Dual or Single Antiplatelet Therapy After Transcatheter Aortic Valve Implantation? A Systematic Review and Meta-Analysis.

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Vavuranakis, Manolis; Siasos, Gerasimos; Zografos, Theodoros; Oikonomou, Evangelos; Vrachatis, Dimitris; Kalogeras, Konstantinos; Papaioannou, Theodoros; Kolokathis, Michail-Aggelos; Moldovan, Carmen; Tousoulis, Dimitrios

2016-01-01

Transcatheter aortic valve implantation (TAVI) has undeniably earned a prestigious post in the quiver of interventional cardiologists against symptomatic severe aortic stenosis. Cerebrovascular events are listed within the most frequent complications. We performed a systematic search of EMBASE, MEDLINE, and the Cochrane library from inception to March 2016 for the following search terms (transcatheter AND antiplatelet) OR (transcatheter AND antithrombotic) to retrieve studies of dual antiplatelet treatment (DAPT) and single antiplatelet treatment (SAPT) in patients after TAVI to study thrombotic, hemorrhagic and cardiovascular events at 30 days post procedure. From a total of 208 records 4 studies met inclusion criteria. In the included studies, 286 patients were enrolled in the DAPT group and 354 patients in the SAPT group. There was no difference in all-cause mortality, cardiovascular mortality, stroke, and myocardial infraction 30 days post TAVI between DAPT and SAPT. However, patients in the DAPT group had a significantly increased incidence of lethal and major bleeding at 30 days of follow-up and the incidence of the combined end-point of stroke, spontaneous MI, all-cause mortality and major bleeding was significantly higher in the DAPT group in comparison to the SAPT group. DAPT compared to SAPT in patients after TAVI increases incidence of hemorrhagic events with no benefits in terms of thrombotic events and cardiovascular mortality. However, these data must be interpreted cautiously and the choice of DAPT over SAPT must be based on an individual patient characteristic according to medical practice criteria.

Prospective observational study of the effect of dual antiplatelet therapy with tranexamic acid treatment on platelet function and bleeding after cardiac surgery.

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Amour, J; Garnier, M; Szymezak, J; Le Manach, Y; Helley, D; Bertil, S; Ouattara, A; Riou, B; Gaussem, P

2016-12-01

The bleeding impact of dual antiplatelet therapy (DAPT), aspirin and clopidogrel, maintained until coronary artery bypass graft surgery (CABG), is still a matter of debate. The lack of preoperative antiplatelet activity measurement and heterogeneity of antifibrinolytic protocols in prior studies make the conclusions questionable. The aim of this prospective study was to determine, after preoperative antiplatelet activity measurement, if the maintenance of DAPT until CABG increases bleeding in patients treated with tranexamic acid (TA). This observational study included 150 consecutive patients, 89 treated with aspirin and 61 treated with DAPT, undergoing a first-time planned on-pump CABG with TA treatment. Antiplatelet activity was measured with platelet aggregation tests and quantification of VASP phosphorylation. Postoperative bleeding at 24 h was recorded and propensity score analysis was performed. Based on VASP assay, 54% of patients showed high on-clopidogrel platelet activity inhibition. Postoperative bleeding at 24 h increased by 22% in the DAPT group, compared with the aspirin group (680 [95% CI: 360-1670] vs 558 [95%CI: 267-1270] ml, P < 0.01), consistent with increased blood transfusion (21% vs 7%, P = 0.01); a higher incidence of mediastinitis did not reach statistical significance (15% vs 4%, P = 0.05). Bleeding correlated with the extent of clopidogrel antiplatelet effect, with the best correlation for the VASP assay. Maintenance of DAPT until the day of CABG in patients treated with TA, increased postoperative bleeding at 24 h in parallel with preoperative antiplatelet activity induced by clopidogrel. © The Author 2016. Published by Oxford University Press on behalf of the British Journal of Anaesthesia. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Urological surgery and antiplatelet drugs after cardiac and cerebrovascular accidents.

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Eberli, Daniel; Chassot, Pierre-Guy; Sulser, Tullio; Samama, Charles Marc; Mantz, Jean; Delabays, Alain; Spahn, Donat R

2010-06-01

The perioperative treatment of patients on dual antiplatelet therapy after myocardial infarction, cerebrovascular event or coronary stent implantation represents an increasingly frequent issue for urologists and anesthesiologists. We assess the current scientific evidence and propose strategies concerning treatment of these patients. A MEDLINE and PubMed search was conducted for articles related to antiplatelet therapy after myocardial infarction, coronary stents and cerebrovascular events, as well as the use of aspirin and/or clopidogrel in the context of surgery. Early discontinuation of antiplatelet therapy for secondary prevention is associated with a high risk of coronary thrombosis, which is further increased by the hypercoagulable state induced by surgery. Aspirin has recently been recommended as a lifelong therapy. Clopidogrel is mandatory for 6 weeks after myocardial infarction and bare metal stents, and for 12 months after drug-eluting stents. Surgery must be postponed beyond these waiting periods or performed with patients receiving dual antiplatelet therapy because withdrawal therapy increases 5 to 10 times the risk of postoperative myocardial infarction, stent thrombosis or death. The shorter the waiting period between revascularization and surgery the greater the risk of adverse cardiac events. The risk of surgical hemorrhage is increased approximately 20% by aspirin and 50% by clopidogrel. The risk of coronary thrombosis when antiplatelet agents are withdrawn before surgery is generally higher than the risk of surgical hemorrhage when antiplatelet agents are maintained. However, this issue has not yet been sufficiently evaluated in urological patients and in many instances during urological surgery the risk of bleeding can be dangerous. A thorough dialogue among surgeon, cardiologist and anesthesiologist is essential to determine all risk factors and define the best possible strategy for each patient. Copyright 2010 American Urological Association

Antiplatelet and Anticoagulant Drugs in Interventional Radiology

International Nuclear Information System (INIS)

Altenburg, Alexander; Haage, Patrick

2012-01-01

In treating peripheral arterial disease, a profound knowledge of antiplatelet and anticoagulative drug therapy is helpful to assure a positive clinical outcome and to anticipate and avoid complications. Side effects and drug interactions may have fatal consequences for the patient, so interventionalists should be aware of these risks and able to control them. Aspirin remains the first-line agent for antiplatelet monotherapy, with clopidogrel added where dual antiplatelet therapy is required. In case of suspected antiplatelet drug resistance, the dose of clopidogrel may be doubled; prasugrel or ticagrelor may be used alternatively. Glycoprotein IIb/IIIa inhibitors (abciximab or eptifibatide) may help in cases of hypercoagulability or acute embolic complications. Desmopressin, tranexamic acid, or platelet infusions may be used to decrease antiplatelet drug effects in case of bleeding. Intraprocedurally, anticoagulant therapy treatment with unfractionated heparin (UFH) still is the means of choice, although low molecular-weight heparins (LMWH) are suitable, particularly for postinterventional treatment. Adaption of LMWH dose is often required in renal insufficiency, which is frequently found in elderly patients. Protamine sulphate is an effective antagonist for UFH; however, this effect is less for LMWH. Newer antithrombotic drugs, such as direct thrombin inhibitors or factor X inhibitors, have limited importance in periprocedural treatment, with the exception of treating patients with heparin-induced thrombocytopenia (HIT). Nevertheless, knowing pharmacologic properties of the newer drugs facilitate correct bridging of patients treated with such drugs. This article provides a comprehensive overview of antiplatelet and anticoagulant drugs for use before, during, and after interventional radiological procedures.

Awareness of antiplatelet resistance in patient with repeated episodes of thrombotic events

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Dalimunthe, N. N.; Hamonangan, R.; Antono, D.; Prasetya, I.; Rusdi, L.

2018-03-01

Antiplatelet has been the cornerstones management of acute coronary syndrome. However, numbers of patients on these agents had episodes of adverse cardiovascular events. A 65-year-old woman post cardiac coronary bypass surgery on dual antiplatelet therapy, Aspirin, and Clopidogrel underwent several episodes of thrombotic events despite good adhered to thedailyantiplatelet regimen.These recurrent events had led to clinical suspicious of antiplatelet resistance. Platelet function test was performed which indicates a poor platelet response to Clopidogrel. Clopidogrelwas discontinued and Ticagrelor was prescribed together with Aspirin. During two months of follow up, there is no episode of chest discomfort.

Antiplatelet therapy in STEMI undergoing primary PCI, when, which one and how long.

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Baralis, Giorgio; Rossini, Roberta; Musumeci, Giuseppe

2018-02-19

Reperfusion therapy for patients presenting with an acute ST-segment elevation myocardial infarction (STEMI) involves primary percutaneous coronary intervention (PPCI) and concomitant dual antiplatelet therapy (DAPT) with combination of a P2Y12 inhibitor and acetylsalicylic acid (ASA). Decision regarding DAPT can be challenging clinically in the modern era with the evolution of newer stents, more potent antiplatelet agents and novel anticoagulant drugs in addition to an older patient population with multiple comorbidities. This review outlines the currently available antiplatelet treatments, and their place within the therapeutic timeline of a patient presenting with STEMI.

Clinical outcomes, health resource use, and cost in patients with early versus late dual or triple anti-platelet treatment for acute coronary syndrome.

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Friedman, Howard; Mollon, Patrick; Lian, Jean; Navaratnam, Prakash

2013-08-01

Acute coronary syndrome (ACS) guidelines recommend early dual anti-platelet therapy (thienopyridines + acetylsalicylic acid [aspirin]). However, triple therapy (thienopyridines + aspirin + glycoprotein IIb/IIIa receptor inhibitors [GRIs]) has shown benefit in clinical trials. This study assessed real-world ACS treatment patterns and outcomes in the acute care setting. A retrospective analysis of patients admitted to hospital with ACS (index event) from January 2007 to December 2009 was conducted (Thomson's MarketScan Hospital Drug Database). Eligible patients were ≥18 years of age, of either sex, and had primary admission and discharge diagnoses of ACS. Cohorts were defined by anti-platelet treatment and then by the timing of treatment initiation (early initiation: within ≤2 days of admission; late initiation: ≥2 days post-admission). Patient characteristics, clinical outcomes, resource utilization, and costs were assessed using descriptive statistics. A total of 249,907 eligible patients were placed into four treatment cohorts (aspirin assumed for all patients): aspirin only; clopidogrel only (dual therapy); GRI only (dual therapy); and clopidogrel + GRI (triple therapy). Patients in the 'clopidogrel-only' cohort were more likely to be older, female, and have more co-morbidities than those in other cohorts; stroke (6.2 %) and re-hospitalization (15.4 %) rates were higher than in the 'GRI-only' and 'triple therapy' cohorts. The GRI-only cohort had higher major bleeding rates (3.3 %), mortality (7.6 %), and costs ($US21,975 [year 2010 values]) than the clopidogrel-only and triple-therapy cohorts. Late initiation cohorts were more likely to be older, female, and have more co-morbidities than early initiation cohorts. Major bleeding was more likely with GRI-only patients (regardless of initiation timing) than with other cohorts. Late-treated clopidogrel-only patients had higher rates of stroke (6.9 %), ACS-related re-admissions (6.1 %), and all

Tailored antiplatelet therapy can overcome clopidogrel and aspirin resistance - The BOchum CLopidogrel and Aspirin Plan (BOCLA-Plan to improve antiplatelet therapy

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Pepinghege Fenena

2011-01-01

Full Text Available Abstract Background Dual antiplatelet therapy using acetylsalicylic acid (ASA, aspirin and clopidogrel is of great importance following coronary stenting. However, the variable platelet inhibitory effectiveness compromises the antithrombotic advantages provided by dual antiplatelet therapy. The aim of this single-center prospective study was to reduce the low response incidence of dual antiplatelet therapy with ASA and clopidogrel according to a prespecified therapy algorithm. Methods Platelet function testing using whole blood aggregometry (Chronolog 590 was performed 48 hours following coronary stenting (for either acute coronary syndromes or stable coronary artery disease on 504 patients. The antiplatelet therapy included a loading dose of 600 mg clopidogrel and 500 mg ASA, followed by 75 mg clopidogrel and 100 mg ASA once daily. Clopidogrel low responders (CLR: >5 ohm; adenosine diphosphate (ADP 5 μM and/or ASA low responders (ALR: >0 ohm; arachidonic acid 10 μM were treated according to a structured therapy plan: in the case of CLR, the maintenance + dose was doubled (repeated loading dose followed by 150 mg daily, and when still ineffective ticlopidine or prasugrel, if available and not contraindicated, were used. ALR was treated by increasing the dose to 300 mg in a first step or to 500 mg ASA when the first modification did not take effect sufficiently. In addition, ADP receptor antagonist 2-methylthioadenosine 5'-monophosphate triethylammonium salt (MeSAMP testing and ASA incubation were performed to rule out either a platelet ADP-receptor defect or an ASA pharmacokinetic resistance. Results Of the total cohort of 504 patients, we detected 30.8% clopidogrel low-responders and 19.4% aspirin low-responders. For ALR, with a dose adjustment of 300 mg ASA daily, 94.6% of ALR were effectively treated and the residual 5.4% by administration of daily dosages of 500 mg ASA. This means that after modification of the ASA maintenance dose, all

Summary of 2017 ESC guidelines on valvular heart disease, peripheral artery disease, STEMI and on dual antiplatelet therapy.

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Van Camp, Guy; De Backer, Tine; Beauloye, Christophe; Desmet, Walter; Claeys, Marc J

2017-12-11

During the ESC congress in September 2017 in Barcelona, the new ESC guidelines were presented and are now available on the ESC website. The new guidelines cover management recommendations on following cardiovascular items: valvular heart disease, peripheral artery disease, ST elevation myocardial infarction (STEMI) and on dual antiplatelet therapy. The present document gives a summary of these guidelines and highlights the most important recommendations and changes in the management of these diseases. It will help to increase awareness about the new guidelines and may stimulate to consult the full document for specific items. Ultimately, the authors hope that this document will enhance implementation of new ESC guidelines in daily clinical practice.

Cost-effectiveness of oral antiplatelet agents--current and future perspectives.

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Arnold, Suzanne V; Cohen, David J; Magnuson, Elizabeth A

2011-08-09

Cardiovascular disease is both highly prevalent and exceedingly costly to treat. Several novel antiplatelet agents have been found to be effective in reducing the morbidity and mortality associated with cardiovascular disease. Understanding both the economic and the clinical implications of these novel therapies is particularly important. In this article, the results of published evaluations of the cost-effectiveness of oral antiplatelet strategies for use across a range of clinical conditions and treatment settings are reviewed. The results of these studies support the use of aspirin for primary prevention in high-risk patients and for secondary prevention in all patients with previous cardiovascular events. Although the optimal duration of dual antiplatelet therapy after an event remains uncertain, favorable cost-effectiveness estimates have been demonstrated for aspirin plus clopidogrel versus aspirin alone after a myocardial infarction or percutaneous coronary intervention. Moreover, prasugrel has been shown to be more cost-effective than clopidogrel for patients with an acute coronary syndrome and planned percutaneous coronary intervention. As novel antiplatelet agents emerge and existing agents are tested in different patient populations, the evaluation of the relative economic efficiency of these oral antiplatelet treatment strategies will continue to be instrumental to optimally inform clinical and health-policy decision-making.

When is the Best Time for the Second Antiplatelet Agent in Non-St Elevation Acute Coronary Syndrome?

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Pedro Gabriel Melo de Barros e Silva

2016-03-01

Full Text Available Abstract Dual antiplatelet therapy is a well-established treatment in patients with non-ST elevation acute coronary syndrome (NSTE-ACS, with class I of recommendation (level of evidence A in current national and international guidelines. Nonetheless, these guidelines are not precise or consensual regarding the best time to start the second antiplatelet agent. The evidences are conflicting, and after more than a decade using clopidogrel in this scenario, benefits from the routine pretreatment, i.e. without knowing the coronary anatomy, with dual antiplatelet therapy remain uncertain. The recommendation for the upfront treatment with clopidogrel in NSTE-ACS is based on the reduction of non-fatal events in studies that used the conservative strategy with eventual invasive stratification, after many days of the acute event. This approach is different from the current management of these patients, considering the established benefits from the early invasive strategy, especially in moderate to high-risk patients. The only randomized study to date that specifically tested the pretreatment in NSTE-ACS in the context of early invasive strategy, used prasugrel, and it did not show any benefit in reducing ischemic events with pretreatment. On the contrary, its administration increased the risk of bleeding events. This study has brought the pretreatment again into discussion, and led to changes in recent guidelines of the American and European cardiology societies. In this paper, the authors review the main evidence of the pretreatment with dual antiplatelet therapy in NSTE-ACS.

Antiplatelet therapy in PCI

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Fanaroff, Alexander; Rao, Sunil

2018-01-01

Platelets play a key role in mediating stent thrombosis, the major cause of ischemic events in the immediate period following percutaneous coronary intervention (PCI). For this reason, antiplatelet therapy, started at the time of PCI and continued for at least 30 days afterwards, is the cornerstone of antithrombotic therapy after PCI. However, the use of antiplatelet agents increase bleeding risk, with more potent antiplatelet agents further increasing bleeding risk. For this reason, balancing prevention of ischemic events with risk of bleeding is fundamental to the effective use of antiplatelet agents. In the past 5 years, potent and fast-acting P2Y12 inhibitors have been introduced, and have augmented the antiplatelet armamentarium available to interventional cardiologists. In this review, we review the preclinical and clinical data surrounding these new agents, and discuss the significant questions and controversies that still exist regarding the optimal antiplatelet strategy. PMID:28582206

Practice points in gynecardiology: Abnormal uterine bleeding in premenopausal women taking oral anticoagulant or antiplatelet therapy.

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Maas, Angela H E M; Euler, Mia von; Bongers, Marlies Y; Rolden, Herbert J A; Grutters, Janneke P C; Ulrich, Lian; Schenck-Gustafsson, Karin

2015-12-01

A growing number of premenopausal women are currently using antithrombotic and/or (dual) antiplatelet therapy for various cardiovascular indications. These may induce or exacerbate abnormal uterine bleeding and more awareness and knowledge among prescribers is required. Heavy and irregular menstrual bleeding is common in women in their forties and may have a variety of underlying causes that require different treatment options. Thus using anticoagulants in premenopausal women demands specific expertise and close collaboration between cardiovascular physicians and gynecologists. In this article we summarize the scope of the problem and provide practical recommendations for the care for young women taking anticoagulants and/or (dual) antiplatelet therapy. We also recommend that more safety data on uterine bleeding with novel anticoagulants in premenopausal women should be obtained. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Practice points in gynecardiology: Abnormal uterine bleeding in premenopausal women taking oral anticoagulant or antiplatelet therapy

NARCIS (Netherlands)

Maas, A.H.E.M.; Euler, M.; Bongers, M.Y.; Rolden, H.J.A.; Grutters, J.P.C.; Ulrich, L.; Schenck-Gustafsson, K.

2015-01-01

A growing number of premenopausal women are currently using antithrombotic and/or (dual) antiplatelet therapy for various cardiovascular indications. These may induce or exacerbate abnormal uterine bleeding and more awareness and knowledge among prescribers is required. Heavy and irregular menstrual

Efficacy and Safety of Dual Antiplatelet Therapy After Complex PCI.

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Giustino, Gennaro; Chieffo, Alaide; Palmerini, Tullio; Valgimigli, Marco; Feres, Fausto; Abizaid, Alexandre; Costa, Ricardo A; Hong, Myeong-Ki; Kim, Byeong-Keuk; Jang, Yangsoo; Kim, Hyo-Soo; Park, Kyung Woo; Gilard, Martine; Morice, Marie-Claude; Sawaya, Fadi; Sardella, Gennaro; Genereux, Philippe; Redfors, Bjorn; Leon, Martin B; Bhatt, Deepak L; Stone, Gregg W; Colombo, Antonio

2016-10-25

Optimal upfront dual antiplatelet therapy (DAPT) duration after complex percutaneous coronary intervention (PCI) with drug-eluting stents (DES) remains unclear. This study investigated the efficacy and safety of long-term (≥12 months) versus short-term (3 or 6 months) DAPT with aspirin and clopidogrel according to PCI complexity. The authors pooled patient-level data from 6 randomized controlled trials investigating DAPT durations after PCI. Complex PCI was defined as having at least 1 of the following features: 3 vessels treated, ≥3 stents implanted, ≥3 lesions treated, bifurcation with 2 stents implanted, total stent length >60 mm, or chronic total occlusion. The primary efficacy endpoint was major adverse cardiac events (MACE), defined as the composite of cardiac death, myocardial infarction, or stent thrombosis. The primary safety endpoint was major bleeding. Intention-to-treat was the primary analytic approach. Of 9,577 patients included in the pooled dataset for whom procedural variables were available, 1,680 (17.5%) underwent complex PCI. Overall, 85% of patients received new-generation DES. At a median follow-up time of 392 days (interquartile range: 366 to 710 days), patients who underwent complex PCI had a higher risk of MACE (adjusted hazard ratio [HR]: 1.98; 95% confidence interval [CI]: 1.50 to 2.60; p PCI group (adjusted HR: 0.56; 95% CI: 0.35 to 0.89) versus the noncomplex PCI group (adjusted HR: 1.01; 95% CI: 0.75 to 1.35; p interaction  = 0.01). The magnitude of the benefit with long-term DAPT was progressively greater per increase in procedural complexity. Long-term DAPT was associated with increased risk for major bleeding, which was similar between groups (p interaction  = 0.96). Results were consistent by per-treatment landmark analysis. Alongside other established clinical risk factors, procedural complexity is an important parameter to take into account in tailoring upfront duration of DAPT. Copyright © 2016 American College

Dual Antiplatelet Therapy Does Not Increase the Risk of Bleeding After Carotid Endarterectomy: Results of a Prospective Study.

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Illuminati, Giulio; Schneider, Fabrice; Pizzardi, Giulia; Masci, Federica; Calio', Francesco G; Ricco, Jean-Baptiste

2017-04-01

The purpose of this study was to evaluate the risk of bleeding and other postoperative complications of carotid endarterectomy (CEA) in patients receiving dual antiplatelet therapy (DAPT). From January 2005 to December 2015, 188 consecutive patients undergoing CEA and receiving DAPT (aspirin 100 mg + clopidogrel 75 mg) were enrolled in a prospective study. All of them underwent coronary artery stenting with drug-eluting stents during the 6 months preceding CEA. In the entire series, DAPT was continued until the evening before CEA and resumed on the evening of the operation. All patients received intraoperative heparinization (5,000 IU before carotid clamping), which was reversed in 5 patients. In addition, all of them were given 2,000 units of enoxaparin every 12 hr after the operation, beginning 6 hr after completion of the operation, and until discharge. All the patients presented with carotid artery stenosis >70% (North American Symptomatic Carotid Endarterectomy Trial [NASCET] criteria), which was symptomatic in 42 patients (transient ischemic attack, n = 32; minor stroke, n = 10) and asymptomatic in 146. The CEA technique was standard, with prosthetic patch closure in 109 cases (58%) and eversion in 79 (42%). The primary endpoints of the study were occurrence of a postoperative cervical hematoma requiring surgical hemostasis and occurrence of cranial nerve injuries. The secondary endpoint was the combined rate of postoperative mortality, stroke, and myocardial ischemia. No postoperative cervical hematoma requiring surgical evacuation occurred in this series. One hypoglossal nerve palsy, regressive within 2 weeks, was observed. Postoperative mortality and neurologic and cardiac morbidity were nil. CEA under DAPT yields results comparable with those obtained in patients receiving a single antiplatelet treatment. No hemorrhagic complications were observed in this prospective series. Copyright © 2017 Elsevier Inc. All rights reserved.

The First World War as Collapse Catalyst of Dual Monarchy Regime in Russia

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Fomenkov А. А.

2014-01-01

Full Text Available The article is devoted to the specific features of the form of government in Russia in the years 1906–1917. The causes of the Dual Monarchy regime collapse in February 1917 have been revealed

NP-184[2-(5-methyl-2-furyl) benzimidazole], a novel orally active antithrombotic agent with dual antiplatelet and anticoagulant activities.

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Kuo, Heng-Lan; Lien, Jin-Cherng; Chung, Ching-Hu; Chang, Chien-Hsin; Lo, Shyh-Chyi; Tsai, I-Chun; Peng, Hui-Chin; Kuo, Sheng-Chu; Huang, Tur-Fu

2010-06-01

The established antiplatelet and anticoagulant agents show beneficial effects in the treatment of thromboembolic diseases; however, these drugs still have considerable limitations. The effects of NP-184, a synthetic compound, on platelet functions, plasma coagulant activity, and mesenteric venule thrombosis in mice were investigated. NP-184 concentration-dependently inhibited the human platelet aggregation induced by collagen, arachidonic acid (AA), and U46619, a thromboxane (TX)A(2) mimic, with IC(50) values of 4.5 +/- 0.2, 3.9 +/- 0.1, and 9.3 +/- 0.5 microM, respectively. Moreover, NP-184 concentration-dependently suppressed TXA(2) formations caused by collagen and AA. In exploring effects of NP-184 on enzymes involved in TXA(2) synthesis, we found that NP-184 selectively inhibited TXA(2) synthase activity with an IC(50) value of 4.3 +/- 0.2 microM. Furthermore, NP-184 produced a right shift of the concentration-response curve of U46619, indicating a competitive antagonism on TXA(2)/prostaglandin H(2) receptor. Intriguingly, NP-184 also caused a concentration-dependent prolongation of the activated partial thromboplastin time (aPTT) with no changes in the prothrombin and thrombin time, indicating that it selectively impairs the intrinsic coagulation pathway. Oral administration of NP-184 significantly inhibited thrombus formation of the irradiated mesenteric venules in fluorescein sodium-treated mice without affecting the bleeding time induced by tail transection. However, after oral administration, NP-184 inhibited the ex vivo mouse platelet aggregation triggered by collagen and U46619 and also prolonged aPTT. Taken together, the dual antiplatelet and anticoagulant activities of NP-184 may have therapeutic potential as an oral antithrombotic agent in the treatment of thromboembolic disorders.

Controllable nonlinearity in a dual-coupling optomechanical system under a weak-coupling regime

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Zhu, Gui-Lei; Lü, Xin-You; Wan, Liang-Liang; Yin, Tai-Shuang; Bin, Qian; Wu, Ying

2018-03-01

Strong quantum nonlinearity gives rise to many interesting quantum effects and has wide applications in quantum physics. Here we investigate the quantum nonlinear effect of an optomechanical system (OMS) consisting of both linear and quadratic coupling. Interestingly, a controllable optomechanical nonlinearity is obtained by applying a driving laser into the cavity. This controllable optomechanical nonlinearity can be enhanced into a strong coupling regime, even if the system is initially in the weak-coupling regime. Moreover, the system dissipation can be suppressed effectively, which allows the appearance of phonon sideband and photon blockade effects in the weak-coupling regime. This work may inspire the exploration of a dual-coupling optomechanical system as well as its applications in modern quantum science.

Newer agents in antiplatelet therapy: a review

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Yeung J

2012-06-01

Full Text Available Jennifer Yeung, Michael HolinstatCardeza Foundation for Hematologic Research, Department of Medicine, Thomas Jefferson University, Philadelphia, PA, USAAbstract: Antiplatelet therapy remains the mainstay in preventing aberrant platelet activation in pathophysiological conditions such as myocardial infarction, ischemia, and stroke. Although there has been significant advancement in antiplatelet therapeutic approaches, aspirin still remains the gold standard treatment in the clinical setting. Limitations in safety, efficacy, and tolerability have precluded many of the antiplatelet inhibitors from use in patients. Unforeseen incidences of increased bleeding risk and recurrent arterial thrombosis observed in patients have hampered the development of superior next generation antiplatelet therapies. The pharmacokinetic and pharmacodynamic profiles have also limited the effectiveness of a number of antiplatelet inhibitors currently in use due to variability in metabolism, time to onset, and reversibility. A focused effort in the development of newer antiplatelet therapies to address some of these shortcomings has resulted in a significant number of potential antiplatelet drugs which target enzymes (phosphodiesterase, cyclooxygenase, receptors (purinergic, prostaglandins, protease-activated receptors, thromboxane, and glycoproteins (αIIbß3, GPVI, vWF, GPIb in the platelet. The validation and search for newer antiplatelet therapeutic approaches proven to be superior to aspirin is still ongoing and should yield a better pharmacodynamic profile with fewer untoward side-effects to what is currently in use today.Keywords: platelet aggregation inhibitors, blood platelets, purinergic P2Y receptor antagonists, receptor, PAR-1, platelet glycoprotein GPIIb-IIIa, thrombosis

Antiplatelet treatment for prevention of cerebrovascular events in patients with vascular diseases: a systematic review and meta-analysis

NARCIS (Netherlands)

Gouya, G.; Arrich, J.; Wolzt, M.; Huber, K.; Verheugt, F.W.A.; Gurbel, P.A.; Pirker-Kees, A.; Siller-Matula, J.M.

2014-01-01

BACKGROUND AND PURPOSE: The efficacy and safety of different antiplatelet regimes for prevention of stroke in patients at high risk were investigated in a systematic review and meta-analysis. METHODS: We searched the Cochrane Central Register of Controlled Trials, MEDLINE, and Web of Science.

Dual antiplatelet therapy versus oral anticoagulation plus dual antiplatelet therapy in patients with atrial fibrillation and low-to-moderate thromboembolic risk undergoing coronary stenting: design of the MUSICA-2 randomized trial.

Science.gov (United States)

Sambola, Antonia; Montoro, J Bruno; Del Blanco, Bruno García; Llavero, Nadia; Barrabés, José A; Alfonso, Fernando; Bueno, Héctor; Cequier, Angel; Serra, Antonio; Zueco, Javier; Sabaté, Manel; Rodríguez-Leor, Oriol; García-Dorado, David

2013-10-01

Oral anticoagulation (OAC) is the recommended therapy for patients with atrial fibrillation (AF) because it reduces the risk of stroke and other thromboembolic events. Dual antiplatelet therapy (DAPT) is required after percutaneous coronary intervention and stenting (PCI-S). In patients with AF requiring PCI-S, the association of DAPT and OAC carries an increased risk of bleeding, whereas OAC therapy or DAPT alone may not protect against the risk of developing new ischemic or thromboembolic events. The MUSICA-2 study will test the hypothesis that DAPT compared with triple therapy (TT) in patients with nonvalvular AF at low-to-moderate risk of stroke (CHADS2 score ≤2) after PCI-S reduces the risk of bleeding and is not inferior to TT for preventing thromboembolic complications. The MUSICA-2 is a multicenter, open-label randomized trial that will compare TT with DAPT in patients with AF and CHADS2 score ≤2 undergoing PCI-S. The primary end point is the incidence of stroke or any systemic embolism or major adverse cardiac events: death, myocardial infarction, stent thrombosis, or target vessel revascularization at 1 year of PCI-S. The secondary end point is the combination of any cardiovascular event with major or minor bleeding at 1 year of PCI-S. The calculated sample size is 304 patients. The MUSICA-2 will attempt to determine the most effective and safe treatment in patients with nonvalvular AF and CHADS2 score ≤2 after PCI-S. Restricting TT for AF patients at high risk for stroke may reduce the incidence of bleeding without increasing the risk of thromboembolic complications. © 2013.

Novel agents for anti-platelet therapy

Directory of Open Access Journals (Sweden)

Ji Xuebin

2011-11-01

Full Text Available Abstract Anti-platelet therapy plays an important role in the treatment of patients with thrombotic diseases. The most commonly used anti-platelet drugs, namely, aspirin, ticlopidine, and clopidogrel, are effective in the prevention and treatment of cardio-cerebrovascular diseases. Glycoprotein IIb/IIIa antagonists (e.g., abciximab, eptifibatide and tirofiban have demonstrated good clinical benefits and safety profiles in decreasing ischemic events in acute coronary syndrome. However, adverse events related to thrombosis or bleeding have been reported in cases of therapy with glycoprotein IIb/IIIa antagonists. Cilostazol is an anti-platelet agent used in the treatment of patients with peripheral ischemia, such as intermittent claudication. Presently, platelet adenosine diphosphate P2Y(12 receptor antagonists (e.g., clopidogrel, prasugrel, cangrelor, and ticagrelor are being used in clinical settings for their pronounced protective effects. The new protease-activated receptor antagonists, vorapaxar and atopaxar, potentially decrease the risk of ischemic events without significantly increasing the rate of bleeding. Some other new anti-platelet drugs undergoing clinical trials have also been introduced. Indeed, the number of new anti-platelet drugs is increasing. Consequently, the efficacy of these anti-platelet agents in actual patients warrants scrutiny, especially in terms of the hemorrhagic risks. Hopefully, new selective platelet inhibitors with high anti-thrombotic efficiencies and low hemorrhagic side effects can be developed.

Strokes attributable to underuse of warfarin and antiplatelets

DEFF Research Database (Denmark)

Olsen, Tom Skyhøj; Rasmussen, Berit Hammershaimb; Kammersgaard, Lars Peter

2007-01-01

Despite their proven efficacy in stroke prevention, warfarin and antiplatelets remain underused. We determined the frequency of ischemic strokes attributable to underuse of warfarin and antiplatelets for stroke prevention in a Danish community. We included all patients with ischemic stroke...... in a Copenhagen community with 302,000 inhabitants admitted to the hospital between September 1999 and May 2000 (n = 426). Patients who did not receive warfarin or antiplatelet medication even though they were at known risk for cardiovascular disease before the incident stroke were identified; they had known...... not received warfarin or antiplatelets on admission, 27 had not received warfarin but had received antiplatelets, and 11 had received warfarin. Assuming that warfarin and antiplatelets reduces the risk of stroke by 66% and 25%, respectively, it was calculated that between 6 and 12 of these strokes with atrial...

Prevalence of antiplatelet therapy in patients with diabetes

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Littenberg Benjamin

2005-12-01

Full Text Available Abstract Objective To determine the prevalence of, and patient characteristics associated with, antiplatelet therapy in a cohort of primary care patients with Type 1 or Type2 diabetes. Methods Subjects participating in a randomized trial of a decision support system were interviewed at home and medication usage verified by a research assistant. Eligibility for antiplatelet therapy was determined by American Diabetes Association criteria and clinical contraindications. The association between antiplatelet use and patient characteristics was examined using bivariate and multivariate logistic regression. Results The mean age of subjects was 64 years (range 31–93. The prevalence of antiplatelet use was 54% overall; 45% for subjects without known CVD vs. 78% for those with CVD; 46% for women vs. 63% for men; and 45% for younger subjects (age = 65 (OR 1.9 [1.3, 2.7]. The prevalence of antiplatelet therapy for younger women without CVD was 32.8% compared to a prevalence of 90.3% for older men with CVD. Conclusion Despite clinical practice guidelines recommending antiplatelet therapy for patients with diabetes, there are still many eligible patients not receiving this beneficial therapy, particularly patients under 65, women, and patients without known CVD. Effective methods to increase antiplatelet use should be considered at the national, community, practice and provider level.

Apixaban Plus Mono Versus Dual Antiplatelet Therapy in Acute Coronary Syndromes: Insights From the APPRAISE-2 Trial

NARCIS (Netherlands)

Hess, C.N.; James, S.; Lopes, R.D.; Wojdyla, D.M.; Neely, M.L.; Liaw, D.; Hagstrom, E.; Bhatt, D.L.; Husted, S.; Goodman, S.G.; Lewis, B.S.; Verheugt, F.W.A.; Caterina, R. De; Ogawa, H.; Wallentin, L.; Alexander, J.H.

2015-01-01

BACKGROUND: Bleeding limits anticoagulant treatment in patients with acute coronary syndromes (ACS). OBJECTIVES: We investigated whether background concomitant antiplatelet therapy influences the effects of apixaban after ACS. METHODS: This study examined high-risk ACS patients who were treated with

ANALYZES OF ANTIPLATELETS AND ANTICOAGULANTS UTILIZATION IN PATIENTS TREATED IN CARDIOVASCULAR REHABILITATION CENTER FROM CROATIA

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Boban Marko

2016-07-01

Full Text Available Purpose: Discordance with the guidelines and underutilization of pharmacotherapy for secondary prevention frequently exists in clinical practice. Aim of our study was to assess the prescription routine and drug utilization patterns for antiplatelets and peroral anticoagulants in tertiary medical center specialized for cardiovascular rehabilitation. Methods: study included 96 consecutive patients scheduled for cardiovascular rehabilitation in period 1-6 months after the acute treatment for ischemic 87(80.2% and valvular heart disease 18(19.8%. Patients were divided according to etiology of heart disease and type of acute cardiovascular treatments (conservative, percutaneous coronary interventions (PCI and surgery. Results: Dual antiplatelet therapy was the most commonly applied regimen in 84(87.5% of conservatively treated myocardial infarctions, 47(61.9% of percutaneous coronary interventions (PCI and 13(58.9% of surgically treated group (p>0.05. Among studied group of patients significant differences in utilization were found for warfarin, or combinations of antiplatelets with warfarin(p0.05. All four of patients that received triple therapy (4.17% were from surgical group. Underutilization of antiplatelets in ischemic heart disease was at 11(14.3% what was congruent with the developed industrial nations. Conclusions: Acute cardiovascular treatment type, but not heart disease etiology, had significant influence on subsequent prescription routine. Decreased use of pharmacological agents for secondary prevention in surgical patients was revealed. Drug utilization analyzes can offer improvement in optimizing medical treatments, quality of care and decrease unnecessary polypragmasia, as well as improve economical efficiency of medical management.

Antiplatelet and anticoagulation regimen in patients with mechanical valve undergoing PCI - State-of-the-art review.

Science.gov (United States)

Gajanana, Deepakraj; Rogers, Toby; Iantorno, Micaela; Buchanan, Kyle D; Ben-Dor, Itsik; Pichard, Augusto D; Satler, Lowell F; Torguson, Rebecca; Okubagzi, Petros G; Waksman, Ron

2018-04-02

A common clinical dilemma regarding treatment of patients with a mechanical valve is the need for concomitant antiplatelet therapy for a variety of reasons, referred to as triple therapy. Triple therapy is when a patient is prescribed aspirin, a P2Y12 antagonist, and an oral anticoagulant. Based on the totality of the available evidence, best practice in 2017 for patients with mechanical valves undergoing percutaneous coronary intervention (PCI) is unclear. Furthermore, the optimal duration of dual antiplatelet therapy after PCI is evolving. With better valve designs that are less thrombogenic, the thromboembolic risks can be reduced at a lower international normalized ratio target, thus decreasing the bleeding risk. This review will offer an in-depth survey of current guidelines, current evidence, suggested approach for PCI in this cohort, and future studies regarding mechanical valve patients undergoing PCI. Copyright © 2017 Elsevier B.V. All rights reserved.

Strokes attributable to underuse of warfarin and antiplatelets

DEFF Research Database (Denmark)

Olsen, Tom Skyhøj; Rasmussen, Berit Hammershaimb; Kammersgaard, Lars Peter

2007-01-01

atrial fibrillation, prior myocardial infarction, angina, or prior stroke transient ischemic attack (TIA). Sufficient information on cardiovascular risk factors before stroke was available in 404 patients. A total of 54 patients had atrial fibrillation known before the stroke. Of these, 16 had...... fibrillation could have been prevented if warfarin or antiplatelets had been given before stroke. A total of 147 patients had known stroke/TIA and/or myocardial infarction/angina before stroke (41 patients had not received antiplatelets on admission). If antiplatelet therapy had been given before stroke, 10...

ANTIPLATELET THERAPY IN THE PREVENTION OF CEREBROVASCULAR ACCIDENTS

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O. V. Rodionova

2017-01-01

Full Text Available Currently the problem of preventing cerebrovascular disorders, in which antiplatelet therapy takes one of the leading places, remains relevant. The efficiency of the therapy depends on a large number of modifiable and non-modifiable factors. There are many methods to assess the severity of the response to antiplatelet therapy, but there is no common approach to the assessment of the results and their prognostic significance. Further studies of this issue are essential with the aim of individualization of antiplatelet therapy thereby increasing its efficiency and safety.

Management of antiplatelet therapy in patients undergoing elective invasive procedures. Proposals from the French Working Group on perioperative haemostasis (GIHP) and the French Study Group on thrombosis and haemostasis (GFHT). In collaboration with the French Society for Anaesthesia and Intensive Care Medicine (SFAR).

Science.gov (United States)

Godier, Anne; Fontana, Pierre; Motte, Serge; Steib, Annick; Bonhomme, Fanny; Schlumberger, Sylvie; Lecompte, Thomas; Rosencher, Nadia; Susen, Sophie; Vincentelli, André; Gruel, Yves; Albaladejo, Pierre; Collet, Jean-Philippe

2018-01-05

The French Working Group on Perioperative Haemostasis (GIHP) and the French Study Group on Haemostasis and Thrombosis (GFHT) in collaboration with the French Society for Anaesthesia and Intensive Care Medicine (SFAR) drafted up-to-date proposals for the management of antiplatelet therapy in patients undergoing elective invasive procedures. The proposals were discussed and validated by a vote; all proposals but one could be assigned with a high strength. The management of antiplatelet therapy is based on their indication and the procedure. The risk of bleeding related to the procedure can be divided into high, moderate and low categories depending on the possibility of performing the procedure in patients receiving antiplatelet agents (none, monotherapy and dual antiplatelet therapy respectively). If discontinuation of antiplatelet therapy is indicated before the procedure, a last intake of aspirin, clopidogrel, ticagrelor and prasugrel 3, 5, 5 and 7 days before surgery respectively is proposed. The thrombotic risk associated with discontinuation should be assessed according to each specific indication of antiplatelet therapy and is higher for patients receiving dual therapy for coronary artery disease (with further refinements based on a few well-accepted items) than for those receiving monotherapy for cardiovascular prevention, for secondary stroke prevention or for lower extremity arterial disease. These proposals also address the issue of the potential role of platelet functional tests and consider management of antiplatelet therapy for regional anaesthesia, including central neuraxial anaesthesia and peripheral nerve blocks, and for coronary artery surgery. Copyright © 2018 The Authors. Published by Elsevier Masson SAS.. All rights reserved.

Risk of bleeding in patients undergoing percutaneous endoscopic gastrotrostomy (PEG tube insertion under antiplatelet therapy: a systematic review with a meta-analysis

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Alfredo J. Lucendo

2015-03-01

Full Text Available Background and aim: Patients undergoing percutaneous endoscopic gastrostomy (PEG tube placement often are under antiplatelet therapy with a potential thromboembolic risk if these medications are discontinued. This systematic review aims to assess if maintaining aspirin and/or clopidogrel treatment increases the risk of bleeding following PEG placement. Methods: A systematic search of the MEDLINE, EMBASE, and SCOPUS databases was developed for studies investigating the risk of bleeding in patients on antiplatelet therapy undergoing PEG tube insertion. Summary estimates, including 95 % confidence intervals (CI, were calculated. A fixed or random effects model was used depending on heterogeneity (I². Publication bias risks were assessed by means of funnel plot analysis. Results: Eleven studies with a total of 6,233 patients (among whom 3,665 were undergoing antiplatelet treatment, met the inclusion criteria and were included in the quantitative summary. Any PEG tube placement-related bleeding was found in 2.67 % (95 % CI 1.66 %, 3.91 % of the entire population and in 2.7 % (95 % CI 1.5 %, 4.1 % of patients not receiving antiplatelet therapy. Pooled relative risk (RR for bleeding in patients under aspirin, when compared to controls, was 1.43 (95 % CI 0.89, 2.29; I² = 0 %; pooled RR for clopidogrel was 1.21 (95 % CI 0.48, 3.04; I² = 0 % and for dual antiplatelet therapy, 2.13; (95 % CI 0.77, 5.91; I² = 47 %. No significant publication bias was evident for the different medications analyzed. Conclusion: Antiplatelet therapy was safe among patients undergoing PEG tube insertion. Future prospective and randomized studies with larger sample sizes are required to confirm the results of this study.

Patent Foramen Ovale Closure or Antiplatelet Therapy for Cryptogenic Stroke

DEFF Research Database (Denmark)

Søndergaard, Lars; Kasner, Scott E; Rhodes, John F

2017-01-01

BACKGROUND: The efficacy of closure of a patent foramen ovale (PFO) in the prevention of recurrent stroke after cryptogenic stroke is uncertain. We investigated the effect of PFO closure combined with antiplatelet therapy versus antiplatelet therapy alone on the risks of recurrent stroke and new...... brain infarctions. METHODS: In this multinational trial involving patients with a PFO who had had a cryptogenic stroke, we randomly assigned patients, in a 2:1 ratio, to undergo PFO closure plus antiplatelet therapy (PFO closure group) or to receive antiplatelet therapy alone (antiplatelet-only group......). Imaging of the brain was performed at the baseline screening and at 24 months. The coprimary end points were freedom from clinical evidence of ischemic stroke (reported here as the percentage of patients who had a recurrence of stroke) through at least 24 months after randomization and the 24-month...

Update on antiplatelet agents, including MATCH, CHARISMA, and ESPRIT.

Science.gov (United States)

Skliut, Maryna; Jamieson, Dara G

2008-02-01

Despite recent advances in the acute treatment of stroke, prevention and risk factor modification remain the mainstays of management for patients with ischemic stroke and transient ischemic attack. The majority of noncardioembolic ischemic strokes are atherothrombotic, presumed to be associated with the activation and aggregation of platelets. Antiplatelet medications have been shown to be effective in the secondary prevention of stroke of presumed arterial origin, both as monotherapy and in combination. Among combination of antiplatelet agents, aspirin plus extended-release dipyridamole has demonstrated statistically significant additive benefit over monotherapy with each agent. Clopidogrel plus aspirin does not prevent recurrent ischemic stroke over each component individually, and the combination increases the risk of hemorrhagic side effects. This article reviews the most recent studies on antiplatelet medications, including the combination of aspirin and clopidogrel or extended-release dipyridamole, and discusses some of the controversies that still exist with the use of antiplatelet agents.

Long-term use of antiplatelet drugs by stroke patients

DEFF Research Database (Denmark)

Ostergaard, Kamilla; Hallas, Jesper; Bak, Søren

2012-01-01

PURPOSE: Treatment with antiplatelet drugs is a key element of secondary stroke prevention. We investigated long-term antiplatelet drug use in stroke patients with a focus on non-persistence. METHODS: Population-based prescription register data were used to determine antiplatelet drug use...... the dosage of a previous prescription had run out, or within 180 days after discharge. Cox regression was used to identify risk factors for non-persistence. RESULTS: The cohort comprised 503 patients with ischaemic stroke discharged in 1999-2001. During follow-up (median 2.8 years, interquartile range 0......-persistent. Stroke severity was inversely associated with the risk of non-persistence [NIHSS score on admission 0-3 (reference); 4-6: hazard risk (HR) 0.87, 95 % confidence interval (CI) 0.61-1.25; 7+: HR 0.47, 95 % CI 0.29-0.74]. CONCLUSIONS: Long-term non-persistence with antiplatelet treatment was high and more...

The peri-operative management of anti-platelet therapy in elective, non-cardiac surgery.

Science.gov (United States)

Alcock, Richard F; Naoum, Chris; Aliprandi-Costa, Bernadette; Hillis, Graham S; Brieger, David B

2013-07-31

Cardiovascular complications are important causes of morbidity and mortality in patients undergoing elective non-cardiac surgery, with adverse cardiac outcomes estimated to occur in approximately 4% of all patients. Anti-platelet therapy withdrawal may precede up to 10% of acute cardiovascular syndromes, with withdrawal in the peri-operative setting incompletely appraised. The aims of our study were to determine the proportion of patients undergoing elective non-cardiac surgery currently prescribed anti-platelet therapy, and identify current practice in peri-operative management. In addition, the relationship between management of anti-platelet therapy and peri-operative cardiac risk was assessed. We evaluated consecutive patients attending elective non-cardiac surgery at a major tertiary referral centre. Clinical and biochemical data were collected and analysed on patients currently prescribed anti-platelet therapy. Peri-operative management of anti-platelet therapy was compared with estimated peri-operative cardiac risk. Included were 2950 consecutive patients, with 516 (17%) prescribed anti-platelet therapy, primarily for ischaemic heart disease. Two hundred and eighty nine (56%) patients had all anti-platelet therapy ceased in the peri-operative period, including 49% of patients with ischaemic heart disease and 46% of patients with previous coronary stenting. Peri-operative cardiac risk score did not influence anti-platelet therapy management. Approximately 17% of patients undergoing elective non-cardiac surgery are prescribed anti-platelet therapy, the predominant indication being for ischaemic heart disease. Almost half of all patients with previous coronary stenting had no anti-platelet therapy during the peri-operative period. The decision to cease anti-platelet therapy, which occurred commonly, did not appear to be guided by peri-operative cardiac risk stratification. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Anticoagulant and Antiplatelet Prescribing Patterns for Patients with Atrial Fibrillation after Percutaneous Coronary Intervention.

Science.gov (United States)

Woods, Erin A; Ackman, Margaret L; Graham, Michelle M; Koshman, Sheri L; Boswell, Rosaleen M; Barry, Arden R

2016-01-01

Current guidelines recommend triple antithrombotic therapy (TAT), defined as acetylsalicylic acid (ASA), clopidogrel, and warfarin, for patients with nonvalvular atrial fibrillation who have undergone percutaneous coronary intervention with stent implantation. The choice of anticoagulant/antiplatelet therapy in this population is ambiguous and complex, and prescribing patterns are not well documented. To characterize local prescribing patterns for anticoagulant/antiplatelet therapy after percutaneous coronary intervention in patients with nonvalvular atrial fibrillation. A chart review was conducted at a single quaternary cardiology centre. Patients with nonvalvular atrial fibrillation were identified via medical records, and those who underwent percutaneous coronary intervention were identified using a local clinical patient registry. Adult inpatients with nonvalvular atrial fibrillation and a CHADS2 score (based on congestive heart failure, hypertension, age ≥ 75 years, diabetes mellitus, prior stroke) of 1 or higher who underwent percutaneous coronary intervention from 2011 to 2013 were included. Patients undergoing cardiovascular surgery or transcatheter aortic valve replacement, those with mechanical devices requiring anticoagulation, and those with an allergy to any component of TAT were excluded. Seventy patients were included. The median age was 75 years, and 52 (74%) were men. At discharge, 30 (43%) were receiving TAT and 27 (39%) were receiving dual antiplatelet therapy (clopidogrel and ASA). No patients received the combination of warfarin and clopidogrel. Among those who received TAT, 90% (19 of 21) who received a bare metal stent had a recommended duration of 1 month, and 75% (6 of 8) who received a drug-eluting stent had a recommended duration of 1 year. Direct-acting oral anticoagulants with 2 antiplatelet drugs were prescribed for 9% (6 of 70) of the patients, and 10% (7 of 70) received ticagrelor and ASA with or without warfarin. Overall, the

Phytochemicalassay and Antiplatelet Activity of Fractions of Velvet Bean Seeds (Mucuna pruriens L.

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WAHYU WIDOWATI

2010-06-01

Full Text Available Platelet aggregation is an important factor contributing to the formation of thrombus due to an uncontrolled blood clotting. An antiplatelet agent is a compound which decreases platelet aggregation and inhibits thrombus formation. The objectives of this study were to determine the class of compound employing phytochemical assay and to determine the in vitro antiplatelet activity of four fraction, namely hexane, ethyl acetate, butanol, and water fractions of velvet bean seeds (Mucuna pruriens L. using epinephrine (EPN as agonist of platelet aggregation. The antiplatelet activities were tested in human platelet rich plasma with hyperaggregation. To determine the activities, EPN was arranged at 4 level of concentrations (300, 150, 75, and 30 ì M, and antiplatelet agents were at 500 µg/ml. The results indicated that ethyl acetate, butanol and water fraction contained high flavonoids and moderate phenols. The water, butanol and ethyl acetate fractions of velvet bean seeds exhibited potential inhibition of EPN-induced platelet aggregation at all concentrations. The strongest antiplatelet agent was water fraction and had the same antiplatelet activity as aspirin at level 150, 75, and 30 ì M of EPN. Butanol fraction had the same antiplatelet activity as aspirin at the lowest EPN (30 ì M.

Antiplatelet effects of Cyperus rotundus and its component (+)-nootkatone.

Science.gov (United States)

Seo, Eun Ji; Lee, Dong-Ung; Kwak, Jong Hwan; Lee, Sun-Mee; Kim, Yeong Shik; Jung, Yi-Sook

2011-04-26

Cyperus rotundus, a well-known oriental traditional medicine, has been reported to exhibit wide spectrum activity in biological systems including the circulatory system, however, little information is available on its antiplatelet activity. This study was undertaken to investigate the antiplatelet effects of Cyperus rotundus EtOH extract (CRE) and its constituent compounds. The antiplatelet activities of CRE and its eight constituent compounds were evaluated by examining their effects on rat platelet aggregations in vitro and ex vivo, and on mice tail bleeding times. During the in vitro platelet aggregation study, CRE showed significant and concentration-dependent inhibitory effects on collagen-, thrombin-, and/or AA-induced platelet aggregation. Of its eight components, (+)-nootkatone was found to have the most potent inhibitory effect on collagen-, thrombin-, and AA-induced platelet aggregation. In addition, CRE- and (+)-nootkatone-treated mice exhibited significantly prolonged bleeding times. Furthermore, (+)-nootkatone had a significant inhibitory effect on rat platelet aggregation ex vivo. This study demonstrates the antiplatelet effects of CRE and its active component (+)-nootkatone, and suggests that these agents might be of therapeutic benefit for the prevention of platelet-associated cardiovascular diseases. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Bleeding tendency in dual antiplatelet therapy with aspirin/clopidogrel: rescue of the template bleeding time in a single-center prospective study

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Altman Raul

2012-01-01

Full Text Available Abstract Background Patients with heightened platelet reactivity in response to antiplatelet agents are at an increased risk of recurrent ischemic events. However, there is a lack of diagnostic criteria for increased response to combined aspirin/clopidogrel therapy. The challenge is to identify patients at risk of bleeding. This study sought to characterize bleeding tendency in patients treated with aspirin and clopidogrel. Patients/methods In a single-center prospective study, 100 patients under long-term aspirin/clopidogrel treatment, the effect of therapy was assayed by template bleeding time (BT and the inhibition of platelet aggregation (IPA by light transmission aggregometry (LTA. Arachidonic acid (0.625 mmol/L and adenosine diphosphate (ADP; 2, 4, and 8 μmol/L were used as platelet agonists. Results Bleeding episodes (28 nuisance, 2 hematuria [1 severe], 1 severe proctorrhagia, 1 severe epistaxis were significantly more frequent in patients with longer BT. Template BT ≥ 24 min was associated with bleeding episodes (28 of 32. Risk of bleeding increased 17.4% for each 1 min increase in BT. Correlation was found between BT and IPAmax in response to ADP 2 μmol/L but not to ADP 4 or 8 μmol/L. Conclusion In patients treated with dual aspirin/clopidogrel therapy, nuisance and internal bleeding were significantly associated with template BT and with IPAmax in response to ADP 2 μmol/L but not in response to ADP 4 μmol/L or 8 μmol/L.

Phytochemical Assay and Antiplatelet Activity of Fractions of Velvet Bean Seeds (Mucuna pruriens L.

Directory of Open Access Journals (Sweden)

VICTOR IMMANUEL

2010-06-01

Full Text Available Platelet aggregation is an important factor contributing to the formation of thrombus due to an uncontrolled blood clotting. An antiplatelet agent is a compound which decreases platelet aggregation and inhibits thrombus formation. The objectives of this study were to determine the class of compound employing phytochemical assay and to determine the in vitro antiplatelet activity of four fraction, namely hexane, ethyl acetate, butanol, and water fractions of velvet bean seeds (Mucuna pruriens L. using epinephrine (EPN as agonist of platelet aggregation. The antiplatelet activities were tested in human platelet rich plasma with hyperaggregation. To determine the activities, EPN was arranged at 4 level of concentrations (300, 150, 75, and 30 μM, and antiplatelet agents were at 500 µg/ml. The results indicated that ethyl acetate, butanol and water fraction contained high flavonoids and moderate phenols. The water, butanol and ethyl acetate fractions of velvet bean seeds exhibited potential inhibition of EPN-induced platelet aggregation at all concentrations. The strongest antiplatelet agent was water fraction and had the same antiplatelet activity as aspirin at level 150, 75, and 30 μM of EPN. Butanol fraction had the same antiplatelet activity as aspirin at the lowest EPN (30 μM.

QCD Dual

DEFF Research Database (Denmark)

Sannino, Francesco

2009-01-01

We uncover a novel solution of the 't Hooft anomaly matching conditions for QCD. Interestingly in the perturbative regime the new gauge theory, if interpreted as a possible QCD dual, predicts the critical number of flavors above which QCD in the nonperturbative regime, develops an infrared stable...

Is anti-platelet therapy interruption a real clinical issue? Its implications in dentistry and particularly in periodontics

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Kumar A

2009-01-01

Full Text Available The use of anti-platelet therapy has reduced the mortality and morbidity of cardiovascular disease remarkably. A considerable number of patients presenting before a dentist or periodontist give a history of anti-platelet therapy. A clinical dilemma whether to discontinue the anti-platelet therapy or continue the same always confronts the practitioner. Diverse opinions exist regarding the management of such patients. While one group of researchers advise continuation of anti-platelet therapy rather than invite remote, but possible, thromboembolic events, another group encourages discontinuation for variable periods. This study aims at reviewing the current rationale of anti-platelet therapy and the various options available to a clinician, with regard to the management of a patient under anti-platelet therapy. Current recommendations and consensus favour no discontinuation of anti-platelet therapy. This recommendation, however, comes with a rider to use caution and consider other mitigating factors as well. With a large number of patients giving a history of anti-platelet therapy, the topic is of interest and helps a clinician to arrive at a decision.

Individual patient data meta-analysis of antiplatelet regimens after noncardioembolic stroke or TIA : Rationale and design

NARCIS (Netherlands)

Greving, Jacoba P.; Diener, Hans Christoph; Csiba, László; Hacke, Werner; Kappelle, L. Jaap; Koudstaal, Peter J.; Leys, Didier; Mas, Jean Louis; Sacco, Ralph L.; Sivenius, Juhani; Algra, Ale

2015-01-01

Background: The Cerebrovascular Antiplatelet Trialists' Collaborative Group was formed to obtain and analyze individual patient data from the major randomized trials of common antiplatelet regimens after cerebral ischemia. Although the risk of stroke can be reduced by antiplatelet drugs, there

Steam-cooking rapidly destroys and reverses onion-induced antiplatelet activity

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Hansen Emilie A

2012-09-01

Full Text Available Abstract Background Foods in the diet that can aid in the prevention of diseases are of major interest. Onions are key ingredients in many cuisines around the world and moreover, onion demand has trended higher over the past three decades. An important pharmacological aspect of onion is the ability to inhibit platelet aggregation. Raw onions inhibit platelet aggregation; however, when onions are boiled or heated, antiplatelet activity may be abolished. Methods Onion quarters were steamed for 0, 1, 3, 6, 10, and 15 min. The in vitro antiplatelet activity of a yellow hybrid storage onion was examined at these times on the blood of 12 human subjects using in vitro whole blood aggregometry. Results Contrary to findings reported for boiling, antiplatelet activity was destroyed between 3 and 6 min of steaming, and at 10 min of steaming, cooked onions stimulated platelet activity. Extracts from cooked onion had the potential to reverse the inhibitory effect on blood platelets by 25%. Responses were consistent across all donors. Total polyphenolic concentration and soluble solids were not affected by steaming time. Conclusions The potential value of cooked onion preparations may result in destruction or reversal of antiplatelet activity, without affecting the polyphenolic concentration.

Tradeoff between bleeding and stent thrombosis in different dual antiplatelet therapy regimes

DEFF Research Database (Denmark)

Jeger, Raban V; Pfisterer, Matthias E; Sørensen, Rikke

2014-01-01

/period; P benefit......-month DAPT was associated with an extrapolated reduction in mortality. Effective treatment periods and case fatality rates seem important in the analysis of different DAPT durations, specifically with regard to ongoing trials....

Prevalence and impact of high platelet reactivity in chronic kidney disease: results from the Assessment of Dual Antiplatelet Therapy with Drug-Eluting Stents registry.

Science.gov (United States)

Baber, Usman; Mehran, Roxana; Kirtane, Ajay J; Gurbel, Paul A; Christodoulidis, Georgios; Maehara, Akiko; Witzenbichler, Bernhard; Weisz, Giora; Rinaldi, Michael J; Metzger, D Christopher; Henry, Timothy D; Cox, David A; Duffy, Peter L; Mazzaferri, Ernest L; Xu, Ke; Parise, Helen; Brodie, Bruce R; Stuckey, Thomas D; Stone, Gregg W

2015-06-01

Chronic kidney disease (CKD) is associated with increased rates of adverse events after percutaneous coronary intervention. We sought to determine the impact of CKD on platelet reactivity in clopidogrel-treated patients and whether high platelet reactivity (HPR) confers a similar or differential risk for adverse events among patients with CKD and non-CKD. We performed a post hoc analysis of the Assessment of Dual Antiplatelet Therapy With Drug-Eluting Stents (ADAPT-DES) registry, which included 8582 patients undergoing percutaneous coronary intervention with drug-eluting stents and platelet function testing using the VerifyNow assay. We compared HPR and its impact on ischemic and bleeding events >2 years among patients with CKD and non-CKD. Patients with CKD (n=1367) were older, more often female, diabetic, and had lower ejection fraction compared with their non-CKD counterparts (n=7043). Although HPR prevalence increased with worsening renal function in unadjusted analyses, these associations were no longer present after adjustment. Major adverse cardiac event rates at 2 years among those without CKD or HPR, HPR alone, CKD alone, and both CKD and HPR were 9.0%, 11.2%, 13.3%, and 17.5%, respectively (Pimpact of HPR on ischemic and bleeding events is similar irrespective of CKD status. URL: http://www.clinicaltrials.gov. Unique identifier: NCT00638794. © 2015 American Heart Association, Inc.

Comparative evaluation of direct thrombin and factor Xa inhibitors with antiplatelet agents under flow and static conditions: an in vitro flow chamber model.

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Kazuya Hosokawa

Full Text Available Dabigatran and rivaroxaban are novel oral anticoagulants that specifically inhibit thrombin and factor Xa, respectively. The aim of this study is to elucidate antithrombotic properties of these anticoagulant agents under arterial and venous shear conditions. Whole blood samples treated with dabigatran or rivaroxaban at 250, 500, and 1000 nM, with/without aspirin and AR-C66096, a P2Y12 antagonist, were perfused over a microchip coated with collagen and tissue thromboplastin at shear rates of 240 and 600 s(-1. Fibrin-rich platelet thrombus formation was quantified by monitoring flow pressure changes. Dabigatran at higher concentrations (500 and 1000 nM potently inhibited thrombus formation at both shear rates, whereas 1000 nM of rivaroxaban delayed, but did not completely inhibit, thrombus formation. Dual antiplatelet agents weakly suppressed thrombus formation at both shear rates, but intensified the anticoagulant effects of dabigatran and rivaroxaban. The anticoagulant effects of dabigatran and rivaroxaban were also evaluated under static conditions using thrombin generation (TG assay. In platelet-poor plasma, dabigatran at 250 and 500 nM efficiently prolonged the lag time (LT and moderately reduce peak height (PH of TG, whereas rivaroxaban at 250 nM efficiently prolonged LT and reduced PH of TG. In platelet-rich plasma, however, both anticoagulants efficiently delayed LT and reduced PH of TG. Our results suggest that dabigatran and rivaroxaban may exert distinct antithrombotic effects under flow conditions, particularly in combination with dual antiplatelet therapy.

A review of the use of common antiplatelet agents in orthopaedic practice.

LENUS (Irish Health Repository)

Dineen, P F

2010-09-01

Antiplatelet agents are widely prescribed for the primary and secondary prevention of cardiovascular events. A common clinical problem facing orthopaedic and trauma surgeons is how to manage patients receiving these agents who require surgery, either electively or following trauma. The dilemma is to balance the risk of increased blood loss if the antiplatelet agents are continued peri-operatively against the risk of coronary artery\\/stent thrombosis and\\/or other vascular event if the drugs are stopped. The traditional approach of stopping these medications up to two weeks before surgery appears to pose significant danger to patients and may require review. This paper covers the important aspects regarding the two most commonly prescribed antiplatelet agents, aspirin and clopidogrel.

A Dual Regime Reactive Transport Model for Simulation of High Level Waste Tank Closure Scenarios - 13375

International Nuclear Information System (INIS)

Sarkar, Sohini; Kosson, David S.; Brown, Kevin; Garrabrants, Andrew C.; Meeussen, Hans; Van der Sloot, Hans

2013-01-01

A numerical simulation framework is presented in this paper for estimating evolution of pH and release of major species from grout within high-level waste tanks after closure. This model was developed as part of the Cementitious Barriers Partnership. The reactive transport model consists of two parts - (1) transport of species, and (2) chemical reactions. The closure grout can be assumed to have varying extents of cracking and composition for performance assessment purposes. The partially or completely degraded grouted tank is idealized as a dual regime system comprising of a mobile region having solid materials with cracks and macro-pores, and an immobile/stagnant region having solid matrix with micropores. The transport profiles of the species are calculated by incorporating advection of species through the mobile region, diffusion of species through the immobile/stagnant region, and exchange of species between the mobile and immobile regions. A geochemical speciation code in conjunction with the pH dependent test data for a grout material is used to obtain a mineral set that best describes the trends in the test data of the major species. The dual regime reactive transport model predictions are compared with the release data from an up-flow column percolation test. The coupled model is then used to assess effects of crack state of the structure, rate and composition of the infiltrating water on the pH evolution at the grout-waste interface. The coupled reactive transport model developed in this work can be used as part of the performance assessment process for evaluating potential risks from leaching of a cracked tank containing elements of human health and environmental concern. (authors)

A Dual Regime Reactive Transport Model for Simulation of High Level Waste Tank Closure Scenarios - 13375

Energy Technology Data Exchange (ETDEWEB)

Sarkar, Sohini; Kosson, David S.; Brown, Kevin; Garrabrants, Andrew C. [Consortium for Risk Assessment with Stakeholder Participation - CRESP, Vanderbilt University, Nashville, TN (United States); Meeussen, Hans [Consortium for Risk Assessment with Stakeholder Participation - CRESP, Nuclear Research and Consultancy Group, Petten (Netherlands); Van der Sloot, Hans [Consortium for Risk Assessment with Stakeholder Participation - CRESP, Hans Van der Sloot Consultancy (Netherlands)

2013-07-01

A numerical simulation framework is presented in this paper for estimating evolution of pH and release of major species from grout within high-level waste tanks after closure. This model was developed as part of the Cementitious Barriers Partnership. The reactive transport model consists of two parts - (1) transport of species, and (2) chemical reactions. The closure grout can be assumed to have varying extents of cracking and composition for performance assessment purposes. The partially or completely degraded grouted tank is idealized as a dual regime system comprising of a mobile region having solid materials with cracks and macro-pores, and an immobile/stagnant region having solid matrix with micropores. The transport profiles of the species are calculated by incorporating advection of species through the mobile region, diffusion of species through the immobile/stagnant region, and exchange of species between the mobile and immobile regions. A geochemical speciation code in conjunction with the pH dependent test data for a grout material is used to obtain a mineral set that best describes the trends in the test data of the major species. The dual regime reactive transport model predictions are compared with the release data from an up-flow column percolation test. The coupled model is then used to assess effects of crack state of the structure, rate and composition of the infiltrating water on the pH evolution at the grout-waste interface. The coupled reactive transport model developed in this work can be used as part of the performance assessment process for evaluating potential risks from leaching of a cracked tank containing elements of human health and environmental concern. (authors)

Mortality in primary angioplasty patients starting antiplatelet therapy with prehospital prasugrel or clopidogrel

DEFF Research Database (Denmark)

Goldstein, Patrick; Grieco, Niccolò; Ince, Hüseyin

2016-01-01

hospitalization, we report here the 1-year follow-up data, including cardiovascular (CV) mortality. METHODS AND RESULTS: MULTIPRAC is a multinational, prospective registry of patients with ST-elevation myocardial infarction (STEMI) from 25 hospitals in nine countries, all of which had an established practice...... of prehospital start of dual antiplatelet therapy in place. The key outcome was CV death at 1 year. Among 2,036 patients followed-up through 1 year, 49 died (2.4%), 10 during the initial hospitalization and 39 within 1 year after hospital discharge. The primary analysis was based on the P2Y12-inhibitor, used...... from prehospital loading dose through hospital discharge. Prasugrel (n=824) was more commonly used than clopidogrel (n=425). The observed 1-year rates for CV death were 0.5% with prasugrel and 2.6% with clopidogrel. After adjustment for differences in baseline characteristics, treatment with prasugrel...

Dissemination of 2014 dual antiplatelet therapy (DAPT) trial results: a systematic review of scholarly and media attention over 7 months.

Science.gov (United States)

Sharp, Melissa K; Haneef, Romana; Ravaud, Philippe; Boutron, Isabelle

2017-11-03

To explore how the results from the 2014 dual antiplatelet therapy (DAPT) trial were disseminated to the scientific community and online media. A a systematic review of scholarly and public attention surrounding the DAPT study. Data were collected from the ISI Web of Knowledge, Google Scholar, PubMed Commons, EurekAlert, the DAPT study website (www.daptstudy.org) and the New England Journal of Medicine website (for scholarly attention) and Altmetric Explorer, Snap Bird, YouTube (for public attention) citing DAPT study results appearing from 16 November 2014 to 10 June 2015. No participants were involved in this study. Proportion of contents highlighting the increased risk of mortality and critical to the author's interpretation of the results. We identified 425 items reported by seven sources; 164 (39%) disseminated the authors' interpretation via an electronic link or a reference, with no additional text. Among 81 items (19 %), the message favoured prolonged treatment and consequently overstated the article conclusions. Among 119 items (28 %), the text was uncertain about the benefit of prolonged treatment but was reported with no or inappropriate mention of increased risk of mortality. Only 34 items (8 %) were uncertain about the benefit of prolonged treatment and mentioned increased risk of mortality. In all, 27 items (6 %) did not favour prolonged treatment, and only 12 of these (3 %) clearly raised some concerns about the reporting of increased risk of death. Dissemination of the DAPT study results to the scientific community and on different media sources rarely criticised the interpretation of the study results. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Proton pump inhibitor co-prescription with dual antiplatelet therapy among patients with acute coronary syndrome in Qatar.

