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Sample records for acute decompensated hf

  1. Cardiac Rhythm Monitoring After Acute Decompensation for Heart Failure: Results from the CARRYING ON for HF Pilot Study

    PubMed Central

    Mortara, Andrea; Diotallevi, Paolo; Gallone, Giuseppe; Mariconti, Barbara; Gronda, Edoardo; Gentili, Alessandra; Bisetti, Silvia; Botto, Giovanni Luca

    2016-01-01

    Background There’s scarce evidence about cardiovascular events (CV) in patients with hospitalization for acute heart failure (HF) and no indication for immediate device implant. Objective The CARdiac RhYthm monitorING after acute decompensatiON for Heart Failure study was designed to assess the incidence of prespecified clinical and arrhythmic events in this patient population. Methods In this pilot study, 18 patients (12 (67%) male; age 72±10; 16 (89%) NYHA II-III), who were hospitalized for HF with low left ventricular ejection fraction (LVEF) (<40%) and no immediate indication for device implant received an implantable loop recorder (ILR) before hospital discharge. Follow-up visits were scheduled at 3 and 6 months, and at every 6 months until study closure; device data were remotely reviewed monthly. CV mortality, unplanned CV hospitalization, and major arrhythmic events during follow-up were analyzed. Results During a median follow-up of 593 days, major CV occurred in 13 patients (72%); of those, 7 patients had at least 1 cardiac arrhythmic event, 2 had at least a clinical event (CV hospitalization or CV death), and 4 had both an arrhythmic and a CV event. Six (33%) patients experienced 10 major clinical events, 5 of them (50%) were HF related. During follow-up, 2 (11%) patients died due to a CV cause and 3 (16%) patients received a permanent cardiac device. Conclusions After an acute HF hospitalization, patients with LVEF<40% and who are not readily eligible for permanent cardiac device implant have a known high incidence of major CV event. In these patients, ILR allows early detection of major cardiac arrhythmias and the ability to react appropriately in a timely manner. Trial Registration ClinicalTrials.gov NCT01216670; https://clinicaltrials.gov/ct2/show/NCT01216670 PMID:27118481

  2. Acute Decompensated Heart Failure Update

    PubMed Central

    Teerlink, John R; Alburikan, Khalid; Metra, Marco; Rodgers, Jo E

    2015-01-01

    Acute decompensated heart failure (ADHF) continues to increase in prevalence and is associated with substantial mortality and morbidity including frequent hospitalizations. The American Heart Association is predicting that more than eight million Americans will have heart failure by 2030 and that the total direct costs associated with the disease will rise from $21 billion in 2012 to $70 billion in 2030. The increase in the prevalence and cost of HF is primarily the result of shifting demographics and a growing population. Although many large, randomized, controlled clinical trials have been conducted in patients with chronic heart failure, it was not until recently that a growing number of studies began to address the management of ADHF. It is the intent of this review to update the clinician regarding the evaluation and optimal management of ADHF. PMID:24251454

  3. Arrival by ambulance in acute heart failure: insights into the mode of presentation from Acute Studies of Nesiritide in Decompensated Heart Failure (ASCEND-HF)

    PubMed Central

    Ezekowitz, Justin A; Podder, Mohua; Hernandez, Adrian F; Armstrong, Paul W; Starling, Randall C; O'Connor, Christopher M; Califf, Robert M

    2016-01-01

    Objectives Limited data exist assessing the relationship between ambulance versus self-presentation and outcomes in patients with acute heart failure (AHF). Setting Clinical trial sites in North America. Participants 1068 patients enrolled in the Acute Studies of Nesiritide in Decompensated Heart Failure (ASCEND-HF) trial. Primary and secondary outcome measures The association between ambulance use and dyspnoea improvement, 30-day mortality or HF rehospitalisation and 180-day mortality. Results Of the 1068 patients in the substudy, 832 (78%) self-presented (SP) and 236 (22%) patients presented via ambulance. Patients presenting via ambulance were older, more likely to be female, have a higher ejection fraction but similar natriuretic peptide levels as patients who SP. Patients presenting by ambulance (compared with SP) trended towards more dyspnoea improvement at 6 (p=0.09) and 24 h (p=0.10). The co-primary end point (30-day mortality or HF rehospitalisation) was similar between groups (ambulance 12.2% vs SP 11.4%, p=0.74). Patients who presented by ambulance had a higher 30-day and 180-day mortality rate than those who SP (30-day: 4.3% vs 2.2%, p=0.08; 180-day: 15.1% vs 10.3%, p=0.04). After adjustment for baseline characteristics, patients arriving by ambulance (compared with SP) had a 2-fold high risk of 30-day mortality (OR 2.12, 95% CI 0.94 to 4.79), but no relationship to the composite of 30-day mortality/HF rehospitalisation (OR 1.01, 95% CI 0.63 to 1.63). Conclusions Among patients with AHF, 30-day and 180-day mortality is 1.5–2 times higher for those with presenting via ambulance compared with patients who self-present. Understanding patient-related and system-related factors of ambulance use for patients with AHF is important. Trial registration number NCT00475852. PMID:26988350

  4. Managing acute decompensated heart failure.

    PubMed

    Pauly, Daniel F

    2014-02-01

    Acute decompensated heart failure may occur de novo, but it most often occurs as an exacerbation of underlying chronic heart failure. Hospitalization for heart failure is usually a harbinger of a chronic disease that will require long-term, ongoing medical management. Leaders in the field generally agree that repeated inpatient admissions for treatment reflect a failure of the health care delivery system to manage the disease optimally. Newer management strategies focus on ameliorating symptoms by optimizing the hemodynamics, restoring neurohormonal balance, and making frequent outpatient adjustments when needed. PMID:24286585

  5. Evaluating the Safety and Efficacy of Sodium-Restricted/Dietary Approaches to Stop Hypertension Diet After Acute Decompensated Heart Failure Hospitalization: Design and Rationale for the Geriatric OUt of hospital Randomized MEal Trial in Heart Failure (GOURMET-HF)

    PubMed Central

    Wessler, Jeffrey D.; Maurer, Mathew S.; Hummel, Scott S.

    2015-01-01

    Background Heart Failure (HF) is a major public health problem affecting predominantly older adults. Non-adherence to diet remains a significant contributor to acute decompensated HF (ADHF). The sodium-restricted Dietary Approaches to Stop Hypertension (DASH/SRD) eating plan reduces cardiovascular dysfunction that can lead to ADHF and is consistent with current HF guidelines. We propose that an intervention that promotes adherence to the DASH/SRD by home-delivering meals will be safe and improve health-related quality of life (QOL) in older adults following hospitalization for ADHF. Methods/Design This is a three center, randomized, single-blind, controlled trial of 12 weeks duration designed to determine the safety and efficacy of home-delivered DASH/SRD-compliant meals in older adults following discharge from ADHF hospitalization. 66 subjects will be randomized in a 1:1 stratified fashion by gender and left ventricular ejection fraction (< vs. ≥50%). Study subjects will receive either pre-prepared, home-delivered DASH/SRD-compliant meals or usual dietary advice for 4 weeks after hospital discharge. Investigators will be blinded to group assignment, food diaries, and urinary electrolyte measurements until study completion. The primary efficacy endpoint is the change in the Kansas City Cardiomyopathy Questionnaire (KCCQ) summary scores for health-related QOL from study enrollment to 4 weeks post-discharge. Safety evaluation will focus on hypotension, renal insufficiency, and hyperkalemia. Exploratory endpoints include echocardiography, non-invasive vascular testing, markers of oxidative stress, and salt taste sensitivity. Conclusion This randomized controlled trial will test the efficacy, feasibility and safety of 4 weeks of DASH/SRD after ADHF hospitalization. By testing a novel dietary intervention supported by multiple levels of evidence including preliminary data in outpatients with stable HF, we will address a critical evidence gap in the care of older

  6. Detecting Heart Failure Decompensation by Measuring Transthoracic Bioimpedance in the Outpatient Setting: Rationale and Design of the SENTINEL-HF Study

    PubMed Central

    Saczynski, Jane S; Darling, Chad E; Riistama, Jarno; Sert Kuniyoshi, Fatima; Meyer, Theo; Goldberg, Robert; McManus, David D

    2015-01-01

    Background Recurrent hospital admissions are common among patients admitted for acute decompensated heart failure (ADHF), but identification of patients at risk for rehospitalization remains challenging. Contemporary heart failure (HF) management programs have shown modest ability to reduce readmissions, partly because they monitor signs or symptoms of HF worsening that appear late during decompensation. Detecting early stages of HF decompensation might allow for immediate application of effective HF therapies, thereby potentially reducing HF readmissions. One of the earliest indicators of HF decompensation is intrathoracic fluid accumulation, which can be assessed using transthoracic bioimpedance. Objective The SENTINEL-HF study is a prospective observational study designed to test a novel, wearable HF monitoring system as a predictor of HF decompensation among patients discharged after hospitalization for ADHF. Methods SENTINEL-HF tests the hypothesis that a decline in transthoracic bioimpedance, as assessed daily with the Philips fluid accumulation vest (FAV) and transmitted using a mobile phone, is associated with HF worsening and rehospitalization. According to pre-specified power calculations, 180 patients admitted with ADHF are enrolled. Participants transmit daily self-assessments using the FAV-mobile phone dyad for 45 days post-discharge. The primary predictor is the deviation of transthoracic bioimpedance for 3 consecutive days from a patient-specific normal variability range. The ADHF detection algorithm is evaluated in relation with a composite outcome of HF readmission, diuretic up-titration, and self-reported HF worsening (Kansas City Cardiomyopathy Questionnaire) during a 90-day follow-up period. Here, we provide the details and rationale of SENTINEL-HF. Results Enrollment in the SENTINEL-HF study is complete and the 90-days follow-up is currently under way. Once data collection is complete, the study dataset will be used to evaluate our ADHF

  7. Management of acute decompensated heart failure.

    PubMed

    Dec, G William

    2007-06-01

    Acute decompensated heart failure is the most common cause for hospitalization among patients over 65 years of age. It may result from new onset of ventricular dysfunction or, more typically, exacerbation of chronic heart failure symptoms. In-hospital mortality remains high for both systolic and diastolic forms of the disease. Therapy is largely empirical as few randomized, controlled trials have focused on this population and consensus practice guidelines are just beginning to be formulated. Treatment should be focused upon correction of volume overload, identifying potential precipitating causes, and optimizing vasodilator and beta-adrenergic blocker therapy. The majority of patients (>90%) will improve without the use of positive inotropic agents, which should be reserved for patients with refractory hypotension, cardiogenic shock, end-organ dysfunction, or failure to respond to conventional oral and/or intravenous diuretics and vasodilators. The role of aldosterone antagonists, biventricular pacing, and novel pharmacological agents including vasopressin antagonists, endothelin blockers, and calcium-sensitizing agents is also reviewed. PMID:17531903

  8. Management of Patients Admitted with Acute Decompensated Heart Failure

    PubMed Central

    Krim, Selim R.; Campbell, Patrick T.; Desai, Sapna; Mandras, Stacy; Patel, Hamang; Eiswirth, Clement; Ventura, Hector O.

    2015-01-01

    Background Hospital admission for the treatment of acute decompensated heart failure is an unfortunate certainty in the vast majority of patients with heart failure. Regardless of the etiology, inpatient treatment for acute decompensated heart failure portends a worsening prognosis. Methods This review identifies patients with heart failure who need inpatient therapy and provides an overview of recommended therapies and management of these patients in the hospital setting. Results Inpatient therapy for patients with acute decompensated heart failure should be directed at decongestion and symptom improvement. Clinicians should also treat possible precipitating events, identify comorbid conditions that may exacerbate heart failure, evaluate and update current guideline-directed medical therapy, and perform risk stratification for all patients. Finally, efforts should be made to educate patients about the importance of restricting salt and fluid, monitoring daily weights, and adhering to a graded exercise program. Conclusion Early discharge follow-up and continued optimization of guideline-directed medical therapy are key to preventing future heart failure readmissions. PMID:26413005

  9. Therapeutic Potential of Nitroxyl (HNO) Donors in the Management of Acute Decompensated Heart Failure.

    PubMed

    Kemp-Harper, Barbara K; Horowitz, John D; Ritchie, Rebecca H

    2016-09-01

    Heart failure (HF) is a major cause of hospital admission in the Western world, yet there remains a paucity of effective pharmacological management options. With the recent development of synthetic, next-generation nitroxyl (HNO) donors and their progress into clinical trials, it is timely to now provide an update on the therapeutic potential of HNO donors in the management of acute decompensated heart failure. In this article, we summarize current understanding of the pharmacology of HNO (in comparison with its redox sibling, nitric oxide), its spectrum of cardioprotective actions, and efforts to translate these into the clinic. Future research directions for this exciting new class of HF drugs are also considered. PMID:27566478

  10. Narrative review: the management of acute decompensated heart failure.

    PubMed

    Marik, Paul E; Flemmer, Mark

    2012-01-01

    Acute decompensated heart failure (ADHF) is the most common reason for hospitalization in Western nations. The prognosis of patients admitted to hospital with ADHF is poor, with up to 64% being readmitted within the first 90 days after discharge and with a 1-year mortality approximating 20%. Epidemiological studies suggest that the majority of patients hospitalized with ADHF receive treatment that is inadequate and which is not based on scientific evidence. Furthermore, emerging data suggest that the "conventional" therapeutic interventions for ADHF including morphine, high-dose diuretics, and inotropic agents may be harmful. The goal of this review is to provide evidence-based recommendations for the diagnosis and management of ADHF. PMID:21616957

  11. Extracorporeal ultrafiltration therapy for acute decompensated heart failure.

    PubMed

    Pourafshar, Negiin; Karimi, Ashkan; Kazory, Amir

    2016-01-01

    Congestion is the most common reason for hospitalization of patients with acute decompensated heart failure (ADHF) and adversely impacts their outcomes. Extracorporeal ultrafiltration (UF) therapy has re-emerged as an effective strategy for decongestion in this setting. This article is intended to discuss key concepts in UF and its technique, provide a brief historical view of UF application for decongestion in ADHF, review the hemodynamic and neurohormonal effects of UF and their positive effects on the pathophysiology of ADHF, discuss the findings of the landmark trials in this field, and explain key findings of these studies as well as the apparent discrepancies in their findings. In a separate section we discuss the intricacies of renal dysfunction in ADHF as it plays a very important role in understanding the current evidence and designing futures clinical trials of UF in ADHF. In the end, the authors provide their perspective on the future role of UF in management of patients with ADHF and congestion. PMID:26523337

  12. Venous Congestion, Endothelial and Neurohormonal Activation in Acute Decompensated Heart Failure: Cause or Effect?

    PubMed Central

    Colombo, Paolo C.; Doran, Amanda C.; Onat, Duygu; Wong, Ka Yuk; Ahmad, Myra; Sabbah, Hani N.; Demmer, Ryan T.

    2015-01-01

    Venous congestion and endothelial and neurohormonal activation are known to occur in acute decompensated heart failure (ADHF), yet the temporal role of these processes in the pathophysiology of decompensation is not fully understood. Conventional wisdom presumes congestion to be a consequence of worsening cardiovascular function; however, the biomechanically driven effects of venous congestion are biologically plausible contributors to ADHF that remain largely unexplored in vivo. Recent experimental evidence from human models suggests that fluid accumulation and venous congestion are not simply consequences of poor cardiovascular function, but rather are fundamental pro-oxidant, pro-inflammatory, and hemodynamic stimuli that contribute to acute decompensation. The latest advances in the monitoring of volume status using implantable devices allow for the detection of venous congestion before symptoms arise. This may ultimately lead to improved treatment strategies including not only diuretics, but also specific, adjuvant interventions to counteract endothelial and neurohormonal activation during early preclinical decompensation. PMID:25740404

  13. Cognitive Status in Patients Hospitalized with Acute Decompensated Heart Failure

    PubMed Central

    Levin, Seth N.; Hajduk, Alexandra M.; McManus, David D.; Darling, Chad E.; Gurwitz, Jerry H.; Spencer, Frederick A.; Goldberg, Robert J.; Saczynski, Jane S.

    2015-01-01

    Structured Abstract Background Cognitive impairment is highly prevalent in patients with heart failure and is associated with adverse outcomes. However, whether specific cognitive abilities (e.g., memory versus executive function) are impaired in heart failure has not been fully examined. We investigated the prevalence of impairment in three cognitive domains in patients hospitalized with acute decompensated heart failure (ADHF) and the associations of impairment with demographic and clinical characteristics. Methods The sample included 744 patients hospitalized with ADHF (mean age = 72 years, 46% female) at 5 medical centers. Impairment was assessed in three cognitive domains (memory, processing speed, executive function) using standardized measures. Demographic and clinical characteristics were obtained from a structured interview and medical record review. Results A total of 593 of 744 (80%) patients were impaired in at least one cognitive domain; 32%, 31%, and 17% of patients were impaired in one, two, or all three cognitive domains, respectively. Patients impaired in more than one cognitive domain were significantly older, had less formal education, and had more non-cardiac comorbidities (all p’s < 0.05). In multivariable adjusted analyses, patients with older age and lower education had higher odds of impairment in two or more cognitive domains. Depressed patients had twice the odds of being impaired in all three cognitive domains (OR = 1.98, 95% CI: 1.08, 3.64). Conclusion Impairments in executive function, processing speed and memory are common among patients hospitalized for ADHF. Recognition of these prevalent cognitive deficits is critical for the clinical management of these high risk patients. PMID:25458656

  14. Interaction between worsening renal function and persistent congestion in acute decompensated heart failure.

    PubMed

    Wattad, Malak; Darawsha, Wisam; Solomonica, Amir; Hijazi, Maher; Kaplan, Marielle; Makhoul, Badira F; Abassi, Zaid A; Azzam, Zaher S; Aronson, Doron

    2015-04-01

    Worsening renal function (WRF) and congestion are inextricably related pathophysiologically, suggesting that WRF occurring in conjunction with persistent congestion would be associated with worse clinical outcome. We studied the interdependence between WRF and persistent congestion in 762 patients with acute decompensated heart failure (HF). WRF was defined as ≥0.3 mg/dl increase in serum creatinine above baseline at any time during hospitalization and persistent congestion as ≥1 sign of congestion at discharge. The primary end point was all-cause mortality with mean follow-up of 15 ± 9 months. Readmission for HF was a secondary end point. Persistent congestion was more common in patients with WRF than in patients with stable renal function (51.0% vs 26.6%, p <0.0001). Both persistent congestion and persistent WRF were significantly associated with mortality (both p <0.0001). There was a strong interaction (p = 0.003) between persistent WRF and congestion, such that the increased risk for mortality occurred predominantly with both WRF and persistent congestion. The adjusted hazard ratio for mortality in patients with persistent congestion as compared with those without was 4.16 (95% confidence interval [CI] 2.20 to 7.86) in patients with WRF and 1.50 (95% CI 1.16 to 1.93) in patients without WRF. In conclusion, persisted congestion is frequently associated with WRF. We have identified a substantial interaction between persistent congestion and WRF such that congestion portends increased mortality particularly when associated with WRF. PMID:25700802

  15. Computational modeling to predict nitrogen balance during acute metabolic decompensation in patients with urea cycle disorders.

    PubMed

    MacLeod, Erin L; Hall, Kevin D; McGuire, Peter J

    2016-01-01

    Nutritional management of acute metabolic decompensation in amino acid inborn errors of metabolism (AA IEM) aims to restore nitrogen balance. While nutritional recommendations have been published, they have never been rigorously evaluated. Furthermore, despite these recommendations, there is a wide variation in the nutritional strategies employed amongst providers, particularly regarding the inclusion of parenteral lipids for protein-free caloric support. Since randomized clinical trials during acute metabolic decompensation are difficult and potentially dangerous, mathematical modeling of metabolism can serve as a surrogate for the preclinical evaluation of nutritional interventions aimed at restoring nitrogen balance during acute decompensation in AA IEM. A validated computational model of human macronutrient metabolism was adapted to predict nitrogen balance in response to various nutritional interventions in a simulated patient with a urea cycle disorder (UCD) during acute metabolic decompensation due to dietary non-adherence or infection. The nutritional interventions were constructed from published recommendations as well as clinical anecdotes. Overall, dextrose alone (DEX) was predicted to be better at restoring nitrogen balance and limiting nitrogen excretion during dietary non-adherence and infection scenarios, suggesting that the published recommended nutritional strategy involving dextrose and parenteral lipids (ISO) may be suboptimal. The implications for patients with AA IEM are that the medical course during acute metabolic decompensation may be influenced by the choice of protein-free caloric support. These results are also applicable to intensive care patients undergoing catabolism (postoperative phase or sepsis), where parenteral nutritional support aimed at restoring nitrogen balance may be more tailored regarding metabolic fuel selection. PMID:26260782

  16. Impact of intravenous nitroglycerin in the management of acute decompensated heart failure.

    PubMed

    den Uil, Corstiaan A; Brugts, Jasper J

    2015-02-01

    Intravenous nitroglycerin is a well-known, but underused, treatment for acute decompensated heart failure. Nitroglycerin has a rapid onset of action and short half-life and there is a clear dose-response curve on both global hemodynamics and peripheral circulation. IV nitroglycerin reduces LV and RV filling pressures and afterload. In the case of acute decompensated heart failure, there is a typical decreased bioavailability of nitric oxide (NO), which needs to be supplemented by exogenous nitrates. Additionally, there is benefit on clinical endpoints, such as fast optimization of arterial oxygenation, lower rates of mechanical ventilation, and improved survival. Drawbacks of therapy include not only side effects such as headache, resistance, and development of tolerability to nitrates but also free radical production. However, nitrates in combination with diuretics remain the cornerstone of acute decompensated heart failure treatment. We propose a more aggressive use of nitrates and a more limited use of inotropes (due to ischemic demand and pro-arrhythmogenic characteristics) in normo- or hypertensive patients with acute heart failure. PMID:25301529

  17. Haemodialysis is an effective treatment in acute metabolic decompensation of maple syrup urine disease

    PubMed Central

    Atwal, P.S.; Macmurdo, C.; Grimm, P.C.

    2015-01-01

    Acute metabolic decompensation in maple syrup urine disease can occur during intercurrent illness and is a medical emergency. A handful of reports in the medical literature describe the use of peritoneal dialysis and haemodialysis as therapeutic inventions. We report the only patient from our centre to have haemodialysis performed in this setting. Combined with dietary BCAA restriction and calorific support, haemodialysis allows rapid reduction in plasma leucine concentrations considerably faster than conservative methods. PMID:26937409

  18. Haemodialysis is an effective treatment in acute metabolic decompensation of maple syrup urine disease.

    PubMed

    Atwal, P S; Macmurdo, C; Grimm, P C

    2015-09-01

    Acute metabolic decompensation in maple syrup urine disease can occur during intercurrent illness and is a medical emergency. A handful of reports in the medical literature describe the use of peritoneal dialysis and haemodialysis as therapeutic inventions. We report the only patient from our centre to have haemodialysis performed in this setting. Combined with dietary BCAA restriction and calorific support, haemodialysis allows rapid reduction in plasma leucine concentrations considerably faster than conservative methods. PMID:26937409

  19. Outcomes associated with nesiritide administration for acute decompensated heart failure in the emergency department observation unit: a single center experience.

    PubMed

    Styron, Joseph F; Jois-Bilowich, Preeti; Tallman, Thomas; Emerman, Charles; Starling, Randall C; Frank Peacock, W

    2009-01-01

    The authors' purpose was to determine 30- and 180-day readmission and mortality rates for acutely decompensated heart failure patients receiving nesiritide in the emergency department observation unit. The authors conducted a retrospective evaluation of all patients admitted to the emergency department observation unit, stratified by nesiritide administration, from January 2002 to January 2004. Eligible patients had a primary diagnosis of acutely decompensated heart failure. Observation unit treatment was by previously published protocols, except for nesiritide administration, which was per attending physician choice. Of 595 patients, 196 (33%) received nesiritide. The crude and adjusted odds ratios comparing readmission rates and mortality rates of the nesiritide group with the control group failed to demonstrate significant differences at either the 30- or the 180-day endpoints. The use of nesiritide for acute decompensated heart failure in the emergency department observation unit is not associated with mortality or readmission differences compared with standard therapy alone. PMID:19522957

  20. Citric acid as the last therapeutic approach in an acute life-threatening metabolic decompensation of propionic acidaemia.

    PubMed

    Siekmeyer, Manuela; Petzold-Quinque, Stefanie; Terpe, Friederike; Beblo, Skadi; Gebhardt, Rolf; Schlensog-Schuster, Franziska; Kiess, Wieland; Siekmeyer, Werner

    2013-01-01

    The tricarboxylic acid (TCA) cycle represents the key enzymatic steps in cellular energy metabolism. Once the TCA cycle is impaired in case of inherited metabolic disorders, life-threatening episodes of metabolic decompensation and severe organ failure can arise. We present the case of a 6 ½-year-old girl with propionic acidaemia during an episode of acute life-threatening metabolic decompensation and severe lactic acidosis. Citric acid given as an oral formulation showed the potential to sustain the TCA cycle flux. This therapeutic approach may become a treatment option in a situation of acute metabolic crisis, possibly preventing severe disturbance of energy metabolism. PMID:23412866

  1. Cardiorenal Syndrome Type 1: Renal Dysfunction in Acute Decompensated Heart Failure

    PubMed Central

    Prins, Kurt W.; Thenappan, Thenappan; Markowitz, Jeremy S.; Pritzker, Marc R.

    2016-01-01

    Objective To present a review of cardiorenal syndrome type 1 (CRS1). Methods Review of the literature. Results Acute kidney injury occurs in approximately one-third of patients with acute decompensated heart failure (ADHF) and the resultant condition was named CRS1. A growing body of literature shows CRS1 patients are at high risk for poor outcomes, and thus there is an urgent need to understand the pathophysiology and subsequently develop effective treatments. In this review we discuss prevalence, proposed pathophysiology including hemodynamic and nonhemodynamic factors, prognosticating variables, data for different treatment strategies, and ongoing clinical trials and highlight questions and problems physicians will face moving forward with this common and challenging condition. Conclusion Further research is needed to understand the pathophysiology of this complex clinical entity and to develop effective treatments. PMID:27158218

  2. Geographic Differences in Patients in a Global Acute Heart Failure Clinical Trial (from the ASCEND-HF Trial).

    PubMed

    Metra, Marco; Mentz, Robert J; Hernandez, Adrian F; Heizer, Gretchen M; Armstrong, Paul W; Clausell, Nadine; Corbalan, Ramon; Costanzo, Maria Rosa; Dickstein, Kenneth; Dunlap, Mark E; Ezekowitz, Justin A; Howlett, Jonathan G; Komajda, Michel; Krum, Henry; Lombardi, Carlo; Fonarow, Gregg C; McMurray, John J V; Nieminen, Markku S; Swedberg, Karl; Voors, Adriaan A; Starling, Randall C; Teerlink, John R; O'Connor, Christopher M

    2016-06-01

    A growing number of countries and geographical regions are involved in major clinical trials. Acute Study of Clinical Effectiveness of Nesiritide in Decompensated Heart Failure is the largest trial in acutely decompensated heart failure (HF) with patients from 5 geographical regions: North America (NA), Latin America (LA), Western Europe (WE), Central Europe (CE), and Asia-Pacific (AP). Data from the 5 geographical areas were compared including baseline characteristics, medications, 30-day outcomes (mortality and mortality or HF hospitalization), and 180-day mortality. Of the 7,141 study patients, 3,243 (45.4%) were from NA (average of 15.2 patients/site), 1,762 (24.7%) from AP (28.4 patients/site), 967 (13.5%) from CE (20.2 patients/site), 665 (9.3%) from LA (17.1 patients/site), and 504 (7.1%) from WE (14.4 patients/site). There were marked differences in co-morbidities, clinical profile, medication use, length of stay, 30-day event rates, and 180-day mortality by region. Compared with NA, the adjusted risk for death or HF hospitalization at 30 days was significantly lower in CE (odds ratio [OR] 0.46, 95% CI 0.33 to 0.64), WE (OR 0.52 95% CI 0.35 to 0.75), and AP (OR 0.62 95% CI 0.48 to 0.79) and numerically lower in LA (OR 0.77, 95% CI 0.57 to 1.04) with similar results for 180-day mortality. In conclusion, in patients with acutely decompensated HF, major differences in baseline characteristics, treatments, length of the hospital stay, and 30-day HF rehospitalization rates, and 180-day mortality were found in patients enrolled from different geographical areas. PMID:27108685

  3. Pheochromocytoma presenting as acute decompensated heart failure reversed with medical therapy

    PubMed Central

    Mulla, Christopher M; Marik, Paul Ellis

    2012-01-01

    A 26-year-old woman presented to hospital with acute chest pain, hypertension, tachycardia and an elevated serum creatinine. She developed respiratory distress requiring endotracheal intubation and mechanical ventilation. She progressed to multiorgan failure due to decompensated congestive heart failure. Echocardiography demonstrated global hypokinesis and an ejection fraction of <10%. Her cardiac function improved with fluid resuscitation and β blockade, and she was eventually discharged home. She was readmitted a few days later with pancreatitis after presenting with nausea, abdominal pain and hypertension. During hospitalisation she had paroxysms of headache, nausea and diaphoresis associated with hypertension and tachycardia. A CT scan of her abdomen revealed an adrenal mass and serum metanephrine studies confirmed the diagnosis of pheochromocytoma. After fluid resuscitation and sympathetic blockade her ejection fraction improved to 55%. The patient underwent an uneventful adrenalectomy and made a complete recovery. PMID:22814979

  4. Acute decompensated heart failure: evolving literature and implications for future practice.

    PubMed

    Cicci, Jonathan D; Reed, Brent N; McNeely, Elizabeth B; Oni-Orisan, Akinyemi; Patterson, J Herbert; Rodgers, Jo E

    2014-01-01

    Acute decompensated heart failure (ADHF) is associated with substantial morbidity and mortality, and represents a considerable financial burden to society. Historically, few prospective, randomized, double-blinded trials have investigated the optimal management of ADHF, and most guideline recommendations are based primarily on expert opinion. However, in the last decade, a considerable amount of research has added to the understanding of the management of ADHF in both patients with fluid overload and low cardiac output. In addition, as mechanical circulatory support devices and heart transplantation continue to evolve, significant advances have also been made with regard to the proper selection of patients for advanced surgical options. Finally, several novel pharmacologic agents have shown promise in early trials and may represent the next steps in ADHF management. Although advances have been made over the past decade, many questions remain. PMID:24214219

  5. Continuous ultrafiltration in acute decompensated heart failure: current issues and future directions.

    PubMed

    Marenzi, Giancarlo; Morpurgo, Marco; Agostoni, Piergiuseppe

    2015-04-01

    Most patients hospitalized for acutely decompensated heart failure (ADHF) present with symptoms and signs of volume overload, which are also associated with high rates of death and re-hospitalization. Several studies have investigated the possible use of extracorporeal ultrafiltration in the management of ADHF, evaluating potential clinical benefits in terms of hospitalization and survival rates versus those of conventional diuretic therapy. Though ultrafiltration remains an extremely appealing therapeutic option for patients with AHDF, some of the most recent studies have reported conflicting results. Differences in the selection of study population, heterogeneity of the indications for the use of ultrafiltration, disparity in the ultrafiltration protocols, and high variability in the pharmacologic therapies used for the control group could explain some of these contradictory findings. The purpose of the present review is to provide an overview and an update on the mechanisms and clinical effects of ultrafiltration and on currently available evidence supporting its use in ADHF. PMID:25650293

  6. Clinical Implications of Cluster Analysis-Based Classification of Acute Decompensated Heart Failure and Correlation with Bedside Hemodynamic Profiles

    PubMed Central

    Ahmad, Tariq; Desai, Nihar; Wilson, Francis; Schulte, Phillip; Dunning, Allison; Jacoby, Daniel; Allen, Larry; Fiuzat, Mona; Rogers, Joseph; Felker, G. Michael; O’Connor, Christopher; Patel, Chetan B.

    2016-01-01

    Background Classification of acute decompensated heart failure (ADHF) is based on subjective criteria that crudely capture disease heterogeneity. Improved phenotyping of the syndrome may help improve therapeutic strategies. Objective To derive cluster analysis-based groupings for patients hospitalized with ADHF, and compare their prognostic performance to hemodynamic classifications derived at the bedside. Methods We performed a cluster analysis on baseline clinical variables and PAC measurements of 172 ADHF patients from the ESCAPE trial. Employing regression techniques, we examined associations between clusters and clinically determined hemodynamic profiles (warm/cold/wet/dry). We assessed association with clinical outcomes using Cox proportional hazards models. Likelihood ratio tests were used to compare the prognostic value of cluster data to that of hemodynamic data. Results We identified four advanced HF clusters: 1) male Caucasians with ischemic cardiomyopathy, multiple comorbidities, lowest B-type natriuretic peptide (BNP) levels; 2) females with non-ischemic cardiomyopathy, few comorbidities, most favorable hemodynamics; 3) young African American males with non-ischemic cardiomyopathy, most adverse hemodynamics, advanced disease; and 4) older Caucasians with ischemic cardiomyopathy, concomitant renal insufficiency, highest BNP levels. There was no association between clusters and bedside-derived hemodynamic profiles (p = 0.70). For all adverse clinical outcomes, Cluster 4 had the highest risk, and Cluster 2, the lowest. Compared to Cluster 4, Clusters 1–3 had 45–70% lower risk of all-cause mortality. Clusters were significantly associated with clinical outcomes, whereas hemodynamic profiles were not. Conclusions By clustering patients with similar objective variables, we identified four clinically relevant phenotypes of ADHF patients, with no discernable relationship to hemodynamic profiles, but distinct associations with adverse outcomes. Our analysis

  7. Post-Exercise Heart Rate Recovery Independently Predicts Clinical Outcome in Patients with Acute Decompensated Heart Failure

    PubMed Central

    Youn, Jong-Chan; Lee, Hye Sun; Choi, Suk-Won; Han, Seong-Woo; Ryu, Kyu-Hyung; Shin, Eui-Cheol; Kang, Seok-Min

    2016-01-01

    Background Post-exercise heart rate recovery (HRR) is an index of parasympathetic function associated with clinical outcome in patients with chronic heart failure. However, its relationship with the pro-inflammatory response and prognostic value in consecutive patients with acute decompensated heart failure (ADHF) has not been investigated. Methods We measured HRR and pro-inflammatory markers in 107 prospectively and consecutively enrolled, recovered ADHF patients (71 male, 59 ± 15 years, mean ejection fraction 28.9 ± 14.2%) during the pre-discharge period. The primary endpoint included cardiovascular (CV) events defined as CV mortality, cardiac transplantation, or rehospitalization due to HF aggravation. Results The CV events occurred in 30 (28.0%) patients (5 cardiovascular deaths and 7 cardiac transplantations) during the follow-up period (median 214 days, 11–812 days). When the patients with ADHF were grouped by HRR according to the Contal and O’Quigley’s method, low HRR was shown to be associated with significantly higher levels of serum monokine-induced by gamma interferon (MIG) and poor clinical outcome. Multivariate Cox regression analysis revealed that low HRR was an independent predictor of CV events in both enter method and stepwise method. The addition of HRR to a model significantly increased predictability for CV events across the entire follow-up period. Conclusion Impaired post-exercise HRR is associated with a pro-inflammatory response and independently predicts clinical outcome in patients with ADHF. These findings may explain the relationship between autonomic dysfunction and clinical outcome in terms of the inflammatory response in these patients. PMID:27135610

  8. The predictability of renin-angiotensin-aldosterone system factors for clinical outcome in patients with acute decompensated heart failure.

    PubMed

    Nakada, Yasuki; Takahama, Hiroyuki; Kanzaki, Hideaki; Sugano, Yasuo; Hasegawa, Takuya; Ohara, Takahiro; Amaki, Makoto; Funada, Akira; Yoshida, Akemi; Yasuda, Satoshi; Ogawa, Hisao; Anzai, Toshihisa

    2016-06-01

    Although counter-regulation between B-type natriuretic peptide (BNP) levels and renin-angiotensin-aldosterone system (RAAS) activation in heart failure (HF) has been suggested, whether the regulation is preserved in acute decompensated heart failure (ADHF) patients remains unclear. This study aimed to determine: (1) the relationship between RAAS activation and clinical outcomes in ADHF patients, and (2) the relationships between plasma BNP levels and degrees of activation in RAAS factors. This study included ADHF patients (n = 103, NYHA3-4, plasma BNP > 200 pg/ml). We studied the predictability of RAAS factors for cardiovascular events and the relationships between plasma BNP levels and the degrees of activation in RAAS factors, which were evaluated by plasma renin activity (PRA) and aldosterone concentration (PAC). PRA was a strong predictor of cardiovascular (CV) events over 1 year, even after accounting for plasma BNP levels (hazard ratio (HR): 1.04, CI [1.02-1.06], p < 0.01) and medication such as RAAS blockers (HR: 1.03, CI [1.01-1.05], p < 0.01), whereas PAC was borderline-significant (univariate analysis, p = 0.06). Cut-off value of PRA (5.3 ng/ml/h) was determined by AUC curve. Of the enrolled patients, higher PRA was found in 40 % of them. Although no correlation between the plasma BNP levels and PRA was found (p = 0.36), after adjusting for hemodynamic parameters, eGFR and medication, a correlation was found between them (p = 0.01). Elevated RAAS factors were found in a substantial number of ADHF patients with high plasma BNP levels in the association with hemodynamic state, which predicts poor clinical outcomes. The measurements of RAAS factors help to stratify ADHF patients at risk for further CV events. PMID:25964073

  9. Galectin-3: A Link between Myocardial and Arterial Stiffening in Patients with Acute Decompensated Heart Failure?

    PubMed Central

    Lala, Radu Ioan; Darabantiu, Dan; Pilat, Luminita; Puschita, Maria

    2016-01-01

    Background Heart failure is accompanied by abnormalities in ventricular-vascular interaction due to increased myocardial and arterial stiffness. Galectin-3 is a recently discovered biomarker that plays an important role in myocardial and vascular fibrosis and heart failure progression. Objectives The aim of this study was to determine whether galectin-3 is correlated with arterial stiffening markers and impaired ventricular-arterial coupling in decompensated heart failure patients. Methods A total of 79 inpatients with acute decompensated heart failure were evaluated. Serum galectin-3 was determined at baseline, and during admission, transthoracic echocardiography and measurements of vascular indices by Doppler ultrasonography were performed. Results Elevated pulse wave velocity and low arterial carotid distensibility are associated with heart failure in patients with preserved ejection fraction (p = 0.04, p = 0.009). Pulse wave velocity, carotid distensibility and Young’s modulus did not correlate with serum galectin-3 levels. Conversely, raised galectin-3 levels correlated with an increased ventricular-arterial coupling ratio (Ea/Elv) p = 0.047, OR = 1.9, 95% CI (1.0‑3.6). Increased galectin-3 levels were associated with lower rates of left ventricular pressure rise in early systole (dp/dt) (p=0.018) and raised pulmonary artery pressure (p = 0.046). High galectin-3 levels (p = 0.038, HR = 3.07) and arterial pulmonary pressure (p = 0.007, HR = 1.06) were found to be independent risk factors for all-cause mortality and readmissions. Conclusions This study showed no significant correlation between serum galectin-3 levels and arterial stiffening markers. Instead, high galectin-3 levels predicted impaired ventricular-arterial coupling. Galectin-3 may be predictive of raised pulmonary artery pressures. Elevated galectin-3 levels correlate with severe systolic dysfunction and together with pulmonary hypertension are independent markers of outcome. PMID:26760784

  10. Comparison of Baseline versus Posttreatment Left Ventricular Ejection Fraction in Patients with Acute Decompensated Heart Failure for Predicting Cardiovascular Outcome: Implications from Single-Center Systolic Heart Failure Cohort

    PubMed Central

    Wang, Chao-Hung; Wen, Ming-Shien; Kuo, Chi-Tai; Tsai, Feng-Chun; Wu, Victor Chien-Chia; Chen, Tien-Hsing

    2016-01-01

    Aims The prognostic values of left ventricular ejection fraction (LVEF) during heart failure (HF) with acute decompensation or after optimal treatment have not been extensively studied. We hypothesized that posttreatment LVEF has superior predictive value for long-term prognosis than LVEF at admission does. Methods and Results In Protocol 1, 428 acute decompensated HF (ADHF) patients with LVEF ≤35% in a tertiary medical center were enrolled and followed for a mean period of 34.7 ± 10.8 months. The primary and secondary end points were all-cause mortality and HF readmission, respectively. In total, 86 deaths and 240 HF readmissions were recorded. The predictive values of baseline LVEF at admission and LVEF 6 months posttreatment were analyzed and compared. The posttreatment LVEFs were predictive for future events (P = 0.01 for all-cause mortality, P < 0.001 for HF readmission), but the baseline LVEFs were not. In Protocol 2, the outcomes of patients with improved LVEF (change of LVEF: ≥+10%), unchanged LVEF (change of LVEF: –10% to +10%), and reduced LVEF (change of LVEF: ≤–10%) were analyzed and compared. Improved LVEF occurred in 171 patients and was associated with a superior long-term prognosis among all groups (P = 0.02 for all-cause mortality, P < 0.001 for HF readmission). In Protocol 3, independent predictors of improved LVEF were analyzed, and baseline LV end-diastolic dimension (LVEDD) was identified as a powerful predictor in ADHF patients (P < 0.001). Conclusions In patients with ADHF, posttreatment LVEF but not baseline LVEF had prognostic power. Improved LVEF was associated with superior long-term prognosis, and baseline LVEDD identified patients who were more likely to have improved LVEF. Therefore, baseline LVEF should not be considered a relevant prognosis factor in clinical practice for patients with ADHF. PMID:26752417

  11. Ularitide for the treatment of acute decompensated heart failure: from preclinical to clinical studies.

    PubMed

    Anker, Stefan D; Ponikowski, Piotr; Mitrovic, Veselin; Peacock, W Frank; Filippatos, Gerasimos

    2015-03-21

    The short- and long-term morbidity and mortality in acute heart failure is still unacceptably high. There is an unmet need for new therapy options with new drugs with a new mode of action. One of the drugs currently in clinical testing in Phase III is ularitide, which is the chemically synthesized form of the human natriuretic peptide urodilatin. Urodilatin is produced in humans by differential processing of pro-atrial natriuretic peptide in distal renal tubule cells. Physiologically, urodilatin appears to be the natriuretic peptide involved in sodium homeostasis. Ularitide exerts its pharmacological actions such as vasodilation, diuresis, and natriuresis through the natriuretic peptide receptor/particulate guanylate cyclase/cyclic guanosine monophosphate pathway. In animal models of heart failure as well as Phase I and II clinical studies in heart failure patients, ularitide demonstrated beneficial effects such as symptom relief and vasodilation, while still preserving renal function. Subsequently, the pivotal acute decompensated heart failure (ADHF) Phase III study, called TRUE-AHF, was started with the objectives to evaluate the effects of ularitide infusion on the clinical status and cardiovascular mortality of patients with ADHF compared with placebo. This review summarizes preclinical and clinical data supporting the potential use of ularitide in the treatment of ADHF. PMID:25670819

  12. Torsemide Versus Furosemide in Patients With Acute Heart Failure (from the ASCEND-HF Trial).

    PubMed

    Mentz, Robert J; Hasselblad, Vic; DeVore, Adam D; Metra, Marco; Voors, Adriaan A; Armstrong, Paul W; Ezekowitz, Justin A; Tang, W H Wilson; Schulte, Phillip J; Anstrom, Kevin J; Hernandez, Adrian F; Velazquez, Eric J; O'Connor, Christopher M

    2016-02-01

    Furosemide is the most commonly used loop diuretic in patients with heart failure (HF) despite data suggesting potential pharmacologic and antifibrotic benefits with torsemide. We investigated patients with HF in Acute Study of Clinical Effectiveness of Nesiritide in Decompensated Heart Failure who were discharged on either torsemide or furosemide. Using inverse probability weighting to account for the nonrandom selection of diuretic, we assessed the relation between choice of diuretic at discharge with 30-day mortality or HF hospitalization and 180-day mortality. Of 7,141 patients in the trial, 4,177 patients were included in this analysis, of which 87% (n = 3,620) received furosemide and 13% (n = 557) received torsemide. Torsemide-treated patients had lower ejection fraction and blood pressure and higher creatinine and natriuretic peptide level compared with furosemide. Torsemide was associated with similar outcomes on unadjusted analysis and nominally lower events on adjusted analysis (30-day mortality/HF hospitalization odds ratio 0.89, 95% CI 0.62 to 1.29, p = 0.55 and 180-day mortality hazard ratio 0.86, 95% CI 0.63 to 1.19, p = 0.37). In conclusion, these data are hypothesis-generating and randomized comparative effectiveness trials are needed to investigate the optimal diuretic choice. PMID:26704029

  13. Initial emergency department systolic blood pressure predicts left ventricular systolic function in acute decompensated heart failure.

    PubMed

    Styron, Joseph F; Jois-Bilowich, Preeti; Starling, Randall; Hobbs, Robert E; Kontos, Michael C; Pang, Peter S; Peacock, W Frank

    2009-01-01

    Ejection fraction (EF) is often unknown in patients who present with acute decompensated heart failure (ADHF). The objective of this study was to determine whether a patient's systolic blood pressure is associated with their left ventricular EF. This study was a retrospective chart review of all patients admitted to an emergency department (ED) observation unit from January 2002 to December 2004. A low EF was defined as <40%. Among 475 patients, the median age was 72 years, 53% were men, 40% were white, 59% were black, and 59% had a low EF. Patients with low EFs were more likely male ( P<.0001), with prior congestive heart disease ( P<.0001), longer QRS duration ( P<.0001), left bundle branch block ( P<.0001), and higher B-type natriuretic peptide ( P<.0001). The low EF group was less likely to have diabetes ( P<.0001). Adjusted odds ratios for an EF >or=40% were significant at all systolic blood pressure readings >120 mm Hg. Having an ED systolic BP >120 mm Hg is associated with significantly higher rates of preserved left ventricular systolic function in patients with ADHF. PMID:19187401

  14. Loop Diuretics in Acute Decompensated Heart Failure: Necessary? Evil? A Necessary Evil?

    PubMed Central

    Felker, G. Michael; O’Connor, Christopher M.; Braunwald, Eugene

    2009-01-01

    Acute decompensated heart failure (ADHF) is a common and highly morbid cardiovascular disorder. Most hospitalizations for ADHF are related to symptoms of congestion, and the vast majority of ADHF patients are treated with intravenous loop diuretics. Despite this nearly ubiquitous use, data supporting the safety and efficacy of loop diuretics in ADHF are limited, and controversy exists about the best way to use loop diuretics with regard to both dosing and means of administration (continuous infusion vs. intermittent boluses). We reviewed the data supporting the safety and efficacy of loop diuretics in patients with ADHF. A large body of observational literature suggests that loop diuretics, especially at higher doses, may be associated with increased mortality in patients with heart failure even after detailed adjustment for other measures of disease severity. Additionally, multiple small underpowered trials suggest that continuous infusion may be equivalent or superior to intermittent bolus dosing. In summary, there is a critical need to develop more robust data on the use of loop diuretics in ADHF. In that context, the NIH Heart Failure Clinical Research Network has begun the Diuretics Optimization Strategies Evaluation (DOSE) study, a multi-center, double-blind, randomized controlled trial that will enroll 300 patients with ADHF. The DOSE study will randomize patients using a 2 × 2 factorial design to low dose vs. high dose furosemide, and intermittent bolus vs. continuous infusion. Successful completion of the DOSE study will provide important data on the optimal clinical use of loop diuretics in ADHF. PMID:19750134

  15. Cardiorenal interactions in acute decompensated heart failure: contemporary concepts facing emerging controversies.

    PubMed

    Kazory, Amir; Elkayam, Uri

    2014-12-01

    Simultaneous dysfunction of the heart and the kidney represents a distinct spectrum of disease states composed of complex clinical scenarios with adverse outcomes. Worsening renal function (WRF) in the setting of acute decompensated heart failure (ADHF) is one such clinical setup for which the underlying mechanisms are poorly understood. Apparent discrepancies exist between the emerging data on the cardiorenal interactions of patients with ADHF and contemporary concepts such as the low forward flow or the high backward pressure hypotheses. The findings of recent retrospective studies also suggest that apparent "improvement in renal function" might be yet another risk factor for untoward outcomes in this patient population, further challenging our current understanding of the cardiorenal interactions. Besides, these data do not seem to fully support our conventional thinking about other aspects of these interactions such as the independent adverse impact of WRF on the outcomes of patients with ADHF, pointing to congestion as a possibly overlooked factor. In this article, we provide an overview of these emerging controversial issues with the goal of identifying the areas where clinical research could be most helpful, because it is of paramount importance to characterize the pathways leading to WRF in ADHF to develop a mechanistically relevant management strategy. Although the paucity of data coupled with the complexity of this field precludes any firm conclusion, these discussions are meant to prompt clinicians and researchers to revisit a number of long-believed concepts surrounding the cardiorenal interactions in ADHF. PMID:25230240

  16. Incremental value of natriuretic peptide measurement in acute decompensated heart failure (ADHF): a systematic review.

    PubMed

    Santaguida, Pasqualina L; Don-Wauchope, Andrew C; Ali, Usman; Oremus, Mark; Brown, Judy A; Bustamam, Amy; Hill, Stephen A; Booth, Ronald A; Sohel, Nazmul; McKelvie, Robert; Balion, Cynthia; Raina, Parminder

    2014-08-01

    The aim of this systematic review was to determine whether B-type natriuretic peptide (BNP) and N-terminal proBNP (NT-proBNP) independently add incremental value for predicting mortality and morbidity in patients with acute decompensated heart failure (ADHF). Medline(®), Embase™, AMED, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, and CINAHL were searched from 1989 to June 2012. We also searched reference lists of included articles, systematic reviews, and the gray literature. Studies were screened for eligibility criteria and assessed for risk of bias. Data were extracted on study design, population demographics, assay cutpoints, prognostic risk prediction model covariates, statistical methods, outcomes, and results. From 183 citations, only seven studies (5 BNP and 2 NT-proBNP) considered incremental value in ADHF subjects admitted to acute care centers. Admission assay levels and length of follow-up varied for BNP studies (31 days to 12 months) and for NT-proBNP studies (25-82 months). All studies presented at least one estimate of incremental value of BNP/NT-proBNP relative to the base prognostic model. Using discrimination or likelihood statistics, these studies consistently showed that BNP or NT-proBNP increased model performance. Three studies used reclassification and model validation computations to establish incremental value; these studies showed less consistency with respect to added value. In conclusion, the literature assessing incremental value of BNP/NT-proBNP in ADHF populations is limited to seven studies evaluating only mortality outcomes and at moderate risk of bias. Although there were differences in the base risk prediction models, assay cutpoints, and lengths of follow-up, there was consistency in BNP/NT-proBNP adding incremental value in prediction models in ADHF patients. PMID:25052418

  17. Temporal Trends in Hospitalization for Acute Decompensated Heart Failure in the United States, 1998-2011.

    PubMed

    Agarwal, Sunil K; Wruck, Lisa; Quibrera, Miguel; Matsushita, Kunihiro; Loehr, Laura R; Chang, Patricia P; Rosamond, Wayne D; Wright, Jacqueline; Heiss, Gerardo; Coresh, Josef

    2016-03-01

    Estimates of the numbers and rates of acute decompensated heart failure (ADHF) hospitalization are central to understanding health-care utilization and efforts to improve patient care. We comprehensively estimated the frequency, rate, and trends of ADHF hospitalization in the United States. Based on Atherosclerosis Risk in Communities (ARIC) Study surveillance adjudicating 12,450 eligible hospitalizations during 2005-2010, we developed prediction models for ADHF separately for 3 International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) code 428 discharge diagnosis groups: 428 primary, 428 nonprimary, or 428 absent. We applied the models to data from the National Inpatient Sample (11.5 million hospitalizations of persons aged ≥55 years with eligible ICD-9-CM codes), an all-payer, 20% probability sample of US community hospitals. The average estimated number of ADHF hospitalizations per year was 1.76 million (428 primary, 0.80 million; 428 nonprimary, 0.83 million; 428 absent, 0.13 million). During 1998-2004, the rate of ADHF hospitalization increased by 2.0%/year (95% confidence interval (CI): 1.8, 2.5) versus a 1.4%/year (95% CI: 0.8, 2.1) increase in code 428 primary hospitalizations (P < 0.001). In contrast, during 2005-2011, numbers of ADHF hospitalizations were stable (-0.5%/year; 95% CI: -1.4, 0.3), while the numbers of 428-primary hospitalizations decreased by -1.5%/year (95% CI: -2.2, -0.8) (P for contrast = 0.03). In conclusion, the estimated number of hospitalizations with ADHF is approximately 2 times higher than the number of hospitalizations with ICD-9-CM code 428 in the primary position. The trend increased more steeply prior to 2005 and was relatively flat after 2005. PMID:26895710

  18. Effects of Beta-Blocker Withdrawal in Acute Decompensated Heart Failure

    PubMed Central

    Prins, Kurt W.; Neill, John M.; Tyler, John O.; Eckman, Peter M.; Duval, Sue

    2015-01-01

    OBJECTIVES This study sought to evaluate the effects of beta-blocker withdrawal in acute decompensated heart failure (ADHF). BACKGROUND Published reports showed trends for either no harm or increased risk of in-hospital mortality, short-term mortality, and rehospitalization rates in patients admitted for ADHF that discontinued beta-blockers; however, a comprehensive analysis has not been conducted. METHODS Relevant studies from January 2000 through January 2015 were identified in the PubMed, EMBASE, and COCHRANE electronic databases. Where appropriate data were available, weighted relative risks were estimated using random-effects meta-analysis techniques. RESULTS Five observational studies and 1 randomized clinical trial (n = 2,704 patients who continued beta-blocker therapy and n = 439 patients who discontinued beta-blocker therapy) that reported the short-term effects of beta-blocker withdrawal in ADHF were included in the analyses. In 2 studies, beta-blocker withdrawal significantly increased risk of in-hospital mortality (risk ratio: 3.72; 95% confidence interval [CI]: 1.51 to 9.14). Short-term mortality (relative risk: 1.61; 95% CI: 1.04 to 2.49; 4 studies) and combined short-term rehospitalization or death (relative risk: 1.59; 95% CI: 1.03 to 2.45; 4 studies) were also significantly increased. CONCLUSIONS Discontinuation of beta-blockers in patients admitted with ADHF was associated with significantly increased in-hospital mortality, short-term mortality, and the combined endpoint of short-term rehospitalization or mortality. These data suggest beta-blockers should be continued in ADHF patients if their clinical picture allows. PMID:26251094

  19. Bedside lung ultrasound in the evaluation of acute decompensated heart failure.

    PubMed

    Leidi, Federica; Casella, Francesco; Cogliati, Chiara

    2016-06-01

    Dyspnea is a common presenting complaint in the emergency department (ED) and a leading cause of hospitalization in intensive care unit (ICU) and medical wards. Ultrasound (US) has traditionally been considered inadequate to explore the aerated lung. However, in the past 15 years LUS gained broader application, at least in part thanks to the interpretation of the artefacts generated by the interaction of US and lung structures/content. The total reflection of US beam occurring at the pleural level determines the artefactual image of the aerated lung: an homogenous 'foggy-like' picture under the pleural line. As the air content of the lungs decreases due to interstitial imbibition, deposition of collagen or presence of blood, vertical artefacts -arising from the pleural line and moving synchronously with the respiration- called B-lines appear. Multiple and bilateral B-lines identify the alveolar-interstitial syndrome (AIS). The most common cause of AIS is the wet lung: the more the congestion burden, the more the extent of the B-lines, which become confluent until the so-called white lung in case of pulmonary edema. Many studies showed a higher accuracy of LUS in diagnosing acute decompensated heart failure (ADHF) as compared to chest X-ray As recently shown, the integration of LUS to clinical assessment allow to differentiate cardiogenic dyspnea with sensitivity and specificity greater than 95 %. Moreover, LUS can easily detect pleural effusion -frequently present in ADHF-appearing as an anechoic area in the recumbent area of the thorax, delimited inferiorly by the diaphragmatic dome and superiorly by the aerated lung. PMID:26885846

  20. Comparison of Frequency of Frailty and Severely Impaired Physical Function in Patients ≥60 Years Hospitalized With Acute Decompensated Heart Failure Versus Chronic Stable Heart Failure With Reduced and Preserved Left Ventricular Ejection Fraction.

    PubMed

    Reeves, Gordon R; Whellan, David J; Patel, Mahesh J; O'Connor, Christopher M; Duncan, Pamela; Eggebeen, Joel D; Morgan, Timothy M; Hewston, Leigh A; Pastva, Amy M; Kitzman, Dalane W

    2016-06-15

    Older patients with acute decompensated heart failure (ADHF) have persistently poor outcomes including frequent rehospitalization despite guidelines-based therapy. We hypothesized that such patients have multiple, severe impairments in physical function, cognition, and mood that are not addressed by current care pathways. We prospectively examined frailty, physical function, cognition, mood, and quality of life in 27 consecutive older patients with ADHF at 3 medical centers and compared these with 197 participants in 3 age-matched cohorts: stable heart failure (HF) with preserved ejection fraction (n = 80), stable HF with reduced ejection fraction (n = 56), and healthy older adults (n = 61). Based on Fried criteria, frailty was present in 56% of patients with ADHF versus 0 for the age-matched chronic HF and health cohorts. Patients with ADHF had markedly reduced Short Physical Performance Battery score (5.3 ± 2.8) and 6-minute walk distance (178 ± 102 m) (p <0.001 vs other cohorts), with severe deficits in all domains of physical function: balance, mobility, strength, and endurance. In the patients with ADHF, cognitive impairment (78%) and depression (30%) were common, and quality of life was poor. In conclusion, older patients with ADHF are frequently frail with severe and widespread impairments in physical function, cognition, mood, and quality of life that may contribute to their persistently poor outcomes, are frequently unrecognized, are not addressed in current ADHF care paradigms, and are potentially modifiable with targeted interventions. PMID:27156830

  1. Clinical factors associated with early readmission among acutely decompensated heart failure patients

    PubMed Central

    Pierre-Louis, Bredy; Rodriques, Shareen; Gorospe, Vanessa; Guddati, Achuta K.; Ahn, Chul; Wright, Maurice

    2016-01-01

    Introduction Congestive heart failure (CHF) is a common cause of hospital readmission. Material and methods A retrospective study was conducted at Harlem Hospital in New York City. Data were collected for 685 consecutive adult patients admitted for decompensated CHF from March, 2009 to December, 2012. Variables including patient demographics, comorbidities, laboratory studies, and medical therapy were compared between CHF patient admissions resulting in early CHF readmission and not resulting in early CHF readmission. Results Clinical factors found to be independently significant for early CHF readmission included chronic obstructive pulmonary disease (odds ratio (OR) = 6.4), HIV infection (OR = 3.4), African-American ethnicity (OR = 2.2), systolic heart failure (OR = 1.9), atrial fibrillation (OR = 2.3), renal disease with glomerular filtration rate < 30 ml/min (OR = 2.7), evidence of substance abuse (OR = 1.7), and absence of angiotensin-converting enzyme inhibitors or angiotensin receptor blocker therapy after discharge (OR = 1.8). The ORs were used to develop a scoring system regarding the risk for early readmission. Conclusions Identifying patients with clinical factors associated with early CHF readmission after an index hospitalization for CHF using the proposed scoring system would allow for an early CHF readmission risk stratification protocol to target particularly high-risk patients. PMID:27279845

  2. TSOC-HFrEF Registry: A Registry of Hospitalized Patients with Decompensated Systolic Heart Failure: Description of Population and Management

    PubMed Central

    Wang, Chun-Chieh; Chang, Hung-Yu; Yin, Wei-Hsian; Wu, Yen-Wen; Chu, Pao-Hsien; Wu, Chih-Cheng; Hsu, Chih-Hsin; Wen, Ming-Shien; Voon, Wen-Chol; Lin, Wei-Shiang; Huang, Jin-Long; Chen, Shyh-Ming; Yang, Ning-I; Chang, Heng-Chia; Chang, Kuan-Cheng; Sung, Shih-Hsien; Shyu, Kou-Gi; Lin, Jiunn-Lee; Mar, Guang-Yuan; Chan, Kuei-Chuan; Kuo, Jen-Yuan; Wang, Ji-Hung; Chen, Zhih-Cherng; Tseng, Wei-Kung; Cherng, Wen-Jin

    2016-01-01

    Introduction Heart failure (HF) is a medical condition with a rapidly increasing incidence both in Taiwan and worldwide. The objective of the TSOC-HFrEF registry was to assess epidemiology, etiology, clinical management, and outcomes in a large sample of hospitalized patients presenting with acute decompensated systolic HF. Methods The TSOC-HFrEF registry was a prospective, multicenter, observational survey of patients presenting to 21 medical centers or teaching hospitals in Taiwan. Hospitalized patients with either acute new-onset HF or acute decompensation of chronic HFrEF were enrolled. Data including demographic characteristics, medical history, primary etiology of HF, precipitating factors for HF hospitalization, presenting symptoms and signs, diagnostic and treatment procedures, in-hospital mortality, length of stay, and discharge medications, were collected and analyzed. Results A total of 1509 patients were enrolled into the registry by the end of October 2014, with a mean age of 64 years (72% were male). Ischemic cardiomyopathy and dilated cardiomyopathy were diagnosed in 44% and 33% of patients, respectively. Coronary artery disease, hypertension, diabetes, and chronic renal insufficiency were the common comorbid conditions. Acute coronary syndrome, non-compliant to treatment, and concurrent infection were the major precipitating factors for acute decompensation. The median length of hospital stay was 8 days, and the in-hospital mortality rate was 2.4%. At discharge, 62% of patients were prescribed either angiotensin-converting enzyme-inhibitors or angiotensin receptor blockers, 60% were prescribed beta-blockers, and 49% were prescribed mineralocorticoid receptor antagonists. Conclusions The TSOC-HFrEF registry provided important insights into the current clinical characteristics and management of hospitalized decompensated systolic HF patients in Taiwan. One important observation was that adherence to guideline-directed medical therapy was suboptimal

  3. Recurrent Acute Decompensated Heart Failure Owing to Severe Iron Deficiency Anemia Caused by Inappropriate Habitual Bloodletting

    PubMed Central

    Lim, Woo-Hyun; Kim, Hack-Lyoung; Kim, Ki-Hwan; Na, Sang Hoon; Lee, Hyun-Jung; Kang, Eun Gyu; Seo, Jae-Bin; Chung, Woo-Young; Zo, Joo-Hee; Hong, Jung Ae; Kim, Kwangyoun; Kim, Myung-A

    2015-01-01

    A 68-year-old woman visited the emergency department twice with symptoms of acute heart failure including shortness of breath, general weakness, and abdominal distension. Laboratory findings showed extremely low level of serum hemoglobin at 1.4 g/dL. Echocardiographic examination demonstrated dilated left ventricular cavity with systolic dysfunction and moderate amount of pericardial effusion. In this patient, acute heart failure due to severe iron deficiency anemia was caused by inappropriate habitual bloodletting. PMID:26755934

  4. The Dose-Dependent Effect of Nesiritide on Renal Function in Patients with Acute Decompensated Heart Failure: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

    PubMed Central

    Xiong, Bo; Wang, Chunbin; Yao, Yuanqing; Huang, Yuwen; Tan, Jie; Cao, Yin; Zou, Yanke; Huang, Jing

    2015-01-01

    Background Conflicting renal effects of nesiritide have been reported in patients with acute decompensated heart failure. To answer this controversy, we performed a meta-analysis of randomized controlled trials to evaluate the influence of nesiritide on renal function in patients with acute decompensated heart failure. Methods Articles were obtained from PubMed, Medline, Cochrane Library and reference review. Randomized controlled studies that investigated the effects of continuous infusion of nesiritide on renal function in adult patients with acute decompensated heart failure were included and analyzed. Fixed-effect model was used to estimate relative risk (RR) and weight mean difference (WMD). The quality assessment of each study, subgroup, sensitivity, and publication bias analyses were performed. Results Fifteen randomized controlled trials were eligible for inclusion. Most of included studies had relatively high quality and no publication bias was found. Overall, compared to control therapies, nesiritide might increase the risk of worsening renal function in patients with acute decompensated heart failure (RR 1.08, 95% CI 1.01–1.15, P = 0.023). In subgroup analysis, high-dose nesiritide strongly associated with renal dysfunction (RR 1.54, 95% CI 1.19-2.00, P = 0.001), but no statistical differences were observed in standard-dose (RR 1.04, 95% CI 0.98-1.12, P = 0.213), low-dose groups (RR 1.01, 95% CI 0.74-1.37, P = 0.968) and same results were identified in the subgroup analysis of placebo controlled trials. Peak mean change of serum creatinine from baseline was no significant difference (WMD -2.54, 95% CI -5.76-0.67, P = 0.121). Conclusions In our meta-analysis, nesiritide may have a dose-dependent effect on renal function in patients with acute decompensated heart failure. High-dose nesiritide is likely to increase the risk of worsening renal function, but standard-dose and low-dose nesiritide probably have no impact on renal function. These findings

  5. Acute-on-chronic and Decompensated Chronic Liver Failure: Definitions, Epidemiology, and Prognostication.

    PubMed

    Olson, Jody C

    2016-07-01

    Chronic liver disease is the fifth leading cause of death worldwide and represents a major burden for the health care community. Cirrhosis is a progressive disease resulting in end-stage liver failure, which in the absence of liver transplantation is fatal. Acute-on-chronic liver failure carries high short-term mortality but is potentially reversible. Viral hepatitis, alcohol, and nonalcoholic fatty liver disease remain the principal causes of liver disease. Though treatments exist for hepatitis B and C, they remain unavailable to many with these diseases. This article reviews the epidemiology of advanced liver disease and the concept of acute-on-chronic liver failure. PMID:27339672

  6. Relaxin for the Treatment of Acute Decompensated Heart Failure: Pharmacology, Mechanisms of Action, and Clinical Evidence.

    PubMed

    Ng, Tien M H; Goland, Sorel; Elkayam, Uri

    2016-01-01

    Acute heart failure remains a major cause of morbidity, and its treatment requires an increasing investment of the health care system. Whereas success in treating chronic heart failure has been achieved over the last decades, several pharmacological approaches for acute heart failure have been introduced but have failed to demonstrate any clinical benefit. Serelaxin is a recombinant human relaxin-2 vasoactive peptide that causes systemic and renal vasodilation. Data suggest that the clinical benefits may be attributable to a potential combination of multiple actions of serelaxin, including improving systemic, cardiac, and renal hemodynamics, and protecting cells and organs from damage via neurohormonal, anti-inflammatory, antiremodeling, antifibrotic, anti-ischemic, and proangiogenic effects. Recently, a number of clinical trials have demonstrated that serelaxin infusion over 48 hours improved dyspnea with more rapid relief of congestion during the first days after admission for heart failure. In addition, administration of serelaxin diminished cardiac, renal, and hepatic damage, which were associated with improved long-term mortality. Available data support substantial clinical benefits and significant promise for serelaxin as a treatment option for patients with acute heart failure. This review focuses on the pharmacology and mechanisms of action of serelaxin and provides a detailed discussion of the clinical evidence for this novel therapy in acute heart failure. PMID:26331289

  7. BNP and NT-proBNP as prognostic markers in persons with acute decompensated heart failure: a systematic review.

    PubMed

    Santaguida, Pasqualina L; Don-Wauchope, Andrew C; Oremus, Mark; McKelvie, Robert; Ali, Usman; Hill, Stephen A; Balion, Cynthia; Booth, Ronald A; Brown, Judy A; Bustamam, Amy; Sohel, Nazmul; Raina, Parminder

    2014-08-01

    A systematic review was undertaken to examine the evidence for B-type natriuretic peptides (BNP and NT-proBNP) as independent predictors of mortality, morbidity, or combined mortality and morbidity outcomes in persons with acute decompensated heart failure (ADHF). Electronic databases (Medline(®), Embase™, AMED, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, and CINAHL) were searched from 1989 to June 2012. Reference lists of included articles, systematic reviews, and the gray literature were also searched. English language studies were eligible if they included subjects with ADHF and measured BNP/NT-proBNP using FDA approved assays. Standardized forms were used to select studies, extract data, and assess risk of bias. Seventy-nine studies, ranging over followup intervals from 14 days to 7 years, evaluating levels of BNP (n = 38), NT-proBNP (n = 35), or both (n = 6) were eligible. The majority of studies predicted mortality outcomes for admission BNP/NT-proBNP levels, with fewer studies evaluating serial, change from admission, or discharge levels. In general, higher levels of admission BNP or NT-proBNP predicted greater risk for all outcomes. Decreased levels post-admission predicted decreased risk. Overall, these studies were rated as having moderate risk of bias. This systematic review shows that BNP and NT-proBNP are independent predictors of mortality (all-cause and cardiovascular) in ADHF despite different cutpoints, time intervals, and prognostic models. Findings for morbidity and composite outcomes were less frequently evaluated and showed inconsistency. Further research is required to assess cutpoints for admission, serial measurements, change following admission, and discharge levels to assist clinical decision-making. PMID:25062653

  8. Sex Differences in Patients With Acute Decompensated Heart Failure: Insights From the Heart Function Assessment Registry Trial in Saudi Arabia.

    PubMed

    AlFaleh, Hussam F; Thalib, Lukman; Kashour, Tarek; Hersi, Ahmad; Mimish, Layth; Elasfar, Abdelfatah A; Almasood, Ali; Al Ghamdi, Saleh; Ghabashi, Abdullah; Malik, Asif; Hussein, Gamal A; Al-Murayeh, Mushabab; Abuosa, Ahmed; Al Habeeb, Waleed; Al Habib, Khalid F

    2016-08-01

    We assessed sex-specific differences in clinical features and outcomes of patients with acute heart failure (AHF). The Heart function Assessment Registry Trial in Saudi Arabia (HEARTS), a prospective registry, enrolled 2609 patients with AHF (34.2% women) between 2009 and 2010. Women were older and more likely to have risk factors for atherosclerosis, history of heart failure (HF), and rheumatic heart and valve disease. Ischemic heart disease was the prime cause for HF in men and women but more so in men (P < .001). Women had higher rates of hypertensive heart disease and primary valve disease (P < .001, for both comparisons). Men were more likely to have severe left ventricular systolic dysfunction. On discharge, a higher use of angiotensin-converting enzyme inhibitors, β-blockers, and aldosterone inhibitors was observed in men (P < .001 for all comparisons). Apart from higher atrial fibrillation in women and higher ventricular arrhythmias in men, no differences were observed in hospital outcomes. The overall survival did not differ between men and women (hazard ratio: 1.0, 95% confidence interval: 0.8-1.2, P = .981). Men and women with AHF differ significantly in baseline clinical characteristics and management but not in adverse outcomes. PMID:26438635

  9. Efficacy and Safety of 1-Hour Infusion of Recombinant Human Atrial Natriuretic Peptide in Patients With Acute Decompensated Heart Failure

    PubMed Central

    Wang, Guogan; Wang, Pengbo; Li, Yishi; Liu, Wenxian; Bai, Shugong; Zhen, Yang; Li, Dongye; Yang, Ping; Chen, Yu; Hong, Lang; Sun, Jianhui; Chen, Junzhu; Wang, Xian; Zhu, Jihong; Hu, Dayi; Li, Huimin; Wu, Tongguo; Huang, Jie; Tan, Huiqiong; Zhang, Jian; Liao, Zhongkai; Yu, Litian; Mao, Yi; Ye, Shaodong; Feng, Lei; Hua, Yihong; Ni, Xinhai; Zhang, Yuhui; Wang, Yang; Li, Wei; Luan, Xiaojun; Sun, Xiaolu; Wang, Sijia

    2016-01-01

    Abstract The aim of the study was to evaluate the efficacy and safety of 1-h infusion of recombinant human atrial natriuretic peptide (rhANP) in combination with standard therapy in patients with acute decompensated heart failure (ADHF). This was a phase III, randomized, double-blind, placebo-controlled, multicenter trial. Eligible patients with ADHF were randomized to receive a 1-h infusion of either rhANP or placebo at a ratio of 3:1 in combination with standard therapy. The primary endpoint was dyspnea improvement (a decrease of at least 2 grades of dyspnea severity at 12 h from baseline). Reduction in pulmonary capillary wedge pressure (PCWP) 1 h after infusion was the co-primary endpoint for catheterized patients. Overall, 477 patients were randomized: 358 (93 catheterized) patients received rhANP and 118 (28 catheterized) received placebo. The percentage of patients with dyspnea improvement at 12 h was higher, although not statistically significant, in the rhANP group than in the placebo group (32.0% vs 25.4%, odds ratio=1.382, 95% confidence interval [CI]: 0.863–2.212, P = 0.17). Reduction in PCWP at 1 h was significantly greater in patients treated with rhANP than in patients treated with placebo (−7.74 ± 5.95 vs −1.82 ± 4.47 mm Hg, P < 0.001). The frequencies of adverse events and renal impairment within 3 days of treatment were similar between the 2 groups. Mortality at 1 month was 3.1% in the rhANP group vs 2.5% in the placebo group (hazard ratio = 1.21, 95% CI: 0.34–4.26; P > 0.99). 1-h rhANP infusion appears to result in prompt, transient hemodynamic improvement with a small, nonsignificant, effect on dyspnea in ADHF patients receiving standard therapy. The safety of 1-h infusion of rhANP seems to be acceptable. (WHO International Clinical Trials Registry Platform [ICTRP] number, ChiCTR-IPR-14005719.) PMID:26945407

  10. Therapeutic effects of intravenous urapidil in elderly patients with hypertension and acute decompensated heart failure: A pilot clinical trial

    PubMed Central

    YANG, WEI; ZHOU, YU-JIE; FU, YAN; QIN, JIAN; TAN, SHU; CHEN, XIAO-MIN; GUO, JIN-CHENG; WANG, DE-ZHAO; ZHAN, HONG; GUAN, WEI; XU, YA-WEI; HE, JING-YU; LI, JING; HUA, QI

    2016-01-01

    Urapidil has been proposed to be an effective vasodilator for the treatment of acute decompensated heart failure (ADHF); however, its effect on cardiac function, as compared with that of nitroglycerin, in elderly patients with hypertension and ADHF has yet to be determined. In the present study, a multicenter, open-label clinical trial was performed, in which 120 elderly patients with hypertension and ADHF were randomly assigned to the treatment (50–400 µg/min intravenous urapidil) or control group (5–40 µg/min intravenous nitroglycerin). The dosages of the medications were adjusted according to the blood pressure of the patients. The systolic and diastolic blood pressure, heart rate and serum level of N-terminal pro B-type natriuretic peptide (NT-proBNP) were evaluated at hospital admission and at days 1, 2, 3 and 7 after treatment. In addition, the left ventricular function was assessed by measuring the left ventricular ejection fraction (LVEF) and left ventricular end-diastolic volume at hospital admission and at days 2 and 7 after treatment. The results indicated that intravenous administration of urapidil and nitroglycerin were effective in lowering the blood pressure and heart rate within 7 days, with no significant differences observed between the two groups (P>0.05). By contrast, greater reduction in the serum NT-proBNP level (2,410.4±546.1 vs. 4,234.1±876.4 pg/ml; P<0.05) and greater improvement in the LVEF (55.3±3.4 vs. 45.2±2.4%; P<0.05) were observed in the urapidil-treated group, as compared with the nitroglycerin-treated group. No adverse events were reported during the treatment period in the two groups. The clinical outcomes at 6 months following discharge were evaluated and were not found to be significantly different between the two groups. In conclusion, the present results of the present study suggested that urapidil was as effective as nitroglycerin in controlling blood pressure and heart rate and was more effective in improving

  11. Clinical trials update from the American Heart Association meeting 2010: EMPHASIS-HF, RAFT, TIM-HF, Tele-HF, ASCEND-HF, ROCKET-AF, and PROTECT.

    PubMed

    Cleland, John G F; Coletta, Alison P; Buga, Laszlo; Antony, Renjith; Pellicori, Pierpaolo; Freemantle, Nick; Clark, Andrew L

    2011-04-01

    This article provides information and a commentary on key trials relevant to the pathophysiology, prevention, and treatment of heart failure presented at the annual meeting of the American Heart Association held in Chicago in 2010. Unpublished reports should be considered as preliminary, since analyses may change in the final publication. In patients with mild heart failure (HF), EMPHASIS-HF showed that the addition of eplerenone to standard therapy was well tolerated and reduced both the risk of death and hospitalization. The addition of cardiac resynchronization therapy to implantable cardioverter defibrillator (ICD) therapy reduced the incidence of all-cause mortality and HF hospitalizations in patients with NYHA class II-III HF compared with ICD alone in RAFT. Telemonitoring failed to improve outcome compared with a high standard of conventional care in patients with chronic HF (TIM-HF study) and a telephone-based interactive voice response system failed to improve outcome in patients recently hospitalized for HF (Tele-HF study). ASCEND-HF suggested that nesiritide was ineffective but safe in patients with acute decompensated HF. ROCKET-AF suggests that the factor-Xa inhibitor rivaroxaban may be as effective as warfarin in patients with atrial fibrillation. The PROTECT study provided more data to suggest that amino-terminal B-type natriuretic peptide guided therapy may be beneficial in patients with left ventricular systolic dysfunction. PMID:21436363

  12. Impact of changes in blood pressure during the treatment of acute decompensated heart failure on renal and clinical outcomes†

    PubMed Central

    Testani, Jeffrey M.; Coca, Steven G.; McCauley, Brian D.; Shannon, Richard P.; Kimmel, Stephen E.

