Co/CoO heterojunction rich in oxygen vacancies introduced by O_(2) plasma embedded in mesoporous walls of carbon nanoboxes covered with carbon nanotubes for rechargeable zinc-air battery

Herein,Co/CoO heterojunction nanoparticles(NPs)rich in oxygen vacancies embedded in mesoporous walls of nitrogen-doped hollow carbon nanoboxes coupled with nitrogen-doped carbon nanotubes(P-Co/CoOV@NHCNB@NCNT)are well designed through zeolite-imidazole framework(ZIF-67)carbonization,chemical vapor deposition,and O_(2) plasma treatment.As a result,the threedimensional NHCNBs coupled with NCNTs and unique heterojunction with rich oxygen vacancies reduce the charge transport resistance and accelerate the catalytic reaction rate of the P-Co/CoOV@NHCNB@NCNT,and they display exceedingly good electrocatalytic performance for oxygen reduction reaction(ORR,halfwave potential[EORR,1/2=0.855 V vs.reversible hydrogen electrode])and oxygen evolution reaction(OER,overpotential(η_(OER,10)=377mV@10mA cm^(−2)),which exceeds that of the commercial Pt/C+RuO_(2) and most of the formerly reported electrocatalysts.Impressively,both the aqueous and flexible foldable all-solid-state rechargeable zinc-air batteries(ZABs)assembled with the P-Co/CoOV@NHCNB@NCNT catalyst reveal a large maximum power density and outstanding long-term cycling stability.First-principles density functional theory calculations show that the formation of heterojunctions and oxygen vacancies enhances conductivity,reduces reaction energy barriers,and accelerates reaction kinetics rates.This work opens up a new avenue for the facile construction of highly active,structurally stable,and cost-effective bifunctional catalysts for ZABs.

Innovative Mn_(3-x)O_(4-y)@NCA design:Leveraging Mn/O vacancies and amorphous architecture for enhanced sodium-ion storage

Manganese-based oxide electrode materials suffer from severe Jahn-Teller(J-T)distortion,leading to severe cycle instability in sodium ion storage.However,it is difficult to adjust the electron at d orbitals exactly to a low spin state to eliminate orbital degeneracy and suppress J-T distortion fundamentally.This article constructed concentration-controllable Mn/O coupled vacancy and amorphous network in Mn_(3)O_(4) and coated it with nitrogen-doped carbon aerogel(Mn_(3-x)O_(4-y)@NCA).The existence of Mn/O vacancies has been confirmed by scanning transmission electron microscopy(STEM)and positron annihilation lifetime spectroscopy(PALS).Atomic absorption spectroscopy(AAS)and X-ray photoelectron spectroscopy(XPS)determine the most optimal ratio of Mn/O vacancies for sodium ion storage is 1:2.Density functional theory(DFT)calculations prove that Mn/O coupled vacancies with the ratio of 1:2could exactly induce a low spin states and a d~4 electron configuration of Mn,suppressing the J-T distortion successfully.The abundant amorphous regions can shorten the transport distance of sodium ions,increase the electrochemically active sites and improve the pseudocapacitance response.From the synergetic effect of Mn/O coupled vacancies and amorphous regions,Mn_(3-x)O_(4-y)@NCA exhibits an energy density of 37.5 W h kg^(-1)and an ultra-high power density of 563 W kg^(-1)in an asymmetric supercapacitor.In sodium-ion batteries,it demonstrates high reversible capacity and exceptional cycling stability.This research presents a new method to improve the Na^(+)storage performance in manganese-based oxide,which is expected to be generalized to other structural distortion.

Introducing oxygen vacancies in TiO_(2) lattice through trivalent iron to enhance the photocatalytic removal of indoor NO

