58 research outputs found
Online Health Information Seeking and Adolescentsâ Intention Towards Health Self-Management
The widespread availability of healthcare websites has changed the traditional healthcare system by enabling patients to play an active role in health management. The emerging field of Health 2.0 has enabled both professionals and patients to engage in content generation; changing the traditionally accepted professional healthcare to a new dimension of patient-centric healthcare. With the easy access to health information online, patients are turning to the Internet to look up for symptoms, diagnose health problems, or determine treatment procedures. Anecdotal evidence suggests that individualsâ health management practices can be highly influenced by online health information. Considering the psychological characteristics of adolescents and their high exposure to the Internet, this study investigates the mechanisms of how online health information can motivate adolescentsâ behavioral intention towards self-management of their health issues. Our results showed that empowerment, attitude towards the website and privacy concerns significantly predict adolescentsâ health self-management behavior. Our findings also revealed that perceived health threat is not directly influencing the intention to self-managed health but instead interacts with other factors to influence intention. The findings provide important implications for theory and practice, by providing a better understanding of an emerging field of health care
Performance analysis of high-speed railway communication systems subjected to co-channel interference and channel estimation errors
The performance of high-speed railway wireless communication systems is studied in the presence of co-channel interference and imperfect channel estimation in the uplink. The authors derive exact closed-form expressions for the outage probability and investigate the impact of fading severity. New explicit expressions are derived for both the level crossing rate and average outage duration for illustrating the impact of mobile speed and channel estimation errors on the achievable system performance. Our results are generalised and hence they subsume a range of previously reported results
Thermo-Responsive Molecularly Imprinted Hydrogels for Selective Adsorption and Controlled Release of Phenol From Aqueous Solution
In this study, thermo-responsive molecularly imprinted hydrogels (T-MIHs) were developed as an effective potential adsorbent for selectively adsorption phenol from wastewater. During the process, N-isopropyl acrylamide (NIPAm) was used as thermal responsive monomer. The obtained materials were characterized in detail by fourier transform infrared (FT-IR) spectrometer, scanning electron microscope (SEM), and thermo gravimetric analysis (TGA). A series of static adsorption studies were performed to investigate the kinetics, specific adsorption equilibrium, and selective recognition ability of phenol. Reversible adsorption and release of phenol were realized by changing temperatures. Three type of phenols, namely 3-chlorophenols (3-CP), 2,4-dichlorophenol (2,4-DCP), and 2,4,6-trichlorophenol (2,4,6-TCP) were selected as model analytes to evaluate the selective recognition performance of T-MIHs. The T-MIHs have good selectivity, temperature response, and reusability, making them ideal in applying in the controlled separation and release of phenol pollutants
Investigation of MIMO Channel Characteristics in a Two-Section Tunnel at 1.4725âGHz
This paper presents results from a wide band single-inputâsingle-output (SISO) and 16 Ă 16 virtual multiple-inputâmultiple-output (MIMO) measurement campaign at a center frequency of 1.4725âGHz in a 100-meter long tunnel laboratory which is terminated by a vertical wall with a metallic door. The path loss, root-mean-square delay spread (RMS-DS) characteristics, and power delay profiles (PDPs) are described. In addition, we provide results for the MIMO channel amplitude matrix, which offers a new perspective in understanding MIMO characteristics in tunnel scenarios. Our measurement results are analyzed and compared to ray tracing simulations. The relationships among the angle spread, channel matrix singular values, and MIMO capacity at various link distances are illustrated, and these provide insights into MIMO system deployment
Intermittent left cervical vagal nerve stimulation damages the stellate ganglia and reduces the ventricular rate during sustained atrial fibrillation in ambulatory dogs
BACKGROUND:
The effects of intermittent open-loop vagal nerve stimulation (VNS) on the ventricular rate (VR) during atrial fibrillation (AF) remain unclear.