    2011-01-01

    Aims One of the primary determinants of blood flow in regional vascular beds is perfusion pressure. Our aim was to investigate if reduction in blood pressure during the treatment of decompensated heart failure would be associated with worsening renal function (WRF). Our secondary aim was to evaluate the prognostic significance of this potentially treatment-induced form of WRF. Methods and results Subjects included in the Evaluation Study of Congestive Heart Failure and Pulmonary Artery Catheterization Effectiveness (ESCAPE) trial limited data were studied (386 patients). Reduction in systolic blood pressure (SBP) was greater in patients experiencing WRF (−10.3 ± 18.5 vs. −2.8 ± 16.0 mmHg, P < 0.001) with larger reductions associated with greater odds for WRF (odds ratio = 1.3 per 10 mmHg reduction, P < 0.001). Systolic blood pressure reduction (relative change > median) was associated with greater doses of in-hospital oral vasodilators (P ≤ 0.017), thiazide diuretic use (P = 0.035), and greater weight reduction (P = 0.023). In patients with SBP-reduction, WRF was not associated with worsened survival [adjusted hazard ratio (HR) = 0.76, P = 0.58]. However, in patients without SBP-reduction, WRF was strongly associated with increased mortality (adjusted HR = 5.3, P < 0.001, P interaction = 0.001). Conclusion During the treatment of decompensated heart failure, significant blood pressure reduction is strongly associated with WRF. However, WRF that occurs in the setting of SBP-reduction is not associated with an adverse prognosis, whereas WRF in the absence of this provocation is strongly associated with increased mortality. These data suggest that WRF may represent the final common pathway of several mechanistically distinct processes, each with potentially different prognostic implications. PMID:21693504

  13. Effect of Home-Based Telemonitoring Using Mobile Phone Technology on the Outcome of Heart Failure Patients After an Episode of Acute Decompensation: Randomized Controlled Trial

    PubMed Central

    Scherr, Daniel; Kastner, Peter; Kollmann, Alexander; Hallas, Andreas; Auer, Johann; Krappinger, Heinz; Schuchlenz, Herwig; Stark, Gerhard; Grander, Wilhelm; Jakl, Gabriele; Schreier, Guenter

    2009-01-01

    Background Telemonitoring of patients with chronic heart failure (CHF) is an emerging concept to detect early warning signs of impending acute decompensation in order to prevent hospitalization. Objective The goal of the MOBIle TELemonitoring in Heart Failure Patients Study (MOBITEL) was to evaluate the impact of home-based telemonitoring using Internet and mobile phone technology on the outcome of heart failure patients after an episode of acute decompensation. Methods Patients were randomly allocated to pharmacological treatment (control group) or to pharmacological treatment with telemedical surveillance for 6 months (tele group). Patients randomized into the tele group were equipped with mobile phone–based patient terminals for data acquisition and data transmission to the monitoring center. Study physicians had continuous access to the data via a secure Web portal. If transmitted values went outside individually adjustable borders, study physicians were sent an email alert. Primary endpoint was hospitalization for worsening CHF or death from cardiovascular cause. Results The study was stopped after randomization of 120 patients (85 male, 35 female); median age was 66 years (IQR 62-72). The control group comprised 54 patients (39 male, 15 female) with a median age of 67 years (IQR 61-72), and the tele group included 54 patients (40 male, 14 female) with a median age of 65 years (IQR 62-72). There was no significant difference between groups with regard to baseline characteristics. Twelve tele group patients were unable to begin data transmission due to the inability of these patients to properly operate the mobile phone (“never beginners”). Four patients did not finish the study due to personal reasons. Intention-to-treat analysis at study end indicated that 18 control group patients (33%) reached the primary endpoint (1 death, 17 hospitalizations), compared with 11 tele group patients (17%, 0 deaths, 11 hospitalizations; relative risk reduction 50%, 95

  14. Acute liver function decompensation in a patient with sickle cell disease managed with exchange transfusion and endoscopic retrograde cholangiography

    PubMed Central

    Ona, Mel A.; Changela, Kinesh; Sadanandan, Swayamprabha; Jelin, Abraham; Anand, Sury; Duddempudi, Sushil

    2014-01-01

    Sickle cell intrahepatic cholestasis is a relatively uncommon complication of homozygous sickle cell anemia, which may lead to acute hepatic failure and death. Treatment is mainly supportive, but exchange transfusion is used as salvage therapy in life threatening situations. We describe a case of a 16-year-old female with homozygous sickle cell anemia who presented to the emergency room with fatigue, malaise, dark urine, lower back pain, scleral icterus and jaundice. She was found to have marked hyperbilirubinemia, which persisted after exchange transfusion. Because of the concomitant presence of gallstones and choledocholithiasis, the patient underwent endoscopic ultrasound and laparoscopic cholecystectomy followed by endoscopic retrograde cholangiography and sphincterotomy. PMID:25177368

  15. Diuretic response in patients with acute decompensated heart failure: characteristics and clinical outcome—an analysis from RELAX-AHF

    PubMed Central

    Voors, Adriaan A; Davison, Beth A; Teerlink, John R; Felker, G Michael; Cotter, Gad; Filippatos, Gerasimos; Greenberg, Barry H; Pang, Peter S; Levin, Bruce; Hua, Tsushung A; Severin, Thomas; Ponikowski, Piotr; Metra, Marco

    2014-01-01

    Aims We studied the characteristics and clinical outcome related to diuretic response and the effects of serelaxin in patients hospitalized for acute heart failure (AHF). Methods and results RELAX-AHF was a double-blind, placebo-controlled trial, enrolling 1161 patients admitted to hospital for AHF who were randomized to 48 h i.v infusions of placebo or serelaxin (30 µg/kg per day) within 16 h from presentation. Diuretic response was defined as Δ weight kg/[(total i.v. dose)/40 mg] + [(total oral dose)/80 mg)] furosemide (or equivalent loop diuretic dose) up to day 5. Median diuretic response was −0.42 (−1.00, −0.14) kg/40 mg. A poor diuretic response was independently associated with Western-like region (Western Europe, North America, Israel, and Poland), lower diastolic blood pressure, the absence of oedema, higher blood urea nitrogen, and lower levels of aspartate aminotransferase and potassium (all P < 0.01). Randomization to serelaxin was associated with lower doses of i.v. loop diuretics and slightly less weight loss, resulting in a neutral effect on diuretic response. Worse diuretic response was independently associated both with less relief of dyspnoea, measured with a visual analogue scale (VAS) at day 5 (primary endpoint; P = 0.0002), and with a higher risk of cardiovascular death or rehospitalization for heart failure or renal failure through day 60 (secondary endpoint, P < 0.0001), but not with increased 180-day cardiovascular mortality (P = 0.507). Conclusions In patients hospitalized for AHF, a poor diuretic response was associated with a poor in-hospital and early post-discharge clinical outcome. Serelaxin had a neutral effect on diuretic response. Trial registration: NCT00520806 PMID:25287144

  16. Role of Neutrophil Gelatinase-Associated Lipocalin in the Diagnosis and Early Treatment of Acute Kidney Injury in a Case Series of Patients with Acute Decompensated Heart Failure: A Case Series

    PubMed Central

    Fogolari, Marta; Morolla, Davide; Capone, Federico; Costantino, Sebastiano; Spoto, Silvia; De Cesaris, Marina; Lo Presti, Alessandra; Ciccozzi, Massimo; Dicuonzo, Giordano

    2016-01-01

    Patients with acute decompensated heart failure (ADHF) frequently develop worsening in renal function until Acute Kidney Injury (AKI). The use of kidney injury biomarkers could be useful in the early diagnosis of AKI. In the present study, the role of the neutrophil gelatinase-associated lipocalin (NGAL), compared to the standard creatinine, in ADHF patients, was analyzed to evaluate if an early treatment could affect the outcome. A case series of 24 ADHF patients was enrolled and patients randomly divided in two groups (Group A and Group B). In Group A, NGAL, creatinine, and eGFR were measured, while in Group B, creatinine and eGFR alone were measured. NGAL was measured by turbidimetric immunoassay and creatinine using an enzymatic spectrophotometric method. In presence of AKI, creatinine increase and eGFR decrease were significantly lower in Group A than in Group B, whereas in absence of AKI the difference between the two groups was not significant. Hospitalization stay was significantly lower in Group A (receiving early treatment based on NGAL) than in Group B. In ADHF patients, plasma NGAL in combination with creatinine was superior to the standard creatinine in the diagnosis and early treatment of AKI with a better outcome and a decreased hospital stay. PMID:27022499

  17. Management options in decompensated cirrhosis

    PubMed Central

    Shah, Neeral L; Banaei, Yasmin Pourkazemi; Hojnowski, Kristen L; Cornella, Scott L

    2015-01-01

    Chronic injury to the liver from a variety of different sources can result in irreversible scarring of the liver, known as cirrhosis. Cirrhosis is a major cause of morbidity and mortality in the USA, and according to the Centers for Disease Control and Prevention was responsible for 31,903 deaths in 2010 alone. It is thus of the utmost importance to appropriately manage these patients in the inpatient and outpatient setting to improve morbidity and mortality. In this review, we address four major areas of cirrhosis management: outpatient management of portal hypertension with decompensation, hepatic encephalopathy, hepatorenal syndrome, and bleeding/coagulation issues. Outpatient management covers recommendations for health care maintenance and screening. Hepatic encephalopathy encompasses a brief review of pathophysiology, treatment in the acute setting, and long-term prevention. Hepatorenal syndrome is discussed in regards to pathophysiology and treatment in the hospital setting. Finally, a discussion of the assessment of coagulation profiles in cirrhosis and recommendations for bleeding and thrombosis complications is included. These topics are not all encompassing with regard to this complicated population, but rather an overview of a few medical problems that are commonly encountered in their care. PMID:26203291

  18. Prednisone lowers serum uric acid levels in patients with decompensated heart failure by increasing renal uric acid clearance.

    PubMed

    Liu, Chao; Zhen, Yuzhi; Zhao, Qingzhen; Zhai, Jian-Long; Liu, Kunshen; Zhang, Jian-Xin

    2016-07-01

    Clinical studies have shown that large doses of prednisone could lower serum uric acid (SUA) in patients with decompensated heart failure (HF); however, the optimal dose of prednisone and underlying mechanisms are unknown. Thirty-eight patients with decompensated HF were randomized to receive standard HF care alone (n = 10) or with low-dose (15 mg/day, n = 8), medium-dose (30 mg/day, n = 10), or high-dose prednisone (60 mg/day, n = 10), for 10 days. At the end of the study, only high-dose prednisone significantly reduced SUA, whereas low- and medium-dose prednisone and standard HF care had no effect on SUA. The reduction in SUA in high-dose prednisone groups was associated with a significant increase in renal uric acid clearance. In conclusion, prednisone can reduce SUA levels by increasing renal uric acid clearance in patients with decompensated HF. PMID:27144905

  19. [Complementary treatment of acute heart failure in patients with diabetes, chronic obstructive pulmonary disease or anemia].

    PubMed

    Carrasco Sánchez, Francisco Javier; Recio Iglesias, Jesús; Grau Amorós, Jordi

    2014-03-01

    Diabetes, chronic obstructive pulmonary disease (COPD) and anemia are comorbidities with a high prevalence and impact in heart failure (HF). The presence of these comorbidities considerably worsens the prognosis of HF. Diabetic patients have a higher likelihood of developing symptoms of HF and both the treatment of diabetes and that of acute HF are altered by the coexistence of both entities. The glycemic targets in patients with acute HF are not well-defined, but could show a U-shaped relationship. Stress hyperglycemia in non-diabetic patients with HF could also have a deleterious effect on the medium-term prognosis. The inter-relationship between COPD and HF hampers diagnosis due to the overlap between the symptoms and signs of both entities and complementary investigations. The treatment of acute HF is also altered by the presence of COPD. Anemia is highly prevalent and is often the direct cause of decompensated HF, the most common cause being iron deficiency anemia. Iron replacement therapy, specifically intravenous forms, has helped to improve the prognosis of acute HF. PMID:24930086

  20. Management of the Cardiorenal Syndrome in Decompensated Heart Failure

    PubMed Central

    Verbrugge, Frederik Hendrik; Grieten, Lars; Mullens, Wilfried

    2014-01-01

    Background The management of the cardiorenal syndrome (CRS) in decompensated heart failure (HF) is challenging, with high-quality evidence lacking. Summary The pathophysiology of CRS in decompensated HF is complex, with glomerular filtration rate (GFR) and urine output representing different aspects of kidney function. GFR depends on structural factors (number of functional nephrons and integrity of the glomerular membrane) versus hemodynamic alterations (volume status, renal perfusion, arterial blood pressure, central venous pressure or intra-abdominal pressure) and neurohumoral activation. In contrast, urine output and volume homeostasis are mainly a function of the renal tubules. Treatment of CRS in decompensated HF patients should be individualized based on the underlying pathophysiological processes. Key Messages Congestion, defined as elevated cardiac filling pressures, is not a surrogate for volume overload. Transient decreases in GFR might be accepted during decongestion, but hypotension must be avoided. Paracentesis and compression therapy are essential to remove fluid overload from third spaces. Increasing the effective circulatory volume improves renal function when cardiac output is depressed. As mechanical support is invasive and inotropes are related to increased mortality, afterload reduction through vasodilator therapy remains the preferred strategy in patients who are normo- or hypertensive. Specific therapies to augment renal perfusion (rolofylline, dopamine or nesiritide) have rendered disappointing results, but recently, serelaxin has been shown to improve renal function, even with a trend towards reduced all-cause mortality in selected patients. Diuretic resistance is associated with worse outcomes, independent of the underlying GFR. Combinational diuretic therapy, with ultrafiltration as a bail-out strategy, is indicated in case of diuretic resistance. PMID:25737682

  1. Early Indication of Decompensated Heart Failure in Patients on Home-Telemonitoring: A Comparison of Prediction Algorithms Based on Daily Weight and Noninvasive Transthoracic Bio-impedance

    PubMed Central

    Bonomi, Alberto G; Goode, Kevin M; Reiter, Harald; Habetha, Joerg; Amft, Oliver; Cleland, John GF

    2016-01-01

    Background Heart Failure (HF) is a common reason for hospitalization. Admissions might be prevented by early detection of and intervention for decompensation. Conventionally, changes in weight, a possible measure of fluid accumulation, have been used to detect deterioration. Transthoracic impedance may be a more sensitive and accurate measure of fluid accumulation. Objective In this study, we review previously proposed predictive algorithms using body weight and noninvasive transthoracic bio-impedance (NITTI) to predict HF decompensations. Methods We monitored 91 patients with chronic HF for an average of 10 months using a weight scale and a wearable bio-impedance vest. Three algorithms were tested using either simple rule-of-thumb differences (RoT), moving averages (MACD), or cumulative sums (CUSUM). Results Algorithms using NITTI in the 2 weeks preceding decompensation predicted events (P<.001); however, using weight alone did not. Cross-validation showed that NITTI improved sensitivity of all algorithms tested and that trend algorithms provided the best performance for either measurement (Weight-MACD: 33%, NITTI-CUSUM: 60%) in contrast to the simpler rules-of-thumb (Weight-RoT: 20%, NITTI-RoT: 33%) as proposed in HF guidelines. Conclusions NITTI measurements decrease before decompensations, and combined with trend algorithms, improve the detection of HF decompensation over current guideline rules; however, many alerts are not associated with clinically overt decompensation. PMID:26892844

  2. Short Term Efficacy and Safety of Low Dose Tolvaptan in Patients with Acute Decompensated Heart Failure with Hyponatremia: A Prospective Observational Pilot Study from a Single Center in South India

    PubMed Central

    Patra, Soumya; Kumar, Basant; Harlalka, Kaushal K.; Jain, Apoorva; Bhanuprakash, H. M.; Sadananda, K. S.; Basappa, Harsha; Santhosh, K.; Rajith, K. S.; Bharathi, K. S.; Manjunath, C. N.

    2014-01-01

    Background: In acute decompensated heart failure (ADHF), diuretic use, the mainstay therapy for congestion, is associated with electrolyte abnormalities and worsening renal function. Vasopressin mediates fluid retention in heart failure. In contrast to diuretics, the vasopressin antagonist tolvaptan may increase net volume loss in heart failure without adversely affecting electrolytes and renal function. Hyponatremia (serum sodium concentration, <135 mEq/L) is a predictor of death among patients with heart failure. Objective: We prospectively observed the short term efficacy and safety of low dose (15 mg) tolvaptan in admitted patients with hyponatremia and ADHF in Indian population. Methodology: A total of 40 patients with ADHF along with hyponatremia (<125 mEq/L) on standard therapy were treated with 15 mg of tolvaptan at a single oral dose for 7 days. Results: Serum sodium concentrations increased significantly after treatment with tolvaptan from baseline (P < 0.02). There was a significant improvement in symptoms and New York Heart Association (NYHA) class after starting tolvaptan (P ≤ 0.05). Total diuretic dose and mean body weight was reduced non-significantly at 7th day from the baseline. Side-effects associated with tolvaptan included increased thirst, dry mouth and increased urination. Few patients had worsening renal function. However, several patients developed hypernatremia. Conclusion: In this small observational study, tolvaptan initiation in patients with ADHF with hyponatremia in addition to standard therapy may hold promise in improvement in NYHA class and serum sodium. At the same time, we observed that serious adverse events such as renal function deterioration and hypernatremia developed after tolvaptan treatment, which needs to be addressed in future by randomized study with larger sample size. PMID:24949180

  3. Canadian Cardiovascular Society Consensus Conference recommendations on heart failure update 2007: Prevention, management during intercurrent illness or acute decompensation, and use of biomarkers

    PubMed Central

    Arnold, J Malcolm O; Howlett, Jonathan G; Dorian, Paul; Ducharme, Anique; Giannetti, Nadia; Haddad, Haissam; Heckman, George A; Ignaszewski, Andrew; Isaac, Debra; Jong, Philip; Liu, Peter; Mann, Elizabeth; McKelvie, Robert S; Moe, Gordon W; Parker, John D; Svendsen, Anna M; Tsuyuki, Ross T; O’Halloran, Kelly; Ross, Heather J; Rao, Vivek; Sequeira, Errol J; White, Michel

    2007-01-01

    Heart failure is common, yet it is difficult to treat. It presents in many different guises and circumstances in which therapy needs to be individualized. The Canadian Cardiovascular Society published a comprehensive set of recommendations in January 2006 on the diagnosis and management of heart failure, and the present update builds on those core recommendations. Based on feedback obtained through a national program of heart failure workshops during 2006, several topics were identified as priorities because of the challenges they pose to health care professionals. New evidence-based recommendations were developed using the structured approach for the review and assessment of evidence adopted and previously described by the Society. Specific recommendations and practical tips were written for the prevention of heart failure, the management of heart failure during intercurrent illness, the treatment of acute heart failure, and the current and future roles of biomarkers in heart failure care. Specific clinical questions that are addressed include: which patients should be identified as being at high risk of developing heart failure and which interventions should be used? What complications can occur in heart failure patients during an intercurrent illness, how should these patients be monitored and which medications may require a dose adjustment or discontinuation? What are the best therapeutic, both drug and nondrug, strategies for patients with acute heart failure? How can new biomarkers help in the treatment of heart failure, and when and how should BNP be measured in heart failure patients? The goals of the present update are to translate best evidence into practice, to apply clinical wisdom where evidence for specific strategies is weaker, and to aid physicians and other health care providers to optimally treat heart failure patients to result in a measurable impact on patient health and clinical outcomes in Canada. PMID:17245481

  4. Efficacy and Safety of 1-Hour Infusion of Recombinant Human Atrial Natriuretic Peptide in Patients With Acute Decompensated Heart Failure: A Phase III, Randomized, Double-Blind, Placebo-Controlled, Multicenter Trial.

    PubMed

    Wang, Guogan; Wang, Pengbo; Li, Yishi; Liu, Wenxian; Bai, Shugong; Zhen, Yang; Li, Dongye; Yang, Ping; Chen, Yu; Hong, Lang; Sun, Jianhui; Chen, Junzhu; Wang, Xian; Zhu, Jihong; Hu, Dayi; Li, Huimin; Wu, Tongguo; Huang, Jie; Tan, Huiqiong; Zhang, Jian; Liao, Zhongkai; Yu, Litian; Mao, Yi; Ye, Shaodong; Feng, Lei; Hua, Yihong; Ni, Xinhai; Zhang, Yuhui; Wang, Yang; Li, Wei; Luan, Xiaojun; Sun, Xiaolu; Wang, Sijia

    2016-03-01

    The aim of the study was to evaluate the efficacy and safety of 1-h infusion of recombinant human atrial natriuretic peptide (rhANP) in combination with standard therapy in patients with acute decompensated heart failure (ADHF).This was a phase III, randomized, double-blind, placebo-controlled, multicenter trial. Eligible patients with ADHF were randomized to receive a 1-h infusion of either rhANP or placebo at a ratio of 3:1 in combination with standard therapy. The primary endpoint was dyspnea improvement (a decrease of at least 2 grades of dyspnea severity at 12 h from baseline). Reduction in pulmonary capillary wedge pressure (PCWP) 1 h after infusion was the co-primary endpoint for catheterized patients. Overall, 477 patients were randomized: 358 (93 catheterized) patients received rhANP and 118 (28 catheterized) received placebo. The percentage of patients with dyspnea improvement at 12 h was higher, although not statistically significant, in the rhANP group than in the placebo group (32.0% vs 25.4%, odds ratio=1.382, 95% confidence interval [CI]: 0.863-2.212, P = 0.17). Reduction in PCWP at 1 h was significantly greater in patients treated with rhANP than in patients treated with placebo (-7.74 ± 5.95 vs -1.82 ± 4.47 mm Hg, P < 0.001). The frequencies of adverse events and renal impairment within 3 days of treatment were similar between the 2 groups. Mortality at 1 month was 3.1% in the rhANP group vs 2.5% in the placebo group (hazard ratio = 1.21, 95% CI: 0.34-4.26; P > 0.99).1-h rhANP infusion appears to result in prompt, transient hemodynamic improvement with a small, nonsignificant, effect on dyspnea in ADHF patients receiving standard therapy. The safety of 1-h infusion of rhANP seems to be acceptable. (WHO International Clinical Trials Registry Platform [ICTRP] number, ChiCTR-IPR-14005719.). PMID:26945407

  5. Change of Serum BNP Between Admission and Discharge After Acute Decompensated Heart Failure Is a Better Predictor of 6-Month All-Cause Mortality Than the Single BNP Value Determined at Admission

    PubMed Central

    De Vecchis, Renato; Ariano, Carmelina; Giandomenico, Giuseppe; Di Maio, Marco; Baldi, Cesare

    2016-01-01

    Background B-type natriuretic peptide (BNP) is regarded as a reliable predictor of outcome in patients with acute decompensated heart failure (ADHF). However, according to some scholars, a single isolated measurement of serum BNP at the time of hospital admission would not be sufficient to provide reliable prognostic information. Methods A retrospective study was carried out on patients hospitalized for ADHF, who had then undergone follow-up of at least 6 months, in order to see if there was any difference in midterm mortality among patients with rising BNP at discharge as compared to those with decreasing BNP at discharge. Medical records had to be carefully examined to divide the case records into two groups, the former characterized by an increase in BNP during hospitalization, and the latter showing a decrease in BNP from the time of admission to the time of discharge. Results Ultimately, 177 patients were enrolled in a retrospective study. Among them, 53 patients (29.94%) had increased BNPs at the time of discharge relative to admission, whereas 124 (70.06%) exhibited decreases in serum BNP during their hospital stay. The group with patients who exhibited BNP increases at the time of discharge had higher degree of congestion evident in the higher frequency of persistent jugular venous distention (odds ratio: 3.72; P = 0.0001) and persistent orthopnea at discharge (odds ratio: 2.93; P = 0.0016). Moreover, patients with increased BNP at the time of discharge had a lower reduction in inferior vena cava maximum diameter (1.58 ± 2.2 mm vs. 6.32 ± 1.82 mm; P = 0.001 (one-way ANOVA)). In contrast, there was no significant difference in weight loss when patients with increased BNP at discharge were compared to those with no such increase. A total of 14 patients (7.9%) died during the 6-month follow-up period. Cox proportional hazard analysis revealed that BNP increase at the time of discharge was an independent predictor of 6-month all-cause mortality after

  6. Prediction of Heart Failure Decompensation Events by Trend Analysis of Telemonitoring Data.

    PubMed

    Henriques, J; Carvalho, P; Paredes, S; Rocha, T; Habetha, J; Antunes, M; Morais, J

    2015-09-01

    This paper aims to assess the predictive value of physiological data daily collected in a telemonitoring study in the early detection of heart failure (HF) decompensation events. The main hypothesis is that physiological time series with similar progression (trends) may have prognostic value in future clinical states (decompensation or normal condition). The strategy is composed of two main steps: a trend similarity analysis and a predictive procedure. The similarity scheme combines the Haar wavelet decomposition, in which signals are represented as linear combinations of a set of orthogonal bases, with the Karhunen-Loève transform, that allows the selection of the reduced set of bases that capture the fundamental behavior of the time series. The prediction process assumes that future evolution of current condition can be inferred from the progression of past physiological time series. Therefore, founded on the trend similarity measure, a set of time series presenting a progression similar to the current condition is identified in the historical dataset, which is then employed, through a nearest neighbor approach, in the current prediction. The strategy is evaluated using physiological data resulting from the myHeart telemonitoring study, namely blood pressure, respiration rate, heart rate, and body weight collected from 41 patients (15 decompensation events and 26 normal conditions). The obtained results suggest, in general, that the physiological data have predictive value, and in particular, that the proposed scheme is particularly appropriate to address the early detection of HF decompensation. PMID:25248206

  7. Enlarging Red Blood Cell Distribution Width During Hospitalization Identifies a Very High-Risk Subset of Acutely Decompensated Heart Failure Patients and Adds Valuable Prognostic Information on Top of Hemoconcentration

    PubMed Central

    Ferreira, João Pedro; Girerd, Nicolas; Arrigo, Mattia; Medeiros, Pedro Bettencourt; Ricardo, Miguel Bento; Almeida, Tiago; Rola, Alexandre; Tolpannen, Heli; Laribi, Said; Gayat, Etienne; Mebazaa, Alexandre; Mueller, Christian; Zannad, Faiez; Rossignol, Patrick; Aragão, Irene

    2016-01-01

    Abstract Red blood cell distribution width (RDW) may serve as an integrative marker of pathological processes that portend worse prognosis in heart failure (HF). The prognostic value of RDW variation (ΔRDW) during hospitalization for acute heart failure (AHF) has yet to be studied. We retrospectively analyzed 2 independent cohorts: Centro Hospitalar do Porto (derivation cohort) and Lariboisière hospital (validation cohort). In the derivation cohort a total of 170 patients (age 76.2 ± 10.3 years) were included and in the validation cohort 332 patients were included (age 76.4 ± 12.2 years). In the derivation cohort the primary composite outcome of HF admission and/or cardiovascular death occurred in 78 (45.9%) patients during the 180-day follow-up period. Discharge RDW and ΔRDW were both increased when hemoglobin levels were lower; peripheral edema was also associated with increased discharge RDW (all P < 0.05). Discharge RDW value was significantly associated with adverse events: RDW > 15% at discharge was associated with a 2-fold increase in event rate, HR = 1.95 (1.05–3.62), P = 0.04, while a ΔRDW >0 also had a strong association with outcome, HR = 2.47 (1.35–4.51), P = 0.003. The addition of both discharge RDW > 15% and ΔRDW > 0 to hemoconcentration was associated with a significant improvement in the net reclassification index, NRI = 18.3 (4.3–43.7), P = 0.012. Overlapping results were found in the validation cohort. As validated in 2 independent AHF cohorts, an in-hospital RDW enlargement and an elevated RDW at discharge are associated with increased rates of mid-term events. RDW variables improve the risk stratification of these patients on top of well-established prognostic markers. PMID:27057905

  8. Association of gender and length of stay among Puerto Ricans hospitalized with decompensated heart failure.

    PubMed

    Alnajashi, Mohammad A; Almasoud, Mohammed A; Aldaham, Sami A; Acuña, Juan Manuel; Zevallos, Juan C

    2016-07-01

    Heart failure (HF) is a serious, chronic, and progressive condition which may require hospitalization if decompensated. Each year, in the UnitedStates, there are approximately 1 million hospitalizations due to decompensated HF at a cost of $39 billion. Because limited information examining the association between gender and length of stay (LOS) is available in the published literature for Puerto Ricans hospitalized with decompensated HF, we aim to investigate gender differences related to LOS in this population.This study is a secondary data analysis of the Puerto Rico Cardiovascular Disease Surveillance System database, which is a nonconcurrent prospective study carried out in 2007 and 2009. LOS was dichotomized into ≤5 days or ≥6 days (extended) categories. The χ test was used to examine associations between categorical variables. Binary logistic regression was used to estimate unadjusted and adjusted odds ratios of extended LOS. Collinearity was assessed using Pearson correlation coefficients. A P value of 0.05 and 95% confidence intervals were used to evaluate statistical significance.A total of 1724 patients (47.6% women) comprised our study population. The average age of women was 72.5 ± 13.4 years; the average age of men was 67.2 ± 14.5 years. For both women and men, median LOS was 5 days (interquartile range = 5 days). Women were more likely than men to have diabetes mellitus, hypertension, and dyslipidemia, but current smoking was higher in men than in women. The proportion of patients with extended LOS was similar for men (43.3%) and women (45.1%) (P = 0.448). Likewise, the odds for extended LOS was comparable for both genders (OR = 1.1, 95% CI = 0.9, 1.4). Patients admitted with recurrent decompensated HF hospitalizations had shorter LOS than patients with initial episodes (OR = 0.7, 95% CI = 0.6, 0.9). However, factors that prolonged the LOS included the presence of renal failure (OR = 1.7; 95% IC = 1.3, 2

  9. Hepatic decompensation in the absence of obvious precipitants: the potential role of cytomegalovirus infection/reactivation

    PubMed Central

    Rosi, Silvia; Poretto, Valentina; Cavallin, Marta; Angeli, Paolo; Amodio, Piero; Sattin, Andrea; Montagnese, Sara

    2015-01-01

    Details of two patients with alcohol-related and mixed aetiology cirrhosis who developed acute-on-chronic liver failure/hepatic decompensation with no obvious precipitants are reported. Cytomegalovirus (CMV) infection or reactivation was diagnosed in both, and required treatment with ganciclovir in one. Both returned to baseline hepatic function and remain well. Physicians should be alert to the possibility that CMV might cause or contribute to hepatic decompensation in patients with cirrhosis, even if they are not severely immunocompromised, and especially if they are alcohol misusers. PMID:26629358

  10. Prognostic significance of dilated inferior vena cava in advanced decompensated heart failure.

    PubMed

    Lee, Hsin-Fu; Hsu, Lung-An; Chang, Chi-Jen; Chan, Yi-Hsin; Wang, Chun-Li; Ho, Wan-Jing; Chu, Pao-Hsien

    2014-10-01

    Dilated inferior vena cava (IVC) is prevalent among patients with heart failure (HF), but whether its presence predicts worsening renal function (WRF) or adverse outcomes is unclear. This cohort study analyzed patients with left ventricular ejection fraction <40 % and repeated hospitalizations (≥2 times) for HF between August 2009 and August 2011. The study endpoints were death and HF re-hospitalization. Among baseline parameters, IVC diameter was the most powerful predictor for the development of WRF (area under the curve = 0.795, cut-off value = 20.5 mm). During the 2-year follow-up, 36 patients (49 %) were re-hospitalized for HF and 14 patients (19 %) died. The event rates were significantly greater in the WRF group than in the non-WRF group (71 vs. 30 %, P < 0.001 for HF re-hospitalization; 29 vs. 10 %, P = 0.03 for death). In Cox regression model, the risk of combined end-points was increased in patients with aging, elevated blood urine nitrogen, IVC >21 mm, and WRF. When adjusted for confounding factors, IVC >21 mm [hazard ratio (HR) 3.73, 95 % confidence interval (CI) 1.66-8.34] and WRF (HR 2.68, 95 % CI 1.07-6.75) were significant predictors for adverse outcomes. In patients with advanced decompensated HF, dilated IVC (>21 mm) predicted the development of WRF and could be a predictor for adverse outcomes. PMID:24939288

  11. [Management of decompensated liver cirrhosis in the intensive care unit].

    PubMed

    Lerschmacher, O; Koch, A; Streetz, K; Trautwein, C; Tacke, F

    2013-11-01

    Liver cirrhosis is the end-stage of long-standing chronic liver diseases. The occurrence of complications from liver cirrhosis increases the mortality risk, but the prognosis can be improved by optimal management in the intensive care unit (ICU). Defined diagnostic algorithms allow the etiology and presence of typical complications upon presentation to the ICU to be identified. Acute variceal bleeding requires endoscopic intervention, vasoactive drugs, antibiotics, supportive intensive care measures and, where necessary, urgent transjugular intrahepatic portosystemic shunt (TIPS) procedure. Spontaneous bacterial peritonitis needs to be diagnosed and immediately treated in patients with ascites. Hepatorenal syndrome should be treated by albumin and terlipressin. In case of respiratory failure, differential diagnosis should not only consider pneumonia, pulmonary embolism and cardiac failure, but also hepatic hydrothorax, portopulmonary hypertension and hepatopulmonary syndrome. The feasibility of liver transplantation should be always discussed in patients with decompensated cirrhosis. Artificial liver support devices may only serve as a bridging procedure until transplant. PMID:24030843

  12. Upper-body extracorporeal membrane oxygenation as a strategy in decompensated pulmonary arterial hypertension

    PubMed Central

    Abrams, Darryl C.; Brodie, Daniel; Rosenzweig, Erika B.; Burkart, Kristin M.; Agerstrand, Cara L.; Bacchetta, Matthew D.

    2013-01-01

    Pulmonary arterial hypertension (PAH) is a disease with significant morbidity and mortality, particularly during an acute decompensation. We describe a single-center experience of three patients with severe Group 1 PAH, refractory to targeted medical therapy, in which an extubated, nonsedated, extracorporeal membrane oxygenation (ECMO) strategy with an upper-body configuration was used as a bridge to recovery or lung transplantation. All three patients were extubated within 24 hours of ECMO initiation. Two patients were successfully bridged to lung transplantation, and the other patient was optimized on targeted PAH therapy with subsequent recovery from an acute decompensation. The upper-body ECMO configuration allowed for daily physical therapy, including one patient, who would otherwise have been unsuitable for transplantation, ambulating over 850 meters daily. This series demonstrates the feasibility of using ECMO to bridge PAH patients to recovery or transplantation while avoiding the complications of immobility and invasive mechanical ventilation. PMID:24015346

  13. [Heart rate and outcome in patients with acute and chronic heart failure].

    PubMed

    Oliva, Fabrizio; Ammirati, Enrico; Campana, Carlo; Carubelli, Valentina; Cirò, Antonio; Di Tano, Giuseppe; Mortara, Andrea; Senni, Michele; Morandi, Fabrizio; Metra, Marco

    2016-03-01

    Heart rate (HR) is not only a physical sign but also a biomarker. High HR in several cardiac disorders is associated with increased mortality. In heart failure (HF), HR represents an important therapeutic target, both in the acute and chronic phase. Beta-blockers are a milestone of recommended treatments in HF patients with reduced ejection fraction. However, hemodynamic profile or intolerance may limit the use or the optimization of beta-blocker treatment, both during hospitalization and outpatient follow-up. More recently, ivabradine has become available, a drug that lowers HR by blocking the I(f) current in the pacemaker cells at the sinoatrial node level. In the SHIFT trial, ivabradine was shown to improve the outcome of patients with chronic HF, in sinus rhythm, with HR >70 b/min while on beta-blockers. Preliminary data have shown that this drug has a good safety profile and lowers effectively HR even during hospitalization due to worsening HF. However, further studies are warranted to understand if an earlier administration of ivabradine can lead to a better prognosis beyond symptom control and improved hemodynamics. In patients with atrial fibrillation and HF, the target is the restoration of sinus rhythm, alternatively rate control should be pursued with beta-blockers, amiodarone or digitalis, even if there is no clear evidence of an association between ventricular rate response in patients with atrial fibrillation at discharge after an HF hospitalization and major cardiovascular events. In this review, the studies that point to a role of HR both as a biomarker and a therapeutic target in patients with acute and chronic HF are described. In addition, the proportions of patients who do not reach target HR values at discharge after an acute decompensated HF episode or in the chronic phase are evaluated based on the Italian registries. PMID:27030005

  14. Biomarkers in acute heart failure.

    PubMed

    Mallick, Aditi; Januzzi, James L

    2015-06-01

    The care of patients with acutely decompensated heart failure is being reshaped by the availability and understanding of several novel and emerging heart failure biomarkers. The gold standard biomarkers in heart failure are B-type natriuretic peptide and N-terminal pro-B-type natriuretic peptide, which play an important role in the diagnosis, prognosis, and management of acute decompensated heart failure. Novel biomarkers that are increasingly involved in the processes of myocardial injury, neurohormonal activation, and ventricular remodeling are showing promise in improving diagnosis and prognosis among patients with acute decompensated heart failure. These include midregional proatrial natriuretic peptide, soluble ST2, galectin-3, highly-sensitive troponin, and midregional proadrenomedullin. There has also been an emergence of biomarkers for evaluation of acute decompensated heart failure that assist in the differential diagnosis of dyspnea, such as procalcitonin (for identification of acute pneumonia), as well as markers that predict complications of acute decompensated heart failure, such as renal injury markers. In this article, we will review the pathophysiology and usefulness of established and emerging biomarkers for the clinical diagnosis, prognosis, and management of acute decompensated heart failure. PMID:25911167

  15. Inflammasome activation in decompensated liver cirrhosis

    PubMed Central

    González-Navajas, José M

    2016-01-01

    Inflammation participates in the pathogenesis of many liver diseases, including liver cirrhosis. Certain inflammatory citokines, such as interleukin (IL)-1β and IL-18, are produced after the activation of a multiprotein complex known as the inflammasome. Activation of the inflammasome has been documented in several liver diseases, but its role in the development and progression of liver cirrhosis or the complications associated with this disease is still largely unknown. We have recently studied the impact of the inflammasome in the sterile inflammatory response that takes place in the ascitic fluid of patients with decompensated cirrhosis, providing evidence that activation of the absent in melanoma 2 (AIM2) inflammasome is an important response in these patients. Ascitic fluid-derived macrophages were able to mount a very robust AIM2-mediated response even in the absence of a priming signal, which is usually required for the full activation of all the inflammasomes. In addition, high level of inflammasome activation in these patients was associated with a higher degree of liver disease and an increased incidence of spontaneous bacterial peritonitis. These results may help explain the exacerbated inflammatory response that usually occurs in patients with decompensated cirrhosis in the absence of detectable infections. Thus, inflammasomes should be considered as possible therapeutic targets in sterile inflammatory complications in patients with cirrhosis. PMID:26855691

  16. How much incisor decompensation is achieved prior to orthognathic surgery?

    PubMed Central

    McNeil, Calum; Laverick, Sean

    2014-01-01

    Objectives: To quantify incisor decompensation in preparation for orthognathic surgery. Study design: Pre-treatment and pre-surgery lateral cephalograms for 86 patients who had combined orthodontic and orthognathic treatment were digitised using OPAL 2.1 [http://www.opalimage.co.uk]. To assess intra-observer reproducibility, 25 images were re-digitised one month later. Random and systematic error were assessed using the Dahlberg formula and a two-sample t-test, respectively. Differences in the proportions of cases where the maxillary (1100 +/- 60) or mandibular (900 +/- 60) incisors were fully decomensated were assessed using a Chi-square test (p<0.05). Mann-Whitney U tests were used to identify if there were any differences in the amount of net decompensation for maxillary and mandibular incisors between the Class II combined and Class III groups (p<0.05). Results: Random and systematic error were less than 0.5 degrees and p<0.05, respectively. A greater proportion of cases had decompensated mandibular incisors (80%) than maxillary incisors (62%) and this difference was statistically significant (p=0.029). The amount of maxillary incisor decompensation in the Class II and Class III groups did not statistically differ (p=0.45) whereas the mandibular incisors in the Class III group underwent statistically significantly greater decompensation (p=0.02). Conclusions: Mandibular incisors were decompensated for a greater proportion of cases than maxillary incisors in preparation for orthognathic surgery. There was no difference in the amount of maxillary incisor decompensation between Class II and Class III cases. There was a greater net decompensation for mandibular incisors in Class III cases when compared to Class II cases. Key words:Decompensation, orthognathic, pre-surgical orthodontics, surgical-orthodontic. PMID:25136421

  17. Impact of Orthodontic Decompensation on Bone Insertion

    PubMed Central

    Guedes, Fabio Pinto; Capelozza Filho, Leopoldino; Garib, Daniela Gamba; Nary Filho, Hugo; Borgo, Evandro José; Cardoso, Mauricio de Almeida

    2014-01-01

    There has always been concern in determining the relationship between orthodontic tooth movement and the consequent biological costs to the periodontium and tooth root. The possibility of evaluating the tooth and bone morphology by CBCT allows more accurate analysis of qualitative and quantitative aspects of these processes. This paper presents a case report of a 20-year-old male patient with Class III malocclusion and hyperdivergent facial pattern, who was surgically treated. A significant amount of labial movement of mandibular incisors was performed during orthodontic treatment before surgery. CBCT was used for evaluation of buccal and lingual bone plates before and after tooth decompensation. The changes in the bone insertion level of maxillary and mandibular incisors in the present case encourage a reflection on the treatment protocol in individuals with dentoskeletal discrepancies. PMID:25436157

  18. Management of hepatitis C patients with decompensated liver disease.

    PubMed

    Hsu, Ching-Sheng; Kao, Jia-Horng

    2016-06-01

    Little is known about the tolerance and effectiveness of novel oral direct acting antivirals (DAA) in hepatitis C patients with decompensated cirrhosis. To examine the studies relevant to the treatment of hepatitis C virus(HCV)-related decompensated liver disease, we performed computer-based searches for English articles between 1947 and August 2015. Fourteen articles including HCV patients with decompensated cirrhosis were reviewed. The combinations of ledipasvir(LDV)/sofosbuvir(SOF)/ribavirin(RBV) for 12 weeks, or daclatasvir/SOF/RBV for 12 weeks are safe and effective for HCV genotype 1 or 4 infection, and daclatasvir/SOF/RBV for 12 weeks or SOF/RBV for 24 weeks might be effective and safe for HCV genotype 2 or 3 infection. In conclusion, current evidence supports the use of all oral DAA regimens in HCV patients with decompensated cirrhosis. PMID:26782619

  19. Northern Territory Heart Failure Initiative–Clinical Audit (NTHFI–CA)–a prospective database on the quality of care and outcomes for acute decompensated heart failure admission in the Northern Territory: study design and rationale

    PubMed Central

    Iyngkaran, Pupalan; Tinsley, Jeff; Smith, David; Haste, Mark; Nadarajan, Kangaharan; Ilton, Marcus; Battersby, Malcolm; Stewart, Simon; Brown, Alex

    2014-01-01

    Introduction Congestive heart failure is a significant cause of morbidity and mortality in Australia. Accurate data for the Northern Territory and Indigenous Australians are not presently available. The economic burden of this chronic cardiovascular disease is felt by all funding bodies and it still remains unclear what impact current measures have on preventing the ongoing disease burden and how much of this filters down to more remote areas. Clear differentials also exist in rural areas including a larger Indigenous community, greater disease burden, differing aetiologies for heart failure as well as service and infrastructure discrepancies. It is becoming increasingly clear that urban solutions will not affect regional outcomes. To understand regional issues relevant to heart failure management, an understanding of the key performance indicators in that setting is critical. Methods and analysis The Northern Territory Heart Failure Initiative—Clinical Audit (NTHFI-CA) is a prospective registry of acute heart failure admissions over a 12-month period across the two main Northern Territory tertiary hospitals. The study collects information across six domains and five dimensions of healthcare. The study aims to set in place an evidenced and reproducible audit system for heart failure and inform the developing heart failure disease management programme. The findings, is believed, will assist the development of solutions to narrow the outcomes divide between remote and urban Australia and between Indigenous and Non-Indigenous Australians, in case they exist. A combination of descriptive statistics and mixed effects modelling will be used to analyse the data. Ethics and dissemination This study has been approved by respective ethics committees of both the admitting institutions. All participants will be provided a written informed consent which will be completed prior to enrolment in the study. The study results will be disseminated through local and international

  20. [Comprehensive therapy of cerebral and cerebrovascular decompensation (author's transl)].

    PubMed

    Hofmann, G

    1980-06-01

    Many psychiatric syndroms in older age are based on cerebral and cerebrovascular decompensation. Diagnosis of metabolic dysfunction or vascular dysregulation--leading to cerebral decompensation--and their therapy is of greater importance than immediate therapy of psychiatric syndroms. We use Strophantin therapy, hemodilation, stabilization of blood pressure, antidiabetics combined with mild sedation by low dose neuroleptics. After achieving metabolic and cerebrovascular equilibrium we start more or less specific psychiatric syndrom therapy like antidepressants. PMID:6109459

  1. Myofilament calcium sensitization delays decompensated hypertrophy differently between the sexes following myocardial infarction

    PubMed Central

    Shioura, Krystyna M.; Farjah, Mariam; Geenen, David L.; Solaro, R. John

    2011-01-01

    Contractile dysfunction is common to many forms of cardiovascular disease. Approaches directed at enhancing cardiac contractility at the level of the myofilaments during heart failure (HF) may provide a means to improve overall cardiovascular function. We are interested in gender-based differences in cardiac function and the effect of sarcomere activation agents that increase contractility. Thus, we studied the effect of gender and time on integrated arterial-ventricular function (A-V relationship) following myocardial infarction (MI). In addition, transgenic mice that overexpress the slow skeletal troponin I isoform were used to determine the impact of increased myofilament Ca2+ sensitivity following MI. Based on pressure-volume (P-V) loop measurements, we used derived parameters of cardiovascular function to reveal the effects of sex, time, and increased myofilament Ca2+ sensitivity among groups of post-MI mice. Analysis of the A-V relationship revealed that the initial increase was similar between the sexes, but the vascular unloading of the heart served to delay the decompensated stage in females. Conversely, the vascular response at 6 and 10 wk post-MI in males contributed to the continuous decline in cardiovascular function. Increasing the myofilament Ca2+ sensitivity appeared to provide sufficient contractile support to improve contractile function in both male and female transgenic mice. However, the improved contractile function was more beneficial in males as the concurrent vascular response contributed to a delayed decompensated stage in female transgenic mice post-MI. This study represents a quantitative approach to integrating the vascular-ventricular relationship to provide meaningful and diagnostic value following MI. Consequently, the data provide a basis for understanding how the A-V relationship is coupled between males and females and the enhanced ability of the cardiovascular system to tolerate pathophysiological stresses associated with HF in

  2. Influence of bilevel positive airway pressure on autonomic tone in hospitalized patients with decompensated heart failure.

    PubMed

    Lacerda, Diego; Costa, Dirceu; Reis, Michel; Gomes, Evelim Leal de F Dantas; Costa, Ivan Peres; Borghi-Silva, Audrey; Marsico, Aline; Stirbulov, Roberto; Arena, Ross; Sampaio, Luciana Maria Malosá

    2016-01-01

    [Purpose] This study evaluated the effect of Bilevel Positive Airway (BiPAP) on the autonomic control of heart rate, assessed by heart rate variability (HRV), in patients hospitalized with decompensated heart failure. [Subjects and Methods] This prospective cross-sectional study included 20 subjects (age: 69±8 years, 12 male, left ventricular ejection fraction: 36 ±8%) diagnosed with heart failure who were admitted to a semi-intensive care unit with acute decompensation. Date was collected for HRV analysis during: 10 minutes spontaneous breathing in the resting supine position; 30 minutes breathing with BiPAP application (inspiratory pressure = 20 cmH2O and expiratory pressure = 10 cmH2O); and 10 minutes immediately after removal of BiPAP, during the return to spontaneous breathing. [Results] Significantly higher values for indices representative of increased parasympathetic activity were found in the time and frequency domains as well as in nonlinear Poincaré analysis during and after BiPAP in comparison to baseline. Linear HRV analysis: standard deviation of the average of all R-R intervals in milliseconds = 30.99±4.4 pre, 40.3±6.2 during, and 53.3±12.5 post BiPAP. Non-linear HRV analysis: standard deviations parallel in milliseconds = 8.31±4.3 pre, 12.9±5.8 during, and 22.8 ±6.3 post BiPAP. [Conclusion] The present findings demonstrate that BiPAP enhances vagal tone in patients with heart failure, which is beneficial for patients suffering from acute decompensation. PMID:26957719

  3. Influence of bilevel positive airway pressure on autonomic tone in hospitalized patients with decompensated heart failure

    PubMed Central

    Lacerda, Diego; Costa, Dirceu; Reis, Michel; Gomes, Evelim Leal de F. Dantas; Costa, Ivan Peres; Borghi-Silva, Audrey; Marsico, Aline; Stirbulov, Roberto; Arena, Ross; Sampaio, Luciana Maria Malosá

    2016-01-01

    [Purpose] This study evaluated the effect of Bilevel Positive Airway (BiPAP) on the autonomic control of heart rate, assessed by heart rate variability (HRV), in patients hospitalized with decompensated heart failure. [Subjects and Methods] This prospective cross-sectional study included 20 subjects (age: 69±8 years, 12 male, left ventricular ejection fraction: 36 ±8%) diagnosed with heart failure who were admitted to a semi-intensive care unit with acute decompensation. Date was collected for HRV analysis during: 10 minutes spontaneous breathing in the resting supine position; 30 minutes breathing with BiPAP application (inspiratory pressure = 20 cmH2O and expiratory pressure = 10 cmH2O); and 10 minutes immediately after removal of BiPAP, during the return to spontaneous breathing. [Results] Significantly higher values for indices representative of increased parasympathetic activity were found in the time and frequency domains as well as in nonlinear Poincaré analysis during and after BiPAP in comparison to baseline. Linear HRV analysis: standard deviation of the average of all R-R intervals in milliseconds = 30.99±4.4 pre, 40.3±6.2 during, and 53.3±12.5 post BiPAP. Non-linear HRV analysis: standard deviations parallel in milliseconds = 8.31±4.3 pre, 12.9±5.8 during, and 22.8 ±6.3 post BiPAP. [Conclusion] The present findings demonstrate that BiPAP enhances vagal tone in patients with heart failure, which is beneficial for patients suffering from acute decompensation. PMID:26957719

  4. Less Invasive and Inotrope-Reduction Approach to Automated Closed-Loop Control of Hemodynamics in Decompensated Heart Failure.

    PubMed

    Uemura, Kazunori; Kawada, Toru; Zheng, Can; Sugimachi, Masaru

    2016-08-01

    We have been developing an automated cardiovascular drug infusion system for simultaneous control of arterial pressure (AP), cardiac output (CO), and left atrial pressure (PLA) in decompensated heart failure (HF). In our prototype system, CO and PLA were measured invasively through thoracotomy. Furthermore, the control logic inevitably required use of inotropes to improve hemodynamics, which was not in line with clinical HF guidelines. The goal of this study was to solve these problems and develop a clinically feasible system. We integrated to the system minimally invasive monitors of CO and pulmonary capillary wedge pressure (PCWP, surrogates for PLA) that we developed recently. We also redesigned the control logic to reduce the use of inotrope. We applied the newly developed system to nine dogs with decompensated HF. Once activated, our system started to control the infusion of vasodilator and diuretics in all the animals. Inotrope was not infused in three animals, and infused at minimal doses in six animals that were intolerant of vasodilator infusion alone. Within 50 min, our system controlled AP, CO, and PCWP to their respective targets accurately. Pulmonary artery catheterization confirmed optimization of hemodynamics (AP, from 98 ± 4 to 74 ± 11 mmHg; CO, from 2.2 ± 0.5 to 2.9 ± 0.3 L·min(-1)·m(-2); PCWP, from 27.0 ± 6.6 to 13.8 ± 3.0 mmHg). In a minimally invasive setting while reducing the use of inotrope, our system succeeded in automatically optimizing the overall hemodynamics in canine models of HF. The present results pave the way for clinical application of our automated drug infusion system. PMID:26571509

  5. [Self-neglect as a sign of decompensation].

    PubMed

    Jean-Louis, Eric

    2015-01-01

    A lack of hygiene to which the patient appears indifferent, self-neglect can be a sign of the decompensation of a mental pathology. This article presents the case of a patient who, after several months of stabilisation and a return home to a relatively clean environment, reactivates a delusion of persecution. PMID:26100293

  6. Retained IOL fragment and corneal decompensation after pseudophakic IOL exchange.

    PubMed

    Hoffman, Richard S; Fine, I Howard; Packer, Mark

    2004-06-01

    A 72-year-old man had exchange of a foldable silicone multifocal intraocular lens (IOL) by transection, removal, and monofocal IOL replacement. One month after the exchange, irreversible corneal edema developed and penetrating keratoplasty was performed. At the time of the corneal transplant, a small silicone fragment was discovered in and removed from the anterior chamber. Histologic evaluation of the patient's cornea demonstrated an absence of corneal endothelium, suggesting the fragment was the etiology of the corneal decompensation. PMID:15177618

  7. Predictors of fifty days in-hospital mortality in decompensated cirrhosis patients with spontaneous bacterial peritonitis

    PubMed Central

    Bal, Chinmaya Kumar; Daman, Ripu; Bhatia, Vikram

    2016-01-01

    AIM: To determine the predictors of 50 d in-hospital mortality in decompensated cirrhosis patients with spontaneous bacterial peritonitis (SBP). METHODS: Two hundred and eighteen patients admitted to an intensive care unit in a tertiary care hospital between June 2013 and June 2014 with the diagnosis of SBP (during hospitalization) and cirrhosis were retrospectively analysed. SBP was diagnosed by abdominal paracentesis in the presence of polymorphonuclear cell count ≥ 250 cells/mm3 in the peritoneal fluid. Student’s t test, multivariate logistic regression, cox proportional hazard ratio (HR), receiver operating characteristics (ROC) curves and Kaplan-Meier survival analysis were utilized for statistical analysis. Predictive abilities of several variables identified by multivariate analysis were compared using the area under ROC curve. P < 0.05 were considered statistical significant. RESULTS: The 50 d in-hospital mortality rate attributable to SBP is 43.11% (n = 94). Median survival duration for those who died was 9 d. In univariate analysis acute kidney injury (AKI), hepatic encephalopathy, septic shock, serum bilirubin, international normalized ratio, aspartate transaminase, and model for end-stage liver disease - sodium (MELD-Na) were significantly associated with in - hospital mortality in patients with SBP (P ≤ 0.001). Multivariate cox proportional regression analysis showed AKI (HR = 2.16, 95%CI: 1.36-3.42, P = 0.001) septic shock (HR = 1.73, 95%CI: 1.05-2.83, P = 0.029) MELD-Na (HR = 1.06, 95%CI: 1.02-1.09, P ≤ 0.001) was significantly associated with 50 d in-hospital mortality. The prognostic accuracy for AKI, MELD-Na and septic shock was 77%, 74% and 71% respectively associated with 50 d in-hospital mortality in SBP patients. CONCLUSION: AKI, MELD-Na and septic shock were predictors of 50 d in-hospital mortality in decompensated cirrhosis patients with SBP. PMID:27134704

  8. Demographics, Clinical Characteristics, Management, and Outcomes of Acute Heart Failure Patients: Observations from the Oman Acute Heart Failure Registry

    PubMed Central

    Panduranga, Prashanth; Sulaiman, Kadhim; Al-Zakwani, Ibrahim; Alazzawi, Aouf AbdlRahman; Abraham, Abraham; Singh, Prit Pal; Narayan, Narayan Anantha; Rajarao, Mamatha Punjee; Khdir, Mohammed Ahmed; Abdlraheem, Mohamad; Siddiqui, Aftab Ahmed; Soliman, Hisham; Elkadi, Osama Abdellatif; Bichu, Ruchir Kumar; Al Lawati, Kumayl Hasan

    2016-01-01

    Objectives We sought to describe the demographics, clinical characteristics, management and outcomes of patients in Oman with acute heart failure (AHF) as part of the Gulf aCute heArt failuRe rEgistry (CARE) project. Methods Data were analyzed from 988 consecutive patients admitted with AHF to 12 hospitals in Oman between 14 February and 14 November 2012. Results The mean age of our patients was 63±12 years. Over half (57%) were male and 95% were Omani citizens. Fifty-seven percent of patients presented with acute decompensated chronic heart failure (ADCHF) while 43% had new-onset AHF. The primary comorbid conditions were hypertension (72%), coronary artery disease (55%), and diabetes mellitus (53%). Ischemic heart disease (IHD), hypertensive heart disease, and idiopathic cardiomyopathy were the most common etiologies of AHF in Oman. The median left ventricular ejection fraction of the cohort was 36% (27–45%) with 56% of the patients having heart failure with reduced ejection fraction (< 40%). Atrial fibrillation was seen in 15% of patients. Acute coronary syndrome (ACS) and non-compliance with medications were the most common precipitating factors. At discharge, angiotensin converting enzyme inhibitors and beta-blockers were prescribed adequately, but aldosterone antagonists were under prescribed. Within 12-months follow-up, one in two patients were rehospitalized for AHF. In-hospital mortality was 7.1%, which doubled to 15.7% at three months and reached 26.4% at one-year post discharge. Conclusions Oman CARE was the first prospective multicenter registry of AHF in Oman and showed that heart failure (HF) patients present at a younger age with recurrent ADCHF and HF with reduced ejection fraction. IHD was the most common etiology of HF with a low prevalence of AHF, but a high prevalence of acute coronary syndrome and non-compliance with medications precipitating HF. A quarter of patients died at one-year follow-up even though at discharge medical therapy was

  9. Response to the NCEPOD report: development of a care bundle for patients admitted with decompensated cirrhosis—the first 24 h

    PubMed Central

    McPherson, Stuart; Dyson, Jessica; Austin, Andrew; Hudson, Mark

    2016-01-01

    Recently, there has been a significant increase in the prevalence of chronic liver disease in the UK, and as a result, hospital admissions and deaths due to liver disease have also increased. The 2013 National Confidential Enquiry into Patient Outcome and Death (NCEPOD) of patients with alcohol-related liver disease (ARLD) found that less than half the number of patients who died from ARLD received ‘good care’, and avoidable deaths were identified. In order to improve the care of patients admitted with ARLD, the NCEPOD report recommended that a ‘toolkit’ for the acute management of patients admitted with decompensated ARLD be developed and made widely available. As a result, we have developed a ‘care bundle’ for patients admitted with decompensated cirrhosis (of all aetiologies) to ensure that effective evidence-based treatments are delivered within the first 24 h. This care bundle provides a checklist to ensure that all appropriate investigations are undertaken when a patient with decompensated cirrhosis presents and provides clinicians with clear guidance on the initial management of alcohol withdrawal, infection, acute kidney injury, gastrointestinal bleeding and encephalopathy. The first 24 h are particularly important, as early intervention can reduce mortality and shorten hospital stay, and specialist gastroenterology/liver advice is not always available during this period. This review will discuss the care bundle and the evidence base behind the treatment recommendations made. PMID:26834955

  10. Prognostic and diagnostic value of plasma soluble ST2 concentrations in Acute Respiratory Distress Syndrome

    PubMed Central

    Bajwa, Ednan K.; Volk, Jessica A.; Christiani, David C.; Harris, R. Scott; Matthay, Michael A.; Thompson, B. Taylor; Januzzi, James L.

    2013-01-01

    Objective Soluble ST2 (sST2) is a biomarker of myocardial strain and inflammation. The characteristics of acute respiratory distress syndrome (ARDS) include inflammation and cardiovascular dysfunction. We sought to determine whether plasma sST2 concentration is associated with outcome and response to conservative fluid management, and whether sST2 concentration discriminates ARDS from decompensated heart failure (HF). Design, Setting, and Patients We assayed plasma sST2 concentrations in 826 patients in the Fluid and Catheter Treatment Trial (FACTT), a multi-center randomized controlled trial of conservative fluid management in ARDS, as well as a cohort of patients with decompensated HF. We tested whether sST2 was associated with outcome, response to therapy, and diagnostic utility for ARDS vs. HF. Measurements and Main Results Non-survivors had higher day 0 (P<.0001) and day 3 (P<.0001) sST2 concentrations. After adjustment for severity of illness, higher sST2 concentration was associated with mortality, with odds ratio (ORadj) 1.47 (95% confidence interval [CI] 0.99 – 2.20, P=.06) at day 0, 2.94 (95% CI 2.00 – 4.33, P<.0001) at day 3, and 3.63 (95% CI 2.38 – 5.53, P<.0001) if sST2 increased between days. Cumulative fluid balance was more positive among patients with higher day 0 (median 5212 mL, interquartile range [IQR] 200 – 12284 vs. 2020 mL, −2034 – 7091; P<0.0001), and day 3 sST2 (median 7678 mL, IQR 2217 – 14278 vs. 1492 mL, −2384 – 6239; P<0.0001). sST2 showed excellent discriminative ability between the FACTT and HF populations (Area under ROC curve=0.98, P<0.0001). Conclusions Higher sST2 concentrations are associated with worse outcome in ARDS and may have value for discriminating ARDS from heart failure. PMID:23939353

  11. Dissociative detachment relates to psychotic symptoms and personality decompensation.

    PubMed

    Allen, J G; Coyne, L; Console, D A

    1997-01-01

    Previous studies have addressed the prominence of psychotic symptoms in conjunction with multiple personality disorder (now dissociative identity disorder). The present study examines the relation between psychotic symptoms and a more pervasive form of dissociative disturbance, namely dissociative detachment. Two hundred sixty-six women in inpatient treatment for severe trauma-related disorders completed the Dissociative Experiences Scale (DES), and 102 of these patients also completed the Millon Clinical Multiaxial Inventory (MCMI-III). A factor analysis of the DES yielded two dimensions of dissociative detachment: detachment from one's own actions and detachment from the self and the environment. Each of these DES dimensions relates strongly to the thought disorder and schizotypal personality disorder scales of the MCMI-III. We propose that severe dissociative detachment, by virtue of loosening the moorings in inner and outer reality, is conducive to psychotic symptoms and personality decompensation. PMID:9406738

  12. Supermarine Spitfire HF VII

    NASA Technical Reports Server (NTRS)

    1944-01-01

    Supermarine Spitfire HF VII: This Supermarine Spitfire HF VII was one of high-altitude versions of the famous fighter, its normal elliptical wingtips replaced by extended 'pointed' tips for its high-altitude role. This is one of the Langley aircraft that has survived. It is in the Smithsonian Institution's National Air and Space Museum's collection.

  13. Prescribing Medications in Patients with Decompensated Liver Cirrhosis

    PubMed Central

    Amarapurkar, Deepak N.

    2011-01-01

    Patients with decompensated liver cirrhosis have various serious complications which require multiple drugs for therapeutic or prophylactic use. Majority of the drugs are primarily metabolized and excreted by hepatobiliary system; hence, liver cell necrosis contributes to impaired drug handling in liver failure while portosystemic shunt can alter drug action in cirrhosis. Hence, in order to decide drug dosing in liver failure, 3 important factors need to be considered (1) pharmacokinetic alterations of drugs, (2) pharmacodynamic alteration of drugs, and (3) increased susceptibility of patients to adverse events particularly hepatotoxicity. Though there is no predictable test which can be used to determine drug dosage in patients with decompensated liver cirrhosis, drugs with first pass metabolism require reduction in oral dosages, for high clearance drugs both loading and maintenance dosages need adjustment, for low clearance drugs maintenance dose needs adjustment, whenever possible measuring drug level in the blood and monitoring of adverse events frequently should be done. No evidence-based guidelines exist for the use of medication in patients' with liver cirrhosis. There are hardly any prospective studies on the safety of drugs in cirrhotic patients. According to the experts opinion, most of the drugs can be used safely in patients with cirrhosis, but drug-induced hepatotoxicity may be poorly tolerated by patients with cirrhosis; hence, potential hepatotoxins should be avoided in patients with liver cirrhosis. Potentially hepatotoxic drugs may be used in patients with liver cirrhosis based on the clinical needs and when there are no alternatives available. Caveat for the prescribing medications in patients with cirrhosis the drug dosing should be individualized depending on a number of factors like nutritional status, renal function, adherence, and drug interaction. Monitoring of the liver function at frequent intervals is highly recommended. PMID:21994861

  14. Decompensated Liver Cirrhosis Presenting as a Spontaneous Left-Sided Bacterial Empyema

    PubMed Central

    Nathoo, Sunina

    2016-01-01

    Decompensation of cirrhosis presents with ascites, encephalopathy, variceal bleeding, or spontaneous bacterial peritonitis. Infrequently, decompensation can result from spontaneous bacterial empyema. A 38-year-old man presented with fevers, chills, and dyspnea. Labs were significant for leukocytosis, transaminitis, and coagulopathy. Imaging showed liver cirrhosis with ascites and a left pleural effusion. Treatment of the effusion consisted of chest tube drainage and antibiotics. Spontaneous bacterial empyema was diagnosed after pleural fluid cultures were positive for Escherichia coli. Our case demonstrates that spontaneous bacterial empyemas can be left-sided, and the first sign of decompensation. PMID:26958567

  15. Decompensated Liver Cirrhosis Presenting as a Spontaneous Left-Sided Bacterial Empyema.

    PubMed

    Chertoff, Jason; Nathoo, Sunina

    2016-01-01

    Decompensation of cirrhosis presents with ascites, encephalopathy, variceal bleeding, or spontaneous bacterial peritonitis. Infrequently, decompensation can result from spontaneous bacterial empyema. A 38-year-old man presented with fevers, chills, and dyspnea. Labs were significant for leukocytosis, transaminitis, and coagulopathy. Imaging showed liver cirrhosis with ascites and a left pleural effusion. Treatment of the effusion consisted of chest tube drainage and antibiotics. Spontaneous bacterial empyema was diagnosed after pleural fluid cultures were positive for Escherichia coli. Our case demonstrates that spontaneous bacterial empyemas can be left-sided, and the first sign of decompensation. PMID:26958567

  16. Acute and subacute toxicity tests of onion coat, natural colorant extracted from onion (Allium cepa L.), in (C57BL/6 x C3H)F1 mice.

    PubMed

    Kojima, T; Tanaka, T; Mori, H; Kato, Y; Nakamura, M

    1993-01-01

    The toxicity test of onion coat colorant (OC), a food colorant extracted from onion (Allium cepa L.), was undertaken using (C57BL/6 x C3H)F1 mice of both sexes for the safety assessment of this product. The acute toxicity test was performed by administration of OC suspended in corn oil by gavage at doses of 2500, 5000, 7500, and 10,000 mg/kg body weight to groups of 5 or 6 males and 6 or 7 females, maintained for 14 d. Six of 12 females dosed at 10,000 mg/kg body weight and 3 of 11 females dosed at 7500 mg/kg body weight were dead before the end of the study, indicating that the tolerated dose of OC was between 7500 and 5000 mg/kg body weight. The subacute toxicity test of OC was examined using 123 mice of both sexes (62 males and 61 females) by feeding a diet mixed with OC at concentrations of 5, 2.5, 1.25, 0.6, and 0.3% for 90 d. All mice tolerated these doses of OC well. The body weight gains of male and female mice were not affected by the treatment. Histopathological examinations showed that hyperplastic changes in the esophagus, forestomach, pancreas, cervix, and endometrium of mice were found in treated and control mice. However, their incidences were not related to the dose of OC. Moreover, only a spontaneous ovarian teratoma was found in an OC-treated mouse. These results suggest that OC has no acute and subacute toxic effects in mice. PMID:8421325

  17. Acute Effects of Continuous Positive Air way Pressure on Pulse Pressure in Chronic Heart Failure

    PubMed Central

    Quintão, Mônica; Chermont, Sérgio; Marchese, Luana; Brandão, Lúcia; Bernardez, Sabrina Pereira; Mesquita, Evandro Tinoco; Rocha, Nazareth de Novaes; Nóbrega, Antônio Claudio L.

    2014-01-01

    Background Patients with heart failure (HF) have left ventricular dysfunction and reduced mean arterial pressure (MAP). Increased adrenergic drive causes vasoconstriction and vessel resistance maintaining MAP, while increasing peripheral vascular resistance and conduit vessel stiffness. Increased pulse pressure (PP) reflects a complex interaction of the heart with the arterial and venous systems. Increased PP is an important risk marker in patients with chronic HF (CHF). Non-invasive ventilation (NIV) has been used for acute decompensated HF, to improve congestion and ventilation through both respiratory and hemodynamic effects. However, none of these studies have reported the effect of NIV on PP. Objective The objective of this study was to determine the acute effects of NIV with CPAP on PP in outpatients with CHF. Methods Following a double-blind, randomized, cross-over, and placebo-controlled protocol, twenty three patients with CHF (17 males; 60 ± 11 years; BMI 29 ± 5 kg/cm2, NYHA class II, III) underwent CPAP via nasal mask for 30 min in a recumbent position. Mask pressure was 6 cmH2O, whereas placebo was fixed at 0-1 cmH2O. PP and other non invasive hemodynamics variables were assessed before, during and after placebo and CPAP mode. Results CPAP decreased resting heart rate (Pre: 72 ± 9; vs. Post 5 min: 67 ± 10 bpm; p < 0.01) and MAP (CPAP: 87 ± 11; vs. control 96 ± 11 mmHg; p < 0.05 post 5 min). CPAP decreased PP (CPAP: 47 ± 20 pre to 38 ± 19 mmHg post; vs. control: 42 ± 12 mmHg, pre to 41 ± 18 post p < 0.05 post 5 min). Conclusion NIV with CPAP decreased pulse pressure in patients with stable CHF. Future clinical trials should investigate whether this effect is associated with improved clinical outcome. PMID:24676373

  18. Chemical pleurodesis for the management of refractory hepatic hydrothorax in patients with decompensated liver cirrhosis

    PubMed Central

    Lee, Woo Jin; Park, Jung Ho; Park, Dong Il; Cho, Yong Kyun; Sohn, Chong Il; Jeon, Woo Kyu; Kim, Byung Ik

    2011-01-01

    Background/Aims Hepatic hydrothorax in patients with decompensated liver cirrhosis is a challenging problem. Treatment with diuretics and intermittent thoracentesis can be effective in selected patients. However, there are few effective therapeutic options in patients who are intolerant of these therapies. This study investigated the clinical usefulness of chemical pleurodesis with or without video-assisted thoracoscopic surgery (VATS) for patients with refractory hepatic hydrothorax. Methods Eleven consecutive patients with refractory hepatic hydrothorax who underwent chemical pleurodesis with or without VATS between July 2007 and February 2011 were enrolled in this study. The medical records and radiologic imagings of these patients were thoroughly reviewed. Results The median number of chemical pleurodesis sessions performed was 3 (range: 2-10). Successful pleurodesis was achieved in 8 of the 11 patients (72.7%), 5 (62.5%) of whom remained asymptomatic and hydrothorax free for a median follow-up of 16 weeks (range: 2-52 weeks). Complications were low-grade fever/leukocytosis (n=11, 100%), pneumonia (n=1, 9.1%), pneumothorax (n=4, 36.4%), azotemia/acute renal failure (n=6, 54.6%), and hepatic encephalopathy (n=4, 36.4%). Five patients were suspected as having procedure-related mortality (45.5%) due to the occurrence of acute renal failure with hepatic failure. The overall survival was significantly longer in the success group than in the non-success group. Conclusions Although chemical pleurodesis may improve the clinical symptoms and the radiologic findings in as many as 72.7% of patients with refractory hepatic hydrothorax, a significantly high prevalence of procedure-related morbidity and mortality hinders the routine application of this procedure for such patients. PMID:22310793

  19. Postoperative Risk of Hepatic Decompensation after Orthopedic Surgery in Patients with Cirrhosis

    PubMed Central

    Nyberg, Eric M.; Batech, Michael; Cheetham, T. Craig; Pio, Jose R.; Caparosa, Susan L.; Chocas, Mary Alice; Singh, Anshuman

    2016-01-01

    Abstract Background and Aims: Previous studies have shown increased hepatic decompensation in patients with cirrhosis undergoing surgery. However, there are little data available in cirrhotics undergoing orthopedic surgery compared to cirrhotics who did not undergo surgery. The aim of this study was to examine the demographics, comorbid conditions, and clinical factors associated with hepatic decompensation within 90 days in cirrhotics who underwent orthopedic surgery. Methods: This is a retrospective matched cohort study. Inclusion criteria were cirrhosis diagnosis, age > 18 years, ≥ 6 months continuous health plan membership, and a procedure code for orthopedic surgery. Up to five cirrhotic controls without orthopedic surgery were matched on age, gender, and cirrhosis diagnosis date. Data abstraction was performed for demographics, socioeconomics, clinical, and decompensation data. Chart review was performed for validation. Multivariable analysis estimated relative risk of decompensation. Results: Eight hundred fifty-three orthopedic surgery cases in cirrhotics were matched with 4,263 cirrhotic controls. Among the cases and matched controls, the mean age was 60.5 years, and 52.2% were female. Within 90 days after surgery, cases had more decompensation compared to matched controls (12.8% vs 4.9%). Using multivariable analysis, orthopedic surgery, a 0.5 g/dL decrease in serum albumin, and a 1-unit increase in Charlson Comorbidity Index were associated with a significant increase in decompensation within 90 days of surgery. Diabetes, chronic obstructive pulmonary disease, and chronic kidney disease were seen with increased frequency in cases vs. matched controls. Conclusions: Cirrhotics who underwent orthopedic surgery had a significant increase in hepatic decompensation within 90 days of surgery compared to matched controls. An incremental decrease in serum albumin and an incremental increase in the Charlson Comorbidity Index were significantly associated with

  20. [Critically ill patients with decompensated liver cirrhosis - New aspects and intensive care management].

    PubMed

    Maschmeier, Miriam; Hüsing, Anna; Schmidt, Hartmut; Kabar, Iyad

    2015-10-01

    The prevalence of liver cirrhosis in the German population is about 1 %. Clinically, compensated liver cirrhosis should be distinguished from decompensated cirrhosis with poor prognosis. Decompensated cirrhosis is defined by the occurrence of complications and consequences of portal hypertension (such as ascites, variceal bleeding, hepatic encephalopathy and hepatorenal syndrome) and progressive liver failure. Optimizing the management of these patients in the intensive care unit could essentially improve their outcome. PMID:26445254

  1. [Acute heart failure: precipitating factors and prevention].

    PubMed

    Aramburu Bodas, Oscar; Conde Martel, Alicia; Salamanca Bautista, Prado

    2014-03-01

    Acute heart failure episodes, whether onset or decompensation of a chronic form, are most often precipitated by a concurrent process or disease, described as precipitating factors of heart failure. In this article, we review these precipitating factors, their proportions and clinical relevance in general and in subgroups of patients, their relationship with prognosis, and their possible prevention. PMID:24930077

  2. Update: Acute Heart Failure (VII): Nonpharmacological Management of Acute Heart Failure.

    PubMed

    Plácido, Rui; Mebazaa, Alexandre

    2015-09-01

    Acute heart failure is a major and growing public health problem worldwide with high morbidity, mortality, and cost. Despite recent advances in pharmacological management, the prognosis of patients with acute decompensated heart failure remains poor. Consequently, nonpharmacological approaches are being developed and increasingly used. Such techniques may include several modalities of ventilation, ultrafiltration, mechanical circulatory support, myocardial revascularization, and surgical treatment, among others. This document reviews the nonpharmacological approach in acute heart failure, indications, and prognostic implications. PMID:26169327

  3. Parathyroid hormone accelerates decompensation following left ventricular hypertrophy

    PubMed Central

    Cha, Hyeseon; Jeong, Hyeon Joo; Jang, Seung Pil; Kim, Joo Yeon; Yang, Dong Kwon; Oh, Jae Gyun

    2010-01-01

    Parathyroid hormone (PTH) treatment was previously shown to improve cardiac function after myocardial infarction by enhancing neovascularization and cell survival. In this study, pressure overload-induced left ventricular hypertrophy (LVH) was induced in mice by transverse aortic banding (TAB) for 2 weeks. We subsequently evaluated the effects of a 2-week treatment with PTH or saline on compensated LVH. After another 4 weeks, the hearts of the mice were analyzed by echocardiography, histology, and molecular biology. Echocardiography showed that hearts of the PTH-treated mice have more severe failing phenotypes than the saline-treated mice following TAB with a greater reduction in fractional shortening and left ventricular posterior wall thickness and with a greater increase in left ventricular internal dimension. Increases in the heart weight to body weight ratio and lung weight to body weight ratio following TAB were significantly exacerbated in PTH-treated mice compared to saline-treated mice. Molecular markers for heart failure, fibrosis, and angiogenesis were also altered in accordance with more severe heart failure in the PTH-treated mice compared to the saline-treated mice following TAB. In addition, the PTH-treated hearts were manifested with increased fibrosis accompanied by an enhanced SMAD2 phosphorylation. These data suggest that the PTH treatment may accelerate the process of decompensation of LV, leading to heart failure. PMID:19887893

  4. Severe steatohepatitis with hepatic decompensation resulting from malnutrition after pancreaticoduodenectomy

    PubMed Central

    Sim, Eun Hui; Kim, Se Young; Jung, Seung Min; Maeng, Lee-So; Jang, Jeong Won; Chung, Kyu Won

    2012-01-01

    The most common finding related to nonalcoholic steatohepatitis is obesity, but a status of severe malnutrition can also induce the steatohepatitis. The authors report a rare case of steatohepatitis leading to hepatic decompensation caused by malnutrition after pancreaticoduodenectomy. A 68-year-old female patient who had been previously diagnosed with pancreatic cancer and had undergone pancreaticoduodenectomy 5 months previously presented with abdominal distension. Routine CT performed 3 months after the surgery revealed severe fatty liver without evidence of tumor recurrence. After undergoing pancreaticoduodenectomy her food intake had reduced, and as a result she had lost 7 kg of body weight over 2 months. At this admission, CT revealed moderate amounts of ascites without tumor recurrence. Furthermore, her albumin and lipid profile levels were markedly decreased, and she had a flapping tremor and slurred speech suggestive of hepatic encephalopathy. Her liver biopsy findings were consistent with steatohepatitis and disclosed macrovesicular steatosis without definite fibrosis. After careful nutritional control, her symptoms disappeared and her laboratory findings improved. PMID:23323257

  5. Role of the acute care nurse in managing patients with heart failure using evidence-based care.

    PubMed

    Paul, Sara; Hice, Amber

    2014-01-01

    Acute heart failure is a major US public health problem, accounting for more than 1 million hospitalizations each year. As part of the health care team, nurses play an important role in the evaluation and management of patients presenting to the emergency department with acute decompensated heart failure. Once acute decompensation is controlled, nurses also play a critical role in preparing patients for hospital discharge and educating patients and caregivers about strategies to improve long-term outcomes and prevent future decompensation and rehospitalization. Nurses' assessment skills and comprehensive knowledge of acute and chronic heart failure are important to optimize patient care and improve outcomes from initial emergency department presentation through discharge and follow-up. This review presents an overview of current heart failure guidelines, with the goal of providing acute care cardiac nurses with information that will allow them to better use their knowledge of heart failure to facilitate diagnosis, management, and education of patients with acute heart failure. PMID:25185764

  6. Serum Sphingolipid Variations Associate with Hepatic Decompensation and Survival in Patients with Cirrhosis

    PubMed Central

    Grammatikos, Georgios; Ferreiròs, Nerea; Waidmann, Oliver; Bon, Dimitra; Schroeter, Sirkka; Koch, Alexander; Herrmann, Eva; Zeuzem, Stefan; Kronenberger, Bernd; Pfeilschifter, Josef

    2015-01-01

    Background Sphingolipids constitute bioactive molecules with functional implications in liver homeostasis. Particularly, ablation of very long chain ceramides in a knockout mouse model has been shown to cause a severe hepatopathy. Methods We aimed to evaluate the serum sphingolipid profile of 244 patients with cirrhosis prospectively followed for a median period of 228±217 days via mass spectrometry. Results We thereby observed a significant decrease of long and very long chain ceramides, particularly of C24ceramide, in patients with increasing severity of cirrhosis (p<0.001). Additionally, hydropic decompensation, defined by clinical presentation of ascites formation, was significantly correlated to low C24ceramide levels (p<0.001) while a significant association to hepatic decompensation and poor overall survival was observed for low serum concentrations of C24ceramide (p<0.001) as well. Multivariate analysis further identified low serum C24ceramide to be independently associated to overall survival (standard beta = -0.001, p = 0.022). Conclusions In our current analysis serum levels of very long chain ceramides show a significant reciprocal correlation to disease severity and hepatic decompensation and are independently associated with overall survival in patients with cirrhosis. Serum sphingolipid metabolites and particularly C24ceramide may constitute novel molecular targets of disease severity, hepatic decompensation and overall prognosis in cirrhosis and should be further evaluated in basic research studies. PMID:26382760

  7. Autonomic Predictors of Hospitalization Due to Heart Failure Decompensation in Patients with Left Ventricular Systolic Dysfunction

    PubMed Central

    Suchecka, Justyna; Niemirycz-Makurat, Agnieszka; Rozwadowska, Katarzyna

    2016-01-01

    Introduction Autonomic nervous system balance can be significantly deteriorated during heart failure exacerbation. However, it is still unknown whether these changes are only the consequence of heart failure decompensation or can also predict development thereof. Objectives were to verify if simple, non-invasive autonomic parameters, such as baroreflex sensitivity and short-term heart rate variability can provide independent of other well-known clinical parameters information on the risk of heart failure decompensation in patients with left ventricular systolic dysfunction. Methods In 142 stable patients with left ventricular ejection fraction ≤ 40%, baroreflex sensitivity and short-term heart rate variability, as well as other well-known clinical parameters, were analyzed. During 23 ± 9 months of follow-up 19 patients were hospitalized due to the heart failure decompensation (EVENT). Results Pre-specified cut-off values of baroreflex sensitivity (≤2.4 ms/mmHg) and low frequency power index of heart rate variability (≤19 ms2) were significantly associated with the EVENTs (hazard ratio 4.43, 95% confidence interval [CI] 1.35–14.54 and 5.41, 95% CI 1.87–15.65 respectively). EVENTs were also associated with other parameters, such as left ventricular ejection fraction, NYHA class, diuretic use, renal function, brain natriuretic peptide and hemoglobin level, left atrial size, left and right ventricular heart failure signs. After adjusting baroreflex sensitivity and low frequency power index for each of the abovementioned parameters, autonomic parameters were still significant predictors of hospitalization due to the heart failure decompensation. Conclusion Simple, noninvasive autonomic indices can be helpful in identifying individuals with increased risk of hospitalization due to the heart failure decompensation among clinically stable patients with left ventricular systolic dysfunction, even when adjusted for other well-known clinical parameters. PMID

  8. Acute Management of Propionic Acidemia

    PubMed Central

    Chapman, Kimberly A; Gropman, Andrea; MacLeod, Erin; Stagni, Kathy; Summar, Marshall L.; Ueda, Keiko; Mew, Nicholas Ah; Franks, Jill; Island, Eddie; Matern, Dietrich; Pena, Loren; Smith, Brittany; Sutton, V. Reid; Urv, Tiina; Venditti, Charles; Chakrapani, Anupam

    2014-01-01

    Propionic Acidemia or aciduria is an intoxication-type disorder of organic metabolism. Patients deteriorate in times of increased metabolic demand and subsequent catabolism. Metabolic decompensation can manifest with lethargy, vomiting, coma and death if not appropriately treated. On January 28-30, 2011 in Washington, D.C., Children's National Medical Center hosted a group of clinicians, scientists and parental group representatives to design recommendations for acute management of individuals with Propionic Acidemia. Although many of the recommendations are geared towards the previously undiagnosed neonate, the recommendations for a severely metabolically decompensated individual are applicable to any known patient as well. Initial management is critical for prevention of morbidity and mortality. The following manuscript provides recommendations for initial treatment and evaluation, a discussion of issues concerning transport to a metabolic center (if patient presents to a non-metabolic center), acceleration of management and preparation for discharge. PMID:22000903

  9. Pulsed inductive HF laser

    NASA Astrophysics Data System (ADS)

    Razhev, A. M.; Churkin, D. S.; Kargapol'tsev, E. S.; Demchuk, S. V.

