; Aslanabadi, Naser; Hadavi Bavil, Mozhgan; Lotfollahi, Hasanali

2017-01-01

Low level of testosterone may be associated with cardiovascular diseases in men, as some evidence suggests a protective role for testosterone in cardiovascular system. Little is known about the possible role of serum testosterone in response to reperfusion therapy in ST-elevation myocardial infarction (STEMI) and its relationship with ST-segment recovery. The present study was conducted to evaluate the association of serum testosterone levels with ST-segment resolution following primary percutaneous coronary intervention (PPCI) in male patients with acute STEMI. Forty-eight men (mean age 54.55 ± 12.20) with STEMI undergoing PPCI were enrolled prospectively. Single-lead ST segment resolution in the lead with maximum baseline ST-elevation was measured and patients were divided into two groups according to the degree of ST-segment resolution: complete (> or =50%) or incomplete (<50%). The basic and demographic data of all patients, their left ventricular ejection fraction (LVEF) and laboratory findings including serum levels of free testosterone and cardiac enzymes were recorded along with angiographic finding and baseline TIMI (Thrombolysis in Myocardial Infarction) flow and also in-hospital complications and then these variables were compared between two groups. A complete ST-resolution (≥50%) was observed in 72.9% of the patients. The serum levels of free testosterone ( P  = 0.04), peak cardiac troponin ( P  = 0.03) were significantly higher and hs-CRP ( P  = 0.02) were lower in patients with complete ST-resolution compared to those with incomplete ST-resolution. In-hospital complications were observed in 31.2% of patients. The patients with a lower baseline TIMI flow ( P  = 0.03) and those who developed complications ( P  = 0.04) had lower levels of free testosterone. A significant positive correlation was observed between the left ventricular function and serum levels of free testosterone ( P  = 0.01 and r = +0.362). This study suggests that in men with STEMI undergoing PPCI, higher serum levels of testosterone are associated with a better reperfusion response, fewer complications and a better left ventricular function.

Myocardial Infarct Size by CMR in Clinical Cardioprotection Studies: Insights From Randomized Controlled Trials.

PubMed

Bulluck, Heerajnarain; Hammond-Haley, Matthew; Weinmann, Shane; Martinez-Macias, Roberto; Hausenloy, Derek J

2017-03-01

The aim of this study was to review randomized controlled trials (RCTs) using cardiac magnetic resonance (CMR) to assess myocardial infarct (MI) size in reperfused patients with ST-segment elevation myocardial infarction (STEMI). There is limited guidance on the use of CMR in clinical cardioprotection RCTs in patients with STEMI treated by primary percutaneous coronary intervention. All RCTs in which CMR was used to quantify MI size in patients with STEMI treated with primary percutaneous coronary intervention were identified and reviewed. Sixty-two RCTs (10,570 patients, January 2006 to November 2016) were included. One-third did not report CMR vendor or scanner strength, the contrast agent and dose used, and the MI size quantification technique. Gadopentetate dimeglumine was most commonly used, followed by gadoterate meglumine and gadobutrol at 0.20 mmol/kg each, with late gadolinium enhancement acquired at 10 min; in most RCTs, MI size was quantified manually, followed by the 5 standard deviation threshold; dropout rates were 9% for acute CMR only and 16% for paired acute and follow-up scans. Weighted mean acute and chronic MI sizes (≤12 h, initial TIMI [Thrombolysis in Myocardial Infarction] flow grade 0 to 3) from the control arms were 21 ± 14% and 15 ± 11% of the left ventricle, respectively, and could be used for future sample-size calculations. Pre-selecting patients most likely to benefit from the cardioprotective therapy (≤6 h, initial TIMI flow grade 0 or 1) reduced sample size by one-third. Other suggested recommendations for standardizing CMR in future RCTs included gadobutrol at 0.15 mmol/kg with late gadolinium enhancement at 15 min, manual or 6-SD threshold for MI quantification, performing acute CMR at 3 to 5 days and follow-up CMR at 6 months, and adequate reporting of the acquisition and analysis of CMR. There is significant heterogeneity in RCT design using CMR in patients with STEMI. The authors provide recommendations for standardizing the assessment of MI size using CMR in future clinical cardioprotection RCTs. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Distribution and Determinants of Myocardial Perfusion Grade Following Late Mechanical Recanalization of Occluded Infarct-Related Arteries Postmyocardial Infarction: A Report From the Occluded Artery Trial

PubMed Central

Jorapur, Vinod; Steigen, Terje K.; Buller, Christopher E.; Dẑavík, Vladimír; Webb, John G.; Strauss, Bradley H.; Yeoh, Eunice E.S.; Kurray, Peter; Sokalski, Leszek; Machado, Mauricio C.; Kronsberg, Shari S.; Lamas, Gervasio A.; Hochman, Judith S.; John Mancini, G.B.

2010-01-01

Objective To evaluate the distribution and determinants of myocardial perfusion grade (MPG) following late recanalization of persistently occluded infarct-related arteries (IRA). Background MPG reflects microvascular integrity. It is an independent prognostic factor following myocardial infarction, but has been studied mainly in the setting of early reperfusion. The occluded artery trial (OAT) enrolled stable patients with persistently occluded IRAs beyond 24 hr and up to 28 days post-MI. Methods Myocardial blush was assessed using TIMI MPG grading in 261 patients with TIMI 3 epicardial flow following IRA PCI. Patients demonstrating impaired (0–1) versus preserved (2–3) MPG were compared with regard to baseline clinical and pre-PCI angiographic characteristics. Results Impaired MPG was observed in 60 of 261 patients (23%). By univariate analysis, impaired MPG was associated with failed fibrinolytic therapy, higher heart rate, lower systolic blood pressure, lower ejection fraction, LAD occlusion, absence of collaterals (P < 0.01) and ST elevation MI, lower diastolic blood pressure, and higher systolic sphericity index (P < 0.05). By multivariable analysis, higher heart rate, LAD occlusion, absence of collaterals and higher systolic sphericity index (P < 0.01), and lower systolic blood pressure (P < 0.05) were independently associated with impaired MPG. Conclusion Preserved microvascular integrity was present in a high proportion of patients following late recanalization of occluded IRAs post-MI. Presence of collaterals was independently associated with preserved MPG and likely accounted for the high frequency of preserved myocardial perfusion in this clinical setting. Impaired MPG was associated with baseline clinical and angiographic features consistent with larger infarct size. PMID:18798327

The Effect of IV Cangrelor and Oral Ticagrelor Study

ClinicalTrials.gov

2016-10-25

Acute Coronary Syndrome (ACS); High On-treatment Platelet Reactivity (HTPR); Microvascular Obstruction (MVO); ST-segment Elevation Myocardial Infarction (STEMI); Thrombolysis in Myocardial Infarction (TIMI); Unstable Angina (UA)

Discharge aspirin dose and clinical outcomes in patients with acute coronary syndromes treated with prasugrel versus clopidogrel: an analysis from the TRITON-TIMI 38 study (trial to assess improvement in therapeutic outcomes by optimizing platelet inhibition with prasugrel-thrombolysis in myocardial infarction 38).

PubMed

Kohli, Payal; Udell, Jacob A; Murphy, Sabina A; Cannon, Christopher P; Antman, Elliott M; Braunwald, Eugene; Wiviott, Stephen D

2014-01-28

The goal of this study was to determine whether there is a relationship between aspirin dose and the potent antiplatelet agent prasugrel in the TRITON-TIMI 38 (Trial to Assess Improvement in Therapeutic Outcomes by Optimizing Platelet Inhibition With Prasugrel-Thrombolysis In Myocardial Infarction 38) study. Optimal aspirin dosing after acute coronary syndromes remains uncertain. Previous studies have raised questions regarding an interaction between high-dose aspirin and the potent antiplatelet agent ticagrelor. In TRITON-TIMI 38, we classified 12,674 patients into low-dose (<150 mg) or high-dose (≥150 mg) aspirin groups based on discharge dose. We identified independent correlates of dose selection and studied the impact of aspirin dose on the clinical effects of prasugrel. There was significant geographical variation in aspirin dosing, with North American patients receiving high-dose aspirin more frequently than other countries (66% vs. 28%; p < 0.001). Clinical factors correlating with high-dose aspirin included previous percutaneous coronary intervention and use of aspirin before randomization. Characteristics associated with the use of low-dose aspirin included age ≥75 years, white race, and use of bivalirudin or a glycoprotein IIb/IIIa inhibitor during coronary intervention. Regardless of low- or high-dose aspirin use, prasugrel had lower rates of the primary efficacy endpoint (cardiovascular death, myocardial infarction, or stroke [CVD/MI/stroke]) (hazard ratio [HR]CVD/MI/stroke = 0.78 [95% confidence interval (CI) 0.64 to 0.95] and HRCVD/MI/stroke = 0.87 [95% CI 0.69 to 1.10], respectively; p value for interaction = 0.48) and higher rates of the primary safety endpoint (HR TIMI major bleeding = 1.40 [95% CI 0.81 to 2.42] and TIMImajor bleeding = 1.30 [95% CI 0.63 to 2.68], respectively; p value for interaction = 0.84) compared with clopidogrel. In TRITON-TIMI 38, the safety and efficacy outcomes of prasugrel compared with those of clopidogrel were directionally consistent regardless of aspirin dose, although only the primary efficacy endpoint achieved statistical significance. There was no clinically meaningful interaction of aspirin with prasugrel, suggesting that previous observations with potent antiplatelet agents indicating differential results are not universal. (A Comparison of Prasugrel [CS-747] and Clopidogrel in Acute Coronary Syndrome Subjects Who Are to Undergo Percutaneous Coronary Intervention; NCT00097591). Copyright © 2014 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Greater clinical benefit of more intensive oral antiplatelet therapy with prasugrel in patients with diabetes mellitus in the trial to assess improvement in therapeutic outcomes by optimizing platelet inhibition with prasugrel-Thrombolysis in Myocardial Infarction 38.

PubMed

Wiviott, Stephen D; Braunwald, Eugene; Angiolillo, Dominick J; Meisel, Simha; Dalby, Anthony J; Verheugt, Freek W A; Goodman, Shaun G; Corbalan, Ramon; Purdy, Drew A; Murphy, Sabina A; McCabe, Carolyn H; Antman, Elliott M

2008-10-14

Patients with diabetes mellitus (DM) are at high risk for recurrent cardiovascular events after acute coronary syndromes, in part because of increased platelet reactivity. The Trial to Assess Improvement in Therapeutic Outcomes by Optimizing Platelet Inhibition With Prasugrel-Thrombolysis in Myocardial Infarction 38 (TRITON-TIMI 38) showed an overall reduction in ischemic events with more intensive antiplatelet therapy with prasugrel than with clopidogrel but with more bleeding. We compared prasugrel with clopidogrel among subjects with DM in TRITON-TIMI 38. We classified 13 608 subjects on the basis of preexisting history of DM and further according to insulin use. Prespecified analyses of the primary (cardiovascular death, nonfatal myocardial infarction, or nonfatal stroke) and key secondary end points, including net clinical benefit (death, nonfatal myocardial infarction, nonfatal stroke, and nonfatal TIMI major bleeding) were compared by use of the log-rank test. We found that 3146 subjects had a preexisting history of DM, including 776 receiving insulin. The primary end point was reduced significantly with prasugrel among subjects without DM (9.2% versus 10.6%; hazard ratio [HR], 0.86; P=0.02) and with DM (12.2% versus 17.0%; HR, 0.70; P<0.001, P(interaction)=0.09). A benefit for prasugrel was observed among DM subjects on insulin (14.3% versus 22.2%; HR, 0.63; P=0.009) and those not on insulin (11.5% versus 15.3%; HR, 0.74; P=0.009). Myocardial infarction was reduced with prasugrel by 18% among subjects without DM (7.2% versus 8.7%; HR, 0.82; P=0.006) and by 40% among subjects with DM (8.2% versus 13.2%; HR, 0.60; P<0.001, P(interaction)=0.02). Although TIMI major hemorrhage was increased among subjects without DM on prasugrel (1.6% versus 2.4%; HR, 1.43; P=0.02), the rates were similar among subjects with DM for clopidogrel and prasugrel (2.6% versus 2.5%; HR, 1.06; P=0.81, P(interaction)=0.29). Net clinical benefit with prasugrel was greater for subjects with DM (14.6% versus 19.2%; HR, 0.74; P=0.001) than for subjects without DM (11.5% versus 12.3%; HR, 0.92; P=0.16, P(interaction)=0.05). Subjects with DM tended to have a greater reduction in ischemic events without an observed increase in TIMI major bleeding and therefore a greater net treatment benefit with prasugrel compared with clopidogrel. These data demonstrate that the more intensive oral antiplatelet therapy provided with prasugrel is of particular benefit to patients with DM.

Coronary Slow Flow is Associated with Depression and Anxiety

PubMed Central

Durmaz, Tahir; Keles, Telat; Erdogan, Kemal Esref; Ayhan, Huseyin; Bilen, Emine; Bayram, Nihal Akar; Akcay, Murat; Oz, Ozgur; Albayrak, Yakup; Ozdemir, Naci; Bozkurt, Engin

2014-01-01

Background There is an established relationship between depression/anxiety disorders and cardiovascular morbidity and mortality which has been previously documented. However, there has been no study evaluating coronary slow flow in association with depression and anxiety. Methods and Results A total of consecutive 90 patients were included in the study. All patients completed scoring scales for depression [Hamilton Rating Scale for Depression (HAMD)] and anxiety (STAI-1, State anxiety subscale of State-Trait Anxiety Inventory; STAI-2, Trait anxiety subscale of State-Trait Anxiety Inventory). Thereafter, they underwent selective coronary angiography and 2 groups were formed: coronary slow flow (n = 42), and normal coronary flow (n = 48). The two groups had comparable baseline characteristics. However, significant differences were found between coronary slow flow and normal coronary flow groups regarding depression (13.1 ± 8.2 and 6.9 ± 6.7, p < 0.001 for HAMD, respectively) and anxiety (46.2 ± 15.0 vs. 32.6 ± 9.9, p < 0.001 for STAI-1 and 51.0 ± 16.7 vs. 43.0 ± 10.7, p = 0.009 for STAI-2, respectively) scores. There were also significant positive correlations between depression/anxiety scores and TIMI frame counts of all major epicardial coronary arteries. In addition, after adjustment for smoking, hypertension, scoring scales, and the presence of depressive mood, all scoring scales and depressive mood were found to be independent risk factors for coronary slow flow in multivariable logistic regression analysis. Conclusions Significant association was found among coronary slow flow, depression/anxiety scores and depressive mood. PMID:27122789

The prognostic value of bleeding academic research consortium (BARC)-defined bleeding complications in ST-segment elevation myocardial infarction: a comparison with the TIMI (Thrombolysis In Myocardial Infarction), GUSTO (Global Utilization of Streptokinase and Tissue Plasminogen Activator for Occluded Coronary Arteries), and ISTH (International Society on Thrombosis and Haemostasis) bleeding classifications.

PubMed

Kikkert, Wouter J; van Geloven, Nan; van der Laan, Mariet H; Vis, Marije M; Baan, Jan; Koch, Karel T; Peters, Ron J; de Winter, Robbert J; Piek, Jan J; Tijssen, Jan G P; Henriques, José P S

2014-05-13

The aim of the present analysis was to compare 1-year mortality prediction of Bleeding Academic Research Consortium (BARC)-defined bleeding complications with existing bleeding definitions in patients with ST-segment elevation myocardial infarction (STEMI) and to investigate the prognostic value of the individual data elements of the bleeding classifications for 1-year mortality. BARC recently proposed a novel standardized bleeding definition. The in-hospital occurrence of bleeding defined according to the BARC, TIMI (Thrombolysis In Myocardial Infarction), GUSTO (Global Utilization of Streptokinase and Tissue Plasminogen Activator for Occluded Coronary Arteries), and ISTH (International Society on Thrombosis and Haemostasis) bleeding classifications was assessed in 2,002 STEMI patients undergoing primary percutaneous coronary intervention between January 1, 2003, and July 31, 2008. BARC types 2, 3, 4, and 5 bleeding occurred in 4.4%, 14.2%, 1.4%, and 0.3% of patients, respectively. By multivariable analysis, GUSTO- and ISTH-defined bleeding was not significantly associated with 1-year mortality, whereas TIMI major and BARC type 3b or 3c bleeding conferred a 2-fold higher risk of 1-year mortality (hazard ratios [HRs]: 2.00 [95% confidence interval (CI): 1.32 to 3.01] and 1.84 [95% CI: 1.23 to 2.77], respectively). Data elements most strongly associated with mortality were a hemoglobin decrease ≥5 g/dl (HR: 1.94 [95% CI: 1.26 to 2.98]), the use of vasoactive agents for bleeding (HR: 2.01 [95% CI: 0.91 to 4.44]), cardiac tamponade (HR: 2.38 [95% CI: 0.56 to 10.1]), and intracranial hemorrhage (HRs for 1-year mortality were not computable because there was only 1 patient with intracranial bleeding). Both the BARC and TIMI bleeding classification identified STEMI patients at risk of 1-year mortality. Copyright © 2014 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Clinical utility of new bleeding criteria: a prospective study of evaluation for the Bleeding Academic Research Consortium definition of bleeding in patients undergoing percutaneous coronary intervention.

PubMed

Choi, Jae-Hyuk; Seo, Jeong-Min; Lee, Dong Hyun; Park, Kyungil; Kim, Young-Dae

2015-04-01

The aim of this study was to evaluate the clinical utility of the new bleeding criteria, proposed by the Bleeding Academic Research Consortium (BARC), compared with the old criteria for determining the action of physicians in contact with bleeding events, after percutaneous coronary intervention (PCI). The BARC criteria were independently associated with an increased risk of 1-year mortality after PCI, and provided a predictive value, in regard to 1-year mortality. The standardized bleeding definitions will be expected to help the physician to correctly analyze the bleeding events, to select an optimal treatment, and to objectively compare the results of multiple trials and registries. All the patients undergoing PCI from June to September 2012 were prospectively enrolled. Patients who experienced a bleeding event were further classified, based on three different bleeding severity criteria: BARC, Thrombolysis In Myocardial Infarction (TIMI), and Global Use of Strategies To Open coronary arteries (GUSTO). The primary outcome was the occurrence of bleeding events requiring interruption of antiplatelet therapy (IAT) by physicians. A total of 376 consecutive patients were included in this study. Total bleeding events occurred in 46 patients (12.2%). BARC type ≥2 bleeding occurred in 30 patients (8.0%); however, TIMI major or minor bleeding, and GUSTO moderate or severe bleeding occurred in 6 (1.6%) and 11 patients (2.9%), respectively. Of the 46 patients, 28 (60.9% of patients) required IAT. On receiver-operating characteristic curve analysis, bleeding defined BARC type ≥2 effectively predicted IAT, with a sensitivity of 89.3%, and a specificity of 98.5% (p<0.001), compared with TIMI (sensitivity, 21.4%; specificity, 100%; p<0.001), and GUSTO (sensitivity, 39.3%; specificity, 100%; p<0.001). Compared with TIMI and GUSTO, the BARC definition may be a more useful tool for the detection of bleeding with clinical relevance, for patients undergoing PCI. Copyright © 2014 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.

Effectiveness and cost-effectiveness of facilitated percutaneous coronary intervention compared with primary percutaneous coronary intervention in patients with ST-segment elevation myocardial infarction transferred from community hospitals.

PubMed

Coleman, Craig I; McKay, Raymond G; Boden, William E; Mather, Jeffrey F; White, C Michael

2006-07-01

Primary percutaneous coronary intervention ([PCI], percutaneous transluminal coronary angioplasty+stenting) for ST-segment elevation myocardial infarction (STEMI) is regarded as superior to fibrinolysis even if it means that patients need to be transferred from one center to another to undergo the procedure. However, this inevitable delay between symptom onset and PCI, caused by the time required to travel, might increase the occurrence of cardiac events. A hybrid method called facilitated PCI uses fibrinolysis and/or glycoprotein (GP) IIb/IIIa inhibitors before transfer to a tertiary medical center where urgent PCI might be performed. This approach, however, has not been systematically evaluated. The purpose of this study was to compare the effectiveness (combined end point of in-hospital mortality, reinfarction, stroke, or emergency revascularization) and cost-effectiveness of utilizing a bolus thrombolytic agent with GP IIb/IIIa inhibitor followed by transfer to a tertiary institution for facilitated PCI or standard of care transfer without primary PCI drugs among patients presenting to a community hospital with STEMI. This was a prospective, single-center, cohort study comprising data from STEMI patients transferred from community hospitals to Hartford Hospital, Hartford, Connecticut, from the years 2000 to 2003. At the time of analysis, patients receiving primary PCI were matched (1:1) with those receiving facilitated PCI, utilizing propensity scores to assure similar demographics. The combined incidence of major adverse cardiac end points (MACE) and total hospital costs was compared between groups. Non-parametric bootstrapping was conducted to calculate CIs for the incremental cost-effectiveness ratio and generate a quadrant analysis. Based on 254 propensity score-matched patients (127 facilitated PCI and 127 primary PCI), in-hospital MACE and total hospital costs were reduced by 61.3% and US 4563 dollars (2005), respectively, in patients receiving facilitated compared with primary PCI (P=0.021 and P=NS, respectively). Patients receiving facilitated PCI were more likely to have target lesion Thrombolysis in Myocardial Infarction (TIMI) III (normal) blood flow on cardiac catheterization than those receiving primary PCI (49.6% vs 30.7%; P=0.002). However, the rate of TIMI bleeding was similar in both groups (21.3% in the facilitated PCI group vs 18.9% in the primary PCI group). Nonsignificant reductions were observed in both intensive care unit (ICU) and total length of stay (LOS) (0.8 day and 1.0 day, respectively) compared with the primary PCI group. Bootstrap analysis revealed that of 25,000 samplings, facilitated PCI would likely be both more effective and less costly 94.6% of the time. The use of facilitated PCI in STEMI patients who initially presented to community hospitals and were transferred for PCI appeared to significantly reduce the incidence of MACE, and increase the likelihood of having baseline TIMI III blood flow at time of catheterization. Nonsignificant reductions were observed in total ICU and hospital LOS. However, there did not appear to be a significant effect on the incidence of bleeding in patients receiving facilitated PCI. Bootstrap analysis confirmed that facilitated PCI would be both a more effective and less costly strategy.

Intensive oral antiplatelet therapy for reduction of ischaemic events including stent thrombosis in patients with acute coronary syndromes treated with percutaneous coronary intervention and stenting in the TRITON-TIMI 38 trial: a subanalysis of a randomised trial.

PubMed

Wiviott, Stephen D; Braunwald, Eugene; McCabe, Carolyn H; Horvath, Ivan; Keltai, Matyas; Herrman, Jean-Paul R; Van de Werf, Frans; Downey, William E; Scirica, Benjamin M; Murphy, Sabina A; Antman, Elliott M

2008-04-19

Intracoronary stenting can improve procedural success and reduce restenosis compared with balloon angioplasty in patients with acute coronary syndromes, but can also increase the rate of thrombotic complications including stent thrombosis. The TRITON-TIMI 38 trial has shown that prasugrel-a novel, potent thienopyridine-can reduce ischaemic events compared with standard clopidogrel therapy. We assessed the rate, outcomes, and prevention of ischaemic events in patients treated with prasugrel or clopidogrel with stents in the TRITON-TIMI 38 study. Patients with moderate-risk to high-risk acute coronary syndromes were included in our analysis if they had received at least one coronary stent at the time of the index procedure following randomisation in TRITON-TIMI 38, and were further subdivided by type of stent received. Patients were randomly assigned in a 1 to 1 fashion to receive a loading dose of study drug (prasugrel 60 mg or clopidogrel 300 mg) as soon as possible after randomisation, followed by daily maintenance therapy (prasugrel 10 mg or clopidogrel 75 mg). All patients were to receive aspirin therapy. Treatment was to be continued for a minimum of 6 months and a maximum of 15 months. Randomisation was not stratified by stents used or stent type. The primary endpoint was the composite of cardiovascular death, non-fatal myocardial infarction, or non-fatal stroke. Stent thrombosis was assessed using Academic Research Consortium definitions, and analysis was by intention to treat. TRITON-TIMI 38 is registered with ClinicalTrials.gov, number NCT00097591. 12,844 patients received at least one coronary stent; 5743 received only drug-eluting stents, and 6461 received only bare-metal stents. Prasugrel compared with clopidogrel reduced the primary endpoint (9.7 vs 11.9%, HR 0.81, p=0.0001) in the stented cohort, in patients with only drug-eluting stents (9.0 vs 11.1%, HR 0.82, p=0.019), and in patients with only bare-metal stents (10.0 vs 12.2%, HR 0.80, p=0.003). Stent thrombosis was associated with death or myocardial infarction in 89% (186/210) of patients. Stent thrombosis was reduced with prasugrel overall (1.13 vs 2.35%, HR 0.48, p<0.0001), in patients with drug-eluting stents only (0.84 vs 2.31%, HR 0.36, p<0.0001), and in those with bare-metal stents only (1.27 vs 2.41%, HR 0.52, p=0.0009). Intensive antiplatelet therapy with prasugrel resulted in fewer ischaemic outcomes including stent thrombosis than with standard clopidogrel. These findings were statistically robust irrespective of stent type, and the data affirm the importance of intensive platelet inhibition in patients with intracoronary stents.

The 'MAP strategy' (Maximum aspiration of atherothrombus and adjunctive glycoprotein IIb/IIIa inhibitor utilization combined with prolonged inflation of balloon/stent) for preventing no-reflow in patients with ST-segment elevation myocardial infarction undergoing percutaneous coronary intervention: A retrospective analysis of seventy-one cases.

PubMed

Potdar, Anil; Sharma, Satyavan

2015-12-01

'No-reflow' phenomenon is a common occurrence in percutaneous coronary intervention (PCI). A three-component 'MAP strategy' was designed to prevent no-reflow by addressing both intralesional and intraluminal thrombus in patients with ST-segment elevation myocardial infarction (STEMI). In this analysis, we observed Thrombolysis In Myocardial Infarction (TIMI) flow grade 3 or 2 in all patients, with no incidence of no-reflow. Myocardial blush grade (MBG) 3 or 2 was observed in most (87.32%) patients. Left ventricular ejection fraction (LVEF) was improved, without any incidence of death up to 9-month follow-up. All patients safely tolerated the strategy-driven prolonged, 35-s inflation of the balloon/stent. Copyright © 2016. Published by Elsevier B.V.

In-Lab Upfront Use of Tirofiban May Reduce the Occurrence of No-Reflow During Primary Percutaneous Coronary Intervention. A Pilot Randomized Study.

PubMed

Lago, Igor Matos; Novaes, Gustavo Caires; Badran, André Vannucchi; Pavão, Rafael Brolio; Barbosa, Ricardo; Figueiredo, Geraldo Luiz de; Lima, Moysés de Oliveira; Haddad, Jorge Luiz; Schmidt, André; Marin, José Antônio

2016-11-01

Despite successful opening of culprit coronary artery, myocardial reperfusion does not always follows primary percutaneous coronary intervention (PPCI). Glycoprotein IIb/IIIa inhibitors are used in the treatment of no-reflow (NR), but their role to prevent it is unproven. To evaluate the effect of in-lab administration of tirofiban on the incidence of NR in ST-elevation myocardial infarction (STEMI) treated with PPCI. STEMI patients treated with PPCI were randomized (24 tirofiban and 34 placebo) in this double-blinded study to assess the impact of intravenous tirofiban on the incidence of NR after PPCI according to angiographic and electrocardiographic methods. End-points of the study were: TIMI-epicardial flow grade; myocardial blush grade (MBG); resolution of ST-elevation < 70% (RST < 70%) at 90min and 24h after PPCI. Baseline anthropometric, clinical and angiographic characteristics were balanced between the groups. The occurrence of TIMI flow < 3 was not significantly different between the tirofiban (25%) and placebo (35.3%) groups. MBG ≤ 2 did not occur in the tirofiban group, and was seen in 11.7% of patients in the placebo group (p=0.13). RST < 70% occurred in 41.6% x 55.8% (p=0.42) at 90min and in 29% x 55.9% (p=0.06) at 24h in tirofiban and placebo groups, respectively. Severe NR (RST ≤ 30%) was detected in 0% x 26.5% (p=0.01) at 90 min, and in 4.2% x 23.5% (p=0.06) at 24h in tirofiban and placebo groups, respectively. This pilot study showed a trend toward reduction of NR associated with in-lab upfront use of tirofiban in STEMI patients treated with PPCI and paves the way for a full-scale study testing this hypothesis. Mesmo com abertura da artéria coronária culpada bem sucedida, a reperfusão miocárdica nem sempre sucede a intervenção coronariana percutânea primária (ICPP). Inibidores da glicoproteína IIb/IIIa são usados no tratamento do fenômeno de não reperfusão (NR), mas seu papel para preveni-lo não está comprovado. Avaliar o efeito da administração, em laboratório, de tirofibana sobre a incidência de NR em infarto agudo do miocárdio com supra do segmento ST (IAMCSST) tratado com ICPP. Pacientes com IAMCSST tratados com ICPP foram randomizados (24 tirofibana e 34 placebo) neste estudo duplo-cego para avaliar o impacto de tirofibana intravenosa sobre a incidência de NR após ICPP de acordo com métodos angiográficos e eletrocardiográfico. Os desfechos do estudo foram: fluxo epicárdico TIMI (grau), grau de fluxo miocárdico (MBG), resolução da elevação do segmento ST < 70% (RST < 70%) aos 90 minutos e 24 horas após ICPP. Características antropométricas, clínicas e angiográficas basais eram equilibradas entre os grupos. A ocorrência de fluxo TIMI < 3 não foi significativamente diferente entre os grupos tirofibana (25%) e placebo (35,3%). MBG ≤ 2 não ocorreu no grupo tirofibana, e foi detectado em 11,7% dos pacientes do grupo placebo (p=0,13). RST < 70% ocorreu em 41,6% x 55,8% (p=0.42) aos 90 minutos, e em 29% x 55,9% (p=0,06) em 24 horas nos grupos tirofibana e placebo, respectivamente. NR grave (RST ≤ 30%) ocorreu em 0% x 26,5% (p=0,01) aos 90 minutos, e em 4,2% x 23,5% (p=0,06) em 24 horas nos grupos tirofibana e placebo, respectivamente. Este estudo piloto mostrou uma tendência de redução de NR associada ao uso, em laboratório, de tirofibana em pacientes com IAMCSST tratados com ICPP, e abre caminho para um estudo em escala real que teste essa hipótese.

Usefulness of tirofiban among patients treated without percutaneous coronary intervention (TIMI high risk patients in PRISM-PLUS).

PubMed

Morrow, David A; Sabatine, Marc S; Antman, Elliott M; Cannon, Christopher P; Braunwald, Eugene; Theroux, Pierre

2004-09-15

Although the efficacy of glycoprotein IIb/IIIa inhibition in non-ST-elevation acute coronary syndromes is greatest in patients who undergo percutaneous coronary intervention (PCI), it was hypothesized that high-risk patients managed without PCI also benefit. The TIMI risk score was calculated for 1,570 patients randomized to tirofiban plus heparin versus heparin in the Platelet Receptor Inhibition in Ischemic Syndrome Management in Patients Limited by Unstable Signs and Symptoms trial. In high-risk patients (score > or =4) treated without PCI, tirofiban reduced the risk for death, myocardial infarction, and refractory ischemia at 30 days (28.8% vs 21.9%; odds ratio [OR] 0.69, p = 0.04). This benefit was similar in magnitude as that for patients who underwent PCI (32.4% vs 22.2%; OR 0.60, p = 0.06). No benefit was evident in low-risk patients.

[Incidence, associated factors, and follow-up of hospital heart failure complicating acute anterior myocardial infarction successfully treated by primary angioplasty].

PubMed

Meimoun, P; M'barek, D; Dragomir, C; Luycx-Bore, A; Elmkies, F; Boulanger, J; Zemir, H; Martis, S; Neykova, A; Tzvetkov, B; Clerc, J

2013-11-01

Heart failure (HF) complicating acute myocardial infarction (AMI) is of poor prognosis and is often associated with patient's characteristics and success of reperfusion strategies. However, few data is available regarding the high-risk subgroup of patients with anterior AMI treated successfully by primary angioplasty. The aim of the study was to assess the incidence, associated factors, and the future of HF occurring during hospitalisation, in the setting of anterior AMI treated successfully by primary angioplasty. Eighty-five consecutive patients with anterior AMI treated successfully by primary angioplasty (final angiographic TIMI flow grade=3, without residual stenosis) were included. Clinical, biochemical, angiographic, and echocardiographic data were prospectively collected and compared between patients with (Killip 2 and 3) and without HF during hospitalisation. Fifteen patients had HF (18%) during hospitalisation and 70 did not. By comparison to patients without HF, patients with HF were more frequently diabetics, had troponin peak and CPK, leucocytes count, and fasting glucose higher, LVEF and wall motion score index in the left anterior descending territory (WMSi-lad) poorer, and a lower non-invasive coronary flow reserve (CFR) in the LAD 24hours after angioplasty (all, P<0.05). In multivariate analysis, fasting glucose, leucocytes count after angioplasty, CFR and WMSi-lad were independently associated with HF, even after adjusting with angiographic variables (all, P<0.05). At 6months, patients with HF had less recovery of LV function and higher frequency of adverse LV remodelling (58% versus 20%, P<0.01) by comparison to patients without HF. In conclusion, HF is not uncommon even after successful primary angioplasty for anterior AMI (nearly one patient out of 5), is associated with hyperglycaemia and inflammation, a poor microvascular reperfusion, and left ventricular systolic function, and is more frequently complicated by adverse LV remodelling and lack of LV recovery. Copyright © 2013. Published by Elsevier SAS.

Changing paradigms in thrombolysis in acute myocardial infarction.

PubMed

Gotsman, M S; Rozenman, Y; Admon, D; Mosseri, M; Lotan, C; Zahger, D; Weiss, A T

1997-05-23

Acute myocardial infarction occurs when a ruptured coronary artery plaque causes sudden thrombotic occlusion of a coronary artery and cessation of coronary artery blood flow. This paper reviews the underlying coronary pathology in progressive coronary atherosclerosis, mechanisms of plaque rupture and arterial occlusion and the time relationship between coronary occlusion and myocardial necrosis. Reperfusion can be achieved by chemical thrombolysis with different thrombolytic agents. Early lysis is achieved best by prehospital administration, a transtelephonic monitor, a mobile intensive care unit, active general practitioner treatment or by warning the emergency room of impending arrival of a patient. Thrombolytic therapy may be unsuccessful and not achieve Grade III TIMI flow in less than 4 h (or even 2 h) due to inadequate or intermittent perfusion or reocclusion. Adjuvant therapy includes aspirin and platelet receptor antagonists. Bleeding is a constant danger. Direct percutaneous transluminal coronary angioplasty (PTCA) may be as effective or better than chemical thrombolysis. Reperfusion protects the myocardium and salvages viable tissue. It also improves mechanical remodelling of the ventricle. Long-term follow-up has shown that quantum leaps of fresh coronary occlusion causes step-wise progression in patient disability and that further early, prompt reperfusion can salvage myocardium and prevent this inexorable progress of the disease.

Pharmacological prevention of reperfusion injury in acute myocardial infarction. A potential role for adenosine as a therapeutic agent.

PubMed

Quintana, Miguel; Kahan, Thomas; Hjemdahl, Paul

2004-01-01

The concept of reperfusion injury, although first recognized from animal studies, is now recognized as a clinical phenomenon that may result in microvascular damage, no-reflow phenomenon, myocardial stunning, myocardial hibernation and ischemic preconditioning. The final consequence of this event is left ventricular (LV) systolic dysfunction leading to increased morbidity and mortality. The typical clinical case of reperfusion injury occurs in acute myocardial infarction (MI) with ST segment elevation in which an occlusion of a major epicardial coronary artery is followed by recanalization of the artery. This may occur either spontaneously or by means of thrombolysis and/or by primary percutaneous coronary intervention (PCI) with efficient platelet inhibition by aspirin (acetylsalicylic acid), clopidogrel and glycoprotein IIb/IIIa inhibitors. Although the pathophysiology of reperfusion injury is complex, the major role that neutrophils play in this process is well known. Neutrophils generate free radicals, degranulation products, arachidonic acid metabolites and platelet-activating factors that interact with endothelial cells, inducing endothelial injury and neutralization of nitrous oxide vasodilator capacity. Adenosine, through its multi-targeted pharmacological actions, is able to inhibit some of the above-mentioned detrimental effects. The net protective of adenosine in in vivo models of reperfusion injury is the reduction of the infarct size, the improvement of the regional myocardial blood flow and of the regional function of the ischemic area. Additionally, adenosine preserves the post-ischemic coronary flow reserve, coronary blood flow and the post-ischemic regional contractility. In small-scale studies in patients with acute MI, treatment with adenosine has been associated with smaller infarcts, less no-reflow phenomenon and improved LV function. During elective PCI adenosine reduced ST segment shifts, lactate production and ischemic symptoms. During the last years, three relatively large placebo-controlled clinical trials have been conducted: Acute Myocardial Infarction Study of Adenosine Trial (AMISTAD) I and II and Attenuation by Adenosine of Cardiac Complications (ATTACC). In the AMISTAD trials, the final infarct size was reduced and the LV systolic function was improved by adenosine treatment, mainly in patients with anterior MI localization. However, morbidity and mortality were not affected. In the ATTACC study, the LV systolic function was not affected by adenosine, however, trends towards improved survival were observed in patients with anterior MI localization. The possibility of obtaining a Thrombolysis in Myocardial Infarction (TIMI) grade 3 flow in the infarct-related artery in up to 95% of patients with acute MI (increasing the occurrence of reperfusion injury) has turned back the interest towards the protection of myocardial cells from the impending ischemic and reperfusion injury in which adenosine alone or together with other cardio-protective agents may exert important clinical effects.

The effects of tirofiban infusion on clinical and angiographic outcomes of patients with STEMI undergoing primary PCI.

PubMed

Kaymaz, Cihangir; Keleş, Nurşen; Özdemir, Nihal; Tanboğa, İbrahim Halil; Demircan, Hacer C; Can, Mehmet M; Koca, Fatih; İzgi, İbrahim Akın; Özkan, Alper; Türkmen, Muhsin; Kırma, Cevat; Esen, Ali M

2015-11-01

The present study was designed to determine the effects of tirofiban (Tiro) infusion on angiographic measures, ST-segment resolution, and clinical outcomes in patients with STEMI undergoing PCI. Glycoprotein (GP) IIb/IIIa inhibitors are beneficial in ST-segment elevation myocardial infarction (STEMI) patients undergoing percutaneous coronary intervention (PCI), while the most effective timing of administration is still under investigation. A total of 1242 patients (83.0% males, mean (standard deviation; SD) age: 54.7 (10.9) years) with STEMI who underwent primary PCI were included in this retrospective non-randomized study in four groups, composed of no tirofiban infusion [Tiro (-); n=248], tirofiban infusion before PCI (pre-Tiro; n=720), tirofiban infusion during PCI (peri-Tiro; n=50), and tirofiban infusion after PCI (post-Tiro; n=224). In all Tiro (+) patients, bolus administration of Tiro (10 µg/kg) was followed by infusion (0.15 µg/kg/min) for a mean (SD) duration of 22.4±6.8 hours. The pre-PCI Tiro group was associated with the highest percentage of patients with TIMI 3 flow (99.4%; p<0.001), the lowest corrected TIMI frame count [21(18-23.4); p<0.001], the highest percentage of patients with >75% ST-segment resolution (78.1%; p<0.001), and the lowest rate of in-hospital sudden cardiac death and in-hospital all-cause mortality (3.2%, p<0.05, 3.3%, p=0.01). Major bleeding was reported in 18 (1.8%) patients who received tirofiban. Use of standard-dose bolus tirofiban in addition to aspirin, high-dose clopidogrel, and unfractionated heparin prior to primary PCI significantly improves myocardial reperfusion, ST-segment resolution, in-hospital mortality rate, and in-hospital sudden cardiac death in patients with STEMI with no increased risk of major bleeding.

The impact of systems-of-care on pharmacoinvasive management with streptokinase: The subgroup analysis of the TN-STEMI programme.

PubMed

Raja, Deep Chandh; Subban, Vijayakumar; Victor, Suma M; Joseph, George; Thomson, Viji Samuel; Kannan, Kumaresan; Gnanaraj, Justin Paul; Veerasekar, Ganesh; Thenpally, Jose G; Livingston, Nandhini; Nallamothu, Brahmajee K; Alexander, Thomas; Mullasari, Ajit S

We evaluated the impact of implementation of the TN-STEMI programme on various characteristics of the pharmacoinvasive group by comparing clinical as well as angiographic outcomes between the pre- and post-implementation groups. The TN-STEMI programme involved 2420 patients of which 423 patients had undergone a pharmacoinvasive strategy of reperfusion. Of these, 407 patients had a comprehensive blinded core-lab evaluation of their angiograms post-lysis and clinical evaluation of various parameters including time-delays and adverse cardio- and cerebro-vascular events at 1year. Streptokinase was used as the thrombolytic agent in 94.6% of the patients. In the post-implementation phase, there was a significant improvement in 'First medical contact (FMC)-to-ECG' (11 vs. 5min, p<0.001) and 'Lysis-to-angiogram' (98.3 vs. 18.2h, p<0.001) times. There was also a significant improvement in the number of coronary angiograms performed within 24h (20.7% vs. 69.3%, p<0.001). The 'Time-to-FMC' (160 vs. 135min, p=0.07) and 'Total ischemic time' (210 vs. 176min, p=0.22) also showed a decreasing trend. IRA patency rate (70.2% vs. 86%, p<0.001) and thrombus burden (TIMI grade 0: 49.1% vs. 73.4%, p<0.001) were superior in this group. The MACCE rates were similar except for fewer readmissions (29.8% vs. 12.6%, p=0.0002) and target revascularizations at 1year (4.8% vs. none, p=0.002) in the post-implementation group. The implementation of a system-of-care (hub-and-spoke model) in the pharmacoinvasive group of the TN-STEMI programme demonstrated shorter lysis-to-angiogram times, better TIMI flow patterns and lower thrombus burden in the post-implementation phase. Copyright © 2017. Published by Elsevier B.V.

Early versus late percutaneous revascularization in patients hospitalized with non ST-segment elevation myocardial infarction: The atherosclerosis risk in communities surveillance study.

PubMed

Arora, Sameer; Matsushita, Kunihiro; Qamar, Arman; Stacey, R Brandon; Caughey, Melissa C

2018-02-01

Current guidelines recommend early invasive intervention (<24 hr) for high risk patients with non-ST-segment elevation myocardial infarction (NSTEMI). A delayed invasive strategy (24-72 hr) is considered reasonable for low risk patients. The real-world effectiveness of this strategy is unknown. The ARIC Study has conducted hospital surveillance of acute myocardial infarction (MI) since 1987. NSTEMI was classified using a validated algorithm. We limited our study to patients undergoing early (<24 hr of the event onset), or late (≥24 hr) percutaneous coronary intervention (PCI). Patients were stratified into low (TIMI score 2-4), and high risk (TIMI score 5-7, or presence of cardiogenic shock, ventricular fibrillation, or cardiac arrest). Associations between early versus late PCI and mortality were analyzed using multivariable logistic regression adjusted for demographics, hospitalization year, TIMI score, and comorbidities. From 1987 to 2012, 6,746 patients were hospitalized with NSTEMI and underwent PCI. Most were white (79%), male (68%), with mean age 61 years. The 28-day and 1-year mortality were 2% and 5%, respectively. Most revascularizations (65%) were late. After accounting for potential confounders, early PCI was associated with a 58% reduced 28-day mortality (OR = 0.42; 95% CI: 0.21-0.84) for the entire population, and 57% reduced mortality (OR = 0.43; 95% CI: 0.21-0.88) for high risk patients. By 1-year of follow up, there was no significant difference in mortality with respect to early vs. late PCI. In hospitalized NSTEMI patients with high risk of clinical events, early PCI is associated with improved 28-day survival. © 2017 Wiley Periodicals, Inc.

A randomized controlled trial of two interventions to increase colorectal cancer screening among Hispanics on the Texas-Mexico border.

PubMed

Fernández, María E; Savas, Lara S; Carmack, Chakema C; Chan, Wenyaw; Lairson, David R; Byrd, Theresa L; Wilson, Katherine M; Arvey, Sarah R; Krasny, Sarah; Vernon, Sally W

2015-01-01

Colorectal cancer (CRC) is the second and third leading cause of cancer death for Hispanic men and women, respectively. CRC can be prevented if precursors are detected early and removed and can be successfully treated if discovered early. While one-on-one interventions for increasing CRC screening (CRCS) are recommended, few studies specifically assess the effectiveness of lay health worker (LHW) approaches using different educational materials. To develop and evaluate the effectiveness of two LHW-delivered CRCS interventions known as Vale la Pena (VLP; "It's Worth It!") on increasing CRCS among Hispanics. The study design was a cluster randomized controlled trial with two treatment arms. Six hundred and sixty five Hispanics 50 years and older were recruited from 24 colonias (neighborhoods) in the Lower Rio Grande Valley of the Texas-Mexico border. The interventions were a small media print intervention (SMPI) (including DVD and flipchart), and a tailored interactive multimedia intervention (TIMI) delivered on tablet computers. A no intervention group served as the comparison group. Data were collected between 2007 and 2009 and analyzed between 2009 and 2013. Measures assessed CRCS behavior, self-efficacy, knowledge, and other psychosocial constructs related to CRCS and targeted through VLP. Among participants reached for follow-up, 18.9 % in the SMPI group, 13.3 % in the TIMI group, and 11.9 % in the comparison group completed CRCS. Intent-to-treat analysis showed that 13.6 % in the SMPI group, 10.2 % in the TIMI group, and 10.8 % in the comparison group completed CRCS. These differences were not statistically significant. Results indicated that there are no significant differences in CRCS uptake between groups.

International Conference on Applied Sciences (ICAS2013)

NASA Astrophysics Data System (ADS)

Lemle, Ludovic Dan; Jiang, Yiwen

2014-03-01

The International Conference on Applied Sciences (ICAS2013) took place in Wuhan, P R China from 26-27 October 2013 at the Military Economics Academy. The conference is regularly organized, alternately in Romania and in P R China, by ''Politehnica'' University of Timişoara, Romania, and Military Economics Academy of Wuhan, P R China, with the aim to serve as a platform for the exchange of information between various areas of applied sciences, and to promote the communication between the scientists of different nations, countries and continents. The conference has been organized for the first time in 15-16 June 2012 at the Engineering Faculty of Hunedoara, Romania. The topics of the conference covered a comprehensive spectrum of issues: Economical sciences Engineering sciences Fundamental sciences Medical sciences The conference gathered qualified researchers whose expertise can be used to develop new engineering knowledge that has applicability potential in economics, defense, medicine, etc. The number of registered participants was nearly 90 from 5 countries. During the two days of the conference 4 invited and 36 oral talks were delivered. A few of the speakers deserve a special mention: Mircea Octavian Popoviciu, Academy of Romanian Scientist — Timişoara Branch, Correlations between mechanical properties and cavitation erosion resistance for stainless steels with 12% chromium and variable contents of nickel; Carmen Eleonora Hărău, ''Politehnica'' University of Timişoara, SWOT analysis of Romania's integration in EU; Ding Hui, Military Economics Academy of Wuhan, Design and engineering analysis of material procurement mobile operation platform; Serban Rosu, University of Medicine and Pharmacy ''Victor Babeş'' Timişoara, Cervical and facial infections — a real life threat, among others. Based on the work presented at the conference, 14 selected papers are included in this volume of IOP Conference Series: Materials Science and Engineering. These papers present new researches in the various fields of materials engineering, mechanical engineering, computers engineering, mathematical engineering and clinical engineering. It's our great pleasure to present this volume of IOP Conference Series: Materials Science and Engineering to the scientific community to promote further researches in these areas. We sincerely hope that the papers published in this volume will contribute to the advancement of knowledge in the respective fields. All papers published in this volume of IOP Conference Series: Materials Science and Engineering (MSE) have been peer reviewed through processes administered by the editors of the ICAS2013 proceedings, Ludovic Dan Lemle and Yiwen Jiang. Special thanks should be directed to the organizing committee for their tremendous efforts in organizing the conference: General Chair Zhou Laixin, Military Economics Academy of Wuhan Co-chairs Du Qifa, Military Economics Academy of Wuhan Serban Viorel-Aurel, ''Politehnica'' University of Timişoara Fen Youmei, Wuhan University Lin Pinghua, Huazhong University of Science and Technology Members Lin Darong, Military Economics Academy of Wuhan Guo Zhonghou, Military Economics Academy of Wuhan Sun Honghong, Military Economics Academy of Wuhan Liu Dong, Military Economics Academy of Wuhan We thank the authors for their contributions and we would also like to express our gratitude everyone who contributed to this conference, especially for the generous support of the sponsor: micromega S C Micro-Mega HD S A Ludovic Dan Lemle and Yiwen Jiang Coordinators of the Scientific Committee of ICAS2013 Deatails of organizers and members of the scientific commmittee are available in the PDF

The cost effectiveness of genetic testing for CYP2C19 variants to guide thienopyridine treatment in patients with acute coronary syndromes: a New Zealand evaluation.

PubMed

Panattoni, Laura; Brown, Paul M; Te Ao, Braden; Webster, Mark; Gladding, Patrick

2012-11-01

A recent clinical trial has demonstrated that patients with acute coronary syndromes (ACS) and the reduced function allele CYP2C19*2 (*2 allele), who are treated with thienopyridines, have an increased risk of adverse cardiac events with clopidogrel, but not with prasugrel. The frequency of the *2 allele varies by ethnicity and the Maoris, Asians and Pacific Islanders of New Zealand have a relatively high incidence. Our objective was to evaluate, from a New Zealand health system perspective, the cost effectiveness of treating all ACS patients with generic clopidogrel compared with prasugrel, and also compared with the genetically guided strategy that *2 allele carriers receive prasugrel and non-carriers receive clopidogrel. A decision-tree model consisting of five health states (myocardial infarction, stroke, bleeding, stent thrombosis and cardiovascular death) was developed. Clinical outcome data (two TRITON-TIMI 38 genetic sub-studies) comparing clopidogrel and prasugrel for both *2 allele carriers and non-carriers were combined with the prevalence of the heterozygosity for the *2 allele in New Zealand Europeans (15%), Maoris (24%), Asians (29%) and Pacific Islanders (45%) to determine the predicted adverse event rate for the New Zealand population. National hospital diagnosis-related group (DRG) discharge codes were used to determine alternative adverse event rates, along with the costs of hospitalizations during the 15 months after patients presented with an ACS. The primary outcome measure was the incremental cost per QALY (calculated using literature-reported weights). Monte Carlo simulations and alternative scenario analysis based on both clinical trial and national hospital incidence were used. Additional analysis considered the overall TRITON-TIMI 38 rates. Costs (in New Zealand dollars [$NZ], year 2009 values) and benefits were discounted at 3% per annum. Actual hospital-based adverse event rates were higher than those reported in the TRITON-TIMI 38 randomized controlled trial and the genetic sub-studies, especially for myocardial infarction and cardiovascular death, and for Maoris and Pacific Islanders. For both sources of adverse event rates, treating the population with prasugrel was associated with worse outcomes (QALYs) than clopidogrel. However, prasugrel became cost effective ($NZ31 751/QALY) when the overall TRITON-TIMI 38 rates were used. A genetic test to guide the selected use of prasugrel was cost effective ($NZ8702/QALY versus $NZ24 617/QALY) for hospital and clinical trial incidence, respectively. Based on the hospital rates, the genetically guided strategy was especially cost effective for Maoris ($NZ7312/QALY) and Pacific Islanders ($NZ7041/QALY). These results were robust to the sensitivity analysis, except the genetically guided strategy under the 15-month clinical trial event rate scenario ($NZ168 748/QALY) did not remain cost effective under a $NZ50 000 threshold. Use of a genetic test to guide thienopyridine treatment in patients with ACS is a potentially cost-effective treatment strategy, especially for Maoris and Pacific Islanders. This treatment strategy also has the potential to reduce ethnic health disparities that exist in New Zealand. However, the results comparing clopidogrel and prasugrel are sensitive to whether the genetic sub-studies or the overall TRITON-TIMI 38 rates are used. While the national hospital event rates may be more appropriate for the New Zealand population, many assumptions are required when they are used to adjust the genetic sub-studies rates.

Primary angioplasty for infarction due to isolated right ventricular artery occlusion.

PubMed

Chahal, Anwar A; Kim, Min-Young; Borg, Alexander N; Al-Najjar, Yahya

2014-11-26

We report an unusual case of an isolated right ventricular infarction with haemodynamic compromise caused by spontaneous isolated proximal occlusion of the right ventricular branch of the right coronary artery (RCA), successfully treated by balloon angioplasty. A 58-year-old gentleman presented with epigastric pain radiating into both arms. Electrocardiograph with right ventricular leads confirmed ST elevation in V4R and a diagnosis of isolated right ventricular infarction was made. Urgent primary percutaneous intervention was performed which revealed occlusion of the right ventricular branch of the RCA. During the procedure, the patient's blood pressure dropped to 80/40 mmHg, and echocardiography showed impaired right ventricular systolic function. Despite aggressive fluid resuscitation, the patient remained hypotensive, continued to have chest pain and persistent electrocardiograph changes, and hence balloon angioplasty was performed on the proximal right ventricular branch which restored flow to the vessel and revealed a severe ostial stenosis. This was treated with further balloon angioplasty which restored TIMI 3 flow with resolution of patient's symptoms. Repeat echocardiography showed complete resolution of the ST-elevation in leads V4R and V5R and partial resolution in V1. Subsequent dobutamine-stress echocardiography at 4 wk showed good left and right ventricular contractions. The patient was discharged after a 3-d in-patient stay without any complications.

Bioresorbable vascular scaffolds for LMCA with double vessel disease under IVUS guidance.

PubMed

Kasturi, Sridhar; Vilvanathan, Vinoth Kumar

2015-12-01

An 80-year-old male patient, presented with chest pain. ECG showed ST elevation in leads V2 to V4 and T wave inversion in leads V2-V6. Check angiogram revealed ostial LMCA 70% lesion & mid-LAD 90% lesion and LCX proximal 80% lesion. Predilatation of LMCA lesion was done with 2.0 × 12 mm NC Trek balloon and the LAD lesion with 2.0 × 12 mm and 2.5 × 08 mm (NC Trek balloons). Prestenting IVUS (Intravascular ultrasound) was done with Atlantis SR pro 40 MHz 3.6 Fr catheter. IVUS showed the LAD to have a minimal lumen area of 2.6 sq mm with 90% fibrotic plaque and a vessel size of 2.5mm and the LMCA to have a minimal lumen area of 8.8 sq mm with 70% fibrotic plaque and vessel size of 3.8mm. Mid-LAD stenting was done with 2.5 × 28 mm Absorb Stent (BVS). Predilatation of LCX lesion was done with 2.5 × 08 mm NC Trek balloon. Then stenting was performed with 3.0 × 28 mm Absorb Stent (BVS). Check angiogram showed edge dissection proximal to the BVS Stent which was covered with 3.0 × 12 mm Xience Xpedtion Stent (DES). Then LMCA Stenting was done with 3.5 × 12 mm Absorb Stent. Post dilatation was done with 4.0 × 08 mm NC Trek balloon. Post Stenting LMCA - LAD IVUS was done. LMCA and LAD Stents were well opposed without any dissection or residual stenosis. TIMI III Flow was achieved in the final results. Copyright © 2015 Cardiological Society of India. Published by Elsevier B.V. All rights reserved.

Short-term and long-term prognostic outcomes of patients with ST-segment elevation myocardial infarction complicated by profound cardiogenic shock undergoing early extracorporeal membrane oxygenator-assisted primary percutaneous coronary intervention.

PubMed

Chung, Sheng-Ying; Tong, Meng-Shen; Sheu, Jiunn-Jye; Lee, Fan-Yen; Sung, Pei-Hsun; Chen, Chien-Jen; Yang, Cheng-Hsu; Wu, Chiung-Jen; Yip, Hon-Kan

2016-11-15

This study investigated the 30-day and long-term prognostic outcomes in patients with ST-segment elevation myocardial infarction (STEMI) complicated with profound cardiogenic shock (CS) undergoing early routine extracorporeal membrane oxygenator (ECMO)-assisted primary percutaneous coronary intervention (PCI). Between December 2005 and December 2014, 65 consecutive STEMI patients with profound CS underwent routine ECMO-supported primary PCI. The incidences of acute pulmonary edema, respiratory failure with requirement of mechanical ventilatory support upon presentation, and 30-day mortality rate were 100%, 95.4%, and 43.1%, respectively. The duration of hospitalization, mean long-term follow-up, and survival rate were 32.1±53.1 (days), 733.6±986.7 (days), and 32.3%, respectively. The mean APACHE score (32.6±8.3 vs. 28.5±7.5), peak serum creatinine level (4.3±2.4 vs. 1.7±1.2mg/dL), incidences of failed ECMO weaning (57.1% vs. 0%), successful ECMO weaning but in-hospital death (40.0% vs. 0%) were significantly lower in 30-day survivors than those in non-survivors (all p<0.05), whereas final thrombolysis in myocardial infarction (TIMI)-3 flow [53.6% vs. 91.9%] showed an opposite pattern compared to that of APACHE score in the two groups (p<0.02). Multivariate analysis demonstrated that unsuccessful reperfusion, failed ECMO weaning, and peak creatinine level were independent predictors of 30-day mortality (all p<0.01). Early ECMO-supported primary PCI in STEMI patients with profound CS was feasible as a life-saving strategy with acceptable 30-day and long-term prognostic outcomes. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Primary Angioplasty in Patients Older Than 75 Years. Profile of Patients and Procedures, Outcomes, and Predictors of Prognosis in the ESTROFA IM+75 Registry.

PubMed

de la Torre Hernández, José M; Brugaletta, Salvatore; Gómez Hospital, Joan A; Baz, José A; Pérez de Prado, Armando; López Palop, Ramón; Cid, Belén; García Camarero, Tamara; Diego, Alejandro; Gimeno de Carlos, Federico; Fernández Díaz, José A; Sanchis, Juan; Alfonso, Fernando; Blanco, Roberto; Botas, Javier; Navarro Cuartero, Javier; Moreu, José; Bosa, Francisco; Vegas Valle, José M; Elízaga, Jaime; Arrebola, Antonio L; Ruiz Arroyo, José R; Hernández-Hernández, Felipe; Salvatella, Neus; Monteagudo, Marta; Gómez Jaume, Alfredo; Carrillo, Xavier; Martín Reyes, Roberto; Lozano, Fernando; Rumoroso, José R; Andraka, Leire; Domínguez, Antonio J

2017-02-01

The proportion of elderly patients undergoing primary angioplasty is growing. The present study describes the clinical profile, procedural characteristics, outcomes, and predictors of outcome. A 31-center registry of consecutive patients older than 75 years treated with primary angioplasty. Clinical and procedural data were collected, and the patients underwent clinical follow-up. The study included 3576 patients (39.3% women, 48.5% with renal failure, 11.5% in Killip III or IV, and 29.8% with>6hours of chest pain). Multivessel disease was present in 55.4% and nonculprit lesions were additionally treated in 24.8%. Radial access was used in 56.4%, bivalirudin in 11.8%, thromboaspiration in 55.9%, and drug-eluting stents in 26.6%. The 1-month and 2-year incidences of cardiovascular death were 10.1% and 14.7%, respectively. The 2-year rates of definite or probable thrombosis, repeat revascularization, and BARC bleeding>2 were 3.1%, 2.3%, and 4.2%, respectively. Predictive factors were diabetes mellitus, renal failure, atrial fibrillation, delay to reperfusion>6hours, ejection fraction<45%, Killip class III-IV, radial access, bivalirudin, drug-eluting stents, final TIMI flow of III, and incomplete revascularization at discharge. Notable registry findings include frequently delayed presentation and a high prevalence of adverse factors such as renal failure and multivessel disease. Positive procedure-related predictors include shorter delay, use of radial access, bivalirudin, drug-eluting stents, and complete revascularization before discharge. Copyright © 2016 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.

Molecular Survey of Hepatozoon canis in Red Foxes (Vulpes vulpes) from Romania.

PubMed

Imre, Mirela; Dudu, Andreea; Ilie, Marius S; Morariu, Sorin; Imre, Kálmán; Dărăbuş, Gheorghe

2015-08-01

Blood samples of 119 red foxes, originating from 44 hunting grounds of 3 western counties (Arad, Hunedoara, and Timiş) of Romania, have been examined for the presence of Hepatozoon canis infection using the conventional polymerase chain reaction (PCR) of the fragment of 18S rRNA gene. Overall, 15 (12.6%) samples were found to be PCR-positive. Of the sampled hunting grounds, 29.5% (13/44) were found positive. Positive samples were recorded in all screened counties with the prevalence of 14.8% (9/61) in Arad, 9.8% (5/51) in Timiş, and 14.3% (1/7) in Hunedoara, respectively. No correlation was found (P > 0.05) between H. canis positivity and gender or territorial distribution of the infection. To confirm PCR results, 9 randomly selected amplicons were sequenced. The obtained sequences were identical to each other, confirmed the results of the conventional PCR, and showed 98-100% homology to other H. canis sequences. The results of the current survey support the role of red foxes as sylvatic reservoirs of H. canis in Romania.

Case Study: Ticagrelor in PLATO and Prasugrel in TRITON-TIMI 38 and TRILOGY-ACS Trials in Patients With Acute Coronary Syndromes

PubMed Central

Husted, Steen; Boersma, Eric

2016-01-01

Cross-trial comparisons are typically inappropriate as there are often numerous differences in study designs, populations, end points, and loading doses of the study drugs. These differences are clearly reflected in the most recent updates to the European Society of Cardiology (ESC) non-ST elevation acute coronary syndrome (NSTE-ACS) and ST elevation myocardial infarction (STEMI) guidelines, which include recommendations for the use of the antiplatelet agents ticagrelor, prasugrel, and clopidogrel, based in part on results from the TRial to assess Improvement in Therapeutic Outcomes by optimizing platelet inhibitioN with prasugrel–Thrombolysis In Myocardial Infarction (TRITON-TIMI) 38, TaRgeted platelet Inhibition to cLarify the Optimal strateGy to medicallY manage Acute Coronary Syndromes (TRILOGY-ACS) and PLATelet inhibition and patient Outcomes (PLATO) trials. Here, we describe each of these trials in detail and explain the differences between them that make direct comparisons difficult. In conclusion, this information, along with the current guidelines and recommendations, will assist clinicians in deciding the most appropriate treatment pathway for their patients with NSTE-ACS and STEMI. PMID:25830867

Safety and tolerability of SCH 530348 in patients undergoing non-urgent percutaneous coronary intervention: a randomised, double-blind, placebo-controlled phase II study.

PubMed

Becker, Richard C; Moliterno, David J; Jennings, Lisa K; Pieper, Karen S; Pei, Jinglan; Niederman, Alan; Ziada, Khaled M; Berman, Gail; Strony, John; Joseph, Diane; Mahaffey, Kenneth W; Van de Werf, Frans; Veltri, Enrico; Harrington, Robert A

2009-03-14

An antithrombotic drug is needed that safely reduces cardiovascular events in patients undergoing percutaneous coronary intervention (PCI). We therefore assessed the tolerability and safety of SCH 530348-an oral platelet protease-activated receptor-1 antagonist. We randomly assigned patients aged 45 years or older and undergoing non-urgent PCI or coronary angiography with planned PCI to an oral loading dose of SCH 530348 (10 mg, 20 mg, or 40 mg) or matching placebo in a 3:1 ratio in a multicentre international study. Those in the SCH 530348 group who subsequently underwent PCI (primary PCI cohort) continued taking an oral maintenance dose (0.5 mg, 1.0 mg, or 2.5 mg per day), and patients in the placebo group continued placebo for 60 days. The primary endpoint was the incidence of clinically significant major or minor bleeding according to the thrombolysis in myocardial infarction (TIMI) scale. Both investigators and patients were unaware of treatment allocation. Analysis was by intention to treat. This study is registered with ClinicalTrials.gov, number NCT00132912. 257 patients were assigned to placebo and 773 to SCH 530348. The primary endpoint occurred in 2 (2%) of 129, 3 (3%) of 120, and 7 (4%) of 173 patients, respectively, in the SCH 530348 10 mg, 20 mg, and 40 mg groups compared with 5 (3%) of 151 patients in the placebo group (p=0.5786). TIMI major plus minor bleeding occurred in 3 (2%) of 136, 5 (4%) of 139, and 4 (3%) of 138 patients given SCH 530348 0.5 mg, 1.0 mg, and 2.5 mg once per day, respectively (p=0.7561). Oral SCH 530348 was generally well tolerated and did not cause increased TIMI bleeding, even when administered concomitantly with aspirin and clopidogrel. Further testing in phase III trials to accurately define the safety and efficacy of SCH 530348 is warranted.

Validation of the Valve Academic Research Consortium Bleeding Definition in Patients With Severe Aortic Stenosis Undergoing Transcatheter Aortic Valve Implantation.

PubMed

Stortecky, Stefan; Stefanini, Giulio G; Pilgrim, Thomas; Heg, Dik; Praz, Fabien; Luterbacher, Fabienne; Piccolo, Raffaele; Khattab, Ahmed A; Räber, Lorenz; Langhammer, Bettina; Huber, Christoph; Meier, Bernhard; Jüni, Peter; Wenaweser, Peter; Windecker, Stephan

2015-09-25

The Valve Academic Research Consortium (VARC) has proposed a standardized definition of bleeding in patients undergoing transcatheter aortic valve interventions (TAVI). The VARC bleeding definition has not been validated or compared to other established bleeding definitions so far. Thus, we aimed to investigate the impact of bleeding and compare the predictivity of VARC bleeding events with established bleeding definitions. Between August 2007 and April 2012, 489 consecutive patients with severe aortic stenosis were included into the Bern-TAVI-Registry. Every bleeding complication was adjudicated according to the definitions of VARC, BARC, TIMI, and GUSTO. Periprocedural blood loss was added to the definition of VARC, providing a modified VARC definition. A total of 152 bleeding events were observed during the index hospitalization. Bleeding severity according to VARC was associated with a gradual increase in mortality, which was comparable to the BARC, TIMI, GUSTO, and the modified VARC classifications. The predictive precision of a multivariable model for mortality at 30 days was significantly improved by adding the most serious bleeding of VARC (area under the curve [AUC], 0.773; 95% confidence interval [CI], 0.706 to 0.839), BARC (AUC, 0.776; 95% CI, 0.694 to 0.857), TIMI (AUC, 0.768; 95% CI, 0.692 to 0.844), and GUSTO (AUC, 0.791; 95% CI, 0.714 to 0.869), with the modified VARC definition resulting in the best predictivity (AUC, 0.814; 95% CI, 0.759 to 0.870). The VARC bleeding definition offers a severity stratification that is associated with a gradual increase in mortality and prognostic information comparable to established bleeding definitions. Adding the information of periprocedural blood loss to VARC may increase the sensitivity and the predictive power of this classification. © 2015 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

Peri-operative Adverse Outcomes in Patients with Atrial Fibrillation Taking Warfarin or Edoxaban: Analysis of the ENGAGE AF-TIMI 48 Trial.

PubMed

Douketis, James D; Murphy, Sabina A; Antman, Elliott M; Grip, Laura T; Mercuri, Michele F; Ruff, Christian T; Weitz, Jeffrey I; Braunwald, Eugene; Giugliano, Robert P

2018-06-01

 Peri-operative management of anticoagulated patients with atrial fibrillation (AF) is challenging. To gain information on the peri-operative management of edoxaban, we compared outcomes in patients on warfarin or edoxaban enrolled in ENGAGE AF-TIMI 48 who underwent a surgery or invasive procedure.  Data from patients undergoing their first surgery/procedure were analysed and results compared by anticoagulant (warfarin vs. higher- or lower-dose edoxaban regimen [HDER and LDER, respectively]). Patients were classified by procedural management: anticoagulant interrupted (last dose 4-10 days pre-procedure) or anticoagulant continued (last dose ≤ 3 days pre-procedure). Stroke/systemic embolism (SSE), major bleeding (MB), MB or clinically relevant non-MB (CRNMB) and death were assessed from 7 days pre- until 30 days post-procedure. The chi-square test was used to compare outcomes across treatment groups.  A total of 7,193 patients (34%) underwent surgery/procedure: 3,116 had anticoagulant interrupted, 4,077 had anticoagulant continued. Among patients on warfarin, HDER and LDER who had anticoagulant interrupted, rates of SSE were 0.6, 0.5 and 0.9% ( p  = 0.53), rates of MB were 1.0, 1.2 and 1.1% ( p  = 0.94) and rates of MB or CRNMB were 3.9, 4.2 and 3.6% ( p  = 0.78); among patients on warfarin, HDER and LDER who had anticoagulant continued, rates of SSE were 1.1, 0.7 and 0.9% ( p  = 0.51), rates of MB were 3.6, 2.6 and 2.4% ( p  = 0.13) and rates of MB or CRNMB were 8.5, 7.9 and 6.6% ( p  = 0.17).  In patients requiring surgery/procedure in ENGAGE AF-TIMI 48, peri-operative rates of SSE, MB and death were not significantly different in patients who received edoxaban or warfarin. Schattauer GmbH Stuttgart.

Efficacy and Safety of Edoxaban in Elderly Patients With Atrial Fibrillation in the ENGAGE AF-TIMI 48 Trial.

