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A Hypothesis Regarding the Origin of Additional Surface Acidity in Solid Complexes with Same Metal Cations
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作者 SHAO Bo TONG Chaoli +5 位作者 WANG Jiaqian HAN Zhongkang ZHANG Yan GE Wenfeng WANG Yong YANG Hangsheng 《材料科学与工程学报》 CAS CSCD 北大核心 2024年第5期718-722,共5页
Based on the criteria for additional surface acidity generation in composite oxides and composite fluorides proposed by Tanabe and Kemnitz et al.A hypothesis for the origin of additional surface acidity in solid compo... Based on the criteria for additional surface acidity generation in composite oxides and composite fluorides proposed by Tanabe and Kemnitz et al.A hypothesis for the origin of additional surface acidity in solid composites with the same metal cations is proposed.The surface acidsites of We analyze three types of solid composite systems,that is,CrF_(3)/Cr_(2)O_(3),MgF_(2)/MgO,and ZnF_(2)/ZnO,is systematically analyzed,which agrees with experimental results.Accordingly,the origin of additional surface acidity in these solid composites is reasonably explained,and the types of acidic sites are also predicted. 展开更多
关键词 Surface acidity Solid composite Local charge imbalance
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Comparison of Acidity Parameters for Soils under Perennial and Annual Pastures in Victoria
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作者 LuoShengguo REWhite 《Journal of Northeast Agricultural University(English Edition)》 CAS 1997年第2期81-88,共8页
There are about 5 million ha of strongly acid soils (pH < 4.8 in 0.01 mol·L -1 CaCl 2 ) in Victoria and about 11 million ha of mildly acid soils (pH 4.8~5.5) that are considered susceptible to furthe... There are about 5 million ha of strongly acid soils (pH < 4.8 in 0.01 mol·L -1 CaCl 2 ) in Victoria and about 11 million ha of mildly acid soils (pH 4.8~5.5) that are considered susceptible to further acidification under current agricultural use. However, there appear to be differences in the rate of acidification, as measured by soil pH change, between soils under perennial pastures in the higher rainfall areas of southern Victoria and soils under annual pastures in the sheep-wheat areas of the north-east. Measurements made on representative soils from both regions showed that the southern soils generally had a higher pH buffer capacity, which was primarily determined by the organic carbon content. There was a consistent relationship between the short-term buffer capacity (measured by titration) and the long-term buffer capacity (measured by incubation), irrespective of the origin of the soils. Exchangeable Al, measured in 0.01 mol·L -1 CaCl 2 , was strongly negatively correlated with pH and the relationship for all soils suggested that Al was adsorbed as a cation with an average charge of 1.2 展开更多
关键词 acidity buffering capacity exchangeable aluminium organic carbon content PASTURES soil pH
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冬季高原盐湖硅藻优良藻种辐节藻Stauroneis sp.S-8的生物学特性分析 被引量:1
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作者 夏皖月 方霞 +7 位作者 姜尔颖 丁晓婷 Phung Nghi Van 王娜 张炜 范勇 李福利 张朝辉 《海洋与湖沼》 北大核心 2025年第1期156-164,共9页
青海位于青藏高原,是世界上海拔最高的地区之一,拥有丰富的盐湖资源和独特的生物种质。在冬季,青海盐湖中生长着大量的底栖硅藻。硅藻作为主要的初级生产者,能够促进固碳增汇和土壤硅循环,是优秀的微藻种质资源。采集青海海西自治州尕... 青海位于青藏高原,是世界上海拔最高的地区之一,拥有丰富的盐湖资源和独特的生物种质。在冬季,青海盐湖中生长着大量的底栖硅藻。硅藻作为主要的初级生产者,能够促进固碳增汇和土壤硅循环,是优秀的微藻种质资源。采集青海海西自治州尕海盐湖12月份的湖水和底泥样品,处理后分别涂布在不同营养条件的平板上。经多轮纯化,从样品中筛选获得一株着生硅藻。该藻种经稀释涂布在平板上,48 h内快速生长并形成肉眼可见的藻斑。该藻具有较强的抗逆性,能够耐受10%的盐度,可以长期在4°C的低温下生存。经18S rRNA基因测序并构建系统发育树,鉴别该藻种与一种硅藻Stauroneis latistauros Xmm1W4具有较高同源性,将其命名为Stauroneis sp.S-8。该藻细胞呈细长的舟状,中央区域包含一个明显的大轴区,形态上稍区别于近源藻种。脂肪酸和色素组成分析表明,该藻的二十碳五烯酸(eicosapentaenoic acid,EPA)占总脂肪酸的24%,并含有丰富的岩藻黄素。作为高原盐湖冬季的优良藻种,该藻具有固碳增汇、促进氮和硅循环等生态效应。这一藻种的发现推动了对低温高原地区盐湖微藻资源的认识与开发。 展开更多
关键词 种质筛选 硅藻 高原盐湖 二十碳五烯酸(eicosapentaenoic acid EPA) 岩藻黄素
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Metal-organic framework-derived sulfur-doped iron-cobalt tannate nanorods for efficient oxygen evolution reaction performance 被引量:1
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作者 ZHAI Haoying WEN Lanzong +3 位作者 LIAO Wenjie LI Qin ZHOU Wenjun CAO Kun 《无机化学学报》 北大核心 2025年第5期1037-1048,共12页
Sulfur-doped iron-cobalt tannate nanorods(S-FeCoTA)derived from metal-organic frameworks(MOFs)as electrocatalysts were synthesized via a one-step hydrothermal method.The optimized S-FeCoTA was interlaced by loose nano... Sulfur-doped iron-cobalt tannate nanorods(S-FeCoTA)derived from metal-organic frameworks(MOFs)as electrocatalysts were synthesized via a one-step hydrothermal method.The optimized S-FeCoTA was interlaced by loose nanorods,which had many voids.The S-FeCoTA catalysts exhibited excellent electrochemical oxygen evolution reaction(OER)performance with a low overpotential of 273 mV at 10 mA·cm^(-2)and a small Tafel slope of 36 mV·dec^(-1)in 1 mol·L^(-1)KOH.The potential remained at 1.48 V(vs RHE)at 10 mA·cm^(-2)under continuous testing for 15 h,implying that S-FeCoTA had good stability.The Faraday efficiency of S-FeCoTA was 94%.The outstanding OER activity of S-FeCoTA is attributed to the synergistic effects among S,Fe,and Co,thus promoting electron transfer,reducing the reaction kinetic barrier,and enhancing the OER performance. 展开更多
