Understanding the impact of antenatal corticosteroids via placenta and fetal lung microphysiological analysis platform (MAP) on a chip.

Antenatal corticosteroids are recommended for preterm births to enhance lung maturity; however, the guidelines are based on limited studies. Here, we present a placenta-fetal lung microphysiological analysis platform (MAP) to study how corticosteroids promote fetal lung maturation and determine their optimal concentration with minimal side effects. We create trophoblast-capillary-pneumocyte MAP on chips to analyze the transport of corticosteroids from mother to fetus through the placenta.

Soft Pneumatic Device Designed to Mimic the Periosteal Environment for Regulating the Fate of Mesenchymal Stem Cells.

Replicating the complex mechanical forces of muscle movement and fluid flow in in vitro cell culture systems is crucial for understanding cell differentiation and development. However, previous research focused on cell differentiation on static micro/nanotextures without a force field or flat 2-dimensional substrates under a continuous in-plane mechanical force. In this study, cell differentiation is reported using a spatial geometric platform that can periodically modulate complex mechanical forces through a custom-made soft pneumatic device (SPD) to mimic the interfaces between periosteum and interstitial fluid.

Development of a Predictive Model for Colorectal Cancer Using Exhaled Volatile Organic Compounds.

Background: Colorectal cancer lacks noninvasive and efficient diagnostic markers. Recently, volatile organic compounds present in exhaled breath have emerged as potential diagnostic indicators for various diseases.

Objective: This study aimed to establish a predictive model that includes exhaled volatile organic compounds for the diagnosis of colorectal cancer.

Creating mini-pregnancy models in vitro with clinical perspectives.

During the last decade, organs-on-chips or organoids microphysiological analysis platforms (MAP) have garnered attention in the practical applications of disease models, drug discovery, and developmental biology. Research on pregnant women has firm limitations due to ethical issues; thus, remodelling human pregnancy in vitro is highly beneficial for treatment modality development via disease remodelling or drug monitoring. This review highlights current efforts in bioengineering devices to reproduce human pregnancy and emphasises the significant convergence of biology, engineering, and maternal-foetal medicine.

Non-Hermitian chiral degeneracy of gated graphene metasurfaces.

Non-Hermitian degeneracies, also known as exceptional points (EPs), have been the focus of much attention due to their singular eigenvalue surface structure. Nevertheless, as pertaining to a non-Hermitian metasurface platform, the reduction of an eigenspace dimensionality at the EP has been investigated mostly in a passive repetitive manner. Here, we propose an electrical and spectral way of resolving chiral EPs and clarifying the consequences of chiral mode collapsing of a non-Hermitian gated graphene metasurface.

On-chip selection of adenosine aptamer using graphene oxide-coated magnetic nanoparticles.

Systematic evolution of ligands by exponential enrichment (SELEX) is a method that is generally used for developing aptamers, which have arisen the promising alternatives for antibodies. However, conventional SELEX methods have limitations, such as a limited selection of target molecules, time-consuming and complex fabrication processes, and labor-intensive processes, which result in low selection yields. Here, we used (i) graphene oxide (GO)-coated magnetic nanoparticles in the selection process for separation and label-free detection and (ii) a multilayered microfluidic device manufactured using a three-dimensionally printed mold that is equipped with automated control valves to achieve precise fluid flows.

Identifying Fibrillization State of Aβ Protein Near-Field THz Conductance Measurement.

Progressive Alzheimer's disease is correlated with the oligomerization and fibrillization of the amyloid beta (Aβ) protein. We identify the fibrillization stage of the Aβ protein through label-free near-field THz conductance measurements in a buffer solution. Frequency-dependent conductance was obtained by measuring the differential transmittance of the time-domain spectroscopy in the THz range with a molar concentration of monomer, oligomer, and fibrillar forms of the Aβ protein.

Fabrication, Flow Control, and Applications of Microfluidic Paper-Based Analytical Devices.

Paper-based microfluidic devices have advanced significantly in recent years as they are affordable, automated with capillary action, portable, and biodegradable diagnostic platforms for a variety of health, environmental, and food quality applications. In terms of commercialization, however, paper-based microfluidics still have to overcome significant challenges to become an authentic point-of-care testing format with the advanced capabilities of analyte purification, multiplex analysis, quantification, and detection with high sensitivity and selectivity. Moreover, fluid flow manipulation for multistep integration, which involves valving and flow velocity control, is also a critical parameter to achieve high-performance devices.

Fabrication of Artificial Leaf to Develop Fluid Pump Driven by Surface Tension and Evaporation.

Plants transport water from roots to leaves via xylem through transpiration, which is an evaporation process that occurs at the leaves. During transpiration, suction pressure is generated by the porous structure of mesophyll cells in the leaves. Here, we fabricate artificial leaf consisting of micro and nano hierarchy structures similar to the mesophyll cells and veins of a leaf using cryo-gel method.

Continuous Purification of Colloidal Quantum Dots in Large-Scale Using Porous Electrodes in Flow Channel.

Colloidal quantum dots (QDs) afford huge potential in numerous applications owing to their excellent optical and electronic properties. After the synthesis of QDs, separating QDs from unreacted impurities in large scale is one of the biggest issues to achieve scalable and high performance optoelectronic applications. Thus far, however, continuous purification method, which is essential for mass production, has rarely been reported.

Dynamics of a capillary invasion in a closed-end capillary.

The position of fluid invasion in an open capillary increases as the square root of time and ceases when the capillary and hydrostatic forces are balanced, when viscous and inertia terms are negligible. Although this fluid invasion into open-end capillaries has been well described, detailed studies of fluid invasion in closed-end capillaries have not been explored thoroughly. Thus, we demonstrated, both theoretically and experimentally, a fluid invasion in closed-end capillaries, where the movement of the meniscus and the invasion velocity are accompanied by adiabatic gas compression inside the capillary.

[Human multi-route exposure assessment of lead and cadmium for Korean volunteers].

Objectives: We wanted to evaluate the main route of exposure to lead and cadmium for the general population in Korea by using multi-route and multi-media exposure assessment

Methods: Samples of air at the homes, samples of the food and water and peripheral blood samples were collected from thirty volunteers living in Seoul (the metropolitan area), Yong-in (the suburban area) and Ansan (the industrial area) in 2001. Graphite furnace atomic absorption spectrometric methods were used for the determination of the Pb and Cd levels in the air, food, water and blood samples.

Results: The average intake of lead through the air, drinking water and food were 5.