Objective:International students frequently face psychological adaptation difficulties while studying and living abroad.As an effective psychological resource,positive solitude has been identified as a potential facto...Objective:International students frequently face psychological adaptation difficulties while studying and living abroad.As an effective psychological resource,positive solitude has been identified as a potential factor for improving psychological well-being,but the underlying mechanism linking the two has not been fully explored.The current study aims to explore the relationship between positive solitude and psychological adaptation of international students,with particular emphasis on the intermediary roles of authenticity and loneliness.Methods:A total of 529 international tertiary students(Mage=23.76,SD=5.08;60.68%male)were surveyed using the Positive Solitude Scale(PSS),Authenticity Scale(AS),6-item UCLA Loneliness Scale(ULS-6),and Brief Psychological Adaptation Scale(BPAS).SPSS27.0 was used for descriptive statistical analysis and Pearson correlation analysis.PROCESS macro(Model 6)was employed to test a serial mediation model,in which authenticity and loneliness function as intermediary variables between positive solitude and psychological adaptation.Results:The correlation analysis indicated significant associations among positive solitude,authenticity,loneliness,and psychological adaptation(r=−0.544~0.511).Positive solitude was directly and positively related to psychological adaptation(β=0.132,t=3.609,p<0.001)and indirectly related to psychological adaptation through two pathways:a single mediation via authenticity(indirect effect=0.089)and a serial mediation through authenticity and loneliness(indirect effect=0.062).Loneliness did not serve as a significant mediator(indirect effect=–0.015,95%CI[–0.049,0.019]).The total indirect effect was 0.136.Conclusions:Interventions targeting international students’capacity for experiencing positive solitude and authenticity can help to reduce loneliness and increase psychological adaptation.The findings derived from this study are conducive to understanding the relationship between positive solitude and psychological adaptation,as well as its underlying mechanisms.In addition,the study offers a new perspective for educational management and psychological counseling services for international students.展开更多
Objectives This study aimed to explore and clarify the concept of reflective supervision as a professional self-care strategy to create a positive Intensive Care Unit(ICU)practice environment.Methods Walker and Avant...Objectives This study aimed to explore and clarify the concept of reflective supervision as a professional self-care strategy to create a positive Intensive Care Unit(ICU)practice environment.Methods Walker and Avant’s eight-step concept analysis approach was utilized to identify and define the attributes,antecedents,and consequences of reflective supervision in the ICU.An extensive literature search was conducted across various databases,including Google Scholar,CINAHL,PubMed.Articles published from 2005 to 2025 were identified.We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses(PRISMA)2020 statement to indicate the included articles and extract related data based on relevance.Results Forty articles were included in the analysis.The identified attributes included the supervisor-supervisee relationship,effective communication,teamwork,collaborations,reflection,competencies,feedback,continuous support,and autonomous choice.The identified antecedents included participation,supportive supervision,flexibility,open-door policy,training,and motivation.Consequences impacting the success of reflective supervision were identified as promotion of resiliency,autonomy,work-life balance,self-awareness,increased self-esteem,professional development,critical thinking,increased job satisfaction,and enhanced commitment.Conclusions Reflective supervision is a complex professional self-care strategy that enhances ICU practice,by promoting nurses’well-being,self-awareness,therapeutic skills,and professional development.展开更多
This paper deals with homogeneous Dirichlet boundary value problem to a class of porous medium equations with viscoelastic term ∂u/∂t-Δu^(m)+∫^(t)_(0)g(t-s)Δu^(m)(x,s)ds=u^(p),x∈Ω,t≥0,where p>m(m>0).We pro...This paper deals with homogeneous Dirichlet boundary value problem to a class of porous medium equations with viscoelastic term ∂u/∂t-Δu^(m)+∫^(t)_(0)g(t-s)Δu^(m)(x,s)ds=u^(p),x∈Ω,t≥0,where p>m(m>0).We prove that the weak solutions of the above problem blow up in finite time when the initial energy is positive and the function g satisfies suitable conditions.Our result generalizes that of S.A.Messaoudi in[1].展开更多
Objective: To evaluate the efficacy of noninvasive positive pressure ventilation (NIPPV) in respiratory support for severe pneumonia. Methods: Data were analyzed from 74 patients with severe pneumonia undergoing respi...Objective: To evaluate the efficacy of noninvasive positive pressure ventilation (NIPPV) in respiratory support for severe pneumonia. Methods: Data were analyzed from 74 patients with severe pneumonia undergoing respiratory support at our hospital between May 2024 and April 2025. Patients were randomly assigned using a random number table to two groups (n = 37 each): the experimental group received NIPPV, while the control group underwent conventional invasive mechanical ventilation. Intergroup differences were compared. Results: Compared with the control group, the experimental group demonstrated significantly higher PaO2 and oxygenation index, significantly lower PaCO2, significantly reduced levels of WBC, CRP, and PCT, significantly higher overall efficacy rate, and significantly lower incidence of adverse reactions after treatment (p < 0.05). Pre-treatment PaO2, oxygenation index, PaCO2, WBC, CRP, and PCT levels showed no significant differences between groups (p > 0.05). Conclusion: Non-invasive positive pressure ventilation demonstrates favorable outcomes in respiratory support for severe pneumonia.展开更多