关键词 hydrothermal method tannic acid metal‑organic framework ELECTROCATALYSIS oxygen evolution reaction
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Methanolysis/Hydrolysis of Polyethylene Terephthalate Over Cu-Mg-Al Oxides Catalysts Promoted by Trace Water
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作者 NIU Tiantian LIANG Changhai CHEN Xiao 《石油学报(石油加工)》 北大核心 2025年第3期707-719,共13页
With the aim to effectively depolymerize polyethylene terephthalate(PET)under mild reaction conditions,PET methanolysis and dimethyl terephthalate(DMT)hydrolysis are integrated in a catalyst system.Firstly,methanolysi... With the aim to effectively depolymerize polyethylene terephthalate(PET)under mild reaction conditions,PET methanolysis and dimethyl terephthalate(DMT)hydrolysis are integrated in a catalyst system.Firstly,methanolysis of PET to DMT is achieved over Cu-Mg-Al oxide catalyst.Next,terephthalic acid(TPA)is prepared by DMT hydrolysis.It is found that hydrolysis of DMT to TPA can be promoted by introducing trace amount of water in this catalyst system.CuO-MgO-4.5Al_2O_(3)catalyst demonstrates the excellent catalytic performance for the depolymerization of PET with high conversion rate and TPA yield(100%and 99.5%,respectively)after reaction at 160℃for 6 h,which provides a new idea for the depolymerization of PET. 展开更多
关键词 polyethylene terephthalate terephthalic acid METHANOLYSIS HYDROLYSIS Cu-Mg-Al oxide
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A self-calibrating fluorescent probe for the selective detection and bioimaging of HClO
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作者 GAO Wei SONG Meiqi +4 位作者 REN Xuan BAI Jianliang SU Jing MA Jianlong WANG Zhijun 《无机化学学报》 北大核心 2025年第6期1173-1182,共10页
In this study,a self-calibrating near-infrared fluorescence probe was designed and synthesized based on the dual-fluorophore strategy utilizing methylene blue and coumarin.The probe utilized methylene blue(emission sp... In this study,a self-calibrating near-infrared fluorescence probe was designed and synthesized based on the dual-fluorophore strategy utilizing methylene blue and coumarin.The probe utilized methylene blue(emission spectrum range:640-740 nm)and coumarin fluorophore(emission spectrum range:440-600 nm)as signal output units,thereby achieving effective spectral separation and highly selective detection of HClO.Under physiological pH conditions,HClO triggers an oxidation-cleavage reaction,releasing methylene blue and coumarin,which emit distinct red and green fluorescence,respectively.This dual-emission feature enabled rapid HClO detection with two-channel detection limits of 25.13 nmol·L^(-1)(green channel)and 31.55 nmol·L^(-1)(red channel).Furthermore,in cell imaging experiments,this probe demonstrated excellent cell membrane permeability and low cytotoxicity,successfully enabling the monitoring of both endogenous and exogenous HClO in living cells.By incorporating a twochannel self-calibration system,the probe effectively mitigated signal variations caused by instrumental or environmental interference,substantially improving detection sensitivity and reliability. 展开更多
关键词 fluorescent probe fluorescent crosstalk self-calibrated hypochloric acid dual channel
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Preparation of Biodegradable Polylactic Acid/Ethyl Cellulose/Zein Composite Film and Its Effect on the Preservation of Chilled Fresh Meat
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作者 ZHOU Ling YU Ya +8 位作者 YUAN Mengting WU Dongxu CHEN Ya LIU Yanan SU Jingjing CHEN Sihan WANG Juhua SHENG Bulei XUE Xiuheng 《食品科学》 北大核心 2025年第15期324-337,共14页
In this study,composite films consisting of polylactic acid(PLA),ethyl cellulose(EC),and zein were prepared by solution casting method,and their performance and application in chilled fresh meat preservation were inve... In this study,composite films consisting of polylactic acid(PLA),ethyl cellulose(EC),and zein were prepared by solution casting method,and their performance and application in chilled fresh meat preservation were investigated.The results showed that the three materials had satisfactory compatibility in the composite film.Addition of EC and zein effectively improved the mechanical properties,thermodynamic properties,surface hydrophilicity,oxygen permeability,and degradation properties of PLA films.When the ratio of PLA to EC was 3:7,the tensile strength and elongation at break reached maximum values of 16.6 MPa and 30.5%,respectively.Moreover,under different conditions,the composite film exhibited better degradability than the PLA film.The composite film with a 3:7 ratio of PLA to EC had the best performance,with a degradation rate of 21.75%after 84 days.Chilled fresh meat wrapped with the composite film showed significantly improved antioxidant,antibacterial,and water-holding properties. 展开更多
