Fluctuation Power Control Strategy for MMC-based SST to Reduce the Submodule Capacitor Voltage Oscillation

Xiaolong Cai,Jianwen Zhang,Gang Shi,Xu Cai,Jianqiao Zhou,Zhuyong Li,Jiacheng Wang,Jiajie Zang 전력전자학회 2019 ICPE(ISPE)논문집 Vol.2019 No.5

In the future AC-DC hybrid distribution system, solid state transformer (SST) will take place of conventional transformer, as it could reduce the weight and volume of transformer, and achieve voltage and current regulation, power flow control, power quality enhancement. MMC-based SST is a novel SST topology, which could provide the MVDC port. However, the excessive bulky submodule capacitors limits this topology into practical application. This paper proposes a fluctuation power control strategy for MMC-based SST to reduce the submodule capacitor voltage oscillation, which could optimize the capacitance and reduce the volume and cost of capacitor. The feasibility of this proposed method is verified by MATLAB simulation.

Glial and Vascular Cell Regulation of the Blood-Brain Barrier in Diabetes

Xiaolong Li,Yan Cai,Zuo Zhang,Jiyin Zhou 대한당뇨병학회 2022 Diabetes and Metabolism Journal Vol.46 No.2

As a structural barrier, the blood-brain barrier (BBB) is located at the interface between the brain parenchyma and blood, and modulates communication between the brain and blood microenvironment to maintain homeostasis. The BBB is composed of endothelial cells, basement membrane, pericytes, and astrocytic end feet. BBB impairment is a distinguishing and pathogenic factor in diabetic encephalopathy. Diabetes causes leakage of the BBB through downregulation of tight junction proteins, resulting in impaired functioning of endothelial cells, pericytes, astrocytes, microglia, nerve/glial antigen 2-glia, and oligodendrocytes. However, the temporal regulation, mechanisms of molecular and signaling pathways, and consequences of BBB impairment in diabetes are not well understood. Consequently, the efficacy of therapies diabetes targeting BBB leakage still lags behind the requirements. This review summarizes the recent research on the effects of diabetes on BBB composition and the potential roles of glial and vascular cells as therapeutic targets for BBB disruption in diabetic encephalopathy.

Transcriptome analysis of Δmig1Δmig2 mutant reveals their roles in methanol catabolism, peroxisome biogenesis and autophagy in methylotrophic yeast Pichia pastoris

Lei Shi,Xiaolong Wang,Jinjia Wang,Ping Zhang,Fei Qi,Menghao Cai,Yuanxing Zhang,Xiangshan Zhou 한국유전학회 2018 Genes & Genomics Vol.40 No.4

Two catabolite repressor genes (MIG1 and MIG2) were previously identified in Pichia pastoris, and the derepression of alcohol oxidase (AOX) expression was realized in Δmig1 or Δmig1Δmig2 mutants grown in glycerol, but not in glucose. In this study, genome-wide RNA-seq analysis of Δmig1Δmig2 and the wild-type strain grown in glycerol revealed that the expression of numerous genes was greatly altered. Nearly 7% (357 genes) of approximately 5276 genes annotated in P. pastoris were significantly upregulated, with at least a two-fold differential expression in Δmig1Δmig2; the genes were mainly related to cell metabolism. Approximately 23% (1197 genes) were significantly downregulated; these were mainly correlated with the physiological characteristics of the cell. The methanol catabolism and peroxisome biogenesis pathways were remarkably enhanced, and the genes AOX1 and AOX2 were upregulated higher than 30-fold, which was consistent with the experimental results of AOX expression. The Mig proteins had a slight effect on autophagy when cells were grown in glycerol. The expression analysis of transcription factors showed that deletion of MIG1 and MIG2 significantly upregulated the binding of an essential transcription activator, Mit1p, with the AOX1 promoter, which suggested that Mig proteins might regulate the AOX1 promoter through the regulation of Mit1p. This work provides a reference for the further exploration of the methanol induction and catabolite repression mechanisms of AOX expression in methylotrophic yeasts.

