Search Results (51)

Low-refresh-rate driving is an effective way to reduce the power consumption of active-matrix organic light-emitting diode (AMOLED) displays. However, in conventional low-temperature polycrystalline silicon (LTPS) thin-film transistor (TFT) pixel circuits, leakage current through switching TFTs can disturb the stored gate voltage of the driving TFT during the long emission period. This causes the time-dependent variation in driving current and visible flicker. In this study, a novel pixel circuit for leakage suppression in low-refresh-rate driving is presented. Bias aging was first applied to reduce the leakage current of the LTPS TFT, and a device model was then built from the characteristics measured at 60 °C. Based on this model, the leakage-induced instability of a conventional 7T1C pixel circuit was analyzed. To suppress this effect, a new 8T1C pixel circuit was proposed. The key idea is to reduce the source–drain voltage of the leakage-sensitive switching TFT during the emission period by raising the initial line potential to a level close to the storage node potential. Simulation results show that the proposed circuit greatly reduces the time-dependent variation in both the driving TFT gate voltage and the driving current compared with the conventional 7T1C circuit. Perceptual evaluation based on human visual sensitivity also confirms stable low-refresh-rate operation down to 20 Hz over the practical gray range. These results show that the proposed circuit is an effective solution for moderate low-refresh-rate operation without relying on low-temperature polycrystalline silicon and oxide (LTPO) technology. Full article

Channel length modulation (CLM) in indium gallium zinc oxide (IGZO) thin film transistors (TFTs) reduces the output resistance (r_o) in the saturation regime. It also degrades current driving accuracy for active matrix organic light emitting diode (AMOLED) backplanes. For top gate, self-aligned devices with nominal channel lengths of 5–15 μm, transmission line method (TLM) analysis yields an effective channel length reduction (ΔL) of about 1.8 μm. This result is consistent with lateral hydrogen redistribution from the self-aligned source/drain (S/D) process. At L = 5 μm, the conventional TFT exhibits r_o = 13.5 ± 2.5 MΩ and an Early voltage (V_A) = 56.1 ± 10.4 V (n = 5). We propose a source connected bottom gate (SCBG) structure that electrostatically stabilizes the pinch-off region and suppresses CLM. The SCBG TFT increases r_o to 475 ± 52 MΩ and V_A to 1159 ± 173 V at L = 5 μm (n = 5), while maintaining normal transfer characteristics. Two-dimensional device simulations reproduce the trend and show that the drain-bias-induced pinch-off shift is reduced, with d(ΔL)/dV_DS decreasing from 0.027 to 0.012 μm/V (about 55%). These results indicate that the SCBG approach is effective for enhancing current saturation in short channel IGZO TFTs for high-resolution AMOLED applications. Full article

Gate driver-on-array (GOA) circuits employing amorphous indium–gallium–zinc oxide (IGZO)-based thin-film transistors (TFTs) have been successfully utilized to generate the driving signals for the commercialization of active-matrix organic light-emitting diode (AMOLED) displays. The depletion-mode TFTs in GOA circuits can be completely turned off by the introduction of series-connected, two-transistor, dual low-voltage-level power signals. Simulation results demonstrate that a GOA exhibits high process stability with a threshold voltage margin from −5 V to +5 V. Furthermore, the GOA output characterization and mobility compensation effect are evaluated by the integration of the GOA and pixel in a 31-inch 4K AMOLED display. Experimental results demonstrate that full-swing driving pulses can be obtained with the GOA. Finally, the stripe mura in the display caused by mobility variation can be successfully eliminated by the introduction of GOA circuits. Full article

