To enhance the anti-resistance efficacy of our previously disclosed naphthyl-triazine 5,structure-based drug design strategy was rationally conducted to design a series of novel biphenyl-piperidine-triazinecontaining ...To enhance the anti-resistance efficacy of our previously disclosed naphthyl-triazine 5,structure-based drug design strategy was rationally conducted to design a series of novel biphenyl-piperidine-triazinecontaining non-nucleoside reverse transcriptase inhibitors.Remarkably,several of these compounds demonstrated single-digit nanomolar antiviral potency against both wild-type(WT)human immunodeficiency virus-1(HIV-1)and five clinically relevant mutant strains.Among these,compound 11s emerged as the most potent inhibitor,showing remarkable efficacy against WT HIV-1(50%effective concentration(EC_(50))=2 nmol/L)and five mutant strains(EC_(50)=0.003-0.073μmol/L),which was significantly superior to that of compound 5.This optimized derivative demonstrated substantially improved pharmacological properties compared to existing drugs etravirine(ETR)and rilpivirine(RPV),showing a 4-fold reduction in cytotoxicity alongside 6-fold enhancement in selectivity index(50%cytotoxic concentration(CC_(50))=19.69μmol/L,selectivity index(SI)=7438).The compound's metabolic profile revealed exceptional stability,with an elimination half-life(t_(1/2)=41.4 min)more than double that of RPV(t_(1/2)=16.03min).Comprehensive safety evaluation indicated minimal cytochrome P450(CYP)enzymes interference,low cardiac ion channel activity,and no observable acute toxicity,collectively suggesting a reduced risk profile for therapeutic applications.These promising characteristics significantly advance the development potential of biphenyl-piperidine-triazine derivatives as next-generation non-nucleoside reverse transcriptase inhibitors(NNRTIs),offering enhanced efficacy,improved safety,and favorable pharmacokinetic properties for antiretroviral therapy.展开更多
The Ni single-atom catalyst dispersed on nitrogen doped graphene support has attracted much interest due to the high selectivity in electro-catalyzing CO_(2)reduction to CO,yet the chemical inertness of the metal cent...The Ni single-atom catalyst dispersed on nitrogen doped graphene support has attracted much interest due to the high selectivity in electro-catalyzing CO_(2)reduction to CO,yet the chemical inertness of the metal center renders it to exhibit electrochemical activity only under high overpotentials.Herein,we report P-and S-doped Ni single-atom catalysts,i.e.symmetric Ni_(1)/PN_(4)and asymmetric Ni1/SN_(3)C can exhibit high catalytic activity of CO_(2)reduction with stable potential windows.It is revealed that the key intermediate*COOH in CO_(2)electroreduction is stabilized by heteroatom doping,which stems from the upward shift of the axial d_(z2)orbital of the active metal Ni atom.Furthermore,we investigate the potential-dependent free energetics and dynamic properties at the electrochemical interface on the Ni1/SN3C catalyst using ab initio molecular dynamics simulations with a full explicit solvent model.Based on the potential-dependent microkinetic model,we predict that S-atom doped Ni SAC shifts the onset potential of CO_(2)electroreduction from–0.88 to–0.80 V vs.RHE,exhibiting better activity.Overall,this work provides an in-depth understanding of structure-activity relationships and atomic-level electrochemical interfaces of catalytic systems,and offers insights into the rational design of heteroatom-doped catalysts for targeted catalysis.展开更多
Atomically precise palladium(Pd)clusters are emerging as versatile nanomaterials with applications in catalysis and biomedicine.This study explores the synthesis,structure evolution,and catalytic properties of Pd clus...Atomically precise palladium(Pd)clusters are emerging as versatile nanomaterials with applications in catalysis and biomedicine.This study explores the synthesis,structure evolution,and catalytic properties of Pd clusters stabilized by cyclohexanethiol(HSC_(6)H_(11))ligands.Using electrospray ionization mass spectrometry(ESI-MS)and single-crystal X-ray diffraction(SXRD),structures of the Pd clusters ranging from Pd4(SC_(6)H_(11))8 to Pd18(SC_(6)H_(11))36 were determined.This analysis revealed a structure evolution from polygonal to elliptical geometries of the PdnS2n frameworks as the cluster size increased.UV-Vis-NIR spectroscopy,combined with quantum chemical calculations,elucidated changes in the electronic structure of the clusters.Catalytic studies on the Sonogashira cross-coupling reactions demonstrated a size-dependent decline in activity attributed to variations in structural arrangements and electronic properties.Mechanistic insights proposed a distinctive Pd(Ⅱ)-Pd(Ⅳ)catalytic cycle.This research underscores how ligands and cluster size influence the structures and properties of Pd clusters,offering valuable insights for the future design and application of Pd clusters in advanced catalysis and beyond.展开更多
