49 research outputs found

    Structural Studies of Lanthanide Double Perovskites

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    This project focuses on the examination of the structures of lanthanide containing double perovskites of the type Ba2LnB'O6-d (Ln = lanthanide or Y3+ and B' = Nb5+, Ta5+, Sb5+ and/or Sn4+) using synchrotron X-ray and neutron powder diffraction. The first part of this project examined the relative stability of R3 rhombohedral and I4/m tetragonal structures as the intermediate phase adopted by the series Ba2LnB'O6 (Ln = lanthanide (III) or Y3+ and B' = Nb5+, Ta5+ or Sb5+). It was found that I4/m tetragonal symmetry was favoured when B' was a transition metal with a small number of d electrons, such as Nb5+ or Ta5+. This is due to the presence of p-bonding in these compounds. In the Ba2LnNbO6 and Ba2LnTaO6 series R3 rhombohedral symmetry was, however, favoured over I4/m tetragonal symmetry when Ln = La3+ or Pr3+ due to the larger ionic radius of these cations. The incompatibility of the d0 and d10 B'-site cations in this family of compounds was indicated by significant regions of phase segregation in the two series Ba2Eu1-xPrxNb1-xSbxO6 and Ba2NdNb1-xSbxO6. In the second part of this project the compounds in the series Ba2LnSnxB'1-xO6-d (Ln = Pr, Nd or Tb and B' = Nb5+ or Sb5+) were examined to understand the relative stability of oxygen vacancies in these materials compared to the oxidation of the lanthanide cations and to determine if any oxygen vacancy ordering occurred. It was found, using a combination of structural characterisation, X ray Absorption Near Edge Structure and Ultra-Violet, Visible and Near Infrared spectroscopies, that with Ln = Pr or Tb increased Sn4+ doping results in a change in the oxidation state of the Ln3+ cations to Ln4+. This leads to those series containing little or no oxygen vacancies. A loss of B site cation ordering was found to accompany this oxidation state change and phase segregation was found to occur in the Ba2PrSnxSb1-xO6-d series most likely due to the Pr3+ and Pr4+ cations segregating into different phases. The Nd3+ cations in the series Ba2NdSnxSb1-xO6-d, however, can not oxidise to the tetravalent state so the number of oxygen vacancies rises with increasing x. It was found that oxygen vacancies concentrate onto the axial site of the compounds with x = 0.6 and 0.8 at ambient temperature. In Ba2Sn0.6Sb0.4O5.7 the oxygen vacancies were found to change to concentrating on the equatorial site at higher temperatures and it is suggested that this oxygen vacancy ordering plays a role in the adoption of I2/m monoclinic symmetry

    Pancreatic fibrosis correlates with exocrine pancreatic insufficiency after pancreatoduodenectomy

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    Background: Obstruction of the pancreatic duct can lead to pancreatic fibrosis. We investigated the correlation between the extent of pancreatic fibrosis and the postoperative exocrine and endocrine pancreatic function. Methods: Fifty-five patients who were treated for pancreatic and periampullary carcinoma and 19 patients with chronic pancreatitis were evaluated. Exocrine pancreatic function was evaluated by fecal elastase-1 test, while endocrine pancreatic function was assessed by plasma glucose level. The extent of fibrosis, duct dilation and endocrine tissue loss was examined histopathologically. Results: A strong correlation was found between pancreatic fibrosis and elastase-1 level less than 100 μg/g (p < 0.0001), reflecting severe exocrine pancreatic insufficiency. A strong correlation was found between pancreatic fibrosis and endocrine tissue loss (p < 0.0001). Neither pancreatic fibrosis nor endocrine tissue loss were correlated with the development of postoperative diabetes mellitus. Duct dilation alone was neither correlated with exocrine nor with endocrine function loss. Conclusion: The majority of patients develop severe exocrine pancreatic insufficiency after pancreatoduodenectomy. The extent of exocrine pancreatic insufficiency is strongly correlated with preoperative fibrosis. The loss of endocrine tissue does not correlate with postoperative diabetes mellitus. Preoperative dilation of the pancreatic duct per se does not predict exocrine or endocrine pancreatic insufficiency postoperatively. Copyrigh