Background:Emerging adulthood is a critical period for ego identity exploration and consolidation,and self-presentation on social media constitutes a salient online context for this developmental process.However,limit...Background:Emerging adulthood is a critical period for ego identity exploration and consolidation,and self-presentation on social media constitutes a salient online context for this developmental process.However,limited research has explored the associations between self-presentation on WeChat Moments and ego identity.This study aims to examine these associations,focusing on the mediating role of online positive feedback and the moderating role of gender.Methods:Using a three-wave longitudinal design,this study followed 767 Chinese college students(Mean age=18.96 years)through cluster sampling.Participants completed self-report questionnaires assessing self-presentation on WeChat Moments,online positive feedback,and ego identity status.Data analyses were conducted using mediation modeling and multi-group structural equation modeling.Results:Authentic self-presentation was positively associated with identity achievement and negatively associated with identity diffusion,whereas positive self-presentation was linked to higher levels of identity foreclosure.Online positive feedback played a significant mediating role in the associations between self-presentation strategies and identity statuses,and gender differences were observed in this mediating pathway.For both males and females,authentic self-presentation was associated with higher identity achievement through online positive feedback.However,indirect associations with identity foreclosure and diffusion were observed only among females:authentic self-presentation was linked to lower levels,whereas positive self-presentation was linked to higher levels of foreclosure and diffusion through online positive feedback.No comparable indirect associations were detected among males.Conclusions:Online positive feedback is closely linked to self-presentation strategies and ego identity statuses,with these associations varying by gender.展开更多
As a core functional refractory in the continuous casting process,the service reliability of the submerged entry nozzle(SEN)is directly related to the stability of continuous casting production,the quality of casting ...As a core functional refractory in the continuous casting process,the service reliability of the submerged entry nozzle(SEN)is directly related to the stability of continuous casting production,the quality of casting billets,and production efficiency.Al_(2)O_(3) inclusions clogging constitutes the predominant failure mode of SEN,particularly during continuous casting of high-grade steels.Although several studies in the literature have demonstrated that electric field application can mitigate SEN clogging to some extent,the underlying mechanism remains poorly understood,which hinders its widespread acceptance and practical implementation.The mechanism of preventing SEN clogging by applying a positive electric field was studied,and experimental verification was conducted on it in a certain steel plant.The results indicate that Al_(2)O_(3) inclusions exhibit a positive charge in molten steel under high-temperature(~1600℃)and low-oxygen-partial-pressure(≤20×10-6)conditions.In the continuous casting process at a Chinese steel plant,applying a positive electric field to the SEN effectively suppressed the migration of Al_(2)O_(3) inclusions toward the SEN wall,significantly enhancing its clogging resistance.展开更多
Let M be a compact n-manifold of positive sectional curvature.We will review classical results on the fundamental group of M,a motivation on the c(n)-cyclic conjecture that the fundamental group of M contains a cyclic...Let M be a compact n-manifold of positive sectional curvature.We will review classical results on the fundamental group of M,a motivation on the c(n)-cyclic conjecture that the fundamental group of M contains a cyclic subgroup of index bounded above by c(n),a constant depending only on n,and we will survey partial results(up to date)on the c(n)-cyclic conjecture.展开更多
This paper focuses on the leader-following positive consensus problems of heterogeneous switched multi-agent systems.First,a state-feedback controller with dynamic compensation is introduced to achieve positive consen...This paper focuses on the leader-following positive consensus problems of heterogeneous switched multi-agent systems.First,a state-feedback controller with dynamic compensation is introduced to achieve positive consensus under average dwell time switching.Then sufficient conditions are derived to guarantee the positive consensus.The gain matrices of the control protocol are described using a matrix decomposition approach and the corresponding computational complexity is reduced by resorting to linear programming and co-positive Lyapunov functions.Finally,two numerical examples are provided to illustrate the results obtained.展开更多
The performance of lithium-sulfur batteries(LSBs)is severely limited by a detrimental negative feedback loop:sluggish polysulfide conversion kinetics lead to Li_(2)S accumulation,which further hinders lithiumion trans...The performance of lithium-sulfur batteries(LSBs)is severely limited by a detrimental negative feedback loop:sluggish polysulfide conversion kinetics lead to Li_(2)S accumulation,which further hinders lithiumion transport and exacerbates capacity decay.To address this,we propose a positive feedback strategy that simultaneously enhances lithium polysulfides(LiPSs)conversion and lithium-ion diffusion through a rationally designed separator.By modifying the separator with phosphorus-doped two-dimensional hollow holey carbon nanosheets(Hollow HCNS),we establish an interconnected network where rapid LiPSs confinement and conversion within the hollow cavities promote efficient lithium-ion transport,while the improved ion flux further accelerates reaction kinetics.This mutual reinforcement mechanism ensures stable cycling by suppressing the shuttle effect and promoting uniform Li_(2)S deposition,as verified by in situ spectroscopic and electrochemical analysis.The resulting LSBs exhibit high-rate capability,ultralow capacity decay,and exceptional stability under high sulfur loading.This work presents a general approach to overcoming the persistent negative feedback problem in high-energy battery systems by synergistically optimizing catalytic conversion and ionic transport.展开更多
Hepatocellular carcinoma(HCC)is a highly heterogenous dis-ease in histology,genetic aberrations,and protein expression.Over the past decade,the development of new omics techniques has fa-cilitated significant advances...Hepatocellular carcinoma(HCC)is a highly heterogenous dis-ease in histology,genetic aberrations,and protein expression.Over the past decade,the development of new omics techniques has fa-cilitated significant advances in the field of molecular typing stud-ies of HCC.In the era of precision medicine,it is of great signif-icance to improve the efficacy of HCC treatment based on tumor molecular subtyping.Cytokeratin(CK)19-positive HCC has gained increasing atten-tion.Although CK19 is a marker of biliary epithelial cells,10%−30%of HCCs are observed to be CK19 positive[1].Differing from com-bined hepatocellular and cholangiocarcinoma,CK19-positive HCC displays typical HCC morphological features,exhibiting strong co-express of both hepatocyte and cholangiocyte markers within the same tumor cells.Consequently,CK19-positive HCC is also referred to as dual-phenotype HCC,with displaying cholangiolar differenti-ation.展开更多
