Real-Time Detection of Yeast Growth on Solid Medium through Passive Microresonator Biosensor.

This study presents a biosensor fabricated based on integrated passive device (IPD) technology to measure microbial growth on solid media in real-time. Yeast (Pichia pastoris, strain GS115) is used as a model organism to demonstrate biosensor performance. The biosensor comprises an interdigital capacitor in the center with a helical inductive structure surrounding it. Additionally, 12 air bridges are added to the capacitor to increase the strength of the electric field radiated by the biosensor at the same height. Feasibility is verified by using a capacitive biosensor, and the change in capacitance values during the capacitance detection process with the growth of yeast indicates that the growth of yeast can induce changes in electrical parameters. The proposed IPD-based biosensor is used to measure yeast drop-added on a 3 mm medium for 100 h at an operating frequency of 1.84 GHz. The resonant amplitude of the biosensor varies continuously from 24 to 72 h due to the change in colony height during vertical growth of the yeast, with a maximum change of 0.21 dB. The overall measurement results also fit well with the Gompertz curve. The change in resonant amplitude between 24 and 72 h is then analyzed and reveals a linear relationship with time with a coefficient of determination of 0.9844, indicating that the biosensor is suitable for monitoring yeast growth. Thus, the proposed biosensor is proved to have potential in the field of microbial proliferation detection.

The potential toxicity of chemically fabricated silver nanomaterials based on accumulation and histological changes in fish (Cyprinus carpio).

The bio-reductive fabrication of nanomaterials is a developing arena of study that seeks to fabricate nanoparticles (NPs) using microorganisms, plants, and animal blood. However, the chemical approach of AgNPs fulfills the need of abundant need of NPs. In contrast, chemically fabricated AgNPs are more toxic than biological AgNPs. Therefore, the current study aimed to assess and evaluate the chemically fabricated silver nanoparticles (AgNPs) for their possible toxicity in Common carp fish (Cyprinus carpio). The chemically synthesized silver nanoparticles were purchased from the market and applied for their possible toxicity. The chemically fabricated AgNPs were used against the Cyprinus carpio for bioaccumulation in different organs and histological alterations in the intestine and muscles. The results revealed that the AgNPs were mostly accumulated in the intestines followed by the gills, liver, and muscles (p < .05). The accumulated AgNPs caused histological alterations in gills and intestines at the highest concentration (0.08 mg/L). However, no alterations were observed by the middle and lowest concentration of AgNPs, particularly, in the intestine. In conclusion, more extensive research is required to establish the hazards related to the use of nanoparticles to disclose their negative effects on fish and the aquatic environment. REASEARCH HIGHLIGHTS: The chemical method fabricates a large amount of AgNPs Additionally, considered more toxic than the bio-reductive method AgNPs have excellent and diverse applications AgNPs deposited in various organs and cause histological changes.

Microwave biosensor for the detection of growth inhibition of human liver cancer cells at different concentrations of chemotherapeutic drug.

Cytotoxicity assays are crucial for assessing the efficacy of drugs in killing cancer cells and determining their potential therapeutic value. Measurement of the effect of drug concentration, which is an influence factor on cytotoxicity, is of great importance. This paper proposes a cytotoxicity assay using microwave sensors in an end-point approach based on the detection of the number of live cells for the first time. In contrast to optical methods like fluorescent labeling, this research uses a resonator-type microwave biosensor to evaluate the effects of drug concentrations on cytotoxicity by monitoring electrical parameter changes due to varying cell densities. Initially, the feasibility of treating cells with ultrapure water for cell counting by a microwave biosensor is confirmed. Subsequently, inhibition curves generated by both the CCK-8 method and the new microwave biosensor for various drug concentrations were compared and found to be congruent. This agreement supports the potential of microwave-based methods to quantify cell growth inhibition by drug concentrations.

Highly Sensitive and Linear Resonator-Based Biosensor for White Blood Cell Counting: Feasible Measurement Method and Intrinsic Mechanism Exploration.