    Українська сангха японського Ордену Ніппондзан Мьоходзі

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    Стаття присвячена дослідженню історії української сангхи японського буддистського Ордену Ніппондзан Мьоходзі. Автор, враховуючи специфіку даної школи, намагався намітити загальний шлях для подальшого дослідження, виявити основні тенденції та періоди розвитку української сангхи Ніппондзан Мьоходзі. Значна увага приділяється діяльності членів української сангхи за межами України, що обумовлено світовими масштабами діяльності Дзюнсея Терасави, безпосереднього вчителя для українських монахів даного ОрденуСтатья посвящена исследованию истории украинской сангхи японского буддийского Ордена Ниппондзан Мёходзи. Автор, учитывая специфику данной школы, старался наметить общий путь для дальнейшего исследования, выявить основные тенденции и периоды развития украинской сангхи Ниппондзан Мёходзи. Значительное внимание уделяется деятельности членов украинской сангхи за пределами Украины, что обусловлено мировыми масштабами деятельности Дзюнсея Терасавы, непосредственного учителя монахов данного Ордена.This article is devoted to the history of Ukrainian Sangha of Japanese Buddhist Order Nippondzan Mehodzi. Taking into account the specificity of the school, the author trying to direct a common way for further research, to identify the key trends and periods of development of Ukrainian Sangha Nippondzan Mehodozi. Considerable attention has been given to the activities of the Ukrainian Sangha members outside of Ukraine, wich is caused by the global scale of Dzyunsey Terasava activity

    2020 ESC Guidelines on acute coronary syndrome without ST-segment elevation: recommendations and critical appraisal from the Dutch ACS and Interventional Cardiology working groups

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    Recently, the European Society of Cardiology (ESC) has updated its guidelines for the management of patients with acute coronary syndrome (ACS) without ST-segment elevation. The current consensus document of the Dutch ACS working group and the Working Group of Interventional Cardiology of the Netherlands Society of Cardiology aims to put the 2020 ESC Guidelines into the Dutch perspective and to provide practical recommendations for Dutch cardiologists, focusing on antiplatelet therapy, risk assessment and criteria for invasive strategy.Cardiolog

    Age-dependent differences in diabetes and acute hyperglycemia between men and women with ST-elevation myocardial infarction: a cohort study

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    Contains fulltext : 119180.pdf (publisher's version ) (Open Access)BACKGROUND: Both acute hyperglycemia as diabetes results in an impaired prognosis in ST-elevation myocardial infarction (STEMI) patients. It is unknown whether there is a different prevalence of diabetes and acute hyperglycemia in men and women within age-groups. METHODS: Between 2004 and 2010, 4640 consecutive patients (28% women) with STEMI, were referred for primary PCI. Patients were stratified into two age groups, /=65 years (2193 patients). Separate analyses were performed in 3901 patients without diabetes. Diabetes was defined as known diabetes or HbA1c >/=6.5 mmol/l at admission. RESULTS: The prevalence of diabetes was comparable between women and men in the younger age group (14% vs 12%, p = 0.52), whereas in the older age group diabetes was more prevalent in women (25% vs 17% p < 0.001). In patients without diabetes, admission glucose was comparable between both genders in younger patients (8.1 +/- 2.0 mmol/l vs 8.0 +/- 2.2 mmol/l p = 0.36), but in older patients admission glucose was higher in women than in men (8.7 +/- 2.1 mmol/l vs 8.4 +/- 2.1 mmol/l p = 0.028). After multivariable analyses, the occurrence of increased admission glucose was comparable between men and women in the younger age group (OR 1.1, 95%CI 0.9-1.5), but increased in women in the older age group (OR 1.3, 95% CI 1.1-1.7). Both diabetes and hyperglycemia were associated with a higher one-year mortality in both men and women. CONCLUSIONS: The differences between men and women in hyperglycemia and diabetes in patients with STEMI are age dependent and can only be observed in older patients. This may have implications for medical treatment and should be investigated further

    The influence of residential distance on time to treatment in ST-elevation myocardial infarction patients

