72 research outputs found
HARD HANDOVER OPTIMIZATION USING TIME WINDOW BASED HANDOVER ALGORITHM
ABSTRACT This paper shows and solves a handover problem occurring with current power control mechanisms in cochannel Wideband Code Division Multiple Access (WCDMA) heterogeneous networks. The problem is the mismatch between the required uplink transmits power when a user is communicating to a small cell and an underlying microcellular base-station. This paper introduces Time Window Handover (TWHO) algorithm to adapt the transmit power of the small cell users during the handover regime to prevent such Signal to Interference plus Noise Ratio (SINR) drops
Preparation, characterization and antibacterial effects of eco-friendly gold nanorods
Purpose: To synthesize and characterize eco-friendly gold nanorods (Au-NRs) and to assess their effects against two bacterial strains.Methods: Synthesis of eco-friendly gold nanorods was done from an aqueous solution of chloroauric acid and cetyltrimethylammonium bromide by mixing Olea europaea fruit and Acacia nilotica husk extracts with the latter as a reducing agent. The synthesis was monitored by ultravioletâvisible (UV) spectrophotmetry and a zetasizer, while the morphology of the resulting nanorods was assessed by transmission electron microscopy (TEM) and scanning electron microscopy (SEM) coupled with an energy-dispersive spectrophotometer (EDS). The effect of the prepared eco-nanorods on growth of Escherichia coli and Staphylococcus aureus bacteria were investigated by agar diffusion method.Results: The synthesized Au-NRs were mostly rod-shaped, with mean size of 96 nm. They exhibited a potent antibacterial activity against Gram-positive and Gram-negative microorganisms (Escherichia coli and Staphylococcus aureus).Conclusion: The findings suggest that the nanoformulation of the biomaterial mix of Olea europaea fruit and Acacia nilotica husk extracts is a cost-effective, eco-friendly, and non-toxic synthesis of Au- NRs which has therpeautic potential.Keywords: Olea europaea, Acacia nilotica, Gold nanorods, Eco-friendly synthesis, Gram-positive and Gram-negative microorganism
Diagnostic Impact of Repeated Expert Review & LongâTerm FollowâUp in Determining Etiology of Idiopathic Cardiac Arrest
Background: Recognizing the etiology of sudden cardiac arrest (SCA) has an enormous impact on the management of victims and their immediate families. A significant proportion of SCA survivors with a structurally normal heart are not offered a diagnosis and there is no clear consensus on the type and duration of followâup. We aimed to assess the utility of a multidisciplinary approach in optimizing diagnosis of cardiac arrest etiology during followâup. Methods and Results: We retrospectively assessed 327 consecutive SCA survivors (mean age 61.9±16.2 years, 80% men) who underwent secondary prevention implantable cardioverter defibrillators between May 2015 and November 2018. The initial diagnosis was recorded at the time of admission and followâup diagnosis was deduced from subsequent clinic records, investigations, and outcomes of multidisciplinary team meetings. Structural heart disease accounted for 282 (86%) of SCAs. Fortyâfive (14%) patients had a structurally normal heart and underwent comprehensive testing and followâup (mean duration 93±52 weeks). On initial evaluation, 14/45 (31%) of these received a diagnosis, rising to 29/45 (64%) with serial reviews during followâup. Discussion in multidisciplinary team meetings and imaging reassessment accounted for 47% of new diagnoses. No additional diagnoses were made beyond 96 weeks. Nineteen (5.8%) fatalities occurred in the entire cohort, exclusively in patients with structural heart disease. Conclusions: Systematic comprehensive testing combined with multidisciplinary expert team review of SCA survivors without structural heart disease improves the yield and time to diagnosis compared with previously published studies. This approach has positive implications in the management of SCA survivors and their families
Cooperative Sensing Approach in Cognitive Radio Network-A Review Paper
ABSTRACT: Radio Spectrum is considered as a base line in Wireless communication network, due to its important role as a transmission medium; and according to the rapid improvement in the technologies which deal with radio spectrum; cognitive radio raised as a promising solution for solving the problem of radio spectrum scarcity. Cognitive radio is based on spectrum sensing as appropriate tool to study surrounding environment in order to illustrate the suitable scenario for sharing spectrum between users. Cooperative sensing is the most sophisticated approach in spectrum sensing depends on base of sharing information to eliminate error in spectrum sensing mechanism. This paper is a review paper. It discusses Cooperative sensing approach features in cognitive radio
Anterior T-Wave Inversion in Young White Athletes and Nonathletes: Prevalance and Significance
