A 500 °C isothermal section for the Al-Au-Cu system

The Al-Au-Cu system and its associated ternary alloys and intermetallic compounds is surprisingly poorly known, and the authors could find no phase diagram for it in the literature. This article addresses this omission by presenting an isothermal section at 500 °C, derived with the aid of X-ray diffraction (XRD), energy-dispersive spectroscopy (EDS), metallography, and hardness measurements. The samples studied had generally received an anneal of 2 hours at 500 °C, primarily in order to complete any transformations that occurred during solidification and cooling of the castings. The possibility of further changes on protracted annealing at 500 °C is not ruled out, and the diagram presented is, therefore, applicable only to material prepared by thermal processing of an industrial nature. The presence of a ternary Β phase with a nominal stoichiometry of AlAu2-xCu1+x (0 ≤ x ≤ 1) was confirmed, and its phase field at 500 °C was determined. A number of the binary intermetallic phases were found to exhibit some solid solubility of the ternary element. In particular, the γ-Al4Cu9 phase extends deep into the ternary and, in the vicinity of the commercially interesting 18-carat line, appears to exist in a ternary ordered form, designated here as γ2

The aluminium-copper-gold ternary system

Despite Au, Al and Cu being individually very well-known elements, their ternary phase diagram has not been studied in as much detail as those of many other Au-containing ternaries. Here we review what is known, and consider the prospects for technological exploitation of some of the ternary compositions. The components of greatest interest in Al-Au-Cu may be the β-phases, at least two of which have shape memory properties. Of these, 'Spangold', which has the nominal stoichiometry Au7Cu5Al4, has received some attention for jewellery applications, while the edge compound Cu3Al is a well-known shape memory composition with corresponding specialised industrial uses. The properties of other β-phase compositions in the system have been scarcely investigated. The system also contains an extensive γ-phase, Al4AuxCu9-x, where x ranges from 0 to ~6.5, and the purple gold phase AuAl2

Clinical Features of Cardio-Renal Syndrome in a Cohort of Consecutive Patients Admitted to an Internal Medicine Ward

Introduction: Cardiorenal syndrome (CRS) is a disorder of the heart and kidney whereby interactions between the 2 organs can occur. We recorded the clinical features of CRS in patients consecutively admitted to an Internal Medicine ward. Patients and Methods: We retrospectively analyzed the anthropometric, history, clinical, biochemical and treatment characteristics in 438 out of 2,998 subjects (14.6%) admitted to our unit (from June 2007 to December 2009), diagnosed with CRS, according to Acute Dialysis Quality Initiative (ADQI) recommendations. Estimated glomerular filtration (eGFR) was calculated using several equations: MDRD (Modification of Diet in Renal Disease; 2 variations GFRMDRD186, GFRMDRD175), Mayo, Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) and Cockroft-Gault. Results: Mean age was 80±8 years, 222 (50.6%) were males, 321 (73.2%) were smokers, 229 (52.2%) were diabetic, 207 (47.2%) had a history of acute myocardial infarction, 167 (38.1%) had angina, 135 (30.8%) were affected by cerebrovascular disease, 339 (77.3%) had peripheral arterial disease. CRS was type 1 in 211 cases (48.2%), type 2 in 96 (21.9%), type 3 in 88 (20.1%), type 4 in 29 (6.6%) and type 5 in 14 (3.2%). eGFR, calculated by different formulae, ranged between 31 and 36 ml/min/1.73 m2. GFR was lower in CRS type 3 than in the other types, and the values ranged between 24 and 27 ml/min/1.73 m2. Mean hospital length-of-stay (LOS) was 9.8±6.3 days. Diuretics were the most prescribed medication (78.7%); only 5 patients underwent haemodialysis. Conclusions: CRS is common, especially in the elderly. CRS Type 1 was the prevalent subset and patients had stage 3-4 renal insufficiency. Results obtained from the GFR equations were similar although the Mayo equation tended to overestimate the eGFR

