COVID-19 passenger screening to reduce travel risk and translocation of disease.

Aviation passenger screening has been used worldwide to mitigate the translocation risk of SARS-CoV-2. We present a model that evaluates factors in screening strategies used in air travel and assess their relative sensitivity and importance in identifying infectious passengers. We use adapted Monte Carlo simulations to produce hypothetical disease timelines for the Omicron variant of SARS-CoV-2 for travelling passengers. Screening strategy factors assessed include having one or two RT-PCR and/or antigen tests prior to departure and/or post-arrival, and quarantine length and compliance upon arrival. One or more post-arrival tests and high quarantine compliance were the most important factors in reducing pathogen translocation. Screening that combines quarantine and post-arrival testing can shorten the length of quarantine for travelers, and variability and mean testing sensitivity in post-arrival RT-PCR and antigen tests decrease and increase with the greater time between the first and second post-arrival test, respectively. This study provides insight into the role various screening strategy factors have in preventing the translocation of infectious diseases and a flexible framework adaptable to other existing or emerging diseases. Such findings may help in public health policy and decision-making in present and future evidence-based practices for passenger screening and pandemic preparedness.

Additive manufacturing of eco-friendly building insulation materials by recycling pulp and paper.

Thermal insulation materials by recycling pulp and paper wastes play an important role in environmental sustainability of green buildings. As society is pursuing the goal of zero carbon emissions, it is highly desirable to use eco-friendly materials and manufacturing technologies for building insulation envelopes. Here we report additive manufacturing of flexible and hydrophobic insulation composites from recycled cellulose-based fibers and silica aerogel. The resultant cellulose-aerogel composites exhibit thermal conductivity of 34.68 mW m-1 K-1, mechanical flexibility with a flexural modulus of 429.21 MPa, and superhydrophobicity with water contact angle of 158.72°. Moreover, we present the additive manufacturing process of recycled cellulose aerogel composites, providing enormous potential for high energy efficiency and carbon-sequestration building applications.

Transparent thermal insulation ceramic aerogel materials for solar thermal conversion.

Thermal management in energy-efficient solar thermal energy conversion and transparent windows requires advanced materials with low thermal conductivity and high transparency, such as transparent silica aerogel materials. However, the large scatter domains in porous silica materials would deteriorate their optical transparency. Herein, we report transparent silica aerogels by controlling hydrolyzation and meanwhile silylation modification to enhance the integrity of the microstructure under ambient pressure drying. The transparent silica aerogel materials show a broad-spectrum transparency of 70% from 400 nm and 800 nm, showing promising applications in transparent windows and solar thermal energy conversion systems. The scalability for transparent windows could be achieved with a composite material by incorporating transparent polymeric materials. The solar receiver coupled with a transparent silica aerogel could reach 122 °C within 12 min at a solar irradiance of 1 Sun, ∼200% higher than that in the ambient atmosphere. The engineered structure of the transparent porous silica backbone provides a pathway for solar thermal systems and transparent window applications.

Associations of connectedness and parental behaviors with adolescent physical activity and mental health during COVID-19: A mediation analysis using the 2021 adolescent behaviors and experiences survey.

The purpose of this study was to examine the associations of connectedness and parental behaviors with adolescent physical activity (PA) and mental health during COVID-19. Participants were a representative sample of US high school students who completed the 2021 Adolescent Behaviors and Experiences Survey (ABES; N = 7705; 50.4% female). ABES was completed online during the spring of 2021 and data were analyzed during the spring of 2022. Independent variables were items asking about perceived school and virtual connectedness, parental emotional abuse, and parental monitoring. Latent variables represented both PA and mental health. Two weighted structural equation models tested the associations between connectedness, parental behaviors, and mental health mediated through PA (Model 1) and between connectedness, parental behaviors, and PA mediated through mental health (Model 2) with indirect effect confidence intervals obtained using Monte Carlo simulations. School connectedness directly associated with better mental health in Model 1 (ß = 0.17, p < 0.001) and with higher PA in Model 2 (ß = 0.19, p < 0.001) while virtual connectedness directly associated with higher PA in Model 2 (ß = 0.08, p < 0.001). Parental emotional abuse directly associated with poorer mental health in Model 1 (ß = -0.43, p < 0.001). Standardized indirect effects to better mental health mediated through higher PA were observed for school connectedness (IE = 0.017, p < 0.001) and virtual connectedness (IE = 0.007, p < 0.001) and indirect effects to lower PA mediated through poorer mental health were observed for parental emotional abuse (IE = -0.050, p < 0.001). Perceptions of school and virtual connectedness and parental emotional abuse both directly and indirectly impacted adolescent PA and mental health during the COVID-19 pandemic.