Electrochemical detection is widely used in environmental, health, and food analysis due to its portability, low cost, and high sensitivity. However, when analytes with similar redox potentials coexist, overlapping voltammetric signals often occur, which compromises detection accuracy and sensitivity. In this study, a simple second-derivative image sharpening (IS) algorithm is applied to the electrochemical detection of chlorophenol (CP) isomers with similar redox behaviors. Specifically, a graphene-modified electrode was employed for the electrochemical detection of two chlorophenol isomers: ortho-CP (o-CP) and meta-chlorophenol (m-CP) in the range from 1.0 to 10.0 μmol/L. After image-sharpening, the peak potential difference between o- and m-CP increased from 0.08 V to 0.12 V. The limits of detection (LOD) for o-CP and m-CP decreased from 0.6 to 0.9 μmol/L to 0.12 and 0.31 μmol/L, respectively. The corresponding sensitivities also improved from 0.92 to 1.35 A/(mol L⁻¹) to 4.11 and 3.71 A/(mol L⁻¹), respectively. Moreover, the sharpened voltammograms showed enhanced peak resolution, facilitating visual discrimination of the two isomers. These results demonstrate that image sharpening can significantly improve peak shape, peak separation, sensitivity, and detection limit in electrochemical analysis. The obtained algorithm is computationally efficient (<30 lines of C++ (Version 6.0)/OpenCV, executable in <1 ms on an ARM-M0 microcontroller) and easily adaptable to various programming environments, offering a promising approach for data processing in portable electrochemical sensing systems. Full article

Mining waste often contains elevated concentrations of V, Cr, As, Sb, and Pb. Stibnite mining, during extraction and processing, generates waste that is deposited directly onto soil without vegetation cover, potentially leading to environmental pollution. This study assessed concentrations of potentially toxic elements (PTEs) in the rhizoids and stems-phyllidia of terrestrial mosses near antimony mines and used these mosses as biomonitors of soil contamination. Results obtained via energy-dispersive X-ray fluorescence spectrometry showed the highest concentrations of As, Sb, and Pb in mosses growing on mining rubble, reflecting elevated contaminant levels in the study area. Concentrations of As, Sb, and Pb differed significantly between mosses from mine rubble sites and those from forest and meander sites. Both rhizoids and stems/phyllidia of mosses from rubble sites showed high enrichment factors (EFs) for As, Sb, and Pb. Notably, PTEs concentrations in mosses from the forest area were lower than values reported for other regions, whereas concentrations in the mine rubble area exceeded those reported for other mining-polluted regions worldwide. Full article

Co-infections pose significant challenges not only clinically, but also in terms of simultaneous diagnoses. The development of sensitive, multiplexed analytical platforms is critical for accurately detecting viral co-infections, particularly in complex biological environments. In this study, we present a mass spectrometry (MS)-based detection strategy employing a target-triggered hybridization chain reaction (HCR) to amplify signals and in situ photocleavable mass tags (PMTs) for the simultaneous detection of multiple targets. Hairpin DNAs modified with PMTs and immobilized loop structures on magnetic particles (Loop@MPs) were engineered for each target, and their hybridization and amplification efficiency was validated using native polyacrylamide gel electrophoresis (PAGE) and laser desorption/ionization MS (LDI-MS), with silica@gold core–shell hybrid (SiAu) nanoparticles being employed as an internal standard to ensure quantitative reliability. The system exhibited excellent sensitivity, with a detection limit of 415.12 amol for the hepatitis B virus (HBV) target and a dynamic range spanning from 1 fmol to 100 pmol. Quantitative analysis in fetal bovine serum confirmed high accuracy and precision, even under low-abundance conditions. Moreover, the system successfully and simultaneously detected multiple targets, i.e., HBV, human immunodeficiency virus (HIV), and hepatitis C virus (HCV), mixed in various ratios, demonstrating clear PMT signals for each. These findings establish our approach as a robust and reliable platform for ultrasensitive multiplexed detection, with strong potential for clinical and biomedical research. Full article

The rapid rise of flexible AMOLED displays has prompted manufacturers to advance technologies to meet growing global demand. However, high costs and quality inconsistencies hinder industry competitiveness and sustainability. This study addresses these challenges by developing an intelligent optimization system for the fine metal mask (FMM) etching process, a critical step in producing high-resolution AMOLED panels. The system integrates advanced optimization techniques, including the Taguchi method, analysis of variance (ANOVA), back-propagation neural network (BPNN), and a hybrid particle swarm optimization–genetic algorithm (PSO-GA) approach to identify optimal process parameters. Experimental results demonstrate a marked improvement in product yield and process stability while reducing manufacturing costs. By ensuring consistent quality and efficiency, this system overcomes limitations of traditional process control; strengthens the AMOLED industry’s global competitiveness; and provides a scalable, sustainable solution for smart manufacturing in next-generation display technologies. Full article

