Spinel metal oxides containing Mn,Co,or Fe(AB_(2)O_(4),A/B=Mn/Fe/Co)are one of the most promising nonPt electrocatalysts for oxygen reduction reaction(ORR)in alkaline conditions.However,the low conductivity of metal o...Spinel metal oxides containing Mn,Co,or Fe(AB_(2)O_(4),A/B=Mn/Fe/Co)are one of the most promising nonPt electrocatalysts for oxygen reduction reaction(ORR)in alkaline conditions.However,the low conductivity of metal oxides and the poor intrinsic activities of transition metal sites lead to unsatisfactory ORR performance.In this study,eutectic molten salt(EMS)treatment is employed to reconstruct the atomic arrangement of MnFe_(2)O_(4)electrocatalyst as a prototype for enhancing ORR performance.Comprehensive analyses by using XAFS,soft XAS,XPS,and electrochemical methods reveal that the EMS treatment reduces the oxygen vacancies and spinel inverse in MnFe_(2)O_(4)effectively,which improves the electric conductivity and increases the population of more catalytically active Mn^(2+)sites with tetrahedral coordination.Moreover,the enhanced Mn-O interaction after EMS treatment is conducive to the adsorption and activation of O_(2),which promotes the first electron transfer step(generally considered as the ratedetermining step)of the ORR process.As a result,the EMS treated MnFe_(2)O_(4)catalyst delivers a positive shift of 40 mV in the ORR half-wave potential and a two-fold enhanced mass/specific activity.This work provides a convenient approach to manipulate the atomic architecture and local electronic structure of spinel oxides as ORR electrocatalysts and a comprehensive understanding of the structureperformance relationship from the molecular/atomic scale.展开更多
BACKGROUND Lymph node(LN)staging in rectal cancer(RC)affects treatment decisions and patient prognosis.For radiologists,the traditional preoperative assessment of LN metastasis(LNM)using magnetic resonance imaging(MRI...BACKGROUND Lymph node(LN)staging in rectal cancer(RC)affects treatment decisions and patient prognosis.For radiologists,the traditional preoperative assessment of LN metastasis(LNM)using magnetic resonance imaging(MRI)poses a challenge.AIM To explore the value of a nomogram model that combines Conventional MRI and radiomics features from the LNs of RC in assessing the preoperative metastasis of evaluable LNs.METHODS In this retrospective study,270 LNs(158 nonmetastatic,112 metastatic)were randomly split into training(n=189)and validation sets(n=81).LNs were classified based on pathology-MRI matching.Conventional MRI features[size,shape,margin,T2-weighted imaging(T2WI)appearance,and CE-T1-weighted imaging(T1WI)enhancement]were evaluated.Three radiomics models used 3D features from T1WI and T2WI images.Additionally,a nomogram model combining conventional MRI and radiomics features was developed.The model used univariate analysis and multivariable logistic regression.Evaluation employed the receiver operating characteristic curve,with DeLong test for comparing diagnostic performance.Nomogram performance was assessed using calibration and decision curve analysis.RESULTS The nomogram model outperformed conventional MRI and single radiomics models in evaluating LNM.In the training set,the nomogram model achieved an area under the curve(AUC)of 0.92,which was significantly higher than the AUCs of 0.82(P<0.001)and 0.89(P<0.001)of the conventional MRI and radiomics models,respectively.In the validation set,the nomogram model achieved an AUC of 0.91,significantly surpassing 0.80(P<0.001)and 0.86(P<0.001),respectively.CONCLUSION The nomogram model showed the best performance in predicting metastasis of evaluable LNs.展开更多
BACKGROUND Chronic obstructive pulmonary disease(COPD)combined with spontaneous pneumothorax,is characterized by significant decline in lung function,and even cause cardiopulmonary failure and hypoxia.AIM To evaluate ...BACKGROUND Chronic obstructive pulmonary disease(COPD)combined with spontaneous pneumothorax,is characterized by significant decline in lung function,and even cause cardiopulmonary failure and hypoxia.AIM To evaluate the clinical effectiveness of central venous catheters and indwelling pleural catheters(IPC)in managing closed thoracic drainage in patients diagnosed with COPD with concomitant by spontaneous pneumothorax.METHODS Retrospective analysis was conducted on the clinical information of 60 elderly patients with COPD complicated by spontaneous pneumothorax admitted to the Shexian Branch of the second affiliated hospital of Zhejiang university school of medicine between March 2020 and March 2023.The clinical efficacy,complications,hospitalization duration,and costs were compared between patients with an indwelling thoracic catheter and those with a central venous catheter.Univariate logistic regression was used to analyze the causes of catheter displacement.RESULTS According to our findings,there were significant differences in the IPC group’s clinical efficacy,catheter operation time,and lung recruitment time(P<0.05).Comparing the complications after catheter treatment between the two groups revealed statistically significant variations in the incidence of postoperative analgesics,catheter abscission,catheter blockage,and subcutaneous emphysema in the IPC group(P<0.05).Univariate analysis demonstrated significant differences between patients with and without catheter dislodgement regarding duty nurse’s working years(less than three),Acute Physiology and Chronic Health Evaluation II(APACHE II)scores(less than 15),lack of catheter suture fixation,and the proportion of catheters not fixed twice(P<0.05).CONCLUSION Our results demonstrated that when treating elderly COPD patients with spontaneous pneumothorax,indwelling thoracic catheters are more effective than the central venous catheter group.Patients’catheter shedding is influenced by the primary nurse’s working years,APACHE II scores,and catheter fixation technique.展开更多
BACKGROUND An acute myocardial infarction(AMI)is often treated with direct coronary intervention and requires home-based rehabilitation.Caregivers of patients with AMI need adequate social support to maintain high-qua...BACKGROUND An acute myocardial infarction(AMI)is often treated with direct coronary intervention and requires home-based rehabilitation.Caregivers of patients with AMI need adequate social support to maintain high-quality care;however,their social support function is low,and relevant indicators for intervention must be identified.AIM To analyze the correlation between social support for primary caregivers,their anxiety,and depression,when caring for patients with AMI after interventional therapy.METHODS Using convenience sampling,we selected 300 primary caregivers of patients with AMI who had undergone interventional therapy.The Social Support Rating Scale(SSRS),Self-Rating Anxiety Scale(SAS),and Self-Rating Depression Scale(SDS)were used to assess the primary caregivers.A Pearson’s correlation analysis was used to analyze the correlations between the SSRS,SAS,and SDS,and a multiple logistic regression analysis was used to analyze the factors influencing the low social support function of primary caregivers.The receiver operating characteristic curve and area under the curve(AUC)were used to evaluate the predictive ability of the SAS and SDS for low social support function in primary caregivers.RESULTS Considering the norm among Chinese people,AMI caregivers’objective support,subjective support,support utilization,and SSRS scores were lower,while their SAS and SDS scores were higher.The SSRS scores of female caregivers were higher than those of the male caregivers(t=2.123,P=0.035).The Pearson correlation analysis showed that objective support,subjective support,support utilization,and SSRS total scores were significantly correlated with both SAS(r=-0.414,-0.460,-0.416,-0.535)and SDS scores(r=-0.463,-0.379,-0.349,-0.472).Among the 300 AMI caregivers,56 cases(18.67%)had a low level of support function(SSRS≤22 points).Logistic regression model analysis showed that SAS and SDS were independent risk factors for low social support function of AMI caregivers,regardless of adjustment for other variables(P<0.05).SAS and SDS predicted that the AUC of AMI caregivers with low support function was 0.84,sensitivity was 67.9 and 71.4,and specificity was 84.0 and 70.9,respectively.CONCLUSION The social support function of the primary caregiver of patients with AMI after interventional therapy was lower and negatively correlated with anxiety and depression in the primary caregiver.展开更多