Science.gov (United States)

Awaisu, Ahmed; Hamou, Fatima; Mekideche, Lylia; El Muabby, Nisrine; Mahfouz, Ahmed; Mohammed, Shaban; Saad, Ahmad

2016-04-01

There are increasing concerns about clinically significant interactions between proton pump inhibitors (PPIs) and clopidogrel, resulting in adverse cardiovascular outcomes in patients with acute coronary syndromes (ACS). However, published evidence on the prevalence and predictors of PPI use with dual antiplatelet therapy (DAPT) is scarce. This study investigated the prevalence of PPI use among patients with ACS receiving DAPT and possible predictors of co-prescribing the PPIs with the DAPT. Heart Hospital, a specialized tertiary care center in Qatar. A retrospective observational study of a prescription database was conducted. Subjects included 626 patients admitted between January and December 2012 with the diagnosis of ACS who received DAPT and discharged with or without a PPI. Univariate analysis and multivariate binary logistic regression analysis were performed to determine the predictors of PPI-DAPT co-prescription. Prevalence of PPI co-prescribing with DAPT in proportions and percentages and odd ratios for the predictors of PPI-DAPT co-prescribing. A total of 626 patients were analyzed for PPI prevalence, with 200 patients (32 %) being prescribed PPI with DAPT upon discharge. After controlling for confounders, PPI use on admission (aOR 14.5; 95 % CI 7.6-27.6, p < 0.001), nationality (aOR 3.2; 95 % CI 1.1-9.9, p = 0.041), and having a history of diabetes (aOR 0.5; 95 % CI 0.24-0.99, p = 0.046) significantly influenced PPI-DAPT co-prescribing. Users of PPI on admission compared to nonusers were about 15 times more likely to be prescribed PPI with DAPT upon discharge; likewise, having Qatari nationality increased the likelihood of co-prescribing PPI with DAPT upon discharge by three folds. Lastly, patients with a history of diabetes were 50 % less likely to be prescribed PPIs upon discharge compared to those with no history of diabetes. The rate of PPI co-prescribing with DAPT in the population studied was relatively high. The strongest predictor of PPI co

[Retrospective analysis of correlative factors between digestive system injury and anticoagulant or antiplatelet-agents].

Science.gov (United States)

Cui, Ning; Luo, Hesheng

2014-05-27

To explore the correlative factors and clinical characteristics of digestive system injury during the treatment of anticoagulant and (or) antiplatelet-agents. A total of 1 443 hospitalized patients on anticoagulant and (or) antiplatelet-agents from January 2010 to December 2013 at Renmin Hospital of Wuhan University were analyzed retrospectively. Their length of hospital stay was from 5 to 27 days. Most of them were elderly males (n = 880, 61.0%) with an average age of (62 ± 6) years. 1 138 patients (78.9%) were farmers, workers or someone without a specific occupation. During the treatment of anticoagulant/antiplatelet-agents, statistical difference existed (P = 0.01) between positively and negatively previous digestive disease groups for actively newly occurring digestive system injury (16.0% (41/256) vs 15.9% (189/1 187)). After the dosing of anticoagulant and (or) antiplatelet-agents, 57 (66.3%, 57/86) patients were complicated by hemorrhage of digestive tract, taking 62.9% (61/97) of all positive result patients for Helicobacter pylori test. Comparing preventive PPI group with no PPI group, there was no marked statistical differences (P = 2.67) for digestive system complication (including hemorrhage of digestive tract) while receiving anticoagulant and (or) antiplatelet-agents (13.9% (74/533) vs 17.1% (156/910)). During anticoagulant and/or antiplatelet-agent therapy, 185 patients (12.8%) were complicated by peptic ulcer or peptic ulcer with bleeding, 40 patients (2.8%) had erosive gastritis and 5 (0.3%) developed acute gastric mucosal lesions. And 42 of 76 patients complicated by hemorrhage of digestive tract underwent endoscopic hemostasis while 2 patients were operated. Ninety-seven patients (6.7%) died, including 61 (62.9%, 61/97) from hemorrhage of digestive tract. The remainder became cured, improved and discharged. Moreover, no significant statistical differences existed (P = 2.29) among three combination group (aspirin, clopidogrel, warfarin), two

2018 Canadian Cardiovascular Society/Canadian Association of Interventional Cardiology Focused Update of the Guidelines for the Use of Antiplatelet Therapy.

Science.gov (United States)

Mehta, Shamir R; Bainey, Kevin R; Cantor, Warren J; Lordkipanidzé, Marie; Marquis-Gravel, Guillaume; Robinson, Simon D; Sibbald, Matthew; So, Derek Y; Wong, Graham C; Abunassar, Joseph G; Ackman, Margaret L; Bell, Alan D; Cartier, Raymond; Douketis, James D; Lawler, Patrick R; McMurtry, Michael S; Udell, Jacob A; van Diepen, Sean; Verma, Subodh; Mancini, G B John; Cairns, John A; Tanguay, Jean-François

2018-03-01

Antiplatelet therapy (APT) has become an important tool in the treatment and prevention of atherosclerotic events, particularly those associated with coronary artery disease. A large evidence base has evolved regarding the relationship between APT prescription in various clinical contexts and risk/benefit relationships. The Guidelines Committee of the Canadian Cardiovascular Society and Canadian Association of Interventional Cardiology publishes regular updates of its recommendations, taking into consideration the most recent clinical evidence. The present update to the 2011 and 2013 Canadian Cardiovascular Society APT guidelines incorporates new evidence on how to optimize APT use, particularly in situations in which few to no data were previously available. The recommendations update focuses on the following primary topics: (1) the duration of dual APT (DAPT) in patients who undergo percutaneous coronary intervention (PCI) for acute coronary syndrome and non-acute coronary syndrome indications; (2) management of DAPT in patients who undergo noncardiac surgery; (3) management of DAPT in patients who undergo elective and semiurgent coronary artery bypass graft surgery; (4) when and how to switch between different oral antiplatelet therapies; and (5) management of antiplatelet and anticoagulant therapy in patients who undergo PCI. For PCI patients, we specifically analyze the particular considerations in patients with atrial fibrillation, mechanical or bioprosthetic valves (including transcatheter aortic valve replacement), venous thromboembolic disease, and established left ventricular thrombus or possible left ventricular thrombus with reduced ejection fraction after ST-segment elevation myocardial infarction. In addition to specific recommendations, we provide values and preferences and practical tips to aid the practicing clinician in the day to day use of these important agents. Copyright © 2018. Published by Elsevier Inc.

Update: Acute coronary syndromes (V). Personalized antiplatelet therapy.

Science.gov (United States)

Gurbel, Paul A; Rafeedheen, Rahil; Tantry, Udaya S

2014-06-01

It is well established that high on-treatment platelet reactivity to adenosine diphosphate during clopidogrel therapy is an independent risk factor for ischemic event occurrences in a postpercutaneous coronary intervention patients. However, the precise role of platelet function testing remains debated. Platelet function testing to ensure optimal platelet inhibition has been recommended by some authorities to improve outcomes in patients treated with clopidogrel. Recent prospective, randomized trials of personalized antiplatelet therapy have failed to demonstrate a benefit of platelet function testing in improving outcomes. In this review article, we discuss the mechanisms responsible for clopidogrel nonreponsiveness, recent trials of platelet function testing, and other new developments in the field of personalized antiplatelet therapy. Copyright © 2014 Sociedad Española de Cardiología. Published by Elsevier Espana. All rights reserved.

Defining predictive values using three different platelet function tests for CYP2C19 phenotype status on maintenance dual antiplatelet therapy after PCI.

Science.gov (United States)

Zhang, Hong-Zhe; Kim, Moo Hyun; Han, Jin-Yeong; Jeong, Young-Hoon

2014-01-01

Published data suggests that the presence of CYP2C19*2 or *3 loss of function (LOF) alleles is indicative of increased platelet aggregation and a higher risk of adverse cardiovascular events after clopidogrel administration. We sought to determine cut-off values using three different assays for prediction of the CYP2C19 phenotype in Korean percutaneous coronary intervention (PCI) patients. We enrolled 244 patients with drug-eluting stent implantation who were receiving clopidogrel and aspirin maintenance therapy for one month or more. Platelet reactivity was assessed with light transmittance aggregometry (LTA), multiple electrode aggregometry (MEA) and the VerifyNow P2Y12 assay (VN). The CYP2C19 genotype was analyzed by polymerase chain reaction (PCR) and snapshot method. The frequency of CYP2C19 LOF allele carriers was 58.6%. The cut-off values from LTA, MEA and VerifyNow for the identification of LOF allele carriers were as follows: 10 µM ADP-induced LTA ≥ 48 %, VN>242 PRU and MEA ≥ 37 U. Between the three tests, correlation was higher between LTA vs. VN assays (r=0.69) and LTA vs. MEA (r=0.56), with moderate agreement (κ=0.46 and κ=0.46), but between VN assay and MEA, both devices using whole blood showed a lower correlation (r=0.42) and agreement (κ=0.3). Our results provide guidance regarding cut-off levels for LTA, VerifyNow and MEA assays to detect the CYP2C19 LOF allele in patients during dual antiplatelet maintenance therapy.

Spontaneous subdural hematoma and antiplatelet therapy: Does efficacy of Ticagrelor come with added risk?

Directory of Open Access Journals (Sweden)

Pattanagere Manjunatha Suryanarayana Sharma

2015-12-01

Full Text Available Antiplatelet therapy has established clinical benefit on cardiovascular outcome and has reduced the rates of re-infarction/in stent thrombosis following percutaneous coronary intervention in acute coronary syndromes. Major bleeding episodes can occur with antiplatelet therapy and intracranial hemorrhage (ICH is one of the most feared complications resulting in significant morbidity and mortality. Identification of high risk groups and judicious use of antiplatelet therapy reduces the bleeding risk. Ticagrelor is a newer P2Y12 receptor antagonist with established clinical benefit. However, risks of having an ICH with these newer molecules cannot be ignored. Here, we report a case of spontaneous acute subdural hematoma developing in a patient on antiplatelet therapy with aspirin and ticagrelor. Early recognition, discontinuation of the medication and appropriate management resulted in resolution of hematoma and good clinical outcome. Authors have reviewed the antithrombotic drugs and their tendencies in causing intracranial bleeds from a neurophysicians perspective.

Antiplatelet antibody may cause delayed transfusion-related acute lung injury

Directory of Open Access Journals (Sweden)

Torii Y

2011-09-01

Full Text Available Yoshitaro Torii1, Toshiki Shimizu1, Takashi Yokoi1, Hiroyuki Sugimoto1, Yuichi Katashiba1, Ryotaro Ozasa1, Shinya Fujita1, Yasushi Adachi2, Masahiko Maki3, Shosaku Nomura11The First Department of Internal Medicine, Kansai Medical University, Osaka, 2Department of Clinical Pathology, Toyooka Hospital, Hyogo, 3First Department of Pathology, Kansai Medical University, Osaka, JapanAbstract: A 61-year-old woman with lung cancer developed delayed transfusion-related acute lung injury (TRALI syndrome after transfusion of plasma- and leukoreduced red blood cells (RBCs for gastrointestinal bleeding due to intestinal metastasis. Acute lung injury (ALI recurred 31 days after the first ALI episode. Both ALI episodes occurred 48 hours after transfusion. Laboratory examinations revealed the presence of various antileukocyte antibodies including antiplatelet antibody in the recipient's serum but not in the donors' serum. The authors speculate that antiplatelet antibodies can have an inhibitory effect in the recipient, which can modulate the bona fide procedure of ALI and lead to a delay in the onset of ALI. This case illustrates the crucial role of a recipient's platelets in the development of TRALI.Keywords: delayed TRALI syndrome, recurrence, anti-platelet antibody

Relationship between Platelet PPARs, cAMP Levels, and P-Selectin Expression: Antiplatelet Activity of Natural Products

Directory of Open Access Journals (Sweden)

Eduardo Fuentes

2013-01-01

Full Text Available Platelets are no longer considered simply as cells participating in thrombosis. In atherosclerosis, platelets are regulators of multiple processes, with the recruitment of inflammatory cells towards the lesion sites, inflammatory mediators release, and regulation of endothelial function. The antiplatelet therapy has been used for a long time in an effort to prevent and treat cardiovascular diseases. However, limited efficacy in some patients, drug resistance, and side effects are limitations of current antiplatelet therapy. In this context, a large number of natural products (polyphenols, terpenoids, alkaloids, and fatty acids have been reported with antiplatelet activity. In this sense, the present paper describes mechanisms of antiplatelet action of natural products on platelet P-selectin expression through cAMP levels and its role as peroxisome proliferator-activated receptors agonists.

Use of thromboelastography to tailor dual-antiplatelet therapy in patients undergoing treatment of intracranial aneurysms with the Pipeline embolization device.

Science.gov (United States)

McTaggart, Ryan A; Choudhri, Omar A; Marcellus, Mary L; Brennan, Tom; Steinberg, Gary K; Dodd, Robert L; Do, Huy M; Marks, Michael P

2015-06-01

Platelet function testing is controversial and not well studied in patients with neurovascular disease. To evaluate the performance of thromboelastography (TEG) as a platelet function test in neurovascular patients treated with the Pipeline embolization device (PED). A prospective protocol was instituted for platelet function testing in patients undergoing repair of intracranial aneurysms with the PED. All patients received dual antiplatelet therapy (DAT) and their response to both P2Y12 inhibitors and aspirin was quantified with TEG. Each patient's DAT induction strategy was tailored based on the percentage ADP-induced and percentage arachidonic acid-induced platelet inhibition reported by TEG. Data collected included clinical presentation, aneurysm characteristics, treatment details, and periprocedural events. Patients were followed up clinically and/or angiographically at 30 days, 6 months, and 1 year. Thirty-four PED procedures were performed on 31 patients. TEG results altered the DAT strategy in 35% of patients. Technical success with the Pipeline placement was 100%. Two patients had minor strokes and five had transient ischemic attacks (TIAs). There have been no hemorrhagic complications. No patient had permanent neurologic deficits. Six of eight (75%) of patients with thromboembolic/TIA events were ADP-induced hyporesponders by TEG. Our 6- and 12-month angiographic occlusion rates were 78.9% and 89.5%, respectively. The 19 major branches covered by the PED that were assessed by follow-up imaging have all remained patent. Platelet function testing with TEG altered our DAT induction strategy in a significant number of cases. No hemorrhagic or disabling thromboembolic complications were seen in this series. Future studies should compare methods of platelet function testing and, possibly, no platelet function testing in neurovascular patients undergoing flow diversion and/or stent-assisted treatment of intracranial aneurysms. Published by the BMJ

Apixaban with antiplatelet therapy after acute coronary syndrome

NARCIS (Netherlands)

Alexander, J.H.; Lopes, R.D.; James, S.; Kilaru, R.; He, Y.; Mohan, P.; Bhatt, D.L.; Goodman, S.; Verheugt, F.W.A.; Flather, M.; Huber, K.; Liaw, D.; Husted, S.E.; Lopez-Sendon, J.; De Caterina, R.; Jansky, P.; Darius, H.; Vinereanu, D.; Cornel, J.H.; Cools, F.; Atar, D.; Leiva-Pons, J.L.; Keltai, M.; Ogawa, H.; Pais, P.; Parkhomenko, A.; Ruzyllo, W.; Diaz, R.; White, H.; Ruda, M.; Geraldes, M.; Lawrence, J.; Harrington, R.A.; Wallentin, L.

2011-01-01

BACKGROUND: Apixaban, an oral, direct factor Xa inhibitor, may reduce the risk of recurrent ischemic events when added to antiplatelet therapy after an acute coronary syndrome. METHODS: We conducted a randomized, double-blind, placebo-controlled clinical trial comparing apixaban, at a dose of 5 mg

Collaborative meta-analysis of randomised trials of antiplatelet therapy for prevention of death, myocardial infarction, and stroke in high risk patients

NARCIS (Netherlands)

Baigent, C; Sudlow, C; Collins, R; Peto, R

2002-01-01

Objective To determine the effects of antiplatelet therapy among patients at high risk of occlusive vascular events. Design Collaborative meta-analyses (systematic overviews). Inclusion criteria Randomised trials of an antiplatelet regimen versus control or of one antiplatelet regimen versus another

Contemporary Parenteral Antiplatelet Bridging Strategies: A Single-Center Real-World Experience at a Tertiary Care Center.

Science.gov (United States)

Stern, Gretchen; Rimsans, Jessica; Qamar, Arman; Vaduganathan, Muthiah; Bhatt, Deepak L

2018-03-13

Oral antiplatelet therapy may require interruption soon after percutaneous coronary intervention (PCI) or acute coronary syndrome. The optimal parenteral antiplatelet bridge strategy with glycoprotein IIb/IIIa inhibitors or cangrelor, a P2Y12 inhibitor, is unclear. We explore real-world use of cangrelor or eptifibatide for antiplatelet bridging at a large tertiary-care center. Thirty-one patients (9 eptifibatide, 20 cangrelor, and 2 both) received bridge therapy from October 2015 to June 2017. Primary bridge therapy indications included surgery (68%), limited enteral access/absorption (16%), and high-perceived bleed risk (16%). Median duration of bridge therapy was 61 (20-100) hours for cangrelor and 83 (19-98) hours for eptifibatide. Severe/life-threatening bleeding or stent thrombosis was not observed. GUSTO-defined bleeding occurred in 30% (cangrelor) and 27% (eptifibatide). Initial dosing errors occurred in 23% of patients. Death during hospitalization occurred in 16% of patients. Parenteral antiplatelet bridging was used for ~3 days in this single-center, tertiary care experience, commonly for unplanned surgery following PCI. Despite high-risk presentations with >15% in-hospital mortality, efficacy profiles were reassuring with no identified stent thrombosis, but bleeding and dosing errors were common. Antiplatelet bridging should only be used in well-selected patients at the appropriate dose for the minimal necessary duration.

Titration of antiplatelet treatment in pregnant women at risk of preeclampsia.

Science.gov (United States)

Sullivan, M H; Clark, N A; de Swiet, M; Nelson-Piercy, C; Elder, M G

1998-04-01

We recruited 111 patients who were considered to be at significantly increased risk of preeclampsia on the basis of previous obstetric history or preexisting medical disorders. All patients were treated with low dose aspirin (75 mg/day) from the first occasion the patient attended the antenatal clinic, regardless of gestational age. If the maternal mean platelet volume (MPV) increased significantly (by > 0.8 fl) from the baseline, antiplatelet treatment was increased. Five pregnancies were lost during the second trimester and 106 of the treated patients had live infants. The incidence of neonatal death (3/106 infants) was much lower than in the previous pregnancies in these patients (32/134 infants). Patients who were treated from the first trimester of pregnancy (group A, 89 patients) did substantially better than those treated from the second trimester (group B, 17 patients) as assessed by the incidence of pre-eclampsia or intrauterine growth restriction (IUGR), gestational age and birthweight at delivery. These data suggest that longitudinal monitoring of the MPV may identify the women who could benefit from increased antiplatelet treatment, and that antiplatelet treatment may be more effective when initiated in the first trimester rather than later in pregnancy.

Discontinuation of antiplatelet treatment and risk of recurrent stroke and all-cause death

DEFF Research Database (Denmark)

Ostergaard, Kamilla; Pottegård, Anton; Hallas, Jesper

2014-01-01

use and followed them up for stroke recurrence, or all-cause death. Person-time was classified by antiplatelet drug use into current use, recent use (≤150 days after last use), and non-use (>150 days after last use). Lipid-lowering drug (LLD) use was classified by the same rules. We used Cox......BACKGROUND: We wished to examine the impact of antiplatelet drug discontinuation on recurrent stroke and all-cause mortality. METHODS: We identified a cohort of incident ischaemic stroke patients in a Danish stroke registry, 2007-2011. Using population-based registries we assessed subjects' drug...... proportional hazard models to calculate the adjusted hazard ratio (HR) and corresponding 95% confidence intervals (CIs) for the risk of recurrent stroke or death associated with discontinuation of antiplatelet or LLD drugs. RESULTS: Among 4,670 stroke patients followed up for up a median of 1.5 years, 237...

Do family policy regimes matter for children's well-being?

Science.gov (United States)

Engster, Daniel; Stensöta, Helena Olofsdotter

2011-01-01

Researchers have studied the impact of different welfare state regimes, and particularly family policy regimes, on gender equality. Very little research has been conducted, however, on the association between different family policy regimes and children's well-being. This article explores how the different family policy regimes of twenty OECD countries relate to children's well-being in the areas of child poverty, child mortality, and educational attainment and achievement. We focus specifically on three family policies: family cash and tax benefits, paid parenting leaves, and public child care support. Using panel data for the years 1995, 2000, and 2005, we test the association between these policies and child well-being while holding constant for a number of structural and policy variables. Our analysis shows that the dual-earner regimes, combining high levels of support for paid parenting leaves and public child care, are strongly associated with low levels of child poverty and child mortality. We find little long-term effect of family policies on educational achievement, but a significant positive correlation between high family policy support and higher educational attainment. We conclude that family policies have a significant impact on improving children's well-being, and that dual-earner regimes represent the best practice for promoting children's health and development.

Antiplatelet therapy and vascular disease: an update.

Science.gov (United States)

Buch, Mamta H; Prendergast, Bernard D; Storey, Robert F

2010-08-01

Atherosclerosis is a diffuse, systemic disorder of the large and medium-sized arterial vessels, affecting the coronary, cerebral and peripheral circulation. Chronic inflammatory processes are the central pathophysiological mechanism largely driven by lipid accumulation, and provide the substrate for occlusive thrombus formation. The clinical sequelae of acute arterial thrombosis, heart attack and stroke, are the most common causes of morbidity and mortality in the industrialized world. Such acute events are characterized by rupture or erosion of the atherosclerotic plaque leading to acute thrombosis. The atherosclerotic process and associated thrombotic complications are collectively termed atherothrombosis. The platelet is a pivotal mediator of various endothelial, immune, thrombotic and inflammatory responses and therefore a key player in the initiation and progression of atherothrombosis. A robust evidence base supports the clear clinical benefits of antiplatelet agents in the primary and secondary therapy of atherothrombotic disorders. Percutaneous coronary and peripheral interventions have an established central role in the management of atherothrombotic disease and demand a greater understanding of platelet biology. In this article, we provide a clinically orientated overview of the pathophysiology of arterial thrombosis and the evidence supporting the use of the various established antiplatelet therapies, and discuss new and future agents.

HMG-CoA reductase inhibitors, other lipid-lowering medication, antiplatelet therapy, and the risk of venous thrombosis

NARCIS (Netherlands)

Ramcharan, A.S.; van Stralen, K.J.; Snoep, J.D.; Mantel-Teeuwisse, A.K.; Doggen, Catharina Jacoba Maria

2009-01-01

Background: Statins [3-hydroxymethyl-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors] and antiplatelet therapy reduce the risk of atherosclerotic disease. Besides a reduction of lipid levels, statins might also have antithrombotic and anti-inflammatory properties, and anti-platelet

Stent thrombosis: insights on outcomes, predictors and impact of dual antiplatelet therapy interruption from the SPIRIT II, SPIRIT III, SPIRIT IV and COMPARE trials.

Science.gov (United States)

Kedhi, Elvin; Stone, Gregg W; Kereiakes, Dean J; Serruys, Patrick W; Parise, Helen; Fahy, Martin; Simonton, Charles A; Sudhir, Krishnankutty; Sood, Poornima; Smits, Pieter C

2012-09-01

Recent studies have suggested that EES may reduce ST compared to PES, but no individual trial has been adequately powered for this endpoint. The incidence of stent thrombosis, as well as the impact of dual antiplatelet therapy (DAPT) discontinuation during the first two years following everolimus-eluting stent (EES) and paclitaxel-eluting stent (PES) deployment were therefore analysed from a pooled, patient-level database derived from four randomised clinical trials. Data from the SPIRIT II, SPIRIT III, SPIRIT IV and COMPARE trials (n=6,789 patients) were analysed. Two-year ST rates were determined using time-to-event methods and compared with the log-rank test. ST rates were also determined after DAPT discontinuation. EES compared to PES significantly reduced the two-year rates of ST (0.7% versus 2.3%, p=0.0001), including the interval rates of ST up to 30 days (0.2% versus 1.0%, p<0.0001), between 31 days and one year (0.2% versus 0.6%, p=0.02), and after one year (0.3% versus 0.8%, p=0.001). EES also reduced the two-year composite rate of cardiac death or MI (4.0% versus 6.6%, p=0.0001). Increased rates of ST after DAPT discontinuation beyond six months were observed in the PES cohort, but not in the EES cohort. In this large pooled analysis from four randomised trials, treatment with EES compared to PES significantly reduced the rates of ST through two years of follow-up, with a concomitant reduction in cardiac death or MI. DAPT discontinuation beyond six months may be safe with EES.

Safety of percutaneous nephrolithotomy in patients on chronic anticoagulant or antiplatelet therapy.

Science.gov (United States)

Fernández-Baltar, C; Pérez-Fentes, D; Sánchez-García, J F; García-Freire, C

2018-01-22

In developed countries, the incidence of cardiovascular disease is increasing, therefore, anticoagulant and antiplatelet drugs are a widespread treatment nowadays. Percutaneous nephrolithotomy (PNL) is the first-line treatment for large or complex stones (> 2 cm) and remains an alternative for the smaller ones. The objective of this study is to analyze whether PNL surgery is a safe procedure in patients under a treatment discontinuation protocol for anticoagulant or antiplatelet therapies. We retrospectively studied 301 patients who underwent PNL in our hospital between 2008 and 2016 and identified 46 patients on chronic antiplatelet or anticoagulation treatment. With respect to PNL outcomes, the stone-free rate was similar (78 vs 74%, p = 0.762) in both groups, without any significant differences in the overall postoperative complications (17 vs 26%, p = 0.203). The incidence of hemorrhagic complications was similar between groups (12 vs 9%, p = 0.492), as demonstrated by the mean drop in hemoglobin (Hb), which was comparable in both cohorts (2.2 ± 1.3 vs 2.0 ± 1.4 p = 0.270) and the blood transfusion rate (14% in group A and 8% in group B, p = 0.205). No thromboembolic events were found within the year after the PNL procedure. PNL is a safe and effective intervention in patients under a treatment discontinuation protocol for anticoagulant or antiplatelet therapies. Although our study demonstrates the feasibility of this protocol, new scientific evidence aims to stratify the thromboembolic and bleeding risk of each patient to individualize the perioperative management thereafter.

Impact of Anemia on Platelet Reactivity and Ischemic and Bleeding Risk: From the Assessment of Dual Antiplatelet Therapy With Drug-Eluting Stents Study.

Science.gov (United States)

Giustino, Gennaro; Kirtane, Ajay J; Baber, Usman; Généreux, Philippe; Witzenbichler, Bernhard; Neumann, Franz-Josef; Weisz, Giora; Maehara, Akiko; Rinaldi, Michael J; Metzger, Christopher; Henry, Timothy D; Cox, David A; Duffy, Peter L; Mazzaferri, Ernest L; Brodie, Bruce R; Stuckey, Thomas D; Gurbel, Paul A; Dangas, George D; Francese, Dominic P; Ozan, Ozgu; Mehran, Roxana; Stone, Gregg W

2016-06-15

Anemic patients remain at increased risk of ischemic and bleeding events. Whether the effects of hemoglobin levels on thrombotic and bleeding risk are independent of platelet reactivity on clopidogrel, however, remains unknown. Patients from the Assessment of Dual Antiplatelet Therapy With Drug-Eluting Stents study were categorized by the presence of anemia at baseline, defined according the World Health Organization criteria. Platelet reactivity was measured with VerifyNow assay; high platelet reactivity (HPR) on clopidogrel was defined as platelet reactive units value >208. Of 8,413 patients included in the study cohort, 1,816 (21.6%) had anemia. HPR was more prevalent in patients with anemia (58.3% vs 38.4%; p <0.001), an association that persisted after multivariate adjustment (adjusted odds ratio: 2.04; 95% confidence interval [CI]: 1.82 to 2.29; p <0.0001). Patients with anemia had higher 2-year rates of major adverse cardiac events (9.5% vs 5.6%; p <0.0001), major bleeding (11.8% vs 7.7%; p <0.0001), and all-cause mortality (4.0% vs 1.4%; p <0.0001); however, after adjustment for baseline clinical confounders, including HPR, anemia was no longer significantly associated with major adverse cardiac events but was still independently associated with all-cause mortality (adjusted HR 1.61, 95% CI 1.23 to 2.12; p <0.0001) and major bleeding (adjusted HR 1.42, 95% CI 1.20 to 1.68; p <0.0001). The effect of HPR on clinical outcomes was uniform according to anemia status, without evidence of interaction. In conclusion, anemia independently correlated with HPR. After percutaneous coronary intervention with drug-eluting stents, anemia at baseline was significantly associated with higher 2-year hemorrhagic and mortality risk; conversely, its association with ischemic risk was attenuated after multivariate adjustment, including HPR. Copyright © 2016 Elsevier Inc. All rights reserved.

TIPdb: A Database of Anticancer, Antiplatelet, and Antituberculosis Phytochemicals from Indigenous Plants in Taiwan

Directory of Open Access Journals (Sweden)

Ying-Chi Lin

2013-01-01

Full Text Available The unique geographic features of Taiwan are attributed to the rich indigenous and endemic plant species in Taiwan. These plants serve as resourceful bank for biologically active phytochemicals. Given that these plant-derived chemicals are prototypes of potential drugs for diseases, databases connecting the chemical structures and pharmacological activities may facilitate drug development. To enhance the utility of the data, it is desirable to develop a database of chemical compounds and corresponding activities from indigenous plants in Taiwan. A database of anticancer, antiplatelet, and antituberculosis phytochemicals from indigenous plants in Taiwan was constructed. The database, TIPdb, is composed of a standardized format of published anticancer, antiplatelet, and antituberculosis phytochemicals from indigenous plants in Taiwan. A browse function was implemented for users to browse the database in a taxonomy-based manner. Search functions can be utilized to filter records of interest by botanical name, part, chemical class, or compound name. The structured and searchable database TIPdb was constructed to serve as a comprehensive and standardized resource for anticancer, antiplatelet, and antituberculosis compounds search. The manually curated chemical structures and activities provide a great opportunity to develop quantitative structure-activity relationship models for the high-throughput screening of potential anticancer, antiplatelet, and antituberculosis drugs.

TIPdb: a database of anticancer, antiplatelet, and antituberculosis phytochemicals from indigenous plants in Taiwan.

Science.gov (United States)

Lin, Ying-Chi; Wang, Chia-Chi; Chen, Ih-Sheng; Jheng, Jhao-Liang; Li, Jih-Heng; Tung, Chun-Wei

2013-01-01

The unique geographic features of Taiwan are attributed to the rich indigenous and endemic plant species in Taiwan. These plants serve as resourceful bank for biologically active phytochemicals. Given that these plant-derived chemicals are prototypes of potential drugs for diseases, databases connecting the chemical structures and pharmacological activities may facilitate drug development. To enhance the utility of the data, it is desirable to develop a database of chemical compounds and corresponding activities from indigenous plants in Taiwan. A database of anticancer, antiplatelet, and antituberculosis phytochemicals from indigenous plants in Taiwan was constructed. The database, TIPdb, is composed of a standardized format of published anticancer, antiplatelet, and antituberculosis phytochemicals from indigenous plants in Taiwan. A browse function was implemented for users to browse the database in a taxonomy-based manner. Search functions can be utilized to filter records of interest by botanical name, part, chemical class, or compound name. The structured and searchable database TIPdb was constructed to serve as a comprehensive and standardized resource for anticancer, antiplatelet, and antituberculosis compounds search. The manually curated chemical structures and activities provide a great opportunity to develop quantitative structure-activity relationship models for the high-throughput screening of potential anticancer, antiplatelet, and antituberculosis drugs.

Dentists' approach to patients on anti-platelet agents and warfarin: a survey of practice.

LENUS (Irish Health Repository)

Murphy, James

2010-04-23

In everyday practice, dentists are confronted with the dilemma of patients on anti-platelet agents and warfarin who require invasive dental procedures and, more pertinently, dental extractions. There may be a divergence of opinion among dentists regarding how they manage these patients. AIMS: To assess general dental practitioners\\' approach to the management of patients taking anti-platelet agents and\\/or warfarin who are undergoing invasive dental procedures. METHODS AND DATA: A semi-structured questionnaire was designed to survey general dental practitioners in a large Irish urban area. RESULTS: A response rate of 89% was achieved in a study population of 54 general dental practitioners. A total of 25% of respondents who carry out extractions on warfarinised patients do not check the INR prior to invasive dental procedures. Some 90% of respondents stop anti-platelet agents prior to extractions. CONCLUSIONS: A significant proportion of respondents fail to check warfarinised patients\\' INR prior to invasive dental procedures. Furthermore, a trend of stopping anti-platelet agents was noted, which is in contrast with current recommendations in the dental literature. Certain practices in this small study population proved alarming and highlight the need for improved awareness of current guidelines. A further large-scale study may be justified, as variation in practice may have clinical and medico-legal repercussions.

Subdural haematoma complicating shunting for normal pressure hydrocephalus in the setting of concomitant antiplatelet medication

DEFF Research Database (Denmark)

Birkeland, Peter; Lauritsen, Jens; Poulsen, Frantz Rom

2016-01-01

OBJECTIVE: To report on the occurrence and management of subdural haematoma after shunt implantation for normal pressure hydrocephalus and to determine the risk of recurrence in the setting of antiplatelet medication. METHODS: From a consecutive series of 80 patients implanted with a cerebrospinal...... fluid shunt for normal pressure hydrocephalus, records from 11 patients taking antiplatelet drugs, who subsequently had surgery for subdural haematoma were extracted and retrospectively reviewed. RESULTS: Patients were followed up for a mean of 1819 days after shunt implantation. Subdural haematomas...... reoperations done before the subdural collection disappeared. Only one patient had a late recurrence almost 11 years after shunt implantation. CONCLUSIONS: Subdural haematoma in the setting of a ventriculoperitoneal implantation for normal pressure hydrocephalus and concomitant antiplatelet medication can...

Analgesic, anti-inflammatory and anti-platelet activities of Buddleja crispa.

Science.gov (United States)

Bukhari, Ishfaq A; Gilani, Anwar H; Meo, Sultan Ayoub; Saeed, Anjum

2016-02-25

Buddleja crispa Benth (Buddlejaceae) is a dense shrub; several species of genus Buddleja have been used in the management of various health conditions including pain and inflammation. The present study was aimed to investigate the analgesic, anti-inflammatory and anti-platelet properties of B. crispa. Male rats (220-270 gm,) and mice (25-30 gm) were randomly divided into different groups (n = 6). Various doses of plant extract of B. crispa, its fractions and pure compounds isolated from the plant were administered intraperitoneally (i.p). The analgesic, anti-inflammatory and anti-platelet activities were assessed using acetic acid and formalin-induced nociception in mice, carrageenan-induced rat paw edema and arachidonic acid-induced platelets aggregation tests. The intraperitoneal administration of the methanolic extract (50 and 100 mg/kg), hexane fraction (10 and 25 mg/kg i.p) exhibited significant inhibition (P < 0.01) of the acetic acid-induced writhing in mice and attenuated formalin-induced reaction time of animals in second phase of the test. Pure compounds BdI-2, BdI-H3 and BH-3 isolated from B. crispa produced significant (P < 0.01) analgesic activity in acetic acid-induced and formalin tests. The crude extract of B. crispa (50-200 mg/kg i.p.) and its hexane fraction inhibited carrageenan-induced rat paw edema with maximum inhibition of 65 and 71% respectively (P < 0.01). The analgesic and anti-inflammatory effect of the plant extract and isolated pure compounds were comparable to diclofenac sodium. B. crispa plant extract (0.5-2.5 mg/mL) produced significant anti-platelet effect (P < 0.01) with maximum inhibition of 78% at 2.5 mg/ml. The findings from our present study suggest that B. crispa possesses analgesic, anti-inflammatory and anti-platelet properties. B. crispa could serve a potential novel source of compounds effective in pain and inflammatory conditions.

Effect of Tomato Industrial Processing on Phenolic Profile and Antiplatelet Activity

Directory of Open Access Journals (Sweden)

Iván Palomo

2013-09-01

Full Text Available Background: Regular consumption of fruits and vegetables (e.g., tomatoes has been shown to be beneficial in terms of reducing the incidence of cardiovascular diseases. The industrial processing of tomatoes into tomato-based products includes several thermal treatments. Very little is known on the effect of tomato industrial processing on antiaggregatory activity and phenolic profile. Methods: It was assessed the effect of tomato and by-products extracts on platelet aggregation induced by ADP, collagen, TRAP-6 and arachidonic acid. These in vitro antithrombotic properties were further supported in an in vivo model of thrombosis. A set of antiplatelet compounds has been selected for HPLC analysis in the different extracts. Results: Some natural compounds such as chlorogenic, caffeic, ferulic and p-coumaric acids were identified by HPLC in tomatoes and its products may inhibit platelet activation. Red tomatoes, tomato products (sauce, ketchup and juice and by-products extracts inhibited platelet aggregation induced adenosine 5'-diphosphate, collagen, thrombin receptor activator peptide-6 and arachidonic acid, but to a different extent. Also, pomace extract presents antithrombotic activity. Conclusions: Processed tomatoes may have a higher content of health-benefiting compounds than fresh ones. Pomace even presents the best antiplatelet activity. Finally, tomato products may be used as a functional ingredient adding antiplatelet activities to processed foods.

Synthesis and antiplatelet activity of thioaryloxyacids analogues of clofibric acid.

Science.gov (United States)

Ammazzalorso, Alessandra; Amoroso, Rosa; Baraldi, Mario; Bettoni, Giancarlo; Braghiroli, Daniela; De Filippis, Barbara; Giampietro, Letizia; Tricca, Maria L; Vezzalini, Francesca

2005-09-01

The thiophene-, benzothiazole- and pyridine-thioaryloxyacids analogues of clofibric acid were synthesized and their antiplatelet activity was screened. Some compounds exhibited antiaggregating properties. The platelet-related haemostasis was measured on a PFA-100 analyzer using bull blood.

Viewpoint: "underutilisation of novel antiplatelet agents--myths, generics, and economics".

Science.gov (United States)

Serebruany, V L; Fortmann, S D

2014-07-03

Two oral antiplatelet agents have been recently introduced for acute coronary syndromes indication providing alternatives for dual therapy with aspirin and clopidogrel. In fact, worldwide prasugrel has been on the market for four years, and ticagrelor for over two years. Despite declared benefits over clopidogrel, including hypothetical cost saving advantages, in real life, the clinical utilisation of both agents is small. Generic clopidogrel, and price differences are claimed as major obstacles to prevent broader prasugrel and ticagrelor use. However, these economic difficulties are barely supported by available evidence, and served mostly to protect questionable management spending, as an exuse to explain why in reality cardiologists are so sceptical about both novel agents, and to convince the sharehoders that their money is not wasted, misleading the owners with regard to future success. Importantly, brand Plavix® is used worldwide 5-10 times more often than new agents, despite heavy generic competition. The future of prasugrel outside Japan, where much lower reasonable dose will be used is not impressive due to lack of further outcome studies, negative results of the latest trials, and less than four years left before patent expiration. The fate of ticagrelor will depend on verification of deaths numbers in the ongoing United States Department of Justice PLATO investigation, and confirmation of the mortality benefit in the PEGASUS TIMI-54 trial.

An investigation of the antiplatelet effects of succinobucol (AGI-1067).

Science.gov (United States)

Houston, Stephanie A; Ugusman, Azizah; Gnanadesikan, Sukanya; Kennedy, Simon

2017-05-01

Succinobucol is a phenolic antioxidant with anti-inflammatory and antiplatelet effects. Given the importance of oxidant stress in modulating platelet-platelet and platelet-vessel wall interactions, the aim of this study was to establish if antioxidant activity was responsible for the antiplatelet activity of succinobucol. Platelet aggregation in response to collagen and adenosine diphosphate (ADP) was studied in rabbit whole blood and platelet-rich plasma using impedance aggregometry. The effect of oxidant stress on aggregation, platelet lipid peroxides, and vascular tone was studied by incubating platelets, washed platelets or preconstricted rabbit iliac artery rings respectively with a combination of xanthine and xanthine oxidase (X/XO). To study the effect of succinobucol in vivo, anaesthetized rats were injected with up to 150 mg/kg succinobucol and aggregation measured in blood removed 15 mins later. Succinobucol (10 -5 -10 -4 M) significantly attenuated platelet aggregation to collagen and ADP in whole blood and platelet-rich plasma. X/XO significantly increased aggregation to collagen and platelet lipid peroxides and this was reversed by succinobucol. Addition of X/XO to denuded rabbit iliac arteries caused a dose-dependent relaxation which was significantly inhibited by succinobucol. In vivo administration up to 150 mg/kg had no effect on heart rate or mean arterial blood pressure but significantly inhibited platelet aggregation to collagen ex vivo. In conclusion, succinobucol displays anti-platelet activity in rabbit and rat blood and reverses the increase in platelet aggregation in response to oxidant stress.

Antiplatelet therapy for recurrent stroke prevention: newer perspectives based on (MATCH), (CHARISMA), and (ESPRIT).

Science.gov (United States)

Gorelick, Philip B

2008-01-01

Antiplatelet therapy is an important component of our armamentarium for recurrent stroke prevention. Aspirin is a safe and effective antiplatelet drug for recurrent stroke prevention, however, it has been challenged recently by the thienopyridine derivative, clopidogrel, and the combination agent, aspirin plus extended release dipyridamole. In this review, we discuss recent studies of thienopyridine derivatives and aspirin plus extended-release dipyridamole in stroke prevention and evidence-based guidelines for the administration of these agents in practice for recurrent stroke prevention.

Current practice of antiplatelet and anticoagulation management in post-cardiac surgery patients: a national audit.

Science.gov (United States)

Hosmane, Sharath; Birla, Rashmi; Marchbank, Adrian

2012-04-01

The Audit and Guidelines Committee of the European Association for Cardio-Thoracic Surgery recently published a guideline on antiplatelet and anticoagulation management in cardiac surgery. We aimed to assess the awareness of the current guideline and adherence to it in the National Health Service through this National Audit. We designed a questionnaire consisting of nine questions covering various aspects of antiplatelet and anticoagulation management in post-cardiac surgery patients. A telephonic survey of the on-call cardiothoracic registrars in all the cardiothoracic centres across the UK was performed. All 37 National Health Service hospitals in the UK with 242 consultants providing adult cardiac surgical service were contacted. Twenty (54%) hospitals had a unit protocol for antiplatelet and anticoagulation management in post-cardiac surgery. Only 23 (62.2%) registrars were aware of current European Association for Cardio-Thoracic Surgery guidelines. Antiplatelet therapy is variable in the cardiac surgical units across the country. Low-dose aspirin is commonly used despite the recommendation of 150-300 mg. The loading dose of aspirin within 24 h as recommended by the guideline is followed only by 60.7% of surgeons. There was not much deviation from the guideline with respect to the anticoagulation therapy.

Baseline characteristics of the 3096 patients recruited into the 'Triple Antiplatelets for Reducing Dependency after Ischemic Stroke' trial

DEFF Research Database (Denmark)

Bath, Philip Mw; Appleton, Jason P; Beridze, Maia

2017-01-01

Background The risk of recurrence following ischemic stroke or transient ischemic attack is highest immediately after the event. Antiplatelet agents are effective in reducing the risk of recurrence and two agents are superior to one in the early phase after ictus. Design The triple antiplatelets...

Antiplatelet Regimen for Patients With Breakthrough Strokes While on Aspirin: A Systematic Review and Meta-Analysis.

Science.gov (United States)

Lee, Meng; Saver, Jeffrey L; Hong, Keun-Sik; Rao, Neal M; Wu, Yi-Ling; Ovbiagele, Bruce

2017-09-01

Optimal antiplatelet therapy after an ischemic stroke or transient ischemic attack while on aspirin is uncertain. We, therefore, conducted a systematic review and meta-analysis. We searched PubMed (1966 to August 2016) and bibliographies of relevant published original studies to identify randomized trials and cohort studies reporting patients who were on aspirin at the time of an index ischemic stroke or transient ischemic attack and reported hazard ratio for major adverse cardiovascular events or recurrent stroke associated with a switch to or addition of another antiplatelet agent versus maintaining aspirin monotherapy. Estimates were combined using a random effects model. Five studies with 8723 patients with ischemic stroke or transient ischemic attack were identified. Clopidogrel was used in 4 cohorts, and ticagrelor was used in 1 cohort. Pooling results showed that addition of or a switch to another antiplatelet agent, versus aspirin monotherapy, was associated with reduced risks of major adverse cardiovascular events (hazard ratio, 0.68; 95% confidence interval, 0.54-0.85) and recurrent stroke (hazard ratio, 0.70; 95% confidence interval, 0.54-0.92). Each of the strategies of addition of and switching another antiplatelet agent showed benefit versus continued aspirin monotherapy, and studies with regimen initiation in the first days after index event showed more homogenous evidence of benefit. Among patients who experience an ischemic stroke or transient ischemic attack while on aspirin monotherapy, the addition of or a switch to another antiplatelet agent, especially in the first days after index event, is associated with fewer future vascular events, including stroke. © 2017 American Heart Association, Inc.

Flow regime identification methodology with MCNP-X code and artificial neural network

International Nuclear Information System (INIS)

Salgado, Cesar M.; Instituto de Engenharia Nuclear; Schirru, Roberto; Brandao, Luis E.B.; Pereira, Claudio M.N.A.

2009-01-01

This paper presents flow regimes identification methodology in multiphase system in annular, stratified and homogeneous oil-water-gas regimes. The principle is based on recognition of the pulse height distributions (PHD) from gamma-ray with supervised artificial neural network (ANN) systems. The detection geometry simulation comprises of two NaI(Tl) detectors and a dual-energy gamma-ray source. The measurement of scattered radiation enables the dual modality densitometry (DMD) measurement principle to be explored. Its basic principle is to combine the measurement of scattered and transmitted radiation in order to acquire information about the different flow regimes. The PHDs obtained by the detectors were used as input to ANN. The data sets required for training and testing the ANN were generated by the MCNP-X code from static and ideal theoretical models of multiphase systems. The ANN correctly identified the three different flow regimes for all data set evaluated. The results presented show that PHDs examined by ANN may be applied in the successfully flow regime identification. (author)

Trends in Ambulatory Prescribing of Antiplatelet Therapy among US Ischemic Stroke Patients: 2000–2007

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Sudeep Karve

2012-01-01

Full Text Available Objective. Study objectives were to assess temporal trends and identify patient- and practice-level predictors of the prescription of antiplatelet medications in a national sample of ischemic stroke (IS patients seeking ambulatory care. Methods. IS-related outpatient visits by adults were identified using the National Ambulatory Medical Care Survey and National Hospital Ambulatory Medical Care Survey for the years 2000–2007. We assessed prescribing of antiplatelet medications using the generic drug code and drug entry codes in these data. Temporal trends in antiplatelet prescribing were assessed using the Cochran-Mantel-Haenszel test for trend. Results. We identified 9.5 million IS-related ambulatory visits. Antiplatelet medications were prescribed at 35.5% of visits. Physician office prescribing of the clopidogrel-aspirin combination increased significantly from 0.5% in 2000 to 22.0% in 2007 (P=0.05, whereas prescribing of aspirin decreased from 17.9% to 7.0% (P=0.50 during the same period. Conclusion. We observed a continued increase in prescription of the aspirin-clopidogrel combination from 2000 to 2007. Clinical trial evidence suggests that the aspirin-clopidogrel combination does not provide any additional benefit compared with clopidogrel alone; however, our study findings indicate that even with lack of adequate clinical evidence physician prescribing of this combination has increased in real-world community settings.

The clinical value of antiplatelet therapy for patients with hemorrhage after thrombolysis based on susceptibility-weighted imaging: A prospective pilot study

International Nuclear Information System (INIS)

Lu, Jing; Li, Yue-Hua; Li, Yong-Dong; Li, Ming-Hua; Zhao, Jun-Gong; Chen, Shi-Wen

2012-01-01

Purpose: To evaluate treatment decision-making based on susceptibility-weighted imaging (SWI) in patients with hemorrhage after thrombolysis. Materials and methods: One hundred and forty-six patients without intracranial hemorrhage on CT after receiving recombinant tissue plasminogen activator (rt-PA) were allocated to two groups: antiplatelets (n = 72), who received antiplatelet therapy 24 h after rt-PA for 10 days; and non-antiplatelets (n = 74), who received no antiplatelet therapy. Twenty-two patients with SWI-detected microbleeds (MBs) or hemorrhagic transformation (HT) in the antiplatelets group (Group A) and 28 with MB or HT in the non-antiplatelets group (Group B) were included in this study. Results: Sixteen patients had MB and six HT in Group A; 18 had MB, six HT, and four parenchymal hemorrhage (PH) in Group B. National Institutes of Health Stroke Scale (NIHSS) scores at 7 and 14 days and the Modified Rankin Scale (mRS) at 90 days post-rt-PA were significantly lower in Group B than in Group A, duration of hospitalization was significantly shorter, and the favorable outcome rate was higher at 90 days (P < 0.05). There were no other significant differences. SWI evaluation at 14 days revealed eight patients with MB, 11 HT, and three PH in Group A; in Group B, 16 had MB, five HT, and one PH, with resolution of hemorrhage in six patients. Conclusions: Treatment decision-making based on SWI in acute stroke after thrombolysis was validated by the significantly reduced NIHSS score after 7/14 days, improved outcome, and reduced mRS in hemorrhage patients without antiplatelet therapy.

Conflicting results between randomized trials and observational studies on the impact of proton pump inhibitors on cardiovascular events when coadministered with dual antiplatelet therapy: systematic review.

Science.gov (United States)

Melloni, Chiara; Washam, Jeffrey B; Jones, W Schuyler; Halim, Sharif A; Hasselblad, Victor; Mayer, Stephanie B; Heidenfelder, Brooke L; Dolor, Rowena J

2015-01-01

Discordant results have been reported on the effects of concomitant use of proton pump inhibitors (PPIs) and dual antiplatelet therapy (DAPT) for cardiovascular outcomes. We conducted a systematic review comparing the effectiveness and safety of concomitant use of PPIs and DAPT in the postdischarge treatment of unstable angina/non-ST-segment-elevation myocardial infarction patients. We searched for clinical studies in MEDLINE, EMBASE, and the Cochrane Database of Systematic Reviews, from 1995 to 2012. Reviewers screened and extracted data, assessed applicability and quality, and graded the strength of evidence. We performed meta-analyses of direct comparisons when outcomes and follow-up periods were comparable. Thirty-five studies were eligible. Five (4 randomized controlled trials and 1 observational) assessed the effect of omeprazole when added to DAPT; the other 30 (observational) assessed the effect of PPIs as a class when compared with no PPIs. Random-effects meta-analyses of the studies assessing PPIs as a class consistently reported higher event rates in patients receiving PPIs for various clinical outcomes at 1 year (composite ischemic end points, all-cause mortality, nonfatal MI, stroke, revascularization, and stent thrombosis). However, the results from randomized controlled trials evaluating omeprazole compared with placebo showed no difference in ischemic outcomes, despite a reduction in upper gastrointestinal bleeding with omeprazole. Large, well-conducted observational studies of PPIs and randomized controlled trials of omeprazole seem to provide conflicting results for the effect of PPIs on cardiovascular outcomes when coadministered with DAPT. Prospective trials that directly compare pharmacodynamic parameters and clinical events among specific PPI agents in patients with unstable angina/non-ST-segment-elevation myocardial infarction treated with DAPT are warranted. © 2015 American Heart Association, Inc.

Anti-Platelet Aggregation and Vasorelaxing Effects of the Constituents of the Rhizomes of Zingiber officinale

Directory of Open Access Journals (Sweden)

Tian-Shung Wu

2012-07-01

Full Text Available In the present study, the chemical investigation of the bioactive fractions of the rhizomes of Zingiber officinale has resulted in the identification of twenty-nine compounds including one new compound, O-methyldehydrogingerol (1. Some of the isolates were subjected into the evaluation of their antiplatelet aggregation and vasorelaxing bioactivities. Among the tested compounds, [6]-gingerol (13 and [6]-shogaol (17 exhibited potent anti-platelet aggregation bioactivity. In addition, [10]-gingerol (15 inhibited the Ca²⁺-dependent contractions in high K⁺ medium. According to the results in the present research, the bioactivity of ginger could be related to the anti-platelet aggregation and vasorelaxing mechanism.

Semiquantitative dynamic computed tomography to predict response to anti-platelet therapy in acute cerebral infarction

International Nuclear Information System (INIS)

Chokyu, K.; Shimizu, K.; Fukumoto, M.; Mori, T.; Mokudai, T.; Mori, K.

2002-01-01

We investigated whether dynamic computed tomography (CT) in patients with acute cerebral infarction could identify patients likely to respond to anti-platelet therapy. Seventy patients underwent semiquantitative dynamic CT within 6 h as well as cerebral angiography. All then received anti-platelet therapy with a thromboxane A2 synthetase inhibitor. Peak value (pv) and time-to-peak (tp) (time-density curves) for the Sylvian fissure were extracted from dynamic CT data and standardizing interpatient data, two indices, PV/TP index and TP index, were prepared following a standard semiquantitative manner. Both PV/TP index and TP index were effective in discriminating between 48 responders (modified Rankin scale (mRS): 0 to 2) and 22 non-responders (mRS: 3 to 5, or death: 6; both P 1.1) and non-compensated rCBF. Intermediate PV/TP values could not predict outcome. Dynamic CT prior to therapy can identify patients with acute cerebral infarction who are treatable with anti-platelet therapy alone. (orig.)

Corporate hedging under a resource rent tax regime

OpenAIRE

Frestad, Dennis

2010-01-01

Accepted version of an article in the journal: Energy Economics. Published version available on Science Direct: http://dx.doi.org/10.1016/j.eneco.2009.10.009 In addition to the ordinary corporate income tax, special purpose taxes are sometimes levied to extract abnormal profits arising from the use of natural resources. Such dual tax regimes exist in Norway for oil and hydropower, where the corresponding special purpose tax bases are unaffected by any derivatives payments. Dual tax firms w...

Prehospital antiplatelet use and functional status on admission of patients with non-haemorrhagic moyamoya disease: a nationwide retrospective cohort study (J-ASPECT study)

Science.gov (United States)

Onozuka, Daisuke; Hagihara, Akihito; Nishimura, Kunihiro; Kada, Akiko; Nakagawara, Jyoji; Ogasawara, Kuniaki; Ono, Junichi; Shiokawa, Yoshiaki; Aruga, Toru; Miyachi, Shigeru; Nagata, Izumi; Toyoda, Kazunori; Matsuda, Shinya; Suzuki, Akifumi; Kataoka, Hiroharu; Nakamura, Fumiaki; Kamitani, Satoru; Nishimura, Ataru; Kurogi, Ryota; Sayama, Tetsuro; Iihara, Koji

2016-01-01

Objectives To elucidate the association between antiplatelet use in patients with non-haemorrhagic moyamoya disease before hospital admission and good functional status on admission in Japan. Design Retrospective, multicentre, non-randomised, observational study. Setting Nationwide registry data in Japan. Participants A total of 1925 patients with non-haemorrhagic moyamoya disease admitted between 1 April 2012 and 31 March 2014 in Japan. Main outcome measure We performed propensity score-matched analysis to examine the association between prehospital antiplatelet use and no significant disability on hospital admission, as defined by a modified Rankin Scale score of 0 or 1. Results Propensity-matched patients who received prehospital antiplatelet drugs were associated with a good outcome on hospital admission (OR adjusted for all covariates, 3.82; 95% CI 1.22 to 11.99) compared with those who did not receive antiplatelet drugs prior to hospital admission. Conclusions Prehospital antiplatelet use was significantly associated with good functional status on hospital admission among patients with non-haemorrhagic moyamoya disease in Japan. Our results suggest that prehospital antiplatelet use should be considered when evaluating outcomes of patients with non-haemorrhagic moyamoya disease. PMID:27008684

Epidemiology and Management of Patients With Acute Coronary Syndromes in Contemporary Real-World Practice: Evolving Trends From the EYESHOT Study to the START-ANTIPLATELET Registry.

Science.gov (United States)

Calabrò, Paolo; Gragnano, Felice; di Maio, Marco; Patti, Giuseppe; Antonucci, Emilia; Cirillo, Plinio; Gresele, Paolo; Palareti, Gualtiero; Pengo, Vittorio; Pignatelli, Pasquale; Pennacchi, Mauro; Granatelli, Antonino; De Servi, Stefano; De Luca, Leonardo; Marcucci, Rossella

2018-01-01

The epidemiology and management of patients with acute coronary syndromes (ACSs) have evolved. We aimed to describe recent demographics and therapeutic changes in the Italian ACS population. We analyzed data from 2 multicenter consecutive Italian registries (the EYESHOT [EmploYEd antithrombotic therapies in patients with acute coronary Syndromes HOspitalised in iTalian cardiac care units] and START-ANTIPLATELET registries) enrolling patients with ACS between December 2013 and June 2016. An overall population of 3756 patients with ACS was enrolled: 2585 in the EYESHOT and 1171 in the START-ANTIPLATELET. Compared with the EYESHOT, patients in the START-ANTIPLATELET registry presented more frequently with ST-segment elevation myocardial infarction and were more often smokers and dyslipidemic (all P START-ANTIPLATELET (all P START-ANTIPLATELET compared with the EYESHOT. The START-ANTIPLATELET and EYESHOT registries provide consecutive snapshots in the contemporary management of patients with ACS in Italy, showing important changes in both demographic characteristics and treatment strategies.

Prior antiplatelet therapy and outcome following intracerebral hemorrhage: a systematic review

DEFF Research Database (Denmark)

Thompson, B B; Béjot, Y; Caso, V

2010-01-01

Antiplatelet therapy (APT) promotes bleeding; therefore, APT might worsen outcome in patients with intracerebral hemorrhage (ICH). We performed a systematic review and meta-analysis to address the hypothesis that pre-ICH APT use is associated with mortality and poor functional outcome following ICH....

Ristocetin induces phosphorylated-HSP27 (HSPB1) release from the platelets of type 2 DM patients: Anti-platelet agent-effect on the release.

Science.gov (United States)

Tokuda, Haruhiko; Kuroyanagi, Gen; Onuma, Takashi; Enomoto, Yukiko; Doi, Tomoaki; Iida, Hiroki; Otsuka, Takanobu; Ogura, Shinji; Iwama, Toru; Kojima, Kumi; Kozawa, Osamu

2018-04-01

It has been previously reported that HSP27 is released from platelets in type 2 diabetes mellitus (DM) patients according to phosphorylation. In the present study, we investigated the effect of ristocetin, a glycoprotein (GP)Ib/IX/V activator, on the release of HSP27 and the effect of anti-platelet agents, such as acetylsalicylic acid (ASA), on this release. Forty-six patients with type 2 DM were recruited, and classified into two groups depending on administration of anti-platelet agents, resulting in 31 patients without these agents (control group) and 15 patients with them (anti-platelet group). Ristocetin potently induced the aggregation of platelets in the two groups. Ristocetin-induced changes of the area under the curve of light transmittance and the ratio of the size of platelet aggregates in the anti-platelet group were slightly different from those in the control group. On the other hand, the levels of phosphorylated-HSP27 induced by ristocetin in the platelets from a patient of the anti-platelet group taking ASA were significantly lower than those from a patient of the control group. The levels of HSP27 release from the ristocetin-stimulated platelets were significantly correlated with the levels of phosphorylated-HSP27 in the platelets from patients in the two groups. The levels of HSP27 release and those of platelet-derived growth factor-AB (PDGF-AB) secretion stimulated by ristocetin in the anti-platelet group were lower than those in the control group. In addition, the levels of HSP27 release and those of PDGF-AB secretion stimulated by ADP in the anti-platelet group were lower than those in the control group. These results strongly suggest that anti-platelet agents inhibit the HSP27 release from platelets stimulated by ristocetin but not the aggregation in type 2 DM patients.

Prehospital antiplatelet use and functional status on admission of patients with non-haemorrhagic moyamoya disease: a nationwide retrospective cohort study (J-ASPECT study).

Science.gov (United States)

Onozuka, Daisuke; Hagihara, Akihito; Nishimura, Kunihiro; Kada, Akiko; Nakagawara, Jyoji; Ogasawara, Kuniaki; Ono, Junichi; Shiokawa, Yoshiaki; Aruga, Toru; Miyachi, Shigeru; Nagata, Izumi; Toyoda, Kazunori; Matsuda, Shinya; Suzuki, Akifumi; Kataoka, Hiroharu; Nakamura, Fumiaki; Kamitani, Satoru; Nishimura, Ataru; Kurogi, Ryota; Sayama, Tetsuro; Iihara, Koji

2016-03-15

To elucidate the association between antiplatelet use in patients with non-haemorrhagic moyamoya disease before hospital admission and good functional status on admission in Japan. Retrospective, multicentre, non-randomised, observational study. Nationwide registry data in Japan. A total of 1925 patients with non-haemorrhagic moyamoya disease admitted between 1 April 2012 and 31 March 2014 in Japan. We performed propensity score-matched analysis to examine the association between prehospital antiplatelet use and no significant disability on hospital admission, as defined by a modified Rankin Scale score of 0 or 1. Propensity-matched patients who received prehospital antiplatelet drugs were associated with a good outcome on hospital admission (OR adjusted for all covariates, 3.82; 95% CI 1.22 to 11.99) compared with those who did not receive antiplatelet drugs prior to hospital admission. Prehospital antiplatelet use was significantly associated with good functional status on hospital admission among patients with non-haemorrhagic moyamoya disease in Japan. Our results suggest that prehospital antiplatelet use should be considered when evaluating outcomes of patients with non-haemorrhagic moyamoya disease. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Microfluidic thrombosis under multiple shear rates and antiplatelet therapy doses.

Directory of Open Access Journals (Sweden)

Melissa Li

Full Text Available The mainstay of treatment for thrombosis, the formation of occlusive platelet aggregates that often lead to heart attack and stroke, is antiplatelet therapy. Antiplatelet therapy dosing and resistance are poorly understood, leading to potential incorrect and ineffective dosing. Shear rate is also suspected to play a major role in thrombosis, but instrumentation to measure its influence has been limited by flow conditions, agonist use, and non-systematic and/or non-quantitative studies. In this work we measured occlusion times and thrombus detachment for a range of initial shear rates (500, 1500, 4000, and 10000 s(-1 and therapy concentrations (0-2.4 µM for eptifibatide, 0-2 mM for acetyl-salicylic acid (ASA, 3.5-40 Units/L for heparin using a microfluidic device. We also measured complete blood counts (CBC and platelet activity using whole blood impedance aggregometry. Effects of shear rate and dose were analyzed using general linear models, logistic regressions, and Cox proportional hazards models. Shear rates have significant effects on thrombosis/dose-response curves for all tested therapies. ASA has little effect on high shear occlusion times, even at very high doses (up to 20 times the recommended dose. Under ASA therapy, thrombi formed at high shear rates were 4 times more prone to detachment compared to those formed under control conditions. Eptifibatide reduced occlusion when controlling for shear rate and its efficacy increased with dose concentration. In contrast, the hazard of occlusion from ASA was several orders of magnitude higher than that of eptifibatide. Our results show similar dose efficacy to our low shear measurements using whole blood aggregometry. This quantitative and statistically validated study of the effects of a wide range of shear rate and antiplatelet therapy doses on occlusive thrombosis contributes to more accurate understanding of thrombosis and to models for optimizing patient treatment.

24-hour antiplatelet effect of aspirin in patients with previous definite stent thrombosis

DEFF Research Database (Denmark)

Würtz, Morten; Hvas, Anne-Mette; Jensen, Lisette O

2014-01-01

OBJECTIVE: Once-daily aspirin is standard treatment, but recent studies point towards increased platelet function at the end of the dosing interval. Stent thrombosis (ST) has been linked with reduced antiplatelet effect of aspirin, so we investigated if platelet inhibition by aspirin declines...... with 100 patients with stable coronary artery disease and 50 healthy volunteers. All participants were on aspirin 75 mg/day mono antiplatelet therapy. Platelet aggregation was measured 1 and 24 h after aspirin intake using platelet aggregometry (Multiplate® Analyzer). Cyclooxygenase-1 activity, platelet...... activation, immature platelets, and thrombopoietin were measured. RESULTS: Platelet aggregation increased by 109±150 (arachidonic acid) and 47±155 (collagen) aggregation units per minute from 1 to 24 h after aspirin intake (p-values

Selective and rapid monitoring of dual platelet inhibition by aspirin and P2Y12 antagonists by using multiple electrode aggregometry

Directory of Open Access Journals (Sweden)

Lorenz Reinhard

2010-05-01

Full Text Available Abstract Background Poor platelet inhibition by aspirin or clopidogrel has been associated with adverse outcomes in patients with cardiovascular diseases. A reliable and facile assay to measure platelet inhibition after treatment with aspirin and a P2Y12 antagonist is lacking. Multiple electrode aggregometry (MEA, which is being increasingly used in clinical studies, is sensitive to platelet inhibition by aspirin and clopidogrel, but a critical evaluation of MEA monitoring of dual anti-platelet therapy with aspirin and P2Y12 antagonists is missing. Design and Methods By performing in vitro and ex vivo experiments, we evaluated in healthy subjects the feasibility of using MEA to monitor platelet inhibition of P2Y12 antagonists (clopidogrel in vivo, cangrelor in vitro and aspirin (100 mg per day in vivo, and 1 mM or 5.4 mM in vitro alone, and in combination. Statistical analyses were performed by the Mann-Whitney rank sum test, student' t-test, analysis of variance followed by the Holm-Sidak test, where appropriate. Results ADP-induced platelet aggregation in hirudin-anticoagulated blood was inhibited by 99.3 ± 1.4% by in vitro addition of cangrelor (100 nM; p 95% and 100 ± 3.2%, respectively (p in vitro or ex vivo. Oral intake of clopidogrel did not significantly reduce AA-induced aggregation, but P2Y12 blockade by cangrelor (100 nM in vitro diminished AA-stimulated aggregation by 53 ± 26% (p Conclusions Selective platelet inhibition by aspirin and P2Y12 antagonists alone and in combination can be rapidly measured by MEA. We suggest that dual anti-platelet therapy with these two types of anti-platelet drugs can be optimized individually by measuring platelet responsiveness to ADP and AA with MEA before and after drug intake.

Dual QCD: A review

International Nuclear Information System (INIS)

Baker, M.; Ball, J.S.; Zachariasen, F.

1991-01-01

We review the attempts to use dual (electric) vector potentials rather than the standard magnetic vector potentials to describe QCD, particularly in the infrared regime. The use of dual potentials is motivated by the fact that in classical electrodynamics, in a medium with a dielectric constant vanishing at small momenta (as is believed to be the case in QCD), electric potentials provide a far more convenient language than do magnetic potentials. To begin with, we outline attempts to construct the QCD Lagrangian in terms of dual potentials and describe the various possibilities, their shortcomings and advantages, which so far exist. We then proceed to use the most attractive (albeit consistent as a field theory only at the tree level) of these Lagrangians in a number of applications. We show that it describes a non-Abelian dual superconductor (so that it automatically confines color), derive the static quark-antiquark potential, and various temperature dependent effects, such as deconfinement and chiral symmetry breaking. (orig.)

Baseline characteristics of the 3096 patients recruited into the 'Triple Antiplatelets for Reducing Dependency after Ischemic Stroke' trial.

Science.gov (United States)

Bath, Philip Mw; Appleton, Jason P; Beridze, Maia; Christensen, Hanne; Dineen, Robert A; Duley, Lelia; England, Timothy J; Heptinstall, Stan; James, Marilyn; Krishnan, Kailash; Markus, Hugh S; Pocock, Stuart; Ranta, Annemarei; Robinson, Thompson G; Flaherty, Katie; Scutt, Polly; Venables, Graham S; Woodhouse, Lisa J; Sprigg, Nikola

2017-07-01

Background The risk of recurrence following ischemic stroke or transient ischemic attack is highest immediately after the event. Antiplatelet agents are effective in reducing the risk of recurrence and two agents are superior to one in the early phase after ictus. Design The triple antiplatelets for reducing dependency after ischemic stroke trial was an international multicenter prospective randomized open-label blinded-endpoint trial that assessed the safety and efficacy of short-term intensive antiplatelet therapy with three agents (combined aspirin, clopidogrel and dipyridamole) as compared with guideline treatment in acute ischemic stroke or transient ischemic attack. The primary outcome was stroke recurrence and its severity, measured using the modified Rankin Scale at 90 days. Secondary outcomes included recurrent vascular events, functional measures (cognition, disability, mood, quality of life), and safety (bleeding, death, serious adverse events). Data are number (%) or mean (standard deviation, SD). Results Recruitment ran from April 2009 to March 2016; 3096 patients were recruited from 106 sites in four countries (Denmark 1.6%, Georgia 2.7%, New Zealand 0.2%, UK 95.4%). Randomization characteristics included: age 69.0 (10.1) years; male 1945 (62.8%); time onset to randomization 29.4 (11.9) h; stroke severity (National Institutes for Health Stroke Scale) 2.8 (3.6); blood pressure 143.5 (18.2)/79.5 (11.4) mmHg; IS 2143 (69.2%), transient ischemic attack 953 (30.8%). Conclusion Triple antiplatelets for reducing dependency after ischemic stroke was a large trial of intensive/triple antiplatelet therapy in acute ischemic stroke and transient ischemic attack, and included participants from four predominantly Caucasian countries who were representative of patients in many western stroke services.