The association between microRNAs and various diseases, especially cancer, has been established in recent years, indicating that miRNAs can potentially serve as biomarkers for these diseases. Determining miRNA concentrations in biological samples is crucial for disease diagnosis. Nevertheless, the stem-loop reverse transcription quantitative PCR method, the gold standard for detecting miRNA, has great challenges in terms of high costs and enzyme limitations when applied to clinical biological samples. In this study, an isothermal signal amplification method based on a duplex-specific nuclease (DSN) enzyme-driven DNA walker and an improved catalytic hairpin assembly (CHA) was designed for miRNA detection. First, biotin–triethylene glycol-modified trigger-releasable DNA probes were conjugated to the streptavidin-coated magnetic beads for recognizing the target miRNA. The DSN enzyme specifically hydrolyzes DNA strands when the DNA probe hybridizes with the targeted miRNA. This recycling process converts the input miRNA into short trigger fragments (catalysts). Finally, three hairpins of improved CHA are driven by this catalyst, resulting in the three-armed CHA products and a fluorescence signal as the output. This dual-cycle biosensor shows a good linear relationship in the detection of miR-21 and miR-141 over the final concentration range of 250 fM to 50 nM, presenting an excellent limit of detection (2.95 amol). This system was used to detect miR-21 and miR-141 in MCF-7 and 22RV1 cells, as well as in 1% human serum. This system can be used to evaluate the expression levels of miRNAs in different biological matrices for the clinical diagnosis and prognosis of different cancers. Full article

The association between microRNA (miRNA) and various diseases has been established; miRNAs have the potential to be biomarkers for these diseases. Nevertheless, the challenge of correctly quantifying an miRNA arises from its low abundance and a high degree of family homology. Therefore, in the present study, we devised a chemiluminescence (CL) detection method for miRNAs, known as the hybridization chain reaction (HCR)-CL, utilizing the enzyme-free signal amplification technology of HCR. The proposed methodology obviates the need for temperature conversion and offers a straightforward procedure owing to the absence of enzymatic participation, and the lumino-H₂O₂-mediated CL reaction occurs at a high rate. The technique successfully detected 2.5 amol of the target analyte and 50 amol of miR-146b in a 1% concentration of human serum. In summary, the method developed in this study is characterized by its ease of operation, cost-effectiveness, remarkable analytical prowess, and ability to detect miRNA without the need for total RNA extraction from serum samples. This method is expected to be widely used for biological sample testing in clinical settings. Full article

In active-matrix organic light-emitting diode (AMOLED) displays, conventional pixel circuits that compensate for the non-uniformity of the threshold voltage (V_T) of low-temperature polycrystalline silicon thin-film transistors (TFTs) can hardly compensate for variations in other TFT parameters, such as carrier mobility (μ₀), subthreshold swing (SS) and the various effects of parasitic capacitance. In recent high-resolution AMOLED displays, as the current required for OLED pixel driving decreases, the current error rate (CER) caused by the non-uniform TFT parameters increases. In this study, we analyzed the influence of each TFT parameter on the CER using SPICE simulation. Based on our analysis, the origin of the increased CER can be classified into two categories: the charging capability of driving TFT and the capacitive coupling effect of the switching TFT. The SS of the driving TFT and the parasitic capacitance of the switching TFT are major factors that affect the CER in terms of the charging capability and capacitive coupling effect, respectively. Our analysis results can be summarized as follows: The SS value of the driving TFT should be high, and its variation should be small to minimize the CER. The variation in the parasitic capacitance of the switching TFT possibly occurs due to long-term bias conditions, as well as process non-uniformity. Therefore, the stability of TFT should also be confirmed for the prevention of anomalous CER caused by long-term bias stress. Full article

