To explore the impact of partial centralization on supply chain performance,this study constructs a two-period game model of a closed-loop supply chain involving a manufacturer and an online retail platform participat...To explore the impact of partial centralization on supply chain performance,this study constructs a two-period game model of a closed-loop supply chain involving a manufacturer and an online retail platform participating in the trade-in strategy.Through mathematical modeling and numerical simulation methods,the optimal decisions were analyzed under conditions where the manufacturer partially owns the retail platform’s partial equity.This study finds that partial centralization yields the highest profits,followed by full centralization,with decentralized decisions yielding the lowest profits.Moderate centralization enhances overall profits by optimizing incentive mechanisms,whereas excessive ownership concentration reduces the flexibility of the retail platform,leading to a decline in profits.Additionally,product durability and trade-in subsidy significantly influence supply chain profitability:high-durability products reduce renewal frequency,while trade-in subsidy effectively stimulates consumer demand and increase overall profits.This study provides theoretical support and practical guidance for companies implementing the trade-in strategy.展开更多
Objective:Limited evidence is available regarding the associations of centralization with gastric cancer patients’quality of care in high surgical volume settings.The current study aimed to explore the effects of hos...Objective:Limited evidence is available regarding the associations of centralization with gastric cancer patients’quality of care in high surgical volume settings.The current study aimed to explore the effects of hospital volume and the Herfindahl-Hirschman index(HHI)on in-hospital mortality,total cost,and length of stay for Chinese gastrectomy patients in a nationwide database.Methods:We extracted data on gastrectomy for gastric cancer from the Hospital Quality Monitoring System Database between 2013 and 2018.Hospital volume was divided into 4 quartiles:low(1-83 cases per year),medium(84-238 cases),high(239-579 cases),and very high(580-1,193 cases).The HHI was divided into 3 categories:highly concentrated(>2,500),moderately concentrated(1,500-2,500),and unconcentrated(<1,500).We used mixed-effects models to analyze the data while accounting for data clustering.Results:We analyzed 125,683 patients in 515 institutions.In the multivariable analyses,hospital volume was significantly associated with in-hospital mortality[medium vs.low:odds ratio(OR)=0.61,95%confidence interval(95%CI)=0.43-0.84,P=0.003;high:OR=0.57,95%CI=0.38-0.87,P=0.009;and very high:OR=0.33,95%CI=0.18-0.61,P<0.001)and length of stay(high vs.low:β=-0.036,95%CI=-0.071--0.002,P=0.039)but not with total cost.Hospitals located in unconcentrated provinces had higher in-hospital mortality(OR=1.52,95%CI=1.03-2.26,P=0.036)and longer lengths of stay(β=0.024,95%CI=0.001-0.047,P=0.041)than hospitals located in highly concentrated provinces.Conclusions:Centralization of gastrectomy,measured by hospital volume and the HHI,was associated with decreased in-hospital mortality and shortened length of stay without increasing total cost.These results support the strategy of centralizing gastrectomy in high-volume settings.展开更多
Established during the long years of revolutionary struggle and the founding of the People's Republic of China (PRC), the Communist Party of China(CPC)-led decision-making system has a historical rationality. Bef...Established during the long years of revolutionary struggle and the founding of the People's Republic of China (PRC), the Communist Party of China(CPC)-led decision-making system has a historical rationality. Before China's reform and opening-up was implemented in 1978, the decision-making system highlighted centralization which led to disadvantages such as non-existent specialized division of functions, a low level of institutionalization, heavy reliance on experience, an enclosed decision-making mode and non-existent self-correction mechanisms. These disadvantages were institutional factors which ultimately caused the historic tragedy of " Cultural Revolution. "After the reform and opening-up, the decision-making structure, mode and mechanism were reformed in order to promote scientific, democratic and law-based decisions. History has shown that the reform has successfully overcome various challenges brought about by China's rapidly changing economy and society. From the perspective of political development, the reform has promoted several transitions: from individual controlled decision-making system to a more democratic decision-making process, from being empirical to scientifically-based, from highly centralized decision-making organizations to decentralized one, from an enclosed mode to an open mode, from passive to active participation in the decision-making process and from a non-institutionalized to an institutionalized system. Therefore, the CPC-led open decision-making model based on science and laws and participated by other parties has taken an initial shape.展开更多
The As-level topology is a hotspot of the recent reseaches. We can understand the centralization of the network clearly by researching the evolvement trend of the Internet macroscopic topology. The massive data we use...The As-level topology is a hotspot of the recent reseaches. We can understand the centralization of the network clearly by researching the evolvement trend of the Internet macroscopic topology. The massive data we use in this paper is from CAIDA (The Cooperative Association for Internet Data Analysis) Skitter project. And the time span of the data is from July, 2001 to January, 2008. This paper introduces the background of the AS-level topology at first, then carries out the evolvement of degree, core and layer. It is believed that the influence of the top-degree nodes on the other nodes decreases and the centralization of network is going to fall off with the decrease of the core. And the nucleus status of network declines.展开更多
Objective:To uncover the impact of centralization of COVID-19 and perceived control of COVID-19 on society during the pandemic.Methods:We recruited a total of 1041 people in this cross-sectional study.The data were co...Objective:To uncover the impact of centralization of COVID-19 and perceived control of COVID-19 on society during the pandemic.Methods:We recruited a total of 1041 people in this cross-sectional study.The data were collected using a questionnaire booklet covering demographics,a COVID-19-related information form,the Centrality of Event Scale,and the Perception of Control of COVID-19 Scale.We utilized independent samples t-test,chi-square test,and one-way analysis of variance to analyze the data.Results:1041 questionnaires were collected and no questionnaire were excluded from our study.Slightly more than half of the participants(51.2%)stated that social isolation impaired public mental health,while 30.1%reported adverse impacts of the pandemic on their sleep quality.Participants with changes to their sleep patterns were found to centralize COVID-19 more.Moreover,measures against COVID-19 and constant announcements of the daily number of cases in the media brought both positive and negative effects on people and further contributed to the participants’centralization of COVID-19.Individuals with low centralization scores were concluded to perceive COVID-19 as a minor disease.Healthcare professionals without a relative diagnosed with COVID-19 and those satisfied with treatment opportunities had a higher perceived control of COVID-19,while those who were not interested in statistical data on COVID-19 and who had difficulty complying with the rules had a lower perceived control of COVID-19.Besides,poorer perceived control of COVID-19 was found to adversely affect sleep quality.Furthermore,healthcare professionals scored higher on the inevitability subscale of the Perception of Control of COVID-19 Scale.Finally,among the participants,most COVID-19 survivors thought COVID-19 to be an avoidable disease.Conclusion:In addition to its physical impacts,COVID-19 adversely impacts on mental health,and these effects are closely linked to a society’s centralization of COVID-19 and perceived control of COVID-19.展开更多
