Prognostic role and predictors of high Killip class in myocardial infarction with non-obstructive coronary artery

Background

Killip classification is a simple clinical tool for risk stratification in patients with acute myocardial infarction (AMI). However, predictors of high Killip class at admission and its prognostic role in myocardial infarction with non-obstructive coronary artery (MINOCA) are still poorly explored.

Purpose

To identify clinical predictors of high Killip class and its potential prognostic role in patients with MINOCA compared to patients with myocardial infarction with obstructive coronary artery (MIOCA).

Methods

We included patients with AMI undergoing coronary angiogram from January 2016 to June 2021. MINOCA were defined according to the current European guidelines criteria. We compared the Killip classes of MINOCA with those of MIOCA and defined a high Killip class if greater than 1. Kaplan-Meier (KM) curves were developed for the comparison of all-cause mortality among MIOCA and MINOCA with high Killip class (>1) compared to the others. Multivariate logistic regression analysis was used to determine the predictors of high Killip class.

Results

Among 3261 AMI, 261 were MINOCA. The median follow-up time was 36.1±15.2 months. Killip class >1 occurred in 24 (8.8%) MINOCA patients compared to 518 (17.3%) MIOCA cases (p=0.001). During long-term follow-up, a high Killip class was associated with a 3-fold increased mortality both in MIOCA and MINOCA populations (p<0.001 and p=0.001). Furthermore, in both groups, the KM survival curves were significantly worse for patients with high Killip class compared to lower classes (p<0.001). Within MIOCA multivariate logistic regression showed that predictors of a high Killip class at admission were older age [OR 1.04, 95% CI (1.03–1.06), p<0.001], diabetes [OR 1.60, 95% CI (1.24–2.07), p<0.001], ST-segment-elevation [OR 1.53, 95% CI (1.12–2.10), p=0.008], left ventricular ejection fraction (LVEF) [OR 0.95, 95% CI (0.94–0.96), p<0.001] and elevated cardiac troponin [OR 1.01, 95% CI (1.00–1.01), p=0.01]. Instead, in MINOCA only older age [OR 1.08, 95% CI (1.03–1.14), p=0.003], ST-segment-elevation [OR 7.40, 95% CI (1.08–50.65), p=0.04] and diabetes [OR 3.60, 95% CI (1.09–11.96), p=0.04] were predictors of a high Killip class whereas LVEF (p=0.3) and elevated cardiac troponin (p=0.6) exhibited a neutral impact in these patients.

Conclusions

High Killip class at admission is a high-risk marker of adverse cardiovascular events even in patients with MINOCA. Simple baseline characteristics (such as older age, diabetes, ST-segment-elevation) predict a high Killip class in MINOCA subjects and can help to identify a high-risk population who might benefit from a stricter management. Furthermore, LVEF and elevated cardiac troponin were identified as predictors of a high Killip class in MIOCA but they did not show a similar impact in the setting of MINOCA. This may reflect the different pathogenesis and myocardial damage extent in MINOCA compared to MIOCA.

Funding Acknowledgement

Type of funding sources: None.

Development and validation of a diagnostic echocardiographic mass (DEM) score in the complex approach to cardiac masses

Background

Cardiac masses (CM) are an extremely heterogeneous clinical entity, including benign and malignant neoformations. 2D Echocardiography is nowadays the first-line approach to define nature and management of CM.

Purpose

The purpose of our study was to identify the echocardiographic predictors of malignancy and create a multiparametric score to further increase the diagnostic yield and accurately suggest the nature of CM.

Material and methods

249 consecutive patients undergoing a complete echocardiographic assessment for suspected cardiac mass were enrolled from January 2004 to December 2020. A definitive diagnosis was achieved by histological examination or, in case of cardiac thrombi, with radiological evidence of thrombus resolution after an appropriate anticoagulant treatment. Logistic regression was performed to evaluate the ability of echocardiography to discriminate benign versus malignant masses.

Results

A scoring system was developed in a derivation cohort of 178 (70%) and validated in 71 (30%) patients. A weighted score [Diagnostic Echocardiographic Mass (DEM) Score] ranging from 0 to 9 was obtained from 6 variables: infiltration, polylobate mass, moderate-severe pericardial effusion, inhomogeneity, sessile and non-left localization. The AUC for the score was 0.965 (95% CI 0.938–0.993). In a logistic regression analysis using the DEM score as a predictor, the likelihood of malignancy increased more than 4 times for a 1-unit increase of the score (OR=4.468; 95% CI 2.733–7.304). The prognostic validity of the score was confirmed by its ability to predict survival during follow-up (median time of 31 months).

Conclusions

The application of a multiparametric echocardiographic score in the approach to CM accurately predicts mass malignancy thereby reducing the need for second-level investigations, and minimizing the diagnostic delay in such a complex clinical scenario.

Funding Acknowledgement

Type of funding sources: None.

Prognostic role of early cardiac magnetic resonance in myocardial infarction with non-obstructive coronary arteries

Background

Myocardial infarction with non-obstructive coronary arteries (MINOCA) represents a significant proportion of acute myocardial infarction (AMI) population. MINOCA is a working diagnosis and an accurate investigation of the underlying causes should always be performed. In this setting, cardiac magnetic resonance (CMR) imaging plays a pivotal diagnostic role. However, a prognostic stratification based on the CMR findings in ischemic MINOCA is still unavailable.

Purpose

To evaluate the potential prognostic impact of specific CMR findings - especially ischemic late gadolinium enhancement (LGE) patterns - in order to look for measurable parameters that may guide the management of this still troubled clinical entity.

Methods

We assessed 461 MINOCA from January 2016 to June 2021. We excluded acute myocarditis, Tako-tsubo syndromes, cardiomyopathies, or non-pathological CMR. According to CMR findings, MINOCA were classified in two phenotypes: LGE-positive (an ischemic subendocardial or transmural LGE pattern) or LGE-negative (cases without LGE but exhibiting regional myocardial injury defined by myocardial edema in a coronary territory with a typically ischemic “wave-front” and/or regional wall motion abnormality consistent with coronary distribution).

All-cause mortality, re-infarction, stroke, heart failure (HF) and the composite endpoint (MACE) were evaluated. Extended LGE was considered as the presence of >2 segments with transmural LGE. The mean follow-up was 36.1±15.2 months and CMR was performed at a mean of 6±2.9 days from the acute presentation.