PubMed

Kato, Eri Toda; Giugliano, Robert P; Ruff, Christian T; Koretsune, Yukihiro; Yamashita, Takeshi; Kiss, Robert Gabor; Nordio, Francesco; Murphy, Sabina A; Kimura, Tetsuya; Jin, James; Lanz, Hans; Mercuri, Michele; Braunwald, Eugene; Antman, Elliott M

2016-05-20

Elderly patients with atrial fibrillation are at higher risk of both ischemic and bleeding events compared to younger patients. In a prespecified analysis from the ENGAGE AF-TIMI 48 trial, we evaluate clinical outcomes with edoxaban versus warfarin according to age. Twenty-one thousand one-hundred and five patients enrolled in the ENGAGE AF-TIMI 48 trial were stratified into 3 prespecified age groups: <65 (n=5497), 65 to 74 (n=7134), and ≥75 (n=8474) years. Older patients were more likely to be female, with lower body weight and reduced creatinine clearance, leading to higher rates of edoxaban dose reduction (10%, 18%, and 41% for the 3 age groups, P<0.001). Stroke or systemic embolic event (1.1%, 1.8%, and 2.3%) and major bleeding (1.8%, 3.3%, and 4.8%) rates with warfarin increased across age groups (Ptrend<0.001 for both). There were no interactions between age group and randomized treatment in the primary efficacy and safety outcomes. In the elderly (≥75 years), the rates of stroke/systemic embolic event were similar with edoxaban versus warfarin (hazard ratio 0.83 [0.66-1.04]), while major bleeding was significantly reduced with edoxaban (hazard ratio 0.83 [0.70-0.99]). The absolute risk difference in major bleeding (-82 events/10 000 pt-yrs) and in intracranial hemorrhage (-73 events/10 000 pt-yrs) both favored edoxaban over warfarin in older patients. Age has a greater influence on major bleeding than thromboembolic risk in patients with atrial fibrillation. Given the higher rates of bleeding and death with increasing age, treatment of elderly patients with edoxaban provides an even greater absolute reduction in safety events over warfarin, compared to treatment with edoxaban versus warfarin in younger patients. URL: https://www.clinicaltrials.gov/. Unique identifier: NCT00781391. © 2016 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

Design and rationale for the Cardiovascular and Metabolic Effects of Lorcaserin in Overweight and Obese Patients-Thrombolysis in Myocardial Infarction 61 (CAMELLIA-TIMI 61) trial.

PubMed

Bohula, Erin A; Scirica, Benjamin M; Fanola, Christina; Inzucchi, Silvio E; Keech, Anthony; McGuire, Darren K; Smith, Steven R; Abrahamsen, Tim; Francis, Bruce H; Miao, Wenfeng; Perdomo, Carlos A; Satlin, Andrew; Wiviott, Stephen D; Sabatine, Marc S

2018-03-29

Lorcaserin, a selective serotonin 2C receptor agonist, is an effective pharmacologic weight-loss therapy that improves several cardiovascular risk factors. The long-term clinical cardiovascular and metabolic safety and efficacy in patients with elevated cardiovascular risk are unknown. CAMELLIA-TIMI 61 (NCT02019264) is a randomized, double-blind, placebo-controlled, multinational clinical trial designed to evaluate the safety and efficacy of lorcaserin with regard to major adverse cardiovascular events and progression to diabetes in overweight or obese patients at high cardiovascular risk. Overweight or obese patients either with established cardiovascular disease or with diabetes and at least 1 other cardiovascular risk factor were randomized in a 1:1 ratio to lorcaserin 10 mg twice daily or matching placebo. The primary safety objective is to assess for noninferiority of lorcaserin for the composite end point of cardiovascular death, myocardial infarction, or stroke (major adverse cardiovascular event [MACE]) (with noninferiority defined as the upper bound of a 1-sided 97.5% CI excluding a hazard ratio of 1.4) compared with placebo assessed at an interim analysis with 460 adjudicated events. The efficacy objectives, assessed at study completion, will evaluate the superiority of lorcaserin for the primary composite end point of cardiovascular death, myocardial infarction, stroke, hospitalization for unstable angina, heart failure, or any coronary revascularization (MACE+) and the key secondary end point of conversion to diabetes. Recruitment began in January 2014 and was completed in November 2015 resulting in a total population of 12,000 patients. The trial is planned to continue until at least 1,401 adjudicated MACE+ events are accrued and the median treatment duration exceeds 2.5 years. CAMELLIA-TIMI 61 is investigating the safety and efficacy of lorcaserin for MACEs and conversion to diabetes in overweight or obese patients with established cardiovascular disease or multiple cardiovascular risk factors. Copyright © 2018. Published by Elsevier Inc.

Correlation of inhibition of platelet aggregation after clopidogrel with post discharge bleeding events: assessment by different bleeding classifications.

PubMed

Serebruany, Victor; Rao, Sunil V; Silva, Matthew A; Donovan, Jennifer L; Kannan, Abir O; Makarov, Leonid; Goto, Shinya; Atar, Dan

2010-01-01

To correlate inhibition of platelet aggregation (IPA) with bleeding events assessed by TIMI, GUSTO, and BleedScore scales in a large cohort of patients with coronary artery disease (CAD) and ischaemic stroke (IS) treated with chronic low-dose aspirin plus clopidogrel. Data from recent trials and registries suggest a link between increased risk of bleeding and cardiovascular mortality. However, the potential association of bleeding risk and IPA is not established. It may play a critical role for the safety of more aggressive platelet inhibition or/and individual tailoring of antiplatelet strategies. Secondary post hoc analyses of 5 microM ADP-induced IPA and bleeding complications assessed by TIMI, GUSTO, and BleedScore scales in a combined data set consisting of patients with documented CAD (n = 246) and previous IS (n = 117). Demographic characteristics differ substantially depending on the underlying vascular disease; however, IPA and bleeding risks were similar between CAD and IS. All three bleeding scales adequately captured serious haemorrhagic events, where the TIMI scale was the most exclusive, whereas BleedScore was the most inclusive. Over half of all patients experienced superficial event(s), most commonly occurring during two to three distinct bleeding episodes. There was no correlation between IPA and duration of antiplatelet therapy. Inhibition of platelet aggregation >50% strongly correlates with minor (r(2) = 0.58, P < 0.001; c-statistic = 0.92), but not severe (r(2) = 0.11, P = 0.038; c-statistic = 0.57), bleeding events. Chronic oral combination antiplatelet regimens are associated with a very high (56.5-60.7%) prevalence of superficial bleeding episodes, which are grossly underestimated in trials and registries. The role of such frequent mild complications for the overall benefit of antiplatelet therapy is entirely unknown, as is their effect on compliance. Although IPA is well suited for defining the risk of minor complications, prediction of more severe bleeding events may be challenging.

Application of computerized exercise ECG digitization. Interpretation in large clinical trials.

PubMed

Caralis, D G; Shaw, L; Bilgere, B; Younis, L; Stocke, K; Wiens, R D; Chaitman, B R

1992-04-01

The authors report on a semiautomated program that incorporates both visual identification of fiducial points and digital determination of the ST-segment at 60 ms and 80 ms from the J point, ST slope, changes in R wave, and baseline drift. The off-line program can enhance the accuracy of detecting electrocardiographic (ECG) changes, as well as reproducibility of the exercise and postexercise ECG, as a marker of myocardial ischemia. The analysis program is written in Microsoft QuickBASIC 2.0 for an IBM personal computer interfaced to a Summagraphics mm1201 microgrid II digitizer. The program consists of the following components: (1) alphanumeric data entry, (2) ECG wave form digitization, (2) calculation of test results, (4) physician overread, and (5) editor function for remeasurements. This computerized exercise ECG digitization-interpretation program is accurate and reproducible for the quantitative assessment of ST changes and requires minimal time allotment for physician overread. The program is suitable for analysis and interpretation of large volumes of exercise tests in multicenter clinical trials and is currently utilized in the TIMI II, TIMI III, and BARI studies sponsored by the National Institutes of Health.

Prognostic value of heart rate turbulence for risk assessment in patients with unstable angina and non-ST elevation myocardial infarction

PubMed Central

Harris, Patricia RE; Stein, Phyllis K; Fung, Gordon L; Drew, Barbara J

2013-01-01

Background We sought to examine the prognostic value of heart rate turbulence derived from electrocardiographic recordings initiated in the emergency department for patients with non-ST elevation myocardial infarction (NSTEMI) or unstable angina. Methods Twenty-four-hour Holter recordings were started in patients with cardiac symptoms approximately 45 minutes after arrival in the emergency department. Patients subsequently diagnosed with NSTEMI or unstable angina who had recordings with ≥18 hours of sinus rhythm and sufficient data to compute Thrombolysis In Myocardial Infarction (TIMI) risk scores were chosen for analysis (n = 166). Endpoints were emergent re-entry to the cardiac emergency department and/or death at 30 days and one year. Results In Cox regression models, heart rate turbulence and TIMI risk scores together were significant predictors of 30-day (model chi square 13.200, P = 0.001, C-statistic 0.725) and one-year (model chi square 31.160, P < 0.001, C-statistic 0.695) endpoints, outperforming either measure alone. Conclusion Measurement of heart rate turbulence, initiated upon arrival at the emergency department, may provide additional incremental value in the risk assessment for patients with NSTEMI or unstable angina. PMID:23976860

Serological survey of Neospora caninum infection in cattle herds from Western Romania.

PubMed

Imre, Kálmán; Morariu, Sorin; Ilie, Marius S; Imre, Mirela; Ferrari, Nicola; Genchi, Claudio; Dărăbuş, Gheorghe

2012-06-01

Serum samples from 376 randomly selected adult cattle, from 25 farms located in 3 counties (Arad, Bihor, and Timiş) from western Romania, were sampled for Neospora caninum antibodies using a commercial ELISA-kit. Seroprevalence values and risk factors for neosporosis (cow age, breed, herd size, farming system, previous abortion, and number of farm dogs) were examined using a generalized linear mixed model with a binomial distribution. Overall, the seroprevalence of N. caninum was 27.7% (104/376) with a prevalence of 27.9% (24/86) in Arad, 26.9% (25/93) in Bihor, and 27.9% (55/197) in Timiş. Of 25 cattle herds, 23 were seropositive with a prevalence ranging from 10.0 to 52.2%. No correlation was found between N. caninum seropositivity and age, breed, herd size, breeding system, and previous abortion. The number of farm dogs was the only factor (P(Wald)  =  0.03) positively associated with seroprevalence in cows and can be considered the risk factor in the acquiring of infection. The present work is the first regarding serological evidence of N. caninum infection in cattle from western Romania.

Importance of tissue perfusion in ST segment elevation myocardial infarction patients undergoing reperfusion strategies: role of adenosine.

PubMed

Forman, Mervyn B; Jackson, Edwin K

2007-11-01

High risk ST segment elevation myocardial infarction (STEMI) patients undergoing reperfusion therapy continue to exhibit significant morbidity and mortality due in part to myocardial reperfusion injury. Importantly, preclinical studies demonstrate that progressive microcirculatory failure (the "no-reflow" phenomenon) contributes significantly to myocardial reperfusion injury. Diagnostic techniques to measure tissue perfusion have validated this concept in humans, and it is now clear that abnormal tissue perfusion occurs frequently in STEMI patients undergoing reperfusion therapy. Moreover, because tissue perfusion correlates poorly with epicardial blood flow (TIMI flow grade), clinical studies show that tissue perfusion is an independent predictor of early and late mortality in STEMI patients and is associated with infarct size, ventricular function, CHF and ventricular arrhythmias. The mechanisms responsible for abnormal tissue perfusion are multifactorial and include both mechanical obstruction and vasoconstrictor humoral factors. Adenosine, an endogenous nucleoside, maintains microcirculatory flow following reperfusion by activating four well-characterized extracellular receptors. Because activation of adenosine receptors attenuates the mechanical and functional mechanisms leading to the "no reflow" phenomenon and activates other cardioprotective pathways as well, it is not surprising that both experimental and clinical studies show striking myocardial salvage with intravenous infusions of adenosine administered in the peri-reperfusion period. For example, a post hoc analysis of the AMISTAD II trial indicates a significant reduction in 1 and 6-month mortality in STEMI patients undergoing reperfusion therapy who are treated with adenosine within 3 hours of symptoms. In conclusion, adenosine's numerous cardioprotective effects, including attenuation of the "no-reflow" phenomenon, support its use in high risk STEMI undergoing reperfusion.

Relationship between blood viscosity and infarct size in patients with ST-segment elevation myocardial infarction undergoing primary percutaneous coronary intervention.

PubMed

Cecchi, Emanuele; Liotta, Agatina Alessandriello; Gori, Anna Maria; Valente, Serafina; Giglioli, Cristina; Lazzeri, Chiara; Sofi, Francesco; Gensini, Gian Franco; Abbate, Rosanna; Mannini, Lucia

2009-05-15

Previous studies explored the association between hemorheological alterations and acute myocardial infarction, pointing out the role of hematological components on microvascular flow. The aim of this study was to evaluate the association between blood viscosity and infarct size, estimated by creatine kinase (CK) peak activity and cardiac Troponin I (cTnI) peak concentration in ST-segment elevation myocardial infarction (STEMI) patients after primary percutaneous coronary intervention (PCI). The study population included 197 patients with diagnosis of STEMI undergoing PCI. Hemorheological studies were performed by assessing whole blood viscosity (measured at shear rates of 0.512 s(-1) and 94.5 s(-1)) and plasma viscosity using the Rotational Viscosimeter LS 30 and erythrocyte deformability index by Myrenne filtrometer. Significant correlations between CK peak activity, cTnI peak concentration, left ventricular ejection fraction and hemorheological variables were observed. At linear regression analysis (adjusted for age, gender, traditional cardiovascular risk factors, renal dysfunction, timeliness of reperfusion, pre-PCI TIMI flow, infarct location, multivessel disease and previous coronary artery disease) leukocytes and whole blood viscosity at 0.512 s(-1) and 94.5 s(-1) were independently and positively associated with infarct size. These results demonstrate a significant and independent association between hemorheology and infarct size in STEMI patients after PCI suggesting that blood viscosity, in a condition of low flow, might worsen myocardial perfusion leading to an increased infarct size. The measurement of whole blood viscosity in STEMI patients could help to identify those who may benefit from new therapeutic strategies.

Prospective Clinical Trial of Robotically Assisted Endoscopic Coronary Grafting With 1-Year Follow-Up

PubMed Central

Prasad, Sunil M.; Ducko, Christopher T.; Stephenson, Edward R.; Chambers, Charles E.; Damiano, Ralph J.

2001-01-01

Objective To follow up in prospective fashion patients with coronary artery anastomoses completed endoscopically with robotic assistance. The robotic system was evaluated for safety and its effectiveness in completing microsurgical coronary anastomoses. Summary Background Data Recently there has been an interest in using robotics and computers to enhance the surgeon’s ability to perform endoscopic cardiac surgery. This interest has stemmed from the rapid advancement of technology and the desire to make cardiac surgery less invasive. Using traditional endoscopic instruments, it has not been possible to perform coronary surgery. Methods Nineteen patients underwent robotically assisted endoscopic coronary artery bypass grafting of the left internal thoracic artery (LITA) to the left anterior descending artery (LAD). Two robotic instruments and one endoscopic camera were placed through three 5-mm ports. A robotic system was used to construct the LITA–LAD anastomosis. All other required grafts were completed by conventional techniques. Results Seventeen LITA–LAD grafts (89%) had adequate intraoperative flow. The mean LITA–LAD graft flow was 38.5 ± 5 mL/min. At 8 weeks, LITA–LAD grafts were assessed by angiography and showed 100% patency with thrombolysis in myocardial infarction (TIMI) I flow. At a mean follow-up of 17 ± 4.2 months, all patients were NYHA class I and there were no adverse cardiac events. Conclusions The results from the first prospective clinical trial of robotically assisted endoscopic coronary bypass surgery in the United States showed favorable short-term outcomes with no adverse events. Robotic assistance is an enabling technology allowing the performance of endoscopic coronary anastomoses. PMID:11371730

Assessment of the relationship between a narrow fragmented QRS complex and coronary slow flow.

PubMed

Cakmak, Huseyin Altug; Aslan, Serkan; Gul, Mehmet; Kalkan, Ali Kemal; Ozturk, Derya; Celik, Omer; Tasbulak, Omer; Satilmisoglu, Muhammet Hulusi

2015-01-01

The coronary slow flow (CSF) phenomenon is a delayed antegrade progression of contrast agent to the distal branch of a coronary artery in the absence of obstructive coronary artery disease (CAD). A narrow fragmented QRS (fQRS) has been reported as a significant predictor of sudden cardiac death in patients with idiopathic dilated cardiomyopathy. The present study aimed to investigate the relationship between a narrow fQRS on the admission electrocardiogram (ECG) and CSF on coronary angiography. This study included 165 consecutive patients (112 CSF, 53 controls) who underwent first-time diagnostic conventional coronary angiography for suspected CAD. Coronary flow was quantified by thrombolysis in myocardial infarction (TIMI) frame count (TFC). The patients were divided into two groups according to the presence or absence of a narrow fQRS complex on the admission ECG. Forty four patients were in the fQRS group (mean age, 52.97 ± 3.13 years). There was no difference between the two groups with respect to age, gender, body mass index, family history, hyperlipidemia, hypertension, or diabetes mellitus. The extent of CSF was significantly greater in the fQRS group compared to the non-fragmented group (p < 0.001). A significant correlation was also found between mean TFC values and fQRS (p < 0.001). On multivariate analysis, only CSF (p = 0.03) was a significant independent predictor for narrow fQRS, after adjustment for other parameters. The narrow fQRS is a simple, inexpensive, and readily available noninvasive ECG parameter that may be a new potential indicator of myocardial damage in patients with CSF.

Edoxaban Plus Aspirin vs Dual Antiplatelet Therapy in Endovascular Treatment of Patients With Peripheral Artery Disease: Results of the ePAD Trial

PubMed Central

Moll, Frans; Baumgartner, Iris; Jaff, Michael; Nwachuku, Chuke; Tangelder, Marco; Ansel, Gary; Adams, George; Zeller, Thomas; Rundback, John; Grosso, Michael; Lin, Min; Mercur, Michele F.; Minar, Erich

2018-01-01

Purpose: To report a randomized study that investigated the safety (risk of major bleeds) and potential efficacy of edoxaban, an oral anticoagulant that targets the major components of arterial thrombi, to prevent loss of patency following endovascular treatment (EVT). Methods: Between February 2012 and June 2014, 203 patients who underwent femoropopliteal EVT were randomized to receive aspirin plus edoxaban or aspirin plus clopidogrel for 3 months in the Edoxaban in Peripheral Arterial Disease (ePAD) study (ClinicalTrials.gov identifier NCT01802775). Randomization assigned 101 patients (mean age 68.0±10.4 years; 67 men) to the edoxaban group and 102 patients (mean age 66.7±8.6 years; 78 men) to the clopidogrel group. The primary safety endpoint was bleeding as classified by the TIMI (Thrombolysis in Myocardial Infarction) criteria and ISTH (International Society of Thrombosis and Hemostasis) criteria; the efficacy endpoint was the rate of restenosis/reocclusion. Results: There were no major or life-threatening bleeding events in the edoxaban group, while there were 2 major and 2 life-threatening bleeding events in the clopidogrel group by the TIMI criteria. By the ISTH classification, there was 1 major and 1 life-threatening bleeding event vs 5 major and 2 life-threatening bleeding events, respectively [relative risk (RR) 0.20, 95% confidence interval (CI) 0.02 to 1.70]. The bleeding risk was not statistically different with either treatment when assessed by TIMI or ISTH. Following 6 months of observation, there was a lower incidence of restenosis/reocclusion with edoxaban compared with clopidogrel (30.9% vs 34.7%; RR 0.89, 95% CI 0.59 to 1.34, p=0.643). Conclusion: These results suggest that patients who have undergone EVT have similar risks for major and life-threatening bleeding events with edoxaban and aspirin compared with clopidogrel and aspirin. The incidence of restenosis/reocclusion events, while not statistically different, was lower with edoxaban and aspirin, but an adequately sized trial will be needed to confirm these findings. PMID:29552984

Edoxaban Plus Aspirin vs Dual Antiplatelet Therapy in Endovascular Treatment of Patients With Peripheral Artery Disease: Results of the ePAD Trial.

PubMed

Moll, Frans; Baumgartner, Iris; Jaff, Michael; Nwachuku, Chuke; Tangelder, Marco; Ansel, Gary; Adams, George; Zeller, Thomas; Rundback, John; Grosso, Michael; Lin, Min; Mercur, Michele F; Minar, Erich

2018-04-01

To report a randomized study that investigated the safety (risk of major bleeds) and potential efficacy of edoxaban, an oral anticoagulant that targets the major components of arterial thrombi, to prevent loss of patency following endovascular treatment (EVT). Between February 2012 and June 2014, 203 patients who underwent femoropopliteal EVT were randomized to receive aspirin plus edoxaban or aspirin plus clopidogrel for 3 months in the Edoxaban in Peripheral Arterial Disease (ePAD) study ( ClinicalTrials.gov identifier NCT01802775). Randomization assigned 101 patients (mean age 68.0±10.4 years; 67 men) to the edoxaban group and 102 patients (mean age 66.7±8.6 years; 78 men) to the clopidogrel group. The primary safety endpoint was bleeding as classified by the TIMI (Thrombolysis in Myocardial Infarction) criteria and ISTH (International Society of Thrombosis and Hemostasis) criteria; the efficacy endpoint was the rate of restenosis/reocclusion. There were no major or life-threatening bleeding events in the edoxaban group, while there were 2 major and 2 life-threatening bleeding events in the clopidogrel group by the TIMI criteria. By the ISTH classification, there was 1 major and 1 life-threatening bleeding event vs 5 major and 2 life-threatening bleeding events, respectively [relative risk (RR) 0.20, 95% confidence interval (CI) 0.02 to 1.70]. The bleeding risk was not statistically different with either treatment when assessed by TIMI or ISTH. Following 6 months of observation, there was a lower incidence of restenosis/reocclusion with edoxaban compared with clopidogrel (30.9% vs 34.7%; RR 0.89, 95% CI 0.59 to 1.34, p=0.643). These results suggest that patients who have undergone EVT have similar risks for major and life-threatening bleeding events with edoxaban and aspirin compared with clopidogrel and aspirin. The incidence of restenosis/reocclusion events, while not statistically different, was lower with edoxaban and aspirin, but an adequately sized trial will be needed to confirm these findings.

Long-term use of ticagrelor in patients with prior myocardial infarction.

PubMed

Bonaca, Marc P; Bhatt, Deepak L; Cohen, Marc; Steg, Philippe Gabriel; Storey, Robert F; Jensen, Eva C; Magnani, Giulia; Bansilal, Sameer; Fish, M Polly; Im, Kyungah; Bengtsson, Olof; Oude Ophuis, Ton; Budaj, Andrzej; Theroux, Pierre; Ruda, Mikhail; Hamm, Christian; Goto, Shinya; Spinar, Jindrich; Nicolau, José Carlos; Kiss, Robert G; Murphy, Sabina A; Wiviott, Stephen D; Held, Peter; Braunwald, Eugene; Sabatine, Marc S

2015-05-07

The potential benefit of dual antiplatelet therapy beyond 1 year after a myocardial infarction has not been established. We investigated the efficacy and safety of ticagrelor, a P2Y12 receptor antagonist with established efficacy after an acute coronary syndrome, in this context. We randomly assigned, in a double-blind 1:1:1 fashion, 21,162 patients who had had a myocardial infarction 1 to 3 years earlier to ticagrelor at a dose of 90 mg twice daily, ticagrelor at a dose of 60 mg twice daily, or placebo. All the patients were to receive low-dose aspirin and were followed for a median of 33 months. The primary efficacy end point was the composite of cardiovascular death, myocardial infarction, or stroke. The primary safety end point was Thrombolysis in Myocardial Infarction (TIMI) major bleeding. The two ticagrelor doses each reduced, as compared with placebo, the rate of the primary efficacy end point, with Kaplan-Meier rates at 3 years of 7.85% in the group that received 90 mg of ticagrelor twice daily, 7.77% in the group that received 60 mg of ticagrelor twice daily, and 9.04% in the placebo group (hazard ratio for 90 mg of ticagrelor vs. placebo, 0.85; 95% confidence interval [CI], 0.75 to 0.96; P=0.008; hazard ratio for 60 mg of ticagrelor vs. placebo, 0.84; 95% CI, 0.74 to 0.95; P=0.004). Rates of TIMI major bleeding were higher with ticagrelor (2.60% with 90 mg and 2.30% with 60 mg) than with placebo (1.06%) (P<0.001 for each dose vs. placebo); the rates of intracranial hemorrhage or fatal bleeding in the three groups were 0.63%, 0.71%, and 0.60%, respectively. In patients with a myocardial infarction more than 1 year previously, treatment with ticagrelor significantly reduced the risk of cardiovascular death, myocardial infarction, or stroke and increased the risk of major bleeding. (Funded by AstraZeneca; PEGASUS-TIMI 54 ClinicalTrials.gov number, NCT01225562.).

Predicting the risk of bleeding during dual antiplatelet therapy after acute coronary syndromes.

PubMed

Alfredsson, Joakim; Neely, Benjamin; Neely, Megan L; Bhatt, Deepak L; Goodman, Shaun G; Tricoci, Pierluigi; Mahaffey, Kenneth W; Cornel, Jan H; White, Harvey D; Fox, Keith Aa; Prabhakaran, Dorairaj; Winters, Kenneth J; Armstrong, Paul W; Ohman, E Magnus; Roe, Matthew T

2017-08-01

Dual antiplatelet therapy (DAPT) with aspirin + a P2Y12 inhibitor is recommended for at least 12 months for patients with acute coronary syndrome (ACS), with shorter durations considered for patients with increased bleeding risk. However, there are no decision support tools available to predict an individual patient's bleeding risk during DAPT treatment in the post-ACS setting. To develop a longitudinal bleeding risk prediction model, we analy sed 9240 patients with unstable angina/non-ST segment elevation myocardial infarction (NSTEMI) from the Targeted Platelet Inhibition to Clarify the Optimal Strategy to Medically Manage Acute Coronary Syndromes (TRILOGY ACS) trial, who were managed without revasculari sation and treated with DAPT for a median of 14.8 months. We identified 10 significant baseline predictors of non-coronary artery bypass grafting (CABG)-related Global Use of Strategies to Open Occluded Arteries (GUSTO) severe/life-threatening/moderate bleeding: age, sex, weight, NSTEMI (vs unstable angina), angiography performed before randomi sation, prior peptic ulcer disease, creatinine, systolic blood pressure, haemoglobin and treatment with beta-blocker. The five significant baseline predictors of Thrombolysis In Myocardial Infarction (TIMI) major or minor bleeding included age, sex, angiography performed before randomi sation, creatinine and haemoglobin. The models showed good predictive accuracy with Therneau's C- indices: 0.78 (SE = 0.024) for the GUSTO model and 0.67 (SE = 0.023) for the TIMI model. Internal validation with bootstrapping gave similar C -indices of 0.77 and 0.65, respectively. External validation demonstrated an attenuated C -index for the GUSTO model (0.69) but not the TIMI model (0.68). Longitudinal bleeding risks during treatment with DAPT in patients with ACS can be reliably predicted using selected baseline characteristics. The TRILOGY ACS bleeding models can inform risk -benefit considerations regarding the duration of DAPT following ACS. ClinicalTrials.gov identifier: https://clinicaltrials.gov/ct2/show/NCT00699998. © 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.

Pharmacovigilance Evaluation of the Association Between DPP-4 Inhibitors and Heart Failure: Stimulated Reporting and Moderation by Drug Interactions.

PubMed

Fadini, Gian Paolo; Sarangdhar, Mayur; Avogaro, Angelo

2018-04-01

In the SAVOR-TIMI trial, the risk of heart failure (HF) was increased by 27% in T2D patients randomized to the dipeptidyl peptidase-4 inhibitor (DPP4i) saxagliptin. Other studies have provided inconsistent results regarding this association. Herein, we performed a pharmacovigilance analysis of the rate of HF associated with DPP4is, focusing on stimulated reporting and moderation by drug-drug interactions. We mined the FDA adverse event (AE) reporting system (FAERS) from 2004q1 to 2017q3, including a total of 9906,642 AE reports. Rates (/1000 reports) of HF within the reports for DPP4is and reports for other antidiabetic drugs were calculated for the period up to 2013q3 (date of publication of the SAVOR-TIMI trial results) and from 2013q4 to 2017q3. Analyses were refined by filtering according to therapeutic area, concomitant diseases and drugs, and competing AEs. The rate of HF among the AE reports filed for DPP4is significantly increased after 2013q3, especially for saxagliptin. When compared to non-insulin non-glitazone antidiabetic drugs, the proportional reporting ratio (PRR) of HF for DPP4is was 0.62 (95% CI 0.56-0.68) up to 2013q3 and 2.12 (95% CI 1.96-2.28) from 2013q4 to 2017q3. This stimulated reporting was consistent in subanalyses based on the presence/absence of cardiac disorders and after controlling for competing AEs. The rate of HF among AE reports for DPP4is was modestly moderated by the concomitant use of metformin (- 15%) and strongly moderated by the concomitant use of SGLT2 inhibitors (- 63%), even after excluding competing AEs. Within the FAERS, the association between HF and DPP4is was biased by stimulated reporting, implying that the publication of the SAVOR-TIMI trial and the subsequent regulatory warnings primed clinicians to report HF events in DPP4i users as drug-related AEs. The rate of HF associated with DPP4is was moderated when they were used in combination with SGLT2 inhibitors.

North American Solitaire Stent Retriever Acute Stroke registry: post-marketing revascularization and clinical outcome results.

PubMed

Zaidat, Osama O; Castonguay, Alicia C; Gupta, Rishi; Sun, Chung-Huan J; Martin, Coleman; Holloway, William E; Mueller-Kronast, Nils; English, Joey D; Linfante, Italo; Dabus, Guilherme; Malisch, Tim W; Marden, Franklin A; Bozorgchami, Hormozd; Xavier, Andrew; Rai, Ansaar T; Froehler, Michael T; Badruddin, Aamir; Nguyen, Thanh N; Taqi, M Asif; Abraham, Michael G; Janardhan, Vallabh; Shaltoni, Hashem; Novakovic, Roberta; Yoo, Albert J; Abou-Chebl, Alex; Chen, Peng R; Britz, Gavin W; Kaushal, Ritesh; Nanda, Ashish; Issa, Mohammad A; Nogueira, Raul G

2014-10-01

Limited post-marketing data exist on the use of the Solitaire FR device in clinical practice. The North American Solitaire Stent Retriever Acute Stroke (NASA) registry aimed to assess the real world performance of the Solitaire FR device in contrast with the results from the SWIFT (Solitaire with the Intention for Thrombectomy) and TREVO 2 (Trevo versus Merci retrievers for thrombectomy revascularization of large vessel occlusions in acute ischemic stroke) trials. The investigator initiated NASA registry recruited North American sites to submit retrospective angiographic and clinical outcome data on consecutive acute ischemic stroke (AIS) patients treated with the Solitaire FR between March 2012 and February 2013. The primary outcome was a Thrombolysis in Myocardial Ischemia (TIMI) score of ≥2 or a Treatment in Cerebral Infarction (TICI) score of ≥2a. Secondary outcomes were 90 day modified Rankin Scale (mRS) score, mortality, and symptomatic intracranial hemorrhage. 354 patients underwent treatment for AIS using the Solitaire FR device in 24 centers. Mean time from onset to groin puncture was 363.4±239 min, mean fluoroscopy time was 32.9±25.7 min, and mean procedure time was 100.9±57.8 min. Recanalization outcome: TIMI ≥2 rate of 83.3% (315/354) and TICI ≥2a rate of 87.5% (310/354) compared with the operator reported TIMI ≥2 rate of 83% in SWIFT and TICI ≥2a rate of 85% in TREVO 2. 42% (132/315) of NASA patients demonstrated a 90 day mRS ≤2 compared with 37% (SWIFT) and 40% (TREVO 2). 90 day mortality was 30.2% (95/315) versus 17.2% (SWIFT) and 29% (TREVO 2). The NASA registry demonstrated that the Solitaire FR device performance in clinical practice is comparable with the SWIFT and TREVO 2 trial results. 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.

Transition of patients from blinded study drug to open-label anticoagulation: the ENGAGE AF-TIMI 48 trial.

PubMed

Ruff, Christian T; Giugliano, Robert P; Braunwald, Eugene; Mercuri, Michele; Curt, Valentin; Betcher, Joshua; Grip, Laura; Cange, Abby L; Crompton, Andrea E; Murphy, Sabina A; Deenadayalu, Naveen; Antman, Elliott M

2014-08-12

At the end of 2 previous trials, an excess of stroke and bleeding was observed in patients with AF randomized to a new oral anticoagulant (NOAC) who transitioned to a vitamin K antagonist (VKA). The ENGAGE AF-TIMI 48 (Effective Anticoagulation with Factor Xa Next Generation in Atrial Fibrillation-Thrombolysis in Myocardial Infarction 48) trial compared once-daily edoxaban to warfarin for stroke prevention in patients with AF. An end-of-trial transition plan was developed to minimize the risks of stroke due to inadequate anticoagulation and bleeding from excessive anticoagulation during this critical period. All patients on the blinded study drug at the trial's conclusion were included in this analysis. In pre-specified analyses, stroke, bleeding, and death that occurred through 30 days after the end-of-trial visit were stratified by randomized treatment allocation and open-label anticoagulant selected post-trial. Of the 13,642 patients taking the blinded study drug at the end of the trial, 9,304 (68.2%) were transitioned to open-label VKA and 4,258 patients (31.2%) to an NOAC. There were 21 strokes evenly distributed across the 3 randomized treatment arms: warfarin 7 (1.90%/year), edoxaban high dose 7 (1.89%/year), edoxaban low dose 7 (1.85%/year). Major bleeding was also similar across the 3 treatment arms: warfarin 11 (2.98%/year), edoxaban high dose 10 (2.69%/year), edoxaban low dose 18 (4.76%/year). In patients transitioned to VKA, 85% of patients had at least 1 INR ≥ 2 by day 14 after the transition and 99% by day 30. The ENGAGE AF-TIMI 48 transition plan protected patients from an excess of thrombotic and bleeding events and should be helpful in clinical practice when patients are transitioned between oral anticoagulants. (Global Study to Assess the Safety and Effectiveness of Edoxaban [DU-176b] vs Standard Practice of Dosing With Warfarin in Patients With Atrial Fibrillation [EngageAFTIMI48]; NCT00781391). Copyright © 2014 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Edoxaban vs warfarin in patients with nonvalvular atrial fibrillation in the US Food and Drug Administration approval population: An analysis from the Effective Anticoagulation with Factor Xa Next Generation in Atrial Fibrillation-Thrombolysis in Myocardial Infarction 48 (ENGAGE AF-TIMI 48) trial.

PubMed

Eisen, Alon; Giugliano, Robert P; Ruff, Christian T; Nordio, Francesco; Gogia, Harinder S; Awasty, Vivek R; Henderson, David A; Mercuri, Michele F; Rutman, Howard; Antman, Elliott M; Braunwald, Eugene

2016-02-01

Edoxaban is a specific anti-Xa inhibitor that, in comparison to warfarin, has been found to be noninferior for the prevention of stroke or systemic embolism (SSE) and to reduce bleeding significantly in patients with nonvalvular atrial fibrillation (AF). The US Food and Drug Administration (FDA) approved the higher-dose edoxaban regimen (60/30 mg) in patients with AF and a creatinine clearance of ≤95 mL/min. We report for the first time the clinical characteristics, efficacy, and safety of the FDA-approved population in the ENGAGE AF--TIMI 48 trial. The patients included had been treated with either warfarin or edoxaban 60/30 mg and had a creatinine clearance of ≤95 mL/min. The primary efficacy was SSE, and the principal safety end point was major bleeding (International Society on Thrombosis and Haemostasis classification). Median follow-up was 2.8 years. Patients in the FDA-approved cohort were older, were more likely female, and had higher CHADS2 and HAS-BLED scores, as compared with patients not included in the FDA label. The primary end point occurred in 1.63%/y with edoxaban vs 2.02%/y with warfarin (hazard ratio [HR] 0.81, 95% CI 0.67-0.97, P = .023). Edoxaban significantly reduced the rate of hemorrhagic stroke (HR 0.47, 95% CI 0.31-0.72, P < .001) and cardiovascular death (HR 0.84, 95% CI 0.73-0.97, P = .015). Ischemic stroke rates were similar between the treatment groups (1.31%/y vs 1.39%/y, P = .97). Major bleeding was significantly lower with edoxaban (3.16%/y vs 3.77%/y; HR 0.84, 95% CI 0.72-0.98, P = .023). In the FDA-approved cohort of the ENGAGE AF--TIMI 48 trial, treatment with edoxaban 60/30 mg was superior to warfarin in the prevention of SSE and significantly reduced cardiovascular death and bleeding, especially fatal bleeding and hemorrhagic stroke. Copyright © 2015 Elsevier Inc. All rights reserved.

Saxagliptin for the treatment of diabetes - a focus on safety.

PubMed

Cernea, Simona; Cahn, Avivit; Raz, Itamar

2016-05-01

The safety of agents used to treat type 2 diabetes (T2D), a chronic disease requiring life-long intervention, is of particular interest. Saxagliptin is a potent and selective DPP-4 inhibitor that has emerged as a therapeutic option for T2D. Its safety was assessed in a development program of 20 phase 2/3 randomized clinical trials and in SAVOR-TIMI 53 trial that evaluated the cardiovascular outcomes. In order to capture any further safety signals, mainly in the long-term, a post-marketing safety surveillance is ongoing. This paper discusses the tolerability and safety profile of the agent, including cardiovascular, renal, pancreatic, hepatic and bone adverse events. Saxagliptin is a safe therapeutic option for patients with T2D, with low risk of hypoglycemia and good tolerability. It demonstrated cardiovascular safety (including in patients with pre-existing cardiovascular disease and/or HF) and safety with respect to all-cause mortality and adverse events of special interest. In SAVOR-TIMI53, saxagliptin was associated with an unexpected increased risk of HF hospitalization, mainly in the first 12 months; a mechanistic explanation for this has not been found. Further research needs to elucidate the effect of antidiabetic drugs on the heart, by including biomarkers and echocardiographic sub-studies within large outcome trials.

Impact of iso-osmolar versus low-osmolar contrast agents on contrast-induced nephropathy and tissue reperfusion in unselected patients with ST-segment elevation myocardial infarction undergoing primary percutaneous coronary intervention (from the Contrast Media and Nephrotoxicity Following Primary Angioplasty for Acute Myocardial Infarction [CONTRAST-AMI] Trial).

PubMed

Bolognese, Leonardo; Falsini, Giovanni; Schwenke, Carsten; Grotti, Simone; Limbruno, Ugo; Liistro, Francesco; Carrera, Arcangelo; Angioli, Paolo; Picchi, Andrea; Ducci, Kenneth; Pierli, Carlo

2012-01-01

Conflicting data have been reported on the effects of low-osmolar and iso-osmolar contrast media on contrast-induced acute kidney injury (CI-AKI). In particular, no clinical trial has yet focused on the effect of contemporary contrast media on CI-AKI, epicardial flow, and microcirculatory function in patients with ST-segment elevation acute myocardial infarction who undergo primary percutaneous coronary intervention. The Contrast Media and Nephrotoxicity Following Coronary Revascularization by Angioplasty for Acute Myocardial Infarction (CONTRAST-AMI) trial is a prospective, randomized, single-blind, parallel-group, noninferiority study aiming to evaluate the effects of the low-osmolar contrast medium iopromide compared to the iso-osmolar agent iodixanol on CI-AKI and tissue-level perfusion in patients with ST-segment elevation acute myocardial infarction. Four hundred seventy-five consecutive, unselected patients who underwent primary percutaneous coronary intervention were randomized to iopromide (n = 239) or iodixanol (n = 236). All patients received high-dose N-acetylcysteine and hydration. The primary end point was the proportion of patients with serum creatinine (sCr) increases ≥25% from baseline to 72 hours. Secondary end points were Thrombolysis In Myocardial Infarction (TIMI) myocardial perfusion grade, increase in sCr ≥50%, increase in sCr ≥0.5 or ≥1 mg/dl, and 1-month major adverse cardiac events. The primary end point occurred in 10% of the iopromide group and in 13% of the iodixanol group (95% confidence interval -9% to 3%, p for noninferiority = 0.0002). A TIMI myocardial perfusion grade of 0 or 1 was present in 14% of patients in the 2 groups. No differences between the 2 groups were found in any of the secondary analyses of sCr increase. No significant difference in 1-month major adverse cardiac events was found (8% vs 6%, p = 0.37). In conclusion, in a population of unselected patients with ST-segment elevation acute myocardial infarction who underwent primary percutaneous coronary intervention, iopromide was not inferior to iodixanol in the occurrence of CI-AKI; no significant differences were found in terms of tissue-level reperfusion and major adverse cardiac events between the 2 contrast agents. Copyright © 2012 Elsevier Inc. All rights reserved.

Anxiety, Depression, and General Psychological Distress in Patients with Coronary Slow Flow

PubMed Central

Karataş, Mehmet Baran; Şahan, Ebru; Özcan, Kazım Serhan; Çanga, Yiğit; Güngör, Barış; Onuk, Tolga; İpek, Göktürk; Çakıllı, Yasin; Arugaslan, Emre; Bolca, Osman

2015-01-01

Background The relationship between psychiatric illness and heart disease has been frequently discussed in the literature. The aim of the present study was to investigate the relationship between anxiety, depression and overall psychological distress, and coronary slow flow (CSF). Methods In total, 44 patients with CSF and a control group of 50 patients with normal coronary arteries (NCA) were prospectively recruited. Clinical data, admission laboratory parameters, and echocardiographic and angiographic characteristics were recorded. Symptom Checklist 90 Revised (SCL-90-R), Beck Depression Inventory (BDI), and Beck Anxiety Inventory (BAI) scales were administered to each patient. Results The groups were comparable with respect to age, sex, and atherosclerotic risk factors. In the CSF group, BAI score, BDI score, and general symptom index were significantly higher than controls (13 [18.7] vs. 7.5 [7], p = 0.01; 11 [14.7] vs. 6.5 [7], p = 0.01; 1.76 [0.81] vs. 1.1[0.24], p = 0.01; respectively). Patients with CSF in more than one vessel had the highest test scores. In univariate correlation analysis, mean thrombolysis in myocardial infarction (TIMI) frame counts were positively correlated with BAI (r = 0.56, p = 0.01), BDI (r = 0.47, p = 0.01), and general symptom index (r = 0.65, p = 0.01). The psychiatric tests were not correlated with risk factors for atherosclerosis. Conclusion Our study revealed higher rates of depression, anxiety, and overall psychological distress in patients with CSF. This conclusion warrants further studies. PMID:26559983

Incidence of pancreatitis and pancreatic cancer in a randomized controlled multicenter trial (SAVOR-TIMI 53) of the dipeptidyl peptidase-4 inhibitor saxagliptin.

PubMed

Raz, Itamar; Bhatt, Deepak L; Hirshberg, Boaz; Mosenzon, Ofri; Scirica, Benjamin M; Umez-Eronini, Amarachi; Im, KyungAh; Stahre, Christina; Buskila, Alona; Iqbal, Nayyar; Greenberger, Norton; Lerch, Markus M

2014-09-01

To determine the incidence of pancreatitis and pancreatic cancer in the SAVOR-TIMI 53 trial. A total of 16,492 type 2 diabetic patients ≥40 years old with established cardiovascular (CV) disease or CV risk factors were randomized to saxagliptin or placebo and followed for 2.1 years. Outcome measures were investigator reported with blinded expert adjudication of total pancreatitis (acute and chronic) and reported cases of pancreatic cancer. Trial investigators reported 35 events of pancreatitis in each treatment arm in 63 patients (33 [0.40%] in the saxagliptin arm and 30 [0.37%] in control arm), with a hazard ratio (HR) of 1.09 (95% CI 0.66-1.79, P = 0.80). Adjudication confirmed pancreatitis in 24 patients (26 events) in the saxagliptin arm (0.29%) and 21 patients (25 events) in placebo arm (0.26%), with an HR of 1.13 (0.63-2.06, P = 0.77). Cases of definite acute pancreatitis were confirmed in 17 (0.2%) vs. 9 (0.1%) (HR 1.88 [0.86-4.41], P = 0.17), definite plus possible pancreatitis in 22 vs. 16 (HR 1.36 [0.72-2.64], P = 0.42), and chronic pancreatitis in 2 vs. 6 (HR 0.33 [0.05-1.44], P = 0.18) in the saxagliptin and placebo arms, respectively. No differences in time to event onset, concomitant risk factors for pancreatitis, investigator-reported causality from study medication or disease severity, and outcome were found between treatment arms. The investigators reported 5 and 12 cases of pancreatic cancer in the saxagliptin and placebo arms, respectively (HR 0.42 [0.13-1.12], P = 0.09). In the SAVOR-TIMI 53 trial, within 2.1 years of follow-up, risk for pancreatitis in type 2 diabetic patients treated with saxagliptin was low and apparently similar to placebo, with no sign of increased risk for pancreatic cancer. Further studies are needed to completely resolve the pancreatic safety issues with incretin-based therapy. © 2014 by the American Diabetes Association. Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered.

The sequential changes in myocardial thickness and thickening which occur during acute transmural infarction, infarct reperfusion and the resultant expression of reperfusion injury.

PubMed

Turschner, Oliver; D'hooge, Jan; Dommke, Christoph; Claus, Piet; Verbeken, Erik; De Scheerder, Ivan; Bijnens, Bart; Sutherland, George R

2004-05-01

Successful primary PTCA (with TIMI 3 reflow) in patients with acute transmural infarction has been observed to result in an immediate abnormal increase in wall thickness associated with persisting abnormal post-systolic thickening. To understand the sequential changes in regional deformation during: (i) the development of acute transmural infarction, (ii) upon TIMI grade 3 infarct reperfusion and (iii) during the subsequent expression of reperfusion injury the following correlative experimental study was performed in a pure animal model in which there was no distal dispersion of thrombotic material causing either no reflow or secondary microvascular obstruction. In 10 closed-chest pigs, a 90 min PTCA circumflex occlusion was used to induce a transmural infarction. This was followed by 60 min of TIMI 3 infarct reperfusion. M-mode ultrasound data from the "at risk" posterior wall infarct segment and from a control remote non-ischemic septal segment were acquired at standardized time intervals. Changes in regional deformation (end-diastolic (EDWT), end-systolic (ESWT) and post-systolic (PSWT) wall thickness, end-systolic strain (epsilonES) and post-systolic strain (epsilonps)) were measured. In this pure animal model of acute transmural infarction/infarct reperfusion (with no pre-existing intra-luminal thrombus), the induced changes in wall thickness and thickening were complex. During prolonged occlusion, after an initial acute fall in ESWT, there was no further change in systolic deformation to indicate the progression of ischaemia to infarction. Both transmurally infarcted and reperfused-infarcted myocardium retained post-systolic thickening indicating that this parameter, taken in isolation, is not a consistent marker of segmental viability and, in this regard, should be interpreted only in combination with other indices of segmental function. The most striking abnormality induced by reperfusion was an immediate increase in EDWT which then increased logarithmically over a 60 min period as reperfusion injury was further expressed. PS did not change significantly during reperfusion. Histology confirmed the wall thickness changes on reperfusion to be due to massive extra-cellular oedema. The identification of an acute increase in regional wall thickness in a reperfused infarct zone by cardiac ultrasound following primary PTCA might be used in patients to both identify successful infarct reperfusion and to monitor the presence, extent and resolution of the oedema associated with reperfusion injury.

One-year Outcomes in Patients with ST-segment Elevation Myocardial Infarction Caused by Unprotected Left Main Coronary Artery Occlusion Treated by Primary Percutaneous Coronary Intervention.

PubMed

Liu, Hai-Wei; Han, Ya-Ling; Jin, Quan-Min; Wang, Xiao-Zeng; Ma, Ying-Yan; Wang, Geng; Wang, Bin; Xu, Kai; Li, Yi; Chen, Shao-Liang

2018-06-20

Very few data have been reported for ST-segment elevation myocardial infarction (STEMI) caused by unprotected left main coronary artery (ULMCA) occlusion, and very little is known about the results of this subgroup of patients who underwent primary percutaneous coronary intervention (PCI). The aim of this study was to determine the clinical features and outcomes of patients with STEMI who underwent primary PCI for acute ULMCA occlusion. From January 2000 to February 2014, 372 patients with STEMI caused by ULMCA acute occlusion (ULMCA-STEMI) who underwent primary PCI at one of two centers were enrolled. The 230 patients with non-ST-segment elevation MI (NSTEMI) caused by ULMCA lesion (ULMCA-NSTEMI) who underwent emergency PCI were designated the control group. The main indexes were the major adverse cardiac events (MACEs) in-hospital, at 1 month, and at 1 year. Compared to the NSTEMI patients, the patients with STEMI had significantly higher rates of Killip class≥III (21.2% vs. 3.5%, χ 2 = 36.253, P < 0.001) and cardiac arrest (8.3% vs. 3.5%, χ 2 = 5.529, P = 0.019). For both groups, the proportions of one-year cardiac death in the patients with a post-procedure thrombolysis in myocardial infarction (TIMI) flow grade<3 were significantly higher than those in the patients with a TIMI flow grade of 3 (STEMI group: 51.7% [15/29] vs. 4.1% [14/343], P < 0.001; NSTEMI group: 33.3% [3/9] vs. 13.6% [3/221], P = 0.001; respectively]. Landmark analysis showed that the patients in STEMI group were associated with higher risks of MACE (16.7% vs. 9.1%, P = 0.009) and cardiac death (5.4% vs. 1.3%, P = 0.011) compared with NSTEMI patients at 1 month. Meanwhile, in patients with ULMCA, the landmark analysis for incidences of MACE and cardiac death was similar between the STEMI and NSTEMI (all P = 0.72) in the intervals of 1-12 months. However, patients who were diagnosed with STEMI or NSTEMI had no significant difference in reinfarction (all P > 0.05) and TVR (all P > 0.05) in the intervals of 0-1 month as well as 1 month to 1 year. The results of Cox regression analysis showed that the differences in the independent predictors for MACE included the variables of Killip class ≥ III and intra-aortic balloon pump support for the STEMI patients and the variables of previous MI, ULMCA distal bifurcation, and 2-stent for distal ULMCA lesions for the NSTEMI patients. Compared to the NSTEMI patients, the patients with STEMI and ULMCA lesions still remain at a much higher risk for adverse events at 1 year, especially on 1 month. If a successful PCI procedure is performed, the 1-year outcomes in those patients might improve.

The Effects of Buffeting and other Transonic Phenomena on Maneuvering Combat Aircraft

DTIC Science & Technology

1975-07-01

Ution no. 1 ( KV7 semi-span. 29’, Cl. M« = O.1»:?. h = lOJ-JK m (K/M V’HZ I’SI^/HZ •i n.t ai.M aw« •>■ KCIMI. oo»ir mi« i» TIMI .«•< : •oi...ACCEL .SPOILER POSITION .STRAIN GAGE CHANNE! S .BUFFET GAGES,, L.E, r^AP POSITION T.L. HAP POSITION PROOf LGAC CHANNELS PROPULSION

Frequency of cancer events with saxagliptin in the SAVOR-TIMI 53 trial.

PubMed

Leiter, L A; Teoh, H; Mosenzon, O; Cahn, A; Hirshberg, B; Stahre, C A M; Hoekstra, J B L; Alvarsson, M; Im, K; Scirica, B M; Bhatt, D L; Raz, I

2016-02-01

The Saxagliptin Assessment of Vascular Outcomes Recorded in Patients with Diabetes Mellitus (SAVOR)-Thrombolysis in Myocardial Infarction (TIMI) 53 trial randomized trial of 16,492 patients (placebo, n = 8212; saxagliptin, n = 8280) treated and followed for a median of 2.1 years afforded an opportunity to explore whether there was any association with cancer reported as a serious adverse event. At least one cancer event was reported by 688 patients (4.1%): 362 (4.3%) and 326 (3.8%) in the placebo and saxagliptin arms, respectively (p = 0.13). There were 59 (0.6%) deaths adjudicated as malignancy deaths with placebo and 53 (0.6%) with saxagliptin. Stratification by gender, age, race and ethnicity, diabetes duration, baseline glycated haemoglobin and pharmacotherapy did not show any clinically meaningful differences between the two study arms. The overall number of cancer events and malignancy-associated mortality rates were generally balanced between the placebo and saxagliptin groups, suggesting a null relationship with saxagliptin use over the median follow-up of 2.1 years. Multivariable modelling showed that male gender, dyslipidaemia and current smoking were independent predictors of cancer. These randomized data with adequate numbers of cancer cases are reassuring but limited, by the short follow-up in a trial not designed to test this hypothesis. © 2015 John Wiley & Sons Ltd.

Enoxaparin vs. unfractionated heparin with fibrinolysis for ST-elevation myocardial infarction in elderly and younger patients: results from ExTRACT-TIMI 25.

PubMed

White, Harvey D; Braunwald, Eugene; Murphy, Sabina A; Jacob, Ashok J; Gotcheva, Nina; Polonetsky, Leonid; Antman, Elliott M

2007-05-01

To determine the effects of age on outcomes in patients with STEMI treated with a strategy of enoxaparin (ENOX) vs. unfractionated heparin (UFH). In the ExTRACT-TIMI 25 trial, 20,479 patients with STEMI were randomized in a double-blind fashion to UFH or ENOX. A novel reduced dose of ENOX was administered to patients >or=75 years, and a reduced dose in those with an estimated creatinine clearance of < 30 mL/min. Anti-Xa levels were measured in a subset of patients (n = 73). The exposure to anti-Xa over time was lower in the elderly (AUC(0-12 h) P < 0.0001; AUC(steady-state) P = 0.0046). The relative risk reduction (RR) with ENOX on the primary endpoint, i.e. death or non-fatal recurrent myocardial infarction, was greater in patients < 75 years (20%) than > 75 years (6%), but the absolute benefits were similar. When compared with UFH, ENOX was associated with an RR of 1.67 for major bleeding, but the magnitude of the excess risk tended to be lower (RR = 1.15) in patients >or= 75 years assigned to ENOX. A dose reduction of ENOX in the elderly appears to be helpful in ameliorating bleeding risk. A strategy of ENOX was superior to UFH in both young and elderly patients with STEMI treated with fibrinolysis.

Metalclad Airship Hull Study. Volume 1 and Volume 2

DTIC Science & Technology

1976-12-01

37.5% weight saving of the hull skin with a maximim pressure of 8.75 in. of water column and maximum-minimum pressure ratio still at comfortable 3.5. The...overall height of 118.98 in.to no more than 100.Oin. with considerable weight saving . Instead of the geometrical height of main frames equal to (.108...changed slightly to obtain uniform spacing. This has negligible effect on the result, but saves a considerable analysis timie. For the purpose of this

From data mining rules to medical logical modules and medical advices.

PubMed

Gomoi, Valentin; Vida, Mihaela; Robu, Raul; Stoicu-Tivadar, Vasile; Bernad, Elena; Lupşe, Oana

2013-01-01

Using data mining in collaboration with Clinical Decision Support Systems adds new knowledge as support for medical diagnosis. The current work presents a tool which translates data mining rules supporting generation of medical advices to Arden Syntax formalism. The developed system was tested with data related to 2326 births that took place in 2010 at the Bega Obstetrics - Gynaecology Hospital, Timişoara. Based on processing these data, 14 medical rules regarding the Apgar score were generated and then translated in Arden Syntax language.

Temporal changes in biomarkers and their relationships to reperfusion and to clinical outcomes among patients with ST segment elevation myocardial infarction.

PubMed

van Diepen, Sean; Alemayehu, Wendimagegn G; Zheng, Yinggan; Theroux, Pierre; Newby, L Kristin; Mahaffey, Kenneth W; Granger, Christopher B; Armstrong, Paul W

2016-10-01

Coronary plaque rupture mediating acute ST segment elevation myocardial infarction (STEMI) is associated with a systemic inflammatory response. Whether early temporal changes in inflammatory biomarkers are associated with angiographic and electrocardiographic markers of reperfusion and subsequent clinical outcomes is unclear. In the APEX-AMI biomarker substudy, 376 patients with STEMI had inflammatory biomarkers measured at the time of hospital presentation and 24 h later. The primary outcome was the 90-day composite of death, shock, or heart failure. Secondary reperfusion outcomes were (1) worst least residual ST segment elevation (ST-E: <1 mm, 1 to <2 mm, ≥2 mm) and (2) post-percutaneous coronary intervention (PCI) TIMI flow grade (0/1/2 vs 3) and TIMI myocardial perfusion grade (TMPG 0/1 vs 2/3). The 90-day incidence of death, shock or heart failure was 21.3 % in this cohort. Electrocardiographic reperfusion (worst residual ST-E <1 mm, 1 to <2 mm, ≥2 mm) was associated with differences in 24 h change in N-terminal proB-type natriuretic peptide (NT-proBNP) (1192.8, 1332.5, 1859.0 ng/mL; p = 0.043) and the pro-inflammatory cytokines Interleukin (IL)-6 (14.0, 13.6, 22.1 pg/mL; p = 0.016), IL-12 (-0.5, -0.9, -0.1 pg/mL; p = 0.013), and tumor necrosis factor α (TNFα) (1.0, 0.6, 3.6 pg/mL; p = 0.023). Angiographic reperfusion (TMPG 0/1 vs 2/3) was associated with changes in median NT-proBNP (2649.3, 1382.7 ng/mL; p = 0.002) and IL-6 (28.7, 15.1; p = 0.040). After adjustment for baseline covariates, the 24 h change in the pro-inflammatory cytokine TNFα [hazard ratio (HR) 0.49; 95 % CI 0.26-0.95; p = 0.035] and the anti-inflammatory cytokine IL 10 (HR 1.41; 95 % CI 1.06-1.87; p = 0.018) were independently associated with the primary composite outcome. Successful coronary reperfusion was associated with less systemic inflammatory response and greater temporal inflammatory changes were independently associated with higher 90-day composite of death, shock, or heart failure. These findings provide support for an association between success of reperfusion, an acute STEMI inflammatory response and subsequent clinical outcomes.

Immediate multivessel percutaneous coronary intervention versus culprit lesion intervention in patients with acute myocardial infarction complicated by cardiogenic shock: results of the ALKK-PCI registry.

PubMed

Zeymer, Uwe; Hochadel, Mathias; Thiele, Holger; Andresen, Dietrich; Schühlen, Helmut; Brachmann, Johannes; Elsässer, Albrecht; Gitt, Anselm; Zahn, Ralf

2015-07-01

Current guidelines recommend immediate multivessel percutaneous coronary intervention (PCI) in patients with cardiogenic shock, despite the lack of randomised trials. We sought to investigate the use and impact on outcome of multivessel PCI in current practice in cardiogenic shock in Germany. Between January 2008 and December 2011 a total of 735 consecutive patients with acute myocardial infarction, cardiogenic shock and multivessel coronary artery disease underwent immediate PCI in 41 hospitals in Germany. Of these, 173 (23.5%) patients were treated with immediate multivessel PCI. The acute success of PCI with respect to TIMI 3 flow did not differ between the groups (82.5% versus 79.6%). In-hospital mortality with multivessel PCI and culprit lesion PCI was 46.8% and 35.8%, respectively. In multivariate analysis multivessel PCI was associated with an increased mortality (odds ratio 1.5; 95% confidence interval 1.15-1.84). In current clinical practice in Germany multivessel PCI is used only in one quarter of patients with cardiogenic shock treated with primary PCI. We observed an adverse effect of immediate multivessel PCI. Therefore, a randomised trial is needed to determine the definitive role of multivessel PCI in cardiogenic shock.

Safety and efficacy of dual vs. triple antithrombotic therapy in patients with atrial fibrillation following percutaneous coronary intervention: a systematic review and meta-analysis of randomized clinical trials.

PubMed

Golwala, Harsh B; Cannon, Christopher P; Steg, Ph Gabriel; Doros, Gheorghe; Qamar, Arman; Ellis, Stephen G; Oldgren, Jonas; Ten Berg, Jurrien M; Kimura, Takeshi; Hohnloser, Stefan H; Lip, Gregory Y H; Bhatt, Deepak L

2018-05-14

Of patients with atrial fibrillation (AF), approximately 10% undergo percutaneous coronary intervention (PCI). We studied the safety and efficacy of dual vs. triple antithrombotic therapy (DAT vs. TAT) in this population. A systematic review and meta-analysis was conducted using PubMed, Embase, EBSCO, Cochrane database of systematic reviews, Web of Science, and relevant meeting abstracts for Phase 3, randomized trials that compared DAT vs. TAT in patients with AF following PCI. Four trials including 5317 patients were included, of whom 3039 (57%) received DAT. Compared with the TAT arm, Thrombolysis in Myocardial Infarction (TIMI) major or minor bleeding showed a reduction by 47% in the DAT arm [4.3% vs. 9.0%; hazard ratio (HR) 0.53, 95% credible interval (CrI) 0.36-0.85, I2 = 42.9%]. In addition, there was no difference in the trial-defined major adverse cardiac events (MACE) (10.4% vs. 10.0%, HR 0.85, 95% CrI 0.48-1.29, I2 = 58.4%), or in individual outcomes of all-cause mortality, cardiac death, myocardial infarction, stent thrombosis, or stroke between the two arms. Compared with TAT, DAT shows a reduction in TIMI major or minor bleeding by 47% with comparable outcomes of MACE. Our findings support the concept that DAT may be a better option than TAT in many patients with AF following PCI.

Left atrial structure and function in atrial fibrillation: ENGAGE AF-TIMI 48

PubMed Central

Gupta, Deepak K.; Shah, Amil M.; Giugliano, Robert P.; Ruff, Christian T.; Antman, Elliott M.; Grip, Laura T.; Deenadayalu, Naveen; Hoffman, Elaine; Patel, Indravadan; Shi, Minggao; Mercuri, Michele; Mitrovic, Veselin; Braunwald, Eugene; Solomon, Scott D.

2014-01-01

Aims The complex relationship between left atrial (LA) structure and function, electrical burden of atrial fibrillation (AF) and stroke risk is not well understood. We aimed to describe LA structure and function in AF. Methods and results Left atrial structure and function was assessed in 971 subjects enrolled in the echocardiographic substudy of ENGAGE AF-TIMI 48. Left atrial size, emptying fraction (LAEF), and contractile function were compared across AF types (paroxysmal, persistent, or permanent) and CHADS2 scores as an estimate of stroke risk. The majority of AF patients (55%) had both LA enlargement and reduced LAEF, with an inverse relationship between LA size and LAEF (R = −0.57, P < 0.001). With an increasing electrical burden of AF and higher CHADS2 scores, LA size increased and LAEF declined. Moreover, 19% of AF subjects had impaired LAEF despite normal LA size, and LA contractile dysfunction was present even among the subset of AF subjects in sinus rhythm at the time of echocardiography. Conclusions In a contemporary AF population, LA structure and function were increasingly abnormal with a greater electrical burden of AF and higher stroke risk estimated by the CHADS2 score. Moreover, LA dysfunction was present despite normal LA size and sinus rhythm, suggesting that the assessment of LA function may add important incremental information in the evaluation of AF patients. Clinical Trial Registration: http://www.clinicaltrials.gov; ID = NCT00781391. PMID:24302269

Efficacy and safety of saxagliptin in older participants in the SAVOR-TIMI 53 trial.

PubMed

Leiter, Lawrence A; Teoh, Hwee; Braunwald, Eugene; Mosenzon, Ofri; Cahn, Avivit; Kumar, K M Prasanna; Smahelova, Alena; Hirshberg, Boaz; Stahre, Christina; Frederich, Robert; Bonnici, Francois; Scirica, Benjamin M; Bhatt, Deepak L; Raz, Itamar

2015-06-01

To examine the safety and cardiovascular (CV) effects of saxagliptin in the predefined elderly (≥65 years) and very elderly (≥75 years) subpopulations of the Saxagliptin Assessment of Vascular Outcomes Recorded in Patients with Diabetes Mellitus-Thrombolysis in Myocardial Infarction 53 (SAVOR-TIMI 53) trial. Individuals ≥40 years (n = 16,492; elderly, n = 8,561; very elderly, n = 2,330) with HbA1c ≥6.5% (47.5 mmol/mol) and ≤12.0% (107.7 mmol/mol) were randomized (1:1) to saxagliptin (5 or 2.5 mg daily) or placebo in a double-blind trial for a median follow-up of 2.1 years. The hazard ratio (HR) for the comparison of saxagliptin versus placebo for the primary end point (composite of CV mortality, myocardial infarction, or ischemic stroke) was 0.92 for elderly patients vs. 1.15 for patients <65 years (P = 0.06) and 0.95 for very elderly patients. The HRs for the secondary composite end points in the entire cohort, elderly cohort, and very elderly cohort were similar. Although saxagliptin increased the risk of hospitalization for heart failure in the overall saxagliptin population, there was no age-based treatment interaction (P = 0.76 for elderly patients vs. those <65 years; P = 0.34 for very elderly patients vs. those <75 years). Among saxagliptin-treated individuals with baseline HbA1c ≥7.6% (59.6 mmol/mol), the mean change from baseline HbA1c at 2 years was -0.69%, -0.64%, -0.66%, and -0.66% for those ≥65, <65, ≥75, and <75 years old, respectively. The incidence of overall adverse events (AEs) and serious AEs was similar between saxagliptin and placebo in all cohorts; however, hypoglycemic events were higher for saxagliptin versus placebo regardless of age. The SAVOR-TIMI 53 trial supports the overall CV safety of saxagliptin in a robust number of elderly and very elderly participants, although the risk of heart failure hospitalization was increased irrespective of age category. AEs and serious AEs as well as glycemic efficacy of saxagliptin in elderly patients are similar to those found in younger patients. © 2015 by the American Diabetes Association. Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered.

Plasma bilirubin values on admission and ventricular remodeling after a first anterior ST-segment elevation acute myocardial infarction.

PubMed

Miranda, Berta; Barrabés, José A; Figueras, Jaume; Pineda, Victor; Rodríguez-Palomares, José; Lidón, Rosa-Maria; Sambola, Antonia; Bañeras, Jordi; Otaegui, Imanol; García-Dorado, David

2016-01-01

Bilirubin may elicit cardiovascular protection and heme oxygenase-1 overexpression attenuated post-infarction ventricular remodeling in experimental animals, but the association between bilirubin levels and post-infarction remodeling is unknown. In 145 patients with a first anterior ST-segment elevation acute myocardial infarction (STEMI), we assessed whether plasma bilirubin on admission predicted adverse remodeling (left ventricular end-diastolic volume [LVEDV] increase ≥20% between discharge and 6 months, estimated by magnetic resonance imaging). Patients' baseline characteristics and management were comparable among bilirubin tertiles. LVEDV increased at 6 months (P < 0.001) with respect to the initial exam, but the magnitude of this increase was similar across increasing bilirubin tertiles (10.8 [30.2], 10.1 [22.9], and 12.7 [24.3]%, P = 0.500). Median (25-75 percentile) bilirubin values in patients with and without adverse remodeling were 0.75 (0.60-0.93) and 0.73 (0.60-0.92) mg/dL (P = 0.693). Absence of final TIMI flow grade 3 (odds ratio 3.92, 95% CI 1.12-13.66) and a history of hypertension (2.04, 0.93-4.50), but not admission bilirubin, were independently associated with adverse remodeling. Bilirubin also did not predict the increase in ejection fraction at 6 months. Admission bilirubin values are not related to LVEDV or ejection fraction progression after a first anterior STEMI and do not predict adverse ventricular remodeling. Key messages Bilirubin levels are inversely related to cardiovascular disease, and overexpression of heme oxygenase-1 (the enzyme that determines bilirubin production) has prevented post-infarction ventricular remodeling in experimental animals, but the association between bilirubin levels and the progression of ventricular volumes and function in patients with acute myocardial infarction remained unexplored. In this cohort of patients with a first acute anterior ST-segment elevation myocardial infarction receiving contemporary management, bilirubin levels on admission were not predictive of the changes in left ventricular volumes or ejection fraction at 6 months measured by serial cardiac magnetic resonance imaging. The data are contrary to a significant protective effect of bilirubin against post-infarction ventricular remodeling.

Effects of Regional Differences in Asia on Efficacy and Safety of Edoxaban Compared With Warfarin--Insights From the ENGAGE AF-TIMI 48 Trial.

PubMed

Shimada, Yuichi J; Yamashita, Takeshi; Koretsune, Yukihiro; Kimura, Tetsuya; Abe, Kenji; Sasaki, Shunichi; Mercuri, Michele; Ruff, Christian T; Giugliano, Robert P

2015-01-01

In 21,105 patients with atrial fibrillation in the ENGAGE AF-TIMI 48 trial, edoxaban was non-inferior to warfarin in preventing thromboembolic events while reducing bleeding. We compared results in Japan with the rest of East Asia (EA), including China, Korea, and Taiwan. We compared baseline characteristics, time-in-therapeutic range (TTR) for warfarin, and outcomes (efficacy: stroke or systemic embolic events [SEE], safety: major bleeding). Interaction P values were used to assess for effect modification of treatment (higher-dose edoxaban [HDE, 60 mg/30 mg] vs. warfarin; lower-dose edoxaban [LDE, 30 mg/15 mg] vs. warfarin) by region with adjustments for baseline characteristics. Fewer patients in Japan (n=1,010) were female, taking aspirin or amiodarone, naïve to warfarin (P<0.001 for each), had a history of stroke or transient ischemic attack (P=0.02), and more patients needed dose reduction (P<0.001) compared with EA (n=933). The mean TTR was higher in Japan (70% vs. 56%, P<0.001). Evidence for statistical interactions was observed for HDE vs. warfarin by region for stroke/SEE (adjusted P-int=0.052) and major bleeding (adjusted P-int=0.048) with greater relative efficacy and safety with HDE in EA compared with Japan. No interactions were observed for LDE vs. warfarin after adjustment. HDE had a greater relative efficacy and safety in EA compared with Japan that was only partially explained by differences in baseline characteristics and TTR.

The POST trial: initial post-market experience of the Penumbra system: revascularization of large vessel occlusion in acute ischemic stroke in the United States and Europe.