Freezing of gait is a significant and debilitating motor symptom often observed in individuals with Parkinson's disease.Resting-state functional magnetic resonance imaging,along with its multi-level feature indice...Freezing of gait is a significant and debilitating motor symptom often observed in individuals with Parkinson's disease.Resting-state functional magnetic resonance imaging,along with its multi-level feature indices,has provided a fresh perspective and valuable insight into the study of freezing of gait in Parkinson's disease.It has been revealed that Parkinson's disease is accompanied by widespread irregularities in inherent brain network activity.However,the effective integration of the multi-level indices of resting-state functional magnetic resonance imaging into clinical settings for the diagnosis of freezing of gait in Parkinson's disease remains a challenge.Although previous studies have demonstrated that radiomics can extract optimal features as biomarkers to identify or predict diseases,a knowledge gap still exists in the field of freezing of gait in Parkinson's disease.This cross-sectional study aimed to evaluate the ability of radiomics features based on multi-level indices of resting-state functional magnetic resonance imaging,along with clinical features,to distinguish between Parkinson's disease patients with and without freezing of gait.We recruited 28 patients with Parkinson's disease who had freezing of gait(15 men and 13 women,average age 63 years)and 30 patients with Parkinson's disease who had no freezing of gait(16 men and 14 women,average age 64 years).Magnetic resonance imaging scans were obtained using a 3.0T scanner to extract the mean amplitude of low-frequency fluctuations,mean regional homogeneity,and degree centrality.Neurological and clinical characteristics were also evaluated.We used the least absolute shrinkage and selection operator algorithm to extract features and established feedforward neural network models based solely on resting-state functional magnetic resonance imaging indicators.We then performed predictive analysis of three distinct groups based on resting-state functional magnetic resonance imaging indicators indicators combined with clinical features.Subsequently,we conducted 100 additional five-fold cross-validations to determine the most effective model for each classification task and evaluated the performance of the model using the area under the receiver operating characteristic curve.The results showed that when differentiating patients with Parkinson's disease who had freezing of gait from those who did not have freezing of gait,or from healthy controls,the models using only the mean regional homogeneity values achieved the highest area under the receiver operating characteristic curve values of 0.750(with an accuracy of 70.9%)and 0.759(with an accuracy of 65.3%),respectively.When classifying patients with Parkinson's disease who had freezing of gait from those who had no freezing of gait,the model using the mean amplitude of low-frequency fluctuation values combined with two clinical features achieved the highest area under the receiver operating characteristic curve of 0.847(with an accuracy of 74.3%).The most significant features for patients with Parkinson's disease who had freezing of gait were amplitude of low-frequency fluctuation alterations in the left parahippocampal gyrus and two clinical characteristics:Montreal Cognitive Assessment and Hamilton Depression Scale scores.Our findings suggest that radiomics features derived from resting-state functional magnetic resonance imaging indices and clinical information can serve as valuable indices for the identification of freezing of gait in Parkinson's disease.展开更多
The mechanistic target of rapamycin(m TOR) is a serinehreonine kinase that plays a pivotal role in cellular growth, proliferation, survival, and metabolism. In the central nervous system(CNS), the mTOR pathway regulat...The mechanistic target of rapamycin(m TOR) is a serinehreonine kinase that plays a pivotal role in cellular growth, proliferation, survival, and metabolism. In the central nervous system(CNS), the mTOR pathway regulates diverse aspects of neural development and function. Genetic mutations within the m TOR pathway lead to severe neurodevelopmental disorders, collectively known as “mTORopathies”(Crino, 2020). Dysfunctions of m TOR, including both its hyperactivation and hypoactivation, have also been implicated in a wide spectrum of other neurodevelopmental and neurodegenerative conditions, highlighting its importance in CNS health.展开更多
Objective To examine the associations of sleep duration and physical activity(PA)with central obesity among Chinese adults.Methods Based on the Prediction for Atherosclerotic Cardiovascular Disease Risk in China(China...Objective To examine the associations of sleep duration and physical activity(PA)with central obesity among Chinese adults.Methods Based on the Prediction for Atherosclerotic Cardiovascular Disease Risk in China(China-PAR)project,175,373 observations from 106,518 participants were included.Generalized estimating equations quantified the associations of sleep duration and PA with waist circumference(WC)and central obesity.Stratified and joint analyses were performed to evaluate combined effects,and an isotemporal substitution model was used to assess substitution effects.Results Suboptimal sleep duration(8 h/day,substituting 30 min/day of sleep with moderate-to-vigorous PA significantly reduced the risk of central obesity.Conclusion Suboptimal sleep duration has a detrimental effect on central obesity,and adequate PA can mitigate this effect.The impact of reallocating sleep duration varies by sleep duration,highlighting the need to optimize both PA and sleep patterns in China.展开更多
The Beishan area(BA),located along the southern margin of the Central Asian orogenic belt,represents a key region for studying the opening of the southern Paleo-Asian Ocean(PAO)during the Neoproterozoic Era.Current un...The Beishan area(BA),located along the southern margin of the Central Asian orogenic belt,represents a key region for studying the opening of the southern Paleo-Asian Ocean(PAO)during the Neoproterozoic Era.Current understanding of BA's Neoproterozoic tectonic evolution remains limited because of insufficient constraints.This study presents petrological,whole-rock geochemical,Sr-Nd isotopic,zircon U-Pb dating,and Hf isotopic analyses of gabbro(765 Ma),dacitic tuff(756 Ma),syenogranite(764 Ma),and monzogranite(770 Ma)from the BA.The gabbros show high MgO(8.06-8.31 wt%)and low K2O(0.23-1.09 wt%)contents,depletion of high-field-strength elements(Nb,Ta,and Ti),(87Sr/86Sr)i ratios of 0.7051-0.7057,and positiveεNd(t)values(+2.55 to+3.19).These geochemical signatures suggest derivation from a depleted mantle metasomatized by subducted slab-derived melts,consistent with formation in a back-arc rift setting.The dacitic tuffs display negativeεNd(t)values(-16.38 to-1.29)and Zr-Hf enrichment,indicating an origin from ancient crustal melting.The syenogranites and monzogranites are characterized by high 10,000 Ga/Al and(Zr+Nb+Ce+Y)values,classifying them as A1-type granites.They yield negativeεNd(t)values(-6.66 to-2.29)and variableεHf(t)values(-3.7 to+4.8),indicating partial melting of Paleoproterozoic crust material.Based on these findings and previous studies,we propose that the initial opening of the southern PAO in the BA occurred no earlier than 770 Ma,likely driven by combined subducted slab rollback and mantle plume upwelling.展开更多
