Extensible Integrated System for Real-Time Monitoring of Cardiovascular Physiological Signals and Limb Health.

In recent decades, the rapid growth in flexible materials, new manufacturing technologies, and wearable electronics design techniques has helped establish the foundations for noninvasive photoelectric sensing systems with shape-adaptability and "skin-like" properties. Physiological sensing includes humidity, mechanical, thermal, photoelectric, and other aspects. Photoplethysmography (PPG), an important noninvasive method for measuring pulse rate, blood pressure, and blood oxygen, uses the attenuated signal obtained by the light absorbed and reflected from living tissue to a light source to realize real-time monitoring of human health status. This work illustrates a patch-type optoelectronic system that integrates a flexible perovskite photodetector and all-inorganic light-emitting diodes (LEDs) to realize the real-time monitoring of human PPG signals. The pulse rate of the human body and the swelling degree of finger joints can be extracted and analyzed using photodetectors, thus monitoring human health for the prevention and early diagnosis of certain diseases. Specifically, this work develops a 3D wrinkled-serpentine interconnection wire that increases the shape adaptability of the device in practical applications. The PPG signal sensor reported in this study has considerable potential for future wearable intelligent medical applications.

Advances in the Study of Probiotics for Immunomodulation and Intervention in Food Allergy.

Food allergies are a serious food safety and public health issue. Soybean, dairy, aquatic, poultry, and nut products are common allergens inducing allergic reactions and adverse symptoms such as atopic dermatitis, allergic eczema, allergic asthma, and allergic rhinitis. Probiotics are assumed as an essential ingredient in maintaining intestinal microorganisms' composition. They have unique physiological roles and therapeutic effects in maintaining the mucosal barrier, immune function, and gastrointestinal tract, inhibiting the invasion of pathogenic bacteria, and preventing diarrhea and food allergies. Multiple pieces of evidence reveal a significant disruptive effect of probiotics on food allergy pathology and progression mechanisms. Thus, this review describes the allergenic proteins as an entry point and briefly describes the application of probiotics in allergenic foods. Then, the role of probiotics in preventing and curing allergic diseases by regulating human immunity through intestinal flora and intestinal barrier, modulating host immune active cells, and improving host amino acid metabolism are described in detail. The anti-allergic role of probiotics in the function and metabolism of the gastrointestinal tract has been comprehensively explored to furnish insights for relieving food allergy symptoms and preventing food allergy.

Structural, antioxidant, and immunomodulatory activities of an acidic exopolysaccharide from Lactiplantibacillus plantarum DMDL 9010.

This study investigated the structural, antioxidant, and immunomodulatory activities of acidic exopolysaccharide (EPS-LP2) isolated from Lactiplantibacillus plantarum DMDL 9010. EPS-LP2 is composed of fucose (Fuc), arabinose (Ara), galactose (Gal), glucose (Glc), mannose (Man), and D-fructose (Fru) with a molar ratio of 0.13: 0.69: 8.32: 27.57: 62.07: 0.58: 0.46, respectively. Structural analysis of EPS-LP2 exhibited a smooth irregular lamellar surface, rod-like structure with swollen ends and slippery surfaces, and good thermal stability. Based on the methylation and NMR analysis, sugar residues including t-Manp, t-Glcp, 2-Manp, 6-Galp, 6-Glcp, and 4-Glcp were found to exist in EPS-LP2. In the 50∼400 µg/ml range, EPS-LP2 showed negligible neurotoxicity to RAW264.7 cells. Moreover, EPS-LP2 could protect RAW264.7 cells from oxidative injury by lowering the generation of reactive oxygen species (ROS), malondialdehyde (MDA), and the secretion of lactate dehydrogenase (LDH). In contrast, an increase in superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), and the concentrations of glutathione (GSH) were observed. Immunoreactivity assays showed that EPS-LP2 could suppress the expression of NO, tumor necrosis factor-α (TNF-α), and interleukin 6 (IL-6) and inhibit the activation of the mitogen-activated protein kinase (MAPK)/nuclear factor-κB-gene binding (NF-κB) cell pathway. Conclusively, EPS-LP2 could be a potential natural antioxidant and immunomodulatory agent in functional foods and medicines.

Self-Powered Flexible Blood Oxygen Monitoring System Based on a Triboelectric Nanogenerator.

Flexible optoelectronics based on inorganic functional components have attracted worldwide attention due to their inherent advantages. However, the power supply problem presents a significant obstacle to the commercialization of wearable optoelectronics. Triboelectric nanogenerator (TENG) technology has the potential to realize self-powered applications compared to the conventional charging technologies. Herein, a flexible self-powered blood oxygen monitoring system based on TENG was first demonstrated. The flexibility of the TENG is mainly due to the inherent properties of polydimethylsiloxane (PDMS) and the continuously undulating surface of crumpled gold (Au) and the rough surface on the electrode and PDMS effectively increased the output performance. The output voltage, output current density, and power density were 75.3 V, 7.4 µA, and 0.2 mW/cm2, respectively. By etching the sacrificial layer, we then derived a flexible blood oxygen and pulse detector without any obvious performance degradation. Powered by the TENG, the detector is mounted onto the thumbnail, from where it detects a stable photoplethysmography (PPG) signal which can be used to calculate the oxyhemoglobin saturation and pulse rate. This self-powered system provides a new way to sustainably monitor physiological parameters, which paves the way for development of wearable electronics and battery-free systems.

Theoretical System of Contact-Mode Triboelectric Nanogenerators for High Energy Conversion Efficiency.

As the rapid expansion of next-generation electronics, portable and efficient energy sources has become one of the most important factors impeding the market development. Triboelectric nanogenerators (TENGs) are a potential candidate for its unsurpassed features. Herein, we deeply analyzed the power and conversion efficiency of contact-mode TENGs considering the whole energy conversion process. Firstly, reaching beyond the conventional analysis, a compressive force was introduced to derive a more versatile motion profile, which provided a better understanding of the working principle of contact-separation process. Then, we deeply analyzed the influence of various parameters on its performance. Especially, the maximum efficiency TENGs can be obtained under optimum force. It is realistic and useful for more efficient TENGs. Furthermore, this research stands a good chance of establishing standards for quantifying the efficiency of TENGs, which lays the basis for the further industrialization and multi-functionization of TENGs technology.

A fully verified theoretical analysis of strain-photonic coupling for quantum wells embedded in wavy nanoribbons.

For optoelectronic devices, an attractive research field involves the flexible adjustment of the band gap in semiconductor quantum well (QW) structures by strain engineering. However, rigid wafer-based technology enables lattice-misfit strain during epitaxial growth, which is biaxial, unchangeable, and not sufficient for the devices fitted on various irregular surfaces. Therefore, exploiting the strain produced by externally deformed configurations offers unique opportunities to continuously and non-defectively tune the QW's band structure. Here, we propose a strategy to induce uniaxially distributed strain in elaborately designed wavy quantum well nanoribbons (QWNRs). Meanwhile, a numerically solved strain-photonic coupling model based on the theory of elasticity and the eight-band k·p method is established to illustrate the strain distribution coupled with the strain-induced band gap shift of the wavy QWNR. The µ-photoluminescence measurements reveal a periodically varied band gap in the QW along the uniaxial tensile direction, which is consistent with the result of theoretical calculations. This model demonstrates the potential application of a wrinkled configuration in arbitrarily controlling and tuning the band gap and thus the optoelectronic performances of quantum well systems.