Higher education is transitioning from mass expansion to high-quality development.In this process,mental health issues among college students have become increasingly prominent,encompassing not only academic stress-in...Higher education is transitioning from mass expansion to high-quality development.In this process,mental health issues among college students have become increasingly prominent,encompassing not only academic stress-induced anxiety but also complex challenges such as interpersonal adaptation difficulties and career planning confusion.Traditional“problem-oriented”intervention models have shown limitations in responsiveness and adaptability,often only passively addressing existing psychological crises rather than preventing them in advance.This study aims to explore an AI-powered“positive psychology”proactive intervention model through developing an intelligent system.The system automatically collects,filters,and personalizes recommendations for positive activities on campus.Using a randomized controlled trial design,we conducted an 8-week intervention study involving 126 college students at a university.The study found that AI-based“campus positive activity”recommendations effectively boost students’positive emotions and promote psychological capital development through cumulative micro-interventions.This provides universities with empirical evidence and innovative methods to implement low-cost,efficient,and scalable mental health promotion programs through smart technology.展开更多
Objective:This study aimed to evaluate the diagnostic accuracy of MRI in the detection of nodal metastasis in urothelial bladder cancer(UBC)and to assess the long-term oncological outcomes of upfront radical cystectom...Objective:This study aimed to evaluate the diagnostic accuracy of MRI in the detection of nodal metastasis in urothelial bladder cancer(UBC)and to assess the long-term oncological outcomes of upfront radical cystectomy(RC)in patients with clinical lymph node-positive(cN^(+))muscle-invasive UBC.Methods:A retrospective analysis of 1053 consecutive UBC patients treated with RC between January 1,2004 and January 31,2014 was performed.Radiological,clinical,pathological data and survival outcomes of cN^(+) patients were collected.Cox regression analyses were used to assess the impact of the radiological,clinical,and pathological variables on survival.Results:A total of 233(22%)patients were diagnosed with cN^(+) UBC with a mean age of 57.3(standard deviation 8.1)years,of whom 144(62%)were found to have pathologically positive lymph nodes at final pathology.Adjuvant chemotherapy was administered to 58(25%)patients.The sensitivity,specificity,positive predictive value,and negative predictive value of MRI to detect pathological lymph node-positive disease were 51%,88%,62%,and 83%,respectively.The overall accuracy was 79% with a calculated area under the curve of 70%.The median follow-up period was 17.0(interquartile range 8.2e58.7)months.During this period,54(23%)patients developed local recurrence while 56(24%)experienced distant metastasis and the estimated 1-,3-,5-,and 10-year recurrence-free survival for cN^(+) patients were 78%,56%,51%,and 48%,respectively.On multivariate analysis,advanced pT stage(pT3e4 vs.pT2)was the only independent predictor of recurrence-free survival.Conclusion:Despite its potential in preoperative assessment of muscle-invasive UBC,MRI showed limited sensitivity for detecting node-positive disease.Notably,in patients with MRIdetected cN^(+) UBC,those who underwent upfront RC demonstrated long-term survival outcomes comparable to those treated with neoadjuvant chemotherapy followed by consolidative cystectomy in previously published studies.展开更多
Fine particulatematter(PM_(2.5))samples were collected in two neighboring cities,Beijing and Baoding,China.High-concentration events of PM_(2.5) in which the average mass concentration exceeded 75μg/m^(3) were freque...Fine particulatematter(PM_(2.5))samples were collected in two neighboring cities,Beijing and Baoding,China.High-concentration events of PM_(2.5) in which the average mass concentration exceeded 75μg/m^(3) were frequently observed during the heating season.Dispersion Normalized Positive Matrix Factorization was applied for the source apportionment of PM_(2.5) as minimize the dilution effects of meteorology and better reflect the source strengths in these two cities.Secondary nitrate had the highest contribution for Beijing(37.3%),and residential heating/biomass burning was the largest for Baoding(27.1%).Secondary nitrate,mobile,biomass burning,district heating,oil combustion,aged sea salt sources showed significant differences between the heating and non-heating seasons in Beijing for same period(2019.01.10–2019.08.22)(Mann-Whitney Rank Sum Test P<0.05).In case of Baoding,soil,residential heating/biomass burning,incinerator,coal combustion,oil combustion sources showed significant differences.The results of Pearson correlation analysis for the common sources between the two cities showed that long-range transported sources and some sources with seasonal patterns such as oil combustion and soil had high correlation coefficients.Conditional Bivariate Probability Function(CBPF)was used to identify the inflow directions for the sources,and joint-PSCF(Potential Source Contribution Function)was performed to determine the common potential source areas for sources affecting both cities.These models facilitated a more precise verification of city-specific influences on PM_(2.5) sources.The results of this study will aid in prioritizing air pollution mitigation strategies during the heating season and strengthening air quality management to reduce the impact of downwind neighboring cities.展开更多
Despite advancements in neuroimaging,false positive diagnoses of intracranial aneurysms remain a significant concern.This article examines the causes,prevalence,and implications of such false-positive diagnoses.We dis...Despite advancements in neuroimaging,false positive diagnoses of intracranial aneurysms remain a significant concern.This article examines the causes,prevalence,and implications of such false-positive diagnoses.We discuss how conditions like arterial occlusion with vascular stump formation and infundibular widening can mimic aneurysms,particularly in the anterior circulation.The article compares various imaging modalities,including computer tomography angiogram,magnetic resonance imaging/angiography,and digital subtraction angiogram,highlighting their strengths and limitations.We emphasize the im-portance of accurate differentiation to avoid unnecessary surgical interventions.The potential of emerging technologies,such as high-resolution vessel wall ima-ging and deep neural networks for automated detection,is explored as promising avenues for improving diagnostic accuracy.This manuscript underscores the need for continued research and clinical vigilance in the diagnosis of intracranial aneurysms.展开更多
In this paper,we study the Bowen entropy of stable sets in positive entropy G-system of amenable group actions.The lower bound of the Bowen entropy of these sets are estimated.