Spinal cord injury is a severe neurological condition with far-reaching consequences for both individuals and society.Its progression involves a complex interplay between the initial mechanical insult and inflammation...Spinal cord injury is a severe neurological condition with far-reaching consequences for both individuals and society.Its progression involves a complex interplay between the initial mechanical insult and inflammation-driven secondary injury.This review interprets recent studies on the spatiotemporal map of the inflammatory microenvironment in spinal cord injury and other neurological disorders,focusing on the latest mechanistic research and treatment options.The postinjury inflammatory microenvironment comprises diverse immune and glial cell populations whose phenotypes and functions change over time.The current consensus suggests that inflammation has a paradoxical nature:while it can limit lesion spread in the acute stage,chronic or dysregulated responses contribute to further neural damage through pathways such as excitotoxicity,oxidative stress,and glial scar formation.Methods such as spatiotemporal transcriptomic analyses and organoid-based models have improved our ability to resolve cell–cell interactions and discover new molecular targets.Numerous therapies targeting this microenvironment have been developed.Stem cell-based approaches,especially human umbilical cord mesenchymal stem cells,show promise in promoting tissue regeneration and immune regulation in experimental and early clinical studies.Bioengineering methods such as using biomaterial scaffolds and controlled drug release are being investigated to improve drug delivery and the injury microenvironment.Pharmacological efforts to modify cytokine networks,oxidative pathways,or immune checkpoints have achieved some success,hampered by patient heterogeneity and injury patterns.Persistent challenges include determining the context-specific mechanisms,identifying the best treatment windows,and combining a few methods for the best effect.In summary,detailed understanding of the spatiotemporal dynamics of post–spinal cord injury inflammation is essential for designing targeted interventions.Future directions include integrating multiomics datasets,identifying predictive biomarkers for patient stratification,and developing adaptive treatment protocols that fine-tune rather than suppress immune responses to promote neural repair and functional recovery.展开更多
Demyelinating diseases of the central nervous system are common,yet few effective strategies for myelin repair and remyelination are available.An increasing number of studies highlight the role of microRNAs(miRNAs)as ...Demyelinating diseases of the central nervous system are common,yet few effective strategies for myelin repair and remyelination are available.An increasing number of studies highlight the role of microRNAs(miRNAs)as key regulators of demyelination.miRNA mimics and inhibitors,which are currently in preclinical development,have shown promise as novel therapeutic agents.However,the mechanisms by which they protect myelin are not fully understood.Using a mouse model of acute central nervous system demyelination induced by infection with Angiostrongylus cantonensis,we investigated alterations in miRNA expression in the mouse brain.Our findings revealed a significant early-stage increase in the levels of miR-200,particularly miR-200a and miR-200c.Subsequent analysis demonstrated that combined miR-200a and miR-200c overexpression improved neurobehavioral outcomes and attenuated demyelination in Angiostrongylus cantonensis-infected mice.Further lipid metabolomic profiling indicated that miR-200a and miR-200c synergistically inhibited the production of phosphatase and tensin homolog(PTEN)and activated the phosphoinositide 3-kinase/protein kinase B/mammalian target of rapamycin signaling pathway,as confirmed by double luciferase reporter assay and western blotting.Additionally,in vitro experiments showed that miR-200a and miR-200c protected oligodendrocyte precursor cells from lipopolysaccharide-induced damage and enhanced their survival.Our study indicates the critical role of miR-200a and miR-200c in protecting against central nervous system demyelination by targeting PTEN and modulating key survival pathways.Furthermore,our findings suggest that miR-200a and miR-200c are promising diagnostic biomarkers of and therapeutic targets for treating demyelination-related disorders.展开更多
Recent studies have shown that fibrotic scar formation following cerebral ischemic injury has varying effects depending on the microenvironment.However,little is known about how fibrosis is induced and regulated after...Recent studies have shown that fibrotic scar formation following cerebral ischemic injury has varying effects depending on the microenvironment.However,little is known about how fibrosis is induced and regulated after cerebral ischemic injury.Sonic hedgehog signaling participates in fibrosis in the heart,liver,lung,and kidney.Whether Shh signaling modulates fibrotic scar formation after cerebral ischemic stroke and the underlying mechanisms are unclear.In this study,we found that Sonic Hedgehog expression was upregulated in patients with acute ischemic stroke and in a middle cerebral artery occlusioneperfusion injury rat model.Both Sonic hedgehog and Mitofusin 2 showed increased expression in the middle cerebral artery occlusion rat model and in vitro fibrosis cell model induced by transforming growth factor-beta 1.Activation of the Sonic hedgehog signaling pathway enhanced the expression of phosphorylated Smad 3 and Mitofusin 2 proteins,promoted the formation of fibrotic scars,protected synapses or promoted synaptogenesis,alleviated neurological deficits following middle cerebral artery occlusioneperfusion injury,reduced cell apoptosis,facilitated the transformation of meninges fibroblasts into myofibroblasts,and enhanced the proliferation and migration of meninges fibroblasts.The Smad3 phosphorylation inhibitor SIS3 reversed the effects induced by Sonic hedgehog signaling pathway activation.Bioinformatics analysis revealed significant correlations between Sonic hedgehog and Smad3,between Sonic hedgehog and Mitofusin 2,and between Smad3 and Mitofusin 2.These findings suggest that Sonic hedgehog signaling may influence Mitofusin 2 expression by regulating Smad3 phosphorylation,thereby modulating the formation of early fibrotic scars following cerebral ischemic stroke and affecting prognosis.The Sonic Hedgehog signaling pathway may serve as a new therapeutic target for stroke treatment.展开更多
The field of acupuncture is currently facing paradigmatic issues,including the difficulty of turning theoretical strengths into technical discourse power,a gap between mechanistic research and clinical imperatives,and...The field of acupuncture is currently facing paradigmatic issues,including the difficulty of turning theoretical strengths into technical discourse power,a gap between mechanistic research and clinical imperatives,and the fragmentation of research activities.Therefore,constructing a research paradigm grounded in traditional Chinese medicine theory and validated through contemporary scientific methods is essential.Hand Twelve Jing-Well Points(HTWP)acupuncture,an ancient therapy known for its rapid efficacy and practical application,offers an optimal solution for these challenges.In this study,the theoretical foundations,clinical effectiveness,biological explanations,and Translational applications of HTWP acupuncture were consolidated by integrating a four-step research framework.Initially,we developed the“Well point-Brain Connection”framework rooted in classical theories and informed by the“Root-Knot”concept.Subsequent clinical practice provided evidence of its effectiveness in modulating awareness and facilitating motor-cognitive rehabilitation for patients with central nervous system issues.Moreover,mechanistic research provides scientific verification of a“Sensation-Transmission-Effect”cascade that encompasses the activation of arousal circuits and the repair of the blood-brain barrier.Ultimately,the promotion of translation,standardization of systems,and the use of wearable technologies have aided the transition from passive therapy to proactive health management.This closed-loop concept offers compelling evidence for the“Well point-Brain Connection”and provides an applicable framework for scientific innovation and global distribution of innovative acupuncture hypotheses.展开更多
In recent years,the field of neuroimmunology has witnessed a profound paradigm shift.Research has expanded beyond the traditional focus on the central nervous system to unravel the dynamic interplay between peripheral...In recent years,the field of neuroimmunology has witnessed a profound paradigm shift.Research has expanded beyond the traditional focus on the central nervous system to unravel the dynamic interplay between peripheral immunity and neural networks.Cutting-edge methodologies have unmasked a tripartite communication axis enabling peripheral immune signals to mediate the CNS:(1)neural communication via vagal afferents,(2)humoral signaling through circumventricular organ cytokine diffusion,and(3)cellular interactions involving bone marrow-derived macrophages[1].展开更多