Age-related associations of hypertension and diabetes mellitus with chronic kidney disease

<p>Abstract</p> <p>Background</p> <p>Studies suggest end-stage renal disease incidence and all-cause mortality rates among patients with chronic kidney disease (CKD) differ by age. The association of diabetes mellitus and hypertension with CKD across the adult lifespan is not well established.</p> <p>Methods</p> <p>Data from NHANES 1999–2004 were used to determine the association of risk factors for stage 3 or 4 CKD (n = 12,518) and albuminuria (n = 12,778) by age grouping (20 to 49, 50 to 69, and ≥70 years). Stage 3 or 4 CKD was defined as an estimated glomerular filtration rate of 15 to 59 ml/min/1.73 m²and albuminuria as an albumin to creatinine ratio ≥30 mg/g.</p> <p>Results</p> <p>For adults 20 to 49, 50 to 69 and ≥70 years of age, the prevalence ratios (95% confidence interval) of stage 3 or 4 CKD associated with hypertension were 1.94 (0.86 – 4.35), 1.51 (1.09 – 2.07), 1.31 (1.15 – 1.49), respectively (p-trend = 0.038). The analogous prevalence ratios (95% confidence interval) were 3.01 (1.35 – 6.74), 1.61 (1.15 – 2.25), 1.40 (1.15 – 1.69), respectively, for diagnosed diabetes mellitus (p-trend = 0.067); and 2.67 (0.53 – 13.4), 1.35 (0.69 – 2.63), 1.08 (0.78 – 1.51), respectively, for undiagnosed diabetes mellitus (p-trend = 0.369). The prevalence ratios of albuminuria associated with hypertension and diagnosed and undiagnosed diabetes mellitus were lower at older age (each p < 0.05).</p> <p>Conclusion</p> <p>Among US adults, diabetes mellitus and hypertension are associated with CKD and albuminuria regardless of age. However, the associations were stronger at younger ages.</p

Kidney function, endothelial activation and atherosclerosis in black and white Africans with rheumatoid arthritis

OBJECTIVE: To determine whether kidney function independently relates to endothelial activation and ultrasound determined carotid atherosclerosis in black and white Africans with rheumatoid arthritis (RA). METHODS: We calculated the Jelliffe, 5 Cockcroft-Gault equations, Salazar-Corcoran, Modification of Diet in Renal Disease (MDRD) and Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) estimated glomerular filtration rate (EGFR) equations in 233 (112 black) RA patients. RESULTS: The CKD-EPI eGFR was 0.1 for comparisons of AUC (SE)) for the other 8 equations. Based on optimal eGFR cutoff values with sensitivities and specificities ranging from 42 to 60% and 70 to 91% respectively, as determined in ROC curve analysis, a low eGFR increased the odds ratio for plaque 2.2 to 4.0 fold. CONCLUSION: Reduced kidney function is independently associated with atherosclerosis and endothelial activation in black and white Africans with RA, respectively. CKD is highly prevalent in black Africans with RA. Apart from the MDRD, eGFR equations are useful in predicting carotid plaque presence, a coronary heart disease equivalent, amongst black African RA patients

Chronic kidney disease increases cardiovascular unfavourable outcomes in outpatients with heart failure

