BACKGROUND No single endoscopic feature can reliably predict the pathological nature of colorectal tumors(CRTs).AIM To establish and validate a simple online calculator to predict the pathological nature of CRTs based...BACKGROUND No single endoscopic feature can reliably predict the pathological nature of colorectal tumors(CRTs).AIM To establish and validate a simple online calculator to predict the pathological nature of CRTs based on white-light endoscopy.METHODS This was a single-center study.During the identification stage,530 consecutive patients with CRTs were enrolled from January 2015 to December 2021 as the derivation group.Logistic regression analysis was performed.A novel online calculator to predict the pathological nature of CRTs based on white-light images was established and verified internally.During the validation stage,two series of 110 images obtained using white-light endoscopy were distributed to 10 endoscopists[five highly experienced endoscopists and five less experienced endoscopists(LEEs)]for external validation before and after systematic training.RESULTS A total of 750 patients were included,with an average age of 63.6±10.4 years.Early colorectal cancer(ECRC)was detected in 351(46.8%)patients.Tumor size,left semicolon site,rectal site,acanthosis,depression and an uneven surface were independent risk factors for ECRC.The C-index of the ECRC calculator prediction model was 0.906(P=0.225,Hosmer-Lemeshow test).For the LEEs,significant improvement was made in the sensitivity,specificity and accuracy(57.6%vs 75.5%;72.3%vs 82.4%;64.2%vs 80.2%;P<0.05),respectively,after training with the ECRC online calculator prediction model.CONCLUSION A novel online calculator including tumor size,location,acanthosis,depression,and uneven surface can accurately predict the pathological nature of ECRC.展开更多
BACKGROUND Efficient and practical methods for predicting the risk of malignancy in patients with pancreatic cystic neoplasms(PCNs)are lacking.AIM To establish a nomogram-based online calculator for predicting the ris...BACKGROUND Efficient and practical methods for predicting the risk of malignancy in patients with pancreatic cystic neoplasms(PCNs)are lacking.AIM To establish a nomogram-based online calculator for predicting the risk of malignancy in patients with PCNs.METHODS In this study,the clinicopathological data of target patients in three medical centers were analyzed.The independent sample t-test,Mann–Whitney U test or chi-squared test were used as appropriate for statistical analysis.After univariable and multivariable logistic regression analysis,five independent factors were screened and incorporated to develop a calculator for predicting the risk of malignancy.Finally,the concordance index(C-index),calibration,area under the curve,decision curve analysis and clinical impact curves were used to evaluate the performance of the calculator.RESULTS Enhanced mural nodules[odds ratio(OR):4.314;95%confidence interval(CI):1.618–11.503,P=0.003],tumor diameter≥40 mm(OR:3.514;95%CI:1.138–10.849,P=0.029),main pancreatic duct dilatation(OR:3.267;95%CI:1.230–8.678,P=0.018),preoperative neutrophil-to-lymphocyte ratio≥2.288(OR:2.702;95%CI:1.008–7.244,P=0.048],and preoperative serum CA19-9 concentration≥34 U/mL(OR:3.267;95%CI:1.274–13.007,P=0.018)were independent risk factors for a high risk of malignancy in patients with PCNs.In the training cohort,the nomogram achieved a C-index of 0.824 for predicting the risk of malignancy.The predictive ability of the model was then validated in an external cohort(C-index:0.893).Compared with the risk factors identified in the relevant guidelines,the current model showed better predictive performance and clinical utility.CONCLUSION The calculator demonstrates optimal predictive performance for identifying the risk of malignancy,potentially yielding a personalized method for patient selection and decision-making in clinical practice.展开更多
The purpose of this study was to grasp current potential problems of dose error in intensity-modulated proton therapy (IMPT) plans. We were interested in dose differences of the Varian Eclipse treatment planning syste...The purpose of this study was to grasp current potential problems of dose error in intensity-modulated proton therapy (IMPT) plans. We were interested in dose differences of the Varian Eclipse treatment planning system (TPS) and the fast dose calculation method (FDC) for single-field optimization (SFO) and multi-field optimization (MFO) IMPT plans. In addition, because some authors have reported dosimetric benefit of a proton arc therapy with ultimate multi-fields in recent years, we wanted to evaluate how the number of fields and beam angles affect the differences for IMPT plans. Therefore, for one brain cancer patient with a large heterogeneity, SFO and MFO IMPT plans with various multi-angle beams were planned by the TPS. Dose distributions for each IMPT plan were calculated by both the TPS’s conventional pencil beam algorithm and the FDC. The dosimetric parameters were compared between the two algorithms. The TPS overestimated 400 - 500 cGy (RBE) for minimum dose to the CTV relative to the dose calculated by the FDC. These differences indicate clinically relevant effect on clinical results. In addition, we observed that the maximum difference in dose calculated between the TPS and the FDC was about 900 cGy (RBE) for the right optic nerve, and this quantity also has a possibility to have a clinical effect. The major difference was not seen in calculations for SFO IMPT planning and those for MFO IMPT planning. Differences between the TPS and the FDC in SFO and MFO IMPT plans depend strongly on beam arrangement and the presence of a heterogeneous body. We advocate use of a Monte Carlo method in proton treatment planning to deliver the most precise proton dose in IMPT.展开更多
Risk calculators have offered a viable tool for clinicians to stratify patients at risk of prostate cancer(PCa)and to mitigate the low sensitivity and specificity of screening prostate specific antigen(PSA).While init...Risk calculators have offered a viable tool for clinicians to stratify patients at risk of prostate cancer(PCa)and to mitigate the low sensitivity and specificity of screening prostate specific antigen(PSA).While initially based on clinical and demographic data,incorporation of multiparametric magnetic resonance imaging(MRI)and the validated prostate imaging reporting and data system suspicion scoring system has standardized and improved risk stratification beyond the use of PSA and patient parameters alone.Biopsy-naïve patients with lower risk profiles for harboring clinically significant PCa are often subjected to uncomfortable,invasive,and potentially unnecessary prostate biopsy procedures.Incorporating risk calculator data into prostate MRI reports can broaden the role of radiologists,improve communication with clinicians primarily managing these patients,and help guide clinical care in directing the screening,detection,and risk stratification of PCa.展开更多