PubMed

Tarr, Robert; Hsu, Dan; Kulcsar, Zsolt; Bonvin, Christophe; Rufenacht, Daniel; Alfke, Karsten; Stingele, Robert; Jansen, Olav; Frei, Donald; Bellon, Richard; Madison, Michael; Struffert, Tobias; Dorfler, Arnd; Grunwald, Iris Q; Reith, Wolfgang; Haass, Anton

2010-12-01

The purpose of this study was to assess the initial post-market experience of the device and how it is compared with the Penumbra Pivotal trial used to support the 510k application. A retrospective case review of 157 consecutive patients treated with the Penumbra system at seven international centers was performed. Primary endpoints were revascularization of the target vessel (TIMI score of 2 or 3), good functional outcome as defined by a modified Rankin scale (mRS) score of ≤2 and incidence of procedural serious adverse events. Results were compared with those of the Penumbra pivotal trial. A total of 157 vessels were treated. Mean baseline values at enrollment were: age 65 years, NIHSS score 16. After use of the Penumbra system, 87% of the treated vessels were revascularized to TIMI 2 (54%) or 3 (33%) as compared with 82% reported in the Pivotal trial. Nine procedural serious adverse events were reported in 157 patients (5.7%). All-cause mortality was 20% (32/157), and 41% had a mRS of ≤2 at 90-day follow-up as compared with only 25% in the Pivotal trial. Patients who were successfully revascularized by the Penumbra system had significantly better outcomes than those who were not. Initial post-market experience of the Penumbra system revealed that the revascularization rate and safety profile of the device are comparable to those reported in the Pivotal trial. However, the proportion of patients who had good functional outcome was higher than expected.

New re-entry device for revascularization of chronic coronary total occlusions: preliminary single Japanese center experience.

PubMed

Tsuchikane, Etsuo; Kimura, Masashi; Suzuki, Takahiko; Habara, Maoto; Kurita, Tairo; Tanaka, Nobuyoshi; Nasu, Kenya; Ito, Tatsuya; Kinoshita, Yoshihisa; Wyman, R Michael

2012-08-01

Although retrograde approach for coronary chronic total occlusion (CTO) has been introduced, the procedure is still time and resource consuming. A simplified antegrade approach mightbe another resort. The aim of this study was to evaluate a new device designed to facilitate guidewire re-entry into the true lumen of a CTO from the adjacent subintimal space. Patients with CTO were entered into a prospective registry regardless of lesion characteristics. A new metal-tip catheter was used initially in primary use cases. If it created subintimal tracking, a new re-entry tool (a flat balloon with 2 exit ports offset by 180 degrees) was used as a platform to attempt guidewire penetration into the distal true lumen. In rescue use cases after unsuccessful conventional wiring, the re-entry procedure was subsequently attempted. In 11 CTO lesions attempted, device success was achieved in 8 cases (72.7%). Re-entry procedure success rate was higher in primary use cases (80%) compared to rescue use cases (33.3%). Retrograde approach was conducted immediately after unsuccessful antegrade procedure using this device in the other 3 cases and successful recanalization was achieved in all cases. All lesions were stented, resulting in TIMI 3 flow without major complications. A new coronary re-entry device may provide another strategic option in the antegrade approach to recanalize CTOs.

Cooperative Effects and Intrinsic Optical Bistability in Collections of Atoms

DTIC Science & Technology

1989-11-01

Wang, M. Scalora and G.M. Bowden, Phys. Rev. A38, 4043 (1988). 8. Y. Ben-Aryeli and G.M. B~owden, "Mirrorless Optical Bistability in a Spacially... Scalora andiC.M. Blowden, i’h~s. age Ii re-Rev. A38 (1988) 4043.ag pssage timie Fkw the parameters chiosen. it re- 121 Y. Ben-Arych. C.M. Bowvden and J.C...685 (1984). 10. M. Dagenais and W.F. Sharfin, Appi. Phys. Lett. 45, 210 (1984). 21 11. J.W. Haus, L. Wang, M. Scalora and C.M. Bowden, Phys. Rev. A38

The Battalion Commander’s Handbook 1984

DTIC Science & Technology

1984-06-01

34MU911 0 4. TITLE (and Swbdas)L rtORERTaPIDCVRD The Battalion Commander’s Handbook 1984 Study Project a. PERFORMING DORG REPORT NUMBER 7 . AM? NOR(q...COTACT OR GRANT 1040SERI’.f) COL James E. Mace plus 22 other students and 7 vives. 9. PERFORMING ORGANIZATION NAME AND ADDRESS IS. PROORA ZLMENT...TIMIS PAGE (0114" Data 81"dwo USvi@WS explessed in this paswr are, these of the authof and du not txwr~y er" re VIP *J ~ 7 c! nE f 1af97 dC ot, A rncem

The protection of RIVERLIFE by mitigation of flood damages RIVERLIFE

NASA Astrophysics Data System (ADS)

Adler, M. J.

2003-04-01

The long-term development objective of the RIVERLIFE project is to contribute to sustainable human end economic development in the Timis-Bega river basin area as part of the Danube River Basin (DRB), through reinforcing the capacities of Romanian central and local authorities to develop effective mechanisms and tools for integrated river basin management in the Timis-Bega basin. The overall objective of the project is to assist the country in the EU enlargement and accession process to meet the EU requirements of water related Directives with emphasis on the EU Water Framework Directive (WFD). The specific objective of the project is to support the WFD implementation process at the level of a sub-unit within the limits of the DRB, through the development of a River Basin Management Plan (RBMP). The project will also facilitate the implementation of the Danube River Protection Convention (DRPC) as an essential element in the implementation of the Directive in the transboundary river basins. Expected outcomes in the recipient country consist of (i) responding to a real hazard problem, which affects the quality of life of many citizens, and (ii) improvement in the environmental conditions in the targeted areas. Flooding is one of the major natural hazards to human society and an important influence on social and economic development for Romania causing financially greater losses per annum on average than any other natural hazard. One key concept of the WFD is the coordination, organization and regulation of water management at the level of river basins. Therefore, river basin districts are shaped in such a way as to include not only the surface run-off through streams and rivers to the sea, but the total area of land and sea together with the associated groundwater and coastal waters. The concept allows even for the small river basins directly discharging into the sea to be combined into one river basin district. As a principle, the complex decisions on the use or interventions in the aquatic systems within the river basin district limits should take place in an integrated and co-coordinated approach as part of the RBMP. The process includes all RBMP plan development phases for Timis-Bega basin from planning and analysis phases to the assessment and the identification of respective programs of measures intended to achieve the defined environmental objectives for the respective river basin. The central administrative tool of the WFD is the River Basin Management Plan, around which all other elements are set. The river basin becomes the basic unit for all water planning and management interventions according with the physical and hydrological boundaries, but not necessary with its political and administrative limits.

Rivaroxaban versus placebo in patients with acute coronary syndromes (ATLAS ACS-TIMI 46): a randomised, double-blind, phase II trial.

PubMed

Mega, J L; Braunwald, E; Mohanavelu, S; Burton, P; Poulter, R; Misselwitz, F; Hricak, V; Barnathan, E S; Bordes, P; Witkowski, A; Markov, V; Oppenheimer, L; Gibson, C M

2009-07-04

Rivaroxaban is an oral direct factor Xa inhibitor that has been effective in prevention of venous thromboembolism in patients undergoing elective orthopaedic surgery. However, its use after acute coronary syndromes has not been investigated. In this setting, we assessed the safety and efficacy of rivaroxaban and aimed to select the most favourable dose and dosing regimen. In this double-blind, dose-escalation, phase II study, undertaken at 297 sites in 27 countries, 3491 patients stabilised after an acute coronary syndrome were stratified on the basis of investigator decision to use aspirin only (stratum 1, n=761) or aspirin plus a thienopyridine (stratum 2, n=2730). Participants were randomised within each strata and dose tier with a block randomisation method at 1:1:1 to receive either placebo or rivaroxaban (at doses 5-20 mg) given once daily or the same total daily dose given twice daily. The primary safety endpoint was clinically significant bleeding (TIMI major, TIMI minor, or requiring medical attention); the primary efficacy endpoint was death, myocardial infarction, stroke, or severe recurrent ischaemia requiring revascularisation during 6 months. Safety analyses included all participants who received at least one dose of study drug; efficacy analyses were by intention to treat. This study is registered with ClinicalTrials.gov, number NCT00402597. Three patients in stratum 1 and 26 in stratum 2 never received the study drug. The risk of clinically significant bleeding with rivaroxaban versus placebo increased in a dose-dependent manner (hazard ratios [HRs] 2.21 [95% CI 1.25-3.91] for 5 mg, 3.35 [2.31-4.87] for 10 mg, 3.60 [2.32-5.58] for 15 mg, and 5.06 [3.45-7.42] for 20 mg doses; p<0.0001). Rates of the primary efficacy endpoint were 5.6% (126/2331) for rivaroxaban versus 7.0% (79/1160) for placebo (HR 0.79 [0.60-1.05], p=0.10). Rivaroxaban reduced the main secondary efficacy endpoint of death, myocardial infarction, or stroke compared with placebo (87/2331 [3.9%] vs 62/1160 [5.5%]; HR 0.69, [95% CI 0.50-0.96], p=0.0270). The most common adverse event in both groups was chest pain (248/2309 [10.7%] vs 118/1153 [10.2%]). The use of an oral factor Xa inhibitor in patients stabilised after an acute coronary syndrome increases bleeding in a dose-dependent manner and might reduce major ischaemic outcomes. On the basis of these observations, a phase III study of low-dose rivaroxaban as adjunctive therapy in these patients is underway. Johnson & Johnson Pharmaceutical Research & Development and Bayer Healthcare AG.

Utilizing Chinese Admission Records for MACE Prediction of Acute Coronary Syndrome

PubMed Central

Hu, Danqing; Huang, Zhengxing; Chan, Tak-Ming; Dong, Wei; Lu, Xudong; Duan, Huilong

2016-01-01

Background: Clinical major adverse cardiovascular event (MACE) prediction of acute coronary syndrome (ACS) is important for a number of applications including physician decision support, quality of care assessment, and efficient healthcare service delivery on ACS patients. Admission records, as typical media to contain clinical information of patients at the early stage of their hospitalizations, provide significant potential to be explored for MACE prediction in a proactive manner. Methods: We propose a hybrid approach for MACE prediction by utilizing a large volume of admission records. Firstly, both a rule-based medical language processing method and a machine learning method (i.e., Conditional Random Fields (CRFs)) are developed to extract essential patient features from unstructured admission records. After that, state-of-the-art supervised machine learning algorithms are applied to construct MACE prediction models from data. Results: We comparatively evaluate the performance of the proposed approach on a real clinical dataset consisting of 2930 ACS patient samples collected from a Chinese hospital. Our best model achieved 72% AUC in MACE prediction. In comparison of the performance between our models and two well-known ACS risk score tools, i.e., GRACE and TIMI, our learned models obtain better performances with a significant margin. Conclusions: Experimental results reveal that our approach can obtain competitive performance in MACE prediction. The comparison of classifiers indicates the proposed approach has a competitive generality with datasets extracted by different feature extraction methods. Furthermore, our MACE prediction model obtained a significant improvement by comparison with both GRACE and TIMI. It indicates that using admission records can effectively provide MACE prediction service for ACS patients at the early stage of their hospitalizations. PMID:27649220

Economic impact of angina after an acute coronary syndrome: insights from the MERLIN-TIMI 36 trial.

PubMed

Arnold, Suzanne V; Morrow, David A; Lei, Yang; Cohen, David J; Mahoney, Elizabeth M; Braunwald, Eugene; Chan, Paul S

2009-07-01

Angina in patients with coronary artery disease is associated with worse quality of life; however, the relationship between angina frequency and resource utilization is unknown. Using data from the MERLIN-TIMI 36 trial, we assessed the association between the extent of angina after an acute coronary syndrome (ACS) and subsequent cardiovascular resource utilization among 5460 stable outpatients who completed the Seattle Angina Questionnaire at 4 months after an ACS and who were then followed for an additional 8 months. Angina frequency was categorized as none (score, 100; 2739 patients), monthly (score, 61 to 99; 1608 patients), weekly (score, 31 to 60; 854 patients), and daily (score, 0 to 30; 259 patients). Multivariable regression models evaluated the association between angina frequency and overall costs attributable to cardiovascular hospitalizations, outpatient visits and procedures, and medications. As compared with no angina, overall costs increased in a graded fashion with higher angina frequency-no angina, $2928 (reference); monthly angina, $3909 (adjusted relative cost ratio, 1.29; 95% CI, 1.21 to 1.39); weekly angina, $4558 (adjusted relative cost ratio, 1.52; 95% CI, 1.48 to 1.67); and daily angina, $6949 (adjusted relative cost ratio, 2.32; 95% CI, 2.01 to 2.69; P for trend <0.001). Differences in costs were attributable primarily to higher rates of ACS hospitalization and coronary revascularization among patients with more severe angina. Among stable outpatients after ACS, a direct graded relationship was found between higher angina frequency and healthcare costs. As compared with patients without angina, patients with daily angina had a >2-fold increase in resource utilization and incremental costs of $4000 after 8 months of follow-up.

Machine learning for prediction of 30-day mortality after ST elevation myocardial infraction: An Acute Coronary Syndrome Israeli Survey data mining study.

PubMed

Shouval, Roni; Hadanny, Amir; Shlomo, Nir; Iakobishvili, Zaza; Unger, Ron; Zahger, Doron; Alcalai, Ronny; Atar, Shaul; Gottlieb, Shmuel; Matetzky, Shlomi; Goldenberg, Ilan; Beigel, Roy

2017-11-01

Risk scores for prediction of mortality 30-days following a ST-segment elevation myocardial infarction (STEMI) have been developed using a conventional statistical approach. To evaluate an array of machine learning (ML) algorithms for prediction of mortality at 30-days in STEMI patients and to compare these to the conventional validated risk scores. This was a retrospective, supervised learning, data mining study. Out of a cohort of 13,422 patients from the Acute Coronary Syndrome Israeli Survey (ACSIS) registry, 2782 patients fulfilled inclusion criteria and 54 variables were considered. Prediction models for overall mortality 30days after STEMI were developed using 6 ML algorithms. Models were compared to each other and to the Global Registry of Acute Coronary Events (GRACE) and Thrombolysis In Myocardial Infarction (TIMI) scores. Depending on the algorithm, using all available variables, prediction models' performance measured in an area under the receiver operating characteristic curve (AUC) ranged from 0.64 to 0.91. The best models performed similarly to the Global Registry of Acute Coronary Events (GRACE) score (0.87 SD 0.06) and outperformed the Thrombolysis In Myocardial Infarction (TIMI) score (0.82 SD 0.06, p<0.05). Performance of most algorithms plateaued when introduced with 15 variables. Among the top predictors were creatinine, Killip class on admission, blood pressure, glucose level, and age. We present a data mining approach for prediction of mortality post-ST-segment elevation myocardial infarction. The algorithms selected showed competence in prediction across an increasing number of variables. ML may be used for outcome prediction in complex cardiology settings. Copyright © 2017 Elsevier Ireland Ltd. All rights reserved.

Clinical events after interruption of anticoagulation in patients with atrial fibrillation: An analysis from the ENGAGE AF-TIMI 48 trial.

PubMed

Cavallari, Ilaria; Ruff, Christian T; Nordio, Francesco; Deenadayalu, Naveen; Shi, Minggao; Lanz, Hans; Rutman, Howard; Mercuri, Michele F; Antman, Elliott M; Braunwald, Eugene; Giugliano, Robert P

2018-04-15

Patients with atrial fibrillation (AF) who interrupt anticoagulation are at high risk of thromboembolism and death. Patients enrolled in the ENGAGE AF-TIMI 48 trial (randomized comparison of edoxaban vs. warfarin) who interrupted study anticoagulant for >3 days were identified. Clinical events (ischemic stroke/systemic embolism, major cardiac and cerebrovascular events [MACCE]) were analyzed from day 4 after interruption until day 34 or study drug resumption. During 2.8 years median follow-up, 13,311 (63%) patients interrupted study drug for >3 days. After excluding those who received open-label anticoagulation during the at-risk window, the population for analysis included 9148 patients. The rates of ischemic stroke/systemic embolism and MACCE post interruption were substantially greater than in patients who never interrupted (15.42 vs. 0.26 and 60.82 vs. 0.36 per 100 patient-years, respectively, p adj  < .001). Patients who interrupted study drug for an adverse event (44.1% of the cohort), compared to those who interrupted for other reasons, had an increased risk of MACCE (HR adj 2.75; 95% CI 2.02-3.74, p < .0001), but similar rates of ischemic stroke/systemic embolism. Rates of clinical events after interruption of warfarin and edoxaban were similar. Interruption of study drug was frequent in patients with AF and was associated with a substantial risk of major cardiac and cerebrovascular events over the ensuing 30 days. This risk was particularly high in patients who interrupted as a result of an adverse event; these patients deserve close monitoring and resumption of anticoagulation as soon as it is safe to do so. Copyright © 2018 Elsevier B.V. All rights reserved.

Frequency and prognostic significance of access site and non-access site bleeding and impact of choice of antithrombin therapy in patients undergoing primary percutaneous coronary intervention. The EUROMAX trial.

PubMed

Kilic, Sinem; Van't Hof, Arnoud W J; Ten Berg, Jurrien; Lopez, Ana Ayesta; Zeymer, Uwe; Hamon, Martial; Soulat, Louis; Bernstein, Debra; Deliargyris, Efthymios N; Steg, Phillippe Gabriel

2016-05-15

The overall impact of post percutaneous coronary intervention (PCI) bleeding on long term prognosis after acute coronary syndromes (ACS) has been established, but it may differ between access and non-access related bleeding events. The impact of antithrombin choice on bleeding may also differ according to the origin of the bleed. We sought to determine the origin of bleeding relative to the access site, its prognostic significance and the respective impact of antithrombin therapy in the EUROMAX trial. We performed a blinded review of the case records of all TIMI major or minor bleeds in the EUROMAX trial and assigned them in one of 2 categories: access site bleeds (ASB), or rest of bleeds (ROB). Incidence of bleeding for each category was assessed according to randomization to antithrombotic treatment. A total of 231 out of 2198 patients suffered a TIMI major/minor bleed (10.5%) and ASB accounted for 48.5%, while ROB for 51.5% of the bleeds. Thirty day mortality was 2.5% (50/1967) for patients without a bleed, 2.7% (3/112, p=0.76 vs. no bleed) for patients with ASB, and 10.9% (13/119, p<0.0001 vs. no bleed) for ROB patients. The use of bivalirudin reduced both ASB and ROB with relative risk reductions of 34% and 46% respectively. In contemporary primary PCI, bleeding originates with equal frequency either at or away from the access site. Access site bleeds were not associated with an excess in 30day mortality, but the rest of the bleeds were. Bivalirudin is associated with a lower risk of bleeding irrespective of origin. ClinicalTrials.gov identifier NCT01087723. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Looking beyond historical patient outcomes to improve clinical models.

PubMed

Chia, Chih-Chun; Rubinfeld, Ilan; Scirica, Benjamin M; McMillan, Sean; Gurm, Hitinder S; Syed, Zeeshan

2012-04-25

Conventional algorithms for modeling clinical events focus on characterizing the differences between patients with varying outcomes in historical data sets used for the model derivation. For many clinical conditions with low prevalence and where small data sets are available, this approach to developing models is challenging due to the limited number of positive (that is, event) examples available for model training. Here, we investigate how the approach of developing clinical models might be improved across three distinct patient populations (patients with acute coronary syndrome enrolled in the DISPERSE2-TIMI33 and MERLIN-TIMI36 trials, patients undergoing inpatient surgery in the National Surgical Quality Improvement Program registry, and patients undergoing percutaneous coronary intervention in the Blue Cross Blue Shield of Michigan Cardiovascular Consortium registry). For each of these cases, we supplement an incomplete characterization of patient outcomes in the derivation data set (uncensored view of the data) with an additional characterization of the extent to which patients differ from the statistical support of their clinical characteristics (censored view of the data). Our approach exploits the same training data within the derivation cohort in multiple ways to improve the accuracy of prediction. We position this approach within the context of traditional supervised (2-class) and unsupervised (1-class) learning methods and present a 1.5-class approach for clinical decision-making. We describe a 1.5-class support vector machine (SVM) classification algorithm that implements this approach, and report on its performance relative to logistic regression and 2-class SVM classification with cost-sensitive weighting and oversampling. The 1.5-class SVM algorithm improved prediction accuracy relative to other approaches and may have value in predicting clinical events both at the bedside and for risk-adjusted quality of care assessment.

On-treatment platelet reactivity: State of the art and perspectives.

PubMed

Marcucci, Rossella; Grifoni, Elisa; Giusti, Betti

2016-02-01

High on-clopidogrel platelet reactivity (HcPR) during dual-antiplatelet therapy is a marker of vascular risk, in particular stent thrombosis, in patients with acute coronary syndromes (ACS). Genetic determinants (CYP2C19*2 polymorphism), advanced age, female gender, diabetes and reduced ventricular function are related to a higher risk to develop HcPR. In addition, inflammation and increased platelet turnover, as revealed by the elevated percentage of reticulated platelets in patients' blood, that characterize the acute phase of acute coronary syndromes, are associated with HcPR. To overcome the limitation of clopidogrel, new antiplatelet agents (prasugrel and ticagrelor) were developed and the demonstration of their superiority over clopidogrel was obtained in the two randomized trials, TRITON TIMI 38 and PLATO. Emerging evidence is accumulating on the role of high-on aspirin platelet reactivity (HaPR), especially in the clinical context of diabetes. Finally, the presence of new, potent antiplatelet drugs has shifted the focus from thrombotic to bleeding risk. Recent data document that low on-treatment platelet reactivity (LPR) is associated with a significantly higher bleeding risk. Due to the current possibility to choose between multiple antiplatelet strategies, the future perspective is to include in the management of ACS, in addition to clinical data and classical risk factors, the definition of platelet function during treatment in order to set a tailored therapy. Copyright © 2015 Elsevier Inc. All rights reserved.

Impact of Admission Glycosylated Hemoglobin A1c on Angiographic Characteristics and Short Term Clinical Outcomes of Nondiabetic Patients with Acute ST-Segment Elevation Myocardial Infarction

PubMed Central

El-sherbiny, Islam; Nabil, Baher; Saber, Tamer; Abdelgawad, Fathy Elsayed

2015-01-01

We aimed to assess the predictive value of admission HbA1c level in nondiabetic patients presented by acute STEMI, on outcome of PCI and short term outcome of adverse cardiac events. Methods. 60 nondiabetic patients were admitted to Cardiology Department, Zagazig University Hospital, with acute STMI: 27 patients with HbA1c levels of 4.5% to 6.4% (group 1), 17 patients with HbA1c levels of 6.5% to 8.5% (group 2), and 16 patients with HbA1c levels higher than 8.5% (group 3). Either invasive intervention was done at admission by (pPCI) or coronary angiography was done within month (3–28 days) from taking thrombolytic. Participants were followed up for 6 months. Results. There was significant difference among different groups of HbA1c as regards the number of diseased vessels, severity of CAD lesions (p value < 0.01), and TIMI flow grades (p value < 0.05). There was significant difference among different groups as regards the adverse cardiac events on short term follow-up period (p value < 0.05). Conclusion. The present study showed that admission higher HbA1c level in patients presented by acute STEMI is associated with more severe CAD, lower rate of complete revascularization, and higher incidence of adverse cardiac events. PMID:26697259

Periprocedural myocardial infarction during percutaneous coronary intervention in an academic tertiary centre in Johannesburg.

PubMed

Tsabedze, Nqoba; McCutcheon, Keir; Mkhwanazi, Lancelot; Garda, Riaz; Vachiat, Ahmed; Ramjee, Rohan; Moosa, Jameel; Maluleke, Themba; Mukeshimana, Gloria; Karolia, Saffiyyah; Mpanya, Dineo; Manga, Pravin

2017-03-01

Percutaneous coronary intervention (PCI) is effective therapy for significant atherosclerotic coronary artery disease. Despite medical and technological advances in PCI, periprocedural myocardial infarction (PMI) remains a common complication. The frequency and factors associated with PMI have been well investigated in the developed world, yet there is a paucity of data from the developing world, especially Sub-Saharan Africa. We prospectively enrolled 153 adult patients undergoing PCI at the Charlotte Maxeke Johannesburg Academic Hospital from the 1st of February 2014 to 31st October 2014. Periprocedural Creatinine Kinase-MB and hs-Troponin I were routinely measured before PCI and at 16-24h post-procedure. The third universal definition of myocardial infarction was used to define a PMI event. 152 participants met the inclusion criteria and were analysed for PMI. 70.4% participants were male. The mean age was 58.8 (SD 10.9) years old. Sixteen (10.5%) participants fulfilled the criteria for PMI. Side branch pinching with preserved TIMI III flow was noted in 62.5% of PMI cases. Duration of procedure (P=0.007), right coronary artery intervention (p=0.042) and total stent length (p=0.045) were independently associated with PMI. PMI occurred in 10.5% of cases undergoing PCI. This is consistent with the prevalence of PMI internationally. Larger multicentre studies are required in our demographic region to further define relevant predictors and outcomes associated with PMI. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Impact of L/D on 90 Degree Sharp-Edge Orifice Flow with Manifold Passage Cross Flow (Preprint)

DTIC Science & Technology

2007-04-30

that are observed by measurement as the flow transitions from non-cavitation to cavitation (turbulent flow), supercavitation , and finally separation in...include inception of cavitation, supercavitation , and separation. 15. SUBJECT TERMS 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF...cavitation to cavitation (turbulent flow), supercavitation , and finally separation in sharp-edge 90 degree orifices. This study includes orifice L/D from

Critical role of electron heat flux on Bohm criterion

DOE PAGES

Tang, Xianzhu; Guo, Zehua

2016-12-05

Bohm criterion, originally derived for an isothermal-electron and cold-ion plasma, is often used as a rule of thumb for more general plasmas. Here, we establish a more precise determination of the Bohm criterion that are quantitatively useful for understanding and modeling collisional plasmas that still have collisional mean-free-path much greater than plasma Debye length. Specifically, it is shown that electron heat flux, rather than the isothermal electron assumption, is what sets the Bohm speed to bemore » $$\\sqrt{k_B(T_e||+3T_i||)/m_i}$$ with T e,i∥ the electron and ion parallel temperature at the sheath entrance and m i the ion mass.« less

[The best of thrombosis in 2002].

PubMed

Maillard, L

2003-01-01

In the area of myocardial infarction one is reminded of the publication of the CADILLAC study which has reopened the debate on the systematic use of GpIIbIIIa inhibitors in the acute phase of myocardial infarction complementing primary angioplasty with the placement of an endoprosthesis. New modalities for thrombolysis are in the course of evaluation, notably Eptibaphide Alteplase combination in the INTRO-AMI study and Tenecteplase Abciximab in association with enoxaparine or non-fractionated heparin in the TIMI 23 study. Several studies comparing angioplasty to lysis have been published. STOPAMI 2 evaluated myocardial salvage in the framework of primary angioplasty with placement of an endoprosthesis combined with abciximab infusion in comparison with half dose fibrinolysis associated with abciximab. CAPTIM is a strategy evaluation comparing the results of pre-hospital fibrinolysis with primary angioplasty. With the RITA 3 study the interventional approach definitely comes top in comparison with a conservative approach for the treatment of unstable angina. One is equally reminded of the changes in the ACC/AHA recommendations for the management of unstable angina. The debate continues on the indications for thrombolysis in submassive pulmonary embolus. In the therapeutic area, one is reminded of the update on the interactions between angiotensin converting enzymes and aspirin in treatment and long term coronary syndrome. Finally, at the end of 2001, the work of French teams was published concerning the evaluation of risk of relapse for cerebral vascular accident in the presence of a foramen ovale or an aneurysm of the inter-atrial septum.

Periprocedural use of tirofiban in elective percutaneous coronary intervention for long coronary lesions in stable patients with overlapping drug-eluting stents--the PETITION study: a prospective, randomized, multicenter study.

PubMed

Zhang, Qi; Wang, Xiao Long; Liao, Min Lei; Hu, Jian; Yang, Zhen Kun; Ding, Feng Hua; Zhang, Jian Sheng; Du, Run; Zhu, Tian Qi; Shen, Wei Feng; Zhang, Rui Yan

2015-03-01

Patients are at risk of developing periprocedural myonecrosis after percutaneous coronary intervention (PCI). We investigated whether the use of the platelet glycoprotein (GP) IIb/IIIa receptor inhibitor tirofiban could reduce periprocedural myocardial infarction (PMI) in patients with stable coronary artery disease undergoing elective PCI with overlapping stent implantation for long lesions. A total of 748 stable angina patients with long lesions (≥ 40 mm in length) treated with overlapping stent implantation were randomly assigned to receive tirofiban (tirofiban group; n = 373) or conventional therapy (control group; n = 375). Intravenous tirofiban was initiated before PCI and maintained for 12 hr after the procedure. The primary endpoint was PMI, defined as an elevation in CK-MB > 3 times the upper limit of normal 12 hr after the index procedure. The secondary endpoint was major adverse cardiac events (MACE), including cardiac death, target vessel revascularization, and recurrent MI (re-MI), at one-year of clinical follow-up. The safety end-points included Thrombolysis in Myocardial Infarction (TIMI) major bleeding and stent thrombosis. Despite comparable angiographic and procedural characteristics, in the intention-to-treatment analysis, the primary endpoint was significantly reduced in the tirofiban group (4.0% vs. 11.5%, P < 0.001). Multivariate analysis revealed that the adjunctive use of tirofiban was the only negative predictor of PMI (OR 0.41, 95% CI 0.28-0.81, P < 0.01). At one-year of clinical follow-up, the overall occurrence of MACE was significantly lower in the tirofiban group (13.4% vs. 22.7%, P = 0.001). The rate of TIMI major bleeding and stent thrombosis did not differ significantly between the two groups. Our results show that the adjunctive use of tirofiban reduces the occurrence of PMI and MACE at one year in stable coronary artery disease patients undergoing elective PCI for long lesions with overlapping stent implantation. © 2015 Wiley Periodicals, Inc.

Impact of treatment with saxagliptin on glycaemic stability and β-cell function in the SAVOR-TIMI 53 study.

PubMed

Leibowitz, G; Cahn, A; Bhatt, D L; Hirshberg, B; Mosenzon, O; Wei, C; Jermendy, G; Sheu, W H-H; Sendon, J L; Im, K; Braunwald, E; Scirica, B M; Raz, I

2015-05-01

To study the effects of saxagliptin, a dipeptidyl peptidase-4 inhibitor, on glycaemic stability and β-cell function in the SAVOR-TIMI 53 trial. We randomized 16,492 patients with type 2 diabetes (T2D) to saxagliptin or placebo, added to current antidiabetic medications, and followed them for a median of 2.1 years. Glycaemic instability was defined by: (i) a glycated haemoglobin (HbA1c) increase of ≥ 0.5% post-randomization; (ii) the initiation of new antidiabetic medications for ≥ 3 months; or (iii) an increase in dose of oral antidiabetic medication or ≥ 25% increase in insulin dose for ≥ 3 months. β-cell function was assessed according to fasting homeostatic model 2 assessment of β-cell function (HOMA-2β) values at baseline and at year 2 in patients not treated with insulin. Compared with placebo, participants treated with saxagliptin had a reduction in the development of glycaemic instability (hazard ratio 0.71; 95% confidence interval 0.68-0.74; p < 0.0001). In participants treated with saxagliptin compared with placebo, the occurrence of an HbA1c increase of ≥ 0.5% was reduced by 35.2%; initiation of insulin was decreased by 31.7% and the increases in doses of an oral antidiabetic drug or insulin were reduced by 19.5 and 23.5%, respectively (all p < 0.0001). At 2 years, HOMA-2β values decreased by 4.9% in participants treated with placebo, compared with an increase of 1.1% in those treated with saxagliptin (p < 0.0001). Saxagliptin improved glycaemia and prevented the reduction in HOMA-2β values. Saxagliptin may reduce the usual decline in β-cell function in T2D, thereby slowing diabetes progression. © 2015 John Wiley & Sons Ltd.

Incidence of Fractures in Patients With Type 2 Diabetes in the SAVOR-TIMI 53 Trial.

PubMed

Mosenzon, Ofri; Wei, Cheryl; Davidson, Jaime; Scirica, Benjamin M; Yanuv, Ilan; Rozenberg, Aliza; Hirshberg, Boaz; Cahn, Avivit; Stahre, Christina; Strojek, Krzysztof; Bhatt, Deepak L; Raz, Itamar

2015-11-01

Patients with type 2 diabetes have an increased risk of bone fractures, the predisposing factors for which are unknown. Treatment with thiazolidinediones (TZDs) further increases the incidence of osteoporotic fractures. In the Saxagliptin Assessment of Vascular Outcomes Recorded in Patients with Diabetes Mellitus-Thrombolysis in Myocardial Infarction 53 (SAVOR-TIMI 53) trial, fractures were considered an adverse event of special interest, and information regarding fractures was collected. We compared the incidence of fractures among the 8,280 patients who were assigned to treatment with saxagliptin with that in the 8,212 patients who were assigned to placebo. We further analyzed the participants' baseline characteristics and fracture risk. During a median follow-up of 2.1 years, 241 patients (2.9%) in the saxagliptin group and 240 (2.9%) in the placebo group experienced a fracture (hazard ratio [HR] 1.00 [95% CI 0.83-1.19]). Event rates for fractures were the same in both treatment arms: 14.7 per 1,000 patient-years in the entire population and 14.0 in the on-treatment population (first event only). Fracture risk was similar in patients treated with saxagliptin or placebo across different subgroups defined by race, cardiovascular risk, and renal function. A multivariable Cox regression analysis showed that risk of fracture was associated with female sex (P < 0.0001), longer diabetes duration (P < 0.0001), older age (P = 0.002), major hypoglycemic events (P = 0.01), noncompliance with study drug (P = 0.01), and treatment with TZDs (P = 0.03). In a large population of older patients with type 2 diabetes, treatment with saxagliptin was not associated with an increased risk of fractures. The association between longer diabetes duration and increased risk of bone fracture is an intriguing finding. © 2015 by the American Diabetes Association. Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered.

American College of Cardiology/American Heart Association/European Society of Cardiology/World Heart Federation universal definition of myocardial infarction classification system and the risk of cardiovascular death: observations from the TRITON-TIMI 38 trial (Trial to Assess Improvement in Therapeutic Outcomes by Optimizing Platelet Inhibition With Prasugrel-Thrombolysis in Myocardial Infarction 38).

PubMed

Bonaca, Marc P; Wiviott, Stephen D; Braunwald, Eugene; Murphy, Sabina A; Ruff, Christian T; Antman, Elliott M; Morrow, David A

2012-01-31

The availability of more sensitive biomarkers of myonecrosis and a new classification system from the universal definition of myocardial infarction (MI) have led to evolution of the classification of MI. The prognostic implications of MI defined in the current era have not been well described. We investigated the association between new or recurrent MI by subtype according to the European Society of Cardiology/American College of Cardiology/American Heart Association/World Health Federation Task Force for the Redefinition of MI Classification System and the risk of cardiovascular death among 13 608 patients with acute coronary syndrome in the Trial to Assess Improvement in Therapeutic Outcomes by Optimizing Platelet Inhibition with Prasugrel-Thrombolysis in Myocardial Infarction 38 (TRITON-TIMI 38). The adjusted risk of cardiovascular death was evaluated by landmark analysis starting at the time of the MI through 180 days after the event. Patients who experienced an MI during follow-up had a higher risk of cardiovascular death at 6 months than patients without an MI (6.5% versus 1.3%, P<0.001). This higher risk was present across all subtypes of MI, including type 4a (peri-percutaneous coronary intervention, 3.2%; P<0.001) and type 4b (stent thrombosis, 15.4%; P<0.001). After adjustment for important clinical covariates, the occurrence of any MI was associated with a 5-fold higher risk of death at 6 months (95% confidence interval 3.8-7.1), with similarly increased risk across subtypes. MI is associated with a significantly increased risk of cardiovascular death, with a consistent relationship across all types as defined by the universal classification system. These findings underscore the clinical relevance of these events and the importance of therapies aimed at preventing MI.

The prognostic significance of cardiac structure and function in atrial fibrillation: the ENGAGE AF-TIMI 48 Echocardiographic Substudy

PubMed Central

Gupta, Deepak K; Giugliano, Robert P; Ruff, Christian T; Claggett, Brian; Murphy, Sabina; Antman, Elliott; Mercuri, Michele F.; Braunwald, Eugene; Solomon, Scott D

2016-01-01

Background Atrial fibrillation (AF) is associated with increased risk for thromboembolism and death; however, the relationships between cardiac structure and function and adverse outcomes among individuals with AF are incompletely understood. Methods The ENGAGE AF –TIMI 48 study tested the once-daily oral factor Xa inhibitor edoxaban in comparison to warfarin for the prevention of stroke (ischemic or hemorrhagic) or systemic embolism in 21,105 subjects with nonvalvular AF and increased risk for thromboembolic events (CHADS2 ≥ 2). In a prospective substudy of 971 subjects who underwent transthoracic echocardiography at baseline, we used Cox proportional hazards models to evaluate the associations between cardiac structure and function and the risks for death and thromboembolism (ischemic stroke, TIA, or systemic embolism). Results Over a median follow up of 2.5 years, 89 (9.2%) deaths and 48 (4.9%) incident thromboembolic events occurred in 971 subjects. In models adjusted for CHADS2 score, aspirin use, and randomized treatment, larger LV end diastolic volume index (HR: 1.49 [95%CI: 1.16,1.91] per 1 SD [12.9 ml/m2]) and higher LV filling pressures measured by E/′e (HR: 1.32 [95%CI: 1.08,1.61] per 1 SD [4.6]) were independently associated with increased risks for death. E/e′ > 13 significantly improved prediction of death beyond clinical factors alone. No features of cardiac structure and function were independently associated with thromboembolism in this population. Findings were similar when adjusted for CHA2DS2-VASc in place of CHADS2. Conclusions In a contemporary population of patients with atrial fibrillation at increased risk for thromboembolic events, larger LV size and higher filling pressures were significantly associated with increased risk for death, but neither left atrial nor left ventricular measures were associated with thromboembolic risk. LV size and filling pressures may help identify AF patients at increased risk of death. PMID:27106009

Enoxaparin is superior to unfractionated heparin in patients with ST elevation myocardial infarction undergoing fibrinolysis regardless of the choice of lytic: an ExTRACT-TIMI 25 analysis.

PubMed

Giraldez, Roberto R; Nicolau, José Carlos; Corbalan, Ramon; Gurfinkel, Enrique P; Juarez, Ursulo; Lopez-Sendon, Jose; Parkhomenko, Alexander; Molhoek, Peter; Mohanavelu, Satishkumar; Morrow, David A; Antman, Elliott M

2007-07-01

We compared outcomes of ST-elevation myocardial infarction (STEMI) patients randomized to a strategy of either enoxaparin or unfractionated heparin (UFH) to support fibrinolysis. In the Enoxaparin and Thrombolysis Reperfusion for Acute Myocardial Infarction Treatment-Thrombolysis in Myocardial Infarction Study 25 (ExTRACT-TIMI 25) trial, 20,479 patients undergoing fibrinolysis for STEMI with a fibrin-specific agent (N = 16,283) or streptokinase (SK) (N = 4139) were randomized to enoxaparin throughout their hospitalization or UFH for at least 48 h. The primary end point of death or nonfatal recurrent MI through 30 days occurred in 12.0% of patients in the UFH and 9.8% in the enoxaparin groups when treated with fibrin-specific lytics [odds ratio(adjusted) (OR(adj)) 0.78; 95% CI 0.70-0.87; P < 0.001] and 11.8 vs. 10.2%, respectively, when treated with SK (OR(adj) 0.83; 95% CI 0.66-1.04; P = 0.10; P(interaction) = 0.58). Major bleeding rates including intracranial hemorrhage within the fibrin-specific cohort were 1.2 and 2.0% in the UFH and enoxaparin groups, respectively (P < 0.001) and 2.0% in UFH and 2.4% in enoxaparin patients in the SK cohort (P = 0.16). Interaction tests between antithrombin- and lytic-type were non-significant (P = 0.20). Death, nonfatal MI, or major bleeding was significantly reduced with enoxaparin in the fibrin-specific cohort (OR(adj) 0.82; 95% CI 0.74-0.91; P < 0.001) and favoured enoxaparin in the SK cohort (OR(adj) 0.89; 95% CI 0.72-1.10; P = 0.29; P(interaction) = 0.53). The benefits of an enoxaparin strategy over UFH were observed in both SK and fibrin-specific-treated STEMI patients. Therefore, an enoxaparin strategy is preferred over UFH to support fibrinolysis for STEMI regardless of lytic agent.

High-Sensitivity C-Reactive Protein as a Predictor of Cardiovascular Events after ST-Elevation Myocardial Infarction

PubMed Central

Ribeiro, Daniel Rios Pinto; Ramos, Adriane Monserrat; Vieira, Pedro Lima; Menti, Eduardo; Bordin, Odemir Luiz; de Souza, Priscilla Azambuja Lopes; de Quadros, Alexandre Schaan; Portal, Vera Lúcia

2014-01-01

Background The association between high-sensitivity C-reactive protein and recurrent major adverse cardiovascular events (MACE) in patients with ST-elevation myocardial infarction who undergo primary percutaneous coronary intervention remains controversial. Objective To investigate the potential association between high-sensitivity C-reactive protein and an increased risk of MACE such as death, heart failure, reinfarction, and new revascularization in patients with ST-elevation myocardial infarction treated with primary percutaneous coronary intervention. Methods This prospective cohort study included 300 individuals aged >18 years who were diagnosed with ST-elevation myocardial infarction and underwent primary percutaneous coronary intervention at a tertiary health center. An instrument evaluating clinical variables and the Thrombolysis in Myocardial Infarction (TIMI) and Global Registry of Acute Coronary Events (GRACE) risk scores was used. High-sensitivity C-reactive protein was determined by nephelometry. The patients were followed-up during hospitalization and up to 30 days after infarction for the occurrence of MACE. Student's t, Mann-Whitney, chi-square, and logistic regression tests were used for statistical analyses. P values of ≤0.05 were considered statistically significant. Results The mean age was 59.76 years, and 69.3% of patients were male. No statistically significant association was observed between high-sensitivity C-reactive protein and recurrent MACE (p = 0.11). However, high-sensitivity C-reactive protein was independently associated with 30-day mortality when adjusted for TIMI [odds ratio (OR), 1.27; 95% confidence interval (CI), 1.07-1.51; p = 0.005] and GRACE (OR, 1.26; 95% CI, 1.06-1.49; p = 0.007) risk scores. Conclusion Although high-sensitivity C-reactive protein was not predictive of combined major cardiovascular events within 30 days after ST-elevation myocardial infarction in patients who underwent primary angioplasty and stent implantation, it was an independent predictor of 30-day mortality. PMID:25120085

Efficacy and safety of bivalirudin in coronary artery disease patients with mild to moderate chronic kidney disease: Meta-analysis.

PubMed

Zeng, Xiaofang; Lincoff, A Michael; Schulz-Schüpke, Stefanie; Steg, Philippe Gabriel; Elbez, Yedid; Mehran, Roxana; Stone, Gregg W; McAndrew, Thomas; Lin, Jianhui; Zhang, Xindan; Shi, Wenhai; Lei, Han; Jing, Zhicheng; Huang, Wei

2018-05-01

Patients with chronic kidney disease (CKD) have elevated bleeding and ischemic outcomes. We aim to assess the short- and long-term efficacy and safety of bivalirudin compared to heparin plus glycoprotein IIb/IIIa inhibitors (GPIs) in coronary artery disease (CAD) patients with CKD. Randomized trials were searched in PubMed, Cochrane, and Embase databases up to January 2017. Among the trials retrieved, efficacy endpoints were defined as mortality, myocardial infarction (MI), repeat revascularization, stent thrombosis, and major adverse cardiac events (MACEs). Safety endpoints were reported as non-coronary artery bypass grafting (CABG) related major bleeding and thrombolysis in myocardial infarction (TIMI) major bleeding. Risk ratio (RR) and 95% confidence interval (CI) were calculated for each outcome using a fixed effect model. Five studies with a total of 3796 patients were included. In short-term follow up (30 days), bivalirudin significantly reduced non-CABG related major bleeding (p=0.0004) and TIMI major bleeding (p=0.007) compared to heparin plus GPIs. No significant differences were observed in rates of mortality, MI, repeat revascularization, stent thrombosis, and MACEs between the two groups in short- and long-term follow up (6 months to 3 years). In patients with ST elevated myocardial infarction (STEMI) with concurrent CKD, the decreased non-CABG related major bleeding (p=0.04) without increasing ischemic events was also observed after short-term follow up. (1) Bivalirudin is safer than and as effective as heparin plus GPIs in CAD patients with CKD. (2) Impaired renal function does not affect the safety benefits of bivalirudin. (3) Similar efficacy profiles were identified between the two groups after both short- and long-term follow up in the CAD patients with CKD. Copyright © 2017 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.

Prasugrel vs. clopidogrel in contemporary Western European patients with acute coronary syndromes receiving drug-eluting stents: Comparative cost-effectiveness analysis from the BASKET-PROVE cohorts.

PubMed

Wein, Bastian; Coslovsky, Michael; Jabbari, Reza; Galatius, Søren; Pfisterer, Matthias; Kaiser, Christoph

2017-12-01

Clinical and cost-effectiveness of prasugrel vs. clopidogrel in acute coronary syndrome (ACS) was only evaluated using TRITON-TIMI 38 event rates. A comparative analysis of both drugs in contemporary European ACS patients is lacking. To address this issue, cardiac and bleeding events of 2 "sister" multicenter stent trials, BASKET-PROVE (BP) I with clopidogrel and BPII with prasugrel (for 12months each) were used in a hybrid analysis. Medication costs were 2015 sales prices, event costs modelled for Denmark (DNK), Germany (GER) and Switzerland (SUI) and quality adjusted life years (QALY) by EQ-5D-3L questionnaire. In BPI and II, 1012 and 985 ACS-patients received drug eluting stents, respectively, followed-up for 2years. Compared to clopidogrel, prasugrel-treated patients had no more major cardiac events (5.2% vs. 6.4%, p=0.422) nor cardiac deaths (1.6% vs. 1.0%, p=0.255), but more major bleedings (4.0% vs. 1.7%, p<0.001) and altogether no difference in QALYs (-0.027 (95%CI: -0.064/0.011)). Prasugrel caused higher total expenditures per patient: 1116.3 (DNK), 1063.5 (GER) and 880.8 (SUI) EURO, respectively. Accordingly, incremental cost-effectiveness was negative for prasugrel vs. clopidogrel with ratios of -45,907 (DNK), -39,909 (GER) and -33,435 (SUI) EURO/QALY gained, making clopidogrel an economically dominant strategy, even after accounting for the non-randomized comparison. Findings of this contemporary European ACS-cohort showed markedly lower cardiac event rates than TRITON-TIMI 38 and no significant difference in 2-year QALYs between prasugrel and clopidogrel-treated patients. At current drug prices, clopidogrel use resulted in an economically dominant treatment strategy in Western European patients. Copyright © 2017 Elsevier B.V. All rights reserved.

Design and Rationale of the LAPLACE-TIMI 57 Trial: A Phase II, Double-Blind, Placebo-Controlled Study of the Efficacy and Tolerability of a Monoclonal Antibody Inhibitor of PCSK9 in Subjects With Hypercholesterolemia on Background Statin Therapy

PubMed Central

Kohli, Payal; Desai, Nihar R.; Giugliano, Robert P.; Kim, Jae B.; Somaratne, Ransi; Huang, Fannie; Knusel, Beat; McDonald, Shannon; Abrahamsen, Timothy; Wasserman, Scott M.; Scott, Robert; Sabatine, Marc S.

2013-01-01

Lowering low-density lipoprotein cholesterol (LDL-C) is a cornerstone for the prevention of atherosclerotic heart disease, improving clinical outcomes and reducing vascular mortality in patients with hypercholesterolemia. The clinical benefits of LDL-C reduction appear to extend even to patients starting with LDL-C as low as 60–80 mg/dL prior to initiating therapy. Statins are the first-line agents for treating hypercholesterolemia and are effective in reducing LDL-C, but many patients are unable to achieve their optimal lipid targets despite intensive statin therapy. Therefore, there has been a strong impetus for the development of novel pharmacologic agents designed to lower LDL-C further in patients already on statin therapy. Genetic mutations resulting in altered cholesterol homeostasis provide valuable information regarding novel approaches for treating hypercholesterolemia. To that end, mutations in proprotein convertase subtilisin/kexin type 9 (PCSK9) were linked to altered levels of LDL-C, illustrating this protein’s role in lipid metabolism. PCSK9 promotes degradation of the LDL receptor, preventing its transport back to the cell surface and thereby increasing circulating LDL-C. Conversely, inhibition of PCSK9 can profoundly decrease circulating LDL-C, and thus is an attractive new target for LDL-C–lowering therapy. AMG 145 is a fully human monoclonal immunoglobulin G2 antibody that binds specifically to human PCSK9 and inhibits its interaction with the low-density lipoprotein receptor. In this manuscript, we describe the rationale and design of LDL-C Assessment with PCSK9 Monoclonal Antibody Inhibition Combined With Statin Therapy–Thrombolysis In Myocardial Infarction 57 (LAPLACE-TIMI 57; NCT01380730), a 12-week, randomized, double-blind, dose-ranging, placebo-controlled study designed to assess the safety and efficacy of AMG 145 when added to statin therapy in patients with hypercholesterolemia. PMID:22714699

Statins are associated with lower risk of gastrointestinal bleeding in patients with unstable coronary syndromes: analysis of the Orbofiban in Patients with Unstable coronary Syndromes-Thrombolysis In Myocardial Infarction 16 (OPUS-TIMI 16) trial.

PubMed

Atar, Shaul; Cannon, Christopher P; Murphy, Sabina A; Rosanio, Salvatore; Uretsky, Barry F; Birnbaum, Yochai

2006-05-01

It has recently been shown that statins increase the myocardial content of prostaglandin (PG) I2 (prostacyclin) and PGE2. A systemic increase of PG production may protect the gastric mucosa and prevent gastrointestinal (GI) bleeding. We hypothesized that statins would lower the risk of GI bleeding associated with antiplatelet therapy in patients with acute coronary syndromes (ACS). We retrospectively analyzed data on 10288 patients with ACS included in the OPUS-TIMI 16 trial and received aspirin and either the oral IIb/IIIa inhibitor orbofiban or placebo. Inhospital GI bleeding rate was significantly lower in patients who were receiving lipid-lowering drugs before admission compared with those who were not (0.2% vs 0.6%, P = .031). Throughout 10 months of follow-up, GI bleeding occurred in 1.8% of non-statin users compared with 1.0% of statin users (P = .001). Statin use was associated with less overall bleeding in both the orbofiban (1.4% vs 2.4%, P = .006) and the placebo groups (0.2% vs 0.8%, P = .047). Severe and major bleeding occurred less frequently with statin use (0.8% vs 1.5%, P = .001) in both the orbofiban (1.1% vs 2.0%, P = .006) and the placebo groups (0.1% vs 0.5%, P = .119). Logistic regression analysis showed that age > 65 years, orbofiban treatment, Killip class > 1, history of cerebrovascular disease, and calcium-channel blocker use were associated with higher risk of GI bleeding, whereas statin therapy was associated with a lower risk (odds ratio 0.68, 95% CI 0.45-1.04, P = .079). Statins may exert protective effect against GI bleeding in patients with ACS. Additional studies are warranted to explore this additional potential benefit of statins.

Early Dynamic Risk Stratification with Baseline Troponin Levels and 90-minute ST Segment Resolution to Predict 30 Day Cardiovascular Mortality in STEMI: Analysis from CLARITY TIMI-28

PubMed Central

Sherwood, Matthew W.; Morrow, David A.; Scirica, Benjamin M.; Jiang, Songtao; Bode, Christoph; Rifai, Nader; Gerszten, Robert E.; Gibson, C. Michael; Cannon, Christopher P.; Braunwald, Eugene; Sabatine, Marc S.

2010-01-01

Background Troponin is the preferred biomarker for risk stratification in non-ST-elevation ACS. The incremental prognostic utility of the initial magnitude of troponin elevation and its value in conjunction with ST segment resolution (STRes) in STEMI is less well-defined. Methods Troponin T (TnT) was measured in 1250 patients at presentation undergoing fibrinolysis for STEMI in CLARITY-TIMI 28. STRes was measured at 90 minutes. Multivariable logistic regression was used to examine the independent association between TnT levels, STRes, and 30-day cardiovascular (CV) mortality. Results Patients were classified into undetectable TnT at baseline (n=594), detectable but below the median of 0.12 ng/ml (n=330), and above the median (n=326). Rates of 30-day CV death were 1.5%, 4.5%, and 9.5% respectively (P<0.0001). Compared with those with undetectable levels and adjusting for baseline factors, the odds ratios for 30-day CV death were 4.56 (1.72-12.08, P=0.002) and 5.81 (2.29-14.73, P=0.0002) for those below and above the median, respectively. When combined with STRes, there was a significant gradient of risk, and in a multivariable model both baseline TnT (P=0.004) and STRes (P=0.003) were significant predictors of 30-day CV death. The addition of TnT and STRes to clinical risk factors significantly improved the C-statistic (0.86 to 0.90, P=0.02) and the integrated discriminative improvement 7.1% (P=0.0009). Conclusions Baseline TnT and 90-minute STRes are independent predictors of 30-day CV death in patients with STEMI. Use of these two simple, readily available tools can aid clinicians in early risk stratification. PMID:20569707

The role of clopidogrel in early and sustained arterial patency after fibrinolysis for ST-segment elevation myocardial infarction: the ECG CLARITY-TIMI 28 Study.

PubMed

Scirica, Benjamin M; Sabatine, Marc S; Morrow, David A; Gibson, C Michael; Murphy, Sabina A; Wiviott, Stephen D; Giugliano, Robert P; McCabe, Carolyn H; Cannon, Christopher P; Braunwald, Eugene

2006-07-04

This study was designed to determine the relationship between clopidogrel and early ST-segment resolution (STRes) and the interaction of the two with clinical outcomes after fibrinolysis. ST-segment resolution is an early noninvasive marker of coronary reperfusion. The CLARITY-TIMI 28 (Clopidogrel as Adjunctive Reperfusion Therapy-Thrombolysis in Myocardial Infarction 28) trial randomized 3,491 patients with ST-segment elevation myocardial infarction (STEMI) undergoing fibrinolysis to clopidogrel versus placebo. ST-segment resolution was defined as complete (>70%), partial (30% to 70%), or none (<30%). Electrocardiograms were valid for interpretation in 2,431 patients at 90 min and 2,087 at 180 min. There was no difference in the rate of complete STRes between the clopidogrel and placebo groups at 90 min (38.4% vs. 36.6% at 90 min). When patients were stratified by STRes category, treatment with clopidogrel resulted in greater benefit among those with evidence of early STRes, with greater odds of an open artery at late angiography in patients with partial (odds ratio [OR] 1.4, p = 0.04) or complete (OR 2.0, p < 0.001) STRes, but no improvement in those with no STRes at 90 min (OR 0.89, p = 0.48) (p for interaction = 0.003). Clopidogrel was also associated with a significant reduction in the odds of an in-hospital death or myocardial infarction in patients who achieved partial (OR 0.30, p = 0.003) or complete STRes at 90 min (OR 0.49, p = 0.056), whereas clinical benefit was not apparent in patients who had no STRes (OR 0.98, p = 0.95) (p for interaction = 0.027). By 30 days, the clinical benefit of clopidogrel was predominately seen in patients with complete STRes. Clopidogrel appears to improve late coronary patency and clinical outcomes by preventing reocclusion of open arteries rather than by facilitating early reperfusion.

Thrombolysis in myocardial infarction frame count in coronary arteries without visible atherosclerosis in coronary angiography of patients with stable coronary artery disease.

PubMed

Tacoy, Gulten A; Yazici, Guliz E; Kocaman, Sinan A; Ozdemir, Murat H

2009-06-01

To investigate the thrombolysis in myocardial infarction (TIMI) frame count (TFC) in the coronary arteries without visible atherosclerosis in coronary angiography of patients with stable coronary artery disease (CAD). Eighty-three patients (mean age 58+/-10, 31 [37%] males), who underwent coronary angiographic evaluation for stable angina in Gazi University, Ankara, Turkey, Cardiology clinic between 2006-2007 were enrolled. Forty patients with normal coronary arteries were defined as group I. Group II consisted of 43 patients, who have one normal coronary artery in the setting of stable CAD defined as stenoses 50% or greater in at least one major coronary artery. Coronary blood flow and microvascular perfusion was evaluated by TFC. In group II, the TFC of left anterior descending artery (LAD) in 15 patients, TFC of circumflex artery (CX) in 18 patient, and TFC of right coronary artery (RCA) in 10 patients were evaluated. In group II, the TFC of LAD (37+/-12 versus 29+/-12, p=0.015) and CX (22+/-8 versus 18+/-9, p=0.035) were significantly higher than those in group I. The TFC of RCA was similar between groups (17+/-9 versus 17+/-8, p=0.990). After the adjustment of the risk factors by multivariate regression analyses, the association between TFC and clinical characteristic was statistically non-significant. The TFC decreased in angiographically normal LAD and CX arteries in the setting of stable angina pectoris. The important predictor was CAD alone, irrespective of the clinical parameters.

Initial experience with a dedicated coronary re-entry device for revascularization of chronic total occlusions.

PubMed

Whitlow, Patrick L; Lombardi, William L; Araya, Mario; Michael Wyman, R; Torres, Humberto; Dauvergne, Christian; Tsuchikane, Etsuo; Lansky, Alexandra; Thompson, Craig A

2012-11-01

The aim of this registry was to evaluate a new device designed to facilitate antegrade guidewire re-entry into the true lumen of a chronic total coronary occlusion (CTO) from the adjacent subintimal space. Successful recanalization of CTOs results in clinical improvement in appropriately selected patients. CTO intervention is time- and resource-consuming, and a simplified approach enabling antegrade guidewire re-entry into the distal true lumen might improve success. Patients with CTO and ischemia were entered into a prospective registry regardless of lesion characteristics. If wire manipulation resulted in subintimal wire entrapment, a new re-entry tool (a 2.5-mm flat subintimal balloon with two exit ports offset by 180°) was used as a platform to attempt guidewire penetration into the distal true lumen. The primary endpoint assessed was successful device-guided re-entry. Standard techniques were then utilized to open the CTO. In 40 consecutive CTO lesions attempted, 19 resulted in subintimal wire entrapment (mean occlusion length 44 mm). Sixteen of these 19 were successfully crossed with an antegrade guidewire into the distal true lumen using the new device (84%). One patient with unsuccessful re-entry was subsequently recanalized with a retrograde technique. All crossed lesions were stented (17/17), resulting in TIMI 3 flow without major complications. Two cases were unsuccessful. One patient had a grade I coronary perforation requiring no treatment. A new device to recanalize CTOs complicated by subintimal wire entrapment can be used successfully by experienced operators. Further study of this coronary re-entry device is ongoing. Copyright © 2011 Wiley Periodicals, Inc.

Measuring Air Quality in a Construction Site Biotope Using the AQM-65 Analyser

NASA Astrophysics Data System (ADS)

Ioana-Alina, Creţan; Nicoleta, Nemeș

2017-10-01

Activities related to the execution of construction works often exert pressure on the quality of environmental factors in adjacent habitat. In various stages of realization of the works if is the opening of the building site and access roads, borrow pits and the storage, or the construction itself, all the related activities will cause harm in various degrees of vegetation on the construction site and its surroundings. Large areas are rendered non-productive and, although they should be restored for use in the same place or elsewhere, sometimes they can lose their natural habitat baseline. The paper is presenting a case study of air quality monitoring using the AQM 65 analyser for a construction site located near Timisoara locality, Timis County, Romania.

[Treatment of acute ST Elevation myocardial infarction in a regional network ("Drip & Ship Network Rostock")].

PubMed

Schneider, Henrik; Ince, Hüseyin; Rehders, Tim; Körber, Thomas; Weber, Frank; Kische, Stephan; Chatterjee, Tuchaar; Nienaber, Christoph A

2007-12-01

Management of acute ST elevation myocardial infarction (STEMI) demands rapid and complete reperfusion of the infarct-related artery (IRA). With postinfarction prognosis depending on time delay from onset of symptoms to complete reperfusion (TIMI 3 flow) of the IRA, primary percutaneous coronary intervention (PPCI) performed by an experienced team has been shown to be superior to thrombolytic therapy with lower mortality, less frequent occurrence of nonfatal reinfarction and stroke, and thus represents the preferred treatment strategy according to the national and international guidelines. For regional implementation of PPCI, particularly in rural areas, information and transfer logistics within networks of care and direct transport of an infarction patient to a PCI hospital rather than to the closest hospital are a challenge. With successful implementation of network logistics and standardized therapeutic pathways, current guidelines and requested timelines versus thrombolysis could be met. The implemented logistics comprised 24 h/7 days stand-by services of an experienced PCI team, direct telephone hotline contact between rescue service/emergency physician and interventional cardiologist on call, and direct open access to a catheterization laboratory at any time. Within the Drip&Ship network Rostock, to date (July 2007) 1,022 consecutive patients with PCI for STEMI were documented and analyzed over 5 years; of these, 490 patients were transferred from a community hospital to the PCI center and 532 patients were admitted directly to the interventional center. In 95.1% of all transferred and in 94.8% of all directly admitted patients, PCI was successfully accomplished upon arrival. A normalized flow to the IRA after PCI was documented in 96% of both groups, no patient was subjected to thrombolytic therapy. At 12-month follow-up, there were no differences between both groups with respect to infarct size and mortality. Moreover, there was no evidence of differences in left ventricular ejection fraction between groups. Thus, transportation of STEMI patients within an established PCI network did not result in any prognostic disadvantage. Efficient network logistics with transportation for PPCI in acute STEMI ensure both safety and outcome profiles similar to patients treated by PCI in metropolitan areas.

Manual Thrombus Aspiration and the Improved Survival of Patients With Unstable Angina Pectoris Treated With Percutaneous Coronary Intervention (30 Months Follow-Up).

PubMed

Yildiz, Bekir S; Bilgin, Murat; Zungur, Mustafa; Alihanoglu, Yusuf I; Kilic, Ismail D; Buber, Ipek; Ergin, Ahmet; Kaftan, Havane A; Evrengul, Harun

2016-02-01

The clinical effect of intracoronary thrombus aspiration during percutaneous coronary intervention in patients with unstable angina pectoris is unknown. In this study, we aimed to assess how thrombus aspiration during percutaneous coronary intervention affects in-hospital and 30-month mortality and complications in patients with unstable angina pectoris.We undertook an observational cohort study of 645 consecutive unstable angina pectoris patients who had performed percutaneous coronary intervention from February 2011 to March 2013. Before intervention, 159 patients who had culprit lesion with thrombus were randomly assigned to group 1 (thrombus aspiration group) and group 2 (stand-alone percutaneous coronary intervention group). All patients were followed-up 30 months until August 2015.Thrombus aspiration was performed in 64 patients (46%) whose cardiac markers (ie, creatinine kinase [CK-MB] mass and troponin T) were significantly lower after percutaneous coronary intervention than in those of group 2 (CK-MB mass: 3.80 ± 1.11 vs 4.23 ± 0.89, P = 0.012; troponin T: 0.012 ± 0.014 vs 0.018 ± 0.008, P = 0.002). Left ventricular ejection fraction at 6, 12, and 24 months postintervention was significantly higher in the group 1. During a mean follow-up period of 28.87 ± 6.28 months, mortality rates were 6.3% in the group 1 versus 12.9% in the group 2. Thrombus aspiration was also associated with significantly less long-term mortality in unstable angina pectoris patients (adjusted HR: 4.61, 95% CI: 1.16-18.21, P = 0.029).Thrombus aspiration in the context of unstable angina pectoris is associated with a limited elevation in cardiac enzymes during intervention that minimises microembolization and significantly improves both of epicardial flow and myocardial perfusion, as shown by angiographic TIMI flow grade and frame count. Thrombus aspiration during percutaneous coronary intervention in unstable angina pectoris patients has better survival over a 30-month follow-up period.

Usefulness of MRI to Differentiate Between Temporary and Long-Term Coronary Artery Occlusion in a Minimally Invasive Model of Experimental Myocardial Infarction

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

Abegunewardene, Nico, E-mail: nico@uni-mainz.de; Vosseler, Markus; Gori, Tommaso

The surgical technique employed to determine an experimental ischemic damage is a major factor in the subsequent process of myocardial scar development. We set out to establish a minimally invasive porcine model of myocardial infarction using cardiac contrast-enhanced magnetic resonance imaging (ce-MRI) as the basic diagnostic tool. Twenty-seven domestic pigs were randomized to either temporary or permanent occlusion of the left anterior descending artery (LAD). Temporary occlusion was achieved by inflation of a percutaneous balloon in the left anterior descending artery directly beyond the second diagonal branch. Occlusion was maintained for 30 or 45 min, followed by reperfusion. Permanent occlusionmore » was achieved via thrombin injection. Thirteen animals died peri- or postinterventionally due to arrhythmias. Fourteen animals survived the 30-min ischemia (four animals; group 1), the 45-min ischemia (six animals; group 2), or the permanent occlusion (4 animals; group 3). Coronary angiography and ce-MRI were performed 8 weeks after coronary occlusion to document the coronary flow grade and the size of myocardial scar tissue. The LAD was patent in all animals in groups 1 and 2, with normal TIMI flow; in group 3 animals, the LAD was totally occluded. Fibrosis of the left ventricle in group 1 (4.9 {+-} 4.4%; p = 0.008) and group 2 (9.4 {+-} 2.9%; p = 0.05) was significantly lower than in group 3 (14.5 {+-} 3.9%). Wall thickness of the ischemic area was significantly lower in group 3 versus group 1 and group 2 (2.9 {+-} 0.3, 5.9 {+-} 0.7, and 6.1 {+-} 0.7 mm; p = 0.005). The extent of late enhancement of the left ventricle was also significantly higher in group 3 (16.9 {+-} 2.1%) compared to group 1 (5.3 {+-} 5.4%; p = 0.003) and group 2 (9.7 {+-} 3.4%, p = 0.013). In conclusion, the present model of minimally invasive infarction coupled with ce-MRI may represent a useful alternative to the open chest model for studies of myocardial infarction and scar development.« less

Best Practices for Continuous Monitoring of Temperature and Flow in Wadeable Streams (Final Report)

EPA Science Inventory

This final report is a technical "best practices" document describing sensor deployment for and collection of continuous temperature and flow data at ungaged sites in wadeable streams. This document addresses questions related to equipment needs; configuration, placement, and ins...

Multicenter, dose-ranging study of efegatran sulfate versus heparin with thrombolysis for acute myocardial infarction: The Promotion of Reperfusion in Myocardial Infarction Evolution (PRIME) trial.

PubMed

2002-01-01

Adjunctive therapies that increase the incidence of normal reperfusion after thrombolysis for acute myocardial infarction (MI) could enhance clinical outcomes. Direct thrombin inhibitors may offer an advantage over standard adjunctive therapies. We randomized 336 patients with acute MI at 33 sites to receive 1 of 5 doses of efegatran sulfate, a direct thrombin inhibitor, or heparin for 72 to 96 hours, both with accelerated alteplase and aspirin. The primary end point was the incidence of thrombolytic failure (death, reinfarction, or TIMI grade 0-2 flow in the infarct artery from 90 minutes to discharge or 30 days, whichever occurred earlier). Significantly more patients randomized to efegatran had evidence of heart failure at admission. The lowest-dose efegatran arm was terminated at 15 patients because of unacceptably increased thrombolytic failure. The primary end point occurred in 53.0% of patients treated with heparin, in 53.8% of patients treated with efegatran overall (P =.90), and in 55.4% of patients given intermediate-dose efegatran (P =.74). These findings were unaffected after adjustment was done for baseline differences. Most bleeding was minor; major bleeding and the use of blood transfusions did not differ significantly by treatment. Three patients in the high-dose efegatran group had intracranial hemorrhage, as did 1 patient in the heparin group. Continuous ST monitoring showed a shorter time to recovery for the efegatran group (median 107 minutes) compared with the heparin group (154 minutes; P =.025). Efegatran sulfate appeared to offer no clear advantage over heparin as an adjunct to thrombolysis for acute myocardial infarction, although there may be a modest improvement in time to reperfusion.

Comparison of early and late clinical outcomes in patients >= 80 versus <80 years of age after successful primary angioplasty for ST segment elevation myocardial infarction.

PubMed

Oduncu, Vecih; Erkol, Ayhan; Tanalp, Ali Cevat; Kırma, Cevat; Bulut, Mustafa; Bitigen, Atila; Pala, Selçuk; Tigen, Kürşat; Esen, Ali M

2013-06-01

We aimed to compare the efficacy of primary percutaneous coronary intervention (p-PCI) in patients >=80 versus <80 years of age with ST-segment elevation myocardial infarction (STEMI). We retrospectively enrolled 2213 patients with acute STEMI. The patients were prospectively followed up for a median of 42 months. Early and late clinical outcomes were compared according to age. One-hundred and seventy-nine (8.1%) of the 2213 patients were aged >=80 years. Post-procedural TIMI grade 3 flow was significantly less frequent in the age >=80 years patients (82.1% vs. 91.1%, p<0.001). Rates of mortality (14.5% vs. 3.4%, p<0.001), heart failure (20.7% vs. 10.5%, p<0.001), major hemorrhage (9.5% vs. 3.3%, p<0.001), secondary VT/VF (10.1% vs. 4.2%, p=0.002) and atrial fibrillation (12.8% vs. 4.3%, p<0.001) during the early hospitalization period were significantly higher in the age >=80 years patient group. Overall rates of mortality (40% vs. 9.7%, p<0.001) and total stroke (5.6% vs. 1.1%, p=0.005) at long-term follow-up were also higher in the age >=80 years patient group. However, there was no difference between the two groups with respect to the reinfarction/revascularization rates. Analysis, using the Cox proportional hazards model, revealed that age >=80 to was an independent predictor of long-term mortality (hazard ratio 2.17, 95% CI 1.23-4.17, p=0.02). Age is an independent predictor of mortality after p-PCI for STEMI. Although it seems to improve early outcomes, the efficacy of p-PCI at long-term follow-up is limited in elderly patients.