Simultaneous removal of NOx and SO2 using two-stage O3 oxidation combined with Ca(OH)2 absorption

Yang Zou,Yan Wang,Xiaolong Liu,Tingyu Zhu,Mengkui Tian,Maoyu Cai 한국화학공학회 2020 Korean Journal of Chemical Engineering Vol.37 No.11

This paper proposes two-stage O3 oxidation combined with Ca(OH)2 for simultaneous removal of NOx and SO2 (NOx: Nitrogen oxides including NO, NO2 and N2O5). In two-stage oxidation, NO was first oxidized to NO2 in an oxidation tube, and NO2 was further oxidized into N2O5 in the spray tower. NOx and SO2 were simultaneously removed in the spray tower. This method can effectively reduce the extra waste of O3 caused by the decomposition of N2O5, especially at high temperature. Effects of various factors on denitrification efficiency were investigated. The results showed that the NOx removal efficiency decreased and O3 extra consumption ratio increased with the increase of oxidation temperature or oxidation reaction time. When the O3/NO molar ratio was 1.8, one-stage O3 oxidation at 150 oC extra wasted 33.3% of O3. With the increase of O3 concentration at site 2, the NOx removal efficiency first increased and then stabilized. Compared with the one-stage O3 oxidation-absorption, the two-stage oxidation-absorption improved NOx removal efficiency from 62.5% to 89%. In addition, the increase of CaSO3 slurry concentration had little effect on the denitrification efficiency.

Genome Sequencing Highlights the Plant Cell Wall Degrading Capacity of Edible Mushroom Stropharia rugosoannulata

Guo Mengpei,Ma Xiaolong,Zhou Yan,Bian Yinbing,Liu Gaolei,Cai Yingli,Huang Tianji,Dong Hongxia,Cai Dingjun,Wan Xueji,Wang Zhihong,Xiao Yang,Kang Heng 한국미생물학회 2023 The journal of microbiology Vol.61 No.1

The basidiomycetous edible mushroom Stropharia rugosoannulata has excellent nutrition, medicine, bioremediation, and biocontrol properties. S. rugosoannulata has been widely and easily cultivated using agricultural by-products showing strong lignocellulose degradation capacity. However, the unavailable high-quality genome information has hindered the research on gene function and molecular breeding of S. rugosoannulata. This study provided a high-quality genome assembly and annotation from S. rugosoannulata monokaryotic strain QGU27 based on combined Illumina-Nanopore data. The genome size was about 47.97 Mb and consisted of 20 scaffolds, with an N50 of 3.73 Mb and a GC content of 47.9%. The repetitive sequences accounted for 17.41% of the genome, mostly long terminal repeats (LTRs). A total of 15,726 coding gene sequences were putatively identified with the BUSCO score of 98.7%. There are 142 genes encoding plant cell wall degrading enzymes (PCWDEs) in the genome, and 52, 39, 30, 11, 8, and 2 genes related to lignin, cellulose, hemicellulose, pectin, chitin, and cutin degradation, respectively. Comparative genomic analysis revealed that S. rugosoannulata is superior in utilizing aldehyde-containing lignins and is possible to utilize algae during the cultivation.

Optimization of Nutrients for Dinactin Production by a Marine Streptomyces sp. from the High Latitude Arctic

Jiao Zhou,Hao He,Xiaolong Wang,Jian Lu,Xiangshan Zhou,Menghao Cai,YuanXingZhang 한국생물공학회 2015 Biotechnology and Bioprocess Engineering Vol.20 No.4