Point-of-care genetic testing for personalisation of antiplatelet treatment (RAPID GENE): a prospective, randomised, proof-of-concept trial.

Science.gov (United States)

Roberts, Jason D; Wells, George A; Le May, Michel R; Labinaz, Marino; Glover, Chris; Froeschl, Michael; Dick, Alexander; Marquis, Jean-Francois; O'Brien, Edward; Goncalves, Sandro; Druce, Irena; Stewart, Alexandre; Gollob, Michael H; So, Derek Y F

2012-05-05

Prospective assessment of pharmacogenetic strategies has been limited by an inability to undertake bedside genetic testing. The CYP2C19*2 allele is a common genetic variant associated with increased rates of major adverse events in individuals given clopidogrel after percutaneous coronary intervention (PCI). We used a novel point-of-care genetic test to identify carriers of the CYP2C19*2 allele and aimed to assess a pharmacogenetic approach to dual antiplatelet treatment after PCI. Between Aug 26, 2010, and July 7, 2011, 200 patients were enrolled into our prospective, randomised, proof-of-concept study. Patients undergoing PCI for acute coronary syndrome or stable angina were randomly assigned to rapid point-of-care genotyping or to standard treatment. Individuals in the rapid genotyping group were screened for the CYP2C19*2 allele. Carriers were given 10 mg prasugrel daily, and non-carriers and patients in the standard treatment group were given 75 mg clopidogrel daily. The primary endpoint was the proportion of CYP2C19*2 carriers with high on-treatment platelet reactivity (P2Y12 reactivity unit [PRU] value of more than 234) after 1 week of dual antiplatelet treatment, which is a marker associated with increased adverse cardiovascular events. Interventional cardiologists and data analysts were masked to genetic status and treatment. Patients were not masked to treatment allocation. All analyses were by intention to treat. This study is registered with ClinicalTrials.gov, NCT01184300. After randomisation, 187 patients completed follow-up (91 rapid genotyping group, 96 standard treatment). 23 individuals in each group carried at least one CYP2C19*2 allele. None of the 23 carriers in the rapid genotyping group had a PRU value of more than 234 at day 7, compared with seven (30%) given standard treatment (p=0·0092). The point-of-care genetic test had a sensitivity of 100% (95% CI 92·3-100) and a specificity of 99·3% (96·3-100). Point-of-care genetic testing after

Implementation of pharmacogenetics: the University of Maryland Personalized Anti-platelet Pharmacogenetics Program.

Science.gov (United States)

Shuldiner, Alan R; Palmer, Kathleen; Pakyz, Ruth E; Alestock, Tameka D; Maloney, Kristin A; O'Neill, Courtney; Bhatty, Shaun; Schub, Jamie; Overby, Casey Lynnette; Horenstein, Richard B; Pollin, Toni I; Kelemen, Mark D; Beitelshees, Amber L; Robinson, Shawn W; Blitzer, Miriam G; McArdle, Patrick F; Brown, Lawrence; Jeng, Linda Jo Bone; Zhao, Richard Y; Ambulos, Nicholas; Vesely, Mark R

2014-03-01

Despite a substantial evidence base, implementation of pharmacogenetics into routine patient care has been slow due to a number of non-trivial practical barriers. We implemented a Personalized Anti-platelet Pharmacogenetics Program (PAP3) for cardiac catheterization patients at the University of Maryland Medical Center and the Baltimore Veterans Administration Medical Center Patients' are offered CYP2C19 genetic testing, which is performed in our Clinical Laboratory Improvement Amendment (CLIA)-certified Translational Genomics Laboratory. Results are returned within 5 hr along with clinical decision support that includes interpretation of results and prescribing recommendations for anti-platelet therapy based on the Clinical Pharmacogenetics Implementation Consortium guidelines. Now with a working template for PAP3, implementation of other drug-gene pairs is in process. Lessons learned as described in this article may prove useful to other medical centers as they implement pharmacogenetics into patient care, a critical step in the pathway to personalized and genomic medicine. © 2014 Wiley Periodicals, Inc.

Corporate hedging under a resource rent tax regime

International Nuclear Information System (INIS)

Frestad, Dennis

2010-01-01

In addition to the ordinary corporate income tax, special purpose taxes are sometimes levied to extract abnormal profits arising from the use of natural resources. Such dual tax regimes exist in Norway for oil and hydropower, where the corresponding special purpose tax bases are unaffected by any derivatives payments. Dual tax firms with hedging programs therefore face the risk of potentially large discrepancies between the tax bases for corporate income tax and special purpose tax. I investigate how this tax base asymmetry influences the extent of hedging of value-maximizing firms facing hedgeable as well as unhedgeable risk. Dual tax firms facing deadweight costs in low-profit events generally demand less hedging than ordinary firms, but otherwise respond similarly to characteristics of the underlying risk exposures. The special purpose tax does not influence firms' hedge portfolios in the absence of deadweight cost. (author)

Corporate hedging under a resource rent tax regime

Energy Technology Data Exchange (ETDEWEB)

Frestad, Dennis [Department of Economics and Business Administration, University of Agder, Serviceboks 422, 4604 Kristiansand (Norway)

2010-03-15

In addition to the ordinary corporate income tax, special purpose taxes are sometimes levied to extract abnormal profits arising from the use of natural resources. Such dual tax regimes exist in Norway for oil and hydropower, where the corresponding special purpose tax bases are unaffected by any derivatives payments. Dual tax firms with hedging programs therefore face the risk of potentially large discrepancies between the tax bases for corporate income tax and special purpose tax. I investigate how this tax base asymmetry influences the extent of hedging of value-maximizing firms facing hedgeable as well as unhedgeable risk. Dual tax firms facing deadweight costs in low-profit events generally demand less hedging than ordinary firms, but otherwise respond similarly to characteristics of the underlying risk exposures. The special purpose tax does not influence firms' hedge portfolios in the absence of deadweight cost. (author)

Safety and efficacy of intensive vs. guideline antiplatelet therapy in high-risk patients with recent ischemic stroke or transient ischemic attack

DEFF Research Database (Denmark)

Christensen, Hanne Krarup

2015-01-01

RATIONALE: The risk of recurrence following a stroke or transient ischemic attack is high, especially immediately after the event. HYPOTHESIS: Because two antiplatelet agents are superior to one in patients with non-cardioembolic events, more intensive treatment might be even more effective. SAMPLE...... SIZE ESTIMATES: The sample size of 4100 patients will allow a shift to less recurrence, and less severe recurrence, to be detected (odds ratio 0·68) with 90% power at 5% significance. METHODS AND DESIGN: Triple Antiplatelets for Reducing Dependency after Ischaemic Stroke (ISRCTN47823388) is comparing...... the safety and efficacy of intensive (combined aspirin, clopidogrel, and dipyridamole) vs. guideline antiplatelet therapy, both given for one-month. This international collaborative parallel-group prospective randomized open-label blinded-end-point phase III trial plans to recruit 4100 patients with acute...

Dual comb generation from a mode-locked fiber laser with orthogonally polarized interlaced pulses.

Science.gov (United States)

Akosman, Ahmet E; Sander, Michelle Y

2017-08-07

Ultra-high precision dual-comb spectroscopy traditionally requires two mode-locked, fully stabilized lasers with complex feedback electronics. We present a novel mode-locked operation regime in a thulium-holmium co-doped fiber laser, a frequency-halved state with orthogonally polarized interlaced pulses, for dual comb generation from a single source. In a linear fiber laser cavity, an ultrafast pulse train composed of co-generated, equal intensity and orthogonally polarized consecutive pulses at half of the fundamental repetition rate is demonstrated based on vector solitons. Upon optical interference of the orthogonally polarized pulse trains, two stable microwave RF beat combs are formed, effectively down-converting the optical properties into the microwave regime. These co-generated, dual polarization interlaced pulse trains, from one all-fiber laser configuration with common mode suppression, thus provide an attractive compact source for dual-comb spectroscopy, optical metrology and polarization entanglement measurements.

In-hospital mortality after pre-treatment with antiplatelet agents or oral anticoagulants and hematoma evacuation of intracerebral hematomas.

Science.gov (United States)

Stein, Marco; Misselwitz, Björn; Hamann, Gerhard F; Kolodziej, Malgorzata; Reinges, Marcus H T; Uhl, Eberhard

2016-04-01

Pre-treatment with antiplatelet agents is described to be a risk factor for mortality after spontaneous intracerebral hemorrhage (ICH). However, the impact of antithrombotic agents on mortality in patients who undergo hematoma evacuation compared to conservatively treated patients with ICH remains controversial. This analysis is based on a prospective registry for quality assurance in stroke care in the State of Hesse, Germany. Patients' data were collected between January 2008 and December 2012. Only patients with the diagnosis of spontaneous ICH were included (International Classification of Diseases 10th Revision codes I61.0-I61.9). Predictors of in-hospital mortality were determined by univariate analysis. Predictors with Phematoma evacuation (odds ratio [OR]: 2.5; 95% confidence interval [CI]: 1.24-4.97; P=0.010) compared to patients without antiplatelet pre-treatment treatment (OR: 0.9; 95% CI: 0.79-1.09; P=0.376). In conclusion a higher rate of in-hospital mortality after pre-treatment with antiplatelet agents in combination with hematoma evacuation after spontaneous ICH was observed in the presented cohort. Copyright © 2015 Elsevier Ltd. All rights reserved.

Effect of B-vitamins on stroke risk among individuals with vascular disease who are not on antiplatelets: A meta-analysis.

Science.gov (United States)

Park, Jong-Ho; Saposnik, Gustavo; Ovbiagele, Bruce; Markovic, Daniela; Towfighi, Amytis

2016-02-01

Retrospective analyses of randomized controlled trials suggest that antiplatelet therapy may modify the potential cerebrovascular benefits of lowering homocysteine with B-vitamins among individuals with cardiovascular disease. We evaluated the effects of B-vitamin supplementation on risk of subsequent stroke among high cardiovascular risk individuals who are not taking antiplatelet medications. We systematically searched the Cochrane Central Register of controlled trials, PubMed, the Internet Stroke Center stroke trials, and the clinical trials.gov website from 1966 to April 2015. Inclusion criteria included: randomized controlled trials of homocysteine-lowering therapy with B-vitamins; high cardiovascular risk population and follow-up ≥1 year. We considered stroke as the primary outcome. Among 11 randomized controlled trials meeting inclusion criteria, three studies assessed stroke as an outcome and reported event rates according to whether or not individuals were taking antiplatelets: Vitamin Intervention for Stroke Prevention (VISP), VITAmins TO Prevent Stroke (VITATOPS), and Heart Outcomes Prevention Evaluation 2 (HOPE-2). A total of 4643 high vascular risk subjects not taking antiplatelets were evaluated. The overall effect size across studies was summarized using the fixed effects model after confirming there was no significant heterogeneity. Heterogeneity was assessed using the Cochran's Q and I(2) statistics. Compared with the control group, those taking B-vitamin supplementation had a lower risk of recurrent stroke (HR 0.86, 95% CI 0.62 to 1.19 for VISP; 0.65, 0.46 to 0.91 for VITATOPS; and 0.60, 0.39 to 0.92 for HOPE-2; overall HR 0.71, 0.58 to 0.88). Homocysteine lowering with B-vitamins among high vascular risk patients who are not taking antiplatelet therapy is related to a significant reduction (29%) in overall stroke risk. A clinical trial of B-vitamins in this group may be warranted. © 2016 World Stroke Organization.

Antioxidant and Antiplatelet Activities in Extracts from Green and Fully Ripe Tomato Fruits (Solanum lycopersicum and Pomace from Industrial Tomato Processing

Directory of Open Access Journals (Sweden)

Eduardo Fuentes

2013-01-01

Full Text Available The consumption of fruits and vegetables is accepted to be one of the strategies to reduce risk factors for these diseases. The aim of this study was to examine potential relationships between the antioxidant and the antiplatelet activities in green mature and fully ripe (red tomatoes and of lycopene-rich byproducts of tomato paste processing such as pomace. The total phenol content of tomato components was the highest in peels, pulp, and in the mucilaginous myxotesta covering the tomato seeds with values 36.9±0.8, 33.3±00.5, and 17.6±0.9 mg GAE/100 g, respectively (P<0.05. Tomato peels had the highest antioxidant activity, both, as measured by the FRAP (46.9±0.9 μmol Fe+2/g, P<0.05 and the DPPH assays (97.4±0.2%, 1000 μg/mL, P<0.05. Pomace extracts showed the highest antiplatelet activity induced by ADP, collagen, TRAP-6, and arachidonic acid. While the maturation stage of the tomato fruit affected the antioxidant effect, antiplatelet activity was independent of fruit ripeness. Finally, based on the present results, tomato and its byproducts may be considered as a valuable source of antioxidant and antiplatelet activities.

Short-versus long-term Dual Antiplatelet therapy after drug-eluting stent implantation in women versus men: A sex-specific patient-level pooled-analysis of six randomized trials.

Science.gov (United States)

Sawaya, Fadi J; Morice, Marie-Claude; Spaziano, Marco; Mehran, Roxana; Didier, Romain; Roy, Andrew; Valgimigli, Marco; Kim, Hyo-Soo; Woo Park, Kyung; Hong, Myeong-Ki; Kim, Byeong-Keuk; Jang, Yangsoo; Feres, Fausto; Abizaid, Alexandre; Costa, Ricardo A; Colombo, Antonio; Chieffo, Alaide; Giustino, Gennaro; Stone, Gregg W; Bhatt, Deepak L; Palmerini, Tullio; Gilard, Martine

2017-02-01

Whether the efficacy and safety of dual antiplatelet therapy (DAPT) are uniform between sexes is unclear. We sought to compare clinical outcomes between short- (≤6 months) versus long-term (≥1 year) DAPT after drug-eluting stent (DES) placement in women and men. We pooled individual patient data from 6 randomized trials of DAPT (EXCELLENT, OPTIMIZE, PRODIGY, RESET, SECURITY, ITALIC PLUS). The primary outcome was 1-year risk of major adverse cardiac events (MACE). The main secondary outcome was 1-year risk of any bleeding. Out of the 11,473 randomized patients included in the pooled dataset, 3,454 (30%) were females. At 1-year follow-up, women had higher risk of MACE (3.6% vs. 2.8%; P = 0.01) but similar risk of bleeding (1.9% vs. 1.6%; P = 0.16) as compared with men. Compared with long-term DAPT, short-term DAPT was associated with similar rates of MACE in both women (HR 0.88; 95% CI 0.62-1.25) and men (HR 1.25; 95% CI 0.95-1.6; P interaction = 0.08)]. At 1-year follow-up, short-term DAPT was associated with lower rates of bleeding as compared with long-term DAPT in both women (HR 0.84; 95% CI 0.51-1.37) and men (HR 0.58; 95% CI 0.40-0.84; P-interaction = 0.25). The presence of MVD was associated with higher MACE rates in the short-term DAPT group in women (HR: 1.16; CI 0.60-2.23) and men (HR: 2.29; CI 1.22-4.29; P interaction = 0.25). Short-term DAPT is associated with similar rates of MACE but lower risk of bleeding when as compared with prolonged DAPT. There was no significant difference between sexes in the population studied. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

[Randomised comparative study of early versus delayed surgery in hip-fracture patients on concomitant treatment with antiplatelet drugs. Determination of platelet aggregation, perioperative bleeding and a review of annual mortality].

Science.gov (United States)

Mas-Atance, J; Marzo-Alonso, C; Matute-Crespo, M; Trujillano-Cabello, J J; Català-Tello, N; de Miguel-Artal, M; Forcada-Calvet, P; Fernández-Martínez, J J

2013-01-01

A review of the perioperative management of patients with hip fractures and concomitant therapy with antiplatelet agents, and to analyse the differences in mortality and perioperative bleeding in early surgery (5 days). Platelet aggregation was measured on admission and immediately before surgery in all patients included in the study A total of 175 patients over 65 years old, with low energy hip fracture were randomised into 3 groups: Patients on antiplatelet therapy undergoing early surgery, patients on antiplatelet therapy undergoing delayed surgery, and patients not on antiplatelet therapy undergoing early surgery. The same clinical and laboratory data were collected prospectively up to 12 months for all the patients. The platelet aggregation was determined by a semi-quantitative computerised system based on impedance aggregometry in whole blood. Bleeding, transfusion requirements and analytical results showed no significant differences between groups. More than half (59.8%) of the patients not taking antiplatelet therapy had normal platelet aggregation on admission, while 13.5% of those taking antiplatelet agents did not. Multivariate analysis showed increased mortality at 12 months for the variables, low Barthel index before hip fracture (OR: 0.9-0.9) and number of transfusions (OR: 1.1-1.5). The average lenth of stay was 4.1 days greater in the delayed surgery group. Early surgery for patients receiving antiplatelet therapy has similar clinical outcomes to the delayed, but improves hospital efficiency by reducing the average length of stay. The antiplatelet drug reported by the patient showed low concordance with the determination of the platelet aggregation. Copyright © 2011 SECOT. Published by Elsevier Espana. All rights reserved.

Iliac artery mural thrombus formation. Effect of antiplatelet therapy on 111In-platelet deposition in baboons

International Nuclear Information System (INIS)

Hanson, S.R.; Paxton, L.D.; Harker, L.A.

1986-01-01

To measure the rate, extent, and time course of arterial mural thrombus formation in vivo and to assess the effects of antiplatelet therapy in that setting, we have studied autologous 111 In-platelet deposition induced by experimental iliac artery aneurysms in baboons. Scintillation camera imaging analyses were performed at 1, 24, 48, and 72 hours after implantation of the device. Correction for tissue attenuation was determined by using a small, comparably located 111 In source implanted at the time of surgery. In five animals, 111 In-platelet activity accumulated progressively after device implantation, reaching a maximum after the third day. Repeat image analysis carried out 2 weeks after the surgical procedure also showed progressive accumulation of 111 In-platelets over 3 days but at markedly reduced amounts as compared with the initial study. In five additional animals, treatment with a combination of aspirin and dipyridamole begun 1 hour after surgical implantation reduced 111 In-platelet deposition to negligible levels by the third day. Although platelet survival time was shortened and platelet turnover was reciprocally increased in all operated animals, platelet survival and turnover were not affected by antiplatelet therapy. We conclude that, in contrast to platelet survival and turnover measurements, 111 In-platelet imaging is a reliable and sensitive method for localizing and quantifying focal arterial thrombi and for assessing the effects of antiplatelet therapy

The Effect of Cilostazol on the Angiographic Outcome of Drug-Eluting Coronary Stents Angiographic Analysis of the CILON-T (Influence of CILostazol-Based Triple Antiplatelet Therapy ON Ischemi Complication after Drug-Eluting StenT Implantation) Trial.

Science.gov (United States)

Suh, Jung-Won; Lee, Seung-Pyo; Park, KyungWoo; Kang, Hyun-Jae; Koo, Bon-Kwon; Cho, Young-Seok; Youn, Tae-Jin; Chae, In-Ho; Choi, Dong-Ju; Rha, Seung-Woon; Bae, Jang-Ho; Kwon, Taek-Geun; Bae, Jang-Whan; Cho, Myeong-Chan; Kim, Hyo-Soo

2017-12-12

It is not clear if anti-restonotic effect of cilostazol is consistent for different types of drug-eluting stents (DES).The purpose of this study was to compare the anti-proliferative effect of cilostazol between DAT and TAT with consideration of confounding influences of DES type.Nine hundred and fifteen patients were randomized to either dual antiplatelet therapy (DAT; aspirin and clopidogrel) or triple antiplatelet therapy (TAT; aspirin, clopidogrel, and cilostazol) in the previous CILON-T trial. After excluding 70 patients who received both or neither stents, we analyzed 845 patients who received exclusively PES or ZES, and compared in-stent late loss at 6 months between both antiplatelet regimens (DAT versus TAT).Baseline angiographic and clinical characteristics were similar between the DAT (656 lesions in 425 patients) and the TAT group (600 lesions in 420 patients). The 6-month follow-up angiography was completed in 745 patients (88.2%). Quantitative coronary angiography showed that TAT significantly reduced in-stent late loss (DAT 0.62 ± 0.62 mm versus TAT 0.54 ± 0.49 mm, P = 0.015). Stent type, diabetes or lesion length did not interact with difference of late loss. However, reduction of late loss by cilostazol did not lead to a significant reduction in the rate of target lesion revascularization (TLR) (DAT 7.8% versus TAT 6.9%, P = 0.69) due to a nonlinear relationship found between late loss and TLR.The TAT group showed less in-stent late loss as compared to the DAT group. This was consistently observed regardless of DES type, lesion length, or diabetic status. However, reduction of late loss by cilostazol did not lead to a significant reduction in TLR.

Evaluation of bleeding following dental extraction in patients on long-term antiplatelet therapy: A clinical trial

Directory of Open Access Journals (Sweden)

K George Varghese

2015-01-01

Conclusion: Hence, we recommend routine single tooth extractions in patients on long-term antiplatelet medication, without interruption or alteration of their medication. Such patients do not have an increased risk of prolonged or excessive postoperative bleeding.

Longitudinal assessment of thrombin generation potential in response to alteration of antiplatelet therapy after TIA or ischaemic stroke.

LENUS (Irish Health Repository)

Tobin, W O

2013-02-01

The impact of changing antiplatelet therapy on thrombin generation potential in patients with ischaemic cerebrovascular disease (CVD) is unclear. We assessed patients within 4 weeks of TIA or ischaemic stroke (baseline), and then 14 days (14d) and >90 days (90d) after altering antiplatelet therapy. Thrombin generation was assessed in platelet poor plasma. Ninety-one patients were recruited. Twenty-four were initially assessed on no antiplatelet therapy, and then after 14d (N = 23) and 90d (N = 8) on aspirin monotherapy; 52 were assessed on aspirin monotherapy, and after 14 and 90 days on aspirin and dipyridamole combination therapy; 21 patients were assessed on aspirin and after 14 days (N = 21) and 90 days (N = 19) on clopidogrel. Peak thrombin generation and endogenous thrombin potential were reduced at 14 and 90 days (p ≤ 0.04) in the overall cohort. We assessed the impact of individual antiplatelet regimens on thrombin generation parameters to investigate the cause of this effect. Lag time and time-to-peak thrombin generation were unchanged at 14 days, but reduced 90 days after commencing aspirin (p ≤ 0.009). Lag time, peak thrombin generation and endogenous thrombin potential were reduced at both 14 and 90 days after adding dipyridamole to aspirin (p ≤ 0.01). Lag time was reduced 14 days after changing from aspirin to clopidogrel (p = 0.045), but this effect was not maintained at 90 days (p = 0.2). This pilot study did not show any consistent effects of commencing aspirin, or of changing from aspirin to clopidogrel on thrombin generation potential during follow-up. The addition of dipyridamole to aspirin led to a persistent reduction in peak and total thrombin generation ex vivo, and illustrates the diverse, potentially beneficial, newly recognised \\'anti-coagulant\\' effects of dipyridamole in ischaemic CVD.

Risk of bleeding and stroke with oral anticoagulation and antiplatelet therapy in patients with atrial fibrillation in Taiwan: a nationwide cohort study.

Directory of Open Access Journals (Sweden)

Pei-Chun Chen

Full Text Available Data on the use of oral anticoagulation (OAC and antiplatelet therapy and the risk of bleeding and stroke amongst Asian patients with atrial fibrillation (AF are limited. We investigated the risks of bleeding and stroke with use of oral anticoagulation (OAC and antiplatelet therapy as mono- or combination therapy, in patients with AF from a Chinese nationwide cohort study.We studied a cohort of 10384 patients (57.2% men, age 67.8 ± 13.2 yrs between 1999 and 2010 from the National Health Insurance Research Database in Taiwan. Records of prescriptions were obtained during follow-up. The main outcome was a recurrent stroke during the follow-up period. Time-dependent Cox proportional hazards models were used for this analysis.We documented 1009 events for bleeding, as well as 224 hemorrhagic stroke and 1642 ischemic stroke events during a median 3.2 (interquartile range, 1.05-6.54 years' follow-up. Compared with warfarin users, patients with antiplatelet therapy had a lower risk of bleeding (adjusted relative risk [RR], 0.59, 95% confidence interval [CI], 0.49-0.71, p<0.001 whilst combination therapy had a non-statistically significant higher bleeding risk (RR, 1.33, 95%, 0.91-1.94, p = 0.20. Patients on antiplatelet monotherapy had a similar risk for ischemic stroke compared with OAC (RR 1.05, 95% CI, 0.89-1.25, p = 0.50, whilst those on combination therapy had a significantly higher risk (RR 1.90, 95% CI, 1.34-2.70, p<0.001.In a national representative cohort, antiplatelet therapy had no significant difference in ischemic stroke risk to warfarin. For bleeding, aspirin had a lower risk compared to warfarin. This may reflect poor anticoagulation control, highlighting important missed opportunities for improved stroke prevention, especially in countries where anticoagulation management is suboptimal.

Antiplatelet Agents and the Prevention of Spontaneous Preterm Birth A Systematic Review and Meta-analysis

NARCIS (Netherlands)

van Vliet, Elvira O. G.; Askie, Lisa A.; Mol, Ben W. J.; Oudijk, Martijn A.

2017-01-01

OBJECTIVE: Spontaneous preterm birth is an important cause of neonatal mortality and morbidity. An increasing body of evidence suggests that uteroplacental ischemia plays an important role in the etiology of spontaneous preterm birth. We aimed to study whether antiplatelet agents reduce the risk of

Council regulation of the European dual use regulation. A never ending story?; Die Novellierung der europaeischen Dual-Use Verordnung. Eine unendliche Geschichte?

Energy Technology Data Exchange (ETDEWEB)

Feldmann, Ulrike

2018-01-15

For the first time, the EC Council Regulation of 19 December 1994 established a Community regime for the control of exports of dual-use items. In 2000, the first major revision of the dual-use regime came into force, subjecting not only sensitive material, i.e. plutonium and highly enriched uranium, but also the entire category 0 (nuclear material, installations, equipment) to a licensing requirement for intra-Community shipments. This revision was revised a few months later due to inappropriate content by removing a small proportion of nuclear goods. A further comprehensive new revision was published in 2009. However, the EU Commission's current proposal to revise Annex IV of the regulation does not do justice to the objective of free trade of goods and the maintenance of the competitiveness of European industry from the point of view of the European nuclear industry, as well as from the point of view of the non-nuclear industry in the EU.

Application of radial basis function in densitometry of stratified regime of liquid-gas two phase flows

International Nuclear Information System (INIS)

Roshani, G.H.; Nazemi, E.; Roshani, M.M.

2017-01-01

In this paper, a novel method is proposed for predicting the density of liquid phase in stratified regime of liquid-gas two phase flows by utilizing dual modality densitometry technique and artificial neural network (ANN) model of radial basis function (RBF). The detection system includes a 137 Cs radioactive source and two NaI(Tl) detectors for registering transmitted and scattered photons. At the first step, a Monte Carlo simulation model was utilized to obtain the optimum position for the scattering detector in dual modality densitometry configuration. At the next step, an experimental setup was designed based on obtained optimum position for detectors from simulation in order to generate the required data for training and testing the ANN. The results show that the proposed approach could be successfully applied for predicting the density of liquid phase in stratified regime of gas-liquid two phase flows with mean relative error (MRE) of less than 0.701. - Highlights: • Density of liquid phase in stratified regime of two phase flows was predicted. • Combination of dual modality densitometry technique and ANN was utilized. • Detection system includes a 137 Cs radioactive source and two NaI(Tl) detectors. • MCNP simulation was done to obtain the optimum position for the scattering detector. • An experimental setup was designed to generate the required data for training the ANN.

A Novel Low Loss, Highly Birefringent Photonic Crystal Fiber in THz Regime

DEFF Research Database (Denmark)

Hasanuzzaman, G. K. M.; Rana, Sohel; Habib, Selim

2016-01-01

We present a new kind of dual-hole unit-based porous-core hexagonal photonic crystal fiber (H-PCF) with low loss and high birefringence in terahertz regime. The proposed fiber offers simultaneously high birefringence and low effective material loss (EML) in the frequency range of 0.5-0.85 THz wit...

Antiplatelet therapy and the effects of B vitamins in patients with previous stroke or transient ischaemic attack: a post-hoc subanalysis of VITATOPS, a randomised, placebo-controlled trial.

Science.gov (United States)

Hankey, Graeme J; Eikelboom, John W; Yi, Qilong; Lees, Kennedy R; Chen, Christopher; Xavier, Denis; Navarro, Jose C; Ranawaka, Udaya K; Uddin, Wasim; Ricci, Stefano; Gommans, John; Schmidt, Reinhold

2012-06-01

Previous studies have suggested that any benefits of folic acid-based therapy to lower serum homocysteine in prevention of cardiovascular events might be offset by concomitant use of antiplatelet therapy. We aimed to establish whether there is an interaction between antiplatelet therapy and the effects of folic acid-based homocysteine-lowering therapy on major vascular events in patients with stroke or transient ischaemic attack enrolled in the vitamins to prevent stroke (VITATOPS) trial. In the VITATOPS trial, 8164 patients with recent stroke or transient ischaemic attack were randomly allocated to double-blind treatment with one tablet daily of placebo or B vitamins (2 mg folic acid, 25 mg vitamin B(6), and 500 μg vitamin B(12)) and followed up for a median 3·4 years (IQR 2·0-5·5) for the primary composite outcome of stroke, myocardial infarction, or death from vascular causes. In our post-hoc analysis of the interaction between antiplatelet therapy and the effects of treatment with B vitamins on the primary outcome, we used Cox proportional hazards regression before and after adjusting for imbalances in baseline prognostic factors in participants who were and were not taking antiplatelet drugs at baseline and in participants assigned to receive B vitamins or placebo. We also assessed the interaction in different subgroups of patients and different secondary outcomes. The VITATOPS trial is registered with ClinicalTrials.gov, number NCT00097669, and Current Controlled Trials, number ISRCTN74743444. At baseline, 6609 patients were taking antiplatelet therapy and 1463 were not. Patients not receiving antiplatelet therapy were more likely to be younger, east Asian, and disabled, to have a haemorrhagic stroke or cardioembolic ischaemic stroke, and to have a history of hypertension or atrial fibrillation. They were less likely to be smokers and to have a history of peripheral artery disease, hypercholesterolaemia, diabetes, ischaemic heart disease, and a

Prospective evaluation of dermatologic surgery complications including patients on multiple antiplatelet and anticoagulant medications.

Science.gov (United States)

Bordeaux, Jeremy S; Martires, Kathryn J; Goldberg, Dori; Pattee, Sean F; Fu, Pingfu; Maloney, Mary E

2011-09-01

Few prospective studies have evaluated the safety of dermatologic surgery. We sought to determine rates of bleeding, infection, flap and graft necrosis, and dehiscence in outpatient dermatologic surgery, and to examine their relationship to type of repair, anatomic location of repair, antibiotic use, antiplatelet use, or anticoagulant use. Patients presenting to University of Massachusetts Medical School Dermatology Clinic for surgery during a 15-month period were prospectively entered. Medications, procedures, and complications were recorded. Of the 1911 patients, 38% were on one anticoagulant or antiplatelet medication, and 8.0% were on two or more. Risk of hemorrhage was 0.89%. Complex repair (odds ratio [OR] = 5.80), graft repair (OR = 7.58), flap repair (OR = 11.93), and partial repair (OR = 43.13) were more likely to result in bleeding than intermediate repair. Patients on both clopidogrel and warfarin were 40 times more likely to have bleeding complications than all others (P = .03). Risk of infection was 1.3%, but was greater than 3% on the genitalia, scalp, back, and leg. Partial flap necrosis occurred in 1.7% of flaps, and partial graft necrosis occurred in 8.6% of grafts. Partial graft necrosis occurred in 20% of grafts on the scalp and 10% of grafts on the nose. All complications resolved without sequelae. The study was limited to one academic dermatology practice. The rate of complications in dermatologic surgery is low, even when multiple oral anticoagulant and antiplatelet medications are continued, and prophylactic antibiotics are not used. Closure type and use of warfarin or clopidogrel increase bleeding risk. However, these medications should be continued to avoid adverse thrombotic events. Copyright © 2011 American Academy of Dermatology, Inc. Published by Mosby, Inc. All rights reserved.

Dual Antithrombotic Therapy with Dabigatran after PCI in Atrial Fibrillation.

Science.gov (United States)

Cannon, Christopher P; Bhatt, Deepak L; Oldgren, Jonas; Lip, Gregory Y H; Ellis, Stephen G; Kimura, Takeshi; Maeng, Michael; Merkely, Bela; Zeymer, Uwe; Gropper, Savion; Nordaby, Matias; Kleine, Eva; Harper, Ruth; Manassie, Jenny; Januzzi, James L; Ten Berg, Jurrien M; Steg, P Gabriel; Hohnloser, Stefan H

2017-10-19

Triple antithrombotic therapy with warfarin plus two antiplatelet agents is the standard of care after percutaneous coronary intervention (PCI) for patients with atrial fibrillation, but this therapy is associated with a high risk of bleeding. In this multicenter trial, we randomly assigned 2725 patients with atrial fibrillation who had undergone PCI to triple therapy with warfarin plus a P2Y 12 inhibitor (clopidogrel or ticagrelor) and aspirin (for 1 to 3 months) (triple-therapy group) or dual therapy with dabigatran (110 mg or 150 mg twice daily) plus a P2Y 12 inhibitor (clopidogrel or ticagrelor) and no aspirin (110-mg and 150-mg dual-therapy groups). Outside the United States, elderly patients (≥80 years of age; ≥70 years of age in Japan) were randomly assigned to the 110-mg dual-therapy group or the triple-therapy group. The primary end point was a major or clinically relevant nonmajor bleeding event during follow-up (mean follow-up, 14 months). The trial also tested for the noninferiority of dual therapy with dabigatran (both doses combined) to triple therapy with warfarin with respect to the incidence of a composite efficacy end point of thromboembolic events (myocardial infarction, stroke, or systemic embolism), death, or unplanned revascularization. The incidence of the primary end point was 15.4% in the 110-mg dual-therapy group as compared with 26.9% in the triple-therapy group (hazard ratio, 0.52; 95% confidence interval [CI], 0.42 to 0.63; Pdual-therapy group as compared with 25.7% in the corresponding triple-therapy group, which did not include elderly patients outside the United States (hazard ratio, 0.72; 95% CI, 0.58 to 0.88; Pdual-therapy groups combined as compared with 13.4% in the triple-therapy group (hazard ratio, 1.04; 95% CI, 0.84 to 1.29; P=0.005 for noninferiority). The rate of serious adverse events did not differ significantly among the groups. Among patients with atrial fibrillation who had undergone PCI, the risk of bleeding was

Antiplatelet activity of white and pink Nelumbo nucifera Gaertn flowers

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Brindha Durairaj

2010-09-01

Full Text Available Nelumbo nucifera Gaertn (Nelumbonaceae a plant used in Ayurvedic medicine (common name: lotus, is a perennial, large and rhizomatous aquatic herb most prevalent in South India. Preliminary phytochemical screening of both white and pink Nelumbo nucifera flowers revealed the presence of phytochemical constituents (flavonoids, alkaloids, phenols etc,. Hence, an attempt has been made to screen the effect of Nelumbo nucifera flowers (both types on platelet aggregation. The antiplatelet activity of hydroethanolic extract of both types of flowers was studied using platelet-rich plasma in different concentrations (100-500µg/ml. Both white and pink Nelumbo nucifera flower extracts showed dose-dependent effective antiplatelet activity with maximum activity at 500µg/ml concentration; prevention of platelet aggregation was 50% of that achieved with standard aspirin. Furthermore, the antiplatelet activity of white flowers was relatively high (pNelumbo nucifera Gaertn (Nelumbonaceae, planta utilizada na medicina Ayurvédica, é erva aquática rizomatosa grande, predominante no sul da Índia. A triagem fitoquímica preliminar das flores brancas e cor-de-rosa de Nelumbo nucifera revelou a presença de constituintes fitoquímicos (flavonoides, alcaloides, fenóis etc. Assim, tentou-se a triagem do efeito das flores de Nelumbo nucifera de ambos os tipos na agregação plaquetária. A atividade antiplaquetária dos extratos hidroetanólico de ambos os tipos de flores foi estudada, utilizando-se plasma rico em plaquetas em duas diferentes concentrações (100 - 500 µg/mL. Tanto os extratos das flores brancas quanto daquelas de cor-de-rosa mostraram atividade antiplaquetária dose-dependente, com o máximo na concentração de 500 µg/mL. A prevenção da agregação plaquetária foi 50% daquela alcançada com o padrão de ácido acetilsalicílico. Além disso, a atividade antiplaquetária das flores brancas foi, relativamente, alta (p<0,05; ANOVA

Comparison of antiplatelet regimens in secondary stroke prevention

DEFF Research Database (Denmark)

Christiansen, Christine Benn; Pallisgaard, Jannik; Gerds, Thomas Alexander

2015-01-01

BACKGROUND: In patients with ischemic stroke of non-cardioembolic origin, acetylsalicylic acid, clopidogrel, or a combination of acetylsalicylic acid and dipyridamole are recommended for the prevention of a recurrent stroke. The purpose of this study was to examine the risk of bleeding or recurrent...... stroke associated with these three treatments. METHODS: Patients who were discharged with first-time ischemic stroke from 2007-2010, with no history of atrial fibrillation were identified from Danish nationwide registries. Hazard ratios (HRs) and 1-year risks of recurrent ischemic stroke and bleeding...... were calculated for each antiplatelet regimen. RESULTS: Among patients discharged after first-time ischemic stroke, 3043 patients were treated with acetylsalicylic acid, 12,295 with a combination of acetylsalicylic acid and dipyridamole, and 3885 with clopidogrel. Adjusted HRs for clopidogrel versus...

Isolation and chemical identification of lipid derivatives from avocado (Persea americana) pulp with antiplatelet and antithrombotic activities.

Science.gov (United States)

Rodriguez-Sanchez, Dariana Graciela; Flores-García, Mirthala; Silva-Platas, Christian; Rizzo, Sheryl; Torre-Amione, Guillermo; De la Peña-Diaz, Aurora; Hernández-Brenes, Carmen; García-Rivas, Gerardo

2015-01-01

Platelets play a pivotal role in physiological hemostasis. However, in coronary arteries damaged by atherosclerosis, enhanced platelet aggregation, with subsequent thrombus formation, is a precipitating factor in acute ischemic events. Avocado pulp (Persea americana) is a good source of bioactive compounds, and its inclusion in the diet as a source of fatty acid has been related to reduced platelet aggregability. Nevertheless, constituents of avocado pulp with antiplatelet activity remain unknown. The present study aims to characterize the chemical nature of avocado constituents with inhibitory effects on platelet aggregation. Centrifugal partition chromatography (CPC) was used as a fractionation and purification tool, guided by an in vitro adenosine diphosphate (ADP), arachidonic acid or collagen-platelet aggregation assay. Antiplatelet activity was initially linked to seven acetogenins that were further purified, and their dose-dependent effects in the presence of various agonists were contrasted. This process led to the identification of Persenone-C (3) as the most potent antiplatelet acetogenin (IC₅₀=3.4 mM) among the evaluated compounds. In vivo evaluations with Persenone A (4) demonstrated potential protective effects against arterial thrombosis (25 mg kg⁻¹ of body weight), as coagulation times increased (2-fold with respect to the vehicle) and thrombus formation was attenuated (71% versus vehicle). From these results, avocado may be referred to as a functional food containing acetogenin compounds that inhibit platelet aggregation with a potential preventive effect on thrombus formation, such as those that occur in ischaemic diseases.

The effect of pre-injury anti-platelet therapy on the development of complications in isolated blunt chest wall trauma: a retrospective study.

Directory of Open Access Journals (Sweden)

Ceri Battle

Full Text Available INTRODUCTION: The difficulties in the management of the blunt chest wall trauma patient in the Emergency Department due to the development of late complications are well recognised in the literature. Pre-injury anti-platelet therapy has been previously investigated as a risk factor for poor outcomes following traumatic head injury, but not in the blunt chest wall trauma patient cohort. The aim of this study was to investigate pre-injury anti-platelet therapy as a risk factor for the development of complications in the recovery phase following blunt chest wall trauma. METHODS: A retrospective study was completed in which the medical notes were analysed of all blunt chest wall trauma patients presenting to a large trauma centre in Wales in 2012 and 2013. Using univariate and multivariable logistic regression analysis, pre-injury platelet therapy was investigated as a risk factor for the development of complications following blunt chest wall trauma. Previously identified risk factors were included in the analysis to address the influence of confounding. RESULTS: A total of 1303 isolated blunt chest wall trauma patients presented to the ED in Morriston Hospital in 2012 and 2013 with complications recorded in 144 patients (11%. On multi-variable analysis, pre-injury anti-platelet therapy was found to be a significant risk factor for the development of complications following isolated blunt chest wall trauma (odds ratio: 16.9; 95% confidence intervals: 8.2-35.2. As in previous studies patient age, number of rib fractures, chronic lung disease and pre-injury anti-coagulant use were also found to be significant risk factors. CONCLUSIONS: Pre-injury anti-platelet therapy is being increasingly used as a first line treatment for a number of conditions and there is a concurrent increase in trauma in the elderly population. Pre-injury anti-platelet therapy should be considered as a risk factor for the development of complications by clinicians managing

Spin-orbit interaction in a dual gated InAs/GaSb quantum well

Science.gov (United States)

Beukman, Arjan J. A.; de Vries, Folkert K.; van Veen, Jasper; Skolasinski, Rafal; Wimmer, Michael; Qu, Fanming; de Vries, David T.; Nguyen, Binh-Minh; Yi, Wei; Kiselev, Andrey A.; Sokolich, Marko; Manfra, Michael J.; Nichele, Fabrizio; Marcus, Charles M.; Kouwenhoven, Leo P.

2017-12-01

The spin-orbit interaction is investigated in a dual gated InAs/GaSb quantum well. Using an electric field, the quantum well can be tuned between a single-carrier regime with exclusively electrons as carriers and a two-carrier regime where electrons and holes coexist. The spin-orbit interaction in both regimes manifests itself as a beating in the Shubnikov-de Haas oscillations. In the single-carrier regime the linear Dresselhaus strength is characterized by β =28.5 meV Å and the Rashba coefficient α is tuned from 75 to 53 meV Å by changing the electric field. In the two-carrier regime a quenching of the spin splitting is observed and attributed to a crossing of spin bands.

The relationship between cerebrovascular complications and previously established use of antiplatelet therapy in left-sided infective endocarditis

DEFF Research Database (Denmark)

Snygg-Martin, Ulrika; Rasmussen, Rasmus Vedby; Hassager, Christian

2011-01-01

Cerebrovascular complications (CVC) in infective endocarditis (IE) are common. The only established treatments to reduce the incidence of CVC in IE are antibiotics and in selected cases early cardiac surgery. Potential effects of previously established antiplatelet therapy are under debate....

In vitro toxicity, antiplatelet and acetylcholinesterase inhibition of Buddleja thyrsoides Lam. leaves.

Science.gov (United States)

Mahlke, Janaína Dorneles; Boligon, Aline Augusti; Machado, Michel Mansur; Athayde, Margareth Linde

2012-01-01

Alzheimer's disease (AD) is a neurodegenerative disorder resulting in impaired memory and behaviour of remarkable socio-economic impact. A decrease in cholinergic activity is a key event in the biochemical of AD. Buddleja thyrsoides is a plant widely distributed in Southern parts of South America. In Brazilian traditional medicine, the infusion of its leaves and flowers is used for the treatment of bronchitis and cough. Crude ethanolic (70%) extract and fractions (dichloromethane, ethyl acetate and n-butanolic) were investigated regarding their toxicities in vitro and antiplatelet action. The enzyme acetylcholinesterase inhibition was evaluated to study the crude extract. The crude extract and fractions were evaluated by means of Brine Shrimp Lethality test and they showed low activities with LC(50) values 1698, 2818, 2187 and 3672 µg mL(-1) for dichloromethane, ethyl acetate, n-butanolic fractions and crude extract, respectively. Buddleja thyrsoides presented great antiplatelet action. The IC(50) values obtained for crude extract and dichloromethane, ethyl acetate and n-butanolic fractions were 361.29, 354.23, 368.75 and 344.30, respectively, while the IC(50) for the standard AAS was 257.01 µg mL(-1). The crude extract showed an inhibition of 22.8% of the acetylcholinesterase enzyme in 24 h.

Synthesis and in Vitro and in Vivo Anticoagulant and Antiplatelet Activities of Amidino- and Non-Amidinobenzamides

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Soo Hyun Lee

2016-05-01

Full Text Available Three amidino- and ten non-amidinobenzamides were synthesized as 3-aminobenzoic acid scaffold-based anticoagulant and antiplatelet compounds. The anticoagulant activities of thirteen synthesized compounds 1–13, and 2b and 3b as prodrugs were preliminary evaluated by screening the prolongation of activated partial thromboplastin time (aPTT and prothrombin time (PT in vitro. From the aPTT results obtained, two amidinobenzamides, N-(3′-amidinophenyl-3-(thiophen-2′′-ylcarbonylamino benzamide (1, 33.2 ± 0.7 s and N-(4′-amidinophenyl-3-(thiophen-2′′-ylcarbonylamino benzamide (2, 43.5 ± 0.6 s were selected to investigate the further anticoagulant and antiplatelet activities. The aPTT results of 1 (33.2 ± 0.7 s and 2 (43.5 ± 0.6 s were compared with heparin (62.5 ± 0.8 s in vitro at 30 μM. We investigated the effect of 1 and 2 on blood anticoagulant activity (ex vivo and on tail bleeding time (in vivo on mice. A tail cutting/bleeding time assay revealed that both 1 and 2 prolonged bleeding time in mice at a dose of 24.1 g/mouse and above. Compounds 1 and 2 dose-dependently inhibited thrombin-catalyzed fibrin polymerization and platelet aggregation. In addition, 1 and 2 were evaluated on the inhibitory activities of thrombin and FXa as well as the generation of thrombin and FXa in human umbilical vein endothelial cells (HUVECs. Collectively, 1 and 2 possess some antiplatelet and anticoagulant activities and offer a basis for development of a novel antithrombotic product.

Pneumatic tube system transport does not alter platelet function in optical and whole blood aggregometry, prothrombin time, activated partial thromboplastin time, platelet count and fibrinogen in patients on anti-platelet drug therapy

Science.gov (United States)

Enko, Dietmar; Mangge, Harald; Münch, Andreas; Niedrist, Tobias; Mahla, Elisabeth; Metzler, Helfried; Prüller, Florian

2017-01-01

Introduction The aim of this study was to assess pneumatic tube system (PTS) alteration on platelet function by the light transmission aggregometry (LTA) and whole blood aggregometry (WBA) method, and on the results of platelet count, prothrombin time (PT), activated partial thromboplastin time (APTT), and fibrinogen. Materials and methods Venous blood was collected into six 4.5 mL VACUETTE® 9NC coagulation sodium citrate 3.8% tubes (Greiner Bio-One International GmbH, Kremsmünster, Austria) from 49 intensive care unit (ICU) patients on dual anti-platelet therapy and immediately hand carried to the central laboratory. Blood samples were divided into 2 Groups: Group 1 samples (N = 49) underwent PTS (4 m/s) transport from the central laboratory to the distant laboratory and back to the central laboratory, whereas Group 2 samples (N = 49) were excluded from PTS forces. In both groups, LTA and WBA stimulated with collagen, adenosine-5’-diphosphate (ADP), arachidonic acid (AA) and thrombin-receptor-activated-peptide 6 (TRAP-6) as well as platelet count, PT, APTT, and fibrinogen were performed. Results No statistically significant differences were observed between blood samples with (Group 1) and without (Group 2) PTS transport (P values from 0.064 – 0.968). The AA-induced LTA (bias: 68.57%) exceeded the bias acceptance limit of ≤ 25%. Conclusions Blood sample transportation with computer controlled PTS in our hospital had no statistically significant effects on platelet aggregation determined in patients with anti-platelet therapy. Although AA induced LTA showed a significant bias, the diagnostic accuracy was not influenced. PMID:28392742

Tympanic membrane bleeding complications during hyperbaric oxygen treatment in patients with or without antiplatelet and anticoagulant drug treatment

NARCIS (Netherlands)

Fijen, Valerie A.; Westerweel, Peter E.; van Ooij, Pieter Jan A. M.; van Hulst, Rob A.

2016-01-01

Middle ear barotrauma (MEBt) is a frequently occurring complication of hyperbaric oxygen treatment (HBOT). High-grade MEBt may involve tympanic membrane (TM) haemorrhaging. Although many patients undergoing HBOT use antiplatelet or anticoagulant drugs, it is unknown whether these drugs increase the

Antiplatelet therapy: aspirin resistance and all that jazz!

Science.gov (United States)

Divani, Afshin A; Zantek, Nicole D; Borhani-Haghighi, Afshin; Rao, Gundu H R

2013-01-01

Platelets play a crucial role in the pathogenesis of atherosclerosis, thrombosis, and stroke. Aspirin used alone or in combination with other antiplatelet drugs has been shown to offer significant benefit to patients at high risk of vascular events. Resistance to the action of aspirin may decrease this benefit. Aspirin resistance has been defined by clinical and/or laboratory criteria; however, detection by laboratory methods prior to experiencing a clinical event will likely provide the greatest opportunity for intervention. Numerous laboratory methods with different cutoff points have been used to evaluate the resistance. Noncompliance with aspirin treatment has also confounded studies. A single assay is currently insufficient to establish resistance. Combinations of results to confirm compliance and platelet inhibition may identify "at-risk" individuals who truly have aspirin resistance. The most effective strategy for managing patients with aspirin resistance is unknown; however, studies are currently underway to address this issue.

Randomized clinical trial

DEFF Research Database (Denmark)

Jensen, Berit E. S.; Hansen, Jane M.; Larsen, Kasper S.

2017-01-01

Objective Dual antiplatelet therapy reduces the risk of ischemic complications after acute coronary syndrome, but increases the risk of bleeding including upper gastrointestinal bleeding (UGIB). The aim of this study was to examine the effect of screening for risk of UGIB and prophylactic proton.......381). Significantly fewer screened patients (5.4%) than controls (8.0%) underwent upper gastrointestinal endoscopy (P=0.026). Screened patients (2.9%) had significantly fewer events of unstable angina pectoris than controls (4.7%) (P=0.036) and a higher compliance to dual antiplatelet therapy (88.3 vs. 85.0%) (P=0...

Contribution of Helicobacter pylori infection to the risk of peptic ulcer bleeding in patients on nonsteroidal anti-inflammatory drugs, antiplatelet agents, anticoagulants, corticosteroids and selective serotonin reuptake inhibitors.

Science.gov (United States)

Venerito, M; Schneider, C; Costanzo, R; Breja, R; Röhl, F-W; Malfertheiner, P

2018-06-01

Nonsteroidal anti-inflammatory drugs, low-dose aspirin, non-aspirin antiplatelet agents, anticoagulants, selective serotonin reuptake inhibitors and corticosteroids increase the risk of gastroduodenal bleeding. To determine in a retrospective cohort study the contribution of Helicobacter pylori infection to the risk of peptic ulcer bleeding in patients taking these drugs. Among patients with peptic ulcer disease diagnosed by endoscopy from 01/2004 to 12/2014 (N = 1719, 60% males, age 65.8 ± 14.5), 56.9% had peptic ulcer bleeding (cases) and 43.1% uncomplicated peptic ulcer disease (controls). Demographics, intake of nonsteroidal anti-inflammatory drugs, aspirin, non-aspirin antiplatelet agents, anticoagulants, selective serotonin reuptake inhibitors, proton pump inhibitors and corticosteroids were documented. H. pylori status was determined by histology, rapid urease test or serology. Adjusted odds ratios (OR) were estimated by logistic regression analysis. Helicobacter pylori infection increased the risk of peptic ulcer bleeding in nonsteroidal anti-inflammatory drug and aspirin users (OR = 2.91, 95% CI = 1.71-4.98 and OR = 2.23, 95% CI = 1.52-3.28, respectively), but not in patients on anticoagulants, selective serotonin reuptake inhibitor or corticosteroid therapy. H. pylori-positive status substantially increased the risk of peptic ulcer bleeding in patients on non-aspirin antiplatelet agents (OR = 4.37, 95% CI = 1.28-14.99), concomitant aspirin/nonsteroidal anti-inflammatory drug intake (OR = 5.85, 95% CI = 1.68-20.36) and combined antiplatelet therapy (OR = 8.43, 95% CI = 1.09-65.17). After further adjustment for proton pump inhibitor intake, H. pylori infection was still a risk factor for peptic ulcer bleeding in nonsteroidal anti-inflammatory drug and aspirin users. Helicobacter pylori infection increases the risk of peptic ulcer bleeding in peptic ulcer disease patients on nonsteroidal anti-inflammatory drugs, aspirin and non

The Emerging Role of miR-223 in Platelet Reactivity: Implications in Antiplatelet Therapy

Science.gov (United States)

Shi, Rui; Zhou, Xin; Ji, Wen-Jie; Zhang, Ying-Ying; Ma, Yong-Qiang; Zhang, Jian-Qi

2015-01-01

Platelets are anuclear cells and are devoid of genomic DNA, but they are capable of de novo protein synthesis from mRNA derived from their progenitor cells, megakaryocytes. There is mounting evidence that microRNA (miRNA) plays an important role in regulating gene expression in platelets. miR-223 is the most abundant miRNAs in megakaryocytes and platelets. One of the miR-223-regulated genes is ADP P2Y12, a key target for current antiplatelet drug therapy. Recent studies showed that a blunted response to P2Y12 antagonist, that is, high on-treatment platelet reactivity (HTPR), is a strong predictor of major cardiovascular events (MACEs) in coronary heart disease (CHD) patients receiving antiplatelet treatment. Recent clinical cohort study showed that the level of circulating miR-223 is inversely associated with MACE in CHD patients. In addition, our recent data demonstrated that the level of both intraplatelet and circulating miR-223 is an independent predictor for HTPR, thus providing a link between miR-223 and MACE. These lines of evidence indicate that miR-223 may serve as a potential regulatory target for HTPR, as well as a diagnostic tool for identification of HTPR in clinical settings. PMID:26221610

Splenic TFH expansion participates in B-cell differentiation and antiplatelet-antibody production during immune thrombocytopenia.

Science.gov (United States)

Audia, Sylvain; Rossato, Marzia; Santegoets, Kim; Spijkers, Sanne; Wichers, Catharina; Bekker, Cornelis; Bloem, Andries; Boon, Louis; Flinsenberg, Thijs; Compeer, Ewoud; van den Broek, Theo; Facy, Olivier; Ortega-Deballon, Pablo; Berthier, Sabine; Leguy-Seguin, Vanessa; Martin, Laurent; Ciudad, Marion; Samson, Maxime; Trad, Malika; Lorcerie, Bernard; Janikashvili, Nona; Saas, Philippe; Bonnotte, Bernard; Radstake, Timothy R D J

2014-10-30

Antiplatelet-antibody-producing B cells play a key role in immune thrombocytopenia (ITP) pathogenesis; however, little is known about T-cell dysregulations that support B-cell differentiation. During the past decade, T follicular helper cells (TFHs) have been characterized as the main T-cell subset within secondary lymphoid organs that promotes B-cell differentiation leading to antibody class-switch recombination and secretion. Herein, we characterized TFHs within the spleen of 8 controls and 13 ITP patients. We show that human splenic TFHs are the main producers of interleukin (IL)-21, express CD40 ligand (CD154), and are located within the germinal center of secondary follicles. Compared with controls, splenic TFH frequency is higher in ITP patients and correlates with germinal center and plasma cell percentages that are also increased. In vitro, IL-21 stimulation combined with an anti-CD40 agonist antibody led to the differentiation of splenic B cells into plasma cells and to the secretion of antiplatelet antibodies in ITP patients. Overall, these results point out the involvement of TFH in ITP pathophysiology and the potential interest of IL-21 and CD40 as therapeutic targets in ITP. © 2014 by The American Society of Hematology.

Novel Antiplatelet Activity of Minocycline Involves Inhibition of MLK3-p38 Mitogen Activated Protein Kinase Axis.

Science.gov (United States)

Jackson, Joseph W; Singh, Meera V; Singh, Vir B; Jones, Letitia D; Davidson, Gregory A; Ture, Sara; Morrell, Craig N; Schifitto, Giovanni; Maggirwar, Sanjay B

2016-01-01

Platelets play an essential role in hemostasis and wound healing by facilitating thrombus formation at sites of injury. Platelets also mediate inflammation and contain several pro-inflammatory molecules including cytokines and chemokines that mediate leukocyte recruitment and activation. Not surprisingly, platelet dysfunction is known to contribute to several inflammatory disorders. Antiplatelet therapies, such as aspirin, adenosine diphosphate (ADP) antagonists, glycoprotein IIb/IIIa (GPIIb/IIIa) inhibitors, and anticoagulants such as warfarin, dampen platelet activity at the risk of unwarranted bleeding. Thus, the development of drugs that reduce platelet-mediated inflammation without interfering with thrombus formation is of importance to combat platelet-associated disorders. We have shown here for the first time that the tetracycline antibiotic, minocycline, administered to HIV-infected individuals reduces plasma levels of soluble CD40L and platelet factor 4 levels, host molecules predominately released by platelets. Minocycline reduced the activation of isolated platelets in the presence of the potent platelet activator, thrombin, as measured by ELISA and flow cytometry. Platelet degranulation was reduced upon exposure to minocycline as shown by mepacrine retention and flow cytometry. However, minocycline had no effect on spreading, aggregation, GPIIb/IIIa activation, or in vivo thrombus formation. Lastly, immunoblot analysis suggests that the antiplatelet activity of minocycline is likely mediated by inhibition of mixed lineage kinase 3 (MLK3)-p38 MAPK signaling axis and loss of p38 activity. Our findings provide a better understanding of platelet biology and a novel repurposing of an established antibiotic, minocycline, to specifically reduce platelet granule release without affecting thrombosis, which may yield insights in generating novel, specific antiplatelet therapies.

Perioperative management of antithrombotic treatment during implantation or revision of cardiac implantable electronic devices

DEFF Research Database (Denmark)

Deharo, Jean-Claude; Sciaraffia, Elena; Leclercq, Christophe

2016-01-01

.7% of patients, with heparin bridging in 25.6%, but accounted for only 25.3% of the oral anticoagulants used. A total of 108 complications were observed in 98 patients. No intracranial haemorrhage or embolic events were observed. Chronic NOAC treatment before surgery was associated with lower rates of minor...... pocket haematoma (1.4%; P= 0.042) vs. dual antiplatelet therapy (13.0%), VKA (11.4%), VKA + antiplatelet (9.2%), or NOAC + antiplatelet (7.7%). Similar results were observed for bleeding complications (P= 0.028). Perioperative management of patients undergoing CIED implantation/surgical revision while...

Comparison on Anticoagulation and Antiplatelet Aggregation Effects of Puerarin with Heparin Sodium and Tirofiban Hydrochloride: An In Vitro Study.

Science.gov (United States)

Li, Si-Wei; Feng, Xue; Xu, Hao; Chen, Ke-Ji

2018-02-01

To detect the anticoagulation and antiplatelet effects of different concentrations of puerarin, heparin sodium and tirofiban hydrochloride on the blood samples of healthy volunteers by Sonoclot coagulation and platelet function analyzer. Peripheral blood samples were extracted from 20 healthy volunteers, followed by adding different concentrations of puerarin, heparin sodium and tirofiban hydrochloride. Samples were detected for activated clotting time (ACT), clot rate (CR) and platelet function (PF) by Sonoclot coagulation and platelet function analyzer instrument. For puerarin and heparin sodium, the values of ACT gradually increased, and the values of CR and PF gradually decreased with increasing in drug concentration. There was a linear (or log linear) relationship between ACT, CR, PF value and drug concentration (Phydrochloride, the values of ACT and CR had no significant changes, while PF values gradually decreased with concentration increasing. There was also a linear relationship between PF values and concentrations of tirofiban hydrochloride (Psodium. For high concentrations of puerarin (e.g. 3.8 mg/600 μL) and tirofiban hydrochloride (e.g. 0.8 μg/600 μL), PF values had no significant difference. However, PF values for high puerarin concentration had a larger variance. Puerarin has similar anticoagulant and antiplatelet effects with the heparin sodium, and may have a lower hemorrhage risk than heparin sodium when obtained the same anticoagulation effect in the concentration range of this experiment. In addition, for high concentration, puerarin had the same antiplatelet function as tirofiban hydrochloride but with a larger individual variability.

Patterns and associations between DAPT cessation and 2-year clinical outcomes in left main/proximal LAD versus other PCI: Results from the Patterns of Non-Adherence to Dual Antiplatelet Therapy in Stented Patients (PARIS) registry.

Science.gov (United States)

Chandrasekhar, Jaya; Baber, Usman; Sartori, Samantha; Aquino, Melissa; Tomey, Matthew; Kruckoff, Mitchell; Moliterno, David; Henry, Timothy D; Weisz, Giora; Gibson, C Michael; Iakovou, Ioannis; Kini, Annapoorna; Faggioni, Michela; Vogel, Birgit; Farhan, Serdar; Colombo, Antonio; Steg, P Gabriel; Witzenbichler, Bernhard; Chieffo, Alaide; Cohen, David; Stuckey, Thomas; Ariti, Cono; Pocock, Stuart; Dangas, George; Mehran, Roxana

2017-09-15

Percutaneous coronary intervention (PCI) of the left main (LM) or proximal left anterior descending artery (pLAD) is considered high-risk as these segments subtend substantial left ventricular myocardial area. We assessed the patterns and associations between dual antiplatelet therapy (DAPT) cessation and 2-year outcomes in LM/pLAD vs. other PCI from the all-comer PARIS registry. Two-year major adverse cardiovascular events (MACE) were a composite of cardiac death, myocardial infarction, definite/probable stent thrombosis or target lesion revascularization. DAPT cessation was predefined as physician-guided permanent discontinuation, temporary interruption, or non-recommended disruption due to non-compliance or bleeding. Of the study population (n=5018), 25.0% (n=1252) underwent LM/pLAD PCI and 75.0% (n=3766) PCI to other segments. Compared to others, LM/pLAD patients presented with fewer comorbidities, less frequent acute coronary syndromes but more multivessel and bifurcation disease treated with greater stent lengths. Two-year adjusted risk of MACE (11.4% vs. 11.6%; HR 1.10, 95% CI 0.90-1.34, p=0.36) was similar between LM/pLAD vs. other patients. DAPT discontinuation was significantly higher (43.3% vs. 39.4%, p=0.01) in LM/pLAD patients with borderline significance for lower disruption (10.0% vs. 14.7%, p=0.059) compared to other patients. DAPT discontinuation was not associated with higher risk of MACE in LM/pLAD (HR 0.65, 95% CI 0.34-1.25) or other PCI groups (HR 0.67, 95% CI 0.47-0.95). LM/pLAD PCI was not an independent predictor of 2-year MACE. Compared to other PCI, patients undergoing LM/pLAD PCI had higher rates of physician recommended DAPT discontinuation, however, discontinuation did not result in greater adverse events. Copyright © 2017 Elsevier B.V. All rights reserved.

Time-domain diagnostics in the picosecond regime

International Nuclear Information System (INIS)

Lumpkin, A.H.

1995-01-01

The measurement of bunch length and longitudinal profile for microbunches of electrons and positrons in the ps and sub-ps regime will be a critical part of validating performance of proposed facilities. Data will be presented showing single-sweep streak camera results at σ res ∼ 68 fs and projected synchroscan sweep resolution at σ ∼ 600 fs. Additionally, an rf cavity operating in a transverse magnetic mode has recently been shown to produce σ res ∼ 280 fs when used with a low-emittance beam. The potential for dual-sweep streak work with σ res < 1 ps on the fast axis is also described

The 'Harmonizing Optimal Strategy for Treatment of coronary artery stenosis - sAfety & effectiveneSS of drug-elUting stents & antiplatelet REgimen' (HOST-ASSURE trial: study protocol for a randomized controlled trial

Directory of Open Access Journals (Sweden)

Park Kyung

2012-03-01

Full Text Available Abstract Background Second-generation drug-eluting stents (DES have raised the bar of clinical performance. These stents are mostly made from cobalt chromium alloy. A newer generation DES has been developed from platinum chromium alloy, but clinical data regarding the efficacy and safety of the platinum chromium-based everolimus-eluting stent (PtCr-EES is limited, with no comparison data against the cobalt chromium-based zotarolimus-eluting stent (CoCr-ZES. In addition, an antiplatelet regimen is an integral component of medical therapy after percutaneous coronary intervention (PCI. A 1-week duration of doubling the dose of clopidogrel (double-dose antiplatelet therapy (DDAT was shown to improve outcome at 1 month compared with conventional dose in acute coronary syndrome (ACS patients undergoing PCI. However in Asia, including Korea, the addition of cilostazol (triplet antiplatelet therapy (TAT is used more commonly than doubling the dose of clopidogrel in high-risk patients. Methods In the 'Harmonizing Optimal Strategy for Treatment of coronary artery stenosis - sAfety & effectiveneSS of drug-elUting stents & antiplatelet REgimen' (HOST-ASSURE trial, approximately 3,750 patients are being prospectively and randomly assigned in a 2 × 2 factorial design according to the type of stent (PtCr-EES vs CoCr-ZES and antiplatelet regimen (TAT vs DDAT. The first primary endpoint is target lesion failure at 1 year for the stent comparison, and the second primary endpoint is net clinical outcome at 1 month for comparison of antiplatelet therapy regimen. Discussion The HOST-ASSURE trial is the largest study yet performed to directly compare the efficacy and safety of the PtCr-EES versus CoCr-ZES in an 'all-comers' population. In addition, this study will also compare the clinical outcome of TAT versus DDAT for 1-month post PCI. Trial registration ClincalTrials.gov number NCT01267734.

Council regulation of the European dual use regulation. A never ending story?

International Nuclear Information System (INIS)

Feldmann, Ulrike

2018-01-01

For the first time, the EC Council Regulation of 19 December 1994 established a Community regime for the control of exports of dual-use items. In 2000, the first major revision of the dual-use regime came into force, subjecting not only sensitive material, i.e. plutonium and highly enriched uranium, but also the entire category 0 (nuclear material, installations, equipment) to a licensing requirement for intra-Community shipments. This revision was revised a few months later due to inappropriate content by removing a small proportion of nuclear goods. A further comprehensive new revision was published in 2009. However, the EU Commission's current proposal to revise Annex IV of the regulation does not do justice to the objective of free trade of goods and the maintenance of the competitiveness of European industry from the point of view of the European nuclear industry, as well as from the point of view of the non-nuclear industry in the EU.

Continuing versus discontinuing antiplatelet drugs, vasodilators, and/or cerebral ameliorators on perioperative total blood loss in total knee arthroplasty without pneumatic tourniquet

Directory of Open Access Journals (Sweden)

Sachiyuki Tsukada, MD

2018-03-01

Full Text Available Background: Although studies have supported the utility of perioperative continuation of antiplatelet drugs, vasodilators, and cerebral ameliorators in most procedures, no study compared total volume of blood loss after total knee arthroplasty (TKA in patients continuing and discontinuing these drugs. Methods: We retrospectively reviewed 266 consecutive patients undergoing TKA, and included 67 patients (25.2% taking antiplatelet drugs, vasodilators, or cerebral ameliorators in this study. All TKAs were performed without a pneumatic tourniquet. The primary outcome was perioperative total blood loss calculated from blood volume and change in hemoglobin. As subgroup analysis, we compared perioperative total blood loss in patients taking antiplatelet drugs. Results: There was no significant difference between the continuing group (n = 38 and discontinuing group (n = 29 in terms of the perioperative total blood loss (1025 ± 364 vs 1151 ± 327 mL, respectively; mean difference 126 mL; 95% confidence interval −45 to 298 mL; P = .15. No major bleeding or thrombotic events occurred in either group until postoperative 3-month follow-up. In patients taking antiplatelet drugs (n = 51, no significant difference was observed in the total blood loss between the continuing group (n = 30 and discontinuing group (n = 21 (1056 ± 287 vs 1151 ± 305 mL, respectively; mean difference 95 mL; 95% confidence interval −75 to 264 mL; P = .27. Conclusions: No significant differences in terms of perioperative total blood loss were observed between patients continuing and discontinuing study drugs. Continuing these drugs may be preferable in the perioperative period of TKA. Keywords: Knee, Primary arthroplasty, Bleeding events, Thrombotic events, Noncardiac surgery

Momentum-space cluster dual-fermion method

Science.gov (United States)

Iskakov, Sergei; Terletska, Hanna; Gull, Emanuel

2018-03-01

Recent years have seen the development of two types of nonlocal extensions to the single-site dynamical mean field theory. On one hand, cluster approximations, such as the dynamical cluster approximation, recover short-range momentum-dependent correlations nonperturbatively. On the other hand, diagrammatic extensions, such as the dual-fermion theory, recover long-ranged corrections perturbatively. The correct treatment of both strong short-ranged and weak long-ranged correlations within the same framework is therefore expected to lead to a quick convergence of results, and offers the potential of obtaining smooth self-energies in nonperturbative regimes of phase space. In this paper, we present an exact cluster dual-fermion method based on an expansion around the dynamical cluster approximation. Unlike previous formulations, our method does not employ a coarse-graining approximation to the interaction, which we show to be the leading source of error at high temperature, and converges to the exact result independently of the size of the underlying cluster. We illustrate the power of the method with results for the second-order cluster dual-fermion approximation to the single-particle self-energies and double occupancies.