<p>Abstract</p> <p>Background</p> <p>Chronic heart failure (CHF) has a high morbidity and mortality. Chronic kidney disease (CKD) has consistently been found to be an independent risk factor for unfavorable cardiovascular (CV) outcomes. Early intervention on CKD reduces the progression of CHF, hospitalizations and mortality, yet there are very few studies about CKD as a risk factor in the early stages of CHF. The aims of our study were to assess the prevalence and the prognostic importance of CKD in patients with systolic CHF stages B and C.</p> <p>Methods</p> <p>This is a prospective cohort study, dealing with prognostic markers for CV endpoints in patients with systolic CHF (ejection fraction ≤ 45%).</p> <p>Results</p> <p>CKD was defined as estimated glomerular filtration rate <60 mL/min/1.73 m²and CV endpoints as death or hospitalization due to CHF, in 12 months follow-up. Eighty three patients were studied, the mean age was 62.7 ± 12 years, and 56.6% were female. CKD was diagnosed in 49.4% of the patients, 33% of patients with CHF stage B and 67% in the stage C. Cardiovascular endpoints were observed in 26.5% of the patients. When the sample was stratified into stages B and C of CHF, the occurrence of CKD was associated with 100% and 64.7%, respectively, of unfavorable CV outcomes. After adjustments for all other prognostic factors at baseline, it was observed that the diagnosis of CKD increased in 3.6 times the possibility of CV outcomes (CI 95% 1.04-12.67, p = 0.04), whereas higher ejection fraction (R = 0.925, IC 95% 0.862-0.942, p = 0.03) and serum sodium (R = 0.807, IC 95% 0.862-0.992, p = 0.03) were protective.</p> <p>Conclusion</p> <p>In this cohort of patients with CHF stages B and C, CKD was prevalent and independently associated with increased risk of hospitalization and death secondary to cardiac decompensation, especially in asymptomatic patients.</p

Hyperhomocysteinemia is independently associated with albuminuria in the population-based CoLaus study

<p>Abstract</p> <p>Background</p> <p>Increased serum levels of homocysteine and uric acid have each been associated with cardiovascular risk. We analyzed whether homocysteine and uric acid were associated with glomerular filtration rate (GFR) and albuminuria independently of each other. We also investigated the association of <it>MTHFR </it>polymorphisms related to homocysteine with albuminuria to get further insight into causality.</p> <p>Methods</p> <p>This was a cross-sectional population-based study in Caucasians (<it>n </it>= 5913). Hyperhomocysteinemia was defined as total serum homocysteine ≥ 15 μmol/L. Albuminuria was defined as urinary albumin-to-creatinine ratio > 30 mg/g.</p> <p>Results</p> <p>Uric acid was associated positively with homocysteine (r = 0.246 in men and r = 0.287 in women, <it>P </it>< 0.001). The prevalence of albuminuria increased across increasing homocysteine categories (from 6.4% to 17.3% in subjects with normal GFR and from 3.5% to 14.5% in those with reduced GFR, <it>P </it>for trend < 0.005). Hyperhomocysteinemia (OR = 2.22, 95% confidence interval: 1.60-3.08, <it>P </it>< 0.001) and elevated serum uric acid (OR = 1.27, 1.08-1.50, per 100 μmol/L, <it>P </it>= 0.004) were significantly associated with albuminuria, independently of hypertension and type 2 diabetes. The 2-fold higher risk of albuminuria associated with hyperhomocysteinemia was similar to the risk associated with hypertension or diabetes. <it>MTHFR </it>alleles related to higher homocysteine were associated with increased risk of albuminuria.</p> <p>Conclusions</p> <p>In the general adult population, elevated serum homocysteine and uric acid were associated with albuminuria independently of each other and of renal function.</p

Renal function at the time of a myocardial infarction maintains prognostic value for more than 10 years