Results

The final cohort included 175 MINOCA with a likely-ischemic etiology: 121 (69.1%) constituted the LGE-positive group. The mean age of the study population was 62.3±12.9 years and more than 61% were females. During follow-up, HF (15.7% vs 1.9%, p=0.008) and MACE (20.7% vs 7.4%, p=0.029) occurred more frequently in MINOCA “LGE-positive” compared to the “LGE-negative” ones. Extended LGE was significantly more prevalent in patients with versus without subsequent HF. On multivariable Cox regression, extended LGE was an independent predictor of HF occurrence (HR 18.49, 95% CI 4.65–73.61, p<0.001) and MACE (HR 14.64, 95% CI 3.91–54.86, p<0.001).

Conclusions

Our data suggest that in MINOCA patients the detection of LGE is correlated with the incidence of major cardiovascular events and heart failure during long-term follow-up. In fact, LGE extension was identified as the strongest predictor of cardiac adverse events. The early execution of CMR is useful in the prognostic stratification of MINOCA and this could guide the subsequent clinical and therapeutic management.

Funding Acknowledgement

Type of funding sources: None.

P212 PROGNOSTIC ROLE OF ACUTE MYOCARDIAL INFARCTION DIAGNOSTIC CRITERIA IN NON–ST SEGMENT ELEVATION MYOCARDIAL INFARCTION

Background

Although the majority of patients with NSTEMI share similar risk factors and similar pathophysiology, their outcomes differ considerably. The Fourth Universal Definition of Myocardial Infarction (UDMI) defined acute myocardial infarction (AMI) by an acute myocardial injury together with clinical evidence of acute myocardial ischaemia. However, the prognostic role of each single diagnostic criteria has never been explored.

Purpose

To evaluate the prognostic role of the different diagnostic criteria of AMI according to the Fourth UDMI in NSTEMI patients.

Methods

We enrolled all consecutive patients with AMI undergoing coronary angiogram at our Centre. We used a combination of criteria, according to the current ESC guidelines, to meet the diagnosis, namely the detection of an increase and/or decrease of high–sensitivity cardiac troponin I, with at least one value above the 99th percentile of the upper reference limit and at least one of the following: symptoms of ischaemia; ECG changes (new ST–T changes or new LBBB); development of pathological Q waves in the ECG; echocardiographic evidence of new loss of viable myocardium or new regional wall motion abnormality. Patients with STEMI and very high risk NSTEMI were excluded. A composite endpoint of all–cause mortality, re–hospitalization for heart failure, and myocardial reinfarction was collected. The predictive value of diagnostic criteria alone and their association were evaluated using Kaplan–Meier survival curves and subsequent Cox–regression analysis to find independent predictors of adverse events.

Results

2791 patients with NSTEMI were evaluate. At admission 196 had clinical criteria alone, 187 had clinic + ECG and 829 had clinic + ECG + echo. The total number of events was 689. The median follow–up was 23.3±14.5 months. We found that patients with clinical criteria alone had a better prognosis at 2 years follow–up (p < 0.001). No other significant prognostic correlation was found. Multivariable Cox–regression model demonstrated that clinical criteria was the only independent predictor of better prognosis in patients with NSTEMI (HR = 0.48; CI 95% 0.31–0.74; p < 0.001).

Conclusions

Our data suggest that in NSTEMI the prognosis is considerably better if clinical criteria alone is present at admission. We hypothesize that the absence of electrocardiographic and echocardiographic alterations in NSTEMI could indirectly indicate smaller infarct sizes or other causes of acute myocardial injury.

P215 PROGNOSTIC IMPACT OF EARLY VERSUS DEFERRED CORONARY ANGIOGRAPHY IN MINOCA PATIENTS

Background

Although an early invasive strategy (coronary angiography performed < 24 hours) is associated with a lower risk of recurrent/refractory ischaemia among patients with acute myocardial infarction (AMI) and obstructive coronary arteries, the optimal timing of invasive examination in patients with non–obstructive coronary arteries and non–ST–segment elevation presentation (NSTE–MINOCA) has not been explored.

Purpose

This study tested the hypothesis that, compared to early (< 24 h) invasive strategy, deferred (≥ 24 h) coronary angiography has an equivalent prognostic impact in patients with NSTE–MINOCA.

Methods

From 2016 to 2020, all consecutive MINOCA patients diagnosed according to the current ESC diagnostic criteria (angiographic conventional cut–off of < 50% coronary stenosis without a clinically apparent alternative diagnosis) and admitted to our Centre with non–ST–segment elevation myocardial infarction (NSTEMI) presentation were enrolled. Very high–risk NSTEMI patients had been excluded from the study. The prognostic value of an early (< 24 h) vs. deferred (≥ 24 h) coronary angiography was assessed. All–cause mortality and a composite endpoint (MACE) of all–cause mortality, stroke, re–hospitalization for heart failure and myocardial re–infarction were evaluated.

Results

198 NSTE–MINOCA patients were enrolled, of which 79 underwent coronary angiography < 24 hours and 119 ≥ 24 hours. MINOCA patients were more frequently females (64%) and the mean age was 66.8±13.2 years. After a median follow–up of 26 [14–40] months, the overall all–cause mortality was 13,6% and the composite endpoint (MACE) was achieved in 27.3% of the entire population. Kaplan–Meier curves showed that there was no statistically significant difference (p = 0.88) between the two study groups depending on the time of invasive strategy adopted. Specifically, rates of death (11.4% vs. 15.1%) and MACE (25.3% vs. 28.6%) were similar in MINOCA patients undergoing early versus deferred coronary angiography.

Conclusions

We demonstrated for the first time that in the MINOCA population the prognosis is not influenced by an early versus deferred coronary angiography, as opposed to AMI patients with obstructive coronary arteries. These results add another piece to the puzzle and pave the way for the initial use of a non–invasive imaging strategy (eg. Coronary–CT), mostly in patients with NSTEMI and high clinical suspicion of non–obstructive coronary arteries.

