Identification of critical genes associated with radiotherapy resistance in cervical cancer by bioinformatics

BackgroundCervical cancer (CC) is one of the common malignant tumors in women, Currently, 30% of patients with intermediate to advanced squamous cervical cancer are still uncontrolled or recurrent after standard radical simultaneous radiotherapy; therefore, the search for critical genes affecting the sensitivity of radiotherapy may lead to new strategies for treatment.MethodsFirstly, differentially expressed genes (DEGs) between radiotherapy-sensitivity and radiotherapy-resistance were identified by GEO2R from the gene expression omnibus (GEO) website, and prognosis-related genes for cervical cancer were obtained from the HPA database. Subsequently, the DAVID database analyzed gene ontology (GO). Meanwhile, the protein-protein interaction network was constructed by STRING; By online analysis of DEGs, prognostic genes, and CCDB data that are associated with cervical cancer formation through the OncoLnc database, we aim to search for the key DEGs associated with CC, Finally, the key gene(s) was further validated by immunohistochemistry.Result298 differentially expressed genes, 712 genes associated with prognosis, and 509 genes related to cervical cancer formation were found. The results of gene function analysis showed that DEGs were mainly significant in functional pathways such as variable shear and energy metabolism. By further verification, two genes, ASPH and NKAPP1 were identified through validation as genes that affect both sensitivities to radiotherapy and survival finally. Then, immunohistochemical results showed that the ASPH gene was highly expressed in the radiotherapy-resistant group and had lower Overall survival (OS) and Progression-free survival (PFS).ConclusionThis study aims to better understand the characteristics of cervical cancer radiation therapy resistance-related genes through bioinformatics and provide further research ideas for finding new mechanisms and potential therapeutic targets related to cervical cancer radiation therapy

Analysis, design and implementation of a non-isolated switched inductor/capacitor converter with low voltage spikes

In order to take the advantage of boost capability and filtering characteristics of the switched inductor/capacitor, a non-isolated switched inductor/capacitor (NSI/C) converter is proposed. The topological structure of the non-isolated switched inductor/capacitor converter is analyzed in detail, and the DC steady-state model is established in continuous conduction mode (CCM). The voltage gain of the converter and the stress of the switch in the converter are theoretically deduced and compared with the existing converters; the parameter design of the inductance and capacitance is calculated. The simulation model was built in MATLAB/Simulink, and the correctness of the theoretical calculation for the proposed converter was verified by simulation results. Finally, the experimental prototypes of the proposed converter and the non-isolated high step-up (NHS) converter were built. Through the comparison of experimental results, the feasibility and validity of the design scheme for the proposed converter are verified.Published versionThis work was financially supported by Key Research and Development Project of Hebei Province (18214302D) and (19212101D), Open Project of Provincial Collaborative Innovation Center of Industrial Energy-saving and Power Quality Control, Anhui Province (KFKT201504), Natural Science Foundation of Hebei Province (F2018205178)

A High-Gain DC-DC Converter with a Wide Range of Output Voltage

In fuel-cell-powered electric vehicles, the output characteristics of the fuel cell are relatively soft, and the output voltage is unstable. Therefore, a DC-DC converter is required between the fuel cell and the inverter to transform the output voltage of the fuel cell into a suitable voltage for the motor drive. Existing non-isolated DC-DC converters cannot meet the requirements of high voltage gain, high efficiency and a wide range of output voltage simultaneously. To improve these performances, a high-gain DC-DC converter with a wide range of output voltage, based on a switched capacitor structure, is proposed in this paper. The converter supplies power to the load by connecting multiple capacitors with the input source in series in switch-on states, while the input source charges the capacitors through a series connection with an inductor in switch-off states. In comparison to existing converters, the proposed converter maintains high voltage gain at lower duty ratios and offers a wide range of output voltage. The operating principles, key waveforms and parameter design of the topology in Continuous Conduction Mode (CCM) are described and analyzed in detail, and the voltage gain of the proposed converter is compared with some other DC-DC converters. Finally, the results of simulations using Simulink and hardware experiments that were conducted to validate the theoretical analysis are described

A Topology Generation and Synthesis Method for Boost Converters Based on Inductive Volt-Second Balance Theory

In this paper, a comprehensive method is proposed to derive the boost DC–DC converter from a given gain formula. The given gain formula is obtained by analyzing, generalizing, and summarizing previous boost structures in the literature. The analysis is based on the volt-second balance theory of inductors. Thus, the gain formula is only related to two elements, the connection between components and the duty cycle of the switches. Therefore, the topology corresponding to the gain can be derived and synthesized according to the connection of the inductors and the capacitor components during the commutation of the switch to meet the demand for different boost converters in different applications. Meanwhile, all the three-order gain formulas generated by this method are analyzed and three of them are selected for topology simplification and focus analysis, and the correctness of the selected topologies is verified by the simulation results and experimental results

Improved Active Islanding Detection Technique with Different Current Injection Waveform

The active frequency drift (AFD) method is an effective method to detect islanding in grid-connected photovoltaic systems. However, it has some inherent drawbacks, such as generating higher harmonics. In order to reduce the harmonics and non-detection zone (NDZ), various improved AFD methods have been proposed, but they still suffer from high harmonics and reduced detection speed. To overcome these limitations, this paper proposes an innovative islanding detection technique based on AFD. Analysis reveals that the proposed method reduces harmonics by 68% compared to conventional AFD and has a larger chopping factor. Therefore, this technique offers several distinct advantages, including accelerated detection speed, reduced NDZ and harm caused by disturbances, and improved power quality. Furthermore, to verify the harmonic impact of this proposed islanding detection method, simulations and analyses are conducted using simulation software of Matlab/Simulink. An experimental prototype is set up in Laboratory. The simulation and experimental results demonstrate the superiority of the proposed method

A five-level inverter based on differential structure

Due to the advantages of low harmonic, low pollution to the power grid, and easy filtering, multilevel inverters have attracted more attention in recent years. In this paper, a five-level inverter based on the differential structure is proposed. It doesn’t need an additional bridge arm to change the polarity of the output voltage, but synthesize the structure of generating multiple voltages and changing the polarity of the output voltage. In addition, the special symmetrical structure of the inverter solves the problem of unbalanced capacitor voltage. The proposed five-level inverter is simulated by MATLAB/Simulink and the prototype is made to experiment.Published versionThis work was financially supported by the S&T Program of Hebei (22352201D) and (19212101D) and the Open Project of Provincial Collaborative Innovation Center of Industrial Energy-saving and Power Quality Control, Anhui Province (KFKT201504) Science Foundation of Hebei Normal University (L2023J03)

TMEM41B and VMP1 are scramblases and regulate the distribution of cholesterol and phosphatidylserine.

TMEM41B and VMP1 are integral membrane proteins of the endoplasmic reticulum (ER) and regulate the formation of autophagosomes, lipid droplets (LDs), and lipoproteins. Recently, TMEM41B was identified as a crucial host factor for infection by all coronaviruses and flaviviruses. The molecular function of TMEM41B and VMP1, which belong to a large evolutionarily conserved family, remains elusive. Here, we show that TMEM41B and VMP1 are phospholipid scramblases whose deficiency impairs the normal cellular distribution of cholesterol and phosphatidylserine. Their mechanism of action on LD formation is likely to be different from that of seipin. Their role in maintaining cellular phosphatidylserine and cholesterol homeostasis may partially explain their requirement for viral infection. Our results suggest that the proper sorting and distribution of cellular lipids are essential for organelle biogenesis and viral infection