Interactions of bupivacaine with a molecularly imprinted polymer in a monolithic format studied by NMR

A trimethylolpropane trimethacrylate-based monolith of dimensions carefully chosen to fit exactly in a standard 4-mm solid-state CP/MAS NMR rotor was photopolymerized and subsequently molecularly imprinted with bupivacaine using a grafting protocol with methacrylic acid and ethylene dimethacrylate as monomers. As no crushing or grinding of the monolith was necessary, additional unspecific surface area was not created. This procedure ascertains that differences observed between imprinted and nonimprinted polymers are due only to graft imprinted surfaces and give therefore better results in NMR spectroscopy due to less unspecific interactions between analyte and monolith. This improves the comparability to chromatographic evaluations where uncrushed monolithic columns are also used. To track interactions between analyte and stationary phase, the saturation transfer difference (STD) technique was applied on the polymer in the suspended state using the same solvent as in the chromatographic evaluation. This relatively new NMR method has to our knowledge not been used on chromatographic materials before. By using STD NMR on pristine monoliths, it was possible to measure large differences between the imprinted or nonimprinted polymers and the analyte indicating significant differences in the interaction mechanisms. These could be directly correlated with retention differences observed in chromatographic evaluations.     

Numerical Solutions for Heat Transfer of An Unsteady Cavity with Viscous Heating

The mechanism of viscous heating of a Newtonian fluid filled inside a cavity under the effect of an external applied force on the top lid is evaluated numerically in this exploration. The investigation is carried out by assuming a two-dimensional laminar in-compressible fluid flow subject to Neumann boundary conditions throughout the numerical iterations in a transient analysis. All the walls of the square cavity are perfectly insulated and the top moving lid produces a constant finite heat flux even though the fluid flow attains the steady-state condition. The objective is to examine the effects of viscous heating in the fully insulated lid-driven cavity under no-slip and free-slip Neumann boundary conditions coupled with variations in Reynolds and Prandtl numbers. The partial differential equations of time-dependent vorticity-stream function and thermal energy are discretized and solved using a self-developed finite difference code in MATLAB^® environment. Time dependence of fluid thermodynamics is envisaged through contour and image plots. A commercial simulation software, Ansys Fluent^® utilizing a finite element code is employed to verify the finite difference results produced. Although the effect of viscous heating is very minimal, Neumann no-slip and free-slip boundary conditions are able to trap the heat inside the fully insulated cavity as the heat flux is constantly supplied at the top lid. A lower Reynolds number and a greater Prandtl number with free-slip effects reduce temperature distribution in the cavity with a faster velocity than in the no-slip condition as the free-slip behaves as a lubricant.     

Partitioning of chemicals—important factors in exposure assessment of offshore discharges

The CHARM (chemical hazard assessment and risk management) model was developed to give operators, chemical suppliers, and environmental authorities a scientific framework for analyzing the environmental hazard and risk of offshore chemicals used and discharged to the marine environment. This paper presents results from an R and D project carried out on partitioning of typical offshore chemicals where the objective was to validate the partitioning algorithms in CHARM. The work included further development and verification of the HPLC (OECD 117) method for determining oil/water partitioning, or fraction released of production chemicals, for evaluation of the applicability of the Shake Flask method (OECD 107) and modification of the sediment/water partitioning test methods, as well as establishment of a calculation method for determining the weighted average log P_ow for chemical mixtures of homologs. The calculation method was recommended adopted in CHARM. Based on the experimental partitioning results, the CHARM partitioning algorithms were evaluated. The test results showed that the HPLC technique is a “robust” method for determining the P_ow, but has limitations for surfactants and chemicals with high log P_ow-values, which are typical offshore chemicals. The traditional correlations reported between P_ow, the BCF, the fraction of a chemical released with produced water, and the P_sw is not valid for typical surfactants. Another approach is therefore used in CHARM, which also was evaluated in this project. There is, however, a need for further validation of the CHARM partitioning algorithms.     

