Multi-Sample Preparation Assay for Isolation of Nucleic Acids Using Bio-Silica with Syringe Filters

The spin-column system for the isolation of nucleic acids (NAs) from multiple samples presents the inconvenience of repeated experimentation, time-consumption, and the risk of contamination in the process of the spin-column exchange. Herein, we propose a convenient and universal assay that can be used to diagnose multiple pathogens using a multi-sample preparation assay. The multi-sample preparation assay combines a 96-well filter/membrane plate, a bio-micromaterial lattice-like micro amine-functional diatomaceous earth (D-APDMS), and homobifunctional imidoesters (HI) for the processing of pathogen enrichment and extraction for multiple samples simultaneously. The purity and quantity of the extracted NAs from pathogens (E. coli and Brucella) using the proposed assay is superior to that of the commercialized spin-column kit. The assay also does not require the replacement of several collection tubes during the reaction processing. For the multi-sample testing, we used as many as six samples simultaneously with the proposed assay. This assay can simultaneously separate up to 96 NAs from one plate, and the use of multichannel pipettes allows faster and simpler experimentation. Therefore, we believe it is a convenient and easy process, and can be easily integrated with other detection methods for clinical diagnostics

A Sample Preparation Technique Using Biocompatible Composites for Biomedical Applications

Infectious diseases, especially pathogenic infections, are a growing threat to public health worldwide. Since pathogenic bacteria usually exist in complex matrices at very low concentrations, the development of technology for rapid, convenient, and biocompatible sample enrichment is essential for sensitive diagnostics. In this study, a cucurbit[6]uril (CB) supermolecular decorated amine-functionalized diatom (DA) composite was fabricated to support efficient sample enrichment and in situ nucleic acid preparation from enriched pathogens and cells. CB was introduced to enhance the rate and effectiveness of pathogen absorption using the CB–DA composite. This novel CB–DA composite achieved a capture efficiency of approximately 90% at an Escherichia coli concentration of 106 CFU/mL within 3 min. Real-time PCR analyses of DNA samples recovered using the CB–DA enrichment system showed a four-fold increase in the early amplification signal strength, and this effective method for capturing nucleic acid might be useful for preparing samples for diagnostic systems

A therapeutic neutralizing antibody targeting receptor binding domain of SARS-CoV-2 spike protein

Therapies and vaccines for COVID-19, caused by the SARS-CoV-2 viral pandemic, are urgently needed. Here the authors establish and screen an antibody library from a convalescent COVID-19 patient to isolate a neutralizing antibody with the ability to reduce viral titer and alleviate symptoms in ferret, hamster, and rhesus monkey infection models

Development of plasma sources and diagnostics for the simulation of fusion edge plasmas

© 2022, The Korean Physical Society.Although the research on divertors and scrape-off layers (SOLs) has been not as focused on as the recent success of the Korean fusion program, a few linear plasma devices have been developed for simulating divertor and SOL plasmas: (1) diversified plasma simulator (DiPS), a versatile linear machine, has been developed for simulations of divertor and space plasmas with various electric probes, such as single, triple, and Mach Probes and gridded energy analyzer. DiPS consists of two major parts: a divertor plasma simulator with a LaB 6 DC plasma source and a space plasma simulator with a helicon RF plasma source, (2) divertor plasma simulator-1 (DiPS-1) is a part of DiPS with only a LaB 6 cathode, where a low-power laser-induced fluorescence (LIF) is added and more electric probe diagnostics are augmented; it is dedicated only for fusion edge and divertor plasmas, (3) Divertor Plasma Simulator-2 (DiPS-2) has been modified from the DiPS-1 by adding a magnetic nozzle with a limiter structure and by removing the helicon source and space chamber. DiPS-2 is a linear plasma device with a 4-inch LaB 6 cathode, the same as DiPS-1, and it is focused on the development of various diagnostics, such as those used for LIF and laser Thomson scattering (LTS) along with various electric probes, on the divertor and scrape-off plasmas and on the plasma-material interaction (PMI) research, such as that of tungsten and graphite as plasma-facing components (PFCs), (4) A Multi-Purpose Plasma (MP 2) device is a renovation of the Hanbit mirror device [Kwon et al., Nucl. Fusion 43, 686 (2003)] with the installation of two plasma sources: LaB 6 (DC) and helicon (RF) plasma sources. A honeycomb-like large-area LaB 6 (HLA-LaB 6) cathode has been developed for the divertor plasma simulation to improve the resistance against the thermal shock fragility for large (8-inch) and high density plasma generation, (5) DiPS-2 has been augmented by adding another cylindrical device, called the Dust interaction with Surfaces Chamber (DiSC) for the generation and diagnostics of dusts. This combined system (DiPS-2+DiSC) has added two more diagnostics: Laser Photo-Detachment (LPD) for dust density and laser Mie Scattering (LMS) for dust size. Moreover, dusts or negative ions have been analyzed by using electric probes and capacitive diagram gauges in Transport and Removal of Dusts (TReD) device.N