A carbon footprint(CF)calculator was developed to apply to a Portuguese touristic accommodation to contribute to a sustainable touristic activity.Although some calculators are available online,they are related to the ...A carbon footprint(CF)calculator was developed to apply to a Portuguese touristic accommodation to contribute to a sustainable touristic activity.Although some calculators are available online,they are related to the country reality or use outdated emission factors.A calculator based on national emission factors is important.The calculator was developed in Microsoft Excel(version 365)and is based on the CO2e emissions resulting from electricity,water,fuels and food use,laundry and waste production.The calculator development involved:study the accommodation emission sources,selection the environmental indicators,determination of the emission factors and development of the CF formulas.Total CF calculation was made considering the partial CF per component,a monthly and annual comparison of each indicator’s emissions contribution using graphs.The emissions amount per overnight stay,per room,per area,were also assessed and these values were transformed into global hectare(gha).Avoided emissions calculation gives the information about the efforts in CF reduction,and two indicators were considered:electricity production from renewable energy sources and the amount of separated waste for recycling.It was considered reforestation measures to achieve carbon neutrality.This calculator incorporates four components not often used:water,laundry,waste,food,and avoided emissions.展开更多
Risk prediction models including the Prostate Health Index(phi)for prostate cancer have been well established and evaluated in the Western population.The aim of this study is to build phi-based risk calculators in a p...Risk prediction models including the Prostate Health Index(phi)for prostate cancer have been well established and evaluated in the Western population.The aim of this study is to build phi-based risk calculators in a prostate biopsy population and evaluate their performanee in predicting prostate cancer(PCa)and high-grade PCa(Gleason score 27)in the Chinese population.We developed risk calculators based on 635 men who underwent initial prostate biopsy.Then,we validated the performance of prostate-specific antigen(PSA),phi,and the risk calculators in an additional observational cohort of 1045 men.We observed that the phi-based risk calculators(risk calculators 2 and 4)outperformed the PSA-based risk calculator for predicting PCa and high-grade PCa in the training cohort.In the validation study,the area under the receiver operating characteristic curve(AUC)for risk calculators 2 and 4 reached 0.91 and 0.92,respectively,for predicting PCa and high-grade PCa,respectively;the AUC values were better than those for risk calculator 1(PSA-based model with an AUC of 0.81 and 0.82,respectively)(all P<0.001).Such superiority was also observed in the stratified population with PSA ranging from 2.0 ng ml^-1 to 10.0 ng ml^-1.Decision curves confirmed that a considerable proportion of unnecessary biopsies could be avoided while applying phi-based risk calculators.In this study,we showed that,compared to risk calculators without phi,phi-based risk calculators exhibited superior discrimination and calibration for PCa in the Chinese biopsy population.Applying these risk calculators also considerably reduced the number of unnecessary biopsies for PCa.展开更多
This paper presents a novel sequential inverse optimal control(SIOC)method for discrete-time systems,which calculates the unknown weight vectors of the cost function in real time using the input and output of an optim...This paper presents a novel sequential inverse optimal control(SIOC)method for discrete-time systems,which calculates the unknown weight vectors of the cost function in real time using the input and output of an optimally controlled discrete-time system.The proposed method overcomes the limitations of previous approaches by eliminating the need for the invertible Jacobian assumption.It calculates the possible-solution spaces and their intersections sequentially until the dimension of the intersection space decreases to one.The remaining one-dimensional vector of the possible-solution space’s intersection represents the SIOC solution.The paper presents clear conditions for convergence and addresses the issue of noisy data by clarifying the conditions for the singular values of the matrices that relate to the possible-solution space.The effectiveness of the proposed method is demonstrated through simulation results.展开更多
Nitrogen electro-reduction under mild conditions is one promising alternative approach of the energyconsuming Haber-Bosch process for the artificial ammonia synthesis.One critical aspect to unlocking this technology i...Nitrogen electro-reduction under mild conditions is one promising alternative approach of the energyconsuming Haber-Bosch process for the artificial ammonia synthesis.One critical aspect to unlocking this technology is to discover the catalysts with high selectivity and efficiency.In this work,the N_(2)-to-NH_(3)conversion on the functional MoS_(2)is fully investigated by density functional theory calculations since the layered MoS_(2)provides the ideal platform for the elaborating copies of the nitrogenase found in nature,wherein the functionalization is achieved via basal-adsorption,basal-substitution or edge-substitution of transition metal elements.Our results reveal that the edge-functionalization is a feasible strategy for the activity promotion;however,the basal-adsorption and basal-substitution separately suffer from the electrochemical instability and the NRR inefficiency.Specifically,MoS_(2)functionalized via edge W-substitution exhibits an exceptional activity.The energetically favored reaction pathway is through the distal pathway and a limiting potential is less than 0.20 V.Overall,this work escalates the rational design of the high-effective catalysts for nitrogen fixation and provides the explanation why the predicated catalyst have a good performance,paving the guidance for the experiments.展开更多