Dual-atom catalysts(DACs),a natural extension of single-atom catalysts(SACs),have emerged as a prominent focal point in the field of heterogeneous catalysis,particularly in the context of chemical and energy conversio...Dual-atom catalysts(DACs),a natural extension of single-atom catalysts(SACs),have emerged as a prominent focal point in the field of heterogeneous catalysis,particularly in the context of chemical and energy conversion processes.Despite the fact that the catalytic activity of DACs is significantly modulated by the electronic structure of the catalyst,understanding how electron spin states are affected by variations in topology and geometric structure remains challenging and relatively unexplored.Herein,we propose the rational design of stable DACs composed of two iron atoms anchored on pristine graphdiyne(GDY),Fe_(2)-GDYn.A comprehensive and systematic investigation was carried out to elucidate the electronic configuration and spin states involved in the deliberate convergence towards the magnetic ground state,with the aim of uncovering the structure-spin relationship.Through an in-depth analysis of spin populations,electronic localization/delocalization,and the chemical bonding characteristics of the central metal atoms and the GDY skeleton,it was revealed that the spin coupling between the two iron atoms is preponderantly dictated by adjacent short-range Fe-Fe interactions.Conversely,spin decoupling can be attributed to the long-rangeπ-bond component within the linkage.Moreover,geometric and chemical bonding asymmetries were found to induce orbital and spin splitting in iron atoms possessing an electronic configuration of d8.These findings provide important insights into the relationship between topology and spin,thereby presenting novel strategies for the rational design of spin-manipulated DACs.展开更多
The microstructure and mechanical behaviors of NiAl-28Cr-5Mo-1Nb eutectic alloy were investigated by using scanning electron microscopy, X-ray diffraction, transmission electron microscopy and compression tests, respe...The microstructure and mechanical behaviors of NiAl-28Cr-5Mo-1Nb eutectic alloy were investigated by using scanning electron microscopy, X-ray diffraction, transmission electron microscopy and compression tests, respectively. The alloy is mainly composed of three phases, which are the gray lamellar Cr（Mo） plate, black NiAI matrix and semicontinuously distributed Cr2Nb-type Laves phase. Through Nb addition, NiAl-Cr（Mo）/Nb alloy exhibits a reasonable balance of high temperature strength and room temperature compression ductility and its mechanical behaviors are superior to the NiAl-28Cr-6Mo eutectic alloy at all temperature. The elevated temperature compression deformation behavior of NiAl-Cr（Mo）/Nb alloy can be properly described by power-law equation.the National High Technology Committee of China （No. 863-715-005-0030） for financial supports.展开更多
A layered perovskite oxide Y0.8Ca0.2BaCoFeO5＋δ（YCBCF） was synthesized as a novel cathode material for intermedi-ate-temperature solid oxide fuel cells （IT-SOFCs） by citric acid-nitrates self-propagating combusti...A layered perovskite oxide Y0.8Ca0.2BaCoFeO5＋δ（YCBCF） was synthesized as a novel cathode material for intermedi-ate-temperature solid oxide fuel cells （IT-SOFCs） by citric acid-nitrates self-propagating combustion method. The phase and micro-structure of YCBCF were investigated by X-ray diffraction （XRD） and scanning electron microscopy （SEM）, respectively. The aver-age thermal expansion coefficient （TEC） of YCBCF was 14.6×10–6 K–1, which was close to other materials of SOFC at the range of RT–1000 oC. An open-circuit potential of 0.75 V and a maximum output power density of 426 mW/cm2 were obtained at 650 oC in a Sm0.2Ce0.8O1.9 （SDC）-based anode-supported SOFC by using humidified （~3%H2O） hydrogen as fuel and static air as oxidant. The results indicated that the YCBCF was a promising cathode candidate for IT-SOFCs.展开更多
A new cyclometalated platinum complex containing 2, 5-bis(naphthalene-1-yl)-1,3,4-oxadiazole ligand was synthesized and characterized. The UV-Vis absorptions and photoluminescent properties of the ligand and its plati...A new cyclometalated platinum complex containing 2, 5-bis(naphthalene-1-yl)-1,3,4-oxadiazole ligand was synthesized and characterized. The UV-Vis absorptions and photoluminescent properties of the ligand and its platinum complex were investigated. A characteristic metal-ligand charge transfer absorption peak at 439 nm in the UV spectrum and a strong emission peak at 625 nm in the photoluminescence spectrum were observed for this complex in dichloromethane. Cyclic voltammtry (CV) analysis shows that the EHOMO (energy level of the highest occupied molecular orbital) and ELUMO (energy level of the lowest unoccupied molecular orbital) of the platinum complex are about 、5.69 and 、3.25 eV, respectively, indicating that the oxadiazole-based platinum complex has a potential application in electrophosphorescent devices used as a red-emitting material.展开更多
Nafion as a universal polymer ionomer was widely applied for nanocatalysts electrode preparation.However,the effect of Nafion on electrocatalytic performance was often overlooked,especially for CO_(2)electrolysis.Here...Nafion as a universal polymer ionomer was widely applied for nanocatalysts electrode preparation.However,the effect of Nafion on electrocatalytic performance was often overlooked,especially for CO_(2)electrolysis.Herein,the key roles of Nafion for CO_(2)RR were systematically studied on Cu nanoparticles(NPs)electrocatalyst.We found that Nafion modifier not only inhibit hydrogen evolution reaction(HER)by decreasing the accessibility of H_(2)O from electrolyte to Cu NPs,and increase the CO_(2)concentration at electrocatalyst interface for enhancing the CO_(2)mass transfer process,but also activate CO_(2)molecule by Lewis acid-base interaction between Nafion and CO_(2)to accelerate the formation of^(*)CO,which favor of C–C coupling for boosting C_(2)product generation.Owing to these features,the HER selectivity was suppressed from 40.6%to 16.8%on optimal Cu@Nafion electrode at-1.2 V versus reversible hydrogen electrode(RHE),and as high as 73.5%faradaic efficiencies(FEs)of C_(2)products were achieved at the same applied potential,which was 2.6 times higher than that on bare Cu electrode(~28.3%).In addition,Nafion also contributed to the long-term stability by hinder Cu NPs morphology reconstruction.Thus,this work provides insights into the impact of Nafion on electrocatalytic CO_(2)RR performance.展开更多