BACKGROUND: Anterior T-wave inversion (ATWI) on electrocardiography (ECG) in young white adults raises the possibility of cardiomyopathy, specifically arrhythmogenic right ventricular cardiomyopathy (ARVC). Whereas the 2010 European consensus recommendations for ECG interpretation in young athletes state that ATWI beyond lead V1 warrants further investigation, the prevalence and significance of ATWI have never been reported in a large population of asymptomatic whites. OBJECTIVES: This study investigated the prevalence and significance of ATWI in a large cohort of young, white adults including athletes. METHODS: Individuals 16 to 35 years of age (n = 14,646), including 4,720 females (32%) and 2,958 athletes (20%), were evaluated by using a health questionnaire, physical examination, and 12-lead ECG. ATWI was defined as T-wave inversion in â„2 contiguous anterior leads (V1 to V4). RESULTS: ATWI was detected in 338 individuals (2.3%) and was more common in women than in men (4.3% vs. 1.4%, respectively; p < 0.0001) and more common among athletes than in nonathletes (3.5% vs. 2.0%, respectively; p < 0.0001). T-wave inversion was predominantly confined to leads V1 to V2 (77%). Only 1.2% of women and 0.2% of men exhibited ATWI beyond V2. No one with ATWI fulfilled diagnostic criteria for ARVC after further evaluation. During a mean follow-up of 23.1 ± 12.2 months none of the individuals with ATWI experienced an adverse event. CONCLUSIONS: ATWI confined to leads V1 to V2 is a normal variant or physiological phenomenon in asymptomatic white individuals without a relevant family history. ATWI beyond V2 is rare, particularly in men, and may warrant investigation
Histopathological Features of Methotrexate Induced Pulmonary Lesions in Rheumatoid Arthritis Patients: A Systematic Review of Case Reports
BACKGROUND: Methotrexate (MTX) is the most commonly used disease-modifying drug in the treatment of rheumatoid arthritis (RA); however, it causes many side effects, including pulmonary lesions. In this review, we characterised the histopathological features of MTX-induced pulmonary lesions in RA patients.AIM: We carried out an electronic search of the relevant literature published during the period from 1990 to 2016. We included only the cases with definitive histo-pathological findings caused by MTX therapy.MATERIAL AND METHODS: The total number of cases is 27. Male: female ratio was 1:3, and ages ranged from 48 to 87 years old, with a mean (SD) = 65.7 (1.0). The cases were originally from Asia (55%), Europe (41%), and America (4%). The major complications of methotrexate therapy were lymphoproliferative disorders (42%) followed by interstitial fibrosis (33), and infections (25%). The incidence of these complications significantly increases with the duration of MTX treatment (p = 0.044). Among the infections, the most common causative organism was pneumocystis jiroveci. The majority of patients who developed infections following methotrexate therapy were from Europe whereas the majority of those who developed lymphoproliferative disorders were from Asia (p = 0.003).CONCLUSION: In conclusion, methotrexate therapy in rheumatoid arthritis patients causes different types pulmonary complications
Abnormal ECG Findings in Athletes: Clinical Evaluation and Considerations.
PURPOSE OF REVIEW: Pre-participation cardiovascular evaluation with electrocardiography is normal practice for most sporting bodies. Awareness about sudden cardiac death in athletes and recognizing how screening can help identify vulnerable athletes have empowered different sporting disciplines to invest in the wellbeing of their athletes. RECENT FINDINGS: Discerning physiological electrical alterations due to athletic training from those representing cardiac pathology may be challenging. The mode of investigation of affected athletes is dependent on the electrical anomaly and the disease(s) in question. This review will highlight specific pathological ECG patterns that warrant assessment and surveillance, together with an in-depth review of the recommended algorithm for evaluation
Green Synthesis, Characterization, and Antibacterial Activity of Silver/Polystyrene Nanocomposite
A novel, nontoxic, simple, cost-effective and ecofriendly technique was used to synthesize green silver nanoparticles (AgNPs). The AgNPs were synthesized using orange peel extract as a reducing agent for silver nitrate salt (AgNO3). The particle size distribution of AgNPs was determined by Dynamic Light Scattering (DLS). The average size of silver nanoparticles was 98.43ânm. The stable dispersion of silver nanoparticles was added slowly to polystyrene solution in toluene maintaining the temperature at 70°C. The AgNPs/polystyrene (PS) nanocomposite solution was cast in a petri dish. The silver nanoparticles encapsulated within polymer chains were characterized by X-ray diffraction (XRD) and Scanning Electron Microscopy (SEM) equipped with Energy Dispersive Spectroscopy (EDS) in addition to Transmission Electron Microscopy (TEM). The green AgNPs/PS nanocomposite film exhibited antimicrobial activity against Gram-negative bacteria Escherichia coli, Klebsiella pneumoniae and Salmonella, and Gram-positive bacteria Staphylococcus aureus. Thus, the key findings of the work include the use of a safe and simple AgNPs/PS nanocomposite which had a marked antibacterial activity which has a potential application in food packaging
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