Solving the problems of low electrical conductivity and poor cycling durability in transition metal oxidesbased anode materials for lithium-ion batteries(LIBs)and sodium-ion batteries(SIBs)has already turned into an u...Solving the problems of low electrical conductivity and poor cycling durability in transition metal oxidesbased anode materials for lithium-ion batteries(LIBs)and sodium-ion batteries(SIBs)has already turned into an urgent requirement.In this paper,we successfully synthesized Co_(2)VO_(4)/Co compounds with Co-VMOF(metal-organic framework)as a sacrificial template and investigated their electrochemical mechanism in order to improve the electrochemical properties of LIBs and SIBs.The optimized heaping configuration and the existence of metallic Co catalyzed the formation of radical ions,thereby facilitating higher conductivity,shortening Li+and Na+transport paths,and providing more active sites.Co_(2)VO_(4)/Co constructed with 2-methylimidazole as a ligand showed a discharge capacity of 1605.1 mA h g^(-1)after 300 cycles at 0.1 A g^(-1)in LIB and 677.2 mA h g^(-1)in SIB.Density functional theory(DFT)calculation emphasizes the crucial role of Co_(2)VO_(4)/Co in enhancing electrode conductivity,decreasing the migratory energy barrier,and thereby strengthening electrochemical properties.This heterostructure building technique may pave the way for the development of high-performance LIBs and SIBs.Furthermore,the problem of the low first-loop coulombic efficiency faced by transition metal oxides is improved.展开更多
Layer-type LiNi0.9Mn0.1O2is promising to be the primary cathode material for lithium-ion batteries(LIBs)due to its excellent electrochemical performance.Unfortunately,the cathode with high nickel content suffers from ...Layer-type LiNi0.9Mn0.1O2is promising to be the primary cathode material for lithium-ion batteries(LIBs)due to its excellent electrochemical performance.Unfortunately,the cathode with high nickel content suffers from severely detrimental structural transformation that causes rapid capacity attenuation.Herein,site-specific dual-doping with Fe and Mg ions is proposed to enhance the structural stability of LiNi0.9Mn0.1O2.The Fe3+dopants are inserted into transition metal sites(3b)and can favorably provide additional redox potential to compensate for charge and enhance the reversibility of anionic redox.The Mg ions are doped into the Li sites(3a)and serve as O_(2)^(-)-Mg^(2+)-O_(2)^(-)pillar to reinforce the electrostatic cohesion between the two adjacent transition-metal layers,which further suppress the cracking and the generation of harmful phase transitions,ultimately improving the cyclability.The theoretical calculations,including Bader charge and crystal orbital Hamilton populations(COHP)analyses,confirm that the doped Fe and Mg can form stable bonds with oxygen and the electrostatic repulsion of O_(2)^(-)-O_(2)^(-)can be effectively suppressed,which effectively mitigates oxygen anion loss at the high delithiation state.This dual-site doping strategy offers new avenues for understanding and regulating the crystalline oxygen redox and demonstrates significant potential for designing high-performance cobalt-free nickel-rich cathodes.展开更多
As a new generation electrode materials for energy storage,perovskites have attracted wide attention because of their unique crystal structure,reversible active sites,rich oxygen vacancies,and good stability.In this r...As a new generation electrode materials for energy storage,perovskites have attracted wide attention because of their unique crystal structure,reversible active sites,rich oxygen vacancies,and good stability.In this review,the design and engineering progress of perovskite materials for supercapacitors(SCs)in recent years is summarized.Specifically,the review will focus on four types of perovskites,perovskite oxides,halide perovskites,fluoride perovskites,and multi-perovskites,within the context of their intrinsic structure and corresponding electrochemical performance.A series of experimental variables,such as synthesis,crystal structure,and electrochemical reaction mechanism,will be carefully analyzed by combining various advanced characterization techniques and theoretical calculations.The applications of these materials as electrodes are then featured for various SCs.Finally,we look forward to the prospects and challenges of perovskite-type SCs electrodes,as well as the future research direction.展开更多
Jet quenching parameter q is essential for characterizing the interaction strength between jet partons and nuclear matter.Based on the quark-meson model,we develop a new framework for calculating q at finite chemical ...Jet quenching parameter q is essential for characterizing the interaction strength between jet partons and nuclear matter.Based on the quark-meson model,we develop a new framework for calculating q at finite chemical potentials,in which q is related to the spectral function of the chiral order parameter.展开更多
The electrochemical methanol oxidation is a crucial reaction in the conversion of renewable energy.To enable the widespread adoption of direct methanol fuel cells(DMFCs),it is essential to create and engineer catalyst...The electrochemical methanol oxidation is a crucial reaction in the conversion of renewable energy.To enable the widespread adoption of direct methanol fuel cells(DMFCs),it is essential to create and engineer catalysts that are both highly effective and robust for conducting the methanol oxidation reaction(MOR).In this work,trimetallic PtCoRu electrocatalysts on nitrogen-doped carbon and multi-wall carbon nanotubes(PtCoRu@NC/MWCNTs)were prepared through a two-pot synthetic strategy.The acceleration of CO oxidation to CO_(2) and the blocking of CO reduction on adjacent Pt active sites were attributed to the crucial role played by cobalt atoms in the as-prepared electrocatalysts.The precise control of Co atoms loading was achieved through precursor stoichiometry.Various physicochemical techniques were employed to analyze the morphology,element composition,and electronic state of the catalyst.Electrochemical investigations and theoretical calculations confirmed that the Pt_(1)Co_(3)Ru_(1)@NC/MWCNTs exhibit excellent electrocatalytic performance and durability for the process of MOR.The enhanced MOR activity can be attributed to the synergistic effect between the multiple elements resulting from precisely controlled Co loading content on surface of the electrocatalyst,which facilitates efficient charge transfer.This interaction between the multiple components also modifies the electronic structures of active sites,thereby promoting the conversion of intermediates and accelerating the MOR process.Thus,achieving precise control over Co loading in PtCoRu@NC/MWCNTs would enable the development of high-performance catalysts for DMFCs.展开更多
