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Dysregulation of β-catenin by hepatitis B virus X protein in HBV-infected human hepatocellular carcinomas

Lei CHEN, Liang HU, Liang LI, Yuan LIU, Qian-Qian TU, Yan-Xin CHANG, He-Xin YAN, Meng-Chao WU, Hong-Yang WANG,

《医学前沿(英文)》 2010年 第4卷 第4期   页码 399-411 doi: 10.1007/s11684-010-0170-y

摘要: β-catenin is a key molecule involved in both cell-cell adhesion and Wnt signaling pathway. In our study, we found that, in the development of hepatocellular carcinoma (HCC), β-catenin was correlated with hepatitis B virus (HBV) X gene encoded protein, which is essential for HBV infectivity and is a potential cofactor in viral carcinogenesis. The expression levels of wild-type β-catenin and E-cadherin were decreased in HepG2 cells expressing hepatitis B virus X protein (HBx), accompanied by destabilization of adherens junction. Reverse transcriptase PCR (RT-PCR), Northern and Western blot showed that reduction of wild-type β-catenin expression involved degradation of the protein. However, RNA interference (RNAi) and luciferase assay indicated that HBx enhanced β-catenin mediated signaling in HepG2 cells. In addition, immunohistochemical and Western blot analysis of β-catenin revealed that a decrease in the β-catenin protein level was found in 58.3% of HBV-related HCCs 19.2% of non-HBV-related tumors. Our data suggest that the expression of HBx contributed to the development of HCC, in part, by repressing the wild-type β-catenin expression and enforcing β-catenin-dependent signaling pathway, thus inducing cellular changes leading to acquisition of metastatic and/or proliferation properties.

关键词: hepatocellular carcinoma     hepatitis B virus X protein     β     -catenin     cell adhesion     E-cadherin     transcriptional activation    

Enhanced activation of peroxymonosulfate by CNT-TiO

Xuemin Hao, Guanlong Wang, Shuo Chen, Hongtao Yu, Xie Quan

《环境科学与工程前沿(英文)》 2019年 第13卷 第5期 doi: 10.1007/s11783-019-1161-0

摘要: CNT-TiO2 composite is used to activate PMS under UV-light assistance. Superior performance is due to the enhanced electron-transfer ability of CNT. SO4•−, •OH and 1O2 play key roles in the degradation of organic pollutants. In this work, a UV-light assisted peroxymonosulfate (PMS) activation system was constructed with the composite catalyst of multi-walled carbon nanotubes (CNT) - titanium dioxide (TiO2). Under the UV light irradiation, the photoinduced electrons generated from TiO2 could be continuously transferred to CNT for the activation of PMS to improve the catalytic performance of organic pollutant degradation. Meanwhile, the separation of photoinduced electron-hole pairs could enhance the photocatalysis efficiency. The electron spin resonance spectroscopy (EPR) and quenching experiments confirmed the generation of sulfate radical (SO4•−), hydroxyl radical (•OH) and singlet oxygen (1O2) in the UV/PMS/20%CNT-TiO2 system. Almost 100% phenol degradation was observed within 20 min UV-light irradiation. The kinetic reaction rate constant of the UV/PMS/20%CNT-TiO2 system (0.18 min−1) was 23.7 times higher than that of the PMS/Co3O4 system (0.0076 min−1). This higher catalytic performance was ascribed to the introduction of photoinduced electrons, which could enhance the activation of PMS by the transfer of electrons in the UV/PMS/CNT-TiO2 system.

关键词: Peroxymonosulfate activation     Carbon nanotubes     TiO2     Water treatment    

Hierarchical porous carbon derived from one-step self-activation of zinc gluconate for symmetric supercapacitors

《化学科学与工程前沿(英文)》 2023年 第17卷 第4期   页码 387-394 doi: 10.1007/s11705-022-2250-3

摘要: Porous carbons with high specific area surfaces are promising electrode materials for supercapacitors. However, their production usually involves complex, time-consuming, and corrosive processes. Hence, a straightforward and effective strategy is presented for producing highly porous carbons via a self-activation procedure utilizing zinc gluconate as the precursor. The volatile nature of zinc at high temperatures gives the carbons a large specific surface area and an abundance of mesopores, which avoids the use of additional activators and templates. Consequently, the obtained porous carbon electrode delivers a satisfactory specific capacitance and outstanding cycling durability of 90.9% after 50000 cycles at 10 A∙g–1. The symmetric supercapacitors assembled by the optimal electrodes exhibit an acceptable rate capability and a distinguished cycling stability in both aqueous and ionic liquid electrolytes. Accordingly, capacitance retention rates of 77.8% and 85.7% are achieved after 50000 cycles in aqueous alkaline electrolyte and 10000 cycles in ionic liquid electrolyte. Moreover, the symmetric supercapacitors deliver high energy/power densities of 49.8 W∙h∙kg–1/2477.8 W∙kg–1 in the Et4NBF4 electrolyte, outperforming the majority of previously reported porous carbon-based symmetric supercapacitors in ionic liquid electrolytes.