P210 VENTRICULAR FIBRILLATION IN AN ELDERLY WOMAN WITH APPARENTLY UNREMARKABLE PAST CARDIOLOGICAL HISTORY: AN UNEXPECTED CULPRIT

An 85–year–old woman experienced cardiac arrest while she was at the supermarket. Cardiopulmonary resuscitation was promptly performed with ROSC after DC shock on ventricular fibrillation and immediate hemodynamic and neurological recovery. The first ECG performed by the rescuers did not show acute ischemic changes and the patient was admitted to the Cardiological Intensive Care Unit. Past medical history revealed only a previous episode of acute pulmonary embolism for which she was on oral anticoagulant therapy for a limited period of time. She had not family history of sudden cardiac death or cardiomyopathies. Before admission she was completely asymptomatic and she never complained of angina pectoris, palpitation or dyspnoea. The echocardiogram at admission showed moderate left atrial enlargement and hypokinesia of left ventricle apex and mid–apical lateral wall with global EF of 50%. Pulmonary and aortic CT angiography showed no pathological findings. In order to rule out an ACS, the patient underwent a coronary angiography which documented the absence of critical coronary stenosis. Finally, a cardiac MRI with gadolinium was performed, revealing the presence of two small areas of transmural LGE affecting inferior basal and lateral mid–apical segments with no edema, consistent with ischaemic myocardial scars. In light of this findings and to rule out paradoxical coronary artery embolism we decided to perform a transcranial echocolordoppler that showed the absence of a patent foramen ovale. Furthermore, continuous ECG monitoring during the hospital stay did not document arrhythmic recurrences. In consideration of the high probability of ischemic heart disease, therapy with antiplatelet agent, beta–blocker, ace–inhibitor and statin was introduced and the patient was discharged after ICD implantation. Three months later, during her first follow–up visit, we documented short episodes of atrial fibrillation at ICD interrogation. This was in line with the hypothesis of a ventricular fibrillation and cardiac arrest in the contest of an ischemic heart disease with myocardial scars probably due to undatale coronary artery embolism. Oral anticoagulant therapy was started in addition to previous therapy.

Hospital Patients’ migration among Italian Regions

Background

At the beginning of the 2000s the federalization of the Italian National Health Service gave to the Regions greater financial and political responsibility: 21 Regional Health Services were set up with administrative and planning independence. They are in a potential competitive regime, since the citizens are free to choose their place of treatment. The aim of our research was to analyze fulfillment of needs for hospital services on site and Patients' migration to hospitals of other Regions.

Methods

We conducted an observational cross sectional study on Hospital Discharge Cards provided by the Ministry of Health, upon specific request, from 2013 to 2017. The subjects of the analysis (catchment areas) were the hospital networks of Italian Regions. Interregional flows were carried out from data of Residents, Attractions and Escapes, which were developed through Attraction and Escape Indexes. Graphic representation was produced with Gandy's Nomogram.

Results

In the studied period, we observed an important decrease in hospitalizations and a simultaneous increase in interregional mobility. At the same time, admissions to hospital managed by Local Health Authorities and to Private Clinics increased. According to the Major Diagnostic Categories the main causes of hospitalizations in mobility were Musculoskeletal System And Connective Tissue Diseases (MDC 8), Cardiovascular System Diseases (MDC 5), Nervous System Diseases (MDC 1) and Digestive System Diseases (MDC 6). There were discrepancies between the Regions of Northern/Central Italy (higher Attraction Indexes) and Southern Italy (higher Escape Indexes). According to Gandy's Nomogram only nine Regions showed a good public hospital planning: Lombardy, A.P. of Bolzano, Veneto, Friuli V.G., E. Romagna, Tuscany, Umbria, Latium and Molise.

Conclusions

The North/Centre Regions have a public hospital planning able to be better to meet the care needs of their citizens and to attract Patients than the South ones.

Key messages

The study of Patients’ mobility is relevant in order to evaluate equity and quality of care provided by different Italian Regions. Patients' mobility has also an important economic implications.

Usefulness of CHA2DS2-VASc scoring system for predicting risk of embolism in patients with cardiac tumours: a single-centre study

Background

The CHA2DS2-VASc score is the most used in predicting thromboembolic risk in patients with atrial fibrillation (AF). However, a higher CHA2DS2-VASc score predicts cardiovascular events even in patients without AF. Up to date, there is limited evidence about the association between CHA2DS2-VASc score and the embolic risk in patient with cardiac tumours (CT).

Purpose

To evaluate the role of the CHA2DS2-VASc score in predicting embolism and to identify other markers of embolization in patients with CT.

Methods

We included all patients with a CT who had a complete echocardiographic evaluation and a histologic diagnosis. We excluded patients with cardiac thrombi because of their higher embolic risk.

Results

Our sample consisted of 221 patients (mean age 60.9±15.6, 7% female). 132 (59.7%) patients had benign CT, usually left-sided (84.8%). In the malignant tumours, 28 (31.5%) were primary and 61 (68.5%) were metastasis. Compared to benign tumours, malignant ones were predominantly right-sided (47.2%) or with pericardial (20.2%) or great-vessels involvement (16.9%). A total of 59 patients (26.6%) experienced an embolic event, of which 33 patients had peripheral embolism, while 28 had pulmonary embolism (PE), 2 patients had both. Patients with embolism were older (p=0.013), had a higher prevalence of diabetes or previous stroke (p=0.019 and p<0.001), had left-sided and not-infiltrating CT (p=0.001 and p=0.04). We did not find any differences in AF prevalence, atrium volumes or other CT characteristics. Moreover, patients who developed an embolic event had a higher CHA2DS2-VASc score than those without embolism (p<0.001). In particular, a CHA2DS2-VASc score >3 had an AUC=0.835 in predicting a peripheral embolic event in the overall population (p<0.001). At multivariate analysis, only CHA2DS2-VASc and left-side localization were significantly associated with embolization (p<0.001 and p=0.009).

Also in patients with right-sided CT, CHA2DS2-VASc score (p=0.017), together with some tumours characteristics (mobility, pericardial effusion and absence of myocardial infiltration (p<0.04 for all) was associated with PE.

Embolization did not impact survival when considering the overall population. Otherwise, when focusing on patients with malignant CT, those who had an embolic event had a worse prognosis (p=0.02), as well as those with PE (p=0.037).

Conclusions

CHA2DS2-VASc and left-side localization are the best markers of embolism. In particular, CHA2DS2-VASc seems to predict embolization in CT, regardless of histology or localization. Many patients with CT and embolism may not be offered surgical treatment given their assumed high-risk profile. By contrast, our analysis showed that survival is not related to the embolic event per se, but by histology. In patients with CT and high CHA2DS2-VASc score, further studies are needed to evaluate the best therapeutic strategy to minimize the embolic risk.

Funding Acknowledgement

Type of funding sources: None.

Cancer incidence during follow-up in patients with new-onset atrial fibrillation treated with DOACs and its impact on bleeding risk

Background

Cancer is increasingly recognized as strictly related to atrial fibrillation (AF). In patients with AF, the relationship between cancer and cardioembolic or bleeding risk during oral anticoagulant therapy is unknown.

Purpose

To assess the bleeding and ischaemic burden of a baseline or newly diagnosed cancer in patients treated with direct oral anticoagulants (DOACs) for non-valvular atrial fibrillation (NVAF).