The synthesis of oxygen vacancies(OVs)-modified TiO_(2)under mild conditions is attractive.In this work,OVs were easily introduced in TiO_(2)lattice during the hydrothermal doping process of trivalent iron ions.Theoretical calculations based on a novel charge-compensation structure model were employed with experimental methods to reveal the intrinsic photocatalytic mechanism of Fe-doped TiO_(2)(Fe-TiO_(2)).The OVs formation energy in Fe-TiO_(2)(1.12 eV)was only 23.6%of that in TiO_(2)(4.74 eV),explaining why Fe^(3+)doping could introduce OVs in the TiO_(2)lattice.The calculation results also indicated that impurity states introduced by Fe^(3+)and OVs enhanced the light absorption activity of TiO_(2).Additionally,charge carrier transport was investigated through the carrier lifetime and relative mass.The carrier lifetime of Fe-TiO_(2)(4.00,4.10,and 3.34 ns for 1at%,2at%,and 3at%doping contents,respectively)was longer than that of undoped TiO_(2)(3.22 ns),indicating that Fe^(3+) and OVs could promote charge carrier separation,which can be attributed to the larger relative effective mass of electrons and holes.Herein,Fe-TiO_(2)has higher photocatalytic indoor NO removal activity compared with other photocatalysts because it has strong light absorption activity and high carrier separation efficiency.

Adjusting oxygen vacancies in perovskite LaCoO_(3)by electrochemical activation to enhance the hydrogen evolution reaction activity in alkaline condition

Developing highly-active,earth-abundant non-precious-metal catalysts for hydrogen evolution reaction(HER)in alkaline solution would be beneficial to sustainable energy storage.Perovskite oxides are generally regarded as low-active HER catalysts,due to their inapposite hydrogen adsorption and water dissociation.Here,we report a detailed study on perovskite LaCoO_(3)epitaxial thin films as a model catalyst to significantly enhance the HER performance via an electrochemical activation process.As a result,the overpotential for the activation films to achieve a current density of 0.36 m A/cm^(2)is 238 m V,reduced by more than 200 m V in comparison with that of original samples.Structural characterization revealed the activation process dramatically increases the concentration of oxygen vacancies(Vo)on the surface of LaCoO_(3).We established the relationship between the electronic structure induced by Vo and the enhanced HER activity.Further theoretical calculations revealed that the Vo optimizes the hydrogen adsorption and dissociation of water on the surface of LaCoO_(3)thin films,thus improving the HER catalytic activity.This work may promote a deepened understanding of perovskite oxides for HER mechanism by Vo adjusting and a new avenue for designing highly active electrochemical catalysts in alkaline solution.

上古汉语OV语序前置宾语的构成、语义特点、语用功能研究

上古汉语OV语序是古汉语中一种特殊句式,其特殊性主要体现在宾语前置于动词。与以往着眼于前置宾语描写的不同,重点关注前置宾语的构成、语义特点、语用功能。在构成上,前置宾语由体词性成分、谓词性成分和主谓结构充当;在语义特点上,具有指同、指别的特点;在语用功能上,具有凸显焦点、篇章衔接和对比的功能。对前置宾语的全面考察,不仅有助于全面认识前置宾语的特点,还有助于更加清晰认识上古汉语OV语序的性质和汉语语法史的建立。更重要的是,它能够为语言类型学理论的丰富和完善提供语料支撑。

Defects and morphology engineering for constructing V_(s)-Ni_(3)S_(2)@V_(s)-Cu_(2)S nanotube heterojunction arrays toward efficient bifunctional electrocatalyst for overall water splitting

The development of highly active,stable and inexpensive electrocatalysts for hydrogen production by defects and morphology engineering remains a great challenge.Herein,S vacancies-rich Ni_(3)S_(2)@Cu_(2)S nan-otube heterojunction arrays were in-situ grown on copper foam(V_(s)-Ni_(3)S_(2)@V_(s)-Cu_(2)S NHAs/CF)for efficient electrocatalytic overall water splitting.With the merits of nanotube arrays and efficient electronic mod-ulation drived by the OD vacancy defect and 2D heterojunction defect,the resultant V_(s)-Ni_(3)S_(2)@V_(s)-Cu_(2)S NHAs/CF electrocatalyst exhibits excellent electrocatalytic activity with a low overpotential of 47 mV for the hydrogen evolution reaction(HER)at 10 mA cm^(-2) current density,and 263 mV for the oxygen evolution reaction(OER)at 50 mA cm^(-2) current density,as well as a cell voltage of 1.48 V at 10 mA cm^(-2).Moreover,the nanotube heterojunction arrays endows V_(s)-Ni_(3)S_(2)@V_(s)-Cu_(2)S NHAs/CF with outstanding stability in long-term catalytic processes,as confirmed by the continuous chronopotentiom-etry tests at current densities of 10 mA cm^(-2) for 100 h.