关键词: self-activation     zinc organic salts     abundant mesopores     symmetric supercapacitor     liquid electrolyte    

Enhanced performance of oxygen vacancies on CO adsorption and activation over different phases of ZrO

《能源前沿(英文)》 2023年 第17卷 第4期   页码 545-554 doi: 10.1007/s11708-023-0867-7

摘要: The effect of oxygen vacancies on the adsorption and activation of CO2 on the surface of different phases of ZrO2 is investigated by density functional theory (DFT) calculations. The calculations show that the oxygen vacancies contribute greatly to both the adsorption and activation of CO2. The adsorption energy of CO2 on the c-ZrO2, t-ZrO2 and, m-ZrO2 surfaces is enhanced to 5, 4, and 3 folds with the help of oxygen vacancies, respectively. Moreover, the energy barrier of CO2 dissociation on the defective surfaces of c-ZrO2, t-ZrO2, and m-ZrO2 is reduced to 1/2, 1/4, and 1/5 of the perfect surface with the assistance of oxygen vacancies. Furthermore, the activation of CO2 on the ZrO2 surface where oxygen vacancies are present, and changes from an endothermic reaction to an exothermic reaction. This finding demonstrates that the presence of oxygen vacancies promotes the activation of CO2 both kinetically and thermodynamically. These results could provide guidance for the high-efficient utilization of CO2 at an atomic scale.

关键词: CO2 activation     oxygen vacancies     ZrO2     different phases    

A density functional theory study of methane activation on MgO supported NiM cluster: role of M on C–Hactivation

《化学科学与工程前沿(英文)》 2022年 第16卷 第10期   页码 1485-1492 doi: 10.1007/s11705-022-2169-8

摘要: Methane activation is a pivotal step in the application of natural gas converting into high-value added chemicals via methane steam/dry reforming reactions. Ni element was found to be the most widely used catalyst. In present work, methane activation on MgO supported Ni–M (M = Fe, Co, Cu, Pd, Pt) cluster was explored through detailed density functional theory calculations, compared to pure Ni cluster. CH4 adsorption on Cu promoted Ni cluster requires overcoming an energy of 0.07 eV, indicating that it is slightly endothermic and unfavored to occur, while the adsorption energies of other promoters M (M = Fe, Co, Pd and Pt) are all higher than that of pure Ni cluster. The role of M on the first C–H bond cleavage of CH4 was investigated. Doping elements of the same period in Ni cluster, such as Fe, Co and Cu, for C–H bond activation follows the trend of the decrease of metal atom radius. As a result, Ni–Fe shows the best ability for C–H bond cleavage. In addition, doping the elements of the same family, like Pd and Pt, for CH4 activation is according to the increase of metal atom radius. Consequently, C–H bond activation demands a lower energy barrier on Ni–Pt cluster. To illustrate the adsorptive dissociation behaviors of CH4 at different Ni–M clusters, the Mulliken atomic charge was analyzed. In general, the electron gain of CH4 binding at different Ni–M clusters follows the sequence of Ni–Cu (–0.02 e) < Ni (–0.04 e) < Ni–Pd (–0.08 e) < Ni–Pt (–0.09 e) < Ni–Co (–0.10 e) < Ni–Fe (–0.12 e), and the binding strength between catalysts and CH 4 raises with the CH4 electron gain increasing. This work provides insights into understanding the role of promoter metal M on thermal-catalytic activation of CH4 over Ni/MgO catalysts, and is useful to interpret the reaction at an atomic scale.