Oxidative dehydrogenation of propane with carbon dioxide(CO_(2)-ODP)characterizes the tandem dehydrogenation of propane to propylene with the reduction of the greenhouse gas of CO_(2)to valuable CO.However,the existin...Oxidative dehydrogenation of propane with carbon dioxide(CO_(2)-ODP)characterizes the tandem dehydrogenation of propane to propylene with the reduction of the greenhouse gas of CO_(2)to valuable CO.However,the existing catalyst is limited due to the poor activity and stability,which hinders its industrialization.Herein,we design the finned Zn-MFI zeolite encapsulated noble metal nanoparticles(NPs)as bifunctional catalysts(NPs@Zn-MFI)for CO_(2)-ODP.Characterization results reveal that the Zn2+species are coordinated with the MFI zeolite matrix as isolated cations and the NPs of Pt,Rh,or Rh Pt are highly dispersed in the zeolite crystals.The isolated Zn2+cations are very effective for activating the propane and the small NPs are favorable for activating the CO_(2),which synergistically promote the selective transformation of propane and CO_(2)to propylene and CO.As a result,the optimal 0.25%Rh0.50%Pt@Zn-MFI catalyst shows the best propylene yield,satisfactory CO_(2)conversion,and long-term stability.Moreover,considering the tunable synergetic effects between the isolated cations and NPs,the developed approach offers a general guideline to design more efficient CO_(2)-ODP catalysts,which is validated by the improved performance of the bifunctional catalysts via simply substituting Sn4+cations for Zn2+cations in the MFI zeolite matrix.展开更多
The demand for clean and sustainable energy has encouraged the production of hydrogen from water electrolyzers.To overcome the obstacle to improving the efficiency of water electrolyzers,it is highly desired to fabric...The demand for clean and sustainable energy has encouraged the production of hydrogen from water electrolyzers.To overcome the obstacle to improving the efficiency of water electrolyzers,it is highly desired to fabricate active electrocatalysts for the sluggish oxygen evolution process.However,there is generally an intrinsic gap between the as-prepared and real electrocatalysts due to structure evolution under the oxidative reaction conditions.Here,we combine in-situ anionic leaching and atomic deposition to realize single-atom catalysts with self-optimized structures.The introduced F ions facilitate structural transformation from Co(OH)xF into CoOOH(F),which generates an amorphous edge surface to provide more anchoring sites for Ir single atoms.Meanwhile,the in-situ anionic leaching of F ions elevates the Co valence state of Ir_(1)/CoOOH(F)more significantly than the counterpart without F ions(Ir_(1)/CoOOH),leading to stronger adsorption of oxygenated intermediates.As revealed by electrochemical measurements,the increased Ir loading together with the favored adsorption of*OH intermediates improve the catalytic activity of Ir_(1)/CoOOH(F).Specifically,Ir_(1)/CoOOH(F)delivered a current density of 10 mA cm-2at an overpotential of 238 mV,being lower than 314 mV for Ir_(1)/CoOOH.The results demonstrated the facility of the in-situ optimization process to optimize catalyst structure for improved performance.展开更多
The nanosheets structured K–Co–MoS_2 catalyst was prepared through a one-step hydrothermal synthesis combined with the wetness impregnation. The fresh catalyst has a high dispersion of Co–Mo–S active phase and no ...The nanosheets structured K–Co–MoS_2 catalyst was prepared through a one-step hydrothermal synthesis combined with the wetness impregnation. The fresh catalyst has a high dispersion of Co–Mo–S active phase and no Co_9S_8 is found. The pure H_2 activated catalyst shows a higher intrinsic activity, especially the C_(2+) OH selectivity for the higher alcohol synthesis compared to the one activated by 5% H_2/N_2 atmosphere. The reason is attributed to that the pure H_2 activation more effectively suppresses the formation of Co_9S_8 and stabilizes the Co–Mo–S active phase during the reaction due to the formation of SH species.展开更多
Autoimmune diseases are affected by complex pathophysiology involving several cell types,cytokines,antibodies,and mimicking factors.Different drugs are used to ameliorate these autoimmune reactions,including nonsteroi...Autoimmune diseases are affected by complex pathophysiology involving several cell types,cytokines,antibodies,and mimicking factors.Different drugs are used to ameliorate these autoimmune reactions,including nonsteroidal anti-inflammatory drugs(NSAIDs),corticosteroids,antiantibodies,and small molecular drugs(DMARDs),and they are clinically in vogue for diseases such as rheumatoid arthritis(RA).Nevertheless,low cost-effectiveness,reduced efficacy,adverse effects,and patient nonresponse are unappealing factors driving the development of new drugs such as iguratimod.Iguratimod is primarily used to ameliorate RA in Japanese and Chinese clinics.However,its efficacy against other autoimmune ailments is also under intense investigation,and the number of investigations is becoming increasingly larger with each passing day.The articular structure comprises synovium,ligaments,and bone.The latter is more complex than the others since it regulates blood cells and autoimmunity in addition to providing skeletal support to the body.Therefore,its protection is also of prime importance in RA and other autoimmune diseases.Herein,we have highlighted the role of iguratimod in autoimmune diseases and bone protection.We suggest that iguratimod’s unique mode of action compared with that of other DMARDs and its good patient response makes it a suitable antirheumatic and bone-protecting drug.展开更多
The aim of this study was to identify whether periodontitis induces gut microbiota dysbiosis via invasion by salivary microbes.First,faecal and salivary samples were collected from periodontally healthy participants(P...The aim of this study was to identify whether periodontitis induces gut microbiota dysbiosis via invasion by salivary microbes.First,faecal and salivary samples were collected from periodontally healthy participants(PH group,n=16)and patients with severe periodontitis(SP group,n=21)and analysed by 16S ribosomal RNA sequencing.Significant differences were observed in both the faecal and salivary microbiota between the PH and SP groups.Notably,more saliva-sourced microbes were observed in the faecal samples of the SP group.Then,the remaining salivary microbes were transplanted into C57BL6/J mice(the C-PH group and the C-SP group),and it was found that the composition of the gut microbiota of the C-SP group was significantly different from that of the C-PH group,with Porphyromonadaceae and Fusobacterium being significantly enriched in the C-SP group.In the colon,the C-SP group showed significantly reduced crypt depth and zonula occludens-1 expression.The m RNA expression levels of pro-inflammatory cytokines,chemokines and tight junction proteins were significantly higher in the C-SP group.To further investigate whether salivary bacteria could persist in the intestine,the salivary microbiota was stained with carboxyfluorescein diacetate succinimidyl ester and transplanted into mice.We found that salivary microbes from both the PH group and the SP group could persist in the gut for at least 24 h.Thus,our data demonstrate that periodontitis may induce gut microbiota dysbiosis through the influx of salivary microbes.展开更多