OBJECTIVE:
The purpose of this study was to test the hypothesis that VNS damages the stellate ganglion (SG) and improves VR control during persistent AF.
METHODS:
We performed left cervical VNS in ambulatory dogs while recording the left SG nerve activity (SGNA) and vagal nerve activity. Tyrosine hydroxylase (TH) staining and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining were used to assess neuronal cell death in the SG.
RESULTS:
We induced persistent AF by atrial pacing in 6 dogs, followed by intermittent VNS with short ON-time (14 seconds) and long OFF-time (66 seconds). The integrated SGNA and VR during AF were 4.84 mV·s (95% confidence interval [CI] 3.08-6.60 mV·s) and 142 beats/min (95% CI 116-168 beats/min), respectively. During AF, VNS reduced the integrated SGNA and VR, respectively, to 3.74 mV·s (95% CI 2.27-5.20 mV·s; P = .021) and 115 beats/min (95% CI 96-134 beats/min; P = .016) during 66-second OFF-time and to 4.07 mV·s (95% CI 2.42-5.72 mV·s; P = .037) and 114 beats/min (95% CI 83-146 beats/min; P = .039) during 3-minute OFF-time. VNS increased the frequencies of prolonged (>3 seconds) pauses during AF. TH staining showed large confluent areas of damage in the left SG, characterized by pyknotic nuclei, reduced TH staining, increased percentage of TH-negative ganglion cells, and positive TUNEL staining. Occasional TUNEL-positive ganglion cells were also observed in the right SG.
CONCLUSION:
VNS damaged the SG, leading to reduced SGNA and better rate control during persistent AF
SmallâConductance CalciumâActivated Potassium Current in Normal Rabbit Cardiac Purkinje Cells
Background: Purkinje cells (PCs) are important in cardiac arrhythmogenesis. Whether smallâconductance calciumâactivated potassium (SK) channels are present in PCs remains unclear. We tested the hypotheses that subtype 2 SK (SK2) channel proteins and apaminâsensitive SK currents are abundantly present in PCs. Methods and Results: We studied 25 normal rabbit ventricles, including 13 patchâclamp studies, 4 for Western blotting, and 8 for immunohistochemical staining. Transmembrane action potentials were recorded in currentâclamp mode using the perforatedâpatch technique. For PCs, the apamin (100 nmol/L) significantly prolonged action potential duration measured to 80% repolarization by an average of 10.4 ms (95% CI, 0.11â20.72) (n=9, P=0.047). Voltageâclamp study showed that apaminâsensitive SK current density was significantly larger in PCs compared with ventricular myocytes at potentials â„0 mV. Western blotting of SK2 expression showed that the SK2 protein expression in the midmyocardium was 58% (P=0.028) and the epicardium was 50% (P=0.018) of that in the pseudotendons. Immunostaining of SK2 protein showed that PCs stained stronger than ventricular myocytes. Confocal microscope study showed SK2 protein was distributed to the periphery of the PCs. Conclusions: SK2 proteins are more abundantly present in the PCs than in the ventricular myocytes of normal rabbit ventricles. Apaminâsensitive SK current is important in ventricular repolarization of normal PCs
Bandwidth Estimation for Admission Control in MANET: Review and Conceptual MANET Admission Control Framework
The widespread of wireless mobile network have increased the demand for its applications. Providing a reliable QoS in wireless medium, especially mobile ad-hoc network (MANET), is quite challenging and remains an ongoing research trend. One of the key issues of MANET is its inability to accurately predict the needed and available resources to avoid interference with already transmitting traffic flow. In this work, we propose a resource allocation and admission control (RAAC) solution. RAAC is an admission control scheme that estimates the available bandwidth needed within a network, using a robust and accurate resource estimation technique. Simulation results obtained show that our proposed scheme for MANET can efficiently estimate the available bandwidth and outperforms other existing approaches for admission control with bandwidth estimation
- âŠ