Aqueous film-forming foams(AFFFs)are the primary source of toxic perfluoroalkyl and polyfluoroalkyl substances(PFAS)in wastewater.Thus,it is urgent to develop a facile and fast method for identifying fluorosurfactants...Aqueous film-forming foams(AFFFs)are the primary source of toxic perfluoroalkyl and polyfluoroalkyl substances(PFAS)in wastewater.Thus,it is urgent to develop a facile and fast method for identifying fluorosurfactants in commercially available AFFFs.In this work,fluorine nuclear magnetic resonance(^(19)F NMR)spectroscopy was optimized to measure AFFFs directly with the extra addition of 5%D_(2)O as the locking reagent,and high-quality spectra could be acquired within 4 min(0.1%fluorosurfactant content).Recovery experiments demonstrated that the use of different AFFFs had no marked influence on the quantitative analysis of fluorosurfactants.Such method works with low-field NMR spectroscopy(1.4 T)as well.Two-dimensional(2D)^(19)F COSY NMR was used to make signal assignments for different fluorosurfactant derivatives.The optimized ^(19)F NMR could quantify the commercially available fluorosurfactants in different AFFFs,identify them being in either the perfluorooctane sulfonate(PFOS)or fluorotelomer sulfonic acid(FTS)categories,and distinguish the head-group of PFOS and FTS derivatives,which exhibits great potentials in the developments of relevant commercial detections.展开更多
As members of doubly salient magnetless linear machines,linear variable flux reluctance(LVFR)and wound field flux reversal(LWFFR)machines inherit the merits of conventional magnetless linear machines such as low cost,...As members of doubly salient magnetless linear machines,linear variable flux reluctance(LVFR)and wound field flux reversal(LWFFR)machines inherit the merits of conventional magnetless linear machines such as low cost,high flux adjustment capability and high reliability.Furthermore,like linear switched reluctance machine,they have a very simple and compact long secondary,which are very attractive for long stroke applications.However,low force capability is their major defect.To solve this issue,new LVFR and LWFFR machine topologies were proposed in recent work,while lacking studies on their force improvement mechanism and further force evaluation.In this paper,LVFR and LWFFR machines with improved force performance are comparatively studied with the emphasis on their force capabilities.The operation principle of the two machines is analyzed based on magnetic field harmonics produced by flux modulation.Contributions of air-gap flux density harmonic components to no-load back electromagnetic forces of the two machines are analyzed and the average force equation is derived.Moreover,force capabilities of the both machines are investigated by means of the time-stepping finite-element analysis to verify the theoretical analysis.展开更多
Objective:To explore the application effect of microteaching combined with problem-based learning(PBL)teaching mode in teaching clinical nursing interns in otorhinolaryngology department.Methods:A total of 72 nursing ...Objective:To explore the application effect of microteaching combined with problem-based learning(PBL)teaching mode in teaching clinical nursing interns in otorhinolaryngology department.Methods:A total of 72 nursing students who interned in our hospital from June 2022 to February 2023 were selected,and all of them were comprehensively trained in basic theoretical knowledge as well as practical skills before the beginning of their learning tasks.The students were randomly divided into the control group and the experimental group,with 36 students in each group.The control group was taught using the traditional clinical nursing teaching mode,and the experimental group was taught using microteaching combined with the PBL teaching mode,subsequently comparing the differences between the two groups of interns in the degree of mastery of theoretical knowledge,hands-on skills,teamwork ability,patient satisfaction,and other aspects.Results:In terms of mastery of theoretical knowledge,the interns in the experimental group(97.22%)were significantly better than that of the control group(75.00%)(P<0.05);the interns in the experimental group had significantly better practical skills(77.78%)than that of the control group(55.56%)(P<0.05);the interns in the experimental group had significantly better teamwork ability than the control group(P<0.05);through the questionnaire survey,it was found that students’satisfaction with teaching in the experimental group(97.22%)was also significantly higher than that in the control group(75.00%)(P<0.05).Conclusion:The application of microteaching combined with PBL teaching mode in the teaching of clinical nursing interns in otorhinolaryngology department achieved significant results.It can not only improve the professional knowledge and application ability of nursing students,but also cultivate their independent thinking,problem-solving skill,as well as teamwork ability.It can also improve the teaching quality and patient satisfaction,and contribute positively to the development of medical education.展开更多
Compensating for photovoltaic(PV)power forecast errors is an important function of energy storage systems.As PV power outputs have strong random fluctuations and uncertainty,it is difficult to satisfy the grid-connect...Compensating for photovoltaic(PV)power forecast errors is an important function of energy storage systems.As PV power outputs have strong random fluctuations and uncertainty,it is difficult to satisfy the grid-connection requirements using fixed energy storage capacity configuration methods.In this paper,a method of configuring energy storage capacity is proposed based on the uncertainty of PV power generation.A k-means clustering algorithm is used to classify weather types based on differences in solar irradiance.The power forecast errors in different weather types are analyzed,and an energy storage system is used to compensate for the errors.The kernel density estimation is used to fit the distributions of the daily maximum power and maximum capacity requirements of the energy storage system;the power and capacity of the energy storage unit are calculated at different confidence levels.The optimized energy storage configuration of a PV plant is presented according to the calculated degrees of power and capacity satisfaction.The proposed method was validated using actual operating data from a PV power station.The results indicated that the required energy storage can be significantly reduced while compensating for power forecast errors.展开更多