Photodeposition is widely adopted for implanting metal/metal oxide cocatalysts on semiconductors.However,it is prerequisite that the photon energy should be sufficient to excite the host semiconductor.Here,we report a...Photodeposition is widely adopted for implanting metal/metal oxide cocatalysts on semiconductors.However,it is prerequisite that the photon energy should be sufficient to excite the host semiconductor.Here,we report a lower-energy irradiation powered deposition strategy for implanting CrO_(x) cocatalyst on TiO_(2).Excitingly,CrO_(x)-400 implanted under visible-light irradiation significantly promotes the CH4 evolution rate on TiO_(2)to 8.4μmolg·^(-1)h^(-1) with selectivity of98%from photocatalytic CO_(2)reduction,which is 15 times of that on CrO_(x)-200 implanted under UV-visible-light irradiation.Moreover,CrO_(x)-400 is identified to be composed of higher valence Cr species compared to CrO_(x)-200.This valence states regulation of Cr species is indicated to provide more active sites for CO_(2) adsorption/activation and to modulate the reaction mechanism from single Cr site to Cr-Cr dual sites,thus endowing the superior CH_(4)production.This work demonstrates an alternative strategy for constructing efficient metal oxides cocatalysts on wide bandgap semiconductor.展开更多
Human depression patients often show abnormal pupillary reflex with morphological changes in hippo campus and prefrontal cortex. This study aimed to find the relationship between the prolonged pupillary light reflex ...Human depression patients often show abnormal pupillary reflex with morphological changes in hippo campus and prefrontal cortex. This study aimed to find the relationship between the prolonged pupillary light reflex （PLR） which had been shown by confined sows with chronic stress or depression and morphological changes in brain, in order to provide theoretical basis for that the confined environment should lead to sows＇ depression. A total of 637 sows of Durac, Landrace and Large White breeds with various parities were observed, and the pupil light reflex （PLR） was measured and the actual pupillary light reflex time （PLRT） were recorded. All the PLRTs were grouped based on the results of confidence interval： t〉10% as group A, 5% 〈t〈10% as group B, 1%〈t〈5% as group C and t〈l% as group D. Three individuals were randomly selected from each group （12 sows in total） and the white tissues of hippocampus and the prefrontal cortex were prepared for HS staining slices （three slices/per tissue） for observation on tissue structure and pathological changes with high magnification （400X） of electronic microscope. The results showed that in group A （t〉10%） pathological change was found in hippocampus, however, as PLRT increased from group B to group D, pathological changes in hippocampus tissues tended to be deteriorated with the increase of inflammatory cells and nuclear pyknosis phenomena. The same as those shown in hippocampus as the increasing of PLRT from groups A to D, more inflammatory cells appeared in prefrontal cortex for groups B and D. The results suggested that the tissue lesions of hippocampus and prefrontal cortex of the confined sows with prolonged PLRT might be the results of chronic stress or depression.展开更多
River ice is a natural phenomenon in cold regions, influenced by meteorology, geomorphology, and hydraulic conditions. River ice processes involve complex interactions between hydrodynamic, mechanical, and thermal pro...River ice is a natural phenomenon in cold regions, influenced by meteorology, geomorphology, and hydraulic conditions. River ice processes involve complex interactions between hydrodynamic, mechanical, and thermal processes, and they are also influenced by weather and hydrologic conditions. Because natural rivers are serpentine, with bends, narrows, and straight reaches, the commonly-used one-dimensional river ice models and two-dimensional models based on the rectangular Cartesian coordinates are incapable of simulating the physical phenomena accurately. In order to accurately simulate the complicated river geometry and overcome the difficulties of numerical simulation resulting from both complex boundaries and differences between length and width scales, a two-dimensional river ice numerical model based on a boundary-fitted coordinate transformation method was developed. The presented model considers the influence of the frazil ice accumulation under ice cover and the shape of the leading edge of ice cover during the freezing process. The model is capable of determining the velocity field, the distribution of water temperature, the concentration distribution of frazil ice, the transport of floating ice, the progression, stability, and thawing of ice cover, and the transport, accumulation, and erosion of ice under ice cover. A MacCormack scheme was used to solve the equations numerically. The model was validated with field observations from the Hequ Reach of the Yellow River. Comparison of simulation results with field data indicates that the model is capable of simulating the river ice process with high accuracy.展开更多
A series of Mn-doped K-Co-Mo catalysts were prepared by a sol-gel method. The catalyst structure was well characterized by X-ray diffraction, N2 physisorption, NH3 temperature- programmed adsorption, in situ diffuse r...A series of Mn-doped K-Co-Mo catalysts were prepared by a sol-gel method. The catalyst structure was well characterized by X-ray diffraction, N2 physisorption, NH3 temperature- programmed adsorption, in situ diffuse reflectance infrared Fourier transform spectroscopy, and X-ray absorption fine structure spectroscopy. The catalytic performance for higher alcohol synthesis from syngas was measured. It was found that the Mn-doped catalysts ex- hibited a much higher activity as compared to the unpromoted catalyst, and in particular the C2＋ alcohol selectivity increased significantly. The distribution of alcohol products de- viated from the Anderson-Schulz-Flory law. The portion of methanol in total alcohol was suppressed remarkably and the ethanol became the predominant product. Characterization results indicated that the incorporation of Mn enhanced the interaction of Co and Mo and thus led to the formation of Co-Mo-O species, which was regarded as the active site for the alcohol synthesis. Secondly, the presence of Mn reduced the amount of strong acid sites significantly and meanwhile promoted the formation of weak acid sites, which had a positive effect on the synthesis of alcohol. Furthermore, it was found that the incorporation of Mn can enhance the adsorption of linear- and bridge-type CO significantly, which contributed to the formation of alcohol and growth of carbon chain and thus increased the selectivity to C2＋OH.展开更多
This study investigated the positive effect of surface modification with ozone on the photocatalytic performance of anatase TiO2 with dominated（001） facets for toluene degradation.The performance of photocatalyst wa...This study investigated the positive effect of surface modification with ozone on the photocatalytic performance of anatase TiO2 with dominated（001） facets for toluene degradation.The performance of photocatalyst was tested on a home-made volatile organic compounds degradation system. The ozone modification, toluene adsorption and degradation mechanism were established by a combination of various characterization methods, in situ diffuse reflectance infrared fourier transform spectroscopy, and density functional theory calculation.The surface modification with ozone can significantly enhance the photocatalytic degradation performance for toluene. The abundant unsaturated coordinated 5 c-Ti sites on（001）facets act as the adsorption sites for ozone. The formed Ti–O bonds reacted with H2O to generate a large amount of isolated Ti5 c-OH which act as the adsorption sites for toluene,and thus significantly increase the adsorption capacity for toluene. The outstanding photocatalytic performance of ozone-modified TiO2 is due to its high adsorption ability for toluene and the abundant surface hydroxyl groups, which produce very reactive OH·radicals under irradiation. Furthermore, the O2 generated via ozone dissociation could combine with the photogenerated electrons to form superoxide radicals which are also conductive to the toluene degradation.展开更多