Lumbar puncture in patients using anticoagulants and antiplatelet agents

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Renan Domingues

2016-08-01

Full Text Available ABSTRACT The use of anticoagulants and antiplatelet agents has largely increased. Diagnostic lumbar puncture in patients taking these drugs represents a challenge considering the opposing risks of bleeding and thrombotic complications. To date there are no controlled trials, specific guidelines, nor clear recommendations in this area. In the present review we make some recommendations about lumbar puncture in patients using these drugs. Our recommendations take into consideration the pharmacology of these drugs, the thrombotic risk according to the underlying disease, and the urgency in cerebrospinal fluid analysis. Evaluating such information and a rigorous monitoring of neurological symptoms after lumbar puncture are crucial to minimize the risk of hemorrhage associated neurological deficits. An individualized patient decision-making and an effective communication between the assistant physician and the responsible for conducting the lumbar puncture are essential to minimize potential risks.

Patent foramen ovale closure with GORE HELEX or CARDIOFORM Septal Occluder vs. antiplatelet therapy for reduction of recurrent stroke or new brain infarct in patients with prior cryptogenic stroke

DEFF Research Database (Denmark)

Kasner, Scott E; Thomassen, Lars; Søndergaard, Lars

2017-01-01

Rationale The utility of patent foramen ovale (PFO) closure for secondary prevention in patients with prior cryptogenic stroke is uncertain despite multiple randomized trials completed to date. Aims The Gore REDUCE Clinical Study (REDUCE) aims to establish superiority of patent foramen ovale...... with truly cryptogenic strokes. Medical therapy is limited to antiplatelet agents in both arms thereby reducing confounding. The trial should determine whether patent foramen ovale closure with the Gore septal occluders is safe and more effective than medical therapy alone for the prevention of recurrent...... closure in conjunction with antiplatelet therapy over antiplatelet therapy alone in reducing the risk of recurrent clinical ischemic stroke or new silent brain infarct in patients who have had a cryptogenic stroke. Methods and design This controlled, open-label trial randomized 664 subjects...

Triple antithrombotic therapy in patients with atrial fibrillation undergoing coronary artery stenting: hovering among bleeding risk, thromboembolic events, and stent thrombosis

Directory of Open Access Journals (Sweden)

Menozzi Mila

2012-10-01

Full Text Available Abstract Dual antiplatelet treatment with aspirin and clopidogrel is the antithrombotic treatment recommended after an acute coronary syndrome and/or coronary artery stenting. The evidence for optimal antiplatelet therapy for patients, in whom long-term treatment oral anticoagulation is mandatory, is however scarce. To evaluate the safety and efficacy of the various antithrombotic strategies adopted in this population, we reviewed the available evidence on the management of patients receiving oral anticoagulation, such as a vitamin-k-antagonists, referred for coronary artery stenting. Atrial fibrillation is the most frequent indication for oral anticoagulation. The need of starting antiplatelet therapy in this clinical scenario raises concerns about the combination to choose: triple therapy with warfarin, aspirin, and a thienopyridine being the most frequent and advised. The safety of this regimen appeared suboptimal because of an increased risk in hemorrhagic complications. On the other hand, the combination of oral anticoagulation and an antiplatelet agent is suboptimal in preventing thromboembolic events and stent thrombosis; dual antiplatelet therapy may be considered only when a high hemorrhagic risk and low thromboembolic risk are perceived. Indeed, the need for prolonged multiple-drug antithrombotic therapy increases the bleeding risks when drug eluting stents are used. Since current evidence derives mainly from small, single-center and retrospective studies, large-scale prospective multicenter studies are urgently needed.

Preventive Aspirin and Other Antiplatelet Medication Use Among U.S. Adults Aged ≥40 Years: Data from the National Health and Nutrition Examination Survey, 2011–2012

Science.gov (United States)

Dillon, Charles F.; Eberhardt, Mark S.; Wright, Jacqueline D.; Burt, Vicki L.

2015-01-01

Objective We estimated the prevalence of preventive aspirin and/or other antiplatelet medication use and the dosage of aspirin use in the U.S. adult population. Methods We conducted cross-sectional analyses of a representative sample (n=3,599) of U.S. adults aged ≥40 years from the National Health and Nutrition Examination Survey, 2011–2012. Results In 2011–2012, one-third of U.S. adults aged ≥40 years reported taking preventive aspirin and/or other antiplatelet medications, 97% of whom indicated preventive aspirin use. Preventive aspirin use increased with age (from 11% of those aged 40–49 years to 54% of those ≥80 years of age, paspirin than non-Hispanic Asian (20%, paspirin. Among those with cardiovascular disease, 76% reported taking preventive aspirin and/or other antiplatelet medications, of whom 91% were taking preventive aspirin. Among adults without cardiovascular disease, 28% reported taking preventive aspirin. Adherence rates to medically recommended aspirin use were 82% overall, 91% for secondary prevention, and 79% for primary prevention. Among current preventive aspirin users, 70% were taking 81 milligrams (mg) of aspirin daily and 13% were taking 325 mg of aspirin daily. Conclusion The vast majority of antiplatelet therapy is preventive aspirin use. A health-care provider's recommendation to take preventive aspirin is an important determinant of current preventive aspirin use. PMID:26556936

TIA Management

Science.gov (United States)

Mijalski, Christina

2015-01-01

Transient ischemic attack (TIA) has gained increasing attention over the last 2 decades with the realization that the condition is common, portends potentially serious consequences, and, when identified early, can be evaluated and treated to modify future risk. In this review, we examine the issues of whether all TIA patients need admission and whether such patients should receive short-term dual antiplatelet therapy. Not all patients require admission if evaluation and treatment are done promptly. There may be a role for dual antiplatelet therapy, but the results of further clinical trials will help provide better clarity on which patients are the best candidates for this treatment. PMID:26288673

Optimal conditions in direct dimethyl ether synthesis from syngas utilizing a dual-type fluidized bed reactor

International Nuclear Information System (INIS)

Yousefi, Ahmad; Eslamloueyan, Reza; Kazerooni, Nooshin Moradi

2017-01-01

Concerns over environmental pollution and ever-increasing energy demand have urged the global community to tap clean-burning fuels among which dimethyl ether is a promising candidate for contribution in the transportation sector. Direct dimethyl ether synthesis from syngas, in which methanol production and dehydration take place simultaneously, is arguably the preferred route for large scale production. In this study, direct dimethyl ether synthesis is proposed in an industrial dual-type fluidized bed reactor. This configuration involves two fluidized bed reactors operating in different conditions. In the first catalytic reactor (water-cooled reactor), the synthesis gas is partly converted to methanol after being preheated by the reaction heat in the second reactor (gas-cooled reactor). A two-phase generalized comprehensive reactor model, comprised of the flow in three different regimes is applied and a smooth transition between flow regimes is provided based on the probabilistic averaging approach. The optimal operating conditions are sought by employing differential evolution algorithm as a robust optimization strategy. The dimethyl ether mole fraction is considered as the objective function during the optimization. The results show considerable dimethyl ether enhancement by 16% and 14% compared to the conventional direct dimethyl ether synthesis reactor and dual-type fixed bed dimethyl ether reactor arrangements, respectively. - Highlights: • Dual-type catalytic fluidized bed reactors for dimethyl ether synthesis is studied. • A two-phase comprehensive model comprised of flow in three regimes is used. • Probabilistic averaging approach is applied for smooth transitions between regimes. • Differential evolution method is employed to determine optimal operating conditions. • Production capacity is remarkably enhanced compared to conventional reactor.

Decree of the State Office for Nuclear Safety No. 147/1997 of 17 June 1997 specifying lists of selected nuclear-related items and dual-use nuclear-related items

International Nuclear Information System (INIS)

1997-01-01

The core of the Decree consists of 2 lists, viz (a) the List of Selected Items (selected nuclear-related materials, equipment and technologies) which are subject to control regimes during imports, exports and transit; and (b) the List of Dual-Use Items (dual-use nuclear-related materials, equipment and technologies) which are subject to control regimes during imports and exports. Both Lists are based on the IAEA document INFCIRC/254/Rev.2/Part 2/Mod.1. (P.A.)

Responsible Code of Conduct for the Life Science and Dual-Use Research

International Nuclear Information System (INIS)

Bokan, S.

2007-01-01

The potential threat from misuse of current and future Dual-Use research in the field of NBC Defense is challenge to which scientific community must respond. The rapid advances in the life sciences and the worldwide growth of biotechnology industry only add urgency of this task. Code of conduct is formal statement of values and professional practices of a group of individuals with a common focus, either an occupation, academic field, or social doctrine. Codes of conduct can help to reduce the risk that scientific research will be misused. 'Dual-use' is a term often used in politics and diplomacy to refer to technology which can be used for both peaceful and military aims, usually in regard to the proliferation of nuclear weapons. Dual-use information and 'know-how' in the field of NBC defense are covered under the Export control regimes. Nearly all WMD production equipment is 'dual-use' and only very large capacity equipment is export controlled. Research in the life sciences, including NBC defense research must be conducted safely, securely, and ethically. Development of an international harmonized regime for control of biological and chemical warfare agents within and between laboratories and facilities is very important. This paper will present very important consideration of the content, promulgation and adoption of codes of conduct for scientists in the field of NBC research, for inducing of discussion between scientists into group of CBMTS members with aim how improve protection of sensitive research results and information in the field of NBC Defense sciences. (author)

UP TO DATE ANTIPLATELET THERAPY IN PATIENTS WITH HIGH RISK OF THROMBOTIC EVENTS AND REAL CLINICAL PRACTICE

Directory of Open Access Journals (Sweden)

S. Yu. Martsevich

2012-01-01

Full Text Available Aim. To assess the real rate of dual antiplatelet therapy (DAT, acetylsalicylic acid + clopidogrel use in patients having appropriate indications according to current clinical guidelines and to study the possibility of prescription rate improvement by education activity directed to doctors. Material and methods. The study consisted of 3 parts. Parts I and II present the results of two questionnaire surveys of patients with acute myocardial infarction, or stenting, who needed in DAT according to current clinical guidelines. The real use of the DAT was assessed in part III on the basis of the multicenter study conducted in different regions of Russia (ROMB study in a large sample of patients having DAT indications. Results. Part I - PROGNOZ-IBS study. According to the questionnaire survey only 112 out of 239 patients (47% having an absolute indications, received DOT. Part II - phone survey of patients with acute myocardial infarction in two towns of Lyubertsy and Podolsk. 28 of 71 patients (39% took the DAT (from some days to 6 months and 35 patients (49% — did not take it. Part III - ROMB study. 519 patients did not take DAT, at that 259 (50% in hospital and 260 (50% - in out-patient clinic. 521 patients took DAT according to indications, at that 238 (46% in hospital and 283 (54% - in out-patient clinic. Conclusion. Less than 50% of patients, having direct indications, received DAT in the real clinical practice. The prescription rate can be improved due to education activity directed to doctors and increase in clopidogrel drugs affordability.

Antiplatelet therapy at the time of coronary artery bypass grafting

DEFF Research Database (Denmark)

Kremke, Michael; Jensen, Mariann Tang; Bak, Mikkel

2013-01-01

OBJECTIVES: The purpose of this multicentre cohort study was to examine the relationship between antiplatelet therapy (APT) at the time of coronary artery bypass grafting (CABG) and postoperative bleeding complications, transfusion requirements and adverse cardiovascular events. METHODS: A matched...... Denmark Heart Registry. RESULTS: Of the 6350 patients enrolled, 1846 (29%) had been exposed to aspirin or clopidogrel within 5 days prior to CABG (the APT group). Matching with the remaining 4504 (71%) patients of the control group resulted in 1132 pairs of patients. Patients in the APT group had greater...... postoperative bleeding (OR: 2.08, 95% CI: 1.55-2.80). Overall, preoperative APT had no significant effect on postoperative 30-day mortality, incidence of myocardial infarction, stroke or need for dialysis. CONCLUSIONS: Preoperative APT is associated with increased bleeding and greater transfusion requirements...

Characteristics of patients with atrial fibrillation prescribed antiplatelet monotherapy compared with those on anticoagulants: insights from the GARFIELD-AF registry

NARCIS (Netherlands)

Verheugt, F.W.A.; Gao, H.; Mahmeed, W. Al; Ambrosio, G.; Angchaisuksiri, P.; Atar, D.; Bassand, J.P.; Camm, A.J.; Cools, F.; Eikelboom, J.; Kayani, G.; Lim, T.W.; Misselwitz, F.; Pieper, K.S.; Eickels, M. van; Kakkar, A.K.

2018-01-01

Aims: Current atrial fibrillation (AF) guidelines discourage antiplatelet (AP) monotherapy as alternative to anticoagulants (ACs). Why AP only is still used is largely unknown. Methods and results: Factors associated with AP monotherapy prescription were analysed in GARFIELD-AF, a registry of

DUAL TIMELIKE NORMAL AND DUAL TIMELIKE SPHERICAL CURVES IN DUAL MINKOWSKI SPACE

OpenAIRE

ÖNDER, Mehmet

2009-01-01

Abstract: In this paper, we give characterizations of dual timelike normal and dual timelike spherical curves in the dual Minkowski 3-space and we show that every dual timelike normal curve is also a dual timelike spherical curve. Keywords: Normal curves, Dual Minkowski 3-Space, Dual Timelike curves. Mathematics Subject Classifications (2000): 53C50, 53C40. DUAL MINKOWSKI UZAYINDA DUAL TIMELIKE NORMAL VE DUAL TIMELIKE KÜRESEL EĞRİLER Özet: Bu çalışmada, dual Minkowski 3-...

A dual-stage sodium thermal electrochemical converter (Na-TEC)

Science.gov (United States)

Limia, Alexander; Ha, Jong Min; Kottke, Peter; Gunawan, Andrey; Fedorov, Andrei G.; Lee, Seung Woo; Yee, Shannon K.

2017-12-01

The sodium thermal electrochemical converter (Na-TEC) is a heat engine that generates electricity through the isothermal expansion of sodium ions. The Na-TEC is a closed system that can theoretically achieve conversion efficiencies above 45% when operating between thermal reservoirs at 1150 K and 550 K. However, thermal designs have confined previous single-stage devices to thermal efficiencies below 20%. To mitigate some of these limitations, we consider dividing the isothermal expansion into two stages; one at the evaporator temperature (1150 K) and another at an intermediate temperature (650 K-1050 K). This dual-stage Na-TEC takes advantage of regeneration and reheating, and could be amenable to better thermal management. Herein, we demonstrate how the dual-stage device can improve the efficiency by up to 8% points over the best performing single-stage device. We also establish an application regime map for the single- and dual-stage Na-TEC in terms of the power density and the total thermal parasitic loss. Generally, a single-stage Na-TEC should be used for applications requiring high power densities, whereas a dual-stage Na-TEC should be used for applications requiring high efficiency.

Gigahertz dual-comb modelocked diode-pumped semiconductor and solid-state lasers

Science.gov (United States)

Link, S. M.; Mangold, M.; Golling, M.; Klenner, A.; Keller, U.

2016-03-01

We present a simple approach to generate simultaneously two gigahertz mode-locked pulse trains from a single gain element. A bi-refringent crystal in the laser cavity splits the one cavity beam into two cross-polarized and spatially separated beams. This polarization-duplexing is successfully demonstrated for both a semiconductor disk laser (i.e. MIXSEL) and a diode-pumped solid-state Nd:YAG laser. The beat between the two beams results in a microwave frequency comb, which represents a direct link between the terahertz optical frequencies and the electronically accessible microwave regime. This dual-output technique enables compact and cost-efficient dual-comb lasers for spectroscopy applications.

Percutaneous coronary intervention and antiplatelet therapy in patients with atrial fibrillation receiving apixaban or warfarin: Insights from the ARISTOTLE trial

NARCIS (Netherlands)

Kopin, D.; Jones, W.S.; Sherwood, M.W.; Wojdyla, D.M.; Wallentin, L.; Lewis, B.S.; Verheugt, F.W.A.; Vinereanu, D.; Bahit, M.C.; Halvorsen, S.; Huber, K.; Parkhomenko, A.; Granger, C.B.; Lopes, R.D.; Alexander, J.H.

2018-01-01

BACKGROUND: We assessed antiplatelet therapy use and outcomes in patients undergoing percutaneous coronary intervention (PCI) during the ARISTOTLE trial. METHODS: Patients were categorized based on the occurrence of PCI during follow-up (median 1.8 years); PCI details and outcomes post-PCI are

Frequency of "Pocket" Hematoma in Patients Receiving Vitamin K Antagonist and Antiplatelet Therapy at the Time of Pacemaker or Cardioverter Defibrillator Implantation (from the POCKET Study).

Science.gov (United States)

Malagù, Michele; Trevisan, Filippo; Scalone, Antonella; Marcantoni, Lina; Sammarco, Giuseppe; Bertini, Matteo

2017-04-01

In patients undergoing cardiac device implantation, anticoagulant and antiplatelet therapy are associated with an increased risk of pocket hematoma. In case of vitamin K antagonist therapy, a strategy of continued warfarin with no heparin bridge showed a reduction of pocket hematoma. Evidence regarding antiplatelet therapy management is limited. This is a single-center observational study which reflects our systematic approach to the problem. In 2012, we proposed an improved management protocol for anticoagulant and antiplatelet therapy (no-bridge protocol) based on individual thromboembolic risk stratification, noninterruption of oral anticoagulation, no bridge with heparin and elastic adherence compression bandage. The primary end point was the incidence of clinically significant pocket hematoma in the first 30 days after implantation. A total of 1,035 patients were enrolled, of whom 522 received the standard management and 513 the new protocol. The primary end point occurred in 34 patients of the standard management group and 8 patients of the no-bridge protocol group (6.5% vs 1.6%, p hematoma (relative risk [RR] 3.48, 95% confidence interval [CI] 1.55 to 7.83 and RR 2.43, 95% CI 1.25 to 4.76, respectively), whereas the no-bridge protocol was associated with a reduction of pocket hematoma (RR 0.33, 95% CI 0.14 to 0.76). New anticoagulant and antiplatelet therapy management protocol was associated with a reduced incidence of clinically significant pocket hematomas, thromboembolic events, pocket infections, and lead dislodgements. Copyright © 2017 Elsevier Inc. All rights reserved.

Antiplatelet therapy with aspirin, clopidogrel, and dipyridamole versus clopidogrel alone or aspirin and dipyridamole in patients with acute cerebral ischaemia (TARDIS)

DEFF Research Database (Denmark)

Bath, Philip M; Woodhouse, Lisa J; Appleton, Jason P

2018-01-01

, and dipyridamole) with that of guideline-based antiplatelet therapy. METHODS: We did an international, prospective, randomised, open-label, blinded-endpoint trial in adult participants with ischaemic stroke or transient ischaemic attack (TIA) within 48 h of onset. Participants were assigned in a 1:1 ratio using...... was stratified by country and index event, and minimised with prognostic baseline factors, medication use, time to randomisation, stroke-related factors, and thrombolysis. The ordinal primary outcome was the combined incidence and severity of any recurrent stroke (ischaemic or haemorrhagic; assessed using...... therapy group, 1540 in the guideline antiplatelet therapy group) were recruited from 106 hospitals in four countries between April 7, 2009, and March 18, 2016. The trial was stopped early on the recommendation of the data monitoring committee. The incidence and severity of recurrent stroke or TIA did...

Topical diclofenac does not affect the antiplatelet properties of aspirin as compared to the intermediate effects of oral diclofenac: A prospective, randomized, complete crossover study.

Science.gov (United States)

Rowcliffe, M; Nezami, B; Westphal, E S; Rainka, M; Janda, M; Bates, V; Gengo, F

2016-04-01

Nonsteroidal anti-inflammatory drugs (NSAIDs) adversely interact with aspirin, diminishing its antiplatelet effect and potentially placing patients at an increased risk for recurrent thrombotic events. This crossover study aimed to determine whether the topical NSAID diclofenac epolamine 1.3% patch or oral diclofenac 50 mg interfered with the antiplatelet effects of aspirin 325 mg. Twelve healthy men and women aged 18-50 were included. Participants were randomized into 5 treatment arms: aspirin, diclofenac potassium 50 mg, diclofenac patch, diclofenac potassium plus ASA 325 mg, and diclofenac patch plus aspirin. Platelet responsiveness was determined using whole-blood impedance aggregation (WBA) to collagen 1 μg/mL and arachidonic acid (AA) 0.5 mM and was sampled every 2 hours. No significant difference in platelet function was observed following the diclofenac patch and aspirin vs aspirin alone. Oral diclofenac produced a mixed effect with significant reduction in platelet inhibition at hour 2 and hour 8 following aspirin administration. Topical diclofenac does not significantly interfere with the antiplatelet effects of aspirin and may be a safer alternative to the oral formulation. © 2015, The American College of Clinical Pharmacology.

Novel direct factor Xa inhibitory compounds from Tenebrio molitor with anti-platelet aggregation activity.

Science.gov (United States)

Lee, Wonhwa; Kim, Mi-Ae; Park, InWha; Hwang, Jae Sam; Na, MinKyun; Bae, Jong-Sup

2017-11-01

Tenebrio molitor is an edible insect that has antimicrobial, anticancer, and antihypertensive effects. The aim of this study was to identify the unreported bioactive compounds from T. molitor larvae with inhibitory activities against factor Xa (FXa) and platelet aggregation. Isolated compounds were evaluated for their anti-FXa and anti-platelet aggregation properties by monitoring clotting time, platelet aggregation, FXa activity, and thrombus formation. A diketopiperazine (1, cyclo( L -Pro- L -Tyr)) and a phenylethanoid (2, N-acetyltyramine) were isolated and inhibited the catalytic activity of FXa in a mixed inhibition model and inhibited platelet aggregation induced by adenosine diphosphate (ADP) and U46619. They inhibited ADP- and U46619-induced phosphorylation of myristoylated alanine-rich C kinase substrate (MARCKS) and the expression of P-selectin and PAC-1 in platelets. They also improved the production of nitric oxide and inhibited the oversecretion of endothelin-1 compared to that of the ADP- or U46619-treated group. In an animal model of arterial and pulmonary thrombosis, the isolated compounds showed enhanced antithrombotic effects. They also elicited anticoagulant effects in mice. Compounds 1-2 inhibited ADP-, collagen-, or U46619-induced platelet aggregation and showed similar anti-thrombotic efficacy to rivaroxaban, a positive control. Therefore, 1-2 could serve as candidates and provide scaffolds for the development of new anti-FXa and anti-platelet drugs. Copyright © 2017 Elsevier Ltd. All rights reserved.

Controlling plasma properties under differing degrees of electronegativity using odd harmonic dual frequency excitation

Science.gov (United States)

Gibson, Andrew R.; Gans, Timo

2017-11-01

The charged particle dynamics in low-pressure oxygen plasmas excited by odd harmonic dual frequency waveforms (low frequency of 13.56 MHz and high frequency of 40.68 MHz) are investigated using a one-dimensional numerical simulation in regimes of both low and high electronegativity. In the low electronegativity regime, the time and space averaged electron and negative ion densities are approximately equal and plasma sustainment is dominated by ionisation at the sheath expansion for all combinations of low and high frequency and the phase shift between them. In the high electronegativity regime, the negative ion density is a factor of 15-20 greater than the low electronegativity cases. In these cases, plasma sustainment is dominated by ionisation inside the bulk plasma and at the collapsing sheath edge when the contribution of the high frequency to the overall voltage waveform is low. As the high frequency component contribution to the waveform increases, sheath expansion ionisation begins to dominate. It is found that the control of the average voltage drop across the plasma sheath and the average ion flux to the powered electrode are similar in both regimes of electronegativity, despite the differing electron dynamics using the considered dual frequency approach. This offers potential for similar control of ion dynamics under a range of process conditions, independent of the electronegativity. This is in contrast to ion control offered by electrically asymmetric waveforms where the relationship between the ion flux and ion bombardment energy is dependent upon the electronegativity.

Formation of Offset and Dual Active Galactic Nuclei

Science.gov (United States)

Barrows, Scott; Comerford, Julia M.; Greene, Jenny E.

2018-06-01

Galaxy mergers are effective mechanisms for triggering accretion onto supermassive black holes (SMBHs) and thereby powering active galactic nuclei (AGN). In the merger scenario, when the SMBH from only one galaxy is accreting we observe a spatially offset AGN, and when the SMBHs from both galaxies are accreting we observe a dual AGN. Understanding the merger conditions that lead to the formation of offset AGN versus dual AGN is fundamental to informing models of hierarchical SMBH growth and the physics leading to the accretion of matter onto SMBHs. However, while the role of galaxy mergers for AGN triggering has been well-studied, the efficiency with which these events trigger offset AGN versus dual AGN is currently unclear. One reason for this gap in knowledge can be attributed to the observational difficulties in distinguishing between offset and dual AGN since doing so requires high spatial resolution, especially in the small separation regime where merger-driven AGN triggering is most likely to occur. To overcome this hurdle, we have utilized the spatial resolution of the Chandra X-ray Observatory to develop a unique sample of AGN hosted by late-stage galaxy mergers. Moreover, we have recently acquired Hubble Space Telescope imaging for a subset of these systems to examine the role that their merger morphologies play in SMBH growth and the formation of offset and dual AGN. We find that offset AGN are predominately found in minor mergers, whereas dual AGN are usually hosted by major mergers and galaxies with large morphological asymmetries. Furthermore, in both offset and dual AGN, the rate of SMBH growth increases toward more major mergers and larger morphological asymmetries. These results are in agreement with numerical simulations predicting that merger morphology is a relevant parameter governing SMBH merger-driven growth, and these results are the first to observationally confirm these trends at small pair separations.

Diagrammatic Monte Carlo approach for diagrammatic extensions of dynamical mean-field theory: Convergence analysis of the dual fermion technique

Science.gov (United States)

Gukelberger, Jan; Kozik, Evgeny; Hafermann, Hartmut

2017-07-01

The dual fermion approach provides a formally exact prescription for calculating properties of a correlated electron system in terms of a diagrammatic expansion around dynamical mean-field theory (DMFT). Most practical implementations, however, neglect higher-order interaction vertices beyond two-particle scattering in the dual effective action and further truncate the diagrammatic expansion in the two-particle scattering vertex to a leading-order or ladder-type approximation. In this work, we compute the dual fermion expansion for the two-dimensional Hubbard model including all diagram topologies with two-particle interactions to high orders by means of a stochastic diagrammatic Monte Carlo algorithm. We benchmark the obtained self-energy against numerically exact diagrammatic determinant Monte Carlo simulations to systematically assess convergence of the dual fermion series and the validity of these approximations. We observe that, from high temperatures down to the vicinity of the DMFT Néel transition, the dual fermion series converges very quickly to the exact solution in the whole range of Hubbard interactions considered (4 ≤U /t ≤12 ), implying that contributions from higher-order vertices are small. As the temperature is lowered further, we observe slower series convergence, convergence to incorrect solutions, and ultimately divergence. This happens in a regime where magnetic correlations become significant. We find, however, that the self-consistent particle-hole ladder approximation yields reasonable and often even highly accurate results in this regime.

The Explicit Determinations Of Dual Plane Curves And Dual Helices In Terms Of Its Dual Curvature And Dual Torsion

OpenAIRE

Lee Jae Won; Choi Jin Ho; Jin Dae Ho

2014-01-01

In this paper, we give the explicit determinations of dual plane curves, general dual helices and dual slant helices in terms of its dual curvature and dual torsion as a fundamental theory of dual curves in a dual 3-space

Antiplatelet Activity of Morus alba Leaves Extract, Mediated via Inhibiting Granule Secretion and Blocking the Phosphorylation of Extracellular-Signal-Regulated Kinase and Akt

Science.gov (United States)

Rhee, Man Hee; Sung, Yoon-Young; Yang, Won-Kyung; Kim, Seung Hyung; Kim, Ho-Kyoung

2014-01-01

Ethnopharmacological Relevance. Morus alba L. leaves (MAE) have been used in fork medicine for the treatment of beriberi, edema, diabetes, hypertension, and atherosclerosis. However, underlying mechanism of MAE on cardiovascular protection remains to be elucidated. Therefore, we investigated whether MAE affect platelet aggregation and thrombosis. Materials and Methods. The anti-platelet activity of MAE was studied using rat platelets. The extent of anti-platelet activity of MAE was assayed in collagen-induced platelet aggregation. ATP and serotonin release was carried out. The activation of integrin α IIb β 3 and phosphorylation of signaling molecules, including MAPK and Akt, were investigated with cytofluorometer and immunoblotting, respectively. The thrombus formation in vivo was also evaluated in arteriovenous shunt model of rats. Results. HPLC chromatographic analysis revealed that MAE contained rutin and isoquercetin. MAE dose-dependently inhibited collagen-induced platelet aggregation. MAE also attenuated serotonin secretion and thromboxane A2 formation. In addition, the extract in vivo activity showed that MAE at 100, 200, and 400 mg/kg significantly and dose-dependently attenuated thrombus formation in rat arterio-venous shunt model by 52.3% (P < 0.001), 28.3% (P < 0.01), and 19.1% (P < 0.05), respectively. Conclusions. MAE inhibit platelet activation, TXB2 formation, serotonin secretion, aggregation, and thrombus formation. The plant extract could be considered as a candidate to anti-platelet and antithrombotic agent. PMID:24701244

Net clinical benefit of combination anticoagulant and antiplatelet therapy versus anticoagulation alone in atrial fibrillation patients: Results from the amadeus trial

NARCIS (Netherlands)

Lane, Deirdre; Kamphuisen, Pieter; Minini, Pascal; De Peuter, Olaf R.; Buller, Harry R.; Lip, Gregory Y. H.

2010-01-01

Background: To compare the effect of combination anticoagulant and antiplatelet (AP) therapy with anticoagulation alone on stroke and bleeding risk in atrial fibrillation (AF) patients and examine predictors of clinically relevant bleeding. Methods: Post-hoc analysis of 4576 AF patients [mean (SD)

Modelling of the dual frequency capacitive sheath in the intermediate pressure range

International Nuclear Information System (INIS)

Boyle, P C; Robiche, J; Turner, M M

2004-01-01

The nonlinearity of the plasma sheath in dual frequency capacitively coupled reactors is investigated for frequencies well above the ion plasma frequency. This work focuses on the behaviour of the voltage and the sheath width with respect to the driving current source and the collisionality regime. For typical plasma processing applications, the gas pressure ranges from a few milliTorrs to hundreds of milliTorrs, and the ion dynamics span different collisional regimes. To describe these different ion dynamics, we have used a collisionless model and a variable mobility model. The sheath widths and the voltages obtained from these two models have then been compared

Comparison of antiplatelet activity of garlic tablets with cardio-protective dose of aspirin in healthy volunteers: a randomized clinical trial

Directory of Open Access Journals (Sweden)

Mojtaba Shafiekhani

2016-08-01

Full Text Available Objective: Some of the adverse effects of aspirin including peptic ulcers, gastrointestinal bleeding and aspirin resistance compelled researchers to find a suitable alternative with fewer adverse effects. In this clinical trial, we aimed to find the effective antiplatelet dose of garlic. Materials and Methods: This randomized controlled clinical trial (RCT was conducted on 62 healthy volunteers of 20-50 years old. All volunteers used 80 mg aspirin per day for 1 week and at the end of this time, platelet aggregation (PA induced by 4 agonists acting in aggregation pathway including adenosinediphosphate (20 μmol/l, epinephrine (20 μmol/l, collagen(0.19 mg/ ml and arachidonic acid (0.5mg/ ml was measured by Light Transmittance Aggregometry (LTA in all participants. After one month washout period, volunteers were randomized into 3 groups and each received 1, 2 or 3 garlic tablets (1250 mg a day for 1 month. After one month, PA was examined in all groups. Results: The mean ±SD of the age of all volunteers was 28.60 ± 9.00 years. In addition, 52.00 % of our volunteers were male and 48.00% of them were female. Garlic tablet didnot have significant effect on PA at any dose. However, 30% of volunteers in the group that used 3 garlic tablets/day reported adverse effect (i.e. bleeding. No significant association between sex, age and PA was observed. Conclusion:  In this study, we were unable to determine the effective anti-platelet dose of garlic which that could be equal to that of aspirin anti-platelet activity, as assessed LTA method.

Spray-dried Eudragit® L100 microparticles containing ferulic acid: Formulation, in vitro cytoprotection and in vivo anti-platelet effect

International Nuclear Information System (INIS)

Nadal, Jessica Mendes; Gomes, Mona Lisa Simionatto; Borsato, Débora Maria; Almeida, Martinha Antunes; Barboza, Fernanda Malaquias; Zawadzki, Sônia Faria; Kanunfre, Carla Cristine; Farago, Paulo Vitor; Zanin, Sandra Maria Warumby

2016-01-01

This paper aimed to obtain new spray-dried microparticles containing ferulic acid (FA) prepared by using a methacrylic polymer (Eudragit® L100). Microparticles were intended for oral use in order to provide a controlled release, and improved in vitro and in vivo biological effects. FA-loaded Eudragit® L100 microparticles were obtained by spray-drying. Physicochemical properties, in vitro cell-based effects, and in vivo platelet aggregation were investigated. FA-loaded Eudragit® L100 microparticles were successfully prepared by spray-drying. Formulations showed suitable encapsulation efficiency, i.e. close to 100%. Microparticles were of spherical and almost-spherical shape with a smooth surface and a mean diameter between 2 and 3 μm. Fourier-transformed infrared spectra demonstrated no chemical bond between FA and polymer. X-ray diffraction and differential scanning calorimetry analyses indicated that microencapsulation led to drug amorphization. FA-loaded microparticles showed a slower dissolution rate than pure drug. The chosen formulation demonstrated higher in vitro cytoprotection, anti-inflammatory and immunomodulatory potential and also improved in vivo anti-platelet effect. These results support an experimental basis for the use of FA spray-dried microparticles as a feasible oral drug delivery carrier for the controlled release of FA and improved cytoprotective and anti-platelet effects. - Highlights: • Ferulic acid-loaded Eudragit® L100 microparticles with high drug-loading were obtained. • Spray-dried Eudragit® L100 microparticles containing ferulic acid showed improved in vitro cytoprotective effect. • Ferulic acid spray-dried microparticles had potential as in vitro anti-inflammatory and immunomodulatory. • In vivo studies demonstrated an enhanced antiplatelet effect for ferulic acid-loaded Eudragit® L100 microparticles.

Spray-dried Eudragit® L100 microparticles containing ferulic acid: Formulation, in vitro cytoprotection and in vivo anti-platelet effect

Energy Technology Data Exchange (ETDEWEB)

Nadal, Jessica Mendes; Gomes, Mona Lisa Simionatto [Postgraduate Program in Pharmaceutical Sciences, Department of Pharmacy, Federal University of Paraná (Brazil); Borsato, Débora Maria [Postgraduate Program in Pharmaceutical Sciences, Department of Pharmaceutical Sciences, State University of Ponta Grossa (Brazil); Almeida, Martinha Antunes [Postgraduate Program in Chemistry, Department of Chemistry, Federal University of Paraná (Brazil); Barboza, Fernanda Malaquias [Postgraduate Program in Pharmaceutical Sciences, Department of Pharmaceutical Sciences, State University of Ponta Grossa (Brazil); Zawadzki, Sônia Faria [Postgraduate Program in Chemistry, Department of Chemistry, Federal University of Paraná (Brazil); Kanunfre, Carla Cristine [Postgraduate Program in Biomedical Science, Department of General Biology, State University of Ponta Grossa (Brazil); Farago, Paulo Vitor, E-mail: pvfarago@gmail.com [Postgraduate Program in Pharmaceutical Sciences, Department of Pharmaceutical Sciences, State University of Ponta Grossa (Brazil); Zanin, Sandra Maria Warumby [Postgraduate Program in Pharmaceutical Sciences, Department of Pharmacy, Federal University of Paraná (Brazil)

2016-07-01

This paper aimed to obtain new spray-dried microparticles containing ferulic acid (FA) prepared by using a methacrylic polymer (Eudragit® L100). Microparticles were intended for oral use in order to provide a controlled release, and improved in vitro and in vivo biological effects. FA-loaded Eudragit® L100 microparticles were obtained by spray-drying. Physicochemical properties, in vitro cell-based effects, and in vivo platelet aggregation were investigated. FA-loaded Eudragit® L100 microparticles were successfully prepared by spray-drying. Formulations showed suitable encapsulation efficiency, i.e. close to 100%. Microparticles were of spherical and almost-spherical shape with a smooth surface and a mean diameter between 2 and 3 μm. Fourier-transformed infrared spectra demonstrated no chemical bond between FA and polymer. X-ray diffraction and differential scanning calorimetry analyses indicated that microencapsulation led to drug amorphization. FA-loaded microparticles showed a slower dissolution rate than pure drug. The chosen formulation demonstrated higher in vitro cytoprotection, anti-inflammatory and immunomodulatory potential and also improved in vivo anti-platelet effect. These results support an experimental basis for the use of FA spray-dried microparticles as a feasible oral drug delivery carrier for the controlled release of FA and improved cytoprotective and anti-platelet effects. - Highlights: • Ferulic acid-loaded Eudragit® L100 microparticles with high drug-loading were obtained. • Spray-dried Eudragit® L100 microparticles containing ferulic acid showed improved in vitro cytoprotective effect. • Ferulic acid spray-dried microparticles had potential as in vitro anti-inflammatory and immunomodulatory. • In vivo studies demonstrated an enhanced antiplatelet effect for ferulic acid-loaded Eudragit® L100 microparticles.

Significant Risk Factors for Postoperative Enlargement of Basal Ganglia Hematoma after Frameless Stereotactic Aspiration: Antiplatelet Medication and Concomitant IVH.

Science.gov (United States)

Son, Wonsoo; Park, Jaechan

2017-09-01

Frameless stereotactic aspiration of a hematoma can be the one of the treatment options for spontaneous intracerebral hemorrhage in the basal ganglia. Postoperative hematoma enlargement, however, can be a serious complication of intracranial surgery that frequently results in severe neurological deficit and even death. Therefore, it is important to identify the risk factors of postoperative hematoma growth. During a 13-year period, 101 patients underwent minimally invasive frameless stereotactic aspiration for basal ganglia hematoma. Patients were classified into two groups according to whether or not they had postoperative hematoma enlargement in a computed tomography scan. Baseline demographic data and several risk factors, such as hypertension, preoperative hematoma growth, antiplatelet medication, presence of concomitant intraventricular hemorrhage (IVH), were analysed via a univariate statistical study. Nine of 101 patients (8.9%) showed hematoma enlargement after frameless stereotactic aspiration. Among the various risk factors, concomitant IVH and antiplatelet medication were found to be significantly associated with postoperative enlargement of hematomas. In conclusion, our study revealed that aspirin use and concomitant IVH are factors associated with hematoma enlargement subsequent to frameless stereotactic aspiration for basal ganglia hematoma.

Flux Tube Dynamics in the Dual Superconductor

International Nuclear Information System (INIS)

Lampert, M.; Svetitsky, B.

1999-01-01

We have studied plasma oscillations in a flux tube created in a dual superconductor. The theory contains an Abelian gauge field coupled magnetically to a Higgs field that confines electric charge via the dual Meissner effect. Starting from a static flux tube configuration, with electric charges at either end, we release a fluid of electric charges in the system that accelerate and screen the electric field. The weakening of the electric field allows the flux tube to collapse, and the inertia of the charges forces it open again. We investigate both Type I and Type II superconductors, with plasma frequencies both above and below the threshold for radiation into the Higgs vacuum. (The parameters appropriate to QCD are in the Type II regime; the plasma frequency depends on the mass taken for the fluid constituents.) The coupling of the plasma oscillations to the Higgs field making up the flux tube is the main new feature in our work

Polymer-free Drug-Coated Coronary Stents in Patients at High Bleeding Risk

DEFF Research Database (Denmark)

Urban, Philip; Meredith, Ian T; Abizaid, Alexandre

2015-01-01

BACKGROUND: Patients at high risk for bleeding who undergo percutaneous coronary intervention (PCI) often receive bare-metal stents followed by 1 month of dual antiplatelet therapy. We studied a polymer-free and carrier-free drug-coated stent that transfers umirolimus (also known as biolimus A9......), a highly lipophilic sirolimus analogue, into the vessel wall over a period of 1 month. METHODS: In a randomized, double-blind trial, we compared the drug-coated stent with a very similar bare-metal stent in patients with a high risk of bleeding who underwent PCI. All patients received 1 month of dual...... ratio, 0.50; 95% CI, 0.37 to 0.69; Pbleeding who underwent PCI, a polymer-free umirolimus-coated stent was superior to a bare-metal stent with respect to the primary safety and efficacy end points when used with a 1-month course of dual antiplatelet...

The Intracranial-B2LEED3S Score and the Risk of Intracranial Hemorrhage in Ischemic Stroke Patients Under Antiplatelet Treatment

NARCIS (Netherlands)

Amarenco, Pierre; Sissani, Leila; Labreuche, Julien; Vicaut, Eric; Bousser, Marie Germaine; Chamorro, Angel; Fisher, Marc; Ford, Ian; Fox, Kim M; Hennerici, Michael G; Mattle, Heinrich; Rothwell, Peter M; Steg, Philippe Gabriel; Diener, Hans-Christoph; Sacco, Ralph L; Greving, Jacoba P; Algra, Ale

2017-01-01

BACKGROUND: Chronic antiplatelet therapy in the post-acute phase of non-cardioembolic ischemic stroke is limited by the risk of intracranial hemorrhage (ICH) complications. METHODS: We developed an ICH risk score based on the PERFORM trial cohort (n = 19,100), which included patients with a

A Novel Role of Eruca sativa Mill. (Rocket Extract: Antiplatelet (NF-κB Inhibition and Antithrombotic Activities

Directory of Open Access Journals (Sweden)

Eduardo Fuentes

2014-12-01

Full Text Available Background: Epidemiological studies have shown the prevention of cardiovascular diseases through the regular consumption of vegetables. Eruca sativa Mill., commonly known as rocket, is a leafy vegetable that has anti-inflammatory activity. However, its antiplatelet and antithrombotic activities have not been described. Methods: Eruca sativa Mill. aqueous extract (0.1 to 1 mg/mL, was evaluated on human platelets: (i P-selectin expression by flow cytometry; (ii platelet aggregation induced by ADP, collagen and arachidonic acid; (iii IL-1β, TGF-β1, CCL5 and thromboxane B2 release; and (iv activation of NF-κB and PKA by western blot. Furthermore, (v antithrombotic activity (200 mg/kg and (vi bleeding time in murine models were evaluated. Results: Eruca sativa Mill. aqueous extract (0.1 to 1 mg/mL inhibited P-selectin expression and platelet aggregation induced by ADP. The release of platelet inflammatory mediators (IL-1β, TGF-β1, CCL5 and thromboxane B2 induced by ADP was inhibited by Eruca sativa Mill. aqueous extract. Furthermore, Eruca sativa Mill. aqueous extract inhibited NF-κB activation. Finally, in murine models, Eruca sativa Mill. aqueous extract showed significant antithrombotic activity and a slight effect on bleeding time. Conclusion: Eruca sativa Mill. presents antiplatelet and antithrombotic activity.

Management of patients taking antiplatelet or anticoagulant medication requiring invasive breast procedures: United Kingdom survey of radiologists' and surgeons' current practice

International Nuclear Information System (INIS)

Pritchard, M.G.; Townend, J.N.; Lester, W.A.; England, D.W.; Kearins, O.; Bradley, S.A.

2008-01-01

Aim: To determine the current practice in the UK National Health Service Breast Screening Programme for invasive diagnostic procedures and surgery in patients taking anticoagulant and antiplatelet medication. Materials and methods: Lead radiologists and surgeons at each breast screening service were surveyed to determine current practice. One hundred and five respondents provided information regarding their services, protocols, and willingness to proceed with combinations of procedures and anti-haemostatic medications. Results: Between units there was wide variation in practice. Within 21 services providing more than one response, 10 (48%) disagreed on whether protocols existed. Decisions to perform biopsies were unrelated to professional group. The taking of a drug history was variable. Surgeons reported more adverse effects than radiologists [21 (48%) versus 12 (26%)], but no difference in self-assessment of knowledge. Conclusion: Both radiologists and surgeons have expressed uncertainty about their understanding of anticoagulant and antiplatelet treatment. This is reflected in a wide range of practice. Guidance regarding the management of these patients is suggested

Practice points in gynecardiology

DEFF Research Database (Denmark)

Maas, Angela H E M; Euler, Mia von; Bongers, Marlies Y

2015-01-01

A growing number of premenopausal women are currently using antithrombotic and/or (dual) antiplatelet therapy for various cardiovascular indications. These may induce or exacerbate abnormal uterine bleeding and more awareness and knowledge among prescribers is required. Heavy and irregular....... In this article we summarize the scope of the problem and provide practical recommendations for the care for young women taking anticoagulants and/or (dual) antiplatelet therapy. We also recommend that more safety data on uterine bleeding with novel anticoagulants in premenopausal women should be obtained....... menstrual bleeding is common in women in their forties and may have a variety of underlying causes that require different treatment options. Thus using anticoagulants in premenopausal women demands specific expertise and close collaboration between cardiovascular physicians and gynecologists...

Pause med trombocytaggregationshaemmere hos kirurgiske patienter med kardiel stent

DEFF Research Database (Denmark)

Johansen, Mathias; Afshari, Arash; Kristensen, Billy

2010-01-01

Dual antiplatelet therapy with aspirin and clopidogrel is increasingly used for secondary prevention of cardiovascular events in patients with percutaneous coronary intervention. Anesthesiologists and surgeons are faced with the challenge of managing these patients prior to a surgical procedure. ....... Premature discontinuation of antiplatelet therapy constitutes a substantial risk of stent thrombosis, myocardial infarction and death. Continuing therapy increases the risk of bleeding. We provide the latest evidence on this topic for patients awaiting non-cardiac surgery....

Raindrop Size Distribution in Different Climatic Regimes from Disdrometer and Dual-Polarized Radar Analysis.

Science.gov (United States)

Bringi, V. N.; Chandrasekar, V.; Hubbert, J.; Gorgucci, E.; Randeu, W. L.; Schoenhuber, M.

2003-01-01

The application of polarimetric radar data to the retrieval of raindrop size distribution parameters and rain rate in samples of convective and stratiform rain types is presented. Data from the Colorado State University (CSU), CHILL, NCAR S-band polarimetric (S-Pol), and NASA Kwajalein radars are analyzed for the statistics and functional relation of these parameters with rain rate. Surface drop size distribution measurements using two different disdrometers (2D video and RD-69) from a number of climatic regimes are analyzed and compared with the radar retrievals in a statistical and functional approach. The composite statistics based on disdrometer and radar retrievals suggest that, on average, the two parameters (generalized intercept and median volume diameter) for stratiform rain distributions lie on a straight line with negative slope, which appears to be consistent with variations in the microphysics of stratiform precipitation (melting of larger, dry snow particles versus smaller, rimed ice particles). In convective rain, `maritime-like' and `continental-like' clusters could be identified in the same two-parameter space that are consistent with the different multiplicative coefficients in the Z = aR1.5 relations quoted in the literature for maritime and continental regimes.

Safety of low-dose aspirin in endovascular treatment for intracranial atherosclerotic stenosis.

Directory of Open Access Journals (Sweden)

Ning Ma

Full Text Available OBJECTIVES: To evaluate the safety of low-dose aspirin plus clopidogrel versus high-dose aspirin plus clopidogrel in prevention of vascular risk within 90 days of duration of dual antiplatelet therapy in patients treated with intracranial endovascular treatment. METHODS: From January 2012 to December 2013, this prospective and observational study enrolled 370 patients with symptomatic intracranial atherosclerotic stenosis of ≥70% with poor collateral undergoing intracranial endovascular treatment. Antiplatelet therapy consists of aspirin, at a low-dose of 100 mg or high-dose of 300 mg daily; clopidogrel, at a dose of 75 mg daily for 5 days before endovascular treatment. The dual antiplatelet therapy continued for 90 days after intervention. The study endpoints include acute thrombosis, subacute thrombosis, stroke or death within 90 days after intervention. RESULTS: Two hundred and seventy three patients received low-dose aspirin plus clopidogrel and 97 patients received high-dose aspirin plus clopidogrel before intracranial endovascular treatment. Within 90 days after intervention, there were 4 patients (1.5% with acute thrombosis, 5 patients (1.8% with subacute thrombosis, 17 patients (6.2% with stroke, and 2 death (0.7% in low-dose aspirin group, compared with no patient (0% with acute thrombosis, 2 patient (2.1% with subacute thrombosis, 6 patients (6.2% with stroke, and 2 death (2.1% in high-dose aspirin group, and there were no significant difference in all study endpoints between two groups. CONCLUSION: Low-dose aspirin plus clopidogrel is comparative in safety with high-dose aspirin plus clopidogrel within 90 days of duration of dual antiplatelet therapy in patients treated with intracranial endovascular treatment.

An epidural catheter removal after recent percutaneous coronary intervention and coronary artery stenting: Epidural catheter and antiaggregation therapy

Directory of Open Access Journals (Sweden)

Joksić Nikola

2016-01-01

Full Text Available Introduction: Anticoagulation and antiplatelet therapy in the presence of the epidural catheter is still controversial. It is well known that dual antiplatelet therapy is indicated for 12 months after the placement of drug-eluting stents (DES. Removal of an epidural catheter during that period is related to an increased risk of stent occlusion in case of discontinuation of platelet function inhibitors or, on the other hand, increased risk of epidural hematoma associated with neurological deficit if suppressed platelet function is still present. Case Report: Here we present a case of a 63-year-old man who was admitted to Institute for Cardiovascular Diseases Dedinje for elective aortic surgery. Before the induction, an epidural catheter was inserted at the Th10-Th11 epidural space. Uneventful surgery was performed under the combined epidural and general anesthesia. On the 2nd postoperative day, the patient sustained a ST depression myocardial infarction treated with percutaneous coronary intervention with DES placement, while epidural catheter was still in place. Dual antiplatelet therapy with 600mg of clopidogrel, 100 mg of acetilsalicylic acid (ASA and low molecular weight heparin (LMWH were started during the procedure. The next day, clopidogrel (75 mg and ASA (100 mg were continued as well as LMWH. The decision to remove the epidural catheter was made on the 9th postoperative day, after platelet aggregation assays were performed. Six hours after catheter removal the patient again received clopidogrel, ASA and LMWH. There were no signs of epidural hematoma. Conclusion: This case shows that point-of-care testing with platelet aggregation assays may be useful in increasing the margin of safety for epidural catheter removal during dual antiplatelet therapy.

Flow regimes

International Nuclear Information System (INIS)

Kh'yuitt, G.

1980-01-01

An introduction into the problem of two-phase flows is presented. Flow regimes arizing in two-phase flows are described, and classification of these regimes is given. Structures of vertical and horizontal two-phase flows and a method of their identification using regime maps are considered. The limits of this method application are discussed. The flooding phenomena and phenomena of direction change (flow reversal) of the flow and interrelation of these phenomena as well as transitions from slug regime to churn one and from churn one to annular one in vertical flows are described. Problems of phase transitions and equilibrium are discussed. Flow regimes in tubes where evaporating liquid is running, are described [ru

The dual Green Revolutions in South Korea: reforestation and agricultural revolution under the authoritarian regime.

Science.gov (United States)

Moon, Manyong

2012-01-01

In South Korea, the Green Revolution has been commonly understood as the development and dissemination of new rice varieties ('Tongil' rice) and the rapid increase of rice yield in the 1970s. However, revolutionary success in agriculture was not the only green revolution South Korea experienced; another green revolution lay in the success of reforestation projects. In the 1970s, South Korea's forest greening was closely related to its agricultural revolution in several ways. Therefore, South Korea's Green Revolution was an intrinsically linked double feature of agriculture and forestry. This two-pronged revolution was initiated by scientific research - yet accomplished by the strong administrative mobilization of President Park Chung Hee's regime. The process of setting goals and meeting them through a military-like strategy in a short time was made possible under the authoritarian regime, known as 'Yushin', though the administration failed to fully acknowledge scientific expertise in the process of pushing to achieve goals.

Dual-anticipating, dual and dual-lag synchronization in modulated time-delayed systems

International Nuclear Information System (INIS)

Ghosh, Dibakar; Chowdhury, A. Roy

2010-01-01

In this Letter, dual synchronization in modulated time delay system using delay feedback controller is proposed. Based on Lyapunov stability theory, we suggest a general method to achieve the dual-anticipating, dual, dual-lag synchronization of time-delayed chaotic systems and we find both its existing and sufficient stability conditions. Numerically it is shown that the dual synchronization is also possible when driving system contain two completely different systems. Effect of parameter mismatch on dual synchronization is also discussed. As an example, numerical simulations for the Mackey-Glass and Ikeda systems are conducted, which is in good agreement with the theoretical analysis.

In Vivo antiplatelet activity aggregation assay of bromelain fractionate by ethanol from extract pineapple core (Ananas comosus [l.] merr.)

Science.gov (United States)

Musfiroh, F. F.; Setiasih, S.; Handayani, S.; Hudiyono, S.; Ilyas, N. M.

2018-01-01

Processed fruit from pineapple is one of largest commodities tropical fruit production in Indonesia and will bring the waste from the skin and core. This study aims to isolate bromelain from the pineapple core (Ananas comusus) are purified by fractionation using ethanol and continued by activity test as an antiplatelets agent by in vivo method using white mice male ddy type with acetosal as positive control. Fractionation of crude enzyme bromelain with ethanol produces highest specific activity on ethanol 30-60% fraction (fraction 2) 3.107 Unit/mg and the protein content 61.25 mg with the degree of purity of 155 times compared to crude enzyme. Antiplatelet aggregation tests from in vivo method shows that faction of bromelain with doses 70 μg/KgBW, 140 μg/KgBW, and 210 μg/KgBW can increase a meaningful bleeding time. The highest percentage of increase shown by the isolate at a dose of 210 μg/KgBW in the amount of 515.10 ± 182.23%, when compared to aspirin (231.20 ± 140.66), the value is relatively higher.

Antiplatelet Treatment After Transient Ischemic Attack and Ischemic Stroke in Patients With Cerebral Microbleeds in 2 Large Cohorts and an Updated Systematic Review.

Science.gov (United States)

Lau, Kui Kai; Lovelock, Caroline E; Li, Linxin; Simoni, Michela; Gutnikov, Sergei; Küker, Wilhelm; Mak, Henry Ka Fung; Rothwell, Peter M

2018-06-01

In patients with transient ischemic attack/ischemic stroke, microbleed burden predicts intracerebral hemorrhage (ICH), and ischemic stroke, but implications for antiplatelet treatment are uncertain. Previous cohort studies have had insufficient follow-up to assess the time course of risks, have not stratified risks by antithrombotic use, and have not reported extracranial bleeds or functional outcome of ICH versus ischemic stroke. In 2 independent prospective cohorts with transient ischemic attack/ischemic stroke (Oxford Vascular Study/mainly white; University of Hong Kong/mainly Chinese), antiplatelet treatment was started routinely irrespective of microbleed burden. Risks, time course and outcome of ICH, extracranial bleeds, and recurrent ischemic events were determined and stratified by microbleed burden (0 versus 1, 2-4, and ≥5), adjusting for age, sex, and vascular risk factors. Microbleeds were more frequent in the Chinese cohort (450 of 1003 versus 165 of 1080; P <0.0001), but risk associations were similar during 7433 patient-years of follow-up. Among 1811 patients on antiplatelet drugs, risk of major extracranial bleeds was unrelated to microbleed burden ( P trend =0.87), but the 5-year risk of ICH was steeply related ( P trend <0.0001), with 11 of 15 (73%) of ICH in 140 of 1811 (7.7%) patients with ≥5 microbleeds. However, risk of ischemic stroke also increased with microbleed burden ( P trend =0.013), such that risk of ischemic stroke and coronary events exceeded ICH and major extracranial bleeds during the first year, even among patients with ≥5 microbleeds (11.6% versus 3.9%). However, this ratio changed over time, with risk of hemorrhage (11.2%) matching that of ischemic events (12.0%) after 1 year. Moreover, whereas the association between microbleed burden and risk of ischemic stroke was due mainly to nondisabling events ( P trend =0.007), the association with ICH was accounted for ( P trend <0.0001) by disabling/fatal events (≥5 microbleeds

An open-label, randomized, controlled, multicenter study exploring two treatment strategies of rivaroxaban and a dose-adjusted oral vitamin K antagonist treatment strategy in subjects with atrial fibrillation who undergo percutaneous coronary intervention (PIONEER AF-PCI)

NARCIS (Netherlands)

Gibson, C.M.; Mehran, R.; Bode, C.; Halperin, J.; Verheugt, F.W.A.; Wildgoose, P.; Eickels, M. van; Lip, G.Y.; Cohen, M.; Husted, S.; Peterson, E.; Fox, K.

2015-01-01

BACKGROUND: Guidelines recommendations regarding anticoagulant therapy after percutaneous coronary intervention (PCI) among patients with atrial fibrillation (AF) rely on retrospective, nonrandomized observational data. Currently, patients are treated with triple-therapy (dual antiplatelet therapy

Gravity Dual for Reggeon Field Theory and Non-linear Quantum Finance

OpenAIRE

Yu Nakayama

2009-01-01

We study scale invariant but not necessarily conformal invariant deformations of non-relativistic conformal field theories from the dual gravity viewpoint. We present the corresponding metric that solves the Einstein equation coupled with a massive vector field. We find that, within the class of metric we study, when we assume the Galilean invariance, the scale invariant deformation always preserves the non-relativistic conformal invariance. We discuss applications to scaling regime of Reggeo...

An investigation on the particulate number and size distributions over the whole engine map from an optimized combustion strategy combining RCCI and dual-fuel diesel-gasoline

International Nuclear Information System (INIS)

Benajes, Jesús; García, Antonio; Monsalve-Serrano, Javier; Boronat, Vicente

2017-01-01

Highlights: • Optimized dual-mode dual-fuel strategy to cover the whole engine map. • High coherence between smoke and total particles number for diffusive dual-fuel mode. • Fully premixed RCCI regime dominated by small particles of 30 nm diameter peak. • Highly premixed RCCI mode has a transitional behavior with two particle diameter peaks. - Abstract: Literature demonstrates that, for premixed low temperature combustion concepts, particulate matter cannot be directly extrapolated from soot emissions measurements, as typically done for conventional diesel combustion. This is because the particulate matter from low temperature combustion has low fraction of carbonaceous compounds and great amount of soluble organic fraction, which is not captured by the smoke measurement techniques such as the optical reflectometry. By this reason, the study of the particulate matter characteristics from this combustion techniques requires using specific equipment. The aim of the current work is to gain understanding on the particulate matter characteristics from the dual-mode dual-fuel combustion, which is an optimized combustion strategy that combines fully and highly premixed RCCI regimes at low and medium loads, and switches to dual-fuel diffusion combustion at full load. The study was performed over the whole engine map, using a 15.3:1 compression ratio medium-duty EURO VI diesel engine. In particular, the particulate number and size distributions were sampled using a scanning mobility particle sizer and a condensation particle counter, which allow measuring the size distribution and total number of particles from 5 to 250 nm. Results demonstrate that the fully premixed RCCI combustion is dominated by small particles (less than 30 nm in mobility diameter), the dual-fuel diffusion mode is dominated by larger particles (around 100 nm in mobility diameter) showing more diesel-like particle size distributions, and the highly premixed reactivity controlled compression

Closed string tachyons on AdS orbifolds and dual Yang-Mills instantons

Energy Technology Data Exchange (ETDEWEB)

Hikida, Y. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Iizuka, N. [California Univ., Santa Barbara, CA (United States). Kavli Inst. for Theoretical Physics

2007-06-15

We study the condensation of localized closed string tachyons on AdS orbifolds both from the bulk and boundary theory viewpoints. We first extend the known results for AdS{sub 5}/Z{sub k} to AdS{sub 3}/Z{sub k} case, and we proposed that the AdS{sub 3}/Z{sub k} decays into AdS{sub 3}/Z{sub k'} with k{sup '} < k. From the bulk viewpoint, we obtain a time-dependent gravity solution describing the decay of AdS orbifold numerically. From the dual gauge theory viewpoint, we calculated the Casimir energies of gauge theory vacua and it is found that their values are exactly the same as the masses of dual geometries, even though they are in different parameter regimes of 't Hooft coupling. We also consider AdS{sub 5} orbifold. The decay of AdS{sub 5}/Z{sub k} is dual to the transition between the vacua of dual gauge theory on R{sub t} x S{sup 3}/Z{sub k}. We constructed the instanton solutions describing the transitions by making use of instanton solutions on R{sub t} x S{sup 2}. (orig.)

Antiplatelet effects of Rhus verniciflua stokes heartwood and its active constituents--fisetin, butein, and sulfuretin--in rats.

Science.gov (United States)

Lee, Jun-Hyeong; Kim, Mikyung; Chang, Kyung-Hwa; Hong, Cheol Yi; Na, Chun-Soo; Dong, Mi-Sook; Lee, Dongho; Lee, Moo-Yeol

2015-01-01

Rhus verniciflua stokes (RVS) is known to promote blood circulation by preventing blood stasis, although the active ingredients and the underlying mechanism are unclear. Platelets are the primary cells that regulate circulation and contribute to the development of diverse cardiovascular diseases by aggregation and thrombosis. The study assessed the antiplatelet activity of RVS and sought to identify the active constituents. Pretreatment of washed platelets with RVS heartwood extract blunted the aggregatory response of platelets to collagen. In the subfractions, fisetin, butein, and sulfuretin were identified as effective inhibitors of platelet aggregation by collagen, thrombin, and adenosine-5'-diphosphate. Antiplatelet activities of all three compounds were concentration dependent, and fisetin had longer in vitro duration of action compared with butein or sulfuretin. Extracellular signal-regulated kinase (ERK) mitogen-activated protein kinase activation by collagen was prevented by fisetin, whereas butein and sulfuretin failed to inhibit ERK and p38 activation was not affected by any of the compounds. Rats orally administered 100 mg/(kg·day(-1)) fisetin for 7 days were resistant to arterial thrombosis, although total extract of RVS heartwood exhibited little effect at a dose of 1000 mg/(kg·day(-1)). RVS heartwood may have cardiovascular protective activity by inhibiting platelet aggregation. The active constituents are fisetin, butein, and sulfuretin, and fisetin is orally effective against thrombosis.

Outage probability of dual-hop FSO fixed gain relay transmission systems

KAUST Repository

Zedini, Emna

2016-12-24

In this paper, we analyze the end-to-end performance of dual-hop free-space optical (FSO) fixed gain relaying systems in the presence of atmospheric turbulence as well as pointing errors. More specifically, an exact closed-form expression for the outage probability is presented in terms of the bivariate Fox\\'s H function that accounts for both heterodyne detection as well as intensity modulation with direct detection. At high signal-to-noise ratio (SNR) regime, we provide very tight asymptotic result for this performance metric in terms of simple elementary functions. By using dual-hop FSO relaying, we demonstrate a better system performance as compared to the single FSO link. Numerical and Monte-Carlo simulation results are provided to verify the accuracy of the newly proposed results, and a perfect agreement is observed.

Optical stretching of giant unilamellar vesicles with an integrated dual-beam optical trap.

Science.gov (United States)

Solmaz, Mehmet E; Biswas, Roshni; Sankhagowit, Shalene; Thompson, James R; Mejia, Camilo A; Malmstadt, Noah; Povinelli, Michelle L

2012-10-01

We have integrated a dual-beam optical trap into a microfluidic platform and used it to study membrane mechanics in giant unilamellar vesicles (GUVs). We demonstrate the trapping and stretching of GUVs and characterize the membrane response to a step stress. We then measure area strain as a function of applied stress to extract the bending modulus of the lipid bilayer in the low-tension regime.

Dual Entwining Structures and Dual Entwined Modules

OpenAIRE

Abuhlail, Jawad Y.

2003-01-01

In this note we introduce and investigate the concepts of dual entwining structures and dual entwined modules. This generalizes the concepts of dual Doi-Koppinen structures and dual Doi-Koppinen modules introduced (in the infinite case over rings) by the author is his dissertation.

Dual-band and high-efficiency polarization converter based on metasurfaces at microwave frequencies

Science.gov (United States)

Liu, Yajun; Xia, Song; Shi, Hongyu; Zhang, Anxue; Xu, Zhuo

2016-06-01

We present a dual-band and high-efficiency polarization converter in microwave regime. The proposed converter can convert a linearly polarized wave to its cross-polarized wave for two distinct bands: Ku (11.5-20.0 GHz) and Ka (28.8-34.0 GHz). It can also convert the linearly polarized wave to a circularly polarized wave at four other frequencies. The experimental results are in good agreement with simulation results for both frequency bands. The polarization conversion ratio is above 0.94 for the Ku-band and 0.90 for the Ka-band. Furthermore, the converter can achieve dual-band and high-efficiency polarization conversion over angles of incidence up to 45°. The converter is also polarization-selective in that only the x- and y-polarized waves can be converted. The physical mechanism of the dual-band polarization conversion effect is interpreted via decomposed electric field components that couple with different plasmon resonance modes of the structure.

Dual-modality and dual-energy gamma ray densitometry of petroleum products using an artificial neural network

International Nuclear Information System (INIS)

Roshani, G.H.; Feghhi, S.A.H.; Setayeshi, S.

2015-01-01

The prediction of volume fractions in order to measure the multiphase flow rate is a very important issue and is the key parameter of multi-phase flow meters (MPFMs). Currently, the gamma ray attenuation technique is known as one of the most precise methods for obtaining volume fractions. The gamma ray attenuation technique is based on the mass attenuation coefficient, which is sensitive to density changes; density is sensitive in turn to temperature and pressure fluctuations. Therefore, MPFM efficiency depends strongly on environmental conditions. The conventional solution to this problem is the periodical recalibration of MPFMs, which is a demanding task. In this study, a method based on dual-modality densitometry and artificial intelligence (AI) is presented, which offers the advantage of the measurement of the oil–gas–water volume fractions independent of density changes. For this purpose, several experiments were carried out and used to validate simulated dual modality densitometry results. The reference density point was established at a temperature of 20 °C and pressure of 1 bar. To cover the full range of likely density fluctuations, four additional density sets were defined (at changes of ±4% and ±8% from the reference point). An annular regime with different percentages of oil, gas and water at different densities was simulated. Four features were extracted from the transmission and scattered detectors and were applied to the artificial neural network (ANN) as inputs. The input parameters included the "2"4"1Am full energy peak, "1"3"7Cs Compton edge, "1"3"7Cs full energy peak and total scattered count, and the outputs were the oil and air percentages. A multi-layer perceptron (MLP) neural network was used to predict the volume fraction independent of the oil and water density changes. The obtained results show that the proposed ANN model achieved good agreement with the real data, with an estimated root mean square error (RMSE) of less than 3

Endoscopy and antiplatelet agents. European Society of Gastrointestinal Endoscopy (ESGE) Guideline.

Science.gov (United States)

Boustière, C; Veitch, A; Vanbiervliet, G; Bulois, P; Deprez, P; Laquiere, A; Laugier, R; Lesur, G; Mosler, P; Nalet, B; Napoleon, B; Rembacken, B; Ajzenberg, N; Collet, J P; Baron, T; Dumonceau, J-M

2011-05-01

With the increasing use of antiplatelet agents (APA), their management during the periendoscopic period has become a more common and more difficult problem. The increase in use is due to the availability of new drugs and the widespread use of drug-eluting coronary stents. Acute coronary syndromes can occur when APA therapy is withheld for noncardiovascular interventions. Guidelines about APA management during the periendoscopic period are traditionally based on assessments of the procedure-related risk of bleeding and the risk of thrombosis if APA are stopped. New data allow better assessment of these risks, of the necessary duration of APA discontinuation before endoscopy, of the use of alternative procedures (mostly for endoscopic retrograde cholangiopancreatography [ERCP]), and of endoscopic methods that can be used to prevent bleeding (following colonic polypectomy). This guideline makes graded, evidence-based, recommendations for the management of APA for all currently performed endoscopic procedures. A short summary and two tables are included for quick reference. © Georg Thieme Verlag KG Stuttgart · New York.

Both antiplatelet and anticoagulant therapy may favorably affect outcome in patients with advanced heart failure. A retrospective analysis of the PRIME-II trial.

NARCIS (Netherlands)

Boer, R.A. de; Hillege, H.L.; Tjeerdsma, G.; Verheugt, F.W.A.; Veldhuisen, D.J. van

2005-01-01

INTRODUCTION: Current guidelines of chronic heart failure (CHF) do not recommend the use of oral anticoagulants (OAC) or antiplatelet therapy (APT). We performed a post-hoc analysis to evaluate the effect of the use of anti-thrombotic therapy with APT and OAC. PATIENTS AND METHODS: We examined 427

A Comparative Study of Molecular Structure, pKa, Lipophilicity, Solubility, Absorption and Polar Surface Area of Some Antiplatelet Drugs

Directory of Open Access Journals (Sweden)

Milan Remko

2016-03-01

Full Text Available Theoretical chemistry methods have been used to study the molecular properties of antiplatelet agents (ticlopidine, clopidogrel, prasugrel, elinogrel, ticagrelor and cangrelor and several thiol-containing active metabolites. The geometries and energies of most stable conformers of these drugs have been computed at the Becke3LYP/6-311++G(d,p level of density functional theory. Computed dissociation constants show that the active metabolites of prodrugs (ticlopidine, clopidogrel and prasugrel and drugs elinogrel and cangrelor are completely ionized at pH 7.4. Both ticagrelor and its active metabolite are present at pH = 7.4 in neutral undissociated form. The thienopyridine prodrugs ticlopidine, clopidogrel and prasugrel are lipophilic and insoluble in water. Their lipophilicity is very high (about 2.5–3.5 logP values. The polar surface area, with regard to the structurally-heterogeneous character of these antiplatelet drugs, is from very large interval of values of 3–255 Å2. Thienopyridine prodrugs, like ticlopidine, clopidogrel and prasugrel, with the lowest polar surface area (PSA values, exhibit the largest absorption. A high value of polar surface area (PSA of cangrelor (255 Å2 results in substantial worsening of the absorption in comparison with thienopyridine drugs.