Silicon has a large impact on the energy supply and economy in the modern world. In industry, high purity silicon is firstly prepared by carbothermic reduction of silica with the produced raw silicon being further ref...Silicon has a large impact on the energy supply and economy in the modern world. In industry, high purity silicon is firstly prepared by carbothermic reduction of silica with the produced raw silicon being further refined by a modified Siemens method. This process suffers from the disadvantages of high cost and contaminant release and emission. As an alternative, the molten salt electrolysis approach, particularly the FFC Cambridge Process(FFC: Fray-Farthing-Chen), could realize high purity silicon products with morphology-controllable nanostructures at low or mild temperatures(generally 650–900 ℃). In this article, we review the development, reaction mechanisms, and electrolysis conditions of silicon production by the FFC Cambridge Process. Applications of the silicon products from electrolysis in molten salts are also discussed in terms of energy applications, including using them as the photovoltaic element in solar cells and as the charge storage phase in the negative electrode(negatrode) of lithium ion batteries.展开更多
Oxygen evolution reaction(OER)is the dominant step for plenty of energy conversion and storage technologies.However,the OER suffers from sluggish kinetics and high overpotential due to its complex 4‐electron/proton t...Oxygen evolution reaction(OER)is the dominant step for plenty of energy conversion and storage technologies.However,the OER suffers from sluggish kinetics and high overpotential due to its complex 4‐electron/proton transfer mechanism.Thus,developing efficient electrocatalysts is particularly urgent to accelerate OER catalysis but still remains a great challenge.Herein,we have synthesized the novel cobalt molybdate nanoflakes(CoMoO_(4)‐O_(v)‐n@GF)with adjustable oxygen vacancies contents by in situ constructing CoMoO_(4) nanoflakes on graphite felt(GF)and annealing treatment under the reduction atmosphere.The best‐performing CoMoO_(4)‐O_(v)‐2@GF with optimal oxygen vacancies content shows splendid electrocatalytic performance with the low overpotential(296 mV at 10 mA cm^(‒2))and also small Tafel slope(62.4 mV dec^(‒1))in alkaline solution,which are comparable to those of the RuO_(2)@GF.The experimental and the density functional theory calculations results reveal that the construction of optimal oxygen vacancies in CoMoO_(4) can expose more active sites,narrow the band‐gap to increase the electrical conductivity,and modulate the free energy of the OER‐related intermediates to accelerate OER kinetics,thus improving its intrinsic activity.展开更多
Surfactant-grafted Polyacrylamide (S-PAM) serves as a novel oil displacement agent in oilfield. Its toxicity and the impact on the occupational safety are unclear. The analysis on composition and chemical structure of...Surfactant-grafted Polyacrylamide (S-PAM) serves as a novel oil displacement agent in oilfield. Its toxicity and the impact on the occupational safety are unclear. The analysis on composition and chemical structure of S-PAM shows that due to its instability the harmful ammonia gas may be generated during the operation of S-PAM or high temperature. The toxicity and safety evaluation of the S-PAM were analyzed, and suggestions on the protection were proposed. It can provide a safe and healthy working environment for the operators with enormous social and economic benefits.展开更多
Purpose:The goal of our research is to suggest specific Web metrics that are useful for evaluating and improving user navigation experience on informational websites.Design/methodology/approach:We revised metrics in a...Purpose:The goal of our research is to suggest specific Web metrics that are useful for evaluating and improving user navigation experience on informational websites.Design/methodology/approach:We revised metrics in a Web forensic framework proposed in the literature and defined the metrics of footprint,track and movement.Data were obtained from user clickstreams provided by a real estate site’s administrators.There were two phases of data analysis with the first phase on navigation behavior based on user footprints and tracks,and the second phase on navigational transition patterns based on user movements.Findings:Preliminary results suggest that the apartment pages were heavily-trafficked while the agent pages and related information pages were underused to a great extent.Navigation within the same category of pages was prevalent,especially when users navigated among the regional apartment listings.However,navigation of these pages was found to be inefficient.Research limitations:The suggestions for navigation design optimization provided in the paper are specific to this website,and their applicability to other online environments needs to be verified.Preference predications or personal recommendations are not made during the current stage of research.Practical implications:Our clickstream data analysis results offer a base for future research.Meanwhile,website administrators and managers can make better use of the readily available clickstream data to evaluate the effectiveness and efficiency of their site navigation design.Originality/value:Our empirical study is valuable to those seeking analysis metrics for evaluating and improving user navigation experience on informational websites based on clickstream data.Our attempts to analyze the log file in terms of footprint,track and movement will enrich the utilization of such trace data to engender a deeper understanding of users’within-site navigation behavior.展开更多
[Objectives]This study was conducted to explore the most suitable irrigation integration mode for"Tinglin snow melon"in Jinshan District,Shanghai City.[Methods]With the field water holding capacity as the st...[Objectives]This study was conducted to explore the most suitable irrigation integration mode for"Tinglin snow melon"in Jinshan District,Shanghai City.[Methods]With the field water holding capacity as the standard,different upper limits of irrigation were set in the four growth stage of snow melon to investigate the effects of such three water-saving irrigation modes as single-row drip irrigation pipes,double-row drip irrigation pipes and drip arrows on the traits and yield of melon plants under the same growth conditions.[Results]The results showed that different irrigation modes had certain effects on the growth,comprehensive quality and yield of snow melon,and the drop arrow mode was better than other two modes.Under the drop arrow mode,the number of snow melons was the highest,7.34 per plant,and the yield was the highest,reaching 15463.35 kg/hm^(2),showing the best yield increasing effect.In addition,the contents of soluble solids and vitamin C in the drop arrow mode were higher than those in the drip irrigation pipe mode.[Conclusions]Compared with other irrigation methods,the drop arrow mode was more suitable for the production of snow melon.展开更多