Vanadium dioxide VO_(2) is a strongly correlated material that undergoes a metal-to-insulator transition around 340 K.In order to describe the electron correlation effects in VO_(2), the DFT+U method is commonly emplo...Vanadium dioxide VO_(2) is a strongly correlated material that undergoes a metal-to-insulator transition around 340 K.In order to describe the electron correlation effects in VO_(2), the DFT+U method is commonly employed in calculations.However, the choice of the Hubbard U parameter has been a subject of debate and its value has been reported over a wide range. In this paper, taking focus on the phase transition behavior of VO_(2), the Hubbard U parameter for vanadium oxide is determined by using the quasi-harmonic approximation(QHA). First-principles calculations demonstrate that the phase transition temperature can be modulated by varying the U values. The phase transition temperature can be well reproduced by the calculations using the Perdew–Burke–Ernzerhof functional combined with the U parameter of 1.5eV. Additionally,the calculated band structure, insulating or metallic properties, and phonon dispersion with this U value are in line with experimental observations. By employing the QHA to determine the Hubbard U parameter, this study provides valuable insights into the phase transition behavior of VO_(2). The findings highlight the importance of electron correlation effects in accurately describing the properties of this material. The agreement between the calculated results and experimental observations further validates the chosen U value and supports the use of the DFT+U method in studying VO_(2).展开更多
To realize the low-resistance shape optimization design of amphibious robots,an efficient optimization design framework is proposed to improve the geometric deformation flexibility and optimization efficiency.In the p...To realize the low-resistance shape optimization design of amphibious robots,an efficient optimization design framework is proposed to improve the geometric deformation flexibility and optimization efficiency.In the proposed framework,the free-form deformation parametric model of the flat slender body is established and an analytical calculation method for the height constraints is derived.CFD method is introduced to carry out the high-precision resistance calculation and a constrained Kriging-based optimization method is built to improve the optimization efficiency by circularly infilling the new sample points which satisfying the constraints.Finally,the shape of an amphibious robot example is optimized to get the low-resistance shape and the results demonstrate that the presented optimization design framework has the advantages of simplicity,flexibility and high efficiency.展开更多
This study investigates the effects of Fe on the oxygen-evolution reaction(OER)in the presence of Au.Two distinct areas of OER were identified:the first associated with Fe sites at low overpotential(~330 mV),and the s...This study investigates the effects of Fe on the oxygen-evolution reaction(OER)in the presence of Au.Two distinct areas of OER were identified:the first associated with Fe sites at low overpotential(~330 mV),and the second with Au sites at high overpotential(~870 mV).Various factors such as surface Fe concentration,electrochemical method,scan rate,potential range,concentration,method of adding K_(2)Fe O_(4),nature of Fe,and temperature were varied to observe diverse behaviors during OER for Fe O_(x)H_(y)/Au.Trace amounts of Fe ions had a significant impact on OER,reaching a saturation point where the activity did not increase further.Strong electronic interaction between Fe and Au ions was indicated by X-ray photoelectron spectroscopy(XPS)and electron paramagnetic resonance(EPR)analyses.In situ visible spectroscopy confirmed the formation of Fe O_(4)^(2-)during OER.In situ Mossbauer and surfaceenhanced Raman spectroscopy(SERS)analyses suggest the involvement of Fe-based species as intermediates during the rate-determining step of OER.A lattice OER mechanism based on Fe O_(x)H_(y)was proposed for operation at low overpotentials.Density functional theory(DFT)calculations revealed that Fe oxide,Fe-oxide clusters,and Fe doping on the Au foil exhibited different activities and stabilities during OER.The study provides insights into the interplay between Fe and Au in OER,advancing the understanding of OER mechanisms and offering implications for the design of efficient electrocatalytic systems.展开更多
Hydrogen evolution reaction(HER)has become a key factor affecting the cycling stability of aqueous Zn-ion batteries,while the corresponding fundamental issues involving HER are still unclear.Herein,the reaction mechan...Hydrogen evolution reaction(HER)has become a key factor affecting the cycling stability of aqueous Zn-ion batteries,while the corresponding fundamental issues involving HER are still unclear.Herein,the reaction mechanisms of HER on various crystalline surfaces have been investigated by first-principle calculations based on density functional theory.It is found that the Volmer step is the ratelimiting step of HER on the Zn(002)and(100)surfaces,while,the reaction rates of HER on the Zn(101),(102)and(103)surfaces are determined by the Tafel step.Moreover,the correlation between HER activity and the generalized coordination number(CN)of Zn at the surfaces has been revealed.The relatively weaker HER activity on Zn(002)surface can be attributed to the higher CN of surface Zn atom.The atomically uneven Zn(002)surface shows significantly higher HER activity than the flat Zn(002)surface as the CN of the surface Zn atom is lowered.The CN of surface Zn atom is proposed as a key descriptor of HER activity.Tuning the CN of surface Zn atom would be a vital strategy to inhibit HER on the Zn anode surface based on the presented theoretical studies.Furthermore,this work provides a theoretical basis for the in-depth understanding of HER on the Zn surface.展开更多
Geomorphological features are commonly used to identify potential landslides.Nevertheless,overemphasis on these features could lead to misjudgment.This research proposes a process-oriented approach for potential lands...Geomorphological features are commonly used to identify potential landslides.Nevertheless,overemphasis on these features could lead to misjudgment.This research proposes a process-oriented approach for potential landslide identification that considers time-dependent behaviors.The method integrates comprehensive remote sensing and geological analysis to qualitatively assess slope stability,and employs numerical analysis to quantitatively calculate aging stability.Specifically,a time-dependent stability calculation method for anticlinal slopes is developed and implemented in discrete element software,incorporating time-dependent mechanical and strength reduction calculations.By considering the time-dependent evolution of slopes,this method highlights the importance of both geomorphological features and time-dependent behaviors in landslide identification.This method has been applied to the Jiarishan slope(JRS)on the Qinghai-Tibet Plateau as a case study.The results show that the JRS,despite having landslide geomorphology,is a stable slope,highlighting the risk of misjudgment when relying solely on geomorphological features.This work provides insights into the geomorphological characterization and evolution history of the JRS and offers valuable guidance for studying slopes with similar landslide geomorphology.Furthermore,the process-oriented method incorporating timedependent evolution provides a means to evaluate potential landslides,reducing misjudgment due to excessive reliance on geomorphological features.展开更多