The thermal equilibrium state of the reference electrode was investigated. The results show that the temperature difference between the inside and the outside of zirconia tube was very small and the Seebeck effect can...The thermal equilibrium state of the reference electrode was investigated. The results show that the temperature difference between the inside and the outside of zirconia tube was very small and the Seebeck effect can be ignored after the sensor was dipped into liquid steel for more than 2 s. A special sensor was designed to test the relation between the EMF （electromotive force） of sensor and the thermal equilibrium state of the reference elec- trode. Based on these results, it is suggested that the peak in EMF curve was caused by the change of oxygen potential in reference electrode before the thermal equilibrium was reached. If NiO was added by 2 M- 5 M to the Cr/Cr2O3 reference electrode, the peak in EMF curve could be eliminated.展开更多
[Objective]The aim was to study the adsorption property of adsorbent Ni-TiO_(2)-SiO_(2)synthesized by using rice husks as silicon source and template to gentian violet.[Method]The renewable dye adsorbent Ni-TiO_(2)-Si...[Objective]The aim was to study the adsorption property of adsorbent Ni-TiO_(2)-SiO_(2)synthesized by using rice husks as silicon source and template to gentian violet.[Method]The renewable dye adsorbent Ni-TiO_(2)-SiO_(2)was synthesized by using rice husks as raw material,and the adsorption property of Ni-TiO_(2)-SiO_(2)to gentian violet was studied.[Result]The adsorption rate of Ni-TiO_(2)-SiO_(2)to gentian violet reached about 90%after 1 h.In 100 ml gentian violet solution with concentration of 25 mg/L and pH=8,Ni-TiO_(2)-SiO_(2)with dosage of 0.07 g had the best adsorption effect.More importantly,Ni-TiO_(2)-SiO_(2)as adsorbent could be used repeatedly,and couldn’t lead to secondary pollution due to leaking.[Conclusion]The study could provide references for practical engineering application.展开更多
Two distinct copper coordination polymers, namely [Cu^Ⅱ2（2,5-pydc）2（bpp）2]·H2O（1） and Cu2^ⅠCu^Ⅱ（2,5-pydc）2（bpp）2（2）（2,5-pydc = pyridine-2,5-dicarboxylic acid, bpp = 1,3-bi（4-pyridyl）propane）, h...Two distinct copper coordination polymers, namely [Cu^Ⅱ2（2,5-pydc）2（bpp）2]·H2O（1） and Cu2^ⅠCu^Ⅱ（2,5-pydc）2（bpp）2（2）（2,5-pydc = pyridine-2,5-dicarboxylic acid, bpp = 1,3-bi（4-pyridyl）propane）, have been successfully synthesized through hydrothermal conditions under different temperatures. Single-crystal X-ray structural analysis revealed that both complexes 1 and 2 are 3D frameworks. Complex 1 is an 8-connected 2-fold interpenetrating network based on [Cu（2,5-pydc）]4 molecular building block（MBB）, and also can be simplified as a 4-connected net if the Cu（Ⅱ） ion is regarded as an independent node, whereas 2 shows a（4,4）-connected non-interpenetrated framework which contains mixed valence Cu（Ⅰ/Ⅱ） centers. The results demonstrate that temperature plays a significant role in the final structures of the complexes.展开更多
A new 3D cobalt metal-organic framework [C_7H_（13）N_2]_2[（CH_3COO）_2Co_7（oba）_5-（Hoba）_2（OH）_2]·H_2O has been synthesized under ionothermal conditions and characterized by elemental analysis, FT-IR, XRD...A new 3D cobalt metal-organic framework [C_7H_（13）N_2]_2[（CH_3COO）_2Co_7（oba）_5-（Hoba）_2（OH）_2]·H_2O has been synthesized under ionothermal conditions and characterized by elemental analysis, FT-IR, XRD, and TG. This complex crystallizes in monoclinic system, space group P21/c with a = 19.4499（4）, b = 10.8839（2）, c = 27.7796（5） ？, β = 104.467（2）o, V = 5694.22（19） ？~3, Z = 2, C_（116）H_（92）Co_7N_4O_（42）, M_r = 2626.45, D_c = 1.532 g/cm^3 , F（000） = 2682, μ = 1.085 mm-1, R = 0.0387 and wR = 0.1177. Its structure is characterized as a 3D open framework constructed by seven nuclear clusters [（CH_3COO）_Co_7（OH）_2] and the 4,4？-oxybisbenzoic acid ligand. The used ILs cations are located in the middle of the pore and compensate for the negative charges of framework. Furthermore, its fluorescence property has also been studied.展开更多
This study evaluates the adsorption ability ofbisphenol A（BPA） on titanium dioxide（TiO2） and its effect on the photocatalysis by advanced oxidation process using UV radiation and TiO2 photocatalyst. Degradation of...This study evaluates the adsorption ability ofbisphenol A（BPA） on titanium dioxide（TiO2） and its effect on the photocatalysis by advanced oxidation process using UV radiation and TiO2 photocatalyst. Degradation of BPA was also evaluated for the system without adsorption prior to photocatalytic reaction. The separation of TiO2 from BPA solution treated by pilot-scale photocatalytic reactor （capacity 0.16 m^3） was studied using submerged ultrafiltration （UF） membrane. It was found that although adsorption capacity of BPA was not high, adsorption played an important role in improving the efficiency ofphotocatalysis. On the other hand, during the separation of TiO2 particles from aqueous suspension, the permeate flux of the membrane was strongly affected by transmembrane pressure and TiO2 dose. The permeate turbidity was decreased below 1 NTU.展开更多
As an attractive C1 synthon,carbon dioxide(CO_(2))has been extensively used in organic synthesis to produce carboxylic acids.In this research,stereoselective electrochemical carboxylation ofα,β-unsaturated sulfones ...As an attractive C1 synthon,carbon dioxide(CO_(2))has been extensively used in organic synthesis to produce carboxylic acids.In this research,stereoselective electrochemical carboxylation ofα,β-unsaturated sulfones has been developed under transition-metal-free conditions.All the cinnamic acids and the derivatives are obtained selectively in the E-configuration.Besides,arylpropiolates also can be produced from alkynyl sulfones.展开更多