Surfactant-grafted Polyacrylamide (S-PAM), as a new type of oil displacement agent in oilfield, integrates the advantages of both polymer and surfactant. The oil displacement experiments using S-PAM in multi-blocks re...Surfactant-grafted Polyacrylamide (S-PAM), as a new type of oil displacement agent in oilfield, integrates the advantages of both polymer and surfactant. The oil displacement experiments using S-PAM in multi-blocks reveal that in-use S-PAMs differ greatly from ordinary polymers and the physical properties remain unclear. This is unfavorable to production application and occupational health and safety. This research compared the physical properties of S-PAMs selected from two producing area, including specific gravity, particle size and viscosity. The compared results showed that specific gravity of Lianhua S-PAM was smaller than Haibo S-PAM;Lianhua S-PAM and Haibo S-PAM accounted for the 93.8% and 80.1% of the total amount via the particles with 40 mesh and 60 mesh;the viscosity of Lianhua S-PAM was higher than that of Haibo S-PAM in two S-PAM solutions with different concentrations.展开更多
Surfactant-grafted Polyacrylamide (S-PAM) serves as a novel oil displacement agent in oilfield. The analysis on composition of S-PAM shows that due to its instability the harmful ammonia gas may be generated during th...Surfactant-grafted Polyacrylamide (S-PAM) serves as a novel oil displacement agent in oilfield. The analysis on composition of S-PAM shows that due to its instability the harmful ammonia gas may be generated during the operation of S-PAM or high temperature. In this paper, stability of S-PAM was studied by measuring the ammonia release from solid and aqueous S-PAM at different temperatures. The results showed that ammonia release of the solid S-PAM was increased with raising temperature. The ammonia release from S-PAM produced by Haibo Company is more than one from Lianhua in the solid state. The ammonia emissions from Lianhua S-PAM are slightly higher than Haibo one in the solutions prepared by both clean water and oilfield water.展开更多
Surfactant-grafted Polyacrylamide (S-PAM) serves as a kind of economical and efficient flooding agents for its single component in the enhanced oil recovery in Daqing oilfield in China. The oil displacement experiment...Surfactant-grafted Polyacrylamide (S-PAM) serves as a kind of economical and efficient flooding agents for its single component in the enhanced oil recovery in Daqing oilfield in China. The oil displacement experiments using S-PAM in multi-blocks revealed that in-use S-PAMs differ greatly from ordinary polymers. Aiming at making clear hazardous substances of S-PAM powder, this study characterized two commonly used S-PAMs in oil field through chemical analysis and instrumental analysis, and analyzed the toxic and hazardous gases of the two S-PAM powders.展开更多
Surfactant-grafted Polyacrylamide (S-PAM) flooding is a new technique used in Daqiang Oil Field in China and also a novel way for improving the recovery efficiency of primary oil layer after polymer flooding. S-PAM fl...Surfactant-grafted Polyacrylamide (S-PAM) flooding is a new technique used in Daqiang Oil Field in China and also a novel way for improving the recovery efficiency of primary oil layer after polymer flooding. S-PAM flooding technology is perfected gradually with the proceeding of multiple polymer surfactant oil displacement tests. Test results showed that the S-PAM used in field was greatly different with conventional ones. Therefore, it is necessary to study the chemical structure of S-PAM. Aiming at making clear the chemical structure of S-PAM, this study characterized the two commonly used S-PAM in oil field through chemical analysis and Fourier infrared spectrometer detection and analyzed the main composition and chemical structure of the two S-PAM.展开更多
Mesoporous TiO2 ceramic films have been prepared upon the Ti alloy substrate by the micro-arc oxidation (MAO) technology. To enhance the photo-catalytic property of the films, Eu2O3 particles were added into the elect...Mesoporous TiO2 ceramic films have been prepared upon the Ti alloy substrate by the micro-arc oxidation (MAO) technology. To enhance the photo-catalytic property of the films, Eu2O3 particles were added into the electrolyte solution of Na2CO3/Na2SiO3. Scanning electron microscope (SEM), energy dispersive (EDS), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) are employed to characterize the modified films. Diffuse reflectance spectra (DRS) test, photo-generated current test and photo decomposition test are applied to evaluate the photo-catalytic property of the modified films. The results show that Eu2O3 transformed into one-dimensional (1-D) nano-wires embedded within the composite film, and the film has high photo-catalytic property.展开更多
Ubiquitously transcribed tetratricopeptide repeat on chromosome X(UTX),also known as lysine(K)-specific demethylase 6A(KDM6A),functions as a tumor suppressor gene or oncogene depending on the tumor type and context.Ho...Ubiquitously transcribed tetratricopeptide repeat on chromosome X(UTX),also known as lysine(K)-specific demethylase 6A(KDM6A),functions as a tumor suppressor gene or oncogene depending on the tumor type and context.However,its tumor-suppressive mechanisms remain largely unknown.Here,we investigated the clinical significance and biological effects of UTX expression in pancreatic ductal adenocarcinoma(PDA)and determined the potential mechanisms of its dysregulation.UTX expression and its association with clinicopathologic characteristics of PDA patients were analyzed using immunohistochemistry.UTX mRNA and protein expression and their regulation in PDA cell lines were measured using quantitative polymerase chain reaction and Western blot analyses.The biological functions of UTX in PDA cell growth,migration,and invasion were determined using gain-and loss-of-function assays with both in vitro and in vivo animal models.UTX expression was reduced in human PDA cell lines and specimens.Low UTX expression was associated with poor differentiation and prognosis in PDA.Forced UTX expression inhibited PDA proliferation,migration,and invasion in vitro and PDA growth and metastasis in vivo,whereas knockdown of UTX expression did the opposite.Mechanistically,UTX expression was trans-activated by GATA6 activation.GATA6-mediated PDA progression could be blocked,at least partially,by silencing UTX expression.In conclusion,loss of GATA6-mediated UTX expression was evident in human PDA and restored UTX expression suppressed PDA growth and metastasis.Thus,UTX is a tumor suppressor in PDA and may serve as a prognostic biomarker and therapeutic target.展开更多
