Search results for "Proportion"

A kinetic study of the cracking, isomerization, and disproportionation of n-heptane on a chromium-exchanged Y zeolite

1982

The kinetic rate constants for the cracking, isomerization, and disproportionation of n-heptane over a CrHNaY (32% chromium exchanged) zeolite catalyst at 400, 450, and 470 °C have been calculated. The interaction of n-heptane with a model Lewis acid such as BF3 and progress along the reaction coordinate have been studied by means of molecular orbital calculations. From the kinetic results, i.e., activation energies and frequency factors, and the theoretical calculations, it can be concluded that the controlling step in these reactions is not the formation of the carbonium ion, but the subsequent transformation of this carbonium ion. In addition, the theoretical calculations show that the a…

2021

AIMS Platelet indices have been associated with traditional cardiovascular risk factors, cardiovascular diseases and all-cause mortality. This study aimed to investigate the role of platelet count, mean platelet volume (MPV) and platelet-to-leukocyte ratio, including platelet-to-monocyte and platelet-to-lymphocyte ratio with cardiac function, heart failure (HF) phenotypes and clinical outcome, worsening of HF. METHODS AND RESULTS Univariate and multivariable linear and Cox regression analyses were used to investigate the associations between platelet indices, cardiac function and worsening of HF in 3250 subjects enrolled in the MyoVasc study. Higher MPV, lower platelet count, lower platelet…

Baseline adherence to the Mediterranean diet and major cardiovascular events: Prevención con dieta mediterránea trial

2014

Lifestyle modification, particularly dietary changes, is the cornerstone of population-based strategies for cardiovascular disease (CVD) prevention.1 Recently the Prevención con Dieta Mediterránea (PREDIMED) study,2 a 5-year randomized primary prevention trial (isrctn.org Identifier: ISRCTN35739639), showed a 30% reduction in incident CVD with Mediterranean diet (MeDiet) intervention in comparison with a control diet. At quarterly visits throughout the study, a validated 14-item MeDiet screening tool (Table 1) was used to assess conformity with this dietary pattern.3 Close monitoring of adherence to dietary instructions for CVD prevention is difficult in the clinical setting. Short dietary …

Metabolic syndrome (MetS) predicts cardio and cerebrovascular events in a twenty years follow-up. A prospective study.

2012

BACKGROUND AND PURPOSE: Metabolic syndrome (MetS) is a cluster of cardiovascular risk factors, considered as emerging and promoting atherosclerosis. This study aimed at the evaluation of the influence of MetS on the prediction of cerebro and cardiovascular events during a 20 years follow-up period in an asymptomatic population of middle-aged subjects. METHODS: We evaluated 529 asymptomatic persons through a prospective study. Study population was divided into two subgroups: patients with and without MetS. Echo-color-Doppler was used in order to assess the presence of subclinical atherosclerosis. A 20 years follow-up study was carried out in order to estimate the incidence of cerebro and car…

Il nesso di causalità

2018

The essay deals with the issue of causation in private law, referring to the broad debate that commits the scholars of criminal law. The basic idea is that in the area of private law, both in the law in action and in the reflections of the doctrine, the causal judgment must be conducted more rigorously. The study proposes to apply in a more inflexible way the model of judgment already experimented in criminal law, corrected with the necessary adaptations to the characteristics of liability in private law and of the civil trial. The proposed model is structured on two levels: the general one of a nomologicaldeductive nature (general causation) and the other concrete one based on logical prob…

A prospective, multi-center, practice-based cohort study on all-ceramic crowns

2021

The aim of this prospective, multi-center, practice-based cohort study was to analyze factors associated with the success of all-ceramic crowns.All-ceramic crowns placed in a practice-based research network ([Ceramic Success Analysis, AG Keramik) were analyzed. Data from 1254 patients with (mostly in-office CAD/CAM) all-ceramic crowns placed by 101 dentists being followed up for more than 5 years were evaluated. At the last follow-up visit crowns were considered as successful (not failed) if they were sufficient, whereas crowns were considered as survived (not lost) if they were still in function. Multi-level Cox proportional hazards models were used to evaluate the association between a ra…

Are pelvic side-wall recurrences of cervical cancer biologically different from central relapses?

1994

Background. By using the Combined Operative and Radiotherapeutic Treatment (CORT) procedure, pelvic side-wall recurrences of gynecologic malignancies arising in a previously irradiated pelvis may be locally controlled. Local control of central relapses may be achieved by exenteration alone. If, in cervical cancer, both relapse patterns are biologically different (as hypothesized by some investigators), distinct disease courses after local treatment may be expected. Methods. Since June, 1989, 32 pelvic recurrences of cervical cancer were treated for local control in this institution. The median size of the recurrent tumors was 5 cm (range, 2–9 cm); 84% of the patients had been extensively ir…

Chemotherapy and Hepatic Steatosis: Impact on Postoperative Morbidity and Survival after Liver Resection for Colorectal Liver Metastases

2020

<b><i>Background:</i></b> Hepatic steatosis and chemotherapy in the treatment of colorectal liver metastases (CLM) are often linked to increased mortality and morbidity after liver resection. This study evaluates the influence of macrovesicular hepatic steatosis and chemotherapeutic regimes on graded morbidity and mortality after liver resection for CLM. <b><i>Methods:</i></b> A total of 323 cases of liver resection for CLM were retrospectively analysed using univariable and multivariable linear, ordinal and Cox regression analyses. The resected liver tissue was re-evaluated by a single observer to determine the grade and type of hepatic steat…

Identification of stiffness, dissipation and input parameters of multi degree of freedom civil systems under unmeasured base excitations

2009

A time domain dynamic identification technique based on a statistical moment approach has been formulated for civil systems under base random excitations in the linear state. This technique is based on the use of classically damped models characterized by a mass proportional damping. By applying the Itô stochastic calculus, special algebraic equations that depend on the statistical moments of the response can be obtained. These equations can be used for the dynamic identification of the mechanical parameters that define the structural model, in the case of unmeasured input as well, and the identification of the input itself. Furthermore, the above equations demonstrate the possibility of id…

Adaptive trial design: a general methodology for censored time to event data.

2008

Adaptive designs allow a clinical trial design to be changed according to interim findings without inflating type I error. The Inverse Normal method can be considered as an adaptive generalization of classical group sequential designs. The use of the Inverse Normal method for censored survival data was demonstrated only for the logrank statistic. However, the logrank statistic is inefficient in the presence of nuisance covariates affecting survival. We demonstrate, how the Inverse Normal method can be applied to Cox regression analysis. The required independence between test statistics of the different stages of the trial can be obtained by two different approaches. One is using the indepen…