Since different quantities of white blood cells (WBCs) in solution possess an adaptive osmotic pressure of cells, the WBCs themselves and in solution have similar concentrations, resulting in them having similar dielectric properties. Therefore, a microwave sensor could have difficulty in sensing the quantity variation when WBCs are in solution. This paper presents a highly sensitive, linear permittivity-inspired microwave biosensor for WBCs, counting through the evaporation method. Such a measurement method is proposed to record measurements after the cell solution is dripped onto the chip and is completely evaporated naturally. The proposed biosensor consists of an air-bridged asymmetric differential inductor and a centrally located circular fork-finger capacitor fabricated on a GaAs substrate using integrated passive fabrication technology. It is optimized to feature a larger sensitive area and improved Q-factor, which increases the effective area of interaction between cells and the electromagnetic field and facilitates the detection of their changes in number. The sensing relies on the dielectric properties of the cells and the change in the dielectric constant for different concentrations, and the change in resonance properties, which mainly represents the frequency shift, corresponds to the macroscopic change in the concentration of the cells. The microwave biosensors are used to measure biological samples with concentrations ranging from 0.25 × 106 to 8 × 106 cells per mL in a temperature (26.00 ± 0.40 °C) and humidity (54.40 ± 3.90 RH%) environment. The measurement results show a high sensitivity of 25.06 Hz/cells·mL-1 with a highly linear response of r2 = 0.99748. In addition, a mathematical modeling of individual cells in suspension is performed to estimate the dielectric constant of individual cells and further explain the working mechanism of the proposed microwave biosensor.

Development of a Microwave Sensor for Real-Time Monitoring of a Micro Direct Methanol Fuel Cell.

Micro direct methanol fuel cells (µDMFCs) are a promising power source for microelectronic devices and systems. As the operating state and performance of a µDMFC is generally determined by both electrochemical polarization and methanol crossover, it is important to monitor the methanol concentration in µDMFCs. Here, we design and fabricate a microwave sensor and integrate it with a µDMFC for the online detection of methanol concentration in a nonintrusive way. The sensing area is set at the bottom of the anode chamber of a µDMFC which exhibits a maximum output power density of 28.8 mW cm-2 at 30 °C. With a square ring structure, the dual-mode microwave sensor shows a sensitivity of 9.5 MHz mol-1 L. Furthermore, the importance of methanol concentration monitoring is demonstrated in the long term. A relatively smooth methanol decline curve was obtained, which indicated a normal and stable operating status of the µDMFC. Derived from real-time recording data, fuel utilization was additionally calculated as 28.5%.

Integrated Passive Sensing Chip for Highly Sensitive and Reusable Detection of Differential-Charged Nanoplastics Concentration.

In this work, a new type, highly sensitive, and reusable nanoplastics (NPs) microwave detection method is proposed, which can be used to rapidly analyze NPs with different surface charges and sizes. The effective dielectric constant of NPs varies according to the different concentrations, particle sizes, and surface charges of NPs in aqueous solution. The feasibility of the microwave method for differential-charged NPs detection is verified using a complementary split ring resonator sensor manufactured on a cost-effective printed circuit board, which shows a high sensitivity only for positively charged NPs (PS-NH2) detection. To achieve microwave detection of both positively and negatively charged NPs (PS-SO3H), a microscale spiral-coupled resonator sensing chip is manufactured through integrated passive technology, which demonstrates extremely low detection limits and high sensitivity for both PS-NH2 and PS-SO3H, with different concentrations, particle sizes, and charges. In addition, for NPs solution doped with methyl orange, the device can still perform stable measurements, overcoming the inability of traditional NPs molecular element determination and optical detection methods to detect NPs aqueous solution with organic matter doping and color presence. The proposed microwave detection method could also be extended to sensing detection for detecting other hazardous environmental substances.

Examine the Moderating Role of Teacher's Self-Efficacy in the Relationship Between the Job Satisfaction and Professional Learning Community in China.