Large-size and high-resolution AMOLED displays have become one of the most attractive display technologies. However, the dependence of the luminance of AMOLED on temperature severely limits wider applications. The accurate temperature distribution is important for implementing compensation into a panel to improve display uniformity. With the increase in size and resolution, the voltage drop (IR-drop) caused by the resistance of the power supply line cannot be ignored, which has influence on temperature distribution. Therefore, this paper proposes a temperature distribution analysis method based on IR-drop. Firstly, an accurate solution of IR-drop of AMOLED panels is achieved by exploiting the sparse representation in the field of artificial intelligence. Secondly, the IR-drop-based power model is established, and the output of the power model is used as the input of the AMOLED thermal simulation model. Finally, the temperature distribution of the AMOLED panel is obtained by finite-element analysis. The temperature measurements are performed on a 95-inch 8K AMOLED panel. The simulation results are compared with the actual measurements, and it is found that the temperature distribution based on IR-drop matches well with the actual measurements than that without considering IR-drop. The analysis method proposed in this paper presents high accuracy and high practicability. Full article

Background: Many epigenetic factors, including microRNAs, are involved in the process of changing gene expressions. Small non-coding RNA molecules, called miRNAs, are responsible for regulating gene translation by silencing or degrading target mRNAs. It is acknowledged that for many diseases, they may be novel diagnostic and prognostic biomarkers. Patients with autoimmune thyroid diseases are more likely to develop nodules in the thyroid tissue, and Hashimoto’s thyroiditis and Graves’ disease predispose patients to thyroid cancer. We evaluated the concentrations of microRNA molecules (miR-15a-5p, miR-126-3p, miR-142-5p, miR-21-5p, miR-150-5p) in the blood of children with thyroid disorders. In addition, we wished to identify molecules whose change in concentration predisposes to the development of thyroid cancer. Aim: The aim of this study is to evaluate selected epigenetic elements by analyzing the levels of miR-15a-5p, miR-126-3p, miR-142-5p, miR-150-5p and miR-21-5p in the blood of pediatric patients with Graves’ disease (n = 25), Hashimoto’s thyroiditis (n = 26) and thyroid nodular disease (n = 20) compared to a control group of healthy children (n = 17). Materials and Methods: The study consists of groups of children and adolescents aged 10–18 years with autoimmune thyroid disease, with thyroid nodular disease compared to a control group. The miR-15a-5p, miR-126-3p, miR-142-5p, miR-21-5p and miR-150-5p molecules were determined through an immunoenzymatic assay using BioVendor reagents. Results: There is a statistically significant decrease in the expression of the miR-15a-5p in children with Graves’ disease (21.61 vs. 50.22 amol/μL, p = 0.03) and in patients with thyroid nodular disease compared to controls (20.23 vs. 50.22 amol/μL, p = 0.04). Higher levels of the miR-142-5p molecule are found in patients with thyroid disease (with GD-3.8 vs. 3.14 amol/μL, p = 0.01; with HT-3.7 vs. 3.14 amol/μL, p = NS, with thyroid nodular disease-4.16 vs. 3.14 amol/μL, p = 0.04). Lower levels of miR-126-3p were noted in the GD group compared to the control group (7.09 vs. 7.24 amol/μL, p = 0.02). No statistically significant changes in the expressions of miR-150-5p and miR-21-5p molecules were observed in the study groups. Conclusions: 1. The overexpression of the miR-142-5p molecule occurs in children and adolescents with thyroid diseases. 2. Decreased blood levels of miR-15a-5p predispose patients to the formation of focal lesions in the thyroid gland. 3. Identifying a lower expression of the miR-126-3p molecule in the blood of children with GD requires careful follow-up for the development of focal lesions in the thyroid gland and evaluation for their potential malignancy. Full article