    2016-03-01

    We report the results of experimentally investigated dependences of temporal, spectral and spatial characteristics of an inductive HF-laser generation on the pump conditions. Gas mixtures H2 – F2(NF3 or SF66) and He(Ne) – H2 – F2(NF3 or SF6) were used as active media. The FWHM pulse duration reached 0.42 μs. This value corresponded to a pulsed power of 45 kW. For the first time, the emission spectrum of an inductive HF laser was investigated, which consisted of seven groups of bands with centres around the wavelengths of 2732, 2736, 2739, 2835, 2837, 2893 and 2913 nm. The cross section profile of the laser beam was a ring with a diameter of about 20 mm and width of about 5 mm. Parameters of laser operation in the repetitively pulsed regime were sufficiently stable. The amplitude instability of light pulses was no greater than 5% – 6%.

  10. A conceptual model of compensation/decompensation in lumbar segmental instability.

    PubMed

    Barz, T; Melloh, M; Lord, S J; Kasch, R; Merk, H R; Staub, L P

    2014-09-01

    Lumbar spinal instability (LSI) is a common spinal disorder and can be associated with substantial disability. The concept of defining clinically relevant classifications of disease or 'target condition' is used in diagnostic research. Applying this concept to LSI we hypothesize that a set of clinical and radiological criteria can be developed to identify patients with this target condition who are at high risk of 'irreversible' decompensated LSI for whom surgery becomes the treatment of choice. In LSI, structural deterioration of the lumbar disc initiates a degenerative cascade of segmental instability. Over time, radiographic signs become visible: traction spurs, facet joint degeneration, misalignment, stenosis, olisthesis and de novo scoliosis. Ligaments, joint capsules, local and distant musculature are the functional elements of the lumbar motion segment. Influenced by non-functional factors, these functional elements allow a compensation of degeneration of the motion segment. Compensation may happen on each step of the degenerative cascade but cannot reverse it. However, compensation of LSI may lead to an alleviation or resolution of clinical symptoms. In return, the target condition of decompensation of LSI may cause the new occurrence of symptoms and pain. Functional compensation and decompensation are subject to numerous factors that can change which makes estimation of an individual's long-term prognosis difficult. Compensation and decompensation may influence radiographic signs of degeneration, e.g. the degree of misalignment and segmental angulation caused by LSI is influenced by the tonus of the local musculature. This conceptual model of compensation/decompensation may help solve the debate on functional and psychosocial factors that influence low back pain and to establish a new definition of non-specific low back pain. Individual differences of identical structural disorders could be explained by compensated or decompensated LSI leading to changes

  11. Predictors of Acute Hemodynamic Decompensation in Early Sepsis: An Observational Study

    PubMed Central

    Lee, Young Im; Smith, Robert L.; Gartshteyn, Yevgeniya; Kwon, Sophia; Caraher, Erin J.; Nolan, Anna

    2016-01-01

    Background The study of sepsis is hindered by its heterogeneous time course and evolution. A subgroup of patients with severe sepsis develops shock soon after the initiation of treatment while others present hypotensive. We sought to determine the incidence of hypotension after the initiation of treatment for sepsis, and characterize their clinical features and course. Methods A retrospective review of electronic medical record of all septic patients (n = 542) that met the definition of septic shock within 24 hours of admission (2011 - 2012) at an urban Veteran Affairs Hospital was performed. Subjects either had 1) initial normotension (INT) with hypotension developing within 24 hours or 2) initial hypotension (IH). Logistic regression was used to model associated factors of INT/IH. Results INT occurred in 62 patients (11%) with average initial blood pressure of 120/71 mm Hg and developed hypotension to 79/48 mm Hg. IH was identified in 52 patients (10%) with average presenting blood pressure of 81/46 mm Hg. INT showed evidence of increased sympathetic tone with significantly higher heart rate, blood pressure and temperature. INT patients were younger, more frequently on alpha-blockers, and more likely septic from pneumonia compared to IH patients. INT and IH patients had similar timing of antibiotic initiation, amount of 24-hour fluid resuscitation, vasopressor use, organ dysfunction and mortality at 28 days. Using alpha-blockers, being Caucasian, and having higher temperatures were independent predictors of INT. Conclusion INT is a distinctive presentation of septic shock characterized by rapid deterioration during early treatment. By further studying this subgroup, mediators of septic shock may be identified that clarify pathophysiology and provide timely targeted treatment. PMID:27429677

  12. Corneal decompensation following filtering surgery with the Ex-PRESS® mini glaucoma shunt device

    PubMed Central

    Tojo, Naoki; Hayashi, Atsushi; Miyakoshi, Akio

    2015-01-01

    Purpose To report a case of corneal decompensation due to the Ex-PRESS® mini glaucoma shunt device (Ex-PRESS). Patient and methods A 75-year-old man had pseudoexfoliation glaucoma in his right eye. He underwent filtration surgery with Ex-PRESS. His intraocular pressure was 7 mmHg after 9 months. Results We observed partial decompensation of the corneal endothelium adjacent to the filtering bleb. Specular microscopy revealed a marked decrease in the endothelial cell density at the center of the cornea. Conclusion Anterior segment optical coherence tomography is very useful for evaluating corneal edema and the position of Ex-PRESS. It is important to follow up with an examination of the corneal endothelial cells. PMID:25834385

  13. The acute cardiorenal syndrome: burden and mechanisms of disease.

    PubMed

    Nijst, Petra; Mullens, Wilfried

    2014-12-01

    Worsening renal function during the treatment of acute decompensated heart failure, so-called acute cardio-renal syndrome, is very common and complicates the treatment course. The underlying pathophysiology of worsening renal function (WRF) involves variable contributions of renal hemodynamics, neurohormonal activity, and oxidative stress. Historically, WRF has been associated with adverse outcomes. However, emerging data support therapeutic strategies that permit WRF while effectively treating congestion as they are associated with improved outcomes. PMID:25135470

  14. Pathogenesis and clinical presentation of acute heart failure.

    PubMed

    Ponikowski, Piotr; Jankowska, Ewa A

    2015-04-01

    Acute heart failure constitutes a heterogeneous clinical syndrome, whose pathophysiology is complex and not completely understood. Given the diversity of clinical presentations, several different pathophysiological mechanisms along with factors triggering circulatory decompensation are involved. This article discusses the available evidence on the pathophysiological phenomena attributed or/and associated with episodes of acute heart failure and describes different clinical profiles, which, from a clinical perspective, constitute a key element for therapeutic decision-making. PMID:25743769

  15. Direct antiviral agent treatment of decompensated hepatitis C virus-induced liver cirrhosis

    PubMed Central

    Ohkoshi, Shogo; Hirono, Haruka; Yamagiwa, Satoshi

    2015-01-01

    Recently, direct antiviral agents (DAAs) have been increasingly used for the treatment of chronic hepatitis C virus (HCV) infections, replacing interferon-based regimens that have severe adverse effects and low tolerability. The constant supply of new DAAs makes shorter treatment periods with enhanced safety possible. The efficacy of DAAs for treatment of compensated liver cirrhosis (LC) is not less than that for treatment of non-cirrhotic conditions. These clinical advantages have been useful in pre- and post-liver transplantation (LT) settings. Moreover, DAAs can be used to treat decompensated HCV-induced LC in elderly patients or those with severe complications otherwise having poor prognosis. Although encouraging clinical data are beginning to appear, the actual efficacy of DAAs for suppressing disease progression, allowing delisting for LT and, most importantly, improving prognosis of patients with decompensated HCV-LC remains unknown. Case-control studies to examine the short- or long-term effects of DAAs for treatment of decompensated HCV-LC are urgently need. PMID:26558145

  16. Entecavir for Patients with Hepatitis B Decompensated Cirrhosis in China: a meta-analysis.

    PubMed

    Wang, F Y; Li, B; Li, Y; Liu, H; Qu, W D; Xu, H W; Qi, J N; Qin, C Y

    2016-01-01

    Evidence about the clinical effects of entecavir (ETV) for patients with hepatitis B decompensated cirrhosis remain controversial. Therefore, we perform this meta-analysis to assess the treatment outcomes of ETV in participants with hepatitis B decompensated cirrhosis. Relevant studies were identified by searching databases until the March 2016. A random-effects model was used to estimate summary relative risks (RRs) and 95% confidence intervals (CIs). GRADEprofiler3.6 was used to evaluate the quality of the evidence. A total of 26 studies (involving 2040 patients) were included. The quality of the evidence was classified from very low to high by the GRADED approach for all included RCTs. Meta-analysis showed that patients were more likely to experience HBV-DNA loss (RR:1.85, 95%CIs: 1.41 to 2.43, P < 0.0001 at 48 weeks), have normalized alanine aminotransferase levels (ALT) (P = 0.003 at 24 weeks, P = 0.02 at 48 weeks), and have a low mortality rate at 24 weeks (P = 0.003) when treated with ETV. There was no significant different between ETV and the control groups at the total mortality (P = 0.06) and HBeAg seroconversion (P = 0.14). In conclusion, ETV could be the first line therapy for patients with HBV related decompensated cirrhosis, because ETV could reduce the early mortality and move HBV DNA load down. PMID:27601086

  17. Entecavir for Patients with Hepatitis B Decompensated Cirrhosis in China: a meta-analysis

    PubMed Central

    Wang, F.Y.; Li, B.; Li, Y.; Liu, H.; Qu, W.D.; Xu, H.W.; Qi, J.N.; Qin, C.Y.

    2016-01-01

    Evidence about the clinical effects of entecavir (ETV) for patients with hepatitis B decompensated cirrhosis remain controversial. Therefore, we perform this meta-analysis to assess the treatment outcomes of ETV in participants with hepatitis B decompensated cirrhosis. Relevant studies were identified by searching databases until the March 2016. A random-effects model was used to estimate summary relative risks (RRs) and 95% confidence intervals (CIs). GRADEprofiler3.6 was used to evaluate the quality of the evidence. A total of 26 studies (involving 2040 patients) were included. The quality of the evidence was classified from very low to high by the GRADED approach for all included RCTs. Meta-analysis showed that patients were more likely to experience HBV-DNA loss (RR:1.85, 95%CIs: 1.41 to 2.43, P < 0.0001 at 48 weeks), have normalized alanine aminotransferase levels (ALT) (P = 0.003 at 24 weeks, P = 0.02 at 48 weeks), and have a low mortality rate at 24 weeks (P = 0.003) when treated with ETV. There was no significant different between ETV and the control groups at the total mortality (P = 0.06) and HBeAg seroconversion (P = 0.14). In conclusion, ETV could be the first line therapy for patients with HBV related decompensated cirrhosis, because ETV could reduce the early mortality and move HBV DNA load down. PMID:27601086

  18. Marburg Hemorrhagic Fever (Marburg HF)

    MedlinePlus

    ... The CDC Cancel Submit Search The CDC Marburg hemorrhagic fever (Marburg HF) Note: Javascript is disabled or is ... was first recognized in 1967, when outbreaks of hemorrhagic fever occurred simultaneously in laboratories in Marburg and Frankfurt, ...

  19. Ultrafiltration in patients with decompensated heart failure and diuretic resistance: an Asian centre’s experience

    PubMed Central

    Teo, Loon Yee Louis; Lim, Choon Pin; Neo, Chia Lee; Teo, Lee Wah; Ng, Swee Ling Elaine; Chan, Laura Lihua; Kaushik, Manish; Sim, Kheng Leng David

    2016-01-01

    INTRODUCTION Diuretics are the mainstay of therapy for restoring the euvolaemic state in patients with decompensated heart failure. However, diuretic resistance remains a challenge. METHODS We conducted a retrospective cohort study to examine the efficacy and safety of ultrafiltration (UF) in 44 hospitalised patients who had decompensated heart failure and diuretic resistance between October 2011 and July 2013. RESULTS Among the 44 patients, 18 received UF (i.e. UF group), while 26 received diuretics (i.e. standard care group). After 48 hours, the UF group achieved lower urine output (1,355 mL vs. 3,815 mL, p = 0.0003), greater fluid loss (5,058 mL vs. 1,915 mL, p < 0.0001) and greater weight loss (5.0 kg vs. 1.0 kg, p < 0.0001) than the standard care group. The UF group also had a shorter duration of hospitalisation (5.0 days vs. 9.5 days, p = 0.0010). There were no differences in the incidence of 30-day emergency department visits and rehospitalisations for heart failure between the two groups. At 90 days, the UF group had fewer emergency department visits (0.2 vs. 0.8, p = 0.0500) and fewer rehospitalisations for heart failure (0.3 vs. 1.0, p = 0.0442). Reduction in EQ-5D™ scores was greater in the UF group, both at discharge (2.7 vs. 1.4, p = 0.0283) and 30 days (2.5 vs. 0.3, p = 0.0033). No adverse events were reported with UF. CONCLUSION UF is an effective and safe treatment that can improve the health outcomes of Asian patients with decompensated heart failure and diuretic resistance. PMID:26778634

  20. Successful treatment of hepatitis C, genotype 3, with sofosbuvir/ledipasvir in decompensated cirrhosis complicated by mixed cryoglobulinaemia.

    PubMed

    Flemming, Jennifer A; Lowe, Catherine E

    2016-01-01

    Advances in the treatment of chronic hepatitis C (HCV) have given HCV providers access to treatment regimens able to achieve sustained virological response (SVR or 'cure') in the majority of patients. There are, however, groups of patients in whom HCV treatment outcomes with direct acting antivirals (DAAs) are suboptimal (genotype (GT) 3 patients, decompensated cirrhosis, renal failure) or have not been studied in large cohorts (patients with cryoglobulinaemia (CG)). This case outlines the successful eradication of GT-3 hepatitis C (HCV) in a patient with decompensated cirrhosis and renal failure secondary to mixed CG with DAA failure, using a 12-week course of sofosbuvir, ledipasvir and ribavirin. The achievement of SVR in this patient resulted in significant improvement in hepatic and renal function. Patients with decompensated cirrhosis and GT-3 disease remain a difficult to treat population, and the safety and efficacy of sofosbuvir, ledipasvir and ribavirin in this cohort require further study. PMID:27284099

  1. Acute hepatitis after amiodarone infusion

    PubMed Central

    Fonseca, Paulo; Dias, Adelaide; Gonçalves, Helena; Albuquerque, Aníbal; Gama, Vasco

    2015-01-01

    Acute hepatitis is a very rare, but potentially fatal, adverse effect of intravenous amiodarone. We present a case of an 88-year-old man with history of ischemic dilated cardiomyopathy and severely depressed left ventricular function that was admitted to our coronary care unit with diagnosis of decompensated heart failure and non-sustained ventricular tachycardia. A few hours after the beginning of intravenous amiodarone he developed an acute hepatitis. There was a completely recovery within the next days after amiodarone withdrawn and other causes of acute hepatitis have been ruled out. This case highlights the need for close monitoring of hepatic function during amiodarone infusion in order to identify any potential hepatotoxicity and prevent a fatal outcome. Oral amiodarone is, apparently, a safe option in these patients. PMID:26488027

  2. Baseline MELD Score Predicts Hepatic Decompensation during Antiviral Therapy in Patients with Chronic Hepatitis C and Advanced Cirrhosis

    PubMed Central

    Dultz, Georg; Seelhof, Martin; Herrmann, Eva; Welker, Martin-Walter; Friedrich-Rust, Mireen; Teuber, Gerlinde; Kronenberger, Bernd; von Wagner, Michael; Vermehren, Johannes; Sarrazin, Christoph; Zeuzem, Stefan; Hofmann, Wolf Peter

    2013-01-01

    Background and Aims In patients with advanced liver cirrhosis due to chronic hepatitis C virus (HCV) infection antiviral therapy with peginterferon and ribavirin is feasible in selected cases only due to potentially life-threatening side effects. However, predictive factors associated with hepatic decompensation during antiviral therapy are poorly defined. Methods In a retrospective cohort study, 68 patients with HCV-associated liver cirrhosis (mean MELD score 9.18±2.72) were treated with peginterferon and ribavirin. Clinical events indicating hepatic decompensation (onset of ascites, hepatic encephalopathy, upper gastrointestinal bleeding, hospitalization) as well as laboratory data were recorded at baseline and during a follow up period of 72 weeks after initiation of antiviral therapy. To monitor long term sequelae of end stage liver disease an extended follow up for HCC development, transplantation and death was applied (240weeks, ±SD 136weeks). Results Eighteen patients (26.5%) achieved a sustained virologic response. During the observational period a hepatic decompensation was observed in 36.8%. Patients with hepatic decompensation had higher MELD scores (10.84 vs. 8.23, p<0.001) and higher mean bilirubin levels (26.74 vs. 14.63 µmol/l, p<0.001), as well as lower serum albumin levels (38.2 vs. 41.1 g/l, p = 0.015), mean platelets (102.64 vs. 138.95/nl, p = 0.014) and mean leukocytes (4.02 vs. 5.68/nl, p = 0.002) at baseline as compared to those without decompensation. In the multivariate analysis the MELD score remained independently associated with hepatic decompensation (OR 1.56, 1.18–2.07; p = 0.002). When the patients were grouped according to their baseline MELD scores, hepatic decompensation occurred in 22%, 59%, and 83% of patients with MELD scores of 6–9, 10–13, and >14, respectively. Baseline MELD score was significantly associated with the risk for transplantation/death (p<0.001). Conclusions Our data suggest that the

  3. Use of carglumic acid in the treatment of hyperammonaemia during metabolic decompensation of patients with propionic acidaemia.

    PubMed

    Abacan, M; Boneh, A

    2013-08-01

    Propionic acidaemia (PA) results from propionyl-CoA carboxylase deficiency. During metabolic decompensation, the accumulation of propionyl-CoA causes secondary hyperammonaemia through N-acetylglutamate synthetase inactivation. Carglumic acid, a structural analogue of N-acetylglutamate, was given to patients with PA (n=3) during episodes of metabolic decompensation (n=8; age range: birth to 4years), in addition to high energy/low protein intake and carnitine. Plasma ammonia concentrations normalised within 6-19h. Carglumic acid was well tolerated with no side effects noted. PMID:23791308

  4. Predicting heart failure decompensation using cardiac implantable electronic devices: a review of practices and challenges.

    PubMed

    Hawkins, Nathaniel M; Virani, Sean A; Sperrin, Matthew; Buchan, Iain E; McMurray, John J V; Krahn, Andrew D

    2016-08-01

    Cardiac implantable electronic devices include remote monitoring tools intended to guide heart failure management. The monitoring focus has been on averting hospitalizations by predicting worsening heart failure. However, although device measurements including intrathoracic impedance correlate with risk of decompensation, they individually predict hospitalizations with limited accuracy. Current 'crisis detection' methods involve repeatedly screening for impending decompensation, and do not adhere to the principles of diagnostic testing. Complex substrate, limited test performance, low outcome incidence, and long test to outcome times inevitably generate low positive and high negative predictive values. When combined with spectrum bias, the generalizability, incremental value, and cost-effectiveness of device algorithms are questionable. To avoid these pitfalls, remote monitoring may need to shift from crisis detection to health maintenance, keeping the patient within an ideal physiological range through continuous 'closed loop' interaction and dynamic therapy adjustment. Test performance must also improve, possibly through combination with physiological sensors in different dimensions, static baseline characteristics, and biomarkers. Complex modelling may tailor monitoring to individual phenotypes, and thus realize a personalized medicine approach. Future randomized controlled trials should carefully consider these issues, and ensure that the interventions tested are generalizable to clinical practice. PMID:26663507

  5. Portal vein thrombosis, mortality and hepatic decompensation in patients with cirrhosis: A meta-analysis

    PubMed Central

    Stine, Jonathan G; Shah, Puja M; Cornella, Scott L; Rudnick, Sean R; Ghabril, Marwan S; Stukenborg, George J; Northup, Patrick G

    2015-01-01

    AIM: To determine the clinical impact of portal vein thrombosis in terms of both mortality and hepatic decompensations (variceal hemorrhage, ascites, portosystemic encephalopathy) in adult patients with cirrhosis. METHODS: We identified original articles reported through February 2015 in MEDLINE, Scopus, Science Citation Index, AMED, the Cochrane Library, and relevant examples available in the grey literature. Two independent reviewers screened all citations for inclusion criteria and extracted summary data. Random effects odds ratios were calculated to obtain aggregate estimates of effect size across included studies, with 95%CI. RESULTS: A total of 226 citations were identified and reviewed, and 3 studies with 2436 participants were included in the meta-analysis of summary effect. Patients with portal vein thrombosis had an increased risk of mortality (OR = 1.62, 95%CI: 1.11-2.36, P = 0.01). Portal vein thrombosis was associated with an increased risk of ascites (OR = 2.52, 95%CI: 1.63-3.89, P < 0.001). There was insufficient data available to determine the pooled effect on other markers of decompensation including gastroesophageal variceal bleeding or hepatic encephalopathy. CONCLUSION: Portal vein thrombosis appears to increase mortality and ascites, however, the relatively small number of included studies limits more generalizable conclusions. More trials with a direct comparison group are needed. PMID:26644821

  6. Rotenone-induced energy stress decompensated in ventral mesocerebrum is associated with Parkinsonism progression in rats

    PubMed Central

    Bai, Qunhua; He, Junlin; Tang, Yong; Wang, Shibo; Qiu, Jingfu; Wang, Yang; Yu, Chao

    2016-01-01

    Parkinson's disease (PD) is the second most common neurodegenerative disorder, which is characterized by the hallmark feature of loss of dopaminergic neurons in the substantia nigra. Energy metabolic disorder is associated with the pathogenesis of PD; however, the development of this disorder is yet to be elucidated. PD-like characteristics have been demonstrated in a rotenone rat model. In the present study, energy metabolism status was investigated in a rat model following intraperitoneal treatment with 1.0 mg/kg rotenone every 48 h. The behavior and tyrosine hydroxylase-positive levels in the substantia nigra of rats that were treated with rotenone for 24 weeks demonstrated that these rats developed more severe parkinsonism, as compared with that were treated for 16 weeks. Detection of ATP, lactic acid, NADH dehydrogenase 1 mRNA and lactate dehydrogenase B mRNA levels in the ventral mesocerebrum (VM) and skeletal muscle (SM) of the rats that had been treated with rotenone for 16 and 24 weeks demonstrated that the energy stress induced by rotenone progressed in both VM and SM. Notably, the energy stress detected in VM was more severe, and this energy stress was decompensated in the VM of rats that had been treated with rotenone for 24 weeks. The progression of energy stress and the incidence of energy decompensation in VM may be important for the improvement of PD pathology. PMID:27446321

  7. Acute massive mitral regurgitation from prosthetic valve dysfunction.

    PubMed Central

    Cooper, D K; Sturridge, M F

    1976-01-01

    Two cases of prosthetic valve dysfunction resulting in acute massive mitral regurgitation are reported; emergency operation was successful in both cases. Survival following complete dislodgement of the occluder of a disc valve, as occurred in one case, does not appear to have been reported before. The diffculty in diagnosis of sudden cardiac decompensation in patients with prosthetic valves is stressed, as is the need for urgent operation. Images PMID:973894

  8. Predictors of Refractory Ascites Development in Patients with Hepatitis B Virus-Related Cirrhosis Hospitalized to Control Ascitic Decompensation

    PubMed Central

    Seo, Ju Hee; Kim, Seung Up; Park, Jun Yong; Kim, Do Young; Han, Kwang-Hyub; Chon, Chae Yoon

    2013-01-01

    Purpose Refractory ascites (RA) is closely related to a high morbidity and mortality. In this study, we investigated predictors of RA development in patients with hepatitis B virus (HBV)-related cirrhosis who were hospitalized to control ascitic decompensation, and determined predictors for survival in patients who experienced RA. Materials and Methods We analyzed 199 consecutive patients with HBV-related cirrhosis who were hospitalized to control ascitic decompensation between January 1996 and December 2008. Results Multivariate analyses showed that only serum potassium at admission predicted RA development independently [p=0.013; hazard ratio (HR), 2.800; 95% confidence interval (CI), 1.166-6.722]. During the follow-up period, 16 (8.0%) patients experienced RA within 4.2 (range, 1.0-39.2) months after admission for controlling ascitic decompensation, and they survived a median of 8.7 (range, 3.9-51.3) months. Child-Pugh class and RA type were identified as independent prognostic factors affecting the survival in patients with RA (p=0.045; HR, 8.079; 95% CI, 1.231-67.984 and p=0.013; HR, 14.510; 95% CI, 1.771-118.874, respectively). Conclusion Serum potassium was an independent predictor of RA development in patients with HBV-related cirrhosis who were hospitalized to control ascitic decompensation. After RA development, Child-Pugh class and RA type were independent predictors for survival. PMID:23225811

  9. Hepatic decompensation/serious adverse events in post-liver transplantation recipients on sofosbuvir for recurrent hepatitis C virus

    PubMed Central

    Patel, Neal; Bichoupan, Kian; Ku, Lawrence; Yalamanchili, Rachana; Harty, Alyson; Gardenier, Donald; Ng, Michel; Motamed, David; Khaitova, Viktoriya; Bach, Nancy; Chang, Charissa; Grewal, Priya; Bansal, Meena; Agarwal, Ritu; Liu, Lawrence; Im, Gene; Leong, Jennifer; Kim-Schluger, Leona; Odin, Joseph; Ahmad, Jawad; Friedman, Scott; Dieterich, Douglas; Schiano, Thomas; Perumalswami, Ponni; Branch, Andrea

    2016-01-01

    AIM: To determine the safety profile of new hepatitis C virus (HCV) treatments in liver transplant (LT) recipients with recurrent HCV infection. METHODS: Forty-two patients were identified with recurrent HCV infection that underwent LT at least 12 mo prior to initiating treatment with a Sofosbuvir-based regimen during December 2013-June 2014. Cases were patients who experienced hepatic decompensation and/or serious adverse events (SAE) during or within one month of completing treatment. Controls had no evidence of hepatic decompensation and/or SAE. HIV-infected patients were excluded. Cumulative incidence of decompensation/SAE was calculated using the Kaplan Meier method. Exact logistic regression analysis was used to identify factors associated with the composite outcome. RESULTS: Median age of the 42 patients was 60 years [Interquartile Range (IQR): 56-65 years], 33% (14/42) were female, 21% (9/42) were Hispanic, and 9% (4/42) were Black. The median time from transplant to treatment initiation was 5.4 years (IQR: 2.1-8.8 years). Thirteen patients experienced one or more episodes of hepatic decompensation and/or SAE. Anemia requiring transfusion, the most common event, occurred in 62% (8/13) patients, while 54% (7/13) decompensated. The cumulative incidence of hepatic decompensation/SAE was 31% (95%CI: 16%-41%). Risk factors for decompensation/SAE included lower pre-treatment hemoglobin (OR = 0.61 per g/dL, 95%CI: 0.40-0.88, P < 0.01), estimated glomerular filtration rate (OR = 0.95 per mL/min per 1.73 m2, 95%CI: 0.90-0.99, P = 0.01), and higher baseline serum total bilirubin (OR = 2.43 per mg/dL, 95%CI: 1.17-8.65, P < 0.01). The sustained virological response rate for the cohort of 42 patients was 45%, while it was 31% for cases. CONCLUSION: Sofosbuvir/ribavirin will continue to be used in the post-transplant population, including those with HCV genotypes 2 and 3. Management of anemia remains an important clinical challenge. PMID:26973423

  10. Autologous Peripheral Blood Stem Cell Transplantation Improves Portal Hemodynamics in Patients with Hepatitis B Virus-related Decompensated Cirrhosis

    PubMed Central

    Deng, Qinzhi; Cai, Ting; Zhang, Shun; Hu, Airong; Zhang, Xingfen; Wang, Yinyin; Huang, Jianrong

    2015-01-01

    Background: Chronic hepatitis B virus (HBV) infection may eventually lead to decompensated liver cirrhosis, which is a terminal illness. Objectives: The aim of this study was to investigate the therapeutic efficacy of autologous peripheral blood stem cell (APBSC) transplantation to improve portal vein hemodynamics in patients with HBV-related decompensated cirrhosis. Patients and Methods: This prospective study included 68 hospitalized patients who were diagnosed with HBV-related decompensated cirrhosis. These patients were divided into two groups: the transplantation group included 33 patients, while the control group included 35. Both groups received conventional medical treatment simultaneously, and APBSC transplantation was performed on the patients in the transplantation group. We evaluated the effects of APBSC transplantation on postoperative liver function using the following indices: total bilirubin, serum prothrombin and albumin, spleen size, and portal vein hemodynamics. Postoperatively, all of the patients were followed up at 24, 36, and 48 weeks. Results: The transplantation group had no serious reactions. Compared with the control group, albumin and prothrombin activity in the transplantation group was significantly improved at 24, 36, and 48 weeks after the procedure, and spleen length and portal vein diameter were substantially reduced at 48 weeks. The velocity of peak portal vein blood flow and mean maximum portal vein blood flow were greatly increased in the APBSC transplantation group at 36 and 48 weeks, respectively; however, there was also decreased portal vein diameter, which reduced portal vein pressure in patients with HBV-related decompensated cirrhosis. Conclusions: APBSC transplantation greatly benefits HBV-linked decompensated cirrhosis patients and should be recommended in clinical practice. PMID:26977164

  11. Crescendo in Depolarization and Repolarization Heterogeneity Heralds Development of Ventricular Tachycardia in Hospitalized Patients with Decompensated Heart Failure

    PubMed Central

    Nearing, Bruce D.; Wellenius, Gregory A.; Mittleman, Murray A.; Josephson, Mark E.; Burger, Andrew J.; Verrier, Richard L.

    2012-01-01

    Background A critical need exists for reliable warning markers of in-hospital life-threatening arrhythmias. We employed a new quantitative method to track interlead heterogeneity of depolarization and repolarization to detect premonitory changes prior to ventricular tachycardia (VT) in hospitalized patients with acute decompensated heart failure. Methods and Results Ambulatory ECGs (leads V1, V5, and aVF) recorded before initiation of drug therapy from patients enrolled in the Prospective Randomized Evaluation of Cardiac Ectopy with Dobutamine or Nesiritide Therapy (PRECEDENT) trial were analyzed. R-wave and T-wave heterogeneity (RWH, TWH) were assessed by second central moment analysis and T-wave alternans (TWA) by Modified Moving Average analysis. Patients (N=44) studied included those (N = 22) with episodes of VT (≥4 beats at heart rates >100 beats/min) following ≥120 minutes of stable sinus rhythm and age- and sex-matched patients (N=22) without VT. TWA increased from 18.6±2.1μV (baseline, mean ± SEM) to 27.9±4.6μV in lead V5 at 15–30 minutes prior to VT (p<0.05) and remained elevated until the arrhythmia occurred. TWA results in V1 and aVF were similar. RWH and TWH were elevated from 164.1±33.1μV and 134.5±20.6μV (baseline) to 299.8±54.5μV and 239.2±37.0μV at 30–45 minutes prior to VT (p<0.05), respectively, preceding the crescendo in TWA by 15 minutes. Matched patients without VT did not display elevated RWH (185.5±29.4μV) or TWH (157.1±27.2μV) during the 24–hour period. Conclusions This is the first clinical demonstration of the potential utility of tracking depolarization and repolarization heterogeneity to detect crescendos in electrical instability that could forewarn of impending nonsustained ventricular tachycardia. Clinical Trial Registration http://clinicaltrials.gov; NCT00270400. PMID:22157521

  12. HfS: Hyperfine Structure fitting tool

    NASA Astrophysics Data System (ADS)

    Estalella, Robert

    2016-07-01

    HfS fits the hyperfine structure of spectral lines, with multiple velocity components. The HfS_nh3 procedures included in HfS fit simultaneously the hyperfine structure of the NH3 (J,K)= (1,1) and (2,2) inversion transitions, and perform a standard analysis to derive the NH3 column density, rotational temperature Trot, and kinetic temperature Tk. HfS uses a Monte Carlo approach for fitting the line parameters, with special attention to the derivation of the parameter uncertainties. HfS includes procedures that make use of parallel computing for fitting spectra from a data cube.

  13. Upscaling cardiac assist devices in decompensated heart failure: Choice of device and its timing.

    PubMed

    Mishra, Sundeep

    2016-04-01

    Advanced heart failure is a heterogeneous condition unified by a very high mortality unless right treatment is instituted at the right time. The first step is understanding the mechanism leading to instability: hemodynamic or ischemic. Right kind of therapy; drugs (ionotropic) or IABP or other cardiac assist devices should be chosen according to mechanism of insult as well as degree of insult. Drugs such as ionotropes are effective only in very early course but if the decompensation has progressed beyond a certain point device such as IABP may be effective but again only early in the course when CPO? 0.6. Beyond a certain point, even IABP may not be effective: here only Impella (2.5, CP or 5) or Tandem Heart may be effective. However, beyond a certain point CPO<0.53, even these devices may not be effective. Thus crux of the matter is choice of a right device/drug and timing of its institution. PMID:27056646

  14. Organ protection possibilities in acute heart failure.

    PubMed

    Montero-Pérez-Barquero, M; Morales-Rull, J L

    2016-04-01

    Unlike chronic heart failure (HF), the treatment for acute HF has not changed over the last decade. The drugs employed have shown their ability to control symptoms but have not achieved organ protection or managed to reduce medium to long-term morbidity and mortality. Advances in our understanding of the pathophysiology of acute HF suggest that treatment should be directed not only towards correcting the haemodynamic disorders and achieving symptomatic relief but also towards preventing organ damage, thereby counteracting myocardial remodelling and cardiac and extracardiac disorders. Compounds that exert vasodilatory and anti-inflammatory action in the acute phase of HF and can stop cell death, thereby boosting repair mechanisms, could have an essential role in organ protection. PMID:26896381

  15. Attentional Bias in Patients with Decompensated Tinnitus: Prima Facie Evidence from Event-Related Potentials.

    PubMed

    Li, Zhicheng; Gu, Ruolei; Zeng, Xiangli; Zhong, Weifang; Qi, Min; Cen, Jintian

    2016-01-01

    Tinnitus refers to the auditory perception of sound in the absence of external sound or electric stimuli. The influence of tinnitus on cognitive processing is at the cutting edge of ongoing tinnitus research. In this study, we adopted an objective indicator of attentional processing, i.e. the mismatch negativity (MMN), to assess the attentional bias in patients with decompensated tinnitus. Three kinds of pure tones, D1 (8,000 Hz), S (8,500 Hz) and D2 (9,000 Hz), were used to induce event-related potentials (ERPs) in the normal ear. Employing the oddball paradigm, the task was divided into two blocks in which D1 and D2 were set as deviation stimuli, respectively. Only D2 induced a significant MMN in the tinnitus group, while neither D1 nor D2 was able to induce MMN in the control group. In addition, the ERPs in the left hemisphere, which were recorded within the time window of 90-150 ms (ERP90-150 ms), were significantly higher than those in the right hemisphere in the tinnitus group, while no significant difference was observed in the control group. Lastly, the amplitude of ERP90-150 ms in the tinnitus group was significantly higher than that in the control group. These findings suggest that patients with decompensated tinnitus showed automatic processing of acoustic stimuli, thereby indicating that these patients allocated more cognitive resources to acoustic stimulus processing. We suggest that the difficulty in disengaging or facilitated attention of patients might underlie this phenomenon. The limitations of the current study are discussed. PMID:26800229

  16. Acute oesophageal necrosis (black oesophagus).

    PubMed

    Galtés, Ignasi; Gallego, María Ángeles; Esgueva, Raquel; Martin-Fumadó, Carles

    2016-03-01

    A 54-year-old man was admitted to hospital after being found unconscious in his home. He had a history of alcoholism, multiple drug addictions, and type I diabetes mellitus. At admission, he had hyperglycaemia (550 mg/dL) with glucosuria and ketone bodies in the urine, along with septic shock refractory to bilateral alveolar infiltrates and severe respiratory failure. The patient died 24 hours post admission due to multiple organ failure, with diabetic ketoacidosis decompensated by possible respiratory infection in a patient with polytoxicomania. The autopsy confirmed the presence of acute bilateral bronchopneumonia, chronic pancreatitis, severe hepatic steatosis, and generalized congestive changes. At the oesophagus, acute oesophageal necrosis was evident. PMID:26949146

  17. The pathophysiology of hypertensive acute heart failure.

    PubMed

    Viau, David M; Sala-Mercado, Javier A; Spranger, Marty D; O'Leary, Donal S; Levy, Phillip D

    2015-12-01

    While acute heart failure (AHF) is often regarded as a single disorder, an evolving understanding recognises the existence of multiple phenotypes with varied pathophysiological alterations. Herein we discuss hypertensive AHF and provide insight into a mechanism where acute fluid redistribution is caused by a disturbance in the ventricular-vascular coupling relationship. In this relationship, acute alterations in vascular elasticity, vasoconstriction and reflected pulse waves lead to increases in cardiac work and contribute to decompensated LV function with associated subendocardial ischaemia and end-organ damage. Chronic predisposing factors (neurohormonal activity, nitric oxide insensitivity, arterial stiffening) and physiological stressors (sympathetic surge, volume overload, physical exertion) that are causally linked to acute symptom onset are discussed. Lastly, we review treatment options including both nitrovasodilators and promising novel therapeutics, and discuss future directions in the management of this phenotypic variant. PMID:26123135

  18. New diagnostic modalities in the diagnosis of heart failure.

    PubMed Central

    Mitchell, Judith E.; Palta, Sanjeev

    2004-01-01

    Heart failure (HF) is the one cardiovascular disease that is increasing in prevalence in the United States. As the population continues to age, the incidence will certainly be amplified. However, some studies have shown that HF is correctly diagnosed initially in only 50% of affected patients. Despite the use of history, physical examination, echocardiogram, and chest x-ray, the percentage of correct initial diagnosis of HF is low. Recognizing the symptoms of HF decompensations is often problematic because other diagnoses can mimic them. There are two new diagnostic modalities that offer promise in improving HF diagnostic accuracy and identifying early HF decompensations. These diagnostic modalities include tests utilizing impedance cardiography and the B-type natriuretic peptide assay. They have the potential of increasing the accuracy of HF diagnosis and guide pharmacological treatment in the inpatient and outpatient settings. They may also assist in the recognition (or prediction) of acute HF decompensations. Images Figure 2 PMID:15586645

  19. Environmentally friendly HF (DF) lasers

    NASA Astrophysics Data System (ADS)

    Apollonov, V. V.

    2016-08-01

    Dedicated to the 100th anniversary of the birth of Academician A M Prokhorov, this paper reviews the physics of self-sustained volume discharge without preionization—self-initiated volume discharge (SIVD)—in the working mixtures of non-chain hydrofluoride HF (deuterofluoride (DF)) lasers. The dynamics of SIVD in discharge gaps with different geometries is thoroughly described. The mechanisms for the restriction of current density in a diffuse channel in electric discharges in SF6 and SF6 based mixtures (which determines whether SIVD is possible) are proposed and analyzed using simple models. The most probable mechanisms are the electron impact dissociation of SF6 and other mixture components, electron–ion recombination and electron attachment to vibrationally excited SF6 molecules. Starting from a comparative analysis of the rate coefficients of these processes, it is shown that electron–ion recombination is capable of compensating for electron detachment from negative ions via electron impact. It is also established that SIVD is not only observed in SF6, but also in other strongly electronegative gases. The factors that determine the uniformity of the active medium in non-chain HF (DF) lasers are analyzed. Some special features of non-chain HF (DF) lasers with different apertures operating are carefully examined. Consideration is given to the problem of increasing the aperture and discharge volume of non-chain HF (DF) lasers. Based on our experimental results, the possibility of increasing the energy of such lasers to ~1 kJ and above is shown.

  20. The GEO-HF project

    NASA Astrophysics Data System (ADS)

    Willke, B.; Ajith, P.; Allen, B.; Aufmuth, P.; Aulbert, C.; Babak, S.; Balasubramanian, R.; Barr, B. W.; Berukoff, S.; Bunkowski, A.; Cagnoli, G.; Cantley, C. A.; Casey, M. M.; Chelkowski, S.; Chen, Y.; Churches, D.; Cokelaer, T.; Colacino, C. N.; Crooks, D. R. M.; Cutler, C.; Danzmann, K.; Dupuis, R. J.; Elliffe, E.; Fallnich, C.; Franzen, A.; Freise, A.; Gholami, I.; Goßler, S.; Grant, A.; Grote, H.; Grunewald, S.; Harms, J.; Hage, B.; Heinzel, G.; Heng, I. S.; Hepstonstall, A.; Heurs, M.; Hewitson, M.; Hild, S.; Hough, J.; Itoh, Y.; Jones, G.; Jones, R.; Huttner, S. H.; Kötter, K.; Krishnan, B.; Kwee, P.; Lück, H.; Luna, M.; Machenschalk, B.; Malec, M.; Mercer, R. A.; Meier, T.; Messenger, C.; Mohanty, S.; Mossavi, K.; Mukherjee, S.; Murray, P.; Newton, G. P.; Papa, M. A.; Perreur-Lloyd, M.; Pitkin, M.; Plissi, M. V.; Prix, R.; Quetschke, V.; Re, V.; Regimbau, T.; Rehbein, H.; Reid, S.; Ribichini, L.; Robertson, D. I.; Robertson, N. A.; Robinson, C.; Romano, J. D.; Rowan, S.; Rüdiger, A.; Sathyaprakash, B. S.; Schilling, R.; Schnabel, R.; Schutz, B. F.; Seifert, F.; Sintes, A. M.; Smith, J. R.; Sneddon, P. H.; Strain, K. A.; Taylor, I.; Taylor, R.; Thüring, A.; Ungarelli, C.; Vahlbruch, H.; Vecchio, A.; Veitch, J.; Ward, H.; Weiland, U.; Welling, H.; Wen, L.; Williams, P.; Winkler, W.; Woan, G.; Zhu, R.

    2006-04-01

    The GEO 600 gravitational wave detector uses advanced technologies including signal recycling and monolithic fused-silica suspensions to achieve a sensitivity close to the kilometre scale LIGO and VIRGO detectors. As soon as the design sensitivity of GEO 600 is reached, the detector will be operated as part of the worldwide network to acquire data of scientific interest. The limited infrastructure at the GEO site does not allow for a major upgrade of the detector. Hence the GEO collaboration decided to improve the sensitivity of the GEO detector by small sequential upgrades some of which will be tested in prototypes first. The development, test and installation of these upgrades are named 'The GEO-HF Project.' This paper describes the upgrades considered in the GEO-HF project as well as their scientific reasons. We will describe the changes in the GEO 600 infrastructure and the prototype work that is planned to support these upgrades. Finally, we will point to some laboratory research that identifies new technologies or optical configurations that might undergo a transition into detector subsystems within the GEO-HF project.

  1. Endocardial Endothelial Dysfunction Progressively Disrupts Initially Anti then Pro-Thrombotic Pathways in Heart Failure Mice

    PubMed Central

    Schoner, Amanda; Tyrrell, Christina; Wu, Melinda; Gelow, Jill M.; Hayes, Alicia A.; Lindner, Jonathan R.; Thornburg, Kent L.; Hasan, Wohaib

    2015-01-01

    Objective An experimental model of endocardial thrombosis has not been developed and endocardial endothelial dysfunction in heart failure (HF) is understudied. We sought to determine whether disruption of the endothelial anti-coagulant activated protein C (APC) pathway in CREBA133 HF mice promotes endocardial thrombosis in the acute decompensated phase of the disease, and whether alterations in von Willebrand factor (vWF) secretion from HF endocardium reduces thrombus formation as HF stabilizes. Approach and results Echocardiography was used to follow HF development and to detect endocardial thrombi in CREBA133 mice. Endocardial thrombi incidence was confirmed with immunohistochemistry and histology. In early and acute decompensated phases of HF, CREBA133 mice had the highest incidence of endocardial thrombi and these mice also had a shorter tail-bleeding index consistent with a pro-thrombotic milieu. Both APC generation, and expression of receptors that promote APC function (thrombomodulin, endothelial protein C receptor, protein S), were suppressed in the endocardium of acute decompensated HF mice. However, in stable compensated HF mice, an attenuation occurred for vWF protein content and secretion from endocardial endothelial cells, vWF-dependent platelet agglutination (by ristocetin), and thrombin generation on the endocardial surface. Conclusions CREBA133 mice develop HF and endocardial endothelial dysfunction. Attenuation of the anti-coagulant APC pathway promotes endocardial thrombosis in early and acute decompensated phases of HF. However, in stable compensated HF mice, disruptions in endothelial vWF expression and extrusion may actually reduce the incidence of endocardial thrombosis. PMID:26565707

  2. Interdisciplinary Peripartum Management of Acute Respiratory Distress Syndrome with Extracorporeal Membrane Oxygenation – a Case Report and Literature Review

    PubMed Central

    Weyrich, J.; Bogdanski, R.; Ortiz, J. U.; Kuschel, B.; Schneider, K. T. M.; Lobmaier, S. M.

    2016-01-01

    Extracorporeal membrane oxygenation (ECMO) is increasingly used for the management of acute severe cardiac and respiratory failure. One of the indications is acute respiratory distress syndrome (ARDS) for which, in some severe cases, ECMO represents the only possibility to save lives. We report on the successful long-term use of ECMO in a postpartum patient with recurrent pulmonary decompensation after peripartum uterine rupture with extensive blood loss. PMID:27065489

  3. Role of albumin in diseases associated with severe systemic inflammation: Pathophysiologic and clinical evidence in sepsis and in decompensated cirrhosis.

    PubMed

    Artigas, Antonio; Wernerman, Jan; Arroyo, Vicente; Vincent, Jean-Louis; Levy, Mitchell

    2016-06-01

    The metabolism of albumin in inflammatory states such as sepsis or major surgery is complex and still not well characterized. Nevertheless, in inflammatory states, albumin synthesis has been observed to increase. By contrast, in decompensated cirrhosis, a disease characterized by systemic inflammation, albumin synthesis by the liver may decrease to 30% to 50% of normal values. Furthermore, in these conditions, there are high capillary leakage and altered albumin kinetics. The discussion regarding the effect of exogenous albumin administration on intravascular volume in inflammatory states should therefore address albumin turnover. To add complexity to our understanding of the effects of albumin, there are many data indicating that the therapeutic action of albumin is mediated not only through the impact on plasma volume expansion but also through a modulatory effect on inflammation and oxidative stress. All these characteristics are relevant to diseases associated with systemic inflammation including sepsis and decompensated cirrhosis. PMID:26831575

  4. [Economic aspects of inpatient treatment for decompensated liver cirrhosis: a prospective study employing an evidence-based clinical pathway].

    PubMed

    Hahn, N; Bobrowski, C; Weber, E; Simon, P; Kraft, M; Aghdassi, A; Raetzell, M; Wilke, M; Lerch, M M; Mayerle, J

    2013-03-01

    The introduction of the G-DRG reimbursement system has greatly increased the pressure to provide cost effective treatment in German hospitals. Reimbursement based on diagnosis-related groups, which requires stratification of costs incurred is still not sufficiently discriminating the disease severity and severity in relation to the intensive costs in gastroenterology. In a combined retrospective and prospective study at a tertial referral centre we investigated whether this also applies for decompensated liver cirrhosis. In 2006, 64 retrospective cases (age 57 ± 12.9; ♂ 69.2 %, ♀ 29.8 %) with decompensated liver cirrhosis (ICD code K76.4) were evaluated for their length of hospitalisation, reimbursement as well as Child and MELD scores. In 2008, 74 cases with decompensated liver cirrhosis were treated in a prospective study according to a standardised and evidence-based clinical pathway (age 57 ± 12.2; 73 % ♂, ♀ 27 %). Besides a trend in the reduction of length of hospital stay (retrospective: 13.6 ± 8.6, prospective 13.0 ± 7.2, p = 0.85) overall revenues from patients treated according to a evidence-based clinical pathway were lower than the calculated costs from the InEK matrix. Costs of medication as a percentage of reimbursement amount increased with increasing severity. In both years we could demonstrate an inverse correlation between daily reimbursement and disease severity which precluded cost coverage. For the cost-covering hospital treatment of patients with decompensated liver cirrhosis an adjustment of the DRG based on clinical severity scores such as Child-Pugh or MELD is warranted, if evidence-based treatment standards are to be kept. PMID:23299901

  5. Modeling the effectiveness of nebulized terbutaline for decompensated chronic obstructive pulmonary disease patients in the emergency department.

    PubMed

    Gueho, Florian; Beaune, Sébastien; Devillier, Philippe; Urien, Saik; Faisy, Christophe

    2016-08-01

    Short-acting β2-agonists (SABA) are widely used in the emergency department (ED) to treat patients with decompensated chronic obstructive pulmonary disease (COPD). We sought to model the effectiveness of nebulized SABA (terbutaline) on clinically relevant parameters associated with a reduction in work of breathing or respiratory muscle fatigue in decompensated COPD patients admitted to the ED.Forty consecutive decompensated COPD patients (having received at least one dose of nebulized terbutaline during their stay in the ED) were included in an observational cohort study. The terbutaline dose received at time t was expressed as cumulative dose and as a rate (mg/day). The associations between the terbutaline dose and time-dependent outcome parameters (respiratory rate, heart rate, arterial blood gases, and, as a marker of terbutaline's systemic effect, serum potassium) were analyzed using a nonlinear, mixed-effects model. The effect of various covariates influencing terbutaline's effectiveness (baseline characteristics and concomitant treatments) was assessed on the model.Among the investigated patients, a total of 377 time-dependent observations were available for analysis. Neither the cumulative dose nor the dose rate at time t significantly influenced the arterial blood gas parameters or heart rate. The cumulative dose of terbutaline was associated with a lower serum potassium level (P < 0.001) and, less significantly, a lower respiratory frequency (P = 0.036). In a tertile analysis, the need for post-ED hospitalization was not associated with the cumulative dose or dose rate of terbutaline.Overall, the results of our modeling study strongly suggest that terbutaline dose did not influence time-dependent outcomes other than serum potassium, and thus call into question the systematic administration of inhaled SABA to patients admitted to the ED for decompensated COPD. PMID:27512880

  6. Modeling the effectiveness of nebulized terbutaline for decompensated chronic obstructive pulmonary disease patients in the emergency department

    PubMed Central

    Gueho, Florian; Beaune, Sébastien; Devillier, Philippe; Urien, Saik; Faisy, Christophe

    2016-01-01

    Abstract Short-acting β2-agonists (SABA) are widely used in the emergency department (ED) to treat patients with decompensated chronic obstructive pulmonary disease (COPD). We sought to model the effectiveness of nebulized SABA (terbutaline) on clinically relevant parameters associated with a reduction in work of breathing or respiratory muscle fatigue in decompensated COPD patients admitted to the ED. Forty consecutive decompensated COPD patients (having received at least one dose of nebulized terbutaline during their stay in the ED) were included in an observational cohort study. The terbutaline dose received at time t was expressed as cumulative dose and as a rate (mg/day). The associations between the terbutaline dose and time-dependent outcome parameters (respiratory rate, heart rate, arterial blood gases, and, as a marker of terbutaline's systemic effect, serum potassium) were analyzed using a nonlinear, mixed-effects model. The effect of various covariates influencing terbutaline's effectiveness (baseline characteristics and concomitant treatments) was assessed on the model. Among the investigated patients, a total of 377 time-dependent observations were available for analysis. Neither the cumulative dose nor the dose rate at time t significantly influenced the arterial blood gas parameters or heart rate. The cumulative dose of terbutaline was associated with a lower serum potassium level (P < 0.001) and, less significantly, a lower respiratory frequency (P = 0.036). In a tertile analysis, the need for post-ED hospitalization was not associated with the cumulative dose or dose rate of terbutaline. Overall, the results of our modeling study strongly suggest that terbutaline dose did not influence time-dependent outcomes other than serum potassium, and thus call into question the systematic administration of inhaled SABA to patients admitted to the ED for decompensated COPD. PMID:27512880

  7. [The character of variations in the relationships of lymphocyte subpopulations in the patients presenting with chronic decompensated tonsillitis].

    PubMed

    Iashan, A I; Gerasimiuk, M I

    2015-01-01

    The palatine tonsils are known to be involved in the formation of cellular and humoral immunity. Apoptosis is believed to be one of the main biological mechanism regulating the quantitative composition of subpopulations of the immunocompetent cells. Therefore, the prevalence of apoptotic and anti-apoptotic processes determines the direction of the immune response. Bearing this in mind, we have undertaken a study with a view to elucidating the relationships between lymphocyte subpopulations in the blood and homogenates of the palatal tonsils in the patients with chronic decompensated tonsillitis and establishing their interdependence with the levels of apoptosis and necrosis. The quantification of apoptosis and necrosis as well as the ratio of these processes in neutrophils and lymphocytes belonging to different subpopulations of palatal tonsil homogenates and peripheral blood was performed by cytofluorometry with the use of the "BecmenCulter Epi XL" apparatus (USA). It has been found that decompensated chronic tonsillitis is associated with the depression of cellular immunity apparent as the 2 or 3-fold reduction of lymphocyte CD3, CD4m and CD8 subsets (as compared with the respective normal levels). The number of CD16 and CD19 lymphocytes remains unaltered witch suggests that humoral immunity is un-affectred. It is concluded that the apoptosis-necrosis index and the relationship between different subpopulations of lymphocytes in the peripheral blood may be the additional indicator to be used for diagnostics of decompensated forms of chronic tonsillitis. PMID:26145740

  8. A Signal Processing Approach for Detection of Hemodynamic Instability before Decompensation

    PubMed Central

    Belle, Ashwin; Ansari, Sardar; Spadafore, Maxwell; Convertino, Victor A.; Ward, Kevin R.; Derksen, Harm; Najarian, Kayvan

    2016-01-01

    Advanced hemodynamic monitoring is a critical component of treatment in clinical situations where aggressive yet guided hemodynamic interventions are required in order to stabilize the patient and optimize outcomes. While there are many tools at a physician’s disposal to monitor patients in a hospital setting, the reality is that none of these tools allow hi-fidelity assessment or continuous monitoring towards early detection of hemodynamic instability. We present an advanced automated analytical system which would act as a continuous monitoring and early warning mechanism that can indicate pending decompensation before traditional metrics can identify any clinical abnormality. This system computes novel features or bio-markers from both heart rate variability (HRV) as well as the morphology of the electrocardiogram (ECG). To compare their effectiveness, these features are compared with the standard HRV based bio-markers which are commonly used for hemodynamic assessment. This study utilized a unique database containing ECG waveforms from healthy volunteer subjects who underwent simulated hypovolemia under controlled experimental settings. A support vector machine was utilized to develop a model which predicts the stability or instability of the subjects. Results showed that the proposed novel set of features outperforms the traditional HRV features in predicting hemodynamic instability. PMID:26871715

  9. [Use of topical non-steroidal anti-inflammatory drugs in aggravated and decompensated arthroses].

    PubMed

    Chlud, K

    1999-01-01

    Pain in osteoarthritis of the big weight bearing joints is either derived from periarticular ligaments, tendons, fascias, muscles, bursae--periarthropathy as sign of decompensation or from the reactive synovitis with or without effusion. NSAIDs (ibuprofen, diclofenac, indometacin, some salicylates, etofenamate and piroxicam) have demonstrated relevant advantages of the percutaneous route over the systemic one in soft tissue rheumatism. NSAIDs, mentioned above, locally administered as cream, gel or spray, quickly penetrate through the corneal layer of the skin and the site of application, reach highly effective concentrations in subcutis, fascias, tendons, ligaments and muscles, less in joint-capsule and -fluid indicating direct penetration. The blood levels of topical NSAIDs are extremely low with no systemic side effects, especially no gastric toxicity; however, local skin irritation is observed (1 to 2%). In contrast to this, systemic (oral) NSAIDs lead primarily via high blood levels to a lower concentration--only one tenth--in periarticular soft tissues with a high incidence of side effects. In conclusion the percutaneous application of certain NSAIDs has become a well established therapeutic regimen in painful osteoarthritis and in all other inflammatory degenerative and posttraumatic alterations of soft tissue structure. PMID:10637963

  10. Plasticity of the central nervous system--a neurosurgeon's experience of cerebral compensation and decompensation.

    PubMed

    Pia, H W

    1985-01-01

    Cerebral plasticity constitutes one of the most decisive factors in recovery and readaptation after cerebral lesions. In contrast to the considerable progress in current studies on normal neuronal plasticity including the idea of "l'homme neuronal", the concept of plasticity postulated by Albrecht Bethe in 1929 received little attention. The author, as a neurosurgeon, has tried to describe cranial morphological plasticity, morphological and functional plasticity in infantile encephalopathies and especially in hemiatrophic lesions. It is supposed that a true morphological substrate exists due to compensatory hyperplasia of the uninvolved hemisphere. Modern neurosurgical techniques have demonstrated that the functional plastic capacity is much larger than has been supposed, even in the elderly. Some aspects of the mechanisms of compensation and decompensation of cortical and subcortical structures as well as of the central regulation systems are discussed. The full extent of the amazing recovery and functional reorganization is reached by plastic capacity, personal motivation, adequate training and sufficient time. The contribution ends with an exposition of a personal philosophy concerning psycho-somatic dualism, the body-mind problem, the future of the human brain and the ethical outlook, based on the progressive biological evolution of the basal neocortex and the immanent functional development (H. Spatz). PMID:4072784

  11. Biostereometric Analysis Of Therapeutic Results In The Treatment Of Chronic, Progressive, Decompensating Postural Back Strain

    NASA Astrophysics Data System (ADS)

    Johnson, David M.

    1980-07-01

    A two year pilot program for biostereometric analysis of treatment effectiveness in five patients with chronic decompensating back strain has been completed. The patients came from the investigators family practice of osteopathic medicine. They all manifested objective signs of ligamentous and muscular strain of their postural biomechanics due to the combined effects of prior injury to the musculoskeletal system, gravity strain and the passage of time. Two of the patients were treated with osteopathic manipulative treatment plus a pelvic leverage treatment device developed by Martin Jungman, M.D. Two patients received osteopathic treatment alone and the fifth individual switched from control to full program status in the middle of the study after the second stereophotography recording. Signs and symptoms of all patients' gravity strain syndrome changed during the program. Those patients who had the full combination of treatment modalities showed the most positive and significant postural changes as demonstrated by the biostereometric technique developed and performed by the Department of Biostereometrics, Texas Institute of Rehabilitation and Research, Baylor College of Medicine, Houston, Texas. Improvement was clearly demonstrated more quickly than with the prior radiographic measuring methods. X-ray and other studies have also been done on this group. All of the data has not been processed yet in this program. The test patients have improved posture, muscle mass and tone, more stamina and reduced pain.

  12. Brainstem evoked response audiometry: an investigatory tool in detecting hepatic encephalopathy in decompensated chronic liver disease.

    PubMed

    Kabali, Balasubramanian; Velayutham, Gowri; Kapali, Suresh Chander

    2014-01-01

    It is estimated that globally there is a marked increase in liver disease with reports of rising morbidity and mortality, particularly in younger age groups. Brainstem auditory evoked potential (BAEP) was recorded in 60 decompensated chronic liver disease (DCLD) subjects who fulfilled the selection criteria and compared to 60 age and gender matched healthy subjects with normal liver functions. DCLD subjects were divided into two inter groups based on presence or absence of hepatic encephalopathy (HE). Group 1 comprises of 30 subjects of grade- I HE and Group 2 included 30 subjects without hepatic encephalopathy (NHE). Absolute and interpeak wave latencies were measured. Results were analysed by student independent t- test using SPSS software 11 version. Statistical significance was tested using P value. From the present study it can be concluded that the central nervous system is involved in liver cirrhosis evidenced by an abnormal BAEP latencies parameters. This shows that there may be progressive demyelination occurring along with axonal loss or dysfunction in liver cirrhosis HE. This study suggests that periodic evaluation of cirrhotic individuals to such test will help in monitoring the progress of encephalopathy. The prime goal of this study is early diagnosis and initiation of treatment before the onset of coma can reduce the fatality rate. PMID:25508308

  13. Brainstem evoked response audiometry: an investigatory tool in detecting hepatic encephalopathy in decompensated chronic liver disease.

    PubMed

    Kabali, Balasubramanian; Velayutham, Gowri; Kapali, Suresh Chander

    2014-01-01

    It is estimated that globally there is a marked increase in liver disease with reports of rising morbidity and mortality, particularly in younger age groups. Brainstem auditory evoked potential (BAEP) was recorded in 60 decompensated chronic liver disease (DCLD) subjects who fulfilled the selection criteria and compared to 60 age and gender matched healthy subjects with normal liver functions. DCLD subjects were divided into two inter groups based on presence or absence of hepatic encephalopathy (HE). Group 1 comprises of 30 subjects of grade- I HE and Group 2 included 30 subjects without hepatic encephalopathy (NHE). Absolute and interpeak wave latencies were measured. Results were analysed by student independent t- test using SPSS software 11 version. Statistical significance was tested using P value. From the present study it can be concluded that the central nervous system is involved in liver cirrhosis evidenced by an abnormal BAEP latencies parameters. This shows that there may be progressive demyelination occurring along with axonal loss or dysfunction in liver cirrhosis HE. This study suggests that periodic evaluation of cirrhotic individuals to such test will help in monitoring the progress of encephalopathy. The prime goal of this study is early diagnosis and initiation of treatment before the onset of coma can reduce the fatality rate. PMID:25464677

  14. A Signal Processing Approach for Detection of Hemodynamic Instability before Decompensation.

    PubMed

    Belle, Ashwin; Ansari, Sardar; Spadafore, Maxwell; Convertino, Victor A; Ward, Kevin R; Derksen, Harm; Najarian, Kayvan

    2016-01-01

    Advanced hemodynamic monitoring is a critical component of treatment in clinical situations where aggressive yet guided hemodynamic interventions are required in order to stabilize the patient and optimize outcomes. While there are many tools at a physician's disposal to monitor patients in a hospital setting, the reality is that none of these tools allow hi-fidelity assessment or continuous monitoring towards early detection of hemodynamic instability. We present an advanced automated analytical system which would act as a continuous monitoring and early warning mechanism that can indicate pending decompensation before traditional metrics can identify any clinical abnormality. This system computes novel features or bio-markers from both heart rate variability (HRV) as well as the morphology of the electrocardiogram (ECG). To compare their effectiveness, these features are compared with the standard HRV based bio-markers which are commonly used for hemodynamic assessment. This study utilized a unique database containing ECG waveforms from healthy volunteer subjects who underwent simulated hypovolemia under controlled experimental settings. A support vector machine was utilized to develop a model which predicts the stability or instability of the subjects. Results showed that the proposed novel set of features outperforms the traditional HRV features in predicting hemodynamic instability. PMID:26871715

  15. Thermal vasodilation using a portable infrared thermal blanket in decompensated heart failure.

    PubMed

    Lima, Marcelo Villaça; Ochiai, Marcelo E; Vieira, Kelly N; Scipioni, Airton; Cardoso, Juliano N; Munhoz, Robinson T; Morgado, Paulo C; Barretto, Antonio C P

    2014-01-01

    Adjunctive and non-pharmacological therapies, such as heat, for the treatment of heart failure patients have been proposed. Positive results have been obtained in clinically stable patients, but no studies of the use of thermal therapy in patients with decompensated heart failure (DHF) have been reported. An open randomized clinical trial was designed in patients with DHF and controls. We studied 38 patients with a mean age of 56.9 years. A total of 86.8% were men, and 71% had nonischemic myocardiopathy. All participants were using dobutamine, and the median brain natriuretic peptide (BNP) level was 1396 pg/mL. An infrared thermal blanket heated the patients, who were divided into 2 groups: group T (thermal therapy) and group C (control). Group T underwent vasodilation using the thermal blanket at 50°C for 40 minutes in addition to drug treatment. The cardiac index increased by 24.1% (P = 0.009), and systemic vascular resistance decreased by 16.0% in group T (P < 0.024) after thermal therapy. Heat as a vasodilator increased the cardiac index and lowered systemic vascular resistance in DHF patients. These data suggest thermal therapy as a therapeutic approach for the adjuvant treatment of DHF patients. PMID:25070123

  16. Safety and efficacy of simeprevir plus sofosbuvir with or without ribavirin in patients with decompensated genotype 1 hepatitis C cirrhosis.

    PubMed

    Modi, Apurva A; Nazario, Hector; Trotter, James F; Gautam, Manjushree; Weinstein, Jeffrey; Mantry, Parvez; Barnes, Maisha; Habib, Adil; McAfee, Jean; Teachenor, Olga; Tujague, Lauren; Gonzalez, Stevan

    2016-03-01

    Combination antiviral therapy involving sofosbuvir (SOF) and simeprevir (SIM) is a treatment option in patients with genotype 1 chronic hepatitis C; however, the safety of this regimen in patients with decompensated cirrhosis is not established. Data from a combined treatment cohort of 2 large hepatology referral centers were evaluated to assess for safety and efficacy of SIM plus SOF with or without ribavirin (RBV) in patients with Child B or C cirrhosis. All (n = 42) patients included in the analysis had Child B (n = 35) or C (n = 7) cirrhosis and received 400 mg daily of SOF plus 150 mg daily of SIM, with (n = 7) or without (n = 35) RBV, for 12 weeks. Of the 42 patients in this cohort, 31 (74%) were male, 22 (52%) had failed prior treatments, and 28 (67%) were genotype 1a. Prior decompensating events included encephalopathy (57%), fluid overload (88%), or variceal hemorrhage (24%). Median Model for End-Stage Liver Disease score was 12 (range, 6-25). Treatment was well tolerated overall with more than one-half (57%) reporting no adverse events. In those reporting adverse events, the most common were fatigue (n = 6), insomnia (n = 4), headache (n = 5), nausea (n = 4), and grade 1 rash (n = 1). One patient developed chemical pancreatitis that did not require treatment discontinuation. Three of 7 patients who received RBV developed anemia, with 2 requiring blood transfusions and 1 requiring a dose reduction. No episodes of decompensation requiring hospitalization or deaths occurred on treatment. Of 42 patients, 38 (90%) patients had negative viral load at end of treatment (EOT), and 31 of 42 patients (74%) achieved sustained virological response 12 weeks after EOT; 10 of 10 patients (100%) with HCV genotype 1b achieved sustained virological response for 12 weeks (SVR12). In conclusion, SOF plus SIM was very well tolerated in patients with advanced Child B/C decompensated cirrhosis. Overall, 74% of patients achieved SVR12

  17. High baseline bilirubin and low albumin predict liver decompensation and serious adverse events in HCV-infected patients treated with sofosbuvir-containing regimens.

    PubMed

    Perumalswami, P V; Patel, N; Bichoupan, K; Ku, L; Yalamanchili, R; Harty, A; Motamed, D; Khaitova, V; Chang, C; Grewal, P; Liu, L; Schiano, T D; Woodward, M; Dieterich, D T; Branch, A D

    2016-09-01

    To conduct surveillance and determine the safety profile of new hepatitis C virus treatments in real-world clinical practice. Hepatic decompensation and other serious adverse events were investigated in an observational cohort study of 511 patients treated with regimens containing sofosbuvir, December 2013-June 2014. Among 499 previously stable patients (no history of hepatic decompensation during the previous 12 months), a nested case-control study was performed to identify predictors of decompensation/serious adverse event. Cases and controls were matched 1:5 based on treatment regimen and duration. Matched conditional logistic regression was used for analysis. Providers scored the likelihood that events were treatment-related (scale = 0-4). The cumulative incidence of decompensation/events was 6.4% for the total cohort. Among 499 previously stable patients, the incidence of decompensation/events was 4.5%; the mortality rate was 0.6%. Sixteen of the 499 experienced one or more serious complications considered to be at least potentially treatment-related, and the sustained virological response rate was 7/16 (44%). Two cases, both on sofosbuvir/simeprevir (without interferon or ribavirin), had complications consistent with autoimmune events (score 3, 'likely treatment-related'), and one experienced a flare of autoimmune hepatitis. Compared to controls, cases had higher baseline median model for end-stage liver disease scores (14 vs 8, P < 0.01). Decompensation/events was independently associated with lower baseline albumin (OR = 0.12/g/dL, P = 0.01) and higher total bilirubin (OR = 4.31/mg/dL, P = 0.01). Reduced hepatic function at baseline increased the risk of liver decompensation/events. PMID:26989855

  18. Acute Onset Anti-Synthetase Syndrome With Pericardial Effusion and Non-Specific Interstitial Pneumonia

    PubMed Central

    Shah, Aditya; Patel, Samir R.

    2016-01-01

    Anti-synthetase syndrome (AS) is a clinical entity which is described classically by the triad of interstitial lung disease (ILD), inflammatory myositis and presence of aminoacyl-tRNA synthetase antibodies (ASA). We describe a rare presentation of this condition with regard to the uncharacteristically acute nature of presentation, acute decompensation in clinical condition, development of acute interstitial pneumonitis requiring rescue extracorporeal membrane oxygenation (ECMO) and accompaniment of significant pericardial effusion on presentation, followed by rapid improvement with initiation of steroids. PMID:27540445

  19. Acute Onset Anti-Synthetase Syndrome With Pericardial Effusion and Non-Specific Interstitial Pneumonia.

    PubMed

    Shah, Aditya; Patel, Samir R

    2016-09-01

    Anti-synthetase syndrome (AS) is a clinical entity which is described classically by the triad of interstitial lung disease (ILD), inflammatory myositis and presence of aminoacyl-tRNA synthetase antibodies (ASA). We describe a rare presentation of this condition with regard to the uncharacteristically acute nature of presentation, acute decompensation in clinical condition, development of acute interstitial pneumonitis requiring rescue extracorporeal membrane oxygenation (ECMO) and accompaniment of significant pericardial effusion on presentation, followed by rapid improvement with initiation of steroids. PMID:27540445

  20. Influence of metabolic dysfunction on cardiac mechanics in decompensated hypertrophy and heart failure.

    PubMed

    Tewari, Shivendra G; Bugenhagen, Scott M; Vinnakota, Kalyan C; Rice, J Jeremy; Janssen, Paul M L; Beard, Daniel A

    2016-05-01

    Alterations in energetic state of the myocardium are associated with decompensated heart failure in humans and in animal models. However, the functional consequences of the observed changes in energetic state on mechanical function are not known. The primary aim of the study was to quantify mechanical/energetic coupling in the heart and to determine if energetic dysfunction can contribute to mechanical failure. A secondary aim was to apply a quantitative systems pharmacology analysis to investigate the effects of drugs that target cross-bridge cycling kinetics in heart failure-associated energetic dysfunction. Herein, a model of metabolite- and calcium-dependent myocardial mechanics was developed from calcium concentration and tension time courses in rat cardiac muscle obtained at different lengths and stimulation frequencies. The muscle dynamics model accounting for the effect of metabolites was integrated into a model of the cardiac ventricles to simulate pressure-volume dynamics in the heart. This cardiac model was integrated into a simple model of the circulation to investigate the effects of metabolic state on whole-body function. Simulations predict that reductions in metabolite pools observed in canine models of heart failure can cause systolic dysfunction, blood volume expansion, venous congestion, and ventricular dilation. Simulations also predict that myosin-activating drugs may partially counteract the effects of energetic state on cross-bridge mechanics in heart failure while increasing myocardial oxygen consumption. Our model analysis demonstrates how metabolic changes observed in heart failure are alone sufficient to cause systolic dysfunction and whole-body heart failure symptoms. PMID:27085901

  1. Micronutrients in African-Americans with decompensated and compensated heart failure.

    PubMed

    Arroyo, Maximiliano; Laguardia, Stephen P; Bhattacharya, Syamal K; Nelson, Maeda D; Johnson, Patti L; Carbone, Laura D; Newman, Kevin P; Weber, Karl T

    2006-12-01

    Heart failure is thought to be more common and of greater severity in African-Americans (AAs). Potential mechanisms remain uncertain. The importance of micronutrient deficiencies in the pathophysiologic expression of congestive heart failure (CHF) in AAs remains to be explored, including hypovitaminosis D, which can promote secondary hyperparathyroidism (SHPT), together with hypozincemia and hyposelenemia, the 2 most crucial trace minerals integral to diverse biologic functions. Serum parathyroid hormone (PTH), 25-hydroxyvitamin D (25(OH)D), Zn, and Se were monitored in 30 AAs hospitalized during June through December 2005, with decompensated failure and reduced ejection fraction (EF) (<35%) of predominantly nonischemic origin treated with an angiotensin-converting enzyme (ACE) inhibitor or an angiotensin receptor blocker (ARB), furosemide, and spironolactone. Based on their symptomatic status before hospitalization, 15 patients were stratified as having protracted (>or=4 weeks) CHF, whereas 15 patients had short-term (1-2 weeks) CHF. These hospitalized patients were compared with 10 AA outpatients with stable, similarly treated compensated failure and comparable EF, and 9 AA normal volunteers without cardiovascular disease. Serum PTH was elevated in all patients with protracted CHF and in 60% of patients with short-term CHF, but not in compensated patients or normal volunteers. However, serum 25(OH)D was reduced in all patients with >or=4 weeks and 80% with either 1-2 weeks CHF or compensated failure compared with volunteers. Serum Zn was below normal in 11 of 15 patients with protracted CHF, in 8 of 15 patients with shorter duration CHF, and in 5 of 10 patients with compensated failure. Serum Se was reduced in all patients with >or=4 weeks, 60% with short-term CHF, and 90% of compensated patients. Concomitant to hypovitaminosis D, hypozincemia, and hyposelenemia, SHPT is a covariant of CHF in housebound AAs. PMID:17162251

  2. Peripartum cardiomyopathy: postpartum decompensation and use of non-invasive cardiac output monitoring.

    PubMed

    Lorello, G; Cubillos, J; McDonald, M; Balki, M

    2014-02-01

    The utility of a non-invasive cardiac output monitor (NICOM™) in guiding the peripartum management and identification of postpartum complications in a patient with severe peripartum cardiomyopathy is reported. A 31-year-old nulliparous woman at 35 weeks of gestation presented with a three-week history of worsening dyspnea and progressive functional deterioration. A transthoracic echocardiogram showed severe left ventricular systolic dysfunction with an ejection fraction <20%. Cardiac status was monitored using NICOM™ during labor and delivery. The baseline values were: cardiac output 5.3 L/min, total peripheral resistance 1549 dynes.sec/cm(5), stroke volume 42.1 mL and stroke volume variation 18%. She received early epidural analgesia during labor, titrated slowly with a loading dose of 0.0625% bupivacaine 10 mL and fentanyl 25 μg, followed by patient-controlled epidural analgesia (0.0625% bupivacaine with fentanyl 2 μg/mL, infusion at 10 mL/h, bolus dose 5 mL and lockout interval 10 min). After epidural drug administration, total peripheral resistance decreased, cardiac output increased, and satisfactory analgesia was obtained. She had an uneventful vaginal delivery with a forceps-assisted second stage after prophylactic administration of furosemide 20 mg. NICOM™ was discontinued after delivery. Fifteen hours post-delivery, the patient developed cardiogenic shock, which resolved after aggressive therapy with inotropes and furosemide. NICOM™ can be used to guide treatment during labor and delivery in patients with critical peripartum cardiomyopathy. We suggest that use of NICOM™ be extended into the postpartum period to detect signs of cardiac decompensation in such patients. PMID:24360329

  3. Atrial Fibrillation in Decompensated Heart Failure: Associated Factors and In-Hospital Outcome

    PubMed Central

    Mendes, Fernanda de Souza Nogueira Sardinha; Atié, Jacob; Garcia, Marcelo Iorio; Gripp, Eliza de Almeida; de Sousa, Andréa Silvestre; Feijó, Luiz Augusto; Xavier, Sergio Salles

    2014-01-01

    Background Studies on atrial fibrillation (AF) in decompensated heart failure (DHF) are scarce in Brazil. Objectives To determine AF prevalence, its types and associated factors in patients hospitalized due to DHF; to assess their thromboembolic risk profile and anticoagulation rate; and to assess the impact of AF on in-hospital mortality and hospital length of stay. Methods Retrospective, observational, cross-sectional study of incident cases including 659 consecutive hospitalizations due to DHF, from 01/01/2006 to 12/31/2011. The thromboembolic risk was assessed by using CHADSVASc score. On univariate analysis, the chi-square, Student t and Mann Whitney tests were used. On multivariate analysis, logistic regression was used. Results The prevalence of AF was 40%, and the permanent type predominated (73.5%). On multivariate model, AF associated with advanced age (p < 0.0001), non-ischemic etiology (p = 0.02), right ventricular dysfunction (p = 0.03), lower systolic blood pressure (SBP) (p = 0.02), higher ejection fraction (EF) (p < 0.0001) and enlarged left atrium (LA) (p < 0.0001). The median CHADSVASc score was 4, and 90% of the cases had it ≥ 2. The anticoagulation rate was 52.8% on admission and 66.8% on discharge, being lower for higher scores. The group with AF had higher in-hospital mortality (11.0% versus 8.1%, p = 0.21) and longer hospital length of stay (20.5 ± 16 versus 16.3 ± 12, p = 0.001). Conclusions Atrial fibrillation is frequent in DHF, the most prevalent type being permanent AF. Atrial fibrillation is associated with more advanced age, non-ischemic etiology, right ventricular dysfunction, lower SBP, higher EF and enlarged LA. Despite the high thromboembolic risk profile, anticoagulation is underutilized. The presence of AF is associated with longer hospital length of stay and high mortality. PMID:25352505

  4. Statistical gamma transitions in {sup 174}Hf

    SciTech Connect

    Farris, L.P.; Cizewski, J.A.; Brinkman, M.J.; Henry, R.G.; Lee, C.S.; Khoo, T.L.; Janssens, R.V.F.; Moore, E.F.; Carpenter, M.P.; Ahmad, I.; Lauritsen, T.; Kolata, J.J.; Beard, K.B.; Ye, D.; Garg, U.; Kaplan, M.S.; Saladin, J.X.; Winchell, D.

    1992-08-01

    Statistical spectrum extracted from the {sup 172}Yb({alpha},2n){sup 174}Hf reaction was fit with Monte Carlo simulations using a modified GDR E1 strength function and several formulations of the level density.

  5. Statistical gamma transitions in sup 174 Hf

    SciTech Connect

    Farris, L.P.; Cizewski, J.A.; Brinkman, M.J.; Henry, R.G.; Lee, C.S. ); Khoo, T.L.; Janssens, R.V.F.; Moore, E.F.; Carpenter, M.P.; Ahmad, I.; Lauritsen, T. ); Kolata, J.J.; Beard, K.B.; Ye, D.; Garg, U. ); Kaplan, M.S.; Saladin, J.X.; Winchell, D. (Pittsburgh Univ., PA (Un

    1992-01-01

    Statistical spectrum extracted from the {sup 172}Yb({alpha},2n){sup 174}Hf reaction was fit with Monte Carlo simulations using a modified GDR E1 strength function and several formulations of the level density.

  6. Pathophysiology of acute heart failure: a world to know.

    PubMed

    Sánchez-Marteles, M; Rubio Gracia, J; Giménez López, I

    2016-01-01

    Our understanding of the pathophysiological mechanisms of heart failure (HF) has changed considerably in recent years, progressing from a merely haemodynamic viewpoint to a concept of systemic and multifactorial involvement in which numerous mechanisms interact and concatenate. The effects of these mechanisms go beyond the heart itself, to other organs of vital importance such as the kidneys, liver and lungs. Despite this, the pathophysiology of acute HF still has aspects that elude our deeper understanding. Haemodynamic overload, venous congestion, neurohormonal systems, natriuretic peptides, inflammation, oxidative stress and its repercussion on cardiac and vascular remodelling are currently considered the main players in acute HF. Starting with the concept of acute HF, this review provides updates on the various mechanisms involved in this disease. PMID:26541707

  7. Vasodilators in Acute Heart Failure: Review of the Latest Studies

    PubMed Central

    Levy, Phillip D.; Laribi, Said; Mebazaa, Alexandre

    2014-01-01

    Vasodilators play an important role in the management of acute heart failure, particularly when increased afterload is the precipitating cause of decompensation. The time-honored approach to afterload reduction has been largely focused on use of intravenous nitrovasodilators and, when properly dosed, this class of agents does provide substantial symptom relief for patients with acute hypertensive heart failure. Despite this, nitrovasodilators have never been shown to diminish mortality or provide any post-discharge outcome benefit leading to an on-going search for viable and more effective alternatives. While no new vasodilators have been approved for use in acute heart failure since nesiritide more than a decade ago, a number of novel agents have been developed, with some showing significant promise in recent clinical trials. In this review, we summarize the latest study data as it relates to vasodilator therapy and provide a glimpse into the not too distant future state of acute heart failure care. PMID:24855585

  8. Sleep and circadian rhythms in hospitalized patients with decompensated cirrhosis: effect of light therapy.

    PubMed

    De Rui, M; Middleton, B; Sticca, A; Gatta, A; Amodio, P; Skene, D J; Montagnese, S

    2015-02-01

    , decompensated patients with cirrhosis are extremely compromised. Treatment with bright light therapy did not show obvious, beneficial effects, most likely in relation to the severity of disturbance at baseline. PMID:25135598

  9. Heart Failure in Acute Ischemic Stroke

    PubMed Central

    Cuadrado-Godia, Elisa; Ois, Angel; Roquer, Jaume

    2010-01-01

    Heart failure (HF) is a complex clinical syndrome that can result from any structural or functional cardiac disorder that impairs the ability of the ventricle to fill with or eject blood. Due to the aging of the population it has become a growing public health problem in recent decades. Diagnosis of HF is clinical and there is no diagnostic test, although some basic complementary testing should be performed in all patients. Depending on the ejection fraction (EF), the syndrome is classified as HF with low EF or HF with normal EF (HFNEF). Although prognosis in HF is poor, HFNEF seems to be more benign. HF and ischemic stroke (IS) share vascular risk factors such as age, hypertension, diabetes mellitus, coronary artery disease and atrial fibrillation. Persons with HF have higher incidence of IS, varying from 1.7% to 10.4% per year across various cohort studies. The stroke rate increases with length of follow-up. Reduced EF, independent of severity, is associated with higher risk of stroke. Left ventricular mass and geometry are also related with stroke incidence, with concentric hypertrophy carrying the greatest risk. In HF with low EF, the stroke mechanism may be embolism, cerebral hypoperfusion or both, whereas in HFNEF the mechanism is more typically associated with chronic endothelial damage of the small vessels. Stroke in patients with HF is more severe and is associated with a higher rate of recurrence, dependency, and short term and long term mortality. Cardiac morbidity and mortality is also high in these patients. Acute stroke treatment in HF includes all the current therapeutic options to more carefully control blood pressure. For secondary prevention, optimal control of all vascular risk factors is essential. Antithrombotic therapy is mandatory, although the choice of a platelet inhibitor or anticoagulant drug depends on the cardiac disease. Trials are ongoing to evaluate anticoagulant therapy for prevention of embolism in patients with low EF who are at

  10. [Diagnosis of acute heart failure and relevance of biomarkers in elderly patients].

