Search results

Filter

Filetype

Your search for "*" yielded 533514 hits

Chemiluminescence of 1,2-dioxetane. Reaction mechanism uncovered

The thermal decomposition of 1,2-dioxetane and the associated production of chemiluminescent products, model for a wide range of chemiluminescent reactions, has been studied at the multistate multiconfigurational second-order perturbation level of theory. This study is in qualitative and quantitative agreement with experimental observations with respect to the activation energy and the observed in

Epicardial right atrial free wall mapping in chronic atrial fibrillation. Documentation of repetitive activation with a focal spread--a hitherto unrecognised phenomenon in man

BACKGROUND: Previous studies have shown that atrial fibrillation of recent onset in man is based on a varying number of simultaneously present activation waves reentering either themselves or each other. In the present study, right atrial activation during chronic atrial fibrillation in man was studied. METHODS AND RESULTS: In 16 patients with chronic atrial fibrillation multiple epicardial record

Prediction from a random time point

In prediction (Wiener-, Kalman-) of a random normal process $\{X(t), t \in R\}$ it is normally required that the time $t_0$ from which prediction is made does not depend on the values of the process. If prediction is made only from time points at which the process takes a certain value $u,$ given a priori, ("prediction under panic"), the Wiener-prediction is not necessarily optimal; optimal should

Maternal drug use in early pregnancy and infant cardiovascular defect

The purpose of the paper is to identify maternal drug use that may be associated with an increased risk for cardiac defects in the offspring. A case-control study was performed with cases (cardiovascular defects without known chromosome anomalies) being identified from three Swedish health registers (n = 5015) and controls being all infants born in Sweden during the period 1 July 1995-2001 (n = 57

Ultrasonic Methods for 2D Arterial Wall Movement Measurements

Popular Abstract in Swedish Hjärt- och kärlsjukdomar är den största enskilda orsaken till en för tidig död i västvärlden. För att öka kunskapen om dessa sjukdomar är det viktigt att finna mätmetoder, gärna icke-invasiva, som kan användas för att studera tidiga yttringar av hjärt- och kärlsjukdomar. Förändringar av de mekaniska egenskaperna i artärerna kan vara en sådan tidig yttring. För att få etCardiovascular diseases constitute the major cause of morbidity and mortality in the Western World. To increase our knowledge of cardiovascular diseases, it is important to find methods, preferably non-invasive ones, to study very early manifestations of vascular disease. Changes in the mechanical properties of the arteries can be an early manifestation of vascular disease. Further, changes in the

Exception Handling in Recipe-Based Batch Control

The focus of this thesis is exception handling in recipe-based batch control. Exception handling is a critical element for achieving long-term success in batch production. It is reported to constitute 40-60 percent of the batch control design and implementation effort. Correct handling of exceptions is a key element in process safety, consistent product quality, and production cost minimization. T

Assessing the carbon balance of circumpolar Arctic tundra using remote sensing and process modeling

This paper reviews the current status of using remote sensing and process-based modeling approaches to assess the contemporary and future circumpolar carbon balance of Arctic tundra, including the exchange of both carbon dioxide and methane with the atmosphere. Analyses based on remote sensing approaches that use a 20-year data record of satellite data indicate that tundra is greening in the Arcti

Burden of illness, metabolic control, and complications in relation to depressive symptoms in IDDM patients

Relationships between demographic-, treatment-, and sickness-related factors, metabolic control (HbA1c), perceived burden of illness, and degree of depressive symptoms were examined in a group of 155 insulin-dependent diabetic patients, aged 35.3 +/- 8.9 years. The patients completed a questionnaire measuring depressive symptoms and three aspects of perceived burden of illness. No gender differenc

Preventive home visits to older people in southern Sweden

Background: It seems urgent to further develop and modify models of preventive measures in order to prolong a healthy functional and social situation for older people, as this population is increasing globally. The aim of the study was to describe a Swedish model of preventive home visits for persons aged 78 years with the focus on the effect on physical and social well-being, and the participants

Tissue expansion 1984-1999: A 15-year review.

We assessed all patients who underwent tissue expansion, excluding breast reconstructions, between 1984 and 1999. A total of 237 patients had 257 expansions, normally for distorted scars, 202 of 257 cases (79%). Their mean age was 27 (range 7- 67) years, most being women, 149 of 237 (63%). The mean duration of expansion was 16 weeks (range 0.4-118). The most common site was the skull (61/257). Pro

Using an Observer to Transform Linear Systems into Strictly Positive Real Systems

In this note, we study the extension of the class of linear time invariant plants that may be transformed into SPR systems introducing an observer. It is shown that for open loop stable systems a cascaded observer achieves the result. For open loop unstable systems an observer-based feedback is required to succeed. In general any stabilizable and observable system may be transformed into an SPR sy