The antiplatelet effects of nitrates: is it of clinical significance in patients with cardiovascular disease?

Science.gov (United States)

Zhou, Rui-Hai; Frishman, William H

2010-01-01

Organic nitrates have been used for over a century in cardiovascular therapy and are still widely used in the treatment of acute coronary syndromes, chronic angina pectoris, and congestive heart failure. Nitrates, together with sodium nitroprusside, generally referred to as nitrovasodilators, exert their biologic effects via the release of nitric oxide. They are also known as nitric oxide donors. The mechanism of action of these drugs is traditionally believed to lie in their arterial vasodilation and venodilation effects, resulting in an improvement of coronary artery blood supply and/or reduction of cardiac workload in the treatment of coronary artery disease and congestive heart failure. Recently it has been recognized that these drugs also have intrinsic antiplatelet and antithrombotic effects, demonstrated both in vitro and in vivo, which would add further rationale for the use of these drugs in atherothrombotic diseases. Research has shown that nitrovasodilators can nonselectively inhibit platelet aggregation induced by multiple stimuli. However, clinical trials have yielded conflicting results regarding clinical outcome, especially with long-term nitrate use. The potentially beneficial effects of nitrates could be negated by the development of tolerance and the generation of deleterious oxidative stress causing endothelial dysfunction during continuous nitrate administration. Much progress has been made in the development of new nitric oxide donors devoid of oxidant-generating properties. Novel combination therapies with nitrovasodilators plus antioxidants or agents with antioxidant properties have shown promise in reducing or reversing tolerance, potentiating antiplatelet effects, and improving clinical outcome. It is expected that clinical introduction of novel nitrovasodilator regimens will provide a new approach to the prevention and treatment of atherothrombotic diseases. Large-scale clinical trials will ultimately provide the evidence-based answers.

Prevalence of Ex Vivo High On-treatment Platelet Reactivity on Antiplatelet Therapy after Transient Ischemic Attack or Ischemic Stroke on the PFA-100(®) and VerifyNow(®).

LENUS (Irish Health Repository)

Kinsella, Justin A

2012-09-12

BACKGROUND: The prevalence of ex vivo high on-treatment platelet reactivity (HTPR) to commonly prescribed antiplatelet regimens after transient ischemic attack (TIA) or ischemic stroke is uncertain. METHODS: Platelet function inhibition was simultaneously assessed with modified light transmission aggregometry (VerifyNow; Accumetrics Inc, San Diego, CA) and with a moderately high shear stress platelet function analyzer (PFA-100; Siemens Medical Solutions USA, Inc, Malvern, PA) in a pilot, cross-sectional study of TIA or ischemic stroke patients. Patients were assessed on aspirin-dipyridamole combination therapy (n = 51) or clopidogrel monotherapy (n = 25). RESULTS: On the VerifyNow, HTPR on aspirin was identified in 4 of 51 patients (8%) on aspirin-dipyridamole combination therapy (≥550 aspirin reaction units on the aspirin cartridge). Eleven of 25 (44%) patients had HTPR on clopidogrel (≥194 P2Y12 reaction units on the P2Y12 cartridge). On the PFA-100, 21 of 51 patients (41%) on aspirin-dipyridamole combination therapy had HTPR on the collagen-epinephrine (C-EPI) cartridge. Twenty-three of 25 patients (92%) on clopidogrel had HTPR on the collagen-adenosine diphosphate (C-ADP) cartridge. The proportion of patients with antiplatelet HTPR was lower on the VerifyNow than PFA-100 in patients on both regimens (P < .001). CONCLUSIONS: The prevalence of ex vivo antiplatelet HTPR after TIA or ischemic stroke is markedly influenced by the method used to assess platelet reactivity. The PFA-100 C-ADP cartridge is not sensitive at detecting the antiplatelet effects of clopidogrel ex vivo. Larger prospective studies with the VerifyNow and with the PFA-100 C-EPI and recently released Innovance PFA P2Y cartridges (Siemens Medical Solutions USA, Inc) in addition to newer tests of platelet function are warranted to assess whether platelet function monitoring predicts clinical outcome in ischemic cerebrovascular disease.

Dual modality densitometry

International Nuclear Information System (INIS)

Tjugum, Stein-Arild

2003-01-01

Different measurement principles and design issues for gamma-ray densitometry for pipe flow are investigated. The dual modality densitometry (DMD) principle for salinity measurement and flow regime identification by multibeam densitometry are tested and verified. The measurement principles are implemented in a compact instrument design with low energy source and compact detectors. The DMD principle is experimentally verified for 3 inch and 2 inch pipes. These measurements are done on homogenous brine/gas mixtures. Both salinity independent GVF measurements and salinity measurements are obtained. The standard deviation of the salinity measurements are about 2 percent. This measurement inaccuracy is mainly caused by inhomogeneity in the liquid/gas distribution, and measurements are thus sensitive to changes in the flow regime. Models for the generation of scattered radiation are developed, and these have been used in the data-analysis and for producing special sensitivity maps for the generation of scattered radiation. The models are a useful tool for further development of the DMD principle. The work on multibeam gamma-ray densitometry has shown that flow regimes can be identified with as few as two detectors. This is verified in the flow-loop tests. Unambiguous flow regime identification will often require that the multibeam measurements are combined with other flow measurements. With a higher number of detectors more detailed information is found, and from the 9-beam measurements with the University of Bergen (UoB) gamma-ray tomography different flow regimes could clearly be identified from time series plots of the data. A laboratory prototype compact gamma-ray densitometer, the MiniGamma, has been built up and tested. Both the DMD measurement principle and the multibeam arrangement for flow regime identification are implemented in the instrument, and are successfully tested. The detector-types tested are CdZnTe semiconductor detectors, a miniature scintillation

9 months after acute coronary syndrome

African Journals Online (AJOL)

... largest single cause of death in the Western Cape Province (12%), followed by stroke (8.8%) and ... particularly IHD and stroke. The use of evidence-based optimal medical therapy (dual antiplatelet ..... Lancet 2011;378(9798):1231-1243.

Clopidogrel Resistance: Current Issues

Directory of Open Access Journals (Sweden)

NS Neki

2016-05-01

Full Text Available Antiplatelet agents are mainly used in the prevention and management of atherothrombotic complications. Dual antiplatelet therapy, combining aspirin and clopidogrel, is the standard care for patients having acute coronary syndromes or undergoing percutaneous coronary intervention according to the current ACC/AHA and ESC guidelines. But in spite of administration of dual antiplatelet therapy, some patients develop recurrent cardiovascular ischemic events especially stent thrombosis which is a serious clinical problem. Antiplatelet response to clopidogrel varies widely among patients based on ex vivo platelet function measurements. Clopidogrel is an effective inhibitor of platelet activation and aggregation due to its selective and irreversible blockade of the P2Y12 receptor. Patients who display little attenuation of platelet reactivity with clopidogrel therapy are labeled as low or nonresponders or clopidogrel resistant. The mechanism of clopidogrel resistance remains incompletely defined but there are certain clinical, cellular and genetic factors including polymorphisms responsible for therapeutic failure. Currently there is no standardized or widely accepted definition of clopidogrel resistance. The future may soon be realised in the routine measurement of platelet activity in the same way that blood pressure, cholesterol and blood sugar are followed to help guide the therapy, thus improving the care for millions of people. This review focuses on the methods used to identify patients with clopidogrel resistance, the underlying mechanisms, metabolism, clinical significance and current therapeutic strategies to overcome clopidogrel resistance. J Enam Med Col 2016; 6(1: 38-46

New oral anticoagulant and antiplatelet agents for neurosurgeons.

Science.gov (United States)

Kimpton, George; Dabbous, Bassam; Leach, Paul

2015-01-01

Until recently, warfarin, clopidogrel and aspirin have provided the mainstay for prevention of thrombotic disease in cardiac patients. However, new classes of drugs have recently emerged that promise better clinical outcomes and lower risks. Use of such agents has increased, but increased risk and severity of intra-cranial haemorrhage (ICH) still remain. These cases of intra-cranial bleeds present as emergencies to neurosurgical units. It is of paramount importance that neurosurgical practitioners are aware of those new drugs, useful monitoring tests and available emergency reversal options in case the patient needs emergency intervention. In this review we survey newly available agents in the U.K. at the time of publication. We look at the data provided by the manufacturers, related publications and international guidelines for their use and reversal. New anticoagulants offer a lower incidence of ICH compared with warfarin. Advanced and accurate monitoring tests are emerging, as are prospective data on reversal of anticoagulation in bleeding. Some standard coagulation tests may be of use, whilst reversal agents are available and being evaluated. The trial data shows that new antiplatelet agents have similar or increased incidence and severity of intra-cranial ICH compared with clopidogrel. There is currently limited data on monitoring or reversal. We suggest they may be managed similarly to clopidogrel by using platelet reactivity assays, optimising platelet count and using platelet transfusion with adjunctive agents.

Molecular spectroscopic and thermodynamic studies on the interaction of anti-platelet drug ticlopidine with calf thymus DNA

Science.gov (United States)

Afrin, Shumaila; Rahman, Yusra; Sarwar, Tarique; Husain, Mohammed Amir; Ali, Abad; Shamsuzzaman; Tabish, Mohammad

2017-11-01

Ticlopidine is an anti-platelet drug which belongs to the thienopyridine structural family and exerts its effect by functioning as an ADP receptor inhibitor. Ticlopidine inhibits the expression of TarO gene in S. aureus and may provide protection against MRSA. Groove binding agents are known to disrupt the transcription factor DNA complex and consequently inhibit gene expression. Understanding the mechanism of interaction of ticlopidine with DNA can prove useful in the development of a rational drug designing system. At present, there is no such study on the interaction of anti-platelet drugs with nucleic acids. A series of biophysical experiments were performed to ascertain the binding mode between ticlopidine and calf thymus DNA. UV-visible and fluorescence spectroscopic experiments confirmed the formation of a complex between ticlopidine and calf thymus DNA. Moreover, the values of binding constant were found to be in the range of 103 M- 1, which is indicative of groove binding between ticlopidine and calf thymus DNA. These results were further confirmed by studying the effect of denaturation on double stranded DNA, iodide quenching, viscometric studies, thermal melting profile as well as CD spectral analysis. The thermodynamic profile of the interaction was also determined using isothermal titration calorimetric studies. The reaction was found to be endothermic and the parameters obtained were found to be consistent with those of known groove binders. In silico molecular docking studies further corroborated well with the experimental results.

Flow regimes

International Nuclear Information System (INIS)

Liles, D.R.

1982-01-01

Internal boundaries in multiphase flow greatly complicate fluid-dynamic and heat-transfer descriptions. Different flow regimes or topological configurations can have radically dissimilar interfacial and wall mass, momentum, and energy exchanges. To model the flow dynamics properly requires estimates of these rates. In this paper the common flow regimes for gas-liquid systems are defined and the techniques used to estimate the extent of a particular regime are described. Also, the current computer-code procedures are delineated and introduce a potentially better method is introduced

Exploring the Possible Use of Information Barriers for future Biological Weapons Verification Regimes

International Nuclear Information System (INIS)

Luke, S.J.

2011-01-01

This report describes a path forward for implementing information barriers in a future generic biological arms-control verification regime. Information barriers have become a staple of discussion in the area of arms control verification approaches for nuclear weapons and components. Information barriers when used with a measurement system allow for the determination that an item has sensitive characteristics without releasing any of the sensitive information. Over the last 15 years the United States (with the Russian Federation) has led on the development of information barriers in the area of the verification of nuclear weapons and nuclear components. The work of the US and the Russian Federation has prompted other states (e.g., UK and Norway) to consider the merits of information barriers for possible verification regimes. In the context of a biological weapons control verification regime, the dual-use nature of the biotechnology will require protection of sensitive information while allowing for the verification of treaty commitments. A major question that has arisen is whether - in a biological weapons verification regime - the presence or absence of a weapon pathogen can be determined without revealing any information about possible sensitive or proprietary information contained in the genetic materials being declared under a verification regime. This study indicates that a verification regime could be constructed using a small number of pathogens that spans the range of known biological weapons agents. Since the number of possible pathogens is small it is possible and prudent to treat these pathogens as analogies to attributes in a nuclear verification regime. This study has determined that there may be some information that needs to be protected in a biological weapons control verification regime. To protect this information, the study concludes that the Lawrence Livermore Microbial Detection Array may be a suitable technology for the detection of the

Exploring the Possible Use of Information Barriers for future Biological Weapons Verification Regimes

Energy Technology Data Exchange (ETDEWEB)

Luke, S J

2011-12-20

This report describes a path forward for implementing information barriers in a future generic biological arms-control verification regime. Information barriers have become a staple of discussion in the area of arms control verification approaches for nuclear weapons and components. Information barriers when used with a measurement system allow for the determination that an item has sensitive characteristics without releasing any of the sensitive information. Over the last 15 years the United States (with the Russian Federation) has led on the development of information barriers in the area of the verification of nuclear weapons and nuclear components. The work of the US and the Russian Federation has prompted other states (e.g., UK and Norway) to consider the merits of information barriers for possible verification regimes. In the context of a biological weapons control verification regime, the dual-use nature of the biotechnology will require protection of sensitive information while allowing for the verification of treaty commitments. A major question that has arisen is whether - in a biological weapons verification regime - the presence or absence of a weapon pathogen can be determined without revealing any information about possible sensitive or proprietary information contained in the genetic materials being declared under a verification regime. This study indicates that a verification regime could be constructed using a small number of pathogens that spans the range of known biological weapons agents. Since the number of possible pathogens is small it is possible and prudent to treat these pathogens as analogies to attributes in a nuclear verification regime. This study has determined that there may be some information that needs to be protected in a biological weapons control verification regime. To protect this information, the study concludes that the Lawrence Livermore Microbial Detection Array may be a suitable technology for the detection of the

Pause med trombocytaggregationshaemmere hos kirurgiske patienter med kardiel stent

DEFF Research Database (Denmark)

Johansen, Mathias; Afshari, Arash; Kristensen, Billy

2010-01-01

Dual antiplatelet therapy with aspirin and clopidogrel is increasingly used for secondary prevention of cardiovascular events in patients with percutaneous coronary intervention. Anesthesiologists and surgeons are faced with the challenge of managing these patients prior to a surgical procedure...

Pharmaco-Mechanical Strategies to Optimize the Balance between Ischemia and Bleeding after Percutaneous Coronary Intervention –Navigating between Scylla and Charybdis–

NARCIS (Netherlands)

F. Costa (Francesco)

2018-01-01

textabstractBeing between Scylla and Charybdis is an idiomatic form originating from Greek mythology, which means the obligation of choosing between two evils. Dual antiplatelet therapy after percutaneous coronary intervention is the cornerstone of the treatment for secondary prevention

Some properties of dual and approximate dual of fusion frames

OpenAIRE

Arefijamaal, Ali Akbar; Neyshaburi, Fahimeh Arabyani

2016-01-01

In this paper we extend the notion of approximate dual to fusion frames and present some approaches to obtain dual and approximate alternate dual fusion frames. Also, we study the stability of dual and approximate alternate dual fusion frames.

Anti-platelet activity of water dispersible curcuminoids in rat platelets.

Science.gov (United States)

Maheswaraiah, Anikisetty; Rao, Lingamallu Jaganmohan; Naidu, Kamatham Akhilender

2015-03-01

Curcuminoids are active principle of turmeric with plethora of health beneficial properties. In this study, we have evaluated for the first time the effect of water dispersible curcuminoids on rat platelet aggregation. Curcuminoids (10-30 µg/mL) significantly inhibited platelet aggregation induced by agonists viz., collagen, ADP and arachidonic acid. Curcuminoids were found to be two-fold more potent than curcumin in inhibiting platelet aggregation. Intracellular curcuminoid concentration was relatively higher than curcumin in rat platelets. Curcuminoids significantly attenuated thromboxane A2 , serotonin levels in rat platelets which play an important role in platelet aggregation. Curcuminoid treatment increased nitric oxide (NO) levels in platelets treated with agonists. Curcuminoids inhibited free radicals such as superoxide anion released from activated platelets, which ultimately inhibits platelet aggregation. Further, curcuminoids inhibited 12-lipoxygenase activity and formation of 12-hydroperoxyeicosatetraenoic acid (12-HPETE) in activated rat platelets which regulates platelet aggregation. The results suggest that curcuminoids have remarkable anti-platelet activity by modulating multiple mechanisms involved in platelet aggregation. Thus curcuminoids may have a therapeutic potential to prevent platelet activation related disorders. Copyright © 2015 John Wiley & Sons, Ltd.

Impact of Martensite Spatial Distribution on Quasi-Static and Dynamic Deformation Behavior of Dual-Phase Steel

Science.gov (United States)

Singh, Manpreet; Das, Anindya; Venugopalan, T.; Mukherjee, Krishnendu; Walunj, Mahesh; Nanda, Tarun; Kumar, B. Ravi

2018-02-01

The effects of microstructure parameters of dual-phase steels on tensile high strain dynamic deformation characteristic were examined in this study. Cold-rolled steel sheets were annealed using three different annealing process parameters to obtain three different dual-phase microstructures of varied ferrite and martensite phase fraction. The volume fraction of martensite obtained in two of the steels was near identical ( 19 pct) with a subtle difference in its spatial distribution. In the first microstructure variant, martensite was mostly found to be situated at ferrite grain boundaries and in the second variant, in addition to at grain boundaries, in-grain martensite was also observed. The third microstructure was very different from the above two with respect to martensite volume fraction ( 67 pct) and its morphology. In this case, martensite packets were surrounded by a three-dimensional ferrite network giving an appearance of core and shell type microstructure. All the three steels were tensile deformed at strain rates ranging from 2.7 × 10-4 (quasi-static) to 650 s-1 (dynamic range). Field-emission scanning electron microscope was used to characterize the starting as well as post-tensile deformed microstructures. Dual-phase steel consisting of small martensite volume fraction ( 19 pct), irrespective of its spatial distribution, demonstrated high strain rate sensitivity and on the other hand, steel with large martensite volume fraction ( 67 pct) displayed a very little strain rate sensitivity. Interestingly, total elongation was found to increase with increasing strain rate in the dynamic regime for steel with core-shell type of microstructure containing large martensite volume fraction. The observed enhancement in plasticity in dynamic regime was attributed to adiabatic heating of specimen. To understand the evolving damage mechanism, the fracture surface and the vicinity of fracture ends were studied in all the three dual-phase steels.

Role of sodium tungstate as a potential antiplatelet agent

Directory of Open Access Journals (Sweden)

Fernández-Ruiz R

2015-05-01

Full Text Available Rebeca Fernández-Ruiz,1,2 Marc Pino,3 Begoña Hurtado,4 Pablo García de Frutos,4 Carolina Caballo,3 Ginés Escolar,3 Ramón Gomis,1,2,5 Maribel Diaz-Ricart3 1Diabetes and Obesity Research Laboratory, Institut d'Investigacions Biomediques August Pi i Sunyer (IDIBAPS, Rosellón, Barcelona, 2Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas, Barcelona, 3Hemotherapy–Hemostasis, Hospital Clínic, Universidad de Barcelona, IDIBAPS, Villarroel, Barcelona, 4Institutode Investigaciones Biomédicas de Barcelona, Consejo Superior de Investigaciones Científicas, Institut d’Investigacions Biomediques August Pi i Sunyer, Rosellón, Barcelona, 5Hospital Clinic, Universitat de Barcelona, Villarroel, Barcelona, Spain Purpose: Platelet inhibition is a key strategy in the management of atherothrombosis. However, the large variability in response to current strategies leads to the search for alternative inhibitors. The antiplatelet effect of the inorganic salt sodium tungstate (Na2O4W, a protein tyrosine phosphatase 1B (PTP1B inhibitor, has been investigated in this study.Methods: Wild-type (WT and PTP1B knockout (PTP1B-/- mice were treated for 1 week with Na2O4W to study platelet function with the platelet function analyzer PFA-100, a cone-and-plate analyzer, a flat perfusion chamber, and thrombus formation in vivo. Human blood aliquots were incubated with Na2O4W for 1 hour to measure platelet function using the PFA-100 and the annular perfusion chamber. Aggregometry and thromboelastometry were also performed.Results: In WT mice, Na2O4W treatment prolonged closure times in the PFA-100 and decreased the surface covered (%SC by platelets on collagen. Thrombi formed in a thrombosis mice model were smaller in animals treated with Na2O4W (4.6±0.7 mg vs 8.9±0.7 mg; P<0.001. Results with Na2O4W were similar to those in untreated PTP1B-/- mice (5.0±0.3 mg. Treatment of the PTP1B-/- mice with Na2O4W modified only

Transition from weak wave turbulence regime to solitonic regime

Science.gov (United States)

Hassani, Roumaissa; Mordant, Nicolas

2017-11-01

The Weak Turbulence Theory (WTT) is a statistical theory describing the interaction of a large ensemble of random waves characterized by very different length scales. For both weak non-linearity and weak dispersion a different regime is predicted where solitons propagate while keeping their shape unchanged. The question under investigation here is which regime between weak turbulence or soliton gas does the system choose ? We report an experimental investigation of wave turbulence at the surface of finite depth water in the gravity-capillary range. We tune the wave dispersion and the level of nonlinearity by modifying the depth of water and the forcing respectively. We use space-time resolved profilometry to reconstruct the deformed surface of water. When decreasing the water depth, we observe a drastic transition between weak turbulence at the weakest forcing and a solitonic regime at stronger forcing. We characterize the transition between both states by studying their Fourier Spectra. We also study the efficiency of energy transfer in the weak turbulence regime. We report a loss of efficiency of angular transfer as the dispersion of the wave is reduced until the system bifurcates into the solitonic regime. This project has recieved funding from the European Research Council (ERC, Grant Agreement No. 647018-WATU).

Tailored antiplatelet therapy to improve prognosis in patients exhibiting clopidogrel low-response prior to percutaneous coronary intervention for stable angina or non-ST elevation acute coronary syndrome

DEFF Research Database (Denmark)

Paarup Dridi, Nadia; Johansson, Pär I; Lønborg, Jacob T

2015-01-01

Abstract Aim: To investigate whether an intensified antiplatelet regimen could improve prognosis in stable or non-ST elevation in acute coronary syndrome (ACS) patients exhibiting high on-treatment platelet reactivity (HTPR) on clopidogrel and treated with percutaneous coronary intervention (PCI...

Meta-analysis of randomized controlled trials and adjusted observational results of use of clopidogrel, aspirin, and oral anticoagulants in patients undergoing percutaneous coronary intervention

DEFF Research Database (Denmark)

D'Ascenzo, Fabrizio; Taha, Salma; Moretti, Claudio

2015-01-01

The optimal antiaggregant therapy after coronary stenting in patients receiving oral anticoagulants (OACs) is currently debated. MEDLINE and Cochrane Library were searched for studies reporting outcomes of patients who underwent PCI and who were on triple therapy (TT) or dual-antiplatelet therapy...

Bioresorbable Polymer Coated Metallic Stents and Fully Bioresorbable Scaffolds: Benefits and limitations in different coronary lesion subsets, -clinical and intracascular imaging results-

NARCIS (Netherlands)

J.M. Fam (Jiang Ming)

2018-01-01

markdownabstractPercutaneous coronary intervention (PCI) which involves the deployment of devices such as metallic drug eluting stents (DES) in coronary artery lesions and concomitant dual antiplatelet therapy (DAPT) is one of the mainstays of management of coronary artery disease and has become one

Anti-platelet and anti-thrombotic effect of a traditional herbal medicine Kyung-Ok-Ko.

Science.gov (United States)

Kim, Tae-Ho; Lee, Kyoung Mee; Hong, Nam Doo; Jung, Yi-Sook

2016-02-03

Kyung-Ok-Ko (KOK), a traditional herbal prescription, contains six main ingredients; Rehmannia glutinosa var. purpurae, Lycium chinense, Aquillaria agallocha, Poria cocos, Panax ginseng, and honey. KOK has been widely taken as a traditional oriental medicine for improving blood circulation or age-related symptoms, such as dementia and stroke. However, the effect of KOK on platelet activity has not been clarified. To evaluate the effect of KOK on platelet function, we evaluated its effect on functional markers of platelet activation such as aggregation and shape change. As a mechanism study for the effect of KOK, we examined its effect on granule secretion, intracellular Ca(2+) increase, and PLCγ and Akt activation. To investigate the effect of orally administered KOK (0.5, 1, 2 g/kg), we examined its ex vivo effect on platelet aggregation in rat, and its in vivo anti-thrombotic effect in mice thromboembolism model. Furthermore, the effect of KOK on bleeding time was examined to estimate its potential side effect. KOK (0.3, 1, 3, 10 mg/ml) inhibited collagen-induced platelet aggregation and shape change in rat platelets in a concentration-dependent manner. The mechanism for the anti-platelet effect of KOK seems to involve the inhibition of ATP release, intracellular Ca(2+) elevation, and the phosphorylation of PLCγ and Akt. In rat ex vivo study, KOK (2 g/kg, p.o. for 1 day, and 0.5, 1, 2 g/kg, p.o. for 7 days) also had significant inhibitory effects on collagen-induced platelet aggregation. In addition, KOK showed a significant protective effect against thrombosis attack in mice. The prolongation of bleeding time by KOK was much less than that by ASA, suggesting a beneficial potential of KOK than ASA in view of side effect. These findings suggest that KOK elicits remarkable anti-platelet and anti-thrombotic effects with less side effect of bleeding, and therefore, it may have a therapeutic potential for the prevention of platelet-associated cardiovascular diseases

Smooth Horizonless Geometries Deep Inside the Black-Hole Regime.

Science.gov (United States)

Bena, Iosif; Giusto, Stefano; Martinec, Emil J; Russo, Rodolfo; Shigemori, Masaki; Turton, David; Warner, Nicholas P

2016-11-11

We construct the first family of horizonless supergravity solutions that have the same mass, charges, and angular momenta as general supersymmetric rotating D1-D5-P black holes in five dimensions. This family includes solutions with arbitrarily small angular momenta, deep within the regime of quantum numbers and couplings for which a large classical black hole exists. These geometries are well approximated by the black-hole solution, and in particular exhibit the same near-horizon throat. Deep in this throat, the black-hole singularity is resolved into a smooth cap. We also identify the holographically dual states in the N=(4,4) D1-D5 orbifold conformal field theory (CFT). Our solutions are among the states counted by the CFT elliptic genus, and provide examples of smooth microstate geometries within the ensemble of supersymmetric black-hole microstates.

Dual-Hop FSO Transmission Systems over Gamma-Gamma Turbulence with Pointing Errors

KAUST Repository

Zedini, Emna

2016-11-18

In this paper, we analyze the end-to-end performance of dual-hop free-space optical (FSO) fixed gain relaying systems under heterodyne detection and intensity modulation with direct detection techniques in the presence of atmospheric turbulence as well as pointing errors. In particular, we derive the cumulative distribution function (CDF) of the end-to-end signal-to-noise ratio (SNR) in exact closed-form in terms of the bivariate Fox’s H function. Capitalizing on this CDF expression, novel closed-form expressions for the outage probability, the average bit-error rate (BER) for different modulation schemes, and the ergodic capacity of dual-hop FSO transmission systems are presented. Moreover, we present very tight asymptotic results for the outage probability and the average BER at high SNR regime in terms of simple elementary functions and we derive the diversity order of the considered system. By using dual-hop FSO relaying, we demonstrate a better system performance as compared to the single FSO link. Numerical and Monte-Carlo simulation results are provided to verify the accuracy of the newly proposed results, and a perfect agreement is observed.

Dual Credit/Dual Enrollment and Data Driven Policy Implementation

Science.gov (United States)

Lichtenberger, Eric; Witt, M. Allison; Blankenberger, Bob; Franklin, Doug

2014-01-01

The use of dual credit has been expanding rapidly. Dual credit is a college course taken by a high school student for which both college and high school credit is given. Previous studies provided limited quantitative evidence that dual credit/dual enrollment is directly connected to positive student outcomes. In this study, predictive statistics…

Antiplatelet effect of phloroglucinol is related to inhibition of cyclooxygenase, reactive oxygen species, ERK/p38 signaling and thromboxane A2 production

International Nuclear Information System (INIS)

Chang, Mei-Chi; Chang, Hsiao-Hua; Chan, Chiu-Po; Chou, Han-Yi; Chang, Bei-En; Yeung, Sin-Yuet; Wang, Tong-Mei; Jeng, Jiiang-Huei

2012-01-01

Platelet dysfunction is a major risk factor of cardiovascular diseases such as atherosclerosis, stroke and myocardial infarction. Many antiplatelet agents are used for prevention and treatment of these diseases. In this study, phloroglucinol (2.5–25 μM) suppressed AA-induced platelet aggregation and thromboxane B 2 (TXB 2 ) production, but not U46619-induced platelet aggregation. Phloroglucinol (100–250 μM) showed little cytotoxicity to platelets. Phloroglucinol inhibited the COX-1 and COX-2 activities by 45–74% and 49–72% respectively at concentrations of 10–50 μM. At concentrations of 1 and 5 μM, phloroglucinol attenuated the AA-induced ROS production in platelets by 30% and 53%, with an IC 50 of 13.8 μM. Phloroglucinol also inhibited the PMA-stimulated ROS production in PMN. Preincubation of platelets by phloroglucinol (10–25 μM) markedly attenuated the AA-induced ERK and p38 phosphorylation. Intravenous administration of phloroglucinol (2.5 and 5 μmol/mouse) suppressed the ex vivo AA-induced platelet aggregation by 57–71%. Phloroglucinol administration also elevated the mice tail bleeding time. Moreover, phloroglucinol inhibited the IL-1β-induced PGE 2 production in pulp fibroblasts. These results indicate that antiplatelet and anti-inflammatory effects of phloroglucinol are related to inhibition of COX, ROS and TXA2 production as well as ERK/p38 phosphorylation in platelets. Phloroglucinol further suppress PMA-induced ROS production in PMN. The antiplatelet effect of phloroglucinol was confirmed by ex vivo study. Clinically, the consumption of phloroglucinol-containing food/natural products as nutritional supplement may be helpful to cardiovascular health. Phloroglucinol has potential pharmacological use. -- Highlights: ► Phloroglucinol suppressed AA-induced platelet aggregation and thromboxane production. ► Phloroglucinol inhibited COX activity and IL-1b-induced PGE2 production in fibroblast. ► Phloroglucinol declined platelet and

Browse Title Index

African Journals Online (AJOL)

... hemorrhage mimicking a pneumopathy: a rare complication of dual antiplatelet therapy for ST elevation myocardial infarction, Abstract PDF. Sara Oualim, Charafeddine Ait Elharda, Dounia Benzeroual, Mustapha El Hattaoui. Vol 12, No 1 (2012), Pulmonary epidermoid carcinoma in a patient with acromegaly: a rare entity ...

Patent foramen ovale closure with GORE HELEX or CARDIOFORM Septal Occluder vs. antiplatelet therapy for reduction of recurrent stroke or new brain infarct in patients with prior cryptogenic stroke: Design of the randomized Gore REDUCE Clinical Study.

Science.gov (United States)

Kasner, Scott E; Thomassen, Lars; Søndergaard, Lars; Rhodes, John F; Larsen, Coby C; Jacobson, Joth

2017-12-01

Rationale The utility of patent foramen ovale (PFO) closure for secondary prevention in patients with prior cryptogenic stroke is uncertain despite multiple randomized trials completed to date. Aims The Gore REDUCE Clinical Study (REDUCE) aims to establish superiority of patent foramen ovale closure in conjunction with antiplatelet therapy over antiplatelet therapy alone in reducing the risk of recurrent clinical ischemic stroke or new silent brain infarct in patients who have had a cryptogenic stroke. Methods and design This controlled, open-label trial randomized 664 subjects with cryptogenic stroke at 63 multinational sites in a 2:1 ratio to either antiplatelet therapy plus patent foramen ovale closure (with GORE® HELEX® Septal Occluder or GORE® CARDIOFORM Septal Occluder) or antiplatelet therapy alone. Subjects will be prospectively followed for up to five years. Neuroimaging is required for all subjects at baseline and at two years or study exit. Study outcomes The two co-primary endpoints for the study are freedom from recurrent clinical ischemic stroke through at least 24 months post-randomization and incidence of new brain infarct (defined as clinical ischemic stroke or silent brain infarct) through 24 months. The primary analyses are an unadjusted log-rank test and a binomial test of subject-based proportions, respectively, both on the intent-to-treat population, with adjustment for testing multiplicity. Discussion The REDUCE trial aims to target a patient population with truly cryptogenic strokes. Medical therapy is limited to antiplatelet agents in both arms thereby reducing confounding. The trial should determine whether patent foramen ovale closure with the Gore septal occluders is safe and more effective than medical therapy alone for the prevention of recurrent clinical ischemic stroke or new silent brain infarct; the neuroimaging data will provide an opportunity to further support the proof of concept. The main results are anticipated in 2017

A time course study on prothrombotic parameters and their modulation by anti-platelet drugs in hyperlipidemic hamsters.

Science.gov (United States)

Singh, Vishal; Jain, Manish; Prakash, Prem; Misra, Ankita; Khanna, Vivek; Tiwari, Rajiv Lochan; Keshari, Ravi Shankar; Singh, Shivendra; Dikshit, Madhu; Barthwal, Manoj Kumar

2011-06-01

The present study was undertaken to assess the chronology of major pathological events associated with high cholesterol (HC) diet and their modulation by anti-platelet drugs. Male Golden Syrian hamsters were fed HC diet up to 90 days. Plasma lipid, glucose and coagulation parameters (commercial kits), platelet activation (whole blood aggregation and static adhesion), endothelial dysfunction (aortic ring vasoreactivity), splenocyte TNF-α, IFN-γ and iNOS mRNA transcripts (RT-PCR), and ferric chloride (time to occlusion) induced thrombosis were monitored at 15, 30, 60, and 90 days after HC feeding and compared with normolipidemic hamsters. A significant increase in plasma lipid levels was observed at 15 days of HC feeding, but other parameters remain unaltered. Enhanced ADP, collagen, and thrombin-induced platelet aggregation, splenocyte TNF-α expression along with endothelial dysfunction were observed from 30 to 90 days of HC feeding. Platelet adhesion on collagen-/fibrinogen-coated surface and IFN-γ expression were augmented only after 60 days, while enhanced iNOS expression, reduction in thrombin time, and potentiation of ferric chloride-induced thrombosis was observed only at 90 days of HC feeding. Thus, pathological changes induced by HC diet depend on the duration and extent of hyperlipidemia. Moreover, hamsters treated with anti-platelet drugs aspirin (5 mg/kg) or clopidogrel (10 mg/kg) along with HC feeding exhibited reduction in platelet activation as well as subsequent changes observed in the abovementioned parameters following HC feeding. Since reduction in TNF-α was associated with reversion in endothelial dysfunction and prothrombotic state, the role of platelets is implicated in the pathological changes associated with HC feeding.

Antiplatelet activity of Allium ursinum and Allium sativum.

Science.gov (United States)

Hiyasat, Bahi; Sabha, Dina; Grotzinger, Kristina; Kempfert, Joerg; Rauwald, Johann-Wilhelm; Mohr, Friedrich-Wilhelm; Dhein, Stefan

2009-01-01

Garlic (Allium sativum) has a well-established reputation as a protective agent against cardiovascular disease, while nearly nothing is known about its cousin Allium ursinum. The aim of this study was to evaluate the antiaggregatory mechanism of garlic and to compare the effects of A. ursinum and A. sativum. In a prospective study, extracts were prepared from A. sativum powder made from fresh A. sativum bulbs and fresh A. ursinum leaves by maceration. The extracts were characterized by thin layer chromatography. Their in vitro effects on human platelet aggregation were examined by light transmission aggregometry after induction by adenosine diphosphate (ADP), collagen, A23187, epinephrine and arachidonic acid (ARA) in platelets from healthy volunteers. A. ursinum and A. sativum exert similar antiaggregatory effects: they inhibit platelet aggregation induced via the ADP pathway and to a lesser extent aggregation induced by epinephrine, whereas ARA-, collagen- and A23187-induced aggregation was not affected. It became clear that the alcoholic extract of A. ursinum is the potent form, while the aqueous extract exerted an unspecific activity. The effects were strictly dose related. A. ursinum and A. sativum extracts exhibited similar potencies. Both A. ursinum and A. sativum exert antiaggregatory effects. Garlic extracts are acting by inhibition of the ADP pathway; their mechanisms of action are comparable to that of the clinically used drug clopidogrel. The pharmacologically active component of the extracts appears to be lipophilic rather than hydrophilic, but the precise chemical substance is still unknown. This is the first report on the antiplatelet activity of A. ursinum. Copyright 2009 S. Karger AG, Basel.

Regime change?

International Nuclear Information System (INIS)

Pilat, Joseph F.; Budlong-Sylvester, K.W.

2004-01-01

Following the 1998 nuclear tests in South Asia and later reinforced by revelations about North Korean and Iraqi nuclear activities, there has been growing concern about increasing proliferation dangers. At the same time, the prospects of radiological/nuclear terrorism are seen to be rising - since 9/11, concern over a proliferation/terrorism nexus has never been higher. In the face of this growing danger, there are urgent calls for stronger measures to strengthen the current international nuclear nonproliferation regime, including recommendations to place civilian processing of weapon-useable material under multinational control. As well, there are calls for entirely new tools, including military options. As proliferation and terrorism concerns grow, the regime is under pressure and there is a temptation to consider fundamental changes to the regime. In this context, this paper will address the following: Do we need to change the regime centered on the Treaty on the Nonproliferation of Nuclear Weapons (NPT) and the International Atomic Energy Agency (IAEA)? What improvements could ensure it will be the foundation for the proliferation resistance and physical protection needed if nuclear power grows? What will make it a viable centerpiece of future nonproliferation and counterterrorism approaches?

Antiplatelet Therapy and Clinical Outcomes Following Myocardial Infarction Among Patients in a U.S. Employer-Based Insurance Database.

Science.gov (United States)

Patel, Mehul D; Wu, David; Chase, Monica Reed; Mavros, Panagiotis; Heithoff, Kim; Hanson, Mary E; Simpson, Ross J

2017-06-01

Estimates of residual cardiovascular risks among patients who have experienced a recent acute myocardial infarction (MI) are predominantly derived from secondary prevention trial populations, patient registries, and population-based cohorts. To generate real-world evidence of antiplatelet treatment and recurrent events following MI in patients on antiplatelet treatment among commercial, employer-based insured patients in a large administrative database. This was a retrospective cohort claims database study using the Truven Health MarketScan Commercial Claims and Encounters and Medicare Supplemental databases between 2007-2011. Patients with an acute MI hospitalization with a discharge date between 2008 and 2010 were included. Excluded were those patients with documentation of stroke, transient ischemic attack (TIA), or severe bleeding at or before index hospitalization and with concomitant use of anticoagulant therapy following index hospitalization. Patients treated with clopidogrel following the index MI hospitalization were followed up to 1 year for repeat MI, stroke, and coronary revascularization. Among 33,943 post-MI continuous clopidogrel users without history of stroke, TIA, or bleeding, 22% had diabetes, whereas angina and renal impairment were less prevalent (5% and 7%, respectively). Over the 1-year follow-up, 2.4% experienced a repeat MI or stroke, and 8.2% underwent coronary revascularization. Angina, diabetes, and renal impairment were associated with elevated 1-year risk of repeat MI or stroke. This study suggests that there is residual cardiovascular risk, although relatively low, in an insured, secondary prevention population on antiplatelet treatment following an MI. In patients with MI, identifying angina, diabetes, and renal impairment may aid risk stratification and guide the effective management of these higher-risk patients. Funding for this research was provided by Merck & Co. Although Merck & Co. formally reviewed a penultimate draft, the

Comparative evaluation of antiplatelet effect of lycopene with aspirin and the effect of their combination on platelet aggregation: An in vitro study.

Science.gov (United States)

Sawardekar, Swapna B; Patel, Tejal C; Uchil, Dinesh

2016-01-01

The objective was to compare antiplatelet effect of lycopene with aspirin and to study effect of combination of the two on platelet aggregation in vitro, using platelets from healthy volunteers. Platelets were harvested; platelet count of platelet-rich plasma adjusted to 2.5 Χ 10(5)/μL. Aspirin (140 μmol/L) and lycopene (4, 6, 8, 10, and 12 μmol/L) were studied in vitro against adenosine-5'- diphosphate (ADP) (2.5 μM/L) and collagen. All the concentrations of lycopene (4-12 μmol/L) exhibited reduction in maximum platelet aggregation induced by aggregating agents ADP and collagen (P Lycopene at concentration 10 μmol/L showed maximum platelet inhibition (47.05% ± 19.56%) against ADP, whereas lycopene at concentration 8 μmol/L showed maximum platelet inhibition (54.26% ± 30.71%) against collagen. Four μmol/L of lycopene combined with 140 μmol/L and 70 μmol/L aspirin showed greater inhibition of platelets as compared to aspirin 140 μmol/L alone, against both ADP and collagen. The study favorably compares lycopene and aspirin with respect to their antiplatelet activities against ADP and collagen. Lycopene can be considered as a potential target for modifying the thrombotic and pro-inflammatory events associated with platelet activation.

Arctic circulation regimes.

Science.gov (United States)

Proshutinsky, Andrey; Dukhovskoy, Dmitry; Timmermans, Mary-Louise; Krishfield, Richard; Bamber, Jonathan L

2015-10-13

Between 1948 and 1996, mean annual environmental parameters in the Arctic experienced a well-pronounced decadal variability with two basic circulation patterns: cyclonic and anticyclonic alternating at 5 to 7 year intervals. During cyclonic regimes, low sea-level atmospheric pressure (SLP) dominated over the Arctic Ocean driving sea ice and the upper ocean counterclockwise; the Arctic atmosphere was relatively warm and humid, and freshwater flux from the Arctic Ocean towards the subarctic seas was intensified. By contrast, during anticylonic circulation regimes, high SLP dominated driving sea ice and the upper ocean clockwise. Meanwhile, the atmosphere was cold and dry and the freshwater flux from the Arctic to the subarctic seas was reduced. Since 1997, however, the Arctic system has been under the influence of an anticyclonic circulation regime (17 years) with a set of environmental parameters that are atypical for this regime. We discuss a hypothesis explaining the causes and mechanisms regulating the intensity and duration of Arctic circulation regimes, and speculate how changes in freshwater fluxes from the Arctic Ocean and Greenland impact environmental conditions and interrupt their decadal variability. © 2015 The Authors.

Causas estruturais e consequências dos regimes internacionais: regimes como variáveis intervenientes

Directory of Open Access Journals (Sweden)

Stephen D. Krasner

2012-06-01

Full Text Available Os regimes internacionais são definidos como princípios, normas, regras e procedimentos de tomada de decisões ao redor dos quais as expectativas dos atores convergem em uma dada área-tema. Como ponto de partida, os regimes são conceituados como variáveis intervenientes, estando entre fatores causais básicos e os resultados e comportamentos relacionados. Há três visões a respeito da importância dos regimes: as orientações estruturais convencionais desvalorizam os regimes como sendo, na melhor das hipóteses, ineficazes; as orientações grocianas vêem os regimes como componentes íntimos do sistema internacional; as perspectivas estruturalistas modificadas vêem os regimes como significativos somente em certas condições restritas. Para os argumentos grociano e estruturalista modificado - que concordam com a visão de que os regimes podem influenciar resultados e comportamentos - , o desenvolvimento de regimes é visto como uma função de cinco variáveis causais básicas: auto-interesse egoísta; poder político; normas e princípios difusos; usos e costumes; conhecimento.

Discovery and antiplatelet activity of a selective PI3Kβ inhibitor (MIPS-9922).

Science.gov (United States)

Zheng, Zhaohua; Pinson, Jo-Anne; Mountford, Simon J; Orive, Stephanie; Schoenwaelder, Simone M; Shackleford, David; Powell, Andrew; Nelson, Erin M; Hamilton, Justin R; Jackson, Shaun P; Jennings, Ian G; Thompson, Philip E

2016-10-21

A series of amino-substituted triazines were developed and examined for PI3Kβ inhibition and anti-platelet function. Structural adaptations of a morpholine ring of the prototype pan-PI3K inhibitor ZSTK474 yielded PI3Kβ selective compounds, where the selectivity largely derives from an interaction with the non-conserved Asp862 residue, as shown by site directed mutagenesis. The most PI3Kβ selective inhibitor from the series was studied in detail through a series of in vitro and in vivo functional studies. MIPS-9922, 10 potently inhibited ADP-induced washed platelet aggregation. It also inhibited integrin αIIbβ3 activation and αIIbβ3 dependent platelet adhesion to immobilized vWF under high shear. It prevented arterial thrombus formation in the in vivo electrolytic mouse model of thrombosis without inducing prolonged bleeding or excess blood loss. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Protease-Activated Receptor 4 (PAR4): A Promising Target for Antiplatelet Therapy.

Science.gov (United States)

Rwibasira Rudinga, Gamariel; Khan, Ghulam Jilany; Kong, Yi

2018-02-14

Cardiovascular diseases (CVDs) are currently among the leading causes of death worldwide. Platelet aggregation is a key cellular component of arterial thrombi and major cause of CVDs. Protease-activated receptors (PARs), including PAR1, PAR2, PAR3 and PAR4, fall within a subfamily of seven-transmembrane G-protein-coupled receptors (GPCR). Human platelets express PAR1 and PAR4, which contribute to the signaling transduction processes. In association with CVDs, PAR4 not only contributes to platelet activation but also is a modulator of cellular responses that serve as hallmarks of inflammation. Although several antiplatelet drugs are available on the market, they have many side effects that limit their use. Emerging evidence shows that PAR4 targeting is a safer strategy for preventing thrombosis and consequently may improve the overall cardiac safety profile. Our present review summarizes the PAR4 structural characteristics, activation mechanism, role in the pathophysiology of diseases and understanding the association of PAR4 targeting for improved cardiac protection. Conclusively, this review highlights the importance of PAR4 antagonists and its potential utility in different CVDs.

Evaluation of the antioxidant properties of N-acetylcysteine in human platelets: prerequisite for bioconversion to glutathione for antioxidant and antiplatelet activity.

Science.gov (United States)

Gibson, Kyle R; Neilson, Ilene L; Barrett, Fiona; Winterburn, Tim J; Sharma, Sushma; MacRury, Sandra M; Megson, Ian L

2009-10-01

N-Acetylcysteine (NAC) is a frequently used "antioxidant" in vitro, but the concentrations applied rarely correlate with those encountered with oral dosing in vivo. Here, we investigated the in vitro antioxidant and antiplatelet properties of NAC at concentrations (10-100 microM) that are achievable in plasma with tolerable oral dosing. The impact of NAC pretreatment (2 hours) on aggregation of platelets from healthy volunteers in response to thrombin and adenosine diphosphate and on platelet-derived nitric oxide (NO) was examined. NAC was found to be a weak reducing agent and a poor antioxidant compared with glutathione (reduced form) (GSH). However, platelets treated with NAC showed enhanced antioxidant activity and depression of reactive oxygen species generation associated with increases in intraplatelet GSH levels. An approximately 2-fold increase in NO synthase-derived nitrite was observed with 10 microM NAC treatment, but the effect was not concentration dependent. Finally, NAC significantly reduced both thrombin-induced and adenosine diphosphate-induced platelet aggregation. NAC should be considered a weak antioxidant that requires prior conversion to GSH to convey antioxidant and antithrombotic benefit at therapeutically relevant concentrations. Our results suggest that NAC might be an effective antiplatelet agent in conditions where increased oxidative stress contributes to heightened risk of thrombosis but only if the intraplatelet machinery to convert it to GSH is functional.

Simulations of magnetic hysteresis loops for dual layer recording media

Science.gov (United States)

Fal, T. J.; Plumer, M. L.; Whitehead, J. P.; Mercer, J. I.; van Ek, J.; Srinivasan, K.

2013-05-01

A Kinetic Monte-Carlo algorithm is applied to examine MH loops of dual-layer magnetic recording media at finite temperature and long time scales associated with typical experimental measurements. In contrast with standard micromagnetic simulations, which are limited to the ns-μs time regime, our approach allows for the direct calculation of magnetic configurations over periods from minutes to years. The model is used to fit anisotropy and coupling parameters to experimental data on exchange-coupled composite media which are shown to deviate significantly from standard micromagnetic results. Sensitivities of the loops to anisotropy, inter-layer exchange coupling, temperature, and sweep rate are examined.

Schwinger type processes via branes and their gravity duals

International Nuclear Information System (INIS)

Gorsky, A.S.; Saraikin, K.A.; Selivanov, K.G.

2002-01-01

We consider Schwinger type processes involving the creation of the charge and monopole pairs in the external fields and propose interpretation of these processes via corresponding brane configurations in type IIB string theory. We suggest simple description of some new interesting nonperturbative processes like monopole/dyon transitions in the electric field and W-boson decay in the magnetic field using the brane language. Nonperturbative pair production in the strong coupling regime using the AdS/CFT correspondence is studied. The treatment of the similar processes in the noncommutative theories when noncommutativity is traded for the background fields is presented and the possible role of the critical magnetic field which is S-dual to the critical electric field is discussed

Prehospital antiplatelet use and functional status on admission of patients with non-haemorrhagic moyamoya disease: a nationwide retrospective cohort study (J-ASPECT study)

OpenAIRE

Onozuka, Daisuke; Hagihara, Akihito; Nishimura, Kunihiro; Kada, Akiko; Nakagawara, Jyoji; Ogasawara, Kuniaki; Ono, Junichi; Shiokawa, Yoshiaki; Aruga, Toru; Miyachi, Shigeru; Nagata, Izumi; Toyoda, Kazunori; Matsuda, Shinya; Suzuki, Akifumi; Kataoka, Hiroharu

2016-01-01

Objectives To elucidate the association between antiplatelet use in patients with non-haemorrhagic moyamoya disease before hospital admission and good functional status on admission in Japan. Design Retrospective, multicentre, non-randomised, observational study. Setting Nationwide registry data in Japan. Participants A total of 1925 patients with non-haemorrhagic moyamoya disease admitted between 1 April 2012 and 31 March 2014 in Japan. Main outcome measure We performed propensity score-matc...

Successful management of aortic thrombi resulting in spinal cord infarction in a patient with antiphospholipid antibody syndrome and acute cholecystitis

Directory of Open Access Journals (Sweden)

Izumi M

2011-12-01

Full Text Available Manabu Izumi, Shoko Teraoka, Keisuke Yamashita, Kenji Matsumoto, Tomohiro Muronoi, Yoshimitsu Izawa, Chikara Yonekawa, Masaki Ano, Masayuki SuzukawaDepartment of Emergency and Critical Care Medicine, Jichi Medical University, Tochigi, JapanAbstract: A 74-year-old man with coronary artery disease was suffering from acute nonobstructive cholecystitis and was admitted to a nearby hospital. Dual antiplatelet (aspirin and ticlopidine therapy was discontinued before preparation for surgical resection of the gall bladder. During his time in hospital he was aware of lumbar pain and weakness in both legs. He was transferred to our hospital for further evaluation and therapy. Diffuse intra-aortic thrombi were revealed by computed tomography with contrast media, and magnetic resonance imaging showed spinal cord infarction. However, computed tomography scans of the descending aorta obtained 4 months before admission exhibited no signs of atherosclerotic plaques or intra-aortic thrombi. Laboratory data suggest that antiphospholipid antibody syndrome might have caused these acute multiple intra-arterial thrombi. By restarting dual antiplatelet therapy and increasing the dose of heparin (from 10,000 IU/day to 15,000 IU/day we successfully managed the patient's clinical condition and symptoms. It is important to understand that stopping antiplatelet therapy may rapidly grow thrombi in patients with a hypercoagulative state.Keywords: intra-aortic thrombus, antiphospholipid antibody syndrome, spinal cord infarction

Aspirin desensitization in patients undergoing percutaneous coronary intervention: a survey of current practice.

Science.gov (United States)

Chapman, Andrew R; Rushworth, Gordon F; Leslie, Stephen J

2013-01-01

Aspirin remains the mainstay of anti-platelet therapy in cardiac patients. However, if a patient is allergic to aspirin and dual anti-platelet therapy is indicated - such as with percutaneous coronary intervention (PCI), then there is no clear guidance. One possibility is aspirin desensitization. A variety of protocols exist for the rapid desensitization of patients with aspirin allergy. The aim of this survey was to assess current knowledge and practice regarding aspirin desensitization in the UK. We conducted a UK wide survey of all UK 116 PCI centers and obtained complete responses from 40 (35.4%) centers. Of these, just 7 (17.5%) centers had previously desensitised patients; 29 (87.9%) centers suggested a lack of a local protocol prevented them from desensitizing, with 10 (30.3%) unsure of how to conduct desensitization. Only 5 (12.5%) centers had a local policy for aspirin desensitization although 25 (64.1%) units had a clinical strategy for dealing with aspirin allergy; the majority (72%) giving higher doses of thienopyridine class drugs. In the UK, there appears to be no consistent approach to patients with aspirin allergy. Patients undergoing PCI benefit from dual anti-platelet therapy (including aspirin), and aspirin desensitization in those with known allergy may facilitate this. Sustained effort should be placed on encouraging UK centers to use desensitization as a treatment modality prior to PCI rather than avoiding aspirin altogether.

Exchange rate regimes and monetary arrangements

Directory of Open Access Journals (Sweden)

Ivan Ribnikar

2005-06-01

Full Text Available There is a close relationship between a country’s exchange rate regime and monetary arrangement and if we are to examine monetary arrangements then exchange rate regimes must first be analysed. Within the conventional and most widely used classification of exchange rate regimes into rigid and flexible or into polar regimes (hard peg and float on one side, and intermediate regimes on the other there, is a much greater variety among intermediate regimes. A more precise and, as will be seen, more useful classification of exchange rate regimes is the first topic of the paper. The second topic is how exchange rate regimes influence or determine monetary arrangements and monetary policy or monetary policy regimes: monetary autonomy versus monetary nonautonomy and discretion in monetary policy versus commitment in monetary policy. Both topics are important for countries on their path to the EU and the euro area

New Exact and Asymptotic Results of Dual-Branch MRC over Correlated Nakagami-m Fading Channels

KAUST Repository

Al-Quwaiee, Hessa

2015-05-01

We present in this paper a new performance analysis results of dual-branch maximal-ratio combining over correlated Nakagami-m fading channels with arbitrary fading parameter. In particular, we derive exact closed-form expressions of the outage probability, the average bit error rate, and the ergodic capacity in terms of the extended generalized bivariate Meijer G- function. Moreover, we also provide simple closed- form asymptotic expressions in the high signal-to- noise ratio regime of these three fundamental performance measures. © 2015 IEEE.

New Exact and Asymptotic Results of Dual-Branch MRC over Correlated Nakagami-m Fading Channels

KAUST Repository

Al-Quwaiee, Hessa; Alouini, Mohamed-Slim

2015-01-01

We present in this paper a new performance analysis results of dual-branch maximal-ratio combining over correlated Nakagami-m fading channels with arbitrary fading parameter. In particular, we derive exact closed-form expressions of the outage probability, the average bit error rate, and the ergodic capacity in terms of the extended generalized bivariate Meijer G- function. Moreover, we also provide simple closed- form asymptotic expressions in the high signal-to- noise ratio regime of these three fundamental performance measures. © 2015 IEEE.

Causas estruturais e consequências dos regimes internacionais: regimes como variáveis intervenientes

OpenAIRE

Krasner, Stephen D.

2012-01-01

Os regimes internacionais são definidos como princípios, normas, regras e procedimentos de tomada de decisões ao redor dos quais as expectativas dos atores convergem em uma dada área-tema. Como ponto de partida, os regimes são conceituados como variáveis intervenientes, estando entre fatores causais básicos e os resultados e comportamentos relacionados. Há três visões a respeito da importância dos regimes: as orientações estruturais convencionais desvalorizam os regimes como sendo, na melhor ...

Dual stator winding variable speed asynchronous generator: optimal design and experiments

International Nuclear Information System (INIS)

Tutelea, L N; Deaconu, S I; Popa, G N

2015-01-01

In the present paper is carried out a theoretical and experimental study of dual stator winding squirrel cage asynchronous generator (DSWA) behavior in the presence of saturation regime (non-sinusoidal) due to the variable speed operation. The main aims are the determination of the relations of calculating the equivalent parameters of the machine windings to optimal design using a Matlab code. Issue is limited to three phase range of double stator winding cage-induction generator of small sized powers, the most currently used in the small adjustable speed wind or hydro power plants. The tests were carried out using three-phase asynchronous generator having rated power of 6 [kVA]. (paper)

Sensitivity to spatial and temporal scale and fire regime inputs in deriving fire regime condition class

Science.gov (United States)

Linda Tedrow; Wendel J. Hann

2015-01-01

The Fire Regime Condition Class (FRCC) is a composite departure measure that compares current vegetation structure and fire regime to historical reference conditions. FRCC is computed as the average of: 1) Vegetation departure (VDEP) and 2) Regime (frequency and severity) departure (RDEP). In addition to the FRCC rating, the Vegetation Condition Class (VCC) and Regime...

The contemporary management of intracranial atherosclerotic disease.

Science.gov (United States)

Leng, Xinyi; Wong, Ka Sing; Leung, Thomas W

2016-06-01

Intracranial atherosclerotic disease is the most common cause of cerebral vasculopathy and an important stroke etiology worldwide, with a higher prevalence in Asian, Hispanic and African ethnicities. Symptomatic intracranial atherosclerotic disease portends a recurrent stroke risk as high as 18% at one year. The key to secondary prevention is an understanding of the underlying stroke mechanism and aggressive control of conventional cardiovascular risks. Contemporary treatment includes antiplatelet therapy, optimal glycemic and blood pressure control, statin therapy and lifestyle modifications. For patients with high-grade (70-99%) symptomatic steno-occlusion, short-term dual antiplatelet therapy with aspirin and clopidogrel followed by life-long single antiplatelet therapy may reduce the recurrent risk. Current evidence does not advocate percutaneous transluminal angioplasty and stenting as an initial treatment. External counterpulsation, encephaloduroarteriosynangiosis and remote limb ischemic preconditioning are treatments under investigation. Future studies should aim at predicting patients prone to recurrence despite of medical therapies and testing the efficacy of emerging therapies.

Self-dual Hopf quivers

International Nuclear Information System (INIS)

Huang Hualin; Li Libin; Ye Yu

2004-07-01

We study pointed graded self-dual Hopf algebras with a help of the dual Gabriel theorem for pointed Hopf algebras. Quivers of such Hopf algebras are said to be self-dual. An explicit classification of self-dual Hopf quivers is obtained. We also prove that finite dimensional coradically graded pointed self-dual Hopf algebras are generated by group-like and skew-primitive elements as associative algebras. This partially justifies a conjecture of Andruskiewitsch and Schneider and may help to classify finite dimensional self-dual pointed Hopf algebras

Performance analysis of dual-hop relaying systems in the presence of Co-channel interference

KAUST Repository

Ikki, Salama Said

2010-12-01

In this paper, we investigate the effect of co-channel interference on the performance of dual-hop communications with amplify-and-forward relaying. Based on the derivation of the effective signal-to-interference-plus-noise ratio (SINR) at the destination node of the system, taking into account co-channel interference, we obtain expressions for the error and outage probabilities. Moreover, we study the performance of the system in the high SINR regime. Monte-Carlo simulations are further provided and confirm the accuracy of the analytical results. ©2010 IEEE.

Protease-Activated Receptor 4 (PAR4: A Promising Target for Antiplatelet Therapy

Directory of Open Access Journals (Sweden)

Gamariel Rwibasira Rudinga

2018-02-01

Full Text Available Cardiovascular diseases (CVDs are currently among the leading causes of death worldwide. Platelet aggregation is a key cellular component of arterial thrombi and major cause of CVDs. Protease-activated receptors (PARs, including PAR1, PAR2, PAR3 and PAR4, fall within a subfamily of seven-transmembrane G-protein-coupled receptors (GPCR. Human platelets express PAR1 and PAR4, which contribute to the signaling transduction processes. In association with CVDs, PAR4 not only contributes to platelet activation but also is a modulator of cellular responses that serve as hallmarks of inflammation. Although several antiplatelet drugs are available on the market, they have many side effects that limit their use. Emerging evidence shows that PAR4 targeting is a safer strategy for preventing thrombosis and consequently may improve the overall cardiac safety profile. Our present review summarizes the PAR4 structural characteristics, activation mechanism, role in the pathophysiology of diseases and understanding the association of PAR4 targeting for improved cardiac protection. Conclusively, this review highlights the importance of PAR4 antagonists and its potential utility in different CVDs.

BaltDC: purification, characterization and infrared spectroscopy of an antiplatelet DC protein isolated from Bothrops alternatus snake venom.

Science.gov (United States)

Matias, Mariana Santos; de Sousa, Bruna Barbosa; da Cunha Pereira, Déborah Fernanda; Dias, Edigar Henrique Vaz; Mamede, Carla Cristine Neves; de Queiroz, Mayara Ribeiro; Silva, Anielle Christine Almeida; Dantas, Noelio Oliveira; Soares, Andreimar Martins; de Oliveira Costa, Júnia; de Oliveira, Fábio

2017-01-01

Snake venoms are a complex mixture of proteins, organic and inorganic compounds. Some of these proteins, enzymatic or non-enzymatic ones, are able to interact with platelet receptors, causing hemostatic disorders. The possible therapeutic potential of toxins with antiplatelet properties may arouse interest in the pharmacological areas. The present study aimed to purify and characterize an antiplatelet DC protein from Bothrops alternatus snake venom. The protein, called BaltDC (DC protein from B. alternatus snake venom), was purified by a combination of ion-exchange chromatography on DEAE-Sephacel column and gel filtration on Sephadex G-75. The molecular mass was estimated by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate (SDS-PAGE). The amino acid sequence of the N-terminal region was carried out by Edman degradation method. Platelet aggregation assays were performed in human platelet-rich plasma (PRP). Infrared (IR) spectroscopy was used in order to elucidate the interactions between BaltDC and platelet membrane. BaltDC ran as a single protein band on SDS-PAGE and showed apparent molecular mass of 32 kDa under reducing or non-reducing conditions. The N-terminal region of the purified protein revealed the amino acid sequence IISPPVCGNELLEVGEECDCGTPENCQNECCDA, which showed identity with other snake venom metalloproteinases (SVMPs). BaltDC was devoid of proteolytic, hemorrhagic, defibrinating or coagulant activities, but it showed a specific inhibitory effect on platelet aggregation induced by ristocetin and epinephrine in PRP. IR analysis spectra strongly suggests that PO 3 2- groups, present in BaltDC, form hydrogen bonds with the PO 2 - groups present in the non-lipid portion of the membrane platelets. BaltDC may be of medical interest since it was able to inhibit platelet aggregation.

Clopidogrel is not associated with major bleeding complications during peripheral arterial surgery.

Science.gov (United States)

Stone, David H; Goodney, Philip P; Schanzer, Andres; Nolan, Brian W; Adams, Julie E; Powell, Richard J; Walsh, Daniel B; Cronenwett, Jack L

2011-09-01

Persistent variation in practice surrounds preoperative clopidogrel management at the time of vascular surgery. While some surgeons preferentially discontinue clopidogrel citing a perceived risk of perioperative bleeding, others will proceed with surgery in patients taking clopidogrel for an appropriate indication. The purpose of this study was to determine whether preoperative clopidogrel use was associated with significant bleeding complications during peripheral arterial surgery. We reviewed a prospective regional vascular surgery registry recorded by 66 surgeons from 15 centers in New England from 2003 to 2009. Preoperative clopidogrel use within 48 hours of surgery was analyzed among patients undergoing carotid endarterectomy (CEA), lower extremity bypass (LEB), endovascular abdominal aortic aneurysm repair (EVAR), and open abdominal aortic aneurysm repair (oAAA). Ruptured AAAs were excluded. Endpoints included postoperative bleeding requiring reoperation, as well as the incidence and volume of blood transfusion. Statistical analysis was performed using analysis of variance, Fisher exact, χ(2), and Wilcoxon rank-sum tests. Over the study interval, a total of 10,406 patients underwent surgery, including 5264 CEA, 2883 LEB, 1125 EVAR, and 1134 oAAA repair. Antiplatelet use among all patients varied, with 19% (n = 2010) taking no antiplatelet agents, 69% (n = 7132) taking aspirin (ASA) alone, 2.2% (n = 229) taking clopidogrel alone, and 9.7% (n = 1017) taking both ASA and clopidogrel. Clopidogrel alone or as dual antiplatelet therapy was most frequently used prior to CEA and least frequently prior to oAAA group (CEA 16.1%, LEB 9.0%, EVAR 6.5%, oAAA 5%). Reoperation for bleeding was not significantly different among patients based on antiplatelet regimen (none 1.5%, ASA 1.3%, clopidogrel 0.9%, ASA/clopidogrel 1.5%, P = .74). When analyzed by operation type, no difference in reoperation for bleeding was seen across antiplatelet regimens. There was also no

Dual Youla parameterization

DEFF Research Database (Denmark)

Niemann, Hans Henrik

2003-01-01

A different aspect of using the parameterisation of all systems stabilised by a given controller, i.e. the dual Youla parameterisation, is considered. The relation between system change and the dual Youla parameter is derived in explicit form. A number of standard uncertain model descriptions...... are considered and the relation with the dual Youla parameter given. Some applications of the dual Youla parameterisation are considered in connection with the design of controllers and model/performance validation....

Technetium-99m-ECD SPECT in antiphospholipid antibody syndrome: a drastic improvement in brain perfusion by antiplatelet therapy

Energy Technology Data Exchange (ETDEWEB)

Tokumaru, Sunao; Yoshikai, Tomonori; Uchino, Akira; Kudo, Sho [Dept. of Radiology, Saga Medical School (Japan); Matsui, Makoto; Kuroda, Yasuo [Dept. of Neurology, Saga Medical School (Japan)

2001-12-01

We present a case of antiphospholipid antibody syndrome (APS) with repeated transient ischemic attacks (TIAs). Magnetic resonance imaging showed multiple cerebral infarcts and ischemic changes in the cerebral white matter. Cerebral angiographies showed no abnormalities. Technetium-99m-ethyl cysteinate dimer (Tc-99m-ECD) brain SPECT showed multiple decreased perfusion areas, which were more extensive than the lesions demonstrated on MRI. After treatment with an antiplatelet agent, the patient subsequently recovered from the TIAs. Although no interval changes were observed by MRI after therapy, follow-up Tc-99m-ECD SPECT revealed a marked improvement in brain perfusion. This is the first imaging report of remarkable post-therapy improvement in brain perfusion in APS cases. (orig.)

Technetium-99m-ECD SPECT in antiphospholipid antibody syndrome: a drastic improvement in brain perfusion by antiplatelet therapy

International Nuclear Information System (INIS)

Tokumaru, Sunao; Yoshikai, Tomonori; Uchino, Akira; Kudo, Sho; Matsui, Makoto; Kuroda, Yasuo

2001-01-01

We present a case of antiphospholipid antibody syndrome (APS) with repeated transient ischemic attacks (TIAs). Magnetic resonance imaging showed multiple cerebral infarcts and ischemic changes in the cerebral white matter. Cerebral angiographies showed no abnormalities. Technetium-99m-ethyl cysteinate dimer (Tc-99m-ECD) brain SPECT showed multiple decreased perfusion areas, which were more extensive than the lesions demonstrated on MRI. After treatment with an antiplatelet agent, the patient subsequently recovered from the TIAs. Although no interval changes were observed by MRI after therapy, follow-up Tc-99m-ECD SPECT revealed a marked improvement in brain perfusion. This is the first imaging report of remarkable post-therapy improvement in brain perfusion in APS cases. (orig.)

Dual Smarandache Curves of a Timelike Curve lying on Unit dual Lorentzian Sphere

OpenAIRE

Kahraman, Tanju; Hüseyin Ugurlu, Hasan

2016-01-01

In this paper, we give Darboux approximation for dual Smarandache curves of time like curve on unit dual Lorentzian sphere. Firstly, we define the four types of dual Smarandache curves of a timelike curve lying on dual Lorentzian sphere.

Towards a Gravity Dual for the Large Scale Structure of the Universe

CERN Document Server

Kehagias, A.

2016-01-01

The dynamics of the large-scale structure of the universe enjoys at all scales, even in the highly non-linear regime, a Lifshitz symmetry during the matter-dominated period. In this paper we propose a general class of six-dimensional spacetimes which could be a gravity dual to the four-dimensional large-scale structure of the universe. In this set-up, the Lifshitz symmetry manifests itself as an isometry in the bulk and our universe is a four-dimensional brane moving in such six-dimensional bulk. After finding the correspondence between the bulk and the brane dynamical Lifshitz exponents, we find the intriguing result that the preferred value of the dynamical Lifshitz exponent of our observed universe, at both linear and non-linear scales, corresponds to a fixed point of the RGE flow of the dynamical Lifshitz exponent in the dual system where the symmetry is enhanced to the Schrodinger group containing a non-relativistic conformal symmetry. We also investigate the RGE flow between fixed points of the Lifshitz...