As a city–county consolidation with Chinese characteristics,China’s countyto-district(CtD)reform transfers a county’s autonomy to a city,thereby strengthening the administrative,decision-making,fiscal and other pow...As a city–county consolidation with Chinese characteristics,China’s countyto-district(CtD)reform transfers a county’s autonomy to a city,thereby strengthening the administrative,decision-making,fiscal and other powers of the prefecture-level municipal government,which effectively enables the centralization of local governments.Based on this exogenous quasi-natural experiment,we use a difference-in-differences(DID)approach to empirically examine the impact of prefecture-level municipal government centralization on companies’ESG performance.The results show that municipal government centralization can significantly promote corporate ESG performance,which represents environmental protection,social responsibility and corporate governance behavior.The mechanism analysis also shows that the CtD reform can address market segmentation,alleviate policy uncertainty and reduce rentseeking,which further improves ESG performance.展开更多
The retina,a laminated neural tissue at the back of the eye,is increasingly recognized as a site of central nervous system pathology in Alzheimer's disease(AD)(Gaire et al.,2024).Developmentally derived from the e...The retina,a laminated neural tissue at the back of the eye,is increasingly recognized as a site of central nervous system pathology in Alzheimer's disease(AD)(Gaire et al.,2024).Developmentally derived from the embryonic diencephalon,the retina maintains a direct anatomical and physiological connection to the brain,comprising neurons,glial populations,and vascular structures that closely resemble those in the cerebral cortex.Both retina and brain originate from the neural ectoderm during embryogenesis and exhibit a layered cytoarchitecture composed of specialized neurons,supportive glia(astrocytes and microglia),and tightly regulated vasculature.展开更多
The thickness of the lubricating film plays a vital role in the operational efficiency and reliability of rolling bearings.Ultrasonic reflection techniques offer a promising noninvasive approach for the in situ evalua...The thickness of the lubricating film plays a vital role in the operational efficiency and reliability of rolling bearings.Ultrasonic reflection techniques offer a promising noninvasive approach for the in situ evaluation of lubricant films.However,accurate identification of the central film thickness remains challenging because of several complex factors,which include dynamic fluctuations,localized elastic deformation,cavitation effects,and variations in the oil supply.In this study,a comprehensive theoretical and numerical framework for elucidating the effects of these factors on ultrasonic wave propagation in lubricated contacts is presented.Numerical simulations in which the elastohydrodynamic lubrication(EHL)regime and cavitation-induced effects are considered are carried out to obtain surface deformation profiles and identify cavitation regions.High-fidelity acoustic simulations are subsequently conducted to interpret the reflected ultrasound data.The reflection coefficient distribution exhibits a symmetric"double peak with central valley"pattern that is induced by the combined effect of the contact geometry and the EHL-induced oil film thickness distribution.Cavitation causes the central valley to shift toward the inlet region and increases the reflection coefficient.Accordingly,the central film thickness is extracted from the distribution of the reflection coefficient under different operating conditions.Experimental validation using both glass-oil-steel and steel-oil-steel bearing setups confirms the effectiveness of the proposed method.The high-resolution fluorescence measurement that is adopted in the glassoilsteel configuration validates the simulation of the reflection coefficient distribution.Furthermore,theoretical EHL calculations are performed for the steeloilsteel configuration to validate the measurement accuracy for the central oil film thickness.展开更多
Migration is one typical behavior that can affect parasite composition and transmission in local host communities,as migratory hosts are often heavily infected and may serve as a'vehicle'to transmit parasites ...Migration is one typical behavior that can affect parasite composition and transmission in local host communities,as migratory hosts are often heavily infected and may serve as a'vehicle'to transmit parasites to new hosts.Therefore,understanding how local parasite transmission is shaped by these highly connected visitors is critical for guiding disease prevention.However,this endeavor is largely hampered by the difficulties of observing transmission processes,especially in natural host-parasite systems.Regarding that,network analysis may provide additional insights to infer cross-species transmission and help identify the reservoir host species.Here,by using a bird-haemosporidian system in the Thousand Island Lake,China,we generated parasite-sharing networks to investigate how migratory hosts may influence sharing patterns and,in turn,the potential transmission in local bird communities.We evaluated the network centrality of migratory birds and assessed the relative importance of host functional traits and phylogenetic relatedness in structuring the propensity of parasite sharing.We found that migratory species significantly shaped the overall network structure by bridging distinct modules,though they exhibited no superior importance than resident birds when referring to node centrality.Moreover,we found that node centrality and the extent of parasite sharing of hosts are mainly predicted by host functional traits,while host phylogenetic relationships played a relatively minor role.Our findings highlight the vital role of migratory birds on parasite sharing in local communities and suggest that host functional traits could be key drivers of potential cross-species transmission.展开更多
Debris flow events are frequent in Tajikistan,yet comprehensive investigations at the regional scale are limited.This study integrates remote sensing,Geographic Information System,and machine learning techniques to ev...Debris flow events are frequent in Tajikistan,yet comprehensive investigations at the regional scale are limited.This study integrates remote sensing,Geographic Information System,and machine learning techniques to evaluate debris flow susceptibility and associated hazards across Tajikistan.A dataset comprising 405 documented debris flow points and 14 influencing factors,encompassing geological,climatic-hydrological,and anthropogenic variables,was established.Three machine learning algorithms—Random Forest,Support Vector Machine(SVM),and Multi-layer Perceptron—were applied to generate susceptibility maps and delineate debris flow risk zones.The results indicate that the areas of higher and high susceptibility accounted for 20.43%and 4.41%of the national area,respectively,and were predominantly concentrated along the Zeravshan and Vakhsh river basins.Among the evaluated models,SVM model demonstrated the highest predictive performance.Beyond conventional topographic and environmental controls,drought conditions were identified as a critical factor influencing debris flow occurrence within the arid and semi-arid mountainous regions of Tajikistan.These findings provide a scientific basis for regional debris flow risk management and disaster mitigation planning,and offer practical guidance for selecting conditioning factors in machine-learning-based susceptibility assessments in other dry mountainous environments.展开更多
摘要To explore the impact of partial centralization on supply chain performance,this study constructs a two-period game model of a closed-loop supply chain involving a manufacturer and an online retail platform participating in the trade-in strategy.Through mathematical modeling and numerical simulation methods,the optimal decisions were analyzed under conditions where the manufacturer partially owns the retail platform’s partial equity.This study finds that partial centralization yields the highest profits,followed by full centralization,with decentralized decisions yielding the lowest profits.Moderate centralization enhances overall profits by optimizing incentive mechanisms,whereas excessive ownership concentration reduces the flexibility of the retail platform,leading to a decline in profits.Additionally,product durability and trade-in subsidy significantly influence supply chain profitability:high-durability products reduce renewal frequency,while trade-in subsidy effectively stimulates consumer demand and increase overall profits.This study provides theoretical support and practical guidance for companies implementing the trade-in strategy.