A novel series of CHOR-HEPT non-nucleoside HIV-1 reverse transcriptase inhibitors were developed by means of structure-based design strategy based on compound 6 reported previously by our group. Most of these compound...A novel series of CHOR-HEPT non-nucleoside HIV-1 reverse transcriptase inhibitors were developed by means of structure-based design strategy based on compound 6 reported previously by our group. Most of these compounds showed moderate to good activity toward wild-type HIV-1 strain with EC50values in the range of 0.18–51.88 μmol/L and SI values in the range of 4–907. The compound 14aj with a CHOH linker and compound 13i with a CHOTMS linker in this series exhibited improved anti-HIV-1 activity(EC50= 0.18 μmol/L, and 0.20 μmol/L) with higher selectivity(SI = 907, and 665) as comparison with the lead compound 6(EC50= 0.59 μmol/L, SI = 9). These two compounds 14aj and 13i were more sensitive than 6 toward clinically relevant mutant L100I, K103N and E138K viruses, which were further evaluated for their activity against wild-type reverse transcriptase and displayed a good correlation with the cell-based activity. Preliminary molecular modeling investigations provided insight for further structural optimization of HEPT.展开更多
Two cationic iridium（Ⅲ） complexes, [（pqcm）2Ir（pybz）]（PF6） （Ir1） and [（pqcm）2Ir（apybz）]（PF6） （Ir2） （pqcmH = 2-phenyl-quinoline-4-carboxylic acid methyl ester, pybz = 2-pyridyl-benzimidazole, apybz =...Two cationic iridium（Ⅲ） complexes, [（pqcm）2Ir（pybz）]（PF6） （Ir1） and [（pqcm）2Ir（apybz）]（PF6） （Ir2） （pqcmH = 2-phenyl-quinoline-4-carboxylic acid methyl ester, pybz = 2-pyridyl-benzimidazole, apybz = 1-allyl-2-pyridyl-benzimidazole）, were readily synthesized from the reaction of IrⅢ-μ-chloro-bridged dimer [Ir（pqcm）2（Cl）]2 and corresponding ancillary ligands, and characterized by NMR and mass spectroscopies. The structure of It2 was also confirmed by single-crystal X-ray diffraction. The photophysical properties of the two complexes were also investigated. Irl shows deep red emission peaked at around 652 nm with the phosphorescence quantum yield of ca. 0.29 and the emission lifetime of 233 ns, while Ir2 shows red emission peaked at around 615 nm with the phosphorescence quantum yield of ca. 0.13 and the emission lifetime of 430 ns. The active hydrogen on pybz ligand is believed to have a great influence on the photophysical properties of Ir1.展开更多
8-Oxoguanine （8-oxoG）, a critical mutagenic DNA lesion induced by reactive oxy- gen species, gives rise to a G·C→T·A transversion during replication and thereby must be repaired. The effects of explicit a...8-Oxoguanine （8-oxoG）, a critical mutagenic DNA lesion induced by reactive oxy- gen species, gives rise to a G·C→T·A transversion during replication and thereby must be repaired. The effects of explicit and implicit solvent molecules on the hydrolysis cleavage of N-Glycosidic bond in 8-oxo-7,8-dihydro-2＇-deoxyguanosine （8-oxo-dG） have been systematically clarified in the present work based upon two types of computational models. Detailed potential energy surface （PES） scans and full unconstraint optimizations for all the representative points on PESs were carried out at the B3LYP/6-31＋G（d） level of theory. The effect of implicit solvent was tested by single-point calculation at the SCRF/IEF-PCM model. The results illustrate that the direct hydrolysis model involving one explicit water molecule can’t provide a complete depiction of the hydrolysis process of 8-oxo-dG, attributed to the insufficiency of nucleophile activation and leaving group stabilization. The expansion hydrolysis model involving four explicit water molecules, however, facilitates discrete proton transfer and therefore produces smooth reaction surfaces for both the dissociative （SN1） and concerted （SN2） pathways. The presence of the implicit solvent substantially lowers all activation energies and the SN1 process is more favorable than the SN2 process. The data and insights present here agree well with the experimental results and have given out a baseline for the enzymatic deglycosylation reaction of 8-oxo-dG.展开更多
It has been introduced several ways for rising fuel burning rate. Using catalyzers is a common way to rising fuel burning rate. Cu-Chromite catalyzer used in solid fuels, as burning rate catalyzer in thermal decomposi...It has been introduced several ways for rising fuel burning rate. Using catalyzers is a common way to rising fuel burning rate. Cu-Chromite catalyzer used in solid fuels, as burning rate catalyzer in thermal decomposition of Ammonium Perchlorate and results were satisfying. This catalyzer is produced by several methods such as: ceramic, coprecipitating, sol-gel, vacuum depositioning, but this paper explains producing catalyzer by Citrate sol-gel. Thermal analysis is used for studying process also SEM, XRD, TEM, FTIR tests used for determination of particle sizes.展开更多
This paper describes the study of cobalt growth mechanism obtained by electrodeposition method with variation of pH solution. The electrochemical impedance spectroscopy （EIS） and scanning electronic microscopy （SEM...This paper describes the study of cobalt growth mechanism obtained by electrodeposition method with variation of pH solution. The electrochemical impedance spectroscopy （EIS） and scanning electronic microscopy （SEM） results were possible conclude that the cobalt electrodeposited at pH = 5.40 presented approximately an area three times larger than the cobalt electrodeposited at pH = 2.70. In addition, the cobalt electrodeposited at pH = 2.70 had a value of charge transfer resistance equal to 151.6 f2＂cm2 and the cobalt electrodeposited at pH = 5.40 this value corresponds to 67.4 f2＇cm. This occurs because the increased in micro-porosity increase the diffusion of electrolyte on cobalt electrodeposits easily the corrosion process.展开更多
