We evaluate the outage performance in a three-terminal full-duplex relay channel that adopts a selective decodeand-forward protocol, taking relay self-interference into account. Previous work focused on coverage extension scenarios where direct source-destination transmissions are neglected or considered as interference. In this work, we account for the relay self-interference, and exploit the cooperative diversity offered by the independently fading source/relay message replicas that arrive at the destination. We present an approximate, yet accurate, closed-form expression for the end-to-end outage probability that captures their joint effect. With the derived expression in hand, we propose a relay transmit power optimization scheme that only requires the relay knowledge of channel statistics. Finally, we corroborate our analysis with simulations. Index TermsFull-duplex relay, self interference, selective decode-and-forward, cooperative diversity, outage probability.

Background: Since the announcement of the World Health Organization of COVID-19 as a global pandemic, the probability of experiencing psychological disturbances and mental health problems among the frontline doctors who deal early with the suspected or confirmed patients is expected to increase, especially among anesthesia and ICU physicians. Objectives: The objective of this study was to assess the magnitude of mental stress among anesthesia and ICU physicians in Cairo university hospitals, Egypt, treating patients exposed to COVID-19. Methods: This cross-sectional, survey-based study collected the demographic and mental health data from anesthesia and ICU physicians working in Cairo university hospitals from March 15 to April 15, 2020, in Egypt. The level of stress was assessed by the perceived stress scale (PSS-10). Results: A total of 193 out of 315 contacted physicians completed the survey. A significant proportion of participants (65%) experienced high levels of psychological distress during this acute situation, with the PSS-10 median score of 21 in the registrar group and 18 in the consultant group; the difference was statistically significant (P = 0.03). The most common causes of stress among the participants were the fears that they might transmit the disease to their loved people and the lack of a clear protocol on how to deal with COVID-19 cases, either suspected or confirmed. Conclusions: In this survey study, anesthesia and ICU physicians responding to the spread of COVID-19 reported high rates of symptoms of mental stress.

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The therapeutic effect of the calcium antagonist; Nifedipine was assessed in 30 patients with pre-eclampsia. Cases were randomly allocated into two groups; a study group (n = 20) who received Nifedipine capsules (20 mg every 8 h for 7 days) and a control group (n = 10) who received placebo capsules with the same regimen. After Nifedipine administration, there was a significant decrease in blood pressure, serum urea and creatinine and 24 h urinary proteins. No significant difference was found in FHR and S/D ratio of the umbilical artery between study and control groups or between initial values and after Nifedipine administration. Preliminary results indicated that Nifedipine decreased blood pressure and improved kidney functions without affecting the umbilical artery blood flow in cases of pre-eclampsia.

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Space-Time Block Codes (STBCs) suffer from a prohibitively high decoding complexity unless the low-complexity decodability property is taken into consideration in the STBC design. For this purpose, several families of STBCs that involve a reduced decoding complexity have been proposed, notably the multi-group decodable and the fast decodable (FD) codes. Recently, a new family of codes that combines both of these families namely the fast group decodable (FGD) codes was proposed. In this paper, we propose a new construction scheme for rate-1 FGD codes for 2 a transmit antennas. The proposed scheme is then applied to the case of four transmit antennas and we show that the new rate-1 FGD code has the lowest worstcase decoding complexity among existing comparable STBCs. The coding gain of the new rate-1 code is optimized through constellation stretching and proved to be constant irrespective of the underlying QAM constellation prior to normalization. Next, we propose a new rate-2 FD STBC by multiplexing two of our rate-1 codes by the means of a unitary matrix. Also a compromise between rate and complexity is obtained through puncturing our rate-2 FD code giving rise to a new rate-3/2 FD code. The proposed codes are compared to existing codes in the literature and simulation results show that our rate-3/2 code has a lower average decoding complexity while our rate-2 code maintains its lower average decoding complexity in the low SNR region. If a time-out sphere decoder is employed, our proposed codes outperform existing codes at high SNR region thanks to their lower worst-case decoding complexity.