Manufacturing silica aerogel and cryogel through ambient pressure and freeze drying.

Achieving a mesoporous structure in superinsulation materials is pivotal for guaranteeing a harmonious relationship between low thermal conductivity, high porosity, and low density. Herein, we report silica-based cryogel and aerogel materials by implementing freeze-drying and ambient-pressure-drying processes respectively. The obtained freeze-dried cryogels yield thermal conductivity of 23 mW m-1 K-1, with specific surface area of 369.4 m2 g-1, and porosity of 96.7%, whereas ambient-pressure-dried aerogels exhibit thermal conductivity of 23.6 mW m-1 K-1, specific surface area of 473.8 m2 g-1, and porosity of 97.4%. In addition, the fiber-reinforced nanocomposites obtained via freeze-drying feature a low thermal conductivity (28.0 mW m-1 K-1) and high mechanical properties (∼620 kPa maximum compressive stress and Young's modulus of 715 kPa), coupled with advanced flame-retardant capabilities, while the composite materials from the ambient pressure drying process have thermal conductivity of 28.8 mW m-1 K-1, ∼200 kPa maximum compressive stress and Young's modulus of 612 kPa respectively. The aforementioned results highlight the capabilities of both drying processes for the development of thermal insulation materials for energy-efficient applications.

Surface Inactivation of Highly Mutated SARS-CoV-2 Variants of Concern: Alpha, Delta, and Omicron.

Continued SARS-CoV-2 transmission among the human population has meant the evolution of the virus to produce variants of increased infectiousness and virulence, coined variants of concern (VOCs). The last wave of pandemic infections was driven predominantly by the delta VOC, but because of continued transmission and adaptive mutations, the more highly transmissible omicron variant emerged and is now dominant. However, due to waning immunity and emergence of new variants, vaccines alone cannot control the pandemic. The application of an antiviral coating to high-touch surfaces and physical barriers such as masks are an effective means to inactivate the virus and their spread. Here, we demonstrate an environmentally friendly water-borne polymer coating that can completely inactivate SARS-CoV-2 independent of the infectious variant. The polymer was designed to target the highly glycosylated spike protein on the virion surface and inactivate the virion by disruption of the viral membrane through a nano-mechanical process. Our findings show that, even with low amounts of coating on the surface (1 g/m2), inactivation of alpha, delta, and omicron VOCs and degradation of their viral genome were complete. Furthermore, our data shows that the polymer induces little to no skin sensitization in mice and is non-toxic upon oral ingestion in rats. We anticipate that our transparent polymer coating can be applied to face masks and many other surfaces to capture and inactivate the virus, aiding in the reduction of SARS-CoV-2 transmission and evolution of new variants of concern.

Printing Air-Stable High-Tc Molecular Magnet with Tunable Magnetic Interaction.

High-Tc molecular magnets have amassed much promise; however, the long-standing obstacle for its practical applications is the inaccessibility of high-temperature molecular magnets showing dynamic and nonvolatile magnetization control. In addition, its functional durability is prone to degradation in oxygen and heat. Here, we introduce a rapid prototyping and stabilizing strategy for high Tc (360 K) molecular magnets with precise spatial control in geometry. The printed molecular magnets are thermally stable up to 400 K and air-stable for over 300 days, a significant improvement in its lifetime and durability. X-ray magnetic circular dichroism and computational modeling reveal the water ligands controlling magnetic exchange interaction of molecular magnets. The molecular magnets also show dynamical and reversible tunability of magnetic exchange interactions, enabling a colossal working temperature window of 86 K (from 258 to 344 K). This study provides a pathway to flexible, lightweight, and durable molecular magnetic devices through additive manufacturing.

Water-Borne Nanocoating for Rapid Inactivation of SARS-CoV-2 and Other Viruses.