关键词 biodegradable film polylactic acid ethyl cellulose ZEIN chilled fresh meat PRESERVATION
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Evaluation of the repairing ability of different active ingredients on the lip
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作者 Donghan Jia Yanyan Wu +3 位作者 Heji Gong Zhewei Liu Changmei Peng Wanping Zhang 《日用化学工业(中英文)》 北大核心 2025年第8期1024-1034,共11页
This study used non-invasive evaluation methods measured six skin physiological parameters of the lower lip in 180 subjects,including moisture content,transepidermal water loss(TEWL),smoothness(SESM),scaliness of the ... This study used non-invasive evaluation methods measured six skin physiological parameters of the lower lip in 180 subjects,including moisture content,transepidermal water loss(TEWL),smoothness(SESM),scaliness of the skin(SESC),wrinkles(SEW),and red area of the lip skin,and compared the effects of 6 groups of lip balms(no-additive group,marine oligosaccharides group,ceramides group,glycyrrhizinic acid group,allantoin group,and mixed group;30 each)on the skin physiological parameters of dry,flaking,and cracked lip subjects.The results showed that the lip mositure content of the subjects in the marine oligosaccharide group,glycyrrhetinic acid group,and allantoin group increased significantly by 44.40%,42.84%and 58.08%after 7 days of lip balm(P<0.05).The TEWL in the ceramide group and the allantoin group was significantly reduced by 21.83%and 24.72%,respectively,after 7 days of lip paste use(P<0.05).The lip skin smoothness values of subjects in the glycyrrhizic acid group and the allantoin group were significantly reduced by 18.76%and 14.97%,respectively,after 28 days of lip balm application(P<0.05).The lip skin scaling indices of subjects in the marine oligosaccharide group,the ceramides group,and the allantoin group were significantly reduced by 33.77%,42.69%,and 38.07%,respectively,after 28 days of lip balm application(P<0.05).The wrinkle parameters of the lip skin of the subjects in the marine oligosaccharide,glycyrrhizinic acid and allantoin groups were significantly reduced by 23.06%,23.29%and 25.98%,respectively,after 28 days of lip balm application(P<0.05).And the area of the red zone of the lip skin of the subjects in the allantoin group was significantly reduced by 4.27%,after 28 days of lip balm application(P<0.05).Combining the effects of the four active ingredients on the secretion of hyaluronic acid(moisturizing effect)and inflammatory factor(IL-6)in HSF cells,it suggests that marine oligosaccharides and allantoin have a perfect impact on enhancing the water content of the skin on the lips of the subjects,and further improve the symptoms of flaking and wrinkles on the lips of the subjects.The ceramide and allantoin can repair the skin barrier well and have a good effect on the chapped and flaky lips of the subjects.After 28 days of using lip balm,the water content of lips in the mixed group increased,the skin barrier was repaired and became smoother,and the wrinkles,scale index,and red zone value were reduced,which could well relieve chronic lip inflammation and lay a foundation for developing lip products for the treatment of chronic cheilitis. 展开更多
关键词 lip skin physiological parameters marine oligosaccharides CERAMIDES glycyrrhetinic acid ALLANTOIN LIPSTICK
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Effective detection of malachite green by folic acid stabilized silver nanoclusters
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作者 CAI Zhifeng WU Ying +3 位作者 LI Ya'nan MENG Guiyu MIAO Tianyu ZHANG Yihao 《无机化学学报》 北大核心 2025年第5期983-993,共11页
Herein,a one-pot chemical reduction method was reported to prepare folic acid(FA)-stabilized silver nanoclusters(FA@Ag NCs),in which FA,hydrazine hydrate,and silver nitrate were used as capping agent,reducing agent,an... Herein,a one-pot chemical reduction method was reported to prepare folic acid(FA)-stabilized silver nanoclusters(FA@Ag NCs),in which FA,hydrazine hydrate,and silver nitrate were used as capping agent,reducing agent,and precursor,respectively.Several technologies were employed to investigate the structures and optical properties of FA@Ag NCs,including transmission electron microscopy(TEM),X-ray photoelectron spectrometer(XPS),Fourier transform infrared spectrometer(FTIR),X-ray diffractometer(XRD),fluorescence spectrometer,and ultraviolet visible absorption spectrometer.FA@Ag NCs were suggested to be highly dispersed and spherical with a size of around 2.8 nm.Moreover,the maximum excitation and emission wavelengths of FA@Ag NCs were 370 and 447 nm,respectively.Under the optimal detection conditions,FA@Ag NCs could be used to effectively detect malachite green with the linear detection range of 0.5-200μmol·L^(-1).The detection limit was 0.084μmol·L^(-1).The fluorescence-quenching mechanism was ascribed to the static quenching.The detection system based on FA@AgNCs was successfully used for the detection of malachite green in actual samples with good accuracy and reproducibility. 展开更多