关键词: CH4 dissociation     Ni–M     C–H bond activation     charge transfer    

Optimal dynamic emergency reserve activation using spinning, hydro and demand-side reserves

S. Surender REDDY,P. R. BIJWE,A. R. ABHYANKAR

《能源前沿(英文)》 2016年 第10卷 第4期   页码 409-423 doi: 10.1007/s11708-016-0431-9

摘要: This paper proposes an optimal dynamic reserve activation plan after the occurrence of an emergency situation (generator/transmission line outage, load increase or both). An optimal plan is developed to handle the emergency, using the coordinated action of fast and slow reserves, for secure operation with minimum overall cost. It considers the reserves supplied by the conventional thermal generators (spinning reserves), hydro power units and load demands (demand-side reserves). The optimal backing down of costly/fast reserves and bringing up of slow reserves in each sub-interval in an integrated manner is proposed. The proposed reserve activation approaches are solved using the genetic algorithm, and some of the simulation results are also compared using the Matlab optimization toolbox and the general algebraic modeling system (GAMS) software. The simulation studies are performed on the IEEE 30, 57 and 300 bus test systems. These results demonstrate the advantage of the proposed integrated/dynamic reserve activation plan over the conventional/sequential approach.

关键词: demand-side reserves     dynamic reserve activation approach     hydro power units     post contingency     sequential reserve activation approach     spinning reserves    

Development of a dual temperature control system for isoprene biosynthesis in

《化学科学与工程前沿(英文)》 2022年 第16卷 第7期   页码 1079-1089 doi: 10.1007/s11705-021-2088-0

摘要: Conflict between cell growth and product accumulation is frequently encountered in the biosynthesis of secondary metabolites. To address the growth-production conflict in yeast strains harboring the isoprene synthetic pathway in the mitochondria, the dynamic control of isoprene biosynthesis was explored. A dual temperature regulation system was developed through engineering and expression regulation of the transcriptional activator Gal4p. A cold-sensitive mutant, Gal4ep19, was created by directed evolution of Gal4p based on an internally developed growth-based high-throughput screening method and expressed under the heat-shock promoter PSSA4 to control the expression of PGAL-driven pathway genes in the mitochondria. Compared to the control strain with constitutively expressed wild-type Gal4p, the dual temperature regulation strategy led to 34.5% and 72% improvements in cell growth and isoprene production, respectively. This study reports the creation of the first cold-sensitive variants of Gal4p by directed evolution and provides a dual temperature control system for yeast engineering that may also be conducive to the biosynthesis of other high-value natural products.

关键词: transcriptional activator     directed evolution     dynamic control     heat-shock     isoprene    

Tumor-derived exosomes induce initial activation by exosomal CD19 antigen but impair the function of

《医学前沿(英文)》 doi: 10.1007/s11684-023-1010-1

摘要: Tumor-derived exosomes induce initial activation by exosomal CD19 antigen but impair the function of CD19-specific CAR T-cells via TGF-β signaling

关键词: exosomes induce activation     impair function CD19     exosomal CD19 antigen    

Coronary leukocyte activation in relation to progression of coronary artery disease

null

《医学前沿(英文)》 2016年 第10卷 第1期   页码 85-90 doi: 10.1007/s11684-016-0435-1

摘要:

Leukocyte activation has been linked to atherogenesis, but there is little in vivo evidence for its role in the progression of atherosclerosis. We evaluated the predictive value for progression of coronary artery disease (CAD) of leukocyte activation markers in the coronary circulation. Monocyte and neutrophil CD11b, neutrophil CD66b expression and intracellular neutrophil myeloperoxidase (MPO) in the coronary arteries were determined by flow cytometry in patients undergoing coronary angiography. The primary outcome included fatal and nonfatal myocardial infarction or arterial vascular intervention due to unstable angina pectoris. In total 99 subjects who were included, 70 had CAD at inclusion (26 patients had single-vessel disease, 18 patients had two-vessel disease and 26 patients had three-vessel disease). The median follow-up duration was 2242 days (interquartile range: 2142–2358). During follow-up, 13 patients (13%) developed progression of CAD. Monocyte CD11b, neutrophil CD11b and CD66b expression and intracellular MPO measured in blood obtained from the coronary arteries were not associated with the progression of CAD. These data indicate that coronary monocyte CD11b, neutrophil CD11b and CD66b expression and intracellular MPO do not predict the risk of progression of CAD.

关键词: coronary artery disease     inflammation     integrin     myeloperoxidase     leukocyte activation    

NETO2 promotes melanoma progression via activation of the Ca/CaMKII signaling pathway

《医学前沿(英文)》 2023年 第17卷 第2期   页码 263-274 doi: 10.1007/s11684-022-0935-0

摘要: Melanoma is the most aggressive cutaneous tumor. Neuropilin and tolloid-like 2 (NETO2) is closely related to tumorigenesis. However, the functional significance of NETO2 in melanoma progression remains unclear. Herein, we found that NETO2 expression was augmented in melanoma clinical tissues and associated with poor prognosis in melanoma patients. Disrupting NETO2 expression markedly inhibited melanoma proliferation, malignant growth, migration, and invasion by downregulating the levels of calcium ions (Ca2+) and the expression of key genes involved in the calcium signaling pathway. By contrast, NETO2 overexpression had the opposite effects. Importantly, pharmacological inhibition of CaMKII/CREB activity with the CaMKII inhibitor KN93 suppressed NETO2-induced proliferation and melanoma metastasis. Overall, this study uncovered the crucial role of NETO2-mediated regulation in melanoma progression, indicating that targeting NETO2 may effectively improve melanoma treatment.