    PubMed

    Ruiz Ortega, Raúl Antonio; Manzano, Luis; Montero-Pérez-Barquero, Manuel

    2014-03-01

    Diagnosis of acute heart failure (HF) is difficult in elderly patients with multiple comorbidities. Risk scales and classification criteria based exclusively on clinical manifestations, such as the Framingham scales, lack sufficient specificity. In addition to clinical manifestations, diagnosis should be based on two key factors: natriuretic peptides and echocardiographic study. When there is clinical suspicion of acute HF, a normal natriuretic peptide level will rule out this process. When a consistent clinical suspicion is present, an echocardiographic study should also be performed. Diagnosis of HF with preserved ejection fraction (HF/pEF) requires detection of an enlarged left atrium or the presence of parameters of diastolic dysfunction. Elevation of cardiac biomarkers seems to be due to myocardial injury and the compensatory mechanisms of the body against this injury (hormone and inflammatory response and repair mechanisms). Elevation of markers of cardiac damage (troponins and natriuretic peptides) have been shown to be useful both in the diagnosis of acute HF and in prediction of outcome. MMP-2 could be useful in the diagnosis of HF/pEF. In addition to biomarkers with diagnostic value, other biomarkers are helpful in prognosis in the acute phase of HF, such as biomarkers of renal failure (eGFR, cystatin and urea), inflammation (cytokines and CRP), and the cell regeneration marker, galectin-3. A promising idea that is under investigation is the use of panels of biomarkers, which could allow more accurate diagnosis and prognosis of acute HF. PMID:24930079

  11. Na(+)-K(+)-ATPase alpha(2)-isoform expression in guinea pig hearts during transition from compensation to decompensation.

    PubMed

    Trouve, P; Carre, F; Belikova, I; Leclercq, C; Dakhli, T; Soufir, L; Coquard, I; Ramirez-Gil, J; Charlemagne, D

    2000-10-01

    Disturbance in ionic gradient across sarcolemma may lead to arrhythmias. Because Na(+)-K(+)-ATPase regulates intracellular Na(+) and K(+) concentrations, and therefore intracellular Ca(2+) concentration homeostasis, our aim was to determine whether changes in the Na(+)-K(+)-ATPase alpha-isoforms in guinea pigs during transition from compensated (CLVH) to decompensated left ventricular hypertrophy (DLVH) were concomitant with arrhythmias. After 12- and 20-mo aortic stenosis, CLVH and DLVH were characterized by increased mean arterial pressure (30% and 52.7%, respectively). DLVH differed from CLVH by significantly increased end-diastolic pressure (34%), decreased sarco(endo)plasmic reticulum Ca(2+)-ATPase (-75%), and increased Na(+)/Ca(2+) exchanger (25%) mRNA levels and by the occurrence of ventricular arrhythmias. The alpha-isoform (mRNA and protein levels) was significantly lower in DLVH (2.2 +/- 0.2- and 1. 4 +/- 0.15-fold, respectively, vs. control) than in CLVH (3.5 +/- 0. 4- and 2.2 +/- 0.13-fold, respectively) and was present in sarcolemma and T tubules. Changes in the levels of alpha(1)- and alpha(3)-isoform in CLVH and DLVH appear physiologically irrelevant. We suggest that the increased level of alpha(2)-isoform in CLVH may participate in compensation, whereas its relative decrease in DLVH may enhance decompensation and arrhythmias. PMID:11009487

  12. Decompensated liver cirrhosis and neural regulation of mesenteric vascular tone in rats: role of sympathetic, nitrergic and sensory innervations.

    PubMed

    Sastre, Esther; Caracuel, Laura; Prieto, Isabel; Llévenes, Pablo; Aller, M Ángeles; Arias, Jaime; Balfagón, Gloria; Blanco-Rivero, Javier

    2016-01-01

    We evaluated the possible alterations produced by liver cholestasis (LC), a model of decompensated liver cirrhosis in sympathetic, sensory and nitrergic nerve function in rat superior mesenteric arteries (SMA). The vasoconstrictor response to electrical field stimulation (EFS) was greater in LC animals. Alpha-adrenoceptor antagonist phentolamine and P2 purinoceptor antagonist suramin decreased this response in LC animals more than in control animals. Both non-specific nitric oxide synthase (NOS) L-NAME and calcitonin gene related peptide (CGRP) (8-37) increased the vasoconstrictor response to EFS more strongly in LC than in control segments. Vasomotor responses to noradrenaline (NA) or CGRP were greater in LC segments, while NO analogue DEA-NO induced a similar vasodilation in both experimental groups. The release of NA was not modified, while those of ATP, nitrite and CGRP were increased in segments from LC. Alpha 1 adrenoceptor, Rho kinase (ROCK) 1 and 2 and total myosin phosphatase (MYPT) expressions were not modified, while alpha 2B adrenoceptor, nNOS expression and nNOS and MYPT phosphorylation were increased by LC. Together, these alterations might counteract the increased splanchnic vasodilation observed in the last phases of decompensated liver cirrhosis. PMID:27484028

  13. Decompensated liver cirrhosis and neural regulation of mesenteric vascular tone in rats: role of sympathetic, nitrergic and sensory innervations

    PubMed Central

    Sastre, Esther; Caracuel, Laura; Prieto, Isabel; Llévenes, Pablo; Aller, M. Ángeles; Arias, Jaime; Balfagón, Gloria; Blanco-Rivero, Javier

    2016-01-01

    We evaluated the possible alterations produced by liver cholestasis (LC), a model of decompensated liver cirrhosis in sympathetic, sensory and nitrergic nerve function in rat superior mesenteric arteries (SMA). The vasoconstrictor response to electrical field stimulation (EFS) was greater in LC animals. Alpha-adrenoceptor antagonist phentolamine and P2 purinoceptor antagonist suramin decreased this response in LC animals more than in control animals. Both non-specific nitric oxide synthase (NOS) L-NAME and calcitonin gene related peptide (CGRP) (8-37) increased the vasoconstrictor response to EFS more strongly in LC than in control segments. Vasomotor responses to noradrenaline (NA) or CGRP were greater in LC segments, while NO analogue DEA-NO induced a similar vasodilation in both experimental groups. The release of NA was not modified, while those of ATP, nitrite and CGRP were increased in segments from LC. Alpha 1 adrenoceptor, Rho kinase (ROCK) 1 and 2 and total myosin phosphatase (MYPT) expressions were not modified, while alpha 2B adrenoceptor, nNOS expression and nNOS and MYPT phosphorylation were increased by LC. Together, these alterations might counteract the increased splanchnic vasodilation observed in the last phases of decompensated liver cirrhosis. PMID:27484028

  14. Acute Kidney Injury: Quoi de Neuf?

    PubMed Central

    Reichel, Ronald R.

    2014-01-01

    Background Acute kidney injury (AKI) is frequently encountered in the nephrology practice. Serum creatinine, with its many shortcomings, is still the main biomarker used to detect AKI. Methods This review focuses on recent advances in definition, diagnosis, risk factors, and molecular mechanisms of AKI. In addition, specific AKI syndromes such as contrast-induced AKI, hepatorenal syndrome, and acute decompensated heart failure are discussed. The connection between AKI and subsequent chronic kidney disease and recent developments in renal replacement therapy are also covered. Results Novel biomarkers such as cystatin C and neutrophil gelatinase–associated lipocalin (NGAL) are being investigated to replace serum creatinine in the detection of AKI. Recent studies suggest that intravenous (IV) fluid use is beneficial for the prevention of contrast-induced AKI, while N-acetylcysteine use is not as well established. Diuretics are clearly beneficial in the treatment of acute decompensated heart failure. Ultrafiltration is less promising and can lead to adverse side effects. Although terlipressin use in hepatorenal syndrome is associated with reduced mortality, it is not available in the United States; combination therapy with midodrine, octreotide, and albumin provides an alternative. Fluid resuscitation is frequently used in critically ill patients with AKI; however, overly aggressive fluid resuscitation is frequently associated with an increased risk of mortality. A 3-step approach that combines guided fluid resuscitation, establishment of an even fluid balance, and an appropriate rate of fluid removal may be beneficial. If fluid resuscitation is needed, crystalloid solutions are preferred over hetastarch solutions. Renal replacement therapy is the last resort in AKI treatment, and timing, modality, and dosing are discussed. Research suggests that AKI leads to an increased incidence of subsequent chronic kidney disease. However, this relationship has not been fully

  15. Management of Acute Variceal Bleeding

    PubMed Central

    2014-01-01

    Acute variceal bleeding could be a fatal complication in patients with liver cirrhosis. In patients with decompensated liver cirrhosis accompanied by ascites or hepatic encephalopathy, acute variceal bleeding is associated with a high mortality rate. Therefore, timely endoscopic hemostasis and prevention of relapse of bleeding are most important. The treatment goals for acute variceal bleeding are to correct hypovolemia; achieve rapid hemostasis; and prevent early rebleeding, complications related to bleeding, and deterioration of liver function. If variceal bleeding is suspected, treatment with vasopressors and antibiotics should be initiated immediately on arrival to the hospital. Furthermore, to obtain hemodynamic stability, the hemoglobin level should be maintained at >8 g/dL, systolic blood pressure >90 to 100 mm Hg, heart rate <100/min, and the central venous pressure from 1 to 5 mm Hg. When the patient becomes hemodynamically stable, hemostasis should be achieved by performing endoscopy as soon as possible. For esophageal variceal bleeding, endoscopic variceal ligation is usually performed, and for gastric variceal bleeding, endoscopic variceal obturation is performed primarily. If it is considered difficult to achieve hemostasis through endoscopy, salvage therapy may be carried out while keeping the patient hemodynamically stable. PMID:25133116

  16. HF Accelerated Electron Fluxes, Spectra, and Ionization

    NASA Astrophysics Data System (ADS)

    Carlson, Herbert C.; Jensen, Joseph B.

    2015-10-01

    Wave particle interactions, an essential aspect of laboratory, terrestrial, and astrophysical plasmas, have been studied for decades by transmitting high power HF radio waves into Earth's weakly ionized space plasma, to use it as a laboratory without walls. Application to HF electron acceleration remains an active area of research (Gurevich in Usp Fizicheskikh Nauk 177(11):1145-1177, 2007) today. HF electron acceleration studies began when plasma line observations proved (Carlson et al. in J Atmos Terr Phys 44:1089-1100, 1982) that high power HF radio wave-excited processes accelerated electrons not to ~eV, but instead to -100 times thermal energy (10 s of eV), as a consequence of inelastic collision effects on electron transport. Gurevich et al (J Atmos Terr Phys 47:1057-1070, 1985) quantified the theory of this transport effect. Merging experiment with theory in plasma physics and aeronomy, enabled prediction (Carlson in Adv Space Res 13:1015-1024, 1993) of creating artificial ionospheres once ~GW HF effective radiated power could be achieved. Eventual confirmation of this prediction (Pedersen et al. in Geophys Res Lett 36:L18107, 2009; Pedersen et al. in Geophys Res Lett 37:L02106, 2010; Blagoveshchenskaya et al. in Ann Geophys 27:131-145, 2009) sparked renewed interest in optical inversion to estimate electron spectra in terrestrial (Hysell et al. in J Geophys Res Space Phys 119:2038-2045, 2014) and planetary (Simon et al. in Ann Geophys 29:187-195, 2011) atmospheres. Here we present our unpublished optical data, which combined with our modeling, lead to conclusions that should meaningfully improve future estimates of the spectrum of HF accelerated electron fluxes. Photometric imaging data can significantly improve detection of emissions near ionization threshold, and confirm depth of penetration of accelerated electrons many km below the excitation altitude. Comparing observed to modeled emission altitude shows future experiments need electron density profiles

  17. Comparison of HfCl4, HfI4, TEMA-Hf, and TDMA-Hf as precursors in early growing stages of HfO2 films deposited by ALD: A DFT study

    NASA Astrophysics Data System (ADS)

    Cortez-Valadez, M.; Fierro, C.; Farias-Mancilla, J. R.; Vargas-Ortiz, A.; Flores-Acosta, M.; Ramírez-Bon, R.; Enriquez-Carrejo, J. L.; Soubervielle-Montalvo, C.; Mani-Gonzalez, P. G.

    2016-06-01

    The final structure of HfO2 films grown by atomic layer deposition (ALD) after reaction with OH- ions has been analyzed by DFT (density functional theory). The interaction of the precursors: HfCl4 (hafnium tetrachloride), HfI4 (hafnium tetraiodide), TEMA-Hf (tetrakis-ethylmethylamino hafnium), and TDMA-Hf (tetrakis-dimethylamino hafnium) with HO-H was studied employing the B3LYP (Becke 3-parameter, Lee-Yang-Parr) hybrid functional and the PBE (Perdew-Burke-Ernzerhof) generalized gradient functional. The structural evolution at the Si(100) surface has been analyzed by LDA (local density approximation). The structural parameters: bond length and bond angle, and the vibrational parameters for the optimized structures are also reported. The presence of hafnium silicate at the interface was detected. The infrared spectra and structural parameters obtained in this work agree with previously reported experimental results.

  18. Diagnostic and Prognostic Properties of Osteoprotegerin in Patients with Acute Dyspnoea: Observations from the Akershus Cardiac Examination (ACE) 2 Study

    PubMed Central

    Pervez, Mohammed Osman; Pedersen, Marit Holmefjord; Brynildsen, Jon; Høiseth, Arne Didrik; Hagve, Tor-Arne; Røsjø, Helge; Omland, Torbjørn

    2016-01-01

    Background Circulating osteoprotegerin (OPG) levels are increased in patients with chronic heart failure (HF). The diagnostic and prognostic merit of OPG measurement in patients admitted with acute dyspnoea is unknown. Objectives To evaluate the diagnostic and prognostic value of measuring OPG in patients admitted to hospital with acute dyspnoea. Methods OPG was analysed by ELISA in 308 patients admitted due to acute dyspnoea. Investigators blinded to OPG results adjudicated the diagnosis for the index hospitalization. Clinical outcomes were obtained from hospital records. Results In total, 139 patients (45%) were hospitalized with acute HF. OPG levels on hospital admission were higher in patients with acute HF vs. no acute HF, 7.8 (5.5–10.4) vs. 5.4 (3.8–7.2) pmol/L, p<0.001. The area under the receiver operator characteristic curve (ROC AUC) of OPG to discriminate between HF vs. non-HF was 0.695 [95% CI 0.636–0.754]. OPG did not provide incremental information to the ED physician’s prediction or N-terminal pro-B-type natriuretic peptide regarding the diagnosis of acute HF. OPG levels (log transformed) were associated with mortality in crude analysis (HR (95% CI) 1.87 (1.34 to 2.61), p<0.001), but this association was attenuated and no longer significant after including established cardiac biomarkers into the model. Conclusion In patients admitted to hospital with acute dyspnoea, OPG levels are higher in patients with acute HF than in those with dyspnoea from other causes. However, OPG does not provide incremental information beyond ED physician assessment for the diagnosis of acute HF or beyond clinical risk variables and established cardiac biomarkers concerning prognosis. PMID:27463973

  19. Autologous Bone Marrow Mononuclear Cell Transplantation in Patients with Decompensated Alcoholic Liver Disease: A Randomized Controlled Trial

    PubMed Central

    Spahr, Laurent; Chalandon, Yves; Terraz, Sylvain; Kindler, Vincent; Rubbia-Brandt, Laura; Frossard, Jean-Louis; Breguet, Romain; Lanthier, Nicolas; Farina, Annarita; Passweg, Jakob; Becker, Christoph D.; Hadengue, Antoine

    2013-01-01

    Objective Impaired liver regeneration is associated with a poor outcome in patients with decompensated alcoholic liver disease (ALD). We assessed whether autologous bone marrow mononuclear cell transplantation (BMMCT) improved liver function in decompensated ALD. Design 58 patients (mean age 54 yrs; mean MELD score 19, all with cirrhosis, 81% with alcoholic steatohepatitis at baseline liver biopsy) were randomized early after hospital admission to standard medical therapy (SMT) alone (n = 30), including steroids in patients with a Maddrey’s score ≥32, or combined with G-CSF injections and autologous BMMCT into the hepatic artery (n = 28). Bone marrow cells were harvested, isolated and reinfused the same day. The primary endpoint was a ≥3 points decrease in the MELD score at 3 months, corresponding to a clinically relevant improvement in liver function. Liver biopsy was repeated at week 4 to assess changes in Ki67+/CK7+ hepatic progenitor cells (HPC) compartment. Results Both study groups were comparable at baseline. After 3 months, 2 and 4 patients died in the BMMCT and SMT groups, respectively. Adverse events were equally distributed between groups. Moderate alcohol relapse occurred in 31% of patients. The MELD score improved in parallel in both groups during follow-up with 18 patients (64%) from the BMMCT group and 18 patients (53%) from the SMT group reaching the primary endpoint (p = 0.43 (OR 1.6, CI 0.49–5.4) in an intention to treat analysis. Comparing liver biopsy at 4 weeks to baseline, steatosis improved (p<0.001), and proliferating HPC tended to decrease in both groups (−35 and −33%, respectively). Conclusion Autologous BMMCT, compared to SMT is a safe procedure but did not result in an expanded HPC compartment or improved liver function. These data suggest either insufficient regenerative stimulation after BMMCT or resistance to liver regenerative drive in patients with decompensated alcoholic cirrhosis. Trial Registration

  20. HF Radio Wave Production of Artificial Ionospheres

    NASA Astrophysics Data System (ADS)

    Carlson, Herbert

    In 1993 it was predicted that artificial ionospheres would be produced by high power HF radio waves, once HF transmitters approached a GWatt ERP. When that threshold was very recently achieved, such production was indeed detected and published at two high latitude high power HF facilities. Here we review: the first-principles logic behind that prediction, which aspects of such production are critically dependent on magnetic latitude, and which aspects of such production depend only on physical parameters independent of latitude. These distinctions follow directly from decomposition of the problem of ionization production into its components of: radio-wave propagation, wave-particle interactions, electron transport, and quantitative elastic/inelastic cross-sections. We outline this analysis to show that, within the context of early observations, the production of ionization is inevitable, and only a question of competing instability thresholds, and scale of ionization production. This illustrates complimentary aeronomy and plasma physics to advance understanding of both.

  1. Ionization Energy Measurements and Spectroscopy of HfO and HfO^+

    NASA Astrophysics Data System (ADS)

    Merritt, J. M.; Bondybey, V. E.; Heaven, M. C.

    2009-06-01

    Rotationally resolved spectra of the HfO^+ cation have been recorded using the pulsed field ionization zero electron kinetic energy (PFI-ZEKE) technique. The F(0^+)← X^1Σ_g band system in HfO was resonantly excited to provide vibrational and rotational state selectivity in the two photon ionization process. Using the PFI-ZEKE technique a value of 7.91687(10) eV was determined for the ionization energy (IE) of HfO, 0.37 eV higher than the values reported previously using electron impact ionization measurements. Underestimation of the IE in the previous studies is attributed to ionization of thermally excited states. A progression in the HfO^+ stretching vibration up to ν^+ = 4 was observed in the PFI-ZEKE spectrum, allowing for determination of the ground electronic state vibrational frequency of ν_e = 1017.7(10) cm^{-1} and anharmonicity of ω_ex_e = 3.2(2) cm^{-1}. The rotational constant of HfO^+ was determined to be 0.403(5) cm^{-1}. Benchmark theoretical ab initio calculations were carried out in order to explore the effects of electron correlation on the predicted molecular properties. Survey scans utilizing laser induced fluorescence and resonance enhanced multiphoton ionization detection revealed many previously unassigned bands in the region of the F-X and G-X bands of HfO, which we attribute to nominally forbidden singlet - triplet transitions of HfO.

  2. Removal of uranium from aqueous HF solutions

    DOEpatents

    Pulley, Howard; Seltzer, Steven F.

    1980-01-01

    This invention is a simple and effective method for removing uranium from aqueous HF solutions containing trace quantities of the same. The method comprises contacting the solution with particulate calcium fluoride to form uranium-bearing particulates, permitting the particulates to settle, and separting the solution from the settled particulates. The CaF.sub.2 is selected to have a nitrogen surface area in a selected range and is employed in an amount providing a calcium fluoride/uranium weight ratio in a selected range. As applied to dilute HF solutions containing 120 ppm uranium, the method removes at least 92% of the uranium, without introducing contaminants to the product solution.

  3. Cystometric parameters and the activity of signaling proteins in association with the compensation or decompensation of bladder function in an animal experimental model of partial bladder outlet obstruction.

    PubMed

    Choi, Bo-Hwa; Jin, Long-Hu; Kim, Khae-Hawn; Kang, Sung-An; Kang, Ju-Hee; Yoon, Sang-Min; Park, Chang-Shin; Lee, Tack

    2013-12-01

    We conducted this study to determine whether the degree of detrusor contractility is associated with the compensation or decompensation of bladder function depending on the residual volume (RV) during the first two weeks after the onset of partial bladder outlet obstruction (BOO). Moreover, we also examined whether the degree of the phosphorylation and expression of signaling proteins [AMP-activated kinase (AMPK), extracellular signal‑regulated protein kinases 1 and 2 (ERK1/2) and protein kinase C (PKC)] is associated with the prevalence of compensation or decompensation of bladder function. Twenty-seven female Sprague-Dawley (SD) rats were randomly assigned to either the sham-operated group (n=7) or the group with partial bladder outlet obstruction (BOO) (n=20). We then measured cystometric parameters from three reproducible micturition cycles and averaged the results for a comparison between the two groups. Based on a cut-off value of a mean RV% of 25%, we subdivided our experimental animals into two subgroups: the subgroup with bladder compensation (mean RV%, <25%) and the subgroup with bladder decompensation (mean RV%, >25%). Our results indicated that the degree of detrusor overactivity (DO) was associated with the compensation or decompensation of bladder function depending on the RV during the first two weeks after the onset of BOO in an animal experimental model of partial BOO. Moreover, we also demonstrate that AMPK and ERK1/2 are involved in the compensation or decompensation of bladder function. Furthermore, our results suggest that PKC is not involved in two-phase bladder contraction. Alterations in the activities of signaling proteins, such as AMPK and ERK1/2 may prove to be helpful in the treatment of patients with voiding difficulty. PMID:24085268

  4. Low Temperature Silicon Surface Cleaning by HF Etching/Ultraviolet Ozone Cleaning (HF/UVOC) Method (I)—Optimization of the HF Treatment—

    NASA Astrophysics Data System (ADS)

    Suemitsu, Maki; Kaneko, Tetsuya; Miyamoto, Nobuo

    1989-12-01

    Several variations of fluoric acid (HF) treatments of silicon substrates were examined for their adaptability as a pretreatment method for a silicon epitaxy process. Treatments with and without distilled, deionized (DI) water rinse, of different HF concentrations, and of different methods of HF supply were tested and their residual carbonic impurity contents were measured using RHEED. As a result, HF treatments by themselves were found to be insufficient in passivating the surface dangling bonds irrespective of the method of HF supply: dipping into the solution or exposure to the vapor. The optimum procedure of HF treatment thus proposed is a succession of (a) HF dipping, (b) DI-water rinsing, (c) nitrogen-gas blowing, and (d) UV-ozone cleaning.

  5. Orthodontic decompensation and correction of skeletal Class III malocclusion with gradual dentoalveolar remodeling in a growing patient.

    PubMed

    Cai, Bin; Zhao, Xiao-Guang; Xiang, Lu-Sai

    2014-03-01

    An 8-year-old girl with a skeletal Class III malocclusion was treated in 2 phases. Maxillary expansion and protraction were carried out as the early intervention. However, her maxillary hypoplasia and mandibular hyperplasia deteriorated with age. The phase 2 comprehensive treatment began with proper mechanics when she was 12 years old with growth potential. In the maxillary arch, an auxiliary rectangular wire was used with a round main wire and an opening spring to create space for the impacted teeth and to bodily move the anterior teeth forward. Decompensation of mandibular incisors and correction of the Class III malocclusion were achieved by short Class III elastics with light forces and a gentle interaction between the rectangular wires and the lingual root-torque slots. The phase 2 active treatment period was 4 years 8 months. The 2-year follow-up indicated that our treatment results were quite stable. PMID:24582028

  6. Morphological and immunohistochemical changes in the liver in coarctation of the aorta during compensation and decompensation stages.

    PubMed

    Shormanov, S V; Kulikov, S V

    2013-12-01

    Compensated coarctation of the aorta is accompanied by a decrease in the tone of hepatic vessels, thinning of the vascular walls, and moderate expression of α-SMA. Bundles of intimal muscles, myoelastic sphincters, and polyp-like pads form in the arteries; the muscle rolls in the efferent veins degenerate. Hepatocyte changes are presented by focal involvement of the organelles. Decompensated coarctation is characterized by more pronounced atrophy of hepatic vascular walls and regulatory structures. The expression of α-SMA in the arteries increases, sclerosis develops, and signs of CD34 expression in the sinusoids and perisinusoidal fibrosis emerge. All these shifts are associated with coarse ultrastructural changes in hepatocytes. PMID:24319767

  7. Efficacy and safety of nesiritide in patients with decompensated heart failure: a meta-analysis of randomised trials

    PubMed Central

    Gong, Bojun; Wu, Zhineng; Li, Zicheng

    2016-01-01

    Objectives Current evidence suggests that nesiritide may have effects on renal function and decrease the incidence of mortality. However, a clear superiority using nesiritide in terms of renal toxicity and mortality in patients with heart failure was not consistently proven by previous studies. We performed a meta-analysis of all randomised trials to obtain the best estimates of efficacy and safety of nesiritide for the initial treatment of decompensated heart failure. Method We performed a meta-analysis of randomised trials of nesiritide in patients with decompensated heart failure (n=38 064 patients, in 22 trials). Two reviewers independently extracted data. Data on efficacy and safety outcomes were collected. We calculated pooled relatives risk (RRs), weighted mean difference and associated 95% CIs. Results Compared with placebo, dobutamine and nitroglycerin, nesiritide indicated no increasing risk of total mortality. Compared with the combined control therapy, nesiritide was associated with non-significant differences in short-term mortality (RR 1.24; 95% CI 0.85 to 1.80; p=0.27), mid-term mortality (RR 0.86; 95% CI 0.60 to 1.24; p=0.42) and long-term mortality (RR 0.94; 95% CI 0.75 to 1.18; p=0.61). Nesiritide therapy increased the risk of hypotension (p<0.00 001) and bradycardia (p=0.02) when compared with control therapy. Compared with dobutamine or placebo therapy, no differences in serum creatinine, blood urea nitrogen and creatinine clearance, and no risk of the need for dialysis was observed in nesiritide therapy. Conclusions Our findings indicated that, in patients with heart failure, nesiritide was not associated with the risk of mortality. However, it increased the risk of cardiovascular adverse events. The change of serum creatinine and creatinine clearance had no significant difference, and no risk of the need for dialysis was observed after low-dose nesiritide treatment. PMID:26739721

  8. Origin of Excess 176Hf in Meteorites

    NASA Astrophysics Data System (ADS)

    Thrane, Kristine; Connelly, James N.; Bizzarro, Martin; Meyer, Bradley S.; The, Lih-Sin

    2010-07-01

    After considerable controversy regarding the 176Lu decay constant (λ176Lu), there is now widespread agreement that (1.867 ± 0.008) × 10-11 yr-1 as confirmed by various terrestrial objects and a 4557 Myr meteorite is correct. This leaves the 176Hf excesses that are correlated with Lu/Hf elemental ratios in meteorites older than ~4.56 Ga meteorites unresolved. We attribute 176Hf excess in older meteorites to an accelerated decay of 176Lu caused by excitation of the long-lived 176Lu ground state to a short-lived 176m Lu isomer. The energy needed to cause this transition is ascribed to a post-crystallization spray of cosmic rays accelerated by nearby supernova(e) that occurred after 4564.5 Ma. The majority of these cosmic rays are estimated to penetrate accreted material down to 10-20 m, whereas a small fraction penetrate as deep as 100-200 m, predicting decreased excesses of 176Hf with depth of burial at the time of the irradiation event.

  9. Characteristics of HfO2/Hf-based bipolar resistive memories

    NASA Astrophysics Data System (ADS)

    Jinshun, Bi; Zhengsheng, Han

    2015-06-01

    Nano-scale Hf/HfO2-based resistive random-access-memory (RRAM) devices were fabricated. The cross-over between top and bottom electrodes of RRAM forms the metal-insulator-metal sandwich structure. The electrical responses of RRAM are studied in detail, including forming process, SET process and RESET process. The correlations between SET voltage and RESET voltage, high resistance state and low resistance state are discussed. The electrical characteristics of RRAM are in a strong relationship with the compliance current in the SET process. The conduction mechanism of nano-scale Hf/HfO2-based RRAM can be explained by the quantum point contact model. Project supported by the National Natural Science Foundation of China (Nos. 11179003, 61176095).

  10. Simultaneous observation of HF-enhanced plasma waves and HF-wave self-focusing

    SciTech Connect

    Frey, A.; Duncan, L.M.

    1984-07-01

    Intense HF-radiowaves of the ordinary mode transmitted from the ground enhance plasma waves near the reflection height. These have been extensively studied in the past by the use of Incohernt-Scatter-Radars. Intense HF-radiowaves propagating in the ionosphere also produce electron density irregularities with scale sizes much larger than the HF wavelength of approx.60 m. These have been observed by radio star intensity scintillations. For the past 2 years a new method was used at Arecibo, P.R. which allows radar- and scintillation-measurements at 430 MHz to be performed simultaneously along the same line of sight. The scale sizes deduced from the scintillation measurements are shorter than the scale sizes observed with the radar and are inconsistent with the HF-power density thresholds predicted by existing theories.

  11. Effectiveness of Remote Patient Monitoring After Discharge of Hospitalized Patients With Heart Failure: The Better Effectiveness After Transition–Heart Failure (BEAT-HF) Randomized Clinical Trial

    PubMed Central

    Ong, Michael K.; Romano, Patrick S.; Edgington, Sarah; Aronow, Harriet U.; Auerbach, Andrew D.; Black, Jeanne T.; De Marco, Teresa; Escarce, Jose J.; Evangelista, Lorraine S.; Hanna, Barbara; Ganiats, Theodore G.; Greenberg, Barry H.; Greenfield, Sheldon; Kaplan, Sherrie H.; Kimchi, Asher; Liu, Honghu; Lombardo, Dawn; Mangione, Carol M.; Sadeghi, Bahman; Sadeghi, Banafsheh; Sarrafzadeh, Majid; Tong, Kathleen; Fonarow, Gregg C.

    2016-01-01

    Importance It remains unclear whether telemonitoring approaches provide benefits for patients with heart failure (HF) after hospitalization. Objective To evaluate the effectiveness of a care transition intervention using remote patient monitoring in reducing 180-day all-cause readmissions among a broad population of older adults hospitalized with HF. Design, Setting, and Participants We randomized 1437 patients hospitalized for HF between October 12, 2011, and September 30, 2013, to the intervention arm (715 patients) or to the usual care arm (722 patients) of the Better Effectiveness After Transition–Heart Failure (BEAT-HF) study and observed them for 180 days. The dates of our study analysis were March 30, 2014, to October 1, 2015. The setting was 6 academic medical centers in California. Participants were hospitalized individuals 50 years or older who received active treatment for decompensated HF. Interventions The intervention combined health coaching telephone calls and telemonitoring. Telemonitoring used electronic equipment that collected daily information about blood pressure, heart rate, symptoms, and weight. Centralized registered nurses conducted telemonitoring reviews, protocolized actions, and telephone calls. Main outcomes and measures The primary outcome was readmission for any cause within 180 days after discharge. Secondary outcomes were all-cause readmission within 30 days, all-cause mortality at 30 and 180 days, and quality of life at 30 and 180 days. Results Among 1437 participants, the median age was 73 years. Overall, 46.2% (664 of 1437) were female, and 22.0% (316 of 1437) were African American. The intervention and usual care groups did not differ significantly in readmissions for any cause 180 days after discharge, which occurred in 50.8% (363 of 715) and 49.2% (355 of 722) of patients, respectively (adjusted hazard ratio, 1.03; 95% CI, 0.88-1.20; P = .74). In secondary analyses, there were no significant differences in 30-day

  12. Collisional quenching of highly rotationally excited HF

    NASA Astrophysics Data System (ADS)

    Yang, B.; Walker, K. M.; Forrey, R. C.; Stancil, P. C.; Balakrishnan, N.

    2015-06-01

    Context. Collisional excitation rate coefficients play an important role in the dynamics of energy transfer in the interstellar medium. In particular, accurate rotational excitation rates are needed to interpret microwave and infrared observations of the interstellar gas for nonlocal thermodynamic equilibrium line formation. Aims: Theoretical cross sections and rate coefficients for collisional deexcitation of rotationally excited HF in the vibrational ground state are reported. Methods: The quantum-mechanical close-coupling approach implemented in the nonreactive scattering code MOLSCAT was applied in the cross section and rate coefficient calculations on an accurate 2D HF-He potential energy surface. Estimates of rate coefficients for H and H2 colliders were obtained from the HF-He collisional data with a reduced-potential scaling approach. Results: The calculation of state-to-state rotational quenching cross sections for HF due to He with initial rotational levels up to j = 20 were performed for kinetic energies from 10-5 to 15 000 cm-1. State-to-state rate coefficients for temperatures between 0.1 and 3000 K are also presented. The comparison of the present results with previous work for lowly-excited rotational levels reveals significant differences. In estimating HF-H2 rate coefficients, the reduced-potential method is found to be more reliable than the standard reduced-mass approach. Conclusions: The current state-to-state rate coefficient calculations are the most comprehensive to date for HF-He collisions. We attribute the differences between previously reported data and our results to differences in the adopted interaction potential energy surfaces. The new He rate coefficients can be used in a variety of applications. The estimated H2 and H collision rates can also augment the smaller datasets previously developed for H2 and electrons. Rate coefficient tables are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130

  13. Acute-on-chronic liver failure in cirrhosis.

    PubMed

    Arroyo, Vicente; Moreau, Richard; Kamath, Patrick S; Jalan, Rajiv; Ginès, Pere; Nevens, Frederik; Fernández, Javier; To, Uyen; García-Tsao, Guadalupe; Schnabl, Bernd

    2016-01-01

    The definition of acute-on-chronic liver failure (ACLF) remains contested. In Europe and North America, the term is generally applied according to the European Association for the Study of the Liver-Chronic Liver Failure (EASL-CLIF) Consortium guidelines, which defines this condition as a syndrome that develops in patients with cirrhosis and is characterized by acute decompensation, organ failure and high short-term mortality. One-third of patients who are hospitalized for acute decompensation present with ACLF at admission or develop the syndrome during hospitalization. ACLF frequently occurs in a closed temporal relationship to a precipitating event, such as bacterial infection or acute alcoholic, drug-induced or viral hepatitis. However, no precipitating event can be identified in approximately 40% of patients. The mechanisms of ACLF involve systemic inflammation due to infections, acute liver damage and, in cases without precipitating events, probably intestinal translocation of bacteria or bacterial products. ACLF is graded into three stages (ACLF grades 1-3) on the basis of the number of organ failures, with higher grades associated with increased mortality. Liver and renal failures are the most common organ failures, followed by coagulation, brain, circulatory and respiratory failure. The 28-day mortality rate associated with ACLF is 30%. Depending on the grade, ACLF can be reversed using standard therapy in only 16-51% of patients, leaving a considerable proportion of patients with ACLF that remains steady or progresses. Liver transplantation in selected patients with ACLF grade 2 and ACLF grade 3 increases the 6-month survival from 10% to 80%. PMID:27277335

  14. Imaging Techniques in Acute Heart Failure.

    PubMed

    Pérez del Villar, Candelas; Yotti, Raquel; Bermejo, Javier

    2015-07-01

    In recent years, imaging techniques have revolutionized the diagnosis of heart failure. In patients with a clinical picture of acute decompensation, prognosis is largely determined by early implementation of general measures and treatment of the underlying cause. Given its diagnostic yield and portability, ultrasound has become an essential tool in the setting of acute heart failure, and is currently found in all medical departments involved in the care of the critically ill patient. Cardiac magnetic resonance and computed tomography allow detailed characterization of multiple aspects of cardiac structure and function that were previously unavailable. This helps guide and monitor many of the treatment decisions in the acute heart failure population in an entirely noninvasive way. This article aims to review the usefulness of the imaging techniques that are clinically relevant in the context of an episode of acute heart failure. We discuss the indications and limitations of these techniques in detail and describe the general principles for the appropriate interpretation of results. PMID:26002273

  15. Saturated hydrides in the HfV2-D system

    NASA Astrophysics Data System (ADS)

    Bogdanova, A. N.; Irodova, A. V.; André, G.

    2007-05-01

    Saturated solid solutions of hydrogen (deuterium) are synthesized up to the ratio D/HfV2 = 5.1 for the HfV2 compound with a structure of the cubic Laves phase (the C15 type) and the HfV2-based alloys (Hf0.7Zr0.3)V2 and Hf(V0.92Ti0.08)2 with partial substitution. The structure of the solid solutions is studied using neutron diffraction at room temperature. The saturated solid solutions of hydrogen are disordered: hydrogen occupies tetrahedral interstices 2Hf + 2V and 1Hf + 3V. The concentration of hydrogen in the solid solutions increases as the occupancy of the 1Hf + 3V interstices increases to the maximum value p 1Hf + 3V ˜ 0.46, whereas the occupancy of the 2Hf + 2V interstices remains constant and equal to p 2Hf + 2V ˜ 0.28. The maximum hydrogen concentration depends linearly on the lattice parameter of the initial intermetallic compound.

  16. Heterogeneous chemistry of HBr and HF

    SciTech Connect

    Hanson, D.R.; Ravishankara, A.R.

    1992-11-12

    The authors present information on heterogeneous chemistry of HF and HBr on glass and ice surfaces at a temperature of 200K. Their objective is to study whether heterogeneous reactions of these species could be important in the atmospheric chemistry occuring on NAT particles or cloud condensation nuclei, and be a contributor to ozone depletion. HF showed no significant uptake or reactions with ClONO{sub 2} or HOCl. HBr was found to adsorb on these surfaces, and did not exhibit saturation for even relative high concentrations. In addition it showed reactivity with ClONO{sub 2}, Cl{sub 2} and N{sub 2}O{sub 5} on ice surfaces.

  17. SERVE-HF: More Questions Than Answers.

    PubMed

    Javaheri, Shahrokh; Brown, Lee K; Randerath, Winfried; Khayat, Rami

    2016-04-01

    The recent online publication of the SERVE-HF trial that evaluated the effect of treating central sleep apnea (CSA) with an adaptive servoventilation (ASV) device in patients with heart failure and reduced ejection fraction (HFrEF) has raised serious concerns about the safety of ASV in these patients. Not only was ASV ineffective but post hoc analysis found excess cardiovascular mortality in treated patients. The authors cited as one explanation an unfounded notion that CSA is a compensatory mechanism with a protective effect in HFrEF patients. We believe that there are several possible considerations that are more likely to explain the results of SERVE-HF. In this commentary, we consider methodological issues including the use of a previous-generation ASV device that constrained therapeutic settings to choices that are no longer in wide clinical use. Patient selection, data collection, and treatment adherence as well as group crossovers were not discussed in the trial as potential confounding factors. We have developed alternative reasons that could potentially explain the results and that can be explored by post hoc analysis of the SERVE-HF data. We believe that our analysis is of critical value to the field and of particular importance to clinicians treating these patients. PMID:26836904

  18. Heparin Saline Versus Normal Saline for Flushing and Locking Peripheral Venous Catheters in Decompensated Liver Cirrhosis Patients

    PubMed Central

    Wang, Rui; Zhang, Ming-Guang; Luo, Ou; He, Liu; Li, Jia-Xin; Tang, Yun-Jing; Luo, Yan-Li; Zhou, Min; Tang, Li; Zhang, Zong-Xia; Wu, Hao; Chen, Xin-Zu

    2015-01-01

    Abstract A prospective randomized, controlled, single-blinded trial to compare the effectiveness and safety of heparin saline (HS) to those of normal saline (NS) as flushing and locking solutions for peripheral venous catheter (PVC) in decompensated liver cirrhosis (DLC) patients. Patients with DLC at our institution between April 2012 and March 2013 were enrolled after obtaining informed consent. The patients were randomly allocated into 2 groups: the NS group received preservative-free 0.9% sodium chloride as the flushing and locking solution, while the HS group received HS (50 U/mL). PVC-related events and the duration of PVC maintenance were compared between the 2 groups. Moreover, the preinfusion and postinfusion levels of prothrombin time (PT), activated partial thromboplastin time (APTT), and platelet (PLT) were also compared. A total of 32 and 36 DLC patients in the NS (125 PVCs) and HS (65 PVCs) groups, respectively, were analyzed. Baseline characteristics, including gender, age, Child–Pugh grade, PVC type and administration of anticoagulant, and irritant agents, were comparable between the 2 groups (P > 0.05). The maintenance times of the HS and NS groups were 80.27 ± 26.47 and 84.19 ± 29.32 hours, respectively (P = 0.397). Removal of PVC for abnormal reasons occurred in 30.7% and 22.4% of patients in the HS and NS groups (P = 0.208). The PVC occlusion rates were 6.2% and 5.6% in the HS and NS groups, respectively (OR = 1.11, 95% CI 0.31–3.92). The PT, APTT, and PLT levels were comparable between the 2 groups both before and after infusion (P > 0.05). Incremental analyses showed that Child–Pugh grade C might be a risk factor for the suppression of PLT in the HS group. We consider NS to be as effective as and safer than conventional HS for flushing and locking PVC in decompensated liver cirrhosis patients. PMID:26252305

  19. [Organ-protection therapy. A new therapeutic approach for acute heart failure?].

    PubMed

    Chivite, David; Formiga, Francesc; Corbella, Xavier

    2014-03-01

    Unlike the prolonged benefit produced by the treatment of chronic heart failure, newer drugs tested for the treatment of acute heart failure in the last decade have failed to provide evidence of clinical benefit beyond some improvement in symptom relief. In particular, no drug has shown the ability to reduce the higher medium- and long-term risk of morbidity and mortality in these patients after an episode of decompensation. Current understanding of the pathophysiology of acute heart failure and its consequences has led to the hypothesis that, beyond symptom control, effective therapies for this syndrome should target not only the hemodynamic changes of the initial phase of the syndrome but should also "protect" the organism from the activation of neurohumoral and inflammatory pathways triggered by the decompensation episode, which persist in time and confer a risk of deleterious effects in several organs and tissues. Serelaxin, a new drug related to the peptidic endogenous hormones of the relaxin family, has recently been shown to provide multiple beneficial effects in terms of "organ protection" - not only in the cardiovascular and renal systems - from these acute heart failure-related deleterious changes. This drug has already been tested in acute heart failure patients with encouraging results in terms of medium-term clinical benefit, rendering serelaxin as a serious candidate for first-line, prognosis-modifying therapy in this syndrome. PMID:24930087

  20. LU-HF Age and Isotope Systematics of ALH84001

    NASA Technical Reports Server (NTRS)

    Righter, M.; Lapen, T. J.; Brandon, A. D.; Beard, B. L.; Shafer, J. T.; Peslier, A. H.

    2009-01-01

    Allan Hills (ALH) 84001 is an orthopyroxenite that is unique among the Martian meteorites in having the oldest inferred crystallization age (approx..4.5 to 4.0 Gyr) [e.g., 1-6 and references therein 7]. Its ancient origin makes this stone a critical constraint on early history of Mars, in particular the evolution of different planetary crust and mantle reservoirs. However, because there is significant variability in reported crystallization ages, determination of initial isotope compositions is imprecise making assessment of planetary reservoirs difficult. Here we report a new Lu-Hf mineral isochron age, initial Hf-176/Hf-177 isotope composition, and inferred Martian mantle source compositions for ALH84001 that place constraints on longlived source reservoirs for the enriched shergottite suite of Martian meteorites including Shergotty, Zagami, NWA4468, NWA856, RBT04262, LAR06319, and Los Angeles. Sm-Nd isotope analyses are under way for the same mineral aliquots analyzed for Lu-Hf. The Lu-Hf system was utilized because Lu and Hf are both lithophile and refractory and are not easily redistributed during short-lived thermal pulses associated with shock metamorphism. Moreover, chromite has relatively modest Hf concentrations with very low Lu/Hf ratios [9] yielding tight constraints on initial Hf-176/Hf-177 isotope compositions

  1. Curious case of calciphylaxis leading to acute mitral regurgitation

    PubMed Central

    Gallimore, Grant Gardner; Curtis, Blair; Smith, Andria; Benca, Michael

    2014-01-01

    Calciphylaxis is uncommon and typically seen in patients with end-stage renal disease. It has been defined as a vasculopathic disorder characterised by cutaneous ischaemia and necrosis due to calcification, intimal fibroplasia and thrombosis of pannicular arterioles. We present the case of a 74-year-old woman with chronic kidney disease stage III who developed calciphylaxis leading to mitral valve calcification, chordae tendineae rupture and acute mitral regurgitation. Although an alternative explanation can typically be found for non-uraemic calciphylaxis, her evaluation did not reveal any usual non-uraemic causes including elevated calcium–phosphorus product, hyperparathyroidism, or evidence of connective tissue disease. Her wounds improved with sodium thiosulfate, pamidronate, penicillin and hyperbaric oxygen therapies but she ultimately decompensated with the onset of acute mitral regurgitation attributed to rupture of a previously calcified chordae tendineae. This case highlights an unusual case of calciphylaxis without clear precipitant as well as a novel manifestation of the disease. PMID:24789150

  2. Electric Field Gradients at Hf and Fe Sites in Hf2Fe Recalculated

    NASA Astrophysics Data System (ADS)

    Belošević-Čavor, J.; Cekić, B.; Novaković, N.; Koteski, V.; Milošević, Z.

    2004-11-01

    The electric field gradients (EFG) of the Hf2Fe intermetallic compound were calculated using the full-potential linearized augmented plain-wave (FP-LAPW) method as embodied in the WIEN 97 code. The obtained values are compared with other ab-initio calculations and on a qualitative basis with the previously reported experimental data obtained from TDPAC. The calculated results, -23.1·1021 V/m2 and 2.7·1021 V/m2 for Hf 48f and Fe 32e position, respectively, are in excellent agreement with experimental data (23.4·1021 V/m2 and 2.7·1021 V/m2), better than those reported in earlier calculations. The calculated EFG for Hf 16c position (4.2·1021 V/m2) is stronger than the experimental one (1.1·1021 V/m2).

  3. Biochemical Monitoring and Management During Pregnancy in Patients with Isovaleric Acidaemia is Helpful to Prevent Metabolic Decompensation.

    PubMed

    Habets, D D J; Schaper, N C; Rogozinski, H; van Spronsen, F J; van Rijn, M; Bierau, J; Bakker, J A

    2012-01-01

    The facilities for neonatal screening, early diagnosis, and effective treatment of isovaleric acidaemia (IVA) have improved greatly over the past decades. Accordingly, IVA patients reach adolescence and may consider having children. The maintenance of a stable metabolic condition is a challenge to both the patients and their multidisciplinary team of care providers. This report presents three women with IVA during their five single or twin pregnancies, whose clinical condition were monitored with contrasting approaches. Metabolic profiles were determined and compared in these pregnancies. In one case, two pregnancies were strictly managed and monitored by measuring plasma acylcarnitine and amino acid profiles, together with adjustment of the diet and/or supplementation of L-carnitine and/or glycine. In addition, complications were prevented by intravenous glucose and L-carnitine during labor and postpartum. In two other cases, the metabolic condition of patients was less frequently monitored and additional treatment with intravenous L-carnitine and intravenous glucose/dextrose was only prescribed during periods of hyperemesis gravidarum. With respect to the differences in management and monitoring of maternal IVA all pregnancies were without complications for mother and child. Despite the favorable outcome in uncontrolled pregnancies in IVA, careful monitoring and management during pregnancy is helpful to prevent life-threatening conditions like metabolic decompensation. PMID:23430878

  4. AST to Platelet Ratio Index Predicts Mortality in Hospitalized Patients With Hepatitis B-Related Decompensated Cirrhosis

    PubMed Central

    Mao, Weilin; Sun, Qinqin; Fan, Jian; Lin, Sha; Ye, Bo

    2016-01-01

    Abstract Aspartate aminotransferase to platelet ratio index (APRI) has originally been considered as a noninvasive marker for detecting hepatic fibrosis in patients with chronic hepatitis B and C. APRI has been used for predicting liver-related mortality in patients with chronic hepatitis C virus infection or alcoholic liver disease. However, whether APRI could be useful for predicting mortality in chronic hepatitis B virus (HBV) infection remains unevaluated. This study aims to address this knowledge gap. A total of 193 hospitalized chronic HBV-infected patients (cirrhosis, n = 100; noncirrhosis, n = 93) and 88 healthy subjects were retrospectively enrolled. All patients were followed up for 4 months. Mortality that occurred within 90 days of hospital stay was compared among patients with different APRI. APRI predictive value was evaluated by univariate and multivariate regression embedded in a Cox proportional hazards model. APRI varied significantly in our cohort (range, 0.16–10.00). Elevated APRI was associated with increased severity of liver disease and 3-month mortality in hospitalized patients with HBV-related cirrhosis. Multivariate analysis demonstrated that APRI (odds ratio: 1.456, P < 0.001) and the model for end-stage liver disease score (odds ratio: 1.194, P < 0.001) were 2 independent markers for predicting mortality. APRI is a simple marker that may serve as an additional predictor of 3-month mortality in hospitalized patients with HBV-related decompensated cirrhosis. PMID:26945406

  5. Hepatitis C in Special Patient Cohorts: New Opportunities in Decompensated Liver Cirrhosis, End-Stage Renal Disease and Transplant Medicine

    PubMed Central

    Hüsing, Anna; Kabar, Iyad; Schmidt, Hartmut H.; Heinzow, Hauke S.

    2015-01-01

    Worldwide, hepatitis C virus (HCV) is a common infection. Due to new antiviral approaches and the approval of direct-acting antiviral agents (DAA), HCV therapy has become more comfortable. Nevertheless, there are special patient groups, in whom treatment of HCV is still challenging. Due to only few data available, tolerability and efficacy of DAAs in special patient cohorts still remain unclear. Such special patient cohorts comprise HCV in patients with decompensated liver disease (Child-Pugh Class B or C), patients with chronic kidney disease, and patients on waiting lists to renal/liver transplantation or those with HCV recurrence after liver transplantation. HCV infection in these patient cohorts has been shown to be associated with increased morbidity and mortality and may lead to reduced graft survival after transplantation. Successful eradication of HCV results in a better outcome concerning liver-related complications and in a better clinical outcome of these patients. In this review, we analyze available data and results from recently published literature and provide an overview of current recommendations of HCV-therapy regimen in these special patient cohorts. PMID:26251895

  6. Hepatitis C in Special Patient Cohorts: New Opportunities in Decompensated Liver Cirrhosis, End-Stage Renal Disease and Transplant Medicine.

    PubMed

    Hüsing, Anna; Kabar, Iyad; Schmidt, Hartmut H; Heinzow, Hauke S

    2015-01-01

    Worldwide, hepatitis C virus (HCV) is a common infection. Due to new antiviral approaches and the approval of direct-acting antiviral agents (DAA), HCV therapy has become more comfortable. Nevertheless, there are special patient groups, in whom treatment of HCV is still challenging. Due to only few data available, tolerability and efficacy of DAAs in special patient cohorts still remain unclear. Such special patient cohorts comprise HCV in patients with decompensated liver disease (Child-Pugh Class B or C), patients with chronic kidney disease, and patients on waiting lists to renal/liver transplantation or those with HCV recurrence after liver transplantation. HCV infection in these patient cohorts has been shown to be associated with increased morbidity and mortality and may lead to reduced graft survival after transplantation. Successful eradication of HCV results in a better outcome concerning liver-related complications and in a better clinical outcome of these patients. In this review, we analyze available data and results from recently published literature and provide an overview of current recommendations of HCV-therapy regimen in these special patient cohorts. PMID:26251895

  7. Acute Bronchitis

    MedlinePlus

    ... or though physical contact (for example, on unwashed hands). Being exposed to tobacco smoke, air pollution, dusts, vapors, and fumes can also cause acute bronchitis. Less often, bacteria can also cause acute bronchitis. To diagnose acute ...

  8. Cystitis - acute

    MedlinePlus

    Uncomplicated urinary tract infection; UTI - acute; Acute bladder infection; Acute bacterial cystitis ... control. Menopause also increases the risk for a urinary tract infection. The following also increase your chances of having ...

  9. Crystal structure refinements of the κ phases in the Hf-Mo-Se and Hf-Mo-Ge systems

    NASA Astrophysics Data System (ADS)

    Ha˚rsta, Anders

    1985-05-01

    The crystal structures of κ-(Hf-Mo-Se) and κ-(Hf-Mo-Ge) were determined using X-ray single-crystal diffractometry. Both structures crystallize in the space group P6 3/mmc (No. 194) with the unit-cell dimensions a = 8.6995(4)A˚, c = 8.6234(7)A˚ for κ-(Hf-Mo-Se) and a = 8.6394(4)A˚, c = 8.6827(5)A˚ for κ-(Hf-Mo-Ge). The structures have been refined on F 2 to R(F 2) values of 0.0784 and 0.0661, respectively. κ-(Hf-Mo-Se) and κ-(Hf-Mo-Ge) are isostructural with κ-(Hf-Mo-P) with a variable degree of hafnium substitution on the molybdenum sites of the structure. In κ-(Hf-Mo-Ge) germanium vacancies were found to occur on the trigonal prismatic 2 c site and the phase was also found to contain oxygen on the octahedral 6g site. According to the final refinements the compositions are Hf 9+xMo 4-xSe with x = 0.40(2) and Hf 9+xMo 4- xGe yO 2 with x = 0.25(2), y = 0.88(1), and z = 1.47(12).

  10. Thermoelectric properties of doped BaHfO3

    NASA Astrophysics Data System (ADS)

    Dixit, Chandra Kr.; Bhamu, K. C.; Sharma, Ramesh

    2016-05-01

    We have studied the structural stability, electronic structure, optical properties and thermoelectric properties of doped BaHfO3 by full potential linearized augmented plane wave (FP-LAPW) method. The electronic structure of BaHfO3 doped with Sr shows enhances the indirect band gaps of 3.53 eV, 3.58 eV. The charge density plots show strong ionic bonding in Ba-Hf, and ionic and covalent bonding between Hf and O. Calculations of the optical spectra, viz., the dielectric function, refractive index and extinction coefficient are performed for the energy range are calculated and analyzed. Thermoelectric properties of semi conducting are also reported first time. The doped BaHfO3 is approximately wide band gap semiconductor with the large p-type Seebeck coefficient. The power factor of BaHfO3 is increased with Sr doping, decreases because of low electrical resistivity and thermal conductivity.

  11. HF sounding of the auroral magnetosphere

    NASA Astrophysics Data System (ADS)

    Gurevich, A. V.; Babichenko, A. M.; Karashtin, A. N.; Rapoport, V. O.

    1992-06-01

    Results are presented from incoherent scatter radar measurements in the magnetosphere, using the Radiophysical Research Institute 'Sura' heating facility operated in the frequency range 4.5-9 MHz. The first magnetosphere sounding experiments were carried out on February 21, 1989; a frequency of 9.310 MHz was used for the sounding, while the effective radiated power was about 30 MW. The results of analyses of the scattered signal spectra showed that, in the auroral region of the polar magnetosphere, ion acoustic oscillations are excited and that the HF sounding technique used in this study was an effective method for magnetosphere sounding.

  12. Epitaxial Thin Films of Y doped HfO2

    NASA Astrophysics Data System (ADS)

    Serrao, Claudy; Khan, Asif; Ramamoorthy, Ramesh; Salahuddin, Sayeef

    Hafnium oxide (HfO2) is one of a few metal oxides that is thermodynamically stable on silicon and silicon oxide. There has been renewed interest in HfO2 due to the recent discovery of ferroelectricity and antiferroelectricity in doped HfO2. Typical ferroelectrics - such as strontium bismuth tantalate (SBT) and lead zirconium titanate (PZT) - contain elements that easily react with silicon and silicon oxide at elevated temperatures; therefore, such ferroelectrics are not suited for device applications. Meanwhile, ferroelectric HfO2 offers promise regarding integration with silicon. The stable phase of HfO2 at room temperature is monoclinic, but HfO2 can be stabilized in the tetragonal, orthorhombic or even cubic phase by suitable doping. We stabilized Y-doped HfO2 thin films using pulsed laser deposition. The strain state can be controlled using various perovskite substrates and controlled growth conditions. We report on Y-doped HfO2 domain structures from piezo-response force microscopy (PFM) and structural parameters via X-ray reciprocal space maps (RSM). We hope this work spurs further interest in strain-tuned ferroelectricity in doped HfO2.

  13. Mitigating Doppler shift effect in HF multitone data modem

    NASA Astrophysics Data System (ADS)

    Sonlu, Yasar

    1989-09-01

    Digital communications over High Frequency (HF) radio channels are getting important in recent years. Current HF requirements are for data transmission at rates 2.4 kbps or more to accommodate computer data links and digital secure voice. HF modems which were produced to meet these speeds are, serial modems and parallel modems. On the other hand, the HF sky-wave communication medium, the ionosphere, has some propagation problems such as multipath and Doppler shift. The effect of Doppler shift in a parallel modem which employs Differential Quadrature Phase Shift Keying (DQPSK) modulation is considered and a correction method to mitigate the Doppler Shift effect is introduced.

  14. Precipitant in acute heart failure in a multiethnic Asian urban cohort study

    PubMed Central

    Leong, Kui Toh Gerard; Yan, Cao; Goh, Ping Ping

    2011-01-01

    Objectives To identify acute heart failure (HF) precipitants in patients with a history of chronic HF, and to analyse any relationship with early outcomes. Background There are limited studies on acute HF precipitants and the relationship with outcomes, and determining this will help to identify the avoidable precipitants and may lead to better outcomes. Methods Patients with a history of HF and admission to the authors' hospital in 2008, with a discharge primary diagnosis of HF, were enrolled. Diagnosis of HF was prospectively defined and reviewed by two cardiology teams. Patients' case records were reviewed, or families were interviewed for 1-month follow-up outcome information. Results 242 admissions by 185 patients constituted our study cohort. Patients were older, and 36.8% were females. The ethnic Chinese, Malay and Indian composition of the cohort were 41.3%, 35.1% and 16.1% respectively. The mean left-ventricular ejection fraction was 34.0±17.5%. Preserved left ventricular ejection fraction (≥45%) constituted 35.1% of the cohort. Acute HF precipitants were identified in 62.8% of admissions and unidentified in 37.2% admissions. Non-compliance issues and infections constituted 27.2% and 13.6% of precipitants respectively. Cardiac precipitants accounted for 10.0% admissions. Multiple precipitants accounted for 8.3% admissions. There were no significant differences in patient profile, including ethnicity and gender, and outcomes between patients with identified precipitants and patients with unidentified precipitants. Conclusion Non-compliance issues were a major precipitant of acute HF in patients with chronic HF. Precipitants were not determined in 37.2% of admissions. There were no significant associations between the different types of precipitants and early 30-day outcomes.

  15. Ferroelectricity of nondoped thin HfO2 films in TiN/HfO2/TiN stacks

    NASA Astrophysics Data System (ADS)

    Nishimura, Tomonori; Xu, Lun; Shibayama, Shigehisa; Yajima, Takeaki; Migita, Shinji; Toriumi, Akira

    2016-08-01

    We report on the impact of TiN interfaces on the ferroelectricity of nondoped HfO2. Ferroelectric properties of nondoped HfO2 in TiN/HfO2/TiN stacks are shown in capacitance–voltage and polarization–voltage characteristics. The Curie temperature is also estimated to be around 500 °C. The ferroelectricity of nondoped HfO2 clearly appears by thinning HfO2 film down to ∼35 nm. We directly revealed in thermal treatments that the ferroelectric HfO2 film on TiN was maintained by covering the top surface of HfO2 with TiN, while it was followed by a phase transition to the paraelectric phase in the case of the open surface of HfO2. Thus, it is concluded that the ferroelectricity in nondoped HfO2 in this study was mainly driven by both of top and bottom TiN interfaces.

  16. Death from undetected acute myocardial infarction secondary to coronary artery dissection after blunt thoracic trauma.

    PubMed

    Puanglumyai, Supot; Thamtakerngkit, Somboon; Lekawanvijit, Suree

    2016-01-01

    Blunt thoracic trauma is a common occurrence in automobile accidents. Acute myocardial infarction (AMI) caused by coronary dissection following blunt thoracic trauma is rare. We report a case of healthy 24-year-old man with a history of blunt thoracic injury with subsequent undetected AMI who died of acute decompensated heart failure 4 days after the insult. The autopsy findings showed a 90% luminal narrowing of the left anterior descending coronary artery by dissecting hematoma, 3 cm in length. The myocardium revealed transmural myocardial infarction affecting apex, most part of left ventricular free wall, and interventricular septum. Both lungs were heavy, wet, and noncrepitant. Histological findings of the infarcted myocardium were consistent with 3-5 days post-AMI. Sections from both lungs revealed massive pulmonary edema, reflecting acute decompensated heart failure following a large AMI secondary to coronary dissection. Blunt thoracic trauma may obscure typical chest pain associated with cardiac ischemia especially in cases with a high tolerance for pain. PMID:26454807

  17. Hf isotope and concentration systematics of the Mariana arc

    NASA Astrophysics Data System (ADS)

    Tollstrup, D. L.; Gill, J. B.

    2004-12-01

    Negative Hf concentration anomalies are common but little-discussed geochemical features of island arcs. Because both light rare earth elements (LREE) and Hf may be mobile even in `fluid-dominated' island arcs, it is important to relate their isotopic and elemental ratios to models of slab-mantle mixing. We report new Hf isotope and trace element data for K-rich submarine basalts from the Kasuga seamounts located 10-20 km behind the volcanic front of the southern Northern Seamount Province (NSP) of the Mariana arc. These data, when combined with published data for other Mariana samples, span the full range from low-K tholeiites to high-K shoshonites. Rear-arc Kasuga seamounts seamounts of the NSP have lower 143Nd/144Nd and 176Hf/177Hf ratios than arc-front volcanoes of the Mariana Central Island Province (CIP). Within the CIP, Hf concentration anomalies correlate positively with 176Hf/177Hf ratios. Radiogenic Hf and little or no concentration anomalies characterize samples from fluid-dominated volcanoes (Guguan and Maug), whereas samples from sediment-melt dominated volcanoes (Anatahan and Sarigan) have less radiogenic Hf and larger concentration anomalies. Samples from the Kasuga and Hiyoshi seamounts have even larger negative concentration anomalies and less radiogenic Hf, although the two are not always correlated. These data are consistent with mixing between a depleted mantle and a partial melt of subducted sediment that is saturated with trace accessory phases including zircon, rutile, and monazite. A more volcaniclastic source is needed for the NSP than the CIP. Implications of these findings are three-fold. Partial melts of subducting sediment affect the HFSE and REE budgets of even fluid-dominated island arcs. Slab temperatures must be high enough for a peraluminous melt to be present, even where old, cold slabs are subducting. Refractory accessory phases have the potential to become exotic "nuggets" in the convecting mantle, potentially controlling the

  18. Loss of the AE3 Anion Exchanger in a Hypertrophic Cardiomyopathy Model Causes Rapid Decompensation and Heart Failure

    PubMed Central

    Al Moamen, Nabeel J.; Prasad, Vikram; Bodi, Ilona; Miller, Marian L.; Neiman, Michelle L.; Lasko, Valerie M.; Alper, Seth L.; Wieczorek, David F.; Lorenz, John N.; Shull, Gary E.

    2010-01-01

    The AE3 Cl−/HCO3− exchanger is abundantly expressed in the sarcolemma of cardiomyocytes, where it mediates Cl−-uptake and HCO3−-extrusion. Inhibition of AE3-mediated Cl−/HCO3− exchange has been suggested to protect against cardiac hypertrophy; however, other studies indicate that AE3 might be necessary for optimal cardiac function. To test these hypotheses we crossed AE3-null mice, which appear phenotypically normal, with a hypertrophic cardiomyopathy mouse model carrying a Glu180Gly mutation in α–tropomyosin (TM180). Loss of AE3 had no effect on hypertrophy; however, survival of TM180/AE3 double mutants was sharply reduced compared with TM180 single mutants. Analysis of cardiac performance revealed impaired cardiac function in TM180 and TM180/AE3 mutants. TM180/AE3 double mutants were more severely affected and exhibited little response to β-adrenergic stimulation, a likely consequence of their more rapid progression to heart failure. Increased expression of calmodulin-dependent kinase II and protein phosphatase 1 and differences in methylation and localization of protein phosphatase 2A were observed, but were similar in single and double mutants. Phosphorylation of phospholamban on Ser16 was sharply increased in both single and double mutants relative to wild-type hearts under basal conditions, leading to reduced reserve capacity for β-adrenergic stimulation of phospholamban phosphorylation. Imaging analysis of isolated myocytes revealed reductions in amplitude and decay of Ca2+ transients in both mutants, with greater reductions in TM180/AE3 mutants, consistent with the greater severity of their heart failure phenotype. Thus, in the TM180 cardiomyopathy model, loss of AE3 had no apparent anti-hypertrophic effect and led to more rapid decompensation and heart failure. PMID:21056571

  19. Fractionation of Zr and Hf in surface processes

    SciTech Connect

    Chyi, L.L.; Garg, A.N.

    1985-01-01

    Zircons from a pegmatite near Tuxedo, North Carolina were crushed and treated with different reagents under different conditions. The treated and untreated samples were determined for Zr and Hf with radiochemical neutron activation analysis. Zircons treated with 50% sulfuric acid were having lowered Zr content and Zr/Hf ratio. The conclusions are that a portion of Zr and Hf in zircons is sensitive to leaching, and Zr appears to be selectively leached over Hf. The conclusions of this work support the observations of small dissolutions of Zr in both acidic podzolic soils and in alkaline laterites, of lower Zr content in soils on glacial drift, and of lower Zr/Hf ratios in loess deposits from various parts of the world. The fractionation of Zr and Hf in surface processes appears to be due to selective leaching. Weakening of Zr-O over Hf-O bonds in zircon by fission projectiles is postulated to be the viable process. The observed fractionation from leaching experiments suggest that areas receiving leachates such as swamps, lakes, and oceans should have high to very high Zr/Hf ratios preserved in rocks. High ratios are found in the Springfield (No. 9) Coal, the Green River Shale, and various limestones. High ratio is also found in orchard leaves, which grow by absorbing leachate from soil.

  20. Crystal structure of Si-doped HfO2

    NASA Astrophysics Data System (ADS)

    Zhao, Lili; Nelson, Matthew; Aldridge, Henry; Iamsasri, Thanakorn; Fancher, Chris M.; Forrester, Jennifer S.; Nishida, Toshikazu; Moghaddam, Saeed; Jones, Jacob L.

    2014-01-01

    Si-doped HfO2 was prepared by solid state synthesis of the starting oxides. Using Rietveld refinement of high resolution X-ray diffraction patterns, a substitutional limit of Si in HfO2 was determined as less than 9 at. %. A second phase was identified as Cristobalite (SiO2) rather than HfSiO4, the latter of which would be expected from existing SiO2-HfO2 phase diagrams. Crystallographic refinement with increased Si-dopant concentration in monoclinic HfO2 shows that c/b increases, while β decreases. The spontaneous strain, which characterizes the ferroelastic distortion of the unit cell, was calculated and shown to decrease with increasing Si substitution.

  1. SAR/InSAR observation by an HF sounder

    NASA Astrophysics Data System (ADS)

    Kobayashi, T.; Ono, T.

    2007-03-01

    Application of SAR imaging algorithm to spaceborne HF sounder observation was studied. Two types of image ambiguity problems were addressed in the application. One is surface/subsurface image ambiguity arising from deep penetration of HF wave, and another is mirror image ambiguity that is inherent to dipole antenna SAR. A numerical model demonstrated that the surface/subsurface ambiguity can be mitigated by taking a synthetic aperture large enough to defocus subsurface objects. In order to resolve the mirror image ambiguity problem, an image superposition technique was proposed. The performance of the technique was demonstrated by using simulation data of the HF sounder observation to confirm the feasibility of HF SAR and HF InSAR observation.

  2. Case report of acute-on-chronic liver failure secondary to diffuse large B-cell lymphoma

    PubMed Central

    Siba, Yahuza; Obiokoye, Kenechukwu; Ferstenberg, Richard; Robilotti, James; Culpepper-Morgan, Joan

    2014-01-01

    Acute liver failure is a rare presentation of hematologic malignancy. Acute on chronic liver failure (ACLF) is a newly recognized clinical entity that describes acute hepatic decompensation in persons with preexisting liver disease. Diffuse large B-cell lymphoma (DLBCL) is an aggressive non-Hodgkin’s lymphoma (NHL) with increasing incidence in older males, females and blacks. However, it has not yet been reported, to present with acute liver failure in patients with preexisting chronic liver disease due to human immunodeficiency virus (HIV)/hepatitis C virus (HCV) co-infection. We describe a case of ACLF as the presenting manifestation of DLBCL in an elderly black man with HIV/HCV co-infection and prior Hodgkin’s disease in remission for three years. The rapidly fatal outcome of this disease is highlighted as is the distinction of ACLF from decompensated cirrhosis. Due to the increased prevalence of HIV/HCV co-infection in the African American 1945 to 1965 birth cohort and the fact that both are risk factors for chronic liver disease and NHL we postulate that the incidence of NHL presenting as ACLF may increase. PMID:25469050

  3. Treat chronic hepatitis C virus infection in decompensated cirrhosis - pre- or post-liver transplantation? the ironic conundrum in the era of effective and well-tolerated therapy.

    PubMed

    Bunchorntavakul, C; Reddy, K Rajender

    2016-06-01

    The management of hepatitis C virus (HCV) infection in patients with decompensated cirrhosis has evolved dramatically over the past few years mainly due to the availability of all-oral antiviral regimens. The currently approved all-oral direct-acting antivirals (DAA) containing sofosbuvir, ledipasvir, daclatasvir and ribavirin, in various combinations, have shown to be safe and effective in patients with decompensated cirrhosis with sustained virological response (SVR) rates nearly comparable to those with well-compensated liver disease. Unique issues yet remain such as the challenges with renal insufficiency, tolerability of ribavirin and risk of further hepatic decompensation with a protease inhibitor-based regimen. While most patients who achieve SVR have demonstrated improvement in hepatic synthetic function over the short course of follow, the long-term beneficial effects are unknown. Further, the baseline predictors of improvement in hepatic function have not been well delineated and thus have left us in a quandary as to what we might expect with successful therapy and thus we are at a loss to well educate our patients. The major concern, in potential liver transplant candidates, is of unintended 'harm' by achieving SVR but without improvement in hepatic function to an extent where the patients might function well. As HCV therapies are as effective in liver transplant recipients, there is a growing sentiment in some of the transplant quarters that those with decompensated liver disease and awaiting liver transplant be treated for HCV after liver transplant. This strategy would thus eliminate any concern of leaving a patient in 'no person's' land by treating HCV successfully pretransplant but not to the point of functional normalcy, while also would maintain the risk of HCC. Yet a contrarian view would be that not all patients have access to liver transplantation (LT), cannot bear the cost, have comorbidities or contraindications to LT. While the debate

  4. [The significance of morphologic changes in acute occlusive cholecystitis for determining the surgical approach].

    PubMed

    Iukhtin, V I; Khripun, A I; Raksha, A P; Zhukotskiĭ, A V; Sergeeva, N A; Dorofeeva, I M; Belous, G G

    1996-01-01

    Specific morphological and functional changes in the liver in acute obturative cholecystitis have been experimentally studied in 30 dogs and clinically examined in 21 patients. No morphological substrate of liver insufficiency were found in early period of acute obturative cholecystitis. Early changes in the liver are of reactive nature and have the features of active nonspecific hepatitis. The reactions of compensation and decompensation are changing each other periodically. The intensive reactions of compensation take place in the first 2 or 3 days of disease. The reactions of compensation weaken gradually. There is no correlation between changes in the liver and in blood serum. The early surgery and laparoscopic procedures in acute obturative cholecystitis are advocated. PMID:8965448

  5. Environmental Hf-Nd isotopic decoupling in World river clays

    NASA Astrophysics Data System (ADS)

    Bayon, Germain; Skonieczny, Charlotte; Delvigne, Camille; Toucanne, Samuel; Bermell, Sylvain; Ponzevera, Emmanuel; André, Luc

    2016-03-01

    The hafnium and neodymium radiogenic isotope systems behave differently during Earth surface processes, causing a wide dispersion of Hf and Nd isotopic compositions in sediments and other sedimentary rocks. The decoupling between Hf and Nd isotopes in sediments is generally attributed to a combination of preferential sorting of zircon during sediment transport and incongruent weathering processes on continents. In this study, we analysed size-fractions of sediment samples collected near the mouth of 53 rivers worldwide to better understand the factors controlling the distribution of Hf and Nd isotopes in sediments. Our results for rivers draining old cratonic areas and volcanic provinces demonstrate that both granite and basalt weathering can lead to significant grain-size dependent Hf isotopic variability. While silt-size fractions mainly plot along the Terrestrial Array, World river clays are systematically shifted towards more radiogenic Hf isotopic compositions, defining together with published data a new Clay Array (εHf = 0.78 ×εNd + 5.23). The Hf-Nd isotope decoupling observed in volcanogenic sediments is best explained by selective alteration of Lu-rich mineral phases (e.g. olivine) and preferential enrichment of resistant unradiogenic minerals, such as spinel and ilmenite, in silt fractions. We also show that the extent to which World river clays deviate from the Clay Array (ΔεHf clay) is not linked to the presence of zircons. Instead, it correlates positively with weathering indices and climatic parameters (temperature, rainfall) of the corresponding drainage basins. Overall, these findings demonstrate that the distribution of Hf-Nd isotopes in clay-size sediments is related to a large extent to weathering conditions on continents, although the precise mechanisms controlling this relationship remain unclear. We finally propose that the Hf-Nd isotope pair proxy could be used in palaeoenvironmental studies to provide semi-quantitative information on

  6. Acute Bronchitis

    MedlinePlus

    Bronchitis is an inflammation of the bronchial tubes, the airways that carry air to your lungs. It ... chest tightness. There are two main types of bronchitis: acute and chronic. Most cases of acute bronchitis ...

  7. Acute Kidney Injury in Patients with Cirrhosis

    PubMed Central

    Russ, Kirk B.; Stevens, Todd M; Singal, Ashwani K.

    2015-01-01

    Acute kidney injury (AKI) occurs commonly in patients with advanced cirrhosis and negatively impacts pre- and post-transplant outcomes. Physiologic changes that occur in patients with decompensated cirrhosis with ascites, place these patients at high risk of AKI. The most common causes of AKI in cirrhosis include prerenal injury, acute tubular necrosis (ATN), and the hepatorenal syndrome (HRS), accounting for more than 80% of AKI in this population. Distinguishing between these causes is particularly important for prognostication and treatment. Treatment of Type 1 HRS with vasoconstrictors and albumin improves short term survival and renal function in some patients while awaiting liver transplantation. Patients with HRS who fail to respond to medical therapy or those with severe renal failure of other etiology may require renal replacement therapy. Simultaneous liver kidney transplant (SLK) is needed in many of these patients to improve their post-transplant outcomes. However, the criteria to select patients who would benefit from SLK transplantation are based on consensus and lack strong evidence to support them. In this regard, novel serum and/or urinary biomarkers such as neutrophil gelatinase-associated lipocalin, interleukins-6 and 18, kidney injury molecule-1, fatty acid binding protein, and endothelin-1 are emerging with a potential for accurately differentiating common causes of AKI. Prospective studies are needed on the use of these biomarkers to predict accurately renal function recovery after liver transplantation alone in order to optimize personalized use of SLK. PMID:26623266

  8. Acute fatal metabolic complications in alkaptonuria.

    PubMed

    Davison, A S; Milan, A M; Gallagher, J A; Ranganath, L R

    2016-03-01

    Alkaptonuria (AKU) is a rare inherited metabolic disorder of tyrosine metabolism that results from a defect in an enzyme called homogentisate 1,2-dioxygenase. The result of this is that homogentisic acid (HGA) accumulates in the body. HGA is central to the pathophysiology of this disease and the consequences observed; these include spondyloarthropathy, rupture of ligaments/muscle/tendons, valvular heart disease including aortic stenosis and renal stones. While AKU is considered to be a chronic progressive disorder, it is clear from published case reports that fatal acute metabolic complications can also occur. These include oxidative haemolysis and methaemoglobinaemia. The exact mechanisms underlying the latter are not clear, but it is proposed that disordered metabolism within the red blood cell is responsible for favouring a pro-oxidant environment that leads to the life threatening complications observed. Herein the role of red blood cell in maintaining the redox state of the body is reviewed in the context of AKU. In addition previously reported therapeutic strategies are discussed, specifically with respect to why reported treatments had little therapeutic effect. The potential use of nitisinone for the management of patients suffering from the acute metabolic decompensation in AKU is proposed as an alternative strategy. PMID:26596578

  9. Early Management of Patients With Acute Heart Failure: State of the Art and Future Directions

    PubMed Central

    Collins, Sean P.; Storrow, Alan B.; Levy, Phillip D.; Albert, Nancy; Butler, Javed; Ezekowitz, Justin A.; Felker, G. Michael; Fermann, Gregory J.; Fonarow, Gregg C.; Givertz, Michael M.; Hiestand, Brian; Hollander, Judd E.; Lanfear, David E.; Pang, Peter S.; Peacock, W. Frank; Sawyer, Douglas B.; Teerlink, John R.; Lenihan, Daniel J.

    2015-01-01

    Heart failure (HF) afflicts nearly 6 million Americans, resulting in 1 million emergency department (ED) visits and over 1 million annual hospital discharges. The majority of inpatient admissions originate in the ED; thus, it is crucial that emergency physicians and other providers involved in early management understand the latest developments in diagnostic testing, therapeutics, and alternatives to hospitalization. This article discusses contemporary ED management as well as the necessary next steps for ED-based acute HF research. PMID:25423908

  10. Large Nd-Hf isotopic decoupling in Himalayan River Sediments

    NASA Astrophysics Data System (ADS)

    Garcon, M.; Chauvel, C.; France-Lanord, C.

    2011-12-01

    Nd isotopic compositions of river sediments are widely used to trace sediment provenance in the Himalayan mountain range. In contrast, Hf isotopic compositions are not used even though they are excellent proxies to record the history of continental areas (Hawkesworth and Kemp, Chem. Geol. 226, 2006). Here, we focus on the Hf isotopic message carried by Himalayan river sediments and combine it to the more classical Nd isotopes to better understand the behavior of the two systems during erosion. We report Nd-Hf isotopic compositions of bedloads and suspended loads sampled at different depths in the Narayani River in Nepal (upstream of the Ganga floodplain), in the Ganga River in Bangladesh (downstream of the Ganga floodplain) and in the Yamuna River, a major tributary of the Ganga in India. Nd-Hf isotopic compositions of bedloads span a small range of values (-18< ɛNd <-16 and -30< ɛHf <-23) and lie next to the terrestrial array in a ɛHf vs. ɛNd diagram. Nd isotopic compositions are similar to those of the main Himalayan sources. By contrast, suspended loads have much more variable ratios (-19< ɛNd <-10 and -25< ɛHf <-7) and plot well above the terrestrial array in a ɛHf vs. ɛNd diagram. Like oceanic sediments, they are characterized by high ɛHf compared to their ɛNd. We explain this Nd-Hf decoupling by mineralogical sorting, a process that enriches bottom sediments in coarse and dense minerals, such as unradiogenic zircons, while the surface sediments are enriched in fine material with radiogenic Hf signatures. Bedloads and suspended loads, collected at the same sampling site at different depths in the Narayani and Ganga Rivers, share similar ɛNd. However, differences of about 5 ɛNd and 15 ɛHf units are observed between bedload and surface samples in the Yamuna River. In this river, both Nd and Hf isotopic ratios decrease from surface to bottom. We believe that part of the Hf isotopic variability is due to mineralogical sorting but the rest of it

  11. Power-Stepped HF Cross Modulation Experiments at HAARP

    NASA Astrophysics Data System (ADS)

    Greene, S.; Moore, R. C.; Langston, J. S.

