资源类型

期刊论文 226

年份

2023 19

2022 24

2021 16

2020 19

2019 17

2018 12

2017 11

2016 12

2015 7

2014 11

2013 5

2012 3

2011 8

2010 6

2009 14

2008 19

2007 14

2005 2

2003 1

2001 1

展开 ︾

关键词

聚偏氟乙烯 2

3D生物打印 1

Anderson 模型 1

CD44 1

Cu(Inx 1

GDM过滤技术 1

Ga1–x)Se2 1

H7N9 1

N3C空位 1

S 特性 1

TBM 隧洞 1

U251细胞 1

iPS细胞 1

三峡工程 1

三维激发极化法 1

不确定时延 1

不良地质体 1

乙烷干重整 1

二氧化碳 1

展开 ︾

检索范围：

排序： 展示方式：

Generation and repair of AID-initiated DNA lesions in B lymphocytes

null

《医学前沿（英文）》 2014年 第8卷 第2期   页码 201-216 doi: 10.1007/s11684-014-0324-4

摘要：

Activation-induced deaminase (AID) initiates the secondary antibody diversification process in B lymphocytes. In mammalian B cells, this process includes somatic hypermutation (SHM) and class switch recombination (CSR), both of which require AID. AID induces U:G mismatch lesions in DNA that are subsequently converted into point mutations or DNA double stranded breaks during SHM/CSR. In a physiological context, AID targets immunoglobulin (Ig) loci to mediate SHM/CSR. However, recent studies reveal genome-wide access of AID to numerous non-Ig loci. Thus, AID poses a threat to the genome of B cells if AID-initiated DNA lesions cannot be properly repaired. In this review, we focus on the molecular mechanisms that regulate the specificity of AID targeting and the repair pathways responsible for processing AID-initiated DNA lesions.

关键词： class switch recombination     somatic hypermutation     activation-induced deaminase     DNA repair     genomic instability    

HTML PDF 收藏

Bavachin enhances NLRP3 inflammasome activation induced by ATP or nigericin and causes idiosyncratic

Nan Qin, Guang Xu, Yan Wang, Xiaoyan Zhan, Yuan Gao, Zhilei Wang, Shubin Fu, Wei Shi, Xiaorong Hou, Chunyu Wang, Ruisheng Li, Yan Liu, Jiabo Wang, Haiping Zhao, Xiaohe Xiao, Zhaofang Bai

《医学前沿（英文）》 2021年 第15卷 第4期   页码 594-607 doi: 10.1007/s11684-020-0809-2

摘要： Psoraleae Fructus (PF) is a well-known traditional herbal medicine in China, and it is widely used for osteoporosis, vitiligo, and other diseases in clinical settings. However, liver injury caused by PF and its preparations has been frequently reported in recent years. Our previous studies have demonstrated that PF could cause idiosyncratic drug-induced liver injury (IDILI), but the mechanism underlying its hepatotoxicity remains unclear. This paper reports that bavachin isolated from PF enhances the specific stimuli-induced activation of the NLRP3 inflammasome and leads to hepatotoxicity. Bavachin boosts the secretion of IL-1β and caspase-1 caused by ATP or nigericin but not those induced by poly(I:C), monosodium urate crystal, or intracellular lipopolysaccharide. Bavachin does not affect AIM2 or NLRC4 inflammasome activation. Mechanistically, bavachin specifically increases the production of nigericin-induced mitochondrial reactive oxygen species among the most important upstream events in the activation of the NLRP3 inflammasome. Bavachin increases the levels of aspartate transaminase and alanine aminotransferase in serum and hepatocyte injury accompanied by the secretion of IL-1β via a mouse model of lipopolysaccharide-mediated susceptibility to IDILI. These results suggest that bavachin specifically enhances the ATP- or nigericin-induced activation of the NLRP3 inflammasome. Bavachin also potentially contributes to PF-induced idiosyncratic hepatotoxicity. Moreover, bavachin and PF should be evaded among patients with diseases linked to the ATP- or nigericin-mediated activation of the NLRP3 inflammasome, which may be a dangerous factor for liver injury.

