Full-Duplex Systems Using Multi-Reconfigurable Antennas

Full-duplex systems are expected to achieve 100% rate improvement over half-duplex systems if the self-interference signal can be significantly mitigated. In this paper, we propose the first full-duplex system utilizing Multi-Reconfigurable Antenna (MRA) with ?90% rate improvement compared to half-duplex systems. MRA is a dynamically reconfigurable antenna structure, that is capable of changing its properties according to certain input configurations. A comprehensive experimental analysis is conducted to characterize the system performance in typical indoor environments. The experiments are performed using a fabricated MRA that has 4096 configurable radiation patterns. The achieved MRA-based passive self-interference suppression is investigated, with detailed analysis for the MRA training overhead. In addition, a heuristic-based approach is proposed to reduce the MRA training overhead. The results show that at 1% training overhead, a total of 95dB self-interference cancellation is achieved in typical indoor environments. The 95dB self-interference cancellation is experimentally shown to be sufficient for 90% full-duplex rate improvement compared to half-duplex systems.Comment: Submitted to IEEE Transactions on Wireless Communication

The Expected Role of Triage Nurse in Emergency Reception of a University Hospital, in Egypt

Triage is a system used by medical or emergency personnel to give care when the number of casualties needing care exceeds the resources available to perform care. It is designed to help those who can most benefit from the available care. The current study aimed to identify the expected role of the triage nurse at EL-Manial University Emergency Reception. A descriptive exploratory design used to achieve the aim of the present study. The study was carried out at EL-Manial University Emergency Reception. Convenient samples of (96) doctors and (34) staff nurses working at EL-Manial University Emergency Reception were included in the study. For the purpose of this study, the investigator developed an expected role of triage nurse questionnaire consisted of two parts as follow: The first part concerned with socio-demographic data and the second part concerned with expected role of triage nurse. Result of this study, the current study showed that there was significant difference between expected role of triage nurse and years of experience. The results concluded that there was a consensus about most activities of the expected role of triage nurse between nurses and medical groups. The study recommended that consider, revise and approve the proposed job description of triage nurse at Emergency department in El-Manial University Hospital: a) dissemination of the triage nurse job description and b) developed the proposed flyer containing information about triage nurse role, triage, and system and disseminated among emergency nurses. Keywords: Triage, Role expectation and Emergency Receptio

Toxico-histological Effects of Sublethal Concentrations of Lead Nitrate on the Gills of the African Catfish, Clarias gariepinus

170-175This study aimed to investigate the effects of subleathal lead doses on the histological architecture of gills in the freshwater African catfish, Clarias gariepinus. Results revealed three stages of changes after exposure to three doses of lead nitrate. The changes were mild in fish exposed to 16.12 mg/L of Pb (NO3)2 (stage I 20% of LC50) and severe in case of 40% of LC50 (stage II, 32.24 mg/L) and 60% of LC50 (stage III 48.37% mg/L) in comparison to control. The histological examination revealed normal architecture of gills in control fish. Normal gills were characterized with primary gill lamellae with a central hyaline cartilage. However, three-stage changes were observed after exposure to the three doses of lead nitrate. In stage I, a cartilaginous matrix appeared along with loosening of the epithelial lining of the cartilaginous core and abundant vascular spaces were observed on the secondary gill lamellae. An extra cartilaginous matrix, loosening of the epithelial lining of the cartilaginous core, de-shaped gill lamellae, and degeneration of the secondary gill lamellae were noted in stage II. Lesions in the gill pattern in stage III were represented by shortening of the tips of secondary gill lamellae, damaged gill lamellae, a cartilaginous matrix, and hyperplasia. This indicated that lead exposure resulted in severe histopathological changes in the gills in a dose-dependent manner

Activity and stability of immobilized Candida rugosa lipase on chitosan coated Fe3O4 nanoparticles in aqueous and organic media

Fe3O4 (magnetite) nanoparticles were prepared by coprecipitation method, coated by chitosan and functionalized by glutaraldehyde. Lipase enzyme from Candida rugosa was immobilized on the prepared particles via cross linking reaction. Synthesis steps and characterization were examined by XRD, TEM, and FTIR.  The immobilization conditions were 10 mL of phosphate buffer (0.1 M, pH 6.5) containing 30 mg of  functionalized magnetic chitosan nanoparticles and 2.0 mg·mL-1 of lipase, immobilization temperature of 4 ℃ and immobilization time of 1 h. Under these conditions, lipase was successfully immobilized with loading capacity of 87 mg/g. The immobilized enzyme showed good operational and storage stability, where it remained stable after 30 days of storage at 4â—¦C.and retained about 61% of its initial activity after twenty repeated uses. Finally enzymatic catalyze synthesis of butyl and hexyl oleate at 40 â—¦C with shaking (200 rpm) was realized in n-hexane and confirmed by GC analysis