Two-dimensional speckle tracking echocardiography prognostic parameters in patients after acute myocardial infarction.

PubMed

Haberka, Maciej; Liszka, Jerzy; Kozyra, Andrzej; Finik, Maciej; Gąsior, Zbigniew

2015-03-01

The aim of the study was to evaluate the left ventricle (LV) function with speckle tracking echocardiography (STE) and to assess its relation to prognosis in patients after acute myocardial infarction (AMI). Sixty-three patients (F/M = 16/47 pts; 62.33 ± 11.85 years old) with AMI (NSTEMI/STEMI 24/39 pts) and successful percutaneous coronary intervention (PCI) with stent implantation (thrombolysis in myocardial infarction; TIMI 3 flow) were enrolled in this study. All patients underwent baseline two-dimensional conventional echocardiography and STE 3 days (baseline) and 30 days after PCI. All patients were followed up for cardiovascular clinical endpoints, major adverse cardiovascular endpoint (MACE), and functional status (Canadian Cardiovascular Society and New York Heart Association). During the follow-up (31.9 ± 5.1 months), there were 3 cardiovascular deaths, 15 patients had AMI, 2 patients had cerebral infarction, 24 patients reached the MACE. Baseline LV torsion (P = 0.035), but none of the other strain parameters were associated with the time to first unplanned cardiovascular hospitalization. Univariate analysis showed that baseline longitudinal two-chamber and four-chamber strain (sLa2 0 and sLa4 0) and the same parameters obtained 30 days after the AMI together with transverse four-chamber strain (sLa2 30, sLa4 30, and sTa4 30) were significantly associated with combined endpoint (MACE). The strongest association in the univariate analysis was found for the baseline sLa2. However, in multivariable analysis only a left ventricular remodeling (LVR - 27% pts) was significantly associated with MACE and strain parameters were not associated with the combined endpoint. The assessment of LV function with STE may improve cardiovascular risk prediction in postmyocardial infarction patients. © 2014, Wiley Periodicals, Inc.

The incidence of kidney injury for patients treated with a high-potency versus moderate-potency statin regimen after an acute coronary syndrome.

PubMed

Sarma, Amy; Cannon, Christopher P; de Lemos, James; Rouleau, Jean L; Lewis, Eldrin F; Guo, Jianping; Mega, Jessica L; Sabatine, Marc S; O'Donoghue, Michelle L

2014-05-01

Observational studies have raised concerns that high-potency statins increase the risk of acute kidney injury. We therefore examined the incidence of kidney injury across 2 randomized trials of statin therapy. PROVE IT-TIMI 22 enrolled 4162 subjects after an acute coronary syndrome (ACS) and randomized them to atorvastatin 80 mg/day versus pravastatin 40 mg/day. A-to-Z enrolled 4497 subjects after ACS and randomized them to a high-potency (simvastatin 40 mg/day × 1 months, then simvastatin 80 mg/day) versus a delayed moderate-potency statin strategy (placebo × 4 months, then simvastatin 20 mg/day). Serum creatinine was assessed centrally at serial time points. Adverse events (AEs) relating to kidney injury were identified through database review. Across both trials, mean serum creatinine was similar between treatment arms at baseline and throughout follow-up. In A-to-Z, the incidence of a 1.5-fold or ≥ 0.3 mg/dL rise in serum creatinine was 11.4% for subjects randomized to a high-potency statin regimen versus 12.4% for those on a delayed moderate-potency regimen (odds ratio [OR], 0.91; 95% confidence interval [CI], 0.76 to 1.10; P=0.33). In PROVE IT-TIMI 22, the incidence was 9.4% for subjects randomized to atorvastatin 80 mg/day and 10.6% for subjects randomized to pravastatin 40 mg/day (OR, 0.88; 95% CI, 0.71 to 1.09; P=0.25). Consistent results were observed for different kidney injury thresholds and in individuals with diabetes mellitus or with moderate renal dysfunction. The incidence of kidney injury-related adverse events (AEs) was not statistically different for patients on a high-potency versus moderate-potency statin regimen (OR, 1.06; 95% CI, 0.68 to 1.67; P=0.78). For patients enrolled in 2 large randomized trials of statin therapy after ACS, the use of a high-potency statin regimen did not increase the risk of kidney injury.

Interleukin-6 and the Risk of Adverse Outcomes in Patients After an Acute Coronary Syndrome: Observations From the SOLID-TIMI 52 (Stabilization of Plaque Using Darapladib-Thrombolysis in Myocardial Infarction 52) Trial.

PubMed

Fanola, Christina L; Morrow, David A; Cannon, Christopher P; Jarolim, Petr; Lukas, Mary Ann; Bode, Christoph; Hochman, Judith S; Goodrich, Erica L; Braunwald, Eugene; O'Donoghue, Michelle L

2017-10-24

Interleukin-6 (IL-6) is an inflammatory cytokine implicated in plaque instability in acute coronary syndrome (ACS). We aimed to evaluate the prognostic implications of IL-6 post-ACS. IL-6 concentration was assessed at baseline in 4939 subjects in SOLID-TIMI 52 (Stabilization of Plaque Using Darapladib-Thrombolysis in Myocardial Infarction 52), a randomized trial of darapladib in patients ≤30 days from ACS. Patients were followed for a median of 2.5 years for major adverse cardiovascular events; cardiovascular death, myocardial infarction, or stroke) and cardiovascular death or heart failure hospitalization. Primary analyses were adjusted first for baseline characteristics, days from index ACS, ACS type, and randomized treatment arm. For every SD increase in IL-6, there was a 10% higher risk of major adverse cardiovascular events (adjusted hazard ratio [adj HR] 1.10, 95% confidence interval [CI] 1.01-1.19) and a 22% higher risk of cardiovascular death or heart failure (adj HR 1.22, 95% CI 1.11-1.34). Patients in the highest IL-6 quartile had a higher risk of major adverse cardiovascular events (adj HR Q4:Q1 1.57, 95% CI 1.22-2.03) and cardiovascular death or heart failure (adj HR 2.29, 95% CI 1.6-3.29). After further adjustment for biomarkers (high-sensitivity C-reactive protein, lipoprotein-associated phospholipase A 2 activity, high-sensitivity troponin I, and B-type natriuretic peptide), IL-6 remained significantly associated with the risk of major adverse cardiovascular events (adj HR Q4:Q1 1.43, 95% CI 1.09-1.88) and cardiovascular death or heart failure (adj HR 1.79, 95% CI 1.22-2.63). In patients after ACS, IL-6 concentration is associated with adverse cardiovascular outcomes independent of established risk predictors and biomarkers. These findings lend support to the concept of IL-6 as a potential therapeutic target in patients with unstable ischemic heart disease. © 2017 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.

Effect of Saxagliptin on Renal Outcomes in the SAVOR-TIMI 53 Trial.

PubMed

Mosenzon, Ofri; Leibowitz, Gil; Bhatt, Deepak L; Cahn, Avivit; Hirshberg, Boaz; Wei, Cheryl; Im, KyungAh; Rozenberg, Aliza; Yanuv, Ilan; Stahre, Christina; Ray, Kausik K; Iqbal, Nayyar; Braunwald, Eugene; Scirica, Benjamin M; Raz, Itamar

2017-01-01

Dipeptidyl peptidase 4 inhibitors may have a protective effect in diabetic nephropathy. We studied renal outcomes of 16,492 patients with type 2 diabetes, randomized to saxagliptin versus placebo and followed for a median of 2.1 years in the Saxagliptin Assessment of Vascular Outcomes Recorded in Patients with Diabetes Mellitus-Thrombolysis in Myocardial Infarction 53 (SAVOR-TIMI 53) trial. At baseline, 9,696 (58.8%) subjects had normoalbuminuria (albumin/creatinine ratio [ACR] <30 mg/g), 4,426 (26.8%) had microalbuminuria (ACR 30-300 mg/g), and 1,638 (9.9%) had macroalbuminuria (ACR >300 mg/g). Treatment with saxagliptin was associated with improvement in and/or less deterioration in ACR categories from baseline to end of trial (EOT) (P = 0.021, P < 0.001, and P = 0.049 for individuals with baseline normoalbuminuria, microalbuminuria, and macroalbuminuria, respectively). At 2 years, the difference in mean ACR change between saxagliptin and placebo arms was -19.3 mg/g (P = 0.033) for estimated glomerular filtration rate (eGFR) >50 mL/min/body surface area per 1.73 m 2 (BSA), -105 mg/g (P = 0.011) for 50 ≥ eGFR ≥ 30 mL/min/BSA, and -245.2 mg/g (P = 0.086) for eGFR <30 mL/min/BSA. Analyzing ACR as a continuous variable showed reduction in ACR with saxagliptin (1 year, P < 0.0001; 2 years, P = 0.0143; and EOT, P = 0.0158). The change in ACR did not correlate with that in HbA 1c (r = 0.041, 0.052, and 0.036; 1 year, 2 years, and EOT, respectively). The change in eGFR was similar in the saxagliptin and placebo groups. Safety renal outcomes, including doubling of serum creatinine, initiation of chronic dialysis, renal transplantation, or serum creatinine >6.0 mg/dL, were similar as well. Treatment with saxagliptin improved ACR, even in the normoalbuminuric range, without affecting eGFR. The beneficial effect of saxagliptin on albuminuria could not be explained by its effect on glycemic control. © 2017 by the American Diabetes Association.

Predisposing Factors for Any and Major Hypoglycemia With Saxagliptin Versus Placebo and Overall: Analysis From the SAVOR-TIMI 53 Trial.

PubMed

Cahn, Avivit; Raz, Itamar; Mosenzon, Ofri; Leibowitz, Gil; Yanuv, Ilan; Rozenberg, Aliza; Iqbal, Nayyar; Hirshberg, Boaz; Sjostrand, Mikaela; Stahre, Christina; Im, KyungAh; Kanevsky, Estella; Scirica, Benjamin M; Bhatt, Deepak L; Braunwald, Eugene

2016-08-01

To analyze the impact of adding saxagliptin versus placebo on the risk for hypoglycemia and to identify predictors of any and major hypoglycemia in patients with type 2 diabetes included in the Saxagliptin Assessment of Vascular Outcomes Recorded in Patients with Diabetes Mellitus-Thrombolysis in Myocardial Infarction 53 (SAVOR-TIMI 53) study. Patients with type 2 diabetes (n = 16,492) were randomized to saxagliptin or placebo and followed for a median of 2.1 years. Associations between any hypoglycemia (symptomatic or glucose measurement <54 mg/dL) or major hypoglycemia (requiring extended assistance) and patient characteristics overall and by treatment allocation were studied. At least one hypoglycemic event was reported in 16.6% of patients, and 1.9% reported at least one major event. Patients allocated to saxagliptin versus placebo experienced higher rates of any (hazard ratio [HR] 1.16 [95% CI 1.08, 1.25]; P < 0.001) or major (HR 1.26 [1.01, 1.58]; P = 0.038) hypoglycemia. Hypoglycemia rates (any or major) were increased with saxagliptin in patients taking sulfonylureas (SURs) but not in those taking insulin. Rates were increased with saxagliptin in those with baseline HbA1c ≤7.0% and not in those with baseline HbA1c >7.0%. Multivariate analysis of the overall population revealed that independent predictors of any hypoglycemia were as follows: allocation to saxagliptin, long duration of diabetes, increased updated HbA1c, macroalbuminuria, moderate renal failure, SUR use, and insulin use. Predictors of major hypoglycemia were allocation to saxagliptin, advanced age, black race, reduced BMI, long duration of diabetes, declining renal function, microalbuminuria, and use of short-acting insulin. Among SURs, glibenclamide was associated with increased risk of major but not any hypoglycemia. The identification of patients at risk for hypoglycemia can guide physicians to better tailor antidiabetic therapy. © 2016 by the American Diabetes Association. Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered.

The nonalcoholic fatty liver disease (NAFLD) fibrosis score, cardiovascular risk stratification and a strategy for secondary prevention with ezetimibe.

PubMed

Simon, Tracey G; Corey, Kathleen E; Cannon, Christopher P; Blazing, Michael; Park, Jeong-Gun; O'Donoghue, Michelle L; Chung, Raymond T; Giugliano, Robert P

2018-05-26

The nonalcoholic fatty liver disease fibrosis score (NFS) is comprised of unique metabolic risk indicators that may accurately predict residual cardiovascular (CV) risk in patients with established coronary disease and metabolic dysfunction. We applied the NFS prospectively to 14,819 post-ACS patients randomized to ezetimibe/simvastatin (E/S) or placebo/simvastatin (P/S), in the IMPROVE-IT trial, using validated NFS cutoffs. The primary endpoint included CV death, myocardial infarction, unstable angina, revascularization or stroke. Outcomes were compared between NFS categories and treatment arms using frequency of events, KM rates and adjusted Cox proportional hazard models. The ability of the NFS to predict recurrent CV events was independently validated in 5395 placebo-treated patients enrolled in the SOLID-TIMI 52 trial. Among 14,819 patients enrolled in IMPROVE-IT, 14.2% (N = 2106) were high-risk (NFS > 0.67). The high-risk group had a 30% increased risk of recurrent major CV events, compared to the low-risk NFS group (HR 1.30 [1.19-1.43]; p < 0.001). Among high-risk patients, ezetimibe/simvastatin conferred a 3.7% absolute reduction in risk of recurrent CV events, compared to placebo/simvastatin (HR 0.85 [0.74-0.98]), translating to a number-needed-to-treat of 27. Similar benefit was not found in the low-risk group (HR ezetimibe/simvastatin vs. placebo/simvastatin, 1.01 [0.91-1.12]; p-interaction = 0.053). The relationship between NFS category and recurrent CV events was independently validated in patients enrolled in SOLID-TIMI 52 (HR for NFS > 0.67 vs. NFS < -1.455 = 1.55 [1.32-1.81]; p < 0.001). Stratification of cardiovascular risk by NFS identifies an independent population of patients who are at highest risk of recurrent events, and most likely to benefit from dual lipid-lowering therapy. Clinical trials.gov: NCT00202878. Copyright © 2017 Elsevier B.V. All rights reserved.

Gastrointestinal Bleeding With Edoxaban Versus Warfarin: Results From the ENGAGE AF-TIMI 48 Trial (Effective Anticoagulation With Factor Xa Next Generation in Atrial Fibrillation-Thrombolysis In Myocardial Infarction).

PubMed

Aisenberg, James; Chatterjee-Murphy, Prapti; Friedman Flack, Kathryn; Weitz, Jeffrey I; Ruff, Christian T; Nordio, Francesco; Mercuri, Michele F; Choi, Youngsook; Antman, Elliott M; Braunwald, Eugene; Giugliano, Robert P

2018-05-01

The ENGAGE AF-TIMI 48 trial (Effective Anticoagulation With Factor Xa Next Generation in Atrial Fibrillation-Thrombolysis In Myocardial Infarction) compared higher-dose edoxaban regimen (HD-ER) and lower-dose edoxaban regimen with well-managed warfarin in 21 105 patients with atrial fibrillation. The risk factors and clinical impact of gastrointestinal bleeding (GIB) in this trial have not been described in detail. This analysis was undertaken to identify risk factors for major GIB (MGIB) and compare the severity and outcomes of GIB with edoxaban and warfarin. During 2.8 years mean follow-up, there were 579 MGIB (1.22% per year), of which 63 were life-threatening or fatal (0.13% per year). Male sex, increased age, prior GIB, concomitant aspirin, lower baseline hemoglobin, renal dysfunction, and higher HAS-BLED and CHADS 2 scores were independently associated with the risk of MGIB. Whereas the annual rate of MGIB was higher with HD-ER than with warfarin (1.53% and 1.25%, respectively; hazard ratio, 1.23; 95% confidence interval, 1.02-1.48; P =0.033), the annual rates of life-threatening or fatal GIB were similar (0.15% and 0.18%, respectively). Several indicators of more severe GIB, including hemodynamic instability, hospitalization, ≥ 4 U transfusion, and hemoglobin loss ≥5 g/dL, were similar with HD-ER and warfarin, whereas surgery required to manage bleeding was less frequent with HD-ER. Lower-dose edoxaban regimen, which achieved 50% lower trough edoxaban levels, was associated with significantly less MGIB than warfarin. MGIB occurred more frequently with HD-ER than warfarin. The rates of life-threatening or fatal GIB were low and similar with both HD-ER and warfarin. Clinical outcomes were generally favorable. The correlation between dose, trough edoxaban level, and the risk of GIB risk suggests GIB is exposure-related. URL: https://www.clinicaltrials.gov. Unique identifier: NCT00781391. © 2018 American Heart Association, Inc.

Early and late benefits of prasugrel in patients with acute coronary syndromes undergoing percutaneous coronary intervention: a TRITON-TIMI 38 (TRial to Assess Improvement in Therapeutic Outcomes by Optimizing Platelet InhibitioN with Prasugrel-Thrombolysis In Myocardial Infarction) analysis.

PubMed

Antman, Elliott M; Wiviott, Stephen D; Murphy, Sabina A; Voitk, Juri; Hasin, Yonathan; Widimsky, Petr; Chandna, Harish; Macias, William; McCabe, Carolyn H; Braunwald, Eugene

2008-05-27

We evaluated the relative contributions of the loading and maintenance doses of prasugrel on events in a TRITON-TIMI 38 (TRial to Assess Improvement in Therapeutic Outcomes by Optimizing Platelet InhibitioN with Prasugrel-Thrombolysis In Myocardial Infarction) analysis. Prasugrel is superior to clopidogrel in preventing ischemic events in patients with an acute coronary syndrome who are undergoing percutaneous coronary intervention, but it is associated with an increased risk of major bleeding. Landmark analyses for efficacy, safety, and net clinical benefit were performed from randomization to day 3 and from day 3 to the end of the trial. Significant reductions in ischemic events, including myocardial infarction, stent thrombosis, and urgent target vessel revascularization, were observed with the use of prasugrel both during the first 3 days and from 3 days to the end of the trial. Thrombolysis In Myocardial Infarction major non-coronary artery bypass graft bleeding was similar to clopidogrel during the first 3 days but was significantly greater with the use of prasugrel from 3 days to the end of the study. Net clinical benefit significantly favored prasugrel both early and late in the trial. Both the loading dose and maintenance dose of prasugrel were superior to clopidogrel for the reduction of ischemic events. This result emphasizes the importance of maintaining high levels of inhibition of platelet aggregation via P2Y(12) receptor inhibition, not only for the prevention of periprocedural ischemic events but also during long-term follow-up. The excess major bleeding observed with the use of prasugrel occurred predominantly during the maintenance phase. Approaches to reduce the relative excess of bleeding with prasugrel should focus on the maintenance dose (e.g., reduction in maintenance dose in previously reported high-risk subgroups, such as the elderly and those patients with low body weight). (A Comparison of CS-747 and Clopidogrel in Acute Coronary Syndrome Subjects Who Are to Undergo Percutaneous Coronary Intervention; NCT00097591).

Association of non-steroidal anti-inflammatory drugs with outcomes in patients with ST-segment elevation myocardial infarction treated with fibrinolytic therapy: an ExTRACT-TIMI 25 analysis.

PubMed

Gibson, C Michael; Pride, Yuri B; Aylward, Philip E; Col, Jacques J; Goodman, Shaun G; Gulba, Dietrich; Bergovec, Mijo; Kunadian, Vijayalakshmi; Zorkun, Cafer; Buros, Jacqueline L; Murphy, Sabina A; Antman, Elliott M

2009-01-01

Non-steroidal anti-inflammatory drugs (NSAIDs) may be prothrombotic, may worsen hypertension or congestive heart failure and obstruct access to the binding site of aspirin to cyclooxygenase-1 and thereby interfere with aspirin's mechanism of action in reducing death and recurrent myocardial infarction (MI). We hypothesized that treatment with NSAIDs prior to an index MI would be associated with an increase in the risk of death, heart failure and recurrent MI among patients with ST-segment elevation MI (STEMI) treated with fibrinolytic therapy. In ExTRACT-TIMI 25, patients with STEMI were treated with aspirin and fibrinolytic therapy and randomized to either enoxaparin or unfractionated heparin. We included patients who had received NSAIDs within 7 days of enrollment and evaluated the incidence of MI, the composite of death and MI and the composite of death, MI, severe heart failure and shock through 30 days. Of 20,479 patients enrolled, 572 (2.8%) received an NSAID within 7 days of enrollment. NSAID treatment prior to entry was associated with a higher incidence of 30-day death or nonfatal recurrent MI (15.9% vs. 10.8%, univariate P < 0.001). In multivariable models adjusting for randomization group and differences in baseline characteristics, NSAID use was associated with higher odds of MI (adjusted odds ratio [OR(adj)] 1.44, 95% confidence interval [CI] 1.01-2.07, P = 0.047), the composite of death and MI (OR(adj) 1.29, 95% CI 1.00-1.66, P = 0.051), and the composite of death, MI, severe heart failure and shock (OR(adj) 1.29, 95% CI 1.02-1.65, P = 0.037). Among STEMI patients treated with a fibrinolytic agent and aspirin, use of NSAIDs in the week preceding the incident event was associated with a higher incidence of MI, the composite of death and MI as well as the composite of death, MI, severe heart failure and shock at 30 days.

Economics, health-related quality of life, and cost-effectiveness methods for the TACTICS (Treat Angina With Aggrastat [tirofiban

PubMed

Weintraub, W S; Culler, S D; Kosinski, A; Becker, E R; Mahoney, E; Burnette, J; Spertus, J A; Feeny, D; Cohen, D J; Krumholz, H; Ellis, S G; Demopoulos, L; Robertson, D; Boccuzzi, S J; Barr, E; Cannon, C P

1999-02-01

Concern over escalating health care costs has led to increasing focus on economics and assessment of outcome measures for expensive forms of therapy. This is being investigated in the Treat Angina With Aggrastat [tirofiban] and Determine Cost of Therapy with Invasive or Conservative Strategy (TACTICS)-TIMI 18 trial, a randomized trial comparing outcome of patients with unstable angina or non-Q-wave myocardial infarction treated with tirofiban and then randomized to an invasive versus a conservative strategy. Hospital and professional costs initially and over 6 months, including outpatient costs, will be assessed. Hospital costs will be determined for patients in the United States from the UB92 formulation of the hospital bill, with costs derived from charges using departmental cost to charge ratios. Professional costs will be determined by accounting for professional services and then converted to resource units using the Resource Based Relative Value Scale and then to costs using the Medicare conversion factor. Follow-up resource consumption, including medications, testing and office visits, will be carefully measured with a Patient Economic Form, and converted to costs from the Medicare fee schedule. Health-related quality of life will be assessed with a specific instrument, the Seattle Angina Questionnaire, and a general instrument, the Health Utilities Index at baseline, 1, and 6 months. The Health Utilities Index will also be used to construct a utility. By knowing utility and survival, quality-adjusted life years will be determined. These measures will permit the performance of a cost-effectiveness analysis, with the cost-effectiveness of the invasive strategy defined and the difference in cost between the invasive and conservative strategies divided by the difference in quality-adjusted life years. The economic and health-related quality of life aspects of TACTICS-TIMI 18 are an integral part of the study design and will provide a comprehensive understanding of the impact of invasive versus conservative management strategies on a broad range of outcomes after hospitalization for unstable angina or non-Q-wave myocardial infarction.

Impact of prasugrel pretreatment and timing of coronary artery bypass grafting on clinical outcomes of patients with non-ST-segment elevation myocardial infarction: From the A Comparison of Prasugrel at PCI or Time of Diagnosis of Non-ST-Elevation Myocardial Infarction (ACCOAST) study.

PubMed

Dudek, Dariusz; Dziewierz, Artur; Widimsky, Petr; Bolognese, Leonardo; Goldstein, Patrick; Hamm, Christian; Tanguay, Jean-Francois; LeNarz, LeRoy; Miller, Debra L; Brown, Eileen; Ten Berg, Jurrien; Montalescot, Gilles

2015-11-01

We evaluated impact of timing of coronary artery bypass grafting (CABG) and prasugrel pretreatment in patients with non-ST-segment elevation myocardial infarction undergoing CABG in the ACCOAST study. Of 4033 enrolled patients, 314 (7.8%) underwent isolated CABG through 30 days. Primary efficacy end point for this analysis was any cardiovascular death, myocardial infarction, stroke, urgent revascularization, or glycoprotein IIb/IIIa inhibitor bailout through 30 days. More CABG versus percutaneous coronary intervention or medically managed patients were men, diabetic, or had peripheral arterial disease. Per randomization, 157 of 314 patients received a 30-mg prasugrel loading dose before CABG, and 157 of 314 received placebo. Patients were stratified by tertile of time from randomization to CABG: <2.98 days (n = 104), ≥2.98 and <6.95 days (n = 106), and ≥6.95 days (n = 104). Primary end point occurred in 12.5%, 4.7%, and 4.8%, respectively (<2.98 days vs other tertiles, hazard ratio [HR] = 2.80; P = .011). Similarly, the rate of all TIMI major bleeding was highest in the lowest tertile (26.0% vs 10.4% and 4.8%; P < .001), but no difference in all-cause death was observed through 30 days (3.9% vs 1.9% and 1.9%; P = .30). Time from randomization to CABG (HR = 0.84 for each day delay), left main disease (HR = 1.76), region of enrollment (Non-Eastern Europe vs Eastern Europe; HR = 3.83), but not prasugrel pretreatment and baseline troponin ≥3× upper limit of normal, were independent predictors of combined 30-day end point of all-cause death/myocardial infarction/stroke/TIMI major bleeding. In ACCOAST, early (<2.98 days) surgical revascularization carried increased risk of bleeding and ischemic complications without affecting all-cause mortality through 30 days. Baseline troponin and prasugrel pretreatment did not impact ischemic clinical outcomes. Copyright © 2015 Elsevier Inc. All rights reserved.

Helicopter Noise Definition Report UH-60A, S-76, A-109, 206-L

DTIC Science & Technology

1981-12-01

ALL THE WORLDS AIRCRAF~ 25 -.. H., . . . I - I’I Fi.I 2.3. Sikrsk UH .0A "Bla *khaw -" | r a’ Fig. 2.3.2 Sikoraky S-76, "Spirit" -. q A,~ ~ j A. "I...1305 1:2 -04830 8545 82+9 75*1 O1,6 87,b Sete 11,5 10s5 1#2 -1*0 31 85.7 83,3 75,1 80.0 86#6 67,7 16#5 150 1#1 -0#7 32 83.7 81.2 73.5 79.3 85,6 8669...RIO. TIMITIKE PNLTP WAR REOORDED RAOD TIMiTIME PNLTM WAS RADIATED R/OlAIORAFT RPATE OLI•ND OR DS6ENT O’D-ANGtOL•IM OR DESCENT ANGE.E G*6GROUND SPEED

9th International Conference on Multiphase Flow (ICMF 2016)

DTIC Science & Technology

2016-08-12

Office of Naval Research Global (ONRG) Final CSP (Collaborative Science Program) Report Administrative Details: Event Name: 9th ...International Conference on Multiphase Flows Event Dates: May 22-27, 2016 Event City and Country: Florence, Italy Grantee (Name and Contact...2043 Date of the Final Report: August 12, 2016 Abstract: This report summarizes the main activities and outcomes of the 9th International

Batch Scheduling for Hybrid Assembly Differentiation Flow Shop to Minimize Total Actual Flow Time

NASA Astrophysics Data System (ADS)

Maulidya, R.; Suprayogi; Wangsaputra, R.; Halim, A. H.

2018-03-01

A hybrid assembly differentiation flow shop is a three-stage flow shop consisting of Machining, Assembly and Differentiation Stages and producing different types of products. In the machining stage, parts are processed in batches on different (unrelated) machines. In the assembly stage, each part of the different parts is assembled into an assembly product. Finally, the assembled products will further be processed into different types of final products in the differentiation stage. In this paper, we develop a batch scheduling model for a hybrid assembly differentiation flow shop to minimize the total actual flow time defined as the total times part spent in the shop floor from the arrival times until its due date. We also proposed a heuristic algorithm for solving the problems. The proposed algorithm is tested using a set of hypothetic data. The solution shows that the algorithm can solve the problems effectively.

Field Detection of Chemical Assimilation in A Basaltic Lava Flow

NASA Technical Reports Server (NTRS)

Young, K. E.; Bleacher, J. E.; Needham, D. H.; Evans, C. A.; Whelley, P. L.; Scheidt, S. P.; Williams, D. A.; Rogers, A. D.; Glotch, T.

2017-01-01

Lava channels are features seen throughout the inner Solar System, including on Earth, the Moon, and Mars. Flow emplacement is therefore a crucial process in the shaping of planetary surfaces. Many studies, including some completed by members of this team at the December 1974 lava flow, have investigated the dynamics of lava flow emplacement, both on Earth and on the Moon and how pre-flow terrain can impact final channel morphology, but far fewer have focused on how the compositional characteristics of the substrate over which a flow was em-placed influenced its final flow morphology. Within the length of one flow, it is common for flows to change in morphology, a quality linked to rheology (a function of multiple factors including viscosi-ty, temperature, composition, etc.). The relationship between rheology and temperature has been well-studied but less is known about the relationship between an older flow's chemistry and how the interaction between this flow and the new flow might affect lava rheology and therefore emplacement dynamics. Lava erosion. Through visual observations of active terrestrial flows, mechanical erosion by flowing lava has been well-documented. Lava erosion by which flow composition is altered as the active lava melts and assimilates the pre-flow terrain over which it moves is also hypothesized to affect channel formation. However, there is only one previous field study that geochemically documents the process in recent basaltic flow systems.

Analytical Chemistry in Microenvironments: Single Nerve Cells.

DTIC Science & Technology

1992-03-16

length of the capillary (34). Electroosmotic flow offers three key advantages for separation of small biological samples. First, this flow, if not...from microenvironments (ie. single cells). Indeed, volumes as low as 270 femtoliters have been injected using electroosmotic flow (15). Finally... electroosmotic flow provides a flat flow profile, since there is no stationary support between the origin of flow (capillary wall) and the bulk of solution

Design and Analyses of High Aspect Ratio Nozzles for Distributed Propulsion Acoustic Measurements

NASA Technical Reports Server (NTRS)

Dippold, Vance F., III

2016-01-01

A series of three convergent, round-to-rectangular high aspect ratio (HAR) nozzles were designed for acoustic testing at the NASA Glenn Research Center Nozzle Acoustic Test Rig (NATR). The HAR nozzles had exit area aspect ratios of 8:1, 12:1, and 16:1. The nozzles were designed to mimic a distributed propulsion system array with a slot nozzle. The nozzle designs were screened using Reynolds-Averaged Navier-Stokes (RANS) simulations. In addition to meeting the geometric constraints required for testing in the NATR, the HAR nozzles were designed to be free of flow features that would produce unwanted noise (e.g., flow separations) and to have uniform flow at the nozzle exit. Multiple methods were used to generate HAR nozzle designs. The final HAR nozzle designs were generated in segments using a computer code that parameterized each segment. RANS screening simulations showed that intermediate nozzle designs suffered flow separation, a normal shockwave at the nozzle exit (caused by an aerodynamic throat produced by boundary layer growth), and non-uniform flow at the nozzle exit. The RANS simulations showed that the final HAR nozzle designs were free of flow separations, but were not entirely successful at producing a fully uniform flow at the nozzle exit. The final designs suffered a pair of counter-rotating vortices along the outboard walls of the nozzle. The 16:1 aspect ratio HAR nozzle had the least uniform flow at the exit plane; the 8:1 aspect ratio HAR nozzles had a fairly uniform flow at the nozzle exit plane.

A prospective multicenter study of factors associated with hospital admission among adults with acute asthma.

PubMed

Weber, Ellen J; Silverman, Robert A; Callaham, Michael L; Pollack, Charles V; Woodruff, Prescott G; Clark, Sunday; Camargo, Carlos A

2002-10-01

We sought to determine patient characteristics associated with hospital admission after emergency treatment for asthma, and whether disposition guidelines are followed. We performed a prospective multicenter cohort study involving 64 emergency departments in the United States and Canada. Consecutive adult patients with asthma exacerbations were interviewed, and their charts were reviewed using standardized protocols. Telephone follow-up at 2 weeks determined relapse. Of 1805 patients, 363 (20%; 95% confidence interval [CI]: 18% to 22%) were hospitalized. Among patients with severe exacerbations (final peak flow <50% of predicted), 122 (49%; 95% CI: 43% to 55%) were hospitalized. Admission was associated with final peak flow, female sex, nonwhite race, severity of chronic illness, and severity of exacerbation. Admission predictors were similar regardless of hospital funding, region, or size. Among patients with mild or moderate exacerbations of asthma (peak flow >or=50% predicted), the likelihood of admission was associated significantly with the number of predefined risk factors for death from asthma. Of patients who were discharged from the emergency department, 62 (5%; 95% CI: 4% to 6%) relapsed within 72 hours. Relapse was not associated with final peak flow (P = 0.39). Associations between patient characteristics and disposition were similar across sites. Despite guidelines to the contrary, half of patients with final peak flow <50% were discharged. After emergency department treatment and discharge, short-term relapse was uncommon among patients with asthma, suggesting that strict peak flow cutoffs may be unnecessary if risk factors in patients with mild or moderate exacerbations are considered.

The calculation of steady non-linear transonic flow over finite wings with linear theory aerodynamics

NASA Technical Reports Server (NTRS)

Cunningham, A. M., Jr.

1976-01-01

The feasibility of calculating steady mean flow solutions for nonlinear transonic flow over finite wings with a linear theory aerodynamic computer program is studied. The methodology is based on independent solutions for upper and lower surface pressures that are coupled through the external flow fields. Two approaches for coupling the solutions are investigated which include the diaphragm and the edge singularity method. The final method is a combination of both where a line source along the wing leading edge is used to account for blunt nose airfoil effects; and the upper and lower surface flow fields are coupled through a diaphragm in the plane of the wing. An iterative solution is used to arrive at the nonuniform flow solution for both nonlifting and lifting cases. Final results for a swept tapered wing in subcritical flow show that the method converges in three iterations and gives excellent agreement with experiment at alpha = 0 deg and 2 deg. Recommendations are made for development of a procedure for routine application.

Variational optical flow estimation based on stick tensor voting.

PubMed

Rashwan, Hatem A; Garcia, Miguel A; Puig, Domenec

2013-07-01

Variational optical flow techniques allow the estimation of flow fields from spatio-temporal derivatives. They are based on minimizing a functional that contains a data term and a regularization term. Recently, numerous approaches have been presented for improving the accuracy of the estimated flow fields. Among them, tensor voting has been shown to be particularly effective in the preservation of flow discontinuities. This paper presents an adaptation of the data term by using anisotropic stick tensor voting in order to gain robustness against noise and outliers with significantly lower computational cost than (full) tensor voting. In addition, an anisotropic complementary smoothness term depending on directional information estimated through stick tensor voting is utilized in order to preserve discontinuity capabilities of the estimated flow fields. Finally, a weighted non-local term that depends on both the estimated directional information and the occlusion state of pixels is integrated during the optimization process in order to denoise the final flow field. The proposed approach yields state-of-the-art results on the Middlebury benchmark.

Ticagrelor for the treatment of atherosclerotic disease: insights from the PARTHENON clinical development program.

PubMed

Held, Peter; Himmelmann, Anders; Ditmarsch, Marc

2016-07-01

Ticagrelor (P2Y12 receptor antagonist) is presently indicated for preventing atherothrombotic events in patients with acute coronary syndrome and patients with a history of myocardial infarction. The PARTHENON clinical development program comprises five randomized, controlled, cardiovascular, indication-seeking outcome studies, aiming to evaluate ticagrelor across the spectrum of patients with atherothrombotic disease. Results of two large-scale trials support a benefit for ticagrelor in patients with acute coronary syndrome (PLATO; ClinicalTrials.gov: NCT00391872) and in patients with a history of myocardial infarction (PEGASUS-TIMI 54; ClinicalTrials.gov: NCT01225562). Ongoing trials will provide information on the efficacy and safety of ticagrelor in patients with acute ischemic stroke or transient ischemic attack (SOCRATES; ClinicalTrials.gov: NCT01994720), peripheral artery disease (EUCLID; ClinicalTrials.gov: NCT01732822) and coronary artery disease in patients with Type 2 diabetes mellitus (THEMIS: ClinicalTrials.gov: NCT01991795).

Defining family elements in adolescence.

PubMed

Băcean, Oana Codruţa Miloicov; Vlaicu, Brigitha

2012-01-01

The family has a permanent partner role on adolescents till adult stage. The adolescent builds up his own identity based on the affiliation to his family, but he gets away from his family for the need of leading his own life and finding his place in society. The adolescent sample was made up of 2908 college students from Timis County, aged between 15-19 years, 51.5% girls and 48.5% boys. The working method was the populational transversal study based on anonymous self-administration of the investigation questionnaire CORT 2004 about the risky comportment in teenagers, in a CNCSIS research project. The study results high lighten the predominance of family organized affiliation, 78.9% living with family, 88.6%; the medium study level of 63.7% of mothers and 59.1% of fathers; the satisfaction towards family members, 71.7%; satisfaction towards family's financial level, 61.2%. In this way is underlined the role of identity development in adolescents.

Supporting diagnosis and treatment in medical care based on Big Data processing.

PubMed

Lupşe, Oana-Sorina; Crişan-Vida, Mihaela; Stoicu-Tivadar, Lăcrămioara; Bernard, Elena

2014-01-01

With information and data in all domains growing every day, it is difficult to manage and extract useful knowledge for specific situations. This paper presents an integrated system architecture to support the activity in the Ob-Gin departments with further developments in using new technology to manage Big Data processing - using Google BigQuery - in the medical domain. The data collected and processed with Google BigQuery results from different sources: two Obstetrics & Gynaecology Departments, the TreatSuggest application - an application for suggesting treatments, and a home foetal surveillance system. Data is uploaded in Google BigQuery from Bega Hospital Timişoara, Romania. The analysed data is useful for the medical staff, researchers and statisticians from public health domain. The current work describes the technological architecture and its processing possibilities that in the future will be proved based on quality criteria to lead to a better decision process in diagnosis and public health.

Final technical report

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

Richman, M.

1996-08-01

Granular flows of nearly elastic, identical spheres down bumpy inclines are described. A numerical technique is developed to overcome the difficulties associated with the ill-defined `tops` of these flows.

Prediction for the Flow-induced Gravity Field of Saturn: Implications for Cassini’s Grand Finale

NASA Astrophysics Data System (ADS)

Galanti, Eli; Kaspi, Yohai

2017-07-01

The Cassini measurements of Saturn’s gravity field during its Grand Finale might shed light on a long-standing question regarding the flow on Saturn. While the cloud-level winds are well known, little is known about whether these winds are confined to the outer layers of the planet or penetrate deep into the interior. An additional complexity is added by the uncertainty in the exact rotation period of Saturn, a key factor in determining the cloud-level winds, with an effect on the north-south symmetric part of the winds. Using Saturn’s cloud-level winds we relate the flow to the gravity harmonics. We give a prediction for the odd harmonics {J}3,{J}5,{J}7,{and} {J}9 as a function of the flow depth, identifying three ranges of depths. Since the odd harmonics depend solely on the flow, and are not influenced by Saturn’s shape and static density distribution, any measured value of the odd harmonics by Cassini can be used to uniquely determine the depth of the flow. We also discuss the flow-induced even harmonics {{Δ }}{J}2,{{Δ }}{J}4,\\ldots ,{{Δ }}{J}12 that are affected by Saturn’s rotation period. While the high-degree even harmonics might also be used to determine the flow depth, the lower-degree even harmonics serve as uncertainties for analysis of the planet’s interior structure and composition. Thus, the gravity harmonics measured during the Cassini Grand Finale may be used to get a first-order estimate of the flow structure and to better constrain the planet’s density structure and composition.

Plastic deformation history in infeed rotary swaging process

NASA Astrophysics Data System (ADS)

Liu, Yang; Herrmann, Marius; Schenck, Christian; Kuhfuss, Bernd

2017-10-01

In bulk forming processes, the net shape of a final product is achieved by plastic deformation as the material flows from the initial shape to the final shape of the workpiece. The material flow during the process is an important issue for its relationship with forging force, heat generation, microstructure transformation and energy consumption. Hence, the final properties of the product are directly influenced. Former researches showed that the material flow in the rotary swaging process is affected by different processing parameters like die angle, feeding velocity and friction condition. Thus, a profound knowledge of detailed material flow during the process is essential for a better understanding of the process. By using FEM, the material flow was investigated by the history of the plastic strain (PEEQ) development. In this study a 2D-axisymmetric model was built by using ABAQUS explicit. Both aluminum alloy (3.3206) and steel (1.0308) are studied with different feeding velocities and coefficients of friction. To achieve the development of PEEQ in different areas, the workpiece was divided into radial layers. The PEEQ history of each layer was tracked during the quasi-static forming process. Based on that, the plastic strain rate (PSR) was calculated and examined in a single stroke of the process. In that way, the material flow in different layers is presented and the material flow on the surface differs from that in the center, just the first 1/4 radial area from the surface is sensitive to different friction conditions.

Effect of darapladib on major coronary events after an acute coronary syndrome: the SOLID-TIMI 52 randomized clinical trial.

PubMed

O'Donoghue, Michelle L; Braunwald, Eugene; White, Harvey D; Steen, Dylan P; Lukas, Mary Ann; Tarka, Elizabeth; Steg, P Gabriel; Hochman, Judith S; Bode, Christoph; Maggioni, Aldo P; Im, KyungAh; Shannon, Jennifer B; Davies, Richard Y; Murphy, Sabina A; Crugnale, Sharon E; Wiviott, Stephen D; Bonaca, Marc P; Watson, David F; Weaver, W Douglas; Serruys, Patrick W; Cannon, Christopher P; Steen, Dylan L

2014-09-10

Lipoprotein-associated phospholipase A2 (Lp-PLA2) has been hypothesized to be involved in atherogenesis through pathways related to inflammation. Darapladib is an oral, selective inhibitor of the Lp-PLA2 enzyme. To evaluate the efficacy and safety of darapladib in patients after an acute coronary syndrome (ACS) event. SOLID-TIMI 52 was a multinational, double-blind, placebo-controlled trial that randomized 13,026 participants within 30 days of hospitalization with an ACS (non-ST-elevation or ST-elevation myocardial infarction [MI]) at 868 sites in 36 countries. Patients were randomized to either once-daily darapladib (160 mg) or placebo on a background of guideline-recommended therapy. Patients were followed up for a median of 2.5 years between December 7, 2009, and December 6, 2013. The primary end point (major coronary events) was the composite of coronary heart disease (CHD) death, MI, or urgent coronary revascularization for myocardial ischemia. Kaplan-Meier event rates are reported at 3 years. During a median duration of 2.5 years, the primary end point occurred in 903 patients in the darapladib group and 910 in the placebo group (16.3% vs 15.6% at 3 years; hazard ratio [HR], 1.00 [95% CI, 0.91-1.09]; P = .93). The composite of cardiovascular death, MI, or stroke occurred in 824 in the darapladib group and 838 in the placebo group (15.0% vs 15.0% at 3 years; HR, 0.99 [95% CI, 0.90-1.09]; P = .78). There were no differences between the treatment groups for additional secondary end points, for individual components of the primary end point, or in all-cause mortality (371 events in the darapladib group and 395 in the placebo group [7.3% vs 7.1% at 3 years; HR, 0.94 [95% CI, 0.82-1.08]; P = .40). Patients were more likely to report an odor-related concern in the darapladib group vs the placebo group (11.5% vs 2.5%) and also more likely to report diarrhea (10.6% vs 5.6%). In patients who experienced an ACS event, direct inhibition of Lp-PLA2 with darapladib added to optimal medical therapy and initiated within 30 days of hospitalization did not reduce the risk of major coronary events. clinicaltrials.gov Identifier: NCT01000727.

Myocardial viability assessed with fluorodeoxyglucose and PET in patients with Q wave myocardial infarction receiving thrombolysis: relationship to coronary anatomy and ventricular function.

PubMed

Fragasso, G; Chierchia, S L; Rossetti, E; Sciammarella, M G; Conversano, A; Lucignani, G; Landoni, C; Calori, G; Margonato, A; Fazio, F

1997-03-01

In previously thrombolysed patients, we analysed residual myocardial viability using the PET-FDG technique and correlated its presence and extent to the angiographic appearance of the infarct-related vessel and left ventricular function. Thirty-six patients who had undergone intravenous thromboloysis for acute myocardial infarction 4.8 +/- 7.2 months previously were studied. Coronary angiography, left ventriculography, and assessment of myocardial perfusion and metabolism were all performed within 1 week. All patients exhibited perfusion defects consistent with the clinically identified myocardial infarction site. Residual viability, as assessed by the PET-FDG technique, was present in 53% of cases. The infarct-related coronary artery was patent in 19 (53%) patients (TIMI grade 3, 79%); of the remaining 17 with occluded infarct-related arteries, 11 had collaterals to the infarct area. Significant FDG uptake was observed in 63% of patients with a patent infarct-related artery and in 41% of those with an occluded infarct-related artery. The same study protocol was adopted in a control group of 30 patients with myocardial infarction who did not receive thrombolysis. The number of infarct-related patent vessels was significantly lower in these patients (30 vs 53%) (TIMI grade 3, 56%), but the overall percentage of PET viability was again 53%. Qualitative analysis of the regional perfusion pattern showed that the magnitude and severity of the perfusion defect was similar in the two groups, regardless of the presence or absence of FDG uptake. Global left ventricular function was also similar in the two groups. However, regional wall motion was significantly better in the thrombolysed patients with a patent infarct-related artery than in those who had not received thrombolysis and whose culprit vessel was also patent. In conclusion, the results of our study support the notion that early recanalization of the infarct-related artery is critical for preserving left ventricular function. Although the number of patent infarct-related coronary arteries is greater and left ventricular function is better in successfully thrombolysed patients, the regional metabolic pattern does not apparently correlate with the patency of the infarct-related artery. This suggests that, in "chronic' myocardial infarction, residual tissue viability as assessed by fluorodeoxyglucose uptake does not necessarily correlate with coronary recanalization.

The treatment of missing data in a large cardiovascular clinical outcomes study.

PubMed

Little, Roderick J; Wang, Julia; Sun, Xiang; Tian, Hong; Suh, Eun-Young; Lee, Michael; Sarich, Troy; Oppenheimer, Leonard; Plotnikov, Alexei; Wittes, Janet; Cook-Bruns, Nancy; Burton, Paul; Gibson, C Michael; Mohanty, Surya

2016-06-01

The potential impact of missing data on the results of clinical trials has received heightened attention recently. A National Research Council study provides recommendations for limiting missing data in clinical trial design and conduct, and principles for analysis, including the need for sensitivity analyses to assess robustness of findings to alternative assumptions about the missing data. A Food and Drug Administration advisory committee raised missing data as a serious concern in their review of results from the ATLAS ACS 2 TIMI 51 study, a large clinical trial that assessed rivaroxaban for its ability to reduce the risk of cardiovascular death, myocardial infarction or stroke in patients with acute coronary syndrome. This case study describes a variety of measures that were taken to address concerns about the missing data. A range of analyses are described to assess the potential impact of missing data on conclusions. In particular, measures of the amount of missing data are discussed, and the fraction of missing information from multiple imputation is proposed as an alternative measure. The sensitivity analysis in the National Research Council study is modified in the context of survival analysis where some individuals are lost to follow-up. The impact of deviations from ignorable censoring is assessed by differentially increasing the hazard of the primary outcome in the treatment groups and multiply imputing events between dropout and the end of the study. Tipping-point analyses are described, where the deviation from ignorable censoring that results in a reversal of significance of the treatment effect is determined. A study to determine the vital status of participants lost to follow-up was also conducted, and the results of including this additional information are assessed. Sensitivity analyses suggest that findings of the ATLAS ACS 2 TIMI 51 study are robust to missing data; this robustness is reinforced by the follow-up study, since inclusion of data from this study had little impact on the study conclusions. Missing data are a serious problem in clinical trials. The methods presented here, namely, the sensitivity analyses, the follow-up study to determine survival of missing cases, and the proposed measurement of missing data via the fraction of missing information, have potential application in other studies involving survival analysis where missing data are a concern. © The Author(s) 2016.

Prevention of Stroke with Ticagrelor in Patients with Prior Myocardial Infarction: Insights from PEGASUS-TIMI 54 (Prevention of Cardiovascular Events in Patients With Prior Heart Attack Using Ticagrelor Compared to Placebo on a Background of Aspirin-Thrombolysis in Myocardial Infarction 54).

PubMed

Bonaca, Marc P; Goto, Shinya; Bhatt, Deepak L; Steg, P Gabriel; Storey, Robert F; Cohen, Marc; Goodrich, Erica; Mauri, Laura; Ophuis, Ton Oude; Ruda, Mikhail; Špinar, Jindřich; Seung, Ki-Bae; Hu, Dayi; Dalby, Anthony J; Jensen, Eva; Held, Peter; Morrow, David A; Braunwald, Eugene; Sabatine, Marc S

2016-09-20

In the PEGASUS-TIMI 54 trial (Prevention of Cardiovascular Events in Patients With Prior Heart Attack Using Ticagrelor Compared to Placebo on a Background of Aspirin-Thrombolysis in Myocardial Infarction 54), ticagrelor reduced the risk of major adverse cardiovascular events when added to low-dose aspirin in stable patients with prior myocardial infarction, resulting in the approval of ticagrelor 60 mg twice daily for long-term secondary prevention. We investigated the incidence of stroke, outcomes after stroke, and the efficacy of ticagrelor focusing on the approved 60 mg twice daily dose for reducing stroke in this population. Patients were followed for a median of 33 months. Stroke events were adjudicated by a central committee. Data from similar trials were combined using meta-analysis. Of 14 112 patients randomly assigned to placebo or ticagrelor 60 mg, 213 experienced a stroke; 85% of these strokes were ischemic. A total of 18% of strokes were fatal and another 15% led to either moderate or severe disability at 30 days. Ticagrelor significantly reduced the risk of stroke (hazard ratio, 0.75; 95% confidence interval, 0.57-0.98; P=0.034), driven by a reduction in ischemic stroke (hazard ratio, 0.76; 95% confidence interval, 0.56-1.02). Hemorrhagic stroke occurred in 9 patients on placebo and 8 patients on ticagrelor. A meta-analysis across 4 placebo-controlled trials of more intensive antiplatelet therapy in 44 816 patients with coronary disease confirmed a marked reduction in ischemic stroke (hazard ratio, 0.66; 95% confidence interval, 0.54-0.81; P=0.0001). High-risk patients with prior myocardial infarction are at risk for stroke, approximately one-third of which are fatal or lead to moderate-to-severe disability. The addition of ticagrelor 60 mg twice daily significantly reduced this risk without an excess of hemorrhagic stroke but with more major bleeding. In high-risk patients with coronary disease, more intensive antiplatelet therapy should be considered not only to reduce the risk of coronary events, but also of stroke. URL: http://www.clinicaltrials.gov. Unique Identifier: NCT01225562. © 2016 American Heart Association, Inc.

Efficacy and Safety of Vorapaxar With and Without a Thienopyridine for Secondary Prevention in Patients With Previous Myocardial Infarction and No History of Stroke or Transient Ischemic Attack: Results from TRA 2°P-TIMI 50.

PubMed

Bohula, Erin A; Aylward, Philip E; Bonaca, Marc P; Corbalan, Ramon L; Kiss, Robert G; Murphy, Sabina A; Scirica, Benjamin M; White, Harvey; Braunwald, Eugene; Morrow, David A

2015-11-17

Vorapaxar antagonizes protease-activated receptor 1, the primary receptor for thrombin on human platelets, and reduces recurrent thrombotic events in stable patients with a previous myocardial infarction (MI). We wished to determine whether the efficacy and safety of antiplatelet therapy with vorapaxar was modified by concurrent thienopyridine use. The Thrombin Receptor Antagonist in Secondary Prevention of Atherothrombotic Ischemic Events-Thrombolysis in Myocardial Infarction 50 (TRA 2°P-TIMI 50) was a randomized, double-blind, placebo-controlled trial of vorapaxar in 26,449 patients with previous atherothrombosis. This prespecified analysis included 16,897 patients who qualified with a MI in the preceding 2 weeks to 12 months and was restricted to patients without a history of stroke or transient ischemic attack given its contraindication in that population. Randomization was stratified on the basis of planned thienopyridine use. Thienopyridine was planned at randomization in 12,410 (73%). Vorapaxar significantly reduced the composite of cardiovascular death, MI, and stroke in comparison with placebo regardless of planned thienopyridine therapy (planned thienopyridine, hazard ratio, 0.80, 0.70-0.91, P<0.001; no planned thienopyridine, hazard ratio, 0.75; 0.60-0.94, P=0.011; P-interaction=0.67). Findings were similar when patients were stratified by actual thienopyridine use at baseline (P-interaction=0.82) and through 18 months (P-interaction=0.44). Global Use of Strategies to Open Occluded Coronary Arteries (GUSTO) moderate or severe bleeding risk was increased with vorapaxar and was not significantly altered by planned thienopyridine (planned, hazard ratio, 1.50; 1.18-1.89, P<0.001; no planned, hazard ratio, 1.90, 1.17-3.07, P=0.009; P-interaction=0.37) or actual thienopyridine use (P-interaction=0.24). Vorapaxar reduced cardiovascular death, MI, or stroke in stable patients with a history of previous MI, whether treated concomitantly with a thienopyridine or not. The relative risk of moderate or severe bleeding was similarly increased irrespective of thienopyridine use. URL: http://www.clinicaltrials.gov. Unique identifier: NCT00526474. © 2015 American Heart Association, Inc.

Preliminary Assessment of the Flow of Used Electronics, In ...

EPA Pesticide Factsheets

Electronic waste (e-waste) is the largest growing municipal waste stream in the United States. The improper disposal of e-waste has environmental, economic, and social impacts, thus there is a need for sustainable stewardship of electronics. EPA/ORD has been working to improve our understanding of the quantity and flow of electronic devices from initial purchase to final disposition. Understanding the pathways of used electronics from the consumer to their final disposition would provide insight to decision makers about their impacts and support efforts to encourage improvements in policy, technology, and beneficial use. This report is the first stage of study of EPA/ORD's efforts to understand the flows of used electronics and e-waste by reviewing the regulatory programs for the selected states and identifying the key lessons learned and best practices that have emerged since their inception. Additionally, a proof-of-concept e-waste flow model has been developed to provide estimates of the quantity of e-waste generated annually at the national level, as well as for selected states. This report documents a preliminary assessment of available data and development of the model that can be used as a starting point to estimate domestic flows of used electronics from generation, to collection and reuse, to final disposition. The electronics waste flow model can estimate the amount of electronic products entering the EOL management phase based on unit sales dat

High-Fidelity Geometric Modeling and Mesh Generation for Mechanics Characterization of Polycrystalline Materials

DTIC Science & Technology

2014-10-26

From the parameterization results, we extract adaptive and anisotropic T-meshes for the further T- spline surface construction. Finally, a gradient flow...field-based method [7, 12] to generate adaptive and anisotropic quadrilateral meshes, which can be used as the control mesh for high-order T- spline ...parameterization results, we extract adaptive and anisotropic T-meshes for the further T- spline surface construction. Finally, a gradient flow-based

A microcomputer model for simulating pressurized flow in a storm sewer system : final report.

DOT National Transportation Integrated Search

1989-01-01

A review was made of several computer programs capable of simulating sewer flows under surcharge or pressurized flow conditions. A modified version of the EXTRAN module of the SYMM model, called PFSM, was developed and attached to the FHYA Pooled Fun...

Fundamental Structure of High-Speed Reacting Flows: Supersonic Combustion and Detonation

DTIC Science & Technology

2016-04-30

AFRL-AFOSR-VA-TR-2016-0195 Fundamental Structure of High-Speed Reacting Flows: Supersonic Combustion and Detonation Kenneth Yu MARYLAND UNIV COLLEGE...MARCH 2016 4. TITLE AND SUBTITLE FUNDAMENTAL STRUCTURE OF HIGH-SPEED REACTING FLOWS: SUPERSONIC COMBUSTION AND DETONATION 5a. CONTRACT NUMBER...public release. Final Report on Fundamental Structure of High-Speed Reacting Flows: Supersonic Combustion and Detonation Grant

Sixty-five-year old final clarifier performance rivals that of modern designs.

PubMed

Barnard, James L; Kunetz, Thomas E; Sobanski, Joseph P

2008-01-01

The Stickney plant of the Metropolitan Wastewater Reclamation District of Greater Chicago (MWRDGC), one of the largest wastewater treatment plants in the world, treats an average dry weather flow of 22 m3/s and a sustained wet weather flow of 52 m3/s that can peak to 63 m3/s. Most of the inner city of Chicago has combined sewers, and in order to reduce pollution through combined sewer overflows (CSO), the 175 km Tunnel and Reservoir Plan (TARP) tunnels, up to 9.1 m in diameter, were constructed to receive and convey CSO to a reservoir from where it will be pumped to the Stickney treatment plant. Pumping back storm flows will result in sustained wet weather flows over periods of weeks. Much of the success of the plant will depend on the ability of 96 circular final clarifiers to produce an effluent of acceptable quality. The nitrifying activated sludge plant is arranged in a plug-flow configuration, and some denitrification takes place as a result of the high oxygen demand in the first pass of the four-pass aeration basins that have a length to width ratio of 18:1. The SVI of the mixed liquor varies between 60 and 80 ml/g. The final clarifiers, which were designed by the District's design office in 1938, have functioned for more than 65 years without major changes and are still producing very high-quality effluent. This paper will discuss the design and operation of these final clarifiers and compare the design with more modern design practices. (c) IWA Publishing 2008.

1D numerical model of muddy subaqueous and subaerial debris flows

USGS Publications Warehouse

Imran, J.; Parker, G.; Locat, J.; Lee, H.

2001-01-01

A 1D numerical model of the downslope flow and deposition of muddy subaerial and subaqueous debris flows is presented. The model incorporates the Herschel-Bulkley and bilinear rheologies of viscoplastic fluid. The more familiar Bingham model is integrated into the Herschel-Bulkley rheological model. The conservation equations of mass and momentum of single-phase laminar debris flow are layer-integrated using the slender flow approximation. They are then expressed in a Lagrangian framework and solved numerically using an explicit finite difference scheme. Starting from a given initial shape, a debris flow is allowed to collapse and propagate over a specified topography. Comparison between the model predictions and laboratory experiments shows reasonable agreement. The model is used to study the effect of the ambient fluid density, initial shape of the failed mass, and rheological model on the simulated propagation of the front and runout characteristics of muddy debris flows. It is found that initial failure shape influence the front velocity but has little bearing on the final deposit shape. In the Bingham model, the excess of shear stress above the yield strength is proportional to the strain rate to the first power. This exponent is free to vary in the Herschel-Bulkley model. When it is set at a value lower than unity, the resulting final deposits are thicker and shorter than in the case of the Bingham rheology. The final deposit resulting from the bilinear model is longer and thinner than that from the Bingham model due to the fact that the debris flow is allowed to act as a Newtonian fluid at low shear rate in the bilinear model.

Burgers approximation for two-dimensional flow past an ellipse

NASA Technical Reports Server (NTRS)

Dorrepaal, J. M.

1982-01-01

A motivation is given for studying Burgers flow and a solution technique is outlined which works equally well for Oseen or Burgers flow past a circular cylinder. The separation behind the cylinder, the drag experienced by the cylinder, and asymptotic behavior far from the cylinder are described. It is shown that the predictions of Burgers flow near the cylinder provide a substantial improvement over those of Oseen flow. Finally, the equations of motion for Burgers flow past an ellipse are formulated and solved.

Novel Air Flow Meter for an Automobile Engine Using a Si Sensor with Porous Si Thermal Isolation

PubMed Central

Hourdakis, Emmanouel; Sarafis, Panagiotis; Nassiopoulou, Androula G.

2012-01-01

An air flow meter for measuring the intake air of an automobile engine is presented. It is based on a miniaturized silicon thermal mass flow sensor using a thick porous Si (Po-Si) layer for local thermal isolation from the Si substrate, on which the sensor active elements are integrated. The sensor is mounted on one side of a printed circuit board (PCB), on the other side of which the readout and control electronics of the meter are mounted. The PCB is fixed on a housing containing a semi-cylindrical flow tube, in the middle of which the sensor is situated. An important advantage of the present air flow meter is that it detects with equal sensitivity both forward and reverse flows. Two prototypes were fabricated, a laboratory prototype for flow calibration using mass flow controllers and a final demonstrator with the housing mounted in an automobile engine inlet tube. The final demonstrator was tested in real life conditions in the engine inlet tube of a truck. It shows an almost linear response in a large flow range between –6,500 kg/h and +6,500 kg/h, which is an order of magnitude larger than the ones usually encountered in an automobile engine. PMID:23202189

Building the Material Flow Networks of Aluminum in the 2007 U.S. Economy.

PubMed

Chen, Wei-Qiang; Graedel, T E; Nuss, Philip; Ohno, Hajime

2016-04-05

Based on the combination of the U.S. economic input-output table and the stocks and flows framework for characterizing anthropogenic metal cycles, this study presents a methodology for building material flow networks of bulk metals in the U.S. economy and applies it to aluminum. The results, which we term the Input-Output Material Flow Networks (IO-MFNs), achieve a complete picture of aluminum flow in the entire U.S. economy and for any chosen industrial sector (illustrated for the Automobile Manufacturing sector). The results are compared with information from our former study on U.S. aluminum stocks and flows to demonstrate the robustness and value of this new methodology. We find that the IO-MFN approach has the following advantages: (1) it helps to uncover the network of material flows in the manufacturing stage in the life cycle of metals; (2) it provides a method that may be less time-consuming but more complete and accurate in estimating new scrap generation, process loss, domestic final demand, and trade of final products of metals, than existing material flow analysis approaches; and, most importantly, (3) it enables the analysis of the material flows of metals in the U.S. economy from a network perspective, rather than merely that of a life cycle chain.

Novel air flow meter for an automobile engine using a Si sensor with porous Si thermal isolation.

PubMed

Hourdakis, Emmanouel; Sarafis, Panagiotis; Nassiopoulou, Androula G

2012-11-02

An air flow meter for measuring the intake air of an automobile engine is presented. It is based on a miniaturized silicon thermal mass flow sensor using a thick porous Si (Po-Si) layer for local thermal isolation from the Si substrate, on which the sensor active elements are integrated. The sensor is mounted on one side of a printed circuit board (PCB), on the other side of which the readout and control electronics of the meter are mounted. The PCB is fixed on a housing containing a semi-cylindrical flow tube, in the middle of which the sensor is situated. An important advantage of the present air flow meter is that it detects with equal sensitivity both forward and reverse flows. Two prototypes were fabricated, a laboratory prototype for flow calibration using mass flow controllers and a final demonstrator with the housing mounted in an automobile engine inlet tube. The final demonstrator was tested in real life conditions in the engine inlet tube of a truck. It shows an almost linear response in a large flow range between –6,500 kg/h and +6,500 kg/h, which is an order of magnitude larger than the ones usually encountered in an automobile engine.

Turbulent structures in cylindrical density currents in a rotating frame of reference

NASA Astrophysics Data System (ADS)

Salinas, Jorge S.; Cantero, Mariano I.; Dari, Enzo A.; Bonometti, Thomas

2018-06-01

Gravity currents are flows generated by the action of gravity on fluids with different densities. In some geophysical applications, modeling such flows makes it necessary to account for rotating effects, modifying the dynamics of the flow. While previous works on rotating stratified flows focused on currents of large Coriolis number, the present work focuses on flows with small Coriolis numbers (i.e. moderate-to-large Rossby numbers). In this work, cylindrical rotating gravity currents are investigated by means of highly resolved simulations. A brief analysis of the mean flow evolution to the final state is presented to provide a complete picture of the flow dynamics. The numerical results, showing the well-known oscillatory behavior of the flow (inertial waves) and a final state lens shape (geostrophic adjustment), are in good agreement with experimental observations and theoretical models. The turbulent structures in the flow are visualized and described using, among others, a stereoscopic visualization and videos as supplementary material. In particular, the structure of the lobes and clefts at the front of the current is presented in association to local turbulent structures. In rotating gravity currents, the vortices observed at the lobes front are not of hairpin type but are rather of Kelvin-Helmholtz type.

Interim Columbia and Snake rivers flow improvement measures for salmon: Final Supplemental Environmental Impact Statement (SEIS)

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

Not Available

1993-03-01

Public comments are sought on this final SEIS, which supplements the 1992 Columbia River Salmon Flow Measures Options Analysis (OA)/Environmental Impact Statement (EIS). The Corps of Engineers, in cooperation with the Bonneville Power Administration and the Bureau of Reclamation proposes five alternatives to improve flows of water in the lower Columbia-Snake rivers in 1993 and future years to assist the migration of juvenile and adult anadromous fish past eight hydropower dams. These are: (1) Without Project (no action) Alternative, (2) the 1992 Operation, (3) the 1992 Operation with Libby/Hungry Horse Sensitivity, (4) a Modified 1992 Operation with Improvements to Salmonmore » Flows from Dworshak, and (5) a Modified 1992 Operation with Upper Snake Sensitivity. Alternative 4, Modified 1992 Operations, has been identified as the preferred alternative.« less

Growth-differentiation factor 15 and osteoprotegerin in acute myocardial infarction complicated by cardiogenic shock: a biomarker substudy of the IABP-SHOCK II-trial.

PubMed

Fuernau, Georg; Poenisch, Christian; Eitel, Ingo; de Waha, Suzanne; Desch, Steffen; Schuler, Gerhard; Adams, Volker; Werdan, Karl; Zeymer, Uwe; Thiele, Holger

2014-08-01

This study investigates the role of osteoprotegerin (OPG) and growth-differentiation factor 15 (GDF-15) as predictors of outcome in cardiogenic shock (CS) complicating acute myocardial infarction. The novel biomarkers OPG and GDF-15 have shown prognostic impact in various cardiovascular diseases including myocardial infarction. In acute myocardial infarction complicated by CS, the diagnostic and prognostic impact of these biomarkers has not been investigated yet. OPG and GDF-15 may have additional prognostic impact on early prognosis assessment, being potentially useful for decision-making in CS. In the randomized Intra-aortic Balloon Pump in cardiogenic Shock II (IABP-SHOCK II)-trial, 600 patients with CS complicating acute myocardial infarction undergoing early revascularization were assigned to therapy with or without IABP. Within a pre-defined substudy, blood samples were collected from 190 patients during PCI. GDF-15 and OPG serum levels were measured with standard enzyme-linked immunosorbent assay kits. Patients with GDF-15 and OPG levels greater than the median showed higher rates of death at 30 days by χ(2) testing (OPG, 51% vs. 32%, P = 0.01; GDF-15, 52% vs. 31%, P = 0.005) and log rank testing [GDF-15, hazard ratio (HR) 1.88, 95% confidence interval (CI) 1.21-2.94; P = 0.005; OPG, HR 1.74, 95% CI 1.11-2.71; P = 0.01]. Both markers were significantly predictive of 30-day mortality in univariable logistic regression analysis. In a multivariable logistic stepwise regression model, GDF-15, TIMI (Thrombolysis In Myocardial Infarction) flow grade <3 after PCI, age, LVEF, and serum lactate remained significant predictors of 30-day mortality. GDF-15 on admission is a significant independent predictor of short-term mortality in infarct-related CS. Trail registration: NCT00491036. © 2014 The Authors. European Journal of Heart Failure © 2014 European Society of Cardiology.

Sequential evaluation of coronary flow patterns after primary angioplasty in acute anterior ST-elevation myocardial infarction predicts recovery of left ventricular systolic function.

PubMed

Sharif, Dawod; Sharif-Rasslan, Amal; Makhoul, Nabeel; Shefer, Arie; Hassan, Amin; Rosenschein, Uri

2014-05-01

Function of the microcirculation after primary percutaneous coronary intervention (PCI) is dynamic and contributes to unpredictability of recovery of left ventricular (LV) systolic function. This study was conducted to evaluate sequential Doppler velocity parameters of the left anterior descending coronary artery (LAD) in predicting recovery of global and regional LV systolic function. Thirty-five consecutive patients, 24 males, age 59 ± 12 years, with acute anterior ST-elevation myocardial infarction (STEMI) who had primary PCI were studied. Thrombolysis in myocardial infarction (TIMI) and myocardial blush grades were evaluated. Transthoracic echocardiographic (TTE) studies, evaluation of left ventricular ejection fraction (LVEF), LAD territory wall-motion score index (WMSI), and sampling of LAD Doppler velocities up to 6 hours post-PCI, 48 hours postprocedure, and predischarge were performed. Thrombolysis in myocardial infarction grade before PCI averaged 0.86 ± 1.19 and post-PCI 2.89 ± 0.32, P < 0.05. Myocardial blush grade before PCI was 0.41 ± 0.98 and after PCI 2.22 ± 0.93, P < 0.05. Diastolic velocity deceleration time (DDT) in the LAD early after PCI was less than 600 ms in 16 subjects. Immediately after PCI, in subjects with DDT > 600 ms, LVEF was 38.5 ± 6% and predischarge 49.2 ± 8.7%, P = 9.77 × 10−5 and LAD-WMSI decreased from 2 ± 0.38 to 1.4 ± 0.48, P = 0.000163. In subjects with DDT < 600 ms LAD-WMSI did not change significantly. Early and minimal LAD-DDT correlated with improvement in LV systolic function, r = 0.6, whereas post-PCI blush grade had lower correlation with LVEF, r = 0.39. Global and regional LV systolic function after PCI in acute anterior MI can be predicted by LAD-DDT better than by post-PCI myocardial blush.

Persistent T-wave inversion predicts myocardial damage after ST-elevation myocardial infarction.