This article studies a class of nonlinear Kirchhoff equations with exponential critical growth,trapping potential,and perturbation.Under appropriate assumptions about f and h,the article obtained the existence of norm...This article studies a class of nonlinear Kirchhoff equations with exponential critical growth,trapping potential,and perturbation.Under appropriate assumptions about f and h,the article obtained the existence of normalized positive solutions for this equation via the Trudinger-Moser inequality and variational methods.Moreover,these solutions are also ground state solutions.Additionally,the article also characterized the asymptotic behavior of solutions.The results of this article expand the research of relevant literature.展开更多
In this paper,we introduce the real pairwise completely positive(RPCP)matrices with one of them is necessarily positive semidefinite while the other one is necessarily entrywise nonnegative,which has a real pairwise c...In this paper,we introduce the real pairwise completely positive(RPCP)matrices with one of them is necessarily positive semidefinite while the other one is necessarily entrywise nonnegative,which has a real pairwise completely positive(RPCP)decomposition.We study the properties of RPCP matrices and give some necessary and sufficient conditions for a matrix pair to be RPCP.First,we give an equivalent decomposition for the RPCP matrices,which is different from the RPCP-decomposition and show that the matrix pair(X,X)is RPCP if and only if X is completely positive.Besides,we also prove that the RPCP matrices checking problem is equivalent to the separable completion problem.A semidefinite algorithm is also proposed for detecting whether or not a matrix pair is RPCP.The asymptotic and finite convergence of the algorithm are also discussed.If it is RPCP,we can further give a RPCP-decomposition for it;if it is not,we can obtain a certificate for this.展开更多
Objective:To evaluate the predictive value of the neutrophil⁃to⁃lymphocyte ratio(NLR)and the systemic immune⁃inflammation index(SII)in predicting patients with anti⁃melanoma differentiation⁃associated gene 5⁃positive(...Objective:To evaluate the predictive value of the neutrophil⁃to⁃lymphocyte ratio(NLR)and the systemic immune⁃inflammation index(SII)in predicting patients with anti⁃melanoma differentiation⁃associated gene 5⁃positive(anti⁃MDA5+)dermatomyositis(DM)develop into the rapidly progressive interstitial lung disease(RPILD).Methods:We retrospectively analyzed the clinical and laboratory data of 124 anti⁃MDA5+DM patients from the First Affiliated Hospital of Nanjing Medical University between March 2019 and September 2023.We identified independent risk factors associated with the development and mortality of RPILD with the Cox regression analysis,and determined the optimal cut⁃off values for predicting adverse outcomes with the receiver operating characteristic(ROC)curve analysis.Results:Among the 124 patients,36 patients(29.03%)developed RPILD,and 39 patients(31.45%)died during the follow⁃up period.The results of multivariate Cox regression analysis showed that the elevated NLR was an independent risk factor for RPILD development,while the elevated SII expression was independently associated with the increased mortality of RPILD.Based on the ROC curve analysis,NLR>6.12 was a predictor for RPILD,and SII>875.79 was associated with increased mortality risk of RPILD.Conclusion:Both NLR and SII are accessible,cost⁃effective,and reliable prognostic indicators for the prognosis of patients with anti⁃MDA5^(+)DM,providing a valuable guidance for clinical management and risk stratification of the disease.展开更多
In life,we are bound to encounter various difficulties and setbacks.However,it is of great significance to maintain a positive attitude when were facing these challenges.For me,this lesson was deeply impressed upon me...In life,we are bound to encounter various difficulties and setbacks.However,it is of great significance to maintain a positive attitude when were facing these challenges.For me,this lesson was deeply impressed upon me during a particularly tough period.展开更多
Adolescence is a crucial period marked by significant developmental changes,during which risk-taking behaviors can be both a normative part of development and a potential source of concern.However,prior research has f...Adolescence is a crucial period marked by significant developmental changes,during which risk-taking behaviors can be both a normative part of development and a potential source of concern.However,prior research has focused predominantly on the adverse aspects of risk-taking(i.e.,negative risk-taking),overlooked the positive counterpart(i.e.,positive risk-taking),and lacked a detailed examination of both.This study aims to elucidate the distinct characteristics and interrelationships of positive and negative risk-taking behaviors among adoles-cents and to identify the key factors that influence these behaviors.Through a comprehensive synthesis of theoretical and empirical literature,we explore the multifaceted nature of risk-taking,highlighting its complex influencing factors,including individual traits,family dynamics,peer influence,school environment,and broader community contexts.By identifying the shared and unique factors contributing to positive and negative risk-taking behaviors,we can enable adolescents to navigate this complex stage of life and design targeted interventions.Future research directions include the application of person-centered approaches,the implementation of longitudinal tracking and the interactive effects of influencing factors,among other aspects.展开更多
基金supported by the 2024 Zhejiang Provincial Women’s Federation&Women’s Studies Association Research Project(202450).
