A Cell State Monitoring System with Integrated In Situ Imaging and pH Detection.

Cell models are one of the most widely used basic models in biological research, and a variety of in vitro cell culture techniques and models have been developed recently to simulate the physiological microenvironment in vivo. However, regardless of the technique or model, cell culture is the most fundamental but crucial component. As a result, we have developed a cell culture monitoring system to assess the functional status of cells within a biochip. This article focuses on a mini-microscope made from a readily available camera for in situ continuous observation of cell growth within a biochip and a pH sensor based on optoelectronic sensing for measuring pH. With the aid of this monitoring system, scientists can keep an eye on cell growth in real time and learn how the pH of the culture medium affects it. This study offers a new approach for tracking cells on biochips and serves as a valuable resource for enhancing cell culture conditions.

Microfluidic Organ-on-a-Chip System for Disease Modeling and Drug Development.

An organ-on-a-chip is a device that combines micro-manufacturing and tissue engineering to replicate the critical physiological environment and functions of the human organs. Therefore, it can be used to predict drug responses and environmental effects on organs. Microfluidic technology can control micro-scale reagents with high precision. Hence, microfluidics have been widely applied in organ-on-chip systems to mimic specific organ or multiple organs in vivo. These models integrated with various sensors show great potential in simulating the human environment. In this review, we mainly introduce the typical structures and recent research achievements of several organ-on-a-chip platforms. We also discuss innovations in models applied to the fields of pharmacokinetics/pharmacodynamics, nano-medicine, continuous dynamic monitoring in disease modeling, and their further applications in other fields.

A new spent coffee grounds based biochar - Persulfate catalytic system for enhancement of urea removal in reclaimed water for ultrapure water production.

The demand for ultrapure water (UPW) in the semiconductor industry has increased in recent years, while the idea to use reclaimed water instead of tap water for UPW production has also attracted more attention. However, since urea concentration in reclaimed water is higher than that in tap water, UPW production has not been efficient. To resolve this problem, this study aims to develop a new spent coffee grounds based biochar (SCG-BC)/persulfate catalytic system as a pretreatment unit. The objective is to enhance urea removal from reclaimed water so that UPW production is more effective. In this study, the biochar used was prepared from spent coffee grounds with detailed characterization. Results strongly suggested that the urea removed by SCG-BC/persulfate catalytic system was very encouraging (up to 73%). The best possible dosages for SCG-BC and persulfate for urea removal were 0.2 and 2.0 g L-1, respectively. Furthermore, this system could remove urea effectively in a wide range of pH (3-10). Moreover, the characterizations of SCG-BC (graphite C, defective edges and functional groups, i.e. -OH, CO, carboxyl C-O) helped to activate persulfate in the catalytic process. OH• and SO4• - were all involved in this process, while the SO4• - was the main radical for urea degradation.

An electrochemical aptasensor for the milk allergen ß-lactoglobulin detection based on a target-induced nicking site reconstruction strategy.

Food allergy is an immune system reaction to a particular food, milk being the most common one. ß-Lactoglobulin (ß-Lg) is the main ingredient of milk protein and the main cause of infant milk allergy. On such an occasion, the determination of ß-Lg is very important and the electrochemical sensors are a good alternative for this purpose since they are sensitive, selective and inexpensive. In this work, an electrochemical aptasensor was fabricated for the quantitative detection of ß-Lg in hypoallergenic formula (HF) milk. A tri-functional hairpin (HP) was designed, which was composed of an aptamer sequence, a nicking site and a DNA sequence (T1). In the absence of ß-Lg, the aptamer part hybridized with T1 to form a stable stem-loop structure. However, in the presence of ß-Lg, the capture of the aptamer sequence towards ß-Lg caused the reconstruction of HP and thus the nicking sites were exposed. Then, the nicking enzyme was activated and T1 could be released, which bound with the end of the hairpin 1-methylene blue (HP1-MB)/HP2-MB conjugation on the Au nanoparticle (AuNP) modified electrode surface. Thus, the insulating property of the electrode was enhanced and the current response of MB decreased, which built the quantitative basis for ß-Lg detection. In this way, the proposed aptasensor exhibited a wide linear range of 0.01-100 ng mL-1 and a low detection limit of 5.7 pg mL-1. This aptasensor also displayed high selectivity, reproducibility and stability, and became a promising platform for ß-Lg detection in real food samples.

UV LED array based NLOS UV turbulence channel modeling and experimental verification.

In this paper, we comprehensively study the NLOV UV turbulence effect through simulated and experimental results. A Monte Carlo NLOS UV turbulence channel model, which incorporates the effects of multiple scattering and turbulence attenuation, is proposed based on previous work. To validate this model, a series of outdoor experiments is conducted to investigate the received-signal energy distribution and channel path loss under the turbulence circumstance for the first time. These experimental and simulated results are valuable for studying NLOS UV channel and communication system design.