Direct Z-scheme CdO-CdS 1-dimensional nanorod arrays were constructed through a facile and simple hydrothermal process. The structure, morphology, photoelectrochemical properties and H2 evolution activity of this cata...Direct Z-scheme CdO-CdS 1-dimensional nanorod arrays were constructed through a facile and simple hydrothermal process. The structure, morphology, photoelectrochemical properties and H2 evolution activity of this catalyst were investigated systematically. The morphology of the obtained nanorod is a regular hexagonal prism with 100-200 nm in diameter. The calcination temperature and time were optimized carefully to achieve the highest photoelectrochemical performance. The as-fabricated hybrid system achieved a photocurrent density up to 6.5 mA/cm2 and H2 evolution rate of 240 μmol·cm-2·h-1 at 0 V vs. Ag/AgCl, which is about 2-fold higher than that of the bare CdS nanorod arrays. The PEC performance exceeds those previously reported similar systems. A direct Z-scheme photocatalytic mechanism was proposed based on the structure and photoelectrochemical performance characterization results, which can well explain the high separation efficiency of photoinduced carriers and the excellent redox ability.展开更多
Capsule catalysts composed of pre-shaped core catalysts and layer zeolites have been widely used in the tandem reactions where multiple continuous reactions are combined into one process. They show excellent catalytic...Capsule catalysts composed of pre-shaped core catalysts and layer zeolites have been widely used in the tandem reactions where multiple continuous reactions are combined into one process. They show excellent catalytic performance in heterogeneous catalysis, including the direct synthesis of middle isoparaflins or dimethyl ether from syngas, as compared to the conventional hybrid catalysts. The present review highlights the recent development in the design of capsule catalysts and their catalytic applications in heterogeneous catalysis. The capsule catalyst preparation methods are introduced in detail, such as hydrothermal synthe- sis method, dual-layer method, physically adhesive method and single crystal crystallization method. Purthermore, several new applications of capsule catalysts in heterogeneous cat- alytic processes are presented such as in the direct synthesis of liquefied petroleum gas from syngas, the direct synthesis of para-xylene from syngas and methane dehydroaromatization. In addition, the development in the design of multifunctional capsule catalysts is discussed, which makes the capsule catalyst not just a simple combination of two dill）rent catalysts, but has some special functions such as changing the surface hydrophobic or acid properties of the core catalysts. Finally, the future perspectives of the design and applications of capsule catalysts in heterogeneous catalysis are provided.展开更多
Objective: It is discussed whether saikosaponin A induces apoptosis of human hepatoma Huh7 cells is related to the change of autophagy level.Methods: The effects of different concentrations of SSA on proliferation and...Objective: It is discussed whether saikosaponin A induces apoptosis of human hepatoma Huh7 cells is related to the change of autophagy level.Methods: The effects of different concentrations of SSA on proliferation and apoptosis of Huh7 cells were detected by MTT and flow cytometry, and then constructed recombinant plasmid pEGFP-N1-LC3B and transfected into Huh7 cells. After intervened by SSA culture medium, the autophagy level was observed under confocal microscope. The expression of apoptosis proteins Bax, Bcl-2, PCNA and autophagy-related proteins LC3B, Beclin1, and Apg12-Apg5 were detected by Western Blot. Results: SSA can significantly inhibit the proliferation of Huh7 cells, promote apoptosis, increase the number of autophagy bodies in the cytoplasm, up-regulate the expression of Bax, LC3B-II, Beclin1, Apg12-Apg5 and down-regulate the expression of Bcl-2, PCNA. Conclusion:SSA induced apoptosis of Huh7 cells in vitro and upregulated the autophagy level.展开更多
Two-dimensional transition metal hydroxides with abundant reserves and low prices have played an indispensable role in energy catalytic applications.Recent reports indicated that the incorporation of Fe species into C...Two-dimensional transition metal hydroxides with abundant reserves and low prices have played an indispensable role in energy catalytic applications.Recent reports indicated that the incorporation of Fe species into Co-based catalysts can synergistically enhance oxygen evolution reaction(OER)activity.Constructing a heterointerface on the surface of Co-based catalysts can provide a platform to investigate the role of heterointerface in reaction kinetics.Herein,we constructed a Fe-O-Co heterointerface without electronic effect by depositing FeO_(x)clusters on the oxygen vacancies of CoOOH surface.FeO_(x)/CoOOH exhibited excellent OER intrinsic activity,which can deliver the turnover frequency(TOF)of 4.56 s^(-1)at the overpotentials of 300 mV and the Tafel slope of 33 mV·dec^(-1).In-situ electrochemical impedance spectroscopy(EIS)and density functional theory(DFT)calculations demonstrated that the synergistic effect between Fe sites and Co sites confined at the Fe-O-Co heterointerface accelerated the charge transfer during OER and optimized the adsorption of oxygen intermediates,consequently enhancing OER.展开更多
A second-order compensation link is adopted to control voltage-controlled inverters(VCIs) in microgrid systems to enhance the performance of the power synchronization process of the inverter. The second-order compensa...A second-order compensation link is adopted to control voltage-controlled inverters(VCIs) in microgrid systems to enhance the performance of the power synchronization process of the inverter. The second-order compensation link is classified as both a real pole compensator(RPC) and a complex pole compensator(CPC) according to the pole position. Given a model for the VCI power output, the design process for the second-order compensation link, which is equipped with an RPC and a CPC, is detailed. Moreover, the frequency-domain compensation effects of the RPC and CPC are analyzed using the root locus and Bode diagrams of the system before and after compensation. Finally, the compensation effects of the two types of second-order compensators are compared with the commonly used high-pass filter using MATLAB/Simulink, which verifies the RPC and CPC strategies. Simulation results show that the two types of compensators designed in this study can effectively increase the system cutting frequency and improve the phase margin in the frequency domain while accelerating the power synchronization process, simultaneously making it smoother and reducing overshoot in the time domain. The RPC has better gain robustness, whereas the CPC has better time constant robustness. By implementing an RPC or a CPC, the dynamic time of the power synchronization compensation strategy is reduced within 0.5 s, and the overshoot is reduced within 10% in the experiments with two inverters.展开更多
基金supported by the National Natural Science Foundation of China (12241502,52002367)the Fundamental Research Funds for the Central Universities (20720220010)the National Key Research and Development Program of China (2019YFA0405602)。
文摘Spinel metal oxides containing Mn,Co,or Fe(AB_(2)O_(4),A/B=Mn/Fe/Co)are one of the most promising nonPt electrocatalysts for oxygen reduction reaction(ORR)in alkaline conditions.However,the low conductivity of metal oxides and the poor intrinsic activities of transition metal sites lead to unsatisfactory ORR performance.In this study,eutectic molten salt(EMS)treatment is employed to reconstruct the atomic arrangement of MnFe_(2)O_(4)electrocatalyst as a prototype for enhancing ORR performance.Comprehensive analyses by using XAFS,soft XAS,XPS,and electrochemical methods reveal that the EMS treatment reduces the oxygen vacancies and spinel inverse in MnFe_(2)O_(4)effectively,which improves the electric conductivity and increases the population of more catalytically active Mn^(2+)sites with tetrahedral coordination.Moreover,the enhanced Mn-O interaction after EMS treatment is conducive to the adsorption and activation of O_(2),which promotes the first electron transfer step(generally considered as the ratedetermining step)of the ORR process.As a result,the EMS treated MnFe_(2)O_(4)catalyst delivers a positive shift of 40 mV in the ORR half-wave potential and a two-fold enhanced mass/specific activity.This work provides a convenient approach to manipulate the atomic architecture and local electronic structure of spinel oxides as ORR electrocatalysts and a comprehensive understanding of the structureperformance relationship from the molecular/atomic scale.