基金supported by Beijing Scholar Project 20182024(No.B00033)。
摘要Objective:Limited evidence is available regarding the associations of centralization with gastric cancer patients’quality of care in high surgical volume settings.The current study aimed to explore the effects of hospital volume and the Herfindahl-Hirschman index(HHI)on in-hospital mortality,total cost,and length of stay for Chinese gastrectomy patients in a nationwide database.Methods:We extracted data on gastrectomy for gastric cancer from the Hospital Quality Monitoring System Database between 2013 and 2018.Hospital volume was divided into 4 quartiles:low(1-83 cases per year),medium(84-238 cases),high(239-579 cases),and very high(580-1,193 cases).The HHI was divided into 3 categories:highly concentrated(>2,500),moderately concentrated(1,500-2,500),and unconcentrated(<1,500).We used mixed-effects models to analyze the data while accounting for data clustering.Results:We analyzed 125,683 patients in 515 institutions.In the multivariable analyses,hospital volume was significantly associated with in-hospital mortality[medium vs.low:odds ratio(OR)=0.61,95%confidence interval(95%CI)=0.43-0.84,P=0.003;high:OR=0.57,95%CI=0.38-0.87,P=0.009;and very high:OR=0.33,95%CI=0.18-0.61,P<0.001)and length of stay(high vs.low:β=-0.036,95%CI=-0.071--0.002,P=0.039)but not with total cost.Hospitals located in unconcentrated provinces had higher in-hospital mortality(OR=1.52,95%CI=1.03-2.26,P=0.036)and longer lengths of stay(β=0.024,95%CI=0.001-0.047,P=0.041)than hospitals located in highly concentrated provinces.Conclusions:Centralization of gastrectomy,measured by hospital volume and the HHI,was associated with decreased in-hospital mortality and shortened length of stay without increasing total cost.These results support the strategy of centralizing gastrectomy in high-volume settings.
摘要Established during the long years of revolutionary struggle and the founding of the People's Republic of China (PRC), the Communist Party of China(CPC)-led decision-making system has a historical rationality. Before China's reform and opening-up was implemented in 1978, the decision-making system highlighted centralization which led to disadvantages such as non-existent specialized division of functions, a low level of institutionalization, heavy reliance on experience, an enclosed decision-making mode and non-existent self-correction mechanisms. These disadvantages were institutional factors which ultimately caused the historic tragedy of " Cultural Revolution. "After the reform and opening-up, the decision-making structure, mode and mechanism were reformed in order to promote scientific, democratic and law-based decisions. History has shown that the reform has successfully overcome various challenges brought about by China's rapidly changing economy and society. From the perspective of political development, the reform has promoted several transitions: from individual controlled decision-making system to a more democratic decision-making process, from being empirical to scientifically-based, from highly centralized decision-making organizations to decentralized one, from an enclosed mode to an open mode, from passive to active participation in the decision-making process and from a non-institutionalized to an institutionalized system. Therefore, the CPC-led open decision-making model based on science and laws and participated by other parties has taken an initial shape.
摘要The As-level topology is a hotspot of the recent reseaches. We can understand the centralization of the network clearly by researching the evolvement trend of the Internet macroscopic topology. The massive data we use in this paper is from CAIDA (The Cooperative Association for Internet Data Analysis) Skitter project. And the time span of the data is from July, 2001 to January, 2008. This paper introduces the background of the AS-level topology at first, then carries out the evolvement of degree, core and layer. It is believed that the influence of the top-degree nodes on the other nodes decreases and the centralization of network is going to fall off with the decrease of the core. And the nucleus status of network declines.
摘要Objective:To uncover the impact of centralization of COVID-19 and perceived control of COVID-19 on society during the pandemic.Methods:We recruited a total of 1041 people in this cross-sectional study.The data were collected using a questionnaire booklet covering demographics,a COVID-19-related information form,the Centrality of Event Scale,and the Perception of Control of COVID-19 Scale.We utilized independent samples t-test,chi-square test,and one-way analysis of variance to analyze the data.Results:1041 questionnaires were collected and no questionnaire were excluded from our study.Slightly more than half of the participants(51.2%)stated that social isolation impaired public mental health,while 30.1%reported adverse impacts of the pandemic on their sleep quality.Participants with changes to their sleep patterns were found to centralize COVID-19 more.Moreover,measures against COVID-19 and constant announcements of the daily number of cases in the media brought both positive and negative effects on people and further contributed to the participants’centralization of COVID-19.Individuals with low centralization scores were concluded to perceive COVID-19 as a minor disease.Healthcare professionals without a relative diagnosed with COVID-19 and those satisfied with treatment opportunities had a higher perceived control of COVID-19,while those who were not interested in statistical data on COVID-19 and who had difficulty complying with the rules had a lower perceived control of COVID-19.Besides,poorer perceived control of COVID-19 was found to adversely affect sleep quality.Furthermore,healthcare professionals scored higher on the inevitability subscale of the Perception of Control of COVID-19 Scale.Finally,among the participants,most COVID-19 survivors thought COVID-19 to be an avoidable disease.Conclusion:In addition to its physical impacts,COVID-19 adversely impacts on mental health,and these effects are closely linked to a society’s centralization of COVID-19 and perceived control of COVID-19.