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    Contains fulltext : 136116.pdf (publisher's version ) (Open Access)AIMS: To evaluate the relation between residential distance and total ischaemic time in patients with acute ST-elevation myocardial infarction (STEMI). METHODS: STEMI patients were transported to the Isala Hospital Zwolle with the intention to perform primary percutaneous coronary intervention PCI (pPCI) from 2004 until 2010 (n = 4149). Of these, 1424 patients (34 %) were referred via a non-PCI 'spoke' centre ('spoke' patients) and 2725 patients (66 %) were referred via field triage in the ambulance (ambulance patients). RESULTS: A longer residential distance increased median total ischaemic time in 'spoke' patients (0-30 km: 228 min, >30-60 km: 235 min, >60-90 km: 264 min, p 30-60 km: 175 min, >60-90 km: 186 min, p = 0.225). After multivariable linear regression analysis, in 'spoke' patients residential distance of >30-60 km compared with 0-30 km was not independently associated with ischaemic time; however, a residential distance of >60-90 km (exp (B) = 1.11, 95 % CI 1.01-1.12) compared with 0-30 km was independently related with ischaemic time. In ambulance patients, residential distance of >30-60 and >60-90 km compared with 0-30 km was not independently associated with ischaemic time. CONCLUSION: A longer distance from the patient's residence to a PCI centre was associated with a small but significant increase in time to treatment in 'spoke' patients, however not in ambulance patients. Therefore, referral via field triage in the ambulance did not lead to a significant increase in time to treatment, especially at long distances (up to 90 km)

    Impact of diabetes on outcome in patients with non-ST-elevation myocardial infarction

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    Item does not contain fulltextBACKGROUND: Diabetes mellitus contributes to the increase of cardiovascular deaths worldwide. Despite continuous treatment evolution, patients with diabetes suffering from an acute coronary syndrome still have a high morbidity and mortality. We aimed to analyze the impact of diabetes on one-year outcome in an unselected patient population with non-ST-elevation myocardial infarction (non-STEMI). METHODS: Retrospective analysis of 847 unselected patients with non-STEMI. We compared the baseline characteristics, treatment and outcome of patients versus those without diabetes. RESULTS: A total of 138 patients had diabetes (16%) and 709 (84%) had no diabetes. Patients with diabetes were older, often had hypertension, hyperlipidemia, previous myocardial infarction and Killip class >/=2 on admission. Approximately 80% of both patients, with and without diabetes, underwent diagnostic coronary angiography. Multivessel disease was more present among patients with diabetes, but patients with diabetes were treated more often conservatively. At one-year follow up rates of death and major adverse cardiac events were significantly higher in patients with diabetes compared to those without diabetes (8% vs. 3%; P=0.001 and 23% vs. 14%; P=0.008, respectively). Even after adjustment for differences in baseline characteristics, diabetes remained an independent predictor of mortality (OR: 2.25; CI95%: 1.05-3.91). CONCLUSIONS: In an unselected patient population with non-STEMI, patients with diabetes have higher risk factors on admission, less often undergo coronary revascularisation and have worse outcome at one-year follow-up. Diabetes is an independent predictor of one-year mortality in patients with non-STEMI

    Predictors and outcome of grade 3 ischemia in patients with ST-segment elevation myocardial infarction undergoing primary percutaneous coronary intervention