PubMed

Reindl, Martin; Reinstadler, Sebastian Johannes; Feistritzer, Hans-Josef; Niess, Lea; Koch, Constantin; Mayr, Agnes; Klug, Gert; Metzler, Bernhard

2017-08-15

Persistent T-wave inversion (PTI) after ST-elevation myocardial infarction (STEMI) is associated with worse clinical outcome; however, the underlying mechanism between PTI and poor prognosis is incompletely understood. We sought to investigate the relationship between PTI and myocardial damage assessed by cardiac magnetic resonance (CMR) following STEMI. In this prospective observational study, we included 142 consecutive revascularized STEMI patients. Electrocardiography to determine the presence and amplitude of PTI and pathological Q-waves was conducted 4months after infarction. CMR was performed within 1week after infarction and at 4months follow-up to evaluate infarct characteristics and myocardial function. Patients with PTI (n=103, 73%) showed a larger acute (21[11-29] vs. 6[1-13]%; p<0.001) and chronic infarct size (IS) (14[8-19] vs. 3[1-8]%; p<0.001) and more frequently microvascular obstruction (59 vs. 33%; p=0.02). The association between PTI and chronic IS remained significant (odds ratio: 9.02, 95%CI 3.49-23.35; p<0.001) after adjustment for pathological Q-wave and other IS estimators (high-sensitivity cardiac troponin T and C-reactive protein, N-terminal pro B-type natriuretic peptide, culprit vessel, pre-interventional TIMI flow). The value of PTI amplitude for the prediction of large chronic IS>11% (AUC: 0.84, 95%CI 0.77-0.90) was significantly higher compared to Q-wave amplitude (AUC: 0.72, 95%CI 0.63-0.80; p=0.009); the combination of PTI with pathological Q-wave (Q-wave/T-wave score) led to a net reclassification improvement of 0.43 (95% CI 0.29-0.57; p<0.001) as compared to PTI alone. PTI following STEMI is independently and incrementally associated with more extensive myocardial damage as visualized by CMR. An electrocardiographic score combining PTI with pathological Q-wave allows for a highly accurate IS estimation post-STEMI. Copyright © 2017 Elsevier B.V. All rights reserved.

Presence of post-systolic shortening is an independent predictor of heart failure in patients following ST-segment elevation myocardial infarction.

PubMed

Brainin, Philip; Haahr-Pedersen, Sune; Sengeløv, Morten; Olsen, Flemming Javier; Fritz-Hansen, Thomas; Jensen, Jan Skov; Biering-Sørensen, Tor

2018-05-01

Following an ischemic event post systolic shortening (PSS) may occur. We investigated the association between PSS in patients with ST-segment elevation myocardial infarction (STEMI) following primary percutaneous coronary intervention (pPCI) and occurrence of cardiovascular events at follow-up. A total of 373 patients admitted with STEMI and treated with pPCI were prospectively included in the study cohort. All patients were examined by echocardiography a median of 2 days after admission (interquartile range, 1-3 days). PSS was measured by color tissue Doppler imaging (TDI) and speckle tracking echocardiography (STE) in six myocardial walls from all three apical projections. During a median follow-up period of 5.4 years (interquartile range, 4.1-6.0 years), 180 events occurred: 59 deaths, 70 heart failures (HF) and 51 new myocardial infarctions (MI). In multivariable analysis adjusting for: age, sex, peak troponin, left ventricle ejection fraction, TIMI flow grade, left ventricle mass index, hypertension and diabetes, presence of PSS by TDI in the culprit region was associated with a nearly twofold increased risk of HF (HR 1.90, 95% CI 1.02-3.53, P = 0.043) and the risk of HF increased incrementally with increasing numbers of walls displaying PSS. The increased risk of HF was confirmed when assessing the post-systolic index by STE (HR 1.29 95% CI 1.09-1.53, P = 0.003, per 1% increase). A regional analysis showed that PSS by TDI in the septal wall was the strongest predictor of HF (HR 1.77, 95% CI 1.08-2.92, P = 0.024). Presence of PSS was not associated with increased risk of death or MI. In patients with STEMI treated with pPCI, the presence of PSS examined by TDI and STE provides prognostic information on development of HF. Presence of PSS in the septal wall is the strongest predictor of HF.

A qualitative and quantitative laser-based computer-aided flow visualization method. M.S. Thesis, 1992 Final Report

NASA Technical Reports Server (NTRS)

Canacci, Victor A.; Braun, M. Jack

1994-01-01

The experimental approach presented here offers a nonintrusive, qualitative and quantitative evaluation of full field flow patterns applicable in various geometries in a variety of fluids. This Full Flow Field Tracking (FFFT) Particle Image Velocimetry (PIV) technique, by means of particle tracers illuminated by a laser light sheet, offers an alternative to Laser Doppler Velocimetry (LDV), and intrusive systems such as Hot Wire/Film Anemometry. The method makes obtainable the flow patterns, and allows quantitative determination of the velocities, accelerations, and mass flows of an entire flow field. The method uses a computer based digitizing system attached through an imaging board to a low luminosity camera. A customized optical train allows the system to become a long distance microscope (LDM), allowing magnifications of areas of interest ranging up to 100 times. Presented in addition to the method itself, are studies in which the flow patterns and velocities were observed and evaluated in three distinct geometries, with three different working fluids. The first study involved pressure and flow analysis of a brush seal in oil. The next application involved studying the velocity and flow patterns in a cowl lip cooling passage of an air breathing aircraft engine using water as the working fluid. Finally, the method was extended to a study in air to examine the flows in a staggered pin arrangement located on one side of a branched duct.

Network-Theoretic Modeling of Fluid Flow

DTIC Science & Technology

2015-07-29

Final Report STIR: Network-Theoretic Modeling of Fluid Flow ARO Grant W911NF-14-1-0386 Program manager: Dr. Samuel Stanton ( August 1, 2014–April 30...Morzyński, M., and Comte , P., “A finite-time thermodynamics of unsteady fluid flows,” Journal of Non-Equilibrium Thermody- namics, Vol. 33, No. 2

Wave number selection in the presence of noise: Experimental results

NASA Astrophysics Data System (ADS)

Zhilenko, Dmitry; Krivonosova, Olga; Gritsevich, Maria; Read, Peter

2018-05-01

In this study, we consider how the wave number selection in spherical Couette flow, in the transition to azimuthal waves after the first instability, occurs in the presence of noise. The outer sphere was held stationary, while the inner sphere rotational speed was increased linearly from a subcritical flow to a supercritical one. In a supercritical flow, one of two possible flow states, each with different azimuthal wave numbers, can appear depending upon the initial and final Reynolds numbers and the acceleration value. Noise perturbations were added by introducing small disturbances into the rotational speed signal. With an increasing noise amplitude, a change in the dominant wave number from m to m ± 1 was found to occur at the same initial and final Reynolds numbers and acceleration values. The flow velocity measurements were conducted by using laser Doppler anemometry. Using these results, the role of noise as well as the behaviour of the amplitudes of the competing modes in their stages of damping and growth were determined.

Final definition and preliminary design study for the initial atmospheric cloud physics laboratory, a Spacelab mission payload

NASA Technical Reports Server (NTRS)

1976-01-01

The following areas related to the final definition and preliminary design study of the initial atmospheric cloud physics laboratory (ACPL) were covered: (1) proposal organization, personnel, schedule, and project management, (2) proposed configurations, (3) study objectives, (4) ACPL experiment program listing and description, (5) mission/flight flexibility and modularity/commonality, (6) study plan, and (7) description of following tasks: requirement analysis and definition task flow, systems analysis and trade studies, subsystem analysis and trade studies, specifications and interface control documents, preliminary design task flow, work breakdown structure, programmatic analysis and planning, and project costs. Finally, an overview of the scientific requirements was presented.

Computation of viscous incompressible flows

NASA Technical Reports Server (NTRS)

Kwak, Dochan

1989-01-01

Incompressible Navier-Stokes solution methods and their applications to three-dimensional flows are discussed. A brief review of existing methods is given followed by a detailed description of recent progress on development of three-dimensional generalized flow solvers. Emphasis is placed on primitive variable formulations which are most promising and flexible for general three-dimensional computations of viscous incompressible flows. Both steady- and unsteady-solution algorithms and their salient features are discussed. Finally, examples of real world applications of these flow solvers are given.

Modular Exhaust Design and Manufacturing Techniques for Low Cost Mid Volume Rapid Buidl to Order Systems

DTIC Science & Technology

2014-08-06

the pressure field is uniform across them, but which allow mass flow to be diverted. Series elements have a constant mass flow across the ports...they can be used to calculate the pressure and mass flow after the element from the pressure and mass flow prior to the element, as shown in...the matrix product of each transfer matrix in turn. The final matrix gives no information about the pressures and mass flows within the element

Are large clinical trials in orthopaedic trauma justified?

PubMed

Sprague, Sheila; Tornetta, Paul; Slobogean, Gerard P; O'Hara, Nathan N; McKay, Paula; Petrisor, Brad; Jeray, Kyle J; Schemitsch, Emil H; Sanders, David; Bhandari, Mohit

2018-04-20

The objective of this analysis is to evaluate the necessity of large clinical trials using FLOW trial data. The FLOW pilot study and definitive trial were factorial trials evaluating the effect of different irrigation solutions and pressures on re-operation. To explore treatment effects over time, we analyzed data from the pilot and definitive trial in increments of 250 patients until the final sample size of 2447 patients was reached. At each increment we calculated the relative risk (RR) and associated 95% confidence interval (CI) for the treatment effect, and compared the results that would have been reported at the smaller enrolments with those seen in the final, adequately powered study. The pilot study analysis of 89 patients and initial incremental enrolments in the FLOW definitive trial favored low pressure compared to high pressure (RR: 1.50, 95% CI: 0.75-3.04; RR: 1.39, 95% CI: 0.60-3.23, respectively), which is in contradiction to the final enrolment, which found no difference between high and low pressure (RR: 1.04, 95% CI: 0.81-1.33). In the soap versus saline comparison, the FLOW pilot study suggested that re-operation rate was similar in both the soap and saline groups (RR: 0.98, 95% CI: 0.50-1.92), whereas the FLOW definitive trial found that the re-operation rate was higher in the soap treatment arm (RR: 1.28, 95% CI: 1.04-1.57). Our findings suggest that studies with smaller sample sizes would have led to erroneous conclusions in the management of open fracture wounds. NCT01069315 (FLOW Pilot Study) Date of Registration: February 17, 2010, NCT00788398 (FLOW Definitive Trial) Date of Registration: November 10, 2008.

10 CFR 431.264 - Uniform test method for the measurement of flow rate for commercial prerinse spray valves.

Code of Federal Regulations, 2010 CFR

2010-01-01

..., the water consumption flow rate of commercial prerinse spray valves. (b) Testing and Calculations. The test procedure to determine the water consumption flow rate for prerinse spray valves, expressed in... the previous step. Round the final water consumption value to one decimal place as follows: (1) A...

A Logical Approach to the Statement of Cash Flows

ERIC Educational Resources Information Center

Petro, Fred; Gean, Farrell

2014-01-01

Of the three financial statements in financial reporting, the Statement of Cash Flows (SCF) is perhaps the most challenging. The most difficult aspect of the SCF is in developing an understanding of how previous transactions are finalized in this document. The purpose of this paper is to logically explain the indirect approach of cash flow whereby…

Flow Visualization Studies in the Novacor Left Ventricular Assist System CRADA PC91-002, Final Report

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

Borovetz, H.S.; Shaffer, F.; Schaub, R.

This paper discusses a series of experiments to visualize and measure flow fields in the Novacor left ventricular assist system (LVAS). The experiments utilize a multiple exposure, optical imaging technique called fluorescent image tracking velocimetry (FITV) to hack the motion of small, neutrally-buoyant particles in a flowing fluid.

Saxagliptin: A Review in Type 2 Diabetes.

PubMed

Dhillon, Sohita

2015-10-01

Saxagliptin (Onglyza(®)) is a highly potent, reversible, competitive dipeptidyl peptidase-4 inhibitor indicated for the treatment of patients with type 2 diabetes. Numerous well-designed clinical studies and their extensions showed that saxagliptin as monotherapy or as dual or triple combination therapy with other antihyperglycaemics improved glycaemic control and was generally well tolerated in patients with type 2 diabetes during ≤2 years' therapy. Saxagliptin was generally weight-neutral and had a low risk of hypoglycaemia (unless coadministered with agents that may be associated with hypoglycaemia, such as sulfonylureas or insulin). In addition, at a median follow-up of 2.1 years in the large SAVOR-TIMI 53 study, with the exception of a 27 % greater risk of hospitalization for heart failure, the addition of saxagliptin to standard of care neither reduced nor increased the rate of ischemic cardiovascular events in at-risk patients. Although further long-term data will be beneficial, current evidence indicates that saxagliptin is a useful option for the treatment of patients with type 2 diabetes.

A pilot study of low-moderate drinking water arsenic contamination and chronic diseases among reproductive age women in Timiş County, Romania.

PubMed

Butts, Celeste D; Bloom, Michael S; Neamtiu, Iulia A; Surdu, Simona; Pop, Cristian; Anastasiu, Doru; Fitzgerald, Edward F; Gurzau, Eugen S

2015-11-01

We conducted a pilot study of associations between drinking water contaminated by inorganic arsenic (iAs), mostly <10 μg/L, and self-reported chronic diseases in 297 pregnant women. Adjusted for confounding variables, we identified a positive association between iAs and heart disease (OR = 1.63, 95%CI 0.81-3.04, p = 0.094), which was stronger for women living at their current residence ≥ 10 years (OR = 2.47, 95%CI 0.87-10.43, p = 0.058). Confounder-adjusted associations were also suggested for iAs with kidney disease (OR = 1.32, 95%CI 0.77-2.21, p = 0.265) and with high blood pressure (OR = 1.36, 95%CI 0.68-2.39, p = 0.300). A post hoc power analysis indicated the need for a larger study with more statistical power. Copyright © 2015 Elsevier B.V. All rights reserved.

Materials in the economy; material flows, scarcity, and the environment

USGS Publications Warehouse

Wagner, Lorie A.

2002-01-01

The importance of materials to the economy of the United States is described, including the levels of consumption and uses of materials. The paths (or flows) that materials take from extraction, through processing, to consumer products, and then final disposition are illustrated. Scarcity and environmental issues as they relate to the flow of materials are discussed. Examples for the three main themes of the report (material flows, scarcity, and the environment) are presented.

FleetForward evaluation : final report

DOT National Transportation Integrated Search

2000-10-01

This document is the final report for the evaluation of the I-95 Corridor Coalitions FleetForward operational test. The objective of this test was to evaluate the usefulness of traffic flow data to motor carrier operations. Cambridge Systematics, in ...

Modelling the Thermal and Infrared Spectral Properties of Active Vents: Comparing Basaltic Lava Flows of Tolbachik, Russia to Arsia Mons, Mars

NASA Astrophysics Data System (ADS)

Ramsey, M. S.; Harris, A. J. L.

2016-12-01

Satellite observations of active vents commonly group into several broad categories: thermal analysis, deformational studies, and gas/ash detection. These observations become increasingly detailed depending on the spatial, spectral and/or temporal resolution of the sensor. Higher temporal resolution thermal infrared (TIR) data are used to determine the time-averaged discharge rate (TADR) and the potential down-slope inundation of the newly-forming flow using thermorheologic-based modelling. Whereas, increased spectral resolution leads to improved measurement of the flow's composition, crystal content, and vesicularity. Combined, these data help to improve the accuracy of cooling-based viscosity models such as FLOWGO. In addition to topography, the dominant (internal) factors controlling flow propagation are the discharge rate combined with cooling and increasing viscosity. The cooling of the glassy lava surface is directly imaged by the TIR instrument to determine temperature, which is then used to calculate the model's starting conditions. Understanding the cooling, formation and dynamics of basaltic surfaces therefore helps to resolve compositional, textural, and silicate structural changes. Models, coupled with accurate knowledge of the characteristics of older, inactive flows (such as those on Mars), can be reversed to predict the vent conditions at the time of the eruption. Being able to directly connect the final flow morphology to specific eruption conditions is a critical goal to understand the last stages of volcanism on Mars and becomes an important educational tool where combined with 3D visualization. The 2012-2013 eruption of Tolbachik volcano, Russia was the largest and most thermally intense flow-forming eruption in the past 50 years, producing longer lava flows than that of a typical eruption at Kilauea or Etna. These flows have been studied using various scales of TIR data at the time of eruption and following cooling. The input parameters for the FLOWGO model are then tuned to produce the best fit of eruptive conditions to final flow morphology. The refined model can then be used to determine the TADR from the vent and make improved estimates of cooling, viscosity, velocity and crystallinity with distance. Final results are visualized and their educational potential assessed.

Modeling granular material flows: The angle of repose, fluidization and the cliff collapse problem

NASA Astrophysics Data System (ADS)

Holsapple, Keith A.

2013-07-01

I discuss theories of granular material flows, with application to granular flows on the earth and planets. There are two goals. First, there is a lingering belief of some that the standard continuum plasticity Mohr-Coulomb and/or Drucker-Prager models are not adequate for many large-scale granular flow problems. The stated reason for those beliefs is the fact that the final slopes of the run-outs in collapse, landslide problems, and large-scale cratering are well below the angle of repose of the material. That observation, combined with the supposition that in those models flow cannot occur with slopes less than the angle of repose, has led to a number of researchers suggesting a need for lubrication or fluidization mechanisms and modeling. That issue is investigated in detail and shown to be false. A complete analysis of slope failures according to the Mohr-Coulomb model is presented, with special attention to the relations between the angle of repose and slope failures. It is shown that slope failure can occur for slope angles both larger than and smaller than the angle of repose. Second, to study the details of landslide run-outs, finite-difference continuum code simulations of the prototypical cliff collapse problem, using the classical plasticity models, are presented, analyzed and compared to experiments. Although devoid of any additional fluidization models, those simulations match experiments in the literature extremely well. The dynamics of this problem introduces additional important features relating to the run-out and final slope angles. The vertical free surface begins to fall at the initial 90° and flow continues to a final slope less than 10°. The detail in the calculation is examined to show why flow persists at slope angles that appear to be less than the angle of repose. The motions include regions of solid-like, fluid-like, and gas-like flows without invoking any additional models.

The Initial Flow of Classical Gluon Fields in Heavy Ion Collisions

NASA Astrophysics Data System (ADS)

Fries, Rainer J.; Chen, Guangyao

2015-03-01

Using analytic solutions of the Yang-Mills equations we calculate the initial flow of energy of the classical gluon field created in collisions of large nuclei at high energies. We find radial and elliptic flow which follows gradients in the initial energy density, similar to a simple hydrodynamic behavior. In addition we find a rapidity-odd transverse flow field which implies the presence of angular momentum and should lead to directed flow in final particle spectra. We trace those energy flow terms to transverse fields from the non-abelian generalization of Gauss' Law and Ampere's and Faraday's Laws.

Applications of magnetohydrodynamics in biological systems-a review on the numerical studies

NASA Astrophysics Data System (ADS)

Rashidi, Saman; Esfahani, Javad Abolfazli; Maskaniyan, Mahla

2017-10-01

Magnetohydrodynamic (MHD) fluid flow in different geometries relevant to human body parts is an interesting and important scientific area due to its applications in medical sciences. This article performs a comprehensive review on the applications of MHD and their numerical modelling in biological systems. Applications of MHD in medical sciences are classified into four categories in this paper. Applications of MHD in simple flow, peristaltic flow, pulsatile flow, and drag delivery are these categories. The numerical researches performed for these categories are reviewed and summarized separately. Finally, some conclusions and suggestions for future works based on the literature review are presented. The results indicated that during a surgery when it is necessary to drop blood flow or reduce tissue temperature, it may be achieved by using a magnetic field. Moreover, the review showed that the trapping is an important phenomenon in peristaltic flows that causes the formation of thrombus in blood and the movement of food bolus in gastrointestinal tract. This phenomenon may be disappeared by using a proper magnetic field. Finally, the concentration of particles that are delivered to the target region increases with an increase in the magnetic field intensity.

Developmental testing resulting in a simplified liquid oxygen check valve for the Space Shuttle Main Propulsion System

NASA Technical Reports Server (NTRS)

Aber, Gregory S.; Barrett, Michael J.; Reith, Timothy W.

1993-01-01

The coil spring in a Space Shuttle liquid oxygen check valve failed due to cyclic fatigue in September, 1991. The dual-flapper, swing check valve is used to prevent reverse flow to the Space Shuttle Main Engines. Upon inspection of the failed component, the spring tangs were found to be missing and heavy wear was observed on the inner diameter of the spring coils. The fracture surfaces revealed that the metal had been steadily worn away until a simple overload caused the final fracture. A series of flow tests using water and a water/gas mixture was conducted to identify the flow phenomenon which produced the cyclic wear. A Plexiglas outlet housing was utilized to view the flapper behavior under different flow conditions and to aid in high speed photography. The tests revealed that flow instabilities induced two oscillatory flapper responses: a rocking mode and a chattering mode. Initially, attempts were made to reduce the spring-flapper oscillations. However, the final solution to the problem was a springless configuration which satisfied the valve's design requirements and eliminated the oscillations. The springless design relied on the inherent ability of the reverse flow momentum to close the flappers.

Parametric Study of Advanced Mixing of Fuel/Oxidant System in High Speed Gaseous Flows and Experimental Validation Planning

DTIC Science & Technology

2001-08-30

Body with Thermo-Chemical destribution of Heat-Protected System . In: Physical and Gasdynamic Phenomena in Supersonic Flows Over Bodies. Edit. By...Final Report on ISTC Contract # 1809p Parametric Study of Advanced Mixing of Fuel/Oxidant System in High Speed Gaseous Flows and Experimental...of Advanced Mixing of Fuel/Oxidant System in High Speed Gaseous Flows and Experimental Validation Planning 5c. PROGRAM ELEMENT NUMBER 5d. PROJECT

Development and verification of methods for predicting flow rates through leaks in valves and couplings

NASA Technical Reports Server (NTRS)

Russell, John M.

1993-01-01

This is the final report of a research effort which addresses the title problem. The report discusses two broad models of flows, which represent the following extreme cases: (1) inertia-dominated flow, where friction is relatively insignificant; and (2) friction-dominated flow where inertia is insignificant. In class (2), the leak channel might consist of the gap between a scratch in a plastic seal and a polished metal plate against which the seal is pressed. Here, the cross section of the leak channel is modeled as a flat bottomed crescent. A publication generated under the present grant period presents an exact solution of the equations of fully-developed laminar pipe flow of a liquid in the case of a crescent beneath a hyperbolic arc. A Master's thesis project supported by the present grant presents the corresponding solution beneath a circular arc. A second publication reviews the flow of a gas through the same channel, which may be analyzed by a standard one-dimensional model (Fanno flow) for an engineering approximation. Finally, the report discusses the design and progress in the fabrication of a leak-test cell, in which one may measure the flow of fluid through a controlled flaw in a seal. The aim of such measurements is to furnish data for comparison with the predictions of the theory.

5A.01: CORONARY ATHEROSCLEROSIS AND ADVERSE OUTCOME IN HYPERTENSIVE PATIENTS WITH RECENT-ONSET ATRIAL FIBRILLATION AND TROPONIN RISE.

PubMed

Conti, A; Angeli, E; Trausi, F; Grifoni, C; Lazzeretti, D; Bianchi, S; Catarzi, S; Covelli, A; Perrotta, M E; Lencioni, A M; Pisani, N; Bertolini, L

2015-06-01

Atrial fibrillation (AF), the most common cardiac-arrhythmia in critical-care, has reached a high prevalence in hypertensive patients. Prevention of systemic-embolism is mandatory; unfortunately, evidence to support the treatment of comorbidities as coronary artery disease (CAD) that contribute to excess mortality is lacking, and the mechanism underlying the troponin-rise during AF without acute coronary syndrome (ACS) is unclear. This study investigates the relationship between CAD, stroke and outcomes in patients with troponin-rise and AF. Patients with a recent-onset AF and without severe comorbidities were enrolled. Baseline characteristics in those with troponin-rise versus those without were adjusted with propensity-score-matching for possible confounders. SPSS-software allowed estimation of the propensity-score using logistic-regression and specifying nearest-neighbor matching in prior-stroke, heart-rate, hypertension, TIMI-risk-score, GRACE-score, CHA2DS2Vasc-score. Patients with a troponin-rise or cardiovascular event (CVE) were considered for angiography. The primary endpoint was the composite of ACS, revascularization (with critical CAD>/ = 70%) and cardiac-death at the follow-up; the secondary endpoint was stroke. Out of 6203 AF patients without severe comorbidities, 3541 with recent-onset AF completed the study; 202(6%) showed a troponin-rise, 91(3%) a CVE. After matching no difference existed in baseline characteristics. On multivariate analysis, in the entire cohort, troponin-rise, know-CAD and hypertension were predictors of the endpoint, whereas only troponin-rise (Odd Ratio, OR: 10, Confidence Interval 95%, CI: 4-22, p < 0.001) and TIMI-score > 2 (OR 4, CI 2-9, p < 0.001) in the matching cohort, suggesting the role of CAD in poor outcomes. Patients with or without troponin-rise achieved the endpoint in 38(19%) and 43(1%), respectively (p < 0.001). Stroke occurred in 4(2%) and 20 (1%), respectively (p = 0.018). Critical CAD account for 23(12%) and 15(1%), respectively (p < 0,001). In the matching cohort, only stroke did not reach the statistical significance. Interestingly, the best cut/off troponin level for decision-making was 0.30 ng/L which, on Receiver Operator Curve analysis, was associated with 68% of sensitivity and 60% specificity; the value > 0.50 ng/L with 55% and 75%, respectively. Patients with a recent-onset AF and troponin-rise showed a high prevalence of CVE but not stroke, thus CAD might have a role in poor outcomes.

Saxagliptin and cardiovascular outcomes in patients with type 2 diabetes and moderate or severe renal impairment: observations from the SAVOR-TIMI 53 Trial.

PubMed

Udell, Jacob A; Bhatt, Deepak L; Braunwald, Eugene; Cavender, Matthew A; Mosenzon, Ofri; Steg, Ph Gabriel; Davidson, Jaime A; Nicolau, Jose C; Corbalan, Ramon; Hirshberg, Boaz; Frederich, Robert; Im, KyungAh; Umez-Eronini, Amarachi A; He, Ping; McGuire, Darren K; Leiter, Lawrence A; Raz, Itamar; Scirica, Benjamin M

2015-04-01

The glycemic management of patients with type 2 diabetes mellitus (T2DM) and renal impairment is challenging, with few treatment options. We investigated the effect of saxagliptin in the Saxagliptin Assessment of Vascular Outcomes Recorded in Patients with Diabetes Mellitus (SAVOR)-Thrombolysis in Myocardial Infarction (TIMI) 53 trial according to baseline renal function. Patients with T2DM at risk for cardiovascular events were stratified as having normal or mildly impaired renal function (estimated glomerular filtration rate [eGFR] >50 mL/min/1.73 m(2); n = 13,916), moderate renal impairment (eGFR 30-50 mL/min/1.73 m(2); n = 2,240), or severe renal impairment (eGFR <30 mL/min/1.73 m(2); n = 336) and randomized to receive saxagliptin or placebo. The primary end point was cardiovascular death, myocardial infarction, or ischemic stroke. After a median duration of 2 years, saxagliptin neither increased nor decreased the risk of the primary and secondary composite end points compared with placebo, irrespective of renal function (all P for interactions ≥ 0.19). Overall, the risk of hospitalization for heart failure among the three eGFR groups of patients was 2.2% (referent), 7.4% (adjusted hazard ratio [HR] 2.38 [95% CI 1.95-2.91], P < 0.001), and 13.0% (adjusted HR 4.59 [95% CI 3.28-6.28], P < 0.001), respectively. The relative risk of hospitalization for heart failure with saxagliptin was similar (P for interaction = 0.43) in patients with eGFR >50 mL/min/1.73 m(2) (HR 1.23 [95% CI 0.99-1.55]), eGFR 30-50 mL/min/1.73 m(2) (HR 1.46 [95% CI 1.07-2.00]), and in patients with eGFR <30 (HR 0.94 [95% CI 0.52-1.71]). Patients with renal impairment achieved reductions in microalbuminuria with saxagliptin (P = 0.041) that were similar to those of the overall trial population. Saxagliptin did not affect the risk of ischemic cardiovascular events, increased the risk of heart failure hospitalization, and reduced progressive albuminuria, irrespective of baseline renal function. © 2015 by the American Diabetes Association. Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered.

Prognostic performance of multiple biomarkers in patients with non-ST-segment elevation acute coronary syndrome: analysis from the MERLIN-TIMI 36 trial (Metabolic Efficiency With Ranolazine for Less Ischemia in Non-ST-Elevation Acute Coronary Syndromes-Thrombolysis In Myocardial Infarction 36).

PubMed

O'Malley, Ryan G; Bonaca, Marc P; Scirica, Benjamin M; Murphy, Sabina A; Jarolim, Petr; Sabatine, Marc S; Braunwald, Eugene; Morrow, David A

2014-04-29

The aim of this study was to assess the prognostic performance of C-terminal provasopressin (copeptin), midregional pro-adrenomedullin (MR-proADM), and midregional pro-atrial natriuretic peptide (MR-proANP) in a large prospective cohort of patients with non-ST-segment elevation acute coronary syndrome (NSTE-ACS). Copeptin, MR-proADM, and MR-proANP are emerging biomarkers of hemodynamic stress that have been associated with adverse cardiovascular (CV) outcomes in heart failure (HF) and stable ischemic disease. We measured copeptin, MR-proADM, and MR-proANP concentrations in 4,432 patients with NSTE-ACS who were randomized to treatment with ranolazine or placebo in the MERLIN-TIMI 36 (Metabolic Efficiency With Ranolazine for Less Ischemia in Non-ST-Elevation Acute Coronary Syndromes-Thrombolysis In Myocardial Infarction 36) trial and followed up for 1 year. A high concentration (quartile 4 vs. quartiles 1 to 3) of each biomarker identified an increased risk of CV death or HF(copeptin: 13.2% vs. 5.0%, p < 0.001; MR-proADM: 15.8% vs. 4.1%, p < 0.001; MR-proANP: 17.7% vs. 3.5%, p < 0.001)as well as CV death, HF, and myocardial infarction individually (all p ≤ 0.001). After adjustment for important covariates, each biomarker remained associated with CV death or HF at 1 year (adjusted hazard ratio: copeptin, 1.71; MR-proADM, 1.96; MR-proANP, 2.20; all p ≤ 0.001).These biomarkers improved prognostic discrimination and patient re-classification for CV death or HF at 1 year(all categorical NRI >10%, p < 0.001), and maintained independent association with composite CV death or HF when concurrently assessed in a model with clinical indicators plus BNP, cTnI, ST2, PAPP-A, and MPO (each p≤0.01) [corrected]. Copeptin, MR-proADM, and MR-proANP are complementary prognostic markers for CV death and HF in patients with NSTE-ACS that perform as well as or better than established and other emerging biomarkers and warrant further investigation of application for therapeutic decision making. (Metabolic Efficiency With Ranolazine for Less Ischemia in Non-ST Elevation Acute Coronary Syndromes; NCT00099788). Copyright © 2014 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Prasugrel versus clopidogrel in patients with ST-segment elevation myocardial infarction according to timing of percutaneous coronary intervention: a TRITON-TIMI 38 subgroup analysis (Trial to Assess Improvement in Therapeutic Outcomes by Optimizing Platelet Inhibition with Prasugrel-Thrombolysis In Myocardial Infarction 38).

PubMed

Udell, Jacob A; Braunwald, Eugene; Antman, Elliott M; Antman, Elliot M; Murphy, Sabina A; Montalescot, Gilles; Wiviott, Stephen D

2014-06-01

This study sought to evaluate the efficacy of prasugrel versus clopidogrel in ST-segment elevation myocardial infarction (STEMI) by the timing of percutaneous coronary intervention (PCI). Treatment strategies and outcomes for patients with STEMI may differ when treated with primary compared with secondary PCI. STEMI patients in the TRITON-TIMI 38 (Trial to Assess Improvement in Therapeutic Outcomes by Optimizing Platelet Inhibition with Prasugrel-Thrombolysis In Myocardial Infarction 38) were randomized to prasugrel or clopidogrel on presentation if primary PCI was intended or later during secondary PCI. Primary PCI was defined as within 12 h of symptom onset. The primary endpoint was cardiovascular death, myocardial infarction (MI), or stroke. Because periprocedural MI is difficult to assess in the setting of STEMI, we performed analyses excluding these events. Reductions in the primary endpoint with prasugrel versus clopidogrel (hazard ratio [HR]: 0.79; 95% confidence interval [CI]: 0.65 to 0.97; p = 0.022) were consistent between primary and secondary PCI patients at 15 months (HR: 0.89; 95% CI: 0.69 to 1.13 vs. HR: 0.65; 95% CI: 0.46 to 0.93; p interaction = 0.15). However, a tendency toward a difference in treatment effect at 30 days (HR: 0.68; 95% CI: 0.54 to 0.87; p = 0.002) was observed between primary and secondary PCI patients (HR: 0.81; 95% CI: 0.60 to 1.09 vs. HR: 0.51; 95% CI: 0.34 to 0.76; p interaction = 0.06). When periprocedural MI was excluded, the efficacy of prasugrel remained consistent among primary and secondary PCI patients at 30 days (HR: 0.53; 95% CI: 0.34 to 0.81 vs. HR: 0.44; 95% CI: 0.22 to 0.88; p interaction = 0.68) and 15 months (HR: 0.76; 95% CI: 0.56 to 1.03 vs. HR: 0.75; 95% CI: 0.46 to 1.21; p interaction = 0.96). The efficacy of prasugrel versus clopidogrel was consistent irrespective of the timing of PCI, particularly in preventing nonprocedural events. (Trial to Assess Improvement in Therapeutic Outcomes by Optimizing Platelet Inhibition with Prasugrel-Thrombolysis in Myocardial Infarction 38; NCT00097591). Copyright © 2014 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Pharmacogenetic meta-analysis of baseline risk factors, pharmacodynamic, efficacy and tolerability endpoints from two large global cardiovascular outcomes trials for darapladib

PubMed Central

Yeo, Astrid; Warren, Liling; Aponte, Jennifer; Johansson, Kelley; Barnes, Allison; MacPhee, Colin; Davies, Richard; Chissoe, Stephanie; O’Donoghue, Michelle L.; White, Harvey D.

2017-01-01

Darapladib, a lipoprotein-associated phospholipase A2 (Lp-PLA2) inhibitor, failed to demonstrate efficacy for the primary endpoints in two large phase III cardiovascular outcomes trials, one in stable coronary heart disease patients (STABILITY) and one in acute coronary syndrome (SOLID-TIMI 52). No major safety signals were observed but tolerability issues of diarrhea and odor were common (up to 13%). We hypothesized that genetic variants associated with Lp-PLA2 activity may influence efficacy and tolerability and therefore performed a comprehensive pharmacogenetic analysis of both trials. We genotyped patients within the STABILITY and SOLID-TIMI 52 trials who provided a DNA sample and consent (n = 13,577 and 10,404 respectively, representing 86% and 82% of the trial participants) using genome-wide arrays with exome content and performed imputation using a 1000 Genomes reference panel. We investigated baseline and change from baseline in Lp-PLA2 activity, two efficacy endpoints (major coronary events and myocardial infarction) as well as tolerability parameters at genome-wide and candidate gene level using a meta-analytic approach. We replicated associations of published loci on baseline Lp-PLA2 activity (APOE, CELSR2, LPA, PLA2G7, LDLR and SCARB1) and identified three novel loci (TOMM5, FRMD5 and LPL) using the GWAS-significance threshold P≤5E-08. Review of the PLA2G7 gene (encoding Lp-PLA2) within these datasets identified V279F null allele carriers as well as three other rare exonic null alleles within various ethnic groups, however none of these variants nor any other loci associated with Lp-PLA2 activity at baseline were associated with any of the drug response endpoints. The analysis of darapladib efficacy endpoints, despite low power, identified six low frequency loci with main genotype effect (though with borderline imputation scores) and one common locus (minor allele frequency 0.24) with genotype by treatment interaction effect passing the GWAS-significance threshold. This locus conferred risk in placebo subjects, hazard ratio (HR) 1.22 with 95% confidence interval (CI) 1.11–1.33, but was protective in darapladib subjects, HR 0.79 (95% CI 0.71–0.88). No major loci for tolerability were found. Thus, genetic analysis confirmed and extended the influence of lipoprotein loci on Lp-PLA2 levels, identified some novel null alleles in the PLA2G7 gene, and only identified one potentially efficacious subgroup within these two large clinical trials. PMID:28753643

Pharmacogenetic meta-analysis of baseline risk factors, pharmacodynamic, efficacy and tolerability endpoints from two large global cardiovascular outcomes trials for darapladib.

PubMed

Yeo, Astrid; Li, Li; Warren, Liling; Aponte, Jennifer; Fraser, Dana; King, Karen; Johansson, Kelley; Barnes, Allison; MacPhee, Colin; Davies, Richard; Chissoe, Stephanie; Tarka, Elizabeth; O'Donoghue, Michelle L; White, Harvey D; Wallentin, Lars; Waterworth, Dawn

2017-01-01

Darapladib, a lipoprotein-associated phospholipase A2 (Lp-PLA2) inhibitor, failed to demonstrate efficacy for the primary endpoints in two large phase III cardiovascular outcomes trials, one in stable coronary heart disease patients (STABILITY) and one in acute coronary syndrome (SOLID-TIMI 52). No major safety signals were observed but tolerability issues of diarrhea and odor were common (up to 13%). We hypothesized that genetic variants associated with Lp-PLA2 activity may influence efficacy and tolerability and therefore performed a comprehensive pharmacogenetic analysis of both trials. We genotyped patients within the STABILITY and SOLID-TIMI 52 trials who provided a DNA sample and consent (n = 13,577 and 10,404 respectively, representing 86% and 82% of the trial participants) using genome-wide arrays with exome content and performed imputation using a 1000 Genomes reference panel. We investigated baseline and change from baseline in Lp-PLA2 activity, two efficacy endpoints (major coronary events and myocardial infarction) as well as tolerability parameters at genome-wide and candidate gene level using a meta-analytic approach. We replicated associations of published loci on baseline Lp-PLA2 activity (APOE, CELSR2, LPA, PLA2G7, LDLR and SCARB1) and identified three novel loci (TOMM5, FRMD5 and LPL) using the GWAS-significance threshold P≤5E-08. Review of the PLA2G7 gene (encoding Lp-PLA2) within these datasets identified V279F null allele carriers as well as three other rare exonic null alleles within various ethnic groups, however none of these variants nor any other loci associated with Lp-PLA2 activity at baseline were associated with any of the drug response endpoints. The analysis of darapladib efficacy endpoints, despite low power, identified six low frequency loci with main genotype effect (though with borderline imputation scores) and one common locus (minor allele frequency 0.24) with genotype by treatment interaction effect passing the GWAS-significance threshold. This locus conferred risk in placebo subjects, hazard ratio (HR) 1.22 with 95% confidence interval (CI) 1.11-1.33, but was protective in darapladib subjects, HR 0.79 (95% CI 0.71-0.88). No major loci for tolerability were found. Thus, genetic analysis confirmed and extended the influence of lipoprotein loci on Lp-PLA2 levels, identified some novel null alleles in the PLA2G7 gene, and only identified one potentially efficacious subgroup within these two large clinical trials.

Methods for estimating selected low-flow frequency statistics and mean annual flow for ungaged locations on streams in North Georgia

USGS Publications Warehouse

Gotvald, Anthony J.

2017-01-13

The U.S. Geological Survey, in cooperation with the Georgia Department of Natural Resources, Environmental Protection Division, developed regional regression equations for estimating selected low-flow frequency and mean annual flow statistics for ungaged streams in north Georgia that are not substantially affected by regulation, diversions, or urbanization. Selected low-flow frequency statistics and basin characteristics for 56 streamgage locations within north Georgia and 75 miles beyond the State’s borders in Alabama, Tennessee, North Carolina, and South Carolina were combined to form the final dataset used in the regional regression analysis. Because some of the streamgages in the study recorded zero flow, the final regression equations were developed using weighted left-censored regression analysis to analyze the flow data in an unbiased manner, with weights based on the number of years of record. The set of equations includes the annual minimum 1- and 7-day average streamflow with the 10-year recurrence interval (referred to as 1Q10 and 7Q10), monthly 7Q10, and mean annual flow. The final regional regression equations are functions of drainage area, mean annual precipitation, and relief ratio for the selected low-flow frequency statistics and drainage area and mean annual precipitation for mean annual flow. The average standard error of estimate was 13.7 percent for the mean annual flow regression equation and ranged from 26.1 to 91.6 percent for the selected low-flow frequency equations.The equations, which are based on data from streams with little to no flow alterations, can be used to provide estimates of the natural flows for selected ungaged stream locations in the area of Georgia north of the Fall Line. The regression equations are not to be used to estimate flows for streams that have been altered by the effects of major dams, surface-water withdrawals, groundwater withdrawals (pumping wells), diversions, or wastewater discharges. The regression equations should be used only for ungaged sites with drainage areas between 1.67 and 576 square miles, mean annual precipitation between 47.6 and 81.6 inches, and relief ratios between 0.146 and 0.607; these are the ranges of the explanatory variables used to develop the equations. An attempt was made to develop regional regression equations for the area of Georgia south of the Fall Line by using the same approach used during this study for north Georgia; however, the equations resulted with high average standard errors of estimates and poorly predicted flows below 0.5 cubic foot per second, which may be attributed to the karst topography common in that area.The final regression equations developed from this study are planned to be incorporated into the U.S. Geological Survey StreamStats program. StreamStats is a Web-based geographic information system that provides users with access to an assortment of analytical tools useful for water-resources planning and management, and for engineering design applications, such as the design of bridges. The StreamStats program provides streamflow statistics and basin characteristics for U.S. Geological Survey streamgage locations and ungaged sites of interest. StreamStats also can compute basin characteristics and provide estimates of streamflow statistics for ungaged sites when users select the location of a site along any stream in Georgia.

Technical report on prototype intelligent network flow optimization (INFLO) dynamic speed harmonization and queue warning.

DOT National Transportation Integrated Search

2015-06-01

This Technical Report on Prototype Intelligent Network Flow Optimization (INFLO) Dynamic Speed Harmonization and Queue Warning is the final report for the project. It describes the prototyping, acceptance testing and small-scale demonstration of the ...

Motor Flow Instabilities - Part 1

DTIC Science & Technology

2004-01-01

by the flow, the structure motions (as possibly affecting the mean and unsteady flows). Finally, the model should be able: a) to propagate the...combustion responses function determinations, Dedicated models for combustion mechanisms and fluid- structure couplings, Dedicated and documented test...associated with these large motors (recall that f1L ≈ a/2L) rendered such oscillations undesirable since they were able to couple to the structural modes

Geostrophic adjustment in a shallow-water numerical model as it relates to thermospheric dynamics

NASA Technical Reports Server (NTRS)

Larsen, M. F.; Mikkelsen, I. S.

1986-01-01

The theory of geostrophic adjustment and its application to the dynamics of the high latitude thermosphere have been discussed in previous papers based on a linearized treatment of the fluid dynamical equations. However, a linearized treatment is only valid for small Rossby numbers given by Ro = V/fL, where V is the wind speed, f is the local value of the Coriolis parameter, and L is a characteristic horizontal scale for the flow. For typical values in the auroral zone, the approximation is not reasonable for wind speeds greater than 25 m/s or so. A shallow-water (one layer) model was developed that includes the spherical geometry and full nonlinear dynamics in the momentum equations in order to isolate the effects of the nonlinearities on the adjustment process. A belt of accelerated winds between 60 deg and 70 deg latitude was used as the initial condition. The adjustment process was found to proceed as expected from the linear formulation, but that an asymmetry between the response for an eastward and westward flow results from the nonlineawr curvature (centrifugal) terms. In general, the amplitude of an eastward flowing wind will be less after adjustment than a westward wind. For instance, if the initial wind velocity is 300 m/s, the linearized theory predicts a final wind speed of 240 m/s, regardless of the flow direction. However, the nonlinear curvature terms modify the response and produce a final wind speed of only 200 m/s for an initial eastward wind and a final wind speed of almost 300 m/s for an initial westward flow direction. Also, less gravity wave energy is produced by the adjustment of the westward flow than by the adjustment of the eastward flow. The implications are that the response of the thermosphere should be significantly different on the dawn and dusk sides of the auroral oval. Larger flow velocities would be expected on the dusk side since the plasma will accelerate the flow in a westward direction in that sector.

Study of the fluid flow characteristics in a porous medium for CO2 geological storage using MRI.

PubMed

Song, Yongchen; Jiang, Lanlan; Liu, Yu; Yang, Mingjun; Zhou, Xinhuan; Zhao, Yuechao; Dou, Binlin; Abudula, Abuliti; Xue, Ziqiu

2014-06-01

The objective of this study was to understand fluid flow in porous media. Understanding of fluid flow process in porous media is important for the geological storage of CO2. The high-resolution magnetic resonance imaging (MRI) technique was used to measure fluid flow in a porous medium (glass beads BZ-02). First, the permeability was obtained from velocity images. Next, CO2-water immiscible displacement experiments using different flow rates were investigated. Three stages were obtained from the MR intensity plot. With increasing CO2 flow rate, a relatively uniform CO2 distribution and a uniform CO2 front were observed. Subsequently, the final water saturation decreased. Using core analysis methods, the CO2 velocities were obtained during the CO2-water immiscible displacement process, which were applied to evaluate the capillary dispersion rate, viscous dominated fractional flow, and gravity flow function. The capillary dispersion rate dominated the effects of capillary, which was largest at water saturations of 0.5 and 0.6. The viscous-dominant fractional flow function varied with the saturation of water. The gravity fractional flow reached peak values at the saturation of 0.6. The gravity forces played a positive role in the downward displacements because they thus tended to stabilize the displacement process, thereby producing increased breakthrough times and correspondingly high recoveries. Finally, the relative permeability was also reconstructed. The study provides useful data regarding the transport processes in the geological storage of CO2. Crown Copyright © 2014. Published by Elsevier Inc. All rights reserved.

Computation of subsonic flow around airfoil systems with multiple separation

NASA Technical Reports Server (NTRS)

Jacob, K.

1982-01-01

A numerical method for computing the subsonic flow around multi-element airfoil systems was developed, allowing for flow separation at one or more elements. Besides multiple rear separation also sort bubbles on the upper surface and cove bubbles can approximately be taken into account. Also, compressibility effects for pure subsonic flow are approximately accounted for. After presentation the method is applied to several examples and improved in some details. Finally, the present limitations and desirable extensions are discussed.

Flow Field Investigations of a Simulated Weapons Cavity at Mach 3.

DTIC Science & Technology

1981-12-01

AD-Alll 843 ARMO" ENGINEERING. DEVELOPMENT CENTER ARNOLD AFS TN F/9 14/2 FLOW FIELD INVESTIGATIONS OF A SIMULATED WEAPONS CAVITY AT MACN--ETC(U) DEC...TEST CHART .. AEDC-TSR-81-V37 FLOW FIELD INVESTIGATIONS OF A _____SIMULATED WEAPONS CAVITY AT MACH 3 _~W. A. Crosby Calspan Field Services, Inc...TYPE OF REPORT & PERIOD COVERED Final Report FLOW FIELD INVESTIGATIONS OF A SIMULATED WEAPONS 27 October 1981 CAVITY AT MACH 3 6. PERFORMING O1G

Monitoring winter flow conditions on the Ivishak River, Alaska : final report.

DOT National Transportation Integrated Search

2017-09-01

The Sagavanirktok River, a braided river on the Alaska North Slope, flows adjacent to the trans-Alaska pipeline for approximately 100 miles south of Prudhoe Bay. During an unprecedented flooding event in mid-May 2015, the pipeline was exposed in an a...

Synthesis of carbohydrates in a continuous flow reactor by immobilized phosphatase and aldolase.

PubMed

Babich, Lara; Hartog, Aloysius F; van Hemert, Lieke J C; Rutjes, Floris P J T; Wever, Ron

2012-12-01

Herein, we report a new flow process with immobilized enzymes to synthesize complex chiral carbohydrate analogues from achiral inexpensive building blocks in a three-step cascade reaction. The first reactor contained immobilized acid phosphatase, which phosphorylated dihydroxyacetone to dihydroxyacetone phosphate using pyrophosphate as the phosphate donor. The second flow reactor contained fructose-1,6-diphosphate aldolase (RAMA, rabbit muscle aldolase) or rhamnulose-1-phosphate aldolase (RhuA from Thermotoga maritima) and acid phosphatase. The immobilized aldolases coupled the formed dihydroxyacetone phosphate to aldehydes, resulting in phosphorylated carbohydrates. A final reactor containing acid phosphatase that dephosphorylated the phosphorylated product yielded the final product. Different aldehydes were used to synthesize carbohydrates on a gram scale. To demonstrate the feasibility of the flow systems, we synthesized 0.6 g of the D-fagomine precursor. By using immobilized aldolase RhuA we were also able to obtain other stereoisomers of the D-fagomine precursor. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

A network analysis of indirect carbon emission flows among different industries in China.

PubMed

Du, Qiang; Xu, Yadan; Wu, Min; Sun, Qiang; Bai, Libiao; Yu, Ming

2018-06-17

Indirect carbon emissions account for a large ratio of the total carbon emissions in processes to make the final products, and this implies indirect carbon emission flow across industries. Understanding these flows is crucial for allocating a carbon allowance for each industry. By combining input-output analysis and complex network theory, this study establishes an indirect carbon emission flow network (ICEFN) for 41 industries from 2005 to 2014 to investigate the interrelationships among different industries. The results show that the ICEFN was consistent with a small-world nature based on an analysis of the average path lengths and the clustering coefficients. Moreover, key industries in the ICEFN were identified using complex network theory on the basis of degree centrality and betweenness centrality. Furthermore, the 41 industries of the ICEFN were divided into four industrial subgroups that are related closely to one another. Finally, possible policy implications were provided based on the knowledge of the structure of the ICEFN and its trend.

Breakup of a thin drop under a stagnation point flow

NASA Astrophysics Data System (ADS)

Hooshanginejad, Alireza; Lee, Sungyon; Shelley, Michael

2017-11-01

Recent studies by Hooshanginejad and Lee (2017) have demonstrated complex depinning behaviors of a partially wetting droplet under wind. Motivated by this study, we examine the coupled evolution of a 2D thin drop and external wind, when it is initially held against a fast stagnation point flow. Our drop lubrication model employs the potential flow and Prandtl boundary layer theory for outer flow to compute the internal drop flow corresponding to drop deformations. Furthermore, both the analytical and numerical steady state solutions provide a partial prediction for the drop's final shape and help identify the range of droplet sizes that undergo a breakup for the given flow condition.

Impacts of moving bottlenecks on traffic flow

NASA Astrophysics Data System (ADS)

Ou, Hui; Tang, Tie-Qiao

2018-06-01

Bottleneck (especially the moving bottleneck) widely exists in the urban traffic system. However, little effort has been made to study the impacts of the moving bottleneck on traffic flow (especially the evolution and propagation of traffic flow). In this article, we introduce the speed of a moving bottleneck into a traffic flow model, then propose an extended macro traffic flow with a moving bottleneck, and finally use the proposed model to study the effects of a moving bottleneck on the evolution and propagation of traffic flow under uniform flow and a small perturbation. The numerical results indicate that the moving bottleneck has prominent influences on the evolution of traffic flow under the two typical traffic situations and that the impacts are dependent on the initial density.

The fluid dynamics of the chocolate fountain

NASA Astrophysics Data System (ADS)

Townsend, Adam K.; Wilson, Helen J.

2016-01-01

We consider the fluid dynamics of the chocolate fountain. Molten chocolate is a mildly shear-thinning non-Newtonian fluid. Dividing the flow into three main domains—the pumped flow up the centre, the film flow over each dome, and the freely falling curtain flow between the domes—we generate a wide-ranging study of Newtonian and non-Newtonian fluid mechanics. The central pumped flow is a benchmark to elucidate the effects of shear-thinning. The dome flow can be modelled as a thin-film flow with the leading-order effects being a simple balance of gravity and viscosity. Finally, the curtain flow is analytically intractable but is related to the existing theory of water bells (both inviscid and viscous). In pipe flow, Newtonian fluids exhibit a parabolic velocity profile; shear-thinning makes the profile more blunted. In thin-film flow over the dome, gravitational and viscous effects balance and the dome shape is not important beyond the local slope. We find that the chocolate thins and slows down as it travels down the dome. Finally, in the curtain flow, we predict the shape of the falling sheet for an inviscid fluid, and compare this with the literature to predict the shape for a viscous fluid, having shown that viscous forces are too great to ignore. We also find that the primary effect driving the shape of the curtain (which falls inwards towards the axis of the fountain) is surface tension. We find that the three domains provide excellent introductions to non-Newtonian mechanics, the important mathematical technique of scaling, and how to manipulate existing data to make our own predictions. We also find that the topic generates interest among the public in our engagement work.

Comparison of Endobronchial and Tracheal Insufflation for Acute Respiratory Distress

DTIC Science & Technology

1990-03-14

normocapnia at a mean flow in dogs of 0.48 + 0.21 L/sec, which is approximately 29 L/min. There was no relationship between body weight and the flow required...0, 0 EE X +1 (𔃾e 0 .O * (’ 3 C, 5 00 uU 0 a- L Io ton 4)0 00 0 0 E 07 o r ( n p E0 56 VETERINARY PATOLOGY FINAL REPORT UNIVERSITYOr M ARYLAND SCHOOL...Comparative Medicine 68 Y7TERInRY PATOLOGY FINAL REPORT UNIVERSITY Or MARYLAND SC2OL OF HADICINE VITBRXINRY RUZOURCZ18 Accession Mo.: 89-992 Date Submitted

Surface tension effects on fully developed liquid layer flow over a convex corner

NASA Astrophysics Data System (ADS)

Bhatti, Ifrah; Farid, Saadia; Ullah, Saif; Riaz, Samia; Faryad, Maimoona

2018-04-01

This investigation deals with the study of fully developed liquid layer flow along with surface tension effects, confronting a convex corner in the direction of fluid flow. At the point of interaction, the related equations are formulated using double deck structure and match asymptotic techniques. Linearized solutions for small angle are obtained analytically. The solutions corresponding to similar flow neglecting surface tension effects are also recovered as special case of our general solutions. Finally, the influence of pertinent parameters on the flow, as well as a comparison between models, are shown by graphical illustration.

Acoustic tests of a 15.2 centimeter-diameter potential flow convergent nozzle

NASA Technical Reports Server (NTRS)

Karchmer, A. M.; Dorsch, R. G.; Friedman, R.

1974-01-01

An experimental investigation of the jet noise radiated to the far field from a 15.2-cm-diam potential flow convergent nozzle has been conducted. Tests were made with unheated airflow over a range of subsonic nozzle exhaust velocities from 62 to 310m/sec. Mean and turbulent velocity measurements in the flow field of the nozzle exhaust indicated no apparent flow anomalies. Acoustic measurements yielded data uncontaminated by internal and/or background noise to velocities as low as 152m/sec. Finally, no significantly different acoustic characteristics between the potential flow nozzle and simple convergent nozzles were found.

Resonance and streaming of armored microbubbles

NASA Astrophysics Data System (ADS)

Spelman, Tamsin; Bertin, Nicolas; Stephen, Olivier; Marmottant, Philippe; Lauga, Eric

2015-11-01

A new experimental technique involves building a hollow capsule which partially encompasses a microbubble, creating an ``armored microbubble'' with long lifespan. Under acoustic actuation, such bubble produces net streaming flows. In order to theoretically model the induced flow, we first extend classical models of free bubbles to describe the streaming flow around a spherical body for any known axisymmetric shape oscillation. A potential flow model is then employed to determine the resonance modes of the armored microbubble. We finally use a more detailed viscous model to calculate the surface shape oscillations at the experimental driving frequency, and from this we predict the generated streaming flows.

Study of Natural Fiber Breakage during Composite Processing

NASA Astrophysics Data System (ADS)

Quijano-Solis, Carlos Jafet

Biofiber-thermoplastic composites have gained considerable importance in the last century. To provide mechanical reinforcement to the polymer, fibers must be larger than a critical aspect ratio (length-to-width ratio). However, biofibers undergo breakage in length or width during processing, affecting their final aspect ratio in the composites. In this study, influence on biofiber breakage by factors related to processing conditions, fiber morphology and the flow type was investigated through: a) experiments using an internal mixer, a twin-screw extruder (TSE) or a capillary rheometer; and b) a Monte Carlo computer simulation. Composites of thermomechanical fibers of aspen or wheat straw mixed with polypropylene were studied. Internal mixer experiments analyzed wheat straw and two batches of aspen fibers, named AL and AS. AL fibers had longer average length. Processing variables included the temperature, rotors speed and fiber concentration. TSE experiments studied AL and AS fiber composites under various screws speeds, temperatures and feeding rates of the polymer and fibers. Capillary rheometers experiments determined AL fiber breakage in shear and elongational flows for composites processed at different concentrations, temperatures, and strain rates. Finally, the internal mixer experimental results where compared to Monte Carlo simulation predictions. The simulation focused on fiber length breakage due to fiber-polymer interactions. Internal mixer results showed that final fiber average length depended almost solely on processing conditions while final fiber average width depended on both processing conditions and initial fiber morphology. In the TSE, processing conditions as well as initial fiber length influenced final average length. TSE results showed that the fiber concentration regime seems to influence the effect of processing variables on fiber breakage. Capillary rheometer experiments demonstrated that biofiber breakage happens in both elongational and shear flows. In some cases, percentage of biofiber breakage in elongational flow is higher. In general, simulation predictions of final average lengths were in good agreement with experiments, indicating the importance of fiber-polymer interactions on fiber breakage. The largest discrepancies were obtained at higher fiber concentration composites; these differences might be resolved, in future simulations, by including the effect of fiber-fiber interactions.

The freight landscape : using secondary data sources to describe metropolitan freight flows : final report.

DOT National Transportation Integrated Search

2015-12-01

Metropolitan areas around the world are seeking to better manage freight flows and reduce negative impacts on local populations. A major challenge to better urban freight management is the lack of data; little is known about freight movements at the ...

A Novel Approach to Adaptive Flow Separation Control

DTIC Science & Technology

2016-09-03

particular, it considers control of flow separation over a NACA-0025 airfoil using microjet actuators and develops Adaptive Sampling Based Model...Predictive Control ( Adaptive SBMPC), a novel approach to Nonlinear Model Predictive Control that applies the Minimal Resource Allocation Network...Distribution Unlimited UU UU UU UU 03-09-2016 1-May-2013 30-Apr-2016 Final Report: A Novel Approach to Adaptive Flow Separation Control The views, opinions

Numerical Simulation of High-Speed Turbulent Reacting Flows

NASA Technical Reports Server (NTRS)

Givi, P.; Taulbee, D. B.; Madnia, C. K.; Jaberi, F. A.; Colucci, P. J.; Gicquel, L. Y. M.; Adumitroaie, V.; James, S.

1999-01-01

The objectives of this research are: (1) to develop and implement a new methodology for large eddy simulation of (LES) of high-speed reacting turbulent flows. (2) To develop algebraic turbulence closures for statistical description of chemically reacting turbulent flows. We have just completed the third year of Phase III of this research. This is the Final Report of our activities on this research sponsored by the NASA LaRC.

CFD Analysis in Advance of the NASA Juncture Flow Experiment

NASA Technical Reports Server (NTRS)

Lee, H. C.; Pulliam, T. H.; Neuhart, D. H.; Kegerise, M. A.

2017-01-01

NASA through its Transformational Tools and Technologies Project (TTT) under the Advanced Air Vehicle Program, is supporting a substantial effort to investigate the formation and origin of separation bubbles found on wing-body juncture zones. The flow behavior in these regions is highly complex, difficult to measure experimentally, and challenging to model numerically. Multiple wing configurations were designed and evaluated using Computational Fluid Dynamics (CFD), and a series of wind tunnel risk reduction tests were performed to further down-select the candidates for the final experiment. This paper documents the CFD analysis done in conjunction with the 6 percent scale risk reduction experiment performed in NASA Langley's 14- by 22-Foot Subsonic Tunnel. The combined CFD and wind tunnel results ultimately helped the Juncture Flow committee select the wing configurations for the final experiment.

Unsteady flow of fractional Oldroyd-B fluids through rotating annulus

NASA Astrophysics Data System (ADS)

Tahir, Madeeha; Naeem, Muhammad Nawaz; Javaid, Maria; Younas, Muhammad; Imran, Muhammad; Sadiq, Naeem; Safdar, Rabia

2018-04-01

In this paper exact solutions corresponding to the rotational flow of a fractional Oldroyd-B fluid, in an annulus, are determined by applying integral transforms. The fluid starts moving after t = 0+ when pipes start rotating about their axis. The final solutions are presented in the form of usual Bessel and hypergeometric functions, true for initial and boundary conditions. The limiting cases for the solutions for ordinary Oldroyd-B, fractional Maxwell and Maxwell and Newtonian fluids are obtained. Moreover, the solution is obtained for the fluid when one pipe is rotating and the other one is at rest. At the end of this paper some characteristics of fluid motion, the effect of the physical parameters on the flow and a correlation between different fluid models are discussed. Finally, graphical representations confirm the above affirmation.

Numerical method for predicting flow characteristics and performance of nonaxisymmetric nozzles. Part 2: Applications

NASA Technical Reports Server (NTRS)

Thomas, P. D.

1980-01-01

A computer implemented numerical method for predicting the flow in and about an isolated three dimensional jet exhaust nozzle is summarized. The approach is based on an implicit numerical method to solve the unsteady Navier-Stokes equations in a boundary conforming curvilinear coordinate system. Recent improvements to the original numerical algorithm are summarized. Equations are given for evaluating nozzle thrust and discharge coefficient in terms of computed flowfield data. The final formulation of models that are used to simulate flow turbulence effect is presented. Results are presented from numerical experiments to explore the effect of various quantities on the rate of convergence to steady state and on the final flowfield solution. Detailed flowfield predictions for several two and three dimensional nozzle configurations are presented and compared with wind tunnel experimental data.

Turbulence and transition modeling for high-speed flows

NASA Technical Reports Server (NTRS)

Wilcox, David C.

1993-01-01

Research conducted during the past three and a half years aimed at developing and testing a turbulence/transition model applicable to high-speed turbulent flows is summarized. The first two years of the project focused on fully turbulent flows, while emphasis shifted to boundary-layer development in the transition region during the final year and a half. A brief summary of research accomplished during the first three years is included and publications that describe research results in greater detail are cited. Research conducted during the final six months of the period of performance is summarized. The primary results of the last six months of the project are elimination of the k-omega model's sensitivity to the freestream value of omega and development of a method for triggering transition at a specified location, independent of the freestream turbulence level.

Association between edoxaban dose, concentration, anti-Factor Xa activity, and outcomes: an analysis of data from the randomised, double-blind ENGAGE AF-TIMI 48 trial.

PubMed

Ruff, Christian T; Giugliano, Robert P; Braunwald, Eugene; Morrow, David A; Murphy, Sabina A; Kuder, Julia F; Deenadayalu, Naveen; Jarolim, Petr; Betcher, Joshua; Shi, Minggao; Brown, Karen; Patel, Indravadan; Mercuri, Michele; Antman, Elliott M

2015-06-06

New oral anticoagulants for stroke prevention in atrial fibrillation were developed to be given in fixed doses without the need for the routine monitoring that has hindered usage and acceptance of vitamin K antagonists. A concern has emerged, however, that measurement of drug concentration or anticoagulant activity might be needed to prevent excess drug concentrations, which significantly increase bleeding risk. In the ENGAGE AF-TIMI 48 trial, higher-dose and lower-dose edoxaban were compared with warfarin in patients with atrial fibrillation. Each regimen incorporated a 50% dose reduction in patients with clinical features known to increase edoxaban drug exposure. We aim to assess whether adjustment of edoxaban dose in this trial prevented excess drug concentration and the risk of bleeding events. We analysed data from the randomised, double-blind ENGAGE AF-TIMI 48 trial. We correlated edoxaban dose, plasma concentration, and anti-Factor Xa (FXa) activity and compared efficacy and safety outcomes with warfarin stratified by dose reduction status. Patients with atrial fibrillation and at moderate to high risk of stroke were randomly assigned in a 1:1:1 ratio to receive warfarin, dose adjusted to an international normalised ratio of 2·0-3·0, higher-dose edoxaban (60 mg once daily), or lower-dose edoxaban (30 mg once daily). Randomisation was done with use of a central, 24 h, interactive, computerised response system. International normalised ratio was measured using an encrypted point-of-care device. To maintain masking, sham international normalised ratio values were generated for patients assigned to edoxaban. Edoxaban (or placebo-edoxaban in warfarin group) doses were halved at randomisation or during the trial if patients had creatinine clearance 30-50 mL/min, bodyweight 60 kg or less, or concomitant medication with potent P-glycoprotein interaction. Efficacy outcomes included the primary endpoint of all-cause stroke or systemic embolism, ischaemic stroke, and all-cause mortality. Safety outcomes included the primary safety endpoint of major bleeding, fatal bleeding, intracranial haemorrhage, and gastrointestinal bleeding. This trial is registered with ClinicalTrials.gov, number NCT00781391. Between Nov 19, 2008 and Nov 22, 2010, 21 105 patients were recruited. Patients who met clinical criteria for dose reduction at randomisation (n=5356) had higher rates of stroke, bleeding, and death compared with those who did not have a dose reduction (n=15 749). Edoxaban dose ranged from 15 mg to 60 mg, resulting in a two-fold to three fold gradient of mean trough drug exposure (16·0-48·5 ng/mL in 6780 patients with data available) and mean trough anti-FXa activity (0·35-0·85 IU/mL in 2865 patients). Dose reduction decreased mean exposure by 29% (from 48·5 ng/mL [SD 45·8] to 34·6 ng/mL [30·9]) and 35% (from 24·5 ng/mL [22·7] to 16·0 ng/mL [14·5]) and mean anti-FXa activity by 25% (from 0·85 IU/mL [0·76] to 0·64 IU/mL [0·54]) and 20% (from 0·44 IU/mL [0·37] to 0·35 IU/mL [0·28]) in the higher-dose and lower-dose regimens, respectively. Despite the lower anti-FXa activity, dose reduction preserved the efficacy of edoxaban compared with warfarin (stroke or systemic embolic event: higher dose pinteraction=0·85, lower dose pinteraction=0·99) and provided even greater safety (major bleeding: higher dose pinteraction 0·02, lower dose pinteraction=0·002). These findings validate the strategy that tailoring of the dose of edoxaban on the basis of clinical factors alone achieves the dual goal of preventing excess drug concentrations and helps to optimise an individual patient's risk of ischaemic and bleeding events and show that the therapeutic window for edoxaban is narrower for major bleeding than thromboembolism. Daiichi-Sankyo Pharma Development. Copyright © 2015 Elsevier Ltd. All rights reserved.

Final Report for Geometric Observers and Particle Filtering for Controlled Active Vision

DTIC Science & Technology

2016-12-15

code) 15-12-2016 Final Report 01Sep06 - 09May11 Final Report for Geometric Observers & Particle Filtering for Controlled Active Vision 49414-NS.1Allen...Observers and Particle Filtering for Controlled Active Vision by Allen R. Tannenbaum School of Electrical and Computer Engineering Georgia Institute of...7 2.2.4 Conformal Area Minimizing Flows . . . . . . . . . . . . . . . . . . . . . . . 8 2.3 Particle Filters

Turbulent Boundary Layer on a Cylinder in Axial Flow

DTIC Science & Technology

1988-09-29

finding the wall shea stress. Finally, ft ;hould be noted that the wall shear stress can be found from the streamwrwise gradient of the mornsntum...somewhat butter collapse than inner scaling, suggesting that the outer flow affects events at the wall. By comparison, the burst frequency in a planar

75 FR 21651 - Final Environmental Impact Statement; Prisoners Harbor Coastal Wetland Restoration Plan, Channel...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-04-26

... after further consultation with the State Historic Preservation Office, the scale house would be... to stream flow erosion in Canada del Puerto by placement of a small earth, log, and cobble berm... visitor experience, historical resources, marine resources, vegetation removal, flood flows, and best...

Two-dimensional motion of Brownian swimmers in linear flows.

PubMed

Sandoval, Mario; Jimenez, Alonso

2016-03-01

The motion of viruses and bacteria and even synthetic microswimmers can be affected by thermal fluctuations and by external flows. In this work, we study the effect of linear external flows and thermal fluctuations on the diffusion of those swimmers modeled as spherical active (self-propelled) particles moving in two dimensions. General formulae for their mean-square displacement under a general linear flow are presented. We also provide, at short and long times, explicit expressions for the mean-square displacement of a swimmer immersed in three canonical flows, namely, solid-body rotation, shear and extensional flows. These expressions can now be used to estimate the effect of external flows on the displacement of Brownian microswimmers. Finally, our theoretical results are validated by using Brownian dynamics simulations.

Methods and results of peak-flow frequency analyses for streamgages in and bordering Minnesota, through water year 2011

USGS Publications Warehouse

Kessler, Erich W.; Lorenz, David L.; Sanocki, Christopher A.

2013-01-01

Peak-flow frequency analyses were completed for 409 streamgages in and bordering Minnesota having at least 10 systematic peak flows through water year 2011. Selected annual exceedance probabilities were determined by fitting a log-Pearson type III probability distribution to the recorded annual peak flows. A detailed explanation of the methods that were used to determine the annual exceedance probabilities, the historical period, acceptable low outliers, and analysis method for each streamgage are presented. The final results of the analyses are presented.

Assessment of nonequilibrium radiation computation methods for hypersonic flows

NASA Technical Reports Server (NTRS)

Sharma, Surendra

1993-01-01

The present understanding of shock-layer radiation in the low density regime, as appropriate to hypersonic vehicles, is surveyed. Based on the relative importance of electron excitation and radiation transport, the hypersonic flows are divided into three groups: weakly ionized, moderately ionized, and highly ionized flows. In the light of this division, the existing laboratory and flight data are scrutinized. Finally, an assessment of the nonequilibrium radiation computation methods for the three regimes in hypersonic flows is presented. The assessment is conducted by comparing experimental data against the values predicted by the physical model.