Methods

All consecutive patients treated with DOACs were enrolled among those with new-onset atrial fibrillation and indication for oral anticoagulant between January 2017 and March 2019. During follow-up, bleeding events, newly diagnosed primitive or metastatic malignancy and major cardiovascular events (MACE) were evaluated. At baseline, CHA2DS2-VASc, HAS-BLED, ATRIA, and ORBIT scores were used to assess the hemorrhagic and ischaemic risk. Major bleedings (MB) were defined according to the ISTH definition. Anemia was defined as haemoglobin levels below 11 g/dL in women and 12 mg/dL in men.

Results

1258 patients constituted the study population and followed for a mean time of 21.6±9.5 months. Overall, 66 patients (5.2%) were affected by malignant neoplasia at baseline, whereas 59 (4.7%) were diagnosed with a malignancy during follow-up. Among baseline characteristics, anemia was associated with cancer at enrolment (43.9% vs 22.5%, p<0.001) but not at follow up (29.3% vs 23.4%, p=0.341). MACEs were not associated with cancer at baseline (5.3% vs 5.2%, p=1.0) and at follow up (5% vs 4.9%, p=1.0). No association was observed between major ischaemic events and cancer at enrolment or follow up (5.3% vs 4.4%, p=0.83 and 4.4% vs 5%, p=0.82). Despite no statistically significant differences in haemorrhagic risk at baseline, the overall bleeding events and MB were associated with newly diagnosed cancer (9.2% vs 3.9%, p=0.001 and 13.8% vs 4.5%, p=0.001, respectively) but not at baseline (5.2% vs 5.5%, p=0.82 and 9.2% vs 5.2%, p=0.162). At multivariate analysis adjusted for age, hypertension and renal function, anemia and a newly diagnosed cancer during follow up remained independent predictors of MB (respectively, HR 1.27, 95% CI 1.52–1.06, p=0.009 and HR 3.53, 95% CI 7.71–1.62, p=0.001).

Conclusion

Bleeding risk assessment is an ongoing challenge in patients with NVAF on DOACs. During follow-up, newly diagnosed primitive or metastatic cancer is a strong predictor of bleeding regardless of baseline haemorrhagic risk assessment. In contrast, such association is not observed with malignancy at baseline. A proper diagnosis and treatment could therefore decrease cancer-related bleeding risk. On the contrary, our study shows that cancer is not an ischaemic risk modifier, either diagnosed at baseline or follow-up.

Funding Acknowledgement

Type of funding sources: None.

Prognostic role of diagnostic criteria of acute myocardial infarction

Background

The term acute myocardial infarction (AMI) reflects cell death of cardiac myocytes caused by ischaemia. The Fourth Universal Definition of Myocardial Infarction (UDMI) defined AMI by a typical rise and fall in the level of biochemical markers of myocardial necrosis together with criteria of myocardial ischaemia. However, the prognostic role of each single diagnostic criteria has never been explored.

Purpose

To evaluate the prognostic role of the different diagnostic criteria of AMI according to the Fourth UDMI.

Methods

We enrolled all consecutive patients with AMI admitted from 2016 to 2019. We used a combination of criteria, according to the current ESC guidelines, to meet the diagnosis, namely the detection of an increase and/or decrease of high-sensitivity cardiac troponin I, with at least one value above the 99th percentile of the upper reference limit and at least one of the following: symptoms of ischaemia; ECG changes (new ST-T changes or new LBBB); development of pathological Q waves in the ECG; imaging evidence of new loss of viable myocardium or new regional wall motion abnormality, in our study evaluated by transthoracic echocardiogram. All-cause mortality and a composite endpoint of all-cause mortality, re-hospitalization for heart failure and myocardial re-infarction were collected. The predictive value of diagnostic criteria alone and its association were evaluated using Kaplan-Meier survival curves and subsequent Cox-regression analysis to find independent predictors of adverse events.

Results

2386 patients were evaluated. The median follow-up time was 23.3±14.5 months. The total number of events was 703 (29.3%). Kaplan-Meier curves showed that major adverse cardiac events (MACE) were statistically different depending on the diagnostic criteria of AMI at admission. Particularly, clinical criteria alone showed a better predictive value (p<0.001) than other diagnostic AMI criteria. Multivariable Cox-regression model demonstrated that clinical criteria was the independent predictor of good prognosis in patients with AMI (HR=0.43; CI 95% 0.28–0.67; p<0.001). Conversely, the others diagnostic criteria (electrocardiographic and echocardiographic) and the combination of all diagnostic criteria were not independent prognostic factors of MACE (HR=1.1 CI 95% 0.6–2.4, p=0.6; HR=1.1 CI 95% 0.7–1.2, p=0.6; HR=0.9 CI 95% 0.7–1.0, p=0.8 respectively).

Conclusions

Our data suggest that the prognosis is considerably better among patients with a diagnosis of AMI if clinical criteria alone are present at admission. We also demonstrated that clinical criteria are a strong prognostic predictor of good outcomes in patients with AMI. We hypothesize that the absence of electrocardiographic and echocardiographic alterations could indirectly indicate a smaller infarct sizes that contribute to patients' outcome.

Funding Acknowledgement

Type of funding sources: Public hospital(s). Main funding source(s): None

Worsening renal function as an outcome predictor in patients with new onset atrial fibrillation on direct oral anticoagulant

Background

In patients with atrial fibrillation (AF), baseline kidney function is used to guide oral anticoagulant (OA) selection and dosing, and chronic kidney disease (CKD) is a significant outcome predictor. However, the incidence of worsening renal function (WRF) and its prognostic role during treatment with direct oral anticoagulants (DOACS) has been poorly explored.

Purpose

To assess the prognostic role of WRF in terms of bleedings and major adverse cardiovascular events (MACEs) in a cohort of patients with newly diagnosed non-valvular AF (NVAF) treated with DOACs.

Methods

Between January 2017 and March 2019, we enrolled all the patients with newly diagnosed NVAF and OA indication, treated with DOACs. Renal function was assessed using the mean value of the estimated glomerular filtration rates (eGFR) calculated using Cockcroft-Gault (CG), Modification of Diet in Renal Disease (MDRD) and Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) formulas. CHA2DS2-VASc and HAS-BLED scores were used at baseline to estimate the ischemic and hemorrhagic risk, respectively. At follow-up, WRF was identified as a decrease in eGFR of at least 20% while bleedings were classified according to the international society of thrombosis and hemostasis (ISTH) criteria. Finally, we defined AF progression as the transition from paroxysmal to persistent or permanent AF or from persistent to permanent AF.