基金supported by the National Natural Science Foundation of China,No.82071909(to GF)the Natural Science Foundation of Liaoning Province,No.2023-MS-07(to HL)。
摘要Freezing of gait is a significant and debilitating motor symptom often observed in individuals with Parkinson's disease.Resting-state functional magnetic resonance imaging,along with its multi-level feature indices,has provided a fresh perspective and valuable insight into the study of freezing of gait in Parkinson's disease.It has been revealed that Parkinson's disease is accompanied by widespread irregularities in inherent brain network activity.However,the effective integration of the multi-level indices of resting-state functional magnetic resonance imaging into clinical settings for the diagnosis of freezing of gait in Parkinson's disease remains a challenge.Although previous studies have demonstrated that radiomics can extract optimal features as biomarkers to identify or predict diseases,a knowledge gap still exists in the field of freezing of gait in Parkinson's disease.This cross-sectional study aimed to evaluate the ability of radiomics features based on multi-level indices of resting-state functional magnetic resonance imaging,along with clinical features,to distinguish between Parkinson's disease patients with and without freezing of gait.We recruited 28 patients with Parkinson's disease who had freezing of gait(15 men and 13 women,average age 63 years)and 30 patients with Parkinson's disease who had no freezing of gait(16 men and 14 women,average age 64 years).Magnetic resonance imaging scans were obtained using a 3.0T scanner to extract the mean amplitude of low-frequency fluctuations,mean regional homogeneity,and degree centrality.Neurological and clinical characteristics were also evaluated.We used the least absolute shrinkage and selection operator algorithm to extract features and established feedforward neural network models based solely on resting-state functional magnetic resonance imaging indicators.We then performed predictive analysis of three distinct groups based on resting-state functional magnetic resonance imaging indicators indicators combined with clinical features.Subsequently,we conducted 100 additional five-fold cross-validations to determine the most effective model for each classification task and evaluated the performance of the model using the area under the receiver operating characteristic curve.The results showed that when differentiating patients with Parkinson's disease who had freezing of gait from those who did not have freezing of gait,or from healthy controls,the models using only the mean regional homogeneity values achieved the highest area under the receiver operating characteristic curve values of 0.750(with an accuracy of 70.9%)and 0.759(with an accuracy of 65.3%),respectively.When classifying patients with Parkinson's disease who had freezing of gait from those who had no freezing of gait,the model using the mean amplitude of low-frequency fluctuation values combined with two clinical features achieved the highest area under the receiver operating characteristic curve of 0.847(with an accuracy of 74.3%).The most significant features for patients with Parkinson's disease who had freezing of gait were amplitude of low-frequency fluctuation alterations in the left parahippocampal gyrus and two clinical characteristics:Montreal Cognitive Assessment and Hamilton Depression Scale scores.Our findings suggest that radiomics features derived from resting-state functional magnetic resonance imaging indices and clinical information can serve as valuable indices for the identification of freezing of gait in Parkinson's disease.
基金supported by grants from Simons Foundation (SFARI 479754),CIHR (PJT-180565)the Scottish Rite Charitable Foundation of Canada (to YL)funding from the Canada Research Chairs program。
摘要The mechanistic target of rapamycin(m TOR) is a serinehreonine kinase that plays a pivotal role in cellular growth, proliferation, survival, and metabolism. In the central nervous system(CNS), the mTOR pathway regulates diverse aspects of neural development and function. Genetic mutations within the m TOR pathway lead to severe neurodevelopmental disorders, collectively known as “mTORopathies”(Crino, 2020). Dysfunctions of m TOR, including both its hyperactivation and hypoactivation, have also been implicated in a wide spectrum of other neurodevelopmental and neurodegenerative conditions, highlighting its importance in CNS health.
基金supported by the Noncommunicable Chronic Diseases-National Science and Technology Major Project(2024ZD0531600,2023ZD0503500)National Natural Science Foundation of China(82030102)+2 种基金Chinese Academy of Medical Sciences Innovation Fund for Medical Sciences(2021-I2M-1-010)the National High Level Hospital Clinical Research Funding(2025-GSP-GG-32,2025-GSP-GG-36)by the Special Research Funds for Central Universities,Peking Union Medical College(3332024213)。
摘要Objective To examine the associations of sleep duration and physical activity(PA)with central obesity among Chinese adults.Methods Based on the Prediction for Atherosclerotic Cardiovascular Disease Risk in China(China-PAR)project,175,373 observations from 106,518 participants were included.Generalized estimating equations quantified the associations of sleep duration and PA with waist circumference(WC)and central obesity.Stratified and joint analyses were performed to evaluate combined effects,and an isotemporal substitution model was used to assess substitution effects.Results Suboptimal sleep duration(8 h/day,substituting 30 min/day of sleep with moderate-to-vigorous PA significantly reduced the risk of central obesity.Conclusion Suboptimal sleep duration has a detrimental effect on central obesity,and adequate PA can mitigate this effect.The impact of reallocating sleep duration varies by sleep duration,highlighting the need to optimize both PA and sleep patterns in China.
基金supported by the China Atomic Energy Authority(CAEA)through the Geological Disposal ProgramFundamental Research Funds for the Central Universities(lzujbky2023-it17)the National Second Tibetan Plateau Expedition Program(2019QZKK0901)。
摘要The Beishan area(BA),located along the southern margin of the Central Asian orogenic belt,represents a key region for studying the opening of the southern Paleo-Asian Ocean(PAO)during the Neoproterozoic Era.Current understanding of BA's Neoproterozoic tectonic evolution remains limited because of insufficient constraints.This study presents petrological,whole-rock geochemical,Sr-Nd isotopic,zircon U-Pb dating,and Hf isotopic analyses of gabbro(765 Ma),dacitic tuff(756 Ma),syenogranite(764 Ma),and monzogranite(770 Ma)from the BA.The gabbros show high MgO(8.06-8.31 wt%)and low K2O(0.23-1.09 wt%)contents,depletion of high-field-strength elements(Nb,Ta,and Ti),(87Sr/86Sr)i ratios of 0.7051-0.7057,and positiveεNd(t)values(+2.55 to+3.19).These geochemical signatures suggest derivation from a depleted mantle metasomatized by subducted slab-derived melts,consistent with formation in a back-arc rift setting.The dacitic tuffs display negativeεNd(t)values(-16.38 to-1.29)and Zr-Hf enrichment,indicating an origin from ancient crustal melting.The syenogranites and monzogranites are characterized by high 10,000 Ga/Al and(Zr+Nb+Ce+Y)values,classifying them as A1-type granites.They yield negativeεNd(t)values(-6.66 to-2.29)and variableεHf(t)values(-3.7 to+4.8),indicating partial melting of Paleoproterozoic crust material.Based on these findings and previous studies,we propose that the initial opening of the southern PAO in the BA occurred no earlier than 770 Ma,likely driven by combined subducted slab rollback and mantle plume upwelling.