The rise in coronavirus variants has resulted in surges of the disease across the globe. The mutations in the spike protein on the surface of the virion membrane not only allow for greater transmission but also raise concerns about vaccine effectiveness. Preventing the spread of SARS-CoV-2, its variants, and other viruses from person to person via airborne or surface transmission requires effective inactivation of the virus. Here, we report a water-borne spray-on coating for the complete inactivation of viral particles and degradation of their RNA. Our nanoworms efficiently bind and, through subsequent large nanoscale conformational changes, rupture the viral membrane and subsequently bind and degrade its RNA. Our coating completely inactivated SARS-CoV-2 (VIC01) and an evolved SARS-CoV-2 variant of concern (B.1.1.7 (alpha)), influenza A, and a surrogate capsid pseudovirus expressing the influenza A virus attachment glycoprotein, hemagglutinin. The polygalactose functionality on the nanoworms targets the conserved S2 subunit on the SARS-CoV-2 virion surface spike glycoprotein for stronger binding, and the additional attachment of guanidine groups catalyze the degradation of its RNA genome. Coating surgical masks with our nanoworms resulted in complete inactivation of VIC01 and B.1.1.7, providing a powerful control measure for SARS-CoV-2 and its variants. Inactivation was further observed for the influenza A and an AAV-HA capsid pseudovirus, providing broad viral inactivation when using the nanoworm system. The technology described here represents an environmentally friendly coating with a proposed nanomechanical mechanism for inactivation of both enveloped and capsid viruses. The functional nanoworms can be easily modified to target viruses in future pandemics, and is compatible with large scale manufacturing processes.

Laser-Induced Cooperative Transition in Molecular Electronic Crystal.

The competing and non-equilibrium phase transitions, involving dynamic tunability of cooperative electronic and magnetic states in strongly correlated materials, show great promise in quantum sensing and information technology. To date, the stabilization of transient states is still in the preliminary stage, particularly with respect to molecular electronic solids. Here, a dynamic and cooperative phase in potassium-7,7,8,8-tetracyanoquinodimethane (K-TCNQ) with the control of pulsed electromagnetic excitation is demonstrated. Simultaneous dynamic and coherent lattice perturbation with 8 ns pulsed laser (532 nm, 15 MW cm-2 , 10 Hz) in such a molecular electronic crystal initiates a stable long-lived (over 400 days) conducting paramagnetic state (≈42 Ωcm), showing the charge-spin bistability over a broad temperature range from 2 to 360 K. Comprehensive noise spectroscopy, in situ high-pressure measurements, electron spin resonance (ESR), theoretical model, and scanning tunneling microscopy/spectroscopy (STM/STS) studies provide further evidence that such a transition is cooperative, requiring a dedicated charge-spin-lattice decoupling to activate and subsequently stabilize nonequilibrium phase. The cooperativity triggered by ultrahigh-strain-rate (above 106 s- 1 ) pulsed excitation offers a collective control toward the generation and stabilization of strongly correlated electronic and magnetic orders in molecular electronic solids and offers unique electro-magnetic phases with technological promises.

Probability and estimated risk of SARS-CoV-2 transmission in the air travel system.

BACKGROUND: As an emerging virus, SARS-CoV-2 and the risk of transmission during air travel is of high interest. This paper is a retrospective estimate of the probability of an infectious passenger in the air travel system transmitting the SARS-CoV-2 virus to a fellow passenger. METHODS: Literature was reviewed from May-September 2020 to identify COVID-19 cases related to air travel. The studies were limited to publicly available literature for passengers; studies of flight crews were not reviewed. A novel quantitative approach was developed to estimate air travel transmission risk that considers secondary cases, the overall passenger population, and correction factors for asymptomatic transmission and underreporting. RESULTS: There were at least 2866 index infectious passengers documented to have passed through the air travel system in a 1.4 billion passenger population. Using correction factors, the global risk of transmission during air travel is estimated at 1:1.7 million; acknowledging that assumptions exist around case detection rate and mass screenings. Uncertainty in the correction factors and a 95% credible interval indicate risk ranges from 1 case for every 712,000 travelers to 1 case for every 8 million travelers. CONCLUSION: The risk of COVID-19 transmission on an aircraft is low, even with infectious persons onboard.