Results

1009 patients with newly diagnosed NVAF started on DOAC were enrolled. They were followed-up for 21.6±9.5 months. Overall, WRF was observed in 181 cases (18%). Patients with WRF had higher rates of progression of atrial fibrillation (18.5% vs 11.8%, p=0.02), MACEs (20.4% vs 12.9%, p=0.09) and major bleedings (MB) (9,4% vs 4,7%, p=0.013). WRF did not correlate with all bleedings, stroke, or acute coronary syndrome (ACS). However, those who presented WRF using CKD-EPI formula had higher ACS incidence (6.1% vs 2.5%, p=0.015), and generally better-predicted MACEs. At multivariate analysis adjusted for age, hypertension, baseline HAS-BLED score and WRF, the latter emerged as an independent predictor of MB (OR 1.9 95% C.I, 1,059–3,51).

Conclusion

In patients with newly diagnosed NVAF treated with DOACs, WRF is associated with atrial fibrillation progression and MACEs, and emerged as an independent predictor of major bleedings. WRF evaluated with CKD-EPI formula better predicted MACEs.

Funding Acknowledgement

Type of funding sources: None.

A multi‐institutional randomized controlled trial comparing first‐generation transrectal high‐resolution micro‐ultrasound with conventional frequency transrectal ultrasound for prostate biopsy

Objectives

To study high‐frequency 29 MHz transrectal side‐fire micro‐ultrasound (micro‐US) for the detection of clinically significant prostate cancer (csPCa) on prostate biopsy, and validate an image interpretation protocol for micro‐US imaging of the prostate.

Materials and methods

A prospective randomized clinical trial was performed where 1676 men with indications for prostate biopsy and without known prostate cancer were randomized 1:1 to micro‐US vs conventional end‐fire ultrasound (conv‐US) transrectal‐guided prostate biopsy across five sites in North America. The trial was split into two phases, before and after training on a micro‐US image interpretation protocol that was developed during the trial using data from the pre‐training micro‐US arm. Investigators received a standardized training program mid‐trial, and the post‐training micro‐US data were used to examine the training effect.

Results

Detection of csPCa (the primary outcome) was no better with the first‐generation micro‐US system than with conv‐US in the overall population (34.6% vs 36.6%, respectively, P = .21). Data from the first portion of the trial were, however, used to develop an image interpretation protocol termed PRI‐MUS in order to address the lack of understanding of the appearance of cancer under micro‐US. Micro‐US sensitivity in the post‐training group improved to 60.8% from 24.6% (P < .01), while specificity decreased (from 84.2% to 63.2%). Detection of csPCa in the micro‐US arm increased by 7% after training (32% to 39%, P < .03), but training instituted mid‐trial did not affect the overall results of the comparison between arms.

Conclusion

Micro‐US provided no clear benefit over conv‐US for the detection of csPCa at biopsy. However, it became evident during the trial that training and increasing experience with this novel technology improved the performance of this first‐generation system.

In this work high‐frequency 29 MHz transrectal side‐fire micro‐ultrasound (US) for the detection of clinically significant prostate cancer on prostate biopsy is studied, and an image interpretation protocol for micro‐US imaging of the prostate is validated.

The YouTube link is here: https://youtu.be/U2Svj-4Ae_k

Mottness at finite doping and charge-instabilities in cuprates

The influence of the Mott physics on the doping-temperature phase diagram of copper oxides represents a major issue that is subject of intense theoretical and experimental effort. Here, we investigate the ultrafast electron dynamics in prototypical single-layer Bi-based cuprates at the energy scale of the O-2p→Cu-3d charge-transfer (CT) process. We demonstrate a clear evolution of the CT excitations from incoherent and localized, as in a Mott insulator, to coherent and delocalized, as in a conventional metal. This reorganization of the high-energy degrees of freedom occurs at the critical doping p_cr ≈0.16 irrespective of the temperature, and it can be well described by dynamical mean field theory calculations. We argue that the onset of the low-temperature charge instabilities is the low-energy manifestation of the underlying Mottness that characterizes the p < p_cr region of the phase diagram. This discovery sets a new framework for theories of charge order and low-temperature phases in underdoped copper oxides.

Structural Texture Induced in SnSe Thermoelectric Compound via Open Die Pressing

Outstanding ZT values registered on single crystals recently renewed the interest of thermoelectric community for SeSn compound. Owing to the strong anisotropy of the phenomenon, so far only single crystals proved to be the suitable for its application. Here we present the production and the characterization of bulk polycrystalline materials processed by open die pressing, aimed at reducing the gap with single crystal materials by taking advantage from the highly texture degree derived by the processing and by the improved phonon scattering promoted by grain boundaries. The resulting bulks display good compaction, improved mechanical properties and strong texture of the phase. Structural and morphological analyses confirmed the successful orientation according to the (400) cleavage plane. The structural transition responsible for the ultra-low thermal conductivity has been investigated and possible irreversible effects on the starting phase due to thermal cycling have been evaluated. Preliminary measurements of thermal conductivity are reported.

NIR transmittance tuneability under a magnetic field of colloidal suspensions of goethite (α-FeOOH) nanorods

Goethite (α-FeOOH) nanorods were synthesized and their size and shape were controlled by synthesis parameters. Stable colloidal suspensions were prepared and their transmittance in NIR range was tuned by modifying magnetic field direction and strength.

Field-Driven Mott Gap Collapse and Resistive Switch in Correlated Insulators

Mott insulators are "unsuccessful metals" in which Coulomb repulsion prevents charge conduction despite a metal-like concentration of conduction electrons. The possibility to unlock the frozen carriers with an electric field offers tantalizing prospects of realizing new Mott-based microelectronic devices. Here we unveil how such unlocking happens in a simple model that shows the coexistence of a stable Mott insulator and a metastable metal. Considering a slab subject to a linear potential drop, we find, by means of the dynamical mean-field theory, that the electric breakdown of the Mott insulator occurs via a first-order insulator-to-metal transition characterized by an abrupt gap collapse in sharp contrast to the standard Zener breakdown. The switch on of conduction is due to the field-driven stabilization of the metastable metallic phase. Outside the region of insulator-metal coexistence, the electric breakdown occurs through a more conventional quantum tunneling across the Hubbard bands tilted by the field. Our findings rationalize recent experimental observations and may offer a guideline for future technological research.

Nanoscale orbital excitations and the infrared spectrum of a molecular Mott insulator: A15-Cs3C60

The quantum physics of ions and electrons behind low-energy spectra of strongly correlated molecular conductors, superconductors and Mott insulators is poorly known, yet fascinating especially in orbitally degenerate cases. The fulleride insulator Cs₃C₆₀ (A15), one such system, exhibits infrared (IR) spectra with low temperature peak features and splittings suggestive of static Jahn-Teller distortions with a breakdown of orbital symmetry in the molecular site. That is puzzling, since there is no detectable static distortion, and because the features and splittings disappear upon modest heating, which they should not. Taking advantage of the Mott-induced collapse of electronic wavefunctions from lattice-extended to nanoscale localized inside a caged molecular site, we show that the unbroken spin and orbital symmetry of the ion multiplets explains the IR spectrum without adjustable parameters. This demonstrates the importance of a fully quantum treatment of nuclear positions and orbital momenta in the Mott insulator sites, dynamically but not statically distorted. The observed demise of these features with temperature is explained by the thermal population of a multiplet term whose nuclear positions are essentially undistorted, but whose energy is very low-lying. That term is in fact a scaled-down orbital excitation analogous to that of other Mott insulators, with the same spin 1/2 as the ground state, but with a larger orbital momentum of two instead of one.