关键词 fluorescence probe silver nanoclusters folic acid malachite green static quenching
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Nickel-molybdenum alloy electrodeposited on nickel substrates for optimized hydrogen evolution reaction in acidic electrolytes
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作者 WANG Haibo WU Zelin +6 位作者 WEN Hui ZHAO Zhiyong WANG Chenbo LU Tongyu GUO Yuxuan WANG Congwei WANG Junying 《燃料化学学报(中英文)》 北大核心 2025年第10期1509-1518,共10页
The utilization of nickel-based catalysts as alternatives to expensive platinum-based(Pt-based)materials for the hydrogen evolution reaction in acidic electrolytes has attracted considerable attention due to their pot... The utilization of nickel-based catalysts as alternatives to expensive platinum-based(Pt-based)materials for the hydrogen evolution reaction in acidic electrolytes has attracted considerable attention due to their potential for enabling cost-effective industrial applications.However,the unsatisfied cyclic stability and electrochemical activity limit their further application.In this work,nickel-molybdenum(Ni-Mo)alloy catalysts were successfully synthesized through a comprehensive process including electrodeposition,thermal annealing,and electrochemical activation.Owing to the synergistic interaction of molybdenum trinickelide(Ni_(3)Mo)and molybdenum dioxide(MoO_(2))in Ni-Mo alloy,the catalyst display superior overall electrochemical properties.A low overpotential of 86 mV at 10 mA/cm^(2)and a Tafel slope of 74.0 mV/dec in 0.5 mol/L H_(2)SO_(4)solution can be achieved.Notably,remarkable stability with negligible performance degradation even after 100 h could be maintained.This work presents a novel and effective strategy for the design and fabrication of high-performance,non-precious metal electrocatalysts for acidic water electrolysis. 展开更多
关键词 nickel-molybdenum alloy acid electrolysis of water hydrogen evolution reaction synergistic effect ELECTROCATALYSIS
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哈茨木霉菌活性物质harzianic acid的异源合成及其抑菌机制研究
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作者 李心芃 宋瑞轲 +2 位作者 高琦 沈标 张建 《南京农业大学学报》 北大核心 2025年第4期880-891,共12页
[目的]本文旨在分离、纯化、鉴定和异源合成harzianic acid,并研究其对病原真菌的抑制机制。[方法]插入突变获得产黄色物质突变株哈茨木霉菌(Trichoderma harzianum)NJAU 5688,结合液相色谱-质谱联用技术(HPLC-MS)、核磁共振(NMR)等数... [目的]本文旨在分离、纯化、鉴定和异源合成harzianic acid,并研究其对病原真菌的抑制机制。[方法]插入突变获得产黄色物质突变株哈茨木霉菌(Trichoderma harzianum)NJAU 5688,结合液相色谱-质谱联用技术(HPLC-MS)、核磁共振(NMR)等数据确定主要成分为harzianic acid;利用同源重组异源表达的方法提高harzianic acid的产量;利用平板试验研究harzianic acid抑制病原菌的能力;利用转录组研究harzianic acid对Fusarium oxysporum f.sp.cubense 4(Foc4)的拮抗机制,研究harzianic acid对Foc4细胞膜的影响。[结果]与野生型Trichoderma harzianum NJAU 4742相比,NJAU 5688的水溶代谢产物对病原真菌具有更强的抑制作用;HPLC-MS、NMR等数据分析确定该突变株的水溶代谢产物主要化合物为harzianic acid;在构巢曲霉(Aspergillus nidulans)A1145中同源重组,异源合成后harzianic acid产量可达19.66 mg·L^(-1)。平板试验表明,harzianic acid对病原真菌的抑制作用具有显著浓度依赖性。用harzianic acid处理后Foc4菌丝中关于质膜和相关成分富集的基因最为显著,用100 mg·L^(-1) harzianic acid处理Foc4胞外溶液的D 260值(0.443)约为对照组(0.232)的1.91倍,表明harzianic acid可能破坏了Foc4的细胞膜。[结论]鉴定突变子NJAU 5688合成了抑菌物质harzianic acid,在A1145中实现异源合成,产量达到19.66 mg·L^(-1);结合转录组和核酸检测,100 mg·L^(-1) harzianic acid破坏Foc4菌丝细胞膜,抑制Foc4生长。 展开更多
关键词 哈茨木霉 harzianic acid 异源合成 转录组分析 细胞膜
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Network Pharmacology and Experimental Verification Unraveled The Mechanism of Pachymic Acid in The Treatment of Neuroblastoma
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作者 LIU Hang ZHU Yu-Xin +6 位作者 GUO Si-Lin PAN Xin-Yun XIE Yuan-Jie LIAO Si-Cong DAI Xin-Wen SHEN Ping XIAO Yu-Bo 《生物化学与生物物理进展》 北大核心 2025年第9期2376-2392,共17页
Objective Traditional Chinese medicine(TCM)constitutes a valuable cultural heritage and an important source of antitumor compounds.Poria(Poria cocos(Schw.)Wolf),the dried sclerotium of a polyporaceae fungus,was first ... Objective Traditional Chinese medicine(TCM)constitutes a valuable cultural heritage and an important source of antitumor compounds.Poria(Poria cocos(Schw.)Wolf),the dried sclerotium of a polyporaceae fungus,was first documented in Shennong’s Classic of Materia Medica and has been used therapeutically and dietarily in China for millennia.Traditionally recognized for its diuretic,spleen-tonifying,and sedative properties,modern pharmacological studies confirm that Poria exhibits antioxidant,anti-inflammatory,antibacterial,and antitumor activities.Pachymic