Uveal and conjunctival melanomas are relatively rare tumors;nonetheless,they pose a significant risk of mortality for a large number of affected individuals.The pathogenesis of melanoma at different sites is very simil...Uveal and conjunctival melanomas are relatively rare tumors;nonetheless,they pose a significant risk of mortality for a large number of affected individuals.The pathogenesis of melanoma at different sites is very similar,however,the prognosis for patients with ocular melanoma remains unfavourable,primarily due to its distinctive genetic profile and tumor microenvironment.Regardless of considerable advances in understanding the genetic characteristics and biological behaviour,the treatment of uveal and conjunctival melanoma remains a formidable challenge.To enhance the prospect of success,collaborative efforts involving medical professionals and researchers in thefields of ocular biology and oncology are essential.Current data show a lack of well-designed randomized clinical trials and limited benefits in current forms of treatment for these tumors.Despite advancements in the development of effective melanoma therapeutic strategies,all current treatments for uveal melanoma(UM)and conjunctival melanoma(CoM)remain unsatisfactory,resulting in a poor long-term prognosis.Ongoing trials offer hope for positive outcomes in advanced and metastatic tumors.A more comprehensive understanding of the genetic and molecular abnormalities involved in the development and progression of ocular melanomas opens the way for the development of personalized therapy,with various potential therapeutic targets currently under consideration.Increased comprehension of the molecular pathogenesis of UM and CoM and their specificities may aid in the development of new and more effective systemic therapeutic agents,with the hope of improving the prognosis for patients with metastatic disease.展开更多
To prepare a conductive polymer actuator with decent performance,a self-built experimental platform for the preparation of polypyrrole film is employed.One of the essential goals is to examine the mechanical character...To prepare a conductive polymer actuator with decent performance,a self-built experimental platform for the preparation of polypyrrole film is employed.One of the essential goals is to examine the mechanical characteristics of the actuator in the presence of various combinations of process parameters,combined with the orthogonal test method of"four factors and three levels".The bending and sensing characteristics of actuators of various sizes are methodically examined using a self-made bending polypyrrole actuator.The functional relationship between the bending displacement and the output voltage signal is established by studying the characteristics of the actuator sensor subjected to various degrees of bending.The experimental results reveal that the bending displacement of the actuator tip almost exhibits a linear variation as a function of length and width.When the voltage reaches 0.8 V,the bending speed of the actuator tends to be stable.Finally,the mechanical properties of the self-assembled polypyrrole actuator are verified by the design and fabrication of the microgripper.展开更多
In order to better describe the phenomenon of biological invasion,this paper introduces a free boundary model of biological invasion.Firstly,the right free boundary is added to the equation with logistic terms.Secondl...In order to better describe the phenomenon of biological invasion,this paper introduces a free boundary model of biological invasion.Firstly,the right free boundary is added to the equation with logistic terms.Secondly,the existence and uniqueness of local solutions are proved by the Sobolev embedding theorem and the comparison principle.Finally,according to the relevant research data and contents of red fire ants,the diffusion area and nest number of red fire ants were simulated without external disturbance.This paper mainly simulates the early diffusion process of red fire ants.In the early diffusion stage,red fire ants grow slowly and then spread over a large area after reaching a certain number.展开更多
BACKGROUND Mild cognitive impairment(MCI)has a high risk of progression to Alzheimer’s disease.The disease is often accompanied by sleep disorders,and whether sleep disorders have an effect on brain function in patie...BACKGROUND Mild cognitive impairment(MCI)has a high risk of progression to Alzheimer’s disease.The disease is often accompanied by sleep disorders,and whether sleep disorders have an effect on brain function in patients with MCI is unclear.AIM To explore the near-infrared brain function characteristics of MCI with sleep disorders.METHODS A total of 120 patients with MCI(MCI group)and 50 healthy subjects(control group)were selected.All subjects underwent the functional near-infrared spec-troscopy test.Collect baseline data,Mini-Mental State Examination,Montreal Cognitive Assessment scale,fatigue severity scale(FSS)score,sleep parameter,and oxyhemoglobin(Oxy-Hb)concentration and peak time of functional near-infrared spectroscopy test during the task period.The relationship