Improved tribological and thermal properties of lubricants by graphene based nano-additives

Enhancing the tribological performance of lubricants with nanoparticle additives is a recent challenge. Addition of graphene based nanostructures in poly-alkylene glycol lubricant could significantly reduce friction and wear for compressors operating with CO₂ refrigerant.

Influence of Cu, TiO2 Nanoparticles and Carbon Nano-Horns on Tribological Properties of Engine Oil

The addition of nanoparticles in lubricating oils recently demonstrated to reduce the coefficient of friction and to increase the load-carrying capability of lubricant in coupled surfaces. In this work, different kinds of nanoparticles were tested as additives to engine oil to improve lubrication: copper and titanium oxide nanoparticles and single walled carbon nanohorns (SWCNHs). Two nanoparticle sizes were also tested in case of copper. The tribological properties of these nanofluids were evaluated by Stribeck tests, in order to compare the effect of nanoparticles on friction coefficient and electric contact resistance in different lubrication regimes. Stribeck curves showed that the coefficient of friction was reduced, compared to raw oil, by the action of Cu nanoparticles having 130 nm diameter, leading to a mean decrease of about 17%, and by SWCNHs, with a mean decrease of about 12%. Conversely, no significant changes were detected in presence of Cu nanoparticles having 50 nm diameter or of TiO2. The suspension viscosity and stability were also tested. Wear tests were also carried out, showing a reduction of wear rate up to nearly 50% for Cu nanoparticles (150 nm diameter) and around 30% for SWCNHs. The measurements showed that nanoparticles having size comparable to the mean roughness of coupled surfaces significantly improved the tribological properties of bare oil. An explanation of nanoparticle action is proposed.

Ferromagnetic Kondo effect in a triple quantum dot system

A simple device of three laterally coupled quantum dots, the central one contacted by metal leads, provides a realization of the ferromagnetic Kondo model, which is characterized by interesting properties like a nonanalytic inverted zero-bias anomaly and an extreme sensitivity to a magnetic field. Tuning the gate voltages of the lateral dots allows us to study the transition from a ferromagnetic to antiferromagnetic Kondo effect, a simple case of a Berezinskii-Kosterlitz-Thouless transition. We model the device by three coupled Anderson impurities that we study by numerical renormalization group. We calculate the single-particle spectral function of the central dot, which at zero frequency is proportional to the zero-bias conductance, across the transition, both in the absence and in the presence of a magnetic field.

Kondo effect of magnetic impurities in nanotubes

Transition metal impurities will yield zero-bias anomalies in the conductance of well contacted metallic carbon nanotubes, but Kondo temperatures and geometry dependences have not been anticipated so far. Applying the density functional plus numerical renormalization group approach of Lucignano et al. to Co and Fe impurities in (4,4) and (8,8) nanotubes, we discover a huge difference of behavior between outside versus inside adsorption of the impurity. The predicted Kondo temperatures and zero-bias anomalies, tiny outside the nanotube, turn large and strongly radius dependent inside, owing to a change of symmetry of the magnetic orbital. Observation of this Kondo effect should open the way to a host of future experiments.

Influence of osmolarity and pH increase to achieve a reduction of monoclonal antibodies aggregates in a production process

Anti PSA monoclonal antibodies for diagnostic use were produced in an in vitro system. After purification using Protein G affinity chromatography a percentage of about 10% of antibody aggregates remained. The use of monoclonal antibodies containing aggregates as a capture antibody in a diagnostic kit reduces the performance of the test making it often unacceptable. The aggregates could be eliminated using gel filtration chromatography but, in that way, the final recovery of the whole production process was only about 50%. Aggregation is favoured when the working pH is near to the isoelectric point of the antibody. We varied the culture medium composition, modifying pH and osmolarity. We tested different values of pH and osmolarity: 7.1, 7.5, 8.0, 8.5 for pH, and 300, 340, 367, 395 mOsm/kg H2O for osmolarity. By modification of the cell culture medium we obtained a significant decrease of monoclonal antibody aggregates in the production cycle. In this way we achieved higher recovery rate and could avoid gel filtration polishing step. The experiments were performed in two stages: first in culture flasks changing one parameter in each experiment, and then in spinner bottle using the best conditions obtained in the first stage. During scale up we used the modifications achieved from the experiment showed in this paper in our production by hollow fibre bioreactor with positive results.

ZnO:Al thin films deposited by RF-magnetron sputtering with tunable and uniform properties

Nanostructured, high quality and large area Al-doped ZnO (ZnO:Al) thin films were obtained by radiofrequency (RF) magnetron sputtering. The sample rotation during deposition has resulted in excellent spatial distribution of thickness and electro-optical properties compared to that obtained under static conditions. ZnO:Al thin films are employed in a large number of devices, including thin film solar cells, where the uniformity of the properties is a key factor for a possible up-scaling of the research results to industrially relevant substrate sizes. A chemical post etching treatment was employed achieving tunable surface nanotextures to generate light scattering at the desired wavelength for improved cell efficiency. Since the film resistivity is only slightly increased by the etching, this post-deposition step allows separating the optimization of electro-optical properties from light scattering behavior. The thin films were characterized by FE-SEM, XRD, UV-VIS spectroscopy, four probe and van der Paw techniques.

Increasing d-wave superconductivity by on-site repulsion

We study, through the variational Monte Carlo technique, an extended Hubbard model away from half filled band density which contains two competing nearest-neighbor interactions: a superexchange J favoring d-wave superconductivity and a repulsion V opposing it. We find that the on-site repulsion U effectively enhances the strength of J while suppressing that of V, thus favoring superconductivity. This result shows that attractions which do not involve charge fluctuations are very well equipped against strong electron-electron repulsion so much to get advantage from it.

Strongly correlated superconductivity

High-temperature superconductivity in doped Mott insulators such as the cuprates contradicts the conventional wisdom that electron repulsion is detrimental to superconductivity. Because doped fullerene conductors are also strongly correlated, the recent discovery of high-critical-temperature, presumably s-wave, superconductivity in C60 field effect devices is even more puzzling. We examine a dynamical mean-field solution of a model for electron-doped fullerenes that shows how strong correlations can indeed enhance superconductivity close to the Mott transition. We argue that the mechanism responsible for this enhancement could be common to a wider class of strongly correlated models, including those for cuprate superconductors.