The development of various enzyme-linked immunosorbent assays (ELISAs) coupled with surface-enhanced Raman scattering (SERS) detection is a growing area in analytical chemistry due to their potentially high sensitivity. A SERS-based ELISA with horseradish peroxidase (HRP) as an enzymatic label, an o-phenylenediamine (oPD) substrate, and a 2,3-diaminophenazine (DAP) enzymatic product was one of the first examples of such a system. However, the full capabilities of this long-known approach have yet to be revealed. The current study addresses a previously unrecognized problem of SERS detection stage performance. Using silver nanoparticles and model mixtures of oPD and DAP, the effects of the pH, the concentration of the aggregating agent, and the particle surface chloride stabilizer were extensively evaluated. At the optimal mildly acidic pH of 3, a 0.93 to 1 M citrate buffer, and AgNPs stabilized with 20 mM chloride, a two orders of magnitude advantage in the limits of detection (LODs) for SERS compared to colorimetry was demonstrated for both DAP and HRP. The resulting LOD for HRP of 0.067 pmol/L (1.3 amol per assay) underscores that the developed approach is a highly sensitive technique. We suppose that this improved detection system could become a useful tool for the development of SERS-based ELISA protocols. Full article

This paper presents a DC-DC converter with wide-range negative output for active-matrix organic light-emitting diode (AMOLED). The generated negative voltage $V_{out}$ is connected to the negative terminal of the organic light-emitting diode (OLED), and the luminous brightness is adjusted by changing the value of $V_{out}$. The negative output voltage of the DC-DC converter is regulated by a Buck–Boost topology structure with a dual-loop control (DLC) system composed of a voltage loop and a current loop. The proposed compensatory peak-current-sensing technique (PCST) and switch MOSFETs adaptive drive technique (ADT) successfully support the implementation of the converter topology and enable the converter to work in continuous conduction mode (CCM). In addition, with the DLC system, the converter can guarantee a negative output voltage that enables both a fast transient response such as excellent load/line regulation, and a small output voltage ripple of the pulse width modulation (PWM) control. The proposed chip is implemented in a $0.18 \mathsf{\mu }\mathrm{m}$ CMOS process that operates at an operating frequency of $2 \mathrm{M}\mathrm{H}\mathrm{z}$ with a maximum efficiency of $85.82\mathrm{\%}$. The output voltage ripple is $1.5 \mathrm{m}\mathrm{V}$ at typical loading of $V_{out}=-4 \mathrm{V}$ and $I_{out}=100 \mathrm{m}\mathrm{A}$. Full article

A comparative analysis of the cytostatic effects of progestins (gestobutanoyl, megestrol acetate, amol, dienogest, and medroxyprogesterone acetate), glucocorticoids (hydrocortisone, dexamethasone), and diclofenac on tumor cells was carried out in order to confirm their in silico predicted probabilities experimentally. The results showed the different sensitivity of HeLa, MCF-7, Hep-2, K-562, and Wi-38 cell lines to progestins, glucocorticoids, and diclofenac. The minimum IC₅₀ was found for progestin gestobutanoyl (GB) as 18 µM for HeLa cells, and varied from 31 to 38 µM for MCF-7, Hep-2, and K-562. Glucocorticoids and diclofenac were much less cytotoxic in the HeLa, MCF-7, and Hep-2 cell lines than progestins, with IC₅₀ values in the range of 150–3000 μM. Myelogenous leukemia K-562 cells were the least sensitive to the action of progestins and glucocorticoids but the most sensitive to diclofenac, which showed a pronounced cytotoxic effect with an IC₅₀ of 31 μM. As we have shown earlier, progestins can uniquely modulate MPTP opening via the binding of adenine nucleotide translocase. On this basis, we evaluated the expression of adenylate nucleotide translocase ANT1 (SLC25 A4) as a possible participant in cytotoxic action in these cell lines after 48 h incubation with drugs. The results showed that progestins differently regulated ANT1 expression in different cell lines. Gestobutanoyl had the opposite effect on ANT1 expression in the HeLa, K562, and Wi-38 cells compared with the other progestins. It increased the ANT1 expression more than twofold in the HeLa and K562 cells but had no influence on the Wi-38 cells. Glucocorticoids and diclofenac increased ANT1 expression in the Wi-38 cells and decreased it in the K562, MCF-7, and Hep-2 cells. The modulation of ANT1 expression discovered in our study can be a new explanation of the cytotoxic and cytoprotective effects of hormones, which can vary depending on the cell type. ANT isoforms in normal and cancerous cells could be a new target for steroid hormone and anti-inflammatory drug action. Full article