Purpose: The study aimed in examining the impact of the professional learning community, and teachers' self-efficacy on the job satisfaction of teachers. Additionally, the study has also examined the moderating role of teachers' self-efficacy in the relationship between the professional learning community (PLC) and job satisfaction. Method: The SEM-PLS is employed for the data analysis. The response rate of the study is 50%. The study is carried out on the primary teachers in China. Results: Three research questions were developed in the current study. The questions were related to the job satisfaction level of PE teachers, which was far beyond the level of satisfaction. As a result, teachers of PE classes had low performance. It was found by the study that professional learning community, job satisfaction of teachers, and self-efficacy are linked with each other. However, the results are inconclusive because of the limitation of the sample. Implications: The study has several implications among researchers, practitioners, and teachers. Significance: The study is among the few earlier studies on the issues related to Job Satisfaction and the professional learning community in China. Originality/Value: The study has highlighted an important issue related to the Job Satisfaction and professional learning community in China.

A Microfabricated Bandpass Filter with Coarse-Tuning and Fine-Tuning Ability Based on IPD Process and PCB Artwork.

In this paper, a bandpass filter (BPF) was developed utilizing GaAs-based integrated passive device technology which comprises an asymmetrical spiral inductor and an interleaved array capacitor, possessing two tuning modes: coarse-tuning and fine-tuning. By altering the number of layers and radius of the GaAs substrate metal spheres, capacitance variation from 0.071 to 0.106 pF for coarse-tuning, and of 0.0015 pF for fine-tuning, can be achieved. Five air bridges were employed in the asymmetrical spiral inductor to save space, contributing to a compact chip area of 0.015λ0 × 0.018λ0. The BPF chip was installed on the printed circuit board artwork with Au bonding wire and attached to a die sink. Measured results demonstrate an insertion loss of 0.38 dB and a return loss of 21.5 dB at the center frequency of 2.147 GHz. Furthermore, under coarse-tuning mode, variation in the center frequency from 1.956 to 2.147 GHz and transmission zero frequency from 4.721 to 5.225 GHz can be achieved. Under fine-tuning mode, the minimum tuning value and the average tuning value of the proposed BPF can be accurate to 1.0 MHz and 4.7 MHz for the center frequency and 1.0 MHz and 12.8 MHz for the transmission zero frequency, respectively.

RFID-Based Microwave Biosensor for Non-Contact Detection of Glucose Solution.

Due to the increasing number of diabetic patients, early monitoring of glucose levels is particularly important; therefore, glucose biosensors have attracted enormous attention from researchers. In this paper, we propose a glucose microwave biosensor based on RFID and achieve a non-contact measurement of the concentration of glucose solutions. The Reader is a complementary split-ring resonator (CSRR), and the Tag is comprised of a squared spiral capacitor (SSC). A polydimethylsiloxane microfluidic quantitative cavity with a volume of 1.56 µL is integrated on the Tag to ensure that the glucose solution can be accurately set to the sensitive area and fully contacted with the electromagnetic flux. Because the SSC exhibits different capacitances when it contacts glucose solutions of different concentrations, changing the resonant frequency of the CSRR, we can use the relationship to characterize the biosensing response. Measurement results show that bare CSRR and RFID-based biosensors have achieved sensitivities of 0.31 MHz/mg·dL-1 and 10.27 kHz/mg·dL-1, and detection limits of 13.79 mg/dL and 1.19 mg/dL, respectively, and both realize a response time of less than 1 s. Linear regression analysis of the abovementioned biosensors showed an excellent linear relationship. The proposed design provides a feasible solution for microwave biosensors aiming for the non-contact measurement of glucose concentration.

Quantitative, Temperature-Calibrated and Real-Time Glucose Biosensor Based on Symmetrical-Meandering-Type Resistor and Intertwined Capacitor Structure.

Here, we propose a glucose biosensor with the advantages of quantification, excellent linearity, temperature-calibration function, and real-time detection based on a resistor and capacitor, in which the resistor works as a temperature sensor and the capacitor works as a biosensor. The resistor has a symmetrical meandering type structure that increases the contact area, leading to variations in resistance and effective temperature monitoring of a glucose solution. The capacitor is designed with an intertwined structure that fully contacts the glucose solution, so that capacitance is sensitively varied, and high sensitivity monitoring can be realized. Moreover, a polydimethylsiloxane microfluidic channel is applied to achieve a fixed shape, a fixed point, and quantitative measurements, which can eliminate influences caused by fluidity, shape, and thickness of the glucose sample. The glucose solution in a temperature range of 25-100 °C is measured with variations of 0.2716 Ω/°C and a linearity response of 0.9993, ensuring that the capacitor sensor can have reference temperature information before detecting the glucose concentration, achieving the purpose of temperature calibration. The proposed capacitor-based biosensor demonstrates sensitivities of 0.413 nF/mg·dL-1, 0.048 nF/mg·dL-1, and 0.011 pF/mg·dL-1; linearity responses of 0.96039, 0.91547, and 0.97835; and response times less than 1 second, respectively, at DC, 1 kHz, and 1 MHz for a glucose solution with a concentration range of 25-1000 mg/dL.