Potassium-Based Dual Ion Battery with Dual-Graphite Electrode.

Science.gov (United States)

Fan, Ling; Liu, Qian; Chen, Suhua; Lin, Kairui; Xu, Zhi; Lu, Bingan

2017-08-01

A potassium ion battery has potential applications for large scale electric energy storage systems due to the abundance and low cost of potassium resources. Dual graphite batteries, with graphite as both anode and cathode, eliminate the use of transition metal compounds and greatly lower the overall cost. Herein, combining the merits of the potassium ion battery and dual graphite battery, a potassium-based dual ion battery with dual-graphite electrode is developed. It delivers a reversible capacity of 62 mA h g -1 and medium discharge voltage of ≈3.96 V. The intercalation/deintercalation mechanism of K + and PF 6 - into/from graphite is proposed and discussed in detail, with various characterizations to support. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Strengthening the nuclear non-proliferation regime

International Nuclear Information System (INIS)

Carlson, J.

2003-01-01

Although the nuclear non-proliferation regime has enjoyed considerable success, today the regime has never been under greater threat. Three states have challenged the objectives of the NPT, and there is a technology challenge - the spread of centrifuge enrichment technology and know-how. A major issue confronting the international community is, how to deal with a determined proliferator? Despite this gloomy scenario, however, the non-proliferation regime has considerable strengths - many of which can be developed further. The regime comprises complex interacting and mutually reinforcing elements. At its centre is the NPT - with IAEA safeguards as the Treaty's verification mechanism. Important complementary elements include: restraint in the supply and the acquisition of sensitive technologies; multilateral regimes such as the CTBT and proposed FMCT; various regional and bilateral regimes; the range of security and arms control arrangements outside the nuclear area (including other WMD regimes); and the development of proliferation-resistant technologies. Especially important are political incentives and sanctions in support of non-proliferation objectives. This paper outlines some of the key issues facing the non-proliferation regime

Autonomia e relevância dos regimes The autonomy and relevance of regimes

Directory of Open Access Journals (Sweden)

Gustavo Seignemartin de Carvalho

2005-12-01

Full Text Available Teorias institucionalistas na disciplina de relações internacionais usualmente definem regimes como um conjunto de normas e regras formais ou informais que permitem a convergência de expectativas ou a padronização do comportamento de seus participantes em uma determinada área de interesses com o objetivo de resolver problemas de coordenação que tenderiam a resultados não pareto-eficientes. Como estas definições baseadas meramente na "eficiência" dos regimes não parecem suficientes para explicar sua efetividade, o presente artigo propõe uma definição diferente para regimes: a de arranjos políticos que permitem a redistribuição dos ganhos da cooperação pelos participantes em uma determinada área de interesses em um contexto de interdependência. Regimes possuiriam efetividade pela sua autonomia e relevância, ou seja, por possuírem existência objetiva autônoma da de seus participantes e por influenciarem seu comportamento e expectativas de maneiras que não podem ser reduzidas à ação individual de nenhum deles. O artigo inicia-se com uma breve discussão sobre as dificuldades terminológicas associadas ao estudo de regimes e a definição dos conceitos de autonomia e relevância. Em seguida, classifica os diversos autores participantes do debate em duas perspectivas distintas, uma que nega (não-autonomistas e outra que atribui (autonomistas aos regimes autonomia e relevância, e faz uma breve análise dos autores e tradições mais significativos para o debate, aprofundando-se nos autonomistas e nos argumentos que reforçam a hipótese aqui apresentada. Ao final, o artigo propõe uma decomposição analítica dos regimes nos quatro elementos principais que lhes propiciam autonomia e relevância: normatividade, atores, especificidade da área de interesses e interdependência complexa com o contexto.Regimes are defined by institutionalist theories in the discipline of International Relations as formal or informal sets

[Acute anterior myocardial infarction as presenting feature of antiphospholipid syndrome related lupus arthritis].

Science.gov (United States)

Capilla-Geay, E; Poyet, R; Brocq, F X; Pons, F; Kerebel, S; Foucault, G; Jego, C; Cellarier, G R

2016-05-01

Antiphospholipid syndrome is an autoimmune disorder causing venous and arterial thrombosis. Acute coronary complications are rare but potentially dramatic. We report a 39-year-old woman who presented with an acute anterior myocardial infarction after intravenous corticosteroids as part of the treatment of lupus arthritis and revealing antiphospholipid syndrome. Emergency coronary angiography was performed with drug-eluting stent angioplasty despite the need for anticoagulation and dual antiplatelet therapy. Antiplatelet and anticoagulant therapy management is pivotal in patients with antiphospholipid syndrome and acute coronary syndrome to prevent thrombosis recurrence. Copyright © 2015 Société nationale française de médecine interne (SNFMI). Published by Elsevier SAS. All rights reserved.

Dynamic analysis of trapping and escaping in dual beam optical trap

Science.gov (United States)

Li, Wenqiang; Hu, Huizhu; Su, Heming; Li, Zhenggang; Shen, Yu

2016-10-01

In this paper, we simulate the dynamic movement of a dielectric sphere in optical trap. This dynamic analysis can be used to calibrate optical forces, increase trapping efficiency and measure viscous coefficient of surrounding medium. Since an accurate dynamic analysis is based on a detailed force calculation, we calculate all forces a sphere receives. We get the forces of dual-beam gradient radiation pressure on a micron-sized dielectric sphere in the ray optics regime and utilize Einstein-Ornstein-Uhlenbeck to deal with its Brownian motion forces. Hydrodynamic viscous force also exists when the sphere moves in liquid. Forces from buoyance and gravity are also taken into consideration. Then we simulate trajectory of a sphere when it is subject to all these forces in a dual optical trap. From our dynamic analysis, the sphere can be trapped at an equilibrium point in static water, although it permanently fluctuates around the equilibrium point due to thermal effects. We go a step further to analyze the effects of misalignment of two optical traps. Trapping and escaping phenomena of the sphere in flowing water are also simulated. In flowing water, the sphere is dragged away from the equilibrium point. This dragging distance increases with the decrease of optical power, which results in escaping of the sphere with optical power below a threshold. In both trapping and escaping process we calculate the forces and position of the sphere. Finally, we analyze a trapping region in dual optical tweezers.

Dual vector multiplet coupled to dual N=1 supergravity in 10D

International Nuclear Information System (INIS)

Nishino, Hitoshi; Rajpoot, Subhash

2005-01-01

We couple in superspace a dual vector multiplet (C m 1 ...m 7 ,λ α ) to the dual version of N=1 supergravity (e m a ,ψ m α ,M m 1 ...m 6 ,χ α ,Φ) in ten dimensions. The 7-form field C has its 8-form field strength H dual to the 2-form field strength F of the conventional vector multiplet. To simplify the computation, we use so-called beta-function-favored superspace constraints for dual supergravity developed for β-function computations. As in a more conventional constraint set, the H-Bianchi identity must have the form N and F, where N is the 7-form field strength in dual supergravity. The potential anomaly for the dual vector multiplet can be cancelled for the particular gauge group U(1) 496 by the Green-Schwarz mechanism. As a by-product, we also give the globally supersymmetric Abelian Dirac-Born-Infeld interactions for the dual vector multiplet for the first time

Gastrointestinal Hemorrhage Related to Fluoxetine in a Patient With Stroke.

Science.gov (United States)

Wee, Tze Chao

2017-11-01

We report on a patient who developed massive gastrointestinal hemorrhage related to the use of fluoxetine in combination with aspirin and clopidogrel. A 58-year-old man was admitted with a posterior circulation infarct with significant weakness in all four limbs and dysarthria. Aspirin and clopidogrel were started. Fluoxetine was started for pharmacological neurostimulation to promote motor recovery and for low mood. He developed gastrointestinal hemorrhage a week after fluoxetine was started. Fluoxetine was suspended and investigations failed to reveal the source of the bleeding. He was then restarted on fluoxetine along with dual antiplatelets, and gastrointestinal hemorrhage recurred after 1 week. He was extensively investigated for a source of gastrointestinal hemorrhage, and again no source could be identified. Eventually, fluoxetine was switched to mirtazapine with no further gastrointestinal hemorrhage. He remained on dual antiplatelets. A number of case-control and cohort studies had identified the association of gastrointestinal hemorrhage with the use of selective serotonin reuptake inhibitor (SSRI). We hope to raise awareness of this association in physical medicine and rehabilitation physicians as the use of SSRI is expected to rise.

Next generation drug-eluting stents: focus on bioabsorbable platforms and polymers

Directory of Open Access Journals (Sweden)

Brendan Doyle

2009-11-01

Full Text Available Brendan Doyle, David R Holmes JrDivision of Cardiovascular Diseases, Department of Internal Medicine, Mayo Clinic College of Medicine, Rochester, Minnesota, USAAbstract: The success of drug-eluting stents in preventing restenosis has shifted the focus of new stent development toward enhancing long term safety and efficacy of these devices, while simultaneously eliminating the need for indefinite dual antiplatelet therapy. A technical advance fulfilling these aims would hold tremendous potential to reduce morbidity, mortality and economic costs associated with the percutaneous treatment of coronary artery disease. An attractive approach is the use of bioabsorbable stent designs. These may include stents with different bioabsorbable drugs, bioabsorbable polymers or even bioabsorbable metallic backbones. A device that could achieve excellent acute and long-term results, but disappear completely within months (thereby avoiding the need for prolonged dual antiplatelet therapy, would be a tremendous advance. Too good to be true? We explore here the scientific rationale and prospects for success with this exciting concept.Keywords: percutaneous coronary intervention, biodegradable, bioabsorbable, polymer, stent

Static converters power supply: transient regimes; Alimentation par convertisseurs statiques: regimes transitoires

Energy Technology Data Exchange (ETDEWEB)

Pasqualini, G. [Ecole Superieure d`Electricite (France)

1997-08-01

Direct current motors, asynchronous and variable speed synchronous motors are generally supplied with static converters. Speed variation is obtained by voltage variation in DC motors and by frequency variation in AC motors. In these conditions, these motors are running continuously in transient regimes: the DC motors current is not direct and the AC motors current is not sinusoidal. This situation leads to pulsing couples in the shaft line and to an increase of Joule effect losses. The aim of this paper is to present the methods of study of the electric motors functioning using the shape of the power voltages given by converters and mathematical models of these machines. The synchronous machines are rapidly described while the asynchronous machines are studied using Ku`s transformation instead of Park`s transformation for simplification. For each type of machine, calculation methods allow to determine their current, additional losses and couple characteristics. The transient regimes considered are those remaining when the motor is running at a constant speed and defined regime (supply voltages are periodical functions of time). These transient regimes are identically reproducing with a frequency which is a multiple of the converters supply frequency. Transient regimes due to functioning changes of the motor, such as resisting couple or power supply frequency variations, are not considered in this study. (J.S.) 9 refs.

Is anti-platelet therapy needed in continuous flow left ventricular assist device patients? A single-centre experience.

Science.gov (United States)

Litzler, Pierre-Yves; Smail, Hassiba; Barbay, Virginie; Nafeh-Bizet, Catherine; Bouchart, François; Baste, Jean-Marc; Abriou, Caroline; Bessou, Jean-Paul

2014-01-01

We report our 5-year experience of continuous flow left ventricular assist device (LVAD) implantation without the use of anti-platelet therapy. Between February 2006 and September 2011, 27 patients (26 men; 1 woman) were implanted with a continuous flow LVAD (HeartMate II, Thoratec Corporation, Pleasanton, CA, USA). The mean age was 55.7 ± 9.9 years. The mean duration of support was 479 ± 436 (1-1555) days with 35.4 patient-years on support. Twenty-one patients were implanted as a bridge to transplantation and 6 for destination therapy. The anticoagulation regimen was fluindione for all patients, with aspirin for only 4 patients. At the beginning of our experience, aspirin was administered to 4 patients for 6, 15, 60 and 460 days. Due to gastrointestinal (GI) bleeding and epistaxis, aspirin was discontinued, and since August 2006, no patients have received anti-platelet therapy. At 3 years, the survival rate during support was 76%. The most common postoperative adverse event was GI bleeding (19%) and epistaxis (30%) (median time: 26 days) for patients receiving fluindione and aspirin. The mean International Normalized Ratio (INR) was 2.58 ± 0.74 during support. Fifteen patients have been tested for acquired Von Willebrand disease. A diminished ratio of collagen-binding capacity and ristocetin cofactor activity to Von Willebrand factor antigen was observed in 7 patients. In the postoperative period, 2 patients presented with ischaemic stroke at 1 and 8 months. One of these 2 patients had a previous history of carotid stenosis with ischaemic stroke. There were no patients with haemorrhagic stroke, transient ischaemic attack or pump thrombosis. The event rate of stroke (ischaemic and haemorrhagic) per patient-year was 0.059 among the patients without aspirin with fluindione regimen only. A fluindione regimen without aspirin in long-duration LVAD support appears to not increase thromboembolic events and could lead to a diminished risk of haemorrhagic stroke.

Age-specific risks, severity, time course, and outcome of bleeding on long-term antiplatelet treatment after vascular events: a population-based cohort study.

Science.gov (United States)

Li, Linxin; Geraghty, Olivia C; Mehta, Ziyah; Rothwell, Peter M

2017-07-29

Lifelong antiplatelet treatment is recommended after ischaemic vascular events, on the basis of trials done mainly in patients younger than 75 years. Upper gastrointestinal bleeding is a serious complication, but had low case fatality in trials of aspirin and is not generally thought to cause long-term disability. Consequently, although co-prescription of proton-pump inhibitors (PPIs) reduces upper gastrointestinal bleeds by 70-90%, uptake is low and guidelines are conflicting. We aimed to assess the risk, time course, and outcomes of bleeding on antiplatelet treatment for secondary prevention in patients of all ages. We did a prospective population-based cohort study in patients with a first transient ischaemic attack, ischaemic stroke, or myocardial infarction treated with antiplatelet drugs (mainly aspirin based, without routine PPI use) after the event in the Oxford Vascular Study from 2002 to 2012, with follow-up until 2013. We determined type, severity, outcome (disability or death), and time course of bleeding requiring medical attention by face-to-face follow-up for 10 years. We estimated age-specific numbers needed to treat (NNT) to prevent upper gastrointestinal bleeding with routine PPI co-prescription on the basis of Kaplan-Meier risk estimates and relative risk reduction estimates from previous trials. 3166 patients (1582 [50%] aged ≥75 years) had 405 first bleeding events (n=218 gastrointestinal, n=45 intracranial, and n=142 other) during 13 509 patient-years of follow-up. Of the 314 patients (78%) with bleeds admitted to hospital, 117 (37%) were missed by administrative coding. Risk of non-major bleeding was unrelated to age, but major bleeding increased steeply with age (≥75 years hazard ratio [HR] 3·10, 95% CI 2·27-4·24; pbleeds (5·53, 2·65-11·54; pbleeds (≥75 years HR 4·13, 2·60-6·57; pbleeds were mostly disabling or fatal (45 [62%] of 73 patients vs 101 [47%] of 213 patients with recurrent ischaemic stroke), and outnumbered

Dual Income Taxes

DEFF Research Database (Denmark)

Sørensen, Peter Birch

This paper discusses the principles and practices of dual income taxation in the Nordic countries. The first part of the paper explains the rationale and the historical background for the introduction of the dual income tax and describes the current Nordic tax practices. The second part...... of the paper focuses on the problems of taxing income from small businesses and the issue of corporate-personal tax integration under the dual income tax, considering alternative ways of dealing with these challenges. In the third and final part of the paper, I briefly discuss whether introducing a dual income...

Dual Diagnosis - Multiple Languages

Science.gov (United States)

... National Library of Medicine Comorbidity or dual diagnosis - Opioid addiction, part 9 - English PDF Comorbidity or dual diagnosis - Opioid addiction, part 9 - español (Spanish) PDF Comorbidity or dual ...

Sustainable urban regime adjustments

DEFF Research Database (Denmark)

Quitzau, Maj-Britt; Jensen, Jens Stissing; Elle, Morten

2013-01-01

The endogenous agency that urban governments increasingly portray by making conscious and planned efforts to adjust the regimes they operate within is currently not well captured in transition studies. There is a need to acknowledge the ambiguity of regime enactment at the urban scale. This direc...

International Food Regime

Directory of Open Access Journals (Sweden)

A. V. Malov

2018-01-01

Full Text Available The review article reveals the content of the concept of Food Regime, which is little-known in the Russian academic reference. The author monitored and codified the semantic dynamic of the terminological unit from its original interpretations to modern formulations based on the retrospective analysis. The rehabilitation of the academic merits of D. Puchala and R. Hopkins — authors who used the concept Food Regime for a few years before its universally recognized origin and official scientific debut, was accomplished with help of historical and comparative methods. The author implemented the method of ascension from the abstract to the concrete to demonstrating the classification of Food Regimes compiled on the basis of geopolitical interests in the sphere of international production, consumption, and distribution of foodstuffs. The characteristic features of historically formed Food Regime were described in the chronological order, as well as modern tendencies possessing reformist potential were identified. In particular, it has been established that the idea of Food Sovereignty (which is an alternative to the modern Corporate Food Regime is the subject for acute academic disputes. The discussion between P. McMichael P. and H. Bernstein devoted to the “peasant question” — mobilization frame of the Food Sovereignty strategy was analyzed using the secondary data processing method. Due to the critical analysis, the author comes to the conclusion that it is necessary to follow the principles of the Food Sovereignty strategy to prevent the catastrophic prospects associated with ecosystem degradation, accelerated erosion of soils, the complete disappearance of biodiversity and corporate autoc racy successfully. The author is convinced that the idea of Food Sovereignty can ward off energetic liberalization of nature, intensive privatization of life and rapid monetization of unconditioned human reflexes.

Mauritia flexuosa Presents In Vitro and In Vivo Antiplatelet and Antithrombotic Activities

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Eduardo Fuentes

2013-01-01

Full Text Available Fruit from the palm Mauritia flexuosa is one of the most important species in Peru, Venezuela, Brazil, Colombia, Bolivia, and Guyana. The present study aimed to investigate the antiplatelet and antithrombotic activities of oil extracted from Mauritia flexuosa. The fatty acid contents were determined by gas chromatography—mass spectrometry. Oil extract of peel of Mauritia flexuosa was extracted by soxhlet extraction. The oil extract inhibited platelet secretion and aggregation induced by ADP, collagen, and TRAP-6 by a concentration-dependent way (0.1 to 1 mg/mL without the participation of the adenylyl cyclase pathway and diminished platelet rolling and firm adhesion under flow conditions. Furthermore, the oil extract induced a marked increase in the rolling speed of leukocytes retained on the platelet surface, reflecting a reduction of rolling and less adhesion. At the concentrations used, the oil extract significantly decreased platelet release of sP-selectin, an atherosclerotic-related inflammatory mediator. Oil extract inhibited thrombus growth at the same concentration as that of aspirin, a classical reference drug. Finally, the data presented herein also demonstrate for the first time to our knowledge the protective effect of oil extracted from Mauritia flexuosa on platelet activation and thrombosis formation.

Self-dual metrics with self-dual Killing vectors

International Nuclear Information System (INIS)

Tod, K.P.; Ward, R.S.

1979-01-01

Twistor methods are used to derive a class of solutions to Einstein's vacuum equations, with anti-self dual Weyl tensor. In particular, all metrics with a Killing vector whose derivative is anti-self-dual and which admit a real positive-definite section are exhibited and shown to coincide with the metrics of Hawking. (author)

Antecedents of Teachers Fostering Effort within Two Different Management Regimes: An Assessment-Based Accountability Regime and Regime without External Pressure on Results

Science.gov (United States)

Christophersen, Knut-Andreas; Elstad, Eyvind; Turmo, Are

2012-01-01

This article focuses on the comparison of organizational antecedents of teachers' fostering of students' effort in two quite different accountability regimes: one management regime with an external-accountability system and one with no external accountability devices. The methodology involves cross-sectional surveys from two different management…

Visões de um objeto incômodo: o regime militar brasileiro An undesirable subject: the Brazilian military regime

Directory of Open Access Journals (Sweden)

Angelo Del Vecchio

2007-05-01

Full Text Available O presente artigo visa a qualificação do regime político vigente no Brasil entre 1964-1985. Para tanto, desenvolvo o resgate do conceito de ditadura, especialmente a partir da obra de Carl Schimitt, e busco aferir a sua adequação à análise do período militar. Palavras-chave: Estado. Regime político. Ditadura. Regime militar. The present article tries to qualify the political regime in Brazil from 1964 to 1985, using the concept of dictatorship mainly developed by Carl Schimitt in his writings and tries to adequate this concept to the Brazilian military regime. Keywords: State. Political regime. Dictatorship. Military regime.

THE INFLUENCED FLOW REGIMES

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Gavril PANDI

2011-03-01

Full Text Available The influenced flow regimes. The presence and activities ofhumanity influences the uniform environmental system, and in this context, therivers water resources. In concordance with this, the natural runoff regime suffersbigger and deeper changes. The nature of these changes depending on the type anddegree of water uses. The multitude of the use cause different types of influence,whit different quantitative aspects. In the same time, the influences havequalitative connotations, too, regarding to the modifications of the yearly watervolume runoff. So the natural runoff regime is modified. After analyzing thedistribution laws of the monthly runoff, there have been differenced four types ofinfluenced runoff regimes. In the excess type the influenced runoff is bigger thanthe natural, continuously in the whole year. The deficient type is characterized byinverse rapports like the first type, in the whole year. In the sinusoidal type, theinfluenced runoff is smaller than the natural in the period when the water isretained in the lake reservoirs, and in the depletion period the situation inverts. Atthe irregular type the ratio between influenced and natural runoff is changeable ina random meaner monthly. The recognition of the influenced regime and the gradeof influence are necessary in the evaluation and analysis of the usable hydrologicalriver resources, in the flood defence activities, in the complex scheme of thehydrographic basins, in the environment design and so on.

Antiplatelet Effects of Qishen Yiqi Dropping Pill in Platelets Aggregation in Hyperlipidemic Rabbits

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Yi Wang

2012-01-01

Full Text Available We investigated the effects of Qishen Yiqi Dropping Pill (QSYQ on platelets aggregation and its possible mechanisms. Hyperlipidemic model in rabbits was produced by a high fat/cholesterol diet for 6 weeks, the therapeutic effect of QSYQ with 2.0 g/kg, 1.0 g/kg, and 0.5 g/kg was observed. Fourteen days after drug treatment, platelet aggregation induced by adenosine diphosphate (ADP, arachidonic acid (AA, and collagen (COLL was significantly reduced in rabbits of model group. Moreover, β-thromboglobulin (β-TG level decreased obviously but no significant change in P-selectin and platelet factor 4 (PF4 level, while QSYQ significantly decreased the ratio of thromboxane B2 (TXB2 to 6-keto-prostaglandin F1α (6-Keto-PGF1α and increased cyclic adenosine monophosphate (cAMP level in rabbits. In summary, QSYQ can improve platelets aggregation and inhibit the over-release of β-TG in hyperlipidemic rabbits; and the increased cAMP level may be involved in this process. These results suggest that the antiplatelet aggregation effect of QSYQ may be due to its ability to increase cAMP level for improving cAMP metabolism.

Acute Carotid Artery Stent Thrombosis Due to Dual Antiplatelet Resistance

International Nuclear Information System (INIS)

Köklü, Erkan; Arslan, Şakir; Yüksel, İsa Öner; Bayar, Nermin; Koç, Pınar

2015-01-01

Carotid artery stenting (CAS) is a revascularization modality that is an alternative to carotid endarterectomy. The efficacy of CAS in primary and secondary prevention from ischemic stroke has been demonstrated in various trials. Acute thrombosis of CAS is a rare complication that can lead to dramatic and catastrophic consequences. We discuss a case of acute CAS thrombosis in a patient who had previously undergone successful CAS. CAS was performed in a 73-year-old man who had had dysarthria lasting 2 weeks with 95 % stenosis in his left internal carotid artery. An acute cerebrovascular event resulting in right-sided hemiplegia developed 24 h after the procedure. Computed tomographic carotid angiography revealed complete occlusion of the stent with thrombus. The cause of stent thrombosis was thought to be antiaggregant resistance to both acetylsalicylic acid and clopidogrel. The most important cause of acute CAS thrombosis is inadequate or ineffective antiaggregant therapy. Evaluating patients who are candidates for CAS for acetylsalicylic acid and clopidogrel resistance may preclude this complication

Flux scaling: Ultimate regime

Indian Academy of Sciences (India)

First page Back Continue Last page Overview Graphics. Flux scaling: Ultimate regime. With the Nusselt number and the mixing length scales, we get the Nusselt number and Reynolds number (w'd/ν) scalings: and or. and. scaling expected to occur at extremely high Ra Rayleigh-Benard convection. Get the ultimate regime ...

Abrupt climate-independent fire regime changes

Science.gov (United States)

Pausas, Juli G.; Keeley, Jon E.

2014-01-01

Wildfires have played a determining role in distribution, composition and structure of many ecosystems worldwide and climatic changes are widely considered to be a major driver of future fire regime changes. However, forecasting future climatic change induced impacts on fire regimes will require a clearer understanding of other drivers of abrupt fire regime changes. Here, we focus on evidence from different environmental and temporal settings of fire regimes changes that are not directly attributed to climatic changes. We review key cases of these abrupt fire regime changes at different spatial and temporal scales, including those directly driven (i) by fauna, (ii) by invasive plant species, and (iii) by socio-economic and policy changes. All these drivers might generate non-linear effects of landscape changes in fuel structure; that is, they generate fuel changes that can cross thresholds of landscape continuity, and thus drastically change fire activity. Although climatic changes might contribute to some of these changes, there are also many instances that are not primarily linked to climatic shifts. Understanding the mechanism driving fire regime changes should contribute to our ability to better assess future fire regimes.

Dual affine isoperimetric inequalities

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Bin Xiong

2006-01-01

Full Text Available We establish some inequalities for the dual -centroid bodies which are the dual forms of the results by Lutwak, Yang, and Zhang. Further, we establish a Brunn-Minkowski-type inequality for the polar of dual -centroid bodies.

Dual (oxygen and nitrogen) isotopic characterization of the museum archived nitrates from the United States of America, South Africa and Australia.

Science.gov (United States)

Mizota, Chitoshi; Hosono, Takahiro; Matsunaga, Midori; Okumura, Azusa

2018-06-01

Dual (oxygen and nitrogen) isotopic composition of the museum archived nitrates from the United States of America, South Africa and Australia was studied. The analyzed specimens were collected in middle 19th to early 20th centuries, and represent world-wide acquisition of the Smithsonian Institution Natural Museum of Natural History (Washington, D. C., USA) and the Natural History Museum (London, UK). The samples consist of transparent to semi-transparent aggregates of minute nitrate, euhedral crystallites which imply precipitation from percolating fluids under ample space and dry regimes. The major nitrate chemistry is saltpetre (KNO 3 ) with minor nitratine (NaNO 3 ). A binary plot of δ 15 N vs. δ 18 O of almost all nitrates indicates a trend, reflecting microbial origin through nitrification of ammonium. The diagram excludes the contribution of meteoric origin formed by mass-independent, photochemical reaction of NO with ozone in stratosphere. Calculated paleo-ambient fluid compositions responsible for microbial nitrification imply extreme evaporative concentration of relevant fluids under dry climatic regimes in the Northern Cape Province (South Africa) and in the Northern Territory (central Australia), and even throughout the United States of America. The dual isotopic characterization provides direct evidence to the origin of the museum archived nitrates. Copyright © 2017 Elsevier B.V. All rights reserved.

Study design and rationale of a comparison of prasugrel and clopidogrel in medically managed patients with unstable angina/non-ST-segment elevation myocardial infarction: the TaRgeted platelet Inhibition to cLarify the Optimal strateGy to medicallY manage Acute Coronary Syndromes (TRILOGY ACS

DEFF Research Database (Denmark)

Chin, Chee Tang; Roe, Matthew T; Fox, Keith A A

2010-01-01

Practice guidelines recommend dual antiplatelet therapy with aspirin and clopidogrel for patients with non-ST-segment elevation acute coronary syndromes (NSTE ACS) regardless of in-hospital management strategy. Prasugrel-a thienopyridine adenosine diphosphate receptor antagonist that provides...... higher and less variable levels of platelet inhibition than clopidogrel-has demonstrated benefit when used to treat ACS patients undergoing percutaneous coronary intervention. However, the optimal approach to antiplatelet therapy for high-risk, medically managed NSTE ACS patients remains uncertain...... revascularization procedures for their index event. Patients will be randomly allocated to prasugrel + aspirin versus clopidogrel + aspirin for a median duration of 18 months. A reduction in the maintenance dose of prasugrel for elderly patients (age >or=75 years) and those with body weight or=75 years). TRILOGY...

The trade regime and the climate regime. Institutional evolution and adaptation

International Nuclear Information System (INIS)

Brewer, Thomas L.

2003-01-01

This article addresses concerns that the multilateral trade regime centered in the WTO and the emerging climate regime may conflict in ways that could be damaging to either or both. The article discusses the institutional and diplomatic context of these concerns, and it identifies the kinds of issues that are in question. The analysis suggests that there are opportunities for win-win outcomes in the interactions of the two regimes, for instance in the possibility of reducing fossil fuel subsidies. However, there are also problematic areas where they intersect. A core issue-and as yet an unresolved one-is whether and how emission credit trading and other activities envisioned by the Kyoto Protocol would be subject to WTO rules. The resolution of this issue will affect many other issues as well. Additional specific issues about the interactions of particular provisions in WTO agreements and the Kyoto Protocol are analyzed in a subsequent companion article in Climate Policy

Synergies between nonproliferation regimes: A pragmatic approach

International Nuclear Information System (INIS)

Findlay, Trevor; Meier, Oliver

2001-01-01

Full text: With the recent progress in establishing international nonproliferation regimes, the question of synergies between different verification and monitoring regimes is becoming more acute. Three multilateral and universal nonproliferation organisations covering safeguards on civil nuclear materials, nuclear testing, and chemical weapons are up and running. A regime on biological weapons is under negotiation. Several regional organisations concerned with monitoring nonproliferation commitments in the nuclear field are in place; others are being established. Past discussions on synergies between these regimes have suffered from being too far-reaching. These discussions often have not reflected adequately the political difficulties of cooperation between regimes with different membership, scope and institutional set-up. This paper takes a pragmatic look at exploiting synergies and identifies some potential and real overlaps in the work between different verification regimes. It argues for a bottom-up approach and identifies building blocks for collaboration between verification regimes. By realising such, more limited potential for cooperation, the ground could be prepared for exploiting other synergies between these regimes. (author)

De Facto Regimes in International Law

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Jonte van Essen

2012-02-01

Full Text Available The ambiguous position of de facto regimes in international law has long been the subject of scholarly debate and a source of political conflict. An assessment of the current standing of these regimes in international law and the consequences of actions by international actors on this status has, however, been long overdue. The manner in which de facto regimes are regarded internationally has serious consequences for the individuals under the influence of this legal grey area. Therefore, the study into this problem and possible solutions is of great significance. The 2011 developments in Northern Africa underline the need of contemporary research into this area. This essay aims to clarify the position of de facto regimes in international law and the influence on their status by actions of international actors. The author first argues that de facto regimes have rights and obligations under international law, which provide them with (some form of international legal personality. He then pleads for a reconsideration of the contemporary legal treatment of these regimes. The author argues against the current system of government recognition and proposes a system that better addresses the needs of both de facto regimes and the international community. 

Antiplatelet drug selection in PCI to vein grafts in patients with acute coronary syndrome and adverse clinical outcomes

DEFF Research Database (Denmark)

Sirker, Alex; Kwok, Chun Shing; Kontopantelis, Evangelos

2018-01-01

OBJECTIVE: This study aims to evaluate outcomes associated with different P2Y12 agents in Saphenous Vein graft (SVG) percutaneous coronary intervention (PCI). BACKGROUND: SVG PCI is associated with greater risks of ischemic complications, compared with native coronary PCI. Outcomes associated...... with the use of potent P2Y12 blocking drugs, Prasugrel and Ticagrelor, in SVG PCI are unknown. METHODS: Patients included in the study underwent SVG PCI in the United Kingdom between 2007 and 2014 for acute coronary syndrome and were grouped by P2Y12 antiplatelet use. In-hospital major adverse cardiac events....... CONCLUSIONS: Our real world national study provides no clear evidence to indicate that use of potent P2Y12 blockers in SVG PCI is associated with improved clinical outcomes....

Multiple growth regimes: Insights from unified growth theory

OpenAIRE

Galor, Oded

2007-01-01

Unified Growth Theory uncovers the forces that contributed to the existence of multiple growth regimes and the emergence of convergence clubs. It suggests that differential timing of take-offs from stagnation to growth segmented economies into three fundamental regimes: slow growing economies in a Malthusian regime, fast growing countries in a sustained growth regime, and economies in the transition between these regimes. In contrast to existing research that links regime switching thresholds...

Multisite Investigation of Strategies for the Implementation of CYP2C19 Genotype-Guided Antiplatelet Therapy.

Science.gov (United States)

Empey, Philip E; Stevenson, James M; Tuteja, Sony; Weitzel, Kristin W; Angiolillo, Dominick J; Beitelshees, Amber L; Coons, James C; Duarte, Julio D; Franchi, Francesco; Jeng, Linda J B; Johnson, Julie A; Kreutz, Rolf P; Limdi, Nita A; Maloney, Kristin A; Owusu Obeng, Aniwaa; Peterson, Josh F; Petry, Natasha; Pratt, Victoria M; Rollini, Fabiana; Scott, Stuart A; Skaar, Todd C; Vesely, Mark R; Stouffer, George A; Wilke, Russell A; Cavallari, Larisa H; Lee, Craig R

2017-12-26

CYP2C19 genotype-guided antiplatelet therapy following percutaneous coronary intervention is increasingly implemented in clinical practice. However, challenges such as selecting a testing platform, communicating test results, building clinical decision support processes, providing patient and provider education, and integrating methods to support the translation of emerging evidence to clinical practice are barriers to broad adoption. In this report, we compare and contrast implementation strategies of 12 early adopters, describing solutions to common problems and initial performance metrics for each program. Key differences between programs included the test result turnaround time and timing of therapy changes, which are both related to the CYP2C19 testing model and platform used. Sites reported the need for new informatics infrastructure, expert clinicians such as pharmacists to interpret results, physician champions, and ongoing education. Consensus lessons learned are presented to provide a path forward for those seeking to implement similar clinical pharmacogenomics programs within their institutions. © 2018, The American Society for Clinical Pharmacology and Therapeutics.

Lp-dual affine surface area

Science.gov (United States)

Wei, Wang; Binwu, He

2008-12-01

According to the notion of Lp-affine surface area by Lutwak, in this paper, we introduce the concept of Lp-dual affine surface area. Further, we establish the affine isoperimetric inequality and the Blaschke-Santaló inequality for Lp-dual affine surface area. Besides, the dual Brunn-Minkowski inequality for Lp-dual affine surface area is presented.

Dual symmetry in gauge theories

International Nuclear Information System (INIS)

Koshkarov, A.L.

1997-01-01

Continuous dual symmetry in electrodynamics, Yang-Mills theory and gravitation is investigated. Dual invariant which leads to badly nonlinear motion equations is chosen as a Lagrangian of the pure classical dual nonlinear electrodynamics. In a natural manner some dual angle which is determined by the electromagnetic strengths at the point of the time-space appears in the model. Motion equations may well be interpreted as the equations of the standard Maxwell theory with source. Alternative interpretation is the quasi-Maxwell linear theory with magnetic charge. Analogous approach is possible in the Yang-Mills theory. In this case the dual-invariant non-Abelian theory motion equations possess the same instanton solutions as the conventional Yang-Mills equations have. An Abelian two-parameter dual group is found to exist in gravitation. Irreducible representations have been obtained: the curvature tensor was expanded into the sum of twice anti-self-dual and self-dual parts. Gravitational instantons are defined as (real )solutions to the usual duality equations. Central symmetry solutions to these equations are obtained. The twice anti-self-dual part of the curvature tensor may be used for introduction of new gravitational equations generalizing Einstein''s equations. However, the theory obtained reduces to the conformal-flat Nordstroem theory

Measuring the effectiveness of international environmental regimes

Energy Technology Data Exchange (ETDEWEB)

Helm, C.; Sprinz, D.F.

1999-05-01

While past research has emphasized the importance of international regimes for international governance, systematic assessments of regime effects are missing. This article derives a standardized measurement concept for the effectiveness of international environmental regimes by developing an operational rational choice calculus to evaluate actual policy simultaneously against a non-regime counterfactual and a collective optimum. Subsequently, the empirical feasibility of the measurement instrument is demonstrated by way of two international treaties regulating transboundary air pollution in Europe. The results demonstrate that the regimes indeed show positive effects - but fall substantially short of the collective optima. (orig.)

Accommodating human values in the climate regime

Directory of Open Access Journals (Sweden)

Rosalind Cook

2008-12-01

Full Text Available The climate regime addresses one of the most important challenges facing humankind today. However, while the environmental and economic sides of the problem are well represented, it lacks the inclusion of social and human aspects. The human rights regime, in contrast, is a regime which has been established precisely to implement human values. This article ex-plains the problems of climate change in terms of human values and argues that some proce-dures from the human rights regime offer possibilities for improvement. It is submitted that through the inclusion of human rights instruments, such as individual communication, pro-gressive realisation and authoritative interpretation, the inclusion of human values into the climate regime will be facilitated. This article presents these instruments and discusses their potential for inclusion in the climate regime.

Contemporary Antithrombotic Treatment in Patients with Non-valvular Atrial Fibrillation Undergoing Percutaneous Coronary Intervention: Rationale and Design of the Greek AntiPlatElet Atrial Fibrillation (GRAPE-AF) Registry.

Science.gov (United States)

Xanthopoulou, Ioanna; Dragona, Vasiliki-Maria; Davlouros, Periklis; Tsioufis, Costas; Iliodromitis, Efstathios; Alexopoulos, Dimitrios

2018-04-20

Approximately 5 to 7% of patients undergoing percutaneous coronary intervention (PCI) for the treatment of coronary artery disease require chronic oral anticoagulation (OAC) on top of aspirin and a P2Y 12 receptor antagonist, mainly due to non-valvular atrial fibrillation (AF). The advent of non-vitamin K antagonist oral anticoagulants (NOACs) increased treatment options, while there is cumulative evidence that dual combination of a NOAC and a P2Y 12 receptor antagonist attenuates risk of bleeding, compared to traditional triple therapy, consisting of a vitamin K antagonist (VKA), aspirin, and a P2Y 12 receptor antagonist, without significantly compromising efficacy. Greek AntiPlatElet Atrial Fibrillation (GRAPE-AF, NCT 03362788) is an observational, nationwide study of non-valvular AF patients undergoing PCI, planning to enroll over 1-year period > 500 participants in 25 tertiary and non-tertiary PCI centers in Greece. Key data to be collected pre-discharge include demographics, detailed past medical history, and antithrombotic and concomitant treatment. Patients will be followed up at 1, 6, and 12 months post hospital discharge. Αt each follow-up visit, data on antithrombotic treatment, ischemic, bleeding, and adverse events will be collected. Study's primary endpoint is clinically significant bleeding (Bleeding Academic Research Consortium, BARC ≥ 2) at 12 months, between VKAs and NOACs-treated patients, analyzed using Cox proportional hazards models, by an intention-to-treat principle. An independent endpoint committee will adjudicate all clinical events. This study aims at providing "real-world" information on current antithrombotic treatment patterns and clinical outcome of patients with non-valvular AF undergoing PCI.

Dual energy CT

DEFF Research Database (Denmark)

Al-Najami, Issam; Drue, Henrik Christian; Steele, Robert

2017-01-01

and inaccurate with existing methods. Dual Energy Computed Tomography (DECT) enables qualitative tissue differentiation by simultaneous scanning with different levels of energy. We aimed to assess the feasibility of DECT in quantifying tumor response to neoadjuvant therapy in loco-advanced rectal cancer. METHODS...... to determine the average quantitative parameters; effective-Z, water- and iodine-concentration, Dual Energy Index (DEI), and Dual Energy Ratio (DER). These parameters were compared to the regression in the resection specimen as measured by the pathologist. RESULTS: Changes in the quantitative parameters...

State Structure and Political Regime Structure

Directory of Open Access Journals (Sweden)

Paul – Iulian Nedelcu

2012-05-01

Full Text Available The political regime is the concrete form of organization and functioning of political system andtherefore, the regime means the concrete way of organize, institutionalize and function a political systemand of the exercise of political power by a social-political force in a social community or global socialistem. The political regime is not limited to institutions and state bodies, but it covers the entire politicalsystem. Form of expression in social practice plan is the result of balance of forces between classes ofcitizens, organizations, between them and civil society and politics.Designates the concrete form ofgovernment formation and organization, of state bodies, in aspect of their characteristics and principles, therelations between them and other state bodies, and also as the relationship between them and otherinstitutionalized forms of political systems. Instead, the political regime is an explicit realization ofaxiological operations, a specific hierarchy of values, in general and political values, in particular. Even ifsome elements of the political regime overlap to some extent and in some respects, those of form orstructure of guvernamnt state, thus they dissolve his identity, distinct quality of being specific traits of thepolitical regime.

Dual Smarandache Curves and Smarandache Ruled Surfaces

OpenAIRE

Tanju KAHRAMAN; Mehmet ÖNDER; H. Hüseyin UGURLU

2013-01-01

In this paper, by considering dual geodesic trihedron (dual Darboux frame) we define dual Smarandache curves lying fully on dual unit sphere S^2 and corresponding to ruled surfaces. We obtain the relationships between the elements of curvature of dual spherical curve (ruled surface) x(s) and its dual Smarandache curve (Smarandache ruled surface) x1(s) and we give an example for dual Smarandache curves of a dual spherical curve.

Totalitäre Regimes

OpenAIRE

Merkel, Wolfgang

2004-01-01

"The development of the term and the analytical concept of totalitarianism have gone through several stages since the 1920s. However, even in its most sophisticated form, the version seen in Friedrich/ Brzezinski, the concept exhibits substantial systematic classification problems and analytical weaknesses. This article attempts to frame the type of totalitarian regime within a general typology of political regimes. Special attention is dedicated to the problem of distinguishing autocra...

'CANDLE' burnup regime after LWR regime

International Nuclear Information System (INIS)

Sekimoto, Hiroshi; Nagata, Akito

2008-01-01

CANDLE (Constant Axial shape of Neutron flux, nuclide densities and power shape During Life of Energy producing reactor) burnup strategy can derive many merits. From safety point of view, the change of excess reactivity along burnup is theoretically zero, and the core characteristics, such as power feedback coefficients and power peaking factor, are not changed along burnup. Application of this burnup strategy to neutron rich fast reactors makes excellent performances. Only natural or depleted uranium is required for the replacing fuels. About 40% of natural or depleted uranium undergoes fission without the conventional reprocessing and enrichment. If the LWR produced energy of X Joules, the CANDLE reactor can produce about 50X Joules from the depleted uranium left at the enrichment facility for the LWR fuel. If we can say LWRs have produced energy sufficient for full 20 years, we can produce the energy for 1000 years by using the CANDLE reactors with depleted uranium. We need not mine any uranium ore, and do not need reprocessing facility. The burnup of spent fuel becomes 10 times. Therefore, the spent fuel amount per produced energy is also reduced to one-tenth. The details of the scenario of CANDLE burnup regime after LWR regime will be presented at the symposium. (author)

Determination of Actual Friction Factors in Metal Forming under Heavy Loaded Regimes Combining Experimental and Numerical Analysis

Science.gov (United States)

Camacho, Ana María; Veganzones, Mariano; Claver, Juan; Martín, Francisco; Sevilla, Lorenzo; Sebastián, Miguel Ángel

2016-01-01

Tribological conditions can change drastically during heavy loaded regimes as experienced in metal forming; this is especially critical when lubrication can only be applied at the early stage of the process because the homogeneous lubricant layer can break along the die-workpiece interface. In these cases, adopting a constant friction factor for the lubricant-surface pair may not be a valid assumption. This paper presents a procedure based on the use of dual friction factor maps to determine friction factors employed in heavy loaded regimes. A finite element (FE) simulation is used to obtain the friction factor map for the alloy UNS A96082. Experiments were conducted using four lubricants (aluminum anti-size, MoS2 grease, silicone oil, and copper paste) to determine the actual friction curves. The experimental procedure is based on the application of lubricant only at the beginning of the first stage of ring compression, and not at intermediate stages as is usual in typical ring compression tests (RCTs). The results show that for small reductions (rh 20%), it is recommended to obtain an average value of the friction factor for every lubricant-surface pair in the range of deformation considered. PMID:28773868

Demonstration and evaluation of dual-fuel technology; Demonstration och utvaerdering av dual-fuel-tekniken

Energy Technology Data Exchange (ETDEWEB)

Staalhammar, Per; Erlandsson, Lennart; Willner, Kristina (AVL MTC Motortestcenter AB (Sweden)); Johannesson, Staffan (Ecoplan AB (Sweden))

2011-06-15

There is an increased interest for Dual Fuel (methane-Diesel) applications in Sweden since this technology is seen as one of the more interesting options for a fast and cost effective introduction of biomethane as fuel for HD engines. The Dual Fuel technology has been used for many years, mainly for stationary purpose (generators, pumps and ships) while the Spark Ignited (SI) 'Otto' technology has been used for trucks and busses. One obstacle for introducing Dual Fuel technology for busses and trucks is the EU legislation that don't allow for HD on road certification of Dual Fuel applications. Challenges with the Dual Fuel technology is to develop cost effective applications that is capable of reaching low emissions (especially CH{sub 4} and NO{sub x}) in combination with high Diesel replacement in the test cycles used for on road applications. AVL MTC Motortestcenter AB (hereinafter called AVL) has on commission by SGC (Swedish Gas technical Centre) carried out this project with the objectives to analyze the Dual Fuel (Diesel-methane) technology with focus on emissions, fuel consumption and technical challenges. One important part of this project was to carry out emission tests on selected Dual Fuel applications in Sweden and to compile experiences from existing Dual Fuel technology. This report also summarizes other commonly used technologies for methane engines and compares the Dual Fuel with conventional Diesel and Otto technologies. The major challenges with Dual Fuel applications for on road vehicles will be to develop robust and cost effective solutions that meet the emission legislations (with aged catalysts) and to increase the Diesel replacement to achieve reasonable reduction of green house gases (GHG). This is especially important when biomethane is available as fuel but not Bio-Diesel. It will probably be possible to reach EURO V emission limits with advanced Dual Fuel systems but none of the tested systems reached EURO V emission levels

Clopidogrel discontinuation within the first year after coronary drug-eluting stent implantation

DEFF Research Database (Denmark)

Thim, Troels; Johansen, Martin Berg; Chisholm, Gro Egholm

2014-01-01

BACKGROUND: The impact of adherence to the recommended duration of dual antiplatelet therapy after first generation drug-eluting stent implantation is difficult to assess in real-world settings and limited data are available. METHODS: We followed 4,154 patients treated with coronary drug-eluting ......BACKGROUND: The impact of adherence to the recommended duration of dual antiplatelet therapy after first generation drug-eluting stent implantation is difficult to assess in real-world settings and limited data are available. METHODS: We followed 4,154 patients treated with coronary drug......-eluting stents in Western Denmark for 1 year and obtained data on redeemed clopidogrel prescriptions and major adverse cardiovascular events (MACE, i.e., cardiac death, myocardial infarction, or stent thrombosis) from medical databases. RESULTS: Discontinuation of clopidogrel within the first 3 months after...... stent implantation was associated with a significantly increased rate of MACE at 1-year follow-up (hazard ratio (HR) 2.06; 95% confidence interval (CI): 1.08-3.93). Discontinuation 3-6 months (HR 1.29; 95% CI: 0.70-2.41) and 6-12 months (HR 1.29; 95% CI: 0.54-3.07) after stent implantation were...

Percutaneous coronary intervention and the management of acute coronary syndromes in patients with von Willebrand disease.

Science.gov (United States)

Rathore, Sulaiman; Deleon, Dexter; Akram, Hafsa; Sane, David; Ball, Timothy

2013-04-01

Von Willebrand disease (vWD) results from quantitative or qualitative deficiency of von Willebrand factor (vWF). The occurrence of myocardial infarction is very rare in patients with vWD. A few case reports of acute coronary syndrome (ACS) in vWD patients are present in the literature, but no definite management recommendations are available for such patients. We report a case of successful percutaneous coronary intervention (PCI) with bare-metal stent (BMS) implantation in a 46-year-old woman with type 1 vWD and history of coronary artery disease (CAD). She received periprocedural dual-antiplatelet therapy for 2 weeks and then continued aspirin without any bleeding complications. The optimal management of patients with vWD and ACS is complex and presents a therapeutic challenge. We propose that dual-antiplatelet therapy can be used safely in most vWD patients presenting with ACS as most of them are type 1 vWD. PCI with BMS can be done safely. Long-term management of these patients requires a systemic approach including hematological consultation, ascertaining vWF levels, as well as patient education and close outpatient follow-up.

Dual Regression

OpenAIRE

Spady, Richard; Stouli, Sami

2012-01-01

We propose dual regression as an alternative to the quantile regression process for the global estimation of conditional distribution functions under minimal assumptions. Dual regression provides all the interpretational power of the quantile regression process while avoiding the need for repairing the intersecting conditional quantile surfaces that quantile regression often produces in practice. Our approach introduces a mathematical programming characterization of conditional distribution f...

Liquid–Solid Dual-Gate Organic Transistors with Tunable Threshold Voltage for Cell Sensing

KAUST Repository

Zhang, Yu

2017-10-17

Liquid electrolyte-gated organic field effect transistors and organic electrochemical transistors have recently emerged as powerful technology platforms for sensing and simulation of living cells and organisms. For such applications, the transistors are operated at a gate voltage around or below 0.3 V because prolonged application of a higher voltage bias can lead to membrane rupturing and cell death. This constraint often prevents the operation of the transistors at their maximum transconductance or most sensitive regime. Here, we exploit a solid–liquid dual-gate organic transistor structure, where the threshold voltage of the liquid-gated conduction channel is controlled by an additional gate that is separated from the channel by a metal-oxide gate dielectric. With this design, the threshold voltage of the “sensing channel” can be linearly tuned in a voltage window exceeding 0.4 V. We have demonstrated that the dual-gate structure enables a much better sensor response to the detachment of human mesenchymal stem cells. In general, the capability of tuning the optimal sensing bias will not only improve the device performance but also broaden the material selection for cell-based organic bioelectronics.

Liquid-Solid Dual-Gate Organic Transistors with Tunable Threshold Voltage for Cell Sensing.

Science.gov (United States)

Zhang, Yu; Li, Jun; Li, Rui; Sbircea, Dan-Tiberiu; Giovannitti, Alexander; Xu, Junling; Xu, Huihua; Zhou, Guodong; Bian, Liming; McCulloch, Iain; Zhao, Ni

2017-11-08

Liquid electrolyte-gated organic field effect transistors and organic electrochemical transistors have recently emerged as powerful technology platforms for sensing and simulation of living cells and organisms. For such applications, the transistors are operated at a gate voltage around or below 0.3 V because prolonged application of a higher voltage bias can lead to membrane rupturing and cell death. This constraint often prevents the operation of the transistors at their maximum transconductance or most sensitive regime. Here, we exploit a solid-liquid dual-gate organic transistor structure, where the threshold voltage of the liquid-gated conduction channel is controlled by an additional gate that is separated from the channel by a metal-oxide gate dielectric. With this design, the threshold voltage of the "sensing channel" can be linearly tuned in a voltage window exceeding 0.4 V. We have demonstrated that the dual-gate structure enables a much better sensor response to the detachment of human mesenchymal stem cells. In general, the capability of tuning the optimal sensing bias will not only improve the device performance but also broaden the material selection for cell-based organic bioelectronics.

Flow structure and heat transfer in a square duct fitted with dual/quadruple twisted-tapes: Influence of tape configuration

International Nuclear Information System (INIS)

Eiamsa-ard, S.; Changcharoen, W.

2015-01-01

Numerical predictions reported of thermohydraulic characteristics of square ducts equipped with dual and quadruple twisted tapes (DTs and QTs) with different configurations. The studied cases include (1) dual co-tapes (Co-DTs), (2) dual counter-tapes (C-DTs), (3) diagonal dual counter-tapes (C-DDTs), (4) diagonal dual co-tapes (Co-DDTs), (5) quadruple co-tapes (Co-QTs), (6) quadruple counter tapes (CC-QTs) and (7) quadruple counter-tapes (PC-QTs). The results of these cases are compared with those of a smooth duct (a duct without tape insert) and also the one with a single tape (ST). The prediction involves using the RNG k-ε turbulent model under constant wall heat flux condition in the turbulent flow regime for the Reynolds number ranging from 6000 to 14000. The prediction indicates that thermohydraulic characteristics in ducts with twisted tape are strongly dependent on number and configuration of tapes. However, the influence of tape number is more significant than that of tape configuration. Heat transfer and friction increase as tape number increases. QTs offer superior heat transfer to DTs but their thermal performance factors are lower. For the tape inserts determined, DTs with diagonal configuration (Co-DDTs and C-DDTs) is the best design as the tapes offer the best thermal performance. The highest thermal performance factors given by Co-DTs, Co-DDTs, C-DTs, C-DDTs, Co-QTs, PC-QTs and CC-QTs, are around 1.21, 1.35, 1.25, 1.38, 1.08, 1.18, and 1.22, respectively

Supply regimes in fisheries

DEFF Research Database (Denmark)

Nielsen, Max

2006-01-01

Supply in fisheries is traditionally known for its backward bending nature, owing to externalities in production. Such a supply regime, however, exist only for pure open access fisheries. Since most fisheries worldwide are neither pure open access, nor optimally managed, rather between the extremes......, the traditional understanding of supply regimes in fisheries needs modification. This paper identifies through a case study of the East Baltic cod fishery supply regimes in fisheries, taking alternative fisheries management schemes and mesh size limitations into account. An age-structured Beverton-Holt based bio......-economic supply model with mesh sizes is developed. It is found that in the presence of realistic management schemes, the supply curves are close to vertical in the relevant range. Also, the supply curve under open access with mesh size limitations is almost vertical in the relevant range, owing to constant...

Dual Orlicz geominimal surface area

Directory of Open Access Journals (Sweden)

Tongyi Ma

2016-02-01

Full Text Available Abstract The L p $L_{p}$ -geominimal surface area was introduced by Lutwak in 1996, which extended the important concept of the geominimal surface area. Recently, Wang and Qi defined the p-dual geominimal surface area, which belongs to the dual Brunn-Minkowski theory. In this paper, based on the concept of the dual Orlicz mixed volume, we extend the dual geominimal surface area to the Orlicz version and give its properties. In addition, the isoperimetric inequality, a Blaschke-Santaló type inequality, and the monotonicity inequality for the dual Orlicz geominimal surface areas are established.

Ferrite channel effect on ductility and strain hardenability of ultra high strength dual phase steel

Energy Technology Data Exchange (ETDEWEB)

Ravi, Kumar B., E-mail: ravik@nmlindia.org [CSIR-National Metallurgical Laboratory, Jamshedpur 831007 (India); Patel, Nand Kumar [O.P Jindal University, Raigarh 496001 (India); Mukherjee, Krishnendu; Walunj, Mahesh; Mandal, Gopi Kishor [CSIR-National Metallurgical Laboratory, Jamshedpur 831007 (India); Venugopalan, T. [Tata Steel Limited, Jamshedpur 831001 (India)

2017-02-08

This study describes an effect of controlled austenite decomposition on microstructure evolution in dual phase steel. Steel sheets austenitized at various annealing temperatures were rapidly cooled to the inter-critical annealing temperature of 800 °C for the isothermal decomposition of austenite and then ultra fast cooled to room temperature. The scanning electron microscope analysis of evolving microstructure revealed ferrite nucleation and growth along prior austenite grain boundaries leading to ferrite network/channel formation around martensite. The extent of ferrite channel formation showed a strong dependence on the degree of undercooling in the inter-critical annealing temperature regime. Uniaxial tensile deformation of processed steel sheets showed extensive local inter-lath martensite damage activity. Extension/propagation of these local micro cracks to neighboring martensite grains was found to be arrested by ferrite channels. This assisted in delaying the onset of global damage which could lead to necking and fracture. The results demonstrated an alternate possible way of inducing ductility and strain hardenability in ultra high strength dual phase steels.

Stochastic dynamical models for ecological regime shifts

DEFF Research Database (Denmark)

Møller, Jan Kloppenborg; Carstensen, Jacob; Madsen, Henrik

the physical and biological knowledge of the system, and nonlinearities introduced here can generate regime shifts or enhance the probability of regime shifts in the case of stochastic models, typically characterized by a threshold value for the known driver. A simple model for light competition between...... definition and stability of regimes become less subtle. Ecological regime shifts and their modeling must be viewed in a probabilistic manner, particularly if such model results are to be used in ecosystem management....

Dual-band dual-polarized array for WLAN applications

CSIR Research Space (South Africa)

Steyn, JM

2009-01-01

Full Text Available dual-band dual-polarized (DBDP) antenna design for WLAN applications. The antenna is in the form of an array consisting of four double-dipole radiators. The basic radiating element consists of a rhombus shaped dipole above a planar ground plane... the ground planes and the respective feedlines. Substrate cuts and difierent heights for the horizontal feedlines were necessary to achieve the latter. The 2nd conflguration (for vertical polarization) has a slightly difierent feeding network layout...

El anillo de los números duales

OpenAIRE

Jiménez, Haydee; Luque, Carlos Julio

2007-01-01

Se inicia con una presentación de la estructura de * - Álgebra de los números duales; se muestran diferentes representaciones que permiten la definición de potencias racionales de números duales, lo que exige una extensión de su estructura a un anillo de números duales con coeficientes complejos. Seguidamente se estudian la función exponencial dual y la función logaritmo dual que permiten la definición de potencias duales de un número dual; luego se estudian ecuaciones en los números duales h...

Evaluation and Treatment of the Acute Cerebral Infarction with Convexal Subarachnoid Hemorrhage.

Science.gov (United States)

Lee, Min Hyung; Kim, Sang Uk; Lee, Dong Hoon; Kim, Young Il; Cho, Chul Bum; Yang, Seung Ho; Kim, Il Sup; Hong, Jae Taek; Sung, Jae Hoon; Lee, Sang Won

2016-09-01

Non-traumatic convexal subarachnoid hemorrhage (CSAH) is a comparatively infrequent with various vascular and nonvascular causes, it rarely occurs concomitant to acute ischemic stroke. We report a case of a 59-year-old woman, visited emergency room with right side subjective weakness spontaneously. Magnetic resonance diffusion-weighted images revealed an acute infarction of anterior cerebral arterial territory. Computed tomographic angiography showed a left frontal CSAH without any vascular lesions. And other laboratory studies were non-specific. We treated with dual antiplatelet drugs (cilostazole [Otsuka Pharmaceutical Co., Ltd. tokyo, Japan] and Aspirin [Bayer Pharma AG., Leverkusen, Germany]). She has done well for a follow-up period. (5 months) This case demonstrates the CSAH with acute infarction is rare but need to work up to identify the etiology and antiplatelet dugs are taken into account for treatments.

Nonword Reading: Comparing Dual-Route Cascaded and Connectionist Dual-Process Models with Human Data

Science.gov (United States)

Pritchard, Stephen C.; Coltheart, Max; Palethorpe, Sallyanne; Castles, Anne

2012-01-01

Two prominent dual-route computational models of reading aloud are the dual-route cascaded (DRC) model, and the connectionist dual-process plus (CDP+) model. While sharing similarly designed lexical routes, the two models differ greatly in their respective nonlexical route architecture, such that they often differ on nonword pronunciation. Neither…

Supercontinuum optimization for dual-soliton based light sources using genetic algorithms in a grid platform.

Science.gov (United States)

Arteaga-Sierra, F R; Milián, C; Torres-Gómez, I; Torres-Cisneros, M; Moltó, G; Ferrando, A

2014-09-22

We present a numerical strategy to design fiber based dual pulse light sources exhibiting two predefined spectral peaks in the anomalous group velocity dispersion regime. The frequency conversion is based on the soliton fission and soliton self-frequency shift occurring during supercontinuum generation. The optimization process is carried out by a genetic algorithm that provides the optimum input pulse parameters: wavelength, temporal width and peak power. This algorithm is implemented in a Grid platform in order to take advantage of distributed computing. These results are useful for optical coherence tomography applications where bell-shaped pulses located in the second near-infrared window are needed.

De Facto Regimes in International Law

OpenAIRE

Essen, Jonte van

2012-01-01

The ambiguous position of de facto regimes in international law has long been the subject of scholarly debate and a source of political conflict. An assessment of the current standing of these regimes in international law and the consequences of actions by international actors on this status has, however, been long overdue. The manner in which de facto regimes are regarded internationally has serious consequences for the individuals under the influence of this legal grey area. Therefore, the ...

Transient regimes in a heavy water reactor; Regimes transitoires dans un reacteur a eau lourde

Energy Technology Data Exchange (ETDEWEB)

Raievski, V [Commissariat a l' Energie Atomique, Saclay(France). Centre d' Etudes Nucleaires

1953-07-01

We studied the variations of power and reactivity of a reactor when we raise in a continuous way the starting plates. During the subcritical regime (negative reactivity), the power is determined by reactivity and by the intensity of the sources of photo neutrons, produced during the previous work of the reactor. When, during the rise of the plates, the reactor, pass by the critical regime (zero reactivity), one notes that the reached power is independent of the initial reactivity. During the sur-critical regime (positive reactivity), the elevation of temperature of the uranium bars slows down the growth of reactivity due to the movements of the plates. The power stretches then toward a value that depends only on the regime of cooling of the reactor and the excess of the available reactivity. This survey permits to choose such a rise speed, that reactivity remains constantly lower to a value beyond which the piloting of the reactor becomes difficult. This result is not more valid, if the intensity of the sources is insufficient, what takes place during the first divergences and after a stop of long length. (author) [French] On etudie les variations de puissance et de reactivite d'un reacteur quand on leve d'une facon continue les plaques de demarrage. Pendant le regime subcritique (reactivite negative), la puissance est determinee par la reactivite et par l'intensite des sources de photoneutrons, produites pendant la marche anterieure du reacteur. Quand, au cours de la montee des plaques, le reacteur passe par le regime critique (reactivite nulle), on constate que la puissance atteinte est independante de la reactivite initiale. Pendant le regime surcritique (reactivite positive), l'elevation de temperature des barres d'uranium ralentit l'accroissement de reactivite due aux mouvements des plaques. La puissance tend alors vers une valeur qui ne depend plus que du regime de refroidissement du reacteur et de l'exces de la reactivite disponible. Cette etude permet de

Spinning self-dual particles

International Nuclear Information System (INIS)

Gamboa, J.; Rivelles, V.O.

1989-02-01

We study spinning self-dual particles in two dimensions. They are obtained from the chiral bosonic particle through the square root technique. We show that the resulting field theory can be either fermionic or bosonic and that the associated self-dual field reveals its Lorentz tensor structure which remains hidden in the usual formulations. We also calculate the spinning self-dual particle propagators using the BFV formalism. (author) [pt

Synthesis of Analogues of Gingerol and Shogaol, the Active Pungent Principles from the Rhizomes of Zingiber officinale and Evaluation of Their Anti-Platelet Aggregation Effects

Science.gov (United States)

Shih, Hung-Cheng; Chern, Ching-Yuh; Kuo, Ping-Chung; Wu, You-Cheng; Chan, Yu-Yi; Liao, Yu-Ren; Teng, Che-Ming; Wu, Tian-Shung

2014-01-01

The present study was aimed at discovering novel biologically active compounds based on the skeletons of gingerol and shogaol, the pungent principles from the rhizomes of Zingiber officinale. Therefore, eight groups of analogues were synthesized and examined for their inhibitory activities of platelet aggregation induced by arachidonic acid, collagen, platelet activating factor, and thrombin. Among the tested compounds, [6]-paradol (5b) exhibited the most significant anti-platelet aggregation activity. It was the most potent candidate, which could be used in further investigation to explore new drug leads. PMID:24599082

Synthesis of Analogues of Gingerol and Shogaol, the Active Pungent Principles from the Rhizomes of Zingiber officinale and Evaluation of Their Anti-Platelet Aggregation Effects

Directory of Open Access Journals (Sweden)

Hung-Cheng Shih

2014-03-01

Full Text Available The present study was aimed at discovering novel biologically active compounds based on the skeletons of gingerol and shogaol, the pungent principles from the rhizomes of Zingiber officinale. Therefore, eight groups of analogues were synthesized and examined for their inhibitory activities of platelet aggregation induced by arachidonic acid, collagen, platelet activating factor, and thrombin. Among the tested compounds, [6]-paradol (5b exhibited the most significant anti-platelet aggregation activity. It was the most potent candidate, which could be used in further investigation to explore new drug leads.

Nonlinear performance of asymmetric coupler based on dual-core photonic crystal fiber: Towards sub-nanojoule solitonic ultrafast all-optical switching

Science.gov (United States)

Curilla, L.; Astrauskas, I.; Pugzlys, A.; Stajanca, P.; Pysz, D.; Uherek, F.; Baltuska, A.; Bugar, I.

2018-05-01

We demonstrate ultrafast soliton-based nonlinear balancing of dual-core asymmetry in highly nonlinear photonic crystal fiber at sub-nanojoule pulse energy level. The effect of fiber asymmetry was studied experimentally by selective excitation and monitoring of individual fiber cores at different wavelengths between 1500 nm and 1800 nm. Higher energy transfer rate to non-excited core was observed in the case of fast core excitation due to nonlinear asymmetry balancing of temporal solitons, which was confirmed by the dedicated numerical simulations based on the coupled generalized nonlinear Schrödinger equations. Moreover, the simulation results correspond qualitatively with the experimentally acquired dependences of the output dual-core extinction ratio on excitation energy and wavelength. In the case of 1800 nm fast core excitation, narrow band spectral intensity switching between the output channels was registered with contrast of 23 dB. The switching was achieved by the change of the excitation pulse energy in sub-nanojoule region. The performed detailed analysis of the nonlinear balancing of dual-core asymmetry in solitonic propagation regime opens new perspectives for the development of ultrafast nonlinear all-optical switching devices.

Fire Regime Characteristics along Environmental Gradients in Spain

Directory of Open Access Journals (Sweden)

María Vanesa Moreno

2016-11-01

Full Text Available Concern regarding global change has increased the need to understand the relationship between fire regime characteristics and the environment. Pyrogeographical theory suggests that fire regimes are constrained by climate, vegetation and fire ignition processes, but it is not obvious how fire regime characteristics are related to those factors. We used a three-matrix approach with a multivariate statistical methodology that combined an ordination method and fourth-corner analysis for hypothesis testing to investigate the relationship between fire regime characteristics and environmental gradients across Spain. Our results suggest that fire regime characteristics (i.e., density and seasonality of fire activity are constrained primarily by direct gradients based on climate, population, and resource gradients based on forest potential productivity. Our results can be used to establish a predictive model for how fire regimes emerge in order to support fire management, particularly as global environmental changes impact fire regime characteristics.

Dual thyroid ectopia

International Nuclear Information System (INIS)

Al-Akeely, Mohammed H.

2003-01-01

Ectopic thyroid gland is a rare embryological fault of thyroid development .Dual ectopic thyroid is more rare and only 8 cases have been reported in the literature. The author presents a case of dual ectopic thyroid in a 16 year old boy with an anterior red neck mass, which is gradually growing in size particularly in last 2 years. The initial diagnosis was thyroglossal duct cyst. Thyroid function test revealed elevated thyroid-stimulating hormone. Ultrasound of the neck did not show thyroid gland in its normal pre tracheal position. Thyroid scan (Technetium 99)revealed the diagnosis of dual thyroid ectopia(lingual and subhyoid). (author)

The Dual Orlicz-Brunn-Minkowski Theory

OpenAIRE

Gardner, Richard J.; Hug, Daniel; Weil, Wolfgang; Ye, Deping

2014-01-01

This paper introduces the dual Orlicz-Brunn-Minkowski theory for star sets. A radial Orlicz addition of two or more star sets is proposed and a corresponding dual Orlicz-Brunn-Minkowski inequality is established. Based on a radial Orlicz linear combination of two star sets, a formula for the dual Orlicz mixed volume is derived and a corresponding dual Orlicz-Minkowski inequality proved. The inequalities proved yield as special cases the precise duals of the conjectured log-Brunn-Minkowski and...

Framing of regimes and transition strategies

DEFF Research Database (Denmark)

Jensen, Jens Stissing

2012-01-01

This article suggests that transition strategies are always formulated in the context of specific representations of the regime and the challenges it faces. It is argued that the framing of a regime affects the envisioning of transition strategies. An analysis of the current development agenda...... for the housing construction sector in Denmark reveals the relevance and impacts of different regime framings. It is proposed that the ability to cope with framing issues as situated and political processes is at the core of the governance of transitions....

Mass thickness measurement of dual-sample by dual-energy X-rays

International Nuclear Information System (INIS)

Chen Mincong; Li Hongmei; Chen Ziyu; Shen Ji

2008-01-01

X-ray equivalent energy can be used to measure mass thicknesses of materials. Based on this, a method of mass thickness measurement of dual-sample was discussed. It was found that in the range of sample mass thickness under investigation, the equivalent mass attenuation coefficient of a component could be used to compute mass thicknesses of a dual-sample, with relative errors of less than 5%. Mass thickness measurement of a fish sample was performed, and the fish bone and flesh could be displayed separately and clearly by their own mass thicknesses. This indicates that the method is effective in mass thickness measurement of dual-sample of suitable thicknesses. (authors)

Ecosystem regime shifts disrupt trophic structure.

