An overview of key technologies in physical layer security

Abstract The open nature of radio propagation enables ubiquitous wireless communication. This allows for seamless data transmission. However, unauthorized users may pose a threat to the security of the data being transmitted to authorized users. This gives rise to network vulnerabilities such as hacking, eavesdropping, and jamming of the transmitted information. Physical layer security (PLS) has been identified as one of the promising security approaches to safeguard the transmission from eavesdroppers in a wireless network. It is an alternative to the computationally demanding and complex cryptographic algorithms and techniques. PLS has continually received exponential research interest owing to the possibility of exploiting the characteristics of the wireless channel. One of the main characteristics includes the random nature of the transmission channel. The aforesaid nature makes it possible for confidential and authentic signal transmission between the sender and the receiver in the physical layer. We start by introducing the basic theories of PLS, including the wiretap channel, information-theoretic security, and a brief discussion of the cryptography security technique. Furthermore, an overview of multiple-input multiple-output (MIMO) communication is provided. The main focus of our review is based on the existing key-less PLS optimization techniques, their limitations, and challenges. The paper also looks into the promising key research areas in addressing these shortfalls. Lastly, a comprehensive overview of some of the recent PLS research in 5G and 6G technologies of wireless communication networks is provided

Correlates of fear of hypoglycemia among patients with type 1 and 2 diabetes mellitus in outpatient hospitals in Zambia

Background: Severe hypoglycemia is a burdensome complication of diabetes mellitus that can induce fear of hypoglycemia and contribute to suboptimal glycemic control. The challenge is to achieve and maintain adequate glycemic control while avoiding episodes of severe hypoglycemia. The purpose of the study was to determine how common fear of hypoglycemia was in Zambian out-patients with diabetes and also to explore correlates of fear of hypoglycemia. Methods: One hundred fifty-seven individuals with types 1 and 2 diabetes participated in the study. Fear of Hypoglycemia Scale, Diabetes Self-Care Inventory, Problem Areas in Diabetes, and the Major Depression Inventory were completed. Multiple linear regression models were computed to assess the association between fear of hypoglycemia and psychological factors. Results: About 19% [16.3% type 1 and 12.6% type 2] of individuals with diabetes based on item endorsement expressed fear of hypoglycemia especially among individuals with type 1 diabetes. After controlling for demographic variables, diabetes self-care (ß = 0.24, p \u3c 0.05), and diabetes specific distress (ß = 0.41, p \u3c 0.001) were associated with fear of hypoglycemia. Conclusion: Fear of hypoglycemia was common and was positively associated with diabetes specific emotional distress and diabetes self-care. Interventions to avert fear of hypoglycemia are needed while optimizing glycemic control through managing diabetes care and emotion distress in individuals with diabetes

Tocilizumab for patients with COVID-19 pneumonia. The single-arm TOCIVID-19 prospective trial

BackgroundTocilizumab blocks pro-inflammatory activity of interleukin-6 (IL-6), involved in pathogenesis of pneumonia the most frequent cause of death in COVID-19 patients.MethodsA multicenter, single-arm, hypothesis-driven trial was planned, according to a phase 2 design, to study the effect of tocilizumab on lethality rates at 14 and 30 days (co-primary endpoints, a priori expected rates being 20 and 35%, respectively). A further prospective cohort of patients, consecutively enrolled after the first cohort was accomplished, was used as a secondary validation dataset. The two cohorts were evaluated jointly in an exploratory multivariable logistic regression model to assess prognostic variables on survival.ResultsIn the primary intention-to-treat (ITT) phase 2 population, 180/301 (59.8%) subjects received tocilizumab, and 67 deaths were observed overall. Lethality rates were equal to 18.4% (97.5% CI: 13.6-24.0, P=0.52) and 22.4% (97.5% CI: 17.2-28.3, P<0.001) at 14 and 30 days, respectively. Lethality rates were lower in the validation dataset, that included 920 patients. No signal of specific drug toxicity was reported. In the exploratory multivariable logistic regression analysis, older age and lower PaO2/FiO2 ratio negatively affected survival, while the concurrent use of steroids was associated with greater survival. A statistically significant interaction was found between tocilizumab and respiratory support, suggesting that tocilizumab might be more effective in patients not requiring mechanical respiratory support at baseline.ConclusionsTocilizumab reduced lethality rate at 30 days compared with null hypothesis, without significant toxicity. Possibly, this effect could be limited to patients not requiring mechanical respiratory support at baseline.Registration EudraCT (2020-001110-38); clinicaltrials.gov (NCT04317092)

Correction to: Tocilizumab for patients with COVID-19 pneumonia. The single-arm TOCIVID-19 prospective trial (Journal of Translational Medicine, (2020), 18, 1, (405), 10.1186/s12967-020-02573-9)

Following publication of the original article [1] the authors identified that the collaborators of the TOCIVID-19 investigators, Italy were only available in the supplementary file. The original article has been updated so that the collaborators are correctly acknowledged. For clarity, all collaborators are listed in this correction article