This paper focuses on the modeling challenges of a multi-cell heterojunction bipolar transistor (HBT) used in radio frequency (RF) power amplifiers and proposes an innovative linear small-signal modeling method. Based on devices with an emitter size of 3 μm × 40 μm × 2-6 (emitter width × emitter length × emitter index-cell number), an equivalent circuit model including peripheral parasitic parameters is constructed by analyzing device layout characteristics in response to additional parasitic effects introduced by the multi-cell structure. A step-by-step parameter extraction method is used, with particular attention paid to the correction of saturated current parameters, temperature coefficients, thermal resistance correction, and the optimization of junction capacitance parameters based on the capacitance ratio relationship.
View Article and Find Full Text PDFCurr Med Chem
January 2025
Prostaglandin E2 (PGE2) plays a crucial role in inflammation. Non-steroidal anti-inflammatory medications are commonly utilized to alleviate pain and address inflammation by blocking the production of PGE2 and cyclooxygenase (COX). However, selective inhibition of COX can easily lead to a series of risks for cardiovascular diseases.
View Article and Find Full Text PDFIEEE Trans Biomed Circuits Syst
June 2025
Cognitive navigation, a high-level and crucial function for organisms' survival in nature, enables autonomous exploration and navigation within the environment. However, most existing works for bio-inspired navigation are implemented with non-neuromorphic computing. This work proposes a bio-inspired memristive spiking neural network (SNN) circuit for goal-oriented navigation, capable of online decision-making through reward-based learning.
View Article and Find Full Text PDFOxidative stress caused by pregnancy-induced hypertension syndrome significantly affects the health of pregnant women. Hydrogen sulfide is a typical gaseous signal molecule against oxidative stress, and it is of profound significance to develop a detection method. In this study, a stimuli-responsive hydrogel was constructed based on the coordination and bonding principle of metal ions and chitosan (CS) to realize the quantitative detection of hydrogen sulfide (HS).
View Article and Find Full Text PDFIEEE Trans Biomed Circuits Syst
June 2024
In this article, a bionic localization memristive circuit is proposed, which mainly consists of head direction cell module, grid cell module, place cell module and decoding module. This work modifies the two-dimensional Continuous Attractor Network (CAN) model of grid cells into two one-dimensional models in X and Y directions. The head direction cell module utilizes memristors to integrate angular velocity and represents the real orientation of an agent.
View Article and Find Full Text PDFBackground: This study aims to explore the infection and age distribution of Ureaplasma urealyticum (UU), Chlamydia trachomatis (CT), Neisseria gonorrhoeae (NG) and Herpes simplex virus type II (HSV II) among the outpatients of Reproductive Medicine Center in Putian, Fujian Province to provide a clinical basis for the early diagnosis and treatment of various reproductive tract diseases and infertility in this region.
Methods: A total of 1736 samples of secretions and exfoliated cervical cells were collected from the outpatients of the Reproductive Medicine Center of the Affiliated Hospital of Putian University from December 2021 to April 2023. The infections of UU, CT, NG and HSVII were detected by real-time fluorescence polymerase chain reaction (PCR), and the infection statuses of the patients with different genders, ages and diagnoses were analysed.
Micromachines (Basel)
January 2023
The aim of this paper is to model the effects of threading dislocations on both gate and drain currents of AlGaN/GaN high electron mobility transistors (HEMTs). The fraction of filled traps increases with the threading dislocations, while the trapping effects cause a decrease in drain current and an increase in gate leakage current. To model the drain current drop, the two simplified RC subcircuits with diodes are proposed to capture the charge trapping/detrapping characteristics.
View Article and Find Full Text PDFBackground: The infection rate of human papillomavirus (HPV) is high in the coastal regions of China. However, the infection rate among high-risk genotypes of women in Putian City is unknown. Therefore, this study aimed to analyse the epidemiology of high-risk HPV infection among women in Putian and provide a reference for the diagnosis, treatment and vaccination of cervical cancer in this region.