between Oxy-RESULTS Compared with the control group,the FSS score of the MCI group was higher(t=11.310),and the scores of Pittsburgh sleep quality index,sleep time,sleep efficiency,nocturnal sleep disturbance,and daytime dysfunction were higher(Z=-10.518,-10.368,-9.035,-10.661,-10.088).Subjective sleep quality and total sleep time scores were lower(Z=-11.592,-9.924).The sleep efficiency of the MCI group was lower,and the awakening frequency,rem sleep latency period,total sleep time,and oxygen desaturation index were higher(t=5.969,5.829,2.887,3.003,5.937).The Oxy-Hb concentration at T0,T1,and T2 in the MCI group was lower(t=14.940,11.280,5.721),and the peak time was higher(t=18.800,13.350,9.827).In MCI patients,the concentration of Oxy-Hb during T0 was negatively correlated with the scores of Pittsburgh sleep quality index,sleep time,total sleep time,and sleep efficiency(r=-0.611,-0.388,-0.563,-0.356).It was positively correlated with sleep efficiency and total sleep time(r=0.754,0.650),and negatively correlated with oxygen desaturation index(r=-0.561)and FSS score(r=-0.526).All comparisons were P<0.05.CONCLUSION Patients with MCI and sleep disorders have lower near-infrared brain function than normal people,which is related to sleep quality.Clinically,a comprehensive assessment of the near-infrared brain function of patients should be carried out to guide targeted treatment and improve curative effect.展开更多
Moringa oleifera Lam.is a Moringa genus in the Moringaceae family that is high in nutrients and has a wide range of applications.Phenolic compounds are widely found in plants and have various health benefits for the h...Moringa oleifera Lam.is a Moringa genus in the Moringaceae family that is high in nutrients and has a wide range of applications.Phenolic compounds are widely found in plants and have various health benefits for the human body.With its high content and wide variety of phenolic compounds,M.oleifera Lam.has been widely studied for its health benefits.The phenolic compounds in M.oleifera Lam.(MOPCs)can be a potential source of functional food ingredients in pharmaceutical and industrial applications.Numerous studies have shown that MOPCs have antioxidant,anti-obesity,anti-diabetic,and antibacterial effects.Although the research on MOPCs has been gradually increasing,the extraction,isolation,identification,biological activities,and comprehensive application of MOPCs need a more systematic summary and generalization.Therefore,this paper reviews the isolation and extraction methods,structure identification,biological activities,and comprehensive applications to provide a further reference for the research and application of MOPCs.展开更多
Introduction: Diabetes remains a real public health problem today, due to its associated morbidity and mortality. It induces numerous metabolic, biochemical, hematological, and immunological changes, responsible for m...Introduction: Diabetes remains a real public health problem today, due to its associated morbidity and mortality. It induces numerous metabolic, biochemical, hematological, and immunological changes, responsible for multiple complications. The objective of this study was to characterize clinically and biologically type 2 diabetic patients followed at the National Center for Diabetology and Arterial Hypertension of the Central Hospital of Yaoundé. Method: This prospective, cross-sectional, and analytical study took place from April 5 to July 31, 2023 (4 months) on 100 diabetic patients of both sexes (61 women and 39 men), aged from 31 to 88 years. Body Mass Index, systolic and diastolic blood pressure, and cardiac frequency were measured on each of the patients. Subsequently, blood was collected from the patients for the determination of the complete blood count, HBA1c, lipid profile, serum albumin, TNF-α, and IL-6 levels. The data were analyzed using SPSS 17.0 software. Results: The age average of our population was 56.99 ± 11.51 years, the population was primarily female (61%) and primarily between the ages of 55 and 88. 67% of respondents were married. 59% went to secondary school. 73% of them lived in urban areas. 30% were obese and 40% were overweight, with an average BMI of 28.75 kg/m2. 76% of patients took oral antidiabetic medications. HbA1c level average was 8.65%, with 60% having readings above 6.5%. Low hemoglobin and hypochromia were among the abnormalities of red blood cells observed. Lipid profiles revealed low HDL-cholesterol and high triglycerides and cholesterol. Elevated levels of TNF-α and IL-6 indicated inflammation and cardiovascular risk. Conclusion: These results indicate the necessity of focused diabetic care and management on diabetic patients attending the central hospital of Yaoundé, Cameroon.展开更多