Objective: In this study, we plan to measure plasma Catalase (CAT), Antioxidant Activity (AOA) and Glu- tathione-S-Transferase (GST) levels to understand whether oxidative stress develops or not and whether or not the...Objective: In this study, we plan to measure plasma Catalase (CAT), Antioxidant Activity (AOA) and Glu- tathione-S-Transferase (GST) levels to understand whether oxidative stress develops or not and whether or not the detoxification mechanism properly functions in children with Attention Deficit and Hyperactivity Disorder (ADHD) with unknown etiology and pathogenesis. Method and Results: Plasma CAT, AOA, and GST activities were spectrophotometrically measured in forty patients (average age 10.27 ± 2.54) and thirty-five (average age, 9.97 ± 2.59) healthy individuals as the control group. While the CAT activity showed no difference in the patient group (P > 0.05) compared to the control group, AOA and GST levels were found significantly meaningful (P = 0.001). Conclusion: In this pilot study ,the study shows that no oxidative stress develops in individuals with ADHD in high AOA and stable CAT activity, and that the de- toxification mechanism functions extremely in high GST activity. These findings need to be supported by other studies.展开更多
基金financially supported by National Natural Science Foundation of China(No.82304297)the State Key Laboratory of Natural and Biomimetic Drugs(No.K202408)。
文摘To enhance the anti-resistance efficacy of our previously disclosed naphthyl-triazine 5,structure-based drug design strategy was rationally conducted to design a series of novel biphenyl-piperidine-triazinecontaining non-nucleoside reverse transcriptase inhibitors.Remarkably,several of these compounds demonstrated single-digit nanomolar antiviral potency against both wild-type(WT)human immunodeficiency virus-1(HIV-1)and five clinically relevant mutant strains.Among these,compound 11s emerged as the most potent inhibitor,showing remarkable efficacy against WT HIV-1(50%effective concentration(EC_(50))=2 nmol/L)and five mutant strains(EC_(50)=0.003-0.073μmol/L),which was significantly superior to that of compound 5.This optimized derivative demonstrated substantially improved pharmacological properties compared to existing drugs etravirine(ETR)and rilpivirine(RPV),showing a 4-fold reduction in cytotoxicity alongside 6-fold enhancement in selectivity index(50%cytotoxic concentration(CC_(50))=19.69μmol/L,selectivity index(SI)=7438).The compound's metabolic profile revealed exceptional stability,with an elimination half-life(t_(1/2)=41.4 min)more than double that of RPV(t_(1/2)=16.03min).Comprehensive safety evaluation indicated minimal cytochrome P450(CYP)enzymes interference,low cardiac ion channel activity,and no observable acute toxicity,collectively suggesting a reduced risk profile for therapeutic applications.These promising characteristics significantly advance the development potential of biphenyl-piperidine-triazine derivatives as next-generation non-nucleoside reverse transcriptase inhibitors(NNRTIs),offering enhanced efficacy,improved safety,and favorable pharmacokinetic properties for antiretroviral therapy.
文摘The Ni single-atom catalyst dispersed on nitrogen doped graphene support has attracted much interest due to the high selectivity in electro-catalyzing CO_(2)reduction to CO,yet the chemical inertness of the metal center renders it to exhibit electrochemical activity only under high overpotentials.Herein,we report P-and S-doped Ni single-atom catalysts,i.e.symmetric Ni_(1)/PN_(4)and asymmetric Ni1/SN_(3)C can exhibit high catalytic activity of CO_(2)reduction with stable potential windows.It is revealed that the key intermediate*COOH in CO_(2)electroreduction is stabilized by heteroatom doping,which stems from the upward shift of the axial d_(z2)orbital of the active metal Ni atom.Furthermore,we investigate the potential-dependent free energetics and dynamic properties at the electrochemical interface on the Ni1/SN3C catalyst using ab initio molecular dynamics simulations with a full explicit solvent model.Based on the potential-dependent microkinetic model,we predict that S-atom doped Ni SAC shifts the onset potential of CO_(2)electroreduction from–0.88 to–0.80 V vs.RHE,exhibiting better activity.Overall,this work provides an in-depth understanding of structure-activity relationships and atomic-level electrochemical interfaces of catalytic systems,and offers insights into the rational design of heteroatom-doped catalysts for targeted catalysis.
基金supported by the Start-Up Research Funding of Fujian Normal University(No.Y0720326K13)the National Natural Science Foundation of China(Nos.22103035 and 22033005)+2 种基金the National Key R&D Program of China(No.2022YFA1503900)Shenzhen Science and Technology Program(No.RCYX20231211090357078)Guangdong Provincial Key Laboratory of Catalysis(No.2020B121201002).
文摘Atomically precise palladium(Pd)clusters are emerging as versatile nanomaterials with applications in catalysis and biomedicine.This study explores the synthesis,structure evolution,and catalytic properties of Pd clusters stabilized by cyclohexanethiol(HSC_(6)H_(11))ligands.Using electrospray ionization mass spectrometry(ESI-MS)and single-crystal X-ray diffraction(SXRD),structures of the Pd clusters ranging from Pd4(SC_(6)H_(11))8 to Pd18(SC_(6)H_(11))36 were determined.This analysis revealed a structure evolution from polygonal to elliptical geometries of the PdnS2n frameworks as the cluster size increased.UV-Vis-NIR spectroscopy,combined with quantum chemical calculations,elucidated changes in the electronic structure of the clusters.Catalytic studies on the Sonogashira cross-coupling reactions demonstrated a size-dependent decline in activity attributed to variations in structural arrangements and electronic properties.Mechanistic insights proposed a distinctive Pd(Ⅱ)-Pd(Ⅳ)catalytic cycle.This research underscores how ligands and cluster size influence the structures and properties of Pd clusters,offering valuable insights for the future design and application of Pd clusters in advanced catalysis and beyond.