Study of the Transition Flow Regime using Monte Carlo Methods

NASA Technical Reports Server (NTRS)

Hassan, H. A.

1999-01-01

This NASA Cooperative Agreement presents a study of the Transition Flow Regime Using Monte Carlo Methods. The topics included in this final report are: 1) New Direct Simulation Monte Carlo (DSMC) procedures; 2) The DS3W and DS2A Programs; 3) Papers presented; 4) Miscellaneous Applications and Program Modifications; 5) Solution of Transitional Wake Flows at Mach 10; and 6) Turbulence Modeling of Shock-Dominated Fows with a k-Enstrophy Formulation.

The Design and Implementation of a Data Flow Multiprocessor.

DTIC Science & Technology

1981-12-01

to thank Captain Charles Papp who taught me how to use the logic analyzer and the storage oscilloscope. Without these tools, I could never have...debugged and repaired the microprocessors. Finally, I wish to thank my thesis readers, Major Charles Lillie and Major Walt Seward, for taking valuable time...Neumann/ Babbage architecture with the a data flow architecture. The next section describes the benefits of data flow computing. The following section

Pre-equilibrium Longitudinal Flow in the IP-Glasma Framework for Pb+Pb Collisions at the LHC

NASA Astrophysics Data System (ADS)

McDonald, Scott; Shen, Chun; Fillion-Gourdeau, François; Jeon, Sangyong; Gale, Charles

2017-08-01

In this work, we debut a new implementation of IP-Glasma and quantify the pre-equilibrium longitudinal flow in the IP-Glasma framework. The saturation physics based IP-Glasma model naturally provides a non-zero initial longitudinal flow through its pre-equilibrium Yang-Mills evolution. A hybrid IP-Glasma+MUSIC+UrQMD frame-work is employed to test this new implementation against experimental data and to make further predictions about hadronic flow observables in Pb+Pb collisions at 5.02 TeV. Finally, the non-zero pre-equilibrium longitudinal flow of the IP-Glasma model is quantified, and its origin is briefly discussed.

Ultrasonic Doppler measurement of renal artery blood flow

NASA Technical Reports Server (NTRS)

Freund, W. R.; Beaver, W. L.; Meindl, J. D.

1976-01-01

Studies were made of (1) blood flow redistribution during lower body negative pressure (LBNP), (2) the profile of blood flow across the mitral annulus of the heart (both perpendicular and parallel to the commissures), (3) testing and evaluation of a number of pulsed Doppler systems, (4) acute calibration of perivascular Doppler transducers, (5) redesign of the mitral flow transducers to improve reliability and ease of construction, and (6) a frequency offset generator designed for use in distinguishing forward and reverse components of blood flow by producing frequencies above and below the offset frequency. Finally methodology was developed and initial results were obtained from a computer analysis of time-varying Doppler spectra.

Poiseuille flow of soft glasses in narrow channels: from quiescence to steady state.

PubMed

Chaudhuri, Pinaki; Horbach, Jürgen

2014-10-01

Using numerical simulations, the onset of Poiseuille flow in a confined soft glass is investigated. Starting from the quiescent state, steady flow sets in at a time scale which increases with a decrease in applied forcing. At this onset time scale, a rapid transition occurs via the simultaneous fluidization of regions having different local stresses. In the absence of steady flow at long times, creep is observed even in regions where the local stress is larger than the bulk yielding threshold. Finally, we show that the time scale to attain steady flow depends strongly on the history of the initial state.

Use DNA solutions to model polymer entanglement in flow: simultaneous rheometric and particle-tracking velocimetric measurements

NASA Astrophysics Data System (ADS)

Boukany, Pouyan; Wang, Shi-Qing

2008-03-01

Entangled aqueous DNA solutions are ideal as a model system to examine nonlinear flow features including stress overshoot in startup shear and shear thinning phenomenon. These soft systems can be strongly entangled with 60 entanglement points per chain and a terminal relaxation time as long as 1000 s at 1 % concentration [1-2]. They allow a comparison between the steady state attained with a startup shear and that attained through an ``infinitely'' slow ramping up of the applied shear rate. Indeed, startup shear in the nonlinear (stress plateau) region causes the DNA solutions to yield inhomogeneously, resulting in permanent shear banding. However, the slowly ramped-up shear into the same final rate as applied in startup shear allowed the solutions to avoid shear inhomogeneity. Thus, we demonstrated that it is possible for the final steady states to be different depending on how an entangled system is brought into the same final experimental condition. This result implies that it is ill-defined to pursue conventional constitutive relationship in flow of entangled polymers. [1] Boukany, P. E.; Hu, T. H.; Wang, S. Q. textitMacromolecules 2007, under review. [2] Boukany, P. E.; Wang, S. Q. J. Rheol. 2007, under review.

Effects of Gravity on Cocurrent Two-Phase Gas-Liquid Flows Through Packed Columns

NASA Technical Reports Server (NTRS)

Motil, Brian J.; Balakotaiah, Vemuri; Kamotani, Yasuhiro

2001-01-01

This work presents the experimental results of research on the influence of gravity on flow pattern transitions, pressure drop and flow characteristics for cocurrent gas-liquid two-phase flow through packed columns. The flow pattern transition data indicates that the pulse flow regime exists over a wider range of gas and liquid flow rates under reduced gravity conditions compared to normal gravity cocurrent down-flow. This is illustrated by comparing the flow regime transitions found in reduced gravity with the transitions predicted by Talmor. Next, the effect of gravity on the total pressure drop in a packed column is shown to depend on the flow regime. The difference is roughly equivalent to the liquid static head for bubbly flow but begins to decrease at the onset of pulse flow. As the spray flow regime is approached by increasing the gas to liquid ratio, the effect of gravity on pressure drop becomes negligible. Finally, gravity tends to suppress the amplitude of each pressure pulse. An example of this phenomenon is presented.

Children acceptance of laser dental treatment

NASA Astrophysics Data System (ADS)

Lazea, Andreea; Todea, Carmen

2016-03-01

Objectives: To evaluate the dental anxiety level and the degree of acceptance of laser assisted pedodontic treatments from the children part. Also, we want to underline the advantages of laser use in pediatric dentistry, to make this technology widely used in treating dental problems of our children patients. Methods: Thirty pediatric dental patients presented in the Department of Pedodontics, University of Medicine and Pharmacy "Victor Babeş", Timişoara were evaluated using the Wong-Baker pain rating scale, wich was administered postoperatory to all patients, to assess their level of laser therapy acceptance. Results: Wong-Baker faces pain rating scale (WBFPS) has good validity and high specificity; generally it's easy for children to use, easy to compare and has good feasibility. Laser treatment has been accepted and tolerated by pediatric patients for its ability to reduce or eliminate pain. Around 70% of the total sample showed an excellent acceptance of laser dental treatment. Conclusions: Laser technology is useful and effective in many clinical situations encountered in pediatric dentistry and a good level of pacient acceptance is reported during all laser procedures on hard and soft tissues.

Low level arsenic contaminated water consumption and birth outcomes in Romania - an exploratory study

PubMed Central

Bloom, Michael S.; Neamtiu, Iulia A.; Surdu, Simona; Pop, Cristian; Anastasiu, Doru; Appleton, Allison A.; Fitzgerald, Edward F.; Gurzau, Eugen S.

2015-01-01

Women are exposed to drinking water with low arsenic concentrations (<10.0 μg/L) worldwide, yet little work has been done to assess the risk. To begin to address this data gap, we conducted an exploratory study of birth outcomes in Timis County, Romania. We prospectively followed 122 women with singleton deliveries, for whom we constructed individual exposure indicators using self-reported water consumption weighted by arsenic measured in drinking water sources. There were no overall confounder-adjusted effects for arsenic exposure on birth outcomes. Yet, higher average arsenic (10 μg/L) was associated with a −2.45 lower birth weight Z-score (P=0.021) and a −1.17 shorter birth length Z-score (P=0.029) among smokers. Higher average iAs (10 μg/L) was also associated with smaller ponderal index in boys (P=0.023). Our results suggest smoking may potentiate an otherwise benign arsenic exposure. A larger, more definitive biomarker-based study is needed to investigate the potential risks in conjunction with smoking. PMID:26518419

Effects of crude oil on the feeding behaviour of the zoanthid Palythoa variabilis.

PubMed

Reimer, A A

1975-01-01

Palythoa variabilis (Duerden 1898) has a well-coordinated, sterotyped feeding response similar to that described for other zoanthids. The feeding reaction can be elicited by the heterocyclic amino acid proline and by some of its analogs. The addition of an OH group (hydroxyproline) or of a glycyl group (prolylglycine) annuls the activity of the proline molecule. Substitutions (thiazolidine-4-carboxylic acid) or additions (glycylproline) to the amino group do not alter the effectivity of the activator. The size of the ring can be altered within certain limits (azetidine-2-carbocylic acid and pipecolic acid) without affecting the activity of the molecule. Feeding reactions culminating with ingestion can be elicited by Marine Diesel and Bunker-C oils. Exposure to oil affects the ability of polyps to discriminate between inert and chemically active particles for 3 to 5 days; responses to proline are not altered for at least 3 days following the exposure, but become slower and are present in fewer polyps after that period. Oil is retained in the coelenteron for several days following exposure and is periodically released in the form of timy droplets.

Hydrodynamic Flow Fluctuations in √sNN = 5:02 TeV PbPbCollisions

NASA Astrophysics Data System (ADS)

Castle, James R.

The collective, anisotropic expansion of the medium created in ultrarelativistic heavy-ion collisions, known as flow, is characterized through a Fourier expansion of the final-state azimuthal particle density. In the Fourier expansion, flow harmonic coefficients vn correspond to shape components in the final-state particle density, which are a consequence of similar spatial anisotropies in the initial-state transverse energy density of a collision. Flow harmonic fluctuations are studied for PbPb collisions at √sNN = 5.02 TeV using the CMS detector at the CERN LHC. Flow harmonic probability distributions p( vn) are obtained using particles with 0.3 < pT < 3.0 GeV/c and ∥eta∥ < 1.0 by removing finite-multiplicity resolution effects from the observed azimuthal particle density through an unfolding procedure. Cumulant elliptic flow harmonics (n = 2) are determined from the moments of the unfolded p(v2) distributions and used to construct observables in 5% wide centrality bins up to 60% that relate to the initial-state spatial anisotropy. Hydrodynamic models predict that fluctuations in the initial-state transverse energy density will lead to a non-Gaussian component in the elliptic flow probability distributions that manifests as a negative skewness. A statistically significant negative skewness is observed for all centrality bins as evidenced by a splitting between the higher-order cumulant elliptic flow harmonics. The unfolded p (v2) distributions are transformed assuming a linear relationship between the initial-state spatial anisotropy and final-state flow and are fitted with elliptic power law and Bessel Gaussian parametrizations to infer information on the nature of initial-state fluctuations. The elliptic power law parametrization is found to provide a more accurate description of the fluctuations than the Bessel-Gaussian parametrization. In addition, the event-shape engineering technique, where events are further divided into classes based on an observed ellipticity, is used to study fluctuation-driven differences in the initial-state spatial anisotropy for a given collision centrality that would otherwise be destroyed by event-averaging techniques. Correlations between the first and second moments of p( vn) distributions and event ellipticity are measured for harmonic orders n = 2 - 4 by coupling event-shape engineering to the unfolding technique.

A catheter-type flow sensor for measurement of aspirated- and inspired-air characteristics in the bronchial region

NASA Astrophysics Data System (ADS)

Shikida, M.; Naito, J.; Yokota, T.; Kawabe, T.; Hayashi, Y.; Sato, K.

2009-10-01

We developed a novel catheter-type flow sensor for measuring the aspirated- and inspired-air characteristics trans-bronchially. An on-wall in-tube thermal flow sensor is mounted inside the tube, and it is used as a measurement tool in a bronchoscope. The external diameter of the tube is less than a few mm, and therefore, it can evaluate the flow characteristics in the small bronchial region. We newly developed a fabrication process to miniaturize it to less than 2.0 mm in the external diameter by using a heat shrinkable tube. A film sensor fabricated by photolithography was inserted into the tube by hand. By applying a heat shrinking process, the film was automatically mounted on the inner wall surface, and the outer size of the tube was miniaturized to almost half its original size. The final inner and outer diameters of the tube were 1.0 mm and 1.8 mm, respectively. The relationship between the input power of the sensor and the flow rate obeyed King's equation in both forward and reverse flow conditions. The sensor output dependence on ambient temperature was also studied, and the curve obtained at 39.2 °C was used as the calibration curve in animal experiments. The sensor characteristics under reciprocating flow were studied by using a ventilator, and we confirmed that the sensor was able to measure the reciprocating flow at 2.0 Hz. Finally, we successfully measured the aspirated- and inspired-air characteristics in the air passage of a rat.

Benchmark testing of DIII-D neutral beam modeling with water flow calorimetry

DOE PAGES

Rauch, J. M.; Crowley, B. J.; Scoville, J. T.; ...

2016-06-02

Power loading on beamline components in the DIII-D neutral beam system is measured in this paper using water flow calorimetry. The results are used to benchmark beam transport models. Finally, anomalously high heat loads in the magnet region are investigated and a speculative hypothesis as to their origin is presented.

40 CFR 63.993 - Absorbers, condensers, carbon adsorbers and other recovery devices used as final recovery devices.

Code of Federal Regulations, 2014 CFR

2014-07-01

... providing a continuous record or an integrating regeneration stream flow monitoring device having an accuracy of ±10 percent or better, capable of recording the total regeneration stream mass or volumetric flow for each regeneration cycle; and a carbon-bed temperature monitoring device, capable of recording...

40 CFR 63.993 - Absorbers, condensers, carbon adsorbers and other recovery devices used as final recovery devices.

Code of Federal Regulations, 2010 CFR

2010-07-01

... providing a continuous record or an integrating regeneration stream flow monitoring device having an accuracy of ±10 percent or better, capable of recording the total regeneration stream mass or volumetric flow for each regeneration cycle; and a carbon-bed temperature monitoring device, capable of recording...

40 CFR 63.993 - Absorbers, condensers, carbon adsorbers and other recovery devices used as final recovery devices.

Code of Federal Regulations, 2011 CFR

2011-07-01

... providing a continuous record or an integrating regeneration stream flow monitoring device having an accuracy of ±10 percent or better, capable of recording the total regeneration stream mass or volumetric flow for each regeneration cycle; and a carbon-bed temperature monitoring device, capable of recording...

40 CFR 63.993 - Absorbers, condensers, carbon adsorbers and other recovery devices used as final recovery devices.

Code of Federal Regulations, 2012 CFR

2012-07-01

... providing a continuous record or an integrating regeneration stream flow monitoring device having an accuracy of ±10 percent or better, capable of recording the total regeneration stream mass or volumetric flow for each regeneration cycle; and a carbon-bed temperature monitoring device, capable of recording...

40 CFR 63.993 - Absorbers, condensers, carbon adsorbers and other recovery devices used as final recovery devices.

Code of Federal Regulations, 2013 CFR

2013-07-01

... providing a continuous record or an integrating regeneration stream flow monitoring device having an accuracy of ±10 percent or better, capable of recording the total regeneration stream mass or volumetric flow for each regeneration cycle; and a carbon-bed temperature monitoring device, capable of recording...

STS-112 final main engine is installed after welding/polishing process

NASA Technical Reports Server (NTRS)

2002-01-01

KENNEDY SPACE CENTER, FLA. -- The last engine is installed in orbiter Atlantis after a welding and polishing process was undertaken on flow liners where cracks were detected. All engines were removed for inspection of flow liners. Atlantis will next fly on mission STS-112, scheduled for launch no earlier than Oct. 2.

Revised Planning Methodology For Signalized Intersections And Operational Analysis Of Exclusive Left-Turn Lanes, A Simulation-Based Method, Part - I: Literature Review (Final Report)

DOT National Transportation Integrated Search

1996-04-01

THE STUDY INVESTIGATES THE APPLICATION OF SIMULATION ALONG WITH FIELD OBSERVATIONS FOR ESTIMATION OF EXCLUSIVE LEFT-TURN SATURATION FLOW RATE AND CAPACITY. THE ENTIRE RESEARCH HAS COVERED THE FOLLOWING PRINCIPAL SUBJECTS: (1) A SATURATION FLOW MODEL ...

Effect of Gravity Level on the Particle Shape and Size During Zeolite Crystal Growth

NASA Technical Reports Server (NTRS)

Song, Hong-Wei; Ilebusi, Olusegun J.; Sacco, Albert, Jr.

2003-01-01

A microscopic diffusion model is developed to represent solute transport in the boundary layer of a growing zeolite crystal. This model is used to describe the effect of gravity on particle shape and solute distribution. Particle dynamics and crystal growth kinetics serve as the boundary conditions of flow and convection-diffusion equations. A statistical rate theory is used to obtain the rate of solute transport across the growing interface, which is expressed in terms of concentration and velocity of solute species. Microgravity can significantly decrease the solute velocity across the growing interface compared to its earth-based counterpart. The extent of this reduction highly depends on solute diffusion constant in solution. Under gravity, the flow towards the crystal enhances solute transport rate across the growing interface while the flow away from crystals reduces this rate, suggesting a non-uniform growth rate and thus an elliptic final shape. However, microgravity can significantly reduce the influence of flow and obtain a final product with perfect spherical shape. The model predictions compare favorably with the data of space experiment of zeolites grown in space.

Two-Equation Low-Reynolds-Number Turbulence Modeling of Transitional Boundary Layer Flows Characteristic of Gas Turbine Blades. Ph.D. Thesis. Final Contractor Report

NASA Technical Reports Server (NTRS)

Schmidt, Rodney C.; Patankar, Suhas V.

1988-01-01

The use of low Reynolds number (LRN) forms of the k-epsilon turbulence model in predicting transitional boundary layer flow characteristic of gas turbine blades is developed. The research presented consists of: (1) an evaluation of two existing models; (2) the development of a modification to current LRN models; and (3) the extensive testing of the proposed model against experimental data. The prediction characteristics and capabilities of the Jones-Launder (1972) and Lam-Bremhorst (1981) LRN k-epsilon models are evaluated with respect to the prediction of transition on flat plates. Next, the mechanism by which the models simulate transition is considered and the need for additional constraints is discussed. Finally, the transition predictions of a new model are compared with a wide range of different experiments, including transitional flows with free-stream turbulence under conditions of flat plate constant velocity, flat plate constant acceleration, flat plate but strongly variable acceleration, and flow around turbine blade test cascades. In general, calculational procedure yields good agreement with most of the experiments.

NMR imaging and hydrodynamic analysis of neutrally buoyant non-Newtonian slurry flows

NASA Astrophysics Data System (ADS)

Bouillard, J. X.; Sinton, S. W.

The flow of solids loaded suspension in cylindrical pipes has been the object of intense experimental and theoretical investigations in recent years. These types of flows are of great interest in chemical engineering because of their important use in many industrial manufacturing processes. Such flows are for example encountered in the manufacture of solid-rocket propellants, advanced ceramics, reinforced polymer composites, in heterogeneous catalytic reactors, and in the pipeline transport of liquid-solids suspensions. In most cases, the suspension microstructure and the degree of solids dispersion greatly affect the final performance of the manufactured product. For example, solid propellant pellets need to be extremely-well dispersed in gel matrices for use as rocket engine solid fuels. The homogeneity of pellet dispersion is critical to allow good uniformity of the burn rate, which in turn affects the final mechanical performance of the engine. Today's manufacturing of such fuels uses continuous flow processes rather than batch processes. Unfortunately, the hydrodynamics of such flow processes is poorly understood and is difficult to assess because it requires the simultaneous measurements of liquid/solids phase velocities and volume fractions. Due to the recent development in pulsed Fourier Transform NMR imaging, NMR imaging is now becoming a powerful technique for the non intrusive investigation of multi-phase flows. This paper reports and exposes a state-of-the-art experimental and theoretical methodology that can be used to study such flows. The hydrodynamic model developed for this study is a two-phase flow shear thinning model with standard constitutive fluid/solids interphase drag and solids compaction stresses. this model shows good agreement with experimental data and the limitations of this model are discussed.

Flow distribution in parallel microfluidic networks and its effect on concentration gradient

PubMed Central

Guermonprez, Cyprien; Michelin, Sébastien; Baroud, Charles N.

2015-01-01

The architecture of microfluidic networks can significantly impact the flow distribution within its different branches and thereby influence tracer transport within the network. In this paper, we study the flow rate distribution within a network of parallel microfluidic channels with a single input and single output, using a combination of theoretical modeling and microfluidic experiments. Within the ladder network, the flow rate distribution follows a U-shaped profile, with the highest flow rate occurring in the initial and final branches. The contrast with the central branches is controlled by a single dimensionless parameter, namely, the ratio of hydrodynamic resistance between the distribution channel and the side branches. This contrast in flow rates decreases when the resistance of the side branches increases relative to the resistance of the distribution channel. When the inlet flow is composed of two parallel streams, one of which transporting a diffusing species, a concentration variation is produced within the side branches of the network. The shape of this concentration gradient is fully determined by two dimensionless parameters: the ratio of resistances, which determines the flow rate distribution, and the Péclet number, which characterizes the relative speed of diffusion and advection. Depending on the values of these two control parameters, different distribution profiles can be obtained ranging from a flat profile to a step distribution of solute, with well-distributed gradients between these two limits. Our experimental results are in agreement with our numerical model predictions, based on a simplified 2D advection-diffusion problem. Finally, two possible applications of this work are presented: the first one combines the present design with self-digitization principle to encapsulate the controlled concentration in nanoliter chambers, while the second one extends the present design to create a continuous concentration gradient within an open flow chamber. PMID:26487905

DIFFEOMORPHIC SURFACE FLOWS: A NOVEL METHOD OF SURFACE EVOLUTION*

PubMed Central

Zhang, Sirong; Younes, Laurent; Zweck, John; Ratnanather, J. Tilak

2009-01-01

We describe a new class of surface flows, diffeomorphic surface flows, induced by restricting diffeomorphic flows of the ambient Euclidean space to a surface. Different from classical surface PDE flows such as mean curvature flow, diffeomorphic surface flows are solutions of integro-differential equations in a group of diffeomorphisms. They have the potential advantage of being both topology-invariant and singularity free, which can be useful in computational anatomy and computer graphics. We first derive the Euler–Lagrange equation of the elastic energy for general diffeomorphic surface flows, which can be regarded as a smoothed version of the corresponding classical surface flows. Then we focus on diffeomorphic mean curvature flow. We prove the short-time existence and uniqueness of the flow, and study the long-time existence of the flow for surfaces of revolution. We present numerical experiments on synthetic and cortical surfaces from neuroimaging studies in schizophrenia and auditory disorders. Finally we discuss unresolved issues and potential applications. PMID:20016768

Final Record of Decision/Remedial Action Plan, Nine Sites, Sierra Army Depot, Lassen County, California.

DTIC Science & Technology

1996-10-01

Associates 1-3 0619100396 RD2 Introduction Honey Lake Valley appears to be isolated because no sin-face water flows from the valley. The United...infiltration of precipitation in upland areas and infiltration of stream flow in alluvial fan areas (Handman et al., 1990). Discharge from the...is slightly higher in elevation than the northern portion of the installation. Figure 1.5 indicates that groundwater flow is generally to the north

An Evaluation of the Effectiveness of Flow Augmentation in the Snake River, 1991-1995 : Phase I: Final Report

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

Giorgi, Albert E.; Schlecte, J.Warren

1997-07-01

The purpose of this evaluation was to estimate the volume and shape of flow augmentation water delivered in the Snake Basin during the years 1991 through 1995, and to assess the biological consequences to ESA-listed salmon stocks in that drainage. HDR Engineering, Inc. calculated flow augmentation estimates and compared their values to those reported by agencies in the Northwest. BioAnalysts, Inc. conducted the biological evaluation.

Validation of the Chemistry Module for the Euler Solver in Unified Flow Solver

DTIC Science & Technology

2012-03-01

traveling through the atmosphere there are three types of flow regimes that exist; the first is the continuum regime, second is the rarified regime and...The second method has been used in a program called Unified Flow Solver (UFS). UFS is currently being developed under collaborative efforts the Air...thermal non-equilibrium case and finally to a thermo-chemical non- equilibrium case. The data from the simulations will be compared to a second code

Numerical investigation for one bad-behaved flow in a Pelton turbine

NASA Astrophysics Data System (ADS)

Wei, X. Z.; Yang, K.; Wang, H. J.; Gong, R. Z.; Li, D. Y.

2015-01-01

The gas-liquid two-phase flow in pelton turbines is very complicated, there are many kinds of bad-behaved flow in pelton turbines. In this paper, CFD numerical simulation for the pelton turbine was conducted using VOF two-phase model. One kind of bad-behaved flow caused by the two jets was captured, and the bad-behaved flow was analysed by torque on buckets. It can be concluded that the angle between the two jets and the value of ratio of runner diameter and jet diameter are important parameters for the bad-behaved flow. Furthermore, the reason why the efficiency of some multi-jet type turbines is very low can be well explained by the analysis of bad-behaved flow. Finally, some suggestions for improvement were also provided in present paper.

Elliptic Flow, Initial Eccentricity and Elliptic Flow Fluctuations in Heavy Ion Collisions at RHIC

NASA Astrophysics Data System (ADS)

Nouicer, Rachid; Alver, B.; Back, B. B.; Baker, M. D.; Ballintijn, M.; Barton, D. S.; Betts, R. R.; Bickley, A. A.; Bindel, R.; Busza, W.; Carroll, A.; Chai, Z.; Decowski, M. P.; García, E.; Gburek, T.; George, N.; Gulbrandsen, K.; Halliwell, C.; Hamblen, J.; Hauer, M.; Henderson, C.; Hofman, D. J.; Hollis, R. S.; Holzman, B.; Iordanova, A.; Kane, J. L.; Khan, N.; Kulinich, P.; Kuo, C. M.; Li, W.; Lin, W. T.; Loizides, C.; Manly, S.; Mignerey, A. C.; Nouicer, R.; Olszewski, A.; Pak, R.; Reed, C.; Roland, C.; Roland, G.; Sagerer, J.; Seals, H.; Sedykh, I.; Smith, C. E.; Stankiewicz, M. A.; Steinberg, P.; Stephans, G. S. F.; Sukhanov, A.; Tonjes, M. B.; Trzupek, A.; Vale, C.; van Nieuwenhuizen, G. J.; Vaurynovich, S. S.; Verdier, R.; Veres, G. I.; Walters, P.; Wenger, E.; Wolfs, F. L. H.; Wosiek, B.; Woźniak, K.; Wysłouch, B.

2008-12-01

We present measurements of elliptic flow and event-by-event fluctuations established by the PHOBOS experiment. Elliptic flow scaled by participant eccentricity is found to be similar for both systems when collisions with the same number of participants or the same particle area density are compared. The agreement of elliptic flow between Au+Au and Cu+Cu collisions provides evidence that the matter is created in the initial stage of relativistic heavy ion collisions with transverse granularity similar to that of the participant nucleons. The event-by-event fluctuation results reveal that the initial collision geometry is translated into the final state azimuthal particle distribution, leading to an event-by-event proportionality between the observed elliptic flow and initial eccentricity.

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

Chambers, Mark S.; Posner, Marshall; Jones, Christopher Uwe

Purpose: To study the efficacy and safety of cevimeline in two double-blind trials (Studies 003 and 004) enrolling patients with head and neck cancer in whom xerostomia developed after radiotherapy. Methods and Materials: Subjects were randomly assigned to receive cevimeline, 30 mg three times daily, or placebo for 12 weeks, with the possibility of dose escalation to 45 mg three times daily at 6 weeks. The primary efficacy endpoint was the patient's final global evaluation of oral dryness; change in unstimulated salivary flow was a secondary endpoint. Results: Five hundred seventy subjects (284 in Study 003 and 286 in Studymore » 004) were randomized. Significantly more cevimeline-treated subjects than placebo recipients (47.4% vs. 33.3%, p = 0.0162) in Study 003 reported improvement in dry mouth in the final global evaluation of oral dryness. No significant difference between groups in the final global evaluation was seen in Study 004, in which a high placebo response rate of 47.6% was observed. In both studies, cevimeline-treated subjects had significantly greater increases in the objective measure of unstimulated salivary flow than placebo recipients (p 0.0093 [Study 003] and p = 0.0215 [Study 004]), whereas no significant differences in stimulated salivary flow were observed. The most frequent adverse event was increased sweating. Conclusion: Cevimeline was well tolerated by patients with xerostomia after radiotherapy for head and neck cancer, and oral administration of 30-45 mg of cevimeline three times daily increased unstimulated salivary flow.« less

Cevimeline for the treatment of postirradiation xerostomia in patients with head and neck cancer.

PubMed

Chambers, Mark S; Posner, Marshall; Jones, Christopher Uwe; Biel, Merrill A; Hodge, Kenneth M; Vitti, Robert; Armstrong, Ingrid; Yen, Cindy; Weber, Randal S

2007-07-15

To study the efficacy and safety of cevimeline in two double-blind trials (Studies 003 and 004) enrolling patients with head and neck cancer in whom xerostomia developed after radiotherapy. Subjects were randomly assigned to receive cevimeline, 30 mg three times daily, or placebo for 12 weeks, with the possibility of dose escalation to 45 mg three times daily at 6 weeks. The primary efficacy endpoint was the patient's final global evaluation of oral dryness; change in unstimulated salivary flow was a secondary endpoint. Five hundred seventy subjects (284 in Study 003 and 286 in Study 004) were randomized. Significantly more cevimeline-treated subjects than placebo recipients (47.4% vs. 33.3%, p = 0.0162) in Study 003 reported improvement in dry mouth in the final global evaluation of oral dryness. No significant difference between groups in the final global evaluation was seen in Study 004, in which a high placebo response rate of 47.6% was observed. In both studies, cevimeline-treated subjects had significantly greater increases in the objective measure of unstimulated salivary flow than placebo recipients (p = 0.0093 [Study 003] and p = 0.0215 [Study 004]), whereas no significant differences in stimulated salivary flow were observed. The most frequent adverse event was increased sweating. Cevimeline was well tolerated by patients with xerostomia after radiotherapy for head and neck cancer, and oral administration of 30-45 mg of cevimeline three times daily increased unstimulated salivary flow.

Final report on CIPM key comparison CCM.FF-K6.2011: Comparison of the primary (national) standards of low-pressure gas flow

NASA Astrophysics Data System (ADS)

Benková, Miroslava; Makovnik, Stefan; Mickan, Bodo; Arias, Roberto; Chahine, Khaled; Funaki, Tatsuya; Li, Chunhui; Choi, Hae Man; Seredyuk, Denys; Su, Chun-Min; Windenberg, Christophe; Wright, John

2014-01-01

The comparison CCM.FF-K6.2011 was organized for the purpose of determination of the degree of equivalence of the national standards for low-pressure gas flow measurement over the range (2 to 100) m3/h. A rotary gas meter was used as a transfer standard. The measurements were provided at prescribed reference conditions. Eleven laboratories from four RMOs participated in this key comparison—EURAMET: PTB, Germany; SMU, Slovakia; LNE-LADG, France; SIM: NIST, USA; CENAM, Mexico; APMP: NMIJ AIST Japan; KRISS, Korea; NMI, Australia; NIM, China; CMS, Chinese Taipei; COOMET: GP GP Ivano-Frankivs'kstandart-metrologia, Ukraine and all participants reported independent traceability chains to the SI. All results were used in the determination of the key comparison reference value (KCRV) and the uncertainty of the KCRV. The reference value was determined at each flow separately following procedure A presented by M G Cox. The degree of equivalence with the KCRV was also calculated for each flow and laboratory. All reported results were consistent with the KCRV. This KCRV can now be used in the further regional comparisons. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Looking inside a debris flow

NASA Astrophysics Data System (ADS)

Bowman, Elisabeth; Sanvitale, Nicoletta; Bird, Joshua

2014-05-01

Debris flows, masses of saturated, channelized, granular materials that flow at high speeds downslope, present a hazard to lives and infrastructure in regions of high relief and runoff. They also present a challenge to modelling due to the heterogeneous, multi-phase, nature of the constituent materials, with particles ranging from boulder-size to silt-size and fluid viscosity being altered by the presence of fine particles and clay. As a debris flow travels on its flow path, it will tend to segregate, with larger particles being focused to the flow front and fluid being concentrated in the tail - resulting in different rheological behaviour in time and space. It will also tend to erode and deposit material as it moves through different channel segments or reaches, with this behaviour influenced by the confinement of the channel and the angle of the slope within each reach. Flume studies offer the potential to examine in detail the behaviour of model debris flows within the penultimate and final (deposit fan area) reaches - zones which are generally of most interest in terms of human risk. Flume studies which are conducted using transparent debris offer additional benefits to more traditional methods that use opaque materials, enabling insights to the flow behaviour that are inaccessible via other physical methods. We present flume model work which has been designed to capture some essential aspects of debris flow behaviour using well graded (polydisperse) transparent debris, albeit at reduced scale. These aspects include the final deposit spread or runout increasing for a lower concentration of solids and a higher penultimate reach slope angle, and observable particle size segregation during downslope motion. We present time-varying measurements made internally and externally at a point in the channel via Plane Laser Induced Fluorescence and Particle Image Velocimetry, PIV. The measurements enable velocity distributions of the segregating flows over time to be determined that can be directly compared with theoretical relationships developed from measurements made at flow margins.

Modeling the 2012-2013 lava flows of Tolbachik, Russia using thermal infrared satellite data and PyFLOWGO

NASA Astrophysics Data System (ADS)

Ramsey, M. S.; Chevrel, O.; Harris, A. J. L.

2017-12-01

Satellite-based thermal infrared (TIR) observations of new volcanic activity and ongoing lava flow emplacement become increasingly more detailed with improved spatial, spectral and/or temporal resolution data. The cooling of the glassy surface is directly imaged by TIR instruments in order to determine temperature, which is then used to initiate thermo-rheological-based models. Higher temporal resolution data (i.e., minutes to hours), are used to detect new eruptions and determine the time-averaged discharge rate (TADR). Calculation of the TADR along with new observations later in time and accurate digital elevation models (DEMs) enable modeling of the advancing flow's down-slope inundation area. Better spectral and spatial resolution data, on the other hand, allow the flow's composition, small-scale morphological changes and real-time DEMs to be determined, in addition to confirming prior model predictions. Combined, these data help improve the accuracy of models such as FLOWGO. A new adaptation of this model in python (PyFLOWGO) has been used to produce the best fit eruptive conditions to the final flow morphology for the 2012-2013 eruption of Tolbachik volcano, Russia. This was the largest and most thermally-intense flow-forming eruption in the past 50 years, producing longer lava flows than that of typical Kilauea or Etna eruptions. The progress of these flows were imaged by a multiple TIR sensors at various spatial, spectral and temporal scales throughout the flow field emplacement. We have refined the model based on the high resolution data to determine the TADR and make improved estimates of cooling, viscosity, velocity and crystallinity with distance. Understanding the cooling and dynamics of basaltic surfaces ultimately produces an improved hazard forecast capability. In addition, the direct connection of the final flow morphology to the specific eruption conditions that produced it allows the eruptive conditions of older flows to be estimated.

Flowing Active Liquids in a Pipe: Hysteretic Response of Polar Flocks to External Fields

NASA Astrophysics Data System (ADS)

Morin, Alexandre; Bartolo, Denis

2018-04-01

We investigate the response of colloidal flocks to external fields. We first show that individual colloidal rollers align with external flows, as would a classical spin with magnetic fields. Assembling polar active liquids from colloidal rollers, we experimentally demonstrate their hysteretic response: Confined colloidal flocks can proceed against external flows. We theoretically explain this collective robustness, using an active hydrodynamic description, and show how orientational elasticity and confinement protect the direction of collective motion. Finally, we exploit the intrinsic bistability of confined active flows to devise self-sustained microfluidic oscillators.

Calculations of transonic boattail flow at small angle of attack

NASA Technical Reports Server (NTRS)

Nakayama, A.; Chow, W. L.

1979-01-01

A transonic flow past a boattailed afterbody under a small angle of attack was examined. It is known that the viscous effect offers significant modifications of the pressure distribution on the afterbody. Thus, the formulation for the inviscid flow was based on the consideration of a flow past a nonaxisymmetric body. The full three dimensional potential equation was solved through numerical relaxation, and quasi-axisymmetric boundary layer calculations were performed to estimate the displacement effect. It was observed again that the viscous effects were not negligible. The trend of the final results agreed well with the experimental data.

Microfluidic assay of circulating endothelial cells in coronary artery disease patients with angina pectoris

PubMed Central

Chen, Shuiyu; Sun, Yukun; Neoh, Kuang Hong; Chen, Anqi; Li, Weiju; Yang, Xiaorui

2017-01-01

Background Circulating endothelial cells (CECs) are widely reported as a promising biomarker of endothelial damage/dysfunction in coronary artery disease (CAD). The two popular methods of CEC quantification include the use of immunomagnetic beads separation (IB) and flow cytometry analysis (FC); however, they suffer from two main shortcomings that affect their diagnostic and prognostic responses: non-specific bindings of magnetic beads to non-target cells and a high degree of variability in rare cell identification, respectively. We designed a microfluidic chip with spatially staggered micropillars for the efficient harvesting of CECs with intact cellular morphology in an attempt to revisit the diagnostic goal of CEC counts in CAD patients with angina pectoris. Methods A label-free microfluidic assay that involved an in-situ enumeration and immunofluorescent identification (DAPI+/CD146+/VEGFR1+/CD45-) of CECs was carried out to assess the CEC count in human peripheral blood samples. A total of 55 CAD patients with angina pectoris [16 with chronic stable angina (CSA) and 39 with unstable angina (UA)], together with 15 heathy controls (HCs) were enrolled in the study. Results CEC counts are significantly higher in both CSA and UA groups compared to the HC group [respective medians of 6.9, 10.0 and 1.5 cells/ml (p < 0.01)]. Further, a significant elevation of CEC count was observed in the three UA subgroups [low risk (5.3) vs. intermediate risk (10.8) vs. high risk (18.0) cells/ml, p < 0.001) classified in accordance to the TIMI NSTEMI/UA risk score system. From the receiver-operating characteristic curve analysis, the AUCs for distinguishing CSA and UA from HC were 0.867 and 0.938, respectively. The corresponding sensitivities were 87.5% and 84.6% and the specificities were 66.7% and 86.7%, respectively. Conclusions Our microfluidic assay system is efficient and stable for CEC capture and enumeration. The results showed that the CEC count has the potential to be a promising clinical biomarker for the assessment of endothelial damage/dysfunction in CAD patients with angina pectoris. PMID:28704506

Microfluidic assay of circulating endothelial cells in coronary artery disease patients with angina pectoris.

PubMed

Chen, Shuiyu; Sun, Yukun; Neoh, Kuang Hong; Chen, Anqi; Li, Weiju; Yang, Xiaorui; Han, Ray P S

2017-01-01

Circulating endothelial cells (CECs) are widely reported as a promising biomarker of endothelial damage/dysfunction in coronary artery disease (CAD). The two popular methods of CEC quantification include the use of immunomagnetic beads separation (IB) and flow cytometry analysis (FC); however, they suffer from two main shortcomings that affect their diagnostic and prognostic responses: non-specific bindings of magnetic beads to non-target cells and a high degree of variability in rare cell identification, respectively. We designed a microfluidic chip with spatially staggered micropillars for the efficient harvesting of CECs with intact cellular morphology in an attempt to revisit the diagnostic goal of CEC counts in CAD patients with angina pectoris. A label-free microfluidic assay that involved an in-situ enumeration and immunofluorescent identification (DAPI+/CD146+/VEGFR1+/CD45-) of CECs was carried out to assess the CEC count in human peripheral blood samples. A total of 55 CAD patients with angina pectoris [16 with chronic stable angina (CSA) and 39 with unstable angina (UA)], together with 15 heathy controls (HCs) were enrolled in the study. CEC counts are significantly higher in both CSA and UA groups compared to the HC group [respective medians of 6.9, 10.0 and 1.5 cells/ml (p < 0.01)]. Further, a significant elevation of CEC count was observed in the three UA subgroups [low risk (5.3) vs. intermediate risk (10.8) vs. high risk (18.0) cells/ml, p < 0.001) classified in accordance to the TIMI NSTEMI/UA risk score system. From the receiver-operating characteristic curve analysis, the AUCs for distinguishing CSA and UA from HC were 0.867 and 0.938, respectively. The corresponding sensitivities were 87.5% and 84.6% and the specificities were 66.7% and 86.7%, respectively. Our microfluidic assay system is efficient and stable for CEC capture and enumeration. The results showed that the CEC count has the potential to be a promising clinical biomarker for the assessment of endothelial damage/dysfunction in CAD patients with angina pectoris.

A systematic diagnostic and therapeutic approach for the treatment of patients after cardio-pulmonary resuscitation: a prospective evaluation of 212 patients over 5 years.

PubMed

von Korn, Hubertus; Stefan, Victor; van Ewijk, Reyn; Chakraborty, Kamalesh; Sanwald, Burkhard; Hemker, Jan; Hink, Ulrich; Ohlow, Marc; Lauer, Bernward; Vagts, Dierk; Gruene, Stefan; Münzel, Thomas

2017-06-01

A literature on systematic treatment protocols for patients after resuscitation for cardiac arrest is lacking. We evaluated a systematic protocol, including ECG, echocardiogram, urgent cardiac catheterisation ("STEMI-like" workflow), CT scans, laboratory findings, IABP, hypothermia, and cMRI, prospectively over 5 years. The primary endpoint was the Cerebral Performance Category Scale (CPCS). During the period from January 2008 to December 2012, 212 patients were included. The mean age was 66.7 years, n = 151 (71.2 %) were male, mean time from the first medical contact to start of catheterisation was 76.6 min, and ventricular fibrillation (VF) was present in n = 99 (46.7 %). A significant coronary artery stenosis was seen in n = 130 (61.3 %), PCI was performed in n = 101 (47.6 %), an ACS was found in n = 100 (47.2 %), n = 91 patients (42.9 %) had another cardiac cause, an extra-cardiac cause was found in n = 12 (5.7 %, mostly a cerebral process), and in 9 patients (4.3 %), no cause was identifiable. A significant difference in mortality was found for patients with TIMI flow 2/3 vs. 0/1 (65.4 vs. 95.7 %, p < 0.01). The difference of intra-aortic balloon pumping vs. no pumping was not significant, performing hypothermia reduced mortality significantly (52.7 vs. 68.2 %, p = 0.04). The survival rate was n = 76 (35.9 %), a CPCS of 1/2 was reached in n = 68 pts (32.1 %), patients with ongoing resuscitation had a 100 % mortality (n = 41), and VF had a lower mortality (54.6 vs. 72.6 %, p < 0.01). A systematic algorithm may improve the outcome of patients after reanimation compared with classically reported outcomes. The data are hypothesis generating for further studies.

Irrigant flow within a prepared root canal using various flow rates: a Computational Fluid Dynamics study.

PubMed

Boutsioukis, C; Lambrianidis, T; Kastrinakis, E

2009-02-01

To study using computer simulation the effect of irrigant flow rate on the flow pattern within a prepared root canal, during final irrigation with a syringe and needle. Geometrical characteristics of a side-vented endodontic needle and clinically realistic flow rate values were obtained from previous and preliminary studies. A Computational Fluid Dynamics (CFD) model was created using FLUENT 6.2 software. Calculations were carried out for five selected flow rates (0.02-0.79 mL sec(-1)) and velocity and turbulence quantities along the domain were evaluated. Irrigant replacement was limited to 1-1.5 mm apical to the needle tip for all flow rates tested. Low-Reynolds number turbulent flow was detected near the needle outlet. Irrigant flow rate affected significantly the flow pattern within the root canal. Irrigation needles should be placed to within 1 mm from working length to ensure fluid exchange. Turbulent flow of irrigant leads to more efficient irrigant replacement. CFD represents a powerful tool for the study of irrigation.

Entrainment at a sediment concentration interface in turbulent channel flow

NASA Astrophysics Data System (ADS)

Salinas, Jorge; Shringarpure, Mrugesh; Cantero, Mariano; Balachandar, S.

2016-11-01

In this work we address the role of turbulence on entrainment at a sediment concentration interface. This process can be conceived as the entrainment of sediment-free fluid into the bottom sediment-laden flow, or alternatively, as the entrainment of sediment into the top sediment-free flow. We have performed direct numerical simulations for fixed Reynolds and Schmidt numbers while varying the values of Richardson number and particle settling velocity. The analysis performed shows that the ability of the flow to pick up a given sediment size decreases with the distance from the bottom, and thus only fine enough sediment particles are entrained across the sediment concentration interface. For these cases, the concentration profiles evolve to a final steady state in good agreement with the well-known Rouse profile. The approach towards the Rouse profile happens through a transient self-similar state. Detailed analysis of the three dimensional structure of the sediment concentration interface shows the mechanisms by which sediment particles are lifted up by tongues of sediment-laden fluid with positive correlation between vertical velocity and sediment concentration. Finally, the mixing ability of the flow is addressed by monitoring the center of mass of the sediment-laden layer. With the support of ExxonMobil, NSF, ANPCyT, CONICET.

High-resolution Monte Carlo simulation of flow and conservative transport in heterogeneous porous media: 1. Methodology and flow results

USGS Publications Warehouse

Naff, R.L.; Haley, D.F.; Sudicky, E.A.

1998-01-01

In this, the first of two papers concerned with the use of numerical simulation to examine flow and transport parameters in heterogeneous porous media via Monte Carlo methods, various aspects of the modelling effort are examined. In particular, the need to save on core memory causes one to use only specific realizations that have certain initial characteristics; in effect, these transport simulations are conditioned by these characteristics. Also, the need to independently estimate length scales for the generated fields is discussed. The statistical uniformity of the flow field is investigated by plotting the variance of the seepage velocity for vector components in the x, y, and z directions. Finally, specific features of the velocity field itself are illuminated in this first paper. In particular, these data give one the opportunity to investigate the effective hydraulic conductivity in a flow field which is approximately statistically uniform; comparisons are made with first- and second-order perturbation analyses. The mean cloud velocity is examined to ascertain whether it is identical to the mean seepage velocity of the model. Finally, the variance in the cloud centroid velocity is examined for the effect of source size and differing strengths of local transverse dispersion.

Risk for Major Bleeding in Patients Receiving Ticagrelor Compared With Aspirin After Transient Ischemic Attack or Acute Ischemic Stroke in the SOCRATES Study (Acute Stroke or Transient Ischemic Attack Treated With Aspirin or Ticagrelor and Patient Outcomes).

PubMed

Easton, J Donald; Aunes, Maria; Albers, Gregory W; Amarenco, Pierre; Bokelund-Singh, Sara; Denison, Hans; Evans, Scott R; Held, Peter; Jahreskog, Marianne; Jonasson, Jenny; Minematsu, Kazuo; Molina, Carlos A; Wang, Yongjun; Wong, K S Lawrence; Johnston, S Claiborne

2017-09-05

Patients with minor acute ischemic stroke or transient ischemic attack are at high risk for subsequent stroke, and more potent antiplatelet therapy in the acute setting is needed. However, the potential benefit of more intense antiplatelet therapy must be assessed in relation to the risk for major bleeding. The SOCRATES trial (Acute Stroke or Transient Ischemic Attack Treated With Aspirin or Ticagrelor and Patient Outcomes) was the first trial with ticagrelor in patients with acute ischemic stroke or transient ischemic attack in which the efficacy and safety of ticagrelor were compared with those of aspirin. The main safety objective was assessment of PLATO (Platelet Inhibition and Patient Outcomes)-defined major bleeds on treatment, with special focus on intracranial hemorrhage (ICrH). An independent adjudication committee blinded to study treatment classified bleeds according to the PLATO, TIMI (Thrombolysis in Myocardial Infarction), and GUSTO (Global Use of Strategies to Open Occluded Coronary Arteries) definitions. The definitions of ICrH and major bleeding excluded cerebral microbleeds and asymptomatic hemorrhagic transformations of cerebral infarctions so that the definitions better discriminated important events in the acute stroke population. A total of 13 130 of 13 199 randomized patients received at least 1 dose of study drug and were included in the safety analysis set. PLATO major bleeds occurred in 31 patients (0.5%) on ticagrelor and 38 patients (0.6%) on aspirin (hazard ratio, 0.83; 95% confidence interval, 0.52-1.34). The most common locations of major bleeds were intracranial and gastrointestinal. ICrH was reported in 12 patients (0.2%) on ticagrelor and 18 patients (0.3%) on aspirin. Thirteen of all 30 ICrHs (4 on ticagrelor and 9 on aspirin) were hemorrhagic strokes, and 4 (2 in each group) were symptomatic hemorrhagic transformations of brain infarctions. The ICrHs were spontaneous in 6 and 13, traumatic in 3 and 3, and procedural in 3 and 2 patients on ticagrelor and aspirin, respectively. In total, 9 fatal bleeds occurred on ticagrelor and 4 on aspirin. The composite of ICrH or fatal bleeding included 15 patients on ticagrelor and 18 on aspirin. Independently of bleeding classification, PLATO, TIMI, or GUSTO, the relative difference between treatments for major/severe bleeds was similar. Nonmajor bleeds were more common on ticagrelor. Antiplatelet therapy with ticagrelor in patients with acute ischemic stroke or transient ischemic attack showed a bleeding profile similar to that of aspirin for major bleeds. There were few ICrHs. URL: http://www.clinicaltrials.gov. Unique identifier: NCT01994720. © 2017 American Heart Association, Inc.

A study of the influence of mean flow on the acoustic performance of Herschel-Quincke tubes

PubMed

Torregrosa; Broatch; Payri

2000-04-01

In this paper, a simple flow model is used in order to assess the influence of mean flow and dissipation on the acoustic performance of the classical two-duct Herschel-Quincke tube. First, a transfer matrix is obtained for the system, which depends on the values of the Mach number in the two branches. These Mach numbers are then estimated separately by means of an incompressible flow calculation. Finally, both calculations are used to study the way in which mean flow affects the position and value of the characteristic attenuation and resonances of the system. The results indicate the nontrivial character of the influence observed.

Advanced Transportation Systems, Alternate Propulsion Subsystem Concepts

NASA Technical Reports Server (NTRS)

1997-01-01

An understanding of the basic flow of of the subject hybrid model has been gained through this series of testing. Changing injectors (axial vs. radial) and inhibiting the flow between the upstream plenum and the CP section changes the basic flow structure, as evidenced by streamline and velocity contour plots. Numerous shear layer structures were identified in the test configurations; these structures include both standing and traveling vortices which may affect combustion ion stability. Standing vortices may play a role in the heat addition process as the oxidizer enters the motor, while traveling vortices may be instability mechanisms in themselves. Finally, the flow visualization and LVD measurements give insight into determining the effects of flow induced shear layers.

Granular flows: fundamentals and applications

NASA Astrophysics Data System (ADS)

Cleary, Paul W.

DEM allows the prediction of complex industrial and geophysical particle flows. The importance of particle shape is demonstrated through a series of simple examples. Shape controls resistance to shear, the magnitude of collision stress, dilation and the angle of repose. We use a periodic flow of a bed of particles to demonstrate the different states of granular matter, the generation of dilute granular flow when granular temperature is high and the flow dependent nature of the granular thermodynamic boundary conditions. A series of industrial case studies examines how DEM can be used to understand and improve processes such as separation, mixing, grinding, excavation, hopper discharge, metering and conveyor interchange. Finally, an example of landslide motion over real topography is presented.

Real-Time Maps of Fluid Flow Fields in Porous Biomaterials

PubMed Central

Mack, Julia J.; Youssef, Khalid; Noel, Onika D.V.; Lake, Michael P.; Wu, Ashley; Iruela-Arispe, M. Luisa; Bouchard, Louis-S.

2013-01-01

Mechanical forces such as fluid shear have been shown to enhance cell growth and differentiation, but knowledge of their mechanistic effect on cells is limited because the local flow patterns and associated metrics are not precisely known. Here we present real-time, noninvasive measures of local hydrodynamics in 3D biomaterials based on nuclear magnetic resonance. Microflow maps were further used to derive pressure, shear and fluid permeability fields. Finally, remodeling of collagen gels in response to precise fluid flow parameters was correlated with structural changes. It is anticipated that accurate flow maps within 3D matrices will be a critical step towards understanding cell behavior in response to controlled flow dynamics. PMID:23245922

Modeling and simulation of flow field in giant magnetostrictive pump

NASA Astrophysics Data System (ADS)

Zhao, Yapeng; Ren, Shiyong; Lu, Quanguo

2017-09-01

Recent years, there has been significant research in the design and analysis of giant magnetostrictive pump. In this paper, the flow field model of giant magnetostrictive pump was established and the relationship between pressure loss and working frequency of piston was studied by numerical simulation method. Then, the influence of different pump chamber height on pressure loss in giant magnetostrictive pump was studied by means of flow field simulation. Finally, the fluid pressure and velocity vector distribution in giant magnetostrictive pump chamber were simulated.

Dose-Dependent Thresholds of 10-ns Electric Pulse Induced Plasma Membrane Disruption and Cytotoxicity in Multiple Cell Lines

DTIC Science & Technology

2011-01-01

normalized to parallel controls. Flow Cytometry and Confocal Microscopy Upon exposure to 10-ns EP, aliquots of the cellular suspension were added to a tube...Survival data was processed and plotted using GrapherH software (Golden Software, Golden, Colorado). Flow cytometry results were processed in C6 software...Accuri Cytometers, Inc., Ann Arbor, MI) and FCSExpress software (DeNovo Software, Los Angeles, CA). Final analysis and presentation of flow cytometry

On accelerated flow of MHD powell-eyring fluid via homotopy analysis method

NASA Astrophysics Data System (ADS)

Salah, Faisal; Viswanathan, K. K.; Aziz, Zainal Abdul

2017-09-01

The aim of this article is to obtain the approximate analytical solution for incompressible magnetohydrodynamic (MHD) flow for Powell-Eyring fluid induced by an accelerated plate. Both constant and variable accelerated cases are investigated. Approximate analytical solution in each case is obtained by using the Homotopy Analysis Method (HAM). The resulting nonlinear analysis is carried out to generate the series solution. Finally, Graphical outcomes of different values of the material constants parameters on the velocity flow field are discussed and analyzed.

A method for computation of inviscid three-dimensional flow over blunt bodies having large embedded subsonic regions

NASA Technical Reports Server (NTRS)

Weilmuenster, K. J.; Hamilton, H. H., II

1981-01-01

A computational technique for computing the three-dimensional inviscid flow over blunt bodies having large regions of embedded subsonic flow is detailed. Results, which were obtained using the CDC Cyber 203 vector processing computer, are presented for several analytic shapes with some comparison to experimental data. Finally, windward surface pressure computations over the first third of the Space Shuttle vehicle are compared with experimental data for angles of attack between 25 and 45 degrees.

Development and analysis of closed cycle circulator elements. Final report 31 Jul 978-31 May 1980

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

Shih, C.C.; Karr, G.R.; Perkins, J.F.

1980-05-01

A series of experiments with various flow rates of laser gas and coolants under several levels of energy inputs has been conducted on the Army Closed Cycle Circulator for pulsed EDL to collect sufficient data for flow calibration and coefficient determination. Verification of the theoretical models depicting the functions of the heat exchangers in maintaining the thermal balance in the flow through the steady and transient states are made through comparison with results of the experimental analysis.

Apparatus for removal of particulate matter from gas streams

DOEpatents

Smith, Peyton L.; Morse, John C.

2000-01-01

An apparatus for the removal of particulate matter from the gaseous product stream of an entrained flow coal gasifier which apparatus includes an initial screen, an intermediate screen which is aligned with the direction of flow of the gaseous product stream and a final screen transversely disposed to the flow of gaseous product and which apparatus is capable of withstanding at least a pressure differential of about 10 psi (68.95 kPa) or greater at the temperatures of the gaseous product stream.

Multigrid solution of internal flows using unstructured solution adaptive meshes

NASA Technical Reports Server (NTRS)

Smith, Wayne A.; Blake, Kenneth R.

1992-01-01

This is the final report of the NASA Lewis SBIR Phase 2 Contract Number NAS3-25785, Multigrid Solution of Internal Flows Using Unstructured Solution Adaptive Meshes. The objective of this project, as described in the Statement of Work, is to develop and deliver to NASA a general three-dimensional Navier-Stokes code using unstructured solution-adaptive meshes for accuracy and multigrid techniques for convergence acceleration. The code will primarily be applied, but not necessarily limited, to high speed internal flows in turbomachinery.

Slip length measurement of gas flow.

PubMed

Maali, Abdelhamid; Colin, Stéphane; Bhushan, Bharat

2016-09-16

In this paper, we present a review of the most important techniques used to measure the slip length of gas flow on isothermal surfaces. First, we present the famous Millikan experiment and then the rotating cylinder and spinning rotor gauge methods. Then, we describe the gas flow rate experiment, which is the most widely used technique to probe a confined gas and measure the slip. Finally, we present a promising technique using an atomic force microscope introduced recently to study the behavior of nanoscale confined gas.

Laser transit anemometer measurements of a JANNAF nozzle base velocity flow field

NASA Technical Reports Server (NTRS)

Hunter, William W., Jr.; Russ, C. E., Jr.; Clemmons, J. I., Jr.

1990-01-01

Velocity flow fields of a nozzle jet exhausting into a supersonic flow were surveyed. The measurements were obtained with a laser transit anemometer (LTA) system in the time domain with a correlation instrument. The LTA data is transformed into the velocity domain to remove the error that occurs when the data is analyzed in the time domain. The final data is shown in velocity vector plots for positions upstream, downstream, and in the exhaust plane of the jet nozzle.

Applications of MGS MOC and MOLA Data to Lava Flows: Investigations of Rheology, Topographic Influences and Tectonic Effects

NASA Technical Reports Server (NTRS)

Glaze, Lori S.

2004-01-01

Proxemy Research had a grant from NASA to perform scientific research using Mars Global Surveyor (MGS) data to study lava flows on Mars. Here we summarize the scientific progress and accomplishments of this grant. Scientific publications and abstracts of presentations are indicated in the final section.

STS-112 final main engine is installed after welding/polishing process

NASA Technical Reports Server (NTRS)

2002-01-01

KENNEDY SPACE CENTER, FLA. - Workers get ready to install the last engine in orbiter Atlantis after a welding and polishing process was undertaken on flow liners where cracks were detected. All engines were removed for inspection of flow liners. Atlantis will next fly on mission STS-112, scheduled for launch no earlier than Oct. 2.

Summary of Geotail Funding Activities. [Period of Performance: 03/1999 - 02/2002

NASA Technical Reports Server (NTRS)

2002-01-01

This final report summarizes results of Geotail project monitoring Earth's magnetotail during funding period. Compares project's transport statistics to those of International Sun-Earth Explorer (ISEE) and Ion Release Module (IRM). Program established relations between disruption and flow events, and made observations on the nature of electric field fluctuations and plasma sheet flows.

Evaluation of laminar flow control system concepts for subsonic commercial transport aircraft

NASA Technical Reports Server (NTRS)

1979-01-01

Results of a 2-year study are reported which were carried out to extend the development of laminar flow control (LFC) technology and evaluate LFC systems concepts. The overall objective of the LFC program is to provide a sound basis for industry decisions on the application of LFC to future commercial transports. The study was organized into major tasks to support the stated objectives through application of LFC systems concepts to a baseline LFC transport initially generated for the study. Based on competitive evaluation of these concepts, a final selection was made for incorporation into the final design of an LFC transport which also included other advanced technology elements appropriate to the 1990 time period.

Minnowbrook IV: 2003 Workshop on Transition and Unsteady Aspects of Turbomachinery Flows

NASA Technical Reports Server (NTRS)

LaGraff, John E. (Editor); Ashpis, David E. (Editor)

2004-01-01

On August 17 to 20, 2003, over 40 attendees participated in a workshop entitled "Minnowbrook IV.2003 Workshop on Transition and Unsteady Aspects of Turbomachinery Flows. Earlier themes focused on improving the understanding of late stage (final breakdown) of boundary layer transition. The specific engineering application of improving design codes for turbomachinery was encouraged by the attendance of representatives from gas turbine manufacturers. Written papers were not requested. Abstracts and copies of figures were the only written record of the workshop aside from specifically commissioned transcriptions of a workshop summary and the extensive working group reports, discussions, and summary that followed on the final morning of the workshop.

Cardiac fluid dynamics meets deformation imaging.

PubMed

Dal Ferro, Matteo; Stolfo, Davide; De Paris, Valerio; Lesizza, Pierluigi; Korcova, Renata; Collia, Dario; Tonti, Giovanni; Sinagra, Gianfranco; Pedrizzetti, Gianni

2018-02-20

Cardiac function is about creating and sustaining blood in motion. This is achieved through a proper sequence of myocardial deformation whose final goal is that of creating flow. Deformation imaging provided valuable contributions to understanding cardiac mechanics; more recently, several studies evidenced the existence of an intimate relationship between cardiac function and intra-ventricular fluid dynamics. This paper summarizes the recent advances in cardiac flow evaluations, highlighting its relationship with heart wall mechanics assessed through the newest techniques of deformation imaging and finally providing an opinion of the most promising clinical perspectives of this emerging field. It will be shown how fluid dynamics can integrate volumetric and deformation assessments to provide a further level of knowledge of cardiac mechanics.

Transport of self-propelling bacteria in micro-channel flow.

PubMed

Costanzo, A; Di Leonardo, R; Ruocco, G; Angelani, L

2012-02-15

Understanding the collective motion of self-propelling organisms in confined geometries, such as that of narrow channels, is of great theoretical and practical importance. By means of numerical simulations we study the motion of model bacteria in 2D channels under different flow conditions: fluid at rest, steady and unsteady flow. We find aggregation of bacteria near channel walls and, in the presence of external flow, also upstream swimming, which turns out to be a very robust result. Detailed analysis of bacterial velocity and orientation fields allows us to quantify the phenomenon by varying cell density, channel width and fluid velocity. The tumbling mechanism turns out to have strong influence on velocity profiles and particle flow, resulting in a net upstream flow in the case of non-tumbling organisms. Finally we demonstrate that upstream flow can be enhanced by a suitable choice of an unsteady flow pattern.

Dilution jets in accelerated cross flows. Ph.D. Thesis Final Report

NASA Technical Reports Server (NTRS)

Lipshitz, A.; Greber, I.

1984-01-01

Results of flow visualization experiments and measurements of the temperature field produced by a single jet and a row of dilution jets issued into a reverse flow combustor are presented. The flow in such combustors is typified by transverse and longitudinal acceleration during the passage through its bending section. The flow visualization experiments are designed to examine the separate effects of longitudinal and transverse acceleration on the jet trajectory and spreading rate. A model describing a dense single jet in a lighter accelerating cross flow is developed. The model is based on integral conservation equations, including the pressure terms appropriate to accelerating flows. It uses a modified entrainment correlation obtained from previous experiments of a jet in a cross stream. The flow visualization results are compared with the model calculations in terms of trajectories and spreading rates. Each experiment is typified by a set of three parameters: momentum ratio, density ratio and the densimetric Froude number.

Numerical Prediction of Turbulent Oscillating Flow and Heat Transfer in Pipes with Various End Geometries. Ph.D. Thesis, Final Report

NASA Technical Reports Server (NTRS)

Oseid, Kirk Leroi

1995-01-01

Unsteady flow is present in man, machine and nature. The flow of blood in arteries and capillaries in the human body is pulsatile-composed of a mean flow superposed with an oscillating component. The tides that wash in and out of rivers, harbors and estuaries are unsteady flows with very long periods of oscillation. Many engineering devices employ pulsatile and oscillating flow. Pulsating flow is defined here as a periodic flow with a net displacement of fluid over each flow cycle. Oscillating flow is defined as a period flow with a zero mean over each cycle. The subject of this thesis is oscillating flow and heat transfer in pipes which make up the heater and cooler sections of the NASA Space Power Research Engine (SPRE) currently under development. This engine uses the Stirling cycle as the thermal energy converter in a power plant for future space applications. The information presented in this thesis will of course be applicable to the design of many types of machinery which employ oscillating flow and heat transfer.

Three-dimensional turbulent near-wall flows in streamwise corners: Current state and questions

NASA Astrophysics Data System (ADS)

Kornilov, V. I.

2017-10-01

Current advances in experimental and computational studies of three-dimensional (3-D) near-wall turbulent flows in streamwise corners (SC) including the boundary-layer transition are reviewed. The focus is the structure, properties and main regularities of such flows in a wide range of variable conditions and basic parameters. A variety of different kinds of near-wall streamwise corner flows is displayed. Analysis of approaches for modeling of the near-wall corner flow in laboratory experiment is given. The problem of simulation of such flows where some ambiguities remain is discussed. The main factors on the structure of the flow in streamwise corners are analyzed. Also, the effectiveness of flow control by streamwise vortices in the junction regions of aerodynamic surfaces is shown. Finally, some important properties of the modified near-wall turbulent corner flows which have been revealed experimentally, in particular, for the flow near the wing/body junction (WBJ), can be used as an attractive alternative for real applications.

Resonant Doppler velocimetry in supersonic nitrogen flow. Ph.D. Thesis. Final Report, 31 Oct. 1979 - 31 Jul. 1982

NASA Technical Reports Server (NTRS)

Cheng, S. W. S.

1982-01-01

The development of the Resonant Doppler Velocimeter (RDV) is discussed. It is a new nonintrusive laser technique for flow diagnosis. The RDV technique is applied to supersonic nitrogen flow with sodium atoms as tracer particles. The measurements are achieved by shining a tunable single frequency laser beam into the flow. The resonant absorption spectrum of the seeded species is determined by observing the fluorescence signal intensity as a function of excitation wavelength. By comparing the peak absorption wavelength with a reference frequency marker, the flow velocity along the excitation beam can be obtained through the Doppler shift relation. By fitting the spectrum with a theoretical line profile, the static temperature and pressure of the flow an be determined.

Identification of vortices in complex flows

NASA Astrophysics Data System (ADS)

Chakraborty, P.; Balachandar, S.; Adrian, R. J.

2007-12-01

Dating back to Leonardo da Vinci's famous sketches of vortices in turbulent flows, fluid dynamicists for over five centuries have continued to visualize and interpret complex flows in terms of motion of vortices. Nevertheless, much debate surrounds the question of how to unambiguously define vortices in complex flows. This debate has resulted in the availability of many vortex identification criteria---mathematical statements of what constitutes a vortex. Here we review the popularly used local or point- wise vortex identification criteria. Based on local flow kinematics, we describe a unified framework to interpret the similarities and differences in the usage of these criteria. We discuss the limitations on the applicability of these criteria when there is a significant component of vortex interactions. Finally, we provide guidelines for applying these criteria to geophysical flows.

Three dimensional drop tracking flow chamber for coalescence studies

DOE PAGES

Grillet, Anne M.; Brooks, Carlton F.; Bourdon, Chris J.; ...

2007-09-12

Here, we have developed a novel flow chamber which imposes a controlled axisymmetric stagnation flow to enable the study of external flow effects on coalescence dynamics. This system allows for the first time the precise positioning of a drop in a three dimensional flow and additionally enforces a highly symmetric flow around the drop. We focus on the study of a single drop approaching a stationary flat plane as this is analogous to two drops approaching each other. A single drop is created and then guided along the unsteady center line of a stagnation flow. The real time computer controlmore » algorithm analyzes video images of the drop in two orthogonal planes and manipulates flow restricting valves along the four outlets of the flow. We demonstrate using particle image velocimetry that the computer control not only controls the drop position but also ensures a symmetric flow inside the flow chamber. Finally, this chamber will enable a detailed investigation of the drainage of the thin film between the drop and the lower surface in order to probe the effect of external flow on coalescence.« less

Analysis of Mass Profiles and Cooling Flows of Bright, Early-Type Galaxies AO2, AO3 and Surface Brightness Profiles and Energetics of Intracluster Gas in Cool Galaxy Clusters AO3

NASA Technical Reports Server (NTRS)

White, Raymond E., III

1998-01-01

This final report uses ROSAT observations to analyze two different studies. These studies are: Analysis of Mass Profiles and Cooling Flows of Bright, Early-Type Galaxies; and Surface Brightness Profiles and Energetics of Intracluster Gas in Cool Galaxy Clusters.

77 FR 31577 - Non-Malleable Cast Iron Pipe Fittings From the People's Republic of China: Final Results of...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-05-29

... as ``flared joint.'' The flared joint, once made fast, permits brake fluid to flow through channels...), or push on ends (PO), or flanged ends and produced to the American Water Works Association (AWWA... flared joint, once made fast, permits brake fluid to flow through channels that never exceed 3.8...

77 FR 13496 - Effective Date for the Water Quality Standards for the State of Florida's Lakes and Flowing Waters

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-07

... Effective Date for the Water Quality Standards for the State of Florida's Lakes and Flowing Waters AGENCY... Protection Agency (EPA) is finalizing an extension of the March 6, 2012 effective date of the ``Water Quality... INFORMATION: I. General Information Does this action apply to me? Citizens concerned with water quality in...

CARBON AND NUTRIENT FLOW THROUGH MULTIPLE TROPHIC LEVELS IN A CO2-ENRICHED SOUTHERN PINE FOREST COMMUNITY - FINAL TECHNICAL REPORT

USDA-ARS?s Scientific Manuscript database

The ability to predict the consequences of global change is predicated on our understanding of controls of energy and material flows through ecosystems. Research was conducted at the Forest Atmosphere CO2 Transfer and Storage-1 (FACTS-1) site at Duke University. This is a flagship experiment of the ...

STS-112 final main engine is installed after welding/polishing process

NASA Technical Reports Server (NTRS)

2002-01-01

KENNEDY SPACE CENTER, FLA. -- Workers on the engine lift get ready to install the last engine in orbiter Atlantis after a welding and polishing process was undertaken on flow liners where cracks were detected. All engines were removed for inspection of flow liners. Atlantis will next fly on mission STS-112, scheduled for launch no earlier than Oct. 2.