Emerging perovskite materials for supercapacitors:Structure,synthesis,modification,advanced characterization,theoretical calculation and electrochemical performance

As a new generation electrode materials for energy storage,perovskites have attracted wide attention because of their unique crystal structure,reversible active sites,rich oxygen vacancies,and good stability.In this review,the design and engineering progress of perovskite materials for supercapacitors(SCs)in recent years is summarized.Specifically,the review will focus on four types of perovskites,perovskite oxides,halide perovskites,fluoride perovskites,and multi-perovskites,within the context of their intrinsic structure and corresponding electrochemical performance.A series of experimental variables,such as synthesis,crystal structure,and electrochemical reaction mechanism,will be carefully analyzed by combining various advanced characterization techniques and theoretical calculations.The applications of these materials as electrodes are then featured for various SCs.Finally,we look forward to the prospects and challenges of perovskite-type SCs electrodes,as well as the future research direction.

Electrospun carbon nanofiber-supported V_(2)O_(3) with enriched oxygen vacancies as a free-standing high-rate anode for an all-vanadium-based full battery

Synergistic regulation of hierarchical nanostructures and defect engineering is effective in accelerating electron and ion transport for metal oxide electrodes.Herein,carbon nanofiber-supported V_(2)O_(3) with enriched oxygen vacancies(OV-V_(2)O_(3)@CNF)was fabricated using the facile electrospinning method,followed by thermal reduction.Differing from the traditional particles embedded within carbon nanofibers or irregularly distributed between carbon nanofibers,the free-standing OV-V_(2)O_(3)@CNF allows for V_(2)O_(3) nanosheets to grow vertically on one-dimensional(1D)carbon nanofibers,enabling abundant active sites,shortened ion diffusion pathway,continuous electron transport,and robust structural stability.Meanwhile,density functional theory calculations confirmed that the oxygen vacancies can promote intrinsic electron conductivity and reduce ion diffusion energy barrier.Consequently,the OV-V_(2)O_(3)@CNF anode delivers a large reversible capacity of 812 mAh g^(-1) at 0.1 A g^(-1),superior rate capability(405 mAh g^(-1) at 5 A g^(-1)),and long cycle life(378 mAh g^(-1) at 5 A g^(-1) after 1000 cycles).Moreover,an all-vanadium full battery(V2O5//OV-V_(2)O_(3)@CNF)was assembled using an OV-V_(2)O_(3)@CNF anode and a V2O5 cathode,which outputs a working voltage of 2.5 V with high energy density and power density,suggesting promising practical application.This work offers fresh perspectives on constructing hierarchical 1D nanofiber electrodes by combining defect engineering and electrospinning technology.

Sulfur vacancies and heterogeneous interfaces promote high performance sodium storage of bimetallic chalcogenide hollow nanospheres

Transition metal sulfides have high theoretical capacities and are considered as potential anode materials for sodium-ion batteries.However,due to low inherent conductivity and significant volume expansion,the electrochemical performance is greatly limited.In this study,a nickel/manganese sulfide material(Ni_(0.96)S_(x)/MnS_(y)-NC)with adjustable sulfur vacancies and heterogeneous hollow spheres was prepared using a simple method.The introduction of a concentration-adjustable sulfur vacancy enables the generation of a heterogeneous interface between bimetallic sulfide and sulfur vacancies.This interface collectively creates an internal electric field,improving the mobility of electrons and ions,increasing the number of electrochemically active sites,and further optimizing the performance of Na~+storage.The direction of electron flow is confirmed by Density functional theory(DFT)calculations.The hollow nano-spherical material provides a buffer for expansion,facilitating rapid transfer kinetics.Our innovative discovery involves the interaction between the ether-based electrolyte and copper foil,leading to the formation of Cu_9S_5,which grafts the active material and copper current collector,reinforcing mechanical supporting.This results in a new heterostructure of Cu_9S_5 with Ni_(0.96)S_(x)/MnS_(y),contributing to the stabilization of structural integrity for long-cycle performance.Therefore,Ni_(0.96)S_(x)/MnS_(y)-NC exhibits excellent electrochemical properties following our modification route.Regarding stability performance,Ni0_(.96)S_(x)/MnS_(y)-NC demonstrates an average decay rate of 0.00944%after 10,000 cycles at an extremely high current density of 10000 mA g^(-1),A full cell with a high capacity of 304.2 mA h g^(-1)was also successfully assembled by using Na_(3)V_(2)(PO_(4))_(3)/C as the cathode.This study explores a novel strategy for interface/vacancy co-modification in the fabrication of high-performance sodium-ion batteries electrode.