    2013-12-01

    High frequency (HF) cross modulation experiments are a well established means for probing the HF-modified characteristics of the D-region ionosphere. In this paper, we apply experimental observations of HF cross-modulation to the related problem of ELF/VLF wave generation. HF cross-modulation measurements are used to evaluate the efficiency of ionospheric conductivity modulation during power-stepped modulated HF heating experiments. The results are compared to previously published dependencies of ELF/VLF wave amplitude on HF peak power. The experiments were performed during the March 2013 campaign at the High Frequency Active Auroral Research Program (HAARP) Observatory. HAARP was operated in a dual-beam transmission format: the first beam heated the ionosphere using sinusoidal amplitude modulation while the second beam broadcast a series of low-power probe pulses. The peak power of the modulating beam was incremented in 1-dB steps. We compare the minimum and maximum cross-modulation effect and the amplitude of the resulting cross-modulation waveform to the expected power-law dependence of ELF/VLF wave amplitude on HF power.

  12. Critical Questions about PARADIGM-HF and the Future

    PubMed Central

    Chen, Chen-Huan

    2016-01-01

    Cardiovascular (CV) diseases in general and heart failure (HF) in particular are major contributors to death and morbidity and are also recognized as important drivers of health care expenditure. The PARADIGM-HF trial was a pivotal trial designed to compare the long-term effects of LCZ696 with enalapril in patients with symptomatic HF with reduced ejection fraction (HFrEF). This review article presents an in-depth view of the PARADIGM-HF trial and the implications of the results in the management of patients with HF and is based on peer reviewed manuscripts, editorials, perspectives and opinions written about the PARADIGM-HF trial. The article presents the key safety and efficacy results of the trial with specific emphasis on the clinical implications of these findings. The review highlights the highly statistically significant, 20% reduction in the primary composite endpoint of cardiovascular death or HF hospitalization, and a 16% reduction in the risk of death from any cause. It also provides an overview of the design, clinical findings, limitations and special areas of clinical interest. The review discusses the future of LCZ696 and additional trials that seek to answer questions in other sub-populations of patients with HF. The article reiterates what has been concluded by many experts in the field of HF- the introduction of LCZ696 into routine clinical care, while dependent on the regulatory approvals in various countries as well as acceptance by physicians, payers and patients, will change the treatment landscape for patients with HFrEF. PMID:27471351

  13. Stratospheric HF and HCl observations /15 June 1981/

    NASA Technical Reports Server (NTRS)

    Traub, W. A.; Chance, K. V.

    1981-01-01

    Balloon measurements of the stratospheric HF/HCl ratio are reported. Seven far-infrared rotational lines of HF and HCl were observed at elevation angles of 25, 18 and 8 deg by a far-infrared Fourier-transform spectrometer on board a balloon platform at 28.5 km. Analysis of line intensities yields an average HF/HCl ratio of 0.18 + or - 0.02 at an effective altitude of 33 km, with a water vapor mixing ratio of about 4 ppmv. Results are noted to be in reasonable agreement with the calculated profile of Sze and Ko (1981) with 4.5 ppmv H2O.

  14. [Electrical properties of limb muscular tissue in acute circulatory hypoxia].

    PubMed

    Kolchev, A I; Nasonkin, O S

    1994-01-01

    The study was undertaken to examine dispersion of the complex electric resistance and capacitive impedance of limb muscular tissue in the frequency range of 1 to 100 kHz in acute circulatory hypoxia caused by blood exfusion from the common carotid artery at 10-50% of the circulatory blood volume (CBV) at the same time local blood flow and oxygen tension in muscles were measured. Blood loss of 10-30% of CBV resulted in increased muscular tissue electric conductivity. Decompensated blood loss was characterized by a steady growth of complex electric resistance and capacitive impedance. There were the greatest changes in electric conductivity in the frequency range of 1-10 kHz. PMID:7824348

  15. Current Management Strategies for Acute Esophageal Variceal Hemorrhage

    PubMed Central

    Fortune, Brett; Garcia-Tsao, Guadalupe

    2014-01-01

    Acute esophageal variceal hemorrhage is one of the clinical events that define decompensated cirrhosis and is associated with high rates of morbidity and mortality. Although recent treatment strategies have led to improved outcomes, variceal hemorrhage still carries a 6-week mortality rate of 15-20%. Current standards in its treatment include antibiotic prophylaxis, infusion of a vasoactive drug and endoscopic variceal ligation. The placement of a transjugular intrahepatic portosystemic shunt (TIPS) is considered for patients that have treatment failure or recurrent bleeding. Recurrent hemorrhage is prevented with the combination of a non-selective beta-blocker and endoscopic variceal ligation. These recommendations however assume that all patients with cirrhosis are equal. Based on a review of recent evidence, a strategy in which patients are stratified by Child class, the main predictor of outcomes, is proposed. PMID:24955303

  16. Acute psychosis in propionic acidemia: 2 case reports.

    PubMed

    Dejean de la Bâtie, C; Barbier, V; Valayannopoulos, V; Touati, G; Maltret, A; Brassier, A; Arnoux, J B; Grévent, D; Chadefaux, B; Ottolenghi, C; Canouï, P; de Lonlay, P

    2014-02-01

    Propionic acidemia is an inborn deficiency of propionyl-coenzyme A (CoA) carboxylase activity, which leads to mitochondrial accumulation of propionyl-CoA and its by-products. Neurologic complications are frequent, but only a few cases presenting with psychiatric symptoms have been reported so far. We report 2 cases of children with chronic psychiatric symptoms who presented with an acute psychotic episode as teenagers. Both patients had hallucinations, panic and grossly disorganized behavior, for several weeks to several months. They had signs of moderate metabolic decompensation at the beginning of the episode, although the psychiatric symptoms lasted longer than the metabolic imbalance. We propose that these episodes were at least partially imputable to propionic acidemia. Such episodes require psychiatric examination and antipsychotic treatment, which may have to be adapted in case of cardiomyopathy or long QT syndrome. PMID:24334345

  17. [Organ damage and cardiorenal syndrome in acute heart failure].

    PubMed

    Casado Cerrada, Jesús; Pérez Calvo, Juan Ignacio

    2014-03-01

    Heart failure is a complex syndrome that affects almost all organs and systems of the body. Signs and symptoms of organ dysfunction, in particular kidney dysfunction, may be accentuated or become evident for the first time during acute decompensation of heart failure. Cardiorenal syndrome has been defined as the simultaneous dysfunction of both the heart and the kidney, regardless of which of the two organs may have suffered the initial damage and regardless also of their previous functional status. Research into the mechanisms regulating the complex relationship between the two organs is prompting the search for new biomarkers to help physicians detect renal damage in subclinical stages. Hence, a preventive approach to renal dysfunction may be adopted in the clinical setting in the near future. This article provides a general overview of cardiorenal syndrome and an update of the physiopathological mechanisms involved. Special emphasis is placed on the role of visceral congestion as an emergent mechanism in this syndrome. PMID:24930080

  18. Influence of heart failure on the prognosis of patients with acute myocardial infarction in southwestern China

    PubMed Central

    DENG, FUXUE; XIA, YONG; FU, MICHAEL; HU, YUNFENG; JIA, FANG; RAHARDJO, YEFFRY; DUAN, YINGYI; HE, LINJING; CHANG, JING

    2016-01-01

    The impact of heart failure (HF) on acute myocardial infarction (AMI) in patients from southwestern China remains unclear. The present study aimed to compare in-hospital cardiovascular events, mortality and clinical therapies in AMI patients with or without HF in southwestern China. In total, 591 patients with AMI hospitalized between February 2009 and December 2012 were examined; those with a history of HF were excluded. The patients were divided into four groups according to AMI type (ST-elevated or non-ST-elevated AMI) and the presence of HF during hospitalization. Clinical characteristics, in-hospital cardiovascular events, mortality, coronary angiography and treatment were compared. Clinical therapies, specifically evidence-based drug use were analyzed in patients with HF during hospitalization, including angiotensin converting enzyme inhibitors (ACEIs) and β-blockers (BBs). AMI patients with HF had a higher frequency of co-morbidities, lower left ventricular ejection fraction, longer length of hospital stay and a greater risk of in-hospital mortality compared with AMI patients without HF. AMI patients with HF were less likely to be examined by cardiac angiography or treated with reperfusion therapy or recommended medications. AMI patients with HF co-treated with ACEIs and BBs had a significantly higher survival rate (94.4 vs. 67.5%; P<0.001) compared with untreated patients or patients treated with either ACEIs or BBs alone. Logistic regression analysis revealed that HF and cardiogenic shock in patients with AMI were the strongest predictors of in-hospital mortality. AMI patients with HF were at a higher risk of adverse outcomes. Cardiac angiography and timely standard recommended medications were associated with improved clinical outcomes. PMID:27284294

  19. What Is Decompensated Cirrhosis?

    MedlinePlus

    ... Minority Veterans Plain Language Surviving Spouses & Dependents Adaptive Sports Program ADMINISTRATION Veterans Health Administration Veterans Benefits Administration National Cemetery Administration U.S. Department of Veterans ...

  20. Electric field gradients in nanoparticles of HfAl2 and HfAl3 intermetallic compounds

    NASA Astrophysics Data System (ADS)

    Kulińska, Agnieszka; Wodniecki, Paweł

    2010-06-01

    Perturbed angular correlation (PAC) method was applied to study the electric field gradients in nanopowders of the HfAl2 and HfAl3 intermetallic compounds, obtained via mechanical alloying or after ball milling of the thermally alloyed compound. The influence of the ball milling procedure on the experimentally obtained hyperfine interaction parameters was determined. A strong dependence of the PAC pattern on the milling time was evidenced and attributed to the structural disorder. The thickness of the outer damaged part of the grains depends on the crystallographic structure of the milled material. In HfAl3 sample the influence of the milling procedure on the phase transformation was observed.

  1. Low-Frequency Waves in HF Heating of the Ionosphere

    NASA Astrophysics Data System (ADS)

    Sharma, A. S.; Eliasson, B.; Milikh, G. M.; Najmi, A.; Papadopoulos, K.; Shao, X.; Vartanyan, A.

    2016-02-01

    Ionospheric heating experiments have enabled an exploration of the ionosphere as a large-scale natural laboratory for the study of many plasma processes. These experiments inject high-frequency (HF) radio waves using high-power transmitters and an array of ground- and space-based diagnostics. This chapter discusses the excitation and propagation of low-frequency waves in HF heating of the ionosphere. The theoretical aspects and the associated models and simulations, and the results from experiments, mostly from the HAARP facility, are presented together to provide a comprehensive interpretation of the relevant plasma processes. The chapter presents the plasma model of the ionosphere for describing the physical processes during HF heating, the numerical code, and the simulations of the excitation of low-frequency waves by HF heating. It then gives the simulations of the high-latitude ionosphere and mid-latitude ionosphere. The chapter also briefly discusses the role of kinetic processes associated with wave generation.

  2. Lu-Hf constraints on the evolution of lunar basalts

    NASA Technical Reports Server (NTRS)

    Fujimaki, H.; Tatsumoto, M.

    1984-01-01

    It is shown that a cumulate-remelting model best explains the recently acquired data on the Lu-Hf systematics of lunar mare basalts. The model is constructed using Lu and Hf concentration data and is strengthened by Hf isotopic evidence of Unruh et al. (1984). It is shown that the similarity in MgO/FeO ratios and Cr2O3 content in high-Ti and low-Ti basalts are not important constraints on lunar basalt petrogenesis. The model demonstrates that even the very low Ti or green glass samples are remelting products of a cumulate formed after at least 80-90 percent of the lunar magma ocean had solidified. In the model, all the mare basalts and green glasses were derived from 100-150 km depth in the lunar mantle. The Lu-Hf systematics of KREEP basalts clearly indicate that they would be the final residual liquid of the lunar magma ocean.

  3. Lu-Hf CONSTRAINTS ON THE EVOLUTION OF LUNAR BASALTS.

    USGS Publications Warehouse

    Fujimaki, Hirokazu; Tatsumoto, Mistunobu

    1984-01-01

    The authors show that a cumulate-remelting model best explains the recently acquired data on the Lu-Hf systematics of lunar mare basalts. The authors model is first constructed using the Lu and Hf concentration data and it is then further strengthened by the Hf isotopic evidence. The authors also show that the similarity of MgO/FeO ratios and the Cr//2O//3 contents between high-Ti and low-Ti basalts, which have been given significance by A. E. Ringwood and D. H. Green are not important constraints for lunar basalt petrogenesis. The authors principal aim is to revive the remelting model for further consideration with the powerful constraints of Lu-Hf systematics of lunar basalts.

  4. Amorphous powders of Al-Hf prepared by mechanical alloying

    SciTech Connect

    Schwarz, R.B.; Hannigan, J.W.; Sheinberg, H.; Tiainen, T.

    1988-01-01

    We synthesized amorphous Al/sub 50/Hf/sub 50/ alloy powder by mechanically alloying an equimolar mixture of crystalline powders of Al and Hf using hexane as a dispersant. We characterized the powder as a function of mechanical-alloying time by scanning electron microscopy, x-ray diffraction, and differential scanning calorimetry. Amorphous Al/sub 50/Hf/sub 50/ powder heated at 10 K s/sup /minus/1/ crystallizes polymorphously at 1003 K into orthorhombic AlHf (CrB-type structure). During mechanical alloying, some hexane decomposes and hydrogen and carbon are incorporated into the amorphous alloy powder. The hydrogen can be removed by annealing the powder by hot pressing at a temperature approximately 30 K below the crystallization temperature. The amorphous compacts have a diamond pyramidal hardness of 1025 DPH. 24 refs., 7 figs., 1 tab.

  5. Theoretical Assessment of 178m2Hf De-Excitation

    SciTech Connect

    Hartouni, E P; Chen, M; Descalle, M A; Escher, J E; Loshak, A; Navratil, P; Ormand, W E; Pruet, J; Thompson, I J; Wang, T F

    2008-10-06

    This document contains a comprehensive literature review in support of the theoretical assessment of the {sup 178m2}Hf de-excitation, as well as a rigorous description of controlled energy release from an isomeric nuclear state.

  6. Numerical studies of HF Doppler variations caused by ionospheric disturbances

    NASA Astrophysics Data System (ADS)

    Takefu, M.; Hiroshige, N.

    HF Doppler variations caused by ionospheric disturbances are studied using an ionosphere model containing sinusoidal traveling electron density fluctuations. The present study uses a more realistic ionosphere model and a more accurate numerical method than previous works using corrugated specular reflector models. The study gives a clue to estimate the TID-associated fluctuations of ionospheric electron density by means of HF Doppler measurements. It is shown that some kinds of characteristic HF Doppler traces result depending on the wavelength of the disturbance and its traveling direction. Numerical results suggest that more or less 5 percent of the background electron density can explain most of the quasi-periodic variations on the observed HF Doppler records.

  7. Acute heart failure: Epidemiology, risk factors, and prevention.

    PubMed

    Farmakis, Dimitrios; Parissis, John; Lekakis, John; Filippatos, Gerasimos

    2015-03-01

    Acute heart failure represents the first cause of hospitalization in elderly persons and is the main determinant of the huge healthcare expenditure related to heart failure. Despite therapeutic advances, the prognosis of acute heart failure is poor, with in-hospital mortality ranging from 4% to 7%, 60- to 90-day mortality ranging from 7% to 11%, and 60- to 90-day rehospitalization from 25% to 30%. Several factors including cardiovascular and noncardiovascular conditions as well as patient-related and iatrogenic factors may precipitate the rapid development or deterioration of signs and symptoms of heart failure, thus leading to an acute heart failure episode that usually requires patient hospitalization. The primary prevention of acute heart failure mainly concerns the prevention, early diagnosis, and treatment of cardiovascular risk factors and heart disease, including coronary artery disease, while the secondary prevention of a new episode of decompensation requires the optimization of heart failure therapy, patient education, and the development of an effective transition and follow-up plan. PMID:25659507

  8. Few-layer HfS2 transistors.

    PubMed

    Kanazawa, Toru; Amemiya, Tomohiro; Ishikawa, Atsushi; Upadhyaya, Vikrant; Tsuruta, Kenji; Tanaka, Takuo; Miyamoto, Yasuyuki

    2016-01-01

    HfS2 is the novel transition metal dichalcogenide, which has not been experimentally investigated as the material for electron devices. As per the theoretical calculations, HfS2 has the potential for well-balanced mobility (1,800 cm(2)/V·s) and bandgap (1.2 eV) and hence it can be a good candidate for realizing low-power devices. In this paper, the fundamental properties of few-layer HfS2 flakes were experimentally evaluated. Micromechanical exfoliation using scotch tape extracted atomically thin HfS2 flakes with varying colour contrasts associated with the number of layers and resonant Raman peaks. We demonstrated the I-V characteristics of the back-gated few-layer (3.8 nm) HfS2 transistor with the robust current saturation. The on/off ratio was more than 10(4) and the maximum drain current of 0.2 μA/μm was observed. Moreover, using the electric double-layer gate structure with LiClO4:PEO electrolyte, the drain current of the HfS2 transistor significantly increased to 0.75 mA/μm and the mobility was estimated to be 45 cm(2)/V·s at least. This improved current seemed to indicate superior intrinsic properties of HfS2. These results provides the basic information for the experimental researches of electron devices based on HfS2. PMID:26926098

  9. Few-layer HfS2 transistors

    PubMed Central

    Kanazawa, Toru; Amemiya, Tomohiro; Ishikawa, Atsushi; Upadhyaya, Vikrant; Tsuruta, Kenji; Tanaka, Takuo; Miyamoto, Yasuyuki

    2016-01-01

    HfS2 is the novel transition metal dichalcogenide, which has not been experimentally investigated as the material for electron devices. As per the theoretical calculations, HfS2 has the potential for well-balanced mobility (1,800 cm2/V·s) and bandgap (1.2 eV) and hence it can be a good candidate for realizing low-power devices. In this paper, the fundamental properties of few-layer HfS2 flakes were experimentally evaluated. Micromechanical exfoliation using scotch tape extracted atomically thin HfS2 flakes with varying colour contrasts associated with the number of layers and resonant Raman peaks. We demonstrated the I-V characteristics of the back-gated few-layer (3.8 nm) HfS2 transistor with the robust current saturation. The on/off ratio was more than 104 and the maximum drain current of 0.2 μA/μm was observed. Moreover, using the electric double-layer gate structure with LiClO4:PEO electrolyte, the drain current of the HfS2 transistor significantly increased to 0.75 mA/μm and the mobility was estimated to be 45 cm2/V·s at least. This improved current seemed to indicate superior intrinsic properties of HfS2. These results provides the basic information for the experimental researches of electron devices based on HfS2. PMID:26926098

  10. Tracking magmatic processes through Zr/Hf ratios in rocks and Hf and Ti zoning in zircons: An example from the Spirit Mountain batholith, Nevada

    USGS Publications Warehouse

    Lowery, Claiborne L.E.; Miller, C.F.; Walker, B.A.; Wooden, J.L.; Mazdab, F.K.; Bea, F.

    2006-01-01

    Zirconium and Hf are nearly identical geochemically, and therefore most of the crust maintains near-chondritic Zr/Hf ratios of ???35-40. By contrast, many high-silica rhyolites and granites have anomalously low Zr/Hf (15-30). As zircon is the primary reservoir for both Zr and Hf and preferentially incorporates Zr, crystallization of zircon controls Zr/ Hf, imprinting low Zr/Hf on coexisting melt. Thus, low Zr/Hf is a unique fingerprint of effective magmatic fractionation in the crust. Age and compositional zonation in zircons themselves provide a record of the thermal and compositional histories of magmatic systems. High Hf (low Zr/ Hf) in zircon zones demonstrates growth from fractionated melt, and Ti provides an estimate of temperature of crystallization (TTiZ) (Watson and Harrison, 2005). Whole-rock Zr/Hf and zircon zonation in the Spirit Mountain batholith, Nevada, document repeated fractionation and thermal fluctuations. Ratios of Zr/Hf are ???30-40 for cumulates and 18-30 for high-SiO2 granites. In zircons, Hf (and U) are inversely correlated with Ti, and concentrations indicate large fluctuations in melt composition and TTiZ (>100??C) for individual zircons. Such variations are consistent with field relations and ion-probe zircon geochronology that indicate a >1 million year history of repeated replenishment, fractionation, and extraction of melt from crystal mush to form the low Zr/Hf high-SiO2 zone. ?? 2006 The Mineralogical Society.

  11. Global potential energy hypersurface for dynamical studies of energy transfer in HF--HF collisions

    SciTech Connect

    Redmon, M.J.; Binkley, J.S.

    1987-07-15

    The interaction energy of two HF molecules at 1332 individual points has been calculated with Moeller--Plesset (many--body) perturbation theory at the MP4-SDTQ level using a 6-311G** basis set. 293 of the points correspond to stretching of one HF molecule from its equilibrium geometry. No attempt was made to use a sufficiently fine grid to accurately describe the well region corresponding to hydrogen bonding. However, the location and minimum energy are consistent with experiment and other accurate theoretical results. An extensive global fit (rms error of 1 kcal/mol) is reported of 1319 points (below 10 eV of potential energy) using a modified London potential with corrections obtained using polynomials through four-body interactions. A model electrostatic potential represents the long-range interaction. In addition, the use of an expansion in products of three Legendre functions is discussed. It is shown that the latter approach, although accurately fitting the ab initio data, has difficulties interpolating in regions of the surface exhibiting diverse magnitudes of potential energy, and therefore must be used with caution. This surface should be useful for studies of T--V--R processes in this system.

  12. Role of Hf on Phase Formation in Ti45Zr(38-x)Hf(x)Ni17 Liquids and Solids

    NASA Technical Reports Server (NTRS)

    Wessels, V.; Sahu, K. K.; Gangopadhyay, A. K.; Huett, V. T.; Canepari, S.; Goldman, A. I.; Hyers, R. W.; Kramer, M. J.; Rogers, J. R.; Kelton, K. F.; Robinson, D.

    2008-01-01

    Hafnium and zirconium are very similar, with almost identical sizes and chemical bonding characteristics. However, they behave differently when alloyed with Ti and Ni. A sharp phase formation boundary near 18-21 at.% Hf is observed in rapidly-quenched and as-cast Ti45Zr38-xHfxNi17 alloys. Rapidly-quenched samples that contain less than 18 at.% Hf form the icosahedral quasicrystal phase, whiles samples containing more than 21 at.% form the 3/2 rational approximant phase. In cast alloys, a C14 structure is observed for alloys with Hf lower than the boundary concentration, while a large-cell (11.93 ) FCC Ti2Ni-type structure is found in alloys with Hf concentrations above the boundary. To better understand the role of Hf on phase formation, the structural evolution with supercooling and the solidification behavior of liquid Ti45Zr38-xHfxNi17 alloys (x=0, 12, 18, 21, 38) were studied using the Beamline Electrostatic Levitation (BESL) technique using 125keV x-rays on the 6ID-D beamline at the Advanced Photon Source, Argonne National Laboratory. For all liquids primary crystallization was to a BCC solid solution phase; interestly, an increase in Hf concentration leads to a decrease in the BCC lattice parameter in spite of the chemical similarity between Zr and Hf. A Reitveld analysis confirmed that as in the cast alloys, the secondary phase that formed was the C14 below the phase formation boundary and a Ti2Ni-type structure at higher Hf concentrations. Both the liquidus temperature and the reduced undercooling change sharply on traversing the phase formation boundary concentration, suggesting a change in the liquid structure. Structural information from a Honeycutt-Anderson index analysis of reverse Monte Carlo fits to the S(q) liquid data will be presented to address this issue.

  13. Acute nephritic syndrome

    MedlinePlus

    Glomerulonephritis - acute; Acute glomerulonephritis; Nephritis syndrome - acute ... Acute nephritic syndrome is often caused by an immune response triggered by an infection or other disease. Common causes ...

  14. Comparison of the ability of the PDD-ICG clearance test, CTP, MELD, and MELD-Na to predict short-term and medium-term mortality in patients with decompensated hepatitis B cirrhosis

    PubMed Central

    Cheng, Xiang-Pu; Zhao, Jing; Chen, Yu; Meng, Fan-Kun; Xu, Bin; Yu, Hong-Wei; Meng, Qing-Hua; Liu, Yan-Min; Zhang, Shi-Bin; Meng, Sha; Zhang, Jing-Yun; Zhang, Jin-Yan; Duan, Zhong-Ping

    2016-01-01

    Objective Various methods, including the indocyanine green (ICG) clearance test, the Child–Turcotte–Pugh score (CTP), model for end-stage liver disease (MELD), and MELD combined with serum sodium concentration (MELD-Na), have been used widely in liver function evaluation in patients with end-stage liver disease. In this study, we compared the ability of these methods to predict mortality in patients with decompensated hepatitis B cirrhosis. Methods A total of 98 patients with decompensated hepatitis B cirrhosis were included in this study and followed up for 12 months. The ICG-derived measurements (ICG-PDR, ICG-R15, EHBF), CTP, MELD, and MELD-Na were obtained within 2 days after patients’ admission and patients’ survival at 1, 3, 6, and 12 months was recorded. Receiver operating curve was used to evaluate the ability of these methods to predict mortality in these patients with decompensated hepatitis B cirrhosis. Results At 1 month, 3 months, 6 months and 12 months, the cumulative number of deaths and liver transplant recipients was 12 (12.2%), 17 (17.3%), 21 (21.4%) and 25 (25.5%), respectively. The ICG-derived measurements, CTP, MELD, and MELD-Na of nonsurvivors were significantly different compared with that in survivors. All methods yielded viable values in predicting short-term and medium-term prognosis for patients with decompensated hepatitis B cirrhosis, with most area under the curve exceeding 0.8. Moreover, the ICG-derived measurements showed a significant correlation with that of CTP, MELD, and MELD-Na. Conclusion All four methods, ICG clearance test, CTP, MELD, and MELD-Na, provided reliable prediction of mortality in patients with decompensated hepatitis B cirrhosis for both short-term and medium-term prognosis. PMID:26649802

  15. Investigation and Development of Data-Driven D-Region Model for HF Systems Impacts

    NASA Technical Reports Server (NTRS)

    Eccles, J. V.; Rice, D.; Sojka, J. J.; Hunsucker, R. D.

    2002-01-01

    Space Environment Corporation (SEC) and RP Consultants (RPC) are to develop and validate a weather-capable D region model for making High Frequency (HF) absorption predictions in support of the HF communications and radar communities. The weather-capable model will assimilate solar and earth space observations from NASA satellites. The model will account for solar-induced impacts on HF absorption, including X-rays, Solar Proton Events (SPE's), and auroral precipitation. The work plan includes: I . Optimize D-region model to quickly obtain ion and electron densities for proper HF absorption calculations. 2. Develop indices-driven modules for D-region ionization sources for low, mid, & high latitudes including X-rays, cosmic rays, auroral precipitation, & solar protons. (Note: solar spectrum & auroral modules already exist). 3. Setup low-cost monitors of existing HF beacons and add one single-frequency beacon. 4. Use PENEX HF-link database with HF monitor data to validate D-region/HF absorption model using climatological ionization drivers. 5. Develop algorithms to assimilate NASA satellite data of solar, interplanetary, and auroral observations into ionization source modules. 6. Use PENEX HF-link & HF-beacon data for skill score comparison of assimilation versus climatological D-region/HF absorption model. Only some satellites are available for the PENEX time period, thus, HF-beacon data is necessary. 7. Use HF beacon monitors to develop HF-link data assimilation algorithms for regional improvement to the D-region/HF absorption model.

  16. Traditional applications and novel approaches in Lu-Hf geochronology

    NASA Astrophysics Data System (ADS)

    Herwartz, D.; Nagel, T. J.; Sandmann, S.; Vitale Brovarone, A.; Rexroth, S.; Rojas-Agramonte, Y.; Froitzheim, N.; Kröner, A.; Skublov, S. G.; Münker, C.

    2012-04-01

    Lutetium-Hf geochronology is currently becoming a routine method for dating metamorphism of garnet bearing rocks, such as eclogites. Prograde garnet growth ages are mostly preserved because blocking temperatures exceed 630 °C [1] and prograde Lu zoning patterns have even been observed in samples that were exposed to temperatures above 800 °C [2]. Here we discuss Lu-Hf ages from various eclogite localities, such as the Northern Tianshan, Kyrgyzstan (~ 470 Ma), the Kola Peninsula, Russia (~ 1900 Ma) [3], Cuba (~70 Ma and ~124 Ma), Alpine Corsica (~ 34 Ma) and the Tauern Window (~32.7 Ma). Age precisions are in the order of 0.1 to 1 % and all ages can be safely attributed to the timing of garnet growth. Some samples, however, contain two garnet populations which complicates Lu-Hf geochronology. In the Adula Nappe (Central Alps) relict garnet has survived a second orogenic cycle, including subduction to mantle depth. By carefully separating the two garnet populations present within the same eclogite sample we obtained a minimum Variscan age of 333 Ma and a maximum Alpine age of 38 Ma [4]. A similar relationship is now evident in samples from the Tauern Window (Eastern Alps), where only one population of garnet generation is visible macroscopically. However, few relics of Variscan garnet inside Alpine garnet are observed in electron microprobe element maps and are also evident from isotopic heterogeneity in 176Lu/177Hf vs. 176Hf/177Hf space. Garnet relics stemming from previous metamorphic events are frequently observed in HP units around the world and the Lu-Hf system is a promising tool to resolve the respective growth ages. Apart from garnet, lawsonite Lu-Hf geochronology was recently identified as a new tool to investigate subduction processes [5]. Here we present a lawsonite Lu-Hf isochron 37,6 ± 1.4 Ma (MSWD = 0.30; n =5) from a lawsonite blueschist from Alpine Corsica. The lawsonite slightly predates the timing of garnet growth (~34 Ma) in three eclogite

  17. Noninvasive mechanical ventilation in chronic obstructive pulmonary disease and in acute cardiogenic pulmonary edema.

    PubMed

    Rialp Cervera, G; del Castillo Blanco, A; Pérez Aizcorreta, O; Parra Morais, L

    2014-03-01

    Noninvasive ventilation (NIV) with conventional therapy improves the outcome of patients with acute respiratory failure due to hypercapnic decompensation of chronic obstructive pulmonary disease (COPD) or acute cardiogenic pulmonary edema (ACPE). This review summarizes the main effects of NIV in these pathologies. In COPD, NIV improves gas exchange and symptoms, reducing the need for endotracheal intubation, hospital mortality and hospital stay compared with conventional oxygen therapy. NIV may also avoid reintubation and may decrease the length of invasive mechanical ventilation. In ACPE, NIV accelerates the remission of symptoms and the normalization of blood gas parameters, reduces the need for endotracheal intubation, and is associated with a trend towards lesser mortality, without increasing the incidence of myocardial infarction. The ventilation modality used in ACPE does not affect the patient prognosis. PMID:23158869

  18. Treatment disparities in acute coronary syndromes, heart failure, and kidney disease.

    PubMed

    McCullough, Peter A; Maynard, Robert C

    2011-01-01

    It has been consistently observed that patients with renal dysfunction have more premature, severe, complicated, and fatal cardiovascular disease than age- and sex-matched individuals with normal renal function. There have been 4 major explanations for this finding: (1) positive confounding by third variables associated with chronic kidney disease (CKD), including diabetes mellitus and hypertension; (2) therapeutic nihilism or lesser use of beneficial therapies in CKD; (3) greater toxicities of therapies, such as bleeding from anticoagulants or contrast-induced kidney injury; (4) biological factors which result directly from CKD that work to promote and accelerate cardiovascular disease. In this paper, we focus on the issue of treatment disparities or therapeutic nihilism and its contribution to poor outcomes in the setting of acute coronary syndromes and acutely decompensated heart failure. This issue is important because if we can overcome barriers to the utilization of beneficial treatments, then clinical outcomes should improve over time. PMID:21625092

  19. Acute-on-chronic liver failure: a new syndrome in cirrhosis

    PubMed Central

    Moreau, Richard

    2016-01-01

    Patients with cirrhosis who are hospitalized for an acute decompensation (AD) and also have organ failure(s) are at high risk of short-term death. These patients have a syndrome called Acute-on-Chronic Liver Failure (ACLF). ACLF is now considered as a new syndrome that it is distinct from “mere” AD not only because of the presence of organ failure(s) and high short-term mortality but also because of younger age, higher prevalence of alcoholic etiology of cirrhosis, higher prevalence of some precipitants (such as bacterial infections, active alcoholism), and more intense systemic inflammatory response. ACLF is a new syndrome also because severe sepsis or severe alcoholic hepatitis do not account for 100% of the observed cases; in fact, almost 50% of the cases are of “unknown” origin. In other words, severe sepsis, severe alcoholic hepatitis and ACLF of “unknown origin” are subcategories of the syndrome. PMID:27044760

  20. Acute-on-chronic liver failure: a new syndrome in cirrhosis.

    PubMed

    Moreau, Richard

    2016-03-01

    Patients with cirrhosis who are hospitalized for an acute decompensation (AD) and also have organ failure(s) are at high risk of short-term death. These patients have a syndrome called Acute-on-Chronic Liver Failure (ACLF). ACLF is now considered as a new syndrome that it is distinct from "mere" AD not only because of the presence of organ failure(s) and high short-term mortality but also because of younger age, higher prevalence of alcoholic etiology of cirrhosis, higher prevalence of some precipitants (such as bacterial infections, active alcoholism), and more intense systemic inflammatory response. ACLF is a new syndrome also because severe sepsis or severe alcoholic hepatitis do not account for 100% of the observed cases; in fact, almost 50% of the cases are of "unknown" origin. In other words, severe sepsis, severe alcoholic hepatitis and ACLF of "unknown origin" are subcategories of the syndrome. PMID:27044760

  1. Prevalence and Prognostic Significance of Hyponatremia in Patients with Acute Exacerbation of Chronic Obstructive Pulmonary Disease: Data from the Akershus Cardiac Examination (ACE) 2 Study

    PubMed Central

    Brynildsen, Jon; Høiseth, Arne Didrik; Følling, Ivar; Brekke, Pål H.; Christensen, Geir; Hagve, Tor-Arne; Verbalis, Joseph G.; Omland, Torbjørn; Røsjø, Helge

    2016-01-01

    Background Hyponatremia is prevalent and associated with mortality in patients with heart failure (HF). The prevalence and prognostic implications of hyponatremia in acute exacerbation of chronic obstructive pulmonary (AECOPD) have not been established. Method We included 313 unselected patients with acute dyspnea who were categorized by etiology of dyspnea according to established guidelines (derivation cohort). Serum Na+ was determined on hospital admission and corrected for hyperglycemia, and hyponatremia was defined as [Na+]<137 mmol/L. Survival was ascertained after a median follow-up of 816 days and outcome was analyzed in acute HF (n = 143) and AECOPD (n = 83) separately. Results were confirmed in an independent AECOPD validation cohort (n = 99). Results In the derivation cohort, median serum Na+ was lower in AECOPD vs. acute HF (138.5 [135.9–140.5] vs. 139.2 [136.7–141.3] mmol/L, p = 0.02), while prevalence of hyponatremia (27% [22/83] vs. 20% [29/143], p = 0.28) and mortality rate (42% [35/83] vs. 46% [66/143], p = 0.56) were similar. By univariate Cox regression analysis, hyponatremia was associated with increased mortality in acute HF (HR 1.85 [95% CI 1.08, 3.16], p = 0.02), but not in AECOPD (HR 1.00 [0.47, 2.15], p = 1.00). Analogous to the results of the derivation cohort, hyponatremia was prevalent also in the AECOPD validation cohort (25% [25/99]), but not associated with mortality. The diverging effect of hyponatremia on outcome between AECOPD and acute HF was statistically significant (p = 0.04). Conclusion Hyponatremia is prevalent in patients with acute HF and AECOPD, but is associated with mortality in patients with acute HF only. PMID:27529844

  2. Quantitative fibrosis estimation by image analysis predicts development of decompensation, composite events and defines event-free survival in chronic hepatitis B patients.

    PubMed

    Bihari, Chhagan; Rastogi, Archana; Sen, Bijoya; Bhadoria, Ajeet Singh; Maiwall, Rakhi; Sarin, Shiv K

    2016-09-01

    The extent of fibrosis is a major determinant of the clinical outcome in patients with chronic liver diseases. We undertook this study to explore the degree of fibrosis in baseline liver biopsies to predict clinical outcomes in chronic hepatitis B (CHB) patients. Fibrosis quantification was done by image analysis on Masson's trichrome-stained sections and correlated with clinical and biochemical parameters, liver stiffness and hepatic vein pressure gradient (n = 96). Follow-up information collected related to clinical outcome. A total of 964 cases was analyzed. Median quantitative fibrosis (QF) was 3.7% (interquartile range, 1.6%-9.7%) with substantial variation in various stages. Median QF was F0, 1% (0.7%-1.65%); F1, 3.03% (2.07%-4.0%); F2, 7.1% (5.6%-8.7%); F3, 12.7% (10.15%-16.7%); F4, 26.9% (20.3%-36.4%). QF positively correlated with METAVIR staging, liver stiffness measurement, and hepatic vein pressure gradient. Eighty-nine cases developed liver-related events: decompensation, hepatocellular carcinoma, liver transplantation and death. Cox regression analysis after adjusting for METAVIR staging-QF, albumin, and AST for composite events; QF and albumin for decompensation; and only QF for hepatocellular carcinoma-were found to be significant predictors of clinical outcomes. QF categorized into five stages: QF1, 0%-5%; QF2, 5.1%-10%; QF3, 10.1%-15%; QF4, 15.1%-20%; QF5, >20.1%. In patients with advanced stages of QF, probability of event-free survival found to be low. Quantitative fibrosis in baseline liver biopsy predicts progression of the disease and disease outcome in CHB patients. QF defines the probability of event-free survival in CHB cases. PMID:27189343

  3. Early management of patients with acute heart failure: state of the art and future directions--a consensus document from the SAEM/HFSA acute heart failure working group.

    PubMed

    Collins, Sean P; Storrow, Alan B; Levy, Phillip D; Albert, Nancy; Butler, Javed; Ezekowitz, Justin A; Felker, G Michael; Fermann, Gregory J; Fonarow, Gregg C; Givertz, Michael M; Hiestand, Brian; Hollander, Judd E; Lanfear, David E; Pang, Peter S; Peacock, W Frank; Sawyer, Douglas B; Teerlink, John R; Lenihan, Daniel J

    2015-01-01

    Heart failure (HF) afflicts nearly 6 million Americans, resulting in 1 million emergency department (ED) visits and over 1 million annual hospital discharges. The majority of inpatient admissions originate in the ED; thus, it is crucial that emergency physicians and other providers involved in early management understand the latest developments in diagnostic testing, therapeutics, and alternatives to hospitalization. This article discusses contemporary ED management as well as the necessary next steps for ED-based acute HF research. PMID:25423908

  4. Acute sacroiliitis.

    PubMed

    Slobodin, Gleb; Rimar, Doron; Boulman, Nina; Kaly, Lisa; Rozenbaum, Michael; Rosner, Itzhak; Odeh, Majed

    2016-04-01

    The purpose of this study was to review the data on the etiology, risk factors, clinical presentations, and diagnosis of acute sacroiliitis. A Pubmed search utilizing the indexing term "acute sacroiliitis" was conducted and the data pertinent to the aim of the review was extracted and organized in accordance with the preplanned structure of the manuscript. The diagnosis of acute sacroiliitis is often challenging because of both the relative rarity of this presentation and diverse character of acute sacroiliac pain, frequently mimicking other, more prevalent disorders. Technetium bone scintigraphy can localize the disease process to the sacroiliac joint, while computed tomography or magnetic resonance imaging can be used for the detailed characterization and the extent of the disease as well as the diagnosis of complications. Pyogenic sacroiliitis is by far the most common cause of acute sacroiliitis. Brucellosis, acute sacroiliitis in the course of reactive arthritis, and crystalline-induced sacroiliitis frequently imitate pyogenic sacroiliitis. Acute sacroiliitis can rarely be also related to hematological malignancies or treatment with isotretinoin. Awareness to the possibility of acute sacroiliitis and a thorough physical examination are the necessary prerequisites to its timely diagnosis, while the appropriate laboratory and imaging studies should confirm the precise diagnosis and direct the appropriate treatment strategy. PMID:26847855

  5. Developments in HF equipment and systems mobile and portable terminals

    NASA Astrophysics Data System (ADS)

    Wilson, Q. C.

    1986-03-01

    Before the advent of satellite platforms, sophisticated high frequency (HF) propagation and system research promised improved capability during disturbed ionospheric propagation conditions. However, satellite relays captured the imaginations and pocketbooks of the communications community in the mid-1960s. Consequently, extant HF systems aged while satellite systems were implemented. During peacetime, satellite systems transmit quality low data rate communications and navigation aids to mobile users, but there is now renewed interest in the low cost and survivability attributes of HF radio. At this time, when old HF prime systems need replacement for logistical reasons, the need for low cost communications that can survive jamming, nuclear effects, and space warfare is not satisfied. The HF renaissance is the response to this challenge. Logistical replacement procurements that provide new capabilities are redressing the attrition of vacuum-tube radio equipment over the last decade. Procuring organizations typically compile specifications comprising state-of-the-art and new capabilities offered by competing vendors. Integrated circuits, which include microprocessors, synthesizer ele ments, and other evolving components, have led to new circuit architectures. The first of the following three sections describes: Receivers; Transceivers and Antenna Couplers; Antenna Kits; and Audio Channel Peripherals.

  6. Suspected acute myocardial infarction in a dystrophin-deficient dog.

    PubMed

    Schneider, Sarah Morar; Coleman, Amanda Erickson; Guo, Lee-Jae; Tou, Sandra; Keene, Bruce W; Kornegay, Joe N

    2016-06-01

    Golden retriever muscular dystrophy (GRMD) is a model for the genetically homologous human disease, Duchenne muscular dystrophy (DMD). Unlike the mildly affected mdx mouse, GRMD recapitulates the severe DMD phenotype. In addition to skeletal muscle involvement, DMD boys develop cardiomyopathy. While the cardiomyopathy of DMD is typically slowly progressive, rare early episodes of acute cardiac decompensation, compatible with myocardial infarction, have been described. We report here a 7-month-old GRMD dog with an apparent analogous episode of myocardial infarction. The dog presented with acute signs of cardiac disease, including tachyarrhythmia, supraventricular premature complexes, and femoral pulse deficits. Serum cardiac biomarkers, cardiac-specific troponin I (cTnI) and N-terminal prohormone of B-type natriuretic peptide (NT-proBNP), were markedly increased. Echocardiography showed areas of hyperechoic myocardial enhancement, typical of GRMD cardiomyopathy. Left ventricular dyskinesis and elevated cTnI were suggestive of acute myocardial damage/infarction. Over a 3-year period, progression to a severe dilated phenotype was observed. PMID:27105608

  7. Polymorphism of HF (beta 1H-globulin) in three Asian populations (Bangladeshis, Tibetans and Indonesians).

    PubMed

    Kido, Akira; Susukida, Rie; Oya, Masakazu; Fujitani, Noboru; Kimura, Hiroshi; Hara, Masaaki

    2003-03-01

    The polymorphism of HF (beta 1H-globulin) was investigated in three Asian populations (Bangladeshis, Tibetans and Indonesians) by means of isoelectric focusing and immunoblotting. Phenotypes associated with three common alleles (HF*A, HF*B and HF*Q0) and a rare allele HF*A1 were identified. The observed numbers of phenotypes were in accordance with the numbers expected under the Hardy-Weinberg equilibrium. HF*A1 seems to be a unique allele of the East-Asian Mongoloids including Tibetans and Indonesians. PMID:12712773

  8. Importance of the Lu-Hf isotopic system in studies of planetary chronology and chemical evolution

    USGS Publications Warehouse

    Patchett, P.J.

    1983-01-01

    The 176Lu-176Hf isotope method and its applications in earth sciences are discussed. Greater fractionation of Lu/Hf than Sm/Nd in planetary magmatic processes makes 176Hf 177Hf a powerful geochemical tracer. In general, proportional variations of 176Hf 177Hf exceed those of 143Nd l44Nd by factors of 1.5-3 in terrestrial and lunar materials. Lu-Hf studies therefore have a major contribution to make in understanding of terrestrial and other planetary evolution through time, and this is the principal importance of Lu-Hf. New data on basalts from oceanic islands show unequivocally that whereas considerable divergences occur in 176Hf 177Hf- 87Sr 86Sr and 143Nd l44Nd- 87Sr 86Sr diagrams, 176Hf 177Hf and 143Nd 144Nd display a single, linear isotopic variation in the suboceanic mantle. These discordant 87Sr 86Sr relationships may allow, with the acquisition of further Hf-Nd-Sr isotopic data, a distinction between processes such as mantle metasomatism, influence of seawater-altered material in the magma source, or recycling of sediments into the mantle. In order to evaluate the Hf-Nd isotopic correlation in terms of mantle fractionation history, there is a need for measurements of Hf distribution coefficients between silicate minerals and liquids, and specifically for a knowledge of Hf behavior in relation to rareearth elements. For studying ancient terrestrial Hf isotopic variations, the best quality Hf isotope data are obtained from granitoid rocks or zircons. New data show that very U-Pb discordant zircons may have upwardly-biased 176Hf 177Hf, but that at least concordant to slightly discordant zircons appear to be reliable carriers of initial 176Hf 177Hf. Until the controls on addition of radiogenic Hf to zircon are understood, combined zircon-whole rock studies are recommended. Lu-Hf has been demonstrated as a viable tool for dating of ancient terrestrial and extraterrestrial samples, but because it offers little advantage over existing methods, is unlikely to find

  9. Interaction between HfC precipitates and vacancies in quenched Cu:Hf as studied by TDPAC and positron lifetime measurements

    NASA Astrophysics Data System (ADS)

    Govindaraj, R.; Rajaraman, R.

    2004-09-01

    A Cu:Hf sample with 1 wt% Hf as prepared by arc melting is characterized by TEM and microdiffraction analysis to contain HfC precipitates. HfC precipitates in a Cu matrix bind vacancies and divacancies strongly in the quenched Cu:Hf sample as deduced by time differential perturbed angular correlation (TDPAC) studies. Isochronal annealing studies using TDPAC and positron lifetime measurements indicate the stability of these vacancy complexes in the quenched sample for annealing treatments up to 1200 K, beyond which the de-trapping of the vacancies from HfC precipitates is observed to occur. This shows that HfC precipitates present in Cu inhibit the formation of voids by strongly binding quenched vacancies.

  10. MIMO communications within the HF band using compact antenna arrays

    NASA Astrophysics Data System (ADS)

    Gunashekar, S. D.; Warrington, E. M.; Feeney, S. M.; Salous, S.; Abbasi, N. M.

    2010-12-01

    Measurements have been made over a 255 km radio path between Durham and Leicester in the UK in order to investigate the potential applicability of multiple input multiple output (MIMO) techniques to communications within the HF band. This paper describes the results from experiments in which compact heterogeneous antenna arrays have been employed. The results of these experiments indicate that traditional spaced HF antenna arrays can be replaced by compact, active, heterogeneous arrays in order to achieve the required levels of decorrelation between the various antenna elements. An example case study is also presented which highlights the importance of the variable nature of the ionosphere in the context of HF-MIMO radio links.

  11. Heterostructures design for Hf-Nitride/V-Nitride system

    NASA Astrophysics Data System (ADS)

    Caicedo, J. C.; Escobar, C.; Aperador, W.; Caicedo, H. H.; Prieto, P.

    2015-12-01

    The multilayered films were grown via reactive r.f. magnetron sputtering technique by systematically varying the bilayer period (Λ) and the bilayer number (n), while maintaining constant the total coating thickness (~2.4 μm) on silicon(100) substrates. The multilayers were characterized through high-angle X-ray diffraction (HA-XRD), low-angle X-ray diffraction (LA-XRD), HfN and VN layers were analyzed via X-ray Photoelectron Spectroscopy (XPS) and electron and transmission microscopy (TEM). The HA-XRD results showed preferential growth in the face-centered cubic (111) crystal structure for HfN/VN multilayer systems with the (111)[100]HfN//(200)[100]VN epitaxial relation. The maximum coherent assembly was observed with presence of satellite peaks.

  12. Feature Modeling of HfO2 Atomic Layer Deposition Using HfCl4/H2O

    NASA Astrophysics Data System (ADS)

    Stout, Phillip J.; Adams, Vance; Ventzek, Peter L. G.

    2003-03-01

    A Monte Carlo based feature scale model (Papaya) has been applied to atomic layer deposition (ALD) of HfO2 using HfCl_4/H_20. The model includes physical effects of transport to surface, specular and diffusive reflection within feature, adsorption, surface diffusion, deposition and etching. Discussed will be the 3D feature modeling of HfO2 deposition in assorted features (vias and trenches). The effect of feature aspect ratios, pulse times, cycle number, and temperature on film thickness, feature coverage, and film Cl fraction (surface/bulk) will be discussed. Differences between HfO2 ALD on blanket wafers and in features will be highlighted. For instance, the minimum pulse times sufficient for surface reaction saturation on blanket wafers needs to be increased when depositing on features. Also, HCl products created during the HfCl4 and H_20 pulses are more likely to react within a feature than at the field, reducing OH coverage within the feature (vs blanket wafer) thus limiting the maximum coverage attainable for a pulse over a feature.

  13. Dynamics of changes in physiological parameters of mice with different radiosensitivity after acute γ-irradiation.

    PubMed

    Alchinova, I B; Arkhipova, E N; Medvedeva, Yu S; Cherepov, A B; Karganov, M Yu

    2014-06-01

    We studied radiosensitivity of 101/Hf, C3H/Sn, and C57Bl mice exposed to sublethal doses of γ-radiation. C57Bl mice responded to radiation much later than 101/Hf and C3H/Sn mice, while their adaptability was high enough. 101/Hf and C3H/Sn mice developed acute radiation sickness in a similar way. However, C3H/Sn mice showed better physiological indicators after radiation crisis. There was no noticeable improvement after the development of radiation sickness in 101/Hf mice. To assess individual radiosensitivity, integrated approach should be applied using the data obtained by different methods on several physiological levels. PMID:24958371

  14. Acute malocclusion.

    PubMed

    Dupont, John S

    2006-01-01

    Acute malocclusion can result from disturbances in the maxillary/mandibular tooth relationship. These alterations in the occlusal position can result from high fillings, sinus problems, abscesses, periodontal disease, and moving or erupting teeth. Conditions seen less frequently include acute malocclusions secondary to an event (such as trauma) that make a stable dental relationship an unstable one. Patients can demonstrate any of a number of clinical conditions that interfere with their comfort and ability to function. This article provides information on some of the less familiar causes of acute malocclusion. PMID:16689064

  15. Effectiveness of Haemodiafiltration with Heat Sterilized High-Flux Polyphenylene HF Dialyzer in Reducing Free Light Chains in Patients with Myeloma Cast Nephropathy

    PubMed Central

    2015-01-01

    Introduction In cases of myeloma cast nephropathy in need of haemodialysis (HD), reduction of free light chains using HD with High-Cut-Off filters (HCO-HD), in combination with chemotherapy, may be associated with better renal recovery. The aim of the present study is to evaluate the effectiveness of haemodiafiltration (HDF) in reducing free light chain levels using a less expensive heat sterilized high-flux polyphenylene HF dialyzer (HF-HDF). Methods In a single-centre prospective cohort study, 327 dialysis sessions were performed using a 2.2 m2 heat sterilized high-flux polyphenylene HF dialyzer (Phylther HF22SD), a small (1.1m2) or large (2.1 m2) high-cut-off (HCO) dialyzer (HCOS and HCOL) in a cohort of 16 patients presenting with dialysis-dependent acute cast nephropathy and elevated free light chains (10 kappa, 6 lambda). The outcomes of the study were the mean reduction ratio (RR) of kappa and lambda, the proportion of treatments with an RR of at least 0.65, albumin loss and the description of patient outcomes. Statistical analysis was performed using linear and logistic regression through generalized estimating equation analysis so as to take into account repeated observation within subjects and adjust for session duration. Results There were no significant differences in the estimated marginal mean of kappa RR, which were respectively 0.67, 0.69 and 0.70 with HCOL-HD, HCOS-HDF and HF-HDF (P = 0.950). The estimated marginal mean of the proportions of treatments with a kappa RR ≥0.65 were 68%, 63% and 71% with HCOL-HD, HCOS-HDF and HF-HDF, respectively (P = 0.913). The estimated marginal mean of lambda RR were higher with HCOL-HDF (0.78), compared to HCOL-HD and HF-HDF (0.62, and 0.61 respectively). The estimated marginal mean proportion of treatments with a lambda RR ≥0.65 were higher with HCOL-HDF (81%), compared to 57% in HF-HDF (P = 0.042). The median albumin loss were 7, 21 and 63 g/session with HF-HDF, HCOL-HD and HCOL-HDF respectively (P = 0

  16. Characteristics, Diagnosis and Prognosis of Acute-on-Chronic Liver Failure in Cirrhosis Associated to Hepatitis B.

    PubMed

    Li, Hai; Chen, Liu-Ying; Zhang, Nan-Nan; Li, Shu-Ting; Zeng, Bo; Pavesi, Marco; Amorós, Àlex; Mookerjee, Rajeshwar P; Xia, Qian; Xue, Feng; Ma, Xiong; Hua, Jing; Sheng, Li; Qiu, De-Kai; Xie, Qing; Foster, Graham R; Dusheiko, Geoffrey; Moreau, Richard; Gines, Pere; Arroyo, Vicente; Jalan, Rajiv

    2016-01-01

    The diagnostic and prognostic criteria of acute-on-chronic liver failure (ACLF) were developed in patients with no Hepatitis B virus (HBV) cirrhosis (CANONIC study). The aims of this study were to evaluate whether the diagnostic (CLIF-C organ failure score; CLIF-C OFs) criteria can be used to classify patients; and the prognostic score (CLIF-C ACLF score) could be used to provide prognostic information in HBV cirrhotic patients with ACLF. 890 HBV associated cirrhotic patients with acute decompensation (AD) were enrolled. Using the CLIF-C OFs, 33.7% (300 patients) were diagnosed as ACLF. ACLF was more common in the younger patients and in those with no previous history of decompensation. The most common organ failures were 'hepatic' and 'coagulation'. As in the CANONIC study, 90-day mortality was extremely low in the non-ACLF patients compared with ACLF patients (4.6% vs 50%, p < 0.0001). ACLF grade and white cell count, were independent predictors of mortality. CLIF-C ACLFs accurately predicted short-term mortality, significantly better than the MELDs and a disease specific score generated for the HBV patients. Current study indicates that ACLF is a clinically and pathophysiology distinct even in HBV patients. Consequently, diagnostic criteria, prognostic scores and probably the management of ACLF should base on similar principles. PMID:27146801

  17. Characteristics, Diagnosis and Prognosis of Acute-on-Chronic Liver Failure in Cirrhosis Associated to Hepatitis B.

    PubMed Central

    Li, Hai; Chen, Liu-Ying; Zhang, Nan-nan; Li, Shu-Ting; Zeng, Bo; Pavesi, Marco; Amorós, Àlex; Mookerjee, Rajeshwar P; Xia, Qian; Xue, Feng; Ma, Xiong; Hua, Jing; Sheng, Li; Qiu, De-kai; Xie, Qing; Foster, Graham R; Dusheiko, Geoffrey; Moreau, Richard; Gines, Pere; Arroyo, Vicente; Jalan, Rajiv

    2016-01-01

    The diagnostic and prognostic criteria of acute-on-chronic liver failure (ACLF) were developed in patients with no Hepatitis B virus (HBV) cirrhosis (CANONIC study). The aims of this study were to evaluate whether the diagnostic (CLIF-C organ failure score; CLIF-C OFs) criteria can be used to classify patients; and the prognostic score (CLIF-C ACLF score) could be used to provide prognostic information in HBV cirrhotic patients with ACLF. 890 HBV associated cirrhotic patients with acute decompensation (AD) were enrolled. Using the CLIF-C OFs, 33.7% (300 patients) were diagnosed as ACLF. ACLF was more common in the younger patients and in those with no previous history of decompensation. The most common organ failures were ‘hepatic’ and ‘coagulation’. As in the CANONIC study, 90-day mortality was extremely low in the non-ACLF patients compared with ACLF patients (4.6% vs 50%, p < 0.0001). ACLF grade and white cell count, were independent predictors of mortality. CLIF-C ACLFs accurately predicted short-term mortality, significantly better than the MELDs and a disease specific score generated for the HBV patients. Current study indicates that ACLF is a clinically and pathophysiology distinct even in HBV patients. Consequently, diagnostic criteria, prognostic scores and probably the management of ACLF should base on similar principles. PMID:27146801

  18. Modeling the interference environment in the HF band

    NASA Astrophysics Data System (ADS)

    Pederick, L. H.; Cervera, M. A.

    2016-02-01

    The performance of systems using high frequency (HF) radio waves, such as over-the-horizon radars (OTHR), can be strongly affected by external interferers at great distances (thousands of kilometers) from the systems receiver. However, the propagation of interference has complex behavior and is known to vary with location, time, season, sunspot number, and radio frequency. Understanding how the level of interference varies with all of these factors is important for the design of new systems such as next generation OTHR. By combining databases of known transmitters, ray-tracing propagation, and a model ionosphere, a model of the behavior of interference at HF has been developed.

  19. Concerted hydrogen atom exchange between three HF molecules

    NASA Technical Reports Server (NTRS)

    Komornicki, Andrew; Dixon, David A.; Taylor, Peter R.

    1992-01-01

    The termolecular reaction involving concerted hydrogen-atom exchange between three HF molecules was investigated with particular attention given to the effects of correlation at the various stationary points along the reaction. Using large segmented Gaussian basis sets to locate the (HF)3 stationary points at the SCF level, the geometries of the stable hydrogen-bonded trimer, which is of C(3h) symmetry, were located, together with the transition state for hydrogen exchange, which is of D(3h) symmetry. Then, using a large atomic natural orbital basis and correlating all valence electrons, the energetics of the exchange reaction were evaluated at the correlated level.

  20. European coordination for coastal HF radar data in EMODnet Physics

    NASA Astrophysics Data System (ADS)

    Mader, Julien; Novellino, Antonio; Gorringe, Patrick; Griffa, Annalisa; Schulz-Stellenfleth, Johannes; Montero, Pedro; Montovani, Carlo; Ayensa, Garbi; Vila, Begoña; Rubio, Anna; Sagarminaga, Yolanda

    2015-04-01

    Historically, joint effort has been put on observing open ocean, organizing, homogenizing, sharing and reinforcing the impact of the acquired information based on one technology: ARGO with profilers Argo floats, EuroSites, ESONET-NoE, FixO3 for deep water platforms, Ferrybox for stations in ships of opportunities, and GROOM for the more recent gliders. This kind of networking creates synergies and makes easier the implementation of this source of data in the European Data exchange services like EMODnet, ROOSs portals, or any applied services in the Blue economy. One main targeted improvement in the second phase of EMODnet projects is the assembling of data along coastline. In that sense, further coordination is recommended between platform operators around a specific technology in order to make easier the implementation of the data in the platforms (4th EuroGOOS DATAMEQ WG). HF radar is today recognized internationally as a cost-effective solution to provide high spatial and temporal resolution current maps (depending on the instrument operation frequency, covering from a few kilometres offshore up to 200 km) that are needed for many applications for issues related to ocean surface drift or sea state characterization. Significant heterogeneity still exists in Europe concerning technological configurations, data processing, quality standards and data availability. This makes more difficult the development of a significant network for achieving the needed accessibility to HF Radar data for a pan European use. EuroGOOS took the initiative to lead and coordinate activities within the various observation platforms by establishing a number of Ocean Observing Task Teams such as HF-Radars. The purpose is to coordinate and join the technological, scientific and operational HF radar communities at European level. The goal of the group is on the harmonization of systems requirements, systems design, data quality, improvement and proof of the readiness and standardization of

  1. Nd and Hf isotopic analysis of Barberton komatiites

    NASA Astrophysics Data System (ADS)

    Robin, Christophe; Blichert-Toft, Janne; Arndt, Nicholas; Wilson, Allan; Byerly, Gary

    2013-04-01

    In order to constrain the origin of komatiites from the Barberton Belt, particularly the nature of their mantle source and the conditions of partial melting, we analyzed the Nd and Hf isotopic compositions of 33 komatiite samples. Of these 15 were from the ca. 3.5 Ga Komati Formation, 3 were from the 3.47 Ga Hooggenoeg Fm and 15 from the 3.3 Ga Weltevreden Fm. The samples were collected from outcrop and represent the three main types of komatiite found in the Barberton Belt: i.e. Al-depleted, Al-undepleted and Al-enriched. The analyses were carried out at ENS Lyon using the procedure described by Blichert-Toft et al. For each sample suite we obtained a relatively large range of calculated initial isotopic values. In each suite, one or more samples gave an unreasonably high or low value, particularly for the Hf isotopic system. Excluding these outliers, the values are as follows: Komati Fm, epsilon Nd = -0.8 to +2.5, epsilon Hf = +1 to +8; Hooggenoeg Fm, epsilon Nd = -0.1 to +0.2, epsilon Hf = +1 to +2; Weltevreden Fm, epsilon Nd = 0.3 to +2.0, epsilon Hf = +4 to +13. There were no systematic differences between the isotopic compositions of the three different types of komatiite. Within the relatively large variability of the data, the epsilon Hf values tend to become more positive with age while the epsilon Nd values remain essentially constant. These results are broadly in line with those obtained in most of the previous studies of Barberton komatiites. Notably: 1) there is a wide range in initial isotopic compositions that is not compatible with normal magmatic processes. At least part of the range can be attributed to disturbance, particularly of the Lu-Hf system, after eruption of the lavas; 2) notwithstanding this uncertainty, both the Nd and Hf isotopic compositions are slightly radiogenic, indicating formation from a moderately depleted mantle source. To obtain more reliable data, we intend a) to analyse carefully chosen and prepared samples from core

  2. Field operations with cesium clocks in HF navigation systems

    NASA Technical Reports Server (NTRS)

    Christy, E. H.; Clayton, D. A.

    1982-01-01

    Networks of HF phase comparison marine navigation stations employing cesium clocks are discussed. The largest permanent network is in the Gulf of Mexico where some fourteen base stations are continuously active and others are activated as needed. These HF phase comparison systems, which operate on a single transmission path, require a clock on the mobile unit as well. Inventory consists of upwards of 70 clocks from two different manufacturers. The maintenance of this network as an operating system requires a coordinated effort involving clock preparation, clock environment control, station performance monitoring and field service.

  3. Ca + HF - The anatomy of a chemical insertion reaction

    NASA Technical Reports Server (NTRS)

    Jaffe, R. L.; Pattengill, M. D.; Mascarello, F. G.; Zare, R. N.

    1987-01-01

    A comprehensive first-principles theoretical investigation of the gas phase reaction Ca + HF - CaF + H is reported. Ab initio potential energy calculations are first discussed, along with characteristics of the computed potential energy surface. Next, the fitting of the computed potential energy points to a suitable analytical functional form is described, and maps of the fitted potential surface are displayed. The methodology and results of a classical trajectory calculation utilizing the fitted potential surface are presented. Finally, the significance of the trajectory study results is discussed, and generalizations concerning dynamical aspects of Ca + HF scattering are drawn.

  4. A routine high-precision method for Lu-Hf isotope geochemistry and chronology

    USGS Publications Warehouse

    Patchett, P.J.; Tatsumoto, M.

    1981-01-01

    A method for chemical separation of Lu and Hf from rock, meteorite and mineral samples is described, together with a much improved mass spectrometric running technique for Hf. This allows (i) geo- and cosmochronology using the176Lu???176Hf+??- decay scheme, and (ii) geochemical studies of planetary processes in the earth and moon. Chemical yields for the three-stage ion-exchange column procedure average 90% for Hf. Chemical blanks are <0.2 ng for Lu and Hf. From 1 ??g of Hf, a total ion current of 0.5??10-11 Ampere can be maintained for 3-5 h, yielding 0.01-0.03% precision on the ratio176Hf/177Hf. Normalisation to179Hf/177Hf=0.7325 is used. Extensive results for the Johnson Matthey Hf standard JMC 475 are presented, and this sample is urged as an international mass spectrometric standard; suitable aliquots, prepared from a single batch of JMC 475, are available from Denver. Lu-Hf analyses of the standard rocks BCR-1 and JB-1 are given. The potential of the Lu-Hf method in isotope geochemistry is assessed. ?? 1980 Springer-Verlag.

  5. Acute Bronchitis

    MedlinePlus

    ... bronchitis? Acute bronchitis is almost always caused by viruses that attack the lining of the bronchial tree ... infection. As your body fights back against these viruses, more swelling occurs and more mucus is produced. ...

  6. Acute Pericarditis

    MedlinePlus

    ... large pericardial effusions). Acute pericarditis usually responds to colchicine or NSAIDs (such as aspirin and ibuprofen ) taken ... reduce pain but relieves it by reducing inflammation. Colchicine also decreases the chance of pericarditis returning later. ...

  7. The anatectic effect on the zircon Hf isotope composition of migmatites and associated granites

    NASA Astrophysics Data System (ADS)

    Chen, Yi-Xiang; Gao, Peng; Zheng, Yong-Fei

    2015-12-01

    Zircon Hf isotope composition is widely used to trace the growth and evolution of continental crust. However, it is controversial whether the Hf isotope composition of magmatic zircons can faithfully reflect that of their sources, especially for S-type granites. In order to provide an insight into this issue, we have revisited the published Lu-Hf isotope data of zircons from well-studied migmatites and associated granites in the Sulu orogen and the Cathaysian terrane, respectively. The results show greatly elevated 176Hf/177Hf ratios (by more than 10ε units) for newly grown zircon domains compared to the relict zircon domains. This indicates considerable contributions from non-zircon Hf to anatectic melts during crustal anatexis and subsequent magmatism. Furthermore, this more radiogenic Hf isotope signature was not erased during magmatic processes such as crystal fractionation during melt ascent and emplacement. The budget of Hf isotopes in source rocks with respect to mineral Lu/Hf ratios suggests the involvement of Hf-bearing major minerals in anatectic reactions by dissolving Hf-bearing major minerals into the anatectic melts. The significant Hf isotope variations in some anatectic and magmatic zircon domains from the migmatites and granites suggest not only the source heterogeneity but also the variable non-zircon Hf contributions. As such, the Hf isotope compositions of anatectic and magmatic zircons are substantially dictated by the mass balance between the non-zircon Hf from anatectic reactions and the zircon-Hf from the dissolution of protolith zircons into the anatectic melts. They are primarily controlled by P-T conditions and mechanism of crustal anatexis, and the magmatic processes during melt evolution. The present study highlights the important contribution of non-zircon Hf to the anatectic and magmatic zircon domains. In this regard, the greatly elevated 176Hf/177Hf ratios for newly grown zircon domains in the migmatites and granites cannot reflect

  8. Combination of lung ultrasound (a comet-tail sign) and N-terminal pro-brain natriuretic peptide in differentiating acute heart failure from chronic obstructive pulmonary disease and asthma as cause of acute dyspnea in prehospital emergency setting

    PubMed Central

    2011-01-01

    Introduction We studied the diagnostic accuracy of bedside lung ultrasound (the presence of a comet-tail sign), N-terminal pro-brain natriuretic peptide (NT-proBNP) and clinical assessment (according to the modified Boston criteria) in differentiating heart failure (HF)-related acute dyspnea from pulmonary (chronic obstructive pulmonary disease (COPD)/asthma)-related acute dyspnea in the prehospital setting. Methods Our prospective study was performed at the Center for Emergency Medicine, Maribor, Slovenia, between July 2007 and April 2010. Two groups of patients were compared: a HF-related acute dyspnea group (n = 129) and a pulmonary (asthma/COPD)-related acute dyspnea group (n = 89). All patients underwent lung ultrasound examinations, along with basic laboratory testing, rapid NT-proBNP testing and chest X-rays. Results The ultrasound comet-tail sign has 100% sensitivity, 95% specificity, 100% negative predictive value (NPV) and 96% positive predictive value (PPV) for the diagnosis of HF. NT-proBNP (cutoff point 1,000 pg/mL) has 92% sensitivity, 89% specificity, 86% NPV and 90% PPV. The Boston modified criteria have 85% sensitivity, 86% specificity, 80% NPV and 90% PPV. In comparing the three methods, we found significant differences between ultrasound sign and (1) NT-proBNP (P < 0.05) and (2) Boston modified criteria (P < 0.05). The combination of ultrasound sign and NT-proBNP has 100% sensitivity, 100% specificity, 100% NPV and 100% PPV. With the use of ultrasound, we can exclude HF in patients with pulmonary-related dyspnea who have positive NT-proBNP (> 1,000 pg/mL) and a history of HF. Conclusions An ultrasound comet-tail sign alone or in combination with NT-proBNP has high diagnostic accuracy in differentiating acute HF-related from COPD/asthma-related causes of acute dyspnea in the prehospital emergency setting. Trial registration ClinicalTrials.gov NCT01235182. PMID:21492424

  9. Acute Exacerbation of Chronic Hepatitis B: The Dilemma of Differentiation from Acute Viral Hepatitis B

    PubMed Central

    Puri, Pankaj

    2013-01-01

    Exacerbations of chronic hepatitis B are common in endemic countries. Acute exacerbation of chronic hepatitis B virus (CHB-AE) causing derangement of liver functions may be seen in a flare of HBV in immune clearance phase or as a reactivation of HBV in patients with inactive or resolved HBV infection. While reactivation of HBV is usually seen in HBsAg positive patients, it is being increasingly recognized in patients with apparently resolved HBV infection who do not have HBsAg in serum but have IgG antibody to core antigen (anti-HBc) in the serum, especially so in patients on chemotherapy, immunosuppressive therapy or undergoing hematopoietic stem cell transplantation. In an icteric patient who is HBsAg positive, it may be difficult to differentiate CHB-AE from acute viral hepatitis B (AVH-B). Both may have similar clinical presentation and even IgM anti-HBc, the traditional diagnostic marker of AVH-B, may also appear at the time of exacerbation of CHB. The differentiation between CHB-AE and AVH-B is important not only for prognostication but also because management strategies are different. Most cases of AVH-B will resolve on their own, HBsAg clearance is achieved spontaneously in 90–95% of adults and treatment is rarely indicated except in the few with severe/fulminant disease. In contrast, in CHB-AE, the onset of jaundice may lead to decompensation of liver disease and treatment is warranted. The mechanisms of acute exacerbation and the differentiating features between AVH-B and CHB-AE are reviewed. PMID:25755518

  10. Composition effects on mechanical properties of HfC-strengthened molybdenum alloys

    NASA Technical Reports Server (NTRS)

    Witzke, W. R.

    1976-01-01

    The mechanical properties of swaged rod thermomechanically processed from arc-melted Mo-2Re-Hf-C alloys containing as much as 0.9 mol pct HfC have been evaluated. The low temperature ductilities of these alloys were not influenced by the amount of HfC present but by the amount of Hf in excess of stoichiometry. Maximum ductility occurred at 0.2 to 0.3 at. pct excess Hf. At 0.3 to 0.5 mol pct HfC, alloy strength varied directly with the Mo content of extracted carbide particles, both decreasing as the amount of excess Hf increased. Additions of 2 at. pct Re had little effect on strength or ductility. Tensile and creep strengths of Mo-2Re-0.7Hf-0.5C alloy equaled or exceeded those of other high strength Mo alloys.

  11. Processing and crystallographic structure of non-equilibrium Si-doped HfO{sub 2}

    SciTech Connect

    Hou, Dong; Fancher, Chris M.; Esteves, Giovanni; Jones, Jacob L.; Zhao, Lili

    2015-06-28

    Si-doped HfO{sub 2} was confirmed to exist as a non-equilibrium state. The crystallographic structures of Si-doped HfO{sub 2} were studied using high-resolution synchrotron X-ray diffraction and the Rietveld refinement method. Incorporation of Si into HfO{sub 2} and diffusion of Si out of (Hf,Si)O{sub 2} were determined as a function of calcination temperature. Higher thermal energy input at elevated calcination temperatures resulted in the formation of HfSiO{sub 4}, which is the expected major secondary phase in Si-doped HfO{sub 2}. The effect of SiO{sub 2} particle size (nano- and micron-sized) on the formation of Si-doped HfO{sub 2} was also determined. Nano-crystalline SiO{sub 2} was found to incorporate into HfO{sub 2} more readily.

  12. Subduction zone Hf-anomalies: Mantle messenger, melting artefact or crustal process?

    NASA Astrophysics Data System (ADS)

    Woodhead, Jon; Hergt, Janet; Greig, Alan; Edwards, Louise

    2011-04-01

    The origin of Hf elemental depletions in subduction zone magmas is investigated using new major- and trace-element data for cumulate xenoliths from the Mariana arc, and deep sea sediments recovered by the DSDP and ODP drilling programmes. Results indicate that most of the rare earth element (REE) and Hf inventory in the xenoliths is contained within two minerals—clinopyroxene and titanomagnetite—and that removal of a typical gabbroic fractionating assemblage reduces the depletion in Hf relative to neighbouring REE on a mantle normalised trace element diagram (commonly denoted Hf/Hf*) in the evolving magmas. Confirmation of this observation is provided by a variety of literature data from different subduction zones in which bulk-rock samples also define a positive correlation between Hf/Hf* and the silica content of the magmas. In agreement with experimental studies on REE-HFSE partitioning, we observe that the ability of clinopyroxene to influence the Hf/Hf* of fractionating magmas is associated with its aluminium content. This decoupling of Hf from the REE in differentiating arc magmas suggests that bulk rock Hf/Hf* values, when used in isolation, are unlikely to provide a robust measure of source REE-Hf characteristics, even when suites are filtered to exclude all but the most mafic samples. It may be possible to normalise data to a constant degree of fractionation, and in this way distinguish subtle changes in source Hf/Hf* but most existing datasets are of neither the size nor quality to attempt such calculations. Modification of Hf/Hf* is also seen when modelling mantle melting processes and there are strong suggestions that source variations are influenced by not only subducted sediment, which exhibits a remarkably wide range in Hf/Hf*, but also subduction zone fluids. These observations remove some of the constraints imposed on recent models that attempt to reconcile Hf isotope data with Hf-REE abundance data in some arc suites. Although a case may be

  13. Noble gas encapsulation: clathrate hydrates and their HF doped analogues.

    PubMed

    Mondal, Sukanta; Chattaraj, Pratim Kumar

    2014-09-01

    The significance of clathrate hydrates lies in their ability to encapsulate a vast range of inert gases. Although the natural abundance of a few noble gases (Kr and Xe) is poor their hydrates are generally abundant. It has already been reported that HF doping enhances the stability of hydrogen hydrates and methane hydrates, which prompted us to perform a model study on helium, neon and argon hydrates with their HF doped analogues. For this purpose 5(12), 5(12)6(8) and their HF doped analogues are taken as the model clathrate hydrates, which are among the building blocks of sI, sII and sH types of clathrate hydrate crystals. We use the dispersion corrected and gradient corrected hybrid density functional theory for the calculation of thermodynamic parameters as well as conceptual density functional theory based reactivity descriptors. The method of the ab initio molecular dynamics (AIMD) simulation is used through atom centered density matrix propagation (ADMP) techniques to envisage the structural behaviour of different noble gas hydrates on a 500 fs timescale. Electron density analysis is carried out to understand the nature of Ng-OH2, Ng-FH and Ng-Ng interactions. The current results noticeably demonstrate that the noble gas (He, Ne, and Ar) encapsulation ability of 5(12), 5(12)6(8) and their HF doped analogues is thermodynamically favourable. PMID:25047071

  14. ORIGIN OF EXCESS {sup 176}Hf IN METEORITES

    SciTech Connect

    Thrane, Kristine; Connelly, James N.; Bizzarro, Martin; Meyer, Bradley S.; The, Lih-Sin

    2010-07-10

    After considerable controversy regarding the {sup 176}Lu decay constant ({lambda}{sup 176}Lu), there is now widespread agreement that (1.867 {+-} 0.008) x 10{sup -11} yr{sup -1} as confirmed by various terrestrial objects and a 4557 Myr meteorite is correct. This leaves the {sup 176}Hf excesses that are correlated with Lu/Hf elemental ratios in meteorites older than {approx}4.56 Ga meteorites unresolved. We attribute {sup 176}Hf excess in older meteorites to an accelerated decay of {sup 176}Lu caused by excitation of the long-lived {sup 176}Lu ground state to a short-lived {sup 176m}Lu isomer. The energy needed to cause this transition is ascribed to a post-crystallization spray of cosmic rays accelerated by nearby supernova(e) that occurred after 4564.5 Ma. The majority of these cosmic rays are estimated to penetrate accreted material down to 10-20 m, whereas a small fraction penetrate as deep as 100-200 m, predicting decreased excesses of {sup 176}Hf with depth of burial at the time of the irradiation event.

  15. A Coupled Ionosphere-Raytrace Model for Artificial HF Heating

    NASA Astrophysics Data System (ADS)

    Zawdie, K.; Huba, J. D.; Drob, D. P.; Bernhardt, P. A.

    2015-12-01

    The first self-consistent 3D model of artificial HF ionospheric heating has been developed. The model combines the first principles ionosphere model SAMI3/ESF and the ray trace code MoJo-15. The location of HF heating is calculated by simulating the ray path through the ionosphere and determining the average heating location. This new model has been used to successfully simulate the snapback effect discovered in a Arecibo HF heating experiment described by Bernhardt et al. [1988]. The simulations provide new insight into the physical mechanism for snapback. As Bernhardt et al. [1988] hypothesized, the heater wave is refracted by the density cavity, thus causing the location of heating to drift in longitude. The cause of snapback, however, is not that the ray snaps back to its original configuration once the density cavity has convected out of range. Instead, the density cavity convects into the path of the refracted ray such that only a small portion of the ray near the original heating location is above the threshold for HF heating. The heating location thus suddenly snaps back to the original location but the ray itself is still refracted in longitude.

  16. HF Doppler Acoustic Imaging of the Ocean Surface and Interior

    NASA Astrophysics Data System (ADS)

    Pinkel, Robert; Smith, Jerome A.

    2004-11-01

    HF phased array Doppler sonar represents a new tool for obtaining Three-dimensional (r,q,t) images of the oceanic surface and interior velocity field. While the capabilities of the approach are unique, the design constraints are also unusual. Examples of both are presented in this work.

