Uranium thermochemical cycle used for hydrogen production

Aimei Chen,Chunxia Liu,Yuxia Liu,Lan Zhang 한국원자력학회 2019 Nuclear Engineering and Technology Vol.51 No.1

Thermochemical cycles have been predominantly used for energy transformation from heat to storedchemical free energy in the form of hydrogen. The thermochemical cycle based on uranium (UTC),proposed by Oak Ridge National Laboratory, has been considered as a better alternative compared toother thermochemical cycles mainly due to its safety and high efficiency. UTC process includes threesteps, in which only the first step is unique. Hydrogen production apparatus with hectogram reactantswas designed in this study. The results showed that high yield hydrogen was obtained, which wasdetermined by drainage method. The results also indicated that the chemical conversion rate ofhydrogen production was in direct proportion to the mass of Na2CO3, while the solid product wasNa2UO4, instead of Na2U2O7. Nevertheless the thermochemical cycle used for hydrogen generation can beclosed, and chemical compounds used in these processes can also be recycled. So the cycle with Na2UO4as its first reaction product has an advantage over the proposed UTC process, attributed to the fast reactionrate and high hydrogen yield in the first reaction step.

Design, synthesis and evaluation of 5-substituted 1-H-tetrazoles as potent anticonvulsant agents

Aimei LIAO,Tiantian Wang,Bangrong Cai,Yi Jin,천승훈,ChangJu Chun,Zengtao Wang 대한약학회 2017 Archives of Pharmacal Research Vol.40 No.4

A series of 5-substituted 1-H-tetrazoles weredesigned and synthesized as potent anticonvulsant agents. Their preliminary anticonvulsant activities were evaluatedusing maximal electroshock and subcutaneouspentylenetetrazole (scPTZ) seizure tests. Neurotoxicity wasdetermined using rotarod test. The results indicated that thecompound 2j in scPTZ model exhibited the ED50 values of83.3 mg/kg, superior to the standard drug ethosuximidewith the maximum activity. In addition, compound 2kshowed the most potent activity in MES model with ED50value of 9.6 mg/kg and TD50 value of 189.5 mg/kg afterintraperitoneal injection in mice, and displayed a highprotective index (TD50/ED50) of 19.7 compared to referenceantiepileptic drugs.

Disheveled-associated activator of morphogenesis 2 promotes invasion of colorectal cancer by activating PAK1 and promoting MMP7 expression

Chen Aimei,Liu Zhiqiang,Wu Quanyan,Li Hailin 한국유전학회 2021 Genes & Genomics Vol.43 No.8

Background Disheveled-associated activator of morphogenesis (DAAM) family, including DAAM1 and DAAM2, is key regulators in Wnt signaling pathway. Although the oncogenic role of Wnt signaling pathway in colorectal cancer (CRC) was investigated in several lines, the expression and function of DAAM in CRC are still obscure. Objective To investigate the expression and function of DAAM in CRC. Methods DAAM1 and DAAM2 expression in high grade dysplasia (HGD), CRCs and corresponding adjacent tissues were detected with qRT-PCR and immunohistochemistry (IHC). The prognostic signifcance of DAAM1/2 were estimated with univariate and multivariate analyses. Moreover, the correlations between clinicopathological factors and DAAM were evaluated with the χ2 test. With experiments in vitro, we investigated the function of DAAM2 in CRC cell proliferation and invasion, and investigated the underlying mechanism of how DAAM2 facilitated CRC invasion. Results DAAM2, instead of DAAM1, was substantially up-regulated in CRCs compared with paired adjacent normal tissues and HGDs. The ratio of high DAAM1 and DAAM2 expression accounted for 44.83% and 46.31%, respectively. High DAAM2, instead of DAAM1, was a risk factor indicating an unfavorable prognosis of CRC. In multivariate analysis, high DAAM2 was identifed as an independent prognostic biomarker of CRC predicting poor prognosis. With experiments in vitro, DAAM2 promoted invasion of CRC cells via activating PAK1 and promoting the expression of MMP7, suggesting an essential role of DAAM2 in CRC invasion. Conclusions High expression of DAAM2, instead of DAAM1, indicated an unfavorable prognosis of CRC independently, which suggested that detecting DAAM2 can help defne the high-risk patients. DAAM2 activated PAK1 and promoted MMP7 expression and facilitated the invasion of CRC cells, indicating that DAAM2 may be a potential drug target of CRC.