基金Supported by Capital’s Funds for Health Improvement and Research,No.2020-4-2085Beijing Science and Technology Plan Project,No.Z211100002921028。
文摘BACKGROUND No single endoscopic feature can reliably predict the pathological nature of colorectal tumors(CRTs).AIM To establish and validate a simple online calculator to predict the pathological nature of CRTs based on white-light endoscopy.METHODS This was a single-center study.During the identification stage,530 consecutive patients with CRTs were enrolled from January 2015 to December 2021 as the derivation group.Logistic regression analysis was performed.A novel online calculator to predict the pathological nature of CRTs based on white-light images was established and verified internally.During the validation stage,two series of 110 images obtained using white-light endoscopy were distributed to 10 endoscopists[five highly experienced endoscopists and five less experienced endoscopists(LEEs)]for external validation before and after systematic training.RESULTS A total of 750 patients were included,with an average age of 63.6±10.4 years.Early colorectal cancer(ECRC)was detected in 351(46.8%)patients.Tumor size,left semicolon site,rectal site,acanthosis,depression and an uneven surface were independent risk factors for ECRC.The C-index of the ECRC calculator prediction model was 0.906(P=0.225,Hosmer-Lemeshow test).For the LEEs,significant improvement was made in the sensitivity,specificity and accuracy(57.6%vs 75.5%;72.3%vs 82.4%;64.2%vs 80.2%;P<0.05),respectively,after training with the ECRC online calculator prediction model.CONCLUSION A novel online calculator including tumor size,location,acanthosis,depression,and uneven surface can accurately predict the pathological nature of ECRC.
基金University Natural Science Research Project of Anhui Province,No.KJ2021ZD0021.
文摘BACKGROUND Efficient and practical methods for predicting the risk of malignancy in patients with pancreatic cystic neoplasms(PCNs)are lacking.AIM To establish a nomogram-based online calculator for predicting the risk of malignancy in patients with PCNs.METHODS In this study,the clinicopathological data of target patients in three medical centers were analyzed.The independent sample t-test,Mann–Whitney U test or chi-squared test were used as appropriate for statistical analysis.After univariable and multivariable logistic regression analysis,five independent factors were screened and incorporated to develop a calculator for predicting the risk of malignancy.Finally,the concordance index(C-index),calibration,area under the curve,decision curve analysis and clinical impact curves were used to evaluate the performance of the calculator.RESULTS Enhanced mural nodules[odds ratio(OR):4.314;95%confidence interval(CI):1.618–11.503,P=0.003],tumor diameter≥40 mm(OR:3.514;95%CI:1.138–10.849,P=0.029),main pancreatic duct dilatation(OR:3.267;95%CI:1.230–8.678,P=0.018),preoperative neutrophil-to-lymphocyte ratio≥2.288(OR:2.702;95%CI:1.008–7.244,P=0.048],and preoperative serum CA19-9 concentration≥34 U/mL(OR:3.267;95%CI:1.274–13.007,P=0.018)were independent risk factors for a high risk of malignancy in patients with PCNs.In the training cohort,the nomogram achieved a C-index of 0.824 for predicting the risk of malignancy.The predictive ability of the model was then validated in an external cohort(C-index:0.893).Compared with the risk factors identified in the relevant guidelines,the current model showed better predictive performance and clinical utility.CONCLUSION The calculator demonstrates optimal predictive performance for identifying the risk of malignancy,potentially yielding a personalized method for patient selection and decision-making in clinical practice.
文摘The purpose of this study was to grasp current potential problems of dose error in intensity-modulated proton therapy (IMPT) plans. We were interested in dose differences of the Varian Eclipse treatment planning system (TPS) and the fast dose calculation method (FDC) for single-field optimization (SFO) and multi-field optimization (MFO) IMPT plans. In addition, because some authors have reported dosimetric benefit of a proton arc therapy with ultimate multi-fields in recent years, we wanted to evaluate how the number of fields and beam angles affect the differences for IMPT plans. Therefore, for one brain cancer patient with a large heterogeneity, SFO and MFO IMPT plans with various multi-angle beams were planned by the TPS. Dose distributions for each IMPT plan were calculated by both the TPS’s conventional pencil beam algorithm and the FDC. The dosimetric parameters were compared between the two algorithms. The TPS overestimated 400 - 500 cGy (RBE) for minimum dose to the CTV relative to the dose calculated by the FDC. These differences indicate clinically relevant effect on clinical results. In addition, we observed that the maximum difference in dose calculated between the TPS and the FDC was about 900 cGy (RBE) for the right optic nerve, and this quantity also has a possibility to have a clinical effect. The major difference was not seen in calculations for SFO IMPT planning and those for MFO IMPT planning. Differences between the TPS and the FDC in SFO and MFO IMPT plans depend strongly on beam arrangement and the presence of a heterogeneous body. We advocate use of a Monte Carlo method in proton treatment planning to deliver the most precise proton dose in IMPT.
文摘Risk calculators have offered a viable tool for clinicians to stratify patients at risk of prostate cancer(PCa)and to mitigate the low sensitivity and specificity of screening prostate specific antigen(PSA).While initially based on clinical and demographic data,incorporation of multiparametric magnetic resonance imaging(MRI)and the validated prostate imaging reporting and data system suspicion scoring system has standardized and improved risk stratification beyond the use of PSA and patient parameters alone.Biopsy-naïve patients with lower risk profiles for harboring clinically significant PCa are often subjected to uncomfortable,invasive,and potentially unnecessary prostate biopsy procedures.Incorporating risk calculator data into prostate MRI reports can broaden the role of radiologists,improve communication with clinicians primarily managing these patients,and help guide clinical care in directing the screening,detection,and risk stratification of PCa.