<p>Abstract</p> <p>Background</p> <p>Renal function is an important predictor of mortality in patients with myocardial infarction (MI), but changes in the impact over time have not been well described.</p> <p>We examined the importance of renal function by estimated GFR (eGFR) and se-creatinine as an independent long-term prognostic factor.</p> <p>Methods</p> <p>Prospective follow-up of 6653 consecutive MI patients screened for entry in the Trandolapril Cardiac Evaluation (TRACE) study. The patients were analysed by Kaplan-Meier survival analysis, landmark analysis and Cox proportional hazard models. Outcome measure was all-cause mortality.</p> <p>Results</p> <p>An eGFR below 60 ml per minute per 1.73 m², consistent with chronic renal disease, was present in 42% of the patients. We divided the patients into 4 groups according to eGFR. Overall, Cox proportional-hazards models showed that eGFR was a significant prognostic factor in the two groups with the lowest eGFR, hazard ratio 1,72 (confidence interval (CI) 1,56-1,91) in the group with the lowest eGFR. Using the eGFR group with normal renal function as reference, we observed an incremental rise in hazard ratio. We divided the follow-up period in 2-year intervals. Landmark analysis showed that eGFR at the time of screening continued to show prognostic effect until 16 years of follow-up. By multivariable Cox regression analysis, the prognostic effect of eGFR persisted for 12 years and of se-creatinine for 10 years. When comparing the lowest group of eGFR with the group with normal eGFR, prognostic significance was present in the entire period of follow-up with a hazard ratio between 1,97 (CI 1,65-2,35) and 1,35 (CI 0,99-1,84) in the 2-year periods.</p> <p>Conclusions</p> <p>One estimate of renal function is a strong and independent long-term prognostic factor for 10-12 years following a MI.</p

Change in albuminuria as a surrogate endpoint for progression of kidney disease: a meta-analysis of treatment effects in randomised clinical trials

Background Change in albuminuria has strong biological plausibility as a surrogate endpoint for progression of chronic kidney disease, but empirical evidence to support its validity is lacking. We aimed to determine the association between treatment effects on early changes in albuminuria and treatment effects on clinical endpoints and surrograte endpoints, to inform the use of albuminuria as a surrogate endpoint in future randomised controlled trials. Methods In this meta-analysis, we searched PubMed for publications in English from Jan 1, 1946, to Dec 15, 2016, using search terms including “chronic kidney disease”, “chronic renal insufficiency”, “albuminuria”, “proteinuria”, and “randomized controlled trial”; key inclusion criteria were quantifiable measurements of albuminuria or proteinuria at baseline and within 12 months of follow-up and information on the incidence of end-stage kidney disease. We requested use of individual patient data from the authors of eligible studies. For all studies that the authors agreed to participate and that had sufficient data, we estimated treatment effects on 6-month change in albuminuria and the composite clinical endpoint of treated end-stage kidney disease, estimated glomerular filtration rate of less than 15 mL/min per 1·73 m2, or doubling of serum creatinine. We used a Bayesian mixed-effects meta-regression analysis to relate the treatment effects on albuminuria to those on the clinical endpoint across studies and developed a prediction model for the treatment effect on the clinical endpoint on the basis of the treatment effect on albuminuria. Findings We identified 41 eligible treatment comparisons from randomised trials (referred to as studies) that provided sufficient patient-level data on 29 979 participants (21 206 [71%] with diabetes). Over a median follow-up of 3·4 years (IQR 2·3–4·2), 3935 (13%) participants reached the composite clinical endpoint. Across all studies, with a meta-regression slope of 0·89 (95% Bayesian credible interval [BCI] 0·13–1·70), each 30% decrease in geometric mean albuminuria by the treatment relative to the control was associated with an average 27% lower hazard for the clinical endpoint (95% BCI 5–45%; median R2 0·47, 95% BCI 0·02–0·96). The association strengthened after restricting analyses to patients with baseline albuminuria of more than 30 mg/g (ie, 3·4 mg/mmol; R2 0·72, 0·05–0·99]). For future trials, the model predicts that treatments that decrease the geometric mean albuminuria to 0·7 (ie, 30% decrease in albuminuria) relative to the control will provide an average hazard ratio (HR) for the clinical endpoint of 0·68, and 95% of sufficiently large studies would have HRs between 0·47 and 0·95. Interpretation Our results support a role for change in albuminuria as a surrogate endpoint for the progression of chronic kidney disease, particularly in patients with high baseline albuminuria; for patients with low baseline levels of albuminuria this association is less certain