文摘Dual-atom catalysts(DACs),a natural extension of single-atom catalysts(SACs),have emerged as a prominent focal point in the field of heterogeneous catalysis,particularly in the context of chemical and energy conversion processes.Despite the fact that the catalytic activity of DACs is significantly modulated by the electronic structure of the catalyst,understanding how electron spin states are affected by variations in topology and geometric structure remains challenging and relatively unexplored.Herein,we propose the rational design of stable DACs composed of two iron atoms anchored on pristine graphdiyne(GDY),Fe_(2)-GDYn.A comprehensive and systematic investigation was carried out to elucidate the electronic configuration and spin states involved in the deliberate convergence towards the magnetic ground state,with the aim of uncovering the structure-spin relationship.Through an in-depth analysis of spin populations,electronic localization/delocalization,and the chemical bonding characteristics of the central metal atoms and the GDY skeleton,it was revealed that the spin coupling between the two iron atoms is preponderantly dictated by adjacent short-range Fe-Fe interactions.Conversely,spin decoupling can be attributed to the long-rangeπ-bond component within the linkage.Moreover,geometric and chemical bonding asymmetries were found to induce orbital and spin splitting in iron atoms possessing an electronic configuration of d8.These findings provide important insights into the relationship between topology and spin,thereby presenting novel strategies for the rational design of spin-manipulated DACs.
基金The authors would like to acknowledge the National Natural Science Foundation of China(No.59895152)the National High Technology Committee of China(No.863-715-005-0030)for financial supports.
文摘The microstructure and mechanical behaviors of NiAl-28Cr-5Mo-1Nb eutectic alloy were investigated by using scanning electron microscopy, X-ray diffraction, transmission electron microscopy and compression tests, respectively. The alloy is mainly composed of three phases, which are the gray lamellar Cr（Mo） plate, black NiAI matrix and semicontinuously distributed Cr2Nb-type Laves phase. Through Nb addition, NiAl-Cr（Mo）/Nb alloy exhibits a reasonable balance of high temperature strength and room temperature compression ductility and its mechanical behaviors are superior to the NiAl-28Cr-6Mo eutectic alloy at all temperature. The elevated temperature compression deformation behavior of NiAl-Cr（Mo）/Nb alloy can be properly described by power-law equation.the National High Technology Committee of China （No. 863-715-005-0030） for financial supports.
基金Project supported by the National Natural Science Foundation of China(51102107,51202080)Anhui Science and Technology Project(1206c0805038)
文摘A layered perovskite oxide Y0.8Ca0.2BaCoFeO5＋δ（YCBCF） was synthesized as a novel cathode material for intermedi-ate-temperature solid oxide fuel cells （IT-SOFCs） by citric acid-nitrates self-propagating combustion method. The phase and micro-structure of YCBCF were investigated by X-ray diffraction （XRD） and scanning electron microscopy （SEM）, respectively. The aver-age thermal expansion coefficient （TEC） of YCBCF was 14.6×10–6 K–1, which was close to other materials of SOFC at the range of RT–1000 oC. An open-circuit potential of 0.75 V and a maximum output power density of 426 mW/cm2 were obtained at 650 oC in a Sm0.2Ce0.8O1.9 （SDC）-based anode-supported SOFC by using humidified （~3%H2O） hydrogen as fuel and static air as oxidant. The results indicated that the YCBCF was a promising cathode candidate for IT-SOFCs.
基金Project(50473046) supported by the National Natural Science Foundation of ChinaProject(204097) supported by the Science Foundation of the Ministry of Education of China+1 种基金Project(04JJ1002) supported by the Outstanding Youth Foundation of Hunan Province,ChinaProject(06JJ2008) supported by the Natural Science Foundation of Hunan Province,China
文摘A new cyclometalated platinum complex containing 2, 5-bis(naphthalene-1-yl)-1,3,4-oxadiazole ligand was synthesized and characterized. The UV-Vis absorptions and photoluminescent properties of the ligand and its platinum complex were investigated. A characteristic metal-ligand charge transfer absorption peak at 439 nm in the UV spectrum and a strong emission peak at 625 nm in the photoluminescence spectrum were observed for this complex in dichloromethane. Cyclic voltammtry (CV) analysis shows that the EHOMO (energy level of the highest occupied molecular orbital) and ELUMO (energy level of the lowest unoccupied molecular orbital) of the platinum complex are about 、5.69 and 、3.25 eV, respectively, indicating that the oxadiazole-based platinum complex has a potential application in electrophosphorescent devices used as a red-emitting material.
基金financially supported by the Natural Science Foundation of Guangdong Province (2022A1515012359)the National Natural Science Foundation of China (21902121)+1 种基金the STU Scientific Research Foundation for Talents (NTF21020)the 2020 Li Ka Shing Foundation Cross-Disciplinary Research Grant (2020LKSFG09A)。
文摘Nafion as a universal polymer ionomer was widely applied for nanocatalysts electrode preparation.However,the effect of Nafion on electrocatalytic performance was often overlooked,especially for CO_(2)electrolysis.Herein,the key roles of Nafion for CO_(2)RR were systematically studied on Cu nanoparticles(NPs)electrocatalyst.We found that Nafion modifier not only inhibit hydrogen evolution reaction(HER)by decreasing the accessibility of H_(2)O from electrolyte to Cu NPs,and increase the CO_(2)concentration at electrocatalyst interface for enhancing the CO_(2)mass transfer process,but also activate CO_(2)molecule by Lewis acid-base interaction between Nafion and CO_(2)to accelerate the formation of^(*)CO,which favor of C–C coupling for boosting C_(2)product generation.Owing to these features,the HER selectivity was suppressed from 40.6%to 16.8%on optimal Cu@Nafion electrode at-1.2 V versus reversible hydrogen electrode(RHE),and as high as 73.5%faradaic efficiencies(FEs)of C_(2)products were achieved at the same applied potential,which was 2.6 times higher than that on bare Cu electrode(~28.3%).In addition,Nafion also contributed to the long-term stability by hinder Cu NPs morphology reconstruction.Thus,this work provides insights into the impact of Nafion on electrocatalytic CO_(2)RR performance.
