Investigation of activated Al-pillared clay efficiency in vegetable oil purification

This paper represents a contribution to the applicability of natural clays and their derivates as adsorbents in the process of purification of vegetable oil. Investigation of textural properties of raw and purified clay samples reveals that during acid activation and Al-pillaring, BET and micropore surface area increases significantly. However, bleaching capacity of clay and its derivates is not determined by using sample surface area, but rather sample total pore volume. Surface area, especially micropore surface area contributes to removal of smaller molecules. This was confirmed by successful elimination of moisture and volatile materials by samples with an appropriate micropore structure. Used samples of clay and its derivates do not significantly influence acid and peroxide values of raw sunflower oil during its treatment

Angiotensin II-receptor subtypes in human atria and evidence for alterations in patients with cardiac dysfunction

Angiotensin II (All) has been implicated as an important factor in the pathophysiology of heart diseases. Following the recent identification of two subtypes of the All receptor in cardiac tissue of animals, we investigated the possible occurrence of these, or similar, subtypes in human atrial tissue. In right-atrial tissue from patients undergoing heart surgery, we determined the All-receptor profile in receptor binding studies, using [125I]-angiotensin as radioligand and All as well as two compounds selective for the receptor subtypes to identify and quantify All-receptor subpopulations. In 35 patients (23 requiring coronary bypasses, 10 vaivular surgery and two combined coronary and valvular surgery), the left-ventricular ejection fraction was determined in the preoperative phase, and right- and left-atrial pressure during surgery. In membranes of human right atria, All receptors are present in high density (median: Bmax= 294 fmol. mg−1 protein, range: 111-2073) and two different subtypes can be distinguished. Type-1 receptors (AT1) accounted for 33 ± l0% of the population whereas type-2 receptors (AT2) made up 67 ± 10% of the population. There was no correlation between any of the measured cardiac functions and total All-receptor density or receptor affinity. However, the percentage of AT1 receptors was higher in the atria of patients with normal right-atrial pressure; left-ventricular ejection fraction was positively and right-atrial pressure inversely correlated with the percentage of AT1 receptors (r=0·740 and -0·901, respectively; P<0·001, for both). Moreover, the percentage of AT receptors was directly correlated with the levels of left-atrial pressure (r=0·853; P<0·001). It is concluded that the ratio of AT1 to AT2 receptors correlates well with right-atrial pressure and left-ventricular function. This is a first indication of a possible involvement of All-receptor subtypes in the pathophysiology of cardiac dysfunction

Metal-support interaction: The key factor governing activity of Pd/SnO2 catalyst for denitration of ground water

Two mesoporous nanocristalline Pd/SnO2 catalysts were prepared by modified solgel technique differing in the pH conditions (pH = 2 and 9.5) of the synthesis of their supports. Samples achieved different activity and selectivity in water denitration reaction using hydrogen. XPS results of reduced samples indicate a strong interaction between the Pd and the Sn possibly as a result of electron shift from Sn to Pd. The solid solution of Pd2+ and SnO2 is formed by taking O from the surface of the support. In such a way some SnO2-X species may stay onto the surface and be responsible for its pronounced activity

Comparative Effects of Haemodialysis and Haemofiltration on Plasma Atrial Natriuretic Peptide

The effects of 4 h haemodialysis (15 patients) or 4 h haemofiltration (five patients) on plasma concentrations of atrial natriuretic peptide (ANP) were compared by means of a sensitive radioreceptor binding assay, and related to accompanying changes in body weight, blood pressure and plasma renin activity. Before dialysis, plasma ANP concentrations were considerably elevated: haemodialysis group 10-484 pmol/l (mean 156 pmol/l); haemofiltration group 72-320 pmol/l (mean 170 pmol/l). Although plasma concentrations of ANP fell markedly with treatment in both groups: post-haemodialysis 2-187 pmol/l (mean 67 pmol/l); post-haemofiltration 47-135 pmol/l (mean 79 pmol/l), after treatment it remained above the normal range in 14 of the 20 patients. Pretreatment plasma ANP was related to systolic blood pressure (r=0.459; P<0.05) but bore no relationship to mean or diastolic blood pressure, or plasma renin activity. The fall in plasma ANP concentration during treatment correlated with the postural blood pressure drop after dialysis (r=0.505; P<0.05), but was unrelated to changes in weight or plasma renin activity with haemodialysis or haemofiltration. Plasma ANP concentrations rose rapidly again in the 60 min after dialysis treatment, without change in body weight. These results show that high levels of biologically active ANP circulate in end-stage renal disease. The fact that these are not reduced to normal by haemodialysis or haemofiltration, despite restoration to normovolaemic or hypovolaemic state, suggests that the increased levels of ANP in end-stage renal failure are due to both hypervolaemia and other factors, which may include occult cardiac dysfunction and loss of renal clearanc

Risk Factors Promoting Hypertensive Crises: Evidence From a Longitudinal Study

Background Current knowledge about risk factors promoting hypertensive crisis originates from retrospective data. Therefore, potential risk factors of hypertensive crisis were assessed in a prospective longitudinal study. Methods Eighty-nine patients of the medical outpatient unit at the University Hospital of Bern (Bern, Switzerland) with previously diagnosed hypertension participated in this study. At baseline, 33 potential risk factors were assessed. All patients were followed-up for the outcome of hypertensive crisis. Cox regression models were used to detect relationships between risk factors and hypertensive crisis (defined as acute rise of systolic blood pressure (BP) ≥200mmHg and/or diastolic BP ≥120mmHg). Results The mean duration of follow-up was 1.6 ± 0.3 years (range 1.0-2.4 years). Four patients (4.5%) were lost to follow-up. Thirteen patients (15.3%) experienced hypertensive crisis during follow-up. Several potential risk factors were significantly associated with hypertensive crisis: female sex, higher grades of obesity, the presence of a hypertensive or coronary heart disease, the presence of a somatoform disorder, a higher number of antihypertensive drugs, and nonadherence to medication. As measured by the hazard ratio, nonadherence was the most important factor associated with hypertensive crisis (hazard ratio 5.88, 95% confidence interval 1.59-21.77, P < 0.01). Conclusions This study identified several potential risk factors of hypertensive crisis. Results of this study are consistent with the hypothesis that improvement of medical adherence in antihypertensive therapy would help to prevent hypertensive crises. However, larger studies are needed to assess potential confounding, other risk factors and the possibility of interaction between predictor

Renale Denervation: Schweizer Erfahrungen im Langzeitverlauf

Despite great advances in pharmacological and non-pharmacological treatment of patients with arterial hypertension, a significant proportion of patients do not reach the target values suggested by the guidelines. A therapy-resistant hypertension is defined as a blood pressure above the suggested target values despite an antihypertensive therapy with three medications at maximal dosis, including a diuretic. The renal denervation is a new and promising method for the treatment of refractory arterial hypertension. An optimal selection of the patients undergoing a renal denervation is extremely important, and this intervention should be performed in highly specialized centers only

Event Generators for WW Physics

The report summarizes the results of the activities of the Working Group on Event Generators for WW Physics at CERN during 1995.Comment: 99 Latex, including 30 figures, 24 tables. The report is part of: G.Altarelli,T.Sjostrand and F.Zwirner (eds), Physics at LEP2 CERN 96-0