基金This work is funded by National Funds through the Foundation for Science and Technology(FCT),I.P.,within the scope of the project RefªUIDB/05583/2020.
文摘A carbon footprint(CF)calculator was developed to apply to a Portuguese touristic accommodation to contribute to a sustainable touristic activity.Although some calculators are available online,they are related to the country reality or use outdated emission factors.A calculator based on national emission factors is important.The calculator was developed in Microsoft Excel(version 365)and is based on the CO2e emissions resulting from electricity,water,fuels and food use,laundry and waste production.The calculator development involved:study the accommodation emission sources,selection the environmental indicators,determination of the emission factors and development of the CF formulas.Total CF calculation was made considering the partial CF per component,a monthly and annual comparison of each indicator’s emissions contribution using graphs.The emissions amount per overnight stay,per room,per area,were also assessed and these values were transformed into global hectare(gha).Avoided emissions calculation gives the information about the efforts in CF reduction,and two indicators were considered:electricity production from renewable energy sources and the amount of separated waste for recycling.It was considered reforestation measures to achieve carbon neutrality.This calculator incorporates four components not often used:water,laundry,waste,food,and avoided emissions.
文摘Risk prediction models including the Prostate Health Index(phi)for prostate cancer have been well established and evaluated in the Western population.The aim of this study is to build phi-based risk calculators in a prostate biopsy population and evaluate their performanee in predicting prostate cancer(PCa)and high-grade PCa(Gleason score 27)in the Chinese population.We developed risk calculators based on 635 men who underwent initial prostate biopsy.Then,we validated the performance of prostate-specific antigen(PSA),phi,and the risk calculators in an additional observational cohort of 1045 men.We observed that the phi-based risk calculators(risk calculators 2 and 4)outperformed the PSA-based risk calculator for predicting PCa and high-grade PCa in the training cohort.In the validation study,the area under the receiver operating characteristic curve(AUC)for risk calculators 2 and 4 reached 0.91 and 0.92,respectively,for predicting PCa and high-grade PCa,respectively;the AUC values were better than those for risk calculator 1(PSA-based model with an AUC of 0.81 and 0.82,respectively)(all P<0.001).Such superiority was also observed in the stratified population with PSA ranging from 2.0 ng ml^-1 to 10.0 ng ml^-1.Decision curves confirmed that a considerable proportion of unnecessary biopsies could be avoided while applying phi-based risk calculators.In this study,we showed that,compared to risk calculators without phi,phi-based risk calculators exhibited superior discrimination and calibration for PCa in the Chinese biopsy population.Applying these risk calculators also considerably reduced the number of unnecessary biopsies for PCa.
文摘This paper presents a novel sequential inverse optimal control(SIOC)method for discrete-time systems,which calculates the unknown weight vectors of the cost function in real time using the input and output of an optimally controlled discrete-time system.The proposed method overcomes the limitations of previous approaches by eliminating the need for the invertible Jacobian assumption.It calculates the possible-solution spaces and their intersections sequentially until the dimension of the intersection space decreases to one.The remaining one-dimensional vector of the possible-solution space’s intersection represents the SIOC solution.The paper presents clear conditions for convergence and addresses the issue of noisy data by clarifying the conditions for the singular values of the matrices that relate to the possible-solution space.The effectiveness of the proposed method is demonstrated through simulation results.
基金financial support from the National Natural Science Foundation of China(21503097,52130101,51701152,21806023,and 51702345)China Scholarship Council(202008320215).
文摘Nitrogen electro-reduction under mild conditions is one promising alternative approach of the energyconsuming Haber-Bosch process for the artificial ammonia synthesis.One critical aspect to unlocking this technology is to discover the catalysts with high selectivity and efficiency.In this work,the N_(2)-to-NH_(3)conversion on the functional MoS_(2)is fully investigated by density functional theory calculations since the layered MoS_(2)provides the ideal platform for the elaborating copies of the nitrogenase found in nature,wherein the functionalization is achieved via basal-adsorption,basal-substitution or edge-substitution of transition metal elements.Our results reveal that the edge-functionalization is a feasible strategy for the activity promotion;however,the basal-adsorption and basal-substitution separately suffer from the electrochemical instability and the NRR inefficiency.Specifically,MoS_(2)functionalized via edge W-substitution exhibits an exceptional activity.The energetically favored reaction pathway is through the distal pathway and a limiting potential is less than 0.20 V.Overall,this work escalates the rational design of the high-effective catalysts for nitrogen fixation and provides the explanation why the predicated catalyst have a good performance,paving the guidance for the experiments.
基金financially supported by the Open Fund of Energy and Materials Chemistry Joint Laboratory of SCNU and TINCI,China (SCNU-TINCI-202207)。
文摘Solving the problems of low electrical conductivity and poor cycling durability in transition metal oxidesbased anode materials for lithium-ion batteries(LIBs)and sodium-ion batteries(SIBs)has already turned into an urgent requirement.In this paper,we successfully synthesized Co_(2)VO_(4)/Co compounds with Co-VMOF(metal-organic framework)as a sacrificial template and investigated their electrochemical mechanism in order to improve the electrochemical properties of LIBs and SIBs.The optimized heaping configuration and the existence of metallic Co catalyzed the formation of radical ions,thereby facilitating higher conductivity,shortening Li+and Na+transport paths,and providing more active sites.Co_(2)VO_(4)/Co constructed with 2-methylimidazole as a ligand showed a discharge capacity of 1605.1 mA h g^(-1)after 300 cycles at 0.1 A g^(-1)in LIB and 677.2 mA h g^(-1)in SIB.Density functional theory(DFT)calculation emphasizes the crucial role of Co_(2)VO_(4)/Co in enhancing electrode conductivity,decreasing the migratory energy barrier,and thereby strengthening electrochemical properties.This heterostructure building technique may pave the way for the development of high-performance LIBs and SIBs.Furthermore,the problem of the low first-loop coulombic efficiency faced by transition metal oxides is improved.