Radiotherapy combined with immunotherapy could improve the immune infiltration of melanoma in mice and enhance the abscopal effect

Yufeng Zheng(Yufeng Zheng),Xue Liu(Xue Liu),Na Li(Na Li),Aimei Zhao(Aimei Zhao),Zhiqiang Sun(Zhiqiang Sun),Meihua Wang(Meihua Wang),Judong Luo(Judong Luo) 대한방사선종양학회 2023 Radiation Oncology Journal Vol.41 No.2

Purpose: To analyze the gene mutation, immune infiltration and tumor growth of primary tumor and distant tumor under different treatment modes. Materials and Methods: Twenty B16 murine melanoma cells were injected subcutaneously into the of both sides of the thigh, simulating a primary tumor and a secondary tumor impacted by the abscopal effect, respectively. They were divided into blank control group, immunotherapy group, radiotherapy group, and radiotherapy combined immunotherapy group. During this period, tumor volume was measured, and RNA sequencing was performed on tumor samples after the test. R software was used to analyze differentially expressed genes, functional enrichment, and immune infiltration. Results: We found that any treatment mode could cause changes in differentially expressed genes, especially the combination treatment. The different therapeutic effects might be caused by gene expression. In addition, the proportions of infiltrating immune cells in the irradiated and abscopal tumors were different. In the combination treatment group, T-cell infiltration in the irradiated site was the most obvious. In the immunotherapy group, CD8+ T-cell infiltration in the abscopal tumor site was obvious, but immunotherapy alone might have a poor prognosis. Whether the irradiated or abscopal tumor was evaluated, radiotherapy combined with anti-programmed cell death protein 1 (anti-PD-1) therapy produced the most obvious tumor control and might have a positive impact on prognosis. Conclusion: Combination therapy not only improves the immune microenvironment but may also have a positive impact on prognosis.

Design, synthesis of methotrexate-diosgenin conjugates and biological evaluation of their effect on methotrexate transport-resistant cells

( Bangrong Cai ),( Aimei Liao ),( Kyung-ku Lee ),( Jae-sam Ban ),( Hyun-sam Yang ),( Young Jun Im ),( Changju Chun ) 전남대학교 약품개발연구소 2016 약품개발연구지 Vol.25 No.-

A series of methotrexate-diosgenin conjugates was designed and synthesized to enhance the passive internalization of methotrexate (MTX) in to transport-resistant cells. The inhibitory effects of these con-jugates on dihydrofolate reductase (DHFR), and their anti-proliferation behaviors against a transport-resistant breast cancer cell line, MDA-MB-231, were investigated. All of the synthesized conjugates retained an ability to inhibit DHFR after the diosgenin substitution. The MTX conjugates were much more potent against methotrexate-resistant MDA-MB-231 cells than MTX. Conjugate 18, containing a disulfide bond, exhibited the most potent anti-proliferative and DHFR inhibitory effects (IC₅₀=4.1 μM and 17.21 nM, respectively). Anti-proliferative activity was higher in the conjugate with a longer space linker (conjugate 21) than those with shorter linkers (conjugates 19 and 20). These results suggest that dios-genin conjugation of MTX may be an effective way to overcome its transport resistance in cancer cells. ⓒ 2016 Elsevier Inc. All rights reserved.