Streptomyces sp. R-527F, which produces the macrotetrolide antibiotic dinactin, was isolated from the sediments of the Arctic Ocean. In this work, optimization of the nutrients required for dinactin production including medium development and precursor stimulation, were investigated. Optimization of the medium and replacement of polar sea water were achieved using a one factor at a time experiment in conjunction with statistical analysis using methods covering Plackett–Burman design, the steepest descent method and central composite design. Dinactin production in the optimized medium was 160.8 mg/L, which was 47 fold higher than the control. Supplementation of the fermentation with exogenous acetate (1.5 mmol/L), succinate (6 mmol/L), malonate (24 mmol/L) and citrate (6 mmol/L) further enhanced dinactin biosynthesis by 42.7, 122.3, 66.7, and 62.1%, respectively. The precursors, in particular succinate, facilitated sugar use and also increased pH levels. Furthermore, a six-pulse feeding of total 6 mmol/L succinate in a 5 L bioreactor fermentation yielded a maximal production of 279.0 mg/L dinactin, 124.1% higher than that without precursor stimulation. This nutritional regulation process is easy to scale up and holds the potential for adaptation to industrial use. Keywords: arctic actinomycete, fermentation, dinactin

Identification and validation of an ECM organization-related gene signature as a prognostic biomarker and therapeutic target for glioma patients

Zhong Qiong,Zhong Qiuxia,Cai Xiaolong,Wu Renrui 한국유전학회 2023 Genes & Genomics Vol.45 No.9

Background Glioma is the most common and devastating form of malignant brain tumor, with a poor prognosis. Extracellular matrix (ECM) organization is a crucial determinant of glioma invasion and progression. However, the clinical significance of ECM organization in glioma patients remains unclear. Objective To evaluate the prognostic value of ECM organization-related genes in glioma patients and identify potential therapeutic targets. Methods Bulk RNA-sequencing and corresponding clinical data for patients with glioma were downloaded from TCGA and GEO databases. Differentially expressed ECM organization genes were identified, and an ECM organization-related gene prognostic model was then generated. Furthermore, the prognostic model has validated in the Chinese Glioma Genome Atlas (CGGA) dataset. The role of TIMP1 in glioma cells by using various functional assays revealed their underlying mechanism in vitro. Results We identified and validated a nine-gene signature (TIMP1, SERPINE1, PTX3, POSTN, PLOD3, PDPN, LOXL1, ITGA2, and COL8A1) related to ECM organization as a robust prognostic biomarker for glioma. Time-dependent ROC curve analysis confirmed the specificity and sensitivity of the signature. The signature was closely related to an immunosuppressive phenotype, and its combination with immune checkpoints served as a good predictor for patients' clinical outcomes. Notably, single-cell RNA sequencing analysis revealed high expression of TIMP1 in astrocytes and oligodendrocyte progenitor cells in glioma patients. Last, we show that TIMP1 regulates glioma cell growth and invasion via the AKT/GSK3β signaling pathway. Conclusion This study provides promising insights into predicting glioma prognosis and identifying a potential therapeutic target in TIMP1.

Effect of Bacterial Wilt on Fungal Community Composition in Rhizosphere Soil of Tobaccos in Tropical Yunnan

Yuanxian Zheng,Jiming Wang,Wenlong Zhao,Xianjie Cai,Yinlian Xu,Xiaolong Chen,Min Yang,Feiyan Huang,Lei Yu,Yuansheng He 한국식물병리학회 2022 Plant Pathology Journal Vol.38 No.3

Bacterial wilt, which is a major soil-borne disease with widespread occurrence, poses a severe danger in the field of tobacco production. However, there is very limited knowledge on bacterial wilt-induced microecological changes in the tobacco root system and on the interaction between Ralstonia solanacearum and fungal communities in the rhizosphere soil. Thus, in this study, changes in fungal communities in the rhizosphere soil of tobaccos with bacterial wilt were studied by 18S rRNA gene sequencing. The community composition of fungi in bacterial wilt-infected soil and healthy soil in two tobacco areas (Gengma and Boshang, Lincang City, Yunnan Province, China) was studied through the paired comparison method in July 2019. The results showed that there were significant differences in fungal community composition between the rhizosphere soil of diseased plants and healthy plants. The changes in the composition and diversity of fungal communities in the rhizosphere soil of tobaccos are vital characteristics of tobaccos with bacterial wilt, and the imbalance in the rhizosphere microecosystem of tobacco plants may further aggravate the disease.