Complications of laparoscopic procedures after concentrated training in urological laparoscopy

PURPOSE

To increase the safety and efficiency of laparoscopic surgery clinical training programs have been developed to increase the skill and efficiency of urological trainees. We evaluated the impact of dedicated laparoscopy training on the rate and type of complications after trainees entered clinical practice.

MATERIALS AND METHODS

Data were obtained from 13 centers where laparoscopy was performed by a single surgeon with at least 12 months of training in urological laparoscopy before clinical practice. Data included training experience, laparoscopic procedures performed after commencing clinical practice and associated complications. Procedures were classified as easy, moderate and difficult.

RESULTS

During training each surgeon participated in a mean of 71 cases. In clinical practice a total of 738 laparoscopic cases were performed with the group reporting an overall complication rate of 11.9%. The rate was unchanged when the initial 20, 30 and 40 cases per surgeon were compared with all subsequent cases (12%, 11.9% and 12% versus 11.8 to 12%, respectively). The re-intervention rate was 1.1%. The complication rate increased with case difficulty. Overall and early complication rates attributable to laparoscopic technique in the initial 20, 30 and 40 cases were identical. The most common complications were neuropathy in 13 patients, urine leakage/urinoma in 9, transfusion in 7 and ileus in 5.

CONCLUSIONS

The complication rate of surgeons who completed at least 12 months of laparoscopy training did not differ according to initial versus subsequent surgical experience. Intensive training seems to decrease the impact of the learning curve for laparoscopy.

Direct transition between a singlet Mott insulator and a superconductor

We argue that a normal Fermi liquid and a singlet, spin-gapped Mott insulator cannot be continuously connected, and that some intermediate phase must intrude between them. By explicitly working out a case study where the singlet insulator is stabilized by orbital degeneracy and an inverted Hund's rule coupling, mimicking a Jahn-Teller effect, we find that the intermediate phase is a superconductor.

Secondary ion mass spectrometric investigation of Au-based composites

The electrodeposition of thick gold layers plays an important role both in traditional and high-tech productions, such as jewelry and microelectronics, respectively. In this work a secondary ion mass spectrometric study will be presented on Au co-deposits with (sub-)micrometric ceramic powders, in order to harden gold. Mass spectra are used to identify the components deposited, providing evidence of the additives and/or eventual contaminants introduced during electrolysis. Furthermore, analysis of ion depth profiles and the intensity distribution of ionic species along the film were studied.

Secondary ion mass spectrometry in the characterisation of boron-based ceramics

A secondary ion mass spectrometry (SIMS) study of Zr- and Ti-based borides is reported: ZrB2 ceramic samples (with and without nickel addition) and a TiB2-Ni-B4C/Cu joint were investigated. For Zr-based samples, SIMS measurements show evidence for induced effects by the presence of nickel with regard to oxygen and hydrogen absorption and zirconia formation. In the case of the TiB2-Ni-B4C/Cu joint, the ceramic-metal interface region was analysed and the extent of Cu diffusion into the ceramic material was established. SIMS results were in agreement with previously obtained SEM-EDS data.

Laparoscopic telesurgery between the United States and Singapore

INTRODUCTION

Telemedicine is the use of electronic digital signals to transfer information from one site to another. With the advent of a telepresence operative system and development of remote robotic arms to hold and manoeuvre the laparoscope, telemedicine is finding its role in surgery, especially laparoscopic surgery. CLINICAL FEATURES AND TREATMENT: We report two successful cases of laparoscopic surgery--radical nephrectomy and varicocelectomy for a 3-cm renal tumour and for bilateral varicoceles causing pain, where a less experienced laparoscopic surgeon in Singapore was telementored by an experienced laparoscopic surgeon located remotely in the United States. Both patients recovered uneventfully and returned home on postoperative day 4 and on the day of surgery, respectively.

OUTCOME

This study demonstrates that telementored laparoscopic systems are feasible and safe, between countries halfway across the world.

CONCLUSIONS

As the Internet expands in utility and the cost of higher bandwidth telecommunication lines decreases, even to remote countries, telementoring systems will become more affordable and may potentially pave the way for advanced surgical and laparoscopic applications and training for the future.

Laparoscopic live donor nephrectomy: pre-operative assessment of technical difficulty

Laparoscopic live donor nephrectomy decreases disincentives to live kidney donation. Thus, many centers are interested in adopting this procedure. However, the high stakes involved for both the donor and the recipient, and the technical difficulties of the operation, have tempered the enthusiasm of some surgeons. Ideally, if early in their series, surgeons could select patients that would be the least challenging technically, it would facilitate the dissemination of this operation. The purpose of this study is to determine if anatomic or radiologic parameters can accurately assess pre-operatively the degree of technical difficulty of laparoscopic live donor nephrectomy for any individual patient. Abdominal spiral three-dimensional CT scanning was performed prior to laparoscopic donor nephrectomy. CT scans were reviewed for six radiographic anatomic parameters. Seven clinical anatomic measurements relating to body habitus were recorded upon induction anesthesia at the time of surgery. Demographic data for gender, age, race, weight, height, and smoking history were collected. Following laparoscopic live donor nephrectomy, the following six component parts of the operation were graded on a scale of 1-4 (1 = easy, 4 = very difficult) for technical difficulty: a) mobilization of the colon; b) mobilization of the upper pole; c) dissection of the renal vein; d) dissection of the renal artery; e) division of the adrenal vein; and f) dissection of the ureter. Also, operative time, estimated blood loss, and intra-operative fluid requirements were recorded as surrogate markers of operative difficulty. Forty-one patients were included in the study. Laparoscopic donor nephrectomy was successfully completed in all cases. The sum of the difficulty scores was 9.9+/-3.1 (mean) (range, 6-18). No anatomic, demographic, or radiologic parameters were predictive of the total operative difficulty score. Of the surrogate markers, only operative time correlated with total difficulty score (R = 0.47, p = 0.003). Donor weight and abdominal girth correlated with operative time (R = 0.50, p = 0.002; R = 0.38, p = 0.019) but not with total difficulty score (R = 0.10, p = 0.51; R = -0.02, p = 0.90, respectively). When the easiest cases and the hardest cases (< or = 25th percentile and > or =75th percentile total difficulty score, respectively) were segregated out, again no anatomic, demographic, or radiologic parameters were predictive of operative technical difficulty. In conclusion, laparoscopic live donor nephrectomy technical difficulty could not be predicted by body habitus from the variables examined in this study. Hence, it was equally likely that performing laparoscopic live donor nephrectomy using a heavy donor would be technically easy, as using a thin donor would be difficult. Although, in general, operative time increased with donor size and weight, it appears that laparoscopic live donor nephrectomy operative technical difficulty is dependent upon such factors as amount of laparoscopic working space, quality of tissue planes, and retractability of the colon and mesocolon; factors that, to date, are not quantifiable.

