The survival of murine hepatitis virus (a surrogate of SARS-CoV-2) on conventional packaging materials under cold chain conditions

IntroductionThe cold chain conditions have been suggested to facilitate long-distance transmission of SARS-CoV-2, but it is unclear how viable the virus is on cold chain packaging materials.MethodsThis study used the MHV-JHM strain of murine hepatitis virus as a model organism to investigate the viability of SARS-CoV-2 on foam, plastic, cardboard, and wood sheets at different temperatures (−40°C, −20°C, and 4°C). In addition, the ability of peracetic acid and sodium hypochlorite to eliminate the MHV-JHM on plastic and cardboard sheets were also evaluated.ResultsThe results indicate that MHV-JHM can survive on foam, plastic, or cardboard sheets for up to 28 days at −40°C and −20°C, and up to 14 days on foam and plastic surfaces at 4°C. Although viral nucleic acids were still detectable after storing at 4°C for 28 days, the corresponding virus titer was below the limit of quantification (LOQ).DiscussionThe study highlights that a positive nucleic acid test result may not indicate that the virus is still viable, and confirms that peracetic acid and sodium hypochlorite can effectively eliminate MHV-JHM on packaging materials under cold chain conditions

Construction and evaluation of a Salmonella minicell-based dendritic cell-targeted multi-epitope vaccine against Helicobacter pylori

BackgroundHelicobacter pylori (H. pylori) infection is a global health concern linked to various gastrointestinal diseases, highlighting the urgent need for effective vaccines.MethodsIn this study, we developed two multi-epitope vaccine candidates based on Salmonella minicells: TA-2m and Apt-TA-2m. Apt-TA-2 is an advanced formulation of TA-2m, coated with dendritic cell-targeting RNA aptamer to enhance antigen delivery and immune activation. The physical properties of the vaccines, including shape, size, particle dispersion index (PDI), and zeta potential, were characterized using transmission electron microscopy (TEM) or dynamic light scattering (DLS). Comprehensive in vitro and in vivo evaluations were conducted to assess their safety, immunogenicity, and protective efficacy.ResultsBoth vaccines demonstrated excellent safety profiles and elicited strong immune responses, significantly reducing H. pylori colonization and alleviating gastric pathology. Notably, Apt-TA-2m demonstrated superior immunogenicity, characterized by enhanced T-cell cytokine production, increased mucosal IgA levels, and greater reductions in gastric bacterial loads.ConclusionsThese findings underscore the potential of minicell-based vaccines for combating H. pylori infections. The enhanced protective efficacy of the Apt-TA-2m vaccine positions it as a promising candidate for further clinical development

Influence of hydrogen plasma treatment on secondary phases in CZTS thin films for energy harvesting

6 pages, 5 figuresCu2ZnSnS4 (CZTS) thin films deposited using direct current magnetron sputtering and sulfurized at argon atmosphere pressures of 950, 460, and 50 mbar are studied in a view of solar cell absorber fabrication. The main novelty in the work is the influence of the radio frequency (RF) electromagnetic field treatment on the Cu2−xS secondary phase. The treatment reduces the amount of the Cu2−xS secondary phase, which is confirmed by Raman spectroscopy. The RF effect is long-term, at least one year later. So, this treatment is a promising technique to achieve higher purities of CZTS absorber layers for solar cells.This research was supported by Key-Area Research and Development Program of Guangdong Province, China [2020B0101030002], and in part by the United Program of National Natural Science Foundation of China with Shenzhen, China [U1613212]; Basic Research Program of the National Academy of Science of Ukraine. Ukraine [0115U005037], Ministry of Education and Science of Ukraine, Ukraine [0119U100308, 0119U100319, 0119U100300], National Research Foundation of Ukraine, Ukraine [2020.02/0022] and by Spanish Ministry of Science, Innovation and Universities Project, Spain [WINCOST, ENE2016-80788-C5-2-R].Peer reviewe