基金Supported by the National Natural Science Foundation of China,No.81602145 and No.82072704Jiangsu Province TCM Science and Technology Development Plan Monographic Project,No.ZT202118+6 种基金Jiangsu Provincial Natural Science Foundation,No.BK20171509China Postdoctoral Science Foundation,No.2018M632265The“333 Talents”Program of Jiangsu Province,No.BRA2020390Key R&D Plan of Jiangsu Provincial Department of Science and Technology,No.BE2020723Nanjing Medical University Project,No.NMUC2020046Nanjing Science and Technology Project,No.202110027Elderly Health Research Project of Jiangsu Provincial Health Commission,No.LR2022006.
文摘BACKGROUND Lymph node(LN)staging in rectal cancer(RC)affects treatment decisions and patient prognosis.For radiologists,the traditional preoperative assessment of LN metastasis(LNM)using magnetic resonance imaging(MRI)poses a challenge.AIM To explore the value of a nomogram model that combines Conventional MRI and radiomics features from the LNs of RC in assessing the preoperative metastasis of evaluable LNs.METHODS In this retrospective study,270 LNs(158 nonmetastatic,112 metastatic)were randomly split into training(n=189)and validation sets(n=81).LNs were classified based on pathology-MRI matching.Conventional MRI features[size,shape,margin,T2-weighted imaging(T2WI)appearance,and CE-T1-weighted imaging(T1WI)enhancement]were evaluated.Three radiomics models used 3D features from T1WI and T2WI images.Additionally,a nomogram model combining conventional MRI and radiomics features was developed.The model used univariate analysis and multivariable logistic regression.Evaluation employed the receiver operating characteristic curve,with DeLong test for comparing diagnostic performance.Nomogram performance was assessed using calibration and decision curve analysis.RESULTS The nomogram model outperformed conventional MRI and single radiomics models in evaluating LNM.In the training set,the nomogram model achieved an area under the curve(AUC)of 0.92,which was significantly higher than the AUCs of 0.82(P<0.001)and 0.89(P<0.001)of the conventional MRI and radiomics models,respectively.In the validation set,the nomogram model achieved an AUC of 0.91,significantly surpassing 0.80(P<0.001)and 0.86(P<0.001),respectively.CONCLUSION The nomogram model showed the best performance in predicting metastasis of evaluable LNs.
文摘BACKGROUND Chronic obstructive pulmonary disease(COPD)combined with spontaneous pneumothorax,is characterized by significant decline in lung function,and even cause cardiopulmonary failure and hypoxia.AIM To evaluate the clinical effectiveness of central venous catheters and indwelling pleural catheters(IPC)in managing closed thoracic drainage in patients diagnosed with COPD with concomitant by spontaneous pneumothorax.METHODS Retrospective analysis was conducted on the clinical information of 60 elderly patients with COPD complicated by spontaneous pneumothorax admitted to the Shexian Branch of the second affiliated hospital of Zhejiang university school of medicine between March 2020 and March 2023.The clinical efficacy,complications,hospitalization duration,and costs were compared between patients with an indwelling thoracic catheter and those with a central venous catheter.Univariate logistic regression was used to analyze the causes of catheter displacement.RESULTS According to our findings,there were significant differences in the IPC group’s clinical efficacy,catheter operation time,and lung recruitment time(P<0.05).Comparing the complications after catheter treatment between the two groups revealed statistically significant variations in the incidence of postoperative analgesics,catheter abscission,catheter blockage,and subcutaneous emphysema in the IPC group(P<0.05).Univariate analysis demonstrated significant differences between patients with and without catheter dislodgement regarding duty nurse’s working years(less than three),Acute Physiology and Chronic Health Evaluation II(APACHE II)scores(less than 15),lack of catheter suture fixation,and the proportion of catheters not fixed twice(P<0.05).CONCLUSION Our results demonstrated that when treating elderly COPD patients with spontaneous pneumothorax,indwelling thoracic catheters are more effective than the central venous catheter group.Patients’catheter shedding is influenced by the primary nurse’s working years,APACHE II scores,and catheter fixation technique.
基金The study procedures were approved by the Ethics Committee of the Affiliated Hospital of Jiangnan University(approval No.WXSY-YXLL-AF/SC-02/01.0).
文摘BACKGROUND An acute myocardial infarction(AMI)is often treated with direct coronary intervention and requires home-based rehabilitation.Caregivers of patients with AMI need adequate social support to maintain high-quality care;however,their social support function is low,and relevant indicators for intervention must be identified.AIM To analyze the correlation between social support for primary caregivers,their anxiety,and depression,when caring for patients with AMI after interventional therapy.METHODS Using convenience sampling,we selected 300 primary caregivers of patients with AMI who had undergone interventional therapy.The Social Support Rating Scale(SSRS),Self-Rating Anxiety Scale(SAS),and Self-Rating Depression Scale(SDS)were used to assess the primary caregivers.A Pearson’s correlation analysis was used to analyze the correlations between the SSRS,SAS,and SDS,and a multiple logistic regression analysis was used to analyze the factors influencing the low social support function of primary caregivers.The receiver operating characteristic curve and area under the curve(AUC)were used to evaluate the predictive ability of the SAS and SDS for low social support function in primary caregivers.RESULTS Considering the norm among Chinese people,AMI caregivers’objective support,subjective support,support utilization,and SSRS scores were lower,while their SAS and SDS scores were higher.The SSRS scores of female caregivers were higher than those of the male caregivers(t=2.123,P=0.035).The Pearson correlation analysis showed that objective support,subjective support,support utilization,and SSRS total scores were significantly correlated with both SAS(r=-0.414,-0.460,-0.416,-0.535)and SDS scores(r=-0.463,-0.379,-0.349,-0.472).Among the 300 AMI caregivers,56 cases(18.67%)had a low level of support function(SSRS≤22 points).Logistic regression model analysis showed that SAS and SDS were independent risk factors for low social support function of AMI caregivers,regardless of adjustment for other variables(P<0.05).SAS and SDS predicted that the AUC of AMI caregivers with low support function was 0.84,sensitivity was 67.9 and 71.4,and specificity was 84.0 and 70.9,respectively.CONCLUSION The social support function of the primary caregiver of patients with AMI after interventional therapy was lower and negatively correlated with anxiety and depression in the primary caregiver.
