41 research outputs found
Preparation and characterization of flexible polyvinylchloride-copper composite films
Flexible PVC films are statically charged due to their low electrical conductivity. This creates fire threat during its handling. Conductive materials are added to films to prevent this. In the present study it was aimed to prepare PVC- copper composite films by sol gel technique and characterize the prepared films. It was aimed to increase the electrical conductivity of the films by adding copper powder. However, the copper particles settled down to bottom instead of forming a conductive network that covers the whole cross section. Thus at the film crosssection a plastic upper phase and a copper rich lower phase were present. The film did not conduct electricity due to this uneven distribution. The minimum volumetric and surface resistivities of the films were at the order of 109 ohm-cm and 1010 ohm square respectively
Aortic valve sclerosis is a sign of increased arterial stiffness in clinically asymptomatic subjects
Background: Classic risk scores may under estimate the risk of cardiovascular (CV) events in specific risk groups requiring appropriate medical and interventional treatment. Arterialstiffness has been known as a sign of CV risk and has a predictive value for CV events beyond classic CV risk factors. The purpose of this study was to investigate the relation between thecardio-ankle vascular index (CAVI) that has been recently reported as a new surrogate marker of arterial stiffness and aortic valve sclerosis (AVS).Methods: Eighty patients with AVS and 80 control subjects were enrolled to the study. Arterial stiffness was evaluated by VaSera-1000 CAVI instrument and AVS was defined by echocardiography as thickening and calcification of the normal trileaflet aortic valve without obstruction to the left ventricular outflow.Results: CAVI was significantly higher in patients with AVS compared to the control subjects (10.5 ± 2.7 vs. 8.6 ± 1.4, p < 0.001). Higher frequency of AVS was detected in patients with abnormal than borderline and normal CAVI values (69% vs. 27% and 20%, respectively, p < 0.001). In univariate analysis, there was a significant association between AVS and CAVI (95% confidence interval [CI] 1.44–2.48, p < 0.001]. Multivariate analysis demonstrated CAVI (95% CI 1.39–2.44, p < 0.001) as an independent determinant of AVS.Conclusions: Detection of increased arterial stiffness could prevent patients from being mistakenly classified as at low or moderate risk, when they actually are at high risk. Assessment of aortic valve during echocardiography examination may offer the opportunity to identify these subjects
HSV Infection Induces Production of ROS, which Potentiate Signaling from Pattern Recognition Receptors: Role for S-glutathionylation of TRAF3 and 6
The innate immune response constitutes the first line of defense against infections. Pattern recognition receptors recognize pathogen structures and trigger intracellular signaling pathways leading to cytokine and chemokine expression. Reactive oxygen species (ROS) are emerging as an important regulator of some of these pathways. ROS directly interact with signaling components or induce other post-translational modifications such as S-glutathionylation, thereby altering target function. Applying live microscopy, we have demonstrated that herpes simplex virus (HSV) infection induces early production of ROS that are required for the activation of NF-κB and IRF-3 pathways and the production of type I IFNs and ISGs. All the known receptors involved in the recognition of HSV were shown to be dependent on the cellular redox levels for successful signaling. In addition, we provide biochemical evidence suggesting S-glutathionylation of TRAF family proteins to be important. In particular, by performing mutational studies we show that S-glutathionylation of a conserved cysteine residue of TRAF3 and TRAF6 is important for ROS-dependent activation of innate immune pathways. In conclusion, these findings demonstrate that ROS are essential for effective activation of signaling pathways leading to a successful innate immune response against HSV infection
Pope Benedict XVI’s visit to Turkey as a global media event: A “frame shift ” in media coverages