A spice formulation study in Burkina Faso was carried out using local ingredients for the benefit of households. The objective of this study was to propose some spice formulations based on local ingredients in order t...A spice formulation study in Burkina Faso was carried out using local ingredients for the benefit of households. The objective of this study was to propose some spice formulations based on local ingredients in order to reduce the use of chemical spices in the preparation of different dishes. The Design of Experiments (DOE) methodology was used for the formulation of the spices and their physicochemical, nutritional and sensory characteristics were evaluated by standardized and standard methods. The results obtained showed lipid contents (g/100 g DM) ranging from 10.41 ± 0.26 to 15.64 ± 0.68, total sugars from 4.39 ± 0.32 to 5.46 ± 0.31, protein from 3.65 ± 0.17 to 12.04 ± 0.35 and ash from 5.83 ± 0.01 to 7.02 ± 0.01. The polyphenol content ranged from 9.09 ± 1.60 to 11.33 ± 0.90, and the flavonoid content ranged from 0.65 ± 0.03 to 1.08 ± 0.13. The sensory analysis carried out showed that the spices have generally satisfactory organoleptic characteristics. These results constitute new information in the diet of populations and are an alternative to the chemical spices used in their cooking.展开更多
In this paper,we present a modeling of the soil-water characteristic curve for residual and sedimentary soils of Bom Brinquedo Hill’s,located in Antonina,Brazil.This mountain range region is characterized as a natura...In this paper,we present a modeling of the soil-water characteristic curve for residual and sedimentary soils of Bom Brinquedo Hill’s,located in Antonina,Brazil.This mountain range region is characterized as a natural disaster risk area,requiring continuous research related to the stability of the area.To obtain the soil-water characteristic curve,undisturbed samples of residual and sedimentary soil were collected,followed by suction testing using the filter paper method.Considering the bimodal characteristic presented by the soil,LABFIT software was employed for curve fitting using the generic formulation“Harris+C”.The results of the tests indicated that the phenomenon of hysteresis had a greater influence in situations with higher suction levels.When comparing the residual moisture values of the macropores between residual soil and sedimentary soil,the former exhibited the lower value.This suggests that the residual soil has a coarser grain size and larger pores,which facilitates the release of water retained in the soil’s macropores.展开更多
In order to contribute to a better understanding of the biodiversity of local chicken populations, this study focused on the description of the essential qualitative parameters in the phenotypic characterization of lo...In order to contribute to a better understanding of the biodiversity of local chicken populations, this study focused on the description of the essential qualitative parameters in the phenotypic characterization of local species. Conducted in 6 localities in the Far North Region of Cameroon (Doukoula, Yagoua, Guidiguis, Dziguilao, Maroua 3rd and Méri), a population of 240 local chickens, including 172 hens and 68 cocks were characterized in family farms. The choice of localities was made on the basis of their strong potential local chicken flocks in the region. To this end, each animal was the subject of a qualitative description based on the identification of the sex of the animal, the description of the colorations of the plumage and extremities, and the description of the types of format, plumage and crests. All observations were made with the naked eye and in daylight and then photographed. The main results show that the plumage colors are multiple and dominated by the White-Pied-Black (21.7%) and the Mille-fleur (20.8%);the wattles are dominated by the red (60%) and the pink (35.4%);the tarsi are dominated by the white (43.8%) and the black (32.08%);the white skin (92.5%) dominates over the pink skin (7.5%);the “Smooth-uniform” feather is dominant (97.08%), followed by the smooth-crested type (2.08%) and the fries type (0.82%);the medium size of the chickens is dominant (86.66%), followed by the dwarf size (9.58%) and the large size (3.75%). The results of this study demonstrate that there is a strong phenotypic diversity within the local chicken population. This diversity can serve as a basis for the development of selection, conservation and genetic potential improvement programs based on rational exploitation of the local chicken.展开更多
Addressing the existing gap in ethical research surrounding distinct technical characteristics of Robotic Process Automation enhanced with Artificial Intelligence (AI-RPA), this analysis examines the unique ethical di...Addressing the existing gap in ethical research surrounding distinct technical characteristics of Robotic Process Automation enhanced with Artificial Intelligence (AI-RPA), this analysis examines the unique ethical dimensions by positioning AI-RPA as a distinct technological subdivision. From an analytical perspective, this study highlights key characteristics such as minimal reliance on programming, rapid development cycles, and restricted algorithmic control, which differentiate AI-RPA from traditional AI systems. These characteristics underscore the need for tailored ethical considerations, to identify ethical perils within AI-RPA’s technological origins. By positioning AI-RPA as a distinct subdivision and examining its unique characteristics alongside their emerging ethical challenges, this paper enriches the evolving discourse on AI ethics, providing valuable insights for researchers, policymakers, and organizations implementing AI-RPA technologies.展开更多