基金supported by the National Natural Science Foundation of China(21902097,21636006 and 21761132025)the China Postdoctoral Science Foundation(2019M653861XB)+1 种基金the Natural Science Foundation of Shaanxi Province(2020JQ-409)the Fundamental Research Funds for the Central Universities(GK201901001 and GK202003035)。
文摘Oxidative dehydrogenation of propane with carbon dioxide(CO_(2)-ODP)characterizes the tandem dehydrogenation of propane to propylene with the reduction of the greenhouse gas of CO_(2)to valuable CO.However,the existing catalyst is limited due to the poor activity and stability,which hinders its industrialization.Herein,we design the finned Zn-MFI zeolite encapsulated noble metal nanoparticles(NPs)as bifunctional catalysts(NPs@Zn-MFI)for CO_(2)-ODP.Characterization results reveal that the Zn2+species are coordinated with the MFI zeolite matrix as isolated cations and the NPs of Pt,Rh,or Rh Pt are highly dispersed in the zeolite crystals.The isolated Zn2+cations are very effective for activating the propane and the small NPs are favorable for activating the CO_(2),which synergistically promote the selective transformation of propane and CO_(2)to propylene and CO.As a result,the optimal 0.25%Rh0.50%Pt@Zn-MFI catalyst shows the best propylene yield,satisfactory CO_(2)conversion,and long-term stability.Moreover,considering the tunable synergetic effects between the isolated cations and NPs,the developed approach offers a general guideline to design more efficient CO_(2)-ODP catalysts,which is validated by the improved performance of the bifunctional catalysts via simply substituting Sn4+cations for Zn2+cations in the MFI zeolite matrix.
基金supported by National Key Research and Development Program of China(2021YFA1500500,2019YFA0405600,2017YFA0204904,2019YFA0405602,and 2017YFA0403402)the National Science Fund for Distinguished Young Scholars(21925204)+8 种基金the National Natural Science Foundation of China(21972132,U1732149,U19A2015,U1732272,21673214,92045301,and 21902149)the Fundamental Research Funds for the Central Universities(20720220010)the Provincial Key Research and Development Program of Anhui(202004a05020074)the Anhui Natural Science Foundation for Young Scholars(2208085QB52)K.C.Wong Education(GJTD2020-15)the Hefei Municipal Natural Science Foundation(2021018)the DNL Cooperation Fund,CAS(DNL202003)Users with Excellence Program of Hefei Science Center CAS(2020HSCUE001)USTC Research Funds of the Double First-Class Initiative(YD2340002002)。
文摘The demand for clean and sustainable energy has encouraged the production of hydrogen from water electrolyzers.To overcome the obstacle to improving the efficiency of water electrolyzers,it is highly desired to fabricate active electrocatalysts for the sluggish oxygen evolution process.However,there is generally an intrinsic gap between the as-prepared and real electrocatalysts due to structure evolution under the oxidative reaction conditions.Here,we combine in-situ anionic leaching and atomic deposition to realize single-atom catalysts with self-optimized structures.The introduced F ions facilitate structural transformation from Co(OH)xF into CoOOH(F),which generates an amorphous edge surface to provide more anchoring sites for Ir single atoms.Meanwhile,the in-situ anionic leaching of F ions elevates the Co valence state of Ir_(1)/CoOOH(F)more significantly than the counterpart without F ions(Ir_(1)/CoOOH),leading to stronger adsorption of oxygenated intermediates.As revealed by electrochemical measurements,the increased Ir loading together with the favored adsorption of*OH intermediates improve the catalytic activity of Ir_(1)/CoOOH(F).Specifically,Ir_(1)/CoOOH(F)delivered a current density of 10 mA cm-2at an overpotential of 238 mV,being lower than 314 mV for Ir_(1)/CoOOH.The results demonstrated the facility of the in-situ optimization process to optimize catalyst structure for improved performance.
基金supported by the National Natural Science Foundation of China(21673214,U1732272)
文摘The nanosheets structured K–Co–MoS_2 catalyst was prepared through a one-step hydrothermal synthesis combined with the wetness impregnation. The fresh catalyst has a high dispersion of Co–Mo–S active phase and no Co_9S_8 is found. The pure H_2 activated catalyst shows a higher intrinsic activity, especially the C_(2+) OH selectivity for the higher alcohol synthesis compared to the one activated by 5% H_2/N_2 atmosphere. The reason is attributed to that the pure H_2 activation more effectively suppresses the formation of Co_9S_8 and stabilizes the Co–Mo–S active phase during the reaction due to the formation of SH species.
基金supported by the Natural Science Foundation of Shandong Province (ZR2012HM038)the Shenzhen Science and Technology Innovation Committee Fund (JCYJ2016033117365255)+1 种基金the China International Medical Foundation (Simcere-Z2014-06-2-1635)the China Torch Program (2013GH021476)
文摘Autoimmune diseases are affected by complex pathophysiology involving several cell types,cytokines,antibodies,and mimicking factors.Different drugs are used to ameliorate these autoimmune reactions,including nonsteroidal anti-inflammatory drugs(NSAIDs),corticosteroids,antiantibodies,and small molecular drugs(DMARDs),and they are clinically in vogue for diseases such as rheumatoid arthritis(RA).Nevertheless,low cost-effectiveness,reduced efficacy,adverse effects,and patient nonresponse are unappealing factors driving the development of new drugs such as iguratimod.Iguratimod is primarily used to ameliorate RA in Japanese and Chinese clinics.However,its efficacy against other autoimmune ailments is also under intense investigation,and the number of investigations is becoming increasingly larger with each passing day.The articular structure comprises synovium,ligaments,and bone.The latter is more complex than the others since it regulates blood cells and autoimmunity in addition to providing skeletal support to the body.Therefore,its protection is also of prime importance in RA and other autoimmune diseases.Herein,we have highlighted the role of iguratimod in autoimmune diseases and bone protection.We suggest that iguratimod’s unique mode of action compared with that of other DMARDs and its good patient response makes it a suitable antirheumatic and bone-protecting drug.
基金supported by the National Science Foundation of China(No.81970939)the Nanjing Clinical Research Center for Oral Diseases(No.2019060009)。
文摘The aim of this study was to identify whether periodontitis induces gut microbiota dysbiosis via invasion by salivary microbes.First,faecal and salivary samples were collected from periodontally healthy participants(PH group,n=16)and patients with severe periodontitis(SP group,n=21)and analysed by 16S ribosomal RNA sequencing.Significant differences were observed in both the faecal and salivary microbiota between the PH and SP groups.Notably,more saliva-sourced microbes were observed in the faecal samples of the SP group.Then,the remaining salivary microbes were transplanted into C57BL6/J mice(the C-PH group and the C-SP group),and it was found that the composition of the gut microbiota of the C-SP group was significantly different from that of the C-PH group,with Porphyromonadaceae and Fusobacterium being significantly enriched in the C-SP group.In the colon,the C-SP group showed significantly reduced crypt depth and zonula occludens-1 expression.The m RNA expression levels of pro-inflammatory cytokines,chemokines and tight junction proteins were significantly higher in the C-SP group.To further investigate whether salivary bacteria could persist in the intestine,the salivary microbiota was stained with carboxyfluorescein diacetate succinimidyl ester and transplanted into mice.We found that salivary microbes from both the PH group and the SP group could persist in the gut for at least 24 h.Thus,our data demonstrate that periodontitis may induce gut microbiota dysbiosis through the influx of salivary microbes.