Hierarchical Structural Engineering of Ultrahigh-Molecular-Weight Polyethylene.

Nature has inspired the design of next-generation lightweight architectured structural materials, for example, nacre-bearing extreme impact and paw-pad absorbing energy. Here, a bioinspired functional gradient structure, consisting of an impact-resistant hard layer and an energy-absorbing ductile layer, is applied to additively manufacture ultrahigh-molecular-weight polyethylene (UHMWPE). Its crystalline graded and directionally solidified structure enables superior impact resistance. In addition, we demonstrate nonequilibrium processing, ultrahigh strain rate pulsed laser shock wave peening, which could trigger surface hardening for enhanced crystallinity and polymer phase transformation. Moreover, we demonstrate the paw-pad-inspired soft- and hard-fiber-reinforced composite structure to absorb the impact energy. The bioinspired design and nonequilibrium processing of graded UHMWPE shed light on lightweight engineering polymer materials for impact-resistant and threat-protection applications.

An All-Ceramic, Anisotropic, and Flexible Aerogel Insulation Material.

To exploit the high-temperature superinsulation potential of anisotropic thermal management materials, the incorporation of ceramic aerogel into the aligned structural networks is indispensable. However, the long-standing obstacle to exploring ultralight superinsulation ceramic aerogels is the inaccessibility of its mechanical elasticity, stability, and anisotropic thermal insulation. In this study, we report a recoverable, flexible ceramic fiber-aerogel composite with anisotropic lamellar structure, where the interfacial cross-linking between ceramic fiber and aerogel is important in its superinsulation performance. The resulting ultralight aerogel composite exhibits a density of 0.05 g/cm3, large strain recovery (over 50%), and low thermal conductivity (0.0224 W m-1 K-1), while its hydrophobicity is achieved by in situ trichlorosilane coating with the water contact angle of 135°. The hygroscopic tests of such aerogel composites demonstrate a reversible thermal insulation. The mechanical elasticity and stability of the anisotropic composites, with its soundproof performance, shed light on the low-cost superelastic aerogel manufacturing with scalability for energy saving building applications.

Flexible and printable dielectric polymer composite with tunable permittivity and thermal stability.

Lightweight and printable polymer dielectrics are ubiquitous in flexible hybrid electronics, exhibiting high breakdown strength and mechanical reliability. However, their advanced electronic applications are limited due to their relatively low permittivity, compared to their ceramic counterparts. Here, we report flexible all organic percolative nanocomposites that contain in situ grown conductive polymer networks and dielectric polymer matrix, in which their dielectric properties can be designed and guided from the percolation theory. High dielectric constant of all organic percolative nanocomposites is shown over a broad frequency range under intensive bending cycles, while their thermal stability is attributed to thermally conductive 2D montmorillonite nanosheets. The printable polymer composites with high dielectric performance and thermal stability will find broader interest in flexible hybrid electronics and radio frequency devices.

A Hierarchical Mesoporous Insulation Ceramic.

Light-weight ceramic aerogels hold promise for superinsulation. However, its mechanical instability and complex manufacturing hampered its technical applications. In this study, we demonstrate lightweight pore-gradient ceramic aerogel-like foam monoliths (PGAFoams) through one-pot and in situ bubble supported pore gradient formation. The mechanically strong PGAFoams exhibit a low thermal conductivity of 0.036 W m-1 K-1 and a compressive strength of 89.85 MPa. The pore gradient and integral ceramic monolith nature provides such hydrophobic PGAFoams with thermal management, robust soundproof, and fire-resistance performance. Highly machinable PGAFoams can be adapted into a variety of shapes and dimensions to accommodate complex geometry applications. The scalable manufacturing of lightweight PGAFoams opens up building insulation with remarkable thermal management, high mechanical strength, low mass density, superior soundproofing, and fire-retardant performances.

Correlation at two-dimensional charge-transfer FeSe interface.

The charge transfer and spin coupling effects are explored at the interface of two-dimensional (2D) superconducting FeSe nanosheets and molecular photochromic potassium-7,7,8,8-tetracyanoquinodimethane (KTCNQ). Light-induced conductivity in 2D FeSe nanosheets is enhanced by the electron doping from KTCNQ by the destabilized spin-Peierls phase through their interface. Furthermore, the spin coupling at the interface of FeSe and KTCNQ shifts the dimerization transition temperature of KTCNQ. Our results suggest 2D exfoliated FeSe nanosheets as a versatile strongly correlated platform for the study of interfacial electron doping and spin coupling.

