Highlights Among patients with severe or fatal coronavirus disease 2019 (COVID-19), the most prevalent comorbidities were obesity and hypertension, followed by diabetes, cardiovascular disease, respiratory disease, cerebrovascular disease, malignancy, chronic kidney disease, and liver disease. Comorbid respiratory disease was identified as the strongest risk factor for COVID-19 severity, followed by hypertension, cardiovascular disease, chronic kidney disease, cerebrovascular disease, malignancy, diabetes, and obesity. Subgroup analyses were conducted according to severe clinical outcomes and country of residence in the study population. Knowledge of these risk factors could help clinicians better identify and manage the high-risk populations.

We report a direct method to amplify the exponential growth of multilayers significantly by the alternating deposition of polyethylenimine (PEI) at high pH and poly(acrylic acid) (PAA) at low pH. The alternating pH switches the degree of ionization of the polyelectrolytes in the multilayers, which enhances the diffusion of PEI into and out of the film and hence increases the deposited mass per cycle. The synergetic action of the pH-tunable charge density and diffusivity of the weak polyelectrolytes provides a new method for the enhanced growth of multilayers with hierarchal micro- and nanostructured surfaces.

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Therapeutics used to treat central nervous system (CNS) injury are designed to promote axonal regeneration and inhibit cell death. Previous studies have shown that liraglutide exerts potent neuroprotective effects after brain injury. However, little is known if liraglutide treatment has neuroprotective effects after spinal cord injury (SCI). This study explores the neuroprotective effects of liraglutide and associated underlying mechanisms. Our results showed that liraglutide could improve recovery after injury by decreasing apoptosis as well as increasing microtubulin acetylation, and autophagy. Autophagy inhibition with 3-methyladenine (3-MA) partially reversed the preservation of spinal cord tissue and decreased microtubule acetylation and polymerization. Additionally, siRNA knockdown of GLP-1R suppressed autophagy and reversed mTOR inhibition induced by liraglutide in vitro, indicating that GLP-1R regulates autophagic flux. GLP-1R knockdown ameliorated the mTOR inhibition and autophagy induction seen with liraglutide treatment in PC12 cells under H 2 O 2 stimulation. Taken together, our study demonstrated that liraglutide could reduce apoptosis, improve functional recovery, and increase microtubule acetylation via autophagy stimulation after SCI. GLP-1R was associated with both the induction of autophagy and suppression of apoptosis in neuronal cultures.

A superhydrophobic/hydrophilic asymmetric free-standing film has been created using layer-bylayer assembly technique. Poly(ethylene-imine)-Ag + complex (PEI-Ag + ) at pH 9.0 was assembled with poly(acrylic acid) (PAA) at pH 3.2 on a Teflon substrate to yield a micro-nanostructured surface that can be turned to be superhydrophobic after being coated with a low surface energy compound. Silver nanoparticle loaded free-standing film with one surface being superhydrophobic while the other surface is hydrophilic was then obtained after detachment from the substrate. The superhydrophobicity enabled the upper surface with anti adhesion and self-cleaning properties and the hydrophilic bottom surface can release silver ions as antibiotic agent. The broad-spectrum antimicrobial capability of silver ions released from the bottom surface coupled with superhydrophobic barrier protection of the upper surface may make the free-standing film a new therapy for open wound.

Black TiO2 nanobelts/g-C3N4 nanosheets laminated heterojunctions (b-TiO2/g-C3N4) as visible-light-driven photocatalysts are fabricated through a simple hydrothermal-calcination process and an in-situ solid-state chemical reduction approach, followed by the mild thermal treatment (350 °C) in argon atmosphere. The prepared samples are evidently investigated by X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, N2 adsorption, and UV-visible diffuse reflectance spectroscopy, respectively. The results show that special laminated heterojunctions are formed between black TiO2 nanobelts and g-C3N4 nanosheets, which favor the separation of photogenerated electron-hole pairs. Furthermore, the presence of Ti3+ and g-C3N4 greatly enhance the absorption of visible light. The resultant b-TiO2/g-C3N4 materials exhibit higher photocatalytic activity than that of g-C3N4, TiO2, b-TiO2 and TiO2/g-C3N4 for degradation of methyl orange (95%) and hydrogen evolution (555.8 μmol h−1 g−1) under visible light irradiation. The apparent reaction rate constant (k) of b-TiO2/g-C3N4 is ~9 times higher than that of pristine TiO2. Therefore, the high-efficient laminated heterojunction composites will have potential applications in fields of environment and energy.

In this study, we investigate the growth and internal properties of polyelectrolyte multilayer films made of poly(l-lysine) and hyaluronan (PLL/HA) under pH-amplified conditions, that is, by alternate deposition of PLL at high pH and HA at low pH. We focus especially on the influence of the molecular weight of HA in this process as well as on its concentration in solution. Film growth was followed by quartz crystal microbalance and by infrared spectroscopy to quantify the deposited mass and to characterize the internal properties of the films, including the presence of hydrogen bonds and the ionization degree of HA in the films. Film growth was significantly faster for HA of high molecular weight (1300 kDa) as compared with 400 and 200 kDa. PLL was found to exhibit a random structure once deposited in the films. Furthermore, we found that PLL-ending films are more stable when they are placed in PBS than their HA counterparts. This was explained on the basis of more cohesive interactions in the films for PLL-ending films. Finally, we quantified PLL(FITC) diffusion into the films and observed that PLL diffusion is enhanced when PLL is paired with the HA of high MW. All together, these results suggest that besides purely physicochemical parameters such as variation in pH, the molecular weight of HA, its concentration in solution, and the possibility to form intermolecular HA association play important roles in film growth, internal cohesion, and stability.

Superhydrophobic surfaces with high reflectivity might provide a promising self-cleaning approach in a wide variety of optical applications ranging from traffic to solar energy industries. However, the contradiction between the hierarchical micronanostructure and the high reflectivity is a challenge for superhydrophobic materials with high reflectivity. Here we report a facile method to fabricate a superhydrophobic silver film with reflectivity as high as that of polished silicon by carefully controlling the seed-induced silver mirror reaction.