文摘Objective:International students frequently face psychological adaptation difficulties while studying and living abroad.As an effective psychological resource,positive solitude has been identified as a potential factor for improving psychological well-being,but the underlying mechanism linking the two has not been fully explored.The current study aims to explore the relationship between positive solitude and psychological adaptation of international students,with particular emphasis on the intermediary roles of authenticity and loneliness.Methods:A total of 529 international tertiary students(Mage=23.76,SD=5.08;60.68%male)were surveyed using the Positive Solitude Scale(PSS),Authenticity Scale(AS),6-item UCLA Loneliness Scale(ULS-6),and Brief Psychological Adaptation Scale(BPAS).SPSS27.0 was used for descriptive statistical analysis and Pearson correlation analysis.PROCESS macro(Model 6)was employed to test a serial mediation model,in which authenticity and loneliness function as intermediary variables between positive solitude and psychological adaptation.Results:The correlation analysis indicated significant associations among positive solitude,authenticity,loneliness,and psychological adaptation(r=−0.544~0.511).Positive solitude was directly and positively related to psychological adaptation(β=0.132,t=3.609,p<0.001)and indirectly related to psychological adaptation through two pathways:a single mediation via authenticity(indirect effect=0.089)and a serial mediation through authenticity and loneliness(indirect effect=0.062).Loneliness did not serve as a significant mediator(indirect effect=–0.015,95%CI[–0.049,0.019]).The total indirect effect was 0.136.Conclusions:Interventions targeting international students’capacity for experiencing positive solitude and authenticity can help to reduce loneliness and increase psychological adaptation.The findings derived from this study are conducive to understanding the relationship between positive solitude and psychological adaptation,as well as its underlying mechanisms.In addition,the study offers a new perspective for educational management and psychological counseling services for international students.
文摘Objectives This study aimed to explore and clarify the concept of reflective supervision as a professional self-care strategy to create a positive Intensive Care Unit(ICU)practice environment.Methods Walker and Avant’s eight-step concept analysis approach was utilized to identify and define the attributes,antecedents,and consequences of reflective supervision in the ICU.An extensive literature search was conducted across various databases,including Google Scholar,CINAHL,PubMed.Articles published from 2005 to 2025 were identified.We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses(PRISMA)2020 statement to indicate the included articles and extract related data based on relevance.Results Forty articles were included in the analysis.The identified attributes included the supervisor-supervisee relationship,effective communication,teamwork,collaborations,reflection,competencies,feedback,continuous support,and autonomous choice.The identified antecedents included participation,supportive supervision,flexibility,open-door policy,training,and motivation.Consequences impacting the success of reflective supervision were identified as promotion of resiliency,autonomy,work-life balance,self-awareness,increased self-esteem,professional development,critical thinking,increased job satisfaction,and enhanced commitment.Conclusions Reflective supervision is a complex professional self-care strategy that enhances ICU practice,by promoting nurses’well-being,self-awareness,therapeutic skills,and professional development.
基金Supported by Scientific Research Project of Jilin Provincial Department of Education(JJKH20250464KJ)。
文摘This paper deals with homogeneous Dirichlet boundary value problem to a class of porous medium equations with viscoelastic term ∂u/∂t-Δu^(m)+∫^(t)_(0)g(t-s)Δu^(m)(x,s)ds=u^(p),x∈Ω,t≥0,where p>m(m>0).We prove that the weak solutions of the above problem blow up in finite time when the initial energy is positive and the function g satisfies suitable conditions.Our result generalizes that of S.A.Messaoudi in[1].
文摘Objective: To evaluate the efficacy of noninvasive positive pressure ventilation (NIPPV) in respiratory support for severe pneumonia. Methods: Data were analyzed from 74 patients with severe pneumonia undergoing respiratory support at our hospital between May 2024 and April 2025. Patients were randomly assigned using a random number table to two groups (n = 37 each): the experimental group received NIPPV, while the control group underwent conventional invasive mechanical ventilation. Intergroup differences were compared. Results: Compared with the control group, the experimental group demonstrated significantly higher PaO2 and oxygenation index, significantly lower PaCO2, significantly reduced levels of WBC, CRP, and PCT, significantly higher overall efficacy rate, and significantly lower incidence of adverse reactions after treatment (p < 0.05). Pre-treatment PaO2, oxygenation index, PaCO2, WBC, CRP, and PCT levels showed no significant differences between groups (p > 0.05). Conclusion: Non-invasive positive pressure ventilation demonstrates favorable outcomes in respiratory support for severe pneumonia.
基金supported by the National Social Science Fund of China(No.23BSH123).