Production of this crop is experiencing significant challenges, resulting in a decline in seed and fiber quality. To address this challenge, generations of high-performance cotton plants of the Gossypium hirsutum L. s...Production of this crop is experiencing significant challenges, resulting in a decline in seed and fiber quality. To address this challenge, generations of high-performance cotton plants of the Gossypium hirsutum L. species have been developed and are currently being commercialized. This study evaluated the impact of gin types on the agro-industrial quality of cotton in Côte d’Ivoire. To this end, cotton from the G3, R1, and R2 generations was harvested, sampled, and ginned on machines with 10 and 170 saws in the localities of Ouangolodougou, Ferkessédougou, Korhogo, M’Bengué, Boundiali, Séguéla, and Mankono, as well as at the Centre National de Recherche Agronomique CNRA) in Bouaké. The results demonstrated that cotton fibers obtained from ginning on 10-saw machines exhibited superior quality compared to those from 170-saw machines. Fiber length, fiber length uniformity, and short fiber rate exhibited the highest deviations according to gin type. The use of 170-saw gins resulted in a notable decline in quality. Conversely, micronaire index, fiber tenacity and elongation, and reflectance remained consistent across machine types. These results will enable us to more effectively regulate and advise cotton-processing factories, which primarily utilize 170-saw gins to enhance agro-industrial quality in Côte d’Ivoire. Furthermore, these results will assist breeders in incorporating them into their processes to enhance the quality of the varieties they offer to farmers.展开更多
BACKGROUND Autoimmune hepatitis(AIH)is typically treated with immunomodulators and steroids.However,some patients are refractory to these treatments,necessitating alternative approaches.Biological therapies have recen...BACKGROUND Autoimmune hepatitis(AIH)is typically treated with immunomodulators and steroids.However,some patients are refractory to these treatments,necessitating alternative approaches.Biological therapies have recently been explored for these difficult cases.AIM To assess the efficacy and safety of biologics in AIH,focusing on patients unresponsive to standard treatments and evaluating outcomes such as serological markers and histological remission.METHODS A case-based systematic review was performed following the PRISMA protocol to evaluate the efficacy and safety of biological therapies in AIH.The primary focus was on serological improvement and histological remission.The secondary focus was on assessing therapy safety and additional outcomes.A standardized search command was applied to MEDLINE,EMBASE,and Cochrane Library databases to identify relevant studies.Inclusion criteria encompassed adult AIH patients treated with biologics.Data were analyzed based on demographics,prior treatments,and therapy-related outcomes.A narrative synthesis was employed to address biases and provide a comprehensive overview of the evidence.RESULTS A total of 352 studies were reviewed,with 30 selected for detailed analysis.Key findings revealed that Belimumab led to a favourable response in five out of eight AIH patients across two studies.Rituximab demonstrated high efficacy,with 41 out of 45 patients showing significant improvement across six studies.Basiliximab was assessed in a single study,where the sole patient treated experienced a beneficial outcome.Additionally,a notable number of AIH cases were induced by anti-tumor necrosis factor(TNF)medications,including 16 cases associated with infliximab and four cases with adalimumab.All these cases showed improvement upon withdrawal of the biologic agent.CONCLUSION Belimumab and Rituximab show promise as effective alternatives for managing refractory AIH,demonstrating significant improvements in clinical outcomes and liver function.However,the variability in patient responses to different therapies highlights the need for personalized treatment strategies.The risk of AIH induced by anti-TNF therapies underscores the need for vigilant monitoring and prompt symptom recognition.These findings support the incorporation of biologic agents into AIH treatment protocols,particularly for patients who do not respond to conventional therapies.展开更多