Complete mitochondrial genome of a carabid beetle, Damaster mirabilissimus mirabilissim (Coleoptera: Carabidae)

Xinlong Wan,홍미연,Aimei LIAO,김만일,김기경,한연수,김익수 한국곤충학회 2012 Entomological Research Vol.42 No.1

In the present study, we report the 16 823-bp long complete mitochondrial genome (mitogenome) of a carabid beetle, Damaster mirabilissimus mirabilissim (Coleoptera: Carabidae), which is endangered in Korea. The gene arrangement of D. m. mirabilissim mitogenome is identical to the most common type found in insects. The start codon of the D. m. mirabilissim COI gene is a typicalATN codon. On the other hand, the initiation codon for ND1 gene is TTG, instead of ATN. All transfer RNAs (tRNAs) exhibit a stable canonical clover-leaf structure, except for tRNASer(AGN), the dihydrouridine arm of which forms a simple loop. The 1703-bp long A+T-rich region is the second longest among the complete adephagan mitogenome sequences, next to Macrogyrus oblongus belonging to Gyrinoidea. One of the unusual features of the genome is the presence of a tRNALeu(UUR)-like sequence in the A+T-rich region. This sequence displays the proper anticodon sequence and the potential to form secondary structures, but also harbors many mismatches in the stems.

Polyamide composite nanofiltration membrane modified by nanoporous TiO2 interlayer for enhanced water permeability

Mingzhu Chi,Pingyun Zheng,Mingxin Wei,Aimei Zhu,Lubin Zhong,Qiugen Zhang,Qinglin Liu 한국공업화학회 2022 Journal of Industrial and Engineering Chemistry Vol.115 No.-

The traditional polyamide composite nanofiltration membrane has high selectivity. However, low waterpermeability is an important problem to be solved. Herein, the conventional polyamide compositenanofiltration (TFC) membrane was modified with nanoporous TiO2 (nTiO2) interlayer throughvacuum-assisted strategy for enhanced water permeability. By tuning the nTiO2 nanoparticles loading,the nTiO2 modified TFC membrane with crumpled structure was fabricated. Besides, the thickness ofpolyamide layer was reduced due to the hydrophilicity and porosity of nTiO2. Because of the larger effectivefiltration area and thinner polyamide layer, the modified membrane had a permeability of12.8 L m2 h1 bar1 (increased by 20.8% than that of TFC membrane) and a rejection of 98.2% when filteringNa2SO4 aqueous solution. This work provided a solution for enhanced water permeability andextended the application of TiO2 in the modification of polyamide composite nanofiltration membrane.

Polyacrylonitrile mesoporous composite membranes with high separation efficiency prepared by fast freeze-extraction process

Ruixue Lv,Faizal Soyekwo,Qiugen Zhang,Runsheng Gao,Jianyang Wu,Yan Qu,Aimei Zhu,Qinglin Liu 한국공업화학회 2017 Journal of Industrial and Engineering Chemistry Vol.49 No.-

Polymer mesoporous membranes are widely employed in many membrane processes includingultrafiltration and dialysis, and become more crucial with increasing demand in chemical and lifefields. Here we report a highly-efficient polymer membrane with sub-5 nm pores and highflux frompolyacrylonitrile (PAN) nanoparticles produced from dilute PAN solution via fast freeze-extractionprocess. The25 nm-size PAN nanoparticles forming brad-like chains are dispersed in ethanol solutionand used to prepare the membrane byfiltration-assisted assembly method across a macroporoussupport. Effects of solvents and usage of PAN on membrane formation is studied in detail. The resultantmembranes comprise of the nanoparticles stacked on the support to form a mesoporous separation layerwith a controllable thickness and a cut-off of below 5 nm. They exhibit excellent separation performancesin ultrafiltration of protein and nanoparticle solutions. Typically, the membrane with 94.6% rejection of5 nm gold nanoparticles has a pure waterflux of 823 L m 1 h 1 bar 1 and perfect rejection for ferritinmolecules and 10 nm gold nanoparticles. The newly developed membranes should have wide applicationin chemical, environment and lifefields.