Pope Benedict XVI’s visit to Turkey as a global media event: A “frame shift” in media coverages This study investigates Pope Benedict’s visit to Turkey as a global media event. The presentation includes the interaction between the global and the local in mass communication studies. The argument is that this visit makes visible some contradictions such as: East/West, EU/Turkey, Christian/ Muslim, Catholic/Orthodox. Before this trip, it was presupposed that these contradictions and stereotypes reinforced by the media were to set the agenda; however, it did not happen to be the case. Instead, the existing frames had been replaced by the new ones, which was called a frame shift in news reporting. The discourse method is used to prove this hypothesis. Data were collected during the trip and the visual materials helped in building our theoretical perspective. The aim is to observe the handling of this media event by Western press. Within this perspective, our sample had been formed by pioneering newspapers: Le Monde, Le Figaro, La Libération, The Guardian, The New York Times, Financial Times, Der Spiegel, BBC on-line and Time magazine.Pope Benedict XVI’s visit to Turkey as a global media event: A “frame shift” in media coverages This study investigates Pope Benedict’s visit to Turkey as a global media event. The presentation includes the interaction between the global and the local in mass communication studies. The argument is that this visit makes visible some contradictions such as: East/West, EU/Turkey, Christian/ Muslim, Catholic/Orthodox. Before this trip, it was presupposed that these contradictions and stereotypes reinforced by the media were to set the agenda; however, it did not happen to be the case. Instead, the existing frames had been replaced by the new ones, which was called a frame shift in news reporting. The discourse method is used to prove this hypothesis. Data were collected during the trip and the visual materials helped in building our theoretical perspective. The aim is to observe the handling of this media event by Western press. Within this perspective, our sample had been formed by pioneering newspapers: Le Monde, Le Figaro, La Libération, The Guardian, The New York Times, Financial Times, Der Spiegel, BBC on-line and Time magazine
The effects of subthreshold visual stimulation on P300 response
THE effects of the subthreshold visual stimuli on the electrical activity of the brain were investigated by an oddball-like paradigm and a single-stimulus paradigm. In the oddball-like paradigm, suprathreshold and subthreshold stimuli were presented randomly where the suprathreshold stimulus probability was 0.24. The single-stimulus paradigm contained only the suprathreshold stimuli and was identical to the oddball-like paradigm apart from the absence of subthreshold stimuli. Suprathreshold P3b amplitude was larger for the oddball-like than for the single-stimulus condition particularly in the centro-parietal region. This result suggests that at least one component of the P300 wave could be assigned to an automatic comparison and memory updating process which runs unconsciously
Factors affecting onset of puberty in Denizli province in Turkey
The relationship between the possible factors affecting pubertal onset and pubertal timing was investigated in the Denizli province in Turkey. A total number of 3311 subjects (1562 girls, 1749 boys) aged 6-16.5 years participated in this study. Body mass index (BMI) was calculated. Pubertal stages were assessed according to methods of Marshall and Tanner. Testicular volume was determined using Prader orchidometer. Menarcheal age was recorded. All parents and students completed different questionnaires on demographic variables affecting pubertal timing such as socioeconomic conditions, psychosocial factors, exercise, nutritional status, chronic diseases, migration and birth weight. Using distribution percentiles of pubertal stages according to age, the relation between pubertal timing and factors affecting puberty was investigated. There was no significant association between exercise, birth weight, migration, chronic disease, and socioeconomic status and age of puberty onset. Menarcheal age of overweight and obese girls was significantly lower than that of girls with normal weight. In-family stress was the cause of early puberty in girls and of delayed puberty in boys
A model for P300 generation based on responses to near-threshold visual stimuli
Near-threshold and suprathreshold visual ERPs and their frequency components were compared with the aim to obtain further information on the generation mechanism of the P300 wave. Decrease of the stimulus energy from suprathreshold to near-threshold level resulted in an increase of the P300 amplitude specifically in the occipital region. This finding was in contrast with the P300 amplitude decrease in central and frontal regions and its constancy in parietal area. Delta and theta responses showed a similar distribution pattern, whereas alpha responses decreased in all regions as the stimulus energy decreased. We conclude that P300 wave may correspond to a delta oscillation during a widespread, transient interruption of afferent inputs from subcortical structures to the cortical neurons including those in the visual sensory area and simultaneous increase of the cortico-cortical interactions. If visual inputs are of suprathreshold strength, they override this effect specifically in the primary visual area and disrupt the cortico-cortical interactions and the emergence of P300 in the occipital cortex. (C) 1999 Elsevier Science B.V. All rights reserved