基金supported by the National Natural Science Foundation of China,Nos.U22A20297,82172433(both to LR),82372400(to BL),823B2060(to YL)The Key Research and Development Program of Guangzhou,No.202206060003(to LR)+4 种基金Guangdong Basic and Applied Basic Research Foundation,Nos.2024A1515012766(to BL),2023A1515010313(to MP)Guangzhou Science and Technology Project,No.2023A03J0203(to BL)Guangdong Provincial Drug Administration Science and Technology Innovation Project,No.2024ZDZ13(to BL)Postdoctoral Fellowship Program of China Postdoctoral Science Foundation,No.GZB20240904(to SY)The China Postdoctoral Science Foundation,Nos.2024M763769,2025T180653(both to SY),2025M782367(to JD)。
摘要Spinal cord injury is a severe neurological condition with far-reaching consequences for both individuals and society.Its progression involves a complex interplay between the initial mechanical insult and inflammation-driven secondary injury.This review interprets recent studies on the spatiotemporal map of the inflammatory microenvironment in spinal cord injury and other neurological disorders,focusing on the latest mechanistic research and treatment options.The postinjury inflammatory microenvironment comprises diverse immune and glial cell populations whose phenotypes and functions change over time.The current consensus suggests that inflammation has a paradoxical nature:while it can limit lesion spread in the acute stage,chronic or dysregulated responses contribute to further neural damage through pathways such as excitotoxicity,oxidative stress,and glial scar formation.Methods such as spatiotemporal transcriptomic analyses and organoid-based models have improved our ability to resolve cell–cell interactions and discover new molecular targets.Numerous therapies targeting this microenvironment have been developed.Stem cell-based approaches,especially human umbilical cord mesenchymal stem cells,show promise in promoting tissue regeneration and immune regulation in experimental and early clinical studies.Bioengineering methods such as using biomaterial scaffolds and controlled drug release are being investigated to improve drug delivery and the injury microenvironment.Pharmacological efforts to modify cytokine networks,oxidative pathways,or immune checkpoints have achieved some success,hampered by patient heterogeneity and injury patterns.Persistent challenges include determining the context-specific mechanisms,identifying the best treatment windows,and combining a few methods for the best effect.In summary,detailed understanding of the spatiotemporal dynamics of post–spinal cord injury inflammation is essential for designing targeted interventions.Future directions include integrating multiomics datasets,identifying predictive biomarkers for patient stratification,and developing adaptive treatment protocols that fine-tune rather than suppress immune responses to promote neural repair and functional recovery.
基金supported by the National Natural Science Foundation of China,Nos.82372277(to ZW),82272361(to XS),82271395(to GL)Guangdong Province Basic and Applied Basic Research Fund Project,No.2024A1515010615(to XS)+1 种基金Guangdong Province Natural Youth Promotion Project,No.2314070000241(to GL)Guangzhou Science and Technology Project,No.2025A04J4740(to GL).
摘要Demyelinating diseases of the central nervous system are common,yet few effective strategies for myelin repair and remyelination are available.An increasing number of studies highlight the role of microRNAs(miRNAs)as key regulators of demyelination.miRNA mimics and inhibitors,which are currently in preclinical development,have shown promise as novel therapeutic agents.However,the mechanisms by which they protect myelin are not fully understood.Using a mouse model of acute central nervous system demyelination induced by infection with Angiostrongylus cantonensis,we investigated alterations in miRNA expression in the mouse brain.Our findings revealed a significant early-stage increase in the levels of miR-200,particularly miR-200a and miR-200c.Subsequent analysis demonstrated that combined miR-200a and miR-200c overexpression improved neurobehavioral outcomes and attenuated demyelination in Angiostrongylus cantonensis-infected mice.Further lipid metabolomic profiling indicated that miR-200a and miR-200c synergistically inhibited the production of phosphatase and tensin homolog(PTEN)and activated the phosphoinositide 3-kinase/protein kinase B/mammalian target of rapamycin signaling pathway,as confirmed by double luciferase reporter assay and western blotting.Additionally,in vitro experiments showed that miR-200a and miR-200c protected oligodendrocyte precursor cells from lipopolysaccharide-induced damage and enhanced their survival.Our study indicates the critical role of miR-200a and miR-200c in protecting against central nervous system demyelination by targeting PTEN and modulating key survival pathways.Furthermore,our findings suggest that miR-200a and miR-200c are promising diagnostic biomarkers of and therapeutic targets for treating demyelination-related disorders.
基金supported by the National Natural Science Foundation of China,Nos.82171456(to QY)and 81971229(to QY)the Natural Science Foundation of Chongqing,Nos.CSTC2021JCYJ-MSXMX0263(to QY)and CSTB2023NSCQ-MSX1015(to XL)Doctoral Innovation Project of The First Affiliated Hospital of Chongqing Medical University,Nos.CYYY-BSYJSCXXM-202318(to JW)and CYYY-BSYJSCXXM-202327(to HT).
摘要Recent studies have shown that fibrotic scar formation following cerebral ischemic injury has varying effects depending on the microenvironment.However,little is known about how fibrosis is induced and regulated after cerebral ischemic injury.Sonic hedgehog signaling participates in fibrosis in the heart,liver,lung,and kidney.Whether Shh signaling modulates fibrotic scar formation after cerebral ischemic stroke and the underlying mechanisms are unclear.In this study,we found that Sonic Hedgehog expression was upregulated in patients with acute ischemic stroke and in a middle cerebral artery occlusioneperfusion injury rat model.Both Sonic hedgehog and Mitofusin 2 showed increased expression in the middle cerebral artery occlusion rat model and in vitro fibrosis cell model induced by transforming growth factor-beta 1.Activation of the Sonic hedgehog signaling pathway enhanced the expression of phosphorylated Smad 3 and Mitofusin 2 proteins,promoted the formation of fibrotic scars,protected synapses or promoted synaptogenesis,alleviated neurological deficits following middle cerebral artery occlusioneperfusion injury,reduced cell apoptosis,facilitated the transformation of meninges fibroblasts into myofibroblasts,and enhanced the proliferation and migration of meninges fibroblasts.The Smad3 phosphorylation inhibitor SIS3 reversed the effects induced by Sonic hedgehog signaling pathway activation.Bioinformatics analysis revealed significant correlations between Sonic hedgehog and Smad3,between Sonic hedgehog and Mitofusin 2,and between Smad3 and Mitofusin 2.These findings suggest that Sonic hedgehog signaling may influence Mitofusin 2 expression by regulating Smad3 phosphorylation,thereby modulating the formation of early fibrotic scars following cerebral ischemic stroke and affecting prognosis.The Sonic Hedgehog signaling pathway may serve as a new therapeutic target for stroke treatment.
基金supported by the Natural Science Foundation of China(82441053,82074534,82474642)The Natural Science Foundation of Jiangxi province(20232BAB206151).
摘要The field of acupuncture is currently facing paradigmatic issues,including the difficulty of turning theoretical strengths into technical discourse power,a gap between mechanistic research and clinical imperatives,and the fragmentation of research activities.Therefore,constructing a research paradigm grounded in traditional Chinese medicine theory and validated through contemporary scientific methods is essential.Hand Twelve Jing-Well Points(HTWP)acupuncture,an ancient therapy known for its rapid efficacy and practical application,offers an optimal solution for these challenges.In this study,the theoretical foundations,clinical effectiveness,biological explanations,and Translational applications of HTWP acupuncture were consolidated by integrating a four-step research framework.Initially,we developed the“Well point-Brain Connection”framework rooted in classical theories and informed by the“Root-Knot”concept.Subsequent clinical practice provided evidence of its effectiveness in modulating awareness and facilitating motor-cognitive rehabilitation for patients with central nervous system issues.Moreover,mechanistic research provides scientific verification of a“Sensation-Transmission-Effect”cascade that encompasses the activation of arousal circuits and the repair of the blood-brain barrier.Ultimately,the promotion of translation,standardization of systems,and the use of wearable technologies have aided the transition from passive therapy to proactive health management.This closed-loop concept offers compelling evidence for the“Well point-Brain Connection”and provides an applicable framework for scientific innovation and global distribution of innovative acupuncture hypotheses.