  17. Predictors of Six-Month Mortality in BNP-Matched Acute Heart Failure Patients.

    PubMed

    Lourenço, Patrícia; Ribeiro, Ana; Pintalhão, Mariana; Silva, Sérgio; Bettencourt, Paulo

    2015-09-01

    Natriuretic peptides have established prognostic value in heart failure (HF). The role of many other clinical and laboratory variables is still to be proved. The aim of this study was to assess prognostic determinants of death in acute HF in B-type natriuretic peptide (BNP)-matched patients. We conducted a case-control study to assess prognostic predictors of 6-month mortality in acute HF. From a prospectively recruited population of hospital-admitted patients with acute HF, we retrospectively selected a convenience sample of age-, gender-, and admission BNP-matched patients who survived (controls) or died (cases) in the follow-up period. Prognostic predictors of death were analyzed using a Cox regression analysis. A multivariate model was built. Variables in the model included atrial fibrillation, hypertension, admission heart rate, systolic blood pressure, the New York Heart Association class, hemoglobin, urea, albumin, systolic dysfunction, ischemic etiology, prognostic-modifying therapy, and BNP decrease during hospitalization. We analyzed 224 patients: 112 surviving and 112 not surviving a 6-month period. Median age was 80 years, 42.9% of the patients were men, and 63.9% had systolic dysfunction. Patients surviving the first 6 months had higher admission systolic blood pressure and heart rate, higher hemoglobin, lower urea, and more often had >30% decrease in BNP during hospitalization; they were more often discharged on HF prognostic modifying therapy. However, in multivariate analysis, the only independent mortality predictor was BNP decrease: patients in whom BNP decreased >30% had an HR of death of 0.57 (0.37 to 0.89). In conclusion, in BNP-matched patients with acute HF, the only independent mortality predictor is BNP decrease. Other literature suggested death predictors do not seem independent of natriuretic peptides. PMID:26115901

  18. Heart failure trials on pharmacological therapy in 2015: lessons learned and future outlook.

    PubMed

    Latini, Roberto; Masson, Serge; Staszewsky, Lidia

    2016-06-01

    Much progress in the medical therapy of chronic heart failure (HF) has been made in the last decades. The last was the introduction of a new treatment strategy based on the combination of the neprilysin inhibitor sacubitril and the angiotensin receptor blocker (ARB) valsartan into the pharmacological armamentarium, as reported in the PARADIGM-HF trial and its ancillary analyses. On the other hand, in the acute setting only scant progress in pharmacological treatments has been achieved, and most published data are based on observational studies or expert opinion. This review critically presents and discusses the most intriguing evidence from clinical trials in HF published in 2015. In particular, we focused on chronic HF with reduced ejection fraction and its comorbidities, while worsening HF or acute decompensated HF were more synthetically treated. PMID:26924687

  19. Prognostic biomarkers in acute coronary syndrome.

    PubMed

    Salvagno, Gian Luca; Pavan, Chiara

    2016-07-01

    The acute coronary syndrome (ACS) is a leading cause of death around the globe. Beside a still high mortality rate, additional complications of ACS include arrhythmias, left ventricular mural thrombus, cardiac fibrosis, heart failure (HF), cardiogenic shock, mitral valve dysfunction, aneurysms, up to cardiac rupture. Despite many prognostic tools have been developed over the past decades, efforts are still ongoing to identify reliable and predictive biomarkers, which may help predict the prognosis of these patients and especially the risk of HF. Recent evidence suggests that the value of a discrete number of biomarkers of myocardial fibrosis, namely the soluble form of suppression of tumorigenicity 2 (sST2) and galectin-3 (GAL-3), may be predictive of HF and death in patients with ACS. Interestingly, the already promising predictive value of these biomarkers when measured alone was shown to be consistently magnified when combined with other and well-established cardiac biomarkers such natriuretic peptides and cardiac troponins. This article is hence aimed to review the current knowledge about cardiac biomarkers of fibrosis and adverse remodeling. PMID:27500159

  20. Prognostic biomarkers in acute coronary syndrome

    PubMed Central

    Pavan, Chiara

    2016-01-01

    The acute coronary syndrome (ACS) is a leading cause of death around the globe. Beside a still high mortality rate, additional complications of ACS include arrhythmias, left ventricular mural thrombus, cardiac fibrosis, heart failure (HF), cardiogenic shock, mitral valve dysfunction, aneurysms, up to cardiac rupture. Despite many prognostic tools have been developed over the past decades, efforts are still ongoing to identify reliable and predictive biomarkers, which may help predict the prognosis of these patients and especially the risk of HF. Recent evidence suggests that the value of a discrete number of biomarkers of myocardial fibrosis, namely the soluble form of suppression of tumorigenicity 2 (sST2) and galectin-3 (GAL-3), may be predictive of HF and death in patients with ACS. Interestingly, the already promising predictive value of these biomarkers when measured alone was shown to be consistently magnified when combined with other and well-established cardiac biomarkers such natriuretic peptides and cardiac troponins. This article is hence aimed to review the current knowledge about cardiac biomarkers of fibrosis and adverse remodeling. PMID:27500159

  1. Heparin Saline Versus Normal Saline for Flushing and Locking Peripheral Venous Catheters in Decompensated Liver Cirrhosis Patients: A Randomized Controlled Trial.

    PubMed

    Wang, Rui; Zhang, Ming-Guang; Luo, Ou; He, Liu; Li, Jia-Xin; Tang, Yun-Jing; Luo, Yan-Li; Zhou, Min; Tang, Li; Zhang, Zong-Xia; Wu, Hao; Chen, Xin-Zu

    2015-08-01

    A prospective randomized, controlled, single-blinded trial to compare the effectiveness and safety of heparin saline (HS) to those of normal saline (NS) as flushing and locking solutions for peripheral venous catheter (PVC) in decompensated liver cirrhosis (DLC) patients.Patients with DLC at our institution between April 2012 and March 2013 were enrolled after obtaining informed consent. The patients were randomly allocated into 2 groups: the NS group received preservative-free 0.9% sodium chloride as the flushing and locking solution, while the HS group received HS (50 U/mL). PVC-related events and the duration of PVC maintenance were compared between the 2 groups. Moreover, the preinfusion and postinfusion levels of prothrombin time (PT), activated partial thromboplastin time (APTT), and platelet (PLT) were also compared.A total of 32 and 36 DLC patients in the NS (125 PVCs) and HS (65 PVCs) groups, respectively, were analyzed. Baseline characteristics, including gender, age, Child-Pugh grade, PVC type and administration of anticoagulant, and irritant agents, were comparable between the 2 groups (P > 0.05). The maintenance times of the HS and NS groups were 80.27 ± 26.47 and 84.19 ± 29.32 hours, respectively (P = 0.397). Removal of PVC for abnormal reasons occurred in 30.7% and 22.4% of patients in the HS and NS groups (P = 0.208). The PVC occlusion rates were 6.2% and 5.6% in the HS and NS groups, respectively (OR = 1.11, 95% CI 0.31-3.92). The PT, APTT, and PLT levels were comparable between the 2 groups both before and after infusion (P > 0.05). Incremental analyses showed that Child-Pugh grade C might be a risk factor for the suppression of PLT in the HS group.We consider NS to be as effective as and safer than conventional HS for flushing and locking PVC in decompensated liver cirrhosis patients. PMID:26252305

  2. Acute myelogenous leukemia (AML) - children

    MedlinePlus

    Acute myelogenous leukemia - children; AML; Acute myeloid leukemia - children; Acute granulocytic leukemia - children; Acute myeloblastic leukemia - children; Acute non-lymphocytic leukemia (ANLL) - children

  3. Effects of Zr impurity on microscopic behavior of Hf metal

    NASA Astrophysics Data System (ADS)

    Dey, S. K.; Dey, C. C.; Saha, S.

    2016-08-01

    Hf metal with ∼ 3 wt% Zr impurity has been reinvestigated by perturbed angular correlation (PAC) spectroscopy using a LaBr3(Ce)-BaF2 detector set up to understand the microscopic behavior of this metal with temperature. From present measurements, five quadrupole interaction frequencies have been found at room temperature where both pure hcp fraction (∼33%) with 12 nearest neighbor Hf surrounding the probe 181Hf atom and the probe-impurity fraction (∼33%) corresponding to 11 nearest neighbor Hf plus one dissimilar Zr atom are clearly distinguished. At room temperature, the results for quadrupole frequency and asymmetry parameter are found to be ωQ=51.6(4) Mrad/s, η=0.20(4) for the impurity fraction and ωQ=46.8(2) Mrad/s, η=0 for the pure fraction with values of frequency distribution width δ=0 for both components. At 77 K, only 1 NN Zr impurity (∼93%) and pure hcp (∼7%) components have been found with a value of δ ∼ 10% for the impurity fraction. A drastic change in microstructural configuration of Hf metal is observed at 473 K where the impurity fraction increases to ∼ 50% and the pure hcp fraction reduces to ∼ 15% with abrupt changes in quadrupole frequencies for both components. The pure fraction then increases with temperature and enhances to ∼50% at 973 K. In the temperature range 473-973 K, quadrupole frequencies for both components are found to decrease slowly with temperature. Using the Arrhenius relation, binding energy (B) for the probe-impurity pair and the entropy of formation are measured from temperature dependent fractions of probe-impurity and pure hcp in the temperature range 473-773 K. The three other minor components found at different temperatures are attributed to crystalline defects.

  4. Two-dimensional semiconductor HfSe{sub 2} and MoSe{sub 2}/HfSe{sub 2} van der Waals heterostructures by molecular beam epitaxy

    SciTech Connect

    Aretouli, K. E.; Tsipas, P.; Tsoutsou, D.; Marquez-Velasco, J.; Xenogiannopoulou, E.; Giamini, S. A.; Vassalou, E.; Kelaidis, N.; Dimoulas, A.

    2015-04-06

    Using molecular beam epitaxy, atomically thin 2D semiconductor HfSe{sub 2} and MoSe{sub 2}/HfSe{sub 2} van der Waals heterostructures are grown on AlN(0001)/Si(111) substrates. Details of the electronic band structure of HfSe{sub 2} are imaged by in-situ angle resolved photoelectron spectroscopy indicating a high quality epitaxial layer. High-resolution surface tunneling microscopy supported by first principles calculations provides evidence of an ordered Se adlayer, which may be responsible for a reduction of the measured workfunction of HfSe{sub 2} compared to theoretical predictions. The latter reduction minimizes the workfunction difference between the HfSe{sub 2} and MoSe{sub 2} layers resulting in a small valence band offset of only 0.13 eV at the MoSe{sub 2}/HfSe{sub 2} heterointerface and a weak type II band alignment.

  5. Acute Pneumonia.

    PubMed

    Arshad, Hammad; Fasanya, Adebayo; Cheema, Tariq; Singh, Anil C

    2016-01-01

    Acute pneumonia is an active infection of the lungs that results when an individual at risk gets exposed to a particular microbiological pathogen. Acute pneumonia is the leading cause of death in the United States that is attributable to an infection. The risk factors, pathogenesis, and microbiological organisms involved differ if the pneumonia develops in the community versus health care-associated environment. The development of concise and comprehensive guidelines has led to an improvement in the management of the problem. However, the emergence of multidrug-resistant organisms and the increase in the percentage of elderly population keep mortality risk very substantial. PMID:26919676

  6. Hf3Fe4Sn4 and Hf9Fe4-xSn10+x: Two stannide intermetallics with low-dimensional iron sublattices

    NASA Astrophysics Data System (ADS)

    Calta, Nicholas P.; Kanatzidis, Mercouri G.

    2016-04-01

    This article reports two new Hf-rich intermetallics synthesized using Sn flux: Hf3Fe4Sn4 and Hf9Fe4-xSn10+x. Hf3Fe4Sn4 adopts an ordered variant the Hf3Cu8 structure type in orthorhombic space group Pnma with unit cell edges of a=8.1143(5) Å, b=8.8466(5) Å, and c=10.6069(6) Å. Hf9Fe4-xSn10+x, on the other hand, adopts a new structure type in Cmc21 with unit cell edges of a=5.6458(3) Å, b=35.796(2) Å, and c=8.88725(9) Å for x=0. It exhibits a small amount of phase width in which Sn substitutes on one of the Fe sites. Both structures are fully three-dimensional and are characterized by pseudo one- and two-dimensional networks of Fe-Fe homoatomic bonding. Hf9Fe4-xSn10+x exhibits antiferromagnetic order at TN=46(2) K and its electrical transport behavior indicates that it is a normal metal with phonon-dictated resistivity. Hf3Fe4Sn4 is also an antiferromagnet with a rather high ordering temperature of TN=373(5) K. Single crystal resistivity measurements indicate that Hf3Fe4Sn4 behaves as a Fermi liquid at low temperatures, indicating strong electron correlation.

  7. First-principles study of electronic properties of La2Hf2O7 and Gd2Hf2O7

    SciTech Connect

    Li, Ni; Xiao, H. Y.; Zu, Xiaotao T.; Wang, Lumin M.; Ewing, R. C.; Lian, Jie; Gao, Fei

    2007-09-15

    The structural and electronic properties of A2Hf2O7 (A=La and Gd) pyrochlore compounds are investigated by means of first-principles total energy calculations. Also, the formation energies of defects are calculated, and the results can be used to explain the stability of pyrochlores. Hybridizations between A 5p and O 2s and between A 5d and O 2p states are observed, but the interaction between A 5p and O 2s orbitals is much stronger in Gd2Hf2O7 than that in La2Hf2O7. Gd2Hf2O7 compound shows much different density of state distribution from that of La2Hf2O7. Mulliken overlap population analysis shows that the A-O48f and A-O8b bonds in Gd2Hf2O7 are more ionic than the corresponding bonds in La2Hf2O7, while the Hf-O48f bond in Gd2Hf2O7 is more covalent. These calculations suggest that A-O48f and A-O8b bonds may play important roles in their responses to irradiation-induced amorphization observed experimentally.

  8. Effect of substitutional carbon-doping in BNNTs on HF adsorption: DFT study

    NASA Astrophysics Data System (ADS)

    Kaur, Jasleen; Singhal, Sonal; Goel, Neetu

    2014-11-01

    We employed density functional calculations to investigate the adsorption behavior of HF gas on the side walls of pure and carbon-doped boron nitride nanotubes (BNNTs). The HF adsorption over the pure BNNT opens a door for its functionalization without causing significant changes in its electronic properties. The substitutional doping of carbon atom on the BNNT considerably enhances its affinity towards HF where the effect of the dopant concentration plays a vital role. The change in electronic properties of the doped BNNT on HF adsorption is significant enough to consider it a potential sensor for HF detection.

  9. Charge storage characteristics and tunneling mechanism of amorphous Ge-doped HfOx films

    NASA Astrophysics Data System (ADS)

    Qiu, X. Y.; Zhang, S. Y.; Zhang, T.; Wang, R. X.; Li, L. T.; Zhang, Y.; Dai, J. Y.

    2016-09-01

    Amorphous Ge-doped HfOx films have been deposited on p-Si(100) substrates by means of RF magnetron sputtering. Microstructural investigations reveal the partial oxidation of doped Ge atoms in the amorphous HfOx matrix and the existence of HfSiOx interfacial layer. Capacitance-voltage hysteresis of the Ag-/Ge-doped HfOx/Si/Ag memory capacitor exhibits a memory window of 3.15 V which can maintain for >5 × 104 cycles. Current-voltage characteristics reveal that Poole-Frenkel tunneling is responsible for electron transport in the Ge-doped HfOx film.

  10. Cardiorenal Syndrome in Acute Heart Failure: Revisiting Paradigms.

    PubMed

    Núñez, Julio; Miñana, Gema; Santas, Enrique; Bertomeu-González, Vicente

    2015-05-01

    Cardiorenal syndrome has been defined as the simultaneous dysfunction of both the heart and the kidney. Worsening renal function that occurs in patients with acute heart failure has been classified as cardiorenal syndrome type 1. In this setting, worsening renal function is a common finding and is due to complex, multifactorial, and not fully understood processes involving hemodynamic (renal arterial hypoperfusion and renal venous congestion) and nonhemodynamic factors. Traditionally, worsening renal function has been associated with worse outcomes, but recent findings have revealed mixed and heterogeneous results, perhaps suggesting that the same phenotype represents a diversity of pathophysiological and clinical situations. Interpreting the magnitude and chronology of renal changes together with baseline renal function, fluid overload status, and clinical response to therapy might help clinicians to unravel the clinical meaning of renal function changes that occur during an episode of heart failure decompensation. In this article, we critically review the contemporary evidence on the pathophysiology and clinical aspects of worsening renal function in acute heart failure. PMID:25758162

  11. Acute Pancreatitis

    PubMed Central

    Geokas, Michael C.

    1972-01-01

    For many decades two types of acute pancreatitis have been recognized: the edematous or interstitial and the hemorrhagic or necrotic. In most cases acute pancreatitis is associated with alcoholism or biliary tract disease. Elevated serum or urinary α-amylase is the most important finding in diagnosis. The presence of methemalbumin in serum and in peritoneal or pleural fluid supports the diagnosis of the hemorrhagic form of the disease in patients with a history and enzyme studies suggestive of pancreatitis. There is no characteristic clinical picture in acute pancreatitis, and its complications are legion. Pancreatic pseudocyst is probably the most common and pancreatic abscess is the most serious complication. The pathogenetic principle is autodigestion, but the precise sequence of biochemical events is unclear, especially the mode of trypsinogen activation and the role of lysosomal hydrolases. A host of metabolic derangements have been identified in acute pancreatitis, involving lipid, glucose, calcium and magnesium metabolism and changes of the blood clotting mechanism, to name but a few. Medical treatment includes intestinal decompression, analgesics, correction of hypovolemia and other supportive and protective measures. Surgical exploration is advisable in selected cases, when the diagnosis is in doubt, and is considered imperative in the presence of certain complications, especially pancreatic abscess. PMID:4559467

  12. Emerging Therapies for Acute and Chronic Heart Failure: Hope or Hype?

    PubMed

    Hanigan, Sarah; DiDomenico, Robert J

    2016-02-01

    Although the period from 1953 to 2001 resulted in the approval of more than 30 medications currently used to treat heart failure (HF), few novel drugs have been approved in the last decade. However, the investigational pipeline for HF medications once again appears promising. In patients with chronic heart failure with reduced ejection fraction (HFrEF), ivabradine and valsartan/sucubitril (LCZ696) were recently approved by the US Food and Drug Administration. Both agents have been shown to reduce the risk of cardiovascular death and HF hospitalization. In the treatment of acute HF, serelaxin and ularitide are the farthest along in development. Both agents have demonstrated favorable effects on surrogate end points and preliminary data suggest a possible mortality benefit with serelaxin. Consequently, phase 3 trials are ongoing to evaluate the effect of serelaxin and ularitide on clinical outcomes. Given the poor history of recent investigational acute HF drugs that have advanced to phase 3/4 studies, enthusiasm for both serelaxin and ularitide must be tempered until these trials are completed. PMID:26759311

  13. Heart Failure in Post-Acute and Long-Term Care: Evidence and Strategies to Improve Transitions, Clinical Care, and Quality of Life.

    PubMed

    Nazir, Arif; Smucker, William D

    2015-10-01

    Heart failure (HF) is highly prevalent among older patients in skilled nursing facilities (SNFs). HF outcomes for SNF patients suffer because of many factors, including staff training, lack of physician availability, and failure to implement evidence-based care. AMDA - The Society for Post-Acute and Long-Term Care Medicine has recently updated the Clinical Practice Guidelines for Heart Failure Management in SNFs. This review supplements the Guidelines with a robust focus on best practices for transitional care, symptom management, treatment and monitoring, and palliative care in patients with HF. PMID:26089116

  14. Review of nutritional screening and assessment tools and clinical outcomes in heart failure.

    PubMed

    Lin, Hong; Zhang, Haifeng; Lin, Zheng; Li, Xinli; Kong, Xiangqin; Sun, Gouzhen

    2016-09-01

    Recent studies have suggested that undernutrition as defined using multidimensional nutritional evaluation tools may affect clinical outcomes in heart failure (HF). The evidence supporting this correlation is unclear. Therefore, we conducted this systematic review to critically appraise the use of multidimensional evaluation tools in the prediction of clinical outcomes in HF. We performed descriptive analyses of all identified articles involving qualitative analyses. We used STATA to conduct meta-analyses when at least three studies that tested the same type of nutritional assessment or screening tools and used the same outcome were identified. Sensitivity analyses were conducted to validate our positive results. We identified 17 articles with qualitative analyses and 11 with quantitative analysis after comprehensive literature searching and screening. We determined that the prevalence of malnutrition is high in HF (range 16-90 %), particularly in advanced and acute decompensated HF (approximate range 75-90 %). Undernutrition as identified by multidimensional evaluation tools may be significantly associated with hospitalization, length of stay and complications and is particularly strongly associated with high mortality. The meta-analysis revealed that compared with other tools, Mini Nutritional Assessment (MNA) scores were the strongest predictors of mortality in HF [HR (4.32, 95 % CI 2.30-8.11)]. Our results remained reliable after conducting sensitivity analyses. The prevalence of malnutrition is high in HF, particularly in advanced and acute decompensated HF. Moreover, undernutrition as identified by multidimensional evaluation tools is significantly associated with unfavourable prognoses and high mortality in HF. PMID:26920682

  15. Role of Hf and Zr in the hydrogen embrittlement of Ta and Cb alloys

    NASA Technical Reports Server (NTRS)

    Stephens, J. R.

    1973-01-01

    Investigation of the hydrogen embrittlement of aged Ta alloy T-111 (Ta-8W-2Hf) and similar Ta and Cb alloys. It is found that aging ternary Ta alloys such as T-111 near 1040 C for 1000 hr or longer increases their sensitivity to low-temperature hydrogen embrittlement. Segregation of Hf to grain boundaries during aging causes embrittlement upon testing at -196 C and is responsible for the observed hydrogen embrittlement. Binary Ta and Cb alloys, Ta-2Hf and Cb-1Zr, are not susceptible to hydrogen embrittlement under the conditions of this study and did not exhibit grain boundary segregation of Hf or Zr. Ternary alloys Ta-8W-.5Hf, Ta-8W-1Hf, and Ta-4W-2Hf are superior to T-111 for containment of alkali metals in that they do not exhibit aging embrittlement. However, these alloys in the aged condition are susceptible to hydrogen embrittlement.

  16. Investigation of new type Cu-Hf-Al bulk glassy alloys

    NASA Astrophysics Data System (ADS)

    Nagy, E.; Rontó, V.; Sólyom, J.; Roósz, A.

    2009-01-01

    In the last years new type Cu-Hf-Al ternary alloys were developed with high glass forming ability and ductility. The addition of Al to Cu-Hf alloys results in improvements in glass formation, thermal stability and mechanical properties of these alloys. We have investigated new Cu-based bulk amorphous alloys in Cu-Hf-Al ternary system. The alloys with Cu49Hf42Al9, Cu46Hf45Al9, Cu50Hf42.5Al7.5 and Cu50Hf45Al5 compositions were prepared by arc melting. The samples were made by centrifugal casting and were investigated by X-ray diffraction method. Thermodynamic properties were examined by differential scanning calorimetry and the structure of the crystallising phases by scanning electron microscopy. The determination of liquidus temperatures of alloys were measured by differential thermal analysis.

  17. HF-LPLI-treated tumor cells induce NO production in macrophage

    NASA Astrophysics Data System (ADS)

    Lu, Cuixia; Zhou, Feifan; Wu, Shengnan; Xing, Da

    2013-02-01

    High fluence low-power laser irradiation (HF-LPLI) provides a new stimulator to trigger cell apoptosis, and it is well known that apoptotic cells provide antigens to effectively trigger recognition by the immune system. In order to investigate the effect of HF-LPLI on the professional antigen-presenting cell (APC) function, in our primary study, we focused our attention on the effect of HF-LPLI-treated tumor cells on macrophages phagocytosis and NO production. Both confocal microscopy and flowcytometry analysis showed that HF-LPLI (120 J/cm2) induced significantly EMT6 death. Further experiments showed that HF-LPLI-treated EMT6 cells could be phagocyted by the murine macrophage cells RAW264.7, and could induce NO production in macrophages. Taken together, our results indicate that HF-LPLI-treated tumor cells effectively regulated the immune system. The HF-LPLI effect on the APC function needs to be further studied.

  18. Precipitant profile of acute heart failure: experience of a tertiary level cardiac centre in Sri Lanka

    PubMed Central

    Matthias, Anne Thushara; Ekanayaka, Ruvan

    2013-01-01

    Introduction and objectives Heart failure (HF) is a common cause of hospitalisation in most countries. Data on acute precipitants of HF and hospitalisation is not available in Sri Lanka. Background and methods A prospective study of 100 sequential admissions with HF to the cardiology unit (National Hospital of Sri Lanka) to describe the precipitants and clinical outcome of HF. Results Fifty-eight male and 42 female admissions were studied. Mean age was 60.66 years. Mean hospital stay was 5.5(SD 4.6) days. Sixty had de novo HF and 40 had pre-existing HF. The most common identifiable precipitants were acute ischaemia 37 (37%), anaemia 41 (41%), respiratory tract infection 10 (10%), arrhythmia 11 (11%), worsening renal function 11 (11%) and alcohol 5 (5.7%). Non-adherence to medication 4 (4.6%), smoking 3 (3.9%), exposure to environmental stress 3 (3.4%) and uncontrolled hypertension 1 (1%) were also observed as precipitants. The most common arrhythmia was atrial fibrillation. Out of 34 patients in whom angiotensin-converting enzyme inhibitors or angiotensin-converting enzyme receptor blockers were indicated, 11% were not on the drug. Among 29 patients in whom spironolactone was indicated, seven patients were not on the drug. Conclusions Most precipitating factors of HF are preventable. Early identification and prevention of anaemia, preventing respiratory tract infection by vaccination, aggressive revascularisation for patients with ischaemia, monitoring of renal functions, and patient education regarding drug and diet compliance, would reduce the number of admissions. PMID:27326091

  19. The Future of HF-Interaction Experiments at EISCAT

    NASA Astrophysics Data System (ADS)

    Rietveld, M. T.

    2007-05-01

    The EISCAT HF facility, co-located with two incoherent scatter radars, has some of the best diagnostics available for doing research in plasma physics and actively probing the ionosphere, upper atmosphere and magnetosphere. The facility is presently undergoing some improvements which will keep it at the forefront of such research. Direct digital synthesis of the HF wave will allow fast changes of frequency and beam direction, and increased flexibility in pulsing. Some of the more important recent results are outlined, and the directions for further progress are suggested. These results include the effect of electron heating on the charging of mesospheric dust which changes the strength of VHF radar echoes from the polar summer mesosphere. Other results involve Langmuir and thermal plasma instabilities from the F region which show a rich variety of dependences on pumping frequency and direction to the Earth's magnetic field. Some of the geometrical effects observed in plasma line observations and artificial optical emissions remain largely unexplained.

  20. Crossbar Nanoscale HfO2-Based Electronic Synapses.

    PubMed

    Matveyev, Yury; Kirtaev, Roman; Fetisova, Alena; Zakharchenko, Sergey; Negrov, Dmitry; Zenkevich, Andrey

    2016-12-01

    Crossbar resistive switching devices down to 40 × 40 nm(2) in size comprising 3-nm-thick HfO2 layers are forming-free and exhibit up to 10(5) switching cycles. Four-nanometer-thick devices display the ability of gradual switching in both directions, thus emulating long-term potentiation/depression properties akin to biological synapses. Both forming-free and gradual switching properties are modeled in terms of oxygen vacancy generation in an ultrathin HfO2 layer. By applying the voltage pulses to the opposite electrodes of nanodevices with the shape emulating spikes in biological neurons, spike-timing-dependent plasticity functionality is demonstrated. Thus, the fabricated memristors in crossbar geometry are promising candidates for hardware implementation of hybrid CMOS-neuron/memristor-synapse neural networks. PMID:26979725

  1. Field emission from single-crystalline HfC nanowires

    SciTech Connect

    Yuan, Jinshi; Tang, Jie; Zhang Han; Shinya, Norio; Nakajima, Kiyomi; Qin, Lu-Chang

    2012-03-12

    Single HfC nanowire field emitter/electrode structures have been fabricated using nano-assembling and electron beam induced deposition. Field ion microscopy has been applied to study the atomic arrangement of facets formed on a field evaporation-modified HfC nanowire tip. Field evaporation and crystal form studies suggest that the {l_brace}111{r_brace} and {l_brace}110{r_brace} crystal planes have lower work functions, while the {l_brace}100{r_brace}, {l_brace}210{r_brace}, and {l_brace}311{r_brace} planes have higher work functions. Field emission measurement permits us to obtain that the work function of the {l_brace}111{r_brace} crystal plane is about 3.4 eV.

  2. Oblique sounding of an auroral ionospheric HF channel

    NASA Astrophysics Data System (ADS)

    Lundborg, Bengt; Broems, Mats; Derblom, Harald

    1995-01-01

    Observations of the HF skywave ionospheric channel during one year over three paths within Sweden are reported. The major aim of the work was to gain insight into prevailing propagation effects on representative fixed circuit paths at auroral latitudes, with a view to being able to assess prediction accuracies, and to exploite abnormal propagation modes so improving circuit reliabilities. The main instruments in the study were chirpsounders, HF FM-CW sounders covering the frequency range from 2 to 30 MHz. A data base of about 250,000 recordings was built up during the campaign, which covers the maximum of solar cylce 22. Some measurements were made with transmissions on fixed frequencies, mostly greater than 20 MHz.

  3. Closed cycle high-repetition-rate pulsed HF laser

    NASA Astrophysics Data System (ADS)

    Harris, Michael R.; Morris, A. V.; Gorton, Eric K.

    1997-04-01

    The design and performance of a closed cycle high repetition rate HF laser is described. A short pulse, glow discharge is formed in a 10 SF6:1 H2 gas mixture at a total pressure of approximately 110 torr within a 15 by 0.5 by 0.5 cm3 volume. Transverse, recirculated gas flow adequate to enable repetitive operation up to 3 kHz is imposed by a centrifugal fan. The fan also forces the gas through a scrubber cell to eliminate ground state HF from the gas stream. An automated gas make-up system replenishes spent gas removed by the scrubber. Typical mean laser output powers up to 3 W can be maintained for extended periods of operation.

  4. Crossbar Nanoscale HfO2-Based Electronic Synapses

    NASA Astrophysics Data System (ADS)

    Matveyev, Yury; Kirtaev, Roman; Fetisova, Alena; Zakharchenko, Sergey; Negrov, Dmitry; Zenkevich, Andrey

    2016-03-01

    Crossbar resistive switching devices down to 40 × 40 nm2 in size comprising 3-nm-thick HfO2 layers are forming-free and exhibit up to 105 switching cycles. Four-nanometer-thick devices display the ability of gradual switching in both directions, thus emulating long-term potentiation/depression properties akin to biological synapses. Both forming-free and gradual switching properties are modeled in terms of oxygen vacancy generation in an ultrathin HfO2 layer. By applying the voltage pulses to the opposite electrodes of nanodevices with the shape emulating spikes in biological neurons, spike-timing-dependent plasticity functionality is demonstrated. Thus, the fabricated memristors in crossbar geometry are promising candidates for hardware implementation of hybrid CMOS-neuron/memristor-synapse neural networks.

  5. CMS HF calorimeter PMTs and Xi(c)+ lifetime measurement

    SciTech Connect

    Akgun, Ugur; /Iowa U.

    2003-12-01

    This thesis consists of two parts: In the first part we describe the Photomultiplier Tube (PMT) selection and testing processes for the Hadronic Forward (HF) calorimeter of the CMS, a Large Hadron Collier (LHC) experiment at CERN. We report the evaluation process of the candidate PMTs from three different manufacturers, the complete tests performed on the 2300 Hamamatsu PMTs which will be used in the HF calorimeter, and the details of the PMT Test Station that is in University of Iowa CMS Laboratories. In the second part we report the {Xi}{sub c}{sup +} lifetime measurement from SELEX, the charm hadro-production experiment at Fermilab. Based upon 301 {+-} 31 events from three di.erent decay channels, by using the binned maximum likelihood technique, we observe the lifetime of {Xi}{sub c}{sup +} as 427 {+-} 31 {+-} 13 fs.

  6. Dislocation structures in Ni{sub 3}(Al,Hf)

    SciTech Connect

    Kruml, T.; Viguier, B.; Bonneville, J.; Martin, J.L.; Spaetig, P.

    1997-12-31

    Single crystalline specimens of Ni{sub 74.8}Al{sub 21.9}Hf{sub 3.3} were subjected to compression tests at different temperatures. Thin foils for transmission electron microscopy observations were prepared from several specimens deformed within and above the yield stress anomaly domain. The dislocation microstructure was studied. The weak beam imaging and image simulation techniques followed by anisotropic elasticity calculations were used for the determination of antiphase boundary energies in both cube and octahedral planes, resulting in values of 237 mJm{sup {minus}2} and 252 mJm{sup {minus}2} respectively. The comparison of the present results with data taken from literature shows the influence of Hf on mechanical properties, dislocation microstructures and APB energies.

  7. HF Doppler observations of acoustic waves excited by the earthquake

    NASA Technical Reports Server (NTRS)

    Ichinose, T.; Takagi, K.; Tanaka, T.; Okuzawa, T.; Shibata, T.; Sato, Y.; Nagasawa, C.; Ogawa, T.

    1985-01-01

    Ionospheric disturbances caused by the earthquake of a relatively small and large epicentral distance have been detected by a network of HF-Doppler sounders in central Japan and Kyoto station, respectively. The HF-Doppler data of a small epicentral distance, together with the seismic data, have been used to formulate a mechanism whereby ionospheric disturbances are produced by the Urakawa-Oki earthquake in Japan. Comparison of the dynamic spectra of these data has revealed experimentally that the atmosphere acts as a low-pass filter for upward-propagating acoustic waves. By surveying the earthquakes for which the magnitude M is larger than 6.0, researchers found the ionospheric effect in 16 cases of 82 seismic events. As almost all these effects have occurred in the daytime, it is considered that it may result from the filtering effect of the upward-propagating acoustic waves.

  8. Growth, microstructure and electrical properties of sputter-deposited hafnium oxide (HfO2) thin films grown using HfO2 ceramic target

    SciTech Connect

    Aguirre, B.; Vemuri, R. S.; Zubia, David; Engelhard, Mark H.; Shutthanandan, V.; Kamala Bharathi, K.; Ramana, Chintalapalle V.

    2011-01-01

    Hafnium oxide (HfO₂) thin films have been made by radio-frequency (rf) magnetron-sputtering onto Si(100) substrates under varying growth temperature (Ts). HfO₂ ceramic target has been employed for sputtering while varying the Ts from room temperature to 500⁰C during deposition. The effect of Ts on the growth and microstructure of deposited HfO₂ films has been studied using grazing incidence x-ray diffraction (GIXRD), X-ray photoelectron spectroscopy (XPS), and high-resolution scanning electron microscopy (HR-SEM) coupled with energy dispersive x-ray spectrometry (EDS). The results indicate that the effect of Ts is significant on the growth, surface and interface structure, morphology and chemical composition of the HfO₂ films. Structural characterization indicates that the HfO₂ films grown at Ts<200 ⁰C are amorphous while films grown at Ts>200 ⁰C are nanocrystalline. An amorphous-to-crystalline transition occurs at Ts=200 ⁰C. Nanocrystalline HfO₂ films crystallized in a monoclinic structure with a (-111) orientation. XPS measurements indicated the high surface-chemical quality and stoichiometric nature of the grown HfO₂ films. An interface layer (IL) formation occurs due to reaction at the HfO₂-Si interface for HfO₂ films deposited at Ts>200 ⁰C. The thickness of IL increases with increasing Ts. XPS and EDS at the HfO₂-Si cross-section indicate the IL is a (Hf, Si)-O compound. The electrical characterization using capacitance-voltage measurements indicate that the dielectric constant decreases from 25 to 16 with increasing Ts.

  9. Development of an obstetric vital sign alert to improve outcomes in acute care obstetrics.

    PubMed

    Behling, Diana J; Renaud, Michelle

    2015-01-01

    Maternal morbidity and mortality is a national health problem. Causal analysis of near-miss and actual serious patient safety events, including those resulting in maternal death, within obstetric units often highlights a failure to promptly recognize and treat women who were exhibiting signs of decompensation/deterioration. The Obstetric Vital Sign Alert (OBVSA) is an early warning tool that leverages discrete data points in the electronic health record, calculating a risk score that is displayed as a visual cue for acute care obstetric staff. When studied in a cohort of women with postpartum hemorrhage, use of the OBVSA reduced symptom-to-response time and intervention time, as well as key process and outcome measures. PMID:25900584

  10. Solidification Effects in MAR-M246(Hf) Alloy

    NASA Technical Reports Server (NTRS)

    Johnston, M. H.; Parr, R. A.

    1987-01-01

    Fatigue properties degraded with crystallographic orientations greater than 10 degrees from {001} axis. Influence of solidification and heat-treatment parameters on structure and fatigue properties of nickel-based superalloy MAR-M246(Hf) described in 24-page report. Superalloys have high strength and corrosion resistance at temperatures up to 1,400 degrees C; their uses range from petrochemical equipment to marine, industrial, aircraft, and vehicular gas turbines.

  11. Hf dopants in γ'-Ni3Al alloy

    NASA Astrophysics Data System (ADS)

    Ivanovski, V. N.; Cekić, B.; Umićević, A.; Belošević-Čavor, J.; Schumacher, G.; Koteski, V.; Barudzija, T.

    2013-08-01

    The Time Differential Perturbed Angular (TDPAC) measurements of nuclear quadrupole interactions (NQIs) at 181Ta ion probe in the polycrystalline intermetallic alloy γ'-Ni3Al doped with 0.2 at. % Hf were performed in the temperature range 78-1230 K, in order to determine the lattice location of Hf atoms in the ordered γ'-Ni3Al structure. The two NQIs obtained are discussed within the present L12 cubic structure and a tetragonal distortion of L12 to another two DO22 and L60 type structures. The first low frequency NQI at the site of the 181Ta ion-probe after substitution of aluminum for hafnium in DO22 at ambient temperature, is vQ1(300 K) = 39(1) MHz with η1 = 0. The corresponding high frequency value on the second crystallographic site in L60, is vQ2(300 K) = 204(14) MHz with η2 = 0.47(11). These two NQI's have different temperature behavior. The presence of both DO22 and L60 tetragonal distortions of the parent cubic L12 lattice, detected after adding 0.2 at. % Hf, are with modulations to the lattice constant (a) with a ratio (c/a), 2.04 and 0.87, respectively. Ab initio calculations of electronic and structural properties and hyperfine parameters at the 181Ta ion probe of the γ'-Ni3Al-0.2 at. % Hf alloy were performed using the full potential augmented plane wave plus local-orbital (APW+lo) method as implemented in the WIEN2k code. The accuracy of the calculations and comparison with the experimental results enabled us to identify the observed hyperfine interactions and to infer the EFG sign that cannot be measured in conventional TDPAC measurements.

  12. Beating HF waves to generate VLF waves in the ionosphere

    NASA Astrophysics Data System (ADS)

    Kuo, Spencer; Snyder, Arnold; Kossey, Paul; Chang, Chia-Lie; Labenski, John

    2012-03-01

    Beat-wave generation of very low frequency (VLF) waves by two HF heaters in the ionosphere is formulated theoretically and demonstrated experimentally. The heater-induced differential thermal pressure force and ponderomotive force, which dominate separately in the D and F regions of the ionosphere, drive an electron current for the VLF emission. A comparison, applying appropriate ionospheric parameters shows that the ponderomotive force dominates in beat-wave generation of VLF waves. Three experiments, one in the nighttime in the absence of D and E layers and two in the daytime in the presence of D and E layers, were performed. X mode HF heaters of slightly different frequencies were transmitted at CW full power. VLF waves at 10 frequencies ranging from 3.5 to 21.5 kHz were generated. The frequency dependencies of the daytime and nighttime radiation intensities are quite similar, but the nighttime radiation is much stronger than the daytime one at the same radiation frequency. The intensity ratio is as large as 9 dB at 11.5 kHz. An experiment directly comparing VLF waves generated by the beat-wave approach and by the amplitude modulation (AM) approach was also conducted. The results rule out the likely contribution of the AM mechanism acting on the electrojet and indicate that beat-wave in the VLF range prefers to be generated in the F region of the ionosphere through the ponderomotive nonlinearity, consistent with the theory. In the nighttime experiment, the ionosphere was underdense to the HF heaters, suggesting a likely setting for effective beat-wave generation of VLF waves by the HF heaters.

  13. Mapping high-latitude plasma convection with coherent HF radars

    NASA Technical Reports Server (NTRS)

    Ruohoniemi, J. M.; Greenwald, R. A.; Baker, K. B.; Villain, J.-P.; Hanuise, C.

    1989-01-01

    Several methods developed for mapping high-latitude plasma convection with a high-latitude HF radar are described, which utilize coherent backscatter from electron density irregularities at F-region altitudes to observe convective plasma motion. Several examples of two-dimensional convection-velocity maps are presented, showing instances of L-shell-aligned flow in the dusk sector, the reversal of convection near magnetic midnight, and counterstreaming in the dayside cleft.

  14. Ferroelectric HfO2 for Emerging Ferroelectric Semiconductor Devices

    NASA Astrophysics Data System (ADS)

    Florent, Karine

    The spontaneous polarization in ferroelectrics (FE) makes them particularly attractive for non-volatile memory and logic applications. Non-volatile FRAM memories using perovskite structure materials, such as Lead Zirconate Titanate (PZT) and Strontium Bismuth Tantalate (SBT) have been studied for many years. However, because of their scaling limit and incompatibility with CMOS beyond 130 nm node, floating gate Flash memory technology has been preferred for manufacturing. The recent discovery of ferroelectricity in doped HfO2 in 2011 has opened the door for new ferroelectric based devices compatible with CMOS technology, such as Ferroelectric Field Effect Transistor (FeFET) and Ferroelectric Tunnel Junctions (FTJ). This work began with developing ferroelectric hysteresis characterization capabilities at RIT. Initially reactively sputtered aluminum doped HfO 2 films were investigated. It was observed that the composition control using co-sputtering was not achievable within the existing capabilities. During the course of this study, collaboration was established with the NaMLab group in Germany to investigate Si doped HfO2 deposited by Atomic Layer Deposition (ALD). Metal Ferroelectric Metal (MFM) devices were fabricated using TiN as the top and bottom electrode with Si:HfO2 thickness ranging from 6.4 nm to 22.9 nm. The devices were electrically tested for P-E, C-V and I-V characteristics. Structural characterizations included TEM, EELS, XRR, XRD and XPS/Auger spectroscopy. Higher remanant polarization (Pr) was observed for films of 9.3 nm and 13.1 nm thickness. Thicker film (22.9 nm) showed smaller Pr. Devices with 6.4 nm thick films exhibit tunneling behavior showing a memristor like I-V characteristics. The tunnel current and ferroelectricity showed decrease with cycling indicating a possible change in either the structure or the domain configurations. Theoretical simulations using the improved FE model were carried out to model the ferroelectric behavior of

  15. Electrochemical characterization of cast Ti-Hf binary alloys.

    PubMed

    Cai, Z; Koike, M; Sato, H; Brezner, M; Guo, Q; Komatsu, M; Okuno, O; Okabe, T

    2005-05-01

    This study characterized the electrochemical behavior of Ti-Hf binary alloys in a simulated oral environment. Ti-Hf alloys (10, 20, 25, 30, 35 and 40 mass% Hf) were prepared by arc-melting titanium sponge and hafnium sponge. Specimens of each alloy (n = 4) were prepared using a dental titanium casting system with a MgO-based investment. Specimens were inspected with X-ray radiography to ensure minimal internal porosity. Castings (n = 4) made from pure titanium and commercially pure titanium were used as controls. The ground flat surface (10 mm x 10 mm) on each specimen where approximately 30 microm was removed was used for the characterization. Sixteen-hour open-circuit potential (OCP) measurement, linear polarization and potentiodynamic cathodic polarization were performed sequentially in aerated (air + 10% CO2) MTZ synthetic saliva at 37 degrees C. Potentiodynamic anodic polarization was conducted in the same medium but deaerated (N2 + 10% CO2) 2 h before and during testing. Polarization resistance (R(P)) and Tafel slopes were determined, as were corrosion current density (I(CORR)) and passive current density (I(PASS)). Results were subjected to nonparametric statistical analysis (alpha = 0.05). The OCP stabilized (mean values -229 mV to -470 mV vs. SCE) for all specimens after the 16-h immersion. Similar passivation was observed for all the metals on their anodic polarization diagrams. The Kruskal-Wallis test showed significant differences in OCP among the test groups (p = 0.006). No significant differences were found in R(P), I(CORR) or I(PASS) among all the metals (p>0.3). Results indicate that the electrochemical behavior of the Ti-Hf alloys examined resembles that of pure titanium. PMID:16701813

  16. A computer based ionospheric sounding and HF noise measuring system

    NASA Astrophysics Data System (ADS)

    Earl, G. F.

    1980-09-01

    A system for the automated collection of ionospheric backscatter sounding and HF noise measurement data is described. The system was configured around a PDP 11/40 minicomputer and modified Barry Research FMCW sounding equipment. The real time digital signal processing associated with the backscatter sounder and noise measurement systems is discussed. The data are displayed and recorded in a calibrated mode, and examples are presented.

  17. Doppler selection of HF radiosignals on long paths

    NASA Astrophysics Data System (ADS)

    Zalizovskii, A. V.; Galushko, V. G.; Kashcheev, A. S.; Koloskov, A. V.; Yampolski, Yu. M.; Egorov, I. B.; Popov, A. V.

    2007-10-01

    The long-term registration of the Doppler spectra of HF radiosignals has been performed on the Moscow-Akademik Vernadsky Ukrainian Antarctic station path. It has been revealed that the spectra are split when the solar terminator crosses direct and return radio lines. The spectral and energy characteristics of direct and return signals have been calculated within the scope of the asymptotic theory of long-range propagation of decametric radiowaves.

  18. Studies of wave phenomena using HF-induced scatter target

    NASA Astrophysics Data System (ADS)

    Blagoveshchenskaya, N.; Borisova, T.; Kornienko, V.; Rietveld, M.; Frolov, V.; Uryadov, V.; Kagan, L.; Yampolski, Y.; Vertogradov, G.; Kelley, M.

    Experimental results from Tromso and Sura heating experiments at high and mid-latitudes are examined It was shown that the combination of HF-induced target and bi-static HF Doppler radio scatter observations is a profitable method for the identification and studies of wave phenomena of different origin We analysed the ULF activity in the Pc 3-4 range and the medium-scale traveling ionospheric disturbances TIDs at high and mid-latitudes Bi-static HF Doppler radio scatter observations were carried out on the London-Tromso-St Petersburg path in the course of Tromso heating experiments During Sura heating experiments multi-position bi-static HF Doppler radio scatter observations were simultaneously performed at three reception points including St Petersburg Kharkov and Rostov-on-Don Ray tracing and Doppler shift simulations were made for all experiments Parameters of ULF waves were found The interesting feature detected from Sura heating experiment was the dependence of the ULF wave parameters from the effective radiated power of the heating facility Medium-scale TIDs were observed in the evening and pre-midnight hours TIDs in the auroral E region with periods of 20-25 min were traveling southward at speeds from 190-250 m s TIDs in the mid-latitudinal F region with periods from 15 to 45 min were at speeds between 40 and 120 m s During quiet magnetic conditions the waves were traveling in the north-east direction In disturbed conditions the waves were moving in the south-west direction with higher speeds as compared with quiet conditions Possible mechanisms

  19. Nonalcoholic Fatty Liver Disease Is Associated With Higher 1-year All-Cause Rehospitalization Rates in Patients Admitted for Acute Heart Failure.

    PubMed

    Valbusa, Filippo; Bonapace, Stefano; Grillo, Cristina; Scala, Luca; Chiampan, Andrea; Rossi, Andrea; Zoppini, Giacomo; Lonardo, Amedeo; Arcaro, Guido; Byrne, Christopher D; Targher, Giovanni

    2016-02-01

    Repeat hospitalization due to acute heart failure (HF) is a global public health problem that markedly impacts on health resource use. Identifying novel predictors of rehospitalization would help physicians to determine the optimal postdischarge plan for preventing HF rehospitalization. Nonalcoholic fatty liver disease (NAFLD) is an emerging risk factor for many heart diseases, including HF. We assessed whether NAFLD at hospital admission predicts 1-year all-cause rehospitalization in patients with acute HF. We enrolled all patients consecutively admitted for acute HF to our General Medicine Division, from January 2013 to April 2014, after excluding patients with acute myocardial infarction, severe heart valve diseases, malignancy, known liver diseases, and those with volume overload related to extracardiac causes. NAFLD was diagnosed by ultrasonography and exclusion of competing etiologies. The primary outcome of the study was the 1-year all-cause rehospitalization rate. Among the 107 patients enrolled in the study, the cumulative rehospitalization rate was 12.1% at 1 month, 25.2% at 3 months, 29.9% at 6 months, and 38.3% at 1 year. Patients with NAFLD had markedly higher 1-year rehospitalization rates than those without NAFLD (58% vs 21% at 1 y; P < 0.001 by the log-rank test). Cox regression analysis revealed that NAFLD was associated with a 5.5-fold increased risk of rehospitalization (adjusted hazard ratio 5.56, 95% confidence interval 2.46-12.1, P < 0.001) after adjustment for multiple HF risk factors and potential confounders. In conclusion, NAFLD was independently associated with higher 1-year rehospitalization in patients hospitalized for acute HF. PMID:26886619

  20. Nonalcoholic Fatty Liver Disease Is Associated With Higher 1-year All-Cause Rehospitalization Rates in Patients Admitted for Acute Heart Failure

    PubMed Central

    Valbusa, Filippo; Bonapace, Stefano; Grillo, Cristina; Scala, Luca; Chiampan, Andrea; Rossi, Andrea; Zoppini, Giacomo; Lonardo, Amedeo; Arcaro, Guido; Byrne, Christopher D.; Targher, Giovanni

    2016-01-01

    Abstract Repeat hospitalization due to acute heart failure (HF) is a global public health problem that markedly impacts on health resource use. Identifying novel predictors of rehospitalization would help physicians to determine the optimal postdischarge plan for preventing HF rehospitalization. Nonalcoholic fatty liver disease (NAFLD) is an emerging risk factor for many heart diseases, including HF. We assessed whether NAFLD at hospital admission predicts 1-year all-cause rehospitalization in patients with acute HF. We enrolled all patients consecutively admitted for acute HF to our General Medicine Division, from January 2013 to April 2014, after excluding patients with acute myocardial infarction, severe heart valve diseases, malignancy, known liver diseases, and those with volume overload related to extracardiac causes. NAFLD was diagnosed by ultrasonography and exclusion of competing etiologies. The primary outcome of the study was the 1-year all-cause rehospitalization rate. Among the 107 patients enrolled in the study, the cumulative rehospitalization rate was 12.1% at 1 month, 25.2% at 3 months, 29.9% at 6 months, and 38.3% at 1 year. Patients with NAFLD had markedly higher 1-year rehospitalization rates than those without NAFLD (58% vs 21% at 1 y; P < 0.001 by the log-rank test). Cox regression analysis revealed that NAFLD was associated with a 5.5-fold increased risk of rehospitalization (adjusted hazard ratio 5.56, 95% confidence interval 2.46–12.1, P < 0.001) after adjustment for multiple HF risk factors and potential confounders. In conclusion, NAFLD was independently associated with higher 1-year rehospitalization in patients hospitalized for acute HF. PMID:26886619

  1. Superconductivity in the noncentrosymmetric compound Re6Hf

    NASA Astrophysics Data System (ADS)

    Chen, Bin; Guo, Yang; Wang, Hangdong; Su, Qiping; Mao, Qianhui; Du, Jianhua; Zhou, Yuxing; Yang, Jinhu; Fang, Minghu

    2016-07-01

    Re6Hf , which crystallizes in α -Mn structure(space group I 4 ¯3 m ) without a spatial inversion center, is a superconductor with a superconducting transition temperature Tc≈6.2 K . The measurements of magnetic susceptibility (χ ), resistivity (ρ ), and specific heat capacity (C ) were carried out. Bulk superconductivity is revealed by the jump at Tc of the specific heat with Δ C /γnTc≈1.63 , suggesting moderate electron-electron coupling strength in this system. The upper critical field μ0Hc2 W H H(0 ) was estimated to be of 89 kOe, and μ0Hc2 G L(0 ) =107 kOe, which is close to the Pauli limiting field. The Ginzburg Landau parameter κG L=50.2 , indicates that Re6Hf is a type-II superconductor. The temperature dependence of the electronic specific heat Ce l(T ) in the superconducting state can be explained by BCS theory. Furthermore, the magnetic-field dependence of γ (H ) is found to be linear with respect to H . These results imply a dominant s -wave superconductivity in Re6Hf .

  2. HF channel modeling for real-time packet transmission

    NASA Astrophysics Data System (ADS)

    Rostami, Mehdi; Angeja, Joao; Tavares, Joao; Navarro, Antonio

    2003-07-01

    The recent rapid growth of multimedia communications has efficiently allowed delivering different services, formats and contents over an enormous variety of digital networks with IP acting as an integration protocol. The main objective of this research work is to evaluate the performance of an high frequency (HF) wireless network for transporting multimedia services according to UDP/IP protocol stack. Besides, allowing civil/amateur communications, HF bands are also used for long distance wireless military communications. Therefore, our work is based on NATO Link and Physical layer standards, STANAG 5066 and STANAG 4539, respectively. A typical transmission bandwidth is about 3 kHz resulting in a varying bit rate in the range between 75 and 12800 bps. This very low bit rate by itself imposes serious challenges for reliable real time multimedia communications. This paper discusses optimal combinations of channel coders, modulators and packet sizes in order to achieve the greatest throughput in function of the signal-to-noise ratio and HF channel conditions.

  3. Spectroscopic ellipsometry studies of HF treated Si (100) surfaces

    NASA Technical Reports Server (NTRS)

    Yao, Huade; Woollam, John A.; Alterovitz, Samuel A.

    1993-01-01

    Both ex situ and in situ spectroscopic ellipsometry (SE) measurements were employed to investigate the effects of HF cleaning on Si surfaces. The hydrogen-terminated (H-terminated) Si surface was modeled as an equivalent dielectric layer, and monitored in real time by SE measurements. The SE analyses indicate that after a 20-s 9:1 HF dip without rinse, the Si(100) surface was passivated by the hydrogen termination and remained chemically stable. Roughness of the HF-etched bare Si(100) surface was observed, in an ultrahigh vacuum (UHV) chamber, and analyzed by the in situ SE. Evidence for desorption of the H-terminated Si surface-layer, after being heated to approximately 550 C in the UHV chamber, is presented and discussed. This is the first use of an ex situ and in situ real-time, nondestructive technique capable of showing state of passivation, the rate of reoxidation, and the surface roughness of the H-terminated Si surfaces.

  4. Spectroscopic ellipsometry studies of HF treated Si (100) surfaces

    NASA Technical Reports Server (NTRS)

    Yao, Huade; Woollam, John A.; Alterovitz, Samuel A.

    1993-01-01

    Both ex situ and in situ spectroscopic ellipsometry (SE) measurements were employed to investigate the effect of HF cleaning on Si surfaces. The hydrogen-terminated (H-terminated) Si surface was modeled as an equivalent dielectric layer, and monitored in real time by SE measurements. The SE analyses indicate that, after a 20-sec 9:1 HF dip without rinse, the Si (100) surface was passivated by the hydrogen termination and remained chemically stable. Roughness of the HF-etched bare Si (100) surface was observed, in an ultrahigh vacuum chamber (UHV), and analyzed by the in situ SE. Evidence for desorption of the H-terminated Si surface layer, after being heated to about 550 C in the UHV chamber, is presented and discussed. This is the first use of an ex situ and in situ real-time, nondestructive technique capable of showing state of passivation, the rate of reoxidation, and the surface roughness of the H-terminated Si surfaces.

  5. Oxidation behavior of FeAl+Hf,Zr,B

    NASA Technical Reports Server (NTRS)

    Smialek, James L.; Doychak, Joseph

    1988-01-01

    The oxidation behavior of Fe-40Al-1Hf, Fe-40Al-1Hf-0.4B, and Fe-40Al-0.1Zr-0.4B (at. percent) alloys was characterized after 900, 1000, and 100 C exposures. Isothermal tests revealed parabolic kinetics after a period of transitional theta-alumina scale growth. The parabolic growth rates for the subsequent alpha-alumina scales were about five times higher than those for NiAl+0.1Zr alloys. The isothermally grown scales showed a propensity toward massive scale spallation due to both extensive rumpling from growth stresses and to an inner layer of HfO2. Cyclic oxidation for 200 1-hr cycles produced little degradation at 900 or 1000 C, but caused significant spallation at 1100 C in the form of small segments of the outer scale. The major difference in the cyclic oxidation of the three FeAl alloys was increased initial spallation for FeAl+Zr,B. Although these FeAl alloys showed many similarities to NiAl alloys, they were generally less oxidation resistant. It is believed that this resulted from nonoptimal levels of dopants and larger thermal expansion mismatch stresses.

  6. The triggering of local substorm activity by HF SURA heater

    NASA Astrophysics Data System (ADS)

    Ruzhin, Yuri; Parrot, Michel; Kovalev, Victor; Plastinin, Yuri; Kuznetsov, Vladimir; Vladimir Frolov, S.

    The results of analysis of helio-geophisical conditions of experiments 2007-2012 on local modification of ionosphere by powerful HF radio waves of SURA facility are presented. All experiment were conducted at sector of local time of Harang discontinuity for most probable influence of powerful HF pumping during the heater functioning on activation of natural processes at subauroral ionosphere - magnetosphere region. The peculiarity of these experiments was that all of these were executed with use of operative frequency, which was higher than upper hybrid frequency for background plasma of F2-layer maximum. It was obtained that, at least, in two experiments the observed substorm activity in zone northern SURA heater could be stimulated by its functionment.In the present study the ray tracing analysis clearly shows that ionosphere density decreasing (from DEMETER and IONEX data) at higher than SURA latitudes can redirect and refocused transmitter beam power in northward structure away from the beam center by refraction. By this way we have chance to participate by means of radiated SURA HF power in subauroral and auroral processes It is shown that results of groundbased, International Space Station and satellite DEMETER measurements as in vicinity a SURA location and in magnetic conjugated region support the conclusion (output) about reasons and possibility of substorm localization by action of SURA heater. The possible mechanisms of the local substorm activation are discussed.

  7. Spectroscopic ellipsometry studies of HF treated Si (100) surfaces

    NASA Astrophysics Data System (ADS)

    Yao, Huade; Woollam, John A.; Alterovitz, Samuel A.

    1993-08-01

    Both ex situ and in situ spectroscopic ellipsometry (SE) measurements were employed to investigate the effects of HF cleaning on Si surfaces. The hydrogen-terminated (H-terminated) Si surface was modeled as an equivalent dielectric layer, and monitored in real time by SE measurements. The SE analyses indicate that after a 20-s 9:1 HF dip without rinse, the Si(100) surface was passivated by the hydrogen termination and remained chemically stable. Roughness of the HF-etched bare Si(100) surface was observed, in an ultrahigh vacuum (UHV) chamber, and analyzed by the in situ SE. Evidence for desorption of the H-terminated Si surface-layer, after being heated to approximately 550 C in the UHV chamber, is presented and discussed. This is the first use of an ex situ and in situ real-time, nondestructive technique capable of showing state of passivation, the rate of reoxidation, and the surface roughness of the H-terminated Si surfaces.

  8. Spectroscopic ellipsometry studies of HF treated Si (100) surfaces

    NASA Astrophysics Data System (ADS)

    Yao, Huade; Woollam, John A.; Alterovitz, Samuel A.

    1993-06-01

    Both ex situ and in situ spectroscopic ellipsometry (SE) measurements were employed to investigate the effect of HF cleaning on Si surfaces. The hydrogen-terminated (H-terminated) Si surface was modeled as an equivalent dielectric layer, and monitored in real time by SE measurements. The SE analyses indicate that, after a 20-sec 9:1 HF dip without rinse, the Si (100) surface was passivated by the hydrogen termination and remained chemically stable. Roughness of the HF-etched bare Si (100) surface was observed, in an ultrahigh vacuum chamber (UHV), and analyzed by the in situ SE. Evidence for desorption of the H-terminated Si surface layer, after being heated to about 550 C in the UHV chamber, is presented and discussed. This is the first use of an ex situ and in situ real-time, nondestructive technique capable of showing state of passivation, the rate of reoxidation, and the surface roughness of the H-terminated Si surfaces.

  9. National Patterns of Risk-Standardized Mortality and Readmission for Acute Myocardial Infarction and Heart Failure: Update on Publicly Reported Outcomes Measures Based on the 2010 Release

    PubMed Central

    Bernheim, Susannah M.; Grady, Jacqueline N.; Lin, Zhenqiu; Wang, Yun; Wang, Yongfei; Savage, Shantal V.; Bhat, Kanchana R.; Ross, Joseph S.; Desai, Mayur M.; Merrill, Angela R.; Han, Lein F.; Rapp, Michael T.; Drye, Elizabeth E.; Normand, Sharon-Lise T.; Krumholz, Harlan M.

    2011-01-01

    Background Patient outcomes provide a critical perspective on quality of care. The Centers for Medicare and Medicaid Services (CMS) is publicly-reporting 30-day risk-standardized mortality rates (RSMRs) and risk-standardized readmission rates (RSRRs) for patients hospitalized with acute myocardial infarction (AMI) and heart failure (HF). We provide a national perspective on hospital performance for the 2010 release of these measures. Methods and Results The RSMRs and RSRRs are calculated from Medicare claims data for fee-for-service Medicare beneficiaries, 65 years or older, hospitalized with AMI or HF between July 1, 2006 and June 30, 2009. The rates are calculated using hierarchical logistic modeling to account for patient clustering, and are risk-adjusted for age, sex and patient comorbidities. The median RSMR for AMI was 16.0% and for HF was 10.8%. Both measures had a wide range of hospital performance with an absolute 5.2% difference between hospitals in the 5th versus 95th percentile for AMI and 5.0% for HF. The median RSRR for AMI was 19.9%, and for HF was 24.5% (3.9% range for 5–95th percentile for AMI, 6.7% for HF). Distinct regional patterns were evident for both measures and both conditions. Conclusions High RSRRs persist for AMI and HF and clinically meaningful variation exists for RSMRs and RSRRs for both conditions. Our results suggest continued opportunities for improvement in patient outcomes for HF and AMI. PMID:20736442

  10. Levosimendan vs. dobutamine: outcomes for acute heart failure patients on β-blockers in SURVIVE†

    PubMed Central

    Mebazaa, Alexandre; Nieminen, Markku S.; Filippatos, Gerasimos S.; Cleland, John G.; Salon, Jeffrey E.; Thakkar, Roopal; Padley, Robert J.; Huang, Bidan; Cohen-Solal, Alain

    2009-01-01

    Aims Many chronic heart failure (CHF) patients take β-blockers. When such patients are hospitalized for decompensation, it remains unclear how ongoing β-blocker treatment will affect outcomes of acute inotrope therapy. We aimed to assess outcomes of SURVIVE patients who were on β-blocker therapy before receiving a single intravenous infusion of levosimendan or dobutamine. Methods and results Cox proportional hazard regression revealed all-cause mortality benefits of levosimendan treatment over dobutamine when the SURVIVE population was stratified according to baseline presence/absence of CHF history and use/non-use of β-blocker treatment at baseline. All-cause mortality was lower in the CHF/levosimendan group than in the CHF/dobutamine group, showing treatment differences by hazard ratio (HR) at days 5 (3.4 vs. 5.8%; HR, 0.58, CI 0.33–1.01, P = 0.05) and 14 (7.0 vs. 10.3%; HR, 0.67, CI 0.45–0.99, P = 0.045). For patients who used β-blockers (n = 669), mortality was significantly lower for levosimendan than dobutamine at day 5 (1.5 vs. 5.1% deaths; HR, 0.29; CI 0.11–0.78, P = 0.01). Conclusion Levosimendan may be better than dobutamine for treating patients with a history of CHF or those on β-blocker therapy when they are hospitalized with acute decompensations. These findings are preliminary but important for planning future studies. PMID:19158152

  11. Lu-Hf and PbSL geochronology of apatites from Proterozoic terranes: A first look at Lu-Hf isotopic closure in metamorphic apatite

    NASA Astrophysics Data System (ADS)

    Barfod, Gry Hoffmann; Krogstad, Eirik Jens; Frei, Robert; Albarède, Francis

    2005-04-01

    The mineral apatite is characterized by elevated and highly variable Lu/Hf ratios that, in some cases, allow for single-crystal dating by the Lu-Hf isotopic system. Apatites from the Adirondack Lowlands and Otter Lake area in the Grenville Province, and from the Black Hills, South Dakota, yield Lu-Hf ages that are consistently older than their respective Pb step leaching ages. Isotopic closure for the Lu-Hf system, therefore, occurs before U-Pb system closure in this mineral. In the Adirondack Lowlands, where H 2O activity was low, Lu-Hf systematics of cm-sized apatite crystals remained undisturbed during upper amphibolite facies metamorphism (˜700 to 675 °C) at 1170-1130 Ma. The relatively old Lu-Hf ages of 1270 and 1230 Ma observed for these apatites correlate with decreasing crystal size. In contrast, apatite from the fluid-rich Otter Lake area and Black Hills yields unrealistically low apparent Lu-Hf closure temperatures, implying that in these apatites, fluids facilitated late exchange. The Lu-Hf ages for the metamorphic apatites were thus controlled either by the prevailing temperature and grain size, or by fluid activity.

  12. Anion Exchange Behavior Of Ti, Zr, Hf, Nb And Ta As Homologues Of Rf And Db In Mixed HF--Acetone Solutions

    SciTech Connect

    Aksenov, N. V.; Bozhikov, G. A.; Starodub, G. Ya.; Dmitriev, S. N.; Filosofov, D. V.; Sun Jin, Jon; Radchenko, V. I.; Lebedev, N. A.; Novgorodov, A. F.

    2010-04-30

    We studied in detail the sorption behavior of Ti, Zr, Hf, Nb and Ta on AG 1 anion exchange resin in HF-acetone mixed solutions as a function of organic cosolvent and acid concentrations. Anion exchange behavior was found to be strongly acetone concentration dependent. The distribution coefficients of Ti, Zr, Hf and Nb increased and those of Ta decreased with increasing content of acetone in HF solutions. With increasing HF concentration anion exchange equilibrium analysis indicated the formation of fluoride complexes of group 4 elements with charge-3 and Ta---2. For Nb the slope of-2 increased up to-5. Optimal conditions for separation of the elements using AIX chromatography were found. Group 4 elements formed MF{sub 7}{sup 3-} (M = Ti, Zr, Hf) complexes whose sorption decreased Ti>Hf>Zr in reverse order of complex stability. This fact is of particular interest for studying ion exchange behavior of Rf compared to Ti. The advantages of studying chemical properties of Rf and Db in aqueous HF solutions mixed with organic solvents are briefly discussed.

  13. Cardiac Failure 30 Years after Treatment Containing Anthracycline for Childhood Acute Lymphoblastic Leukemia

    PubMed Central

    Goldberg, John M.; Scully, Rebecca E.; Sallan, Stephen E.; Lipshultz, Steven E.

    2012-01-01

    In 1977, a 5-year-old girl diagnosed with acute lymphoblastic leukemia (ALL) was treated on DFCI Childhood ALL Protocol 77-01, receiving a cumulative doxorubicin dose of 465 mg/m2, cranial radiation, and other drugs. After being in continuous complete remission for 34 months, she developed heart failure (HF) and was treated with digoxin and furosemide. At 16, she was diagnosed and treated for dilated cardiomyopathy. Over the years she continued to have bouts of HF, which became less responsive to treatment. At 36, she received a heart transplant. Six months later, she stopped taking her medications and suffered a sudden cardiac death. PMID:22584777

  14. Acute and Chronic Fetal Anemia as a Result of Fetomaternal Hemorrhage

    PubMed Central

    Swanson, Tara

    2014-01-01

    Introduction. Fetomaternal hemorrhage represents a transfer of fetal blood to the maternal circulation. Although many etiologies have been described, most causes of fetomaternal hemorrhage remain unidentified. The differentiation between acute and chronic fetomaternal hemorrhage may be accomplished antenatally and may influence perinatal management. Case. A 36-year-old gravida 6 para 3 presented at 37 and 5/7 completed gestational weeks with ultrasound findings suggestive of chronic fetal anemia such as right ventricular enlargement, diminished cerebral vascular resistance, and elevated middle cerebral artery end-diastolic velocity. On the other hand, signs of acute fetal decompensation such as deterioration of the fetal heart tracing, diminished biophysical score, decreased cord pH, and increased cord base deficit were noted. Following delivery, the neonate's initial hemoglobin was 4.0 g/dL and the maternal KB ratio was 0.015 indicative of a significant fetomaternal hemorrhage. Discussion. One should consider FMH as part of the differential diagnosis for fetal or immediate neonatal anemia. We describe a unique case of FMH that demonstrated both acute and chronic clinical features. It is our hope that this case will assist practitioners in differentiating acute FMH that may require emergent delivery from chronic FMH which may be able to be expectantly managed. PMID:24804127

  15. Risk-adapted management of acute pulmonary embolism: recent evidence, new guidelines.

    PubMed

    Käberich, Anja; Wärntges, Simone; Konstantinides, Stavros

    2014-10-01

    Venous thromboembolism (VTE), the third most frequent acute cardiovascular syndrome, may cause life-threatening complications and imposes a substantial socio-economic burden. During the past years, several landmark trials paved the way towards novel strategies in acute and long-term management of patients with acute pulmonary embolism (PE). Risk stratification is increasingly recognized as a cornerstone for an adequate diagnostic and therapeutic management of the highly heterogeneous population of patients with acute PE. Recently published European Guidelines emphasize the importance of clinical prediction rules in combination with imaging procedures (assessment of right ventricular function) and laboratory biomarkers (indicative of myocardial stress or injury) for identification of normotensive PE patients at intermediate risk for an adverse short-term outcome. In this patient group, systemic full-dose thrombolysis was associated with a significantly increased risk of intracranial bleeding, a complication which discourages its clinical application unless hemodynamic decompensation occurs. A large-scale clinical trial program evaluating new oral anticoagulants in the initial and long-term treatment of venous thromboembolism showed at least comparable efficacy and presumably increased safety of these drugs compared to the current standard treatment. Research is continuing on catheter-directed, ultrasound-assisted, local, low-dose thrombolysis in the management of intermediate-risk PE. PMID:25386356

  16. Risk-Adapted Management of Acute Pulmonary Embolism: Recent Evidence, New Guidelines

    PubMed Central

    Käberich, Anja; Wärntges, Simone; Konstantinides, Stavros

    2014-01-01

    Venous thromboembolism (VTE), the third most frequent acute cardiovascular syndrome, may cause life-threatening complications and imposes a substantial socio-economic burden. During the past years, several landmark trials paved the way towards novel strategies in acute and long-term management of patients with acute pulmonary embolism (PE). Risk stratification is increasingly recognized as a cornerstone for an adequate diagnostic and therapeutic management of the highly heterogeneous population of patients with acute PE. Recently published European Guidelines emphasize the importance of clinical prediction rules in combination with imaging procedures (assessment of right ventricular function) and laboratory biomarkers (indicative of myocardial stress or injury) for identification of normotensive PE patients at intermediate risk for an adverse short-term outcome. In this patient group, systemic full-dose thrombolysis was associated with a significantly increased risk of intracranial bleeding, a complication which discourages its clinical application unless hemodynamic decompensation occurs. A large-scale clinical trial program evaluating new oral anticoagulants in the initial and long-term treatment of venous thromboembolism showed at least comparable efficacy and presumably increased safety of these drugs compared to the current standard treatment. Research is continuing on catheter-directed, ultrasound-assisted, local, low-dose thrombolysis in the management of intermediate-risk PE. PMID:25386356

  17. Acute diarrhea.

    PubMed

    Barr, Wendy; Smith, Andrew

    2014-02-01

    Acute diarrhea in adults is a common problem encountered by family physicians. The most common etiology is viral gastroenteritis, a self-limited disease. Increases in travel, comorbidities, and foodborne illness lead to more bacteria-related cases of acute diarrhea. A history and physical examination evaluating for risk factors and signs of inflammatory diarrhea and/or severe dehydration can direct any needed testing and treatment. Most patients do not require laboratory workup, and routine stool cultures are not recommended. Treatment focuses on preventing and treating dehydration. Diagnostic investigation should be reserved for patients with severe dehydration or illness, persistent fever, bloody stool, or immunosuppression, and for cases of suspected nosocomial infection or outbreak. Oral rehydration therapy with early refeeding is the preferred treatment for dehydration. Antimotility agents should be avoided in patients with bloody diarrhea, but loperamide/simethicone may improve symptoms in patients with watery diarrhea. Probiotic use may shorten the duration of illness. When used appropriately, antibiotics are effective in the treatment of shigellosis, campylobacteriosis, Clostridium difficile, traveler's diarrhea, and protozoal infections. Prevention of acute diarrhea is promoted through adequate hand washing, safe food preparation, access to clean water, and vaccinations. PMID:24506120

  18. Sinusitis (acute)

    PubMed Central

    2008-01-01

    Introduction Acute sinusitis is defined pathologically, by transient inflammation of the mucosal lining of the paranasal sinuses lasting less than 4 weeks. Clinically, it is characterised by nasal congestion, rhinorrhoea, facial pain, hyposmia, sneezing, and, if more severe, additional malaise and fever. It affects 1−5% of the adult population each year in Europe. Methods and outcomes We conducted a systematic review and aimed to answer the following clinical questions: What are the effects of treatments in people with clinically diagnosed acute sinusitis, and with radiologically or bacteriologically confirmed acute sinusitis? We searched: Medline, Embase, The Cochrane Library and other important databases up to August 2007 (BMJ Clinical Evidence reviews are updated periodically; please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA). Results We found 19 systematic reviews, RCTs, or observational studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions. Conclusions In this systematic review we present information relating to the effectiveness and safety of the following interventions: antibiotics (amoxicillin, co-amoxiclav, doxycycline, cephalosporins, macrolides, different doses [amoxicillin, co-amoxiclav, doxycycline, cephalosporins, macrolides], long-course regimens), antihistamines, cephalosporins or macrolides, decongestants (xylometazoline, phenylephrine, pseudoephedrine), doxycycline, saline nasal washes, steam inhalation, and topical corticosteroids (intra-nasal). PMID:19450327

  19. Sinusitis (acute)

    PubMed Central

    2011-01-01

    Introduction Acute sinusitis is defined pathologically, by transient inflammation of the mucosal lining of the paranasal sinuses lasting less than 4 weeks. Clinically, it is characterised by nasal congestion, rhinorrhoea, facial pain, hyposmia, sneezing, and, if more severe, additional malaise and fever. It affects 1% to 5% of the adult population each year in Europe. Methods and outcomes We conducted a systematic review and aimed to answer the following clinical questions: What are the effects of treatments in people with clinically diagnosed acute sinusitis, and in people with radiologically or bacteriologically confirmed acute sinusitis? We searched: Medline, Embase, The Cochrane Library, and other important databases up to June 2011 (Clinical Evidence reviews are updated periodically; please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA). Results We found 19 systematic reviews, RCTs, or observational studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions. Conclusions In this systematic review we present information relating to the effectiveness and safety of the following interventions: antibiotics (amoxicillin, amoxicillin–clavulanic acid [co-amoxiclav], doxycycline, cephalosporins, macrolides; different doses, long-course regimens), antihistamines, decongestants (xylometazoline, phenylephrine, pseudoephedrine), saline nasal washes, steam inhalation, and topical corticosteroids (intranasal). PMID:22189346

  20. Acute glomerulonephritis.

    PubMed

    Yoshizawa, N

    2000-09-01

    Acute glomerulonephritis (AGN) is a representative disease of acute nephritic syndrome characterized by the sudden appearance of edema, hematuria, proteinuria, and hypertension. The prototype of AGN is acute poststreptococcal glomerulonephritis (APSGN). "Nephritogenic streptococci" are defined as organisms that are cultured from a patient who develops AGN. Although only a limited number of M-types of streptococci have been recognized as "nephritogenic streptococci", all M-types of streptococci may have nephritogenic potential because the genes for major putative nephritogenic antigens such as SPEB and NAPIr are found to be present in all group A streptococci thus far examined. Pathogenic mechanisms for APSGN involving both humoral and cell-mediated immunity have been recently proposed. The role of humoral immunity is presumed to be mediated by the in situ formation of nephritogenic streptococcal antigen-antibody complexes and circulating immune complexes. While in the cellular immune component a role for delayed-type hypersensitivity has been suggested to contribute to the pathogenesis of APSGN. PMID:10969898

  1. Empirical Study of the Multiaxial, Thermomechanical Behavior of NiTiHf Shape Memory Alloys

    NASA Technical Reports Server (NTRS)

    Shukla, Dhwanil; Noebe, Ronald D.; Stebner Aaron P.

    2013-01-01

    An empirical study was conducted to characterize the multiaxial, thermomechanical responses of new high temperature NiTiHf alloys. The experimentation included loading thin walled tube Ni(sub 50.3)Ti(sub 29.7)Hf(sub 20) alloy samples along both proportional and nonproportional axial-torsion paths at different temperatures while measuring surface strains using stereo digital image correlation. A Ni(sub 50.3)Ti(sub 33.7)Hf(sub 16) alloy was also studied in tension and compression to document the effect of slightly depleting the Hf content on the constitutive responses of NiTiHf alloys. Samples of both alloys were made from nearly texture free polycrystalline material processed by hot extrusion. Analysis of the data shows that very small changes in composition significantly alter NiTiHf alloy properties, as the austenite finish (Af) temperature of the 16-at Hf alloy was found to be approximately 60 C less than the 20-at Hf alloy (approximately 120 C vs. 180 C). In addition, the 16-at Hf alloy exhibited smaller compressive transformation strains (2 vs. 2.5 percent). Multi-axial characterization of the 20-at % Hf alloy showed that while the random polycrystal transformation strains in tension (4 percent) and compression (2.5 percent) are modest in comparison with binary NiTi (6 percent, 4 percent), the torsion performance is superior (7 vs. 4 shear strain width to the pseudoelastic plateau).

  2. Crystallography of the NiHfSi Phase in a NiAl (0.5 Hf) Single-Crystal Alloy

    NASA Technical Reports Server (NTRS)

    Garg, A.; Noebe, R. D.; Darolia, R.

    1996-01-01

    Small additions of Hf to conventionally processed NiAl single crystals result in the precipitation of a high density of cuboidal G-phase along with a newly identified silicide phase. Both of these phases form in the presence of Si which is not an intentional alloying addition but is a contaminant resulting from contact with the ceramic shell molds during directional solidification of the single-crystal ingots. The morphology, crystal structure and Orientation Relationship (OR) of the silicide phase in a NiAl (0.5 at.%Hf) single-crystal alloy have been determined using transmission electron microscopy, electron microdiffraction and energy dispersive X-ray spectroscopy. Qualitative elemental analysis and indexing of the electron microdiffraction patterns from the new phase indicate that it is an orthorhombic NiHfSi phase with unit cell parameters, a = 0.639 nm, b = 0.389 nm and c = 0.72 nm, and space group Pnma. The NiHfSi phase forms as thin rectangular plates on NiAl/111/ planes with an OR that is given by NiHfSi(100))(parallel) NiAl(111) and NiHfSi zone axes(010) (parallel) NiAl zone axes (101). Twelve variants of the NiHfSi phase were observed in the alloy and the number of variants and rectangular morphology of NiHfSi plates are consistent with symmetry requirements. Quenching experiments indicate that nucleation of the NiHfSi phase in NiAI(Hf) alloys is aided by the formation of NiAl group of zone axes (111) vacancy loops that form on the NiAl /111/ planes.

  3. Crystallography of the NiHfSi phase in a NiAl(0.5Hf) single-crystal alloy

    SciTech Connect

    Garg, A.; Noebe, R.D.; Darolia, R.

    1996-07-01

    Small additions of Hf to conventionally processed NiAl single crystals result in the precipitation of a high density of cuboidal G-phase along with a newly identified silicide phase. Both of these phases form in the presence of Si which is not an intentional alloying addition but is a contaminant resulting from contact with the ceramic shell molds during directional solidification of the single-crystal ingots. The morphology, crystal structure and orientation relationship (O.R.) of the silicide phase in a NiAl(0.5at.%Hf) single-crystal alloy have been determined using transmission electron microscopy, electron microdiffraction and energy dispersive X-ray spectroscopy. Qualitative elemental analysis and indexing of the electron microdiffraction patterns from the new phase indicate that it is an orthorhombic NiHfSi phase with unit cell parameters, a = 0.639 nm, b = 0.389 nm and c = 0.72 nm, and space group Pnma. The NiHfSi phase forms as thin rectangular plates on {l_brace}111{r_brace}{sub NiAl} planes with an O.R. that is given by (100){sub NiHfSi}{parallel}(111){sub NiAl} and [010]{sub NiHfSi}{parallel}[{bar 1}01]{sub NiAl}. Twelve variants of the NiHfSi phase were observed in the alloy and the number of variants and rectangular morphology of NiHfSi plates are consistent with symmetry requirements. Quenching experiments indicate that nucleation of the NiHfSi phase in NiAl(Hf) alloys is aided by the formation of <111>{sub NiAl} vacancy loops that form on the {l_brace}111{r_brace}{sub NiAl} planes.

  4. A coupled ionosphere-raytrace model for high-power HF heating

    NASA Astrophysics Data System (ADS)

    Zawdie, K. A.; Huba, J. D.; Drob, D. P.; Bernhardt, P. A.

    2015-11-01

    The first 3-D model of artificial HF ionospheric heating to self-consistently calculate the modification in heating location due to evolving ionospheric gradients has been developed. The model combines the ionosphere model SAMI3/ESF and the HF propagation code MoJo-15. At each time step, the simulated path of the HF wave through the ionosphere is used to determine the HF heating location. These calculations have been used to explain the physical mechanism responsible for the snapback effect observed in an Arecibo HF heating experiment described by Bernhardt et al. (1988). The heater wave is refracted by the density cavity, which causes the heating location to drift in longitude. Eventually, the density cavity convects into the path of the refracted ray, such that only a small portion of the ray is above the threshold for HF heating and the heating location snaps back even though the ray itself is still refracted in longitude.