Modeling the Interaction between Vacancies and Grain Boundaries during Ductile Fracture

The experimental results in previous studies have indicated that during the ductile fracture of pure metals,vacancies aggregate and form voids at grain boundaries.However,the physical mechanism underlying this phenomenon remains not fully understood.This study derives the equilibrium distribution of vacancies analytically by following thermodynamics and the micromechanics of crystal defects.This derivation suggests that vacancies cluster in regions under hydrostatic compression to minimize the elastic strain energy.Subsequently,a finite element model is developed for examining more general scenarios of interaction between vacancies and grain boundaries.This model is first verified and validated through comparison with some available analytical solutions,demonstrating consistency between finite element simulation results and analytical solutions within a specified numerical accuracy.A systematic numerical study is then conducted to investigate the mechanism that might govern the micromechanical interaction between grain boundaries and the profuse vacancies typically generated during plastic deformation.The simulation results indicate that the reduction in total elastic strain energy can indeed drive vacancies toward grain boundaries,potentially facilitating void nucleation in ductile fracture.

Engineering oxygen vacancies on Tb-doped ceria supported Pt catalyst for hydrogen production through steam reforming of long-chain hydrocarbon fuels

Steam reforming of long-chain hydrocarbon fuels for hydrogen production has received great attention for thermal management of the hypersonic vehicle and fuel-cell application.In this work,Pt catalysts supported on CeO_(2)and Tb-doped CeO_(2)were prepared by a precipitation method.The physical structure and chemical properties of the as-prepared catalysts were characterized by powder X-ray diffraction,scanning electron microscopy,transmission electron microscopy,Raman spectroscopy,H_(2)temperature programmed reduction,and X-ray photoelectron spectroscopy.The results show that Tb-doped CeO_(2)supported Pt possesses abundant surface oxygen vacancies,good inhibition of ceria sintering,and strong metal-support interaction compared with CeO_(2)supported Pt.The catalytic performance of hydrogen production via steam reforming of long-chain hydrocarbon fuels(n-dodecane)was tested.Compared with 2Pt/CeO_(2),2Pt/Ce_(0.9)Tb_(0.1)O_(2),and 2Pt/Ce_(0.5)Tb_(0.5)O_(2),the 2Pt/Ce_(0.7)Tb_(0.3)O_(2)has higher activity and stability for hydrogen production,on which the conversion of n-dodecane was maintained at about 53.2%after 600 min reaction under 700℃at liquid space velocity of 9 ml·g^(-1)·h^(-1).2Pt/CeO_(2)rapidly deactivated,the conversion of n-dodecane was reduced to only 41.6%after 600 min.

上古汉语OV语序结构助词“是”“之”差异及原因

借助“是”“之”前置的OV语序是上古汉语OV语序的重要类型之一,对“是”“之”的差异及原因进行探索,有助于全面认识OV语序。从历时角度看,其差异在西周时期开始出现,春秋战国时期二者差异全面呈现,两汉时期随着OV语序的消失二者差异也随之消失。从数量上看,受语体的影响,不同时期使用数量不同。在使用上,因二者出现的时间不同、来源不同,其差异体现在三个大的方面,是与“将”搭配、前置宾语、语气强弱等,其中语气强弱还包括否定词句法位置、否定对称、与疑问词的搭配、句末是否有语气词、主语为人称代词“我”或“吾”等五个小的方面的差异。从差异产生的原因看,依次为时间表达、连接性强弱、语气强弱。

Increased Oxygen Vacancies in CuO-ZnO Snowflake-like Composites Drive the Hydrogenation of CO_(2) to Methanol

Cu/ZnO is widely used in the hydrogenation of carbon dioxide (CO_(2)) to methanol (CH_(3)OH) to improve the lowconversion rate and selectivity generally observed. In this work, a series of In, Zr, Co, and Ni-doped CuO-ZnO catalysts wassynthesized via a hydrothermal method. By introducing a second metal element, the activity and dispersion of the activesites can be adjusted and the synergy between the metal and the carrier can be enhanced, forming an abundance of oxygenvacancies. Oxygen vacancies not only adsorb CO_(2) but also activate the intermediates in methanol synthesis, playing a keyrole in the entire reaction. Co3O4-CuO-ZnO had the best catalytic performance (a CO_(2) conversion rate of 9.17%;a CH_(3)OHselectivity of 92.77%). This study describes a typical strategy for multi-component doping to construct a catalyst with anabundance of oxygen vacancies, allowing more effective catalysis to synthesize CH_(3)OH from CO_(2).