基金the financial supports from the Key Research and Development Project in Shaanxi Province(2023-YBGY-446)the Shanxi-Zheda Institute of Advanced Materials and Chemical Engineering(2022SX-TD003)。
文摘Layer-type LiNi0.9Mn0.1O2is promising to be the primary cathode material for lithium-ion batteries(LIBs)due to its excellent electrochemical performance.Unfortunately,the cathode with high nickel content suffers from severely detrimental structural transformation that causes rapid capacity attenuation.Herein,site-specific dual-doping with Fe and Mg ions is proposed to enhance the structural stability of LiNi0.9Mn0.1O2.The Fe3+dopants are inserted into transition metal sites(3b)and can favorably provide additional redox potential to compensate for charge and enhance the reversibility of anionic redox.The Mg ions are doped into the Li sites(3a)and serve as O_(2)^(-)-Mg^(2+)-O_(2)^(-)pillar to reinforce the electrostatic cohesion between the two adjacent transition-metal layers,which further suppress the cracking and the generation of harmful phase transitions,ultimately improving the cyclability.The theoretical calculations,including Bader charge and crystal orbital Hamilton populations(COHP)analyses,confirm that the doped Fe and Mg can form stable bonds with oxygen and the electrostatic repulsion of O_(2)^(-)-O_(2)^(-)can be effectively suppressed,which effectively mitigates oxygen anion loss at the high delithiation state.This dual-site doping strategy offers new avenues for understanding and regulating the crystalline oxygen redox and demonstrates significant potential for designing high-performance cobalt-free nickel-rich cathodes.
基金financial support from the National Natural Science Foundation of China(21676036)the Natural Science Foundation of Chongqing(CSTB2023NSCQ-MSX0580)the Graduate Research and Innovation Foundation of Chongqing(CYS-20040)。
文摘As a new generation electrode materials for energy storage,perovskites have attracted wide attention because of their unique crystal structure,reversible active sites,rich oxygen vacancies,and good stability.In this review,the design and engineering progress of perovskite materials for supercapacitors(SCs)in recent years is summarized.Specifically,the review will focus on four types of perovskites,perovskite oxides,halide perovskites,fluoride perovskites,and multi-perovskites,within the context of their intrinsic structure and corresponding electrochemical performance.A series of experimental variables,such as synthesis,crystal structure,and electrochemical reaction mechanism,will be carefully analyzed by combining various advanced characterization techniques and theoretical calculations.The applications of these materials as electrodes are then featured for various SCs.Finally,we look forward to the prospects and challenges of perovskite-type SCs electrodes,as well as the future research direction.
基金supported by the National Natural Science Foundation of China(Grant Nos.12105129,12175122,2021867,and 12247101)。
文摘Jet quenching parameter q is essential for characterizing the interaction strength between jet partons and nuclear matter.Based on the quark-meson model,we develop a new framework for calculating q at finite chemical potentials,in which q is related to the spectral function of the chiral order parameter.
基金financially supported by the National Natural Science Foundation of China (52200076,22169005,52370057)the Growth Project of Young Scientific and Technological Talents in General Colleges and Universities in Guizhou Province ([2022]143)+4 种基金the Science and Technology Foundation of Guizhou Province ([2022]109)the Natural Science Special Foundation of Guizhou University (202017,702775203301)the Natural Science Foundation of Chongqing (CSTB2022NSCQ-BHX0035)the Special Research Assistant Program of Chinese Academy of Sciencethe Research Foundation of Chongqing University of Science and Technology (ckrc2022026)。
文摘The electrochemical methanol oxidation is a crucial reaction in the conversion of renewable energy.To enable the widespread adoption of direct methanol fuel cells(DMFCs),it is essential to create and engineer catalysts that are both highly effective and robust for conducting the methanol oxidation reaction(MOR).In this work,trimetallic PtCoRu electrocatalysts on nitrogen-doped carbon and multi-wall carbon nanotubes(PtCoRu@NC/MWCNTs)were prepared through a two-pot synthetic strategy.The acceleration of CO oxidation to CO_(2) and the blocking of CO reduction on adjacent Pt active sites were attributed to the crucial role played by cobalt atoms in the as-prepared electrocatalysts.The precise control of Co atoms loading was achieved through precursor stoichiometry.Various physicochemical techniques were employed to analyze the morphology,element composition,and electronic state of the catalyst.Electrochemical investigations and theoretical calculations confirmed that the Pt_(1)Co_(3)Ru_(1)@NC/MWCNTs exhibit excellent electrocatalytic performance and durability for the process of MOR.The enhanced MOR activity can be attributed to the synergistic effect between the multiple elements resulting from precisely controlled Co loading content on surface of the electrocatalyst,which facilitates efficient charge transfer.This interaction between the multiple components also modifies the electronic structures of active sites,thereby promoting the conversion of intermediates and accelerating the MOR process.Thus,achieving precise control over Co loading in PtCoRu@NC/MWCNTs would enable the development of high-performance catalysts for DMFCs.
基金supported by the National Natural Science Foundation of China (Grant Nos.21933006 and 21773124)the Fundamental Research Funds for the Central Universities Nankai University (Grant Nos.010-63233001,63221346,63213042,and ZB22000103)+1 种基金the support from the China Postdoctoral Science Foundation (Grant No.2021M691674)the Hefei National Laboratory for Physical Sciences at the Microscale (Grant No.KF2020105)。
文摘Vanadium dioxide VO_(2) is a strongly correlated material that undergoes a metal-to-insulator transition around 340 K.In order to describe the electron correlation effects in VO_(2), the DFT+U method is commonly employed in calculations.However, the choice of the Hubbard U parameter has been a subject of debate and its value has been reported over a wide range. In this paper, taking focus on the phase transition behavior of VO_(2), the Hubbard U parameter for vanadium oxide is determined by using the quasi-harmonic approximation(QHA). First-principles calculations demonstrate that the phase transition temperature can be modulated by varying the U values. The phase transition temperature can be well reproduced by the calculations using the Perdew–Burke–Ernzerhof functional combined with the U parameter of 1.5eV. Additionally,the calculated band structure, insulating or metallic properties, and phonon dispersion with this U value are in line with experimental observations. By employing the QHA to determine the Hubbard U parameter, this study provides valuable insights into the phase transition behavior of VO_(2). The findings highlight the importance of electron correlation effects in accurately describing the properties of this material. The agreement between the calculated results and experimental observations further validates the chosen U value and supports the use of the DFT+U method in studying VO_(2).