Simulations of fusion edge plasmas by linear plasma devices: physics and plasma–material interactions

© 2022, The Korean Physical Society.Because a fusion edge plasma contains various atomic and molecular processes, along with various plasma–material interactions (PMIs) for post-mortem analyses, a linear plasma device can simulate divertor and scrape-off layer (SOL) plasmas with DC edge relevant parameters, although it cannot generate a high ion temperature and toroidicity with much less power density compared to toroidal devices. The Divertor Plasma Simulator-2 (DiPS-2), a linear device with an LaB6 DC cathode, has been used for a few fusion-relevant physics experiments, including edge localized mode (ELM) simulation and edge transport of diffusion and convection. An ELM simulation has been performed by modulating the magnetic field relevant to the pressure modulation of a toroidal device, and the diffusion coefficients of free and bound presheaths have been measured in simulations of divertor or limiter transport. Moreover, the convection of the filament or the bubble expansion to the first wall has also been analyzed. In addition to various atomic and molecular processes in SOL and divertor plasmas, PMIs must be analyzed both on and beneath the surface of the plasma-facing components (PFCs) because of surface modification. Using DiPS-2 and other linear devices along with Korea Superconducting Tokamak Advanced Research (KSTAR), PMIs have been analyzed in terms of the following elements or processes: (1) boronizations, both for dust interactions with the surface chamber (DiSC) and KSTAR device, are analyzed; (2) carbon damage by the dense heat flux of DiPS-2 is experimentally investigated; (3) the density profile of the lithium injection gettering of hydrogen and its transport experiments (LIGHT-1) device is analytically calculated; (4) the effect of nitrogen on the relaxation of the heat flux to the divertor tile is experimentally analyzed; and (5) tungsten as the divertor tile material is analyzed via laser ELM simulations in terms of dust generation and surface modification.N

Measurement of the angle between jet axes in Pb−-Pb collisions at sNN=5.02\sqrt{s_{\rm NN}} = 5.02 TeV

International audienceThis letter presents the first measurement of the angle between different jet axes (denoted as ${\Delta}R$) in Pb$-$Pb collisions. The measurement is carried out in the 0$-$10% most-central events at $\sqrt{s_{\rm NN}} = 5.02$ TeV. Jets are assembled by clustering charged particles at midrapidity using the anti-$k_{\rm T}$ algorithm with resolution parameters $R=0.2$ and $0.4$ and transverse momenta in the intervals $40 < p_{\rm T}^{\rm ch jet} < 140$ GeV/$c$ and $80 < p_{\rm T}^{\rm ch jet} < 140$ GeV/$c$, respectively. Measurements at these low transverse momenta enhance the sensitivity to quark$-$gluon plasma (QGP) effects. A comparison to models implementing various mechanisms of jet energy loss in the QGP shows that the observed narrowing of the Pb$-$Pb distribution relative to pp can be explained if quark-initiated jets are more likely to emerge from the medium than gluon-initiated jets. These new measurements discard intra-jet $p_{\rm T}$ broadening as described in a model calculation with the BDMPS formalism as the main mechanism of energy loss in the QGP. The data are sensitive to the angular scale at which the QGP can resolve two independent splittings, favoring mechanisms that incorporate incoherent energy loss