acid(PA;a triterpenoid with the chemical structure 3β-acetyloxy-16α-hydroxy-lanosta-8,24(31)-dien-21-oic acid),isolated from Poria,is a principal bioactive constituent.Emerging evidence indicates PA exerts antitumor effects through multiple mechanisms,though these remain incompletely characterized.Neuroblastoma(NB),a highly malignant pediatric extracranial solid tumor accounting for 15%of childhood cancer deaths,urgently requires safer therapeutics due to the limitations of current treatments.Although PA shows multi-mechanistic antitumor potential,its efficacy against NB remains uncharacterized.This study systematically investigated the potential molecular targets and mechanisms underlying the anti-NB effects of PA by integrating network pharmacology-based target prediction with experimental validation of multi-target interactions through molecular docking,dynamic simulations,and in vitro assays,aimed to establish a novel perspective on PA’s antitumor activity and explore its potential clinical implications for NB treatment by integrating computational predictions with biological assays.Methods This study employed network pharmacology to identify potential targets of PA in NB,followed by validation using molecular docking,molecular dynamics(MD)simulations,MM/PBSA free energy analysis,RT-qPCR and Western blot experiments.Network pharmacology analysis included target screening via TCMSP,GeneCards,DisGeNET,SwissTargetPrediction,SuperPred,and PharmMapper.Subsequently,potential targets were predicted by intersecting the results from these databases via Venn analysis.Following target prediction,topological analysis was performed to identify key targets using Cytoscape software.Molecular docking was conducted using AutoDock Vina,with the binding pocket defined based on crystal structures.MD simulations were performed for 100 ns using GROMACS,and RMSD,RMSF,SASA,and hydrogen bonding dynamics were analyzed.MM/PBSA calculations were carried out to estimate the binding free energy of each protein-ligand complex.In vitro validation included RT-qPCR and Western blot,with GAPDH used as an internal control.Results The CCK-8 assay demonstrated a concentration-dependent inhibitory effect of PA on NB cell viability.GO analysis suggested that the anti-NB activity of PA might involve cellular response to chemical stress,vesicle lumen,and protein tyrosine kinase activity.KEGG pathway enrichment analysis suggested that the anti-NB activity of PA might involve the PI3K/AKT,MAPK,and Ras signaling pathways.Molecular docking and MD simulations revealed stable binding interactions between PA and the core target proteins AKT1,EGFR,SRC,and HSP90AA1.RT-qPCR and Western blot analyses further confirmed that PA treatment significantly decreased the mRNA and protein expression of AKT1,EGFR,and SRC while increasing the HSP90AA1 mRNA and protein levels.Conclusion It was suggested that PA may exert its anti-NB effects by inhibiting AKT1,EGFR,and SRC expression,potentially modulating the PI3K/AKT signaling pathway.These findings provide crucial evidence supporting PA’s development as a therapeutic candidate for NB. 展开更多
关键词 pachymic acid network pharmacology molecular dynamics simulation
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cis/trans-Octahedral configuration induced topologically different MOFs:Syntheses,structures,and Hirshfeld surface analyses
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作者 PENG Ri BAI Yingxiang +1 位作者 XIE Yuxin ZHU Dunru 《无机化学学报》 北大核心 2025年第8期1650-1660,共11页
Two metal-organic frameworks(MOFs),trans-[Co(L)(μ_(2)-H_(2)O)(H_(2)O)2]·2H_(2)O(1)and cis-[Mn(L)(Bipy)](2)(H_(2)L=2,2'-dimethyl-4,4'-biphenyldicarboxylic acid,Bipy=4,4'-bipyridine),have been synthesi... Two metal-organic frameworks(MOFs),trans-[Co(L)(μ_(2)-H_(2)O)(H_(2)O)2]·2H_(2)O(1)and cis-[Mn(L)(Bipy)](2)(H_(2)L=2,2'-dimethyl-4,4'-biphenyldicarboxylic acid,Bipy=4,4'-bipyridine),have been synthesized and character-ized by FTIR,thermogravimetric analysis(TGA),powder and single crystal X-ray diffraction.MOF 1 crystallizes in the triclinic system with a P1 space group and contains two crystallographically different Coions.Each trans-[CoO_(6)]octahedron is connected byμ_(2)-H_(2)O and L^(2-)ligand with a bis(unidentate)coordination mode to produce a 2D sql topological network.MOF 2 crystallizes in the monoclinic system with a C2/c space group.The Mncation adopts a cis-[MnO_(4)N_(2)]octahedron as a 6-connected node and is linked by L^(2-)ligand as a 4-connected node to gener-ate a binodal(4,6)-connected 3D fsc framework.The intermolecular interactions in 1 and 2 have been investigated by 3D Hirshfeld surface analyses and 2D fingerprint plots to reveal that the main interactions are H…H and O…H/H…O contacts in 1,and H…H and C…H/H…C contacts in 2.The TGA indicated that 1 and 2 were stable below 390 and 370℃,respectively. 展开更多