Tuning the crystalline and electronic structure of ZrO_(2)via oxygen vacancies and nano-structuring for polysulfides conversion in lithium-sulfur batteries

The recent emergence of tetragonal phases zirconium dioxide(ZrO_(2))with vacancies has generated significant interest as a highly efficient and stable electrocatalyst with potential applications in trapping polysulfides and facilitating rapid conversion in lithium-sulfur batteries(LSBs).However,the reduction of ZrO_(2)is challenging,even under strong reducing atmospheres at high temperatures and pressures.Consequently,the limited presence of oxygen vacancies results in insufficient active sites and reaction interfaces,thereby hindering practical implementation.Herein,we successfully introduced abundant oxygen vacancies into ZrO_(2)at the nanoscale with the help of carbon nanotubes(CNTs-OH)through hydrogen-etching at lower temperatures and pressures.The introduced oxygen vacancies on ZrO_(2-x)/CNTs-OH can effectively rearrange charge distribution,enhance sulfiphilicity and increase active sites,contributing to high ionic and electronic transfer kinetics,strong binding energy and low redox barriers between polysulfides and ZrO_(2-x).These findings have been experimentally validated and supported by theory calculations.As a result,LSBs assembled with the ZrO_(2-x)/CNTs-OH modified separators demonstrate excellent rate performance,superior cycling stability,and ultra-high sulfur utilization.Especially,at high sulfur loading of 6 mg cm^(-2),the area capacity is still up to 6.3 mA h cm^(-2).This work provides valuable insights into the structural and functional optimization of electrocatalysts for batteries.

Ca and Sr co-doping induced oxygen vacancies in 3DOM La_(2-x)Sr_(x)Ce_(2-y)CayO_(7-δ)catalysts for boosting low-temperature oxidative coupling of methane

It is urgent to develop catalysts with application potential for oxidative coupling of methane(OCM)at relatively lower temperature.Herein,three-dimensional ordered macro porous(3 DOM)La_(2-x)Sr_(x)Ce_(2-y)CayO_(7-δ)(A_(2)B_(2)O_(7)-type)catalysts with disordered defective cubic fluorite phased structure were successfully prepared by a colloidal crystal template method.3DOM structure promotes the accessibility of the gaseous reactants(O2and CH4)to the active sites.The co-doping of Ca and Sr ions in La_(2-x)Sr_(x)Ce_(2-y)CayO_(7-δ)catalysts improved the formation of oxygen vacancies,thereby leading to increased density of surface-active oxygen species(O_(2)^(-))for the activation of CH4and the formation of C2products(C2H6and C2H4).3DOM La_(2-x)Sr_(x)Ce_(2-y)CayO_(7-δ)catalysts exhibit high catalytic activity for OCM at low temperature.3DOM La1.7Sr0.3Ce1.7Ca0.3O7-δcatalyst with the highest density of O_(2)^(-)species exhibited the highest catalytic activity for low-temperature OCM,i.e.,its CH4conversion,selectivity and yield of C2products at 650℃are 32.2%,66.1%and 21.3%,respectively.The mechanism was proposed that the increase in surface oxygen vacancies induced by the co-doping of Ca and Sr ions boosts the key step of C-H bond breaking and C-C bond coupling in catalyzing low-temperature OCM.It is meaningful for the development of the low-temperature and high-efficient catalysts for OCM reaction in practical application.