Graphene oxide nanosheets to improve permeability and selectivity of PIM-1 membrane for carbon dioxide separation

Mengmeng Chen,Faizal Soyekwo,Qiugen Zhang,Chuan Hu,Aimei Zhu,Qinglin Liu 한국공업화학회 2018 Journal of Industrial and Engineering Chemistry Vol.63 No.-

Polymers of intrinsic microporosity (PIMs) have attracted increasing interest in gas separation membranes due to their high permeability. However, the moderate selectivity limits their wide applications in CO2 separation. Herein we report a facile strategy to improve simultaneously the permeability and CO2 selectivity of PIMs membrane using the prepared PIM-1/graphene oxide (GO) nanosheets mixed matrix membrane. The GO nanosheets improves the hydrophilicity and surface roughness of PIM-1 membrane whereas the uniform assembly of GO nanosheets in the PIM-1 matrix creates the hydrophilic/hydrophobic microphase segregation in the membrane. The as-prepared mixed matrix membrane is also very porous and has a pore size of about 0.78 nm. The combination of these properties significantly contributes to the enhancement of the gas separation performance of PIM-1 membrane, with the resultant membrane exhibiting an exceptionally high CO2 permeability of up to 6169 barrer as well as a high CO2/N2 selectivity of 123.5, which is more than 7 times that of the pure PIM-1 membrane. The developed PIM-1/GO mixed matrix membrane should have a wide application in the CO2 separation.

High yield engineered nanovesicles from ADSC with enriched miR-21-5p promote angiogenesis in adipose tissue regeneration

Sun Di,Mou Shan,Chen Lifeng,Yang Jie,Wang Rongrong,Zhong Aimei,Wang Wei,Tong Jing,Wang Zhenxing,Sun Jiaming 한국생체재료학회 2023 생체재료학회지 Vol.27 No.00

Background: Mesenchymal stem cell-derived extracellular vesicles (MSC-EVs) have been found to have a great potential for soft tissue repair due to various biological functions, including pro-angiogenesis and low immunogenicity. However, the low yield and heterogeneity of MSC-EVs limited their clinical transformation. This study was designed to develop a novel adipose-derived stem cell engineered nanovesicles (ADSC-NVs) with high production and explore its pro-angiogenetic effect and application in adipose tissue regeneration. Methods: Adipose-derived stem cell-derived extracellular vesicles (ADSC-EVs) were isolated from an EVs-free culture medium for human ADSCs (hADSCs). ADSC-NVs were prepared by sequentially extruding ADSCs followed by iodixanol density gradient ultracentrifugation and were compared with ADSC-EVs in morphology, size distribution, protein contents and yield. The pro-angiogenetic effect of ADSC-NVs in different doses (0, 5, 20 and 80 μg/mL) in vitro was determined using transwell assay, tube formation assay, western blot and qRT-PCR. In vivo, BALB/c nude mice were administered injection of a mixture of fat granules and different dose of ADSC-NVs and grafts were harvested at 12 weeks post-transplantation for further analysis. By analyzing the weight and volume of grafts and histological evaluation, we investigated the effect of ADSC-NVs in vessel formation and adipose tissue regeneration. Results: Our results showed yield of purified ADSC-NVs was approximately 20 times more than that of ADSC-EVs secreted by the same number of ADSCs. In vitro, both ADSC-NVs and ADSC-EVs exhibited a dose-dependent proangiogenetic effect, despite their distinct miRNA profiles. These effects of ADSC-NVs may be mediated by enriched miR-21-5p via PTEN inhibition and PI3K/p-Akt signaling activation. Furthermore, after a mixed injection of ADSC-NVs, vessel formation and adipose regeneration were observed in vivo in fat implants. Conclusions: Our study developed a potent alternative of ADSC-EVs. ADSC-NVs have a high pro-angiogenesis potential and can be used as cell-free therapeutic biomaterials in soft tissue regeneration.