Selecting coronavirus disease 2019 patients with negligible risk of progression: early experience from non-hospital isolation facility in Korea.

Background/aims: As the novel coronavirus (coronavirus disease 2019 [COVID-19]) outbreak progresses rapidly, staying home is recommended for suspected patients; however, the safety of this recommendation is uncertain. In Korea, non-hospital facilities called "living and treatment centers (LTCs)" have been established since 5 March 2020. The LTCs provided a unique opportunity to evaluate the safety of selection criteria for low-risk groups.

LIN28A loss of function is associated with Parkinson's disease pathogenesis.

Parkinson's disease (PD) is neurodegenerative movement disorder characterized by degeneration of midbrain-type dopamine (mDA) neurons in the substantia nigra (SN). The RNA-binding protein Lin28 plays a role in neuronal stem cell development and neuronal differentiation. In this study, we reveal that Lin28 conditional knockout (cKO) mice show degeneration of mDA neurons in the SN, as well as PD-related behavioral deficits.

Fabry-Perot cavity resonance enabling highly polarization-sensitive double-layer gold grating.

We present experimental and theoretical investigations on the polarization properties of a single- and a double-layer gold (Au) grating, serving as a wire grid polarizer. Two layers of Au gratings form a cavity that effectively modulates the transmission and reflection of linearly polarized light. Theoretical calculations based on a transfer matrix method reveals that the double-layer Au grating structure creates an optical cavity exhibiting Fabry-Perot (FP) resonance modes.

Cyclewise Operation of Printed MoS Transistor Biosensors for Rapid Biomolecule Quantification at Femtomolar Levels.

Field-effect transistors made from MoS and other emerging layered semiconductors have been demonstrated to be able to serve as ultrasensitive biosensors. However, such nanoelectronic sensors still suffer seriously from a series of challenges associated with the poor compatibility between electronic structures and liquid analytes. These challenges hinder the practical biosensing applications that demand rapid, low-noise, highly specific biomolecule quantification at femtomolar levels.

Biotunable Nanoplasmonic Filter on Few-Layer MoS for Rapid and Highly Sensitive Cytokine Optoelectronic Immunosensing.

Monitoring of the time-varying immune status of a diseased host often requires rapid and sensitive detection of cytokines. Metallic nanoparticle-based localized surface plasmon resonance (LSPR) biosensors hold promise to meet this clinical need by permitting label-free detection of target biomolecules. These biosensors, however, continue to suffer from relatively low sensitivity as compared to conventional immunoassay methods that involve labeling processes.

Multiplexed Nanoplasmonic Temporal Profiling of T-Cell Response under Immunomodulatory Agent Exposure.

Immunomodulatory drugs-agents regulating the immune response-are commonly used for treating immune system disorders and minimizing graft versus host disease in persons receiving organ transplants. At the cellular level, immunosuppressant drugs are used to inhibit pro-inflammatory or tissue-damaging responses of cells. However, few studies have so far precisely characterized the cellular-level effect of immunomodulatory treatment.

Doxycycline supplementation allows for the culture of human ESCs/iPSCs with media changes at 3-day intervals.

Culturing human embryonic stem and induced pluripotent stem cells (hESCs/iPSCs) is one of the most costly and labor-intensive tissue cultures, as media containing expensive factors/cytokines should be changed every day to maintain and propagate undifferentiated hESCs/iPSCs in vitro. We recently reported that doxycycline, an anti-bacterial agent, had dramatic effects on hESC/iPSC survival and promoted self-renewal. In this study, we extended the effects of doxycycline to a more practical issue to save cost and labor in hESC/iPSC cultures.

Multiple MoS2 Transistors for Sensing Molecule Interaction Kinetics.

Atomically layered transition metal dichalcogenides (TMDCs) exhibit a significant potential to enable next-generation low-cost transistor biosensors that permit single-molecule-level quantification of biomolecules. To realize such potential biosensing capability, device-oriented research is needed for calibrating the sensor responses to enable the quantification of the affinities/kinetics of biomolecule interactions. In this work, we demonstrated MoS2-based transistor biosensors capable of detecting tumor necrosis factor--alpha (TNF-α) with a detection limit as low as 60 fM.

Integrated nanoplasmonic sensing for cellular functional immunoanalysis using human blood.

Localized surface plasmon resonance (LSPR) nanoplasmonic effects allow for label-free, real-time detection of biomolecule binding events on a nanostructured metallic surface with simple optics and sensing tunability. Despite numerous reports on LSPR bionanosensing in the past, no study thus far has applied the technique for a cytokine secretion assay using clinically relevant immune cells from human blood. Cytokine secretion assays, a technique to quantify intercellular-signaling proteins secreted by blood immune cells, allow determination of the functional response of the donor's immune cells, thus providing valuable information about the immune status of the donor.

Surface-micromachined microfiltration membranes for efficient isolation and functional immunophenotyping of subpopulations of immune cells.

An accurate measurement of the immune status in patients with immune system disorders is critical in evaluating the stage of diseases and tailoring drug treatments. The functional cellular immunity test is a promising method to establish the diagnosis of immune dysfunctions. The conventional functional cellular immunity test involves measurements of the capacity of peripheral blood mononuclear cells to produce pro-inflammatory cytokines when stimulated ex vivo.

An integrated microfluidic platform for in situ cellular cytokine secretion immunophenotyping.

Rapid, quantitative detection of cell-secreted biomarker proteins with a low sample volume holds great promise to advance cellular immunophenotyping techniques for personalized diagnosis and treatment of infectious diseases. Here we achieved such an assay with the THP-1 human acute moncytic leukemia cell line (a model for human monocyte) using a highly integrated microfluidic platform incorporating a no-wash bead-based chemiluminescence immunodetection scheme. Our microfluidic device allowed us to stimulate cells with lipopolysaccharide (LPS), which is an endotoxin causing septic shock due to severely pronounced immune response of the human body, under a well-controlled on-chip environment.

Optofluidic detection for cellular phenotyping.

Quantitative analysis of the output of processes and molecular interactions within a single cell is highly critical to the advancement of accurate disease screening and personalized medicine. Optical detection is one of the most broadly adapted measurement methods in biological and clinical assays and serves cellular phenotyping. Recently, microfluidics has obtained increasing attention due to several advantages, such as small sample and reagent volumes, very high throughput, and accurate flow control in the spatial and temporal domains.

Copy number variation of β-defensin genes in Behçet's disease.

Objectives: Behçet's disease (BD) may be triggered by infectious agents in genetically susceptible persons. Human β-defensin 2 is an inducible antimicrobial peptide, the level of which can be influenced by copy number (CN) of the DEFB4. We investigated the relationship between copy number variation (CNV) of DEFB4 and BD.