In this study,a class of rare earth composite sandwich phthalocyanines(MPcs,M=La,Y,Yb,Sc) were prepared and compounded with graphene and carbon nanotubes to obtain MPc/Gr and MPc/CNTs composites.The electrocatalytic b...In this study,a class of rare earth composite sandwich phthalocyanines(MPcs,M=La,Y,Yb,Sc) were prepared and compounded with graphene and carbon nanotubes to obtain MPc/Gr and MPc/CNTs composites.The electrocatalytic behaviors of MPc/Gr and MPc/CNTs electrodes were further investigated.The results show that the central rare earth metal has a large influence on the electrocatalytic performance.For the MPcs/Gr samples,ScPc with the smallest ionic radius and molecular size can be more uniformly dispersed in graphene,and the hydrogen precipitation overpotential of ScPc/Gr electrode is514 mV,corresponding to a Tafel slope of 148 mV/dec,with better electrocatalytic performance than other rare earth metal phthalocyanines.As for the MPc/CNTs composites,LaPc,which has the largest ionic radius and molecular size,is more uniformly dispersed on the surface of CNTs,so that the LaPc/CNT electrode exhibits the best LSV performance with the smallest corresponding Tafel slope(176 mV/dec).The main reason is the different binding modes of MPcs molecules in Gr and CNTs.When rare earth phthalocyanine is combined with layered graphene,the smallest size of rare earth phthalocyanine(ScPc)is more easily embedded in the graphene layer,resulting in better homogeneity of the composite,larger effective contact area and better electrocatalytic performance.In contrast,when rare earth phthalocyanine is bound to carbon nanotubes in a tubular structure,it is mainly bound by attaching to the surface or being entangled by the carbon nanotubes.In this case,the rare-earth phthalocyanine molecules(LaPc)with larger layer spacing can provide more contact area with CNTs,forming a more uniform and effective composite,which eventually provides more active sites and better electrocatalytic performance.展开更多
Transcriptional factor Forkhead box M1(FOXM1)plays an important role in pancreatic ductal adenocarcinoma(PDAC)development and progression.The molecular mechanisms underlying its dysregulation remain unclear.We identif...Transcriptional factor Forkhead box M1(FOXM1)plays an important role in pancreatic ductal adenocarcinoma(PDAC)development and progression.The molecular mechanisms underlying its dysregulation remain unclear.We identified and functionally validated the microRNAs(miRNAs)that critically regulate FOXM1 expression in PDAC.The expression levels of miRNA-23a(miR-23a-3p and-5p)were altered in PDAC cell lines and their effects on FOXM1 signaling and cell proliferation and migration and tumorigenesis were examined in vitro and in vivo using mouse PDAC models.Compared with non-tumor pancreatic tissues,PDAC tissues and cell lines exhibited significantly reduced levels of miR-23a expression.Reduced miR-23a expression and concomitant increase in FOXM1 expression were also observed in acinar-toductal metaplasia and pancreatic intraepithelial neoplasia,the major premalignant lesions of PDAC.Transgenic expression of miR-23a reduced the expression of FOXM1 and suppressed cell proliferation and migration in PDAC cells,whereas the inhibitors of miR-23a did the opposite.Loss or reduced levels of miR-23a increased the levels of FOXM1 expression,while increased expression of FOXM1 down-regulated miR-23a expression,suggesting that miR-23a and FOXM1 were mutual negative regulators of their expression in PDAC cells.Therefore,the miR-23a/FOXM1 signaling axis is important in PDAC initiation and progression and could serve as an interventional or therapeutic target for patients with early or late stages of PDAC.展开更多
To explore the impact of ursodeoxycholic acid(UDCA)on severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)infection and clinical outcomes in patients with autoimmune liver disease(AILD).Patients diagnosed with ...To explore the impact of ursodeoxycholic acid(UDCA)on severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)infection and clinical outcomes in patients with autoimmune liver disease(AILD).Patients diagnosed with AILD were enrolled and divided into a UDCA group and a non-UDCA group based on whether they received UDCA treatment.Relevant data were collected regarding AILD diagnosis,treatment,biochemical indicators,and imaging examination.The incidence of SARS-CoV-2 infection and the prognosis of AILD patients were observed.A total of 1,138 patients completed follow-up.The usage rate of hormone(P=0.003)and immunosuppressant(P=0.001)used for treating AILD in the non-UDCA group was markedly lower than in the UDCA group.The UDCA usage rate was markedly lower in SARS-CoV-2 infected patients than in uninfected patients(P=0.003).The rate of SARS-CoV-2 infection in the non-UDCA group was significantly higher than in the UDCA group(P=0.018).Logistic regression analysis showed that UDCA use(P=0.003)was correlated to a lower incidence of SARS-CoV-2,while immunosuppressant use(P=0.017)increased the incidence.Recovery time from SARS-CoV-2 infection was markedly longer for those receiving UDCA treatment than those in the non-UDCA group(P=0.018).UDCA is associated with low SARS-CoV-2 incidence in AILD patients,while immunosuppressant increases its incidence instead.Patients receiving UDCA treatment have a longer recovery time after being infected.展开更多
基金financially supported by the“National Key R&D Program of China”(No.2022YFC3004900)“Basic Research Fund of TFRI”(No.2022SJ07)。
文摘Aqueous film-forming foams(AFFFs)are the primary source of toxic perfluoroalkyl and polyfluoroalkyl substances(PFAS)in wastewater.Thus,it is urgent to develop a facile and fast method for identifying fluorosurfactants in commercially available AFFFs.In this work,fluorine nuclear magnetic resonance(^(19)F NMR)spectroscopy was optimized to measure AFFFs directly with the extra addition of 5%D_(2)O as the locking reagent,and high-quality spectra could be acquired within 4 min(0.1%fluorosurfactant content).Recovery experiments demonstrated that the use of different AFFFs had no marked influence on the quantitative analysis of fluorosurfactants.Such method works with low-field NMR spectroscopy(1.4 T)as well.Two-dimensional(2D)^(19)F COSY NMR was used to make signal assignments for different fluorosurfactant derivatives.The optimized ^(19)F NMR could quantify the commercially available fluorosurfactants in different AFFFs,identify them being in either the perfluorooctane sulfonate(PFOS)or fluorotelomer sulfonic acid(FTS)categories,and distinguish the head-group of PFOS and FTS derivatives,which exhibits great potentials in the developments of relevant commercial detections.