文摘Background:Emerging adulthood is a critical period for ego identity exploration and consolidation,and self-presentation on social media constitutes a salient online context for this developmental process.However,limited research has explored the associations between self-presentation on WeChat Moments and ego identity.This study aims to examine these associations,focusing on the mediating role of online positive feedback and the moderating role of gender.Methods:Using a three-wave longitudinal design,this study followed 767 Chinese college students(Mean age=18.96 years)through cluster sampling.Participants completed self-report questionnaires assessing self-presentation on WeChat Moments,online positive feedback,and ego identity status.Data analyses were conducted using mediation modeling and multi-group structural equation modeling.Results:Authentic self-presentation was positively associated with identity achievement and negatively associated with identity diffusion,whereas positive self-presentation was linked to higher levels of identity foreclosure.Online positive feedback played a significant mediating role in the associations between self-presentation strategies and identity statuses,and gender differences were observed in this mediating pathway.For both males and females,authentic self-presentation was associated with higher identity achievement through online positive feedback.However,indirect associations with identity foreclosure and diffusion were observed only among females:authentic self-presentation was linked to lower levels,whereas positive self-presentation was linked to higher levels of foreclosure and diffusion through online positive feedback.No comparable indirect associations were detected among males.Conclusions:Online positive feedback is closely linked to self-presentation strategies and ego identity statuses,with these associations varying by gender.
基金supported by the National Outstanding Youth Science Fund Project of National Natural Science Foundation of China(No.52302031)National Natural Science Foundation of China(No.51932008).
文摘As a core functional refractory in the continuous casting process,the service reliability of the submerged entry nozzle(SEN)is directly related to the stability of continuous casting production,the quality of casting billets,and production efficiency.Al_(2)O_(3) inclusions clogging constitutes the predominant failure mode of SEN,particularly during continuous casting of high-grade steels.Although several studies in the literature have demonstrated that electric field application can mitigate SEN clogging to some extent,the underlying mechanism remains poorly understood,which hinders its widespread acceptance and practical implementation.The mechanism of preventing SEN clogging by applying a positive electric field was studied,and experimental verification was conducted on it in a certain steel plant.The results indicate that Al_(2)O_(3) inclusions exhibit a positive charge in molten steel under high-temperature(~1600℃)and low-oxygen-partial-pressure(≤20×10-6)conditions.In the continuous casting process at a Chinese steel plant,applying a positive electric field to the SEN effectively suppressed the migration of Al_(2)O_(3) inclusions toward the SEN wall,significantly enhancing its clogging resistance.
文摘Let M be a compact n-manifold of positive sectional curvature.We will review classical results on the fundamental group of M,a motivation on the c(n)-cyclic conjecture that the fundamental group of M contains a cyclic subgroup of index bounded above by c(n),a constant depending only on n,and we will survey partial results(up to date)on the c(n)-cyclic conjecture.
基金supported by the National Natural Science Foundation of China(62463007,62463005)the Natural Science Foundation of Hainan Province(625RC710,625MS047)+1 种基金the System Control and Information Processing Education Ministry Key Laboratory Open Funding,China(Scip20240119)the Science Research Funding of Hainan University,China(KYQD(ZR)22180,KYQD(ZR)23180).
文摘This paper focuses on the leader-following positive consensus problems of heterogeneous switched multi-agent systems.First,a state-feedback controller with dynamic compensation is introduced to achieve positive consensus under average dwell time switching.Then sufficient conditions are derived to guarantee the positive consensus.The gain matrices of the control protocol are described using a matrix decomposition approach and the corresponding computational complexity is reduced by resorting to linear programming and co-positive Lyapunov functions.Finally,two numerical examples are provided to illustrate the results obtained.
基金the support from the National Science Foundation of China(22471226,22272142)the 111 Project(B16029)。
文摘The performance of lithium-sulfur batteries(LSBs)is severely limited by a detrimental negative feedback loop:sluggish polysulfide conversion kinetics lead to Li_(2)S accumulation,which further hinders lithiumion transport and exacerbates capacity decay.To address this,we propose a positive feedback strategy that simultaneously enhances lithium polysulfides(LiPSs)conversion and lithium-ion diffusion through a rationally designed separator.By modifying the separator with phosphorus-doped two-dimensional hollow holey carbon nanosheets(Hollow HCNS),we establish an interconnected network where rapid LiPSs confinement and conversion within the hollow cavities promote efficient lithium-ion transport,while the improved ion flux further accelerates reaction kinetics.This mutual reinforcement mechanism ensures stable cycling by suppressing the shuttle effect and promoting uniform Li_(2)S deposition,as verified by in situ spectroscopic and electrochemical analysis.The resulting LSBs exhibit high-rate capability,ultralow capacity decay,and exceptional stability under high sulfur loading.This work presents a general approach to overcoming the persistent negative feedback problem in high-energy battery systems by synergistically optimizing catalytic conversion and ionic transport.
基金supported by grants from the Major Re-search Plan of the National Natural Science Foundation of China(92159202)the National Key Research and Development Pro-gram of China(2021YFA1100500)+5 种基金the Key Research&Develop-ment Plan of Zhejiang Province(2024C03051)the Innovation Team of Hangzhou Medical College(CXLJ202401)Joint TCM Science&Technology Projects of National Demonstration Zones for Compre-hensive TCM Reform(GZY-KJS-ZJ-2025-002)the National Natural Science Foundation of China(82303387)the Natural Science Foun-dation of Zhejiang Province(LQ23H160048)the Construction Fund of Key Medical Disciplines of Hangzhou(2025HZGF05).