关键词 metal-organic framework 2 2'-dimethyl-4 4'-biphenyldicarboxylic acid cis/trans-octahedron TOPOLOGY
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Effect of retinoic acid on delayed encephalopathy after acute carbon monoxide poisoning:Role of the lncRNA SNHG15/LINGO-1/BDNF/TrkB axis
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作者 HUANG Fangling WANG Su’e +2 位作者 PENG Zhengrong HUANG Xu BAI Sufen 《中南大学学报(医学版)》 北大核心 2025年第6期955-969,共15页
Objective:The neurotoxicity of carbon monoxide(CO)to the central nervous system is a key pathogenesis of delayed encephalopathy after acute carbon monoxide poisoning(DEACMP).Our previous study found that retinoic acid... Objective:The neurotoxicity of carbon monoxide(CO)to the central nervous system is a key pathogenesis of delayed encephalopathy after acute carbon monoxide poisoning(DEACMP).Our previous study found that retinoic acid(RA)can suppress the neurotoxic effects of CO.This study further explores,in vivo and in vitro,the molecular mechanisms by which RA alleviates CO-induced central nervous system damage.Methods:A cytotoxic model was established using the mouse hippocampal neuronal cell line HT22 and primary oligodendrocytes exposed to CO,and a DEACMP animal model was established in adult Kunming mice.Cell viability and apoptosis of hippocampal neurons and oligodendrocytes were assessed using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide(MTT)assay and Annexin V/propidium iodide(PI)double staining.The transcriptional and protein expression of each gene was detected using real time fluorescence quantitative PCR(RT-qPCR)and Western blotting.Long noncoding RNA(lncRNA)SNHG15 and LINGO-1 were knocked down or overexpressed to observe changes in neurons and oligodendrocytes.In DEACMP mice,SNHG15 or LINGO-1 were knocked down to assess changes in central nervous tissue and downstream protein expression.Results:RA at 10 and 20μmol/L significantly reversed CO-induced apoptosis of hippocampal neurons and oligodendrocytes,downregulation of SNHG15 and LINGO-1,and upregulation of brain-derived neurotrophic factor(BDNF)and tyrosine kinase receptor B(TrkB)(all P<0.05).Overexpression of SNHG15 or LINGO-1 weakened the protective effect of RA against CO-induced cytotoxicity(all P<0.05).Knockdown of SNHG15 or LINGO-1 alleviated CO-induced apoptosis of hippocampal neurons and oligodendrocytes and upregulated BDNF and TrkB expression levels(all P<0.05).Experiments in DEACMP model mice showed that knockdown of SNHG15 or LINGO-1 mitigated central nervous system injury in DEACMP(all P<0.05).Conclusion:RA alleviates CO-induced apoptosis of hippocampal neurons and oligodendrocytes,thereby reducing central nervous system injury and exerting neuroprotective effects.LncRNA SNHG15 and LINGO-1 are key molecules mediating RA induced inhibition of neuronal apoptosis and are associated with the BDNF/TrkB pathway.These findings provide a theoretical framework for optimizing the clinical treatment of DEACMP and lay an experimental foundation for elucidating its molecular mechanisms. 展开更多
关键词 delayed encephalopathy after acute carbon monoxide poisoning apoptosis retinoic acid NEUROPROTECTION LINGO-1 lncRNA SNHG15
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Synthesis and fluorescence sensing of a highly sensitive and multi-response cadmium coordination polymer
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作者 REN Jing YAN Ruikui +3 位作者 CHEN Xiaoli CUI Huali YANG Hua WANG Jijiang 《无机化学学报》 北大核心 2025年第3期574-586,共13页
A coordination polymer{[Cd(H_(2)dpa)(bpy)]·3H_(2)O}_(n)(Cd-CP)was designed and hydrothermal synthesized based on 4-(2,4-dicarboxyphenoxy)phthalic acid(H_(4)dpa),2,2'-bipyridine(bpy)and Cd(NO_(3))_(2)·4H_... A coordination polymer{[Cd(H_(2)dpa)(bpy)]·3H_(2)O}_(n)(Cd-CP)was designed and hydrothermal synthesized based on 4-(2,4-dicarboxyphenoxy)phthalic acid(H_(4)dpa),2,2'-bipyridine(bpy)and Cd(NO_(3))_(2)·4H_(2)O.The structure was characterized by single-crystal X-ray diffraction,powder X-ray diffraction,elemental analysis,and infrared spectroscopy.Cd-CP belongs to the monoclinic crystal system with the P2_1/c space group and performs in a 1D double-chain structure.The adjacent double chains further form a 3D supramolecular network structure through hydrogen bonding.Thermogravimetric analysis shows that Cd-CP has good thermal stability.Fluorescence analysis showed that Cd-CP had good choosing selectively and was sensitive to metal ions(Fe^(3+)and Zn^(2+)),2,4,6-trinitrophenylhydrazine(TRI),and pyrimethanil(Pth).Interestingly,when Cd-CP was used for fluorescence detection of metal ions,it was found to have a fluorescence quenching effect on Fe^(3+)but had an obvious enhancement effect on Zn^(2+).Therefore,we designed an“on-off-on”logic gate.In addition,the mechanism of fluorescence sensing has been deeply explored.CCDC:2258625. 展开更多
关键词 coordination polymer 4⁃(2 4⁃dicarboxylic phenoxyl)phthalic acid fluorescence sensing logic gate