文摘The thermal equilibrium state of the reference electrode was investigated. The results show that the temperature difference between the inside and the outside of zirconia tube was very small and the Seebeck effect can be ignored after the sensor was dipped into liquid steel for more than 2 s. A special sensor was designed to test the relation between the EMF （electromotive force） of sensor and the thermal equilibrium state of the reference elec- trode. Based on these results, it is suggested that the peak in EMF curve was caused by the change of oxygen potential in reference electrode before the thermal equilibrium was reached. If NiO was added by 2 M- 5 M to the Cr/Cr2O3 reference electrode, the peak in EMF curve could be eliminated.
基金Supported by Research Funds of Educational Commission of Yunnan Province(09Y0392)Scientific Research Funds of Qujing Normal University(2009QN032)+1 种基金Teaching Reform Project of Qujing Normal University about"Key Course of Analytical Chemistry"and"Excellent Course of Instrumental Analysis"Scientific Funds of Baoshan University(11B004K)
文摘[Objective]The aim was to study the adsorption property of adsorbent Ni-TiO_(2)-SiO_(2)synthesized by using rice husks as silicon source and template to gentian violet.[Method]The renewable dye adsorbent Ni-TiO_(2)-SiO_(2)was synthesized by using rice husks as raw material,and the adsorption property of Ni-TiO_(2)-SiO_(2)to gentian violet was studied.[Result]The adsorption rate of Ni-TiO_(2)-SiO_(2)to gentian violet reached about 90%after 1 h.In 100 ml gentian violet solution with concentration of 25 mg/L and pH=8,Ni-TiO_(2)-SiO_(2)with dosage of 0.07 g had the best adsorption effect.More importantly,Ni-TiO_(2)-SiO_(2)as adsorbent could be used repeatedly,and couldn’t lead to secondary pollution due to leaking.[Conclusion]The study could provide references for practical engineering application.
基金supported by the application basis research key project of Yunnan Province science and technology department(201401CB00299)the major project of Qujing Normal University(2012ZD002)
文摘Two distinct copper coordination polymers, namely [Cu^Ⅱ2（2,5-pydc）2（bpp）2]·H2O（1） and Cu2^ⅠCu^Ⅱ（2,5-pydc）2（bpp）2（2）（2,5-pydc = pyridine-2,5-dicarboxylic acid, bpp = 1,3-bi（4-pyridyl）propane）, have been successfully synthesized through hydrothermal conditions under different temperatures. Single-crystal X-ray structural analysis revealed that both complexes 1 and 2 are 3D frameworks. Complex 1 is an 8-connected 2-fold interpenetrating network based on [Cu（2,5-pydc）]4 molecular building block（MBB）, and also can be simplified as a 4-connected net if the Cu（Ⅱ） ion is regarded as an independent node, whereas 2 shows a（4,4）-connected non-interpenetrated framework which contains mixed valence Cu（Ⅰ/Ⅱ） centers. The results demonstrate that temperature plays a significant role in the final structures of the complexes.
基金Project supported by College Programs SNIE(No.2014ZDKJ011)
文摘A new 3D cobalt metal-organic framework [C_7H_（13）N_2]_2[（CH_3COO）_2Co_7（oba）_5-（Hoba）_2（OH）_2]·H_2O has been synthesized under ionothermal conditions and characterized by elemental analysis, FT-IR, XRD, and TG. This complex crystallizes in monoclinic system, space group P21/c with a = 19.4499（4）, b = 10.8839（2）, c = 27.7796（5） ？, β = 104.467（2）o, V = 5694.22（19） ？~3, Z = 2, C_（116）H_（92）Co_7N_4O_（42）, M_r = 2626.45, D_c = 1.532 g/cm^3 , F（000） = 2682, μ = 1.085 mm-1, R = 0.0387 and wR = 0.1177. Its structure is characterized as a 3D open framework constructed by seven nuclear clusters [（CH_3COO）_Co_7（OH）_2] and the 4,4？-oxybisbenzoic acid ligand. The used ILs cations are located in the middle of the pore and compensate for the negative charges of framework. Furthermore, its fluorescence property has also been studied.
文摘This study evaluates the adsorption ability ofbisphenol A（BPA） on titanium dioxide（TiO2） and its effect on the photocatalysis by advanced oxidation process using UV radiation and TiO2 photocatalyst. Degradation of BPA was also evaluated for the system without adsorption prior to photocatalytic reaction. The separation of TiO2 from BPA solution treated by pilot-scale photocatalytic reactor （capacity 0.16 m^3） was studied using submerged ultrafiltration （UF） membrane. It was found that although adsorption capacity of BPA was not high, adsorption played an important role in improving the efficiency ofphotocatalysis. On the other hand, during the separation of TiO2 particles from aqueous suspension, the permeate flux of the membrane was strongly affected by transmembrane pressure and TiO2 dose. The permeate turbidity was decreased below 1 NTU.
基金Financial support from the National Natural Science Foundation of China(No.21901041)the Fuzhou University(No.0041/511095)。
文摘As an attractive C1 synthon,carbon dioxide(CO_(2))has been extensively used in organic synthesis to produce carboxylic acids.In this research,stereoselective electrochemical carboxylation ofα,β-unsaturated sulfones has been developed under transition-metal-free conditions.All the cinnamic acids and the derivatives are obtained selectively in the E-configuration.Besides,arylpropiolates also can be produced from alkynyl sulfones.