  5. Corrosion characteristics of anodized Ti-(10-40wt%)Hf alloys for metallic biomaterials use.

    PubMed

    Jeong, Yong-Hoon; Choe, Han-Cheol; Brantley, William A

    2011-01-01

    The effect of anodizing on corrosion resistance of Ti-xHf alloys has been investigated. Ti-xHf alloys were prepared and anodized at 120, 170 and 220 V in 1 M H(3)PO(4) solution, and crystallized at 300 and 500°C. Corrosion experiments were carried out using a potentiostat in 0.15 M NaCl solution at 36.5 ± 1°C. The Ti-xHf alloys exhibited the α' and anatase phases. The pore size on the anodized surface increases as the applied voltage is increased, whereas the pore size decreases as the Hf content is increased. The anodized Ti-xHf alloys exhibited better corrosion resistance than non-anodized Ti-xHf alloys. PMID:21104193

  6. Estimation of the Doppler frequency and direction of arrival of the ionospherically propagated HF signals

    NASA Astrophysics Data System (ADS)

    Su, Hongtao; Liu, Hongwei; Shui, Penglang; Bao, Zheng

    2009-08-01

    High-frequency (HF) signals reflected from different points within each ionospheric layer may have slightly different Doppler frequencies and angles of arrival. The superposition of these signals leads to time varying and nonplanar wavefronts. Investigation of temporal and spatial characteristics of the ionospherically propagated HF signals plays an important role in designing the signal processing algorithms for the HF over-the-horizon radar (OTHR). A cost-efficient superresolution algorithm for simultaneously estimating the Doppler frequencies and angles of arrival of the ionospherically propagated HF signals is proposed in this paper. The effectiveness of the proposed algorithm is verified by the experimental data from a trial HF OTHR. Furthermore, the superposition model with the HF signal reflected by a smooth ionospheric layer consisting of a number of submode signals is also confirmed by the experimental data processing results.

  7. Meteorite zircon constraints on the bulk Lu−Hf isotope composition and early differentiation of the Earth

    PubMed Central

    Iizuka, Tsuyoshi; Yamaguchi, Takao; Hibiya, Yuki; Amelin, Yuri

    2015-01-01

    Knowledge of planetary differentiation is crucial for understanding the chemical and thermal evolution of terrestrial planets. The 176Lu−176Hf radioactive decay system has been widely used to constrain the timescales and mechanisms of silicate differentiation on Earth, but the data interpretation requires accurate estimation of Hf isotope evolution of the bulk Earth. Because both Lu and Hf are refractory lithophile elements, the isotope evolution can be potentially extrapolated from the present-day 176Hf/177Hf and 176Lu/177Hf in undifferentiated chondrite meteorites. However, these ratios in chondrites are highly variable due to the metamorphic redistribution of Lu and Hf, making it difficult to ascertain the correct reference values for the bulk Earth. In addition, it has been proposed that chondrites contain excess 176Hf due to the accelerated decay of 176Lu resulting from photoexcitation to a short-lived isomer. If so, the paradigm of a chondritic Earth would be invalid for the Lu−Hf system. Herein we report the first, to our knowledge, high-precision Lu−Hf isotope analysis of meteorite crystalline zircon, a mineral that is resistant to metamorphism and has low Lu/Hf. We use the meteorite zircon data to define the Solar System initial 176Hf/177Hf (0.279781 ± 0.000018) and further to identify pristine chondrites that contain no excess 176Hf and accurately represent the Lu−Hf system of the bulk Earth (176Hf/177Hf = 0.282793 ± 0.000011; 176Lu/177Hf = 0.0338 ± 0.0001). Our results provide firm evidence that the most primitive Hf in terrestrial zircon reflects the development of a chemically enriched silicate reservoir on Earth as far back as 4.5 billion years ago. PMID:25870298

  8. Meteorite zircon constraints on the bulk Lu-Hf isotope composition and early differentiation of the Earth.

    PubMed

    Iizuka, Tsuyoshi; Yamaguchi, Takao; Hibiya, Yuki; Amelin, Yuri

    2015-04-28

    Knowledge of planetary differentiation is crucial for understanding the chemical and thermal evolution of terrestrial planets. The (176)Lu-(176)Hf radioactive decay system has been widely used to constrain the timescales and mechanisms of silicate differentiation on Earth, but the data interpretation requires accurate estimation of Hf isotope evolution of the bulk Earth. Because both Lu and Hf are refractory lithophile elements, the isotope evolution can be potentially extrapolated from the present-day (176)Hf/(177)Hf and (176)Lu/(177)Hf in undifferentiated chondrite meteorites. However, these ratios in chondrites are highly variable due to the metamorphic redistribution of Lu and Hf, making it difficult to ascertain the correct reference values for the bulk Earth. In addition, it has been proposed that chondrites contain excess (176)Hf due to the accelerated decay of (176)Lu resulting from photoexcitation to a short-lived isomer. If so, the paradigm of a chondritic Earth would be invalid for the Lu-Hf system. Herein we report the first, to our knowledge, high-precision Lu-Hf isotope analysis of meteorite crystalline zircon, a mineral that is resistant to metamorphism and has low Lu/Hf. We use the meteorite zircon data to define the Solar System initial (176)Hf/(177)Hf (0.279781 ± 0.000018) and further to identify pristine chondrites that contain no excess (176)Hf and accurately represent the Lu-Hf system of the bulk Earth ((176)Hf/(177)Hf = 0.282793 ± 0.000011; (176)Lu/(177)Hf = 0.0338 ± 0.0001). Our results provide firm evidence that the most primitive Hf in terrestrial zircon reflects the development of a chemically enriched silicate reservoir on Earth as far back as 4.5 billion years ago. PMID:25870298

  9. Oscillatory zoning in synthetic Hf-Y-doped zircon

    NASA Astrophysics Data System (ADS)

    Hoskin, P.

    2003-04-01

    Onion-skin-like growth-layers, known as oscillatory zoning patterns (OZPs), are commonly observed in igneous zircon. OZPs are also observed in synthetic zircon although the conditions of growth differ significantly from those formed naturally—synthetic zircons are usually grown in anhydrous simple chemical fluxes at higher temperatures (900--1200^oC) and ZrO_2 compositions (1--3 wt.%), at 1 atm pressure, and under laboratory time scales (days to weeks). In order to investigate the role of temperature only as a cause of OZP formation, two simultaneous zircon-growth experiments were performed. An initial starting mix of ZrO_2 (with ˜1 wt.% HfO_2 impurity) and SiO_2 (at 1:10 molar ratio) was doped with Y_2O_3, La_2O_3 and CeO_2 each representing 2 wt.% of the combined weight of ZrO_2+SiO_2. Equal halves of the doped mix were added to a flux comprising Na_2WO_4 and WO_3. Experiments were performed in sealed Pt crucibles in air at 1 atm and were heated at 1300^oC for 24 h. The first experiment was left at that temperature (a total of 70 h) until quenching in air. The second experiment was reduced in temperature four times before quenching in air (1: 1300--1200^oC in 2 min, held for 14 h; 2: 1200--1100^oC at 12.5^oC/h; 3: 1100--1000^oC in 2 min, held for 16 h; 4: 1000--900^oC at 12.5^oC/h), a total experimental time of 70 h. Zircons (50--130 mm-long) were recovered from the flux and represented a ˜30% yield by weight. Crystals from both experiments were analysed by EMPA and cathodoluminescence (CL). Zircon from experiment 1 are unzoned and have an average composition of (Zr0.97Hf0.03)SiO_4. Zircon from experiment 2 is zoned. Each crystal ((Zr0.950-0.958Hf0.014-0.034Y0.000-0.005)SiO_4) has 5 zones, which may vary in thickness between crystals, that are interpreted to represent growth at 1300^oC (zone 1) and the four other temperature ranges of experimentation (zones 2--5). Only Hf and Y were above the detection limit for EMPA. CL intensities correspond with Y

  10. Temporal Development of HF-Excited Langmuir and Ion Turbulence at Arecibo

    NASA Astrophysics Data System (ADS)

    Djuth, F. T.; DuBois, D. F.

    2015-10-01

    The Arecibo high-power, high-frequency (HF) facility and 430 MHz radar are used to examine the temporal development of the HF-induced Langmuir and ion turbulences from 1 ms to many minutes after the turn-on of the HF beam in the F region. All HF observations begin in a smooth, stratified, stable plasma. "Cold start" HF transmissions are employed to avoid remnant irregularities from prior HF transmissions. HF-excited plasma line (HFPL) and ion line echoes are used to monitor the evolution of the turbulence. In the evening/nighttime the HFPL develops in three reproducible stages. Over time scales of 0 to 10-20 ms (possibly 40 ms), the smooth plasma conditions are maintained, and the results are consistent with theoretical models of the excitation of strong Langmuir turbulence near HF reflection. This entails the initiation of the so-called "caviton production cycle." The turbulence from the parametric decay instability is detected at lower altitudes where the radar wave vector matches those of the HF-enhanced waves. The data suggests that the two processes coexist in the region in between. After ~40 ms the "overshoot process" begins and consists of a downward extension of the HFPL from the HF reflection region to heights ~1.1 km below followed by a retreat back to the reflection region. The whole overshoot process takes place over a time scale of ~3 s. Thereafter the echo remains near HF reflection for 20-90 s after HF turn-on. The HFPL echo subsequently breaks up into patches because of the formation of large-scale electron density structures in the plasma. New kinetic models indicate that suprathermal electrons excited in the plasma by, for example, caviton burn-out serve to regulate plasma turbulence in the modified ionospheric volume.

  11. Estimation of planetary surface roughness by HF sounder observation

    NASA Astrophysics Data System (ADS)

    Kobayashi, T.; Ono, T.

    Japanese Martian exploration project "Nozomi" was to carry out several science missions. Plasma Wave Sounder, one of those onboard missions, was an HF sounder to study Martian plasma environment, and Martian surface with the altimetry mode (Oya and Ono, 1998) as well. The altimetry mode observation was studied by means of computer simulations utilizing the KiSS code which had been originally designed to simulate the SELENE Lunar Radar Sounder, a spaceborne HF GPR, based on Kirchhoff approximation theory (Kobayashi, Oya and Ono, 2002). We found an empirical power law for the standard deviation of observed altitudes over Gaussian random rough surfaces: it varies in proportion to the square of the RMS gradient of the surface √{2} hRMS{λ_0, where hRMS and λ_0 are the RMS height of the surface and the correlation distance of the surface, respectively. We applied Geometrical optics to understand this empirical power law, and derived a square power law for the standard deviation of the observed altitude. Our Geometrical optics model assumed the followings: 1) the observed surface is a Gaussian random rough surface, 2) the mean surface is a flat horizontal plane, 3) the observed surface echo is the back scattering echoes, 4) the observed altitude is the mean value of the apparent range of those back scattering echoes. These results imply that HF sounder may be utilized to measure the surface roughness of planetary bodies in terms of the RMS gradient of the surface. Refrence: H. Oya and T. Ono, A new altimeter for Mars land shape observations utilizing the ionospheric sounder system onboard the Planet-B spacecraft, Earth Planets Space, Vol. 50, pp.229-234, 1998 T. Kobayashi, H. Oya, and T. Ono, A-scope analysis of subsurface radar sounding of lunar mare region, Earth Planets Space, Vol. 54, pp.973-982, 2002

  12. Coalescence of silver clusters by immersion in diluted HF solution

    SciTech Connect

    Milazzo, R. G.; Mio, A. M.; D’Arrigo, G.; Spinella, C.; Grimaldi, M. G.; Rimini, E.

    2015-07-14

    The galvanic displacement deposition of silver on H-terminated Si (100) in the time scale of seconds is instantaneous and characterized by a cluster density of 10{sup 11}-10{sup 12} cm{sup −2}. The amount of deposited Ag follows a t{sup 1/2} dependence in agreement with a Cottrell diffusion limited mechanism. At the same time, during the deposition, the cluster density reduces by a factor 5. This behavior is in contrast with the assumption of immobile clusters. We show in the present work that coalescence and aggregation occur also in the samples immersed in the diluted hydrofluoric acid (HF) solution without the presence of Ag{sup +}. Clusters agglomerate according to a process of dynamic coalescence, typical of colloids, followed by atomic redistribution at the contact regions with the generation of multiple internal twins and stacking-faults. The normalized size distributions in terms of r/r{sub mean} follow also the prediction of the Smoluchowski ripening mechanism. No variation of the cluster density occurs for samples immersed in pure H{sub 2}O solution. The different behavior might be associated to the strong attraction of clusters to oxide-terminated Si surface in presence of water. The silver clusters are instead weakly bound to hydrophobic H-terminated Si in presence of HF. HF causes then the detachment of clusters and a random movement on the silicon surface with mobility of about 10{sup −13} cm{sup 2}/s. Attractive interaction (probably van der Waals) among particles promotes coarsening.

  13. Right heart failure in acute respiratory distress syndrome: An unappreciated albeit a potential target for intervention in the management of the disease.

    PubMed

    Biswas, Abhishek

    2015-10-01

    Mortality from acute respiratory distress syndrome (ARDS) has gone down recently. In spite of this trend, the absolute numbers continue to be high even with improvements in ventilator strategies and a better understanding of fluid management with this disease. A possible reason for this could be an under-recognized involvement of the pulmonary vasculature and the right side of the heart in ARDS. The right heart is not designed to function under situations leading to acute elevations in afterload as seen in ARDS, and hence it decompensates. This brief review focuses on the magnitude of the problem, its detection in the intensive care unit, and recognizes the beneficial effect of prone-positioning on the pulmonary vasculature and right heart. PMID:26628826

  14. Enhanced resistive switching and multilevel behavior in bilayered HfAlO/HfAlO{sub x} structures for non-volatile memory applications

    SciTech Connect

    Faita, F. L.; Silva, J. P. B.; Pereira, M.; Gomes, M. J. M.

    2015-12-14

    In this work, hafnium aluminum oxide (HfAlO) thin films were deposited by ion beam sputtering deposition technique on Si substrate. The presence of oxygen vacancies in the HfAlO{sub x} layer deposited in oxygen deficient environment is evidenced from the photoluminescence spectra. Furthermore, HfAlO(oxygen rich)/HfAlO{sub x}(oxygen poor) bilayer structures exhibit multilevel resistive switching (RS), and the switching ratio becomes more prominent with increasing the HfAlO layer thickness. The bilayer structure with HfAlO/HfAlO{sub x} thickness of 30/40 nm displays the enhanced multilevel resistive switching characteristics, where the high resistance state/intermediate resistance state (IRS) and IRS/low resistance state resistance ratios are ≈10{sup 2} and ≈5 × 10{sup 5}, respectively. The switching mechanisms in the bilayer structures were investigated by the temperature dependence of the three resistance states. This study revealed that the multilevel RS is attributed to the coupling of ionic conduction and the metallic conduction, being the first associated to the formation and rupture of conductive filaments related to oxygen vacancies and the second with the formation of a metallic filament. Moreover, the bilayer structures exhibit good endurance and stability in time.

  15. Limited vocabulary voice recognition and synthesis for HF communication

    NASA Astrophysics Data System (ADS)

    Smith, R.

    Since most military and commercial transmissions usually implement only a 256 word vocabulary for communications, then actual voice communications are not required, particularly in military jamming environments. The voice can be synthesized at the receiving end after transmission of a code sequence. A look-up table will suffice for synthesis of analog baseband signals. The system could also recognize the phonetic-letters-spelled-out (PLSO) system (e.g., Tango, Charley, Able, etc.). The technique permits HF utilization with an ionospheric hop and acceptable reception in all but very extreme jamming situations. It is noted that the simplified coding permits translation between operators who do not speak the same language.

  16. Application of polarimetric sounding to HF ionospheric remote sensing

    NASA Astrophysics Data System (ADS)

    Bezrodny, V. G.; Ponomarenko, P. V.; Yampolski, Y. M.

    1997-01-01

    It is shown that the scattering of electromagnetic waves by refractive index inhomogeneities in a continuous random medium is accompanied by a certain polarimetric phenomenon that is analogous to the Brewster effect of classic electrodynamics. In this paper, an observational method and results are discussed for the case of bistatic HF radar sounding of small-scale ionospheric inhomogeneities at frequencies above MUF. The height of the scattering layer, its thickness, and characteristic plasma drift velocity in the ionosphere are estimated as a result of statistical processing.

  17. Silicon/HfO2 interface: Effects of gamma irradiation

    NASA Astrophysics Data System (ADS)

    Maurya, Savita

    2016-05-01

    Quality of MOS devices is a strong function of substrate and oxide interface. In this work we have studied how gamma photon irradiation affects the interface of a 13 nm thick, atomic layer deposited hafnium dioxide deposited on silicon wafer. CV and GV measurements have been done for pristine and irradiated samples to quantify the effect of gamma photon irradiation. Gamma photon irradiation not only introduces positive charge in the oxide and at the interface of Si/HfO2 interface but also induce phase change of oxide layer. Maximum oxide capacitances are affected by gamma photon irradiation.

  18. Lu-Hf total-rock age for the Amitsoq gneisses, West Greenland

    NASA Technical Reports Server (NTRS)

    Pettingill, H. S.; Patchett, P. J.

    1981-01-01

    Lu-Hf total-rock data for the Amitsoq gneisses of West Greenland yield an age of 3.55 + or - 0.22 billion years, based on the decay constant for Lu-176 of 1.96 x 10 to the -11th/year, and an initial Hf-176/Hf-177 ratio of 0.280482 + or - 33. The result is in good agreement with Rb-Sr total-rock and U-Pb zircon ages. In spite of severe metamorphism of the area at 2.9 billion years, zircons from two of the samples have remained on the total-rock line, and define points close to the initial Hf ratio. The initial Hf-176/Hf-177 lies close to a chondritic Hf isotopic evolution curve from 4.55 billion years to present. This is consistent with the igneous precursors to the Amitsoq gneisses having been derived from the mantle at or shortly before 3.6 billion years. Anomalous relationships between Hf concentration and the Lu-176/Hf-177 ratio may suggest that trace element abundances in the Amitsoq gneisses are partly controlled by processes related to metamorphism.

  19. Ab initio calculation of relative permittivity of La-doped HfO2

    NASA Astrophysics Data System (ADS)

    Ong, T. M.; Xu, S.

    2014-12-01

    First principles calculations of HfO2 and La-doped HfO2 structures were carried out to investigate the effect of La doping on the relative permittivity of HfO2 films. In this study 6.25% of La was incorporated into HfO2. Upon examination, we found out that La addition increased the value of the relative permittivity from 19 to 26 and this was because the La-induced distortion increased the range of frequencies that contribute to the IR-active modes.

  20. Electron beam induced local crystallization of HfO2 nanopores for biosensing applications

    PubMed Central

    Shim, Jiwook; Rivera, Jose; Bashir, Rashid

    2013-01-01

    We report the development of single, locally crystallized nanopores in HfO2 membranes for biosensing applications. HfO2 is chosen for its isoelectric point of 7.0, mechanical and chemical stability in solution, and for its potential as a high-k material for nanopore ionic field effect transistor applications. The HfO2 membrane is deposited on a graphene layer suspended over a 300 nm FIB hole, where graphene is used as the mechanical support. Exposure of the membrane to a focused electron beam causes crystallization in the vicinity of the nanopore during pore formation. We investigate the effects of crystallization on the electrical and surface properties of HfO2 films. Our surface analysis of HfO2 reveals improved hydrophilicity of crystallized HfO2, a notable advantage over the hydrophobicity of as-deposited HfO2. We also demonstrate detection of dsDNA translocation through HfO2 nanopores under various applied bias levels. In addition, our device architecture also presents a promising first step toward the realization of high-k HfO2 nanopore transistors. PMID:23945603

  1. Importance of the Lu-Hf isotopic system in studies of planetary chronology and chemical evolution

    NASA Technical Reports Server (NTRS)

    Patchett, P. J.

    1983-01-01

    The Lu-176-Hf-176 isotope method and its applications in earth sciences are discussed with regard to planetary-evolution studies. From new data on basalts from oceanic islands, Hf-176/Hf-177 and Nd-143/Nd-144 are found to display a single linear isotopic variation in the suboceanic mantle, whereas considerable divergences occur in Hf-176/Hf-177-Sr-87/Sr-86 and Nd-143/Nd-144-Sr87/Sr-86 diagrams. With the acquisition of further Hf-Sr-Nd isotopic data, these discordant Sr-87/Sr-86 relationships may allow a distinction between processes such as mantle metasomatism, influence of sea-water altered material in the magma source, or recycling of sediments into the mantle. The best quality Hf isotope data are obtained from granitoid or zircons, and are most suitable for studying ancient terrestrial Hf isotopic variations. Lu-Hf is shown to be a viable method for dating ancient terrestrial and extraterrestrial samples, but is unlikely to find wide application in pure chronological studies because it offers little advantage over existing methods.

  2. Lu-hf total-rock isochron for the eucrite meteorites

    USGS Publications Warehouse

    Patchett, P.J.; Tatsumoto, M.

    1980-01-01

    The isotope 176Lu (2.6% of natural lutetium) decays by ??- to 176Hf, with a long half life. We present here the first Lu-Hf isochron. The eucrite meteorites, a suite of planetary igneous rocks of known age, 4,550 Myr, define a 10-point total-rock isochron with a slope of 0.0934 ?? 40, leading to a value of 3.53 ?? 0.14 ??1010yr for the ??--decay half life of 176Lu. The isochron intercept of 0.27973 ?? 12 gives the initial 176Hf/177Hf for the inner Solar System at the time of accretion. ?? 1980 Nature Publishing Group.

  3. Lu-Hf total-rock age for the Amîtsoq gneisses, West Greenland

    USGS Publications Warehouse

    Pettingill, H.S.; Patchett, P.J.

    1981-01-01

    Lu-Hf total-rock data for the Amîtsoq gneisses of West Greenland yield an age of 3.55±0.22Gy(2σ), based on the decay constant λ176Lu=1.96×10−11y−1, and an initial176Hf/177Hf ratio of 0.280482±33. The result is in good agreement with Rb-Sr total-rock and U-Pb zircon ages. In spite of severe metamorphism of the area at 2.9 Gy, zircons from two of the samples have remained on the total-rock line, and define points close to the initial Hf ratio. The initial176Hf/177Hf lies close to a chondritic Hf isotopic evolution curve from 4.55 Gy to present. This is consistent with the igneous precursors to the Amîtsoq gneisses having been derived from the mantle at or shortly before 3.6 Gy. Anomalous relationships between Hf concentration and the176Lu/177Hf ratio may suggest that trace element abundances in the Amîtsoq gneisses are partly controlled by processes related to metamorphism.

  4. The use of anhydrous HF solvolysis in conversion of biomass to glucose

    NASA Astrophysics Data System (ADS)

    Mort, A.; Parker, S.

    1982-12-01

    Anhydrous hydrogen fluoride solubilizes and deploymerizes crystalline cellulose, cellulose imbedded in lignin, and amorphous polysaccharides in less than 15 minutes at temperatures as low as 0 C. It is suggested that this reaction may be used to convert crude cellulosic biomass materials into sugar monomers suitable for microbial fermentation. No degradation of the sugars during the HF-catalyzed deploymerization is noted. Because the HF is very volatile it is easily removed from the reaction for reuse with more biomass. The characterization of this reaction and the many advantages of HF solvolysis over acid and enzymatic hydrolysis are examined. Some of the special problems associated with HF are discussed.

  5. Reduced-temperature processing and consolidation of ultra-refractory Ta4HfC5

    SciTech Connect

    Gaballa, Osama; Cook, B. A.; Russell, A. M.

    2013-04-26

    TaC, HfC, and WC powders were subjected to high-energy milling and hot pressing to produce Ta4HfC5, a composite of Ta(4)HfC5 + 30 vol.% WC, and a composite of Ta4HfC5 + 50 vol.% WC. Sub-micron powders were examined after four different milling intervals prior to hot pressing. XRD was used to verify proper phase formation. SEM, relative density, and hardness measurements were used to examine the resulting phases. Hot pressed compacts of Ta4HfC5 showed densification as high as 98.6% along with Vickers hardness values of 21.4 GPa. Similarly, Ta4HfC5 + 30 vol.% WC exhibited 99% densification with a Vickers hardness of 22.5 GPa. These levels of densification were achieved at 1500 degrees C, which is lower than any previously reported sintering temperature for Ta4HfC5. Microhardness values measured in this study were higher than those previously reported for Ta4HfC5. The WC additions to Ta4HfC5 were found to improve densification and increase microhardness. (C) 2013 Elsevier Ltd. All rights reserved.

  6. Clinical trials update from the European Society of Cardiology-Heart Failure meeting 2015: AUGMENT-HF, TITRATION, STOP-HF, HARMONIZE, LION HEART, MOOD-HF, and renin-angiotensin inhibitors in patients with heart and renal failure.

    PubMed

    Pellicori, Pierpaolo; Clark, Andrew L

    2015-09-01

    This article provides an overview on the key trials relevant to the pathophysiology, prevention, and treatment of heart failure (HF) presented at the Heart Failure Association (HFA) of the European Society of Cardiology (ESC) annual meeting held in Seville, Spain in May 2015. Trials reported include AUGMENT-AF (myocardial injections of calcium-alginate hydrogel), a propensity score-matched study of renin-angiotensin system antagonists in patients with HF and severe renal dysfunction, HARMONIZE (sodium zirconium cyclosilicate used to bind potassium), TITRATION, comparing two regimes for introducing LCZ696, STOP-HF, a trial of intramyocardial stromal cell-derived factor-1, MOOD-HF (escitalopram for patients with heart failure and depression), and LION HEART, a trial of intermittent levosimendan therapy. Unpublished reports should be considered as preliminary, since analyses may change in the final publication. PMID:26289928

  7. [Acute myocarditis].

    PubMed

    Combes, Alain

    2012-06-01

    Myocarditis is defined as inflammation of the myocardium accompanied by myocellular necrosis. Acute myocarditis must be considered in patients who present with recent-onset of cardiac failure or arrhythmia. Fulminant myocarditis is a distinct entity characterized by sudden onset of severe congestive heart failure or cardiogenic shock, usually following a flu-like illness, parvovirus B19, human herpesvirus 6, coxsackievirus and adenovirus being the most frequently viruses responsible for the disease. Treatment of myocarditis remains largely supportive, since immunosuppression has not been proven to be beneficial for acute lymphocytic myocarditis. Trials of antiviral therapies, or immunostimulants such as interferons, suggest a potential therapeutic role but require further investigation. Lastly, early recognition of patients rapidly progressing to refractory cardiac failure and their immediate transfer to a medical-surgical center experienced in mechanical circulatory support is warranted. In this setting, ECMO should be the first-line mechanical assistance. For highly unstable patients, a Mobile Cardiac Assistance Unit, that rapidly travels to primary care hospitals with a portable ECMO system and hooks it up before refractory multiorgan failure takes hold, is the preferred option. PMID:22515999

  8. [Acute myocarditis].

    PubMed

    Combes, Alain

    2013-05-01

    Myocarditis is defined as inflammation of the myocardium accompanied by myocellular necrosis. Acute myocarditis must be considered in patients who present with recent onset of cardiac failure or arrhythmia. Fulminant myocarditis is a distinct entity characterized by sudden onset of severe congestive heart failure or cardiogenic shock, usually following a flu-like illness, parvovirus B19, human herpesvirus 6, coxsackievirus and adenovirus being the most frequently viruses responsible for the disease. Treatment of myocarditis remains largely supportive, since immunosuppression has not been proven to be beneficial for acute lymphocytic myocarditis. Trials of antiviral therapies, or immunostimulants such as interferons, suggest a potential therapeutic role but require further investigation. Lastly, early recognition of patients rapidly progressing to refractory cardiac failure and their immediate transfer to a medical-surgical center experienced in mechanical circulatory support is warranted. In this setting, ECMO should be the first-line mechanical assistance. For highly unstable patients, a Mobile Cardiac Assistance Unit, that rapidly travels to primary care hospitals with a portable ECMO system and hooks it up before refractory multiorgan failure takes hold, is the preferred option. PMID:23789482

  9. Continuous internal counterpulsation as a bridge to recovery in acute and chronic heart failure

    PubMed Central

    Kontogiannis, Christos D; Malliaras, Konstantinos; Kapelios, Chris J; Mason, Jay W; Nanas, John N

    2016-01-01

    Cardiac recovery from cardiogenic shock (CS) and end-stage chronic heart failure (HF) remains an often insurmountable therapeutic challenge. The counterpulsation technique exerts numerous beneficial effects on systemic hemodynamics and left ventricular mechanoenergetics, rendering it attractive for promoting myocardial recovery in both acute and chronic HF. Although a recent clinical trial has questioned the clinical effectiveness of short-term hemodynamic support with intra-aortic balloon pump (IABP, the main representative of the counterpulsation technique) in CS complicating myocardial infarction, the issue remains open to further investigation. Moreover, preliminary data suggest that long-term IABP support in patients with end-stage HF is safe and may mediate recovery of left- or/and right-sided cardiac function, facilitating long-term weaning from mechanical support or enabling the application of other permanent, life-saving solutions. The potential of long-term counterpulsation could possibly be enhanced by implementation of novel, fully implantable counterpulsation devices. PMID:27011909

  10. Low plasma levels of brain natriuretic peptide in severe acute heart failure: merely a case?

    PubMed

    Brentana, Loretta; Temporelli, Pier Luigi; Corrà, Ugo; Gattone, Marinella; Pistono, Massimo; Imparato, Alessandro; Gnemmi, Marco; Giannuzzi, Pantaleo

    2007-11-30

    Brain natriuretic peptide (BNP) is commonly used for diagnosis and prognosis of patients with congestive heart failure (HF). High levels of BNP are associated with high probability of cardiogenic dyspnea and higher risk of subsequent cardiovascular events. We describe a case of acute HF (worsening chronic HF) in a 74-year-old male with low plasma BNP levels on admission, in whom a rapid and consistent increase in the marker's concentration occurred after administration of diuretics and vasodilators, despite a prompt clinical and hemodynamic improvement. Reports of cardiogenic dyspnea with moderate increase or normal plasma levels of BNP have been recently published: does this signify a pitfall for BNP as a useful diagnostic and prognostic tool? Clinical implications of our observation are discussed, and we conclude that neurohumoral biomarkers do not obviate the need for a careful physical and instrumental examination of patient. PMID:17382416

  11. Acute cerebellar ataxia

    MedlinePlus

    Cerebellar ataxia; Ataxia - acute cerebellar; Cerebellitis; Post-varicella acute cerebellar ataxia; PVACA ... Acute cerebellar ataxia in children, especially younger than age 3, may occur several weeks after an illness caused by a virus. ...

  12. Ear infection - acute

    MedlinePlus

    Otitis media - acute; Infection - inner ear; Middle ear infection - acute ... Casselbrandt ML, Mandel EM. Acute otitis media and otitis media with effusion. In: Flint PW, Haughey BH, Lund V, et al, eds. Cummings Otolaryngology: Head & Neck Surgery . 6th ed. ...

  13. Anticooperativity of FHF hydrogen bonds in clusters of the type F- × (HF)n, RF × (HF)n and XF × (HF)n, R = alkyl and X = H, Br, Cl, F

    NASA Astrophysics Data System (ADS)

    Kucherov, S. Yu.; Bureiko, S. F.; Denisov, G. S.

    2016-02-01

    Properties of twenty five hydrogen-bonded complexes, namely, F- × (HF)n (n = 1-6), RF × (HF)n (R = t-Bu, i-Pr, Et, Me; n = 1-3), XF × (HF)n (X = H, Br, Cl; n = 1-2), and FF…HF with the hydrogen bond energy varying in a wide range have been calculated using ab initio methods at the MP2/6-31++G** level. For the first time, the energies, geometrical parameters and vibrational frequencies are obtained for the series of clusters, where the bonding character changes from covalent to van der Waals on the variation of proton-acceptor ability of the base, and the energies are in the range of 45-1 kcal/mol. The mutual influence of multiple hydrogen bonds of F…HF type in clusters, in which a fluorine anion or an atom participates in hydrogen bond formation as the acceptor, is systematically investigated. The relative changes in the values of the considered parameters on the sequential addition of an HF molecule (anticooperativity) were determined. It was shown that non-additivity of the interaction is most strongly pronounced in the energy and vibrational frequency values, geometrical parameters of hydrogen bonds are less sensitive to the mutual influence. The anticooperative effect is more pronounced on the hydrogen bridge length R(F...F) than on the geometry of proton donor r(HF). The hydrogen bond formation and the increase of the number n of ligands lead to successive lengthening of the r(XF) bond adjacent to the hydrogen bridge. The length of an XF bond changes stronger on formation of each hydrogen bond than the HF bond length.

  14. Microstructure And Oxidation Properties Of Laser Clad Ni70AL20Cr7Hf3 Alloys With Extended Solid Solution Of Hf

    NASA Astrophysics Data System (ADS)

    Mazumder, J.; Sircar, S.; Ribaudo, C.; Kar, A.,

    1989-01-01

    Alloys coatings for superalloys for improved higher temperature (1200°C) service life under aggressive atmospheres are of great interest at present. There is a general consensus that addition of rare earths such as hafnium (Hf) to these alloys has a pronounced effect on the oxidation resistance properties at high temperatures. In situ laser cladding technique was used to produce Ni-Al-Cr-Hf alloys with extended solid solution of Hf in a near stoichiometric Ni3Al matrix. A 10 kW CW CO2 laser was used in conjunction with a screw-feed powder dispenser to perform the in situ cladding process.

  15. Rationale, Design, Methodology and Hospital Characteristics of the First Gulf Acute Heart Failure Registry (Gulf CARE)

    PubMed Central

    Sulaiman, Kadhim J.; Panduranga, Prashanth; Al-Zakwani, Ibrahim; Alsheikh-Ali, Alawi; Al-Habib, Khalid; Al-Suwaidi, Jassim; Al-Mahmeed, Wael; Al-Faleh, Husam; El-Asfar, Abdelfatah; Al-Motarreb, Ahmed; Ridha, Mustafa; Bulbanat, Bassam; Al-Jarallah, Mohammed; Bazargani, Nooshin; Asaad, Nidal; Amin, Haitham

    2014-01-01

    Background: There is paucity of data on heart failure (HF) in the Gulf Middle East. The present paper describes the rationale, design, methodology and hospital characteristics of the first Gulf acute heart failure registry (Gulf CARE). Materials and Methods: Gulf CARE is a prospective, multicenter, multinational registry of patients >18 year of age admitted with diagnosis of acute HF (AHF). The data collected included demographics, clinical characteristics, etiology, precipitating factors, management and outcomes of patients admitted with AHF. In addition, data about hospital readmission rates, procedures and mortality at 3 months and 1-year follow-up were recorded. Hospital characteristics and care provider details were collected. Data were entered in a dedicated website using an electronic case record form. Results: A total of 5005 consecutive patients were enrolled from February 14, 2012 to November 13, 2012. Forty-seven hospitals in 7 Gulf States (Oman, Saudi Arabia, Yemen, Kuwait, United Gulf Emirates, Qatar and Bahrain) participated in the project. The majority of hospitals were community hospitals (46%; 22/47) followed by non-University teaching (32%; 15/47 and University hospitals (17%). Most of the hospitals had intensive or coronary care unit facilities (93%; 44/47) with 59% (28/47) having catheterization laboratory facilities. However, only 29% (14/47) had a dedicated HF clinic facility. Most patients (71%) were cared for by a cardiologist. Conclusions: Gulf CARE is the first prospective registry of AHF in the Middle East, intending to provide a unique insight into the demographics, etiology, management and outcomes of AHF in the Middle East. HF management in the Middle East is predominantly provided by cardiologists. The data obtained from this registry will help the local clinicians to identify the deficiencies in HF management as well as provide a platform to implement evidence based preventive and treatment strategies to reduce the burden of HF in

  16. Electron Microprobe Analysis of Hf in Zircon: Suggestions for Improved Accuracy of a Difficult Measurement

    NASA Astrophysics Data System (ADS)

    Fournelle, J.; Hanchar, J. M.

    2013-12-01

    It is not commonly recognized as such, but the accurate measurement of Hf in zircon is not a trivial analytical issue. This is important to assess because Hf is often used as an internal standard for trace element analyses of zircon by LA-ICPMS. The issues pertaining to accuracy revolve around: (1) whether the Hf Ma or the La line is used; (2) what accelerating voltage is applied if Zr La is also measured, and (3) what standard for Hf is used. Weidenbach, et al.'s (2004) study of the 91500 zircon demonstrated the spread (in accuracy) of possible EPMA values for six EPMA labs, 2 of which used Hf Ma, 3 used Hf La, and one used Hf Lb, and standards ranged from HfO2, a ZrO2-HfO2 compound, Hf metal, and hafnon. Weidenbach, et al., used the ID-TIMS values as the correct value (0.695 wt.% Hf.), for which not one of the EPMA labs came close to that value (3 were low and 3 were high). Those data suggest: (1) that there is a systematic underestimation error of the 0.695 wt% Hf (ID-TIMS Hf) value if Hf Ma is used; most likely an issue with the matrix correction, as the analytical lines and absorption edges of Zr La, Si Ka and Hf Ma are rather tightly packed in the electromagnetic spectrum. Mass absorption coefficients are easily in error (e.g., Donovan's determination of the MAC of Hf by Si Ka of 5061 differs from the typically used Henke value of 5449 (Donovan et al, 2002); and (2) For utilization of the Hf La line, however, the second order Zr Ka line interferes with Hf La if the accelerating voltage is greater than 17.99 keV. If this higher keV is used and differential mode PHA is applied, only a portion of the interference is removed (e.g., removal of escape peaks), causing an overestimation of Hf content. Unfortunately, it is virtually impossible to apply an interference correction in this case, as it is impossible to locate Hf-free Zr probe standard. We have examined many of the combinations used by those six EPMA labs and concluded that the optimal EPMA is done with Hf

  17. Chemistry of H2O and HF Under Extreme Conditions

    SciTech Connect

    Fried, L; Goldman, N; Kuo, I W; Mundy, C

    2005-11-28

    The predicted high pressure superionic phases of water and HF are investigated via ab initio molecular dynamics. These phases could potentially be achieved through either static compression with heating or through shock compression. We study water at densities of 2.0-3.0 g/cc (34-115 GPa) along the 2000K isotherm.We find that extremely rapid (superionic) diffusion of protons occurs in a fluid phase at pressures between 34 and 58 GPa. A transition to a stable body-centered cubic (bcc) O lattice with superionic proton conductivity is observed between 70 and 75 GPa, a much higher pressure than suggested in prior work. We find that all molecular species at pressures greater than 75 GPa are too short lived to be classified as bound states. Up to 95 GPa, we find a solid superionic phase characterized by covalent O-H bonding. Above 95 GPa, a transient network phase is found characterized by symmetric O-H hydrogen bonding with nearly 50% covalent character. Ab initio molecular dynamics simulations of HF were conducted at densities of 1.8-4.0 g/cc along the 900 K isotherm. According to our simulations, a unique form of (symmetric) hydrogen bonding could play a significant role in superionic conduction. Our work shows that superionic phases could be more prevalent in hydrogen bonded systems than previously thought, such as HCl and HBr.

  18. Radiation effects in Zr and Hf containing garnets

    NASA Astrophysics Data System (ADS)

    Whittle, Karl R.; Blackford, Mark G.; Smith, Katherine L.; Zaluzec, Nestor J.; Weyland, Matthew; Lumpkin, Gregory R.

    2015-07-01

    Garnets have been considered as host phases for the safe immobilisation of high-level nuclear waste, as they have been shown to accommodate a wide range of elements across three different cation sites, such as Ca, Y, Mn on the a-site, Fe, Al, U, Zr, and Ti on the b-site, and Si, Fe, Al on the c-site. Garnets, due to their ability to have variable composition, make ideal model materials for the examination of radiation damage and recovery in nuclear materials, including as potential waste forms. Kimzeyite, Ca3Zr2FeAlSiO12, has been shown naturally to contain up to 30 wt% Zr, and has previously been examined to elucidate both the structure and ordering within the lattice. This study examines the effects of radiation damage and recovery using in-situ ion beam irradiation with 1 MeV Kr ions at the IVEM-TANDEM facility, Argonne National Laboratory. The complementary Hf containing system Ca3Hf2FeAlSiO12 was also examined, and found to have a different response to irradiation damage. A sample of irradiated Ca3Zr2FeAlSiO12, at 1000 K, was characterised using aberration corrected (S)TEM and found to contain discreet, nano-sized, crystalline Fe rich particles, indicating a competing process during recovery is occurring.

  19. Observations of HF backscatter decay rates from HAARP generated FAI

    NASA Astrophysics Data System (ADS)

    Bristow, William; Hysell, David

    2016-07-01

    Suitable experiments at the High-frequency Active Auroral Research Program (HAARP) facilities in Gakona, Alaska, create a region of ionospheric Field-Aligned Irregularities (FAI) that produces strong radar backscatter observed by the SuperDARN radar on Kodiak Island, Alaska. Creation of FAI in HF ionospheric modification experiments has been studied by a number of authors who have developed a rich theoretical background. The decay of the irregularities, however, has not been so widely studied yet it has the potential for providing estimates of the parameters of natural irregularity diffusion, which are difficult measure by other means. Hysell, et al. [1996] demonstrated using the decay of radar scatter above the Sura heating facility to estimate irregularity diffusion. A large database of radar backscatter from HAARP generated FAI has been collected over the years. Experiments often cycled the heater power on and off in a way that allowed estimates of the FAI decay rate. The database has been examined to extract decay time estimates and diffusion rates over a range of ionospheric conditions. This presentation will summarize the database and the estimated diffusion rates, and will discuss the potential for targeted experiments for aeronomy measurements. Hysell, D. L., M. C. Kelley, Y. M. Yampolski, V. S. Beley, A. V. Koloskov, P. V. Ponomarenko, and O. F. Tyrnov, HF radar observations of decaying artificial field aligned irregularities, J. Geophys. Res. , 101, 26,981, 1996.

  20. Multianode Photomultiplier Testing for 2013 CMS Hadronic Forward (HF) Upgrades

    NASA Astrophysics Data System (ADS)

    Funk, Garrett; Jia, Zhe; Onel, Yasar

    2012-03-01

    The Hadronic Forward (HF) section of the Compact Muon Solenoid, a detector at the Large Hadron Collider at CERN, will undergo various upgrades in 2013. HF requires photomultiplier tubes (PMTs) to detect the energy signatures of hadronic collisions. The University of Iowa High Energy Physics group is responsible for testing new PMTs for the upgrade. These tests provide seven different operational parameters that will be used for calibration and quality control before installation. The dark current test checks the noise generated by the PMTs at different voltages when there is no light source. The after pulse test measures the degradation of the vacuum chamber of each PMT as it relates to pulse noise. The gain test measures the degree of amplification provided by the PMT. This is the most vital test, as it allows for the reconstruction of the energies observed by the PMT. The surface non-uniformity test checks the active face of the PMTs for signal uniformity and ``hot spot'' sensitivity to light. The timing test observes the PMT's reading and recovery speed. The linearity test measures the tube's output under varying levels of light. The double pulse test checks the linearity of the PMT with two signals occurring 25 nanoseconds apart.

  1. Identification of triaxial strongly deformed band in {sup 168}Hf.

    SciTech Connect

    Yadav, R. B.; Ma, W. C.; Hagemann, G. B.; Bengtsson, R.; Ryde, H.; Carpenter, M. P.; Janssens, R. V. F.; Khoo, T. L.; Kondev, F. G.; Lauritsen, T.; Lister, C. J.; Mississippi State Univ.; Niels Bohr Inst.; Lund Inst. of Tech.; Lund. Univ.; Univ. di Milano; Univ. of Bonn; U.S. Naval Academy; Univ. of Oslo; Univ. of Tennessee

    2008-01-01

    Possible decay pathways associated with three candidates for triaxial strongly deformed (TSD) bands in {sup 168}Hf have been investigated. The spin and excitation energy of the strongest band, TSD1, were determined approximately based on {gamma}-ray coincidence relationships. Discrete links were established for the second band. The overall agreement between the observed properties of the bands and cranking calculations using the ULTIMATE CRANKER code provides strong support for an interpretation where band TSD1 is associated with a TSD minimum, ({var_epsilon}{sub 2},{gamma}) {approx} (0.43,20{sup o}), involving the {pi}(i{sub 13/2}){sup 2} and the {nu}(j{sub 15/2}) high-j orbitals. This constitutes the first identification of a TSD band in Hf isotopes, which has been long-predicted by theoretical studies. The second band is understood as being associated with a near-prolate shape and a deformation enhanced with respect to the normal deformed bands. It is proposed to be built on the {pi}(i{sub 13/2}h{sub 9/2}) {nu}(i{sub 13/2}){sup 2} configuration.

  2. Concerted hydrogen atom exchange between three HF molecules

    NASA Technical Reports Server (NTRS)

    Komornicki, Andrew; Dixon, David A.; Taylor, Peter R.

    1992-01-01

    We have investigated the termolecular reaction involving concerted hydrogen exchange between three HF molecules, with particular emphasis on the effects of correlation at the various stationary points along the reaction. Using an extended basis, we have located the geometries of the stable hydrogen-bonded trimer, which is of C(sub 3h) symmetry, and the transition state for hydrogen exchange, which is of D(sub 3h) symmetry. The energies of the exchange reation were then evaluated at the correlated level, using a large atomic natural orbital basis and correlating all valence electrons. Several correlation treatments were used, namely, configration interaction with single and double excitations, coupled-pair functional, and coupled-cluster methods. We are thus able to measure the effect of accounting for size-extensivity. Zero-point corrections to the correlated level energetics were determined using analytic second derivative techniques at the SCF level. Our best calculations, which include the effects of connected triple excitations in the coupled-cluster procedure, indicate that the trimer is bound by 9 +/- 1 kcal/mol relative to three separate monomers, in excellent agreement with previous estimates. The barrier to concerted hydrogen exchange is 15 kcal/mol above the trimer, or only 4.7 kcal/mol above three separated monomers. Thus the barrier to hydrogen exchange between HF molecules via this termolecular process is very low.

  3. Sleep-disordered breathing is associated with depletion of circulating endothelial progenitor cells and elevation in pulmonary arterial pressure in patients with decompensated systolic heart failure

    PubMed Central

    Zhang, Han; Feng, Liu; Wan, Qi-Lin; Hong, Yan; Li, Yan-Ming; Cheng, Guan-Chang; Han, Xin-Qiang

    2015-01-01

    Background Sleep-disordered breathing (SDB) is known to occur frequently in and may predict worsening progression of patients with congestive heart failure (CHF). SDB is also known to play an important role in the development of idiopathic pulmonary arterial hypertension (PAH) via inducing endothelial dysfunction and vascular remodeling, a pathological process that can be significantly influenced by factors such as osteoprotegerin (OPG) and endothelial progenitor cells (EPCs). The objective of this study is to determine if CHF with SDB is associated with changes in OPG, EPCs, and PAH. Methods EPCs were isolated, cultured, and quantified from CHF patients with SDB (n = 52), or without SDB (n = 68). OPG and N-terminal pro-brain natriuretic peptide (NT-proBNP) from each group was analyzed and correlated with EPCs and the mean pulmonary artery pressure (mPAP) measured by right heart catheterization. Results A significant decrease in circulating EPCs (29.30 ± 9.01 vs. 45.17 ± 10.51 EPCs/× 200 field; P < 0.05) was found in CHF patients with SDB compared to those without SDB. Both OPG (789.83 ± 89.38 vs. 551.29 ± 42.12 pg/mL; P < 0.05) and NT-proBNP (5946.50 ± 1434.50 vs. 3028.60 ± 811.90 ng/mL; P < 0.05) were also significantly elevated in SDB CHF patients who also had significantly elevated mPAP (50.2 ± 9.5 vs. 36.4 ± 4.1 mm Hg; P < 0.05). EPC numbers correlated inversely with the episodes of apnea and hypopnea per hour (RDI, r = –0.45, P = 0.037) and blood level of OPG (r = –0.53, P = 0.011). Although NT-proBNP was also increased significantly in patients with SDB, it had no correlation with either EPCs or RDI. Conclusions SDB due to hypoxemia from decompensated CHF is associated with (1) OPG elevation, (2) EPC depletion, and (3) mPAP elevation. The inverse relationship of circulating OPG with EPCs suggests a likely mechanism for hypoxemia and OPG in the development of pulmonary vascular dysfunction via depleting EPCs, thus worsening prognosis of CHF. PMID

  4. Acute pain.

    PubMed

    Good, M

    1999-01-01

    The review of acute pain describes the problem of unresolved pain and its effects on the neural, autonomic, and immune systems. Conceptualizations and mechanisms of pain are reviewed as well as theories of pain management. Descriptive studies of patient and nurse factors that inhibit effective pain management are discussed, followed by studies of pharmacological and nonpharmacological interventions. Critical analysis reveals that most studies were atheoretical, and therefore, this proliferation of information lacked conceptual coherence and organization. Furthermore, the nature and extent of barriers to pain management were described, but few intervention studies have been devised, as yet, to modify the knowledge, beliefs, and attitudes of nurses and patients that are barriers to pain management. Although some of the complementary therapies have sufficient research support to be used in clinical pain management, the physiological mechanisms and outcomes need to be studied. It is critical at this time to design studies of interventions to improve assessment, decision making, attentive care, and patient teaching. PMID:10418655

  5. Evolution of continental crust and mantle heterogeneity: Evidence from Hf isotopes

    USGS Publications Warehouse

    Jonathan, Patchett P.; Kouvo, O.; Hedge, C.E.; Tatsumoto, M.

    1982-01-01

    We present initial 176Hf/177 Hf ratios for many samples of continental crust 3.7-0.3 Gy old. Results are based chiefly on zircons (1% Hf) and whole rocks: zircons are shown to be reliable carriers of essentially the initial Hf itself when properly chosen on the basis of U-Pb studies. Pre-3.0 Gy gneisses were apparently derived from an unfractionated mantle, but both depleted and undepleted mantle are evident as magma sources from 2.9 Gy to present. This mantle was sampled mainly from major crustal growth episodes 2.8, 1.8 and 0.7 Gy ago, all of which show gross heterogeneity of 176Hf/177Hf in magma sources from ??Hf=0 to +14, or about 60% of the variability of the present mantle. The approximate ??Hf=2??Nd relationship in ancient and modern igneous rocks shows that 176Lu/177Hf fractionates in general twice as much as 147Sm/144Nd in mantle melting processes. This allows an estimation of the relative value of the unknown bulk solid/liquid distribution coefficient for Hf. DLu/DHf=??? 2.3 holds for most mantle source regions. For garnet to be an important residual mantle phase, it must hold Hf strongly in order to preserve Hf-Nd isotopic relationships. The ancient Hf initials are consistent with only a small proportion of recycled older cratons in new continental crust, and with quasi-continuous, episodic growth of the continental crust with time. However, recycling of crust less than 150 My old cannot realistically be detected using Hf initials. The mantle shows clearly the general positive ??Hf resulting from a residual geochemical state at least back to 2.9 Gy ago, and seems to have repeatedly possessed a similar degree of heterogeneity, rather than a continuously-developing depletion. This is consistent with a complex dynamic disequilibrium model for the creation, maintenance and destruction of heterogeneity in the mantle. ?? 1981 Springer-Verlag.

  6. The role of Upper Hybrid Turbulence on HF Artificial Ionization

    NASA Astrophysics Data System (ADS)

    Papadopoulos, Konstantinos Dennis; Najmi, Amir; Eliasson, Bengt; Milikh, Gennady

    2016-07-01

    One of the most fascinating and scientifically interesting phenomena of active space experiments is the discovery of artificial ionization by Todd Pedersen when the HAARP ERP reached the GW level. The phenomenon has been well documented experimentally. A theoretical model based on ionization by energetic electrons accelerated by 50-100 V/m localized electric fields due to Strong Langmuir Turbulence (SLT) near the reflection surface of the HF pump wave, reproduced the observed dynamics of the descending plasma layer quite accurately. A major defect of the model was that the electron temperature in the SLT region was a free parameter. When taken as the 2000 K representing the ambient electron temperature the SLT driven electron flux was insufficient to produce ionization. An equivalent electron temperature of 5000 K or higher was necessary to reproduce the observations. The needed electron heating was attributed to the interaction of the HF at the Upper Hybrid (UH) resonant layer, approximately 5 Km below the reflection region where the HF electric field is perpendicular to the ambient magnetic field. The heated electrons expanded upwards along the magnetic field line and interacted with SLT fields near the resonance region. A consequence of this defect was that the theory could not explain the puzzling double resonance effect. Namely the observation that the ionization level was much stronger when the HF frequency and the UH resonance were a multiple of the electron cyclotron frequency. To remedy this we used a series of Vlasov simulations to explore the HF-plasma interaction in the vicinity of the UH resonance. The simulations followed the evolution of the spectral density of the electric field over a 7.5 MHz frequency band and cm scale lengths and of the electron distribution function over one millisecond for both double resonant and non-resonant cases. Many new features were revealed by the analysis of the simulations such as: 1. Broadening of the wave

  7. Acute heart failure: inotropic agents and their clinical uses.

    PubMed

    Endoh, Masao; Hori, Masatsugu

    2006-11-01

    Inotropic agents are indispensable for the improvement of cardiac contractile dysfunction in acute or decompensated heart failure. Clinically available agents, including sympathomimetic amines (dopamine, dobutamine, noradrenaline) and selective phosphodiesterase-3 inhibitors (amrinone, milrinone, olprinone and enoximone) act via cAMP/protein kinase A (PKA)-mediated facilitation of intracellular Ca2+ mobilisation. Phosphodiesterase-3 inhibitors also have a vasodilatory action, which plays a role in improving haemodynamic parameters in certain patients, and are termed inodilators. The available inotropic agents suffer from risks of Ca2+ overload leading to arrhythmias, myocardial cell injury and ultimately, cell death. In addition, they are energetically disadvantageous because of an increase in activation energy and cellular metabolism. Furthermore, they lose their effectiveness under pathophysiological conditions, such as acidosis, stunned myocardium and heart failure. Pimobendan and levosimendan (that act by a combination of an increase in Ca2+ sensitivity and phosphodiesterase-3 inhibition) appear to be more beneficial among existing agents. Novel Ca2+ sensitisers that are under basic research warrant clinical trials to replace available inotropic agents. PMID:17059376

  8. Enhancement of longitudinal magneto-optical Kerr effect in HfO2/Co/HfO2/Al/silicon thin films

    NASA Astrophysics Data System (ADS)

    Zhang, Shaoyin; Gao, Jinlong; Xia, Wenbin; Chen, Leyi; Tang, Yanmei; Li, Daoyong; Tang, Shaolong; Du, Youwei

    2014-06-01

    In this paper, the longitudinal magneto-optical Kerr effect (MOKE) properties of the quadrilayer structure HfO2/Co/HfO2/Al/silicon are investigated experimentally and theoretically. The cavity enhancement of HfO2 on the magneto-optical (MO) Kerr response of the quadrilayer has been confirmed. The giant longitudinal Kerr rotation of -1.04° at wavelength of 570 nm is tested when the cap and intermediate HfO2 layer thicknesses are 15 nm and 30 nm, respectively. The longitudinal Kerr rotation reversal in the wavelength range (440-720 nm) is also observed. It is strongly suggested that the enhanced MOKE stems from the optical reflection and interference of the quadrilayer structure.

  9. Analysis and Measurement of Volume Change by Transformation of Crystal Between Hf and HfOx Thin Film During Oxidation Using Nanoindenter.

    PubMed

    Park, Myung Joon; Kim, Soo In; Lee, Chang Woo

    2015-10-01

    In this study, nanomechanical properties were analyzed using a nanotribology method. The nanoindenter system is the main analysis method in nanotribology. The nanoindenter can measure the induced stresses, elastic modulus, and stabilities of Hf and HfO2 thin film surfaces as a function of the annealing temperature. The surface hardness and elastic modulus decreased, except at 600 °C, from 8.1 to 6.22 GPa and from 143.87 to 93.68 GPa, respectively, as the annealing temperature was increased from the as-deposited state to 800 °C. These results were related to the surface oxidation of the Hf thin film or the formation of a HfO2 monoclinic crystal. The change in the crystal structure caused an increase in volume that subsequently induced a compressive stress. PMID:26726379

  10. Evolution of E 2 transition strength in deformed hafnium isotopes from new measurements on 172Hf,174Hf, and 176Hf

    NASA Astrophysics Data System (ADS)

    Rudigier, M.; Nomura, K.; Dannhoff, M.; Gerst, R.-B.; Jolie, J.; Saed-Samii, N.; Stegemann, S.; Régis, J.-M.; Robledo, L. M.; Rodríguez-Guzmán, R.; Blazhev, A.; Fransen, Ch.; Warr, N.; Zell, K. O.

    2015-04-01

    Background: The available data for E 2 transition strengths in the region between neutron-deficient hafnium and platinum isotopes are far from complete. More and precise data are needed to enhance the picture of structure evolution in this region and to test state-of-the-art nuclear models. In a simple model, the maximum collectivity is expected at the middle of the major shell. However, for actual nuclei, particularly in heavy-mass regions, which should be highly complex, this picture may no longer be the case, and one should use a more realistic nuclear-structure model. We address this point by studying the spectroscopy of Hf as a representative case. Purpose: We remeasure the 21+ half-lives of 172,174,176Hf, for which there is some disagreement in the literature. The main goal is to measure, for the first time, the half-lives of higher-lying states of the rotational band. The new results are compared to a theoretical calculation for absolute transition strengths. Method: The half-lives were measured using γ -γ and conversion-electron-γ delayed coincidences with the fast timing method. For the determination of half-lives in the picosecond region, the generalized centroid difference method was applied. For the theoretical calculation of the spectroscopic properties, the interacting boson model is employed, whose Hamiltonian is determined based on microscopic energy-density functional calculations. Results: The measured 21+ half-lives disagree with results from earlier γ -γ fast timing measurements, but are in agreement with data from Coulomb excitation experiments and other methods. Half-lives of the 41+ and 61+ states were measured, as well as a lower limit for the 81+ states. Conclusions: This work shows the importance of a mass-dependent effective boson charge in the interacting boson model for the description of E 2 transition rates in chains of nuclei. It encourages further studies of the microscopic origin of this mass dependence. New experimental

  11. Natriuretic peptides for the treatment of acute heart failure: a focus on nesiritide in recent clinical trials.

    PubMed

    Fajardo, Jeff; Heywood, J Thomas; Patterson, J Herbert; Adams, Kirkwood; Chow, Sheryl L

    2015-01-01

    Nesiritide, a recombinant form of B-type natriuretic peptide, is a vasodilator and currently recommended as an additive therapy for patients with acute decompensated heart failure (ADHF) who have been optimized on loop diuretics. With hospitalizations for ADHF rising, appropriate selection of therapy becomes even more important to optimize efficacy and reduce adverse events. Nesiritide has many properties that antagonize the pathophysiologic processes of heart failure and has demonstrated a comparative benefit in previous reports; however, controversy still remains with respect to its efficacy and safety. Based on results from recent clinical trials, nesiritide has been shown to be safe at currently approved doses and strongly considered for the treatment of ADHF in patients who remain symptomatic despite optimal doses of intravenous loop divertics. PMID:26028173

  12. Exposure to Discrimination and Heart Rate Variability Reactivity to Acute Stress among Women with Diabetes.

    PubMed

    Wagner, Julie; Lampert, Rachel; Tennen, Howard; Feinn, Richard

    2015-08-01

    Exposure to racial discrimination has been linked to physiological reactivity. This study investigated self-reported exposure to racial discrimination and parasympathetic [high-frequency heart rate variability (HF-HRV)] and sympathetic (norepinephrine and cortisol) activity at baseline and then again after acute laboratory stress. Lifetime exposure to racial discrimination was measured with the Schedule of Racist Events scale. Thirty-two women (16 Black and 16 White) with type 2 diabetes performed a public speaking stressor. Beat-to-beat intervals were recorded on electrocardiograph recorders, and HF-HRV was calculated using spectral analysis and natural log transformed. Norepinephrine and cortisol were measured in blood. Higher discrimination predicted lower stressor HF-HRV, even after controlling for baseline HF-HRV. When race, age, A1c and baseline systolic blood pressure were also controlled, racial discrimination remained a significant independent predictor of stressor HF-HRV. There was no association between lifetime discrimination and sympathetic markers. In conclusion, preliminary data suggest that among women with type 2 diabetes mellitus (T2DM), exposure to racial discrimination is adversely associated with parasympathetic, but not sympathetic, reactivity. PMID:24194397

  13. Doppler shift simulation of scattered HF signals during the Tromsø HF pumping experiment on 16 February 1996

    NASA Astrophysics Data System (ADS)

    Borisova, T. D.; Blagoveshchenskaya, N. F.; Moskvin, I. V.; Rietveld, M. T.; Kosch, M. J.; Thidé, B.

    2002-09-01

    Comparisons between bistatic scatter measurements and simulation results during the Tromsø HF pumping experiment on 16 February 1996 are made. Doppler measurements of an HF diagnostic signal scattered from the field-aligned irregularities (FAIs) in the auroral E-region were carried out on the London Tromsø St. Petersburg path at 9410 kHz from 21:00 to 22:00 UT. The scattered signals were observed both from natural and artificial ionospheric irregularities located in the vicinity of Tromsø. To simulate the Doppler frequency shifts, fd , of scattered signals, a radio channel model, named CONE, was developed. The model allows for ray tracing, group and phase paths, and Doppler frequency shift calculations. The calculated Doppler shifts were analyzed for dependence on the magnitude and direction of plasma velocities in the scattering volume. It was found that the velocity components in the north-south direction are crucial for explaining the Doppler frequency shifts of the scattered diagnostic signals. To simulate fd , real velocities obtained from the EISCAT UHF radar at an altitude of 278 km and from the digital all-sky imager during the experiment were employed. The simulation results of Doppler frequency shift variations with time are in reasonable agreement with the experimental Doppler shifts of scattered signals on the London Tromsø St. Petersburg path.

  14. Structural characterization of Nd-doped Hf-zirconolite Ca 1-xNd xHfTi 2-xAl xO 7 ceramics

    NASA Astrophysics Data System (ADS)

    Caurant, Daniel; Loiseau, Pascal; Bardez, Isabelle

    2010-12-01

    Because of its high incorporation capacity and of the high thermal neutron capture cross-section of hafnium, Hf-zirconolite (CaHfTi 2O 7) ceramic can be envisaged as a potential waste form for minor actinides (Np, Am, Cm) and plutonium immobilization. In this work, Nd-doped Hf-zirconolite Ca 1-xNd xHfTi 2-xAl xO 7 ( x = 0; 0.01 and 0.2) ceramics have been prepared by solid state reaction. Neodymium has been used as trivalent actinide surrogate. The ceramic samples structure has been studied by X-ray diffraction and refined by the Rietveld method. This revealed that Nd 3+ ions only enter the Ca site, whereas part of Hf 4+ ions substitute titanium into Ti(1) sites and Al 3+ ions mainly occupy the Ti(2) split sites and Ti(3) sites of the zirconolite structure. Using various spectroscopic techniques (electron spin resonance, optical absorption and fluorescence), the environment of Nd 3+ cations in Hf-zirconolite has been studied and compared with that of Nd 3+ cations in Zr-zirconolite (CaZrTi 2O 7). Different local environments of Nd 3+ cations have been detected in Hf-zirconolite that can be attributed to the existence of an important disorder around Nd in the Ca site probably due to the statistical occupancy of the next nearest cationic site of neodymium (a split Ti site) by Ti 4+, Al 3+ cations and vacancies. No significant differences were observed concerning Nd 3+ cations environment and distribution in Hf- and Zr-zirconolite ceramics.

  15. Investigation on electronic, mechanical and thermal properties of Hf-H system

    NASA Astrophysics Data System (ADS)

    Wang, Hao; Konashi, Kenji

    2013-11-01

    Hf hydride is proposed to be used as neutron control materials for fast reactors. The electronic, mechanical and thermal properties of its three phases: δ‧-HfH1.5, δ-HfH1.75, ε-HfH2, are investigated. Their relative stabilities at 0 K by our calculation are consistent with the explanation of Jahn-Teller mechanism. The mechanical properties like elastic constants are calculated and agree well with the experiments. At finite temperatures, in addition to the direct method for phonon calculation, electronic free energy is also calculated in order to investigate the thermal expansion and bulk moduli of three phases. Hf-H system has an increasing relationship in bulk moduli with respect to the H concentration before about 360 K, after which ε-HfH2 seems to decrease more quickly in the softness of the structure than δ-HfH1.75 as the temperature increases. The relation between heat capacity and Hf and H atoms vibration is discussed.

  16. Lu-Hf and Sm-Nd evolution in lunar mare basalts

    NASA Technical Reports Server (NTRS)

    Unruh, D. M.; Tatsumoto, M.; Stille, P.; Patchett, P. J.

    1984-01-01

    Existing cumulate remelting models for mare basalt genesis are evaluated in light of Lu-Hf, Rb-Sr, Sm-Nd data and overall REE characteristics in order to determine the simplest model that can account for these data. A data base for comparing Lu-Hf evolution in the lunar mantle as inferred from Lu-Hf analyses of oceanic basalts is presented along with a preliminary comparison of Lu-Hf and Sm-Nd evolution betwee mare basalts and terrestrial oceanic basalts. It is found that Lu/Hf characteristics of mare basalts cannot be explained in terms of modal melting of cumulate sources formed from a magma ocean with chondritic Lu/Hf. The data are consistent with a model in which the cumulate sources formed from a light REE + HF-enriched magma ocean. Nonmodal melting of ilmenite in the sources is also required. The Lu-Hf data suggest that even the high-Ti basalt sources contained no more than about 3 percent ilmenite.

  17. Effects of constant voltage stressing on HfTaOx/SiGe gate stack

    NASA Astrophysics Data System (ADS)

    Mallik, S.; Mahata, C.; Hota, M. K.; Sarkar, C. K.; Maiti, C. K.

    2012-10-01

    Ultrathin HfTaOx gate dielectric has been deposited on Si0.81Ge0.19 by RF co-sputtering of HfO2 and Ta2O5 targets. X-ray photoelectron spectroscopic (XPS) analyses indicate an interfacial layer containing GeOx, Hf silicate, SiOx (layer of Hf- Si-Ge-O) formation during deposition of HfTaOx. No evidence of Ta-silicate or Ta incorporation was found at the interface. X-ray diffraction (GIXRD) measurements show that as-deposited HfTaOx films are amorphous; however, the crystallization temperature of HfTaOx film is found to increase significantly after annealing beyond 500 °C (for 5 min) along with the incorporation of Ta (with 18% Ta). It has been found that HfTaOx gate dielectric on Si0.81Ge0.19 exhibit excellent electrical properties with low interface state density (~6.0×1011 cm-2eV-1) and hysteresis voltage (<70 mV). Charge trapping/detrapping behavior of the gate stacks has been studied under constant voltage stressing and the degradation mechanism of the dielectrics has been studied in detail.

  18. Role of HF in oxygen removal from carbon nanotubes: implications for high performance carbon electronics.

    PubMed

    Li, Xiaokai; Huang, Jing-Shun; Nejati, Siamak; McMillon, Lyndsey; Huang, Su; Osuji, Chinedum O; Hazari, Nilay; Taylor, André D

    2014-11-12

    Oxygen removal from SWNTs is crucial for many carbon electronic devices. This work shows that HF treatment followed by current stimulation is a very effective method for oxygen removal. Using a procedure involving HF treatment, current stimulation and spin-casting AgNWs onto a SWNT thin film, record high efficiency SWNT/p-Si solar cells have been developed. PMID:25286024

  19. Fast neutron capture on the Hf isotopes: Cross sections, isomer production, and stellar aspects

    SciTech Connect

    Wisshak, K.; Voss, F.; Kaeppeler, F.; Kazakov, L.; Becvar, F.; Krticka, M.; Gallino, R.; Pignatari, M.

    2006-04-15

    The (n,{gamma}) cross sections of {sup 176}Hf, {sup 177}Hf, {sup 178}Hf, {sup 179}Hf, and {sup 180}Hf have been measured in the energy range from 3 to 225 keV relative to the gold standard. Neutrons were produced via the {sup 7}Li(p,n){sup 7}Be reaction and capture events were registered with the Karlsruhe 4{pi} barium fluoride detector. The overall uncertainties are between 0.9 and 2.6%, about 5 times smaller than in previous experiments. Partial cross sections to ground and isomeric states could be experimentally identified for neutron capture on {sup 176,177,178,179}Hf, indicating a strong population of yet-unknown isomeric states in {sup 177}Hf and {sup 180}Hf. This feature was confirmed by extensive GEANT simulations based on calculated capture cascades. The deduced Maxwellian-averaged (n,{gamma}) cross sections for thermal energies between kT=8 and 100 keV contribute to the analysis of the s-process branchings at A=176 and A=179/180 and have significant consequences for the separation of the solar s- and r-process components.

  20. MoS2 on an amorphous HfO2 surface: An ab initio investigation

    NASA Astrophysics Data System (ADS)

    Scopel, W. L.; Miwa, R. H.; Schmidt, T. M.; Venezuela, P.

    2015-05-01

    The energetic stability, electronic and structural properties of MoS2 adsorbed on an amorphous a-HfO2 surface (MoS2/HfO2) are examined through ab initio theoretical investigations. Our total energy results indicate that the formation of MoS2/HfO2 is an exothermic process with an adsorption energy of 34 meV/Å2, which means that it is more stable than similar systems like graphene/HfO2 and MoS2/SiO2. There are no chemical bonds at the MoS2-HfO2 interface. Upon formation of MoS2/HfO2, the electronic charge distribution is mostly localized at the interface region with no net charge transfer between the adsorbed MoS2 sheet and -HfO2 surface. However, the MoS2 sheet becomes n-type doped when there are oxygen vacancies in the HfO2 surface. Further investigation of the electronic distribution reveals that there are no electron- and hole-rich regions (electron-hole puddles) on the MoS2 sheet, which makes this system promising for use in high-speed nanoelectronic devices.

  1. Interfacial and structural properties of sputtered HfO{sub 2} layers

    SciTech Connect

    Aygun, G.; Yildiz, I.

    2009-07-01

    Magnetron sputtered HfO{sub 2} layers formed on a heated Si substrate were studied by spectroscopic ellipsometer (SE), x-ray diffraction (XRD), Fourier transform infrared (FTIR), and x-ray photoelectron spectroscopy (XPS) depth profiling techniques. The results show that the formation of a SiO{sub x} suboxide layer at the HfO{sub 2}/Si interface is unavoidable. The HfO{sub 2} thickness and suboxide formation are highly affected by the growth parameters such as sputtering power, O{sub 2}/Ar gas ratio during sputtering, sputtering time, and substrate temperature. XRD spectra show that the deposited film has (111) monoclinic phase of HfO{sub 2}, which is also supported by FTIR spectra. The atomic concentration and chemical environment of Si, Hf, and O have been measured as a function of depth starting from the surface of the sample by XPS technique. It shows that HfO{sub 2} layers of a few nanometers are formed at the top surface. Below this thin layer, Si-Si bonds are detected just before the Si suboxide layer, and then the Si substrate is reached during the depth profiling by XPS. It is clearly understood that the highly reactive sputtered Hf atoms consume some of the oxygen atoms from the underlying SiO{sub 2} to form HfO{sub 2}, leaving Si-Si bonds behind.

  2. Measurement and analysis of muonic x rays of 176,177,178,179,180Hf

    NASA Astrophysics Data System (ADS)

    Tanaka, Y.; Steffen, R. M.; Shera, E. B.; Reuter, W.; Hoehn, M. V.; Zumbro, J. D.

    1984-07-01

    Monopole and quadrupole charge distributions of 176Hf, 177Hf, 178Hf, 179Hf, and 180Hf were investigated by muonic atom K and L x-ray measurements. The model-independent Barrett charge radii Rk and the isotope shifts ΔRk were measured, and values of and Δ were deduced. A weak odd-even staggering of the nuclear charge radii was observed for the series 176-178Hf and 178-180Hf. A large negative isomer shift was observed in the 2+ state of the 176Hf nucleus, a fact that existing theories do not explain. The quadrupole moments of the first excited states of the hafnium nuclei were determined to be Q176(2+)=-2.10(2) e b, Q177(92-)=1.30(2) e b, Q178(2+)=-2.02(2) e b, Q179(112+)=1.88(3) e b, and Q180(2+)=-2.00(2) e b. These quadrupole moments and the simultaneously determined B (E 2) values for the respective nuclei are in satisfactory agreement with the predictions of the axially symmetric rotor model.

  3. Interface properties of Ge on cubic SrHfO3 (001)

    NASA Astrophysics Data System (ADS)

    Wang, Jianli; Wang, Chenxiang; Tang, Gang; Zhang, Junting; Guo, Sandong; Han, Yujia

    2016-06-01

    High quality Ge-on-high-k oxide interface is essential to facilitate the high performance metal-oxide semiconductor field-effect transistors and monolithically integrated optoelectronics device performance. The atomic structure and electronic properties of Ge on perfect and defective (001) SrHfO3 are investigated by first-principle calculations. The amplitude of the surface rumpling for the SrO-terminated surface is much larger than that for HfO2-terminated surface, although both SrO- and HfO2-terminated surfaces are stable for a comparable range of the HfO2 chemical potential. The distance between the first and second planes compresses while that of the second and third planes expands due to the relaxation of the slab. We investigated systematically the specific adsorption sites and the atomic structure at the initial growth stage of Ge on the SrHfO3 (001) substrate. The top sites of the oxygen atoms are favorable for 1/2 (1/3) monolayer Ge adsorbate at SrO (HfO2)-terminated surface. We calculated the surface grand potential and presented the complete surface phase diagram. We also pointed out the energetically favorable interfaces among the atomic arrangements of the Ge/SrHfO3 (001) interfaces. The atomic structure and electronic properties of the intrinsic point defects were calculated and analyzed for the Ge/SrHfO3 (001) interfaces.

  4. Hf-Nd Isotopic and Trace-Element Geochemistry of Global Subducting Sediments

    NASA Astrophysics Data System (ADS)

    Vervoort, J. D.; Plank, T.; Patchett, P. J.

    2001-12-01

    Ferromanganese nodules, crusts, and associated metalliferous clays have long been known to have anomalously high Lu/Hf ratios and highly radiogenic Hf relative to Nd (Patchett et al., 1984; White et al., 1986). These oceanic sediments are some of the few terrestrial materials where Hf and Nd isotopes deviate from the crust-mantle array. This distinctive isotopic signature, therefore, has the potential to trace the fate of oceanic sediments through the subduction zone and into the mantle. It has recently been suggested, for example, that pelagic sediments can be detected in some Hawaiian basalts (Blichert-Toft et al., 1999) and in volcanic rocks from the Luzon arc (Marini et al., 2000) based on their Hf-Nd isotopic compositions. The weak link in this approach, however, is that we do not know, in any quantitative way, how widespread this anomalous signature is in oceanic sediments, what compositions are responsible for this signature, or how volumetrically important these compositions are in terms of the total sediment flux into subduction zones and the mantle. Most marine sediments analyzed thus far have been collected on or near the ocean floor and constitute an incomplete and unrepresentative inventory of the sediment column bound for the subduction zone. There is some reason to suspect that much of the sediment flux is not particularly anomalous, either in terms of Lu/Hf ratios or Hf and Nd isotopic compositions. The most dominant sediment types entering many subduction zones (terrigenous and other continentally derived sediments), have normal Lu/Hf ratios and Hf-Nd isotopic compositions that are indistinguishable from the crust-mantle array. An examination is needed of the Hf-Nd isotopic composition of oceanic sediments, the major and trace-element geochemistry of global sediment flux, how such compositions may relate to Hf-Nd isotopic behavior, and potential Lu/Hf and Nd/Hf fractionation in subduction zones. In addition, the origin of the high Lu/Hf and

  5. Schirmwirkung von Hochfrequenz (HF)-Schutzkleidung: Untersuchung verschiedener Konstruktionsmerkmale

    NASA Astrophysics Data System (ADS)

    Arps, V.; Scheibe, K.

    2005-05-01

    Die Messverfahren zur Bestimmung der Schutzwirkung von HF-Schutzkleidung sind in der Norm DIN 32780-100 festgelegt. Entsprechend diesen Anforderungen wird die elektrische und magnetische Schirmdämpfung bestimmt und daraus als Maß für die Schutzwirkung die elektromagnetische Schirmdämpfung berechnet. Diese ist eine der SAR vergleichbare Größe. In diesem Beitrag werden die Einflüsse verschiedener Konstruktionsmerkmale von HF-Schutzanzügen auf die elektromagnetische Schirmdämpfung untersucht. Zu diesen gehören die nach MIL STD 285 vermessene elektrische Schirmdämpfung der verwendeten Gewebe. Weiter werden verschiedene Teilbereiche der HF-Schutzkleidung auf ihre Schutzwirkung untersucht. Der Schwerpunkt liegt hierbei auf der Fragestellung inwieweit Verschlüsse, Reißverschlüsse oder leitfähiges Klettband, die Schutzwirkung beeinträchtigen. Zu diesem Zweck werden zwei Schutzanzüge unterschiedlicher Konstruktion vergleichend vermessen. Es handelt sich dabei um einen bereits im Handel befindlichen und entsprechend der Norm zertifizierten Anzug und einen neuen Prototyp, welcher nach verschiedenen Gesichtspunkten optimiert wurde. Schwachstellen der Konstruktion werden herausgearbeitet und Ansatzpunkte für weitere Verbesserungen erarbeitet. The measuring methods for determining the shielding effectiveness of radiofrequency (RF)-protective clothing are defined in German Standard DIN 32780-100. According to this standard, both the electric and the magnetic shielding effectiveness are measured in order to calculate the electromagnetic shielding effectiveness. The electromagnetic shielding effectiveness is an adequate quality criterion for the degree of protection and also compares well with the Specific Absorption Rate (SAR). In this article, the impact of different design features on the electromagnetic shielding effectiveness is analyzed. The electric shielding effectiveness of the used shielding materials is measured according to MIL STD 285 and thereupon

  6. Lu-Hf AND Sm-Nd EVOLUTION IN LUNAR MARE BASALTS.

    USGS Publications Warehouse

    Unruh, D.M.; Stille, P.; Patchett, P.J.; Tatsumoto, M.

    1984-01-01

    Lu-Hf and Sm-Nd data for mare basalts combined with Rb-Sr and total REE data taken from the literature suggest that the mare basalts were derived by small ( less than equivalent to 10%) degrees of partial melting of cumulate sources, but that the magma ocean from which these sources formed was light REE and hf-enriched. Calculated source compositions range from lherzolite to olivine websterite. Nonmodal melting of small amounts of ilmenite ( less than equivalent to 3%) in the sources seems to be required by the Lu/Hf data. A comparison of the Hf and Nd isotopic characteristics between the mare basalts and terrestrial oceanic basalts reveals that the epsilon Hf/ epsilon Nd ratios in low-Ti mare basalts are much higher than in terrestrial ocean basalts.

  7. Oxidation behavior and mechanical properties of laminated Hf-Ta coatings

    NASA Astrophysics Data System (ADS)

    Chen, Yung-I.; Huang, Yu-Ren; Chang, Li-Chun

    2015-11-01

    This study explores the internal oxidation of laminated Hf-Ta coatings with a cyclically gradient chemical concentration distribution along the growth direction. The oxidation behavior was examined by annealing the coatings at 400-600 °C in a 15 ppm O2-N2 atmosphere for 30 min. The variations in crystalline structure, nanohardness, chemical states, and chemical composition profiles in depth after various annealing conditions were investigated. The results indicate that all the Hf-Ta coatings maintain a laminated structure after annealing at 400-600 °C. Internal oxidation conducts during 500 and 600 °C annealing, but part of the outmost layers exhibits complex oxides after annealing at 600 °C. The nanohardness of annealed Hf-Ta coatings related to the formation of HfO2, Hf6Ta2O17, and amorphous Ta-oxide were studied.

  8. Synthesis of polymorph A-enriched beta zeolites in a HF-concentrated system.

    PubMed

    Zhang, Guanqun; Wang, Bingchun; Zhang, Weiping; Li, Mingrun; Tian, Zhijian

    2016-04-21

    Polymorph A-enriched beta zeolites were synthesized by employing high HF concentrations in the synthesis medium. The polymorphic compositions of the synthesized beta zeolites were determined by the complementary characterization methods (19)F NMR analysis and PXRD simulation. With a variety of SDAs, a high HF concentration (HF/SDA > 1.0) in the synthesis medium results in the A-rich feature (55-65% A) of beta zeolites, while a moderate HF concentration only results in typical beta zeolites. A systematic study on the synthesis conditions reveals the existence of a buffered system of H(+) and F(-) formed in the highly HF-concentrated medium. This buffer results in a small but continuous supply of F(-) during zeolite crystallization, in contrast to the conventional fluoride route where all F(-) are discharged all-at-once at the initial stage. PMID:26974286

  9. Room temperature interactions of water vapor with HfO2 films on Si

    NASA Astrophysics Data System (ADS)

    Driemeier, C.; Gusev, E. P.; Baumvol, I. J. R.

    2006-05-01

    HfO2/SiO2/Si(001) thin film structures were exposed at room temperature to water vapor isotopically enriched in H2 and O18 followed by quantification and profiling of these nuclides by nuclear reaction analysis. We showed (i) the formation of strongly bonded hydroxyls at the HfO2 surface; (ii) room temperature migration of oxygen and water-derived oxygenous species through the HfO2 films, indicating that HfO2 is a weak diffusion barrier for these oxidizing species; (iii) hydrogenous, water-derived species attachment to the SiO2 interlayer, resulting in detrimental hydrogenous defects therein. Consequences of these results to HfO2-based metal-oxide-semiconductor devices are discussed.