Da-Bu-Yin-Wan and Qian-Zheng-San Ameliorate Mitochondrial Dynamics in the Parkinson's Disease Cell Model Induced by MPP.

To investigate the effect of Da-Bu-Yin-Wan and Qian-Zheng-San (DBYW and QZS) on mitochondrial mass in Parkinson's disease (PD) cell model induced by 1-Methyl-4-phenylpyridinium Ion (MPP+). The SH-SY5Y cell was selected and treated with MPP+. The PD model was intervened with DBYW and QZS. CCK-8 method was used to detect the survival rate of cells in each group. Mitochondria was labeled by mitoTracker®Red CMXRos probe and observed by laser scanning confocal microscope, and ImageJ software was used to process images and measure mitochondrial form factors; Tetramethylrhodamine methyl ester was used to detect mitochondrial membrane potential (ΔΨm); Luciferase method was used to detect cellular ATP levels; Western-Blot technique was applied to detect the expression levels of Parkin protein, and the expression levels of Mfn1, Mfn2, OPA1, Drp1, and Fis1. We found that DBYW and QZS treatment significantly increased the cell survival rate, form factor (F-factor), mitochondrial activity and ΔΨm after MPP+ treatment, while the increase of ATP levels was not significant. In addition, the results of western blot analysis showed that the MPP+ induced increase in the expression of Drp1 and Fis1, as well as decrease in Parkin, Mfn1, Mfn2, and OPA1 were all partially revised by DBYW and QZS. In summary, our data strongly suggested that DBYW and QZS treatment can exert protective effects against PD related neuronal injury through regulation the homeostasis between mitochondrial fission and fusion.

A High-Frequency-Compatible Miniaturized Bandpass Filter with Air-Bridge Structures Using GaAs-Based Integrated Passive Device Technology.

This paper reports on the use of gallium arsenide-based integrated passive device technology for the implementation of a miniaturized bandpass filter that incorporates an intertwined circle-shaped spiral inductor and an integrated center-located capacitor. Air-bridge structures were introduced to the outer inductor and inner capacitor for the purpose of space-saving, thereby yielding a filter with an overall chip area of 1178 µm × 970 µm. Thus, not only is the chip area minimized, but the magnitude of return loss is also improved as a result of selective variation of bridge capacitance. The proposed device possesses a single passband with a central frequency of 1.71 GHz (return loss: 32.1 dB), and a wide fractional bandwidth (FBW) of 66.63% (insertion loss: 0.50 dB). One transmission zero with an amplitude of 43.42 dB was obtained on the right side of the passband at 4.48 GHz. Owing to its miniaturized chip size, wide FBW, good out-band suppression, and ability to yield high-quality signals, the fabricated bandpass filter can be implemented in various L-band applications such as mobile services, satellite navigation, telecommunications, and aircraft surveillance.

Quantitative detection of glucose level based on radiofrequency patch biosensor combined with volume-fixed structures.