关键词： Psoraleae Fructus     bavachin     idiosyncratic drug-induced liver injury     caspase-1     IL-1β     NLRP3 inflammasome    

HTML PDF 收藏

Phase separation time/temperature dependence of thermoplastics-modified thermosetting systems

ZHANG Xiujuan, XU Yuanze, YI Xiaosu

《化学科学与工程前沿（英文）》 2008年 第2卷 第3期   页码 276-285 doi: 10.1007/s11705-008-0057-5

摘要： The cure-induced phase separation processes of various thermoplastics(TP)-modified thermosetting systems which show upper critical solution temperature (UCST) or lower critical solution temperature (LCST) were studied with emphasis on the temperature dependency of the phase separation time and its potential application in the cure time-temperature processing window. We found that the phase separation time/temperature relationship follows the simple Arrhenius equation. The cure-induced phase separation activation energy (ps) generated from the linear fitting of the Arrhenius equation is irrelevant to the detection means of phase separation time. We also found that (ps) is insensitive to TP content, TP molecular weight and curing rate, but it changes with the cure reaction kinetics and the chemical environment of the systems. With the established phase separation time-temperature dependence relation, we can easily establish the whole cure time-temperature transformation (TTT) diagram with morphology information which is a useful map for the TP/TS composites processing industry.

关键词： separation time-temperature     temperature dependency     cure-induced     separation activation     temperature    

HTML PDF 收藏

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    

HTML PDF 收藏

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    

HTML PDF 收藏

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    

HTML PDF 收藏

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    

HTML PDF 收藏

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    

HTML PDF 收藏

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    

HTML PDF 收藏

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    

HTML PDF 收藏

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    

HTML PDF 收藏

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    

HTML PDF 收藏

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    

HTML PDF 收藏

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    

HTML PDF 收藏

Enhanced activation of persulfate using mesoporous silica spheres augmented Cu–Al bimetallic oxide particles

《化学科学与工程前沿（英文）》 2023年 第17卷 第10期   页码 1581-1592 doi: 10.1007/s11705-023-2327-7

摘要： Herein, Cu–Al bimetallic oxide was synthesized and mixed with mesoporous silica spheres via a simple hydrothermal method. The prepared sample was then analyzed and employed to activate potassium peroxydisulfate for bisphenol A removal. Based on the results of X-ray diffraction, scanning electron microscopy, and energy dispersion spectroscopy, Cu–Al bimetallic oxide was determined as CuO-Al2O3, and mesoporous silica spheres were found around the these particles. At 30 min, a bisphenol A degradation level of 90% was achieved, and it remained at over 60% after five consecutive cycles, indicating the catalyst’s superior capacity and stability. In terms of removal performance, the radical pathway (including SO4•‒, OH •, and O2•‒) and singlet oxygen (1O2) played minor roles, while electron migration between bisphenol A, potassium peroxydisulfate, and the catalyst played a dominant role. The introduction of Al2O3 promoted the formation of surface oxygen vacancies, which improved ligand complex formation between potassium peroxydisulfate and the catalyst, thereby facilitating electron migration. Furthermore, mesoporous silica spheres augment not only enhanced bisphenol A adsorption but also alleviated Cu leaching. Overall, this work is expected to provide significant support for the rational development of catalysts with high catalytic activity for persulfate activation via surface electron migration.

关键词： Cu–Al bimetallic oxides     mesoporous silica spheres     peroxydisulfate     bisphenol A    

HTML PDF 收藏

标题 作者 时间 类型 操作

Generation and repair of AID-initiated DNA lesions in B lymphocytes

null

期刊论文

Bavachin enhances NLRP3 inflammasome activation induced by ATP or nigericin and causes idiosyncratic

Nan Qin, Guang Xu, Yan Wang, Xiaoyan Zhan, Yuan Gao, Zhilei Wang, Shubin Fu, Wei Shi, Xiaorong Hou, Chunyu Wang, Ruisheng Li, Yan Liu, Jiabo Wang, Haiping Zhao, Xiaohe Xiao, Zhaofang Bai

期刊论文

Phase separation time/temperature dependence of thermoplastics-modified thermosetting systems

ZHANG Xiujuan, XU Yuanze, YI Xiaosu

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

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

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

Jianzhi Huang, Huichun Zhang

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

Enhanced activation of persulfate using mesoporous silica spheres augmented Cu–Al bimetallic oxide particles

期刊论文