Integrated Central Blood Pressure-aortic Stiffness Risk Categories and Cardiovascular Mortality in End-stage Renal Disease

BACKGROUND: Our aim was to study the predictive power of integrated central blood pressure-aortic stiffness (ICPS) risk categories on cardiovascular (CV) mortality in end-stage renal disease (ESRD) patients. METHODS: This is a secondary analysis of a prospective study of 91 ESRD patients on hemodialysis therapy. At baseline, pulse wave velocity (PWV), central systolic blood pressure (cSBP) and central pulse pressure (cPP) were measured and patients were followed up for CV mortality for a median 29.5 months. Based on the shape of the association of each individual ICPS parameter with the CV outcome, patients were assigned ICPS scores: one point was given, if either the cSBP value was in the 3rd, or if the PWV or cPP was in the 2nd or 3rd tertiles (ICPS range: 0–3). We then evaluated the role of ICPS risk categories (average: 0–1, high: 2, very high: 3 points) in the prediction of CV outcomes using Cox proportional hazard regression analysis and compared its discrimination (Harrell’s C) to that of each of its components. RESULTS: We found a strong dose–response association between ICPS risk categories and CV outcome (high risk HR = 2.62, 95% CI: 0.82–8.43, p for trend = 0.106; very high risk HR = 10.03, 95% CI: 1.67–60.42, p = 0.02) even after adjustment for multiple potential confounders. ICPS risk categories had a modest discrimination (C: 0.622, 95% CI: 0.525–0.719) that was significantly better than that of cSBP (dC: 0.061, 95% CI: 0.006–0.117). CONCLUSIONS: The ICPS risk categories may improve the identification of ESRD patients with high CV mortality risk

A blended learning módszer alkalmazásának lehetőségei a számítástechnika oktatásában

A blended learning (magyarul vegyes oktatás vagy kombinált tanulás) egy olyan oktatási forma, amely összeköti a hagyományos oktatási formákat az e-learninggel (elektronikus oktatás). A blended learning tehát olyan oktatási módszer mely a manapság igen divatos e-learning mellett személyes jelenlétet is megkövetel a tanár és a diák oldaláról. Ilyen alkalmakkor zajlanak a konzultációk, a mentori tevékenységek, a csapatmunka, azaz kombinálható az elektronikus felület a nyomtatott tananyagokkal és a személyes jelenléttel. A blended learning, a hagyományos jelenléten alapuló oktatás és konzultáció, valamint a távoktatás elektronikus tanulási környezetének illetve tananyagainak változatából alakult ki. A blended learning egyben egyéni és társasági oktatási- tanulási módszer, irányított és felfedezés-orientált. A blended learning oktatási módszer egyre népszerűbb, számos oktatási intézményben alkalmazzák már világszerte, így Magyarországon és Szerbiában is. Kutatásunkban a számítástechnika oktatásában való hatékonyságát vizsgáltuk ki a középiskolában

Discriminatory processor sharing with access rate limitations

In the access part of communication networks user access rates are usually limited by technology and are much lower than the bottleneck link transmission capacity carrying the traffic flows aggregated. A possible model for bandwidth sharing of the bottleneck link is the Discriminatory Processor Sharing (DPS) models, in which the server capacity (link bandwidth) is distributed among different classes of users in an unequal manner. Recently, some DPS variants incorporating the access rate limits of users have been analyzed. These models are not bandwidth sparing in a sense, that the capacity share of a class may simply be cut at its access rate limit, and the incidentally residual bandwidth is not reused in other classes. In this paper we introduce and analyze a novel variant of DPS in which the original processor sharing effect and the access rate limit constraints are combined in a bandwidth economical way resulting a truly capacity-conserving operation. Besides the state space characterization of this model, two asymptotic behaviors are also presented. We also argue in the favor of practical significance of these asymptotics, that is it could greatly help in finding high quality approximate solutions of this DPS system, i.e.q in terms of the average waiting times of flows

Age- and season-dependent pattern of flavonol glycosides in Cabernet Sauvignon grapevine leaves

Flavonols play key roles in many plant defense mechanisms, consequently they are frequently investigated as stress sensitive factors in relation to several oxidative processes. It is well known that grapevine (Vitis vinifera L.) can synthesize various flavonol glycosides in the leaves, however, very little information is available regarding their distribution along the cane at different leaf levels. In this work, taking into consideration of leaf position, the main flavonol glycosides of a red grapevine cultivar (Cabernet Sauvignon) were profiled and quantified by HPLC–DAD analysis. It was found that amount of four flavonol glycosides, namely, quercetin-3-O-galactoside, quercetin-3-O-glucoside, kaempferol-3-O-glucoside and kaempferol-3-O-glucuronide decreased towards the shoot tip. Since leaf age also decreases towards the shoot tip, the obtained results suggest that these compounds continuously formed by leaf aging, resulting in their accumulation in the older leaves. In contrast, quercetin-3-O-glucuronide (predominant form) and quercetin-3-O-rutinoside were not accumulated significantly by aging. We also pointed out that grapevine boosted the flavonol biosynthesis in September, and flavonol profile differed significantly in the two seasons. Our results contribute to the better understanding of the role of flavonols in the antioxidant defense system of grapevine

Hyperthymic affective temperament and hypertension are independent determinants of serum brain-derived neurotrophic factor level

BACKGROUND: Brain-derived neurotrophic factor (BDNF) has neuroprotective, proangiogenic and myogenic effects and, therefore, possibly acts as a psychosomatic mediator. Here, we measured serum BDNF (seBDNF) level in hypertensive patients (HT) and healthy controls (CONT) and its relation to affective temperaments, depression and anxiety scales, and arterial stiffness parameters. METHODS: In this cross-sectional study, affective temperaments, anxiety, and depression were studied with questionnaires (TEMPS-A, HAM-A, and BDI, respectively). SeBDNF level and routine laboratory parameters were measured as well. Arterial stiffness was evaluated with a tonometric method. RESULTS: Allover, 151 HT, and 32 CONT subjects were involved in the study. SeBDNF level was significantly higher in HT compared to CONT (24880 +/- 8279 vs 21202.6 +/- 6045.5 pg/mL, p < 0.05). In the final model of regression analysis, hyperthymic temperament score (Beta = 405.8, p = 0.004) and the presence of hypertension (Beta = 6121.2, p = 0.001) were independent determinants of seBDNF. In interaction analysis, it was found that in HT, a unit increase in hyperthymic score was associated with a 533.3 (95 %CI 241.3-825.3) pg/mL higher seBDNF. This interaction was missing in CONT. CONCLUSIONS: Our results suggest a complex psychosomatic involvement of BDNF in the pathophysiology of hypertension, where hyperthymic affective temperament may have a protective role. BDNF is not likely to have an effect on large arteries