文摘Hepatocellular carcinoma(HCC)is a highly heterogenous dis-ease in histology,genetic aberrations,and protein expression.Over the past decade,the development of new omics techniques has fa-cilitated significant advances in the field of molecular typing stud-ies of HCC.In the era of precision medicine,it is of great signif-icance to improve the efficacy of HCC treatment based on tumor molecular subtyping.Cytokeratin(CK)19-positive HCC has gained increasing atten-tion.Although CK19 is a marker of biliary epithelial cells,10%−30%of HCCs are observed to be CK19 positive[1].Differing from com-bined hepatocellular and cholangiocarcinoma,CK19-positive HCC displays typical HCC morphological features,exhibiting strong co-express of both hepatocyte and cholangiocyte markers within the same tumor cells.Consequently,CK19-positive HCC is also referred to as dual-phenotype HCC,with displaying cholangiolar differenti-ation.
文摘Higher education is transitioning from mass expansion to high-quality development.In this process,mental health issues among college students have become increasingly prominent,encompassing not only academic stress-induced anxiety but also complex challenges such as interpersonal adaptation difficulties and career planning confusion.Traditional“problem-oriented”intervention models have shown limitations in responsiveness and adaptability,often only passively addressing existing psychological crises rather than preventing them in advance.This study aims to explore an AI-powered“positive psychology”proactive intervention model through developing an intelligent system.The system automatically collects,filters,and personalizes recommendations for positive activities on campus.Using a randomized controlled trial design,we conducted an 8-week intervention study involving 126 college students at a university.The study found that AI-based“campus positive activity”recommendations effectively boost students’positive emotions and promote psychological capital development through cumulative micro-interventions.This provides universities with empirical evidence and innovative methods to implement low-cost,efficient,and scalable mental health promotion programs through smart technology.
文摘Objective:This study aimed to evaluate the diagnostic accuracy of MRI in the detection of nodal metastasis in urothelial bladder cancer(UBC)and to assess the long-term oncological outcomes of upfront radical cystectomy(RC)in patients with clinical lymph node-positive(cN^(+))muscle-invasive UBC.Methods:A retrospective analysis of 1053 consecutive UBC patients treated with RC between January 1,2004 and January 31,2014 was performed.Radiological,clinical,pathological data and survival outcomes of cN^(+) patients were collected.Cox regression analyses were used to assess the impact of the radiological,clinical,and pathological variables on survival.Results:A total of 233(22%)patients were diagnosed with cN^(+) UBC with a mean age of 57.3(standard deviation 8.1)years,of whom 144(62%)were found to have pathologically positive lymph nodes at final pathology.Adjuvant chemotherapy was administered to 58(25%)patients.The sensitivity,specificity,positive predictive value,and negative predictive value of MRI to detect pathological lymph node-positive disease were 51%,88%,62%,and 83%,respectively.The overall accuracy was 79% with a calculated area under the curve of 70%.The median follow-up period was 17.0(interquartile range 8.2e58.7)months.During this period,54(23%)patients developed local recurrence while 56(24%)experienced distant metastasis and the estimated 1-,3-,5-,and 10-year recurrence-free survival for cN^(+) patients were 78%,56%,51%,and 48%,respectively.On multivariate analysis,advanced pT stage(pT3e4 vs.pT2)was the only independent predictor of recurrence-free survival.Conclusion:Despite its potential in preoperative assessment of muscle-invasive UBC,MRI showed limited sensitivity for detecting node-positive disease.Notably,in patients with MRIdetected cN^(+) UBC,those who underwent upfront RC demonstrated long-term survival outcomes comparable to those treated with neoadjuvant chemotherapy followed by consolidative cystectomy in previously published studies.
基金supported by the National Institute of Environmental Research(NIER)funded by the Ministry of Environment(No.NIER-2019-04-02-039)supported by Particulate Matter Management Specialized Graduate Program through the Korea Environmental Industry&Technology Institute(KEITI)funded by the Ministry of Environment(MOE).
文摘Fine particulatematter(PM_(2.5))samples were collected in two neighboring cities,Beijing and Baoding,China.High-concentration events of PM_(2.5) in which the average mass concentration exceeded 75μg/m^(3) were frequently observed during the heating season.Dispersion Normalized Positive Matrix Factorization was applied for the source apportionment of PM_(2.5) as minimize the dilution effects of meteorology and better reflect the source strengths in these two cities.Secondary nitrate had the highest contribution for Beijing(37.3%),and residential heating/biomass burning was the largest for Baoding(27.1%).Secondary nitrate,mobile,biomass burning,district heating,oil combustion,aged sea salt sources showed significant differences between the heating and non-heating seasons in Beijing for same period(2019.01.10–2019.08.22)(Mann-Whitney Rank Sum Test P<0.05).In case of Baoding,soil,residential heating/biomass burning,incinerator,coal combustion,oil combustion sources showed significant differences.The results of Pearson correlation analysis for the common sources between the two cities showed that long-range transported sources and some sources with seasonal patterns such as oil combustion and soil had high correlation coefficients.Conditional Bivariate Probability Function(CBPF)was used to identify the inflow directions for the sources,and joint-PSCF(Potential Source Contribution Function)was performed to determine the common potential source areas for sources affecting both cities.These models facilitated a more precise verification of city-specific influences on PM_(2.5) sources.The results of this study will aid in prioritizing air pollution mitigation strategies during the heating season and strengthening air quality management to reduce the impact of downwind neighboring cities.