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Syntheses and luminescence of four Cd(Ⅱ)/Zn(Ⅱ)complexes constructed by 1,3-bis(4H-1,2,4-triazole)benzene
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作者 PENG Yanfen WANG Xinyue +2 位作者 LIU Tianbao WU Xiaoshuo WEI Yujing 《无机化学学报》 北大核心 2025年第7期1416-1426,共11页
Four new coordination polymers,{[Cd(mbtx)(4OHphCOO)]NO_(3)}n(1),{[Zn(mbtx)(1,4-bdc)_(0.5)(H_(2)O)_(2)]·(1,4-bdc)_(0.5)·4H_(2)O}n(2),{[Cd2(mbtx)(5NO_(2)-bdc)_(2)(H_(2)O)_(3)]·4.5H_(2)O}n(3),and{[Zn(H_(2)... Four new coordination polymers,{[Cd(mbtx)(4OHphCOO)]NO_(3)}n(1),{[Zn(mbtx)(1,4-bdc)_(0.5)(H_(2)O)_(2)]·(1,4-bdc)_(0.5)·4H_(2)O}n(2),{[Cd2(mbtx)(5NO_(2)-bdc)_(2)(H_(2)O)_(3)]·4.5H_(2)O}n(3),and{[Zn(H_(2)O)6][Zn_(2)(mbtx)_(2)(btc)_(2)(H_(2)O)_(4)]·2H_(2)O}n(4)(mbtx=1,3-bis(4H-1,2,4-triazole)benzene,4OHphCOO-=p-hydroxybenzoate,1,4-bdc2-=1,4-benzenedicarboxylate,5NO_(2)-bdc2-=5-nitro-isophthalate,btc3-=1,3,5-benzenetricarboxylate),were synthesized under room temperature condition and characterized by single-crystal X-ray diffraction,elemental analyses,and powder X-ray diffraction.Single-crystal X-ray structural analysis shows that complexes 1 and 3 are 2D networks.In 1,the adjacent 2D networks are linked to a 3D network byπ-πstacking interaction.2 and 4 exhibit 1D chains,and the 1D chains are connected into a 3D network byπ-πstacking interaction and intermolecular hydrogen bond.Luminescence and thermogravimetric analysis of the four complexes were discussed.CCDC:2416406,1;2416407,2;2416408,3;2416409,4. 展开更多
关键词 1 3-bis(4H-1 2 4-triazole)benzene π-πstacking interaction LUMINESCENCE aromatic carboxylic acid hydrogen bond
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QUANTUM CHEMICAL STUDY ON STRUCTURAL ACIDITY OF HZSM-5 ZEOLITE
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作者 Wu Suochuan Wu Xiangyang (Department of Chemistry, Nanj ing Normal University, Nanjing, China) 《分子催化》 EI CAS CSCD 1990年第S1期103-110,共8页
The basic units of the framework structure of HZSM-5 zeolite are the five-membered rings which are linked by bridging oxygen atoms and as a result form units of four-membered rings or six membered rings. Semiempirical... The basic units of the framework structure of HZSM-5 zeolite are the five-membered rings which are linked by bridging oxygen atoms and as a result form units of four-membered rings or six membered rings. Semiempirical CNDO/2 quantum chemical method is used to calculate the charge density distribution for all these basic units, i.e., 4-, 5- and 6-membered rings of HZSM-5 zeolite. Quantitative relations between the structural parameter α<sub>0</sub> of the acidity of HZSM-5 zeolite and the number of aluminum atoms N<sub>Al</sub> per unit cell are obtained. Zeolite may be considered as solids acting more or less as protonic polyacids in solution. This protonic acidity is expressed as activity, a<sub>H<sup>+</sup></sub>= [H<sup>+</sup>]f<sub>H<sup>+</sup></sub> ,were =n<sub>H<sup>+</sup></sub>aN<sub>Al</sub>/Z<sub>cat</sub> and the activity coefficient f<sub>H<sup>+</sup></sub> is equal to a constant multiplied by the structural parameter, f<sub>H<sup>+</sup></sub>= Kα<sub>0</sub>, K is taken to be 32. Upder different (SiO<sub>2</sub>/Al<sub>2</sub>O<sub>3</sub>) ratios, therefore, the protonic activities could be obtained theoretically, and the calculation results are 展开更多
关键词 ZEOLITE membered acidity RINGS BRIDGING HEXANE solids terminated CONSTANTS proton
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Effects of Dietary Guanidinoacetic Acid on Growth Performance,Meat Quality,Antioxidant Activity,and Antioxidant-related Gene Expression in Ducks
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作者 Yu Xilong Lin Yu +2 位作者 Dou Renkai Xu Liangmei Wu Hongzhi 《Journal of Northeast Agricultural University(English Edition)》 2025年第1期1-18,共18页
This study aimed to investigate the effects of dietary guanidinoacetic acid on growth performance,meat quality,antioxidant activity,and antioxidant-related gene expression in ducks.Total 48042-day-old female ducks wer... This study aimed to investigate the effects of dietary guanidinoacetic acid on growth performance,meat quality,antioxidant activity,and antioxidant-related gene expression in ducks.Total 48042-day-old female ducks were randomly divided into four groups with six replicates and 20 ducks per replicate and fed the basal diet to the control group.The experimental groups were fed the basal diet with 400,600 and 800 mg·kg^(-1) guanidinoacetic acid,respectively.The trial lasted 48 days.Compared with the control group,(1)the body weight at 90 days and average daily gain were increased(P<0.05),the feed conservation ratio was decreased(P<0.05);(2)the dressing percentage and breast muscle percentage were increased(P<0.05);(3)the total amino acid content,polyunsaturated fatty acids to monounsaturated fatty acids ratio were increased(P<0.05)in breast and thigh muscles;(4)activities of superoxide dismutase,catalase and glutathione peroxidase enzyme were increased(P<0.05)in thigh muscles;(5)the relative expressions of superoxide dismutase 1,glutathione peroxidase 1,and catalase were significantly increased(P<0.05)in the liver.In this study,the optimum dosage of 600 mg·kg^(-1) guanidinoacetic acid improved the growth performance,meat quality,antioxidant activity,and antioxidant-related gene expression in ducks. 展开更多