基金supported in part by the National Natural Science Foundation of China under Grant 51977099 and Grant 52177044in part by the Hong Kong Scholars Program under Grant XJ2019031+2 种基金in part by the China Postdoctoral Science Foundation under Grant 2019T120395in part by the Natural Science Foundation of Jiangsu Higher Education Institutions under Grant 21KJA470004in part by the Priority Academic Program Development of Jiangsu Higher Education Institutions.
文摘As members of doubly salient magnetless linear machines,linear variable flux reluctance(LVFR)and wound field flux reversal(LWFFR)machines inherit the merits of conventional magnetless linear machines such as low cost,high flux adjustment capability and high reliability.Furthermore,like linear switched reluctance machine,they have a very simple and compact long secondary,which are very attractive for long stroke applications.However,low force capability is their major defect.To solve this issue,new LVFR and LWFFR machine topologies were proposed in recent work,while lacking studies on their force improvement mechanism and further force evaluation.In this paper,LVFR and LWFFR machines with improved force performance are comparatively studied with the emphasis on their force capabilities.The operation principle of the two machines is analyzed based on magnetic field harmonics produced by flux modulation.Contributions of air-gap flux density harmonic components to no-load back electromagnetic forces of the two machines are analyzed and the average force equation is derived.Moreover,force capabilities of the both machines are investigated by means of the time-stepping finite-element analysis to verify the theoretical analysis.
文摘Objective:To explore the application effect of microteaching combined with problem-based learning(PBL)teaching mode in teaching clinical nursing interns in otorhinolaryngology department.Methods:A total of 72 nursing students who interned in our hospital from June 2022 to February 2023 were selected,and all of them were comprehensively trained in basic theoretical knowledge as well as practical skills before the beginning of their learning tasks.The students were randomly divided into the control group and the experimental group,with 36 students in each group.The control group was taught using the traditional clinical nursing teaching mode,and the experimental group was taught using microteaching combined with the PBL teaching mode,subsequently comparing the differences between the two groups of interns in the degree of mastery of theoretical knowledge,hands-on skills,teamwork ability,patient satisfaction,and other aspects.Results:In terms of mastery of theoretical knowledge,the interns in the experimental group(97.22%)were significantly better than that of the control group(75.00%)(P<0.05);the interns in the experimental group had significantly better practical skills(77.78%)than that of the control group(55.56%)(P<0.05);the interns in the experimental group had significantly better teamwork ability than the control group(P<0.05);through the questionnaire survey,it was found that students’satisfaction with teaching in the experimental group(97.22%)was also significantly higher than that in the control group(75.00%)(P<0.05).Conclusion:The application of microteaching combined with PBL teaching mode in the teaching of clinical nursing interns in otorhinolaryngology department achieved significant results.It can not only improve the professional knowledge and application ability of nursing students,but also cultivate their independent thinking,problem-solving skill,as well as teamwork ability.It can also improve the teaching quality and patient satisfaction,and contribute positively to the development of medical education.
基金supported by Nation Key R&D Program of China(2021YFE0102400).
文摘Compensating for photovoltaic(PV)power forecast errors is an important function of energy storage systems.As PV power outputs have strong random fluctuations and uncertainty,it is difficult to satisfy the grid-connection requirements using fixed energy storage capacity configuration methods.In this paper,a method of configuring energy storage capacity is proposed based on the uncertainty of PV power generation.A k-means clustering algorithm is used to classify weather types based on differences in solar irradiance.The power forecast errors in different weather types are analyzed,and an energy storage system is used to compensate for the errors.The kernel density estimation is used to fit the distributions of the daily maximum power and maximum capacity requirements of the energy storage system;the power and capacity of the energy storage unit are calculated at different confidence levels.The optimized energy storage configuration of a PV plant is presented according to the calculated degrees of power and capacity satisfaction.The proposed method was validated using actual operating data from a PV power station.The results indicated that the required energy storage can be significantly reduced while compensating for power forecast errors.