Pharmacology for renal calculi

Stone disease is as old as recorded history but despite advances in diagnosis and treatment, it continues to cause significant morbidity. This review summarises the current pharmacologic management of urinary calculi based upon the stone type. All patients with stone disease are advised to increase fluid intake, limit dietary protein and limit sodium. Calcium oxalate stones can be managed on a selective or non-selective basis depending on the cause of the hypercalciuria or hyperoxaluria. Agents currently in use include sodium cellulose phosphate, thiazides, orthophosphates, oral calcium supplements, pyridoxine, cholestyramine, citrate, magnesium and allopurinol. Classically, struvite stones occur in the presence of urea splitting organisms and are composed of magnesium, ammonium phosphate and carbonate apatite. The goal of treatment is to make patients stone free as bacteria retained in stone fragments lead to stone growth. Urease inhibitors, aluminium hydroxide gel, hemiacidrin, and Suby G and M solutions are infrequently used in treatment. Cystine stones are the result of an autosomal recessive disorder. D-Penicillamine, captopril and alpha-mercaptopropionylglycine (MPG) are all oral agents that have proven to be efficacious. As more randomised trials are conducted and the understanding of endogenous stone inhibitors progresses, the medical management of stone disease will continue to improve.

Laboratory evaluation of chemical-biological control of the rice weevil (Sitophilus oryzae L.) in stored grains

The virulence of ten different fungal isolates of: Beauveria bassiana, Metarhizium anisopliae, Verticillium lecanii and Paecilomyces farinosus to the rice weevil Sitophilus oryzae was tested. A fungal mix of the most efficient isolates, B. bassiana ARSEF 5500+M. anisopliae ARSEF 2974, which caused the highest mortality, was assayed in combination with fenitrothion at a concentration lower (3 ppm) than the normal 6 ppm. Fungal inoculation of insects was done by spraying conidial suspensions of each fungus on wheat. Insecticide formulations were added by spraying wheat. Treated and untreated insects were incubated on durum wheat. Insects were kept in a climatized chamber for 30 days. Observations were performed at 7, 14 and 30 days to record insect mortality. Highly significant differences were demonstrated for B. bassiana 5500 and 5501 and for M. anisopliae 2974. The level of mortality produced by treatments was: 6 ppm insecticide=97.50%, B. bassiana ARSEF 5500+M. anisopliae ARSEF 2974+3 ppm insecticide=74.17%, B. bassiana ARSEF 5500+M.anisopliae ARSEF 2974=50% and 3 ppm insecticide=37.50%. There was a statistically significant difference (p<0.05) among treatments.

Surface chemistry of RuO(2)/IrO(2)/TiO(2) mixed-oxide electrodes: secondary ion mass spectrometric study of the changes induced by electrochemical treatment

The IrO(2)/RuO(2)/TiO(2) ternary system is well known for its electrocatalytic activity towards oxygen- and chlorine-evolution reactions. Electrochemical processing induces noticeable chemical and morphological modifications on these electrodes, depending on the noble metal oxide content. In this work, cathodic/anodic polarization and the oxygen-evolution reaction were studied in order to evaluate the electrocatalytic activity at various noble metal oxide percentages. The best performing electrode (30 mol% noble metal oxides) was analyzed before and after electrochemical tests by means of secondary ion mass spectrometry (SIMS) in order to determine the chemical composition modification which occurred on the surface and in deeper regions of the mixed-oxide film.

Ni-Zr alloys: relationship between surface characteristics and electrocatalytic behavior

A relationship between electrocatalytic activity for the hydrogen evolution reaction and the surface composition of the electrode was established for Ni-Zr crystalline and amorphous alloys by means of secondary ion mass spectrometry (SIMS). Electrocatalytic activity was tested by means of cathodic polarization in 1 M KOH at 25 degrees C and the resulting exchange current density has been taken as a measure of catalytic efficiency. Surface activation treatment involved chemical etching in HF solutions; the consequent morphological and compositional surface changes were studied by differential scanning calorimetry (DSC), X-ray diffraction (XRD) and scanning electron microscopy (SEM). The electrochemical behavior of the pure elements (Ni and Zr) was also considered for comparison. All samples submitted to chemical etching in HF solutions showed an increase in electrocatalytic activity, particularly the alloy with the highest Ni content. The beneficial effect of chemical etching is due to dissolution of the zirconium oxide layer and to the formation of nanocrystalline Ni on the surfaces.

Secondary ion mass spectrometric investigation on ruthenium oxide systems: a comparison between poly- and nanocrystalline deposits

The influence of different RuO(2) crystallite sizes was investigated by secondary ion mass spectrometry (SIMS) on the oxide deposited on various support materials (Ni, Ti, Al(2)O(3), oxidized Si(100)). In order to examine the effect of an oxidic environment on the film structure, RuO(2) 20%-TiO(2) 80% at. mixed oxide was deposited on Ti. The polycrystalline coatings were prepared by heating the Ru (and Ti)-containing solution dropped on the supports.1 RuO(2) nanocrystalline coatings were grown by chemical vapor deposition (CVD) from Ru(COD)(eta(3)-allyl)(2).2 The identification of mixed oxide clusters showed the higher reactivity of Ni and Al(2)O(3) over the other substrates. Diffusion and migration characteristics were observed to be influenced by the nature of the support. The results are complementary to those of a previous SIMS investigation.3 Copyright 2000 John Wiley & Sons, Ltd.

Ureteroscopic and radiographic imaging of the upper urinary tract

Direct endoscopic viewing of the upper urinary tract offers multiple benefits, including recognition and diagnosis, and also permits unsurpassed accuracy in positioning working instruments for biopsy and treatment. We have demonstrated the normal and abnormal endoscopic findings within the upper urinary tract in patients who were treated ureteroscopically for numerous indications, including calculi, filling defects, or ureteral obstruction. Small (7 to 7.5F) rigid and flexible ureteroscopes were employed in all patients. Selected endoscopic images of the subject lesions were photographed using a 35-mm camera with an endoscopic zoom lens and ISO-400 film. Endoscopic findings are illustrated in 13 patients, with case summaries in 11. Selected radiographic and endoscopic images show the essential features in each case and demonstrate the value of ureteroscopic examination.