关键词 guanidinoacetic acid carcass characteristics fatty acid amino acid antioxidant activity
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Metal extraction and recovery from cathode material of spent lithium-ion batteries utilizing an organic acid reagent scheme
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作者 WU Jia-jia KIM Jaeyeon +1 位作者 AHN Junmo LEE Jaeheon 《Journal of Central South University》 2025年第9期3645-3656,共12页
This study focuses on using a green reagent scheme of methanesulfonic acid (MSA) and citric acid (CA) to extract valuable metals from the cathodes, aiming to minimize environmental impact during the recycling process.... This study focuses on using a green reagent scheme of methanesulfonic acid (MSA) and citric acid (CA) to extract valuable metals from the cathodes, aiming to minimize environmental impact during the recycling process. Leaching studies on LiCoO_(2) identified optimal conditions as follows: 2.4 mol/L MSA, 1.6 mol/L CA, S/L ratio of 80 g/L, leaching temperature of 90oC and leaching time of 6 h. The maximum Co and Li extraction achieved was 92% and 85%, respectively. LiCoO_(2) dissolution in MSA-CA leaching solution is highly impacted by temperature;Avrami equation showed a good fitting for the leaching data. The experimental activation energy of Co and Li was 50.98 kJ/mol and 50.55 kJ/mol, respectively, indicating that it is a chemical reaction-controlled process. Furthermore, cobalt was efficiently recovered from the leachate using oxalic acid, achieving a precipitation efficiency of 99.91% and a high-purity cobalt oxalate product (99.85 wt.%). In the MSA-CA leaching solution, MSA served as a lixiviant, while CA played a key role in reducing Co in LiCoO_(2). The overall organic acid leaching methodology presents an attractive option due to its reduced environmental impact. 展开更多
关键词 methanesulfonic acid citric acid cathode material leaching organic acid reagent scheme
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Surface pretreatment effect on the separation and purification of magnesite and dolomite
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作者 GONG Xiu-feng YAO Jin +4 位作者 JIA Yu-kun YIN Chao YIN Wan-zhong WANG Yu-lian FU Ya-feng 《Journal of Central South University》 2025年第3期977-990,共14页
Surface pretreatment can change the surface properties of minerals,placing them in either a favorable or an unfavorable state for flotation.To solve the separation problem associated with magnesite and dolomite,surfac... Surface pretreatment can change the surface properties of minerals,placing them in either a favorable or an unfavorable state for flotation.To solve the separation problem associated with magnesite and dolomite,surface pretreatment experiments with citric acid,tartaric acid,and tannic acid(TA)on magnesite and dolomite as well as flotation experiments on pretreated samples were performed in this study.Experimental results demonstrated that when citric acid and tartaric acid are used for surface pretreatment,the separation effect of magnesite and dolomite is poor.However,when TA is used,the separation effect of magnesite and dolomite improves.SEM and BET analysis indicated that surface pretreatment with TA changes the surface morphology of the two minerals,resulting in additional concave pores on the dolomite surface,and a significant increase in pore size and specific surface area.The adsorption quantity test and contact angle measurement demonstrated that after surface pretreatment with TA,the magnesite adsorption capacity on sodium oleate(NaOL)slightly decreases and the dolomite adsorption capacity on NaOL considerably decreases.XPS detection concluded that the surface pretreatment of TA on the magnesite surface mainly relies on physical adsorption with weak adsorption ability and poor ability to act on Mg sites.The TA surface pretreatment action on the dolomite surface is mainly through chemical adsorption,and it is strongly and selectively adsorbed on the Ca site of dolomite through O.Actual ore rough selection experiments reveal that TA pretreatment successfully removes dolomite from magnesite,resulting in a high-quality magnesite concentrate characterized by a MgO grade of 45.49%and a CaO grade of 0.75%. 展开更多
关键词 surface pretreatment tannic acid MAGNESITE DOLOMITE SEPARATION PURIFICATION
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