基金supported by the STI2030-Major Projects(2021ZD0200600)the National Natural Science Foundation of China(81971269).
摘要In recent years,the field of neuroimmunology has witnessed a profound paradigm shift.Research has expanded beyond the traditional focus on the central nervous system to unravel the dynamic interplay between peripheral immunity and neural networks.Cutting-edge methodologies have unmasked a tripartite communication axis enabling peripheral immune signals to mediate the CNS:(1)neural communication via vagal afferents,(2)humoral signaling through circumventricular organ cytokine diffusion,and(3)cellular interactions involving bone marrow-derived macrophages[1].
基金supported by the National Natural Science Foundation of China(Grant No.T2293773 and No.T2293770).
摘要As a city–county consolidation with Chinese characteristics,China’s countyto-district(CtD)reform transfers a county’s autonomy to a city,thereby strengthening the administrative,decision-making,fiscal and other powers of the prefecture-level municipal government,which effectively enables the centralization of local governments.Based on this exogenous quasi-natural experiment,we use a difference-in-differences(DID)approach to empirically examine the impact of prefecture-level municipal government centralization on companies’ESG performance.The results show that municipal government centralization can significantly promote corporate ESG performance,which represents environmental protection,social responsibility and corporate governance behavior.The mechanism analysis also shows that the CtD reform can address market segmentation,alleviate policy uncertainty and reduce rentseeking,which further improves ESG performance.
基金supported,in part,by the National Institutes of Health (NIH)/National Institute on Aging(NIA) grant numbers:R01AG056478,R01AG055865,and R01AG075998 (to MKH)supported by the Snyder,Jona Goldrich,Gordon Foundationsthe Hertz Innovation Fund (to MKH)。
摘要The retina,a laminated neural tissue at the back of the eye,is increasingly recognized as a site of central nervous system pathology in Alzheimer's disease(AD)(Gaire et al.,2024).Developmentally derived from the embryonic diencephalon,the retina maintains a direct anatomical and physiological connection to the brain,comprising neurons,glial populations,and vascular structures that closely resemble those in the cerebral cortex.Both retina and brain originate from the neural ectoderm during embryogenesis and exhibit a layered cytoarchitecture composed of specialized neurons,supportive glia(astrocytes and microglia),and tightly regulated vasculature.
基金financial support from the National Natural Science Foundation of China(52405597 and 52275126)support received from the Engineering and Physical Sciences Research Council,United Kingdom(EPSRC)via the InFUSE Prosperity Partnership(EP/V038044/1)support of the Royal Academy of Engineering(RAEng)for the Shell/RAEng Research Chair in Complex Engineering Interfaces。
摘要The thickness of the lubricating film plays a vital role in the operational efficiency and reliability of rolling bearings.Ultrasonic reflection techniques offer a promising noninvasive approach for the in situ evaluation of lubricant films.However,accurate identification of the central film thickness remains challenging because of several complex factors,which include dynamic fluctuations,localized elastic deformation,cavitation effects,and variations in the oil supply.In this study,a comprehensive theoretical and numerical framework for elucidating the effects of these factors on ultrasonic wave propagation in lubricated contacts is presented.Numerical simulations in which the elastohydrodynamic lubrication(EHL)regime and cavitation-induced effects are considered are carried out to obtain surface deformation profiles and identify cavitation regions.High-fidelity acoustic simulations are subsequently conducted to interpret the reflected ultrasound data.The reflection coefficient distribution exhibits a symmetric"double peak with central valley"pattern that is induced by the combined effect of the contact geometry and the EHL-induced oil film thickness distribution.Cavitation causes the central valley to shift toward the inlet region and increases the reflection coefficient.Accordingly,the central film thickness is extracted from the distribution of the reflection coefficient under different operating conditions.Experimental validation using both glass-oil-steel and steel-oil-steel bearing setups confirms the effectiveness of the proposed method.The high-resolution fluorescence measurement that is adopted in the glassoilsteel configuration validates the simulation of the reflection coefficient distribution.Furthermore,theoretical EHL calculations are performed for the steeloilsteel configuration to validate the measurement accuracy for the central oil film thickness.
基金supported by the National Natural Science Foundation of China(32001124,32030066,32271605)São Paulo Research Foundation(2025/09699-4)。
摘要Migration is one typical behavior that can affect parasite composition and transmission in local host communities,as migratory hosts are often heavily infected and may serve as a'vehicle'to transmit parasites to new hosts.Therefore,understanding how local parasite transmission is shaped by these highly connected visitors is critical for guiding disease prevention.However,this endeavor is largely hampered by the difficulties of observing transmission processes,especially in natural host-parasite systems.Regarding that,network analysis may provide additional insights to infer cross-species transmission and help identify the reservoir host species.Here,by using a bird-haemosporidian system in the Thousand Island Lake,China,we generated parasite-sharing networks to investigate how migratory hosts may influence sharing patterns and,in turn,the potential transmission in local bird communities.We evaluated the network centrality of migratory birds and assessed the relative importance of host functional traits and phylogenetic relatedness in structuring the propensity of parasite sharing.We found that migratory species significantly shaped the overall network structure by bridging distinct modules,though they exhibited no superior importance than resident birds when referring to node centrality.Moreover,we found that node centrality and the extent of parasite sharing of hosts are mainly predicted by host functional traits,while host phylogenetic relationships played a relatively minor role.Our findings highlight the vital role of migratory birds on parasite sharing in local communities and suggest that host functional traits could be key drivers of potential cross-species transmission.
基金supported by the National Natural Science Foundation of China(42361144880)the Science and Technology Program of Xizang Autonomous Region,China(XZ202402ZD0001)the Qinghai Province Basic Research Program Project,China(2024-ZJ-904).
摘要Debris flow events are frequent in Tajikistan,yet comprehensive investigations at the regional scale are limited.This study integrates remote sensing,Geographic Information System,and machine learning techniques to evaluate debris flow susceptibility and associated hazards across Tajikistan.A dataset comprising 405 documented debris flow points and 14 influencing factors,encompassing geological,climatic-hydrological,and anthropogenic variables,was established.Three machine learning algorithms—Random Forest,Support Vector Machine(SVM),and Multi-layer Perceptron—were applied to generate susceptibility maps and delineate debris flow risk zones.The results indicate that the areas of higher and high susceptibility accounted for 20.43%and 4.41%of the national area,respectively,and were predominantly concentrated along the Zeravshan and Vakhsh river basins.Among the evaluated models,SVM model demonstrated the highest predictive performance.Beyond conventional topographic and environmental controls,drought conditions were identified as a critical factor influencing debris flow occurrence within the arid and semi-arid mountainous regions of Tajikistan.These findings provide a scientific basis for regional debris flow risk management and disaster mitigation planning,and offer practical guidance for selecting conditioning factors in machine-learning-based susceptibility assessments in other dry mountainous environments.