基金supported by the National Key Research and Development Program of China(2016YFB0700205,2017YFA0403402,2019YFA0405602,2017YFA0204904)the National Natural Science Foundation of China(52002367,21673214,U1732272,U1632273,U1832165)+1 种基金the foundation from Users with Excellence Program of Hefei Science Center CAS(2020HSC-UE001)the Fundamental Research Funds for the Central Universities(WK2310000093)。
文摘Photodeposition is widely adopted for implanting metal/metal oxide cocatalysts on semiconductors.However,it is prerequisite that the photon energy should be sufficient to excite the host semiconductor.Here,we report a lower-energy irradiation powered deposition strategy for implanting CrO_(x) cocatalyst on TiO_(2).Excitingly,CrO_(x)-400 implanted under visible-light irradiation significantly promotes the CH4 evolution rate on TiO_(2)to 8.4μmolg·^(-1)h^(-1) with selectivity of98%from photocatalytic CO_(2)reduction,which is 15 times of that on CrO_(x)-200 implanted under UV-visible-light irradiation.Moreover,CrO_(x)-400 is identified to be composed of higher valence Cr species compared to CrO_(x)-200.This valence states regulation of Cr species is indicated to provide more active sites for CO_(2) adsorption/activation and to modulate the reaction mechanism from single Cr site to Cr-Cr dual sites,thus endowing the superior CH_(4)production.This work demonstrates an alternative strategy for constructing efficient metal oxides cocatalysts on wide bandgap semiconductor.
基金Supported by the National Natural Science Foundation of China(NSFC,31472131/C170109,31201834/C170109)Scientific Research Foundation for Doctorship of Northeast Agricultural University(2010RCB37)
文摘Human depression patients often show abnormal pupillary reflex with morphological changes in hippo campus and prefrontal cortex. This study aimed to find the relationship between the prolonged pupillary light reflex （PLR） which had been shown by confined sows with chronic stress or depression and morphological changes in brain, in order to provide theoretical basis for that the confined environment should lead to sows＇ depression. A total of 637 sows of Durac, Landrace and Large White breeds with various parities were observed, and the pupil light reflex （PLR） was measured and the actual pupillary light reflex time （PLRT） were recorded. All the PLRTs were grouped based on the results of confidence interval： t〉10% as group A, 5% 〈t〈10% as group B, 1%〈t〈5% as group C and t〈l% as group D. Three individuals were randomly selected from each group （12 sows in total） and the white tissues of hippocampus and the prefrontal cortex were prepared for HS staining slices （three slices/per tissue） for observation on tissue structure and pathological changes with high magnification （400X） of electronic microscope. The results showed that in group A （t〉10%） pathological change was found in hippocampus, however, as PLRT increased from group B to group D, pathological changes in hippocampus tissues tended to be deteriorated with the increase of inflammatory cells and nuclear pyknosis phenomena. The same as those shown in hippocampus as the increasing of PLRT from groups A to D, more inflammatory cells appeared in prefrontal cortex for groups B and D. The results suggested that the tissue lesions of hippocampus and prefrontal cortex of the confined sows with prolonged PLRT might be the results of chronic stress or depression.
基金supported by the National Natural Science Foundation of China(Grant No.50579030)
文摘River ice is a natural phenomenon in cold regions, influenced by meteorology, geomorphology, and hydraulic conditions. River ice processes involve complex interactions between hydrodynamic, mechanical, and thermal processes, and they are also influenced by weather and hydrologic conditions. Because natural rivers are serpentine, with bends, narrows, and straight reaches, the commonly-used one-dimensional river ice models and two-dimensional models based on the rectangular Cartesian coordinates are incapable of simulating the physical phenomena accurately. In order to accurately simulate the complicated river geometry and overcome the difficulties of numerical simulation resulting from both complex boundaries and differences between length and width scales, a two-dimensional river ice numerical model based on a boundary-fitted coordinate transformation method was developed. The presented model considers the influence of the frazil ice accumulation under ice cover and the shape of the leading edge of ice cover during the freezing process. The model is capable of determining the velocity field, the distribution of water temperature, the concentration distribution of frazil ice, the transport of floating ice, the progression, stability, and thawing of ice cover, and the transport, accumulation, and erosion of ice under ice cover. A MacCormack scheme was used to solve the equations numerically. The model was validated with field observations from the Hequ Reach of the Yellow River. Comparison of simulation results with field data indicates that the model is capable of simulating the river ice process with high accuracy.
文摘A series of Mn-doped K-Co-Mo catalysts were prepared by a sol-gel method. The catalyst structure was well characterized by X-ray diffraction, N2 physisorption, NH3 temperature- programmed adsorption, in situ diffuse reflectance infrared Fourier transform spectroscopy, and X-ray absorption fine structure spectroscopy. The catalytic performance for higher alcohol synthesis from syngas was measured. It was found that the Mn-doped catalysts ex- hibited a much higher activity as compared to the unpromoted catalyst, and in particular the C2＋ alcohol selectivity increased significantly. The distribution of alcohol products de- viated from the Anderson-Schulz-Flory law. The portion of methanol in total alcohol was suppressed remarkably and the ethanol became the predominant product. Characterization results indicated that the incorporation of Mn enhanced the interaction of Co and Mo and thus led to the formation of Co-Mo-O species, which was regarded as the active site for the alcohol synthesis. Secondly, the presence of Mn reduced the amount of strong acid sites significantly and meanwhile promoted the formation of weak acid sites, which had a positive effect on the synthesis of alcohol. Furthermore, it was found that the incorporation of Mn can enhance the adsorption of linear- and bridge-type CO significantly, which contributed to the formation of alcohol and growth of carbon chain and thus increased the selectivity to C2＋OH.
基金the National Natural Science Foundation of China (U1632273, 21673214,U1732272, U1832165).
文摘This study investigated the positive effect of surface modification with ozone on the photocatalytic performance of anatase TiO2 with dominated（001） facets for toluene degradation.The performance of photocatalyst was tested on a home-made volatile organic compounds degradation system. The ozone modification, toluene adsorption and degradation mechanism were established by a combination of various characterization methods, in situ diffuse reflectance infrared fourier transform spectroscopy, and density functional theory calculation.The surface modification with ozone can significantly enhance the photocatalytic degradation performance for toluene. The abundant unsaturated coordinated 5 c-Ti sites on（001）facets act as the adsorption sites for ozone. The formed Ti–O bonds reacted with H2O to generate a large amount of isolated Ti5 c-OH which act as the adsorption sites for toluene,and thus significantly increase the adsorption capacity for toluene. The outstanding photocatalytic performance of ozone-modified TiO2 is due to its high adsorption ability for toluene and the abundant surface hydroxyl groups, which produce very reactive OH·radicals under irradiation. Furthermore, the O2 generated via ozone dissociation could combine with the photogenerated electrons to form superoxide radicals which are also conductive to the toluene degradation.