基金supported by the National Natural Science Foundation of China (No.51602234)Ningbo Municipal Government (3315 Plan and 2014A35001-1)UK Engineering and Physical Science Research Council (EP/J000582/1, GR/R68078)。
文摘Silicon has a large impact on the energy supply and economy in the modern world. In industry, high purity silicon is firstly prepared by carbothermic reduction of silica with the produced raw silicon being further refined by a modified Siemens method. This process suffers from the disadvantages of high cost and contaminant release and emission. As an alternative, the molten salt electrolysis approach, particularly the FFC Cambridge Process(FFC: Fray-Farthing-Chen), could realize high purity silicon products with morphology-controllable nanostructures at low or mild temperatures(generally 650–900 ℃). In this article, we review the development, reaction mechanisms, and electrolysis conditions of silicon production by the FFC Cambridge Process. Applications of the silicon products from electrolysis in molten salts are also discussed in terms of energy applications, including using them as the photovoltaic element in solar cells and as the charge storage phase in the negative electrode(negatrode) of lithium ion batteries.
文摘Oxygen evolution reaction(OER)is the dominant step for plenty of energy conversion and storage technologies.However,the OER suffers from sluggish kinetics and high overpotential due to its complex 4‐electron/proton transfer mechanism.Thus,developing efficient electrocatalysts is particularly urgent to accelerate OER catalysis but still remains a great challenge.Herein,we have synthesized the novel cobalt molybdate nanoflakes(CoMoO_(4)‐O_(v)‐n@GF)with adjustable oxygen vacancies contents by in situ constructing CoMoO_(4) nanoflakes on graphite felt(GF)and annealing treatment under the reduction atmosphere.The best‐performing CoMoO_(4)‐O_(v)‐2@GF with optimal oxygen vacancies content shows splendid electrocatalytic performance with the low overpotential(296 mV at 10 mA cm^(‒2))and also small Tafel slope(62.4 mV dec^(‒1))in alkaline solution,which are comparable to those of the RuO_(2)@GF.The experimental and the density functional theory calculations results reveal that the construction of optimal oxygen vacancies in CoMoO_(4) can expose more active sites,narrow the band‐gap to increase the electrical conductivity,and modulate the free energy of the OER‐related intermediates to accelerate OER kinetics,thus improving its intrinsic activity.
文摘Surfactant-grafted Polyacrylamide (S-PAM) serves as a novel oil displacement agent in oilfield. Its toxicity and the impact on the occupational safety are unclear. The analysis on composition and chemical structure of S-PAM shows that due to its instability the harmful ammonia gas may be generated during the operation of S-PAM or high temperature. The toxicity and safety evaluation of the S-PAM were analyzed, and suggestions on the protection were proposed. It can provide a safe and healthy working environment for the operators with enormous social and economic benefits.
基金supported by the National Natural Science Foundation of China(Grant No.:71203163)the Foundation for Humanities and Social Sciences of the Chinese Ministry of Education(Grant No.:12YJC870011)
文摘Purpose:The goal of our research is to suggest specific Web metrics that are useful for evaluating and improving user navigation experience on informational websites.Design/methodology/approach:We revised metrics in a Web forensic framework proposed in the literature and defined the metrics of footprint,track and movement.Data were obtained from user clickstreams provided by a real estate site’s administrators.There were two phases of data analysis with the first phase on navigation behavior based on user footprints and tracks,and the second phase on navigational transition patterns based on user movements.Findings:Preliminary results suggest that the apartment pages were heavily-trafficked while the agent pages and related information pages were underused to a great extent.Navigation within the same category of pages was prevalent,especially when users navigated among the regional apartment listings.However,navigation of these pages was found to be inefficient.Research limitations:The suggestions for navigation design optimization provided in the paper are specific to this website,and their applicability to other online environments needs to be verified.Preference predications or personal recommendations are not made during the current stage of research.Practical implications:Our clickstream data analysis results offer a base for future research.Meanwhile,website administrators and managers can make better use of the readily available clickstream data to evaluate the effectiveness and efficiency of their site navigation design.Originality/value:Our empirical study is valuable to those seeking analysis metrics for evaluating and improving user navigation experience on informational websites based on clickstream data.Our attempts to analyze the log file in terms of footprint,track and movement will enrich the utilization of such trace data to engender a deeper understanding of users’within-site navigation behavior.
基金Shanghai Agriculture Applied Technology Development Program,China(Grant No.T20180304)Jinshan District Science and Technology Innovation Fund Project(Grant No.T20200115).
文摘[Objectives]This study was conducted to explore the most suitable irrigation integration mode for"Tinglin snow melon"in Jinshan District,Shanghai City.[Methods]With the field water holding capacity as the standard,different upper limits of irrigation were set in the four growth stage of snow melon to investigate the effects of such three water-saving irrigation modes as single-row drip irrigation pipes,double-row drip irrigation pipes and drip arrows on the traits and yield of melon plants under the same growth conditions.[Results]The results showed that different irrigation modes had certain effects on the growth,comprehensive quality and yield of snow melon,and the drop arrow mode was better than other two modes.Under the drop arrow mode,the number of snow melons was the highest,7.34 per plant,and the yield was the highest,reaching 15463.35 kg/hm^(2),showing the best yield increasing effect.In addition,the contents of soluble solids and vitamin C in the drop arrow mode were higher than those in the drip irrigation pipe mode.[Conclusions]Compared with other irrigation methods,the drop arrow mode was more suitable for the production of snow melon.
