Several studies reported the accompaniment of severe COVID-19 with comorbidities. However, there is not a systematic evaluation of all aspects of this association. Therefore, this meta-analysis aimed to assess the association between all underlying comorbidities in COVID-19 infection severity. Electronic literature search was performed via scientific search engines. After the removal of duplicates and selection of articles of interest, 28 studies were included. A fixed-effects model was used; however, if heterogeneity was high (I2 > 50%) a random-effects model was applied to combine the data. A total of 6,270 individuals were assessed (1,615 severe and 4,655 non-severe patients). The median age was 63 (95% confidence interval [CI] 49-74) and 47 (95% CI 19-63) years in the severe and non-severe groups, respectively. Moreover, about 41% of patients had comorbidities. Severity was higher in patients with a history of cerebrovascular disease OR 4.85 (95% CI 3.11-7.57). The odds of being in a severe group increase by 4.81 (95% CI 3.43-6.74) for a history of cardiovascular disease (CVD). This was 4.19 (95% CI 2.84-6.19) for chronic lung disease and 3.18, 95% CI 2.09-4.82 for cancer. The odds ratios of diabetes and hypertension were 2.61 (95% CI 2.02-3.3) and 2.37 (95% CI 1.80-3.13), respectively. The presence of comorbidities is associated with severity of COVID-19 infection. see more The strongest association was observed for cerebrovascular disease, followed by CVD, chronic lung disease, cancer, diabetes, and hypertension.The presence of comorbidities is associated with severity of COVID-19 infection. The strongest association was observed for cerebrovascular disease, followed by CVD, chronic lung disease, cancer, diabetes, and hypertension.The determination of intrinsic Gilbert damping is one of the central interests in the field of spintronics. However, some external factors in magnetic films tend to play a remarkable role in the magnetization dynamics. Here, we present a comprehensive study of the magnetic relaxation in ferromagnetic films with various in-plane magnetic anisotropy via ferromagnetic resonance technique. We find that the magnetic drag effect can result in the resonant linewidth broadening and the nonlinear dependence of linewidth on frequency stemming from field-magnetization misalignment. As a result, this could lead to the imprecise extraction of the key dynamic parameter-Gilbert damping and cause the confusing behaviors of ultra-low and anisotropic damping in thin films and multi-layers with high magnetic anisotropy. Our results provide a crucial way for the accurately quantitative estimation of the Gilbert damping in spintronics measurements.Exploring new two-dimensional (2D) materials is of great significance for both basic research and practical applications. Although boron can form various 3D and 2D allotropes due to its ease of forming multi-center bonds, the coexistence of honeycomb and kagome boron structures has never been observed in any 2D material yet. In this article we apply first-principle swarm structural searches to predict the existence of a stable MnB5structure, consisting of a sandwich of honeycomb and kagome borophenes. More interestingly, a MnB5nanosheet is a semiconductor with a band gap of 1.07 eV and a high optical absorption in a broad band, which satisfies the requirements of a very good photovoltaic material. Upon moderate strain, MnB5undergoes a conversion from an indirect to a direct band gap semiconductor. The power conversion efficiency of a heterostructure solar cell made of MnB5is up to 18%. The MnB5nanosheet shows a robust dynamical and thermal stability, stemming from the presence of intra- and interlayer multi-center σ and π bonds. These characteristics make MnB5a promising photovoltaic material.We demonstrate a gate-tunable quantum dot (QD) located between two potential barriers defined in a few-layer MoS2. Although both local gates used to tune the potential barriers have disorder-induced QDs, we observe diagonal current stripes in current resonant islands formed by the alignment of the Fermi levels of the electrodes and the energy levels of the disorder-induced QDs, as evidence of the gate-tunable QD. We demonstrate that the charging energy of the designed QD can be tuned in the range of 2-6 meV by changing the local-gate voltages in ∼1 V.In recent years, there has been an increasing interest in nanoelectromechanical devices, current-driven quantum machines, and the mechanical effects of electric currents on nanoscale conductors. Here, we carry out a thorough study of the current-induced forces and the electronic friction of systems whose electronic effective Hamiltonian can be described by an archetypal model, a single energy level coupled to two reservoirs. Our results can help better understand the general conditions that maximize the performance of different devices modeled as a quantum dot coupled to two electronic reservoirs. Additionally, they can be useful to rationalize the role of current-induced forces in the mechanical deformation of one-dimensional conductors.Due to the unique optical and electrochemical properties, large surface area, tunable properties, and high thermal stability, nanoporous anodic aluminum oxide (AAO) has become one of the most popular materials with a large potential to develop emerging applications in numerous areas, including biosensors, desalination, high-risk pollutants detection, capacitors, solar cell devices, photonic crystals, template-assisted fabrication of nanostructures, and so on. This review covers the mechanism of AAO formation, manufacturing technology, the relationship between the properties of AAO and fabrication conditions, and applications of AAO. Properties of AAO, like pore diameter, interpore distance, wall thickness, and anodized aluminum layer thickness, can be fully controlled by fabrication conditions, including electrolyte, applied voltage, anodizing and widening time. Generally speaking, the pore diameter of AAO will affect its specific application to a large extent. Moreover, manufacturing technology like one/two/multi step anodization, nanoimprint lithography anodization, and pulse/cyclic anodization also have a major impact on overall array arrangement.