A concept for characterizing a radiofrequency (RF) patch biosensor combined with volume-fixed structures is presented for timely monitoring of an individual's glucose levels based on frequency variation. Two types of patch biosensors-separately integrated with a backside slot (0.53µL) and a front-side tank (0.70µL) structure-were developed to achieve precise and efficient detection while excluding the effects of interference due to the liquidity, shape, and thickness of the tested glucose sample. A glucose test analyte at different concentrations (50-600mg/dL) was dropped into the volume-fixed structures. It fully interacted with the RF patch electromagnetic field, effectively and sensitively changing the resonance frequency and magnitude of the reflection coefficient. Measurement results based on the resonance frequency showed high sensitivity up to 1.13MHz and 1.97MHz per mg/dL, and low detection limits of 26.54mg/dL and 15.22mg/dL, for the two types of patch biosensors, respectively, as well as a short response time of less than 1s. Excellent reusability of the proposed biosensors was verified through three sets of measurements for each individual glucose sample. Regression analysis revealed a good linear correlation between glucose concentrations and the resonance frequency shift. Moreover, to facilitate a multi-parameter-sensitive detection of glucose, the magnitude of the reflection coefficient was also tested, and it showed a good linear correlation with the glucose concentration. Thus, the proposed approach can be adopted for distinguishing glucose solution levels, and it is a potential candidate for early-stage detection of glucose levels in diabetes patients.

Vertical and bevel-structured SiC etching techniques incorporating different gas mixture plasmas for various microelectronic applications.

This study presents a detailed fabrication method, together with validation, discussion, and analysis, for state-of-the-art silicon carbide (SiC) etching of vertical and bevelled structures by using inductively coupled plasma reactive ion etching (ICP-RIE) for microelectronic applications. Applying different gas mixtures, a maximum bevel angle of 87° (almost vertical), large-angle bevels ranging from 40° to 80°, and small-angel bevels ranging from 7° to 17° were achieved separately using distinct gas mixtures at different ratios. We found that SF6 with additive O2 was effective for vertical etching, with a best etching rate of 3050 Å/min. As for the large-angle bevel structures, BCl3 + N2 gas mixtures show better characteristics, exhibiting a controllable and large etching angle range from 40° to 80° through the adjustment of the mixture ratio. Additionally, a Cl2 + O2 mixture at different ratios is applied to achieve a small-angel bevels ranging from 7° to 17°. A minimum bevel angel of approximately 7° was achieved under the specific volume of 2.4 sccm Cl2 and 3.6 sccm O2. These results can be used to improve performance in various microelectronic applications including MMIC via holes, PIN diodes, Schottky diodes, JFETs' bevel mesa, and avalanche photodiode fabrication.

Enhanced invasion of lung adenocarcinoma cells after co-culture with THP-1-derived macrophages via the induction of EMT by IL-6.

Lung cancer is the leading cause of cancer mortality worldwide, and the cause of death is metastasis. The epithelial-to-mesenchymal transition (EMT) plays a key role in the process of metastasis. Macrophages within the lung cancer microenvironment release cytokines, such as interleukin-6 (IL-6), and promote lung cancer cell invasion and metastasis. However, the interaction between macrophages and lung cancer cells and the effect of this interaction on the expression of IL-6, EMT, and the invasiveness of lung cancer cells remain unclear. Therefore, we established an in vitro co-culture model of human lung adenocarcinoma A549 or H1299 cells with THP-1-derived macrophages to illuminate the important role of macrophages in the invasion of lung cancer. In this study, we demonstrated that the concentrations of IL-6 in the co-culture supernatants were significantly increased compared with controls. Thus, a complex chemical cross-talk is induced by the indirect cell-to-cell contact between lung cancer cells and THP-1-derived macrophages. THP-1-derived macrophages appeared to play an important initiator role in the process. The analysis of the mRNA expression profiles of the sorted cells from the co-culture system revealed that the co-cultured lung cancer cells are the main source of the observed increase in IL-6 secretion. In addition, the interactions between lung cancer cells and THP-1-derived macrophages are bidirectional. The THP-1-derived macrophages underwent differentiation towards the M2-macrophage phenotype during the co-culture process. The expression of IL-6 was correlated with the induction of EMT, which contributed to a significant increase in the invasiveness of the A549 and H1299 cells in vitro. In addition, the addition of an anti-IL-6 antibody reversed these changes. In summary, we demonstrated that the in vitro co-culture of A549 or H1299 cells with THP-1-derived macrophages upregulates IL-6 expression, which increases the invasion ability of the A549 and H1299 cells through the EMT pathway. The THP-1-derived macrophages that interacted with the lung cancer cells differentiated towards the M2-macrophage phenotype. Thus, the inhibition of IL-6 or of the interactions between lung cancer cells and macrophages may be an effective target for anti-cancer therapy in patients with non-small cell lung cancer.