View Article and Find Full Text PDFIEEE Trans Biomed Circuits Syst
October 2022
Classical conditioning (CC) and operant conditioning (OC), also known as associative memory, are two of the most fundamental and critical learning mechanisms in the biological brain. However, the existing designs of associative memory memristive circuits mainly focus on CC, and few studies have used memristors to imitate OC at the behavioral level, as well as the OC-CC cascaded associative memories that are widespread in biological learning processes. This work proposes an OC-CC cascaded circuit composed of OC and CC circuits.
View Article and Find Full Text PDFAs the occurrence and development of HCC are often accompanied by inflammation, the combination of sorafenib with other therapeutic drugs, especially anti-inflammatory drugs, is one of the directions to be explored at present. Our previous research has been focused on the anti-inflammatory drug 2,5-dimethylcelecoxib (DMC), whether DMC combined with sorafenib could elevate the effect of inhibiting HCC deserves further exploration. In this study, we found that DMC induced CYP3A5 expression in HCC cells in a time-dependent and concentration dependent manner.
View Article and Find Full Text PDFBackground: 2,5-dimethylcelecoxib (DMC) is a targeted inhibitor of microsomal prostaglandin E synthase-1 (mPGES-1), a key enzyme in the PGE2 synthesis pathway of inflammatory mediators. Previous studies have confirmed that DMC can inhibit the growth of hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC). However, it is not known whether DMC is involved in the changes of tumor immune microenvironment.
View Article and Find Full Text PDFIn recent years, immune checkpoint inhibitor has achieved remarkable success in multiple cancer treatment. However, how to pre-judge which patients are suitable for immune checkpoint inhibitor is a difficult problem. We use the existing public bioinformatics database to comprehensively analyze the relationship between clinical data of various cancers with immune checkpoint blocking molecules and long non-coding RNAs (lncRNAs), and try to find the potential predictive value of lncRNA for immunotherapy with checkpoint inhibitors.
View Article and Find Full Text PDFJ Enzyme Inhib Med Chem
December 2019
mPGES-1 is a terminal rate-limiting enzyme responsible for inflammation-induced PGE2 production. The inhibition of mPGES-1 has been considered as a safe and effective target for the treatment of inflammation and cancer. However, a specific, efficient, and simple method for high-throughput screening of mPGES-1 inhibitors is still lacking.
View Article and Find Full Text PDFPregnane X Receptor (PXR), a nuclear receptor transcription factor, participates in a wide range of physiological activities, but the regulation of ammonia-induced hepatocyte autophagy by PXR is not yet clear. In this study, the levels of down-regulated LC3B-II and up-regulated SQSTM1 were found in ammonia-induced PXR-overexpressing (PXR+) liver cells, but the opposite appeared in PXR-knockdown (PXR-) liver cells. Rifampicin, a PXR-activating agent, elicits a similar effect as PXR+ cells.
View Article and Find Full Text PDFThe HepG2 cell line is widely used in studying liver diseases because of its immortalization, but its clinical application is limited by its low expression of the urea synthesis key enzymes and cytochromes P450 (CYPs). On the basis of our previous work, we investigated the transcriptional regulation of arginase 1 (Arg1) and ornithine transcarbamylase (OTC) in HepG2 cells. We also screened for the optimal combination of liver enrichment transcription factors (LETFs) and xenobiotic nuclear receptors that can promote the expression of key urea synthases and five major CYPs in HepG2 cells.
View Article and Find Full Text PDFCarbamoyl phosphate synthase 1 (CPS1) is the rate-limiting enzyme in the first step of the urea cycle and an indispensable enzyme in the metabolism of human liver. However, CPS1 epigenetic regulation involves promoter analysis and the role of liver-enriched transcription factors (LETFs), which is not fully elucidated. In this work, the promoter region of hCPS1 gene was cloned, and its activity was investigated.
View Article and Find Full Text PDFThe polyamidoamine (PAMAM) dendrimer, a type of macromolecule material, has been used in spheroidal cell culture and drug delivery in recent years. However, PAMAM is not involved in the study of hepatic cell-spheroid culture or its biological activity, particularly in detoxification function. Here, we constructed a PAMAM-dendrimer conjugate decorated by an integrin ligand: arginine-glycine-aspartic acid (RGD) peptide.
View Article and Find Full Text PDF