Autophagy,Unfolded Protein Response,and Neuropilin-1 Cross-Talk in SARS-CoV-2 Infection: What Can Be Learned from Other Coronaviruses

The COVID-19 pandemic is caused by the 2019–nCoV/SARS-CoV-2 virus. This severe acute respiratory syndrome is currently a global health emergency and needs much effort to generate an urgent practical treatment to reduce COVID-19 complications and mortality in humans. Viral infection activates various cellular responses in infected cells, including cellular stress responses such as unfolded protein response (UPR) and autophagy, following the inhibition of mTOR. Both UPR and autophagy mechanisms are involved in cellular and tissue homeostasis, apoptosis, innate immunity modulation, and clearance of pathogens such as viral particles. However, during an evolutionary arms race, viruses gain the ability to subvert autophagy and UPR for their benefit. SARS-CoV-2 can enter host cells through binding to cell surface receptors, including angiotensin-converting enzyme 2 (ACE2) and neuropilin-1 (NRP1). ACE2 blockage increases autophagy through mTOR inhibition, leading to gastrointestinal complications during SARS-CoV-2 virus infection. NRP1 is also regulated by the mTOR pathway. An increased NRP1 can enhance the susceptibility of immune system dendritic cells (DCs) to SARS-CoV-2 and induce cytokine storm, which is related to high COVID-19 mortality. Therefore, signaling pathways such as mTOR, UPR, and autophagy may be potential therapeutic targets for COVID-19. Hence, extensive investigations are required to confirm these potentials. Since there is currently no specific treatment for COVID-19 infection, we sought to review and discuss the important roles of autophagy, UPR, and mTOR mechanisms in the regulation of cellular responses to coronavirus infection to help identify new antiviral modalities against SARS-CoV-2 virus.     

Adaptation and readaptation to different shift work schedules measured with sleep diary and actigraphy.

In this study we examine sleep during adaptation and readaptation to different shift work schedules in the offshore oil industry. The sleep of 19 offshore workers was assessed daily for 1 week before, during the work period, and for 1 week after 3 different work schedules: (1) day (14 consecutive days of work), (2) night (14 consecutive nights of work), and (3) swing shift work (first 7 nights with night work then 7 days of day work). The workers' sleep was assessed for 84 days. Actigraphy and sleep diary estimates of sleep was applied assessing: (1) adaptation to offshore shift work, (2) sleep across the 2 offshore work weeks, and (3) readaptation after the work period. Regarding adaptation, sleep efficiency was higher when working day than night and swing shift the first week of work. Sleep quality was better during swing than regular day/night shifts the first week of work. Total sleep time was longer during day and night shift than swing shift across the 2 work weeks. Sleep efficiency, based on sleep diaries, was higher during day than night and swing shift during the 2 work weeks. There were no significant differences between the shifts in readaptation in terms of sleep. To conclude, adaptation to swing shift was more difficult than adaptation to regular day and night shifts in terms of sleep. Readaptation to day work after 1 week of night work affected sleep negatively. There were no differences between the shift schedules the week after the work period. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Representing scientific data sets in KML: Methods and challenges

Virtual Globes such as Google Earth and NASA World Wind permit users to explore rich imagery and the topography of the Earth. While other online services such as map servers provide ways to view, query, and download geographic information, the public has become captivated with the ability to view the Earth’s features virtually. The National Snow and Ice Data Center began to display scientific data on Virtual Globes in 2006. The work continues to evolve with the production of high-quality Keyhole Markup Language (KML) representations of scientific data and an assortment of technical experiments. KML files are interoperable with many Virtual Globe or mapping software packages. This paper discusses the science benefits of Virtual Globes, summarizes KML creation methods, and introduces a guide for selecting tools and methods for authoring KML for use with scientific data sets.     

Ge-modified Pt/SiO2 catalysts used in preferential CO oxidation (CO-PROX)

A bimetallic PtGe catalyst was prepared by a controlled surface reaction and studied for the PROX reaction. The good activity of the bimetallic catalyst can be assigned to the presence of a “noble metal-oxidized metal promoter” ensemble site in close contact, the noble metal (Pt) being the CO adsorption site and the oxidized metal promoter (Ge) the O₂ adsorption site. The stability of the PtGe clusters is confirmed by the EXAFS spectra and activity measurements in the preferential oxidation reaction that show similar values for samples subjected to different oxidation–reduction cycles.     

Edge Computing-Based Joint Client Selection and Networking Scheme for Federated Learning in Vehicular IoT

In order to support advanced vehicular Internet-of-Things(IoT)applications,information ex-changes among different vehicles are required to find efficient soluti...