文摘Surfactant-grafted Polyacrylamide (S-PAM), as a new type of oil displacement agent in oilfield, integrates the advantages of both polymer and surfactant. The oil displacement experiments using S-PAM in multi-blocks reveal that in-use S-PAMs differ greatly from ordinary polymers and the physical properties remain unclear. This is unfavorable to production application and occupational health and safety. This research compared the physical properties of S-PAMs selected from two producing area, including specific gravity, particle size and viscosity. The compared results showed that specific gravity of Lianhua S-PAM was smaller than Haibo S-PAM;Lianhua S-PAM and Haibo S-PAM accounted for the 93.8% and 80.1% of the total amount via the particles with 40 mesh and 60 mesh;the viscosity of Lianhua S-PAM was higher than that of Haibo S-PAM in two S-PAM solutions with different concentrations.
文摘Surfactant-grafted Polyacrylamide (S-PAM) serves as a novel oil displacement agent in oilfield. The analysis on composition of S-PAM shows that due to its instability the harmful ammonia gas may be generated during the operation of S-PAM or high temperature. In this paper, stability of S-PAM was studied by measuring the ammonia release from solid and aqueous S-PAM at different temperatures. The results showed that ammonia release of the solid S-PAM was increased with raising temperature. The ammonia release from S-PAM produced by Haibo Company is more than one from Lianhua in the solid state. The ammonia emissions from Lianhua S-PAM are slightly higher than Haibo one in the solutions prepared by both clean water and oilfield water.
文摘Surfactant-grafted Polyacrylamide (S-PAM) serves as a kind of economical and efficient flooding agents for its single component in the enhanced oil recovery in Daqing oilfield in China. The oil displacement experiments using S-PAM in multi-blocks revealed that in-use S-PAMs differ greatly from ordinary polymers. Aiming at making clear hazardous substances of S-PAM powder, this study characterized two commonly used S-PAMs in oil field through chemical analysis and instrumental analysis, and analyzed the toxic and hazardous gases of the two S-PAM powders.
文摘Surfactant-grafted Polyacrylamide (S-PAM) flooding is a new technique used in Daqiang Oil Field in China and also a novel way for improving the recovery efficiency of primary oil layer after polymer flooding. S-PAM flooding technology is perfected gradually with the proceeding of multiple polymer surfactant oil displacement tests. Test results showed that the S-PAM used in field was greatly different with conventional ones. Therefore, it is necessary to study the chemical structure of S-PAM. Aiming at making clear the chemical structure of S-PAM, this study characterized the two commonly used S-PAM in oil field through chemical analysis and Fourier infrared spectrometer detection and analyzed the main composition and chemical structure of the two S-PAM.
文摘Mesoporous TiO2 ceramic films have been prepared upon the Ti alloy substrate by the micro-arc oxidation (MAO) technology. To enhance the photo-catalytic property of the films, Eu2O3 particles were added into the electrolyte solution of Na2CO3/Na2SiO3. Scanning electron microscope (SEM), energy dispersive (EDS), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) are employed to characterize the modified films. Diffuse reflectance spectra (DRS) test, photo-generated current test and photo decomposition test are applied to evaluate the photo-catalytic property of the modified films. The results show that Eu2O3 transformed into one-dimensional (1-D) nano-wires embedded within the composite film, and the film has high photo-catalytic property.
基金supported by the Jiangxi Science Fund for Distinguished Young Scholars(China)(No.20212ACB216012)the Funding Program for Academic and Technical Leaders of Main Subjects in Jiangxi Province,China(No.20213BCJ22009 to H.Q.Zhang)+4 种基金the National Natural Science Foundation of China(No.81460372 to H.Q.Zhang,No.81960528 to S.Zheng)the Hainan Province Science and Technology special fund(China)(ZDYF2020132 to S.Zheng)the Innovation Platform for Academicians of Hainan Province(China)(YSPTZX202208 to S.Zheng)Hainan Province Clinical Medical Center(QWYH2021276)the Cardiovascular Disease Research Science Innovation Group of Hainan Medical University(China).
文摘Ubiquitously transcribed tetratricopeptide repeat on chromosome X(UTX),also known as lysine(K)-specific demethylase 6A(KDM6A),functions as a tumor suppressor gene or oncogene depending on the tumor type and context.However,its tumor-suppressive mechanisms remain largely unknown.Here,we investigated the clinical significance and biological effects of UTX expression in pancreatic ductal adenocarcinoma(PDA)and determined the potential mechanisms of its dysregulation.UTX expression and its association with clinicopathologic characteristics of PDA patients were analyzed using immunohistochemistry.UTX mRNA and protein expression and their regulation in PDA cell lines were measured using quantitative polymerase chain reaction and Western blot analyses.The biological functions of UTX in PDA cell growth,migration,and invasion were determined using gain-and loss-of-function assays with both in vitro and in vivo animal models.UTX expression was reduced in human PDA cell lines and specimens.Low UTX expression was associated with poor differentiation and prognosis in PDA.Forced UTX expression inhibited PDA proliferation,migration,and invasion in vitro and PDA growth and metastasis in vivo,whereas knockdown of UTX expression did the opposite.Mechanistically,UTX expression was trans-activated by GATA6 activation.GATA6-mediated PDA progression could be blocked,at least partially,by silencing UTX expression.In conclusion,loss of GATA6-mediated UTX expression was evident in human PDA and restored UTX expression suppressed PDA growth and metastasis.Thus,UTX is a tumor suppressor in PDA and may serve as a prognostic biomarker and therapeutic target.