Numerical study of soap-film flow by nonuniform alternating electric fields

NASA Astrophysics Data System (ADS)

Nasiri, M.; Shirsavar, R.; Mollaei, S.; Ramos, A.

2017-02-01

Fluid flow of suspended liquid films induced by non-uniform alternating electric fields has been reported. The electric fields were generated by two rod-like electrodes perpendicular to the fluid surface. The observed fluid flow was explained qualitatively by considering a charge induction mechanism, where the electric field actuates on the charge induced on the film surface. In this paper we perform a numerical study of this fluid flow taking into account the charge induction mechanism. The numerical results are compared with experiments and good agreement is found. Finally, we propose the application of the device as a new kind of two dimensional fluid pump.

Numerical study of soap-film flow by nonuniform alternating electric fields.

PubMed

Nasiri, M; Shirsavar, R; Mollaei, S; Ramos, A

2017-02-01

Fluid flow of suspended liquid films induced by non-uniform alternating electric fields has been reported. The electric fields were generated by two rod-like electrodes perpendicular to the fluid surface. The observed fluid flow was explained qualitatively by considering a charge induction mechanism, where the electric field actuates on the charge induced on the film surface. In this paper we perform a numerical study of this fluid flow taking into account the charge induction mechanism. The numerical results are compared with experiments and good agreement is found. Finally, we propose the application of the device as a new kind of two dimensional fluid pump.

Transition to turbulence in plane channel flows

NASA Technical Reports Server (NTRS)

Biringen, S.

1984-01-01

Results obtained from a numerical simulation of the final stages of transition to turbulence in plane channel flow are described. Three dimensional, incompressible Navier-Stokes equations are numerically integrated to obtain the time evolution of two and three dimensional finite amplitude disturbances. Computations are performed on CYBER-203 vector processor for a 32x51x32 grid. Results are presented for no-slip boundary conditions at the solid walls as well as for periodic suction blowing to simulate active control of transition by mass transfer. Solutions indicate that the method is capable of simulating the complex character of vorticity dynamics during the various stages of transition and final breakdown. In particular, evidence points to the formation of a lambda-shape vortex and the subsequent system of horseshoe vortices inclined to the main flow direction as the main elements of transition. Calculations involving periodic suction-blowing indicate that interference with a wave of suitable phase and amplitude reduces the disturbance growth rates.

Key Technology of Real-Time Road Navigation Method Based on Intelligent Data Research

PubMed Central

Tang, Haijing; Liang, Yu; Huang, Zhongnan; Wang, Taoyi; He, Lin; Du, Yicong; Ding, Gangyi

2016-01-01

The effect of traffic flow prediction plays an important role in routing selection. Traditional traffic flow forecasting methods mainly include linear, nonlinear, neural network, and Time Series Analysis method. However, all of them have some shortcomings. This paper analyzes the existing algorithms on traffic flow prediction and characteristics of city traffic flow and proposes a road traffic flow prediction method based on transfer probability. This method first analyzes the transfer probability of upstream of the target road and then makes the prediction of the traffic flow at the next time by using the traffic flow equation. Newton Interior-Point Method is used to obtain the optimal value of parameters. Finally, it uses the proposed model to predict the traffic flow at the next time. By comparing the existing prediction methods, the proposed model has proven to have good performance. It can fast get the optimal value of parameters faster and has higher prediction accuracy, which can be used to make real-time traffic flow prediction. PMID:27872637

Chemical reacting flows

NASA Astrophysics Data System (ADS)

Lezberg, Erwin A.; Mularz, Edward J.; Liou, Meng-Sing

1991-03-01

The objectives and accomplishments of research in chemical reacting flows, including both experimental and computational problems are described. The experimental research emphasizes the acquisition of reliable reacting-flow data for code validation, the development of chemical kinetics mechanisms, and the understanding of two-phase flow dynamics. Typical results from two nonreacting spray studies are presented. The computational fluid dynamics (CFD) research emphasizes the development of efficient and accurate algorithms and codes, as well as validation of methods and modeling (turbulence and kinetics) for reacting flows. Major developments of the RPLUS code and its application to mixing concepts, the General Electric combustor, and the Government baseline engine for the National Aerospace Plane are detailed. Finally, the turbulence research in the newly established Center for Modeling of Turbulence and Transition (CMOTT) is described.

Variable mass diffusion effects on free convection flow past an impulsively started infinite vertical plate

NASA Astrophysics Data System (ADS)

Rushi Kumar, B.; Jayakar, R.; Vijay Kumar, A. G.

2017-11-01

An exact analysis of the problem of free convection flow of a viscous incompressible chemically reacting fluid past an infinite vertical plate with the flow due to impulsive motion of the plate with Newtonian heating in the presence of thermal radiation and variable mass diffusion is performed. The resulting governing equations were tackled by Laplace transform technique. Finally the effects of pertinent flow parameters such as the radiation parameter, chemical reaction parameter, buoyancy ratio parameter, thermal Grashof number, Schmidt number, Prandtl number and time on the velocity, temperature, concentration and skin friction for both aiding and opposing flows were examined in detail when Pr=0.71(conducting air) and Pr=7.0(water).

Sap flow sensors: construction, quality control and comparison.

PubMed

Davis, Tyler W; Kuo, Chen-Min; Liang, Xu; Yu, Pao-Shan

2012-01-01

This work provides a design for two types of sensors, based on the thermal dissipation and heat ratio methods of sap flow calculation, for moderate to large scale deployments for the purpose of monitoring tree transpiration. These designs include a procedure for making these sensors, a quality control method for the final products, and a complete list of components with vendors and pricing information. Both sensor designs were field tested alongside a commercial sap flow sensor to assess their performance and show the importance for quality controlling the sensor outputs. Results show that for roughly 2% of the cost of commercial sensors, self-made sap flow sensors can provide acceptable estimates of the sap flow measurements compared to the commercial sensors.

Shock formation induced by poloidal flow and its effects on the edge stability in tokamaks

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

Seol, J.; Aydemir, A. Y.; Shaing, K. C.

2016-04-15

In the high confinement mode of tokamaks, magnitude of the radial electric field increases at the edge. Thus, the poloidal flow inside the transport barrier can be sonic when the edge pressure gradient is not steep enough to make the poloidal flow subsonic. When the poloidal Mach number is close to unity, a shock appears in the low field side and causes a large density perturbation. In this study, we describe a shock induced by the sonic poloidal plasma flow. Then, an entropy production across the shock is calculated. Finally, we introduce a simple model for Type III edge localizedmore » modes using the poloidal density variation driven by the sonic poloidal flow.« less

Load-Flow in Multiphase Distribution Networks: Existence, Uniqueness, Non-Singularity, and Linear Models

DOE PAGES

Bernstein, Andrey; Wang, Cong; Dall'Anese, Emiliano; ...

2018-01-01

This paper considers unbalanced multiphase distribution systems with generic topology and different load models, and extends the Z-bus iterative load-flow algorithm based on a fixed-point interpretation of the AC load-flow equations. Explicit conditions for existence and uniqueness of load-flow solutions are presented. These conditions also guarantee convergence of the load-flow algorithm to the unique solution. The proposed methodology is applicable to generic systems featuring (i) wye connections; (ii) ungrounded delta connections; (iii) a combination of wye-connected and delta-connected sources/loads; and, (iv) a combination of line-to-line and line-to-grounded-neutral devices at the secondary of distribution transformers. Further, a sufficient condition for themore » non-singularity of the load-flow Jacobian is proposed. Finally, linear load-flow models are derived, and their approximation accuracy is analyzed. Theoretical results are corroborated through experiments on IEEE test feeders.« less

Installation of a Low Flow Unit at the Abiquiu Hydroelectric Facility

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

Jack Q. Richardson

2012-06-28

Final Technical Report for the Recovery Act Project for the Installation of a Low Flow Unit at the Abiquiu Hydroelectric Facility. The Abiquiu hydroelectric facility existed with two each 6.9 MW vertical flow Francis turbine-generators. This project installed a new 3.1 MW horizontal flow low flow turbine-generator. The total plant flow range to capture energy and generate power increased from between 250 and 1,300 cfs to between 75 and 1,550 cfs. Fifty full time equivalent (FTE) construction jobs were created for this project - 50% (or 25 FTE) were credited to ARRA funding due to the ARRA 50% project costmore » match. The Abiquiu facility has increased capacity, increased efficiency and provides for an improved aquatic environment owing to installed dissolved oxygen capabilities during traditional low flow periods in the Rio Chama. A new powerhouse addition was constructed to house the new turbine-generator equipment.« less

Driving Parameters for Distributed and Centralized Air Transportation Architectures

NASA Technical Reports Server (NTRS)

Feron, Eric

2001-01-01

This report considers the problem of intersecting aircraft flows under decentralized conflict avoidance rules. Using an Eulerian standpoint (aircraft flow through a fixed control volume), new air traffic control models and scenarios are defined that enable the study of long-term airspace stability problems. Considering a class of two intersecting aircraft flows, it is shown that airspace stability, defined both in terms of safety and performance, is preserved under decentralized conflict resolution algorithms. Performance bounds are derived for the aircraft flow problem under different maneuver models. Besides analytical approaches, numerical examples are presented to test the theoretical results, as well as to generate some insight about the structure of the traffic flow after resolution. Considering more than two intersecting aircraft flows, simulations indicate that flow stability may not be guaranteed under simple conflict avoidance rules. Finally, a comparison is made with centralized strategies to conflict resolution.

Evolution of secondary whirls in thermoconvective vortices: Strengthening, weakening, and disappearance in the route to chaos

NASA Astrophysics Data System (ADS)

Castaño, D.; Navarro, M. C.; Herrero, H.

2016-01-01

The appearance, evolution, and disappearance of periodic and quasiperiodic dynamics of fluid flows in a cylindrical annulus locally heated from below are analyzed using nonlinear simulations. The results reveal a route of the transition from a steady axisymmetric vertical vortex to a chaotic flow. The chaotic flow regime is reached after a sequence of successive supercritical Hopf bifurcations to periodic, quasiperiodic, and chaotic flow regimes. A scenario similar to the Ruelle-Takens-Newhouse scenario is verified in this convective flow. In the transition to chaos we find the appearance of subvortices embedded in the primary axisymmetric vortex, flows where the subvortical structure strengthens and weakens, that almost disappears before reforming again, leading to a more disorganized flow to a final chaotic regime. Results are remarkable as they connect to observations describing formation, weakening, and virtual disappearance before revival of subvortices in some atmospheric swirls such as dust devils.

Load-Flow in Multiphase Distribution Networks: Existence, Uniqueness, Non-Singularity, and Linear Models

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

Bernstein, Andrey; Wang, Cong; Dall'Anese, Emiliano

This paper considers unbalanced multiphase distribution systems with generic topology and different load models, and extends the Z-bus iterative load-flow algorithm based on a fixed-point interpretation of the AC load-flow equations. Explicit conditions for existence and uniqueness of load-flow solutions are presented. These conditions also guarantee convergence of the load-flow algorithm to the unique solution. The proposed methodology is applicable to generic systems featuring (i) wye connections; (ii) ungrounded delta connections; (iii) a combination of wye-connected and delta-connected sources/loads; and, (iv) a combination of line-to-line and line-to-grounded-neutral devices at the secondary of distribution transformers. Further, a sufficient condition for themore » non-singularity of the load-flow Jacobian is proposed. Finally, linear load-flow models are derived, and their approximation accuracy is analyzed. Theoretical results are corroborated through experiments on IEEE test feeders.« less

The Glider registry.

PubMed

Secco, Gioel Gabrio; Rittger, Harald; Hoffmann, Stefan; Richardt, Gert; Abdel-Wahab, Mohamed; Reinecke, Holger; Lotan, Chaim; Werner, Gerald; Sievert, Horst; Foin, Nicolas; Di Mario, Carlo

2017-01-01

Provisional stenting of the side-branch (SB) is the universally accepted gold standard while there is still controversy on the usefulness of routine dilatation of the SB ostium. Recrossing the struts of a previously deployed stent with a wire and a balloon can prove challenging and is occasionally unsuccessful, mainly because the balloon tip hits a stent strut. This prospective multicenter international registry tested the crossing ability procedural results of a new-dedicated ultrashort balloon specifically designed for side branch dilatation (Glider, TriReme Medical, Pleasanton, CA, USA). One hundred and twenty five patients (for a total of 131 bifurcation lesions) were enrolled in the registry between January 2009 and May 2012. The Glider was used as first choice in alternative to conventional balloon (group I, 72%) or as bail-out after unsuccessful previous attempt at crossing with small conventional low-profile balloons (group II, 28%). Postprocedural coronary artery dissections and in-hospital MACE (death, myocardial infarction and repeat revascularization) were assessed. Technical success was defined as the ability of the Glider to recross the struts of a previously deployed stent while procedural success was defined as less of residual 50% diameter stenosis at the origin of the SB with a final TIMI 3 and/or freedom from in-hospital MACE. Technical success was achieved, respectively, in 92% (group I), and 83% (group II). Clinical and angiographic procedural success was achieved in 98% of the lesions. In Group II, no other balloon of the same size could cross in cases where Glider could not. A total of 13 complications were observed, including nine ostial SB dissection four of which needed a second stent on the SB, one stent loss, two severe coronary spasms, and two by thrombus formation. The unique possibility offered by this short dedicated balloon to orientate its beveled tip provides an effective strategy for recrossing stent struts when conventional low profile balloons fail achieving greater SB ostial expansion thus reducing the incidence of strut malapposition during provisional treatment of bifurcational lesions. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Statistical Distribution of Inflation on Lava Flows: Analysis of Flow Surfaces on Earth and Mars

NASA Technical Reports Server (NTRS)

Glazel, L. S.; Anderson, S. W.; Stofan, E. R.; Baloga, S.

2003-01-01

The surface morphology of a lava flow results from processes that take place during the emplacement of the flow. Certain types of features, such as tumuli, lava rises and lava rise pits, are indicators of flow inflation or endogenous growth of a lava flow. Tumuli in particular have been identified as possible indicators of tube location, indicating that their distribution on the surface of a lava flow is a junction of the internal pathways of lava present during flow emplacement. However, the distribution of tumuli on lava flows has not been examined in a statistically thorough manner. In order to more rigorously examine the distribution of tumuli on a lava flow, we examined a discrete flow lobe with numerous lava rises and tumuli on the 1969 - 1974 Mauna Ulu flow at Kilauea, Hawaii. The lobe is located in the distal portion of the flow below Holei Pali, which is characterized by hummocky pahoehoe flows emplaced from tubes. We chose this flow due to its discrete nature allowing complete mapping of surface morphologies, well-defined boundaries, well-constrained emplacement parameters, and known flow thicknesses. In addition, tube locations for this Mauna Ulu flow were mapped by Holcomb (1976) during flow emplacement. We also examine the distribution of tumuli on the distal portion of the hummocky Thrainsskjoldur flow field provided by Rossi and Gudmundsson (1996). Analysis of the Mauna Ulu and Thrainsskjoldur flow lobes and the availability of high-resolution MOC images motivated us to look for possible tumuli-dominated flow lobes on the surface of Mars. We identified a MOC image of a lava flow south of Elysium Mons with features morphologically similar to tumuli. The flow is characterized by raised elliptical to circular mounds, some with axial cracks, that are similar in size to the tumuli measured on Earth. One potential avenue of determining whether they are tumuli is to look at the spatial distribution to see if any patterns similar to those of tumuli-dominated terrestrial flows can be identified. Since tumuli form by the injection of lava beneath a crust, the distribution of tumuli on a flow should represent the distribution of thermally preferred pathways beneath the surface of the crust. That distribution of thermally preferred pathways may be a function of the evolution of a basaltic lava flow. As a longer-lived flow evolves, initially broad thermally preferred pathways would evolve to narrower, more well-defined tube-like pathways. The final flow morphology clearly preserves the growth of the flow over time, with inflation features indicating pathways that were not necessarily contemporaneously active. Here, we test using statistical analysis whether this final flow morphology produces distinct distributions that can be used to readily determine the distribution of thermally preferred pathways beneath the surface of the crust.

Resin impregnation process for producing a resin-fiber composite

NASA Technical Reports Server (NTRS)

Palmer, Raymond J. (Inventor); Moore, William E. (Inventor)

1994-01-01

Process for vacuum impregnation of a dry fiber reinforcement with a curable resin to produce a resin-fiber composite, by drawing a vacuum to permit flow of curable liquid resin into and through a fiber reinforcement to impregnate same and curing the resin-impregnated fiber reinforcement at a sufficient temperature and pressure to effect final curing. Both vacuum and positive pressure, e.g. autoclave pressure, are applied to the dry fiber reinforcement prior to application of heat and prior to any resin flow to compact the dry fiber reinforcement, and produce a resin-fiber composite of reduced weight, thickness and resin content, and improved mechanical properties. Preferably both a vacuum and positive pressure, e.g. autoclave pressure, are also applied during final curing.

Analysis of fast chlorophyll fluorescence rise (O-K-J-I-P) curves in green fruits indicates electron flow limitations at the donor side of PSII and the acceptor sides of both photosystems.

PubMed

Kalachanis, Dimitrios; Manetas, Yiannis

2010-07-01

Limited evidence up to now indicates low linear photosynthetic electron flow and CO(2) assimilation rates in non-foliar chloroplasts. In this investigation, we used chlorophyll fluorescence techniques to locate possible limiting steps in photosystem function in exposed, non-stressed green fruits (both pericarps and seeds) of three species, while corresponding leaves served as controls. Compared with leaves, fruit photosynthesis was characterized by less photon trapping and less quantum yields of electron flow, while the non-photochemical quenching was higher and potentially linked to enhanced carotenoid/chlorophyll ratios. Analysis of fast chlorophyll fluorescence rise curves revealed possible limitations both in the donor (oxygen evolving complex) and the acceptor (Q(A)(-)--> intermediate carriers) sides of photosystem II (PSII) indicating innately low PSII photochemical activity. On the other hand, PSI was characterized by faster reduction of its final electron acceptors and their small pool sizes. We argue that the fast reductive saturation of final PSI electron acceptors may divert electrons back to intermediate carriers facilitating a cyclic flow around PSI, while the partial inactivation of linear flow precludes strong reduction of plastoquinone. As such, the photosynthetic attributes of fruit chloroplasts may act to replenish the ATP lost because of hypoxia usually encountered in sink organs with high diffusive resistance to gas exchange.

Convective thinning of the lithosphere: A mechanism for rifting and mid-plate volcanism on Earth, Venus, and Mars

NASA Technical Reports Server (NTRS)

Spohn, T.; Schubert, G.

1982-01-01

Thinning of the Earth's lithosphere by heat advected to its base is a possible mechanism for continental rifting and continental and oceanic mid-plate volcanism. It might also account for continental rifting-like processes and volcanism on Venus and Mars. Earth's continental lithosphere can be thinned to the crust in a few tens of million years by heat advected at a rate of 5 to 10 times the normal basal heat flux. This much heat is easily carried to the lithosphere by mantle plumes. The continent is not required to rest over the mantle hot spot but may move at tens of millimeters per year. Because of the constant level of crustal radioactive heat production, the ratio of the final to the initial surface heat flow increases much less than the ratio of the final to initial basal heat flow. For large increases in asthenospheric heat flow, the lithosphere is almost thinned to the crust before any significant change in surface heat flow occurs. Uplift due to thermal expansion upon thinning is a few kilometers. The oceanic lithosphere can be thinned to the crust in less than 10 million years if the heat advection is at a rate around 5 or more times the basal heat flow into 100 Ma old lithosphere. Uplift upon thinning can compensate the subsidence of spreading and cooling lithosphere.

An Approach to Estimate the Flow Through an Irregular Fracture

NASA Astrophysics Data System (ADS)

Liu, Q. Q.; Fan, H. G.

2011-09-01

A new model to estimate the flow in a fracture has been developed in this paper. This model used two sinusoidal-varying walls with different phases to replace the flat planes in the cubic law model. The steady laminar flow between non-symmetric sinusoidal surfaces was numerically solved. The relationships between the effective hydraulic apertures and the phase retardation for different amplitudes and wavelengths are investigated respectively. Finally, a formula of the effective hydraulic aperture of the fracture was carried out based on the numerical results.

Steady and unsteady three-dimensional transonic flow computations by integral equation method

NASA Technical Reports Server (NTRS)

Hu, Hong

1994-01-01

This is the final technical report of the research performed under the grant: NAG1-1170, from the National Aeronautics and Space Administration. The report consists of three parts. The first part presents the work on unsteady flows around a zero-thickness wing. The second part presents the work on steady flows around non-zero thickness wings. The third part presents the massively parallel processing implementation and performance analysis of integral equation computations. At the end of the report, publications resulting from this grant are listed and attached.

Recent advances in hypersonic technology

NASA Technical Reports Server (NTRS)

Dwoyer, Douglas L.

1990-01-01

This paper will focus on recent advances in hypersonic aerodynamic prediction techniques. Current capabilities of existing numerical methods for predicting high Mach number flows will be discussed and shortcomings will be identified. Physical models available for inclusion into modern codes for predicting the effects of transition and turbulence will also be outlined and their limitations identified. Chemical reaction models appropriate to high-speed flows will be addressed, and the impact of their inclusion in computational fluid dynamics codes will be discussed. Finally, the problem of validating predictive techniques for high Mach number flows will be addressed.

Assessment and application of Reynolds stress closure models to high-speed compressible flows

NASA Technical Reports Server (NTRS)

Gatski, T. B.; Sarkar, S.; Speziale, C. G.; Balakrishnan, L.; Abid, R.; Anderson, E. C.

1990-01-01

The paper presents results from the development of higher order closure models for the phenomological modeling of high-speed compressible flows. The work presented includes the introduction of an improved pressure-strain correlationi model applicable in both the low- and high-speed regime as well as modifications to the isotropic dissipation rate to account for dilatational effects. Finally, the question of stiffness commonly associated with the solution of two-equation and Reynolds stress transport equations in wall-bounded flows is examined and ways of relaxing these restrictions are discussed.

View of equipment used for Heat Flow and Convection Experiment

NASA Image and Video Library

1972-12-17

AS17-162-24063 (7-19 Dec. 1972) --- A close-up view of the equipment used for the Heat Flow and Convection Experiment, an engineering and operational test and demonstration carried out aboard the Apollo 17 command module during the final lunar landing mission in NASA's Apollo program. Three test cells were used in the demonstration for measuring and observing fluid flow behavior in the absence of gravity in space flight. Data obtained from such demonstrations will be valuable in the design of future science experiments and for manufacturing processes in space.

Fluid mechanics of fusion lasers. Final report, September 11, 1978-June 5, 1980

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

Shwartz, J; Kulkarny, V A; Ausherman, D A

1980-01-01

Flow loop components required to operate continuous-flow, repetitively-pulsed CO/sub 2/ and KrF laser drivers for ICF were identified and their performance requirements were specified. It was found that the laser flow loops can have a major effect on the laser beam quality and overall efficiency. The pressure wave suppressor was identified as the most critical flow loop component. The performance of vented side-wall suppressors was evaluated both analytically and experimentally and found capable of meeting the performance requirements of the CO/sub 2/ and KrF fusion lasers. All other laser flow loop components are essentially similar to those used in conventional,more » low speed wind tunnels and are therefore well characterized and can be readily incorporated into fusion laser flow systems designs.« less

Two-dimensional dynamics of a trapped active Brownian particle in a shear flow

NASA Astrophysics Data System (ADS)

Li, Yunyun; Marchesoni, Fabio; Debnath, Tanwi; Ghosh, Pulak K.

2017-12-01

We model the two-dimensional dynamics of a pointlike artificial microswimmer diffusing in a harmonic trap subject to the shear flow of a highly viscous medium. The particle is driven simultaneously by the linear restoring force of the trap, the drag force exerted by the flow, and the torque due to the shear gradient. For a Couette flow, elliptical orbits in the noiseless regime, and the correlation functions between the particle's displacements parallel and orthogonal to the flow are computed analytically. The effects of thermal fluctuations (translational) and self-propulsion fluctuations (angular) are treated separately. Finally, we discuss how to extend our approach to the diffusion of a microswimmer in a Poiseuille flow. These results provide an accurate reference solution to investigate, both numerically and experimentally, hydrodynamics corrections to the diffusion of active matter in confined geometries.

Laser velocimetry in highly three-dimensional and vortical flows

NASA Technical Reports Server (NTRS)

Novak, C. J.; Huie, C. R.; Cornelius, K. C.

1986-01-01

The need for experimentally determined 3-D velocity information is crucial to the understanding of highly 3-dimensional and vortical flow fields. In addition to gaining an understanding of the physics of flow fields, a correlation of velocity data is needed for advanced computational modelling. A double pass method for acquiring 3-D flow field information using a 2-D laser velocimeter (LV) is described. The design and implementation of a 3-D LV with expanded capabilities to acquire real-time 3-D flow field information are also described. Finally, the use of such an instrument in a wind tunnel study of a generic fighter configuration is described. The results of the wind tunnel study highlight the complexities of 3-D flow fields, particularly when the vortex behavior is examined over a range of angles of attack.

The effects of radiation drag on radial, relativistic hydromagnetic winds

NASA Technical Reports Server (NTRS)

Li, Zhi-Yun; Begelman, Mitchell C.; Chiueh, Tzihong

1992-01-01

The effects of drag on an idealized relativistic MHD wind of radial geometry are studied. The astrophysical motivation is to understand the effects of radiation drag on the dynamics of a jet or wind passing through the intense radiation field of an accreting compact object. From a critical point analysis, it is found that a slow magnetosonic point can appear in a dragged flow even in the absence of gravitational force, as a result of a balance between the drag force and the combination of thermal pressure and centrifugal forces. As in the undragged case, the Alfven point does not impose any constraints on the flow. Although it is formally possible for a dragged flow to possess more than one fast magnetosonic point, it is shown that this is unlikely in practice. In the limit of a 'cold', centrifugally driven flow, it is shown that the fast magnetosonic point moves to infinite radius, just as in the drag-free case. For a given mass flux, the total energy output carried to infinity, and the final partition between the kinetic energy and the Poynting flux, are the same for the dragged and the drag-free flows. The main effects of radiation drag are to increase the amount of energy and angular momentum extracted from the source and to redistribute the regions where acceleration occurs in the flow. This is accomplished through the storage and release of magnetic energy, as a result of additional winding and compression of the field caused by the action of the drag. For a relativistic wind, the dissipated energy can exceed the final kinetic energy of the flow and may be comparable to the total flow energy (which is dominated by Poynting flux). The energy lost to radiation drag will appear as a Doppler-boosted beam of scattered radiation, which could dominate the background radiation if the flow is well-collimated.

Rheological of chocolate-flavored, reduced-calories coating as a function of conching process.

PubMed

Medina-Torres, Luis; Sanchez-Olivares, Guadalupe; Nuñez-Ramirez, Diola Marina; Moreno, Leonardo; Calderas, Fausto

2014-07-01

Continuous flow and linear viscoelasticity rheology of chocolate coating is studied in this work using fat substitute gums (xanthan, GX). An alternative conching process, using a Rotor-Estator (RE) type impeller, is proposed. The objective is to obtain a chocolate coating material with improved flow properties. Characterization of the final material through particle size distribution (PSD), differential scanning calorimetry (DSC) and proximal analysis is reported. Particle size distribution of the final material showed less polydispersity and therefore, greater homogeneity; fusion points were also generated at around 20 °C assuming crystal type I (β'2) and II (α). Moreover, the final material exhibited crossover points (higher structure material), whereas the commercial brand chocolate used for comparison did not. The best conditions to produce the coating were maturing of 36 h and 35 °C, showing crossover points around 76 Pa and a 0.505 solids particle dispersion (average particle diameter of 0.364 μm), and a fusion point at 20.04 °C with a ΔHf of 1.40 (J/g). The results indicate that xanthan gum is a good substitute for cocoa butter and provides stability to the final product.

Observation of improved and degraded confinement with driven flow on the LAPD

NASA Astrophysics Data System (ADS)

Schaffner, David

2012-10-01

External continuous control over azimuthal flow and flow shear has been achieved in a linear plasma device for the first time allowing for a careful study of the effect of flow shear on pressure-gradient-driven turbulence and transport in the edge of the Large Plasma Device (LAPD). The flow is controlled using biasable iris-like limiters situated axially between the cathode source and main plasma chamber. LAPD rotates spontaneously in the ion diamagnetic direction (IDD); positive limiter bias first reduces, then minimizes (producing a near-zero shear state), and finally reverses the flow into the electron diamagnetic direction (EDD). Degradation of particle confinement is observed in the minimum shearing state and reduction in turbulent particle flux is observed with increasing shearing in both flow directions. Near-complete suppression of turbulent particle flux is observed for shearing rates comparable to the turbulent autocorrelation rate measured in the minimum shear state. Turbulent flux suppression is dominated by amplitude reduction in low-frequency (>10kHz) density fluctuations and a reduction in the radial correlation length. An increase in fluctuations for the highest shearing states is observed with the emergence of a coherent mode which does not lead to net particle transport. Magnetic field is varied in order to explore whether and how field effects transport modification. Calculations of transport equations are used to predict density profiles given source and temperature profiles and can show the level of transport predicted to be necessary in order to produce the experimental density profiles observed. Finally, the variations of density fluctuations and radial correlation length are fit well with power-laws and compare favorably to simple models of shear suppression of transport.

Experimental Study of Impinging Jets Flow-Fields

DTIC Science & Technology

2016-07-27

1 Grant # N000141410830 Experimental Study of Impinging Jet Flow-Fields Final Report for Period: Jun 15, 2014 – Jun 14, 2016 PI: Dennis K...impinging jet model in the absence of any jet heating. The results of the computations had been compared with the experimental data produced in the...of the validity of the computations, and also of the experimental approach. Figure 12a. Initial single

AMTEC Generator: Phase 1 Propane System

DTIC Science & Technology

2002-10-15

Final Report 15 October 2002 17 Figure 18. Model Predictions with a 28W Gross AMTEC Converter, 27 g/hr, 8.3% Overall Efficiency 5 10 15...hot) (C ) fuel flow rate (mg/s) efficiency electrical output cell hot temp Design point: cell power = 28.3 W η thermal = 8.3% fuel flow rate = 7.4...Metal Thermal to Electric Conversion ( AMTEC ) technology converts the heat from

Study of the Cost and Flows of Capital in the Guaranteed Student Loan Program. Final Report.

ERIC Educational Resources Information Center

Touche Ross and Co., Washington, DC.

The flow of capital to and through the Guaranteed Student Loan (GSL) Program and the cost of that capital to the federal government and the individual borrower were studied. A review of the research on student loan capital was conducted, and automated cost models were developed to test assumptions and project future costs. Attention was directed…

Recent advances in two-phase flow numerics

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

Mahaffy, J.H.; Macian, R.

1997-07-01

The authors review three topics in the broad field of numerical methods that may be of interest to individuals modeling two-phase flow in nuclear power plants. The first topic is iterative solution of linear equations created during the solution of finite volume equations. The second is numerical tracking of macroscopic liquid interfaces. The final area surveyed is the use of higher spatial difference techniques.

A modified Fermi-Walker derivative for inextensible flows of binormal spherical image

NASA Astrophysics Data System (ADS)

Suroğlu, Gülden Altay

2018-03-01

Fermi-Walker derivative and biharmonic particle play an important role in skillful applications. We obtain a new characterization on binormal spherical indicatrix by using the Fermi-Walker derivative and parallelism in space. We suggest that an inextensible flow is the necessary and sufficient condition for this particle. Finally, we give some characterizations for a non-rotating frame of this binormal spherical indicatrix.

Physical limits of flow sensing in the left-right organizer

PubMed Central

Ferreira, Rita R; Vilfan, Andrej; Jülicher, Frank; Supatto, Willy; Vermot, Julien

2017-01-01

Fluid flows generated by motile cilia are guiding the establishment of the left-right asymmetry of the body in the vertebrate left-right organizer. Competing hypotheses have been proposed: the direction of flow is sensed either through mechanosensation, or via the detection of chemical signals transported in the flow. We investigated the physical limits of flow detection to clarify which mechanisms could be reliably used for symmetry breaking. We integrated parameters describing cilia distribution and orientation obtained in vivo in zebrafish into a multiscale physical study of flow generation and detection. Our results show that the number of immotile cilia is too small to ensure robust left and right determination by mechanosensing, given the large spatial variability of the flow. However, motile cilia could sense their own motion by a yet unknown mechanism. Finally, transport of chemical signals by the flow can provide a simple and reliable mechanism of asymmetry establishment. DOI: http://dx.doi.org/10.7554/eLife.25078.001 PMID:28613157

Computation of multi-dimensional viscous supersonic flow

NASA Technical Reports Server (NTRS)

Buggeln, R. C.; Kim, Y. N.; Mcdonald, H.

1986-01-01

A method has been developed for two- and three-dimensional computations of viscous supersonic jet flows interacting with an external flow. The approach employs a reduced form of the Navier-Stokes equations which allows solution as an initial-boundary value problem in space, using an efficient noniterative forward marching algorithm. Numerical instability associated with forward marching algorithms for flows with embedded subsonic regions is avoided by approximation of the reduced form of the Navier-Stokes equations in the subsonic regions of the boundary layers. Supersonic and subsonic portions of the flow field are simultaneously calculated by a consistently split linearized block implicit computational algorithm. The results of computations for a series of test cases associated with supersonic jet flow is presented and compared with other calculations for axisymmetric cases. Demonstration calculations indicate that the computational technique has great promise as a tool for calculating a wide range of supersonic flow problems including jet flow. Finally, a User's Manual is presented for the computer code used to perform the calculations.

Regimes of Flow over Complex Structures of Endothelial Glycocalyx: A Molecular Dynamics Simulation Study.

PubMed

Jiang, Xi Zhuo; Feng, Muye; Ventikos, Yiannis; Luo, Kai H

2018-04-10

Flow patterns on surfaces grafted with complex structures play a pivotal role in many engineering and biomedical applications. In this research, large-scale molecular dynamics (MD) simulations are conducted to study the flow over complex surface structures of an endothelial glycocalyx layer. A detailed structure of glycocalyx has been adopted and the flow/glycocalyx system comprises about 5,800,000 atoms. Four cases involving varying external forces and modified glycocalyx configurations are constructed to reveal intricate fluid behaviour. Flow profiles including temporal evolutions and spatial distributions of velocity are illustrated. Moreover, streamline length and vorticity distributions under the four scenarios are compared and discussed to elucidate the effects of external forces and glycocalyx configurations on flow patterns. Results show that sugar chain configurations affect streamline length distributions but their impact on vorticity distributions is statistically insignificant, whilst the influence of the external forces on both streamline length and vorticity distributions are trivial. Finally, a regime diagram for flow over complex surface structures is proposed to categorise flow patterns.

Air flow measurement techniques applied to noise reduction of a centrifugal blower

NASA Astrophysics Data System (ADS)

Laage, John W.; Armstrong, Ashli J.; Eilers, Daniel J.; Olsen, Michael G.; Mann, J. Adin

2005-09-01

The air flow in a centrifugal blower was studied using a variety of flow and sound measurement techniques. The flow measurement techniques employed included Particle Image Velocimetry (PIV), pitot tubes, and a five hole spherical probe. PIV was used to measure instantaneous and ensemble-averaged velocity fields over large area of the outlet duct as a function of fan position, allowing for the visualization of the flow as it leave the fan blades and progressed downstream. The results from the flow measurements were reviewed along side the results of the sound measurements with the goal of identifying sources of noise and inefficiencies in flow performance. The radiated sound power was divided into broadband and tone noise and measures of the flow. The changes in the tone and broadband sound were compared to changes in flow quantities such as the turbulent kinetic energy and Reynolds stress. Results for each method will be presented to demonstrate the strengths of each flow measurement technique as well as their limitations. Finally, the role that each played in identifying noise sources is described.

Aerodynamic Analysis of Multistage Turbomachinery Flows in Support of Aerodynamic Design

NASA Technical Reports Server (NTRS)

Adamczyk, John J.

1999-01-01

This paper summarizes the state of 3D CFD based models of the time average flow field within axial flow multistage turbomachines. Emphasis is placed on models which are compatible with the industrial design environment and those models which offer the potential of providing credible results at both design and off-design operating conditions. The need to develop models which are free of aerodynamic input from semi-empirical design systems is stressed. The accuracy of such models is shown to be dependent upon their ability to account for the unsteady flow environment in multistage turbomachinery. The relevant flow physics associated with some of the unsteady flow processes present in axial flow multistage machinery are presented along with procedures which can be used to account for them in 3D CFD simulations. Sample results are presented for both axial flow compressors and axial flow turbines which help to illustrate the enhanced predictive capabilities afforded by including these procedures in 3D CFD simulations. Finally, suggestions are given for future work on the development of time average flow models.

Collapse of Capillary Flows in Wedge-Shaped Channels

NASA Astrophysics Data System (ADS)

Klatte, Jörg; Dreyer, Michael E.

The low gravity environment of the Bremen Drop Tower has been used to study free surface channel flows for different flow rates. In general the flow is dominated by inertia and surface-tension effects. The analysis of inertia-dominated free surface flows is of major interest because flow rate is limited due to a collapse of the free surface, which is one major design limit e.g. for propellant management devices in space. High-Resolution Experiments with convective dominated systems have been performed where the flow rate was increased up to the maximum value. In comparison to this we present unique three-dimensional computations to determine important characteristics of the flow, such as the free surface shape, the limiting flow rate and the developing flow profiles. The excellent agreement validates the capabilities of the numerical solver. Finally, the results of an para-metric study with a unique scaling which captures both inertia and viscous-dominated collapse behavior will be presented. The support for this research by the German Federal Ministry of Education and Research (BMBF) through the German Aerospace Center (DLR) under grant number 50WM0535/845 is gratefully acknowledged.

Method and apparatus for making articles from particle based materials

DOEpatents

Moorhead, Arthur J.; Menchhofer, Paul A.

1995-01-01

A method and apparatus for the production of articles made of a particle-based material; e.g., ceramics and sintered metals. In accordance with the invention, a thermally settable slurry containing a relatively high concentration of the particles is conveyed through an elongate flow area having a desired cross-sectional configuration. The slurry is heated as it is advanced through the flow area causing the slurry to set or harden in a shape which conforms to the cross-sectional configuration of the flow area. The material discharges from the flow area as a self-supporting solid of near net final dimensions. The article may then be sintered to consolidate the particles and provide a high density product.

Viscous Flow

NASA Astrophysics Data System (ADS)

Ockendon, Hilary; Ockendon, John

1995-01-01

Viscous flow crops up in many real-life situations such as aerodynamics and lubrication, and because of its universality it is a paradigm for the application of mathematics to the real world. This book is a coherent account of the ways in which mathematics can both give insight into viscous flow and suggest analogies and implications for other branches of applied mathematics. The authors place particular emphasis on the unification brought about by the use of asymptotic analysis and scaling properties and the use of everyday observations from the real world (especially industry) to illustrate the theory. The book is aimed at final-year undergraduate and beginning graduate students in applied mathematics, physics, and engineering courses on fluid flow.

Study of dynamics of two-phase flow through a minichannel by means of recurrences

NASA Astrophysics Data System (ADS)

Litak, Grzegorz; Górski, Grzegorz; Mosdorf, Romuald; Rysak, Andrzej

2017-05-01

By changing air and water flow rates in the two-phase (air-water) flow through a minichannel, we observed the evolution of air bubbles and slugs patterns. This spatiotemporal behaviour was identified qualitatively by using a digital camera. Simultaneously, we provided a detailed analysis of these phenomena by using the corresponding sequences of light transmission time series recorded with a laser-phototransistor sensor. To distinguish particular patterns, we used recurrence plots and recurrence quantification analysis. Finally, we showed that the maxima of various recurrence quantificators obtained from the laser time series could follow the bubble and slugs patterns in studied ranges of air and water flows.

Numerical investigation of the thermal and electrical performances for combined solar photovoltaic/thermal (PV/T) modules based on internally extruded fin flow channel

NASA Astrophysics Data System (ADS)

Deng, Y. C.; Li, Q. P.; Wang, G. J.

2017-11-01

A solar photovoltaic/thermal (PV/T) module based on internally extruded fin flow channel was investigated numerically in this paper. First of all, the structures of the thin plate heat exchanger and the PV/T module were presented. Then, a numerical model of the PV/T module considering solar irradiation, fluid flow and heat transfer was developed to analyze the performance of the module. Finally, the steady electrical and thermal efficiencies of the PV/T module at different inlet water temperatures and mass flow rates were achieved. These numerical results supply theory basis for practical application of the PV/T module.

Contribution to the optimal shape design of two-dimensional internal flows with embedded shocks

NASA Technical Reports Server (NTRS)

Iollo, Angelo; Salas, Manuel D.

1995-01-01

We explore the practicability of optimal shape design for flows modeled by the Euler equations. We define a functional whose minimum represents the optimality condition. The gradient of the functional with respect to the geometry is calculated with the Lagrange multipliers, which are determined by solving a co-state equation. The optimization problem is then examined by comparing the performance of several gradient-based optimization algorithms. In this formulation, the flow field can be computed to an arbitrary order of accuracy. Finally, some results for internal flows with embedded shocks are presented, including a case for which the solution to the inverse problem does not belong to the design space.

Dynamic Control of Particle Deposition in Evaporating Droplets by an External Point Source of Vapor.

PubMed

Malinowski, Robert; Volpe, Giovanni; Parkin, Ivan P; Volpe, Giorgio

2018-02-01

The deposition of particles on a surface by an evaporating sessile droplet is important for phenomena as diverse as printing, thin-film deposition, and self-assembly. The shape of the final deposit depends on the flows within the droplet during evaporation. These flows are typically determined at the onset of the process by the intrinsic physical, chemical, and geometrical properties of the droplet and its environment. Here, we demonstrate deterministic emergence and real-time control of Marangoni flows within the evaporating droplet by an external point source of vapor. By varying the source location, we can modulate these flows in space and time to pattern colloids on surfaces in a controllable manner.

High-Performance Oligomeric Catholytes for Effective Macromolecular Separation in Nonaqueous Redox Flow Batteries

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

Hendriks, Koen H.; Robinson, Sophia G.; Braten, Miles N.

Nonaqueous redox flow batteries (NRFBs) represent an attractive technology for energy storage from intermittent renewable sources. In these batteries, electrical energy is stored in and extracted from electrolyte solutions of redox-active molecules (termed catholytes and anolytes) that are passed through an electrochemical flow cell. To avoid battery self-discharge, the anolyte and catholyte solutions must be separated by a membrane in the flow cell. This membrane prevents crossover of the redox active molecules, while simultaneously allowing facile transport of charge-balancing ions. A key unmet challenge for the field is the design of redox-active molecule/membrane pairs that enable effective electrolyte separation whilemore » maintaining optimal battery properties. Herein, we demonstrate the development of oligomeric catholytes based on tris(dialkylamino)cyclopropenium (CP) salts that are specifically tailored for pairing with size-exclusion membranes composed of polymers of intrinsic microporosity (PIMs). Systematic studies were conducted to evaluate the impact of oligomer size/structure on properties that are crucial for flow battery performance, including cycling stability, charge capacity, solubility, electron transfer kinetics, and crossover rates. These studies have led to the identification of a CP-derived tetramer in which these properties are all comparable, or significantly improved, relative to the monomeric counterpart. Finally, a proof-of-concept flow battery is demonstrated by pairing this tetrameric catholyte with a PIM membrane. After 6 days of cycling, no crossover is detected, demonstrating the promise of this approach. Finally, these studies provide a template for the future design of other redox-active oligomers for this application.« less

High-Performance Oligomeric Catholytes for Effective Macromolecular Separation in Nonaqueous Redox Flow Batteries

DOE PAGES

Hendriks, Koen H.; Robinson, Sophia G.; Braten, Miles N.; ...

2018-01-17

Nonaqueous redox flow batteries (NRFBs) represent an attractive technology for energy storage from intermittent renewable sources. In these batteries, electrical energy is stored in and extracted from electrolyte solutions of redox-active molecules (termed catholytes and anolytes) that are passed through an electrochemical flow cell. To avoid battery self-discharge, the anolyte and catholyte solutions must be separated by a membrane in the flow cell. This membrane prevents crossover of the redox active molecules, while simultaneously allowing facile transport of charge-balancing ions. A key unmet challenge for the field is the design of redox-active molecule/membrane pairs that enable effective electrolyte separation whilemore » maintaining optimal battery properties. Herein, we demonstrate the development of oligomeric catholytes based on tris(dialkylamino)cyclopropenium (CP) salts that are specifically tailored for pairing with size-exclusion membranes composed of polymers of intrinsic microporosity (PIMs). Systematic studies were conducted to evaluate the impact of oligomer size/structure on properties that are crucial for flow battery performance, including cycling stability, charge capacity, solubility, electron transfer kinetics, and crossover rates. These studies have led to the identification of a CP-derived tetramer in which these properties are all comparable, or significantly improved, relative to the monomeric counterpart. Finally, a proof-of-concept flow battery is demonstrated by pairing this tetrameric catholyte with a PIM membrane. After 6 days of cycling, no crossover is detected, demonstrating the promise of this approach. Finally, these studies provide a template for the future design of other redox-active oligomers for this application.« less

Analysis of artery blood flow before and after angioplasty

NASA Astrophysics Data System (ADS)

Tomaszewski, Michał; Baranowski, Paweł; Małachowski, Jerzy; Damaziak, Krzysztof; Bukała, Jakub

2018-01-01

The study presents a comparison of results obtained from numerical simulations of blood flow in two different arteries. One of them was considered to be narrowed in order to simulate an arteriosclerosis obstructing the blood flow in the vessel, whereas the second simulates the vessel after angioplasty treatment. During the treatment, a biodegradable stent is inserted into the artery, which prevents the vessel walls from collapsing. The treatment was simulated through the use of numerical simulation using the finite element method. The final mesh geometry obtained from the analysis was exported to the dedicated software in order to create geometry in which a flow domain inside the artery with the stent was created. The flow analysis was conducted in ANSYS Fluent software with non-deformable vessel walls.

Aerodynamics of advanced axial-flow turbomachinery

NASA Technical Reports Server (NTRS)

Serovy, G. K.; Kavanagh, P.; Kiishi, T. H.

1980-01-01

A multi-task research program on aerodynamic problems in advanced axial-flow turbomachine configurations was carried out at Iowa State University. The elements of this program were intended to contribute directly to the improvement of compressor, fan, and turbine design methods. Experimental efforts in intra-passage flow pattern measurements, unsteady blade row interaction, and control of secondary flow are included, along with computational work on inviscid-viscous interaction blade passage flow techniques. This final report summarizes the results of this program and indicates directions which might be taken in following up these results in future work. In a separate task a study was made of existing turbomachinery research programs and facilities in universities located in the United States. Some potentially significant research topics are discussed which might be successfully attacked in the university atmosphere.

Computational and experimental aftbody flow fields for hypersonic, airbreathing configurations with scramjet exhaust flow simulation

NASA Technical Reports Server (NTRS)

Huebner, Lawrence D.; Tatum, Kenneth E.

1991-01-01

Computational results are presented for three issues pertinent to hypersonic, airbreathing vehicles employing scramjet exhaust flow simulation. The first issue consists of a comparison of schlieren photographs obtained on the aftbody of a cruise missile configuration under powered conditions with two-dimensional computational solutions. The second issue presents the powered aftbody effects of modeling the inlet with a fairing to divert the external flow as compared to an operating flow-through inlet on a generic hypersonic vehicle. Finally, a comparison of solutions examining the potential of testing powered configurations in a wind-off, instead of a wind-on, environment, indicate that, depending on the extent of the three-dimensional plume, it may be possible to test aftbody powered hypersonic, airbreathing configurations in a wind-off environment.

Soap-film flow induced by electric fields in asymmetric frames

NASA Astrophysics Data System (ADS)

Mollaei, S.; Nasiri, M.; Soltanmohammadi, N.; Shirsavar, R.; Ramos, A.; Amjadi, A.

2018-04-01

Net fluid flow of soap films induced by (ac or dc) electric fields in asymmetric frames is presented. Previous experiments of controllable soap film flow required the simultaneous use of an electrical current passing through the film and an external electric field or the use of nonuniform ac electric fields. Here a single voltage difference generates both the electrical current going through the film and the electric field that actuates on the charge induced on the film. The film is set into global motion due to the broken symmetry that appears by the use of asymmetric frames. If symmetric frames are used, the film flow is not steady but time dependent and irregular. Finally, we study numerically these film flows by employing the model of charge induction in ohmic liquids.

Soap-film flow induced by electric fields in asymmetric frames.

PubMed

Mollaei, S; Nasiri, M; Soltanmohammadi, N; Shirsavar, R; Ramos, A; Amjadi, A

2018-04-01

Net fluid flow of soap films induced by (ac or dc) electric fields in asymmetric frames is presented. Previous experiments of controllable soap film flow required the simultaneous use of an electrical current passing through the film and an external electric field or the use of nonuniform ac electric fields. Here a single voltage difference generates both the electrical current going through the film and the electric field that actuates on the charge induced on the film. The film is set into global motion due to the broken symmetry that appears by the use of asymmetric frames. If symmetric frames are used, the film flow is not steady but time dependent and irregular. Finally, we study numerically these film flows by employing the model of charge induction in ohmic liquids.

Investigation of Flow Separation in a Transonic-fan Linear Cascade Using Visualization Methods

NASA Technical Reports Server (NTRS)

Lepicovsky, Jan; Chima, Rodrick V.; Jett, Thomas A.; Bencic, Timothy J.; Weiland, Kenneth E.

2000-01-01

An extensive study into the nature of the separated flows on the suction side of modem transonic fan airfoils at high incidence is described in the paper. Suction surface.flow separation is an important flow characteristic that may significantly contribute to stall flutter in transonic fans. Flutter in axial turbomachines is a highly undesirable and dangerous self-excited mode of blade oscillations that can result in high cycle fatigue blade failure. The study basically focused on two visualization techniques: surface flow visualization using dye oils, and schlieren (and shadowgraph) flow visualization. The following key observations were made during the study. For subsonic inlet flow, the flow on the suction side of the blade is separated over a large portion of the blade, and the separated area increases with increasing inlet Mach number. For the supersonic inlet flow condition, the flow is attached from the leading edge up to the point where a bow shock from the upper neighboring blade hits the blade surface. Low cascade solidity, for the subsonic inlet flow, results in an increased area of separated flow. For supersonic flow conditions, a low solidity results in an improvement in flow over the suction surface. Finally, computational results modeling the transonic cascade flowfield illustrate our ability to simulate these flows numerically.

Dipeptidyl peptidase-4 independent cardiac dysfunction links saxagliptin to heart failure.

PubMed

Koyani, Chintan N; Kolesnik, Ewald; Wölkart, Gerald; Shrestha, Niroj; Scheruebel, Susanne; Trummer, Christopher; Zorn-Pauly, Klaus; Hammer, Astrid; Lang, Petra; Reicher, Helga; Maechler, Heinrich; Groschner, Klaus; Mayer, Bernd; Rainer, Peter P; Sourij, Harald; Sattler, Wolfgang; Malle, Ernst; Pelzmann, Brigitte; von Lewinski, Dirk

2017-12-01

Saxagliptin treatment has been associated with increased rate of hospitalization for heart failure in type 2 diabetic patients, though the underlying mechanism(s) remain elusive. To address this, we assessed the effects of saxagliptin on human atrial trabeculae, guinea pig hearts and cardiomyocytes. We found that the primary target of saxagliptin, dipeptidyl peptidase-4, is absent in cardiomyocytes, yet saxagliptin internalized into cardiomyocytes and impaired cardiac contractility via inhibition of the Ca 2+ /calmodulin-dependent protein kinase II-phospholamban-sarcoplasmic reticulum Ca 2+ -ATPase 2a axis and Na + -Ca 2+ exchanger function in Ca 2+ extrusion. This resulted in reduced sarcoplasmic reticulum Ca 2+ content, diastolic Ca 2+ overload, systolic dysfunction and impaired contractile force. Furthermore, saxagliptin reduced protein kinase C-mediated delayed rectifier K + current that prolonged action potential duration and consequently QTc interval. Importantly, saxagliptin aggravated pre-existing cardiac dysfunction induced by ischemia/reperfusion injury. In conclusion, our novel results provide mechanisms for the off-target deleterious effects of saxagliptin on cardiac function and support the outcome of SAVOR-TIMI 53 trial that linked saxagliptin with the risk of heart failure. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Molecular characterisation of Cryptosporidium (Apicomplexa) in children and cattle in Romania.

PubMed

Vieira, Patricia Manuela; Mederle, Narcisa; Lobo, Maria Luisa; Imre, Kalman; Mederle, Ovidiu; Xiao, Lihua; Darabus, Gheorghe; Matos, Olga

2015-01-01

To investigate the transmission of species of Cryptosporidium Tyzzer, 1907 in Timis County, Romania, 48 isolates of Cryptosporidium coccidia from 11 children, 29 calves and eight pigs were characterised by molecular analysis of two loci (SSU rRNA and 60-kDa glycoprotein gene). Overall, 22 isolates were amplified and sequence analyses revealed that all isolates were Cryptosporidium parvum Tyzzer, 1912. Two subtype families were identified, IIa and IId. Subtype IIdA22G1 (n = 4) was the single C. parvum subtype found in children. Subtypes found in calves included IIdA27G1 (n = 8), a novel subtype, IIdA25G1 (n = 5), IIdA22G1 (n = 2), IIdA21G1a (n = 1), and IIaA16G1R1 (n = 1). Subtype IIdA26G1 was found in a pig. These results were significantly different from previous Romanian reports, as the five subtypes of family IId identified in this study were never identified previously in this country. Thus, cattle may be a source of Cryptosporidium infections for humans and the transmission dynamics of C. parvum in Romania is more complex than previously believed.

HEAD CIRCUMFERENCE REFERENCES FOR SCHOOL AGE CHILDREN IN WESTERN ROMANIA.

PubMed

Chirita-Emandi, Adela; Doros, Gabriela; Simina, Iulia Jurca; Gafencu, Mihai; Puiu, Maria

2015-01-01

To provide head circumference references for school-aged children in western Romania, and compare them with references from other European countries. A total of 2742 children, aged 6-19 years, from Timis county, were examined by medical students, between February 2010-June 2011. Head circumference references were constructed by Cole's LMS method with LMSChartMaker software. The Romanian 3rd, 50th and 97th percentiles for head circumference were compared with recent references from Belgium and Germany. Generally, boys show significantly larger head circumference compared to girls at any age. The head circumference increments between 6 and 19 years are < 1 cm/year. Head circumference increments decrease in increasing age of the children. In girls, adult head circumference is reached at the age of 16 years, whereas head circumference growth continues, in boys, slowly until 18 years. The comparison of Romanian head percentiles with those from Belgium and Germany revealed a smaller head circumference in Romanian children (both girls and boys). Comparing head circumference references from Romania to those from Germany and Belgium, we found lower median head circumference in Romanian boys and girls, that could be explained by a taller stature of boys and girls in Germany and Belgium compared to Romania.

Lorcaserin Hcl for the treatment of obesity.

PubMed

Shukla, Alpana P; Kumar, Rekha B; Aronne, Louis J

2015-01-01

Obesity is a major health priority necessitating safe and effective strategies to address the obesity epidemic. Lorcaserin is a serotonergic agonist specific to the 5HT- 2C receptor approved for chronic management of obesity in patients with a BMI ≥ 30 kg/m(2) or a BMI ≥ 27 kg/m(2) with comorbidities related to obesity. In this paper, the pharmacodynamic and pharmacokinetic properties of lorcaserin are reviewed followed by a discussion of efficacy and safety data from major clinical trials. Lorcaserin is a unique highly selective serotonergic agonist designed to mitigate the risks associated with previous agents in this class. At therapeutic doses, it is well tolerated and produces modest but clinically meaningful weight loss with significant improvement in cardiometabolic parameters. Therapeutic efficacy should be assessed at 12 weeks (≥ 5% weight loss) to identify responders who will derive maximum weight loss and metabolic benefit from long-term therapy. The results of the ongoing cardiovascular outcomes trial (CAMELLIA TIMI 61) will determine the role of lorcaserin in primary prevention of diabetes in overweight/obese individuals and its use in the high-risk population of patients with established cardiovascular disease or multiple cardiovascular risk factors.

Measurement of the hadronic final state in deep inelastic scattering at HERA

NASA Astrophysics Data System (ADS)

Ahmed, T.; Andreev, V.; Andrieu, B.; Arpagaus, M.; Babaev, A.; Bärwolff, H.; Bán, J.; Baranov, P.; Barrelet, E.; Bartel, W.; Bassler, U.; Beck, G. A.; Beck, H. P.; Behrend, H.-J.; Belousov, A.; Berger, Ch.; Bergstein, H.; Bernardi, G.; Bernet, R.; Berthon, U.; Bertrand-Coremans, G.; Besançon, M.; Biddulph, P.; Binder, E.; Bizot, J. C.; Blobel, V.; Borras, K.; Bosetti, P. C.; Boudry, V.; Bourdarios, C.; Brasse, F.; Braun, U.; Braunschweig, W.; Brisson, V.; Bruncko, D.; Bürger, J.; Büsser, F. W.; Buniatian, A.; Burke, S.; Buschhorn, G.; Campbell, A. J.; Carli, T.; Charles, F.; Clarke, D.; Clegg, A. B.; Colombo, M.; Coughlan, J. A.; Courau, A.; Coutures, Ch.; Cozzika, G.; Criegee, L.; Cvach, J.; Dainton, J. B.; Danilov, M.; Dann, A. W. E.; Dau, W. D.; David, M.; Deffur, E.; Delcourt, B.; Del Buono, L.; Devel, M.; De Roeck, A.; Dingus, P.; Dollfus, C.; Dowell, J. D.; Dreis, H. B.; Drescher, A.; Duboc, J.; Düllmann, D.; Dünger, O.; Duhm, H.; Eberle, M.; Ebert, J.; Ebert, T. R.; Eckerlin, G.; Efremenko, V.; Egli, S.; Eichenberger, S.; Eichler, R.; Eisele, F.; Eisenhandler, E.; Ellis, N. N.; Ellison, R. J.; Elsen, E.; Erdmann, M.; Evrard, E.; Favart, L.; Fedotov, A.; Feeken, D.; Felst, R.; Feltesse, J.; Feng, Y.; Fensome, I. F.; Ferencei, J.; Ferrarotto, F.; Flauger, W.; Fleischer, M.; Flower, P. S.; Flügge, G.; Fomenko, A.; Fominykh, B.; Forbush, M.; Formánek, J.; Foster, J. M.; Franke, G.; Fretwurst, E.; Fuhrmann, P.; Gabathuler, E.; Gamerdinger, K.; Garvey, J.; Gayler, J.; Gellrich, A.; Gennis, M.; Gensch, U.; Genzel, H.; Gerhards, R.; Gillespie, D.; Godfrey, L.; Goerlach, U.; Goerlich, L.; Goldberg, M.; Goodall, A. M.; Gorelov, I.; Goritchev, P.; Grab, C.; Grässler, H.; Grässler, R.; Greenshaw, T.; Greif, H.; Grindhammer, G.; Gruber, C.; Haack, J.; Haidt, D.; Hajduk, L.; Hamon, O.; Handschuh, D.; Hanlon, E. M.; Hapke, M.; Haries, J.; Hartz, P.; Haydar, R.; Haynes, W. J.; Heatherington, J.; Hedberg, V.; Hedgecock, R.; Heinzelmann, G.; Henderson, R. C. W.; Henschel, H.; Herma, R.; Herynek, I.; Hildesheim, W.; Hill, P.; Hilton, C. D.; Hladký, J.; Hoeger, K. C.; Huet, Ph.; Hufnagel, H.; Huot, N.; Ibbotson, M.; Jabiol, M. A.; Jacholkowska, A.; Jacobsson, C.; Jaffre, M.; Jöhnsson, L.; Johannsen, K.; Johnson, D. P.; Johnson, L.; Jung, H.; Kalmus, P. I. P.; Kasarian, S.; Kaschowitz, R.; Kasselmann, P.; Kathage, U.; Kaufmann, H. H.; Kenyon, I. R.; Kermiche, S.; Kiesling, C.; Klein, M.; Kleinwort, C.; Knies, G.; Köhler, T.; Kolanoski, H.; Kole, F.; Kolya, S. D.; Korbel, V.; Korn, M.; Kostka, P.; Kotelnikov, S. K.; Krasny, M. W.; Krehbiel, H.; Krücker, D.; Krüger, U.; Kubenka, J. P.; Küster, H.; Kuhlen, M.; Kurça, T.; Kurzhöfer, J.; Kuznik, B.; Lander, R.; London, M. P. J.; Langkau, R.; Lanius, P.; Laporte, J. F.; Lebedev, A.; Lebedev, A.; Leuschner, A.; Leverenz, C.; Levin, D.; Levonian, S.; Ley, Ch.; Lindner, A.; Lindström, G.; Loch, P.; Lohmander, H.; Lopez, G. C.; Lüers, D.; Magnussen, N.; Malinovski, E.; Mani, S.; Marage, P.; Marks, J.; Marshall, R.; Martens, J.; Martin, R.; Martyn, H.-U.; Martyniak, J.; Masson, S.; Mavroidis, A.; Maxfield, S. J.; McMahon, S. J.; Mehta, A.; Meier, K.; Merz, T.; Meyer, C. A.; Meyer, H.; Meyer, J.; Mikocki, S.; Milone, V.; Monnier, E.; Moreau, F.; Moreels, J.; Morris, J. V.; Morton, J. M.; Müller, K.; Murín, P.; Murray, S. A.; Nagovizin, V.; Naroska, B.; Naumann, Th.; Newton, D.; Nguyen, H. K.; Niebergall, F.; Nisius, R.; Nowak, G.; Noyes, G. W.; Nyberg, M.; Oberlack, H.; Obrock, U.; Olsson, J. E.; Orenstein, S.; Ould-Saada, F.; Pascaud, C.; Patel, G. D.; Peppel, E.; Peters, S.; Phillips, H. T.; Phillips, J. P.; Pichler, Ch.; Pilgram, W.; Pitzl, D.; Prosi, R.; Raupach, F.; Rauschnabel, K.; Reimer, P.; Ribarics, P.; Riech, V.; Riedlberger, J.; Rietz, M.; Robertson, S. M.; Robmann, P.; Roosen, R.; Rostovtsev, A.; Royon, C.; Rudowicz, M.; Ruffer, M.; Rusakov, S.; Rybicki, K.; Ryseck, E.; Sacton, J.; Sahlmann, N.; Sanchez, E.; Sankey, D. P. C.; Savitsky, M.; Schacht, P.; Schleper, P.; von Schlippe, W.; Schmidt, C.; Schmidt, D.; Schmitz, W.; Schröder, V.; Schulz, M.; Schwind, A.; Scobel, W.; Seehausen, U.; Sell, R.; Seman, M.; Semenov, A.; Shekelyan, V.; Sheviakov, I.; Shooshtari, H.; Siegmon, G.; Siewert, U.; Sirois, Y.; Skillicorn, I. O.; Smirnov, P.; Smith, J. R.; Smolik, L.; Soloviev, Y.; Spitzer, H.; Staroba, P.; Steenbock, M.; Steffen, P.; Steinberg, R.; Steiner, H.; Stella, B.; Stephens, K.; Stier, J.; Strachota, J.; Straumann, U.; Struczinski, W.; Sutton, J. P.; Taylor, R. E.; Thompson, G.; Thompson, R. J.; Tichomirov, I.; Trenkel, C.; Truöl, P.; Tchernyshov, V.; Turnau, J.; Tutas, J.; Urban, L.; Usik, A.; Valkar, S.; Valkarova, A.; Vallee, C.; Van Esch, P.; Vartapetian, A.; Vazdik, Y.; Vecko, M.; Verrecchia, P.; Vick, R.; Villet, G.; Vogel, E.; Wacker, K.; Walker, I. W.; Walther, A.; Weber, G.; Wegener, D.; Wegner, A.; Wellisch, H. P.; Willard, S.; Winde, M.; Winter, G.-G.; Wolff, Th.; Womersley, L. A.; Wright, A. E.; Wulff, N.; Yiou, T. P.; Ząçek, J.; Závada, P.; Zeitnitz, C.; Ziaeepour, H.; Zimmer, M.; Zimmermann, W.; Zomer, F.; H1 Collaboration

1993-01-01

We report on the first experimental study of the hadronic final state in deep inelastic electron-proton scattering with the H1 detector at HERA. Energy flow and transverse momentum characteristics are measured and presented both in the laboratory and in the hadronic center of mass frames. Comparison is made with QCD models distinguished by their different treatment of parton emission.

Fluid Mechanics, Arterial Disease, and Gene Expression.

PubMed

Tarbell, John M; Shi, Zhong-Dong; Dunn, Jessilyn; Jo, Hanjoong

2014-01-01

This review places modern research developments in vascular mechanobiology in the context of hemodynamic phenomena in the cardiovascular system and the discrete localization of vascular disease. The modern origins of this field are traced, beginning in the 1960s when associations between flow characteristics, particularly blood flow-induced wall shear stress, and the localization of atherosclerotic plaques were uncovered, and continuing to fluid shear stress effects on the vascular lining endothelial) cells (ECs), including their effects on EC morphology, biochemical production, and gene expression. The earliest single-gene studies and genome-wide analyses are considered. The final section moves from the ECs lining the vessel wall to the smooth muscle cells and fibroblasts within the wall that are fluid me chanically activated by interstitial flow that imposes shear stresses on their surfaces comparable with those of flowing blood on EC surfaces. Interstitial flow stimulates biochemical production and gene expression, much like blood flow on ECs.

Data flow modeling techniques

NASA Technical Reports Server (NTRS)

Kavi, K. M.

1984-01-01

There have been a number of simulation packages developed for the purpose of designing, testing and validating computer systems, digital systems and software systems. Complex analytical tools based on Markov and semi-Markov processes have been designed to estimate the reliability and performance of simulated systems. Petri nets have received wide acceptance for modeling complex and highly parallel computers. In this research data flow models for computer systems are investigated. Data flow models can be used to simulate both software and hardware in a uniform manner. Data flow simulation techniques provide the computer systems designer with a CAD environment which enables highly parallel complex systems to be defined, evaluated at all levels and finally implemented in either hardware or software. Inherent in data flow concept is the hierarchical handling of complex systems. In this paper we will describe how data flow can be used to model computer system.

Transient disturbance growth in flows over convex surfaces

NASA Astrophysics Data System (ADS)

Karp, Michael; Hack, M. J. Philipp

2017-11-01

Flows over curved surfaces occur in a wide range of applications including airfoils, compressor and turbine vanes as well as aerial, naval and ground vehicles. In most of these applications the surface has convex curvature, while concave surfaces are less common. Since monotonic boundary-layer flows over convex surfaces are exponentially stable, they have received considerably less attention than flows over concave walls which are destabilized by centrifugal forces. Non-modal mechanisms may nonetheless enable significant disturbance growth which can make the flow susceptible to secondary instabilities. A parametric investigation of the transient growth and secondary instability of flows over convex surfaces is performed. The specific conditions yielding the maximal transient growth and strongest instability are identified. The effect of wall-normal and spanwise inflection points on the instability process is discussed. Finally, the role and significance of additional parameters, such as the geometry and pressure gradient, is analyzed.

Exploring Inflated Pahohoe Lava Flow Morphologies and the Effects of Cooling Using a New Simulation Approach

NASA Technical Reports Server (NTRS)

Glaze, L. S.; Baloga, S. M.

2014-01-01

Pahoehoe lavas are recognized as an important landform on Earth, Mars and Io. Observations of such flows on Earth (e.g., Figure 1) indicate that the emplacement process is dominated by random effects. Existing models for lobate a`a lava flows that assume viscous fluid flow on an inclined plane are not appropriate for dealing with the numerous random factors present in pahoehoe emplacement. Thus, interpretation of emplacement conditions for pahoehoe lava flows on Mars requires fundamentally different models. A new model that implements a simulation approach has recently been developed that allows exploration of a variety of key influences on pahoehoe lobe emplacement (e.g., source shape, confinement, slope). One important factor that has an impact on the final topographic shape and morphology of a pahoehoe lobe is the volumetric flow rate of lava, where cooling of lava on the lobe surface influences the likelihood of subsequent breakouts.

Patterns and processes: Subaerial lava flow morphologies: A review

NASA Astrophysics Data System (ADS)

Gregg, Tracy K. P.

2017-08-01

Most lava flows have been emplaced away from the watchful eyes of volcanologists, so there is a desire to use solidified lava-flow morphologies to reveal important information about the eruption that formed them. Our current understanding of the relationship between solidified basaltic lava morphology and the responsible eruption and emplacement processes is based on decades of fieldwork, laboratory analyses and simulations, and computer models. These studies have vastly improved our understanding of the complex interactions between the solids, liquids, and gases that comprise cooling lava flows. However, the complex interactions (at millimeter and sub-millimeter scales) between the temperature-dependent abundances of the distinct phases that comprise a lava flow and the final morphology remain challenging to model and to predict. Similarly, the complex behavior of an active pahoehoe flow, although almost ubiquitous on Earth, remains difficult to quantitatively model and precisely predict.

Two-phase flow in the cooling circuit of a cryogenic rocket engine

NASA Astrophysics Data System (ADS)

Preclik, D.

1992-07-01

Transient two-phase flow was investigated for the hydrogen cooling circuit of the HM7 rocket engine. The nuclear reactor code ATHLET/THESEUS was adapted to cryogenics and applied to both principal and prototype experiments for validation and simulation purposes. The cooling circuit two-phase flow simulation focused on the hydrogen prechilling and pump transient phase prior to ignition. Both a single- and a multichannel model were designed and employed for a valve leakage flow, a nominal prechilling flow, and a prechilling with a subsequent pump-transient flow. The latter case was performed in order to evaluate the difference between a nominal and a delayed turbo-pump start-up. It was found that an extension of the nominal prechilling sequence in the order of 1 second is sufficient to finally provide for liquid injection conditions of hydrogen which, as commonly known, is undesirable for smooth ignition and engine starting transients.