补肾调经汤治疗卵巢储备功能下降患者对性激素、AMH水平及AFC、OV的影响

目的探讨补肾调经汤治疗卵巢储备功能下降患者对性激素及抗苗勒管激素(AMH)水平、窦卵泡计数(AFC)、卵巢体积(OV)的影响。方法将2022年6月~2023年5月于我院收治的92例卵巢储备功能下降患者作为研究对象,按照随机数字表法分为对照组及观察组。对照组46例采用常规西药治疗,观察组46例采用补肾调经汤治疗。比较两组患者中医症状评分、性激素和AMH水平、AFC、OV,并评价临床疗效。结果治疗后,观察组雌二醇(E2)和AMH水平均高于对照组,观察组卵泡刺激素(FSH)、黄体生成素(LH)、睾酮(T)水平均低于对照组,差异有统计学意义(P<0.05)。治疗后,两组AFC增多,OV增大,且观察组改善程度优于对照组,差异有统计学意义(P<0.05)。治疗后,两组月经量异常、月经周期异常、经血颜色异常、腰骶酸痛、头晕耳鸣、潮热多汗、失眠健忘和性欲减退等中医症状评分均降低,且观察组低于对照组,差异有统计学意义(P<0.05)。观察组总有效率为93.48%,对照组总有效率为73.91%,观察组高于对照组,差异有统计学意义(P<0.05)。结论补肾调经汤治疗卵巢储备功能下降患者疗效显著,可以减轻患者的临床症状,改善患者的性激素、AMH水平和AFC、OV。

基于STM32F4+OV2640的HPV生物芯片阅读装置设计

定期开展HPV分型筛查,对提高妇女健康水平、预防宫颈癌发生的意义重大。为提高检测的自动化水平,减少人工介入和人为误判,设计HPV生物芯片阅读装置的重要性显著。采用STM32F429处理器结合OV2640CMOS传感器,配备M12镜头和可移动30 mm的载物台,可充分发挥可见光显色的TIB-23型HPV生物芯片的筛查优势。结果表明,所设计的HPV生物芯片阅读装置可直接使用HPV芯片杂交仪生化反应托盘,成功阅读四联装TIB-23型HPV生物芯片。该装置对提高HPV分型筛查自动化水平具有重要意义。

紫草素通过Keap1/Nrf2信号通路介导的自噬对卵巢癌SK-OV-3细胞的影响

目的探讨紫草素通过Keap1/Nrf2信号通路介导的自噬对卵巢癌SK-OV-3细胞的影响。方法采用MTT法检测细胞增殖情况,计算顺铂、紫草素及在紫草素作用下顺铂的半数抑制浓度(IC50),以确定后续干预浓度。采用pcDNA3-EGFP-C4-Nrf2质粒及其阴性对照对SK-OV-3细胞进行转染,分别记为OE-Nrf2组、NC-Nrf2组。将SK-OV-3细胞分为对照组、顺铂(14μmol·L^(-1))组、顺铂(14μmol·L^(-1))+紫草素(9μmol·L^(-1))组,以及将转染后细胞分为顺铂(14μmol·L^(-1))+紫草素(9μmol·L^(-1))+NC-Nrf2组、顺铂(14μmol·L^(-1))+紫草素(9μmol·L^(-1))+OE-Nrf2组;培养48 h后,采用MTT法检测细胞的增殖抑制情况;RT-qPCR法检测细胞Nrf2mRNA表达情况;Transwell实验检测细胞侵袭能力;AO染色法检测细胞自噬情况;Western Blot法检测细胞增殖、侵袭及自噬相关蛋白(CyclinD1、PCNA、E-cadherin、N-cadherin、Vimentin、Beclin-1、LC3II/I、ULK、Keap1、Nrf2、p62)表达情况。结果(1)与对照组比较,紫草素4~20μmol·L^(-1)浓度组的SK-OV-3细胞活力明显降低(P<0.05),紫草素对SK-OV-3细胞的IC50为9.04μmol·L^(-1);单用顺铂10~80μmol·L^(-1)浓度组及紫草素(9μmol·L^(-1))+顺铂10~80μmol·L^(-1)浓度组的SK-OV-3细胞活力均明显降低(P<0.05)。与单用顺铂组比较,紫草素(9μmol·L^(-1))+顺铂10~80μmol·L^(-1)浓度组的SK-OV-3细胞活力均明显降低(P<0.05)。单用顺铂对SK-OV-3细胞的IC50为28.49μmol·L^(-1);与紫草素(9μmol·L^(-1))联用时,顺铂对SK-OV-3细胞的IC50为14.00μmol·L^(-1)。(2)与NC-Nrf2组比较,OE-Nrf2组SK-OV-3细胞的Nrf2 mRNA表达水平明显升高(P<0.05)。与对照组比较,顺铂组SK-OV-3细胞的Nrf2 mRNA及蛋白表达水平明显升高(P<0.05),Keap1蛋白表达水平明显降低(P<0.05);顺铂组、顺铂+紫草素组SK-OV-3细胞的增殖抑制率明显升高(P<0.05),CyclinD1、PCNA蛋白表达明显下调(P<0.05);单个视野细胞侵袭数目及N-cadherin、Vimentin蛋白表达水平明显降低(P<0.05),E-cadherin蛋白表达水平明显升高(P<0.05);细胞的红色荧光自噬囊泡明显增多,Beclin-1、LC3II/I、ULK1、p62蛋白表达水平明显升高(P<0.05)。与顺铂组比较,顺铂+紫草素组SK-OV-3细胞的Nrf2 mRNA及蛋白表达水平明显降低(P<0.05),Keap1蛋白表达水平明显升高(P<0.05);细胞的增殖抑制率明显升高(P<0.05),CyclinD1、PCNA蛋白表达明显下调(P<0.05);单个视野细胞侵袭数目及N-cadherin、Vimentin蛋白表达水平明显降低(P<0.05),E-cadherin蛋白表达水平明显升高(P<0.05);细胞的红色荧光自噬囊泡减少,Beclin-1、LC3II/I、ULK1、p62蛋白表达水平明显降低(P<0.05)。与顺铂+紫草素+NC-Nrf2组比较,顺铂+紫草素+OE-Nrf2组SK-OV-3细胞的增殖抑制率明显降低(P<0.05),CyclinD1、PCNA蛋白表达明显上调(P<0.05);单个视野细胞侵袭数目及N-cadherin、Vimentin蛋白表达水平明显升高(P<0.05),E-cadherin蛋白表达水平明显降低(P<0.05);细胞的红色荧光自噬囊泡增多,Beclin-1、LC3II/I、ULK1、p62蛋白表达水平明显升高(P<0.05)。结论紫草素可降低顺铂对卵巢癌SK-OV-3细胞的IC50,提高其对顺铂的敏感性,并抑制其增殖、侵袭能力,可能与其抑制Keap1/Nrf2通路介导的自噬有关。