基金financially supported by the National Natural Science Foundation of China(Grant No.52372356).
文摘To realize the low-resistance shape optimization design of amphibious robots,an efficient optimization design framework is proposed to improve the geometric deformation flexibility and optimization efficiency.In the proposed framework,the free-form deformation parametric model of the flat slender body is established and an analytical calculation method for the height constraints is derived.CFD method is introduced to carry out the high-precision resistance calculation and a constrained Kriging-based optimization method is built to improve the optimization efficiency by circularly infilling the new sample points which satisfying the constraints.Finally,the shape of an amphibious robot example is optimized to get the low-resistance shape and the results demonstrate that the presented optimization design framework has the advantages of simplicity,flexibility and high efficiency.
基金the National Elite Foundationthe Institute for Advanced Studies in Basic Sciences for their financial supportfinancially supported by the National Natural Science Foundation of China(22173026,22350410386,22375200,U22A202175,21961142006)。
文摘This study investigates the effects of Fe on the oxygen-evolution reaction(OER)in the presence of Au.Two distinct areas of OER were identified:the first associated with Fe sites at low overpotential(~330 mV),and the second with Au sites at high overpotential(~870 mV).Various factors such as surface Fe concentration,electrochemical method,scan rate,potential range,concentration,method of adding K_(2)Fe O_(4),nature of Fe,and temperature were varied to observe diverse behaviors during OER for Fe O_(x)H_(y)/Au.Trace amounts of Fe ions had a significant impact on OER,reaching a saturation point where the activity did not increase further.Strong electronic interaction between Fe and Au ions was indicated by X-ray photoelectron spectroscopy(XPS)and electron paramagnetic resonance(EPR)analyses.In situ visible spectroscopy confirmed the formation of Fe O_(4)^(2-)during OER.In situ Mossbauer and surfaceenhanced Raman spectroscopy(SERS)analyses suggest the involvement of Fe-based species as intermediates during the rate-determining step of OER.A lattice OER mechanism based on Fe O_(x)H_(y)was proposed for operation at low overpotentials.Density functional theory(DFT)calculations revealed that Fe oxide,Fe-oxide clusters,and Fe doping on the Au foil exhibited different activities and stabilities during OER.The study provides insights into the interplay between Fe and Au in OER,advancing the understanding of OER mechanisms and offering implications for the design of efficient electrocatalytic systems.
基金This work was financially supported by the National Natural Science Foundation of China(22075171)Natural Science Foundation of Shanghai(23ZR1423400)The firstprinciples calculations were supported by the High Performance Computing Center of Shanghai University.
文摘Hydrogen evolution reaction(HER)has become a key factor affecting the cycling stability of aqueous Zn-ion batteries,while the corresponding fundamental issues involving HER are still unclear.Herein,the reaction mechanisms of HER on various crystalline surfaces have been investigated by first-principle calculations based on density functional theory.It is found that the Volmer step is the ratelimiting step of HER on the Zn(002)and(100)surfaces,while,the reaction rates of HER on the Zn(101),(102)and(103)surfaces are determined by the Tafel step.Moreover,the correlation between HER activity and the generalized coordination number(CN)of Zn at the surfaces has been revealed.The relatively weaker HER activity on Zn(002)surface can be attributed to the higher CN of surface Zn atom.The atomically uneven Zn(002)surface shows significantly higher HER activity than the flat Zn(002)surface as the CN of the surface Zn atom is lowered.The CN of surface Zn atom is proposed as a key descriptor of HER activity.Tuning the CN of surface Zn atom would be a vital strategy to inhibit HER on the Zn anode surface based on the presented theoretical studies.Furthermore,this work provides a theoretical basis for the in-depth understanding of HER on the Zn surface.
基金This research was supported by the National Natural Science Foundation of China(Grant Nos.41972284 and 42090054)This work was also supported by the State Key Laboratory of Geohazard Prevention and Geoenvironment Protection Independent Research Project(Grant No.SKLGP2020Z005).
文摘Geomorphological features are commonly used to identify potential landslides.Nevertheless,overemphasis on these features could lead to misjudgment.This research proposes a process-oriented approach for potential landslide identification that considers time-dependent behaviors.The method integrates comprehensive remote sensing and geological analysis to qualitatively assess slope stability,and employs numerical analysis to quantitatively calculate aging stability.Specifically,a time-dependent stability calculation method for anticlinal slopes is developed and implemented in discrete element software,incorporating time-dependent mechanical and strength reduction calculations.By considering the time-dependent evolution of slopes,this method highlights the importance of both geomorphological features and time-dependent behaviors in landslide identification.This method has been applied to the Jiarishan slope(JRS)on the Qinghai-Tibet Plateau as a case study.The results show that the JRS,despite having landslide geomorphology,is a stable slope,highlighting the risk of misjudgment when relying solely on geomorphological features.This work provides insights into the geomorphological characterization and evolution history of the JRS and offers valuable guidance for studying slopes with similar landslide geomorphology.Furthermore,the process-oriented method incorporating timedependent evolution provides a means to evaluate potential landslides,reducing misjudgment due to excessive reliance on geomorphological features.