  10. Spectroscopic analysis of Al and N diffusion in HfO2

    NASA Astrophysics Data System (ADS)

    Lysaght, P. S.; Woicik, J. C.; Sahiner, M. A.; Price, J.; Weiland, C.; Kirsch, P. D.

    2012-09-01

    X-ray photoelectron core level spectroscopy, secondary ion mass spectroscopy, spectroscopic ellipsometry, and extended x-ray absorption fine structure measurements have been employed to distinguish the effects of Al and N diffusion on the local bonding and microstructure of HfO2 and its interface with the Si substrate in (001)Si/SiOx/2 nm HfO2/1 nm AlOx film structures. The diffusion of Al from the thin AlOx cap layer deposited on both annealed and unannealed HfO2 has been observed following anneal in N2 and NH3 ambient. Both N2 and NH3 subsequent anneals were performed to decouple incorporated nitrogen from thermal reactions alone. Causal variations in the HfO2 microstructure combined with the dependence of Al and N diffusion on initial HfO2 conditions are presented with respect to anneal temperature and ambient.

  11. Mid-latitude Ionospheric HF Channel Reciprocity: Evidence from the Ionospheric Oblique Incidence Sounding Experiments

    NASA Astrophysics Data System (ADS)

    Zhou, Chen; Zhao, Zhengyu; Zhang, Yuannong

    The mid-latitude ionospheric HF channel reciprocity is studied in this paper through theoret-ical considerations and ionospheric oblique incidence sounding experiments. The reciprocity of ionospheric HF channel experiments were carried out by using two identical Wuhan Iono-spheric Oblique Incidence Sounding Systems (WIOISS) located in Wuhan (30° 32N, 114° 21E) and Wanning (18° 58N, 110° 31E) respectively. The comparisons of group distance and Doppler shift between Wuhan-Wanning and Wanning-Wuhan HF ionospheric propagation paths show that the reciprocity of ionospheric HF channel is satisfied to some extent. The group dis-tances of two paths are calculated by a 3-D ray tracing simulation as well. The theoretical and experimental results could be widely used for HF communication systems and sky wave over-the-horizon radar.

  12. Midlatitude ionospheric HF channel reciprocity: Evidence from the ionospheric oblique incidence sounding experiments

    NASA Astrophysics Data System (ADS)

    Zhou, Chen; Zhao, Zhengyu; Deng, Feng; Ni, Binbin; Chen, Gang

    2010-12-01

    Ionospheric HF channel reciprocity is investigated at middle latitudes on the basis of ionospheric oblique incidence sounding experiments. Two identical Wuhan Ionospheric Oblique Incidence Sounding Systems (WIOISS), located at Wuhan (30°32'N, 114°21'E) and Wanning (18°58'N, 110°31'E), are used to carry out the campaign. Comparisons of group distance and Doppler shift between Wuhan-Wanning and Wanning-Wuhan HF ionospheric propagation paths indicate that the reciprocity of the ionospheric HF channel is satisfied at midlatitude region. A 3-D ray tracing simulation is also implemented to evaluate the group distances of the two paths. Midlatitude ionospheric HF channel reciprocity, as verified both experimentally and theoretically in the present study, can be useful for HF communication systems and sky wave over-the-horizon radars.

  13. Crystal structure of Si-doped HfO{sub 2}

    SciTech Connect

    Zhao, Lili; Nelson, Matthew; Fancher, Chris M.; Aldridge, Henry; Iamsasri, Thanakorn; Forrester, Jennifer S.; Jones, Jacob L.; Nishida, Toshikazu; Moghaddam, Saeed

    2014-01-21

    Si-doped HfO{sub 2} was prepared by solid state synthesis of the starting oxides. Using Rietveld refinement of high resolution X-ray diffraction patterns, a substitutional limit of Si in HfO{sub 2} was determined as less than 9 at. %. A second phase was identified as Cristobalite (SiO{sub 2}) rather than HfSiO{sub 4}, the latter of which would be expected from existing SiO{sub 2}-HfO{sub 2} phase diagrams. Crystallographic refinement with increased Si-dopant concentration in monoclinic HfO{sub 2} shows that c/b increases, while β decreases. The spontaneous strain, which characterizes the ferroelastic distortion of the unit cell, was calculated and shown to decrease with increasing Si substitution.

  14. Work function tuning at Au-HfO2 interfaces using organophosphonate monolayers

    NASA Astrophysics Data System (ADS)

    Kwan, Matthew; Cardinal, Thomas; Mutin, P. Hubert; Ramanath, Ganpati

    2016-05-01

    We show that introducing organophosphonate nanomolecular monolayers (NMLs) at Au-HfO2 interfaces shift the effective work function by 0.2 eV ≥ ΔΦeff ≥ -0.6 eV, due to NML body and bonding dipoles. Electron spectroscopy of NML-Au, NML-HfO2, and Au-NML-HfO2 structures indicate that the Au-NML bond strength is the major factor. Au-NML covalent bonding yields ΔΦeff ˜ - 0.2 eV, while weak bonding yields ΔΦeff ˜ 0.6 eV. In contrast, NMLs on HfO2 decrease Φeff by ˜0.4 eV due to competing contributions from NML-HfO2 bonding strength and NML orientation. These findings are relevant for nanomolecularly tailoring the electronic properties of metal-ceramic interfaces for applications.

  15. Surface treatment for the atomic layer deposition of HfO{sub 2} on silicon

    SciTech Connect

    Damlencourt, J-F.; Renault, O.; Martin, F.; Semeria, M-N.; Billon, T; Bedu, F.

    2005-04-04

    The atomic layer deposition (ALD) of HfO{sub 2} on silicon with a Cl{sub 2} surface treatment is investigated by physicochemical and electrical techniques. The specificity of this treatment is to create, on a HF-dipped silicon surface, the nucleation sites necessary for the ALD growth. The growth rates obtained by spectroscopic ellipsometry and total x-ray fluorescence spectroscopy indicate that the nucleation sites (i.e., the -OH groups), which are necessary to perform some bidimensional ALD growth, are generated during this surface treatment. After deposition of thin HfO{sub 2} layers (from a few monolayers up to 8.7 nm), a very thin parasitic SiO{sub x} layer, underneath 1 monolayer of Hf silicate, is observed by x-ray photoelectron spectroscopy. Nevertheless, an equivalent oxide thickness of 1.1 nm is obtained with an as-deposited 3.7 nm thick HfO{sub 2} layer.

  16. Thermal decomposition of HfCl{sub 4} as a function of its hydration state

    SciTech Connect

    Barraud, E.; Begin-Colin, S. . E-mail: begin@ipcms.u-strasbg.fr; Le Caer, G.; Villieras, F.; Barres, O.

    2006-06-15

    The thermogravimetric behavior of HfCl{sub 4} powders with different hydration states has been compared. Strongly hydrated powders consist of HfOCl{sub 2}.nH{sub 2}O with n>4. Partially hydrated powders consist of particles with a HfCl{sub 4} core and a hydrated outerlayer of HfOCl{sub 2}.nH{sub 2}O with n in the range of 0-8. Hydrated powders decomposed at temperature lower than 200 deg. C whereas the decomposition of partially hydrated powders was completed at a temperature of around 450 deg. C. The observed differences in decomposition temperature is related to the structure of HfOCl{sub 2}.nH{sub 2}O, which is different if n is higher or smaller than 4 and leads to intermediate compounds, which decompose at different temperatures.

  17. Electronic Structure Differences in ZrO2 vs. HfO2

    SciTech Connect

    Zheng, Weijun; Bowen Jr., K.H.; Li, Jun; Dabkowska, Iwona; Gutowski, Maciej S.

    2005-12-22

    While ZrO2 and HfO2 are, for the most part, quite similar chemically, subtle differences in their electronic structures appear to be responsible for differing MO2/Si (M = Zr, Hf) interface stabilities. In order to shed light on the electronic structure differences between ZrO2 and HfO2, we have conducted joint experimental/theoretical studies. Since electron affinities are a sensitive probe of electronic structure, we have measured them by conducting photoelectron spectroscopic experiments on ZrO2- and HfO2-. The electron affinity of HfO2 was determined to be 2.14? 0.03 eV, while that of ZrO2 was determined to be 1.64 ? 0.03 eV. Concurrently, electronic structure calculations were conducted to determine electron affinities, vibrational frequencies, and geometries of these systems. The calculated electron affinities of HfO2 and ZrO2 were found to be 2.05 and 1.62 eV, respectively. The molecular results confirm earlier predictions from solid phases that HfO2 is more ionic than ZrO2. The excess electron in MO2- occupies an sd-type hybrid orbital localized on the M atom (M=Zr, Hf). The structural parameters of ZrO2 and HfO2 were found to be very similar. The difference in geometries between the neutral and the anion is along the symmetrical stretching and bending modes. Together, these studies unveil significant differences in the electronic structures of ZrO2 and HfO2.

  18. Analysis of D-Region Absorption via HF Cross-Modulation Experiments at HAARP

    NASA Astrophysics Data System (ADS)

    Braun, E. M.; Moore, R. C.

    2010-12-01

    Experimental observations performed near the High-frequency Active Auroral Research Program (HAARP) HF transmitter in Gakona, Alaska are used to implement a new method quantifying the rate of absorption of HF radio waves in the D-region ionosphere. Quantifying the ambient and HF-modified characteristics of the D-region ionosphere in the vicinity of ionospheric HF heaters has historically proven to be a difficult task. For example, the electron density in the 60-90 km altitude range is typically too low to employ radio-sounding techniques; LIDAR observations typically require significant temporal averaging, precluding the investigation of physical processes that occur on sub-millisecond time scales; ELF/VLF wave generation experiments typically have difficulty providing reliable spatial resolution and also cannot experimentally distinguish between the spatial distribution of the ionospheric conductivity modulation produced by modulated HF heating and that of the current-driving electric fields associated with the auroral electrojet. Yet, the majority of HF signal absorption occurs in this region of the ionosphere, and the ability to characterize HF absorption in this region benefits a wide range of ionospheric HF heating experiments. The technique described and demonstrated in this paper combines ionosonde-style radio sounding with ELF/VLF cross-modulation experiments to identify the altitude of maximum D-region absorption as a function of HF frequency. Observations are presented and compared with the predictions of a theoretical model, demonstrating excellent agreement between experiment and theory and indicating that the technique may be used successfully in practice. Based on the success of this first experiment, another HF cross-modulation experiment has been performed at HAARP and analyzed theoretically. Pulsed-modulation experiments are used to assess the relative absorption as a function of altitude within the D-region ionosphere, and a method to chart the

  19. Magnetic zenith effect in the ionospheric modification by an X-mode HF heater wave

    NASA Astrophysics Data System (ADS)

    Blagoveshchenskaya, N. F.; Borisova, T. D.; Haggstrom, I.; Rietveld, M. T.; Yeoman, T. K.

    2013-12-01

    We report experimental results aimed at an investigation of the magnetic zenith effect in the high latitude ionosphere F region from ionospheric modification by powerful HF heater wave with X-polarization. The ionospheric modification was produced by the HF heating facility at Tromsø (Norway) using the phased array with a narrow beam with of 6 degrees. Effective radiated power was varied between 450 and 1000 MW. The HF pump wave radiated in different directions relative to the magnetic field from 90 degrees (vertical) to 78 degrees (magnetic zenith) at frequencies near or above the ordinary-mode critical frequency. The response of the ionosphere plasma to the HF pump wave impact was checked by the UHF incoherent scatter radar located in the immediate vicinity of the HF heater. UHF radar was probing the plasma parameters, such as electron density and temperature (Ne and Te), HF-induced plasma and ion lines in the altitude range from 90 to 600 km. It was running in a scanning mode when UHF radar look angles were changed from 74 to 90 degrees by 1 or 2 degree step. It was clearly demonstrated that the strongest heater-induced effects took place in the magnetic field-aligned direction when HF pointing was also to the magnetic zenith. It was found that strong Ne enhancement of up to 80 % along magnetic field (artificial density ducts) were excited only under HF pumping towards magnetic zenith. The width of the artificial ducts comes to only 2 degrees. The Ne increases were accompanied by the Te enhancements of up to about 50 %. Less pronounced Te increases were also observed in the directions of 84 and 90 degrees. Strong Ne enhancements can be accompanied by excitation of strong HF-induced plasma and ion lines. Thus experimental results obtained points to the strong magnetic zenith effect due to self-focusing powerful HF radio wave with X-mode polarization.

  20. Hyperfine spectroscopic study of Laves phase HfFe 2

    NASA Astrophysics Data System (ADS)

    Belošević-Čavor, J.; Novaković, N.; Cekić, B.; Ivanović, N.; Manasijević, M.

    2004-05-01

    Hyperfine fields in HfFe 2 were measured at 181Ta probe using the time-differential perturbed angular correlation method (TDPAC) in the temperature range 78-1200 K. Analysis of the spectra revealed two interactions with hyperfine fields of 13.82(7) T and 8.0(2) T, at 293 K. First is ascribed to the interaction at the 8a position in the cubic C15 structure. The second can be assigned to a minor amount of hexagonal C14 phase, or to an irregular position of the probe in the C15 lattice. Results of calculations using LAPW-WIEN97 are in a good agreement with experiment.

  1. Observation of weak HF electrostatic turbulence in the auroral ionosphere

    NASA Astrophysics Data System (ADS)

    Pottelette, R.; Illiano, J. M.

    1982-07-01

    A numerical calculation of the cross spectrum of random signals received by two small antennas that were immersed in a two-component magnetoplasma has been conducted, for the case of a plasma model consisting of a cool and a warm component. The data were compiled by the HF electrostatic wave detection experiment of the Porcupine F3 rocket. A linear calculation of the natural electrostatic emissions detected around the electron gyrofrequency three-halves harmonic and around the upper hybrid frequency shows that their amplitudes are above the plasma thermal noise level. It is noted that the low energy precipitating suprathermal electrons present are highly anisotropic and enhance the three-halves electron gyrofrequency noise, although the electron distribution function remains stable and the most intense emissions are observed around the upper hybrid frequency.

  2. Automatic scaling of HF swept-frequency backscatter ionograms

    NASA Astrophysics Data System (ADS)

    Song, Huan; Hu, Yaogai; Jiang, Chunhua; Zhou, Chen; Zhao, Zhengyu

    2015-05-01

    This paper describes a method for automatically scaling HF swept-frequency backscatter ionograms, which can be applied to a low-power oblique backscatter sounding system. Based on the information of vertical echo in the ionogram, propagation mode is recognized from the amplitude differences between E layer and F layer echoes. Points on the leading edge are extracted by using minimum group path delay theory. The spurious points are removed by using residual analysis. A multiple linear polynomial was adopted to fit the extracted leading edge points. Smooth fitting curves can then be obtained. Automatic scaling results from 362 ionograms show that the proposed method can efficiently recognize propagation modes and extract leading edge curves by taking full advantages of echo characteristics and echo amplitudes in the ionograms. This novel method can be applied into real-time backscatter ionogram scaling, which facilitates the extensive usage of oblique backscatter soundings.

  3. HF-driven currents in the polar ionosphere

    NASA Astrophysics Data System (ADS)

    Papadopoulos, K.; Gumerov, N. A.; Shao, X.; Doxas, I.; Chang, C. L.

    2011-06-01

    Polar ionospheric heaters have generated ULF/ELF/VLF waves by modulating the auroral electrojet at D/E region altitudes. We present theoretical/computational results indicating that modulated F-region HF heating can generate ionospheric currents even in the absence of electrojet currents. The ELF currents are driven in a two-step process. First, the pressure gradient associated with F-region electron heating drives a local diamagnetic current. This acts as an antenna to inject Magneto-Sonic (MS) waves in the ionospheric plasma. Second, the electric field of the magneto-sonic wave drives Hall currents when it reaches the E region of the ionosphere. The Hall currents act as a secondary antenna that injects waves in the Earth-Ionosphere Waveguide below and Shear Alfven waves upwards to the conjugate regions. The paper examines the scaling and limitations of the concept and suggests proof-of-principle experiments using the HAARP ionospheric heater.

  4. Assimilation of HF radar data into the SWAN wave model

    NASA Astrophysics Data System (ADS)

    Siddons, L. A.; Wyatt, L. R.; Wolf, J.

    2009-05-01

    Data assimilation is a method used for optimally combining information to improve forecasting and model parameters. Three data assimilation algorithms are investigated and used for assimilating HF radar data into the SWAN wave model. The schemes under consideration are the Ensemble Kalman Filter, Ensemble Optimal Interpolation and a Three-Dimensional Variational scheme. Two approaches for updating the ocean wave spectrum are considered which consist of describing the spectrum using integral wave parameters of the whole spectrum and wave parameters within various frequency bands. The results show improvement in the wave parameters at the buoy location for the 3DVAR and ENS-OI scheme. The EnKF only shows good performance in one of the considered runs which leads to a conclusion that the methods used for calculating the errors for the EnKF scheme need further analysis.

  5. Ternary ceramic alloys of Zr-Ce-Hf oxides

    DOEpatents

    Becher, P.F.; Funkenbusch, E.F.

    1990-11-20

    A ternary ceramic alloy is described which produces toughening of zirconia and zirconia composites through the stress transformation from tetragonal phase to monoclinic phase. This alloy, having the general formula Ce[sub x]Hf[sub y]Zr[sub 1[minus]x[minus]y]O[sub 2], is produced through the addition of appropriate amounts of ceria and hafnia to the zirconia. Typically, improved toughness is achieved with about 5 to about 15 mol % ceria and up to about 40 mol % hafnia. The preparation of alloys of these compositions are given together with data as to the densities, tetragonal phase content, hardness and fracture toughness. The alloys are useful in preparing zirconia bodies as well as reinforcing ceramic composites. 1 fig.

  6. Ternary ceramic alloys of ZR-CE-HF oxides

    DOEpatents

    Becher, Paul F.; Funkenbusch, Eric F.

    1990-01-01

    A ternary ceramic alloy which produces toughening of zirconia and zirconia composites through the stress transformation from tetragonal phase to monoclinic phase. This alloy, having the general formula Ce.sub.x Hf.sub.y Zn.sub.1-x-y O.sub.2, is produced through the addition of appropriate amounts of ceria and hafnia to the zirconia. Typically, improved toughness is achieved with about 5 to about 15 mol % ceria and up to about 40 mol % hafnia. The preparation of alloys of these compositions are given together with data as to the densities, tetragonal phase content, hardness and fracture toughness. The alloys are useful in preparing zirconia bodies as well as reinforcing ceramic composites.

  7. Digital hf radar observations of equatorial spread-F

    SciTech Connect

    Argo, P.E.

    1984-01-01

    Modern digital ionosondes, with both direction finding and doppler capabilities can provide large scale pictures of the Spread-F irregularity regions. A morphological framework has been developed that allows interpretation of the hf radar data. A large scale irregularity structure is found to be nightward of the dusk terminator, stationary in the solar reference frame. As the plasma moves through this foehn-wall-like structure it descends, and irregularities may be generated. Localized upwellings, or bubbles, may be produced, and they drift with the background plasma. The spread-F irregularity region is found to be best characterized as a partly cloudy sky, due to the patchiness of the substructures. 13 references, 16 figures.

  8. Revisiting the Ariel Trough Work for HF Telecommunication Purposes

    NASA Astrophysics Data System (ADS)

    Tulunay, Y.; Stanisławska, I.; Rothkaehl, H.

    2003-07-01

    Muldrew [1] was the pioneer who reported the midlatitude electron density trough at the topside ionosphere. For about ten to fifteen years the trough, its morphology, dynamical behavior, relationship to the equatorial plasmapause, and physical and chemical processes which lead to the trough formation had been extensively investigated. Then, the work on the trough had been slowed down gradually. As the new space systems have become more vulnerable to space weather effects, a need for robust programs and a long track record in space environment sensing and modeling to produce new space environment models and products that would meet high-priority defense and commercial needs arises naturally. In this context, it is intended to go over the reported trough work dating back to the 1970s and some typical findings of later developments briefly. Most of the aspects of the trough studies have been repeated with new data for newer physical models. From this point of view, the Ariel 3 and Ariel 4 satellite trough results are chosen since the work on the Ariel trough had been very original and very extensive quantitatively and qualitatively in the 1970s. The results reviewed here are based on more than 1000 beautiful selected trough cases. Due to the good quality and quantity of the Ariel satellite data, equal coverage in space and time were maintained, which makes the trough results very important. This paper will end with some reference to the trough models, results that establish a link between the topside and the F2 region of the ionosphere. As one typical application, HF radiocommunication is chosen to be the point of interest. In practical applications of the HF radiocommunications any model that does not include the trough is not complete.

  9. HF Doppler radar observations of low-latitude spread F

    NASA Astrophysics Data System (ADS)

    Reddi, C. R.; Sarma, M. S. S. R. K. N.; Niranjan, K.

    2009-06-01

    HF (5.5 MHz) Doppler radar observations of nonspread F and spread F echoes over Visakhapatnam (17.7°N, 83.3°E; dip 20°) are presented. The echoes appearing suddenly and nearly simultaneously in 16 successive range bins at 7.5 km intervals in association with spread F have been investigated. Two to five episodes of spread F activity were found to appear at intervals of 1-2 hours during individual nights. At the time of onset of spread F conditions, the Doppler velocity for each range bin changed rapidly from a negative maximum to a positive maximum followed by a gradual decrease to a steady ±10-15 m/s or to a large negative velocity and then again to a large positive. At the time of small constant velocity or velocity change from negative to positive, the spread F echoes were weak or even below the detection level of the radar. This disappearance in the higher ranges causes the decrease in range extent of spread F echoes. The positive and negative maximum velocities of spread F were in the range of +70 to -60 m/s. The maximum upward and downward velocity is not the same in all events of spread F activity. The width of the Doppler velocity spectrum for spread F echoes was found to vary with velocity. For zero velocity the width was a minimum of 50 m/s in contrast to 25 m/s for nonspread F events. These features were consistently observed for all spread F incidences. The observed results are compared with already reported HF/VHF observations and are discussed in the light of equatorial plasma dynamics during the growth phase of Rayleigh Taylor instability leading the incidence of spread F.

  10. Hf and Nd isotopes in marine sediments: Constraints on global silicate weathering

    NASA Astrophysics Data System (ADS)

    Bayon, G.; Burton, K. W.; Soulet, G.; Vigier, N.; Dennielou, B.; Etoubleau, J.; Ponzevera, E.; German, C. R.; Nesbitt, R. W.

    2009-01-01

    The combined use of Lu-Hf and Sm-Nd isotope systems potentially offers a unique perspective for investigating continental erosion, but little is known about whether, and to what extent, the Hf-Nd isotope composition of sediments is related to silicate weathering intensity. In this study, Hf and Nd elemental and isotope data are reported for marine muds, leached Fe-oxide fractions and zircon-rich turbidite sands collected off the Congo River mouth, and from other parts of the SE Atlantic Ocean. All studied samples from the Congo fan (muds, Fe-hydroxides, sands) exhibit indistinguishable Nd isotopic composition (ɛ Nd ~ - 16), indicating that Fe-hydroxides leached from these sediments correspond to continental oxides precipitated within the Congo basin. In marked contrast, Hf isotope compositions for the same samples exhibit significant variations. Leached Fe-hydroxide fractions are characterized by ɛ Hf values (from - 1.1 to + 1.3) far more radiogenic than associated sediments (from - 7.1 to - 12.0) and turbidite sands (from - 27.2 to - 31.6). ɛ Hf values for Congo fan sediments correlate very well with Al/K (i.e. a well-known index for the intensity of chemical weathering in Central Africa). Taken together, these results indicate that (1) silicate weathering on continents leads to erosion products having very distinctive Hf isotope signatures, and (2) a direct relationship exists between ɛ Hf of secondary clay minerals and chemical weathering intensity. These results combined with data from the literature have global implications for understanding the Hf-Nd isotope variability in marine precipitates and sediments. Leached Fe-hydroxides from Congo fan sediments plot remarkably well on an extension of the 'seawater array' (i.e. the correlation defined by deep-sea Fe-Mn precipitates), providing additional support to the suggestion that the ocean Hf budget is dominated by continental inputs. Fine-grained sediments define a diffuse trend, between that for igneous

  11. Effect of Hf and Y Alloy Additions on Aluminide Coating Performance

    SciTech Connect

    Pint, Bruce A; Haynes, James A; Besmann, Theodore M

    2010-01-01

    Iron- and Ni-base alloys, with and without Hf or Hf and Y alloy additions, were aluminized by chemical vapor deposition to study the potential for minor alloy additions to improve oxidation resistance of coated alloys. Compared to uncoated specimens, the coated specimens showed improved cyclic oxidation resistance at 1100 and 1150 C. However, alumina scale spallation was observed at relatively short times and, particularly for the Ni-base alloy X, the aluminized lab-cast alloy with Hf tended to have poor coating performance compared to the commercial alloy without Hf. Internal oxidation of Hf at 1150 C and rapid Al depletion in the relatively thin aluminide coatings contributed to the observed detrimental Hf effect. For the Ni-base alloys, the increased scale spallation could be attributed to much higher S contents (10-50 ppma) in the laboratory-cast alloys. Oxide scale spallation from the coating surface was minimized when Hf and Y were added to a casting and the [Y]/[S] content ratio was {approx}1.

  12. Photocurrent generation in carbon nanotube/cubic-phase HfO2 nanoparticle hybrid nanocomposites

    PubMed Central

    Galeckas, Augustinas; Salumaa, Martin; Ducroquet, Frédérique; Rauwel, Erwan

    2016-01-01

    Summary A hybrid material consisting of nonfunctionalized multiwall carbon nanotubes (MWCNTs) and cubic-phase HfO2 nanoparticles (NPs) with an average diameter of 2.6 nm has been synthesized. Free standing HfO2 NPs present unusual optical properties and a strong photoluminescence emission in the visible region, originating from surface defects. Transmission electron microscopy studies show that these NPs decorate the MWCNTs on topological defect sites. The electronic structure of the C K-edge in the nanocomposites was probed by electron energy loss spectroscopy, highlighting the key role of the MWCNT growth defects in anchoring HfO2 NPs. A combined optical emission and absorption spectroscopy approach illustrated that, in contrast to HfO2 NPs, the metallic MWCNTs do not emit light but instead expose their discrete electronic structure in the absorption spectra. The hybrid material manifests characteristic absorption features with a gradual merger of the MWCNT π-plasmon resonance band with the intrinsic defect band and fundamental edge of HfO2. The photoluminescence of the nanocomposites indicates features attributed to combined effects of charge desaturation of HfO2 surface states and charge transfer to the MWCNTs with an overall reduction of radiative recombination. Finally, photocurrent generation under UV–vis illumination suggests that a HfO2 NP/MWCNT hybrid system can be used as a flexible nanodevice for light harvesting applications. PMID:27547626

  13. Photocurrent generation in carbon nanotube/cubic-phase HfO2 nanoparticle hybrid nanocomposites.

    PubMed

    Rauwel, Protima; Galeckas, Augustinas; Salumaa, Martin; Ducroquet, Frédérique; Rauwel, Erwan

    2016-01-01

    A hybrid material consisting of nonfunctionalized multiwall carbon nanotubes (MWCNTs) and cubic-phase HfO2 nanoparticles (NPs) with an average diameter of 2.6 nm has been synthesized. Free standing HfO2 NPs present unusual optical properties and a strong photoluminescence emission in the visible region, originating from surface defects. Transmission electron microscopy studies show that these NPs decorate the MWCNTs on topological defect sites. The electronic structure of the C K-edge in the nanocomposites was probed by electron energy loss spectroscopy, highlighting the key role of the MWCNT growth defects in anchoring HfO2 NPs. A combined optical emission and absorption spectroscopy approach illustrated that, in contrast to HfO2 NPs, the metallic MWCNTs do not emit light but instead expose their discrete electronic structure in the absorption spectra. The hybrid material manifests characteristic absorption features with a gradual merger of the MWCNT π-plasmon resonance band with the intrinsic defect band and fundamental edge of HfO2. The photoluminescence of the nanocomposites indicates features attributed to combined effects of charge desaturation of HfO2 surface states and charge transfer to the MWCNTs with an overall reduction of radiative recombination. Finally, photocurrent generation under UV-vis illumination suggests that a HfO2 NP/MWCNT hybrid system can be used as a flexible nanodevice for light harvesting applications. PMID:27547626

  14. Structure, mechanical and tribological properties of HfCx films deposited by reactive magnetron sputtering

    NASA Astrophysics Data System (ADS)

    Shuo, Wang; Kan, Zhang; Tao, An; Chaoquan, Hu; Qingnan, Meng; Yuanzhi, Ma; Mao, Wen; Weitao, Zheng

    2015-02-01

    Hafnium carbide (HfC) films have been deposited on Si (1 0 0) substrates by direct current reactive magnetron sputtering. The microstructure, compressive stress, hardness and tribological behaviors show great dependence on carbon (C) concentration and chemical bonding state. With C content in HfCx films rising, phase transforms from hexagonal-close-packed (HCP) Hf(C) to face-centered-cubic (FCC) HfC, and nanocomposite structure consisting of HfCx nanocrystalline grains encapsulated by amorphous carbon (a-C) matrix forms at moderate C content. The hardness of HfCx films increases significantly from 10.4 GPa (14 at.% C) to 34.4 GPa (58 at.% C) and then keeps dropping with further increasing C content. a-C appears in HfCx films with more than 32 at.% C and it obviously lowers coefficient of friction (COF). The wear resistance can be remarkably worsened by high compressive stress. The film with 76 at.% C exhibits relatively high hardness and low compressive stress, good fracture toughness and self-lubrication transfer layer, showing great combination of the lowest COF of 0.10 and lowest wear rate of 1.10 × 10-6 mm3/Nm.

  15. Directionally solidified pseudo-binary eutectics of Ni-Cr-(Hf, Zr)

    NASA Technical Reports Server (NTRS)

    Kim, Y. G.; Ashbrook, R. L.

    1975-01-01

    A pseudo-binary eutectic, in which the intermetallic Ni7Hf2 reinforces the Ni-Cr solid solution phase, was previously predicted in the Ni-Cr-Hf system by a computer analysis. The experimental determination of pseudo binary eutectic compositions and the directional solidification of the Ni-Cr-Hf, Zr, and Ni-Cr-Zr eutectic alloys are discussed. To determine unknown eutectics, chemical analyses were made of material bled from near eutectic ingots during incipient melting. Nominal compositions in weight percent of Ni-18.6Cr-24.0HF, Ni19.6Cr-12.8Zr-2.8Hf, and Ni-19.2Cr-14.8Zr formed aligned pseudo-binary eutectic structures. The melting points were about 1270 C. The reinforcing intermetallic phases were identified as noncubic (Ni,Cr)7Hf2 and (Ni,Cr)7(Hf,Zr)2, and face centered cubic (Ni,Cr)5Zr. The volume fraction of the reinforcing phases were about 0.5.

  16. Hf-Nd isotope decoupling in the oceanic lithosphere: constraints from spinel peridotites from Oahu, Hawaii

    NASA Astrophysics Data System (ADS)

    Bizimis, Michael; Sen, Gautam; Salters, Vincent J. M.

    2004-01-01

    We present a detailed geochemical investigation on the Hf, Nd and Sr isotope compositions and trace and major element contents of clinopyroxene mineral separates from spinel lherzolite xenoliths from the island of Oahu, Hawaii. These peridotites are believed to represent the depleted oceanic lithosphere beneath Oahu, which is a residue of a MORB-related melting event some 80-100 Ma ago at a mid-ocean ridge. Clinopyroxenes from peridotites from the Salt Lake Crater (SLC) show a large range of Hf isotopic compositions, from ɛHf=12.2 (similar to the Honolulu volcanics series) to extremely radiogenic, ɛHf=65, at nearly constant 143Nd/ 144Nd ratios ( ɛNd=7-8). None of these samples show any isotopic evidence for interaction with Koolau-type melts. A single xenolith from the Pali vent is the only sample with Hf and Nd isotopic compositions that falls within the MORB field. The Hf isotopes correlate positively with the degree of depletion in the clinopyroxene (e.g. increasing Mg#, Cr#, decreasing Ti and heavy REE contents), but also with increasing Zr and Hf depletions relative to the adjacent REE in a compatibility diagram. The Lu/Hf isotope systematics of the SLC clinopyroxenes define apparent ages of 500 Ma or older and these compositions cannot be explained by mixing between any type of Hawaiian melts and the depleted Pacific lithosphere. Metasomatism of an ancient (e.g. 1 Ga or older) depleted peridotite protolith can, in principle, explain these apparent ages and the Nd-Hf isotope decoupling, but requires that the most depleted samples were subject to the least amount of metasomatism. Alternatively, the combined isotope, trace and major element compositions of these clinopyroxenes are best described by metasomatism of the 80-100 Ma depleted oceanic lithosphere by melts products of extensive mantle-melt interaction between Honolulu Volcanics-type melts and the depleted lithosphere.

  17. Microstructure and Phase Stability of Single Crystal NiAl Alloyed with Hf and Zr

    NASA Technical Reports Server (NTRS)

    Locci, I. E.; Dickerson, R. M.; Garg, A.; Noebe, R. D.; Whittenberger, J. D.; Nathal, M. V.; Darolia, R.

    1996-01-01

    Six near stoichiometric, NiAl single-crystal alloys, with 0.05-1.5 at.% of Hf and Zr additions plus Si impurities, were microstructurally analyzed in the as-cast, homogenized, and aged conditions. Hafnium-rich interdendritic regions, containing the Heusler phase (Ni2AlHf), were found in all the as-cast alloys containing Hf. Homogenization heat treatments partially reduced these interdendritic segregated regions. Transmission electron microscopy (TEM) observations of the as-cast and homogenized microstructures revealed the presence of a high density of fine Hf (or Zr) and Si-rich precipitates. These were identified as G-phase, Nil6X6Si7, or as an orthorhombic NiXSi phase, where X is Hf or Zr. Under these conditions the expected Heusler phase (beta') was almost completely absent. The Si responsible for the formation of the G and NiHfSi phases is the result of molten metal reacting with the Si-containing crucible used during the casting process. Varying the cooling rates after homogenization resulted in the refinement or complete suppression of the G and NiHfSi phases. In some of the alloys studied, long-term aging heat treatments resulted in the formation of Heusler precipitates, which were more stable at the aging temperature and coarsened at the expense of the G-phase. In other alloys, long-term aging resulted in the formation of the NiXSi phase. The stability of the Heusler or NiXSi phases can be traced to the reactive element (Hf or Zr) to silicon ratio. If the ratio is high, then the Heusler phase appears stable after long time aging. If the ratio is low, then the NiHfSi phase appears to be the stable phase.

  18. Clinical experiment of mutant herpes simplex virus HF10 therapy for cancer.

    PubMed

    Nakao, A; Takeda, S; Shimoyama, S; Kasuya, H; Kimata, H; Teshigahara, O; Sawaki, M; Kikumori, T; Kodera, Y; Nagasaka, T; Goshima, F; Nishiyama, Y; Imai, T

    2007-03-01

    We reviewed our clinical trial using mutant herpes simplex virus "HF10". We have evaluated the safety and effect of HF10 against recurrent breast cancer since 2003 and also applied HF10 to non-resectable pancreatic cancer since 2005. An oncolytic herpes simplex virus type 1, mutant HF10, has been isolated and evaluated for anti-tumor efficacy in syngeneic immunocompetent mouse models. From long time before clinical trial, we have found that the mutant virus can have remarkable potential to effectively treat cancer in experimental studies using animals, and that all of the surviving mice acquire resistance to rechallenge of the tumor cells. A number of studies have shown that HF10 is effective and safe for use in localized or peritoneally disseminated malignant tumors of non-neuronal origin in animals. Pilot studies using HF10 have been initiated in patients with metastatic breast cancer. For each patient, 0.5 ml HF10 diluents at various doses were injected into test nodule, and 0.5 ml sterile saline was injected into a second nodule. All patients were monitored for local and systemic adverse effects, and the nodules were excised 14 days after viral injection for histopathological studies. All patients tolerated the clinical trial well. While no adverse effects occurred, there was cancer cell death and 30-100% regression histopathologically in recurrent breast cancer. As mentioned above, intratumoral injection of mutant herpes simplex virus HF10 for recurrent metastatic breast cancer was safe and effective. Also a trial for non-resectable pancreatic cancer being carried out on the basis of the above result has proved to be innocuous and has been in progress to assess the clinical benefit and enhance the potentiality of HF10 against cancer. PMID:17346108

  19. DIRECT DETERMINATION OF THE HF/H{sub 2} ABUNDANCE RATIO IN INTERSTELLAR GAS

    SciTech Connect

    Indriolo, Nick; Neufeld, D. A.; Seifahrt, A.; Richter, M. J.

    2013-02-20

    We report the first detection of the v = 1-0, R(0) ro-vibrational transition of HF at 2.499385 {mu}m arising from interstellar gas. The line is seen in absorption toward three background sources-HD 154368, Elias 29, and AFGL 2136 IRS 1-all of which have reported H{sub 2} column densities determined from observations of H{sub 2}. This allows for the first direct determination of the HF/H{sub 2} abundance ratio. We find values of N(HF)/N(H{sub 2}) = 1.15 Multiplication-Sign 10{sup -8} and 0.69 Multiplication-Sign 10{sup -8} for HD 154368 and Elias 29, respectively. The sight line toward AFGL 2136 IRS 1 also shows absorption from the v = 1-0, R(1) transition of HF, indicating warm, dense (n {sub H} {approx}> 10{sup 9} cm{sup -3}) gas, likely very close to the central protostar. Ascribing portions of the HF absorption to warm and cold gas, we find N(HF)/N(H{sub 2}) = (1.7-2.9) Multiplication-Sign 10{sup -8} and (0.33-0.58) Multiplication-Sign 10{sup -8} for the two components, respectively. Except for the warm component toward AFGL 2136 IRS 1, all observed HF/H{sub 2} ratios are well below N(HF)/N(H{sub 2}) = 3.6 Multiplication-Sign 10{sup -8}, the value predicted if nearly all gas phase fluorine is in the form of HF. Models of fluorine chemistry that account for depletion onto grains are able to reproduce the results toward HD 154368, but not in the cold, dense gas toward AFGL 2136 IRS 1 and Elias 29. Most likely, some combinations of simplifying assumptions made in the chemical models are responsible for these discrepancies.

  20. Breakdown-induced thermochemical reactions in HfO2 high-κ/polycrystalline silicon gate stacks

    NASA Astrophysics Data System (ADS)

    Ranjan, R.; Pey, K. L.; Tung, C. H.; Tang, L. J.; Ang, D. S.; Groeseneken, G.; De Gendt, S.; Bera, L. K.

    2005-12-01

    The chemistry of dielectric-breakdown-induced microstructural changes in HfO2 high-κ/polycrystalline silicon gate nMOSFETs under constant voltage stress has been studied. Based on an electron energy loss spectrometry analysis, the hafnium and oxygen chemical bonding in the breakdown induced Hf-based compounds of a "ball-shaped" defect is found to be different compared to the stoichiometric HfO2 and SiO2. The formation of possibly HfSixOy and HfSix compounds in the "ball-shaped" defect is attributed to a thermochemical reaction triggered by the gate dielectric breakdown.

  1. Toward High-Performance Top-Gate Ultrathin HfS2 Field-Effect Transistors by Interface Engineering.

    PubMed

    Xu, Kai; Huang, Yun; Chen, Bo; Xia, Yang; Lei, Wen; Wang, Zhenxing; Wang, Qisheng; Wang, Feng; Yin, Lei; He, Jun

    2016-06-01

    Top-gate HfS2 field-effect transistors (FETs) with 5 nm HfO2 as dielectrics are successfully demonstrated, with on/off ratio of 10(5) and subthreshold swing of 95 mV dec(-1) . Moreover, due to the self-functionalization of HfS2 , uniform and ultrathin HfO2 film free of pinhole-like defects could be deposited on HfS2 , which is dramatically different from other transition metal dichalcogenide FETs. PMID:27120487

  2. Real-time Specification and Forecasting for HF Links During Disturbed Conditions

    NASA Astrophysics Data System (ADS)

    Rice, D.; Hunsuker, R. D.; Eccles, J.; Sojka, J. J.

    2004-05-01

    The HF communications community has long been dependent on climatological ionosphere descriptions to support HF propagation programs. Additionally, these programs include solar zenith angle and frequency-squared variation of HF absorption but do not include space weather effects due to solar x-ray events and sporadic E layers. The usefulness of real-time specification and forecasting of HF links is desired in programs such as Operational Space Environment Network Display (OpSend). The creation of HF illumination maps requires proper specifications of D, E and F regions of the ionosphere. We present results and validation efforts of the Data-Driven D region (DDDR) model of HF absorption for mid-latitude HF paths. The DDDR programs assimilate real-time data such as the NOAA/GOES 12 x-ray measurements to produce space weather related absorption predictions. The data-driven model is being validated with observations from the HF Investigation of D-Region Ionospheric Variation Experiment (HIDIVE). Monitoring of standard time-frequency HF stations has been employed for the past three decades. The passive monitoring technique used in HIDIVE was mainly applied for studies of the high-latitude and equatorial ionosphere, thus long-term, quantitative data on the mid-latitude ionosphere are difficult to find in archival literature. HIDIVE is a careful examination of long-term observations HF absorption to study seasonal variation and space weather events. Simultaneous continuous measurements of NOAA/GOES 12 solar x-ray flux and calibrated HF signal strength were initiated in December 2002 to provide validation data for the DDDR model. Continuous recording of transmissions of standard time-frequency stations (WWV and WWVH) over the range of 2.5 to 20.0 MHz and 5-minute averages of 1.0 to 8.0 nm solar x-ray flux have been studied for 35 solar flares ranging from Class C to Class X from March through August 2003 during the descending phase of solar cycle 23. The monitoring

  3. Artificial Ionization and UHF Radar Response Associated with HF Frequencies near Electron Gyro-Harmonics (Invited)

    NASA Astrophysics Data System (ADS)

    Watkins, B. J.; Fallen, C. T.; Secan, J. A.

    2013-12-01

    We present new results from O-mode ionospheric heating experiments at the HAARP facility in Alaska to demonstrate that the magnitude of artificial ionization production is critically dependent on the choice of HF frequency near gyro-harmonics. For O-mode heating in the lower F-region ionosphere, typically about 200 km altitude, artificial ionization enhancements are observed in the lower ionosphere (about 150 - 220 km) and also in the topside ionosphere above about 500 km. Lower ionosphere density enhancements are inferred from HF-enhanced ion and plasma-line signals observed with UHF radar. Upper ionospheric density enhancements have been observed with TEC (total electron content) experiments by monitoring satellite radio beacons where signal paths traverse the HF-modified ionosphere. Both density enhancements and corresponding upward plasma fluxes have also been observed in the upper ionosphere via in-situ satellite observations. The data presented focus mainly on observations near the third and fourth gyro-harmonics. The specific values of the height-dependent gyro-harmonics have been computed from a magnetic model of the field line through the HF heated volume. Experiments with several closely spaced HF frequencies around the gyro-harmonic frequency region show that the magnitude of the lower-ionosphere artificial ionization production maximizes for HF frequencies about 1.0 - 1.5 MHz above the gyro-harmonic frequency. The response is progressively larger as the HF frequency is increased in the frequency region near the gyro-harmonics. For HF frequencies that are initially greater than the gyro-harmonic value the UHF radar scattering cross-section is relatively small, and non-existent or very weak signals are observed; as the signal returns drop in altitude due to density enhancements the HF interaction region passes through lower altitudes where the HF frequency is less than the gyro-harmonic value, for these conditions the radar scattering cross-section is

  4. Structural and thermal properties of Cu-Hf-Ti bulk amorphous alloys

    NASA Astrophysics Data System (ADS)

    Rontó, V.; Nagy, E.; Svéda, M.; Roósz, A.; Tranta, F.

    2009-01-01

    Cu-Hf-Ti amorphous alloys are high strength and wear resistant materials. Master alloys of Cu57.5Hf27.5Ti15 and Cu57.5Hf25Ti17.5 ternary alloys have been prepared by arc melting, and wedge and rod shaped samples have been cast by centrifugal casting. Liquidus and solidus temperatures of the alloys were determined by DTA. The fully amorphous size was determined by X-ray diffraction. Thermodynamic properties of the amorphous alloys were studied by DSC measurements and Kissinger analyses were performed.

  5. Ionospheric and Geomagnetic Activity Investigated Using Oblique Sounding Comparisons With an HF Radio Propagation Model

    NASA Astrophysics Data System (ADS)

    Neudegg, D.; Layoun, M.; Hutchinson, S.

    2008-12-01

    Oblique HF sounder paths over ~2000km have been operating between New Zealand and Australia for a number of years. The maximum observed frequencies (MOF) are compared with predictions from the climatological HF radio skywave propagation model used by IPS. Variations from predicted median (MUF),lower (OWF) and upper decile frequencies may be interpreted in terms of ionospheric and geomagnetic activity and the effectiveness of parameterisation of ionospheric support for HF by the T-index examined. Closely spaced multiple paths provide opportunities to investigate small scale F2 layer structures.

  6. Simulation of a two-frequency cw chemical HF-HBr laser

    SciTech Connect

    Aleksandrov, B P; Katorgin, B I; Stepanov, A A

    2008-10-31

    An autonomous cw chemical HF-HBr laser emitting simultaneously at {approx}2.7 {mu}m (HF molecules) and {approx}4.2 {mu}m (HBr molecules) is studied numerically by using complete Navier-Stokes equations. It is shown that the output power of the HBr laser per unit area of the nozzle array can achieve {approx}20 W cm{sup -2} for the laser region length {approx}20 cm. The relation between the radiation intensities emitted by HF and HBr molecules is controlled by diluting the secondary fuel by bromine. (lasers)

  7. High local disorder in Tb2Hf2O7 pyrochlore oxide nanocrystals

    NASA Astrophysics Data System (ADS)

    Kabanova, V. A.; Popov, V. V.; Zubavichus, Ya V.; Kulik, E. S.; Yaroslavtsev, A. A.; Chernikov, R. V.; Menushenkov, A. P.

    2016-05-01

    The process of Tb2Hf2O7 nanocrystals formation upon annealing to 1600°C was investigated by means of X-ray absorption fine structure (XAFS) spectroscopy combined with X-ray diffraction (XRD) and pair distribution function (PDF) analysis. The structure ordering and the growth of nanocrystals upon annealing were estimated independently from XRD patterns and PDF. The probable content of Tb4+ ions in Tb2Hf2O7 was estimated from XANES. All studies indicate a high disorder and a large number of local structure defects in Tb2Hf2O7 pyrochlore oxide.

  8. Lu-Hf isotope systematics of fossil biogenic apatite and their effects on geochronology

    NASA Astrophysics Data System (ADS)

    Herwartz, Daniel; Münker, Carsten; Tütken, Thomas; Hoffmann, J. Elis; Wittke, Andreas; Barbier, Bruno

    2013-01-01

    Reliable methods for direct dating of biogenic apatite from pre-Pleistocene fossils are currently not available, and recent attempts using the Lu-Hf decay system yielded highly inaccurate ages for both bones and teeth. The geological processes accounting for this poor accuracy of Lu-Hf chronometry are not yet understood. Here we explore Lu-Hf systematics in fossil bones and teeth in detail, by applying five different sample digestion techniques that are tested on bones and composites of bone and sediment. Our current dataset implies that dissolution methods only slightly affect the resulting Lu-Hf ages, while clear differences between the individual digestion techniques became apparent for element concentrations. By analysing the insoluble leftovers from incomplete sample dissolution, four main reservoirs of Hf in fossil bones were identified: (1) a radiogenic end-member associated with apatite; (2) an unradiogenic end-member represented by the authigenic minerals or the embedding sediment; (3) a highly unradiogenic end-member that can be attributed to detrital zircon; and (4) a moderately soluble phase (probably a Zr(Hf)-phosphate) that yielded very low Lu/Hf but a highly radiogenic Hf isotope composition at the same time. This Zr(Hf)-phase must have been precipitated within the fossil bone sample at a late stage of burial history, thereby incorporating radiogenic 176Hf released from apatite surfaces over geological timescales. A second focus of our study is the effect of different sediment matrices and of crystal size on the preservation of pristine Lu-Hf isotope compositions in bioapatite. Because near-depositional Lu-Hf ages of phosphate fossils have previously been reported for the London Clay (England) and a calcareous marl from Tendaguru (Tanzania), we herein investigate specimens fossilised in carbonate matrices (calcareous marl from Oker, Germany; carbonate concretions from the Santana Formation, Brazil; carbonate from the Eifel, Germany) and argillaceous

  9. Mineralocorticoid receptor antagonists as diuretics: Can congestive heart failure learn from liver failure?

    PubMed Central

    Ortiz, Fernando; Radhakrishnan, Jai; Schrier, Robert W.; Colombo, Paolo C.

    2014-01-01

    Despite significant improvements in diagnosis, understanding the pathophysiology and management of the patients with acute decompensated heart failure (ADHF), diuretic resistance, yet to be clearly defined, is a major hurdle. Secondary hyperaldosteronism is a pivotal factor in pathogenesis of sodium retention, refractory congestion in heart failure (HF) as well as diuretic resistance. In patients with decompensated cirrhosis who suffer from ascites, similar pathophysiological complications have been recognized. Administration of natriuretic doses of mineralocorticoid receptor antagonists (MRAs) has been well established in management of cirrhotic patients. However, this strategy in patients with ADHF has not been well studied. This article will discuss the potential use of natriuretic doses of MRAs to overcome the secondary hyperaldosteronism as an alternative diuretic regimen in patients with HF. PMID:25447845

  10. Lu-Hf and Sm-Nd Isotopic Studies of Shergottites and Nakhlites: Implications for Martian Mantle Sources

    NASA Technical Reports Server (NTRS)

    Debaille, V.; Yin, Q.-Z.; Brandon, A. D.; Jacobsen, B.; Treiman, A. H.

    2007-01-01

    We present a new Lu-Hf and Sm-Nd isotope systematics study of four enriched shergottites (Zagami, Shergotty, NWA856 and Los Angeles), and three nakhlites (Nakhla, MIL03346 and Yamato 000593) in order to further understand processes occurring during the early differentiation of Mars and the crystallization of its magma ocean. Two fractions of the terrestrial petrological analogue of nakhlites, the Archaean Theo's flow (Ontario, Canada) were also measured. The coupling of Nd and Hf isotopes provide direct insights on the mineralogy of the melt sources. In contrast to Sm/Nd, Lu/Hf ratios can be very large in minerals such as garnet. Selective partial melting of garnet bearing mantle sources can therefore lead to characteristic Lu/Hf signatures that can be recognized with Hf-176/Hf-177Hf ratios.

  11. Effects of C and Hf concentration on phase relations and microstructure of a wrought powder-metallurgy superalloy

    NASA Technical Reports Server (NTRS)

    Miner, R. V., Jr.

    1977-01-01

    NASA IIB-11, a candidate alloy for advanced temperature turbine engine disks, and four modifications with varying C and Hf concentrations were produced from prealloyed powders. Several notable effects of C and Hf concentration in the alloys were observed. Both the amount of the gamma-prime phase and its solvus temperature increased with decreasing C, but only the gamma-prime solvus was affected by Hf, increasing with increasing Hf. Hf also promoted a cellular gamma-prime precipitation. Hf was, however, about equally distributed between gamma-prime and gamma. Hf and C both affected the carbides formed. Increasing both promoted formation of an MC relative to that of an M6C.

  12. Structural and electrical properties of thin SrHfON films for high-k gate dielectric

    SciTech Connect

    Feng Liping; Liu Zhengtang

    2009-06-22

    Thin SrHfON films were prepared by reactive cosputtering of Hf-O and Sr-O targets in Ar/N{sub 2} ambient environment. Structural and electrical properties of the as-deposited and annealed SrHfON films used as gate dielectrics have been investigated. The SrHfON films have crystallization temperature higher than 900 deg. C. After annealing at 900 deg. C, high dielectric constant of 19.3 and effective work function of 4.13 eV was obtained for the SrHfON films. It is worth mentioning that the leakage current density of Au/SrHfON/IL SiO{sub x} gate stack is two orders of magnitude lower than that of polycrystalline silicon/HfO{sub 2} structure.

  13. Acute kidney failure

    MedlinePlus

    Kidney failure; Renal failure; Renal failure - acute; ARF; Kidney injury - acute ... There are many possible causes of kidney damage. They include: ... cholesterol (cholesterol emboli) Decreased blood flow due to very ...

  14. Acute arterial occlusion - kidney

    MedlinePlus

    Acute renal arterial thrombosis; Renal artery embolism; Acute renal artery occlusion; Embolism - renal artery ... kidneys need a good blood supply. The main artery to the kidney is called the renal artery. ...

  15. Acute arterial occlusion - kidney

    MedlinePlus

    ... arterial thrombosis; Renal artery embolism; Acute renal artery occlusion; Embolism - renal artery ... often result in permanent kidney failure. Acute arterial occlusion of the renal artery can occur after injury ...

  16. Acute Lymphocytic Leukemia

    MedlinePlus

    ... hard for blood to do its work. In acute lymphocytic leukemia (ALL), also called acute lymphoblastic leukemia, there are too ... of white blood cells called lymphocytes or lymphoblasts. ALL is the most common type of cancer in ...

  17. The Li···HF van der Waals minimum and the barrier to the deep HF-Li potential well

    NASA Astrophysics Data System (ADS)

    Fan, Qunchao; Feng, Hao; Sun, Weiguo; Xie, Yaoming; Wu, Chia-Hua; Allen, Wesley D.; Schaefer, Henry F., III

    2014-03-01

    Molecular beam experiments (lithium atom plus hydrogen fluoride) by both Becker and co-workers (C.H. Becker, P. Casavecchia, P.W. Tiedemann, J.J.Valentini, and Y.T. Lee, J. Chem. Phys. 73, 2833 (1980)) and Loesch and Stienkemeier (H.J. Loesch and F. Stienkemeier, J. Chem. Phys. 98, 9570 (1993)) deduced a van der Waals complex of type Li...HF. In this research, molecular electronic structure theory [aug-cc-pCVQZ CCSD(T)] has been used to predict a well depth of 0.86 kcal mol-1 relative to separated Li + HF. However, the barrier from this vdW well to the more strongly bound (∼6.2 kcal mol-1) HFLi complex lies 0.43 kcal mol-1 below separated Li + HF. Special Issue of Molecular Physics: Seventh Molecular Quantum Mechanics Conference, Lugano, Switzerland, 2-7 June 2013.

  18. Acute phase treatment of venous thromboembolism: advanced therapy. Systemic fibrinolysis and pharmacomechanical therapy.

    PubMed

    Konstantinides, Stavros V; Wärntges, Simone

    2015-06-01

    Venous thromboembolism, which encompasses deep-vein thrombosis and acute pulmonary embolism (PE), represents a major contributor to global disease burden worldwide. For patients who present with cardiogenic shock or persistent hypotension (acute high-risk PE), there is consensus that immediate reperfusion treatment applying systemic fibrinolysis or, in the case of a high bleeding risk, surgical or catheter-directed techniques, is indicated. On the other hand, for the large, heterogeneous group of patients presenting without overt haemodynamic instability, the indications for advanced therapy are less clear. The recently updated guidelines of the European Society of Cardiology emphasise the importance of clinical prediction rules in combination with imaging procedures (assessment of right ventricular function) and laboratory biomarkers (indicative of myocardial stress or injury) for distinguishing between an intermediate and a low risk for an adverse early outcome. In intermediate-high-risk PE defined by the presence of both right ventricular dysfunction on echocardiography (or computed tomography) and a positive troponin (or natriuretic peptide) test, the bleeding risks of full-dose fibrinolytic treatment have been shown to outweigh its potential clinical benefits unless clinical signs of haemodynamic decompensation appear (rescue fibrinolysis). Recently published trials suggest that catheter-directed, ultrasound-assisted, low-dose local fibrinolysis may provide an effective and particularly safe treatment option for some of these patients. PMID:25789580

  19. [Bronchial asthma and chronic obstructive pulmonary disease with acute exacerbation: preclinical differential diagnostic and emergency treatment].

    PubMed

    Friege, B; Friege, L; Pelz, J; Weber, M; von Spiegel, T; Schröder, S

    2009-06-01

    Chronic obstructive pulmonary disease (COPD) and bronchial asthma are the most common causes of obstructive pulmonary diseases and acute dyspnoea. In the preclinical emergency situation a distinction between bronchial asthma and exacerbated COPD is difficult because symptoms are similar. Although the preclinical measures differ only marginally, a differential diagnosis from other causes of respiratory obstruction and acute dyspnoea, such as cardiac decompensation, anaphylaxis, aspiration of foreign bodies, tension pneumothorax and inhalation trauma is necessary because alternative treatment options are required. In the treatment of COPD and bronchial asthma inhalative bronchodilatory beta(2)-mimetics are the first choice especially for serious obstructive emergencies because there is an unfavorable relationship between effect and side-effects for the intravenous route. Dosable aerosols, nebulization and if necessary, continuous nebulization, are appropriate application forms even for serious obstructive crises with the need of a respirator. In these cases a minimal inspiratory flow in patients is not required. Theophylline only plays a minor role to beta(2)-mimetics and anticholinergics as a bronchodilator in asthma and COPD guidelines, even in serious obstructive diseases. For severe asthma attacks the administration of magnesium is a possible additional option. Systemic intravenous administration of steroids has an anti-inflammatory effect and for this reason is the second column of treatment for both diseases. Invasive ventilation remains a last resort to ensure respiratory function and indications for this are given in patients with clinical signs of impending exhaustion of breathing. PMID:19424670

  20. Liver dialysis in acute-on-chronic liver failure: current and future perspectives.

    PubMed

    Maiwall, Rakhi; Maras, Jaswinder Singh; Nayak, Suman Lata; Sarin, Shiv Kumar

    2014-09-01

    Patients with acute-on-chronic liver failure (ACLF) are known to have a very high mortality rate as the majority of these patients succumb to multiorgan failure. Liver transplant remains the only option for these patients; however, there are problems with its availability, cost and also the complications and side effects associated with immunosuppression. Unlike advanced decompensated liver disease, there is a potential for hepatic regeneration and recovery in patients with ACLF. A liver support system, cell or non-cell based, logically is likely to provide temporary functional support until the donor liver becomes available or the failing liver survives the onslaught of the acute insult and spontaneously regenerates. Understanding the pathogenesis of liver failure and regeneration is essential to define the needs for a support system. Removal of hepatotoxic metabolites and inhibitors of hepatic regeneration by liver dialysis, a non-cell-based hepatic support, could help to provide a suitable microenvironment and support the failing liver. The current systems, i.e., MARS and Prometheus, have failed to show survival benefits in patients with ACLF based on which newer devices with improved functionality are currently under development. However, larger randomized trials are needed to prove whether these devices can enable restoration of the complex dysregulated immune system and impact organ failure and mortality in these patients. PMID:26201332

  1. LU-HF Age of Martian Meteorite Larkman Nunatek 06319

    NASA Technical Reports Server (NTRS)

    Shafer, J. T.; Brandon, A. D.; Lapen, T. J.; Righter, M.; Beard, B.; Peslier, A. H.

    2009-01-01

    Lu-Hf isotopic data were collected on mineral separates and bulk rock powders of LAR 06319, yielding an age of 197+/- 29 Ma. Sm-Nd isotopic data and in-situ LA-ICP-MS data from a thin section of LAR 06319 are currently being collected and will be presented at the 2009 LPSC. These new data for LAR 06319 extend the existing data set for the enriched shergottite group. Martian meteorites represent the only opportunity for ground truth investigation of the geochemistry of Mars [1]. At present, approximately 80 meteorites have been classified as Martian based on young ages and distinctive isotopic signatures [2]. LAR 06319 is a newly discovered (as part of the 2006 ANSMET field season) martian meteorite that represents an important opportunity to further our understanding of the geochemical and petrological constraints on the origin of Martian magmas. Martian meteorites are traditionally categorized into the shergottite, nakhlite, and chassignite groups. The shergottites are further classified into three distinct isotopic groups designated depleted, intermediate, and enriched [3,4] based on the isotope systematics and compositions of their source(s).

  2. Anomalous phenomena on HF radio paths during geomagnetic disturbances

    NASA Astrophysics Data System (ADS)

    Blagoveshchenskii, D. V.

    2016-07-01

    We analyze ionospheric oblique sounding data on three high-latitude and one high-latitude-midlatitude HF radio paths for February 15 and 16, 2014, when two substorms and one magnetic storm occurred. We investigate cases of anomalous propagation of signals: their reflection from sporadic layer Es, lateral reflections, type "M" or "N" modes, the presence of traveling ionospheric disturbances, and the diffusivity of signals and triplets. The most significant results are the following. In geomagnetically undisturbed times, sporadic Es-layers with reduced maximum observed frequencies (MOF Es) on three high-latitude paths were observed in both days. The values of MOF Es during disturbances are large, which leads to the screening of other oblique sounding signals reflected from the ionosphere. On all four paths, the most frequently traveling ionospheric disturbances due to the terminator were observed in quiet hours from 03:00 to 15:00 UT on the first day and from 06:00 to 13:00 UT on the second day of the experiment. In addition, both the sunset terminator and the magnetic storm on the high-latitude-mid-latitude path were found to generate traveling ionospheric disturbances jointly. No such phenomenon was found on high-latitude paths.

  3. Noise properties of HF radar measurement of ocean surface currents

    NASA Astrophysics Data System (ADS)

    Forget, Philippe

    2015-08-01

    High-frequency (HF) radars are commonly used for coastal circulation monitoring. The objective of the study is to assess what is the minimum timescale of variability of the geophysical surface currents that are accessible to the radar measurement given the intrinsic noise of this measurement. Noise properties are derived from the power density spectra (PDSs) of radial current records, which are compared to a model of the PDS of idealized currents contaminated by an additive white noise. The data were collected by two radar systems operating in the Northwestern Mediterranean. Periods of 3 weeks to 7 months are considered. Most of measured currents are affected by a white noise effect. Noise properties vary in time and space and are not specific to a particular radar station or to the radar signal processing method used (beam forming or direction finding). An increase of the noise level reduces the effective temporal resolution of radar-derived currents and then increases the minimum observable timescale of variability of geophysical currents. Our results are consistent with results of comparison found in literature between in situ sensors and radar measurements as well as between two radars operating along a same base line. The study suggests a self-sufficient method, requiring no external data, to estimate the minimum sampling period to consider for getting data sets having a minimized contamination by instrumental noise. This period can also be taken for smoothing or filtering measured currents.

  4. Enhancing the ADMX-HF Search Rate via Quantum Squeezing

    NASA Astrophysics Data System (ADS)

    Palken, Daniel; Malnou, Maxime; Lehnert, Konrad

    2016-03-01

    ADMX-HF seeks to detect dark matter axions in the 4-12 GHz band by reading out the state of a microwave cavity. Utilizing a quantum-limited, phase-insensitive amplifier such as a Josephson Parametric Amplifier (JPA) to read out both quadratures of the putative axion signal adds a full quantum of noise atop that signal. The two halves of that quantum are attributed to the noncommutation of the quadrature operators with the cavity Hamiltonian and with one another. We propose a method whereby both halves of this quantum may be circumvented. A JPA is used to create a squeezed microwave state and inject it into the axion cavity, whereupon an axion field, if present, displaces the squeezed state in phase space. The squeezed state then decays out of the cavity, and a second JPA is used for a phase-sensitive readout of only the squeezed quadrature of the field. A single quadrature measurement need not add noise, and, because the cavity field will be prepared in an approximate eigenstate of one quadrature operator, and not of its Hamiltonian, that half-quantum is averted as well. The limiting factor in this protocol will be the efficient transport of the squeezed microwave state between the JPAs and the axion cavity. We estimate that with currently achievable efficiency, we can increase the axion search rate by a factor of four.

  5. High-pulse-repetition-rate HF laser with plate electrodes

    SciTech Connect

    Andramanov, A V; Kabaev, S A; Lazhintsev, B V; Nor-Arevyan, V A; Pisetskaya, A V; Selemir, Victor D

    2006-03-31

    A high-pulse-repetition-rate electric-discharge HF laser with inductive-capacitive discharge stabilisation in the active H{sub 2}-SF{sub 6}-He mixture is studied. The multisectional discharge gap with a total length of 250 mm is formed by pairs of anode-cathode plates arranged in a zigzag pattern. The width of the discharge gap between each pair of plates is {approx}1 mm and its height is {approx}12 mm. The laser-beam cross section at the output cavity mirror is {approx}9 mm x 11 mm. The maximum laser pulse energy and the maximum laser efficiency for the H{sub 2}-SF{sub 6} mixture are 14.3 mJ and 2.1%, respectively. The addition of He to the mixture reduced the laser pulse energy by 10%-15%. The maximum gas velocity in the gap between the electrodes achieves 20 m s{sup -1}. The limiting pulse repetition rate f{sub lim} for which a decrease in the laser pulse energy is still not observed is {approx}2kHz for the H{sub 2}-SF{sub 6} mixture and {approx}2.4kHz for the H{sub 2}-SF{sub 6}-He mixture. The average output power {approx}27 W is obtained for a pulse repetition rate of 2.4 kHz. (lasers)

  6. N2F4 combustion drivers for CW HF lasers

    NASA Astrophysics Data System (ADS)

    Warren, W. R., Jr.; Schneider, L. E.; Warren, D.

    1993-07-01

    The Pacific Applied Research combustion-driven blowdown test facility, PAR/BDF, was used to study the specific energy and other HF laser performance characteristics of the HYLTE-7 high performance nozzle-cavity injector configuration. Of particular interest was the determination of improvements associated with the use of an N2F4/D2 combustor over an NF3/D2 combustor in the laser device. Specific observations include: a 21 percent increase in optimum specific energy performance for the N2F4/D2 combustor driving low-diluent lasing flow and a 30 percent increase for moderate-diluent, dual shear-layer laser flow; the hypergolic nature of N2F4/He-D2 mixes when injected into a combustion chamber through a ox/fuel/ox multiple triplet system over property ranges compatible with efficient laser operation (NF3/He/Dx mixes are not hypergolic); a combustor bypass modification to eliminate highly-wall-cooled combustion products from laser cavity flows roughly doubled peak specific energy performance over that of a no-bypass combustor for both combustion systems.

  7. Multiphoton population transfer between rovibrational states of HF

    NASA Astrophysics Data System (ADS)

    Topcu, Turker; Robicheaux, Francis

    2011-05-01

    Efficient population transfer by adiabatically chirping through a multiphoton resonance in microwave driven and impulsively kicked Rydberg atoms has been reported both experimentally and theoretically. Previous work has demonstrated that the physical mechanism responsible for the transition can be viewed as a classical process in phase space as well as a quantum mechanical resonant transition. Here we report on our classical and quantum mechanical simulations in which we have exploited this mechanism to vibrationally excite an HF molecule up to | ν = 4 , J > from its ground state using an intense IR pulse. We compare one-dimensional quantum and classical models where there are no rotational degrees of freedom. We find that for low laser intensities, the transition is classically forbidden although it occurs quantum mechanically through tunneling. We show that for larger peak intensities, the transfer can be looked upon as a classical transition in phase space, similar to that observed in the atomic case. We extend our simulations to fully three-dimensional quantum calculations and investigate the effect of coupling between different rotational pathways. We briefly discuss the effect of thermal averaging over the final J-states. This work was supported by the Office of Basic Energy Sciences, U.S. Department of Energy.

  8. Central adiponectin acutely improves glucose tolerance in male mice.

    PubMed

    Koch, Christiane E; Lowe, Chrishanthi; Legler, Karen; Benzler, Jonas; Boucsein, Alisa; Böttiger, Gregor; Grattan, David R; Williams, Lynda M; Tups, Alexander

    2014-05-01

    Adiponectin, an adipocyte-derived hormone, regulates glucose and lipid metabolism. It is also antiinflammatory. During obesity, adiponectin levels and sensitivity are reduced. Whereas the action of adiponectin in the periphery is well established the neuroendocrine role of adiponectin is largely unknown. To address this we analyzed the expression of adiponectin and the 2 adiponectin receptors (AdipoR1 and AdipoR2) in response to fasting and to diet-induced and genetic obesity. We also investigated the acute impact of adiponectin on central regulation of glucose homeostasis. Adiponectin (1 μg) was injected intracerebroventricularly (ICV), and glucose tolerance tests were performed in dietary and genetic obese mice. Finally, the influence of ICV adiponectin administration on central signaling cascades regulating glucose homeostasis and on markers of hypothalamic inflammation was assessed. Gene expression of adiponectin was down-regulated whereas AdipoR1 was up-regulated in the arcuate nucleus of fasted mice. High-fat (HF) feeding increased AdipoR1 and AdipoR2 gene expression in this region. In mice on a HF diet and in leptin-deficient mice acute ICV adiponectin improved glucose tolerance 60 minutes after injection, whereas normoglycemia in control mice was unaffected. ICV adiponectin increased pAKT, decreased phospho-AMP-activated protein kinase, and did not change phospho-signal transducer and activator of transcription 3 immunoreactivity. In HF-fed mice, ICV adiponectin reversed parameters of hypothalamic inflammation and insulin resistance as determined by the number of phospho-glycogen synthase kinase 3 β(Ser9) and phospho-c-Jun N-terminal kinase (Thr183/Tyr185) immunoreactive cells in the arcuate nucleus and ventromedial hypothalamus. This study demonstrates that the insulin-sensitizing properties of adiponectin are at least partially based on a neuroendocrine mechanism that involves centrally synthesized adiponectin. PMID:24564394

  9. In situ characterization of initial growth of HfO{sub 2}

    SciTech Connect

    Wang, L.; Chu, Paul K.; Xue, K.; Xu, J. B.

    2009-01-19

    The initial growth of HfO{sub 2} on Si (111) is monitored in situ by ultrahigh vacuum (UHV) scanning probe microscopy. UHV scanning tunneling microscopy and UHV atomic force microscopy reveal the topography of HfO{sub 2} films in the initial stage. The chemical composition is further confirmed by x-ray photoelectron spectroscopy. Scanning tunneling spectroscopy is utilized to inspect the evolution of the bandgap. When the film thickness is less than 0.6 nm, the bandgap of HfO{sub 2} is not completely formed. A continuous usable HfO{sub 2} film with thickness of about 1.2 nm is presented in this work.

  10. Deposition of HfO2 on germanium and the impact of surface pretreatments

    NASA Astrophysics Data System (ADS)

    Van Elshocht, S.; Brijs, B.; Caymax, M.; Conard, T.; Chiarella, T.; De Gendt, S.; De Jaeger, B.; Kubicek, S.; Meuris, M.; Onsia, B.; Richard, O.; Teerlinck, I.; Van Steenbergen, J.; Zhao, C.; Heyns, M.

    2004-10-01

    The deposition behavior of HfO2 by metalorganic chemical vapor deposition on germanium has been investigated. HfO2 films can be deposited on Ge with equally good quality as compared to high-k growth on silicon. Surface preparation is very important: compared to an HF-last, NH3 pretreatments result in smoother films with strongly reduced diffusion of germanium in the HfO2 film, resulting in a much better electrical performance. We clearly show that much thinner interfacial layers can be obtained, approximately half the thickness of what is typically found for depositions on silicon, suggesting the possibility of more aggressive equivalent oxide thickness/leakage scaling.

  11. Internally nitrided refractory alloy (INRA) development. FY 1986 report. [Nitridation of Mo-1. 86 Hf alloy

    SciTech Connect

    Mitchell, J.B.; Walter, C.E.

    1986-10-06

    Internal structure studies show that by controlling grain size and amount of cold work, the results of the nitriding process can be modified. A uniform hardness can be obtained by properly controlling the nitriding parameters. The ability to control nitrogen pressure during the process over a broad range, including above one atmosphere is expected to provide greater uniformity of hardness. Limited welding efforts have produced sound welds using TIG and E-beam techniques in Mo-1.86 Hf alloy sheet. Fabrication of space power components thus appears to be achievable. Alloy compositions Mo-1.86 Hf and Mo-15 Re-1.86 Hf have been successfully produced in sheet form. Additional effort is required to reduce carbon, oxygen and nitrogen impurities. Creep resistance of Mo-HfN alloy is 100 to 1000 times greater than that observed for other molybdenum based alloys. Greater design flexibility yielding lighter and more reliable components would be available with this material.

  12. Crystal growth of HfS 2 by chemical vapour transport with halogen (Cl, Br, I)

    NASA Astrophysics Data System (ADS)

    Fiechter, S.; Eckert, K.

    1988-05-01

    Single crystals of HfS 2 have been prepared by chemical vapour transport (CVT) with halogen. Depending on the transporting agent added, exergonic or endergonic transport was observed. Employing 0.5 mg/cm 3 chlorine or bromine in evacuated and sealed quartz ampoules, exergonic transport occurs. In a temperature gradient from 850 to 870 K transparent reddish-orange crystal platelets of pseudohexagonal shape (10×10×0.05 mm3) were obtained. Endergonic transport, found with iodine as transporting agent, first starts at higher temperatures (1270-1220 K). A thermochemical study of the vapour phase composition revealed that gaseous HfHal 4 and HfHal 3 ( Hal = Cl, Br) are responsible for the exergonic transport observed. Because of the higher stability of HfS 2 against iodine, CVT first starts at elevated temperatures. In the vapour phase Hfl and Hfl 2 dominate and effect a reversal of the transport direction.

  13. Modulation of auroral electrojet currents using dual HF beams with ELF phase offset

    NASA Astrophysics Data System (ADS)

    Golkowski, M.; Cohen, M.; Moore, R. C.

    2012-12-01

    The modulation of naturally occuring ionospheric currents with high power radio waves in the high frequency (HF, 3-10 MHz) band is a well known technique for generation of extremely low frequency (ELF, 3-3000 Hz) and very low frequency (VLF, 3-30 kHz) waves. We use the heating facility of the High Frequency Active Auroral Research Program (HAARP) to investigate the effect of using dual HF beams with an ELF/VLF phase offset between the modulation waveforms. Experiments with offset HF beams confirm the model of independent ELF/VLF sources. Experiments with co-located HF beams exhibit interaction between the first and second harmonics of the modulated tones when square and sine wave modulation waveforms are employed. Using ELF/VLF phase offsets for co-loacted beams is also shown to be a potential diagnostic for the D-region ionospheric profile.

  14. Two-dimensional electron gas in GaAs/SrHfO3 heterostructure

    NASA Astrophysics Data System (ADS)

    Wang, Jianli; Yuan, Mengqi; Tang, Gang; Li, Huichao; Zhang, Junting; Guo, Sandong

    2016-06-01

    The III-V/perovskite-oxide system can potentially create new material properties and new device applications by combining the rich properties of perovskite-oxides together with the superior optical and electronic properties of III-Vs. The structural and electronic properties of the surface and interface are studied using first-principles calculations for the GaAs/SrHfO3 heterostructure. We investigate the specific adsorption sites and the atomic structure at the initial growth stage of GaAs on the SrHfO3 (001) substrate. Ga and As adsorption atoms preferentially adsorb at the top sites of oxygen atoms under different coverage. The energetically favorable interfaces are presented among the atomic arrangements of the GaAs/SrHfO3 interfaces. Our calculations predict the existing of the two-dimensional electron gas in the GaAs/SrHfO3 heterostructure.

  15. Strongly reduced Si surface recombination by charge injection during etching in diluted HF/HNO3.

    PubMed

    Greil, Stefanie M; Schöpke, Andreas; Rappich, Jörg

    2012-08-27

    Herein, we investigate the behaviour of the surface recombination of light-induced charge carriers during the etching of Si in alkaline (KOH) and acidic etching solutions of HF/HNO(3)/CH(3)COOH (HNA) or HF/HNO(3)/H(3)PO(4) (HNP) at different concentration ratios of HF and HNO(3) by means of photoluminescence (PL) measurements. The surface recombination velocity is strongly reduced during the first stages of etching in HF/HNO(3)-containing solutions pointing to a interface well passivated by the etching process, where a positive surface charge is induced by hole injection from NO-related surface species into the Si near-surface region (back surface field effect). This injected charge leads to a change in band bending by about 150 mV that repulses the light-induced charge carriers from the surface and therefore enhances the photoluminescence intensity, since non-radiative surface recombination is reduced. PMID:22761060

  16. An error-resilient approach for real-time packet communications by HF-channel diversity

    NASA Astrophysics Data System (ADS)

    Navarro, Antonio; Rodrigues, Rui; Angeja, Joao; Tavares, Joao; Carvalho, Luis; Perdigao, Fernando

    2004-08-01

    This paper evaluates the performance of a high frequency (HF) wireless network for transporting packet multimedia services. Beyond of allowing civil/amateur communications, HF bands are also used for long distance wireless military communications. Therefore, our work is based on NATO Link and Physical layer standards, STANAG 5066 and STANAG 4539 respectively. At each HF channel, a typical transmission bandwidth is about 3 kHz with the resulting throughput bit rate up to 12800 bps. This very low bit rate by itself imposes serious challenges for reliable and low delay real time multimedia communications. Thus, this paper discusses the performance of a real time communication system designed to allow an end-to-end communication through "best effort" networks. With HF channel diversity, the packet loss percentage, on average considering three channel conditions, is decreased by 16% in the channel SNR range from 0 to 45 dB.

  17. Lu-Hf total-rock isochron for the eucrite meteorites

    NASA Technical Reports Server (NTRS)

    Patchett, P. J.; Tatsumoto, M.

    1980-01-01

    The isotope Lu-176 (2.6% of natural lutetium) decays by beta(-) to Hf-176, with a long half life. The first Lu-Hf isochron is presented. The eucrite meteorites, a suite of planetary igneous rocks of known age, 4,550 Myr, define a 10-point total-rock isochron with a slope of 0.0934 + or - 40, leading to a value of 3.53 + or - 0.14 x 10 to the 10th yr for the beta(-) decay half life of Lu-176. The isochron intercept of 0.27973 + or - 12 gives the initial Hf-176/Hf-177 for the inner solar system at the time of accretion.

  18. Chiral anomaly and ultrahigh mobility in crystalline HfT e5

    NASA Astrophysics Data System (ADS)

    Wang, Huichao; Li, Chao-Kai; Liu, Haiwen; Yan, Jiaqiang; Wang, Junfeng; Liu, Jun; Lin, Ziquan; Li, Yanan; Wang, Yong; Li, Liang; Mandrus, David; Xie, X. C.; Feng, Ji; Wang, Jian

    2016-04-01

    HfT e5 is predicted to be a promising platform for studying topological phases. Here through an electrical transport study, we present an observation of chiral anomaly and ultrahigh mobility in HfT e5 crystals. Negative magnetoresistivity in HfT e5 is observed when the external magnetic and electrical fields are parallel (B//E) and quickly disappears once B deviates from the direction of E. Quantitative fitting further confirms the chiral anomaly as the underlying physics. Moreover, by analyzing the conductivity tensors of longitudinal and Hall traces, ultrahigh mobility and ultralow carrier density are revealed in HfT e5 , which paves the way for potential electronic applications.

  19. Does a threshold stress for creep exist in HfC-dispersed NiAl?

    NASA Technical Reports Server (NTRS)

    Whittenberger, J. D.; Ray, Ranjan; Jha, Sunil C.

    1991-01-01

    Recently it was proposed (Jha et al., 1989; Whittenberger et al., 1990) on the basis of constant velocity testing at 1300 K that dispersion strengthened NiAl composites containing about 4 wt pct HfC possess threshold stresses for creep. Further, 1300 K compression testing has been conducted on NiAl+4HfC, and diametrically opposite behavior has been found: for constant load creep tests a normal power law behavior was observed. However, additional constant velocity testing still indicates that the flow stress is essentially independent of strain rate below 10 exp -6/s. Examination of NiAl+4.3HfC specimens deformed under constant velocity conditions revealed that the original hot extruded small grain structure could be converted to large, elongated grains during testing. Such a transformation appears to be responsible for the apparent threshold stress behavior in HfC dispersed NiAl.

  20. Spectroscopic requirements for HALOE: An analysis of the HCl and HF channels

    NASA Technical Reports Server (NTRS)

    Rinsland, C. P.; Smith, M. A. H.; Park, J. H.; Harvey, G. A.; Russell, J. M., III; Richardson, D. J.

    1982-01-01

    Spectral line parameters that have absorption features within the HCl and HF channels of the Halogen Occultation Experiment (HALOE) were evaluated. Line positions and identification of stratospheric and solar absorption features in both channels are presented based on an analysis of high-resolution, balloon-borne solar occultation spectra. For the relevant HCl and HF lines and for transitions of the interfering species, the accuracy of the following spectral parameters was assessed: line positions, line strengths, lower state energies, air-broadened collisional half-widths, and temperature dependence of the air-broadened half-widths. In addition, since the HALOE instrument and calibration cells are filled with mixtures of HCl in N2 and HF in N2, the self-broadened and N2-broadened HF and HCl half-widths were also considered.