A Bilayer Skin-Inspired Hydrogel with Strong Bonding Interface

Conductive hydrogels are widely used in sports monitoring, healthcare, energy storage, and other fields, due to their excellent physical and chemical properties. However, synthesizing a hydrogel with synergistically good mechanical and electrical properties is still challenging. Current fabrication strategies are mainly focused on the polymerization of hydrogels with a single component, with less emphasis on combining and matching different conductive hydrogels. Inspired by the gradient modulus structures of the human skin, we propose a bilayer structure of conductive hydrogels, composed of a spray-coated poly(3,4-dihydrothieno-1,4-dioxin): poly(styrene sulfonate) (PEDOT:PSS) as the bonding interface, a relatively low modulus hydrogel on the top, and a relatively high modulus hydrogel on the bottom. The spray-coated PEDOT:PSS constructs an interlocking interface between the top and bottom hydrogels. Compared to the single layer counterparts, both the mechanical and electrical properties were significantly improved. The as-prepared hydrogel showed outstanding stretchability (1763.85 ± 161.66%), quite high toughness (9.27 ± 0.49 MJ/m3), good tensile strength (0.92 ± 0.08 MPa), and decent elastic modulus (69.16 ± 8.02 kPa). A stretchable strain sensor based on the proposed hydrogel shows good conductivity (1.76 S/m), high sensitivity (a maximum gauge factor of 18.14), and a wide response range (0–1869%). Benefitting from the modulus matching between the two layers of the hydrogels, the interfacial interlocking network, and the patch effect of the PEDOT:PSS, the strain sensor exhibits excellent interface robustness with stable performance (>12,500 cycles). These results indicate that the proposed bilayer conductive hydrogel is a promising material for stretchable electronics, soft robots, and next-generation wearables

A Bilayer Skin-Inspired Hydrogel with Strong Bonding Interface

Conductive hydrogels are widely used in sports monitoring, healthcare, energy storage, and other fields, due to their excellent physical and chemical properties. However, synthesizing a hydrogel with synergistically good mechanical and electrical properties is still challenging. Current fabrication strategies are mainly focused on the polymerization of hydrogels with a single component, with less emphasis on combining and matching different conductive hydrogels. Inspired by the gradient modulus structures of the human skin, we propose a bilayer structure of conductive hydrogels, composed of a spray-coated poly(3,4-dihydrothieno-1,4-dioxin): poly(styrene sulfonate) (PEDOT:PSS) as the bonding interface, a relatively low modulus hydrogel on the top, and a relatively high modulus hydrogel on the bottom. The spray-coated PEDOT:PSS constructs an interlocking interface between the top and bottom hydrogels. Compared to the single layer counterparts, both the mechanical and electrical properties were significantly improved. The as-prepared hydrogel showed outstanding stretchability (1763.85 ± 161.66%), quite high toughness (9.27 ± 0.49 MJ/m3), good tensile strength (0.92 ± 0.08 MPa), and decent elastic modulus (69.16 ± 8.02 kPa). A stretchable strain sensor based on the proposed hydrogel shows good conductivity (1.76 S/m), high sensitivity (a maximum gauge factor of 18.14), and a wide response range (0–1869%). Benefitting from the modulus matching between the two layers of the hydrogels, the interfacial interlocking network, and the patch effect of the PEDOT:PSS, the strain sensor exhibits excellent interface robustness with stable performance (&gt;12,500 cycles). These results indicate that the proposed bilayer conductive hydrogel is a promising material for stretchable electronics, soft robots, and next-generation wearables.</jats:p

Electrolytic Preparation of Al-Sm Alloy in SmF3-LiF-Sm2O3 Molten Salt System

In the present paper, an Al rod as liquid cathode was added into the SmF3-LiF-Sm2O3 molten salt system and subsequently the Al-Sm alloy was prepared by the liquid cathode electrolysis method. The effects of electrolysis temperature, cathode current density and electrolyte composition on the current efficiency were studied. The results demonstrated that the maximum content of Sm in the Al-Sm interalloy could reach up to 32.8 wt.%, whereas the alloy was mainly composed of the Al substrate, Al4Sm and Al3Sm phases. The current efficiency increased first subsequently decreased as the electrolysis temperature and cathode current density increased. Simultaneously, the electrolyte composition had a high impact on the current efficiency. When the mass ratio of SmF3and LiF was 4, the current efficiency was 62.8 %.</jats:p