Strongly Correlated Aromatic Molecular Conductor.

Strongly correlated electronic molecules open the way for strong coupling between charge, spin, and lattice degrees of freedom to enable interdisciplinary fields, such as molecular electronic switches and plasmonics, spintronics, information storage, and superconducting circuits. However, despite exciting computational predictions and promising advantages to prepare flexible geometries, the electron correlation effect in molecules has been elusive. Here, the electron correlation effects of molecular plasmonic films are reported to uncover their coupling of charge, spin, lattice, and orbital for the switchable metal-to-insulator transition under external stimuli, at which the simultaneous transition occurs from the paramagnetic, electrical, and thermal conducting state to the diamagnetic, electrical, and thermal insulating state. In addition, density functional theory calculation and spectroscopic studies are combined to provide the mechanistic understanding of electronic transitions and molecular plasmon resonance observed in molecular conducting films. The self-assembled molecular correlated conductor paves the way for the next generation integrated micro/nanosystems.

Alkali-Metal-Intercalated Percolation Network Regulates Self-Assembled Electronic Aromatic Molecules.

In the continuously growing field of correlated electronic molecular crystals, there is significant interest in addressing alkali-metal-intercalated aromatic hydrocarbons, in which the possibility of high-temperature superconductivity emerges. However, searching for superconducting aromatic molecular crystals remains elusive due to their small shielding fraction volume. To exploit this potential, a design principle for percolation networks of technologically important film geometry is indispensable. Here the effect of potassium-intercalation is shown on the percolation network in self-assembled aromatic molecular crystals. It is demonstrated that one-dimensional (1D) dipole pairs, induced by dipole interaction, regulate the conductivity, as well as the electronic and optical transitions, in alkali-metal-intercalated molecular electronic crystals. A solid-solution growth methodology of aromatic molecular films with a broad range of stability is developed to uncover electronic and optical transitions of technological importance. The light-induced electron interactions enhance the charge-carrier itinerancy, leading to a switchable metal-to-insulator transition. This discovery opens a route for the development of aromatic molecular electronic solids and long-term modulation of electronic efficacy in nanotechnologically important thin films.

Eutectic melt crystallization of L10-FePt.

Herein, we report the eutectic growth control of ordered L10-FePt, which directs the nucleation, growth and crystallization of FePt sheets in a single-step reaction. The nature of eutectic crystallization at the eutectic point suggests its role as a high-temperature solvent, exhibiting an advantage in the scale-up production of metastable alloys.

Dabigatran deliberate overdose: two cases and suggestions for laboratory monitoring.

CONTEXT: Dabigatran etexilate (dabigatran) is a direct thrombin inhibitor anticoagulant agent. There is limited information about the changes in coagulation profile and outcomes in overdose. A monoclonal antibody has been developed to neutralize the anticoagulant effect of dabigatran. Case reports describe enhanced clearance of dabigatran by haemodialysis as an intervention to prevent haemorrhagic complications - however, the threshold for initiating haemodialysis is not well defined in an asymptomatic patient with normal renal function. CASE DETAILS: Two patients presented following deliberate dabigatran overdoses. A 55-year-old woman ingested 10 × 150 mg dabigatran. A 21-year-old woman with a history of systemic lupus erythematosus and pulmonary embolus ingested 100 × 110 mg dabigatran. Both were admitted to the intensive care unit and managed expectantly. Serial coagulation tests normalized over 60 h. The half-life of dabigatran was not prolonged following overdose, being calculated between 7 and 11 h in each case. There was positive correlation between international normalized ratio (INR), prothrombin time (PT) and activated partial thromboplastin time (aPTT) with plasma dabigatran levels. CONCLUSION: There is limited experience with dabigatran overdoses. Normal aPTT, PT and INR assays 12 h following deliberate ingestion indicate that the drug concentration is not high. Individual risk assessment of bleeding risk needs to be formulated for each patient and expectant management is reasonable in the presence of normal renal function and absent risk factors for bleeding.