Intershot Analysis of Flows in DIII-D

NASA Astrophysics Data System (ADS)

Meyer, W. H.; Allen, S. L.; Samuell, C. M.; Howard, J.

2016-10-01

Analysis of the DIII-D flow diagnostic data require demodulation of interference images, and inversion of the resultant line integrated emissivity and flow (phase) images. Four response matrices are pre-calculated: the emissivity line integral and the line integral of the scalar product of the lines-of-site with the orthogonal unit vectors of parallel flow. Equilibrium data determines the relative weight of the component matrices used in the final flow inversion matrix. Serial processing has been used for the lower divertor viewing flow camera 800x600 pixel image. The full cross section viewing camera will require parallel processing of the 2160x2560 pixel image. We will discuss using a Posix thread pool and a Tesla K40c GPU in the processing of this data. Prepared by LLNL under Contract DE-AC52-07NA27344. This material is based upon work supported by the U.S. DOE, Office of Science, Fusion Energy Sciences.

Chemical reacting flows

NASA Technical Reports Server (NTRS)

Mularz, Edward J.; Sockol, Peter M.

1987-01-01

Future aerospace propulsion concepts involve the combination of liquid or gaseous fuels in a highly turbulent internal air stream. Accurate predictive computer codes which can simulate the fluid mechanics, chemistry, and turbulence combustion interaction of these chemical reacting flows will be a new tool that is needed in the design of these future propulsion concepts. Experimental and code development research is being performed at Lewis to better understand chemical reacting flows with the long term goal of establishing these reliable computer codes. The approach to understanding chemical reacting flows is to look at separate simple parts of this complex phenomena as well as to study the full turbulent reacting flow process. As a result research on the fluid mechanics associated with chemical reacting flows was initiated. The chemistry of fuel-air combustion is also being studied. Finally, the phenomena of turbulence-combustion interaction is being investigated. This presentation will highlight research, both experimental and analytical, in each of these three major areas.

Chemical reacting flows

NASA Technical Reports Server (NTRS)

Mularz, Edward J.; Sockol, Peter M.

1990-01-01

Future aerospace propulsion concepts involve the combustion of liquid or gaseous fuels in a highly turbulent internal airstream. Accurate predictive computer codes which can simulate the fluid mechanics, chemistry, and turbulence-combustion interaction of these chemical reacting flows will be a new tool that is needed in the design of these future propulsion concepts. Experimental and code development research is being performed at LeRC to better understand chemical reacting flows with the long-term goal of establishing these reliable computer codes. Our approach to understand chemical reacting flows is to look at separate, more simple parts of this complex phenomenon as well as to study the full turbulent reacting flow process. As a result, we are engaged in research on the fluid mechanics associated with chemical reacting flows. We are also studying the chemistry of fuel-air combustion. Finally, we are investigating the phenomenon of turbulence-combustion interaction. Research, both experimental and analytical, is highlighted in each of these three major areas.

Development of standardized air-blown coal gasifier/gas turbine concepts for future electric power systems, Volume 4. Appendix C: Design and performance of standardized fixed bed air-blown gasifier IGCC systems for future electric power generation: Final report

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

Not Available

1991-02-01

This appendix is a compilation of work done to predict overall cycle performance from gasifier to generator terminals. A spreadsheet has been generated for each case to show flows within a cycle. The spreadsheet shows gaseous or solid composition of flow, temperature of flow, quantity of flow, and heat heat content of flow. Prediction of steam and gas turbine performance was obtained by the computer program GTPro. Outputs of all runs for each combined cycle reviewed has been added to this appendix. A process schematic displaying all flows predicted through GTPro and the spreadsheet is also added to this appendix.more » The numbered bubbles on the schematic correspond to columns on the top headings of the spreadsheet.« less

Experimental study on hydraulic characteristic around trash rack of a pumping station

NASA Astrophysics Data System (ADS)

Zhou, MinZhe; Li, TongChun; Lin, XiangYang; Liu, XiaoQing; Ding, Yuan; Liu, GuangYuan

2017-11-01

This paper focuses on flow pattern around trash rack of intake of a pumping station project. This pumping station undertake the task of supplying up to 3,500,000 m3 water per day for a megacity. Considering the large flow rate, high lift, multi-pipe supply and long-time operation in this water conveyance pumping station, we built a physical model test to measure the flow velocity and observe the flow pattern to verify the reasonability of preliminary design. In this test, we set 3 layers of current meters around each trash rack of intake in reservoir to collect the flow velocity. Furthermore, we design 2 operating conditions of 9 pumps to observe the change of flow pattern. Finally, we found the velocity data were in a normal range under 2 different operating conditions of the 9 pump units.

Influence of magnetic field on chemically reactive blood flow through stenosed bifurcated arteries

NASA Astrophysics Data System (ADS)

Hossain, Khan Enaet; Haque, Md. Mohidul

2017-06-01

Dynamic response of mass transfer in chemically reactive blood flow through bifurcated arteries under the stenotic condition is numerically studied in the present of a uniform magnetic field. The blood flowing through the artery is assumed an incompressible, fully developed and Newtonian. The nonlinear unsteady flow phenomena are governed by the Navier-Stokes and concentration equations. All these equations together with the appropriate boundary conditions describing the present biomechanical problem are transformed by using a radial transformation and the numerical results are obtained using a finite difference technique. Effects of stenosed bifurcation and externally applied magnetic field on the blood flow with chemical reaction are discussed with the help of graph. All the flow characteristics are found to be affected by the presence of chemical reaction and exposure of magnetic field of different intensities. Finally some important findings of the problem are concluded in this work.

The two-stroke poppet valve engine. Part 2: Numerical investigations of intake and exhaust flow behaviour

NASA Astrophysics Data System (ADS)

Kamili Zahidi, M.; Razali Hanipah, M.

2017-10-01

A two-stroke poppet valve engine is developed to overcome the common problems in conventional two-stroke engine designs. However, replacing piston control port with poppet valve will resulted different flow behaviour. This paper presents the model and simulation result of three-dimensional (3D) port flow investigation of a two-stroke poppet valve engine. The objective of the investigation is to conduct a numerical investigation on port flow performance of two-stroke poppet valve engine and compare the results obtained from the experimental investigation. The model is to be used for the future numerical study of the engine. The volume flow rate results have been compared with the results obtained experimentally as presented in first part of this paper. The model has shown good agreement in terms of the flow rate at initial and final valve lifts but reduced by about 50% during half-lift region.

Passenger flow analysis of Beijing urban rail transit network using fractal approach

NASA Astrophysics Data System (ADS)

Li, Xiaohong; Chen, Peiwen; Chen, Feng; Wang, Zijia

2018-04-01

To quantify the spatiotemporal distribution of passenger flow and the characteristics of an urban rail transit network, we introduce four radius fractal dimensions and two branch fractal dimensions by combining a fractal approach with passenger flow assignment model. These fractal dimensions can numerically describe the complexity of passenger flow in the urban rail transit network and its change characteristics. Based on it, we establish a fractal quantification method to measure the fractal characteristics of passenger follow in the rail transit network. Finally, we validate the reasonability of our proposed method by using the actual data of Beijing subway network. It has been shown that our proposed method can effectively measure the scale-free range of the urban rail transit network, network development and the fractal characteristics of time-varying passenger flow, which further provides a reference for network planning and analysis of passenger flow.

Modeling Flows Around Merging Black Hole Binaries

NASA Technical Reports Server (NTRS)

Centrella, Joan

2008-01-01

Coalescing massive black hole binaries are produced by the merger of galaxies. The final stages of the black hole coalescence produce strong gravitational radiation that can be detected by the space-borne LISA. In cases in which the black hole merger takes place in the presence of gas and magnetic fields, various types of electromagnetic signals may also be produced. Modeling such electromagnetic counterparts of the final merger requires evolving the behavior of both gas and fields in the strong-field regions around the black holes. We have taken a first step towards this problem by mapping the flow of pressureless matter in the dynamic, 3-D general relativistic spacetime around the merging black holes. We report on the results of these initial simulations and discuss their likely importance for future hydrodynamical simulations.

Accountable Information Flow for Java-Based Web Applications

DTIC Science & Technology

2010-01-01

runtime library Swift server runtime Java servlet framework HTTP Web server Web browser Figure 2: The Swift architecture introduced an open-ended...On the server, the Java application code links against Swift’s server-side run-time library, which in turn sits on top of the standard Java servlet ...AFRL-RI-RS-TR-2010-9 Final Technical Report January 2010 ACCOUNTABLE INFORMATION FLOW FOR JAVA -BASED WEB APPLICATIONS

A perspective on unstructured grid flow solvers

NASA Technical Reports Server (NTRS)

Venkatakrishnan, V.

1995-01-01

This survey paper assesses the status of compressible Euler and Navier-Stokes solvers on unstructured grids. Different spatial and temporal discretization options for steady and unsteady flows are discussed. The integration of these components into an overall framework to solve practical problems is addressed. Issues such as grid adaptation, higher order methods, hybrid discretizations and parallel computing are briefly discussed. Finally, some outstanding issues and future research directions are presented.

Visualization of Flow Separation Around an Atmospheric Entry Capsule at Low-Subsonic Mach Number Using Background-Oriented Schlieren (BOS)

NASA Technical Reports Server (NTRS)

Mizukaki, Toshiharu; Borg, Stephen E.; Danehy, Paul M.; Murman, Scott M.

2014-01-01

This paper presents the results of visualization of separated flow around a generic entry capsule that resembles the Apollo Command Module (CM) and the Orion Multi-Purpose Crew Vehicle (MPCV). The model was tested at flow speeds up to Mach 0.4 at a single angle of attack of 28 degrees. For manned spacecraft using capsule-shaped vehicles, certain flight operations such as emergency abort maneuvers soon after launch and flight just prior to parachute deployment during the final stages of entry, the command module may fly at low Mach number. Under these flow conditions, the separated flow generated from the heat-shield surface on both windward and leeward sides of the capsule dominates the wake flow downstream of the capsule. In this paper, flow visualization of the separated flow was conducted using the background-oriented schlieren (BOS) method, which has the capability of visualizing significantly separated wake flows without the particle seeding required by other techniques. Experimental results herein show that BOS has detection capability of density changes on the order of 10(sup-5).

Microfluidic rheology of active particle suspensions: Kinetic theory

NASA Astrophysics Data System (ADS)

Alonso-Matilla, Roberto; Ezhilan, Barath; Saintillan, David

2016-11-01

We analyze the effective rheology of a dilute suspension of self-propelled slender particles between two infinite parallel plates in a pressure-driven flow. We use a continuum kinetic model to study the dynamics and transport of particles, where hydrodynamic interactions induced by the swimmers are taken into account. Using finite volume simulations we study how the activity of the swimmer and the external flow modify the rheological properties of the system. Results indicate that at low flow rates, activity decreases the value of the viscosity for pushers and increases its value for pullers. Both effects become weaker with increasing the flow strength due to the alignment of the particles with the flow. In the case of puller particles, shear thinning is observed over the entire range of flow rates. Pusher particles exhibit shear thickening at intermediate flow rates, where passive stresses start dominating over active stresses, reaching a viscosity greater than that of the Newtonian fluid. Finally shear thinning is observed at high flow rates. Both pushers and pullers exhibit a Newtonian plateau at very high flow rates. We demonstrate a good agreement between numerical results and experiments.

Stochastic four-way coupling of gas-solid flows for Large Eddy Simulations

NASA Astrophysics Data System (ADS)

Curran, Thomas; Denner, Fabian; van Wachem, Berend

2017-11-01

The interaction of solid particles with turbulence has for long been a topic of interest for predicting the behavior of industrially relevant flows. For the turbulent fluid phase, Large Eddy Simulation (LES) methods are widely used for their low computational cost, leaving only the sub-grid scales (SGS) of turbulence to be modelled. Although LES has seen great success in predicting the behavior of turbulent single-phase flows, the development of LES for turbulent gas-solid flows is still in its infancy. This contribution aims at constructing a model to describe the four-way coupling of particles in an LES framework, by considering the role particles play in the transport of turbulent kinetic energy across the scales. Firstly, a stochastic model reconstructing the sub-grid velocities for the particle tracking is presented. Secondly, to solve particle-particle interaction, most models involve a deterministic treatment of the collisions. We finally introduce a stochastic model for estimating the collision probability. All results are validated against fully resolved DNS-DPS simulations. The final goal of this contribution is to propose a global stochastic method adapted to two-phase LES simulation where the number of particles considered can be significantly increased. Financial support from PetroBras is gratefully acknowledged.

Polymer stress tensor in turbulent shear flows.

PubMed

L'vov, Victor S; Pomyalov, Anna; Procaccia, Itamar; Tiberkevich, Vasil

2005-01-01

The interaction of polymers with turbulent shear flows is examined. We focus on the structure of the elastic stress tensor, which is proportional to the polymer conformation tensor. We examine this object in turbulent flows of increasing complexity. First is isotropic turbulence, then anisotropic (but homogenous) shear turbulence, and finally wall bounded turbulence. The main result of this paper is that for all these flows the polymer stress tensor attains a universal structure in the limit of large Deborah number De > 1. We present analytic results for the suppression of the coil-stretch transition at large Deborah numbers. Above the transition the turbulent velocity fluctuations are strongly correlated with the polymer's elongation: there appear high-quality "hydroelastic" waves in which turbulent kinetic energy turns into polymer potential energy and vice versa. These waves determine the trace of the elastic stress tensor but practically do not modify its universal structure. We demonstrate that the influence of the polymers on the balance of energy and momentum can be accurately described by an effective polymer viscosity that is proportional to the cross-stream component of the elastic stress tensor. This component is smaller than the streamwise component by a factor proportional to De2. Finally we tie our results to wall bounded turbulence and clarify some puzzling facts observed in the problem of drag reduction by polymers.

Evaluation and Comparison of Three Types of Spray Dried Coprocessed Excipient Avicel® for Direct Compression

PubMed Central

Solný, Tomaš

2018-01-01

As coprocessed excipients (CPE) gain a lot of focus recently, this article compares three commercially available CPE of Avicel brand, namely, CE 15, DG, and HFE 102. Comparison is based on measured physical properties of coprocessed mixtures, respectively, flow properties, pycnometric density, mean particle size, specific surface area, moisture content, hygroscopicity, solubility, pH leaching, electrostatic charge, SEM images, and DSC. Tablets were made employing three pressure sets. Viscoelastic properties and ejection force were assessed during compression, as well as pycnometric density, mass uniformity, height, tensile strength, friability, disintegration, and wetting times. Avicel CE 15 is of mid-range flow properties, contains mid-size and nonspherical particles, and has high hygroscopicity, growing negative charge, best lubricity, lowest tensile strength, and mid-long disintegration times. Avicel DG possesses the worst flow properties, small asymmetrical particles, lowest hygroscopicity, stable charge, intermediate lubricity, and tensile strength and exhibits fast disintegration of tablets. Finally, Avicel HFE 102 has the best flow properties, large symmetrical particles, and middle hygroscopicity and its charge fluctuates throughout blending. It also exhibits inferior lubricity, the highest tensile strength, and slow disintegration of tablets. Generally, it is impossible to select the best CPE, as their different properties fit versatile needs of countless manufacturers and final products. PMID:29850496

Teaching the effects of gravity and intravascular and alveolar pressures on the distribution of pulmonary blood flow using a classic paper by West et al.

PubMed

Levitzky, Michael G

2006-03-01

"Distribution of blood flow in isolated lung; relation to vascular and alveolar pressures" by J. B. West, C. T. Dollery, and A. Naimark (J Appl Physiol 19: 713-724, 1964) is a classic paper, although it has not yet been included in the Essays on the American Physiological Society Classic Papers Project (http://www.the-aps.org/publications/classics/). This is the paper that originally described the "zones of the lung." The final figure in the paper, which synthesizes the results and discussion, is now seen in most textbooks of physiology or respiratory physiology. The paper is also a model of clear, concise writing. The paper and its final figure can be used to teach or review a number of physiological concepts. These include the effects of gravity on pulmonary blood flow and pulmonary vascular resistance; recruitment and distention of pulmonary vessels; the importance of the transmural pressure on the diameter of collapsible distensible vessels; the Starling resistor; the interplay of the pulmonary artery, pulmonary vein, and alveolar pressures; and the vascular waterfall. In addition, the figure can be used to generate discovery learning and discussion of several physiological or pathophysiological effects on pulmonary vascular resistance and the distribution of pulmonary blood flow.

Direct numerical simulation of the flow around an aerofoil in ramp-up motion

NASA Astrophysics Data System (ADS)

Rosti, Marco E.; Omidyeganeh, Mohammad; Pinelli, Alfredo

2016-02-01

A detailed analysis of the flow around a NACA0020 aerofoil at Rec = 2 × 104 undergoing a ramp up motion has been carried out by means of direct numerical simulations. During the manoeuvre, the angle of attack is linearly varied in time between 0° and 20° with a constant rate of change of α ˙ rad = 0 . 12 U ∞ / c . When the angle of incidence has reached the final value, the lift experiences a first overshoot and then suddenly decreases towards the static stall asymptotic value. The transient instantaneous flow is dominated by the generation and detachment of the dynamic stall vortex, a large scale structure formed by the merging of smaller scales vortices generated by an instability originating at the trailing edge. New insights on the vorticity dynamics leading to the lift overshoot, lift crisis, and the damped oscillatory cycle that gradually matches the steady condition are discussed using a number of post-processing techniques. These include a detailed analysis of the flow ensemble average statistics and coherent structures identification carried out using the Q -criterion and the finite-time Lyapunov exponent technique. The results are compared with the one obtained in a companion simulation considering a static stall condition at the final angle of incidence α = 20°.

Analysis of Convective Weather Impact on Pre-Departure Routing of Flights from Fort Worth Center to New York Center

NASA Technical Reports Server (NTRS)

Arneson, Heather; Bombelli, Alessandro; Segarra-Torne, Adria; Tse, Elmer

2017-01-01

In response to severe weather conditions, Traffic Managers specify flow constraints and reroutes to route air traffic around affected regions of airspace. Providing analysis and recommendations of available reroute options and associated airspace capacities would assist Traffic Managers in making more efficient decisions in response to convective weather. These recommendations can be developed by examining historical data to determine which previous reroute options were used in similar weather and traffic conditions. This paper describes the initial steps and methodology used towards this goal. The focus of this work is flights departing from Fort Worth Center destined for New York Center. Dominant routing structures used in the absence of convective weather are identified. A method to extract relevant features from the large volume of weather data available to quantify the impact of convective weather on this routing structure over a given time range is presented. Finally, a method of estimating flow rate capacity along commonly used routes during convective weather events is described. Results show that the flow rates drop exponentially as a function of the values of the proposed feature and that convective weather on the final third of the route was found to have a greater impact on the flow rate restriction than other portions of the route.

Experimental and analytical investigation of a freezing point depressant fluid ice protection system. M.S. Thesis. Final Report

NASA Technical Reports Server (NTRS)

Albright, A. E.

1984-01-01

A glycol-exuding porous leading edge ice protection system was tested in the NASA Icing Research Tunnel. Stainless steel mesh, laser drilled titanium, and composite panels were tested on two general aviation wing sections. Two different glycol-water solutions were evaluated. Minimum glycol flow rates required for anti-icing were obtained as a function of angle of attack, liquid water content, volume median drop diameter, temperature, and velocity. Ice accretions formed after five minutes of icing were shed in three minutes or less using a glycol fluid flow equal to the anti-ice flow rate. Two methods of predicting anti-ice flow rates are presented and compared with a large experimental data base of anti-ice flow rates over a wide range of icing conditions. The first method presented in the ADS-4 document typically predicts flow rates lower than the experimental flow rates. The second method, originally published in 1983, typically predicts flow rates up to 25 percent higher than the experimental flow rates. This method proved to be more consistent between wing-panel configurations. Significant correlation coefficients between the predicted flow rates and the experimental flow rates ranged from .867 to .947.

Optical measurement of blood flow in exercising skeletal muscle: a pilot study

NASA Astrophysics Data System (ADS)

Wang, Detian; Baker, Wesley B.; Parthasarathy, Ashwin B.; Zhu, Liguo; Li, Zeren; Yodh, Arjun G.

2017-07-01

Blood flow monitoring during rhythm exercising is very important for sports medicine and muscle dieases. Diffuse correlation spectroscopy(DCS) is a relative new invasive way to monitor blood flow but suffering from muscle fiber motion. In this study we focus on how to remove exercise driven artifacts and obtain accurate estimates of the increase in blood flow from exercise. Using a novel fast software correlator, we measured blood flow in forearm flexor muscles of N=2 healthy adults during handgrip exercise, at a sampling rate of 20 Hz. Combining the blood flow and acceleration data, we resolved the motion artifact in the DCS signal induced by muscle fiber motion, and isolated the blood flow component of the signal from the motion artifact. The results show that muscle fiber motion strongly affects the DCS signal, and if not accounted for, will result in an overestimate of blood flow more than 1000%. Our measurements indicate rapid dilation of arterioles following exercise onset, which enabled blood flow to increase to a plateau of 200% in 10s. The blood flow also rapidly recovered to baseline following exercise in 10s. Finally, preliminary results on the dependence of blood flow from exercise intensity changes will be discussed.

International food trade reduces environmental effects of nitrogen pollution in China.

PubMed

Shi, Yaxing; Wu, Shaohua; Zhou, Shenglu; Wang, Chunhui; Chen, Hao

2016-09-01

The globalization of agricultural trade has dramatically altered global nitrogen flows by changing the spatial pattern of nitrogen utilization and emissions at a global scale. As a major trading country, China uses a large amount of nitrogen, which has a profound impact on global nitrogen flows. Using data on food production and trade between China and 26 other countries and regions, we calculated nitrogen inputs and outputs in food production ecosystem in each country. We estimated nitrogen flows in international food trade and analyzed their impact on nitrogen pollution in China. We divided nitrogen flows into embodied and virtual nitrogen flows. Embodied nitrogen is taken up by the plant and incorporated into the final food product, whereas virtual nitrogen is lost to the environment throughout the food production process and is not contained in the final food product. Our results show that China mainly imports food products from America and Asia, accounting for 95 % of all imported food. Asia (mainly Japan) and Europe are the main exporters of food from China, with Japan and the EU accounting for 17 and 10 % of all exported food, respectively. Total nitrogen inputs and outputs in food production in China were 55,400 and 61,000 Gg respectively, which were much higher than in other countries. About 1440 and 950 Gg of embodied and virtual nitrogen respectively flow into China through the food trade, mainly from food-exporting countries such as the USA, Argentina, and Brazil. Meanwhile, 177 and 160 Gg of embodied and virtual nitrogen respectively flow out of China from the export of food products, mainly to Japan. China's net food imports have reduced 720 and 458 Gg for nitrogen utilization and outputs, respectively, which accounted for 1.3 and 0.78 % of total nitrogen inputs and outputs in China. These results suggest that food trade in China has a profound effect on nitrogen flows and has greatly reduced environmental impacts on nitrogen pollution in China.

Effects of surface coal mining and reclamation on the geohydrology of six small watersheds in West-Central Indiana

USGS Publications Warehouse

Martin, Jeffrey D.; Duwelius, Richard F.; Crawford, Charles G.

1990-01-01

Hydrologic effects of mining and reclamation were identified by comparing the hydrologic systems at mined and reclaimed watersheds with those at unmined agricultural watersheds. The presence or absence of a large final-cut lake in the reclaimed watershed greatly influences the hydrologic systems and the effects of mining and reclamation. Surface coal mining and reclamation can decrease base flow, annual runoff, and peak flow rates; increase the variability of flow and recharge to the bedrock; reestablish the premining relation between surface- and ground-water divides; and lower the water table in upland areas.

Transitional flow in thin tubes for space station freedom radiator

NASA Technical Reports Server (NTRS)

Loney, Patrick; Ibrahim, Mounir

1995-01-01

A two dimensional finite volume method is used to predict the film coefficients in the transitional flow region (laminar or turbulent) for the radiator panel tubes. The code used to perform this analysis is CAST (Computer Aided Simulation of Turbulent Flows). The information gathered from this code is then used to augment a Sinda85 model that predicts overall performance of the radiator. A final comparison is drawn between the results generated with a Sinda85 model using the Sinda85 provided transition region heat transfer correlations and the Sinda85 model using the CAST generated data.

Role of zonal flow predator-prey oscillations in triggering the transition to H-mode confinement.

PubMed

Schmitz, L; Zeng, L; Rhodes, T L; Hillesheim, J C; Doyle, E J; Groebner, R J; Peebles, W A; Burrell, K H; Wang, G

2012-04-13

Direct evidence of zonal flow (ZF) predator-prey oscillations and the synergistic roles of ZF- and equilibrium E×B flow shear in triggering the low- to high-confinement (L- to H-mode) transition in the DIII-D tokamak is presented. Periodic turbulence suppression is first observed in a narrow layer at and just inside the separatrix when the shearing rate transiently exceeds the turbulence decorrelation rate. The final transition to H mode with sustained turbulence and transport reduction is controlled by equilibrium E×B shear due to the increasing ion pressure gradient.

The Role of Cooling in Pahohoe Emplacement on Planetary Surfaces.

NASA Technical Reports Server (NTRS)

Glaze, L. S.; Baloga, S. M.

2015-01-01

Abundant evidence is emerging that many lavas on Mars were emplaced as slow-moving pahoehoe flows. Models for such scenarios contrast sharply with those for steep-sloped applications where gravity is the dominant force. The mode of flow emplacement on low slopes is characterized by toe formation and inflation. In the latter phase of pahoehoe flow emplacement, stagnation, inflation, and toe formation are most closely tied to the final topography, dimensions, and morphologic features. This mode of emplacement is particularly relevant to the low slopes of planetary surfaces such as the plains of Mars, Io and the Moon.

Research on Closed Residential Area Based on Balanced Distribution Theory

NASA Astrophysics Data System (ADS)

Lan, Si; Fang, Ni; Lin, Hai Peng; Ye, Shi Qi

2018-06-01

With the promotion of the street system, residential quarters and units of the compound gradually open. In this paper, the relationship between traffic flow and traffic flow is established for external roads, and the road resistance model is established by internal roads. We propose a balanced distribution model from the two aspects of road opening conditions and traffic flow inside and outside the district, and quantitatively analyze the impact of the opening and closing on the surrounding roads. Finally, it puts forward feasible suggestions to improve the traffic situation and optimize the network structure.

Wind-US Unstructured Flow Solutions for a Transonic Diffuser

NASA Technical Reports Server (NTRS)

Mohler, Stanley R., Jr.

2005-01-01

The Wind-US Computational Fluid Dynamics flow solver computed flow solutions for a transonic diffusing duct. The calculations used an unstructured (hexahedral) grid. The Spalart-Allmaras turbulence model was used. Static pressures along the upper and lower wall agreed well with experiment, as did velocity profiles. The effect of the smoothing input parameters on convergence and solution accuracy was investigated. The meaning and proper use of these parameters are discussed for the benefit of Wind-US users. Finally, the unstructured solver is compared to the structured solver in terms of run times and solution accuracy.

Realistic generation of natural phenomena based on video synthesis

NASA Astrophysics Data System (ADS)

Wang, Changbo; Quan, Hongyan; Li, Chenhui; Xiao, Zhao; Chen, Xiao; Li, Peng; Shen, Liuwei

2009-10-01

Research on the generation of natural phenomena has many applications in special effects of movie, battlefield simulation and virtual reality, etc. Based on video synthesis technique, a new approach is proposed for the synthesis of natural phenomena, including flowing water and fire flame. From the fire and flow video, the seamless video of arbitrary length is generated. Then, the interaction between wind and fire flame is achieved through the skeleton of flame. Later, the flow is also synthesized by extending the video textures using an edge resample method. Finally, we can integrate the synthesized natural phenomena into a virtual scene.

Multicomponent, flow diazotization/Mizoroki-Heck coupling protocol: dispelling myths about working with diazonium salts.

PubMed

Nalivela, Kumara S; Tilley, Michael; McGuire, Michael A; Organ, Michael G

2014-05-26

A single pass flow diazotization/Mizoroki-Heck protocol has been developed for the production of cinnimoyl and styryl products. The factors that govern aryl diazonium salt stability have been examined in detail leading to the development of a MeOH/DMF co-solvent system in which the diazonium salts can be generated in the presence of all other reaction components and then coupled selectively to give the desired products. Finally the key role of the reaction quench for flow reactions has been demonstrated. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Adaptive Management of Environmental Flows

NASA Astrophysics Data System (ADS)

Webb, J. Angus; Watts, Robyn J.; Allan, Catherine; Conallin, John C.

2018-03-01

Adaptive management enables managers to work with complexity and uncertainty, and to respond to changing biophysical and social conditions. Amid considerable uncertainty over the benefits of environmental flows, governments are embracing adaptive management as a means to inform decision making. This Special Issue of Environmental Management presents examples of adaptive management of environmental flows and addresses claims that there are few examples of its successful implementation. It arose from a session at the 11th International Symposium on Ecohydraulics held in Australia, and is consequently dominated by papers from Australia. We classified the papers according to the involvement of researchers, managers and the local community in adaptive management. Five papers report on approaches developed by researchers, and one paper on a community-led program; these case studies currently have little impact on decision making. Six papers provide examples involving water managers and researchers, and two papers provide examples involving water managers and the local community. There are no papers where researchers, managers and local communities all contribute equally to adaptive management. Successful adaptive management of environmental flows occurs more often than is perceived. The final paper explores why successes are rarely reported, suggesting a lack of emphasis on reflection on management practices. One major challenge is to increase the documentation of successful adaptive management, so that benefits of learning extend beyond the project where it takes place. Finally, moving towards greater involvement of all stakeholders is critical if we are to realize the benefits of adaptive management for improving outcomes from environmental flows.

Lava flow-field morphology: A case study from Mount Etna, Sicily

NASA Technical Reports Server (NTRS)

Guest, J. E.; Hughes, J. W.; Duncan, A. M.

1987-01-01

The morphology of lava flows is often taken as an indicator of the broad chemical composition of the lava, especially when interpreting extraterrestrial volcanoes using spacecraft images. The historical lavas of the active volcano Mount Etna in Sicily provide an excellent opportunity to examine the controls on flow field morphology. In this study only flow produced by flank eruptions after the middle of the 18th century are examined. The final form of a flow-field may be more indicative of the internal plumbing of the volcano, which may control such factors as the effusion, rate, duration of eruption, volume of available magma, rate of de-gassing, and lava rheology. Different flow morphologies on Etna appear to be a good indicator of differing conditions within the volcanic pile. Thus the spatial distribution of different flow types on an extraterrestrial volcano may provide useful information about the plumbing conditions of that volcano, rather than necessarily providing information on the composition of materials erupted.

Confined turbulent swirling recirculating flow predictions. Ph.D. Thesis. Final Report

NASA Technical Reports Server (NTRS)

Abujelala, M. T.; Lilley, D. G.

1985-01-01

The capability and the accuracy of the STARPIC computer code in predicting confined turbulent swirling recirculating flows is presented. Inlet flow boundary conditions were demonstrated to be extremely important in simulating a flowfield via numerical calculations. The degree of swirl strength and expansion ratio have strong effects on the characteristics of swirling flow. In a nonswirling flow, a large corner recirculation zone exists in the flowfield with an expansion ratio greater than one. However, as the degree of inlet swirl increases, the size of this zone decreases and a central recirculation zone appears near the inlet. Generally, the size of the central zone increased with swirl strength and expansion ratio. Neither the standard k-epsilon turbulence mode nor its previous extensions show effective capability for predicting confined turbulent swirling recirculating flows. However, either reduced optimum values of three parameters in the mode or the empirical C sub mu formulation obtained via careful analysis of available turbulence measurements, can provide more acceptable accuracy in the prediction of these swirling flows.

Columbus Payloads Flow Rate Anomalies

NASA Technical Reports Server (NTRS)

Quaranta, Albino; Bufano, Gaetana; DePalo, Savino; Holt, James M.; Szigetvari, Zoltan; Palumberi, Sergio; Hinderer, S.

2011-01-01

The Columbus Active Thermal Control System (ATCS) is the main thermal bus for the pressurized racks working inside the European laboratory. One of the ATCS goals is to provide proper water flow rate to each payload (P/L) by controlling actively the pressure drop across the common plenum distribution piping. Overall flow measurement performed by the Water Pump Assembly (WPA) is the only flow rate monitor available at system level and is not part of the feedback control system. At rack activation the flow rate provided by the system is derived on ground by computing the WPA flow increase. With this approach, several anomalies were raised during these 3 years on-orbit, with the indication of low flow rate conditions on the European racks FSL, BioLab, EDR and EPM. This paper reviews the system and P/Ls calibration approach, the anomalies occurred, the engineering evaluation on the measurement approach and the accuracy improvements proposed, the on-orbit test under evaluation with NASA and finally discusses possible short and long term solutions in case of anomaly confirmation.

Simulations of Heterogeneous Detonations and Post Detonation Turbulent Mixing and Afterburning

NASA Astrophysics Data System (ADS)

Menon, Suresh; Gottiparthi, Kalyana

2011-06-01

Most metal-loaded explosives and thermobaric explosives exploit the afterburning of metals to maintain pressure and temperature conditions.The use of such explosives in complex environment can result in post detonation flow containing many scales of vortical motion, flow jetting and shear, as well as plume-surface interactions due to flow impingement and wall flows. In general, all these interactions can lead to highly turbulent flow fields even if the initial ambient conditions were quiescent. Thus, turbulent mixing can dominate initial mixing and impact the final afterburn. We conduct three-dimensional numerical simulations of the propagation of detonation resulting from metal-loaded (inert or reacting) explosives and analyze the afterburn process as well as the generation of multiple scales of mixing in the post detonation flow field. Impact of the detonation and post-detonation flow field on solid surface is also considered for a variety of initial conditions. Comparison with available data is carried out to demonstrate validity of the simulation method. Supported by Defense Threat Reduction Agency

A three-dimensional turbulent compressible flow model for ejector and fluted mixers

NASA Technical Reports Server (NTRS)

Rushmore, W. L.; Zelazny, S. W.

1978-01-01

A three dimensional finite element computer code was developed to analyze ejector and axisymmetric fluted mixer systems whose flow fields are not significantly influenced by streamwise diffusion effects. A two equation turbulence model was used to make comparisons between theory and data for various flow fields which are components of the ejector system, i.e., (1) turbulent boundary layer in a duct; (2) rectangular nozzle (free jet); (3) axisymmetric nozzle (free jet); (4) hypermixing nozzle (free jet); and (5) plane wall jet. Likewise, comparisons of the code with analytical results and/or other numerical solutions were made for components of the axisymmetric fluted mixer system. These included: (1) developing pipe flow; (2) developing flow in an annular pipe; (3) developing flow in an axisymmetric pipe with conical center body and no fluting and (4) developing fluted pipe flow. Finally, two demonstration cases are presented which show the code's ability to analyze both the ejector and axisymmetric fluted mixers.

Measurement and simulation of thermoelectric efficiency for single leg

NASA Astrophysics Data System (ADS)

Hu, Xiaokai; Yamamoto, Atsushi; Ohta, Michihiro; Nishiate, Hirotaka

2015-04-01

Thermoelectric efficiency measurements were carried out on n-type bismuth telluride legs with the hot-side temperature at 100 and 150 °C. The electric power and heat flow were measured individually. Water coolant was utilized to maintain the cold-side temperature and to measure heat flow out of the cold side. Leg length and vacuum pressure were studied in terms of temperature difference across the leg, open-circuit voltage, internal resistance, and heat flow. Finite-element simulation on thermoelectric generation was performed in COMSOL Multiphysics, by inputting two-side temperatures and thermoelectric material properties. The open-circuit voltage and resistance were in good agreement between the measurement and simulation. Much larger heat flows were found in measurements, since they were comprised of conductive, convective, and radiative contributions. Parasitic heat flow was measured in the absence of bismuth telluride leg, and the conductive heat flow was then available. Finally, the maximum thermoelectric efficiency was derived in accordance with the electric power and the conductive heat flow.

Continuous Flow Chemistry: Reaction of Diphenyldiazomethane with p-Nitrobenzoic Acid.

PubMed

Aw, Alex; Fritz, Marshall; Napoline, Jonathan W; Pollet, Pamela; Liotta, Charles L

2017-11-15

Continuous flow technology has been identified as instrumental for its environmental and economic advantages leveraging superior mixing, heat transfer and cost savings through the "scaling out" strategy as opposed to the traditional "scaling up". Herein, we report the reaction of diphenyldiazomethane with p-nitrobenzoic acid in both batch and flow modes. To effectively transfer the reaction from batch to flow mode, it is essential to first conduct the reaction in batch. As a consequence, the reaction of diphenyldiazomethane was first studied in batch as a function of temperature, reaction time, and concentration to obtain kinetic information and process parameters. The glass flow reactor set-up is described and combines two types of reaction modules with "mixing" and "linear" microstructures. Finally, the reaction of diphenyldiazomethane with p-nitrobenzoic acid was successfully conducted in the flow reactor, with up to 95% conversion of the diphenyldiazomethane in 11 min. This proof of concept reaction aims to provide insight for scientists to consider flow technology's competitiveness, sustainability, and versatility in their research.

Generation of Martian chaos and channels by debris flows

NASA Technical Reports Server (NTRS)

Nummedal, D.; Prior, D. B.

1981-01-01

A debris flow mechanism is proposed to account for the formation of chaos and the large channels debouching into Crysae Planitia from the adjacent southern uplands of Mars. Based on considerations of the juxtaposition of individual channel environments, the morphological assemblages within each environment and flow dynamics, it is suggested that the debris flows were triggered by the large-scale failure of subsurface sediments, possibly initiated by a seismic event. During the initial, slow-moving phase of the flow, the debris would have formed gently sinuous channels with multiple side-wall slumps, grooves and ridges, and elongate erosional remnants. The flow would have gained mobility as the debris moved downslope, producing travel distances greatly in excess of those characteristic of terrestrial examples, and eroded, streamlined remnants at the distal reaches of the channel. Finally, due to internal and boundary friction, the flow would have been slowed down once it entered the Chryse plains, resulting in a thin debris blanket with no depositional relief.

Salivary buffer effect in relation to late pregnancy and postpartum.

PubMed

Laine, M; Pienihäkkinen, K

2000-02-01

We studied the salivary pH, buffer effect (BE), and flow rates of unstimulated and paraffin-stimulated saliva of 8 women in their late pregnancy and postpartum. Salivary samples were collected about 1 month prior to and about 2 months after delivery. In non-pregnant control women, two paraffin-stimulated salivary samples were collected 1 month apart. The salivary BE increased significantly from late pregnancy to postpartum without exception. The increase was 2.04 +/- 1.17 pH units (P < 0.001) on average. The BE increased from 4.79 +/- 1.64 (final pH) to 6.82 +/- 1.01 (final pH). This change was not due to variation in salivary flow rates, since both unstimulated and paraffin-stimulated flow rates remained unchanged. In control women the difference between the 2 BE measurements was only 0.13 +/- 0.47 pH units on average. We concluded that women with high postpartum BE values may have moderate or even low BE values in late pregnancy. In control women, individual variation was found to be low in all variables studied.

Documenting Chemical Assimilation in a Basaltic Lava Flow

NASA Technical Reports Server (NTRS)

Young, K. E.; Bleacher, J. E.; Needham, D. H.; Evans, C.; Whelley, P. L.; Scheidt, S.; Williams, D.; Rogers, A. D.; Glotch, T.

2017-01-01

Lava channels are features seen throughout the inner Solar System, including on Earth, the Moon, and Mars. Flow emplacement is therefore a crucial process in the shaping of planetary surfaces. Many studies have investigated the dynamics of lava flow emplacement, both on Earth and on the Moon [1,2,3] but none have focused on how the compositional and structural characteristics of the substrate over which a flow was emplaced influenced its final flow morphology. Within the length of one flow, it is common for flows to change in morphology, a quality linked to lava rheology (a function of multiple factors including viscosity, temperature, composition, etc.). The relationship between rheology and temperature has been well-studied [4,5,6] but less is understood about the relationship between a pre-flow terrain's chemistry and how the interaction between this flow and the new flow might affect lava rheology and therefore emplacement dynamics. Lava erosion. Through visual observations of active terrestrial flows, lava erosion has been well-documented [i.e. 7,8,9,10]. Lava erosion is the process by which flow composition is altered as the active lava melts and assimilates the pre-flow terrain over which it moves. Though this process has been observed, there is only one instance of where it was been geochemically documented.

Flow visualization for investigating stator losses in a multistage axial compressor

NASA Astrophysics Data System (ADS)

Smith, Natalie R.; Key, Nicole L.

2015-05-01

The methodology and implementation of a powder-paint-based flow visualization technique along with the illuminated flow physics are presented in detail for application in a three-stage axial compressor. While flow visualization often accompanies detailed studies, the turbomachinery literature lacks a comprehensive study which both utilizes flow visualization to interrupt the flow field and explains the intricacies of execution. Lessons learned for obtaining high-quality images of surface flow patterns are discussed in this study. Fluorescent paint is used to provide clear, high-contrast pictures of the recirculation regions on shrouded vane rows. An edge-finding image processing procedure is implemented to provide a quantitative measure of vane-to-vane variability in flow separation, which is approximately 7 % of the suction surface length for Stator 1. Results include images of vane suction side corner separations from all three stages at three loading conditions. Additionally, streakline patterns obtained experimentally are compared with those calculated from computational models. Flow physics associated with vane clocking and increased rotor tip clearance and their implications to stator loss are also investigated with this flow visualization technique. With increased rotor tip clearance, the vane surface flow patterns show a shift to larger separations and more radial flow at the tip. Finally, the effects of instrumentation on the flow field are highlighted.

Evaluation of Ischemic and Bleeding Risks Associated With 2 Parenteral Antiplatelet Strategies Comparing Cangrelor With Glycoprotein IIb/IIIa Inhibitors: An Exploratory Analysis From the CHAMPION Trials.

PubMed

Vaduganathan, Muthiah; Harrington, Robert A; Stone, Gregg W; Deliargyris, Efthymios N; Steg, Ph Gabriel; Gibson, C Michael; Hamm, Christian W; Price, Matthew J; Menozzi, Alberto; Prats, Jayne; Elkin, Steven; Mahaffey, Kenneth W; White, Harvey D; Bhatt, Deepak L

2017-02-01

In the context of contemporary pharmacotherapy, optimal antiplatelet management with percutaneous coronary intervention (PCI) has not been well established. To compare the ischemic and bleeding risks associated with glycoprotein IIb/IIIa inhibitors (GPIs) and a potent P2Y12 antagonist, cangrelor, in patients undergoing PCI. An exploratory analysis of pooled patient-level data from the 3 phase 3 Cangrelor vs Standard Therapy to Achieve Optimal Management of Platelet Inhibition (CHAMPION PCI, CHAMPION PLATFORM, and CHAMPION PHOENIX) trials of patients undergoing elective or nonelective PCI. The participants included 10 929 patients assigned to cangrelor but not receiving GPIs (cangrelor alone) and 1211 patients assigned to clopidogrel (or placebo) and receiving routine GPIs (clopidogrel-GPI). Patients requiring bailout or rescue GPI therapy were excluded. To account for risk imbalances, 1:1 propensity score matching based on 16 baseline clinical variables yielded 1021 unique matched pairs. The present study's data analysis was conducted from October 28, 2015, to August 6, 2016. The primary efficacy end point was the composite of all-cause mortality, myocardial infarction, ischemia-driven revascularization, or stent thrombosis at 48 hours. Safety was assessed by 3 validated bleeding scales (Global Use of Strategies to Open Occluded Coronary Arteries [GUSTO], Thrombolysis in Myocardial Infarction [TIMI], and Acute Catheterization and Urgent Intervention Triage) and requirement for blood transfusions. Of the 12 140 patients included in the analysis, 8779 were men (72.3%), and the mean (SD) age was 63.2 (11.3) years. Patients in the clopidogrel-GPI group were more likely to be male (75.6% vs 71.9%), younger (median, 60 [range, 23-91] years vs 64 [range, 26-95] years), enrolled from the United States (77.9% vs 40.0%), and present with an acute coronary syndrome, but they had lower comorbid disease burden and were less likely to receive bivalirudin (8.8% vs 27.3%). In the matched cohorts, the rates of the primary efficacy end point were not significantly different between the cangrelor alone and clopidogrel-GPI groups (2.6% vs 3.3%; odds ratio [OR], 0.79; 95% CI, 0.48-1.32). There was a nonsignificant trend toward lower rates of GUSTO-defined severe/life-threatening bleeding with cangrelor alone compared with clopidogrel-GPI (0.3% vs 0.7%; OR, 0.43; 95% CI, 0.11-1.66). Rates of TIMI-defined major or minor bleeding were significantly lower in patients treated with cangrelor alone (0.7% vs 2.4%; OR, 0.29; 95% CI, 0.13-0.68). Based on a pooled analysis from the 3 phase 3 CHAMPION trials, cangrelor alone was associated with similar ischemic risk and lower risk-adjusted bleeding risk compared with clopidogrel-GPIs. clinicaltrials.gov Identifiers: NCT00305162, NCT00385138, and NCT01156571.

A Wavelet Neural Network Optimal Control Model for Traffic-Flow Prediction in Intelligent Transport Systems

NASA Astrophysics Data System (ADS)

Huang, Darong; Bai, Xing-Rong

Based on wavelet transform and neural network theory, a traffic-flow prediction model, which was used in optimal control of Intelligent Traffic system, is constructed. First of all, we have extracted the scale coefficient and wavelet coefficient from the online measured raw data of traffic flow via wavelet transform; Secondly, an Artificial Neural Network model of Traffic-flow Prediction was constructed and trained using the coefficient sequences as inputs and raw data as outputs; Simultaneous, we have designed the running principium of the optimal control system of traffic-flow Forecasting model, the network topological structure and the data transmitted model; Finally, a simulated example has shown that the technique is effectively and exactly. The theoretical results indicated that the wavelet neural network prediction model and algorithms have a broad prospect for practical application.

Supersonic quiet-tunnel development for laminar-turbulent transition research

NASA Technical Reports Server (NTRS)

Schneider, Steven P.

1995-01-01

This grant supported research into quiet-flow supersonic wind-tunnels, between February 1994 and February 1995. Quiet-flow nozzles operate with laminar nozzle-wall boundary layers, in order to provide low-disturbance flow for studies of laminar-turbulent transition under conditions comparable to flight. Major accomplishments include: (1) development of the Purdue Quiet-Flow Ludwieg Tube, (2) computational evaluation of the square nozzle concept for quiet-flow nozzles, and (3) measurement of the presence of early transition on the flat sidewalls of the NASA LaRC Mach 3.5 supersonic low-disturbance tunnel. Since items (1) and (2) are described in the final report for companion grant NAG1-1133, only item (3) is described here. A thesis addressing the development of square nozzles for high-speed, low-disturbance wind tunnels is included as an appendix.

Little Goose Dam Full Flow PIT-Tag Detection System Project Summary.

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

Warf, Don; Livingston, Scott

2009-04-16

In 2006, the design phase of this project was kicked off and was for the most part modeled after the Full Flow PIT installation installed at Lower Monumental Dam during winter and spring of 2006 and 2007. As the Goose Full Flow design progressed and the project started to move towards construction, issues within contracting occurred and the project was put on delay for 1 year. Starting in mid December of 2008, Harcon Inc. was awarded the contract and construction of the new Goose Full Flow PIT-tag detection system began. The purpose of this document is to summarize the installationmore » of the Little Goose Full Flow project from start to finish and to highlight the notable successes and challenges that the installation presented along with the final results and current status.« less

Triboelectric-based harvesting of gas flow energy and powerless sensing applications

NASA Astrophysics Data System (ADS)

Taghavi, Majid; Sadeghi, Ali; Mazzolai, Barbara; Beccai, Lucia; Mattoli, Virgilio

2014-12-01

In this work, we propose an approach that can convert gas flow energy to electric energy by using the triboelectric effect, in a structure integrating at least two conductive parts (i.e. electrodes) and one non-conductive sheet. The gas flow induces vibration of the cited parts. Therefore, the frequent attaching and releasing between a non-conductive layer with at least one electrode generates electrostatic charges on the surfaces, and then an electron flow between the two electrodes. The effect of blown gas on the output signals is studied to evaluate the gas flow sensing. We also illustrate that the introduced system has an ability to detect micro particles driven by air into the system. Finally we show how we can use this approach for a self sustainable system demonstrating smoke detection and LED lightening.

Verification of rain-flow reconstructions of a variable amplitude load history. M.S. Thesis, 1990 Final Report

NASA Technical Reports Server (NTRS)

Clothiaux, John D.; Dowling, Norman E.

1992-01-01

The suitability of using rain-flow reconstructions as an alternative to an original loading spectrum for component fatigue life testing is investigated. A modified helicopter maneuver history is used for the rain-flow cycle counting and history regenerations. Experimental testing on a notched test specimen over a wide range of loads produces similar lives for the original history and the reconstructions. The test lives also agree with a simplified local strain analysis performed on the specimen utilizing the rain-flow cycle count. The rain-flow reconstruction technique is shown to be a viable test spectrum alternative to storing the complete original load history, especially in saving computer storage space and processing time. A description of the regeneration method, the simplified life prediction analysis, and the experimental methods are included in the investigation.

A Comparison of Simplified Two-dimensional Flow Models Exemplified by Water Flow in a Cavern

NASA Astrophysics Data System (ADS)

Prybytak, Dzmitry; Zima, Piotr

2017-12-01

The paper shows the results of a comparison of simplified models describing a two-dimensional water flow in the example of a water flow through a straight channel sector with a cavern. The following models were tested: the two-dimensional potential flow model, the Stokes model and the Navier-Stokes model. In order to solve the first two, the boundary element method was employed, whereas to solve the Navier-Stokes equations, the open-source code library OpenFOAM was applied. The results of numerical solutions were compared with the results of measurements carried out on a test stand in a hydraulic laboratory. The measurements were taken with an ADV probe (Acoustic Doppler Velocimeter). Finally, differences between the results obtained from the mathematical models and the results of laboratory measurements were analysed.

One-dimensional analysis of unsteady flows due to supercritical heat addition in high speed condensing steam

NASA Astrophysics Data System (ADS)

Malek, N. A.; Hasini, H.; Yusoff, M. Z.

2013-06-01

Unsteadiness in supersonic flow in nozzles can be generated by the release of heat due to spontaneous condensation. The heat released is termed "supercritical" and may be responsible for turbine blades failure in turbine cascade as it causes a supersonic flow to decelerate. When the Mach number is reduced to unity, the flow can no longer sustain the additional heat and becomes unstable. This paper aims to numerically investigate the unsteadiness caused by supercritical heat addition in one-dimensional condensing flows. The governing equations for mass, momentum and energy, coupled with the equations describing the wetness fraction and droplet growth are integrated and solved iteratively to reveal the final solution. Comparison is made with well-established experimental and numerical solution done by previous researchers that shows similar phenomena.

Method and apparatus for making articles from particle based materials

DOEpatents

Moorhead, A.J.; Menchhofer, P.A.

1995-12-19

A method and apparatus are disclosed for the production of articles made of a particle-based material; e.g., ceramics and sintered metals. In accordance with the invention, a thermally settable slurry containing a relatively high concentration of the particles is conveyed through an elongate flow area having a desired cross-sectional configuration. The slurry is heated as it is advanced through the flow area causing the slurry to set or harden in a shape which conforms to the cross-sectional configuration of the flow area. The material discharges from the flow area as a self-supporting solid of near net final dimensions. The article may then be sintered to consolidate the particles and provide a high density product. 10 figs.

Flow Visualization of Density in a Cryogenic Wind Tunnel Using Planar Rayleigh and Raman Scattering

NASA Technical Reports Server (NTRS)

Herring, Gregory C.; Shirinzadeh, Behrooz

2002-01-01

Using a pulsed Nd:YAG laser (532 nm) and a gated, intensified charge-coupled device, planar Rayleigh and Raman scattering techniques have been used to visualize the unseeded Mach 0.2 flow density in a 0.3-meter transonic cryogenic wind tunnel. Detection limits are determined for density measurements by using both unseeded Rayleigh and Raman (N2 vibrational) methods. Seeding with CO2 improved the Rayleigh flow visualization at temperatures below 150 K. The seeded Rayleigh version was used to demonstrate the observation of transient flow features in a separated boundary layer region, which was excited with an oscillatory jet. Finally, a significant degradation of the laser light sheet, in this cryogenic facility, is discussed.

Current status of computational methods for transonic unsteady aerodynamics and aeroelastic applications

NASA Technical Reports Server (NTRS)

Edwards, John W.; Malone, John B.

1992-01-01

The current status of computational methods for unsteady aerodynamics and aeroelasticity is reviewed. The key features of challenging aeroelastic applications are discussed in terms of the flowfield state: low-angle high speed flows and high-angle vortex-dominated flows. The critical role played by viscous effects in determining aeroelastic stability for conditions of incipient flow separation is stressed. The need for a variety of flow modeling tools, from linear formulations to implementations of the Navier-Stokes equations, is emphasized. Estimates of computer run times for flutter calculations using several computational methods are given. Applications of these methods for unsteady aerodynamic and transonic flutter calculations for airfoils, wings, and configurations are summarized. Finally, recommendations are made concerning future research directions.

Using the Richtmyer-Meshkov flow to infer the strength of LY-12 aluminum at extreme conditions

NASA Astrophysics Data System (ADS)

Yin, Jianwei; Pan, Hao; Peng, Jiangxiang; Wu, Zihui; Yu, Yuying; Hu, Xiaomian

2017-06-01

An improved analytical model of the Richtmyer-Meshkov (RM) flow in the elastoplastic materials is presented in this paper. This model describes the stabilization by yield strength (Y) effect on the RM flow in solids and linear relationships between initial configurations of perturbation and the growth. Then we make use of the model to analysis the explosion driven RM flow experiments with solid LY12 and test our model by comparing the predicted Y of existing strength models. Finally, we perform a plate impact experiment with solid LY12 aluminium alloy to validate our model and infer Y is about 1.23 GPa for a 28 GPa shock and a strain rate of 7.5 ×106 .

Estimating Flow-Through Balance Momentum Tares with CFD

NASA Technical Reports Server (NTRS)

Melton, John E.; James, Kevin D.; Long, Kurtis R.; Flamm, Jeffrey D.

2016-01-01

This paper describes the process used for estimating flow-through balance momentum tares. The interaction of jet engine exhausts on the BOEINGERA Hybrid Wing Body (HWB) was simulated in the NFAC 40x80 wind tunnel at NASA Ames using a pair of turbine powered simulators (TPS). High-pressure air was passed through a flow-through balance and manifold before being delivered to the TPS units. The force and moment tares that result from the internal shear and pressure distribution were estimated using CFD. Validation of the CFD simulations for these complex internal flows is a challenge, given limited experimental data due to the complications of the internal geometry. Two CFD validation efforts are documented, and comparisons with experimental data from the final model installation are provided.

Research on configuration of railway self-equipped tanker based on minimum cost maximum flow model

NASA Astrophysics Data System (ADS)

Yang, Yuefang; Gan, Chunhui; Shen, Tingting

2017-05-01

In the study of the configuration of the tanker of chemical logistics park, the minimum cost maximum flow model is adopted. Firstly, the transport capacity of the park loading and unloading area and the transportation demand of the dangerous goods are taken as the constraint condition of the model; then the transport arc capacity, the transport arc flow and the transport arc edge weight are determined in the transportation network diagram; finally, the software calculations. The calculation results show that the configuration issue of the tankers can be effectively solved by the minimum cost maximum flow model, which has theoretical and practical application value for tanker management of railway transportation of dangerous goods in the chemical logistics park.

Dynamic Control of Particle Deposition in Evaporating Droplets by an External Point Source of Vapor

PubMed Central

2018-01-01

The deposition of particles on a surface by an evaporating sessile droplet is important for phenomena as diverse as printing, thin-film deposition, and self-assembly. The shape of the final deposit depends on the flows within the droplet during evaporation. These flows are typically determined at the onset of the process by the intrinsic physical, chemical, and geometrical properties of the droplet and its environment. Here, we demonstrate deterministic emergence and real-time control of Marangoni flows within the evaporating droplet by an external point source of vapor. By varying the source location, we can modulate these flows in space and time to pattern colloids on surfaces in a controllable manner. PMID:29363979

City traffic flow breakdown prediction based on fuzzy rough set

NASA Astrophysics Data System (ADS)

Yang, Xu; Da-wei, Hu; Bing, Su; Duo-jia, Zhang

2017-05-01

In city traffic management, traffic breakdown is a very important issue, which is defined as a speed drop of a certain amount within a dense traffic situation. In order to predict city traffic flow breakdown accurately, in this paper, we propose a novel city traffic flow breakdown prediction algorithm based on fuzzy rough set. Firstly, we illustrate the city traffic flow breakdown problem, in which three definitions are given, that is, 1) Pre-breakdown flow rate, 2) Rate, density, and speed of the traffic flow breakdown, and 3) Duration of the traffic flow breakdown. Moreover, we define a hazard function to represent the probability of the breakdown ending at a given time point. Secondly, as there are many redundant and irrelevant attributes in city flow breakdown prediction, we propose an attribute reduction algorithm using the fuzzy rough set. Thirdly, we discuss how to predict the city traffic flow breakdown based on attribute reduction and SVM classifier. Finally, experiments are conducted by collecting data from I-405 Freeway, which is located at Irvine, California. Experimental results demonstrate that the proposed algorithm is able to achieve lower average error rate of city traffic flow breakdown prediction.

The mutual causality analysis between the stock and futures markets

NASA Astrophysics Data System (ADS)

Yao, Can-Zhong; Lin, Qing-Wen

2017-07-01

In this paper we employ the conditional Granger causality model to estimate the information flow, and find that the improved model outperforms the Granger causality model in revealing the asymmetric correlation between stocks and futures in the Chinese market. First, we find that information flows estimated by Granger causality tests from futures to stocks are greater than those from stocks to futures. Additionally, average correlation coefficients capture some important characteristics between stock prices and information flows over time. Further, we find that direct information flows estimated by conditional Granger causality tests from stocks to futures are greater than those from futures to stocks. Besides, the substantial increases of information flows and direct information flows exhibit a certain degree of synchronism with the occurrences of important events. Finally, the comparative analysis with the asymmetric ratio and the bootstrap technique demonstrates the slight asymmetry of information flows and the significant asymmetry of direct information flows. It reveals that the information flows from futures to stocks are slightly greater than those in the reverse direction, while the direct information flows from stocks to futures are significantly greater than those in the reverse direction.

Kvichak River RISEC Project Resource Reconnaissance and Physical Characterization

DOE Data Explorer

Jarlath McEntee

2015-10-01

During the summer and fall of 2011 TerraSond Ltd. (TerraSond) completed a bathymetric survey and hydrokinetic energy assessment of the Kvichak River at Igiugig, Alaska. The purpose of this work was to characterize the initial site conditions for the design and installation of a hydrokinetic turbine to provide electric power for the village. There were six distinct phases of work for this project. The first was a literature review and investigation of prior surveys and hydrologic studies done in the area. The second, third, fourth, and fifth phases consisted of four field expeditions conducted over the summer and fall of 2011. These expeditions consisted of an initial reconnaissance, multi beam bathymetric surveys, flow velocity and discharge measurements, a survey of water levels, and detailed flow velocity studies. The final phase of the project was complete data reduction, and preparation of the final report with its accompanying map sheets and data packages. This submission contains the final report for the Kvichak River RiISEC Project in addition to weather data for Igiugig, AK, Summer 2015.

A Mathematical Theory of System Information Flow

DTIC Science & Technology

2016-06-27

AFRL-AFOSR-VA-TR-2016-0232 A Mathematical Theory of System Information Flow Michael Mislove ADMINISTRATORS OF THE TULANE EDUCATIONAL FUND THE 6823...MM-YYYY) 17-06-2016 2. REPORT TYPE Final 3. DATES COVERED (From - To) 27MAR2013 - 31MAR2016 4. TITLE AND SUBTITLE A Mathematical Theory of System...systems using techniques from information theory , domain theory and other areas of mathematics and computer science. Over time, the focus shifted

JEFI: a cash flow analysis program (Version 3.0 for Windows). [Computer program].

Treesearch

Bruce Hansen; Jeff Palmer

1998-01-01

JEFFI/3 is a Windows-version of JEFFI/2. The differences between the two versions are the new interface, an investment term of 1 to 30 years (instead of 4 to 30), and a rich set of detailed online help documents. JEFFI/3 still retains a number of unique features of JEFFII2 related to treatment of the final year cash flows, depreciation, working capital, and derivation...

Investigation of blown boundary layers with an improved wall jet system. Ph.D. Thesis. Final Technical Report, 1 Jul. 1978 - Dec. 1979; [to prevent turbulent boundary layer separation

NASA Technical Reports Server (NTRS)

Saripalli, K. R.; Simpson, R. L.

1979-01-01

The behavior of two dimensional incompressible turbulent wall jets submerged in a boundary layer when they are used to prevent boundary layer separation on plane surfaces is investigated. The experimental set-up and instrumentation are described. Experimental results of zero pressure gradient flow and adverse pressure gradient flow are presented. Conclusions are given and discussed.

Flow Studies of Decelerators at Supersonic Speeds

NASA Technical Reports Server (NTRS)

1959-01-01

Wind tunnel tests recorded the effect of decelerators on flow at various supersonic speeds. Rigid parachute models were tested for the effects of porosity, shroud length, and number of shrouds. Flexible model parachutes were tested for effects of porosity and conical-shaped canopy. Ribbon dive brakes on a missile-shaped body were tested for effect of tension cable type and ribbon flare type. The final test involved a plastic sphere on riser lines.

Flow Field Analysis of Fully Coupled Computations of a Flexible Wing undergoing Stall Flutter

DTIC Science & Technology

2016-01-01

unsteady aerodynamic loads due to structural displacements. In terms of actuation , most, if not all, active ∗Research Associate, Department of...flutter suppression techniques, conventional trailing edge flap actuators with a bandwidth of 10 Hz5 was used. Interestingly, the frequencies associated...influence of the flow features on the aeroelastic instability are quantified. Finally, the influence of actuation through a blowing port at 75% span is

The role of transvaginal power Doppler ultrasound in the differential diagnosis of benign intrauterine focal lesions.

PubMed

Cogendez, Ebru; Eken, Meryem Kurek; Bakal, Nuray; Gun, Ismet; Kaygusuz, Ecmel Isik; Karateke, Ates

2015-10-01

The purpose of this prospective study was to assess the role of power Doppler imaging in the differential diagnosis of benign intrauterine focal lesions such as endometrial polyps and submucous myomas using the characteristics of power Doppler flow mapping. A total of 480 premenopausal patients with abnormal uterine bleeding were evaluated by transvaginal ultrasonography (TVS) searching for intrauterine pathology. Sixty-four patients with a suspicious focal endometrial lesion received saline infusion sonography (SIS) after TVS. Fifty-eight patients with focal endometrial lesions underwent power Doppler ultrasound (PDUS). Three different vascular flow patterns were defined: Single vessel pattern, multiple vessel pattern, and circular flow pattern. Finally, hysteroscopic resection was performed in all cases, and Doppler flow characteristics were then compared with the final histopathological findings. Histopathological results were as follows: endometrial polyp: 40 (69 %), submucous myoma: 18 (31 %). Of the cases with endometrial polyps, 80 % demonstrated a single vessel pattern, 7.5 % a multiple vessel pattern, and 0 % a circular pattern. Vascularization was not observed in 12.5 % of patients with polyps. Of the cases with submucousal myomas, 72.2 % demonstrated a circular flow pattern, 27.8 % a multiple vessel pattern, and none of them showed a single vessel pattern. The sensitivity, specificity, and positive and negative predictive values of the single vessel pattern in diagnosing endometrial polyps were 80, 100, 100, and 69.2 %, respectively; and for the circular pattern in diagnosing submucous myoma, these were 72.2, 100, 100, and 88.9 %, respectively. Power Doppler blood flow mapping is a useful, practical, and noninvasive diagnostic method for the differential diagnosis of benign intrauterine focal lesions. Especially in cases of recurrent abnormal uterine bleeding, recurrent abortion, and infertility, PDUS can be preferred as a first-line diagnostic method.

A Semi-Analytical Solution to Time Dependent Groundwater Flow Equation Incorporating Stream-Wetland-Aquifer Interactions

NASA Astrophysics Data System (ADS)

Boyraz, Uǧur; Melek Kazezyılmaz-Alhan, Cevza

2017-04-01

Groundwater is a vital element of hydrologic cycle and the analytical & numerical solutions of different forms of groundwater flow equations play an important role in understanding the hydrological behavior of subsurface water. The interaction between groundwater and surface water bodies can be determined using these solutions. In this study, new hypothetical approaches are implemented to groundwater flow system in order to contribute to the studies on surface water/groundwater interactions. A time dependent problem is considered in a 2-dimensional stream-wetland-aquifer system. The sloped stream boundary is used to represent the interaction between stream and aquifer. The rest of the aquifer boundaries are assumed as no-flux boundary. In addition, a wetland is considered as a surface water body which lies over the whole aquifer. The effect of the interaction between the wetland and the aquifer is taken into account with a source/sink term in the groundwater flow equation and the interaction flow is calculated by using Darcy's approach. A semi-analytical solution is developed for the 2-dimensional groundwater flow equation in 5 steps. First, Laplace and Fourier cosine transforms are employed to obtain the general solution in Fourier and Laplace domain. Then, the initial and boundary conditions are applied to obtain the particular solution. Finally, inverse Fourier transform is carried out analytically and inverse Laplace transform is carried out numerically to obtain the final solution in space and time domain, respectively. In order to verify the semi-analytical solution, an explicit finite difference algorithm is developed and analytical and numerical solutions are compared for synthetic examples. The comparison of the analytical and numerical solutions shows that the analytical solution gives accurate results.

Custom 3D printer and resin for 18 μm × 20 μm microfluidic flow channels.

PubMed

Gong, Hua; Bickham, Bryce P; Woolley, Adam T; Nordin, Gregory P

2017-08-22

While there is great interest in 3D printing for microfluidic device fabrication, to-date the achieved feature sizes have not been in the truly microfluidic regime (<100 μm). In this paper we demonstrate that a custom digital light processor stereolithographic (DLP-SLA) 3D printer and a specifically-designed, low cost, custom resin can readily achieve flow channel cross sections as small as 18 μm × 20 μm. Our 3D printer has a projected image plane resolution of 7.6 μm and uses a 385 nm LED, which dramatically increases the available selection of UV absorbers for resin formulation compared to 3D printers with 405 nm LEDs. Beginning with 20 candidate absorbers, we demonstrate the evaluation criteria and process flow required to develop a high-resolution resin. In doing so, we introduce a new mathematical model for characterizing the resin optical penetration depth based only on measurement of the absorber's molar absorptivity. Our final resin formulation uses 2-nitrophenyl phenyl sulfide (NPS) as the UV absorber. We also develop a novel channel narrowing technique that, together with the new resin and 3D printer resolution, enables small flow channel fabrication. We demonstrate the efficacy of our approach by fabricating 3D serpentine flow channels 41 mm long in a volume of only 0.12 mm 3 , and by printing high aspect ratio flow channels <25 μm wide and 3 mm tall. These results indicate that 3D printing is finally positioned to challenge the pre-eminence of methods such as soft lithography for microfluidic device prototyping and fabrication.

Analysing the accuracy of machine learning techniques to develop an integrated influent time series model: case study of a sewage treatment plant, Malaysia.

PubMed

Ansari, Mozafar; Othman, Faridah; Abunama, Taher; El-Shafie, Ahmed

2018-04-01

The function of a sewage treatment plant is to treat the sewage to acceptable standards before being discharged into the receiving waters. To design and operate such plants, it is necessary to measure and predict the influent flow rate. In this research, the influent flow rate of a sewage treatment plant (STP) was modelled and predicted by autoregressive integrated moving average (ARIMA), nonlinear autoregressive network (NAR) and support vector machine (SVM) regression time series algorithms. To evaluate the models' accuracy, the root mean square error (RMSE) and coefficient of determination (R 2 ) were calculated as initial assessment measures, while relative error (RE), peak flow criterion (PFC) and low flow criterion (LFC) were calculated as final evaluation measures to demonstrate the detailed accuracy of the selected models. An integrated model was developed based on the individual models' prediction ability for low, average and peak flow. An initial assessment of the results showed that the ARIMA model was the least accurate and the NAR model was the most accurate. The RE results also prove that the SVM model's frequency of errors above 10% or below - 10% was greater than the NAR model's. The influent was also forecasted up to 44 weeks ahead by both models. The graphical results indicate that the NAR model made better predictions than the SVM model. The final evaluation of NAR and SVM demonstrated that SVM made better predictions at peak flow and NAR fit well for low and average inflow ranges. The integrated model developed includes the NAR model for low and average influent and the SVM model for peak inflow.

Fluid-Dynamic Optimal Design of Helical Vascular Graft for Stenotic Disturbed Flow

PubMed Central

Ha, Hojin; Hwang, Dongha; Choi, Woo-Rak; Baek, Jehyun; Lee, Sang Joon

2014-01-01

Although a helical configuration of a prosthetic vascular graft appears to be clinically beneficial in suppressing thrombosis and intimal hyperplasia, an optimization of a helical design has yet to be achieved because of the lack of a detailed understanding on hemodynamic features in helical grafts and their fluid dynamic influences. In the present study, the swirling flow in a helical graft was hypothesized to have beneficial influences on a disturbed flow structure such as stenotic flow. The characteristics of swirling flows generated by helical tubes with various helical pitches and curvatures were investigated to prove the hypothesis. The fluid dynamic influences of these helical tubes on stenotic flow were quantitatively analysed by using a particle image velocimetry technique. Results showed that the swirling intensity and helicity of the swirling flow have a linear relation with a modified Germano number (Gn*) of the helical pipe. In addition, the swirling flow generated a beneficial flow structure at the stenosis by reducing the size of the recirculation flow under steady and pulsatile flow conditions. Therefore, the beneficial effects of a helical graft on the flow field can be estimated by using the magnitude of Gn*. Finally, an optimized helical design with a maximum Gn* was suggested for the future design of a vascular graft. PMID:25360705