关键词: melanoma     neuropilin and tolloid-like 2     Ca2+/CaMKII signaling pathway    

Insights into the electron transfer mechanisms of permanganate activation by carbon nanotube membrane

《环境科学与工程前沿(英文)》 2023年 第17卷 第9期 doi: 10.1007/s11783-023-1706-0

摘要:

● A CNT filter enabled effective KMnO4 activation via facilitated electron transfer.

关键词: KMnO4     Carbon nanotubes     Non-radical pathway     Electron transfer     Water treatment    

Transcriptional modules related to hepatocellular carcinoma survival: coexpression network analysis

null

《医学前沿(英文)》 2016年 第10卷 第2期   页码 183-190 doi: 10.1007/s11684-016-0440-4

摘要:

We performed weighted gene coexpression network analysis (WGCNA) to gain insights into the molecular aspects of hepatocellular carcinoma (HCC). Raw microarray datasets (including 488 samples) were downloaded from the Gene Expression Omnibus (GEO) website. Data were normalized using the RMA algorithm. We utilized the WGCNA to identify the coexpressed genes (modules) after non-specific filtering. Correlation and survival analyses were conducted using the modules, and gene ontology (GO) enrichment was applied to explore the possible mechanisms. Eight distinct modules were identified by the WGCNA. Pink and red modules were associated with liver function, whereas turquoise and black modules were inversely correlated with tumor staging. Poor outcomes were found in the low expression group in the turquoise module and in the high expression group in the red module. In addition, GO enrichment analysis suggested that inflammation, immune, virus-related, and interferon-mediated pathways were enriched in the turquoise module. Several potential biomarkers, such as cyclin-dependent kinase 1 (CDK1), topoisomerase 2α (TOP2A), and serpin peptidase inhibitor clade C (antithrombin) member 1 (SERPINC1), were also identified. In conclusion, gene signatures identified from the genome-based assays could contribute to HCC stratification. WGCNA was able to identify significant groups of genes associated with cancer prognosis.

关键词: hepatocellular carcinoma     coexpression     module     microarray     prognosis    

The role of manganese oxides in the activation of peroxymonosulfate (PMS)

Jianzhi Huang, Huichun Zhang

《环境科学与工程前沿(英文)》 2019年 第13卷 第5期 doi: 10.1007/s11783-019-1158-8

摘要: Manganese oxides (MnOx) have been demonstrated to be effective materials to activate Oxone (i.e., PMS) to degrade various contaminants. However, the contribution of direct oxidation by MnOx to the total contaminant degradation under acidic conditions was often neglected in the published work, which has resulted in different and even conflicting interpretations of the reaction mechanisms. Here, the role of MnOx (as both oxidants and catalysts) in the activation of Oxone was briefly discussed. The findings offered new insights into the reaction mechanisms in PMS-MnOx and provided a more accurate approach to examine contaminant degradation for water/wastewater treatment.

关键词: Peroxymonosulfate     Manganese oxides     Catalyst     Oxidant    

Distinct gene expression pattern of mutations coordinated by target repression and promoter hypermethylation in acute myeloid leukemia

《医学前沿(英文)》 2022年 第16卷 第4期   页码 627-636 doi: 10.1007/s11684-020-0815-4

摘要: Runt-related transcription factor 1 (RUNX1) is an essential regulator of normal hematopoiesis. Its dysfunction, caused by either fusions or mutations, is frequently reported in acute myeloid leukemia (AML). However, RUNX1 mutations have been largely under-explored compared with RUNX1 fusions mainly due to their elusive genetic characteristics. Here, based on 1741 patients with AML, we report a unique expression pattern associated with RUNX1 mutations in AML. This expression pattern was coordinated by target repression and promoter hypermethylation. We first reanalyzed a joint AML cohort that consisted of three public cohorts and found that RUNX1 mutations were mainly distributed in the Runt domain and almost mutually exclusive with NPM1 mutations. Then, based on RNA-seq data from The Cancer Genome Atlas AML cohort, we developed a 300-gene signature that significantly distinguished the patients with RUNX1 mutations from those with other AML subtypes. Furthermore, we explored the mechanisms underlying this signature from the transcriptional and epigenetic levels. Using chromatin immunoprecipitation sequencing data, we found that RUNX1 target genes tended to be repressed in patients with RUNX1 mutations. Through the integration of DNA methylation array data, we illustrated that hypermethylation on the promoter regions of RUNX1-regulated genes also contributed to dysregulation in RUNX1-mutated AML. This study revealed the distinct gene expression pattern of RUNX1 mutations and the underlying mechanisms in AML development.