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    PURPOSE: Grade 3 ischemia (G3I: distortion of the terminal portion of the QRS complex) is a predictor of serious complications after acute myocardial infarction. However, less is known about which patients are more prone to present with G3I. METHODS: Patients who were enrolled in the Ongoing Tirofiban In Myocardial infarction Evaluation trial 2 were included. These patients were divided in 2 groups based on the enrolment electrocardiogram: grade 2 ischemia (G2I) or G3I. RESULTS: Between June 2004 and November 2007, 1308 patients with interpretable electrocardiograms were enrolled. Grade 3 ischemia was found in 426 (32.6%) patients. Patients with G3I were older, more often male, more often had diabetes, had a Thrombolysis In Myocardial Infarction (TIMI) risk score of greater than 3, had 3 vessel disease, had an anterior infarction, more often presented in Killip class greater than 1, less often had a preprocedural TIMI 3 flow, and less often had a myocardial blush grade 3 post-PCI. One hour post-PCI, residual ST deviation was higher in patients with G3I compared with patients with G2I. Furthermore, G3I was associated with more major cardiac events (including death, myocardial infarction, urgent target vessel revascularization). After multivariate adjustment, G3I was an independent predictor of failure of ST-segment resolution 1 hour post-PCI (odds ratio, 1.4; 95% confidence interval, 1.1-1.9) and 30-day mortality (odds ratio, 3.2; 95% confidence interval, 1.2-8.7). CONCLUSION: Grade 3 ischemia was associated with high-risk patient criteria (older age, diabetes, TIMI risk score >3, Killip class >1, and anterior myocardial infarction) and represents a subgroup of high-risk patients who seems to be associated with poor myocardial reperfusion and worse outcome

    Two-year outcome after early or late Intervention in non-ST elevation acute coronary syndrome

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    Contains fulltext : 182932.pdf (publisher's version ) (Open Access)OBJECTIVE: To compare long-term outcome of an early to a delayed invasive strategy in high-risk patients with non-ST elevation acute coronary syndrome (NSTE-ACS). METHODS: This prospective, multicentre trial included patients with NSTE-ACS and at least two out of three of the following high-risk criteria: (1) evidence of extensive myocardial ischaemia on ECG, (2) elevated biomarkers for myocardial necrosis and (3) age above 65 years. Patients were randomised to either an early (angiography and revascularisation if appropriate 48 hours after randomisation). Endpoint for this prespecified long-term follow-up was the composite incidence of death or reinfarction after 2 years. Data collection was performed by telephone contact with the patients, their relatives or general practitioner and by review of hospital records. RESULTS: Endpoint status after 2-year follow-up was collected in 521 of 542 initially enrolled patients. Incidence of death or reinfarction was 11.8% in the early and 13.1% in the delayed treatment group (relative risk (RR)=0.90, 95% CI 0.57 to 1.42). No significant differences were found in occurrence of the individual components of the primary endpoint: death 6.1% vs 8.9%, RR 0.69 (95% CI 0.37 to 1.27), reinfarction 6.5% vs 5.4%, RR 1.20 (95% CI 0.60 to 2.38). Post-hoc subgroup analysis showed statistical significant interaction between age and treatment strategy on outcome (p=0.02). CONCLUSIONS: After 2 years follow-up, no difference in incidence of death or reinfarction was seen between early to late invasive strategy. These findings are in line with results of other studies with longer follow-up. Older patients seem to benefit more from early invasive treatment

    Cardiogenic Shock Predicts Long-term Mortality in Hospital Survivors of STEMI Treated With Primary Percutaneous Coronary Intervention

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    BACKGROUND: ST-segment elevation myocardial infarction (STEMI) complicated by cardiogenic shock (CS) has a poor prognosis. Recently published data suggested, however, that CS does not affect long-term mortality in hospital survivors of STEMI. We investigated whether this could be confirmed in a larger cohort. HYPOTHESIS: STEMI complicated by CS leads to worse long-term survival. METHODS: A prospective cohort study was performed in 7412 consecutive patients with STEMI treated by primary percutaneous coronary intervention (angioplasty). The predictive value of CS on long-term mortality was assessed in hospital survivors. Multivariate analysis, adjusting for differences in baseline variables, was performed to assess the independent prognostic value of CS. RESULTS: Cardiogenic shock was observed in 387 patients (5.2%). The total in-hospital mortality was 254 (3.4%), and mortality was significantly higher in patients with CS (20.0% vs 2.6%; P < 0.001). The 1-year mortality in hospital survivors was 10.3% in patients with CS and 3.9% in patients without CS (P < 0.001). After multivariate analysis, CS was still a significant predictor of long-term mortality in hospital survivors (hazard ratio: 2.6, 95% confidence interval: 1.64-4.01). CONCLUSIONS: Cardiogenic shock remains a strong predictor of long-term mortality in hospital survivors of STEMI treated by primary percutaneous coronary intervention
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