基金financially supported by National Natural Science Foundation of China (No. 22077018)National Key R&D Program of China (No. 2017YFA0506000)。
文摘A novel series of CHOR-HEPT non-nucleoside HIV-1 reverse transcriptase inhibitors were developed by means of structure-based design strategy based on compound 6 reported previously by our group. Most of these compounds showed moderate to good activity toward wild-type HIV-1 strain with EC50values in the range of 0.18–51.88 μmol/L and SI values in the range of 4–907. The compound 14aj with a CHOH linker and compound 13i with a CHOTMS linker in this series exhibited improved anti-HIV-1 activity(EC50= 0.18 μmol/L, and 0.20 μmol/L) with higher selectivity(SI = 907, and 665) as comparison with the lead compound 6(EC50= 0.59 μmol/L, SI = 9). These two compounds 14aj and 13i were more sensitive than 6 toward clinically relevant mutant L100I, K103N and E138K viruses, which were further evaluated for their activity against wild-type reverse transcriptase and displayed a good correlation with the cell-based activity. Preliminary molecular modeling investigations provided insight for further structural optimization of HEPT.
基金financially supported by the National Natural Science Foundation of China (No. 50903001)the Guangxi Department of Education research project (200911MS281, 200911MS282)
文摘Two cationic iridium（Ⅲ） complexes, [（pqcm）2Ir（pybz）]（PF6） （Ir1） and [（pqcm）2Ir（apybz）]（PF6） （Ir2） （pqcmH = 2-phenyl-quinoline-4-carboxylic acid methyl ester, pybz = 2-pyridyl-benzimidazole, apybz = 1-allyl-2-pyridyl-benzimidazole）, were readily synthesized from the reaction of IrⅢ-μ-chloro-bridged dimer [Ir（pqcm）2（Cl）]2 and corresponding ancillary ligands, and characterized by NMR and mass spectroscopies. The structure of It2 was also confirmed by single-crystal X-ray diffraction. The photophysical properties of the two complexes were also investigated. Irl shows deep red emission peaked at around 652 nm with the phosphorescence quantum yield of ca. 0.29 and the emission lifetime of 233 ns, while Ir2 shows red emission peaked at around 615 nm with the phosphorescence quantum yield of ca. 0.13 and the emission lifetime of 430 ns. The active hydrogen on pybz ligand is believed to have a great influence on the photophysical properties of Ir1.
基金supported by the National Natural Science Foundation of China(21203153 and 21173151)Science&Technology Department(2011JY0136)+1 种基金Department of Education(12ZA174)of Sichuan ProvinceChina West Normal University(11B002)
文摘8-Oxoguanine （8-oxoG）, a critical mutagenic DNA lesion induced by reactive oxy- gen species, gives rise to a G·C→T·A transversion during replication and thereby must be repaired. The effects of explicit and implicit solvent molecules on the hydrolysis cleavage of N-Glycosidic bond in 8-oxo-7,8-dihydro-2＇-deoxyguanosine （8-oxo-dG） have been systematically clarified in the present work based upon two types of computational models. Detailed potential energy surface （PES） scans and full unconstraint optimizations for all the representative points on PESs were carried out at the B3LYP/6-31＋G（d） level of theory. The effect of implicit solvent was tested by single-point calculation at the SCRF/IEF-PCM model. The results illustrate that the direct hydrolysis model involving one explicit water molecule can’t provide a complete depiction of the hydrolysis process of 8-oxo-dG, attributed to the insufficiency of nucleophile activation and leaving group stabilization. The expansion hydrolysis model involving four explicit water molecules, however, facilitates discrete proton transfer and therefore produces smooth reaction surfaces for both the dissociative （SN1） and concerted （SN2） pathways. The presence of the implicit solvent substantially lowers all activation energies and the SN1 process is more favorable than the SN2 process. The data and insights present here agree well with the experimental results and have given out a baseline for the enzymatic deglycosylation reaction of 8-oxo-dG.
文摘It has been introduced several ways for rising fuel burning rate. Using catalyzers is a common way to rising fuel burning rate. Cu-Chromite catalyzer used in solid fuels, as burning rate catalyzer in thermal decomposition of Ammonium Perchlorate and results were satisfying. This catalyzer is produced by several methods such as: ceramic, coprecipitating, sol-gel, vacuum depositioning, but this paper explains producing catalyzer by Citrate sol-gel. Thermal analysis is used for studying process also SEM, XRD, TEM, FTIR tests used for determination of particle sizes.
文摘This paper describes the study of cobalt growth mechanism obtained by electrodeposition method with variation of pH solution. The electrochemical impedance spectroscopy （EIS） and scanning electronic microscopy （SEM） results were possible conclude that the cobalt electrodeposited at pH = 5.40 presented approximately an area three times larger than the cobalt electrodeposited at pH = 2.70. In addition, the cobalt electrodeposited at pH = 2.70 had a value of charge transfer resistance equal to 151.6 f2＂cm2 and the cobalt electrodeposited at pH = 5.40 this value corresponds to 67.4 f2＇cm. This occurs because the increased in micro-porosity increase the diffusion of electrolyte on cobalt electrodeposits easily the corrosion process.
文摘Objective: In this study, we plan to measure plasma Catalase (CAT), Antioxidant Activity (AOA) and Glu- tathione-S-Transferase (GST) levels to understand whether oxidative stress develops or not and whether or not the detoxification mechanism properly functions in children with Attention Deficit and Hyperactivity Disorder (ADHD) with unknown etiology and pathogenesis. Method and Results: Plasma CAT, AOA, and GST activities were spectrophotometrically measured in forty patients (average age 10.27 ± 2.54) and thirty-five (average age, 9.97 ± 2.59) healthy individuals as the control group. While the CAT activity showed no difference in the patient group (P > 0.05) compared to the control group, AOA and GST levels were found significantly meaningful (P = 0.001). Conclusion: In this pilot study ,the study shows that no oxidative stress develops in individuals with ADHD in high AOA and stable CAT activity, and that the de- toxification mechanism functions extremely in high GST activity. These findings need to be supported by other studies.