Evaluation of hepatitis B vaccine responsiveness in ‎hemodialysis and peritoneal dialysis patients

Background: Hepatitis B Virus (HBV) infection is considered as a major cause of liver ‎cirrhosis and hepatocellular carcinoma. Patients with End Stage Renal Disease (ESRD) are a risk group for HBV infection. The vaccine of hepatitis B has ‎been recommended for prevention of HBV infection in ESRD patient ‎especially on renal replacement therapy.  Methods: Eighty seven patients with ESRD on peritoneal ‎dialysis and hemodialysis requiring primary hepatitis B vaccination were ‎enrolled in the study. Each of them received 40 µg of recombinant hepatitis B ‎vaccine in a four-dose schedule. Antibody response was determined by the ‎levels of antibodies to the hepatitis B surface antigen (anti-HBs) after last ‎doses of the vaccination schedule.  Results: We observed three response patterns to the ‎immunizations in all patients after vaccination, the nonresponders (24.7%) ‎never reached the minimum protective titer of 10 mIU/mL, the poor responders (18.5%) had titers between 10 and 100 mIU/mL, and the good responders (56.8%) had antibody titers above 100 mIU/mL. Despite a reduction in anti-‎HBs over time, the good responders did not become unprotected during the ‎observation period, especially those participants who had titers above 1000 ‎mIU/mL after the initial immunization.  Conclusions: We concluded that the immune ‎response of the HBV vaccine was reduced in the HD and PD patients, which ‎need yearly re-evaluation of seroconversion with booster doses of HBV ‎vaccination if needed‎.

Immunological and Neurological Manifestations of COVID-19: An Intimate Relationship

Background: COVID-19 has superseded all medical scientific challenges in 2020. It presented with a range of respiratory involvement from the mild upper respiratory tract to severe pneumonia with ARDS. A percentage of these patients manifested variable neurological presentations expanding the challenges of patients’ assessment, care, and management. Objective: To discuss the neurological manifestations and the possible immunopathology of COVID-19. Methods: A literature search was performed in the PubMed database for the relevant articles published in English language between April 9th , 2020 and June 1, 2020. Few papers were extracted from Google Scholar and pre-print material as well. The keywords used to perform search included “COVID-19,” “SARS Cov2,” “neurological manifestations,” and “immunology and pathology of COVID-19”. However, animal studies were excluded in the neurological manifestations, and the final number of literature search outcome was 27 articles. Results: The immunopathology involves angiotensin-converting enzyme (ACE) receptor 2 and spike protein S1. COVID-19 has a tremendous affinity to the ACE2 receptor. The status of secondary hemophagocytic lymphohistiocytosis (sHLH) and the cytokine storm lead to different organ damage and the corresponding clinical manifestations. The documented neurological manifestations mainly include acute ischemic stroke, hemorrhagic stroke, temporal lobe, thalamic encephalitis, and one case of Guillain-Barre Syndrome, in addition to agitation, headache, and seizures. Conclusion: Although the intimate relationship between the neurons and the immune activation is the basic concept of COVID-19 immunopathology, the definite routes of entry to the neuronal cells are yet to be disclosed. Acute stroke, myositis, headache, and meningoencephalitis are the most common types of complications of COVID-19 so far

THE EFFECTS OF TEMPERATURE DEPENDENT VISCOSITY AND VISCOUS DISSIPATION ON MHD CONVECTION FLOW FROM AN ISOTHERMAL HORIZONTAL CIRCULAR CYLINDER IN THE PRESENCE OF STRESS WORK AND HEAT GENERATION

Temperature dependent viscosity and Viscous Dissipation effects are considered on hydromagnetic natural convection flow from horizontal circular cylinder immersed in an electrically conducting fluid with viscosity proportional to a linear function of temperature in the presence of stress work and heat generation. The partial differential governing equations are transformed to dimensionless forms. The numerical computations are carried out for several values of physical parameters involved in the transformed equations. The resulting nonlinear system of partial differential equations is solved numerically by Keller box method which is an implicit finite difference technique with Newton's linearization method. The features of the flow and heat transfer characteristics for different values of the governing parameters are analyzed and discussed. To support the accuracy of the numerical results, a comparison is made with known results from the open literature for some particular cases of the present study and the results are found to be in good agreement