Science.gov (United States)

Hempson, Tessa N; Graham, Nicholas A J; MacNeil, M Aaron; Hoey, Andrew S; Wilson, Shaun K

2018-01-01

Regime shifts between alternative stable ecosystem states are becoming commonplace due to the combined effects of local stressors and global climate change. Alternative states are characterized as substantially different in form and function from pre-disturbance states, disrupting the delivery of ecosystem services and functions. On coral reefs, regime shifts are typically characterized by a change in the benthic composition from coral to macroalgal dominance. Such fundamental shifts in the benthos are anticipated to impact associated fish communities that are reliant on the reef for food and shelter, yet there is limited understanding of how regime shifts propagate through the fish community over time, relative to initial or recovery conditions. This study addresses this knowledge gap using long-term data of coral reef regime shifts and recovery on Seychelles reefs following the 1998 mass bleaching event. It shows how trophic structure of the reef fish community becomes increasingly dissimilar between alternative reef ecosystem states (regime-shifted vs. recovering) with time since disturbance. Regime-shifted reefs developed a concave trophic structure, with increased biomass in base trophic levels as herbivorous species benefitted from increased algal resources. Mid trophic level species, including specialists such as corallivores, declined with loss of coral habitat, while biomass was retained in upper trophic levels by large-bodied, generalist invertivores. Recovering reefs also experienced an initial decline in mid trophic level biomass, but moved toward a bottom-heavy pyramid shape, with a wide range of feeding groups (e.g., planktivores, corallivores, omnivores) represented at mid trophic levels. Given the importance of coral reef fishes in maintaining the ecological function of coral reef ecosystems and their associated fisheries, understanding the effects of regime shifts on these communities is essential to inform decisions that enhance ecological

Dual-Use Threat Assessment Framework - An Attempt to Quantify the Risk

International Nuclear Information System (INIS)

Stephen, E. R.; Lavigne, J. J.; Colton, B.

2007-01-01

Advances in the biosciences over the past decade have been rapid and transformative. While these advances offer significant benefit to society, they also provide very significant challenges in terms of security. Concerns over misuse and/or accidental use/release (dual use) although not new, are now being viewed through the security lens. There is a wide-spread view that public or private sector scientists, supported through investments by pharmaceutical, environmental and agricultural interests working in the fields that comprise biotechnology, posses the ability to assess the implications of their own work and work within a regime of self-control that is for the most part self-governing (codes of practice). On the other end of the spectrum are those that would codify or legislative control. All this is being done in the absence of a mechanism for quantifying the threat. This presentation will discuss the development of an assessment framework that addresses both actual and potential threats. The framework was developed based on available intelligence and other open source information along with interviews with those persons familiar with the concept of dual use and the multiple, sometimes competing agendas of a variety of interest groups. The framework will help to bring some clarity to the discussion and at the same time, help to inform those that are positioned to respond to the threat. (author)

New Fukui, dual and hyper-dual kernels as bond reactivity descriptors.

Science.gov (United States)

Franco-Pérez, Marco; Polanco-Ramírez, Carlos-A; Ayers, Paul W; Gázquez, José L; Vela, Alberto

2017-06-21

We define three new linear response indices with promising applications for bond reactivity using the mathematical framework of τ-CRT (finite temperature chemical reactivity theory). The τ-Fukui kernel is defined as the ratio between the fluctuations of the average electron density at two different points in the space and the fluctuations in the average electron number and is designed to integrate to the finite-temperature definition of the electronic Fukui function. When this kernel is condensed, it can be interpreted as a site-reactivity descriptor of the boundary region between two atoms. The τ-dual kernel corresponds to the first order response of the Fukui kernel and is designed to integrate to the finite temperature definition of the dual descriptor; it indicates the ambiphilic reactivity of a specific bond and enriches the traditional dual descriptor by allowing one to distinguish between the electron-accepting and electron-donating processes. Finally, the τ-hyper dual kernel is defined as the second-order derivative of the Fukui kernel and is proposed as a measure of the strength of ambiphilic bonding interactions. Although these quantities have never been proposed, our results for the τ-Fukui kernel and for τ-dual kernel can be derived in zero-temperature formulation of the chemical reactivity theory with, among other things, the widely-used parabolic interpolation model.

Dual Credit Report

Science.gov (United States)

Light, Noreen

2016-01-01

In 2015, legislation to improve access to dual-credit programs and to reduce disparities in access and completion--particularly for low income and underrepresented students--was enacted. The new law focused on expanding access to College in the High School but acknowledged issues in other dual-credit programs and reinforced the notion that cost…

The Effect of Combined Aspirin and Clopidogrel Treatment on Cancer Incidence.

Science.gov (United States)

Leader, Avi; Zelikson-Saporta, Ravit; Pereg, David; Spectre, Galia; Rozovski, Uri; Raanani, Pia; Hermoni, Doron; Lishner, Michael

2017-07-01

Multiple studies have shown an association between aspirin treatment and a reduction in newly diagnosed cancer. Conversely, there are conflicting clinical and laboratory data on the effect of combined clopidogrel and aspirin therapy on cancer incidence, including analyses suggesting an increased cancer risk. No large-scale cohort study has been performed to address this issue in a heterogeneous real-world scenario. We investigated the effect of clopidogrel and aspirin on cancer incidence compared with aspirin alone and no antiplatelet therapy. A population-based historical cohort study of subjects aged ≥50 years covered by Clalit Health Services, an Israeli health maintenance organization, was performed. Patients treated with the newer antiplatelet drugs, prasugrel or ticagrelor, which, like clopidogrel, inhibit adenosine diphosphate receptors, and those with prior cancer were excluded. Prescription records of antiplatelet medication were retrieved. The cohort included 183,912 subjects diagnosed with 21,974 cancer cases based upon the International Classification of Diseases, Ninth Revision. Dual aspirin and clopidogrel was prescribed in 9.6%, while 49% received aspirin alone and 41% used neither. Compared with nonusers, there was a lower risk of cancer in subjects exposed to aspirin with (hazard ratio [HR] 0.46; 95% confidence interval [CI], 0.44-0.49) or without clopidogrel (HR 0.54; 95% CI, 0.52-0.56), on long-term follow-up. Combined treatment was associated with a lower cancer risk than the aspirin-only group (HR 0.92; 95% CI, 0.86-0.97). Dual clopidogrel and aspirin treatment is safe regarding the cancer risk. This study generates the hypothesis that clopidogrel may reduce cancer incidence. Copyright © 2017 Elsevier Inc. All rights reserved.

A tomographic particle image velocimetry investigation of the flow development over dual step cylinders

Energy Technology Data Exchange (ETDEWEB)

Morton, C., E-mail: chris.morton@ucalgary.ca [Department of Mechanical and Manufacturing Engineering, University of Calgary, 2500 University Dr NW, Calgary, Alberta T2N 1N4 (Canada); Yarusevych, S. [Department of Mechanical and Mechatronics Engineering, University of Waterloo, 200 University Ave W, Waterloo, Ontario N2L 3G1 (Canada); Scarano, F. [Department of Aerospace Engineering, Delft University of Technology, 2628 Delft (Netherlands)

2016-02-15

This experimental study focuses on the near wake development of a dual step cylinder geometry consisting of a long base cylinder of diameter d to which a larger diameter (D) cylinder of length L is attached coaxially at mid-span. The experiments cover a range of Reynolds numbers, 2000 ≤ Re{sub D} ≤ 5000, diameter ratios, 1.33 ≤ D/d ≤ 2.0 and large cylinder aspect ratios, 0.5 ≤ L/D ≤ 5 using Tomographic particle image velocimetry. Distinct changes in wake topology are observed varying the above parameters. Supporting previous experimental studies on the same geometry involving flow visualization and planar measurements, four distinct flow regimes are identified to which a distinct three-dimensional wake topology can be associated. The vortex-dominated wake dynamical behaviour is investigated with Proper Orthogonal Decomposition (POD) and conditional averaging of three-dimensional velocity fields is used to exemplify the different shedding regimes. The conditionally averaged flow fields are shown to quantitatively resolve flow features equivalent to those obtained from a reduced order model consisting of the first ten to twenty POD modes, identifying the dominant vortex shedding cells and their interactions.

Regime identification in ASDEX Upgrade

International Nuclear Information System (INIS)

Giannone, L; Sips, A C C; Kardaun, O; Spreitler, F; Suttrop, W

2004-01-01

The ability to recognize the transition from the L-mode to the H-mode or from the H-mode to the improved H-mode reliably from a conveniently small number of measurements in real time is of increasing importance for machine control. Discriminant analysis has been applied to regime identification of plasma discharges in the ASDEX Upgrade tokamak. An observation consists of a set of plasma parameters averaged over a time slice in a discharge. The data set consists of all observations over different discharges and time slices. Discriminant analysis yields coefficients allowing the classification of a new observation. The results of a frequentist and a formal Bayesian approach to discriminant analysis are compared. With five plasma variables, a failure rate of 1.3% for predicting the L-mode and the H-mode confinement regime was achieved. With five plasma variables, a failure rate of 5.3% for predicting the H-mode and the improved H-mode confinement regime was achieved. The coefficients derived by discriminant analysis have been applied subsequently to discharges to illustrate the operation of regime identification in a real time control system

Synthesis and Antiplatelet Activity of Antithrombotic Thiourea Compounds: Biological and Structure-Activity Relationship Studies

Directory of Open Access Journals (Sweden)

André Luiz Lourenço

2015-04-01

Full Text Available The incidence of hematological disorders has increased steadily in Western countries despite the advances in drug development. The high expression of the multi-resistance protein 4 in patients with transitory aspirin resistance, points to the importance of finding new molecules, including those that are not affected by these proteins. In this work, we describe the synthesis and biological evaluation of a series of N,N'-disubstituted thioureas derivatives using in vitro and in silico approaches. New designed compounds inhibit the arachidonic acid pathway in human platelets. The most active thioureas (compounds 3d, 3i, 3m and 3p displayed IC50 values ranging from 29 to 84 µM with direct influence over in vitro PGE2 and TXA2 formation. In silico evaluation of these compounds suggests that direct blockage of the tyrosyl-radical at the COX-1 active site is achieved by strong hydrophobic contacts as well as electrostatic interactions. A low toxicity profile of this series was observed through hemolytic, genotoxic and mutagenic assays. The most active thioureas were able to reduce both PGE2 and TXB2 production in human platelets, suggesting a direct inhibition of COX-1. These results reinforce their promising profile as lead antiplatelet agents for further in vivo experimental investigations.

spinning self-dual particles

International Nuclear Information System (INIS)

Gamboa, J.; Rivelles, V.O.

1989-01-01

Self-dual particles in two-dimensions are presented. They were obtained from chiral boson particle by square root technique. The propagator of spinning self-dual particle is calculated using the BFV formalism. (M.C.K.)

Fiscal Policy and Welfare under Different Exchange Rate Regimes

DEFF Research Database (Denmark)

Østrup, Finn

a representativeindividual's utility, it is demonstrated that there are differences betweenexchange rate regimes with respect to the level of government spending. Thesedifferences arise first because a rise in government spending affects macroeconomicvariables differently under different exchange rate regimes......, and secondbecause the government's inclination to expand government spending is affectedby inflation which depends on the exchange rate regime. At low rates of inflation,the government is inclined to set a higher level of government spending under afixed exchange rate regime than under a floating exchange rate...... regime in whichthe monetary authority optimises preferences which include an employment targetand an inflation target. As government spending affects the representativeindividual's utility, the choice of exchange rate regime has an impact on welfare.Keywords: exchange rate regimes; fiscal policy...

Determination of Actual Friction Factors in Metal Forming under Heavy Loaded Regimes Combining Experimental and Numerical Analysis

Directory of Open Access Journals (Sweden)

Ana María Camacho

2016-09-01

Full Text Available Tribological conditions can change drastically during heavy loaded regimes as experienced in metal forming; this is especially critical when lubrication can only be applied at the early stage of the process because the homogeneous lubricant layer can break along the die-workpiece interface. In these cases, adopting a constant friction factor for the lubricant-surface pair may not be a valid assumption. This paper presents a procedure based on the use of dual friction factor maps to determine friction factors employed in heavy loaded regimes. A finite element (FE simulation is used to obtain the friction factor map for the alloy UNS A96082. Experiments were conducted using four lubricants (aluminum anti-size, MoS2 grease, silicone oil, and copper paste to determine the actual friction curves. The experimental procedure is based on the application of lubricant only at the beginning of the first stage of ring compression, and not at intermediate stages as is usual in typical ring compression tests (RCTs. The results show that for small reductions (rh < 20%, the conventional RCT can be applied because the tribological conditions remain similar. For large reductions (rh > 20%, it is recommended to obtain an average value of the friction factor for every lubricant-surface pair in the range of deformation considered.

The Two Regimes of Postwar Shipping

DEFF Research Database (Denmark)

Iversen, Martin Jes; Tenold, Stig

2014-01-01

the bargaining that accompanied the shift from the national regime to the competitive regime. Specifically, we show that the new regime primarily accommodated the interests of private actors such as shipping companies, rather than the interests of the authorities and the trade unions.......The aim of this article is to illustrate the most important changes in the regulatory framework of the shipping sector from the 1960s to 2010, and to analyse the basis for, and effects of, these changes. In order to explain how the transformation has occurred, we use two traditional maritime...... nations—Denmark and Norway—as case studies. First, we introduce the two regimes of Danish and Norwegian shipping: ‘the national regime’ from the early 1960s to the mid-1970s; and ‘the competitive regime’, which was fully established by the middle of the 1990s and still persists. Then, we briefly sketch...

In vitro differentiation of renal stone composition using dual-source, dual-energy CT

International Nuclear Information System (INIS)

Zhou Changsheng; Zhang Longjiang; Xu Feng; Qi Li; Zhao Yan'e; Zheng Ling; Huang Wei; Liu Youhuang; Lu Guangming

2012-01-01

Objective: To evaluate the ability of dual-source. dual-energy CT in differentiating uric acid stones from non-uric acid stones with infrared spectroscopy as reference standard. Materials and Methods: Urinary calculus from 308 patients were scanned in first generation dual-source CT with dual-energy mode between July 2011 and June 2012. Renal Stone application was used to analyze their composition. The uric acid stones color were coded red and non-uric acid stones were blue. CT values were measured in 60 selective urinary calculus including 30 uric acid stones and 30 non-uric acid stones. The accuracy of dual energy CT to differentiate uric acid and no-uric acid stones was calculated. Results: Of 308 patients, 60 patients had uric acid stones and 248 non-uric acid stones. No difference was found for uric acid stone at 80 kV and 140 kV (375.8±69.2 HU vs. 374.1±69.4 HU; t=-0.217, P=0.830), while CT values of non-uric acid stones were higher at 80 kV than those at 140 kV (1455.1±312.4 HU vs. 1039.6±194.4 HU; t=-12.16. P<0.001). CT values of non-uric acid stones at 80 kV, 140 kV, and average weighted images (1455.1±312.4 HU, 1 039.6±194.4 HU, and 882.0±176.4 HU, respectively) were higher than those of uric acid stones (375.8±69.2 HU, 374.1±69.4 HU, and 366.3±80.1 HU, respectively; P<0.001). With infrared spectrum findings as reference standard, the accuracy of dual energy CT in differentiating uric acid stones from non-uric acid stones was 100%. Conclusions: Dual-source, dual-energy CT can accurately differentiate uric acid stones from non-uric acid stones, and plays an important role in treatment planning of renal stones. (authors)

Dual coil ignition system

Energy Technology Data Exchange (ETDEWEB)

Huberts, Garlan J.; Qu, Qiuping; Czekala, Michael Damian

2017-03-28

A dual coil ignition system is provided. The dual coil ignition system includes a first inductive ignition coil including a first primary winding and a first secondary winding, and a second inductive ignition coil including a second primary winding and a second secondary winding, the second secondary winding connected in series to the first secondary winding. The dual coil ignition system further includes a diode network including a first diode and a second diode connected between the first secondary winding and the second secondary winding.

A two-dimensional (2D) analytical subthreshold swing and transconductance model of underlap dual-material double-gate (DMDG) MOSFET for analog/RF applications

Science.gov (United States)

Narendar, Vadthiya; Rai, Saurabh; Tiwari, Siddharth; Mishra, R. A.

2016-12-01

The double-gate (DG) metal-oxide-semiconductor field effect transistors (MOSFETs) are the choice of technology in sub -100 nm regime of leading microelectronics industry. To enhance the analog and RF performance of DG MOSFET, an underlap dual-material (DM) DG MOSFET device structure has been considered because, it has the advantages of both underlap as well as that of dual-material gate (DMG). A 2D analytical surface potential, subthreshold current, subthreshold swing as well as transconductance modelling of underlap DMDG MOSFET has been done by solving the Poisson's equation. It has also been found that, numerically simulated data approves the analytically modelled data with commendable accuracy. As underlap length (Lun) increases, a substantial reduction of subthreshold current due to enhanced gate control over channel regime is observed. DMG structure facilitates to improve the average velocity of carriers which leads to superior drive current of the device. The underlap DMDG MOSFET device structure demonstrates an ameliorated subthreshold characteristic. The analog figure of merits (FOMs) such as transconductance (gm), transconductance generation factor (TGF), output conductance (gd), early voltage (VEA), intrinsic gain (AV) and RF FOMs namely cut-off frequency (fT), gain frequency product (GFP), transconductance frequency product (TFP) and gain transconductance frequency product (GTFP) have been evaluated. The aforesaid analysis revels that, the device is best suited for communication related Analog/RF applications.

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

Science.gov (United States)

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.

Endogenous Monetary Policy Regime Change

OpenAIRE

Troy Davig; Eric M. Leeper

2006-01-01

This paper makes changes in monetary policy rules (or regimes) endogenous. Changes are triggered when certain endogenous variables cross specified thresholds. Rational expectations equilibria are examined in three models of threshold switching to illustrate that (i) expectations formation effects generated by the possibility of regime change can be quantitatively important; (ii) symmetric shocks can have asymmetric effects; (iii) endogenous switching is a natural way to formally model preempt...

Statistics of exchange rate regimes in Nigeria | Iwueze | Global ...

African Journals Online (AJOL)

The three distinct exchange rate regimes of Nigeria were subjected to Autoregressive Integrated Moving Average (ARIMA) modeling in order to compare them with respect to model structure. It was found that the three regimes admit different models. Regime one admits Moving average model of order 2, Regime two admits ...

Dynamic dual-tracer PET reconstruction.

Science.gov (United States)

Gao, Fei; Liu, Huafeng; Jian, Yiqiang; Shi, Pengcheng

2009-01-01

Although of important medical implications, simultaneous dual-tracer positron emission tomography reconstruction remains a challenging problem, primarily because the photon measurements from dual tracers are overlapped. In this paper, we propose a simultaneous dynamic dual-tracer reconstruction of tissue activity maps based on guidance from tracer kinetics. The dual-tracer reconstruction problem is formulated in a state-space representation, where parallel compartment models serve as continuous-time system equation describing the tracer kinetic processes of dual tracers, and the imaging data is expressed as discrete sampling of the system states in measurement equation. The image reconstruction problem has therefore become a state estimation problem in a continuous-discrete hybrid paradigm, and H infinity filtering is adopted as the estimation strategy. As H infinity filtering makes no assumptions on the system and measurement statistics, robust reconstruction results can be obtained for the dual-tracer PET imaging system where the statistical properties of measurement data and system uncertainty are not available a priori, even when there are disturbances in the kinetic parameters. Experimental results on digital phantoms, Monte Carlo simulations and physical phantoms have demonstrated the superior performance.

Dual leadership in a hospital practice

DEFF Research Database (Denmark)

Thude, Bettina Ravnborg; Thomsen, Svend Erik; Stenager, Egon

2017-01-01

, this study aims to analyse three different dual leadership pairs at a Danish hospital. Furthermore, this study develops a tool to characterize dual leadership teams from each other. Design/methodology/approach This is a qualitative study using semi-structured interviews. Six leaders were interviewed...... to clarify how dual leadership works in a hospital context. All interviews were transcribed and coded. During coding, focus was on the nine principles found in the literature and another principle was found by looking at the themes that were generic for all six interviews. Findings Results indicate......Purpose Despite the practice of dual leadership in many organizations, there is relatively little research on the topic. Dual leadership means two leaders share the leadership task and are held jointly accountable for the results of the unit. To better understand how dual leadership works...

Choice of exchange rate regimes for African countries: Fixed or Flexible Exchange rate regimes?

OpenAIRE

Simwaka, Kisu

2010-01-01

The choice of an appropriate exchange rate regime has been a subject of ongoing debate in international economics. The majority of African countries are small open economies and thus where the choice of the exchange rate regime is an important policy issue. Aside from factors such as interest rates and inflation, the exchange rate is one of the most important determinants of a country’s relative level of economic health. For this reason, exchange rates are among the most watched analyzed and ...

Capacitance densitometer for flow regime identification

International Nuclear Information System (INIS)

Shipp, R.L. Jr.

1978-01-01

This invention relates to a capacitance densitometer for determining the flow regime of a two-phase flow system. A two-element capacitance densitometer is used in conjunction with a conventional single-beam gamma densitometer to unambiguously identify the prevailing flow regime and the average density of a flowing fluid

Multiscale regime shifts and planetary boundaries

NARCIS (Netherlands)

Hughes, T.P.; Carpenter, S.; Rockstrom, J.; Scheffer, M.; Walker, B.

2013-01-01

Life on Earth has repeatedly displayed abrupt and massive changes in the past, and there is no reason to expect that comparable planetary-scale regime shifts will not continue in the future. Different lines of evidence indicate that regime shifts occur when the climate or biosphere transgresses a

Cognitive and motor dual task gait training improve dual task gait performance after stroke - A randomized controlled pilot trial.

Science.gov (United States)

Liu, Yan-Ci; Yang, Yea-Ru; Tsai, Yun-An; Wang, Ray-Yau

2017-06-22

This study investigated effects of cognitive and motor dual task gait training on dual task gait performance in stroke. Participants (n = 28) were randomly assigned to cognitive dual task gait training (CDTT), motor dual task gait training (MDTT), or conventional physical therapy (CPT) group. Participants in CDTT or MDTT group practiced the cognitive or motor tasks respectively during walking. Participants in CPT group received strengthening, balance, and gait training. The intervention was 30 min/session, 3 sessions/week for 4 weeks. Three test conditions to evaluate the training effects were single walking, walking while performing cognitive task (serial subtraction), and walking while performing motor task (tray-carrying). Parameters included gait speed, dual task cost of gait speed (DTC-speed), cadence, stride time, and stride length. After CDTT, cognitive-motor dual task gait performance (stride length and DTC-speed) was improved (p = 0.021; p = 0.015). After MDTT, motor dual task gait performance (gait speed, stride length, and DTC-speed) was improved (p = 0.008; p = 0.008; p = 0.008 respectively). It seems that CDTT improved cognitive dual task gait performance and MDTT improved motor dual task gait performance although such improvements did not reach significant group difference. Therefore, different types of dual task gait training can be adopted to enhance different dual task gait performance in stroke.

Accuracy of iodine quantification using dual energy CT in latest generation dual source and dual layer CT.

Science.gov (United States)

Pelgrim, Gert Jan; van Hamersvelt, Robbert W; Willemink, Martin J; Schmidt, Bernhard T; Flohr, Thomas; Schilham, Arnold; Milles, Julien; Oudkerk, Matthijs; Leiner, Tim; Vliegenthart, Rozemarijn

2017-09-01

To determine the accuracy of iodine quantification with dual energy computed tomography (DECT) in two high-end CT systems with different spectral imaging techniques. Five tubes with different iodine concentrations (0, 5, 10, 15, 20 mg/ml) were analysed in an anthropomorphic thoracic phantom. Adding two phantom rings simulated increased patient size. For third-generation dual source CT (DSCT), tube voltage combinations of 150Sn and 70, 80, 90, 100 kVp were analysed. For dual layer CT (DLCT), 120 and 140 kVp were used. Scans were repeated three times. Median normalized values and interquartile ranges (IQRs) were calculated for all kVp settings and phantom sizes. Correlation between measured and known iodine concentrations was excellent for both systems (R = 0.999-1.000, p < 0.0001). For DSCT, median measurement errors ranged from -0.5% (IQR -2.0, 2.0%) at 150Sn/70 kVp and -2.3% (IQR -4.0, -0.1%) at 150Sn/80 kVp to -4.0% (IQR -6.0, -2.8%) at 150Sn/90 kVp. For DLCT, median measurement errors ranged from -3.3% (IQR -4.9, -1.5%) at 140 kVp to -4.6% (IQR -6.0, -3.6%) at 120 kVp. Larger phantom sizes increased variability of iodine measurements (p < 0.05). Iodine concentration can be accurately quantified with state-of-the-art DECT systems from two vendors. The lowest absolute errors were found for DSCT using the 150Sn/70 kVp or 150Sn/80 kVp combinations, which was slightly more accurate than 140 kVp in DLCT. • High-end CT scanners allow accurate iodine quantification using different DECT techniques. • Lowest measurement error was found in scans with largest photon energy separation. • Dual-source CT quantified iodine slightly more accurately than dual layer CT.

Current US nuclear liability regime

International Nuclear Information System (INIS)

Brown, O.F.

2000-01-01

The Price-Anderson Act Adopted by US Congress in 1957 as the world's first national nuclear liability regime. It is a comprehensive, complicated and unique system and stems from special features of US legal regime and federal system of government. It differs from other systems by providing for 'economic', not legal; channeling of liability to facility operator and not recommended as model for other states, but most features adopted by other states and international conventions

Level-ARCH Short Rate Models with Regime Switching

DEFF Research Database (Denmark)

Christiansen, Charlotte

This paper introduces regime switching volatility into level- ARCH models for the short rates of the US, the UK, and Germany. Once regime switching and level effects are included there are no gains from including ARCH effects. It is of secondary importance exactly how the regime switching is spec...

How Welfare Regimes Generate and Erode Social Capital

DEFF Research Database (Denmark)

Larsen, Christian Albrekt

2007-01-01

in the USA and other liberal welfare regimes, while social capital is stable in the so-called social democratic and conservative welfare regimes. The second puzzle is why the group of social democratic regimes have extremely high levels of social trust. It is argued that both puzzles have to do......Comparative studies of social capital, operationalised as social trust between citizens, have revealed two major puzzles. The first puzzle has to do with the decline in social trust in the USA, which fuelled considerable debate about social capital. The question is why social capital erodes...... with the presence or absence of a poor and culturally distinct underclass. The social democratic welfare regimes hinder – while the liberal welfare regime generate – such underclass phenomena....

Dual of QCD with One Adjoint Fermion

DEFF Research Database (Denmark)

Mojaza, Matin; Nardecchia, Marco; Pica, Claudio

2011-01-01

We construct the magnetic dual of QCD with one adjoint Weyl fermion. The dual is a consistent solution of the 't Hooft anomaly matching conditions, allows for flavor decoupling and remarkably constitutes the first nonsupersymmetric dual valid for any number of colors. The dual allows to bound...

Technical Note: Insertion of digital lesions in the projection domain for dual-source, dual-energy CT.

Science.gov (United States)

Ferrero, Andrea; Chen, Baiyu; Li, Zhoubo; Yu, Lifeng; McCollough, Cynthia

2017-05-01

To compare algorithms performing material decomposition and classification in dual-energy CT, it is desirable to know the ground truth of the lesion to be analyzed in real patient data. In this work, we developed and validated a framework to insert digital lesions of arbitrary chemical composition into patient projection data acquired on a dual-source, dual-energy CT system. A model that takes into account beam-hardening effects was developed to predict the CT number of objects with known chemical composition. The model utilizes information about the x-ray energy spectra, the patient/phantom attenuation, and the x-ray detector energy response. The beam-hardening model was validated on samples of iodine (I) and calcium (Ca) for a second-generation dual-source, dual-energy CT scanner for all tube potentials available and a wide range of patient sizes. The seven most prevalent mineral components of renal stones were modeled and digital stones were created with CT numbers computed for each patient/phantom size and x-ray energy spectra using the developed beam-hardening model. Each digital stone was inserted in the dual-energy projection data of a water phantom scanned on a dual-source scanner and reconstructed with the routine algorithms in use in our practice. The geometry of the forward projection for dual-energy data was validated by comparing CT number accuracy and high-contrast resolution of simulated dual-energy CT data of the ACR phantom with experimentally acquired data. The beam-hardening model and forward projection method accurately predicted the CT number of I and Ca over a wide range of tube potentials and phantom sizes. The images reconstructed after the insertion of digital kidney stones were consistent with the images reconstructed from the scanner, and the CT number ratios for different kidney stone types were consistent with data in the literature. A sample application of the proposed tool was also demonstrated. A framework was developed and validated

Can Old Regimes Handle New Wars?

DEFF Research Database (Denmark)

Henningsen, Troels

Research on New Wars argues that since the 1980s states and regimes have become more vulnerable to violence from non-state actors. Two developments in the Sahel region support the New Wars thesis: an increase in Islamist radicalization and new access to the global black market, both of which......, the paper finds that regimes in the Sahel region are still able to cope with the rise in non-state threats. The paper first shortly compares the longevity of the present regimes in the Sahel region to all previous ones, second examines in-depth how Chad and Mali fight the insurgents. Findings are that since...

FEL in transverse optical klystron regime

International Nuclear Information System (INIS)

Scarlat, F.; Baltateanu, N.

1994-01-01

Among all operational regimes of free electron laser (FEL), the transverse optical regime (TOK) requires the least stringent electron beam parameters. The device associated to this regime, also defined as FEL with two or more components, consists of two or more identical interaction sections separated by one or more drift distances among themselves. Starting from the motion equations which describe the interaction between an electron and the radiation inside the undulator, one can obtain some practical expressions for the calculation of the efficiency of the energy transfer from the electron to the radiation, and the gain of the external coherent radiation for a FEL in TOK with three cavities. (Author)

The role of the media in establishing international security regimes

Directory of Open Access Journals (Sweden)

Chanan Naveh

2005-04-01

Full Text Available This article focuses primarily on the media's impact on international security regimes. It explores the ways in which the media affect the lifecycles of international regimes, from the time they are first conceived of, through their establishment, consolidation and stabilization, up until their ultimate demise. Although this paper highlights the media's role in the evolution of security regimes, it is clear that, regardless of the regime in question, media play a role throughout the lifecycle of all international regimes, whatever their character. In order to analyze the relationships of the media with security regimes in general, and specifically their contribution to each stage in their development, the article utilizes methodologies from the field of communication studies. It examines the media's agenda, "news values" and various functions, and their ability to mobilize public support for the particular issue of the regime. To date, most studies have explored the interaction between media communication patterns and global developments at the state level, or in relation to the formulation of foreign policy, while largely ignoring the international dimension of the relationship. This article attempts to remedy this situation, and the relevant processes are analysed in a case study of the anti-Iraq international security regime. It should be noted that although the paper focuses on the specific anti-Iraqi regime, it is part of a more general Anti-Rogue actors regime which includes the war against global terrorism. The study of the development of the anti-Iraq press-security regime teaches us that during international crises the media mobilize and unanimously support the regime fighting the "bad guys." But, when the regime develops and enters disputed turfs and begins to lose its legitimacy, media support diminishes, and the media may even develop into an opposing force and may join the actors fighting against this regime. Moreover, the study of

Regimes of mini black hole abandoned to accretion

Science.gov (United States)

Paik, Biplab

2018-01-01

Being inspired by the Eddington’s idea, along with other auxiliary arguments, it is unveiled that there exist regimes of a black hole that would prohibit accretion of ordinary energy. In explicit words, there exists a lower bound to black hole mass below which matter accretion process does not run for black holes. Not merely the baryonic matter, but, in regimes, also the massless photons could get prohibited from rushing into a black hole. However, unlike the baryon accretion abandoned black hole regime, the mass-regime of a black hole prohibiting accretion of radiation could vary along with its ambient temperature. For example, we discuss that earlier to 10‑8 s after the big-bang, as the cosmological temperature of the Universe grew above ˜ 1014 K, the mass range of black hole designating the radiation accretion abandoned regime, had to be in varying state being connected with the instantaneous age of the evolving Universe by an “one half” power law. It happens to be a fact that a black hole holding regimes prohibiting accretion of energy is gigantic by its size in comparison to the Planck length-scale. Hence the emergence of these regimes demands mini black holes for not being viable as profound suckers of energy. Consideration of accretion abandoned regimes could be crucial for constraining or judging the evolution of primordial black holes over the age of the Universe.

TARIFFS AND REGIMES OF POWER CONSUMPTION

Directory of Open Access Journals (Sweden)

S. V. Batsova

2010-01-01

Full Text Available Analysis of regimes of electro-consumption at RUP «BMZ» is carried out. It is shown that in conditions of rapid growth of prices for electric power one of the conditions of reduction of production expenses is to be the increase of efficiency of the electro-consumption regimes control.

Dual antiretroviral therapy for HIV infection.

Science.gov (United States)

Soriano, Vicente; Fernandez-Montero, Jose Vicente; Benitez-Gutierrez, Laura; Mendoza, Carmen de; Arias, Ana; Barreiro, Pablo; Peña, José M; Labarga, Pablo

2017-08-01

For two decades, triple combinations of antiretrovirals have been the standard treatment for HIV infection. The challenges of such lifelong therapy include long-term side effects, high costs and reduced drug adherence. The recent advent of more potent and safer antiretrovirals has renewed the interest for simpler HIV regimens. Areas covered: We discuss the pros and cons of dual antiretroviral therapies in both drug-naïve and in treatment-experienced patients with viral suppression (switch strategy). Expert opinion: Some dual antiretroviral regimens are safe and efficacious, particularly as maintenance therapy. At this time, combinations of dolutegravir plus rilpivirine represent the best dual regimen. Longer follow-up and larger study populations are needed before supporting dolutegravir plus lamivudine. In contrast, dual therapy based on maraviroc is less effective. Although dual regimens with boosted protease inhibitors plus either lamivudine or raltegravir may be effective, they are penalized by metabolic side effects and risk for drug interactions. The newest dual regimens could save money, reduce toxicity and spare drug options for the future. For the first time in HIV therapeutics, less can be more. Dual therapy switching has set up a new paradigm in HIV treatment that uses induction-maintenance.

Dual Enrollment Academy Programs

Science.gov (United States)

Gonzalez, Nicolas; Chavez, Guadalupe

2009-01-01

Dual Enrollment Engineering (DEEA) and Medical Science (DEMSA) Academies are two-year dual enrollment programs for high school students. Students explore engineering and medical careers through college coursework. Students prepare for higher education in engineering and medical fields while completing associate degrees in biology or engineering…

A Dual Egalitarian Solution

NARCIS (Netherlands)

Klijn, F.; Slikker, M.; Tijs, S.H.

2000-01-01

In this note we introduce an egalitarian solution, called the dual egalitarian solution, that is the natural counterpart of the egalitarian solution of Dutta and Ray (1989).We prove, among others, that for a convex game the egalitarian solution coincides with the dual egalitarian solution for its

Cargo liability regimes

Science.gov (United States)

2001-01-01

There are at present at least three international regimes of maritime cargo liability in force in different countries of the world - the original Hague rules (1924), the updated version known as the Hague-Visby rules (1968, further amended 1979), and...

Dual-specificity phosphatase 3 deficiency or inhibition limits platelet activation and arterial thrombosis.

Science.gov (United States)

Musumeci, Lucia; Kuijpers, Marijke J; Gilio, Karen; Hego, Alexandre; Théâtre, Emilie; Maurissen, Lisbeth; Vandereyken, Maud; Diogo, Catia V; Lecut, Christelle; Guilmain, William; Bobkova, Ekaterina V; Eble, Johannes A; Dahl, Russell; Drion, Pierre; Rascon, Justin; Mostofi, Yalda; Yuan, Hongbin; Sergienko, Eduard; Chung, Thomas D Y; Thiry, Marc; Senis, Yotis; Moutschen, Michel; Mustelin, Tomas; Lancellotti, Patrizio; Heemskerk, Johan W M; Tautz, Lutz; Oury, Cécile; Rahmouni, Souad

2015-02-17

A limitation of current antiplatelet therapies is their inability to separate thrombotic events from bleeding occurrences. A better understanding of the molecular mechanisms leading to platelet activation is important for the development of improved therapies. Recently, protein tyrosine phosphatases have emerged as critical regulators of platelet function. This is the first report implicating the dual-specificity phosphatase 3 (DUSP3) in platelet signaling and thrombosis. This phosphatase is highly expressed in human and mouse platelets. Platelets from DUSP3-deficient mice displayed a selective impairment of aggregation and granule secretion mediated by the collagen receptor glycoprotein VI and the C-type lectin-like receptor 2. DUSP3-deficient mice were more resistant to collagen- and epinephrine-induced thromboembolism compared with wild-type mice and showed severely impaired thrombus formation on ferric chloride-induced carotid artery injury. Intriguingly, bleeding times were not altered in DUSP3-deficient mice. At the molecular level, DUSP3 deficiency impaired Syk tyrosine phosphorylation, subsequently reducing phosphorylation of phospholipase Cγ2 and calcium fluxes. To investigate DUSP3 function in human platelets, a novel small-molecule inhibitor of DUSP3 was developed. This compound specifically inhibited collagen- and C-type lectin-like receptor 2-induced human platelet aggregation, thereby phenocopying the effect of DUSP3 deficiency in murine cells. DUSP3 plays a selective and essential role in collagen- and C-type lectin-like receptor 2-mediated platelet activation and thrombus formation in vivo. Inhibition of DUSP3 may prove therapeutic for arterial thrombosis. This is the first time a protein tyrosine phosphatase, implicated in platelet signaling, has been targeted with a small-molecule drug. © 2014 American Heart Association, Inc.

Simulating the transient regime for main condensate system at Cernavoda NPP

International Nuclear Information System (INIS)

Nita, Iulian; Gheorghiu, Mihai; Prisecaru, Ilie; Dupleac, Daniel

2005-01-01

The purpose of this project is to make a Thermal Hydraulic Analysis of Main Condensate System for getting real-time answer of installation during regimes occurring during normal and abnormal operation. To obtain the analyses the MMS code was used. The boundaries of the systems analysis are extended to Main Feedwater System in order to get a realistic response of Deaerator equipment which are situated between those two systems and have entrances from both systems. In this way we made a complex analysis with main condenser and steam generators as boundaries. We obtained a model for the entire chain of condensate and feedwater preheater with interface just turbine bleed steam. From that we could reduce the number of assumptions necessary to make the analysis. The analyses consist in hydraulics and thermal hydraulics analyses, respectively. For the first case analysed are: - the nominal operation regime with main condensate pumps; - start-up regime with total circulate of condensate to condenser; - 25% MCR (Maximum Continuous Rate) regime (this regime was used in designing the condensate regulating valves at low flow; - 40% MCR regime (with circulate of some condensate flow to condenser); - operating regime of 60% MCR with one main condensate pump operating; - operating regime with auxiliary condensate pump; - operating regime with discharging a condensate flow to condensate storage tank. The thermal hydraulic analyses deal with normal and abnormal operating regimes, respectively. In the first case analysed are the following regimes: - nominal operating regime with main condensate pump operating 100% MCR; - transient regime, 100-80% MCR; - transient regime, 100-80-60% MCR with two pumps in operation and 60 % MCR with one main condensate pump in operation; - transient regime, 100-80-60-60-40 % MCR; - shut-down regime; - start-up regime from Hot zero power to rated power regime. Finally, for the abnormal operating regimes the analyses concerned: - transient regime 100

A Hodge dual for soldered bundles

International Nuclear Information System (INIS)

Lucas, Tiago Gribl; Pereira, J G

2009-01-01

In order to account for all possible contractions allowed by the presence of the solder form, a generalized Hodge dual is defined for the case of soldered bundles. Although for curvature the generalized dual coincides with the usual one, for torsion it gives a completely new dual definition. Starting from the standard form of a gauge Lagrangian for the translation group, the generalized Hodge dual yields precisely the Lagrangian of the teleparallel equivalent of general relativity, and consequently also the Einstein-Hilbert Lagrangian of general relativity

Asymptotic preserving and all-regime Lagrange-Projection like numerical schemes: application to two-phase flows in low mach regime

International Nuclear Information System (INIS)

Girardin, Mathieu

2014-01-01

Two-phase flows in Pressurized Water Reactors belong to a wide range of Mach number flows. Computing accurate approximate solutions of those flows may be challenging from a numerical point of view as classical finite volume methods are too diffusive in the low Mach regime. In this thesis, we are interested in designing and studying some robust numerical schemes that are stable for large time steps and accurate even on coarse meshes for a wide range of flow regimes. An important feature is the strategy to construct those schemes. We use a mixed implicit-explicit strategy based on an operator splitting to solve fast and slow phenomena separately. Then, we introduce a modification of a Suliciu type relaxation scheme to improve the accuracy of the numerical scheme in some regime of interest. Two approaches have been used to assess the ability of our numerical schemes to deal with a wide range of flow regimes. The first approach, based on the asymptotic preserving property, has been used for the gas dynamics equations with stiff source terms. The second approach, based on the all-regime property, has been used for the gas dynamics equations and the homogeneous two-phase flows models HRM and HEM in the low Mach regime. We obtained some robustness and stability properties for our numerical schemes. In particular, some discrete entropy inequalities are shown. Numerical evidences, in 1D and in 2D on unstructured meshes, assess the gain in term of accuracy and CPU time of those asymptotic preserving and all-regime numerical schemes in comparison with classical finite volume methods. (author) [fr

On R-duals and the duality principle

DEFF Research Database (Denmark)

Christensen, Ole; Stoeva, Diana

2015-01-01

. In this paper we discuss the relationship between the R-duals and a variant, called R-duals of type III, introduced in 2014. In contrast to the original R-duals, it is known that the R-duals of type III generalize the duality principle for all Gabor frames, but we believe that a smaller and more convenient...

Dual-Doppler Feasibility Study

Science.gov (United States)

Huddleston, Lisa L.

2012-01-01

When two or more Doppler weather radar systems are monitoring the same region, the Doppler velocities can be combined to form a three-dimensional (3-D) wind vector field thus providing for a more intuitive analysis of the wind field. A real-time display of the 3-D winds can assist forecasters in predicting the onset of convection and severe weather. The data can also be used to initialize local numerical weather prediction models. Two operational Doppler Radar systems are in the vicinity of Kennedy Space Center (KSC) and Cape Canaveral Air Force Station (CCAFS); these systems are operated by the 45th Space Wing (45 SW) and the National Weather Service Melbourne, Fla. (NWS MLB). Dual-Doppler applications were considered by the 45 SW in choosing the site for the new radar. Accordingly, the 45th Weather Squadron (45 WS), NWS MLB and the National Aeronautics and Space Administration tasked the Applied Meteorology Unit (AMU) to investigate the feasibility of establishing dual-Doppler capability using the two existing systems. This study investigated technical, hardware, and software requirements necessary to enable the establishment of a dual-Doppler capability. Review of the available literature pertaining to the dual-Doppler technique and consultation with experts revealed that the physical locations and resulting beam crossing angles of the 45 SW and NWS MLB radars make them ideally suited for a dual-Doppler capability. The dual-Doppler equations were derived to facilitate complete understanding of dual-Doppler synthesis; to determine the technical information requirements; and to determine the components of wind velocity from the equation of continuity and radial velocity data collected by the two Doppler radars. Analysis confirmed the suitability of the existing systems to provide the desired capability. In addition, it is possible that both 45 SW radar data and Terminal Doppler Weather Radar data from Orlando International Airport could be used to alleviate any

Policy Ideas, Knowledge Regimes and Comparative Political Economy

DEFF Research Database (Denmark)

Campbell, John L.; Pedersen, Ove K.

2015-01-01

Despite much attention to how ideas affect policy making, where these ideas come from is a blind spot in comparative political economy. We show that an important source of policy ideas are knowledge regimes—fields of policy research organizations. We show as well that the organization of knowledge...... to restore it by transforming their knowledge regimes, albeit in ways that are still shaped by the surrounding political and economic institutions. The effectiveness of their efforts is not guaranteed. The argument is based on an analysis of the evolution of knowledge regimes since the 1970s in the USA...... regimes is heavily influenced by the organization of their surrounding political economies such that knowledge regimes have particular national characters. Furthermore, when people perceive that the utility of their knowledge regime for the rest of the political economy breaks down, they often try...

Dual Enrollment for High School Students

Science.gov (United States)

Edwards, Linsey; Hughes, Katherine

2011-01-01

Dual enrollment programs allow high school students to enroll in college courses and potentially earn college credit. The term concurrent enrollment is sometimes used interchangeably with dual enrollment, and sometimes to refer to a particular model of dual enrollment. In some programs, students earn high school and college credit simultaneously;…

Exchange Rate Regimes – A periodical overview and a critical analysis of exchange rate regimes in Kosovo

Directory of Open Access Journals (Sweden)

Flamur Bunjaku

2015-03-01

Full Text Available Exchange rate regimes and the monetary policy are the key instruments governments use to achieve their economic and financial objectives. Moreover, due to global financial crisis the latter instruments get more importance. Empirical evidences show that exchange rate regimes in Kosovo and its monetary policy throughout their development were mainly influenced by different political and historical developments. In regard of Euroisation of monetary system in Kosovo it was found that this action generated macro - financial stability in terms of inflation and price fluctuation. However, in terms of microeconomic aspects, the unilateral adaptation of Euro as the official currency of Kosovo failed to provide microeconomic advantages such as to export stimulation, and so forth. The main exchange rate regime systems were discussed focusing in their advantages and disadvantages, and it was concluded that there is no commonly accepted theory regarding the optimality of exchange rate regimes. In addition, the global financial crisis impact in the financial system of Kosovo is also discussed and it was found that negative impacts of global financial crisis were moderate and indirect.

Transient dynamics of a quantum-dot: From Kondo regime to mixed valence and to empty orbital regimes

Science.gov (United States)

Cheng, YongXi; Li, ZhenHua; Wei, JianHua; Nie, YiHang; Yan, YiJing

2018-04-01

Based on the hierarchical equations of motion approach, we study the time-dependent transport properties of a strongly correlated quantum dot system in the Kondo regime (KR), mixed valence regime (MVR), and empty orbital regime (EOR). We find that the transient current in KR shows the strongest nonlinear response and the most distinct oscillation behaviors. Both behaviors become weaker in MVR and diminish in EOR. To understand the physical insight, we examine also the corresponding dot occupancies and the spectral functions, with their dependence on the Coulomb interaction, temperature, and applied step bias voltage. The above nonlinear and oscillation behaviors could be understood as the interplay between dynamical Kondo resonance and single electron resonant-tunneling.

Characterization of hot deformation behavior and processing map of FGH4096–GH4133B dual alloys

Energy Technology Data Exchange (ETDEWEB)

Liu, Yanhui; Ning, Yongquan, E-mail: ningke521@163.com; Nan, Yang; Liang, Houquan; Li, Yuzhi; Zhao, Zhanglong

2015-06-05

Highlights: • Hot deformation behavior of dual superalloys FGH4096–GH4133B was investigated. • Power dissipation maps built at different strains exhibit a continuous dynamic course. • Processing map approach was adopted to optimize hot forging process for dual superalloys. • Microstructure evolution at different deformation temperature and strain rate of dual superalloys was researched. - Abstract: The dual superalloys FGH4096–GH4133B were joined by the electron beam welding. Isothermal compression tests were carried out on electron beam weldments FGH4096–GH4133B alloys at the temperatures of 1020–1140 °C (the nominal γ′-transus temperature is about 1080 °C) and strain rates of 0.001–1.0 s{sup −1} with the height reduction of 50%. The results showed that the true stress–true strain curves are greatly affected by deformation temperature and strain rate. There is an intrinsic and necessary connection between the flow stress and thermal–dynamic behavior, which can be indicated by the true stress–true strain curves. The power dissipation maps at different strains exhibit that true strain has a great effect on processing maps. Processing maps under different strains were constructed for evaluation of the flow instability regime and optimization of processing parameters. When the true strain is 0.69, the optimum processing condition is around 1090−1130 °C/0.1−1.0 s{sup −1} with the peak efficiency of 0.58. The dynamic recrystallization mechanism and microstructure evolution in the welding seam of the studied dual-alloys have been discussed. High temperature and low strain rate are instrumental to dynamic recrystallization. The size of dynamically recrystallized grain decreased with the increase of strain rate and increased with the increase of deformation temperature. Based on the established combine processing map and microstructures, hot deformation process should be carried out under the condition of 1100−1120 °C/0.3−1.0 s

Characterization of hot deformation behavior and processing map of FGH4096–GH4133B dual alloys

International Nuclear Information System (INIS)

Liu, Yanhui; Ning, Yongquan; Nan, Yang; Liang, Houquan; Li, Yuzhi; Zhao, Zhanglong

2015-01-01

Highlights: • Hot deformation behavior of dual superalloys FGH4096–GH4133B was investigated. • Power dissipation maps built at different strains exhibit a continuous dynamic course. • Processing map approach was adopted to optimize hot forging process for dual superalloys. • Microstructure evolution at different deformation temperature and strain rate of dual superalloys was researched. - Abstract: The dual superalloys FGH4096–GH4133B were joined by the electron beam welding. Isothermal compression tests were carried out on electron beam weldments FGH4096–GH4133B alloys at the temperatures of 1020–1140 °C (the nominal γ′-transus temperature is about 1080 °C) and strain rates of 0.001–1.0 s −1 with the height reduction of 50%. The results showed that the true stress–true strain curves are greatly affected by deformation temperature and strain rate. There is an intrinsic and necessary connection between the flow stress and thermal–dynamic behavior, which can be indicated by the true stress–true strain curves. The power dissipation maps at different strains exhibit that true strain has a great effect on processing maps. Processing maps under different strains were constructed for evaluation of the flow instability regime and optimization of processing parameters. When the true strain is 0.69, the optimum processing condition is around 1090−1130 °C/0.1−1.0 s −1 with the peak efficiency of 0.58. The dynamic recrystallization mechanism and microstructure evolution in the welding seam of the studied dual-alloys have been discussed. High temperature and low strain rate are instrumental to dynamic recrystallization. The size of dynamically recrystallized grain decreased with the increase of strain rate and increased with the increase of deformation temperature. Based on the established combine processing map and microstructures, hot deformation process should be carried out under the condition of 1100−1120 °C/0.3−1.0 s −1 with

Determination of HER2 amplification in primary breast cancer using dual-colour chromogenic in situ hybridization is comparable to fluorescence in situ hybridization: a European multicentre study involving 168 specimens

Science.gov (United States)

García-Caballero, Tomás; Grabau, Dorthe; Green, Andrew R; Gregory, John; Schad, Arno; Kohlwes, Elke; Ellis, Ian O; Watts, Sarah; Mollerup, Jens

2010-01-01

García-Caballero T, Grabau D, Green A R, Gregory J, Schad A, Kohlwes E, Ellis I O, Watts S & Mollerup J (2010) Histopathology56, 472–480 Determination of HER2 amplification in primary breast cancer using dual-colour chromogenic in situ hybridization is comparable to fluorescence in situ hybridization: a European multicentre study involving 168 specimens Aims: Fluorescence in situ hybridization (FISH) can be used to reveal several genomic imbalances relevant to proper cancer diagnosis and to the correct treatment regime. However, FISH requires expensive and advanced fluorescence microscopes in addition to expertise in fluorescence microscopy. To determine whether a newly developed dual-colour chromogenic in situ hybridization (CISH) method is a suitable alternative to FISH, we analysed the human epidermal growth factor receptor 2 gene (HER2) amplification level of 168 breast cancer specimens using dual-colour CISH and FISH and compared the results. Methods and results: We found 100% agreement between HER2 status determined by FISH and dual-colour CISH. Furthermore, we observed that the time used to score slides was significantly reduced by 28% in dual-colour CISH compared with the FISH protocol. Concordance between HER2 protein status and dual-colour CISH or FISH was equally good with an overall agreement of 96.8%. Correlation between the HER2/centromere 17 gene ratios obtained with dual-colour CISH and FISH was highly significant with an overall correlation coefficient (ρ) of 0.96. Conclusions: We conclude that dual-colour CISH and bright field microscopy are excellent alternatives to FISH when analysing the HER2 status of primary breast cancer. PMID:20459554

Unified flow regime predictions at earth gravity and microgravity

International Nuclear Information System (INIS)

Crowley, C.J.

1990-01-01

This paper illustrates the mechanistic models developed to predict flow regime transitions at earth gravity for various pipe inclinations can be successfully applied to existing microgravity flow regime data from several experiments. There is a tendency in the literature for flow regime comparisons in several inclination ranges and at various gravity (acceleration) levels to be treated by separate models, resulting in a proliferation of models for the prediction of flow regimes. One set of mechanistic models can be used to model the transitions between stratified, slug, bubbly, and annular flow regimes in pipes for all acceleration vectors and magnitudes from earth gravity to microgravity

On the regimes of premixing

Energy Technology Data Exchange (ETDEWEB)

Angelini, S.; Theofanous, T.G.; Yuen, W.W. [California Univ., Santa Barbara, CA (United States). Center for Risk Studies and Safety

1998-01-01

The conditions of the MAGICO-2000 experiment are extended to more broadly investigate the regimes of premixing, and the corresponding internal structures of mixing zones. With the help of the data and numerical simulations using the computer code PM-ALPHA, we can distinguish extremes of behavior dominated by inertia and thermal effects - we name these the inertia and thermal regimes, respectively. This is an important distinction that should guide future experiments aimed at code verification in this area. Interesting intermediate behaviors are also delineated and discussed. (author)

A Differentially Driven Dual-Polarized Dual-Wideband Complementary Antenna for 2G/3G/LTE Applications

Directory of Open Access Journals (Sweden)

Botao Feng

2014-01-01

Full Text Available A novel differentially driven dual-polarized dual-wideband complementary patch antenna with high isolation is proposed for 2G/3G/LTE applications. In order to generate dual-polarization and dual-wideband properties, a pair of biorthogonal dual-layer η-shaped tapered line feeding structures is utilized to feed two pairs of dual-layer U-shaped patches, respectively. The upper-layer U-shaped patches mainly serve the upper frequency band, while the lower-layer ones chiefly work for the lower frequency band. Besides, a horned reflector is introduced to improve radiation patterns and provide stable gain. The prototype antenna can achieve a bandwidth of 25.7% (0.78 GHz–1.01 GHz with a stable gain of 7.8±0.7 dBi for the lower band, and a bandwidth of 45.7% (1.69 GHz–2.69 GHz with a gain of 9.5±1.1 dBi for the upper band. Input isolation exceeding 30 dB has been obtained in the wide bandwidth. Thus, it can be potentially used as a base station antenna for 2G/3G/LTE networks.

Refrigeration. Two-Phase Flow. Flow Regimes and Pressure Drop

DEFF Research Database (Denmark)

Knudsen, Hans-Jørgen Høgaard

2002-01-01

The note gives the basic definitions used in two-phase flow. Flow regimes and flow regimes map are introduced. The different contributions to the pressure drop are stated together with an imperical correlation from the litterature.......The note gives the basic definitions used in two-phase flow. Flow regimes and flow regimes map are introduced. The different contributions to the pressure drop are stated together with an imperical correlation from the litterature....

Dual-core Itanium Processor

CERN Multimedia

2006-01-01

Intel’s first dual-core Itanium processor, code-named "Montecito" is a major release of Intel's Itanium 2 Processor Family, which implements the Intel Itanium architecture on a dual-core processor with two cores per die (integrated circuit). Itanium 2 is much more powerful than its predecessor. It has lower power consumption and thermal dissipation.

Transition from the constant ion mobility regime to the ion-atom charge-exchange regime for bounded collisional plasmas

International Nuclear Information System (INIS)

Poggie, Jonathan; Sternberg, Natalia

2005-01-01

A numerical and analytical study of a planar, collisional, direct-current, plasma-wall problem is presented. The fluid model for the problem is first validated by comparing numerical solutions with experimental data for low-pressure (∼0.1 Pa) electrode sheaths with wall potentials on the order of -100 V. For electric potential, ion number density, and ion velocity, good agreement was found between theory and experiment from within the sheath out to the bulk plasma. The frictional drag resulting from ion-neutral collisions is described by a model incorporating both linear and quadratic velocity terms. In order to study the transition from the constant ion mobility regime (linear friction) to the ion-atom charge-exchange collision regime (quadratic friction), the theoretical model was examined numerically for a range of ion temperatures and ion-neutral collision rates. It was found that the solution profiles in the quasineutral plasma depend on the ion temperature. For low ion temperatures they are governed mainly by the ion-atom charge-exchange regime, whereas for high temperatures they are governed by the constant ion mobility regime. Quasineutral plasma models corresponding to these two limiting cases were solved analytically. In particular, an analytical plasma solution is given for the ion-atom charge exchange regime that includes the effects of ion inertia. In contrast to the quasineutral plasma, the sheath is always governed for low to moderate collision rates by the ion-atom charge-exchange regime, independent of the ion temperature. Varying the collision rate, it was shown that when the wall potential is sufficiently high, the sheath cannot be considered collisionless, even if the collision rate is quite small

Assessment of platelet function in healthy cats in response to commonly prescribed antiplatelet drugs using three point-of-care platelet function tests.

Science.gov (United States)

Ho, Kimberly K; Abrams-Ogg, Anthony Cg; Wood, R Darren; O'Sullivan, M Lynne; Kirby, Gordon M; Blois, Shauna L

2017-06-01

Objectives The objective was to determine if decreased platelet function could be detected after treatment with aspirin and/or clopidogrel in healthy cats using three point-of-care platelet function tests that evaluate platelet function by different methods: Multiplate (by impedance), Platelet Function Analyzer 100 (by mechanical aperture closure) and Plateletworks (by platelet counting). Methods Thirty-six healthy cats were randomly assigned to receive one of three oral treatments over an 8 day period: (1) aspirin 5 mg q72h; (2) aspirin 20.25 mg q72h; or (3) clopidogrel 18.75 mg q24h. Cats treated with 5 and 20.25 mg aspirin also received clopidogrel on days 4-8. Platelet aggregation in response to adenosine diphosphate and collagen ± arachidonic acid was assessed on days 1 (baseline), 4 and 8. Aspirin and clopidogrel metabolites were measured by high-performance liquid chromatography. Platelet function in response to treatment was analyzed by ANCOVA, linear regression and Spearman correlation. Results The only solitary aspirin effect was detected using Plateletworks with collagen in cats treated with 20.25 mg. The only effect detected by Multiplate was using arachidonic acid in cats treated with both aspirin 20.25 mg and clopidogrel. All clopidogrel treatment effects were detected by Platelet Function Analyzer 100, Plateletworks (adenosine diphosphate) and Plateletworks (collagen). Drug metabolites were present in all cats, but concentrations were minimally correlated to platelet function test results. Conclusions and relevance Platelet Function Analyzer 100 and Plateletworks using adenosine diphosphate ± collagen agonists may be used to detect decreased platelet function in response to clopidogrel treatment. Either aspirin is not as effective an antiplatelet drug as clopidogrel, or the tests used were not optimal to measure aspirin effect. Cats with heart disease are commonly prescribed antiplatelet drugs to decrease the risk of aortic thromboembolism

Yukon's common oil and gas regime

International Nuclear Information System (INIS)

Love, B.

1998-01-01

The Yukon's common oil and gas regime was developed in partnership with First Nations and it sets out the rules that will apply throughout the Yukon and on Yukon and First Nation lands. While separate and distinct, it conforms with and is compatible with other government systems and regimes. The major elements of the common regime include the Oil and Gas Act, regulations, policies, processes and agreements. The specific opportunities that are available in each phase of oil and gas development in the Yukon are described, with a map showing all basins, reserves and sites of current oil and gas activity. The Yukon has eight potential oil and gas basins: North Coast, Old Crow, Kandik, Eagle Plain, Peel Plateau, Bonnet Plume, Whitehorse Trough, and Liard Plateau. Only three of the eight, the Liard Plateau, Whitehorse Trough and Eagle Plain, have been explored. No wells have been drilled in several of Yukon's basins. Factors influencing economic opportunities in the Territory are also described, including: (1) international events and energy markets, (2) North American gas markets, (3) environmental factors, (4) competitiveness of the Yukon regime, and (5) the commitment of industry resources. 4 figs

Modulational Instability in Linearly Coupled Asymmetric Dual-Core Fibers

Directory of Open Access Journals (Sweden)

Arjunan Govindarajan

2017-06-01

Full Text Available We investigate modulational instability (MI in asymmetric dual-core nonlinear directional couplers incorporating the effects of the differences in effective mode areas and group velocity dispersions, as well as phase- and group-velocity mismatches. Using coupled-mode equations for this system, we identify MI conditions from the linearization with respect to small perturbations. First, we compare the MI spectra of the asymmetric system and its symmetric counterpart in the case of the anomalous group-velocity dispersion (GVD. In particular, it is demonstrated that the increase of the inter-core linear-coupling coefficient leads to a reduction of the MI gain spectrum in the asymmetric coupler. The analysis is extended for the asymmetric system in the normal-GVD regime, where the coupling induces and controls the MI, as well as for the system with opposite GVD signs in the two cores. Following the analytical consideration of the MI, numerical simulations are carried out to explore nonlinear development of the MI, revealing the generation of periodic chains of localized peaks with growing amplitudes, which may transform into arrays of solitons.

Dual-wavelength passive and hybrid mode-locking of 3, 4.5 and 10 GHz InAs/InP(100) quantum dot lasers.

Science.gov (United States)

Tahvili, M S; Du, L; Heck, M J R; Nötzel, R; Smit, M K; Bente, E A J M

2012-03-26

We present an investigation of passive and hybrid mode-locking in Fabry-Pérot type two-section InAs/InP(100) quantum dot lasers that show dual wavelength operation. Over the whole current and voltage range for mode-locking of these lasers, the optical output spectra show two distinct lobes. The two lobes provide a coherent bandwidth and are verified to lead to two synchronized optical pulses. The generated optical pulses are elongated in time due to a chirp which shows opposite signs over the two spectral lobes. Self-induced mode-locking in the single-section laser shows that the dual-wavelength spectra correspond to emission from ground state. In the hybrid mode-locking regime, a map of locking range is presented by measuring the values of timing jitter for several values of power and frequency of the external electrical modulating signal. An overview of the systematic behavior of InAs/InP(100) quantum dot mode-locked lasers is presented as conclusion.

A Burke-Schumann Analysis of Dual-Flame Structure Supported by a Burning Droplet

Science.gov (United States)

Nayagam, V.; Dietrich, D.; Williams, F. A.

2016-01-01

Droplet combustion experiments carried out onboard the International Space Station (ISS), using pure fuels and fuel mixtures, have shown that quasi-steady burning can be sustained by a non-traditional flame configuration, namely a "cool flame" burning in the "partial-burning" regime where both fuel and oxygen leak through the low-temperature controlled flame-sheet. Recent experiments involving large, bi-component fuel (n-decane and hexanol, 50/50 by volume) droplets at elevated pressures show that the visible, hot flame becomes extremely weak while the burning rate remains relatively high, suggesting the possibility of simultaneous presence of "cool" and "hot" flames of roughly equal importance. The radiant output from these bi-component droplets is relatively high and cannot be accounted for only by the presence of a visible hot-flame. In this analysis we explore the theoretical possibility of a dual-flame structure, where one flame lies close to the droplet surface called the "cool-flame," and other farther away from the droplet surface, termed the "hot-flame." A Burke-Schumann analysis of this dual-structure seems to indicate such flame structures are possible over a narrow range of initial conditions. Theoretical results can be compared against available experimental data for pure and bi-component fuel droplet combustion to test how realistic the model may be.

Brazil in the global anticorruption regime

Directory of Open Access Journals (Sweden)

Marcos Tourinho

2018-03-01

Full Text Available Abstract Brazilian anticorruption law and institutions were significantly transformed in recent decades. This article traces those transformations and explains how the international anticorruption and money laundering regimes contributed to their development. It argues that those international regimes were internalised in the Brazilian system through three mechanisms: inspiration and legitimation, coercion, and implementation support, and were critical to the transformation of Brazilian institutions.

GPM GROUND VALIDATION DUAL-FREQUENCY DUAL-POLARIZED DOPPLER RADAR (D3R) IFLOODS V1

Data.gov (United States)

National Aeronautics and Space Administration — The GPM Ground Validation Dual-frequency Dual-polarized Doppler Radar (D3R) IFloodS data set contain radar reflectivity and doppler velocity measurements. The D3R...

A new lumped-parameter approach to simulating flow processes in unsaturated dual-porosity media

Energy Technology Data Exchange (ETDEWEB)

Zimmerman, R.W.; Hadgu, T.; Bodvarsson, G.S. [Lawrence Berkeley Laboratory, CA (United States)

1995-03-01

We have developed a new lumped-parameter dual-porosity approach to simulating unsaturated flow processes in fractured rocks. Fluid flow between the fracture network and the matrix blocks is described by a nonlinear equation that relates the imbibition rate to the local difference in liquid-phase pressure between the fractures and the matrix blocks. This equation is a generalization of the Warren-Root equation, but unlike the Warren-Root equation, is accurate in both the early and late time regimes. The fracture/matrix interflow equation has been incorporated into a computational module, compatible with the TOUGH simulator, to serve as a source/sink term for fracture elements. The new approach achieves accuracy comparable to simulations in which the matrix blocks are discretized, but typically requires an order of magnitude less computational time.

Pharmacotherapy in the cardiac catheterization laboratory: evolution and recent developments

Directory of Open Access Journals (Sweden)

Thind GS

2014-10-01

Full Text Available Guramrinder S Thind,1 Raunak Parida,1 Nishant Gupta2 1SDM College of Medical Sciences and Hospital, Dharwad, Karnataka, India; 2University of Texas at Houston, Houston, TX, USAAbstract: Many recent innovations have been made in developing new antiplatelet and ­anticoagulant drugs in the last few years, with a total of nine new antithrombotic drugs approved by the Food and Drug Administration after the year 2000. This has revolutionized the medical therapy given to manage acute coronary syndrome and support cardiac catheterization. The concept of dual antiplatelet therapy has been emphasized, and clopidogrel has emerged as the most-popular second antiplatelet drug after aspirin. Newer P2Y12 inhibitors like prasugrel and ticagrelor have been extensively studied and compared to clopidogrel. The role of glycoprotein (Gp IIb/IIIa inhibitors is being redefined. Other alternatives to unfractionated heparin have become available, of which enoxaparin and bivalirudin have been studied the most. Apart from these, many more drugs with novel therapeutic targets are being studied and are currently under development. In this review, current evidence on these drugs is presented and analyzed in a way that would facilitate decision making for the clinician. For this analysis, various high-impact clinical trials, pharmacological studies, meta-analyses, and reviews were accessed through the MEDLINE database. Adopting a unique interdisciplinary approach, an attempt has been made to integrate pharmacological and clinical evidence to better understand and appreciate the pros and cons of each of these classes of drugs. Keywords: acute coronary syndrome, anticoagulants, antiplatelets, percutaneous coronary intervention

The application of neural networks to flow regime identification

International Nuclear Information System (INIS)

Embrechts, M.; Yapo, T.C.; Lahey, R.T. Jr.

1993-01-01

This paper deals with the application of a Kohonen map for the identification of two-phase flow regimes where a mixture of gas and fluid flows through a horizontal tube. Depending on the relative flow velocities of the gas and the liquid phase, four distinct flow regimes can be identified: Wavy flow, plug flow, slug flow and annular flow. A schematic of these flow regimes is presented. The objective identification of two-phase flow regimes constitutes an important and challenging problem for the design of safe and reliable nuclear power plants. Previous attempts to classify these flow regimes are reviewed by Franca and Lahey. The authors describe how a Kohonen map can be applied to distinguish between flow regimes based on the Fourier power spectra and wavelet transforms of pressure drop fluctuations. The Fourier power spectra allowed the Kohonen map to identify the flow regimes successfully. In contrast, the Kohonen maps based on a wavelet transform could only distinguish between wavy and annular flows. An analysis of typical two-phase pressure drop data for an air/water mixture in a horizontal pipe is presented. Use of the wavelet transform and the Kohonen feature map are discussed

Preliminary study of single contrast enhanced dual energy heart imaging using dual-source CT

International Nuclear Information System (INIS)

Peng Jin; Zhang Longjiang; Zhou Changsheng; Lu Guangming; Ma Yan; Gu Haifeng

2009-01-01

Objective: To evaluate the feasibility and preliminary applications of single contrast enhanced dual energy heart imaging using dual-source CT (DSCT). Methods: Thirty patients underwent dual energy heart imaging with DSCT, of which 6 cases underwent SPECT or DSA within one week. Two experienced radiologists assessed image quality of coronary arteries and iodine map of myocardium. and correlated the coronary artery stenosis with the perfusion distribution of iodine map. Results: l00% (300/300) segments reached diagnostic standards. The mean score of image for all patients was 4.68±0.57. Mural coronary artery was present in 10 segments in S cases, atherosclerotic plaques in 32 segments in 12 cases, of which 20 segments having ≥50% stenosis, 12 segments ≤50% stenosis; dual energy CT coronary angiography was consistent with the DSA in 3 patients. 37 segmental perfusion abnormalities on iodine map were found in 15 cases, including 28 coronary blood supply segment narrow segment and 9 no coronary stenosis (including three negative segments in SPECD. Conclusion: Single contrast enhanced dual energy heart imaging can provide good coronary artery and myocardium perfusion images in the patients with appropriate heart rate, which has a potential to be used in the clinic and further studies are needed. (authors)

Dual education and industrial cooperation in electrical engineering

Science.gov (United States)

Váradiné Szarka, A.