基金supported by the National Natural Science Foundation of China(No.U1632273,No.21673214,No.U1732272,and No.U1832165)
文摘Direct Z-scheme CdO-CdS 1-dimensional nanorod arrays were constructed through a facile and simple hydrothermal process. The structure, morphology, photoelectrochemical properties and H2 evolution activity of this catalyst were investigated systematically. The morphology of the obtained nanorod is a regular hexagonal prism with 100-200 nm in diameter. The calcination temperature and time were optimized carefully to achieve the highest photoelectrochemical performance. The as-fabricated hybrid system achieved a photocurrent density up to 6.5 mA/cm2 and H2 evolution rate of 240 μmol·cm-2·h-1 at 0 V vs. Ag/AgCl, which is about 2-fold higher than that of the bare CdS nanorod arrays. The PEC performance exceeds those previously reported similar systems. A direct Z-scheme photocatalytic mechanism was proposed based on the structure and photoelectrochemical performance characterization results, which can well explain the high separation efficiency of photoinduced carriers and the excellent redox ability.
基金supported by the Key R&D plan(East-West Cooperation) of Ningxiathe First-rate Discipline Construction Project of Ningxia(NXYLXK2017A04)
文摘Capsule catalysts composed of pre-shaped core catalysts and layer zeolites have been widely used in the tandem reactions where multiple continuous reactions are combined into one process. They show excellent catalytic performance in heterogeneous catalysis, including the direct synthesis of middle isoparaflins or dimethyl ether from syngas, as compared to the conventional hybrid catalysts. The present review highlights the recent development in the design of capsule catalysts and their catalytic applications in heterogeneous catalysis. The capsule catalyst preparation methods are introduced in detail, such as hydrothermal synthe- sis method, dual-layer method, physically adhesive method and single crystal crystallization method. Purthermore, several new applications of capsule catalysts in heterogeneous cat- alytic processes are presented such as in the direct synthesis of liquefied petroleum gas from syngas, the direct synthesis of para-xylene from syngas and methane dehydroaromatization. In addition, the development in the design of multifunctional capsule catalysts is discussed, which makes the capsule catalyst not just a simple combination of two dill）rent catalysts, but has some special functions such as changing the surface hydrophobic or acid properties of the core catalysts. Finally, the future perspectives of the design and applications of capsule catalysts in heterogeneous catalysis are provided.
基金This study was supported by National Natural Science Foundation(81273745).
文摘Objective: It is discussed whether saikosaponin A induces apoptosis of human hepatoma Huh7 cells is related to the change of autophagy level.Methods: The effects of different concentrations of SSA on proliferation and apoptosis of Huh7 cells were detected by MTT and flow cytometry, and then constructed recombinant plasmid pEGFP-N1-LC3B and transfected into Huh7 cells. After intervened by SSA culture medium, the autophagy level was observed under confocal microscope. The expression of apoptosis proteins Bax, Bcl-2, PCNA and autophagy-related proteins LC3B, Beclin1, and Apg12-Apg5 were detected by Western Blot. Results: SSA can significantly inhibit the proliferation of Huh7 cells, promote apoptosis, increase the number of autophagy bodies in the cytoplasm, up-regulate the expression of Bax, LC3B-II, Beclin1, Apg12-Apg5 and down-regulate the expression of Bcl-2, PCNA. Conclusion:SSA induced apoptosis of Huh7 cells in vitro and upregulated the autophagy level.
基金This work was supported by the National Key Research and Development Program of China(Nos.2017YFA0403402,2019YFA0405600,2019YFA0405602,and 2021YFA1500500)National Natural Science Foundation of China(NSFC,Nos.21972132,21673214,22202192,U19A2015,92045301,U1732149,and U1732272)+8 种基金National Science Fund for Distinguished Young Scholars(No.21925204)Fundamental Research Funds for the Central Universities(No.20720220010)Provincial Key Research and Development Program of Anhui(No.202004a05020074)K.C.Wong Education(No.GJTD-2020-15)the DNL Cooperation Fund,Chinese Academy of Sciences(CAS,No.DNL202003)Users with Excellence Program of Hefei Science Center CAS(No.2020HSC-UE001)USTC Research Funds of the Double First-Class Initiative(No.YD2340002002)Anhui Natural Science Foundation for Young Scholars(Nos.2208085QB52 and 2208085QB41)CAS Project for Young Scientists in Basic Research(No.YSBR-051).
文摘Two-dimensional transition metal hydroxides with abundant reserves and low prices have played an indispensable role in energy catalytic applications.Recent reports indicated that the incorporation of Fe species into Co-based catalysts can synergistically enhance oxygen evolution reaction(OER)activity.Constructing a heterointerface on the surface of Co-based catalysts can provide a platform to investigate the role of heterointerface in reaction kinetics.Herein,we constructed a Fe-O-Co heterointerface without electronic effect by depositing FeO_(x)clusters on the oxygen vacancies of CoOOH surface.FeO_(x)/CoOOH exhibited excellent OER intrinsic activity,which can deliver the turnover frequency(TOF)of 4.56 s^(-1)at the overpotentials of 300 mV and the Tafel slope of 33 mV·dec^(-1).In-situ electrochemical impedance spectroscopy(EIS)and density functional theory(DFT)calculations demonstrated that the synergistic effect between Fe sites and Co sites confined at the Fe-O-Co heterointerface accelerated the charge transfer during OER and optimized the adsorption of oxygen intermediates,consequently enhancing OER.
基金supported by the National Key R&D Program Funding Projects (No.2018YFB1503001)the Science and Technology Plan Project of the Shanghai Science and Technology Commission (No.21DZ1207300)the Industrial Strengthening Program Projects from the Shanghai Municipal Commission of Economy and Informatization (No.GYQJ-2022-1-14)。
文摘A second-order compensation link is adopted to control voltage-controlled inverters(VCIs) in microgrid systems to enhance the performance of the power synchronization process of the inverter. The second-order compensation link is classified as both a real pole compensator(RPC) and a complex pole compensator(CPC) according to the pole position. Given a model for the VCI power output, the design process for the second-order compensation link, which is equipped with an RPC and a CPC, is detailed. Moreover, the frequency-domain compensation effects of the RPC and CPC are analyzed using the root locus and Bode diagrams of the system before and after compensation. Finally, the compensation effects of the two types of second-order compensators are compared with the commonly used high-pass filter using MATLAB/Simulink, which verifies the RPC and CPC strategies. Simulation results show that the two types of compensators designed in this study can effectively increase the system cutting frequency and improve the phase margin in the frequency domain while accelerating the power synchronization process, simultaneously making it smoother and reducing overshoot in the time domain. The RPC has better gain robustness, whereas the CPC has better time constant robustness. By implementing an RPC or a CPC, the dynamic time of the power synchronization compensation strategy is reduced within 0.5 s, and the overshoot is reduced within 10% in the experiments with two inverters.