基金Project supported by the National Natural Science Foundation of China(21762019)the China Postdoctoral Special Grant Program(2021T140138)+1 种基金Natural Science Foundation of Jiangxi Province(20224ACB204004)Guangdong Yangfan Innovative&Enterpreneurial Research Team Program(2016YT03N101)。
文摘In this study,a class of rare earth composite sandwich phthalocyanines(MPcs,M=La,Y,Yb,Sc) were prepared and compounded with graphene and carbon nanotubes to obtain MPc/Gr and MPc/CNTs composites.The electrocatalytic behaviors of MPc/Gr and MPc/CNTs electrodes were further investigated.The results show that the central rare earth metal has a large influence on the electrocatalytic performance.For the MPcs/Gr samples,ScPc with the smallest ionic radius and molecular size can be more uniformly dispersed in graphene,and the hydrogen precipitation overpotential of ScPc/Gr electrode is514 mV,corresponding to a Tafel slope of 148 mV/dec,with better electrocatalytic performance than other rare earth metal phthalocyanines.As for the MPc/CNTs composites,LaPc,which has the largest ionic radius and molecular size,is more uniformly dispersed on the surface of CNTs,so that the LaPc/CNT electrode exhibits the best LSV performance with the smallest corresponding Tafel slope(176 mV/dec).The main reason is the different binding modes of MPcs molecules in Gr and CNTs.When rare earth phthalocyanine is combined with layered graphene,the smallest size of rare earth phthalocyanine(ScPc)is more easily embedded in the graphene layer,resulting in better homogeneity of the composite,larger effective contact area and better electrocatalytic performance.In contrast,when rare earth phthalocyanine is bound to carbon nanotubes in a tubular structure,it is mainly bound by attaching to the surface or being entangled by the carbon nanotubes.In this case,the rare-earth phthalocyanine molecules(LaPc)with larger layer spacing can provide more contact area with CNTs,forming a more uniform and effective composite,which eventually provides more active sites and better electrocatalytic performance.
基金Guangzhou Ruiqian Biotech Company(China)(No.20230330 to TJ)the National Natural Science Foundation of China(No.82072632)+1 种基金Guangzhou Municipality Bureau of Science and Technology,Guangzhou,China(No.202102010033)the Natural Science Foundation of Guangdong Province,China(No.2022A1515012585 to KX).
文摘Transcriptional factor Forkhead box M1(FOXM1)plays an important role in pancreatic ductal adenocarcinoma(PDAC)development and progression.The molecular mechanisms underlying its dysregulation remain unclear.We identified and functionally validated the microRNAs(miRNAs)that critically regulate FOXM1 expression in PDAC.The expression levels of miRNA-23a(miR-23a-3p and-5p)were altered in PDAC cell lines and their effects on FOXM1 signaling and cell proliferation and migration and tumorigenesis were examined in vitro and in vivo using mouse PDAC models.Compared with non-tumor pancreatic tissues,PDAC tissues and cell lines exhibited significantly reduced levels of miR-23a expression.Reduced miR-23a expression and concomitant increase in FOXM1 expression were also observed in acinar-toductal metaplasia and pancreatic intraepithelial neoplasia,the major premalignant lesions of PDAC.Transgenic expression of miR-23a reduced the expression of FOXM1 and suppressed cell proliferation and migration in PDAC cells,whereas the inhibitors of miR-23a did the opposite.Loss or reduced levels of miR-23a increased the levels of FOXM1 expression,while increased expression of FOXM1 down-regulated miR-23a expression,suggesting that miR-23a and FOXM1 were mutual negative regulators of their expression in PDAC cells.Therefore,the miR-23a/FOXM1 signaling axis is important in PDAC initiation and progression and could serve as an interventional or therapeutic target for patients with early or late stages of PDAC.
基金the National Key Research and Development Program(2022YFC2603500,2022YFC2603505)Beijing Municipal Health Commission high-level public health technical personnel construction project,discipline leader-03-26,Beijing Hospitals Authority Clinical medicine Development of special funding support(XMLX 202127)+1 种基金the capital health research and development of special public health project(2022-1-2172)The Digestive Medical Coordinated Development Center of Beijing Hospitals Authority(XXZ0302).
文摘To explore the impact of ursodeoxycholic acid(UDCA)on severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)infection and clinical outcomes in patients with autoimmune liver disease(AILD).Patients diagnosed with AILD were enrolled and divided into a UDCA group and a non-UDCA group based on whether they received UDCA treatment.Relevant data were collected regarding AILD diagnosis,treatment,biochemical indicators,and imaging examination.The incidence of SARS-CoV-2 infection and the prognosis of AILD patients were observed.A total of 1,138 patients completed follow-up.The usage rate of hormone(P=0.003)and immunosuppressant(P=0.001)used for treating AILD in the non-UDCA group was markedly lower than in the UDCA group.The UDCA usage rate was markedly lower in SARS-CoV-2 infected patients than in uninfected patients(P=0.003).The rate of SARS-CoV-2 infection in the non-UDCA group was significantly higher than in the UDCA group(P=0.018).Logistic regression analysis showed that UDCA use(P=0.003)was correlated to a lower incidence of SARS-CoV-2,while immunosuppressant use(P=0.017)increased the incidence.Recovery time from SARS-CoV-2 infection was markedly longer for those receiving UDCA treatment than those in the non-UDCA group(P=0.018).UDCA is associated with low SARS-CoV-2 incidence in AILD patients,while immunosuppressant increases its incidence instead.Patients receiving UDCA treatment have a longer recovery time after being infected.