关键词: RUNX1     gene mutation     acute myeloid leukemia     transcriptional repression     DNA methylation    

to water purification for resource-constrained settings: Production of activated biochar by chemical activation

Mohit Nahata, Chang Y. Seo, Pradeep Krishnakumar, Johannes Schwank

《化学科学与工程前沿(英文)》 2018年 第12卷 第1期   页码 194-208 doi: 10.1007/s11705-017-1647-x

摘要: A significant portion of the world’s population does not have access to safe drinking water. This problem is most acute in remote, resource-constrained rural settings in developing countries. Water filtration using activated carbon is one of the important steps in treating contaminated water. Lignocellulosic biomass is generally available in abundance in such locations, such as the African rain forests. Our work is focused on developing a simple method to synthesize activated biochar from locally available materials. The preparation of activated biochar with diammonium hydrogenphosphate (DAP) as the activating agent is explored under N flow and air. The study, carried out with cellulose as a model biomass, provides some insight into the interaction between DAP and biomass, as well as the char forming mechanism. Various characterization techniques such as N physisorption, X-ray photoelectron spectroscopy, scanning electron microscopy, transmission electron microscopy and Raman spectroscopy are utilized to compare the properties between biochar formed under nitrogen and partial oxidative conditions. At a temperature of 450 °C, the loading of DAP over cellulose is systematically varied, and its effect on activation is examined. The activated biochar samples are predominantly microporous in the range of concentrations studied. The interaction of DAP with cellulose is investigated and the nature of bonding of the heteroatoms to the carbonaceous matrix is elucidated. The results indicate that the quality of biochar prepared under partial oxidation condition is comparable to that of biochar prepared under nitrogen, leading to the possibility of an activated biochar production scheme on a small scale in resource-constrained settings.

关键词: cellulose     DAP     activation     heteroatom     microporous    

标题 作者 时间 类型 操作

Dysregulation of β-catenin by hepatitis B virus X protein in HBV-infected human hepatocellular carcinomas

Lei CHEN, Liang HU, Liang LI, Yuan LIU, Qian-Qian TU, Yan-Xin CHANG, He-Xin YAN, Meng-Chao WU, Hong-Yang WANG,

期刊论文

Enhanced activation of peroxymonosulfate by CNT-TiO

Xuemin Hao, Guanlong Wang, Shuo Chen, Hongtao Yu, Xie Quan

期刊论文

Hierarchical porous carbon derived from one-step self-activation of zinc gluconate for symmetric supercapacitors

期刊论文

Enhanced performance of oxygen vacancies on CO adsorption and activation over different phases of ZrO

期刊论文

A density functional theory study of methane activation on MgO supported NiM cluster: role of M on C–Hactivation

期刊论文

Optimal dynamic emergency reserve activation using spinning, hydro and demand-side reserves

S. Surender REDDY,P. R. BIJWE,A. R. ABHYANKAR

期刊论文

Development of a dual temperature control system for isoprene biosynthesis in

期刊论文

Tumor-derived exosomes induce initial activation by exosomal CD19 antigen but impair the function of

期刊论文

Coronary leukocyte activation in relation to progression of coronary artery disease

null

期刊论文

NETO2 promotes melanoma progression via activation of the Ca/CaMKII signaling pathway

期刊论文

Insights into the electron transfer mechanisms of permanganate activation by carbon nanotube membrane

期刊论文

Transcriptional modules related to hepatocellular carcinoma survival: coexpression network analysis

null

期刊论文

The role of manganese oxides in the activation of peroxymonosulfate (PMS)

Jianzhi Huang, Huichun Zhang

期刊论文

Distinct gene expression pattern of mutations coordinated by target repression and promoter hypermethylation in acute myeloid leukemia

期刊论文

to water purification for resource-constrained settings: Production of activated biochar by chemical activation

Mohit Nahata, Chang Y. Seo, Pradeep Krishnakumar, Johannes Schwank

期刊论文