2016-11-01

Dual education in higher education is a new system in Hungary introduced by Mercedes Benz with cooperation of Kecskemet College. In the new system companies support certain number of students and provide them strong practical education in their field. Students applying successfully for dual education study together with non-dual students at the university, so they go through the same university courses as their non-dual colleagues, but while non-dual students’ academic year includes 2×14 weeks active semester and 2×6 weeks exam session, all over 40 weeks, dual students have 48 working weeks including study at the university and practicing at the company. The main question of the success which one is the most effective model to be applied. This paper summarises 2 models of dual education with their advantages and disadvantages and also it presents practical realization at the University of Debrecen with special attention to measurement and instrumentation. Dual education in BSc level electrical engineering course cooperates with 6 multinational companies of the region in four specialization. Dual education also has great impact to the modernisation of engineering education. Detailed study of dual education in field of instrumentation and measurement is provided in the paper.

Dual energy CT: New horizon in medical imaging

Energy Technology Data Exchange (ETDEWEB)

Goo, Hyun Woo [Dept. of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul (Korea, Republic of); Goo, Jin Mo [Dept. of Radiology, Seoul National University College of Medicine, Seoul (Korea, Republic of)

2017-08-01

Dual-energy CT has remained underutilized over the past decade probably due to a cumbersome workflow issue and current technical limitations. Clinical radiologists should be made aware of the potential clinical benefits of dual-energy CT over single-energy CT. To accomplish this aim, the basic principle, current acquisition methods with advantages and disadvantages, and various material-specific imaging methods as clinical applications of dual-energy CT should be addressed in detail. Current dual-energy CT acquisition methods include dual tubes with or without beam filtration, rapid voltage switching, dual-layer detector, split filter technique, and sequential scanning. Dual-energy material-specific imaging methods include virtual monoenergetic or monochromatic imaging, effective atomic number map, virtual non-contrast or unenhanced imaging, virtual non-calcium imaging, iodine map, inhaled xenon map, uric acid imaging, automatic bone removal, and lung vessels analysis. In this review, we focus on dual-energy CT imaging including related issues of radiation exposure to patients, scanning and post-processing options, and potential clinical benefits mainly to improve the understanding of clinical radiologists and thus, expand the clinical use of dual-energy CT; in addition, we briefly describe the current technical limitations of dual-energy CT and the current developments of photon-counting detector.

Dual-Energy CT: New Horizon in Medical Imaging.

Science.gov (United States)

Goo, Hyun Woo; Goo, Jin Mo

2017-01-01

Dual-energy CT has remained underutilized over the past decade probably due to a cumbersome workflow issue and current technical limitations. Clinical radiologists should be made aware of the potential clinical benefits of dual-energy CT over single-energy CT. To accomplish this aim, the basic principle, current acquisition methods with advantages and disadvantages, and various material-specific imaging methods as clinical applications of dual-energy CT should be addressed in detail. Current dual-energy CT acquisition methods include dual tubes with or without beam filtration, rapid voltage switching, dual-layer detector, split filter technique, and sequential scanning. Dual-energy material-specific imaging methods include virtual monoenergetic or monochromatic imaging, effective atomic number map, virtual non-contrast or unenhanced imaging, virtual non-calcium imaging, iodine map, inhaled xenon map, uric acid imaging, automatic bone removal, and lung vessels analysis. In this review, we focus on dual-energy CT imaging including related issues of radiation exposure to patients, scanning and post-processing options, and potential clinical benefits mainly to improve the understanding of clinical radiologists and thus, expand the clinical use of dual-energy CT; in addition, we briefly describe the current technical limitations of dual-energy CT and the current developments of photon-counting detector.

Novel CFT duals for extreme black holes

International Nuclear Information System (INIS)

Chen Bin; Zhang Jiaju

2012-01-01

In this paper, we study the CFT duals for extreme black holes in the stretched horizon formalism. We consider the extremal RN, Kerr-Newman-AdS-dS, as well as the higher dimensional Kerr-AdS-dS black holes. In all these cases, we reproduce the well-established CFT duals. Actually we show that for stationary extreme black holes, the stretched horizon formalism always gives rise to the same dual CFT pictures as the ones suggested by ASG of corresponding near horizon geometries. Furthermore, we propose new CFT duals for 4D Kerr-Newman-AdS-dS and higher dimensional Kerr-AdS-dS black holes. We find that every dual CFT is defined with respect to a rotation in certain angular direction, along which the translation defines a U(1) Killing symmetry. In the presence of two sets of U(1) symmetry, the novel CFT duals are generated by the modular group SL(2,Z), and for n sets of U(1) symmetry there are general CFT duals generated by T-duality group SL(n,Z).

Regimes of the magnetized Rayleigh endash Taylor instability

International Nuclear Information System (INIS)

Winske, D.

1996-01-01

Hybrid simulations with kinetic ions and massless fluid electrons are used to investigate the linear and nonlinear behavior of the magnetized Rayleigh endash Taylor instability in slab geometry with the plasma subject to a constant gravity. Three regimes are found, which are determined by the magnitude of the complex frequency ω=ω r +iγ. For |ω| i (Ω i = ion gyrofrequency), one finds the typical behavior of the usual fluid regime, namely the development of open-quote open-quote mushroom-head close-quote close-quote spikes and bubbles in the density and a strongly convoluted boundary between the plasma and magnetic field, where the initial gradient is not relaxed much. A second regime, where |ω|∼0.1Ω i , is characterized by the importance of the Hall term. Linearly, the developing flute modes are more finger-like and tilted along the interface; nonlinearly, clump-like structures form, leading to a significant broadening of the interface. The third regime is characterized by unmagnetized ion behavior, with |ω|∼Ω i . Density clumps, rather than flutes, form in the linear stage, while nonlinearly, longer-wavelength modes that resemble those in fluid regime dominate. Finite Larmor radius stabilization of short-wavelength modes is observed in each regime. copyright 1996 American Institute of Physics

Numerical simulation of transitions between back discharge regimes

International Nuclear Information System (INIS)

Jansky, Jaroslav; Lemont, Florent; Bessieres, Delphine; Paillol, Jean

2014-01-01

This paper presents numerical simulations of transitions between back discharge regimes. Back discharge refers to any discharge initiated at or near a dielectric layer covering a passive electrode. In this work, a pinhole in a dielectric layer on a plane anode serves as a model for back discharge activity. We have studied transitions between back discharge regimes by varying the surface charge density on the dielectric layer and the electric field in front of the pinhole. From the variation of these two independent parameters, the back discharge regimes have been depicted as a mode diagram inspired by the experimental study of Masuda and Mizuno. The resulting diagram includes the different discharge regimes that are commonly observed in experiments. The propagation of a positive ionizing wave inside the pinhole toward its edge, and the resulting formation of a plasma zone at its exit constitute the onset stage of back discharge. From this stage, the transitions to volume discharge or surface discharge can occur. The volume discharge regime consists of the propagation of a discharge in space toward the cathode which can be superimposed with the propagation of a discharge above the dielectric layer surface. The diagram reveals the conditions for transitions between back discharge regimes. (authors)

QCD in the {delta}-regime

Energy Technology Data Exchange (ETDEWEB)

Bietenholz, W. [Universidad Nacional Autonoma de Mexico, Mexico City (Mexico). Inst. de Ciencias Nucleares; Cundy, N. [Seoul National Univ. (Korea, Republic of). Lattice Gauge Theory Research Center; Goeckeler, M. [Regensburg Univ. (Germany). Inst. fuer Theoretische Physik; Horsley, R.; Zanotti, J.M. [Edinburgh Univ. (United Kingdom). School of Physics; Nakamura, Y. [Tsukuba Univ., Ibaraki (Japan). Center for Computational Sciences; Pleiter, D. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Rakow, P.E.L. [Liverpool Univ. (United Kingdom). Theoretical Physics Div.; Schierholz, G. [Regensburg Univ. (Germany). Inst. fuer Theoretische Physik; Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

2011-03-15

The {delta}-regime of QCD is characterised by light quarks in a small spatial box, but a large extent in (Euclidean) time. In this setting a specific variant of chiral perturbation theory - the {delta}-expansion - applies, based on a quantum mechanical treatment of the quasi onedimensional system. In particular, for vanishing quark masses one obtains a residual pion mass M{sup R}{sub {pi}}, which has been computed to the third order in the {delta}-expansion. A comparison with numerical measurements of this residual mass allows for a new determination of some Low Energy Constants, which appear in the chiral Lagrangian. We first review the attempts to simulate 2-flavour QCD directly in the {delta}-regime. This is very tedious, but results compatible with the predictions for M{sup R}{sub {pi}} have been obtained. Then we show that an extrapolation of pion masses measured in a larger volume towards the {delta}-regime leads to good agreement with the theoretical predictions. From those results, we also extract a value for the (controversial) sub-leading Low Energy Constant anti l{sub 3}. (orig.)

QCD in the δ-regime

International Nuclear Information System (INIS)

Bietenholz, W.; Rakow, P.E.L.

2011-03-01

The δ-regime of QCD is characterised by light quarks in a small spatial box, but a large extent in (Euclidean) time. In this setting a specific variant of chiral perturbation theory - the δ-expansion - applies, based on a quantum mechanical treatment of the quasi onedimensional system. In particular, for vanishing quark masses one obtains a residual pion mass M R π , which has been computed to the third order in the δ-expansion. A comparison with numerical measurements of this residual mass allows for a new determination of some Low Energy Constants, which appear in the chiral Lagrangian. We first review the attempts to simulate 2-flavour QCD directly in the δ-regime. This is very tedious, but results compatible with the predictions for M R π have been obtained. Then we show that an extrapolation of pion masses measured in a larger volume towards the δ-regime leads to good agreement with the theoretical predictions. From those results, we also extract a value for the (controversial) sub-leading Low Energy Constant anti l 3 . (orig.)

Competition Regime

Directory of Open Access Journals (Sweden)

Danilo Icaza Ortiz

2013-01-01

Full Text Available This paper is a review of the competition regime works of various authors, published under the auspices of the University of the Hemispheres and the Corporation for Studies and Publications. Analyzes the structure, the general concepts, case law taken for development. Includes comments on the usefulness of this work for the study of competition law and the contribution to the lawyers who want to practice in this branch of economic law.

The international climate regime: towards consolidation collapse

International Nuclear Information System (INIS)

Berthaud, P.; Cavard, D.; Criqui, P.

2003-10-01

This article deals with the different modalities that exist to manage a problem of collective action in the field of climate negotiation. It uses two concepts of the International Political Economy (IPE): the concept of International Regime (IR) and the concept of Hegemony and / or Leadership. The course the international negotiation has taken between 1992 (Rio Convention) and march 2001 (the US rejection of the Kyoto Protocol of 1997) leads us, first, to question the conditions of existence as well as the viability of a non-hegemonic International Regime (Part One). Then, we discuss the perspectives for the 'post - Kyoto' era. After having examined the preferences of the three most active actors in the negotiation (USA, Europe, G77 + China) combined with the leadership capacities they possess, we identify three scenarios for the future: i) anarchy, ii) an international regime under the American hegemony, iii) an international regime under the European leadership (Part Two). (author)

Institutional design and regime effectiveness in transboundary river management – the Elbe water quality regime

Directory of Open Access Journals (Sweden)

I. Dombrowsky

2008-02-01

Full Text Available The literature on transboundary river management suggests that institutions play an important role in bringing about cooperation. However, knowledge about how such institutions should be designed in order to do so remains limited. One way to learn more about adequate institutional design is to assess the effectiveness of existing regimes, and to trace the causal relationships that lead to the respective outcomes. In order to gain further insights into the relationship between institutional design and regime effectiveness, this paper presents a study on the water quality regime of the International Commission for the Protection of the Elbe (ICPE. The analysis is based on a review of pertinent documents and ten qualitative interviews with Czech and German Commission members and NGO representatives. Particular emphasis has been put on determining the ICPE's specific contribution and the no-regime counterfactual as well as on the perceived expediency of the institutional arrangements. The study shows overall that the countries were relatively successful in improving water quality in the Elbe basin. However, this outcome can only partly be attributed to the ICPE itself. Furthermore, the ICPE's contribution towards achieving the various goals varied significantly between the different areas of activity: it was relatively significant where the main responsibility for action lay with the public authorities, such as in the area of wastewater treatment and the establishment of an international alarm plan and model, but was practically non-existent in the reduction of non-point pollution from agriculture, where success depended on the behavior of individual private actors (farmers. The commission contributed towards problem solving by serving as a forum for the joint identification of priorities for action from a basin-wide perspective. The resulting international obligations increased the power of national water administrations and their access to funds

Are factors related to dual-task performance in people with Parkinson's disease dependent on the type of dual task?

Science.gov (United States)

Strouwen, Carolien; Molenaar, Esther A L M; Keus, Samyra H J; Münks, Liesbeth; Heremans, Elke; Vandenberghe, Wim; Bloem, Bastiaan R; Nieuwboer, Alice

2016-02-01

Impaired dual-task performance significantly impacts upon functional mobility in people with Parkinson's disease (PD). The aim of this study was to identify determinants of dual-task performance in people with PD in three different dual tasks to assess their possible task-dependency. We recruited 121 home-dwelling patients with PD (mean age 65.93 years; mean disease duration 8.67 years) whom we subjected to regular walking (control condition) and to three dual-task conditions: walking combined with a backwards Digit Span task, an auditory Stroop task and a Mobile Phone task. We measured dual-task gait velocity using the GAITRite mat and dual-task reaction times and errors on the concurrent tasks as outcomes. Motor, cognitive and descriptive variables which correlated to dual-task performance (p task gait velocity and executive function, tested by the alternating intake test, was significantly associated with gait velocity during the Digit Span (R(2) = 0.65; p task (R(2) = 0.62; p task. Age was a surplus determinant of gait velocity while using a mobile phone. Single-task gait velocity and executive function as measured by a verbal fluency switching task were independent determinants of dual-task gait performance in people with PD. In contrast to expectation, these factors were the same across different tasks, supporting the robustness of the findings. Future study needs to determine whether these factors predict dual-task abnormalities prospectively. Copyright © 2015 Elsevier Ltd. All rights reserved.

Image quality optimization and evaluation of linearly mixed images in dual-source, dual-energy CT

International Nuclear Information System (INIS)

Yu Lifeng; Primak, Andrew N.; Liu Xin; McCollough, Cynthia H.

2009-01-01

In dual-source dual-energy CT, the images reconstructed from the low- and high-energy scans (typically at 80 and 140 kV, respectively) can be mixed together to provide a single set of non-material-specific images for the purpose of routine diagnostic interpretation. Different from the material-specific information that may be obtained from the dual-energy scan data, the mixed images are created with the purpose of providing the interpreting physician a single set of images that have an appearance similar to that in single-energy images acquired at the same total radiation dose. In this work, the authors used a phantom study to evaluate the image quality of linearly mixed images in comparison to single-energy CT images, assuming the same total radiation dose and taking into account the effect of patient size and the dose partitioning between the low-and high-energy scans. The authors first developed a method to optimize the quality of the linearly mixed images such that the single-energy image quality was compared to the best-case image quality of the dual-energy mixed images. Compared to 80 kV single-energy images for the same radiation dose, the iodine CNR in dual-energy mixed images was worse for smaller phantom sizes. However, similar noise and similar or improved iodine CNR relative to 120 kV images could be achieved for dual-energy mixed images using the same total radiation dose over a wide range of patient sizes (up to 45 cm lateral thorax dimension). Thus, for adult CT practices, which primarily use 120 kV scanning, the use of dual-energy CT for the purpose of material-specific imaging can also produce a set of non-material-specific images for routine diagnostic interpretation that are of similar or improved quality relative to single-energy 120 kV scans.

Global regime shift dynamics of catastrophic sea urchin overgrazing

Science.gov (United States)

Ling, S. D.; Scheibling, R. E.; Rassweiler, A.; Johnson, C. R.; Shears, N.; Connell, S. D.; Salomon, A. K.; Norderhaug, K. M.; Pérez-Matus, A.; Hernández, J. C.; Clemente, S.; Blamey, L. K.; Hereu, B.; Ballesteros, E.; Sala, E.; Garrabou, J.; Cebrian, E.; Zabala, M.; Fujita, D.; Johnson, L. E.

2015-01-01

A pronounced, widespread and persistent regime shift among marine ecosystems is observable on temperate rocky reefs as a result of sea urchin overgrazing. Here, we empirically define regime-shift dynamics for this grazing system which transitions between productive macroalgal beds and impoverished urchin barrens. Catastrophic in nature, urchin overgrazing in a well-studied Australian system demonstrates a discontinuous regime shift, which is of particular management concern as recovery of desirable macroalgal beds requires reducing grazers to well below the initial threshold of overgrazing. Generality of this regime-shift dynamic is explored across 13 rocky reef systems (spanning 11 different regions from both hemispheres) by compiling available survey data (totalling 10 901 quadrats surveyed in situ) plus experimental regime-shift responses (observed during a total of 57 in situ manipulations). The emergent and globally coherent pattern shows urchin grazing to cause a discontinuous ‘catastrophic’ regime shift, with hysteresis effect of approximately one order of magnitude in urchin biomass between critical thresholds of overgrazing and recovery. Different life-history traits appear to create asymmetry in the pace of overgrazing versus recovery. Once shifted, strong feedback mechanisms provide resilience for each alternative state thus defining the catastrophic nature of this regime shift. Importantly, human-derived stressors can act to erode resilience of desirable macroalgal beds while strengthening resilience of urchin barrens, thus exacerbating the risk, spatial extent and irreversibility of an unwanted regime shift for marine ecosystems.

Interference of Spin-2 Self-Dual Modes

OpenAIRE

Ilha, Anderson; Wotzasek, Clovis

2001-01-01

We study the effects of interference between the self-dual and anti self-dual massive modes of the linearized Einstein-Chern-Simons topological gravity. The dual models to be used in the interference process are carefully analyzed with special emphasis on their propagating spectrum. We identify the opposite dual aspects, necessary for the application of the interference formalism on this model. The soldered theory so obtained displays explicitly massive modes of the Proca type. It may also be...

Republic of Croatia's Experiences in the Implementation of the EU Directive About Dual-Use Items

International Nuclear Information System (INIS)

Vidas, Z.; Orehovec, Z.; Superina, V.

2007-01-01

The Republic of Croatia is undergoing a process of adjusting its own legislation to the legislation of EU. It is one of the most important obligations of the EU-Croatia Stabilization and Association Agreement. It is also a basic prerequisite for the practical realization of the modern, unique and integral Export and Import Control system of the Sensitive Items. At the same time, it is a very important step towards better understanding of real and great danger of the weapons of mass destruction (WMD) proliferation and their possible usage in terrorism. That means that Republic of Croatia will act along with EU in the complex activities to prevent and minimize the WMD proliferation, to participate in antiterrorism activities, and to maintain regional and global security. In the year 2004, along the lines of the EU Legislation, the Croatian Parliament adopted the basic legal act - Act on export of Dual-use Items and its accompanying rules and regulations. The existing act on dual-purpose items in Croatia is mostly in harmony with the 2000 and 2003 EU Decrees which regulate te regime of the dual-purpose items export control. Nevertheless, the EU legislation experiences constant amendments in the field. And the Croatian Government is committed to following the improvements of te system and adjusting its own. However, during this process, a series of vague wordings and inconsistencies were noticed in the WMD nonproliferation policy and in the legislation to control the export of high technology products which could be abused for the WMD development. In addition, there is neither regulation on import control system nor control on the export of knowledge through scientific and professional cooperation. The purpose of this article is to professionally elaborate the value wordings and inconsistencies. It can be done on the basis of Croatia's experiences in the export and import control system of the dual-purpose items and knowledge and experience acquired through the

Perspectives on the International and Internal Nuclear Security Regime

International Nuclear Information System (INIS)

Jang, Sung Soon

2015-01-01

The term, 'Nuclear Security' became more familiar to Korean public after the government hosted 2012 Seoul Nuclear Security Summit. Nuclear Security is prevention of, detection of and response to criminal or intentional unauthorized acts involving or directed at nuclear material, other radioactive material, associated facilities, or associated activities. Nuclear Security includes physical protection, security of radioactive sources, nuclear forensics, nuclear smuggling prevention, border monitoring, and cyber security with regard to nuclear and other radiological materials. This abstract will review recent international trends and discuss the nuclear security regime in the Republic of Korea (ROK). The international Nuclear Security Regime has been strengthened. The upcoming Chicago Summit in 2016 and the entry into force of the Amendment of Convention on Physical Protection of Nuclear Materials (CPPNM) will bring major changes in nuclear security. The Republic of Korea hosted the 2012 Seoul Summit and strengthened domestic regime to meet international standards. The ROK has worked hard to contribute to the international security regime and to establish a robust domestic security regime against terrorist threats. Even if the nuclear security regime is robust, Risk-informed Nuclear Security management should be established to meet international standards and to implement effective as well as an efficient nuclear security regime

Perspectives on the International and Internal Nuclear Security Regime

Energy Technology Data Exchange (ETDEWEB)

Jang, Sung Soon [Korea Nuclear Non-proliferation and Control, Daejeon (Korea, Republic of)

2015-10-15

The term, 'Nuclear Security' became more familiar to Korean public after the government hosted 2012 Seoul Nuclear Security Summit. Nuclear Security is prevention of, detection of and response to criminal or intentional unauthorized acts involving or directed at nuclear material, other radioactive material, associated facilities, or associated activities. Nuclear Security includes physical protection, security of radioactive sources, nuclear forensics, nuclear smuggling prevention, border monitoring, and cyber security with regard to nuclear and other radiological materials. This abstract will review recent international trends and discuss the nuclear security regime in the Republic of Korea (ROK). The international Nuclear Security Regime has been strengthened. The upcoming Chicago Summit in 2016 and the entry into force of the Amendment of Convention on Physical Protection of Nuclear Materials (CPPNM) will bring major changes in nuclear security. The Republic of Korea hosted the 2012 Seoul Summit and strengthened domestic regime to meet international standards. The ROK has worked hard to contribute to the international security regime and to establish a robust domestic security regime against terrorist threats. Even if the nuclear security regime is robust, Risk-informed Nuclear Security management should be established to meet international standards and to implement effective as well as an efficient nuclear security regime.

Limitations in dual-task performance

NARCIS (Netherlands)

Pannebakker, Merel Mathilde

2009-01-01

In this thesis, the effect of information-processing overload on working-memory dependent information processing was examined using dual-task paradigms. The experiments described strengthen the importance of a functional explanation for dual-task limitations. First, it showed evidence for a unified

Change of secondary water regime of Paks NPP. Change of secondary water regime at Unit 2

International Nuclear Information System (INIS)

Doma, A.; Patek, G.; Pinter, T.; Bajari, M.; Tilky, P.

2001-01-01

The installation of high pH water regime during the 17th cycle of Unit 2 aimed to decrease the amount of transportation inlet of erosion-corrosion products (magnitude) in feedwater to SGs. The resolution of OAH-NBI permitting the installation ordained to make an evaluation of the process. The main conclusions and results are discussed. The high pH water regime proved to be adequate in the case of Unit 2 as well, similarly to Units 3, 4 and 1. (R.P.)

Aerial Triangulation Close-range Images with Dual Quaternion

Directory of Open Access Journals (Sweden)

SHENG Qinghong

2015-05-01

Full Text Available A new method for the aerial triangulation of close-range images based on dual quaternion is presented. Using dual quaternion to represent the spiral screw motion of the beam in the space, the real part of dual quaternion represents the angular elements of all the beams in the close-range area networks, the real part and the dual part of dual quaternion represents the line elements corporately. Finally, an aerial triangulation adjustment model based on dual quaternion is established, and the elements of interior orientation and exterior orientation and the object coordinates of the ground points are calculated. Real images and large attitude angle simulated images are selected to run the experiments of aerial triangulation. The experimental results show that the new method for the aerial triangulation of close-range images based on dual quaternion can obtain higher accuracy.

Institutional effectiveness in international regimes. An analysis of the effectiveness of the nuclear non-proliferation regime coping with the political malignity in the case of Iran

Energy Technology Data Exchange (ETDEWEB)

Oezden, Tugba

2015-07-01

Among the international security regimes, the Nuclear Non-Proliferation Regime has a prominent ranking due to the destructive power of the nuclear weapons over regional and global peace and stability. The NPT Regime has come across with two major challenges in the recent decade: North Korea and Iran. Contrary to North Korea, Iran is determined to stay as a state party to the Nuclear Non-Proliferation Treaty. The Regime still did not confirm the character and extent of Iranian nuclear program. The question of this study is ''why the processes of the NPT Regime cannot specify the nature and scope of Irans nuclear program?'' The three main the processes of the regime, which are the International Atomic Energy Agency (IAEA), the UN Security Council (UNSC) and the multilateral negotiations, are examined to determine the weaknesses of the regime. This study argues that the regime is modulated to cope with operational challenges and it remains relatively incompetent when a political challenge arises.

Transition to ballistic regime for heat transport in helium II

Energy Technology Data Exchange (ETDEWEB)

Sciacca, Michele, E-mail: michele.sciacca@unipa.it [Dipartimento Scienze Agrarie e Forestali, Università degli studi di Palermo, Viale delle Scienze, 90128 Palermo (Italy); Departament de Física, Universitat Autònoma de Barcelona, 08193 Bellaterra, Catalonia (Spain); Sellitto, Antonio, E-mail: ant.sellitto@gmail.com [Dipartimento di Matematica, Informatica ed Economia, Università della Basilicata, Campus Macchia Romana, 85100 Potenza (Italy); Jou, David, E-mail: david.jou@uab.cat [Departament de Física, Universitat Autònoma de Barcelona, 08193 Bellaterra, Catalonia (Spain); Institut d' Estudis Catalans, Carme 47, 08001 Barcelona, Catalonia (Spain)

2014-07-04

The size-dependent and flux-dependent effective thermal conductivity of narrow capillaries filled with superfluid helium is analyzed from a thermodynamic continuum perspective. The classical Landau evaluation of the effective thermal conductivity of quiescent superfluid, or the Gorter–Mellinck regime of turbulent superfluids, is extended to describe the transition to ballistic regime in narrow channels wherein the radius R is comparable to (or smaller than) the phonon mean-free path ℓ in superfluid helium. To do so, we start from an extended equation for the heat flux incorporating non-local terms, and take into consideration a heat slip flow along the walls of the tube. This leads from an effective thermal conductivity proportional to R{sup 2} (Landau regime) to another one proportional to Rℓ (ballistic regime). We consider two kinds of flows: along cylindrical pipes and along two infinite parallel plates. - Highlights: • Heat transport in counterflow helium in the ballistic regime. • The one-fluid model based on the Extended Thermodynamics is used. • The transition from the Landau regime to the ballistic regime. • The transition from quantum turbulence to ballistic regime.

Performance Enhancements Under Dual-task Conditions

Science.gov (United States)

Kramer, A. F.; Wickens, C. D.; Donchin, E.

1984-01-01

Research on dual-task performance has been concerned with delineating the antecedent conditions which lead to dual-task decrements. Capacity models of attention, which propose that a hypothetical resource structure underlies performance, have been employed as predictive devices. These models predict that tasks which require different processing resources can be more successfully time shared than tasks which require common resources. The conditions under which such dual-task integrality can be fostered were assessed in a study in which three factors likely to influence the integrality between tasks were manipulated: inter-task redundancy, the physical proximity of tasks and the task relevant objects. Twelve subjects participated in three experimental sessions in which they performed both single and dual-tasks. The primary task was a pursuit step tracking task. The secondary tasks required the discrimination between different intensities or different spatial positions of a stimulus. The results are discussed in terms of a model of dual-task integrality.

Evaluation of Myc Gene Amplification in Prostate Cancer Using a Dual Color Chromogenic in-Situ Hybridization (Dual CISH) Assay

OpenAIRE

Daniel Lerda; Marta Cabrera; Jorge Flores; Luis Gutierrez; Armando Chierichetti; Martin Revol; Hernan Garcia Onto

2013-01-01

Objetive: The overall purpose of the study was to demonstrate applicability of the Dako dual-color chromogenic in situ hybridization (CISH) assay (DAKO Denmark, Glostrup) with respect to fluorescence in situ hybridization (FISH) probes MYC-C. Methods: MYC gene amplification by FISH and Dako dual-color CISH Results: The study showed that the dual-color CISH assay can convert Texas red and fluorescein isothiocyanate (FITC) signals into chromogenic signals. The dual –color CISH assay was p...

Dual-Mode Combustor

Science.gov (United States)

Trefny, Charles J (Inventor); Dippold, Vance F (Inventor)

2013-01-01

A new dual-mode ramjet combustor used for operation over a wide flight Mach number range is described. Subsonic combustion mode is usable to lower flight Mach numbers than current dual-mode scramjets. High speed mode is characterized by supersonic combustion in a free-jet that traverses the subsonic combustion chamber to a variable nozzle throat. Although a variable combustor exit aperture is required, the need for fuel staging to accommodate the combustion process is eliminated. Local heating from shock-boundary-layer interactions on combustor walls is also eliminated.

Considerations on nonproliferation regime meeting in a changing world

International Nuclear Information System (INIS)

Kurihara, Hiroyoshi; Kikuchi, Masahiro

1994-01-01

This paper summarizes the past history of worldwide nonproliferation regime, then proposes the future improvements on the regime. Present worldwide nonproliferation regime have been formulated during the cold war era. Therefore, the structure and measures of the regime were heavily influenced by the features of cold war era. Though the cold war was over, still new international order does not seem to be on the horizon, we need to review the present regime and to improve the regime compatible to new world situation. Generally speaking, the nonproliferation regime have gained moderate success so far. We could point out the following features as a kind of success: 1) No increase of overt Nuclear Weapon State (NWS), 2) All five NWSs have finally participated to the NPT, 3) South Africa has destroyed its nuclear weapons and became Non-Nuclear Weapon State (NNWS), 4) Successful conclusions of some regional arrangements, such as Tlatelolco, Ralotonga, and 5) Strengthening of export control on sensitive items. On the other hand, we recognize the following points as the failures of the regime. 6) India, Pakistan and Israel reject to join the NPT, 7) Existence of some violation against NPT regime, i.e. Iraqi case and DPRK case, 8) Insufficient effective measures against brain drain problem, 9) Risk exists for the long term extension of NPT, and 10) Insufficient flexibility to meet changing boundary conditions. We would propose the various measures for strengthening to meet changing boundary conditions, as follows: 11) Measures to be taken along with future civil use of Plutonium, 12) Strengthening and rationalizing international safeguards, 13) Countermeasures for emerging new types of nuclear proliferation, 14) Strengthening nuclear material control in NWS, 15) Measures to be taken for nuclear material from dismantled nuclear weapons, and 16) Nuclear disarmament. (author)

Dual Headquarters Involvement in Multibusiness Firms

DEFF Research Database (Denmark)

Nell, Phillip Christopher; Kappen, Philip; Dellestrand, Henrik

The strategy literature has shown that headquarters involve themselves into subsidiary operations to add value. Yet, little is known about the extent to which multiple headquarters do so. Therefore, we investigate antecedents of corporate and divisional headquarters’ involvement in innovation...... development projects of subsidiaries. Analyses of 85 innovation development projects reveal that dual innovation importance (innovation that is important for the division and the rest of the firm), and dual dual embeddedness (innovating subsidiary is embedded both within the division and in the rest...... of the firm) lead to greater dual headquarters involvement, especially when the innovation development network is large. The results contribute to the literature on complex parenting and theory of selective headquarters involvement....

Beta Risk and Regime Shift in Market Volatility

OpenAIRE

Don U.A. Galagedera; Roland G. Shami

2004-01-01

In this paper, we relate security returns in the thirty securities in the Dow Jones index to regime shifts in the market portfolio (S&P500) volatility. We model market volatility as a multiple-state Markov switching process of order one and estimate non-diversifiable security risk (beta) in the different market volatility regimes. We test the significance of the premium of the beta risk associated with the different market regimes and find evidence of a relationship between security return an...

The clinical significance and risk factors of anti-platelet factor 4/heparin antibody on maintenance hemodialysis patients: a two-year prospective follow-up.

Directory of Open Access Journals (Sweden)

Delong Zhao

Full Text Available BACKGROUND: Heparin-induced thrombocytopenia is an immune response mediated by anti-PF4/heparin antibody, which is clinically characterized by thrombocytopenia and thromboembolic events. In this study, a prospective and multi-center clinical investigation 1 determined the positive rate of anti-PF4/heparin antibody in maintenance hemodialysis patients in China, 2 identified the related risk factors, and 3 further explored the effect of the anti-PF4/heparin antibody on bleeding, thromboembolic events, and risk of death in the patients. METHODS: The serum anti-PF4/heparin antibody was measured in 661 patients from nine hemodialysis centers, detected by IgG-specific ELISA and followed by confirmation with excess heparin. Risk factors of these patients were analyzed. Based on a two-year follow-up, the association between the anti-PF4/heparin antibody and bleeding, thromboembolic events, and risk of death in the patients was investigated. RESULTS: 1 The positivity rate of the anti-PF4/heparin antibody in maintenance hemodialysis patients was 5.6%. With diabetes as an independent risk factor, the positivity rate of the anti-PF4/heparin antibody decreased in the patients undergoing weekly dialyses ≥3 times. 2 The positivity rate of the anti-PF4/heparin antibody was not related to the occurrence of clinical thromboembolic events and was not a risk factor for death within two years in maintenance hemodialysis patients. 3 Negativity for the anti-PF4/heparin antibody combined with a reduction of the platelet count or combined with the administration of antiplatelet drugs yielded a significant increase in bleeding events. However, the composite determination of the anti-PF4/heparin antibody and thrombocytopenia, as well as the administration of antiplatelet drugs, was not predictive for the risk of thromboembolic events in the maintenance hemodialysis patients. CONCLUSIONS: A single detection of the anti-PF4/heparin antibody did not predict the occurrence

[Dual pathology].

Science.gov (United States)

Rougier, A

2008-05-01

Dual pathology is defined as the association of two potentially epileptogenic lesions, hippocampal (sclerosis, neuronal loss) and extrahippocampal (temporal or extratemporal). Epileptic activity may be generated by either lesion and the relative importance of every lesion's epileptogenicity conditions the surgical strategy adopted. Most frequently associated with hippocampal sclerosis are cortical dysplasias. The common physiopathology of the two lesions is not clearly established. Extrahippocampal lesions may be undetectable on MRI (microdysgenesis, for example) and ictal discharge patterns may vary among dual pathology patients. The surgical strategy depends on the location of the extrahippocampal lesion and its relative role in seizure generation; however, reported surgical results suggest that simultaneous resection of mesial temporal structures along with the extrahippocampal lesion should be performed.

The concept of regime values: Are revitalization and regime change possible?

NARCIS (Netherlands)

Overeem, P.

2015-01-01

Among the plethora of public values, one special class is that of “regime values.” This notion plays a central role in the constitutional approach to public administration mainly developed by the late John A. Rohr. In this article, an attempt is made to assess the viability of Rohr’s concept of

Dual Coding and Bilingual Memory.

Science.gov (United States)

Paivio, Allan; Lambert, Wallace

1981-01-01

Describes study which tested a dual coding approach to bilingual memory using tasks that permit comparison of the effects of bilingual encoding with verbal-nonverbal dual encoding items. Results provide strong support for a version of the independent or separate stories view of bilingual memory. (Author/BK)

Switchable dual-wavelength single-longitudinal-mode erbium fiber laser utilizing a dual-ring scheme with a saturable absorber

Science.gov (United States)

Yang, Zi-Qing; Huang, Tzu-Jung; Chang, Yao-Jen; Yeh, Chien-Hung; Chow, Chi-Wai; Chen, Jing-Heng; Chen, Kun-Huang

2018-06-01

In this work, we propose and demonstrate a switchable dual-wavelength erbium-doped fiber (EDF) ring laser with stable single-longitudinal-mode (SLM) output. Here, a dual-ring (DR) structure with an unpumped EDF of 2 m is designed to achieve SLM oscillation. Five fiber Bragg gratings (FBGs) are applied in the laser cavity serving as the reflective element to generate different dual-wavelength outputs. In the measurement, six sets of generated dual-wavelengths with various mode-spacing (Δλ) can be achieved via the five FBGs. Additionally, the stability performance of the proposed EDF DR laser is also demonstrated.

Hypolipidaemic and antiplatelet activity of phenoxyacetic acid derivatives related to alpha-asarone.

Science.gov (United States)

Pérez-Pastén, Ricardo; García, Rosa Virginia; Garduño, Leticia; Reyes, Elba; Labarrios, Fernando; Tamariz, Joaquín; Chamorro, Germán

2006-10-01

The phenoxyacetic acid derivatives 1-6 [2-methoxy-4-(2-propenyl)phenoxyacetic acid (1); 2-methoxy-5-nitro-4-(2-propenyl)phenoxyacetic acid (2); methyl 2-methoxy-4-(2-propenyl)phenoxyacetate (3); ethyl 2-methoxy-4-(2-propenyl)phenoxyacetate (4); methyl 2-methoxy-5-nitro-4-(2-propenyl)phenoxyacetate (5); ethyl 2-methoxy-5-nitro-4-(2-propenyl)phenoxyacetate (6)] related to alpha-asarone have been reported previously as hypolipidaemic agents in diet-induced hyperlipidaemic mice. We have aimed to expand the pharmacological profile of these derivatives by investigating their hypolipidaemic activity in rats and mice under different experimental conditions. The antiplatelet activity was tested also in-vitro from blood derived from consenting healthy volunteers. In normolipidaemic rats, compounds 2, 3 and 5 at oral doses of 40 and 80 mg kg(-1) significantly decreased total cholesterol and LDL-cholesterol levels. Moreover, analogues 3 and 5 administered to hypercholesterolaemic rats at the same doses for seven days also produced a reduction in the content of these same lipoproteins. In neither case were the high-density lipoprotein cholesterol and triglyceride concentrations affected. However, practically all tested compounds were found to be hypocholesterolaemic agents, and were shown to effectively lower low-density lipoprotein cholesterol and triglyceride levels in Triton-induced hyperlipidaemic mice at oral doses of 50 and 100 mg kg(-1). In all tests, all animals appeared to be healthy throughout the experimental period in their therapeutic ranges. Triton-induced hypercholesterolaemic mice appeared to be a desirable model for this class of hypolipidaemic drugs. On the other hand, compounds 1, 2, 4 and 5 significantly inhibited ADP-induced aggregation in-vitro. These findings indicated that all of these compounds appeared to be promising for the treatment of human hyperlipidaemia and thrombotic diseases.

Data sharing and dual-use issues.

Science.gov (United States)

Bezuidenhout, Louise

2013-03-01

The concept of dual-use encapsulates the potential for well-intentioned, beneficial scientific research to also be misused by a third party for malicious ends. The concept of dual-use challenges scientists to look beyond the immediate outcomes of their research and to develop an awareness of possible future (mis)uses of scientific research. Since 2001 much attention has been paid to the possible need to regulate the dual-use potential of the life sciences. Regulation initiatives fall under two broad categories-those that develop the ethical education of scientists and foster an awareness and responsibility of dual-use issues, and those which assess the regulation of information being generated by current research. Both types of initiatives are premised on a cautious, risk-adverse philosophy which advocates careful examination of all future endpoints of research endeavors. This caution advocated within initiatives such as pre-publication review of journal articles contrasts to the obligation to share underpinning data sharing discussions. As the dual-use debate has yet to make a significant impact on data sharing discussions (and vice versa) it is possible that these two areas of knowledge control may present areas of ethical conflict for scientists, and thus need to be more closely examined. This paper examines the tension between the obligation to share exemplified by data sharing principles and the concerns raised by the risk-cautious culture of the dual-use debates. The paper concludes by reflecting on the issues of responsibility as raised by dual-use as relating to data sharing, such as the chain of custody for shared data.

Unraveling Executive Functioning in Dual Diagnosis.

Science.gov (United States)

Duijkers, Judith C L M; Vissers, Constance Th W M; Egger, Jos I M

2016-01-01

In mental health, the term dual-diagnosis is used for the co-occurrence of Substance Use Disorder (SUD) with another mental disorder. These co-occurring disorders can have a shared cause, and can cause/intensify each other's expression. Forming a threat to health and society, dual-diagnosis is associated with relapses in addiction-related behavior and a destructive lifestyle. This is due to a persistent failure to control impulses and the maintaining of inadequate self-regulatory behavior in daily life. Thus, several aspects of executive functioning like inhibitory, shifting and updating processes seem impaired in dual-diagnosis. Executive (dys-)function is currently even seen as a shared underlying key component of most mental disorders. However, the number of studies on diverse aspects of executive functioning in dual-diagnosis is limited. In the present review, a systematic overview of various aspects of executive functioning in dual-diagnosis is presented, striving for a prototypical profile of patients with dual-diagnosis. Looking at empirical results, inhibitory and shifting processes appear to be impaired for SUD combined with schizophrenia, bipolar disorder or cluster B personality disorders. Studies involving updating process tasks for dual-diagnosis were limited. More research that zooms in to the full diversity of these executive functions is needed in order to strengthen these findings. Detailed insight in the profile of strengths and weaknesses that underlies one's behavior and is related to diagnostic classifications, can lead to tailor-made assessment and indications for treatment, pointing out which aspects need attention and/or training in one's self-regulative abilities.

Radiative effects of global MODIS cloud regimes

Science.gov (United States)

Oreopoulos, Lazaros; Cho, Nayeong; Lee, Dongmin; Kato, Seiji

2018-01-01

We update previously published MODIS global cloud regimes (CRs) using the latest MODIS cloud retrievals in the Collection 6 dataset. We implement a slightly different derivation method, investigate the composition of the regimes, and then proceed to examine several aspects of CR radiative appearance with the aid of various radiative flux datasets. Our results clearly show the CRs are radiatively distinct in terms of shortwave, longwave and their combined (total) cloud radiative effect. We show that we can clearly distinguish regimes based on whether they radiatively cool or warm the atmosphere, and thanks to radiative heating profiles to discern the vertical distribution of cooling and warming. Terra and Aqua comparisons provide information about the degree to which morning and afternoon occurrences of regimes affect the symmetry of CR radiative contribution. We examine how the radiative discrepancies among multiple irradiance datasets suffering from imperfect spatiotemporal matching depend on CR, and whether they are therefore related to the complexity of cloud structure, its interpretation by different observational systems, and its subsequent representation in radiative transfer calculations. PMID:29619289

Negotiating a regime to control global warming

International Nuclear Information System (INIS)

Sebenius, J.K.

1991-01-01

For purposes of analysis, this paper has uncritically maintained that the prospect of a serious climate problem exists and has only lightly examined the broader advantages and drawbacks of various proposed policy and institutional responses. Crucial as they are to a full treatment of the issues, these underlying substantive and policy questions enter the analysis primarily insofar as they affect the likely outcomes of pending and potential negotiations. To an advocate of a new greenhouse control regime, the fundamental negotiating task is to craft and sustain a meaningful winning coalition of countries backing such a regime. Two centrally necessary conditions for the fundamental task are: (1) that each member of the coalition see enough gain in the regime relative to the alternatives to adhere and (2) the potential and actual blocking coalitions of interests opposed to the regime be prevented from forming and from being acceptably accommodated or otherwise neutralized. The analysis of this paper is organized around key questions whose answers will influence whether and how these two necessary conditions might (or might not) be met

Radiative Effects of Global MODIS Cloud Regimes

Science.gov (United States)

Oraiopoulos, Lazaros; Cho, Nayeong; Lee, Dong Min; Kato, Seiji

2016-01-01

We update previously published MODIS global cloud regimes (CRs) using the latest MODIS cloud retrievals in the Collection 6 dataset. We implement a slightly different derivation method, investigate the composition of the regimes, and then proceed to examine several aspects of CR radiative appearance with the aid of various radiative flux datasets. Our results clearly show the CRs are radiatively distinct in terms of shortwave, longwave and their combined (total) cloud radiative effect. We show that we can clearly distinguish regimes based on whether they radiatively cool or warm the atmosphere, and thanks to radiative heating profiles to discern the vertical distribution of cooling and warming. Terra and Aqua comparisons provide information about the degree to which morning and afternoon occurrences of regimes affect the symmetry of CR radiative contribution. We examine how the radiative discrepancies among multiple irradiance datasets suffering from imperfect spatiotemporal matching depend on CR, and whether they are therefore related to the complexity of cloud structure, its interpretation by different observational systems, and its subsequent representation in radiative transfer calculations.

Emerging Trends in Development of International Information Security Regime

Directory of Open Access Journals (Sweden)

Elena S. Zinovieva

2016-01-01

Full Text Available The article discusses the key trends shaping the international regime on information security. International cooperation in this area at the global level encounters contradictions of state interest. The main actors of the information security are the United States, Russia, China and the EU countries (Britain, France and Germany. The main contradiction is developing between the US on one side and Russia and China on the other. EU countries occupy the middle position, gravitating to that of US. The article proves that international cooperation on information security will reflect the overall logic of the development of international cooperation, which is characterized by a new model of cooperation, with the participation of state and non-state actors, known as multi-stakeholder partnerships and multi-level cooperation. The logic of the formation of an international regime on information security is closest to the logic of the formation of the international non-proliferation regime. It is in the interest of Russia to support the trend towards regionalization of information security regime. Russia can form a regional information security regime in the former Soviet Union on the basis of the CSTO and SCO and potentially on a wider Eurasian space. Such regional regime would give Russia an opportunity to shape the international regime and closely monitor emerging information security issues in the former Soviet Union, and remove the potential threat of "color revolutions".

Inclusive and Women-friendly in a time of Diversity? The Scandinavian citizenship regime – the ‘childcare lesson’

Directory of Open Access Journals (Sweden)

Cecilie Thun

2015-01-01

Full Text Available In this article, I ask: Is the Scandinavian citizenship regime inclusive and women-friendly in a time of diversity? I approach this question by addressing the intersection of gender and ethnicity in relation to social citizenship with the main concern being childcare. I emphasize Norway as a case but also see Norway in comparison with Sweden and Denmark. In comparative studies, the Scandinavian citizenship regime is presented as being the most ‘women-friendly’. However, faced with an increasingly multicultural population, a pertinent question is whether this citizenship model is able to accommodate diversity. I explore two tensions that are basic to the inclusiveness and women-friendliness of the Scandinavian citizenship regime in diverse societies: 1 The tension between principles of gender equality and cultural diversity, and 2 the tension between liberating and controlling aspects of the welfare state. This article discusses the Norwegian family policy ‘hybrid’, which combines dual-earner support with traditional breadwinner elements. One might say that the Norwegian family ‘hybrid’ can be a solution to the tension between, on the one hand, a specific gender-equality family norm, and, on the other hand, the respect for other family norms. However, I argue that there is a double standard with regard to minority women, and it can be understood in light of a discourse about Norwegianness. Parental choice is considered a good thing – as long as the mother in question is considered ‘fully’ Norwegian. However, assumed cultural and ethnic differences – often based on stereotypical collective categories of difference – are used as boundary-markers between the majority and minorities. I conclude that, despite variations, all the Scandinavian countries grapple with the same tensions, and that there is a Scandinavian double standard regarding minority women.

Dune growth under multidirectional wind regimes

Science.gov (United States)

Gadal, C.; Rozier, O.; Claudin, P.; Courrech Du Pont, S.; Narteau, C.

2017-12-01

Under unidirectional wind regimes, flat sand beds become unstable to produce periodic linear dunes, commonly called transverse dunes because their main ridges are oriented perpendicular to the air flow. In areas of low sediment availability, the same interactions between flow, transport and topography produce barchan dunes, isolated sand-pile migrating over long distances with a characteristic crescentic shape. For the last fifteen years, barchan dunes and the instability at the origin of transverse dunes have been the subject of numerous studies that have identified a set of characteristic length and time scales with respect to the physical properties of both grains and fluid. This is not the case for dunes developing under multidirectional wind regimes. Under these conditions, dune orientation is measured with respect to the direction of the resultant sand flux. Depending on the wind regime, dunes do not always line up perpendicularly to the resultant sand flux, but can also be at an oblique angle or even parallel to it. These oblique and longitudinal dunes are ubiquitous in all deserts on Earth and planetary bodies because of the seasonal variability of wind orientation. They are however poorly constrained by observations and there is still no complete theoretical framework providing a description of their orientation and initial wavelength. Here, we extend the linear stability analysis of a flat sand of bed done in two dimensions for a unidirectional flow to three dimensions and multidirectional flow regimes. We are able to recover transitions from transverse to oblique or longitudinal dune patterns according to changes in wind regimes. We besides give a prediction for the initial dune wavelength. Our results compare well to previous theory of dune orientation and to field, experimental and numerical data.

The Gulf crisis (1990-91) and the Kuwait regime : legitimacy and stability in a rentier state Gulf crisis (1990-91) and the Kuwait regime

OpenAIRE

Maktabi, Rania

1992-01-01

THE GULF CRISIS (1990-91) & THE KUWAITI REGIME - LEGITIMACY AND STABILITY IN A RENTIER STATE Among the central questions I address are: What are the factors that contribute to regime stability in Kuwait? How do we understand the relationship between rulers and ruled? In which ways did the regime maintain political authority during the Crisis, and how does it ensure its stability after the experience of the Crisis? It is argued that the legitimacy of the Kuwaiti regime could be seen a...

Properties of dual codes defined by nondegenerate forms

Directory of Open Access Journals (Sweden)

Steve Szabo

2017-01-01

Full Text Available Dual codes are defined with respect to non-degenerate sesquilinear or bilinear forms over a finite Frobenius ring. These dual codes have the properties one expects from a dual code: they satisfy a double-dual property, they have cardinality complementary to that of the primal code, and they satisfy the MacWilliams identities for the Hamming weight.

Comparison of bioavailability and antiplatelet action of ticagrelor in patients with ST-elevation myocardial infarction and non-ST-elevation myocardial infarction: A prospective, observational, single-centre study.

Directory of Open Access Journals (Sweden)

Piotr Adamski

Full Text Available Data from available studies suggest that the presence of ST-elevation myocardial infarction (STEMI may be associated with delayed and attenuated ticagrelor bioavailability and effect compared with non-ST-elevation myocardial infarction (NSTEMI.In a single-center, prospective, observational trial 73 patients with myocardial infarction (STEMI n = 49, NSTEMI n = 24 underwent a pharmacokinetic and pharmacodynamic assessment after a 180 mg ticagrelor loading dose (LD. Ticagrelor and its active metabolite (AR-C124910XX plasma concentrations were determined with liquid chromatography tandem mass spectrometry, and their antiplatelet effect was measured with the VASP assay and multiple electrode aggregometry.During the first six hours after ticagrelor LD, STEMI patients had 38% and 34% lower plasma concentration of ticagrelor and AR-C124910XX, respectively, than NSTEMI (ticagrelor AUC(0-6: 2491 [344-5587] vs. 3991 [1406-9284] ng*h/mL; p = 0.038; AR-C124910XX AUC(0-6: 473 [0-924] vs. 712 [346-1616] ng*h/mL; p = 0.027. STEMI patients also required more time to achieve maximal concentration of ticagrelor (tmax: 4.0 [3.0-12.0] vs. 2.5 [2.0-6.0] h; p = 0.012. Impaired bioavailability of ticagrelor and AR-C124910XX seen in STEMI subjects was associated with diminished platelet inhibition in this group, which was most pronounced during the initial hours of treatment.Plasma concentrations of ticagrelor and AR-C124910XX during the first hours after ticagrelor LD were one third lower in STEMI than in NSTEMI patients. This reduced and delayed ticagrelor bioavailability was associated with weaker antiplatelet effect in STEMI.ClinicalTrials.gov identifier: NCT02602444 (November 09, 2015.

Socio-ecological regime transitions in Austria and the United Kingdom

International Nuclear Information System (INIS)

Krausmann, Fridolin; Schandl, Heinz; Sieferle, Rolf Peter

2008-01-01

We employ the concepts of socio-ecological regime and regime transition to better understand the biophysical causes and consequences of industrialization. For two case studies, the United Kingdom and Austria we describe two steps in a major transition from an agrarian to an industrial socio-ecological regime and the resulting consequences for energy use, land use and labour organization. In a first step, the coal based industrial regime co-existed with an agricultural sector remaining within the bounds of the old regime. In a second step, the oil/electricity based industrial regime, agriculture was integrated into the new pattern and the socio-ecological transition had been completed. Industrialization offers an answer to the input and growth related sustainability problems of the agrarian regime but creates new sustainability problems of a larger scale. While today's industrial societies are stabilizing their resource use albeit at an unsustainable level large parts of the global society are in midst of the old industrial transition. This poses severe problems for global sustainability. (author)

Socio-ecological regime transitions in Austria and the United Kingdom

Energy Technology Data Exchange (ETDEWEB)

Krausmann, Fridolin [Institute of Social Ecology, Klagenfurt University, Klagenfurt (Austria); Schandl, Heinz [CSIRO Sustainable Ecosystems, Canberra (Australia); Sieferle, Rolf Peter [Department of Humanities and Social Sciences, University of St. Gallen, Sankt Gallen (Switzerland)

2008-03-15

We employ the concepts of socio-ecological regime and regime transition to better understand the biophysical causes and consequences of industrialization. For two case studies, the United Kingdom and Austria we describe two steps in a major transition from an agrarian to an industrial socio-ecological regime and the resulting consequences for energy use, land use and labour organization. In a first step, the coal based industrial regime co-existed with an agricultural sector remaining within the bounds of the old regime. In a second step, the oil/electricity based industrial regime, agriculture was integrated into the new pattern and the socio-ecological transition had been completed. Industrialization offers an answer to the input and growth related sustainability problems of the agrarian regime but creates new sustainability problems of a larger scale. While today's industrial societies are stabilizing their resource use albeit at an unsustainable level large parts of the global society are in midst of the old industrial transition. This poses severe problems for global sustainability. (author)

Detecting spatial regimes in ecosystems

Science.gov (United States)

Sundstrom, Shana M.; Eason, Tarsha; Nelson, R. John; Angeler, David G.; Barichievy, Chris; Garmestani, Ahjond S.; Graham, Nicholas A.J.; Granholm, Dean; Gunderson, Lance; Knutson, Melinda; Nash, Kirsty L.; Spanbauer, Trisha; Stow, Craig A.; Allen, Craig R.

2017-01-01

Research on early warning indicators has generally focused on assessing temporal transitions with limited application of these methods to detecting spatial regimes. Traditional spatial boundary detection procedures that result in ecoregion maps are typically based on ecological potential (i.e. potential vegetation), and often fail to account for ongoing changes due to stressors such as land use change and climate change and their effects on plant and animal communities. We use Fisher information, an information theory-based method, on both terrestrial and aquatic animal data (U.S. Breeding Bird Survey and marine zooplankton) to identify ecological boundaries, and compare our results to traditional early warning indicators, conventional ecoregion maps and multivariate analyses such as nMDS and cluster analysis. We successfully detected spatial regimes and transitions in both terrestrial and aquatic systems using Fisher information. Furthermore, Fisher information provided explicit spatial information about community change that is absent from other multivariate approaches. Our results suggest that defining spatial regimes based on animal communities may better reflect ecological reality than do traditional ecoregion maps, especially in our current era of rapid and unpredictable ecological change.

Cloud regimes as phase transitions

Science.gov (United States)

Stechmann, Samuel; Hottovy, Scott

2017-11-01

Clouds are repeatedly identified as a leading source of uncertainty in future climate predictions. Of particular importance are stratocumulus clouds, which can appear as either (i) closed cells that reflect solar radiation back to space or (ii) open cells that allow solar radiation to reach the Earth's surface. Here we show that these clouds regimes - open versus closed cells - fit the paradigm of a phase transition. In addition, this paradigm characterizes pockets of open cells (POCs) as the interface between the open- and closed-cell regimes, and it identifies shallow cumulus clouds as a regime of higher variability. This behavior can be understood using an idealized model for the dynamics of atmospheric water as a stochastic diffusion process. Similar viewpoints of deep convection and self-organized criticality will also be discussed. With these new conceptual viewpoints, ideas from statistical mechanics could potentially be used for understanding uncertainties related to clouds in the climate system and climate predictions. The research of S.N.S. is partially supported by a Sloan Research Fellowship, ONR Young Investigator Award N00014-12-1-0744, and ONR MURI Grant N00014-12-1-0912.

Risk of Gastrointestinal Bleeding with Rivaroxaban: A Comparative Study with Warfarin

Directory of Open Access Journals (Sweden)

Muhammed Sherid

2016-01-01

Full Text Available Introduction. The risk of gastrointestinal (GI bleeding with rivaroxaban has not been studied extensively. The aim of our study was to assess this risk in comparison to warfarin. Methods. We examined the medical records for patients who were started on rivaroxaban or warfarin from April 2011 to April 2013. Results. We identified 300 patients (147 on rivaroxaban versus 153 on warfarin. GI bleeding occurred in 4.8% patients with rivaroxaban when compared to 9.8% patients in warfarin group (p=0.094. GI bleeding occurred in 8% with therapeutic doses of rivaroxaban (>10 mg/d compared to 9.8% with warfarin (p=0.65. Multivariate analysis showed that patients who were on rivaroxaban for ≤40 days had a higher incidence of GI bleeding than those who were on it for >40 days (OR = 2.8, p=0.023. Concomitant use of dual antiplatelet agents was associated with increased risk of GI bleeding in the rivaroxaban group (OR = 7.4, p=0.0378. Prior GI bleeding was also a risk factor for GI bleeding in rivaroxaban group (OR = 15.5. Conclusion. The incidence of GI bleeding was similar between rivaroxaban and warfarin. The risk factors for GI bleeding with rivaroxaban were the first 40 days of taking the drug, concomitant dual antiplatelet agents, and prior GI bleeding.

Peaceful Protest, Political Regimes, and the Social Media Challenge

Science.gov (United States)

2016-06-01

University, 2012 Randolph J. Fleming, II Major, United States Army B.A., Virginia Commonwealth University, 2004 Submitted in partial fulfillment of...intermediate regimes or transitioning regimes carrying the burden of instability and conflict.23 In a similar vein, Henderson identifies democracies, as...spreading infectious ideologies through ICT.25 Furthermore, Regan and Henderson indicate that intermediate, anocratic regimes tend to oppress

An Efficient Construction of Self-Dual Codes

OpenAIRE

Lee, Yoonjin; Kim, Jon-Lark

2012-01-01

We complete the building-up construction for self-dual codes by resolving the open cases over $GF(q)$ with $q \\equiv 3 \\pmod 4$, and over $\\Z_{p^m}$ and Galois rings $\\GR(p^m,r)$ with an odd prime $p$ satisfying $p \\equiv 3 \\pmod 4$ with $r$ odd. We also extend the building-up construction for self-dual codes to finite chain rings. Our building-up construction produces many new interesting self-dual codes. In particular, we construct 945 new extremal self-dual ternary $[32,16,9]$ codes, each ...

Dual Kidney Allocation Score: A Novel Algorithm Utilizing Expanded Donor Criteria for the Allocation of Dual Kidneys in Adults.

Science.gov (United States)

Johnson, Adam P; Price, Thea P; Lieby, Benjamin; Doria, Cataldo

2016-09-08

BACKGROUND Dual kidney transplantation (DKT) of expanded-criteria donors is a cost-intensive procedure that aims to increase the pool of available deceased organ donors and has demonstrated equivalent outcomes to expanded-criteria single kidney transplantation (eSKT). The objective of this study was to develop an allocation score based on predicted graft survival from historical dual and single kidney donors. MATERIAL AND METHODS We analyzed United Network for Organ Sharing (UNOS) data for 1547 DKT and 26 381 eSKT performed between January 1994 and September 2013. We utilized multivariable Cox regression to identify variables independently associated with graft survival in dual and single kidney transplantations. We then derived a weighted multivariable product score from calculated hazard ratios to model the benefit of transplantation as dual kidneys. RESULTS Of 36 donor variables known at the time of listing, 13 were significantly associated with graft survival. The derived dual allocation score demonstrated good internal validity with strong correlation to improved survival in dual kidney transplants. Donors with scores less than 2.1 transplanted as dual kidneys had a worsened median survival of 594 days (24%, p-value 0.031) and donors with scores greater than 3.9 had improved median survival of 1107 days (71%, p-value 0.002). There were 17 733 eSKT (67%) and 1051 DKT (67%) with scores in between these values and no differences in survival (p-values 0.676 and 0.185). CONCLUSIONS We have derived a dual kidney allocation score (DKAS) with good internal validity. Future prospective studies will be required to demonstrate external validity, but this score may help to standardize organ allocation for dual kidney transplantation.

The high-energy dual-beam facility

International Nuclear Information System (INIS)

Kaletta, D.

1984-07-01

This proposal presents a new experimental facility at the Kernforschungszentrum Karlsruhe (KfK) to study the effects of irradiation on the first wall and blanket materials of a fusion reactor. A special effort is made to demonstrate the advantages of the Dual Beam Technique (DBT) as a future research tool for materials development within the European Fusion Technology Programme. The Dual-Beam-Technique allows the production both of helium and of damage in thick metal and ceramic specimens by simultaneous irradiation with high energy alpha particles and protons produced by the two KfK cyclotrons. The proposal describes the Dual Beam Technique the planned experimental activities and the design features of the Dual Beam Facility presently under construction. (orig.) [de

Sparsity and spectral properties of dual frames

DEFF Research Database (Denmark)

Krahmer, Felix; Kutyniok, Gitta; Lemvig, Jakob

2013-01-01

We study sparsity and spectral properties of dual frames of a given finite frame. We show that any finite frame has a dual with no more than $n^2$ non-vanishing entries, where $n$ denotes the ambient dimension, and that for most frames no sparser dual is possible. Moreover, we derive an expressio...

Water regime of steam power plants

International Nuclear Information System (INIS)

Oesz, Janos

2011-01-01

The water regime of water-steam thermal power plants (secondary side of pressurized water reactors (PWR); fossil-fired thermal power plants - referred to as steam power plants) has changed in the past 30 years, due to a shift from water chemistry to water regime approach. The article summarizes measures (that have been realised by chemists of NPP Paks) on which the secondary side of NPP Paks has become a high purity water-steam power plant and by which the water chemistry stress corrosion risk of heat transfer tubes in the VVER-440 steam generators was minimized. The measures can also be applied to the water regime of fossil-fired thermal power plants with super- and subcritical steam pressure. Based on the reliability analogue of PWR steam generators, water regime can be defined as the harmony of construction, material(s) and water chemistry, which needs to be provided in not only the steam generators (boiler) but in each heat exchanger of steam power plant: - Construction determines the processes of flow, heat and mass transfer and their local inequalities; - Material(s) determines the minimal rate of general corrosion and the sensitivity for local corrosion damage; - Water chemistry influences the general corrosion of material(s) and the corrosion products transport, as well as the formation of local corrosion environment. (orig.)

Dual Treatments as Starting Point for Integrative Perceptions in Teaching Mathematics

Science.gov (United States)

Kërënxhi, Svjetllana; Gjoci, Pranvera

2015-01-01

In this paper, we recommend mathematical teaching through dual treatments. The dual treatments notion, classified in dual interpretations, dual analyses, dual solutions, and dual formulations, is explained through concrete examples taken from mathematical textbooks of elementary education. Dual treatments provide opportunities for creating…

Direct-contact condensation regime map for core makeup tank of passive reactors

International Nuclear Information System (INIS)

Lee, Sang Il; No, Hee Cheon

1998-01-01

The condensation regime map in the core makeup tank of passive reactors is experimentally investigated. The condensation regimes identified through the experiments are divided into three distinct ones: sonic jet, subsonic jet, and steam cavity. The steam cavity regime is a unique regime of downward injection with the present geometry not previously observed in other experiments. The condensation regime map is constructed using Froude number and Jacob number. It turns out that the buoyancy force has a large influence on the regime transition because the regime map using the Froude number better fits data with different geometries than other dimensionless parameters. Simple correlations for the regime boundaries are proposed using the Froude number and the Jacob number

Dual Coding, Reasoning and Fallacies.

Science.gov (United States)

Hample, Dale

1982-01-01

Develops the theory that a fallacy is not a comparison of a rhetorical text to a set of definitions but a comparison of one person's cognition with another's. Reviews Paivio's dual coding theory, relates nonverbal coding to reasoning processes, and generates a limited fallacy theory based on dual coding theory. (PD)

Flow regimes in vertical gas-solid contact systems

Energy Technology Data Exchange (ETDEWEB)

Yerushalmi, J.; Cankurt, N. T.; Geldart, D.; Liss, B.

1976-01-01

The flow characteristics in fluidized beds, i.e., gas-solid systems, was studied to determine the flow regimes, the interaction of gas and solid in the various flow regimes and the dependence of this interaction and of transition between flow regimes on the properties of the gas and solid, on the gas and solid flow rates, and on the containing vessel. Fluidized beds with both coarse and fine particles are considered. Test results using high speed photography to view the operation of a 2-dimensional bed are discussed. (LCL)

Dual-source dual-energy CT for the differentiation of urinary stone composition: preliminary study

International Nuclear Information System (INIS)

Yang Qifang; Zhang Wanshi; Meng Limin; Shi Huiping; Wang Dong; Bi Yongmin; Li Xiangsheng; Fang Hong; Guo Heqing; Yan Jingmin

2011-01-01

Objective: To evaluate dual-source dual-energy CT (DSCT) for the differentiation of' urinary stone composition in vitro. Methods: Ninety-seven urinary stones were obtained by endoscopic lithotripsy and scanned using dual-source dual-energy CT. The stones were divided into six groups according to infrared spectroscopy stone analysis: uric acid (UA) stones (n=10), cystine stones (n=5), struvite stones (n=6), calcium oxalate (CaOx) stones (n=22), mixed UA stones (n=7) and mixed calcium stones (n=47). Hounsfield units (HU) of each stone were recorded for the 80 kV and the 140 kV datasets by hand-drawing method. HU difference, HU ratio and dual energy index (DEI) were calculated and compared among the stone groups with one-way ANOVA. Using dual energy software to determine the composition of all stones, results were compared to infrared spectroscopy analysis. Results: There were statistical differences in HU difference [(-17±13), (229±34), (309±45), (512±97), (201±64) and (530±71) HU respectively], in HU ratio (0.96±0.03, 1.34±0.04, 1.41±0.03, 1.47±0.03, 1.30±0.07, and 1.49±0.03 respectively), and DEI (-0.006±0.004, 0.064±0.007, 0.080± 0.007, 0.108±0.011, 0.055±0.014 and 0.112±0.008 respectively) among different stone groups (F= 124.894, 407.028, 322.864 respectively, P<0.01). There were statistical differences in HU difference, HU ratio and DEI between UA stones and the other groups (P<0.01). There were statistical differences in HU difference, HU ratio and DEI between CaOx or mixed calcium stones and the other four groups (P< 0.01). There was statistical difference in HU ratio between cystine and struvite stones (P<0.01). There were statistical differences in HU difference, HU ratio and DEI between struvite and mixed UA stones (P< 0.05). Dual energy software correctly characterized 10 UA stones, 4 cystine stones, 22 CaOx stones and 6 mixed UA stones. Two struvite stones were considered to contain cystine. One cystine stone, 1 mixed UA stone, 4

Dual method use among long-acting reversible contraceptive users.

Science.gov (United States)

Bernard, Caitlin; Zhao, Qiuhong; Peipert, Jeffrey F

2018-03-27

To compare rates of dual method use (concurrent use of condoms and an effective method of contraception) in long-acting reversible contraceptive (LARC) and non-LARC hormonal contraceptive users, and to determine factors associated with dual method use. We conducted a secondary analysis of the Contraceptive CHOICE Project, an observational, prospective cohort study of 9256 women in St. Louis, MO, USA. Our sample included 6744 women who initiated a contraceptive method within 3 months of enrollment, continued use at 6 months post-enrollment, and responded regarding dual method use. Our primary outcome was the rate of dual method use at 6 months post-enrollment. Dual method use was reported by 32% of LARC and 45% of non-LARC hormonal contraceptive users (p dual method use (RR adj 0.76, 95% CI 0.70-0.83). Factors associated with dual method use in our multivariable analysis were age dual method use, baseline diagnosis of sexually transmitted infection (STI), greater partner willingness to use a condom, and higher condom self-efficacy score. LARC users are less likely to report dual method use compared to non-LARC hormonal contraceptive users, but other factors also impact dual method use. Further studies should be performed to determine whether this lower dual method use increases the risk of STI. Clinicaltrials.gov Identifier NCT01986439.

Terms of trade and exchange rate regimes in developing countries

OpenAIRE

Christian Broda

2002-01-01

Since Friedman (1953), an advantage often attributed to flexible exchange rate regimes over fixed regimes is their ability to insulate more effectively the economy against real shocks. I use a post-Bretton Woods sample (1973-96) of seventy-five developing countries to assess whether the responses of real GDP, real exchange rates, and prices to terms-of-trade shocks differ systematically across exchange rate regimes. I find that responses are significantly different across regimes in a way tha...

The dual of the Carroll-Field-Jackiw model

International Nuclear Information System (INIS)

Guimaraes, M.S.; Grigorio, L.; Wotzasek, C.

2006-01-01

In this work we apply different duality techniques, both the dual projection, based on the soldering formalism and the master action, in order to obtain and study the dual description of the Carroll- Field-Jackiw model [1], a theory with a Chern-Simons-like explicitly Lorentz and CPT violating term, including the interaction with external charges. This Maxwell-Chern-Simons-like model may be rewritten in terms of the interacting modes of a massless scalar model and a topologically massive model [2], that are mapped, through duality, into interacting massless Maxwell and massive self-dual modes [3]. It is also shown that these dual modes might be represented into an unified rank-two self-dual model that represents the direct dual of the vector Maxwell-Chern-Simons-like model

Trust in regulatory regimes

NARCIS (Netherlands)

Six, Frédérique; Verhoest, Koen

2017-01-01

Within political and administrative sciences generally, trust as a concept is contested, especially in the field of regulatory governance. This groundbreaking book is the first to systematically explore the role and dynamics of trust within regulatory regimes. Conceptualizing, mapping and analyzing