Enhanced photocatalytic NO removal and toxic NO2 production inhibition over ZIF‐8‐derived ZnO nanoparticles with controllable amount of oxygen vacancies

The controlled introduction of oxygen vacancies(OVs)in photocatalysts has been demonstrated to be an efficient approach for improving the separation of photogenerated charge carriers,and thus,for enhancing the photocatalytic performance of photocatalysts.In this study,a two‐step calcination method where ZIF‐8 was used as the precursor was explored for the synthesis of ZIF‐8‐derived ZnO nanoparticles with gradient distribution of OVs.Electron paramagnetic resonance measurements indicated that the concentration of OVs in the samples depended on the temperature treatment process.Ultraviolet–visible spectra supported that the two‐step calcined samples presented excellent light‐harvesting ability in the ultraviolet‐to‐visible light range.Moreover,it was determined that the two‐step calcined samples presented superior photocatalytic performance for the removal of NO,and inhibited the generation of NO2.These properties could be attributed to the contribution of the OVs present in the two‐step calcined samples to their photocatalytic performance.The electrons confined by the OVs could be transferred to O2 to generate superoxide radicals,which could oxidize NO to the final product,nitrate.In particular,the NO removal efficiency of Z 350‐400(which was a sample first calcined at 350℃ for 2 h,then at 400℃ for 1 h)was 1.5 and 4.6 times higher than that of Z 400(which was one‐step directly calcined at 400℃)and commercial ZnO,respectively.These findings suggested that OV‐containing metal oxides that derived from metal‐organic framework materials hold great promise as highly efficient photocatalysts for the removal of NO.

BiOBr-OV/RGO复合物的制备及其光催化CO_(2)还原性能

采用水热合成方法先制得四方相BiOBr纳米片与还原氧化石墨烯(RGO)相结合的二元复合物BiOBr/RGO,再经真空热处理获得富含氧空位(OV)的复合光催化剂BiOBr-OV/RGO。通过一系列分析测试方法对样品的结构、组成和光电性能进行了表征。BiOBr-OV/RGO表现出了最佳的模拟太阳光光催化CO_(2)还原活性,主要还原产物CO的生成速率达到15.67μmol·g^(-1)·h^(-1),分别是纯BiOBr、BiOBr-OV和BiOBr/RGO的4.5倍、2.5倍和1.4倍,体现了OV和RGO协同增强的可见光吸收和促进光生载流子在空间上的分离作用,从而提高光催化反应活性。