文摘Despite advancements in neuroimaging,false positive diagnoses of intracranial aneurysms remain a significant concern.This article examines the causes,prevalence,and implications of such false-positive diagnoses.We discuss how conditions like arterial occlusion with vascular stump formation and infundibular widening can mimic aneurysms,particularly in the anterior circulation.The article compares various imaging modalities,including computer tomography angiogram,magnetic resonance imaging/angiography,and digital subtraction angiogram,highlighting their strengths and limitations.We emphasize the im-portance of accurate differentiation to avoid unnecessary surgical interventions.The potential of emerging technologies,such as high-resolution vessel wall ima-ging and deep neural networks for automated detection,is explored as promising avenues for improving diagnostic accuracy.This manuscript underscores the need for continued research and clinical vigilance in the diagnosis of intracranial aneurysms.
基金Supported by NSFC(No.11861010),also supported by NSFC(No.12171175),also supported by NSFC(No.12261006)NSF of Guangxi Province(No.2018GXNSFFA281008)Project of Guangxi First Class Disciplines of Statistics(No.GJKY-2022-01)。
文摘In this paper,we study the Bowen entropy of stable sets in positive entropy G-system of amenable group actions.The lower bound of the Bowen entropy of these sets are estimated.
基金Supported by National Natural Science Foundation of China(11671403,11671236)Henan Provincial General Natural Science Foundation Project(232300420113)。
文摘This article studies a class of nonlinear Kirchhoff equations with exponential critical growth,trapping potential,and perturbation.Under appropriate assumptions about f and h,the article obtained the existence of normalized positive solutions for this equation via the Trudinger-Moser inequality and variational methods.Moreover,these solutions are also ground state solutions.Additionally,the article also characterized the asymptotic behavior of solutions.The results of this article expand the research of relevant literature.
文摘In this paper,we introduce the real pairwise completely positive(RPCP)matrices with one of them is necessarily positive semidefinite while the other one is necessarily entrywise nonnegative,which has a real pairwise completely positive(RPCP)decomposition.We study the properties of RPCP matrices and give some necessary and sufficient conditions for a matrix pair to be RPCP.First,we give an equivalent decomposition for the RPCP matrices,which is different from the RPCP-decomposition and show that the matrix pair(X,X)is RPCP if and only if X is completely positive.Besides,we also prove that the RPCP matrices checking problem is equivalent to the separable completion problem.A semidefinite algorithm is also proposed for detecting whether or not a matrix pair is RPCP.The asymptotic and finite convergence of the algorithm are also discussed.If it is RPCP,we can further give a RPCP-decomposition for it;if it is not,we can obtain a certificate for this.
文摘Objective:To evaluate the predictive value of the neutrophil⁃to⁃lymphocyte ratio(NLR)and the systemic immune⁃inflammation index(SII)in predicting patients with anti⁃melanoma differentiation⁃associated gene 5⁃positive(anti⁃MDA5+)dermatomyositis(DM)develop into the rapidly progressive interstitial lung disease(RPILD).Methods:We retrospectively analyzed the clinical and laboratory data of 124 anti⁃MDA5+DM patients from the First Affiliated Hospital of Nanjing Medical University between March 2019 and September 2023.We identified independent risk factors associated with the development and mortality of RPILD with the Cox regression analysis,and determined the optimal cut⁃off values for predicting adverse outcomes with the receiver operating characteristic(ROC)curve analysis.Results:Among the 124 patients,36 patients(29.03%)developed RPILD,and 39 patients(31.45%)died during the follow⁃up period.The results of multivariate Cox regression analysis showed that the elevated NLR was an independent risk factor for RPILD development,while the elevated SII expression was independently associated with the increased mortality of RPILD.Based on the ROC curve analysis,NLR>6.12 was a predictor for RPILD,and SII>875.79 was associated with increased mortality risk of RPILD.Conclusion:Both NLR and SII are accessible,cost⁃effective,and reliable prognostic indicators for the prognosis of patients with anti⁃MDA5^(+)DM,providing a valuable guidance for clinical management and risk stratification of the disease.
文摘In life,we are bound to encounter various difficulties and setbacks.However,it is of great significance to maintain a positive attitude when were facing these challenges.For me,this lesson was deeply impressed upon me during a particularly tough period.
基金Soft Science Special Project of Gansu Basic Research Plan,No.25JRZA072Youth Project of Philosophy and Social Science Foundation of Gansu Province,No.2024QN015+1 种基金General Project of Philosophy and Social Science Foundation of Gansu Province,No.2024YB049Lanzhou Philosophy and Social Science Planning Project,No.24-B13.
文摘Adolescence is a crucial period marked by significant developmental changes,during which risk-taking behaviors can be both a normative part of development and a potential source of concern.However,prior research has focused predominantly on the adverse aspects of risk-taking(i.e.,negative risk-taking),overlooked the positive counterpart(i.e.,positive risk-taking),and lacked a detailed examination of both.This study aims to elucidate the distinct characteristics and interrelationships of positive and negative risk-taking behaviors among adoles-cents and to identify the key factors that influence these behaviors.Through a comprehensive synthesis of theoretical and empirical literature,we explore the multifaceted nature of risk-taking,highlighting its complex influencing factors,including individual traits,family dynamics,peer influence,school environment,and broader community contexts.By identifying the shared and unique factors contributing to positive and negative risk-taking behaviors,we can enable adolescents to navigate this complex stage of life and design targeted interventions.Future research directions include the application of person-centered approaches,the implementation of longitudinal tracking and the interactive effects of influencing factors,among other aspects.