Influenced by complex external factors,the displacement-time curve of reservoir landslides demonstrates both short-term and long-term diversity and dynamic complexity.It is difficult for existing methods,including Reg...Influenced by complex external factors,the displacement-time curve of reservoir landslides demonstrates both short-term and long-term diversity and dynamic complexity.It is difficult for existing methods,including Regression models and Neural network models,to perform multi-characteristic coupled displacement prediction because they fail to consider landslide creep characteristics.This paper integrates the creep characteristics of landslides with non-linear intelligent algorithms and proposes a dynamic intelligent landslide displacement prediction method based on a combination of the Biological Growth model(BG),Convolutional Neural Network(CNN),and Long ShortTerm Memory Network(LSTM).This prediction approach improves three different biological growth models,thereby effectively extracting landslide creep characteristic parameters.Simultaneously,it integrates external factors(rainfall and reservoir water level)to construct an internal and external comprehensive dataset for data augmentation,which is input into the improved CNN-LSTM model.Thereafter,harnessing the robust feature extraction capabilities and spatial translation invariance of CNN,the model autonomously captures short-term local fluctuation characteristics of landslide displacement,and combines LSTM's efficient handling of long-term nonlinear temporal data to improve prediction performance.An evaluation of the Liangshuijing landslide in the Three Gorges Reservoir Area indicates that BG-CNN-LSTM exhibits high prediction accuracy,excellent generalization capabilities when dealing with various types of landslides.The research provides an innovative approach to achieving the whole-process,realtime,high-precision displacement predictions for multicharacteristic coupled landslides.展开更多
Using complex network methods,we construct undirected and directed heatwave networks to systematically analyze heatwave events over China from 1961 to 2023,exploring their spatiotemporal evolution patterns in differen...Using complex network methods,we construct undirected and directed heatwave networks to systematically analyze heatwave events over China from 1961 to 2023,exploring their spatiotemporal evolution patterns in different regions.The findings reveal a significant increase in heatwaves since the 2000s,with the average occurrence rising from approximately 3 to 5 times,and their duration increasing from 15 to around 30 days,nearly doubling.An increasing trend of“early onset and late withdrawal”of heatwaves has become more pronounced each year.In particular,eastern regions experience heatwaves that typically start earlier and tend to persist into September,exhibiting greater interannual variability compared to western areas.The middle and lower reaches of the Yangtze River and Xinjiang are identified as high-frequency heatwave areas.Complex network analysis reveals the dynamics of heatwave propagation,with degree centrality and synchronization distance indicating that the middle and lower reaches of the Yangtze River,Northeast China,and Xinjiang are key nodes in heatwave spread.Additionally,network divergence analysis shows that Xinjiang acts as a“source”area for heatwaves,exporting heat to surrounding regions,while the central region functions as a major“sink,”receiving more heatwave events.Further analysis from 1994 to 2023 indicates that heatwave events exhibit stronger network centrality and more complex synchronization patterns.These results suggest that complex networks provide a refined framework for depicting the spatiotemporal dynamics of heatwave propagation,offering new avenues for studying their occurrence and development patterns.展开更多
This paper systematically introduces the extraction process of the active components from the essential oil of Melaleuca alternifolia,elucidates the biological functions of these active components,and summarizes their...This paper systematically introduces the extraction process of the active components from the essential oil of Melaleuca alternifolia,elucidates the biological functions of these active components,and summarizes their applications in agricultural pest control.Furthermore,the paper examines the future developmental directions of M.alternifolia essential oil in pest control,along with the current challenges associated with its application.The aim is to offer insights for future research on botanical essential oils,particularly regarding their biological functions and applications in agricultural pest control.展开更多
Microplastic contamination is considered a major threat to the marine environment.Although microplastic pollution in the Pacific Ocean has been studied,its abundance,distribution,composition,and origin in the western ...Microplastic contamination is considered a major threat to the marine environment.Although microplastic pollution in the Pacific Ocean has been studied,its abundance,distribution,composition,and origin in the western Pacific Ocean remain unclear.Here,we investigated the abundance and distribution characteristics of microplastics in surface waters of the western Pacific Ocean and analyzed their potential sources.Results show that microplastics were widespread in the western Pacific Ocean,with abundance ranging from 0.03 to 2.36 particles/m^(3)(average 0.37±0.47 particles/m^(3)).Fibers/filaments and fragments were the main shapes of microplastics(71.6%)and the most abundant microplastic size class was<1.0 mm(42.4%).Significant differences in microplastic abundance were observed in different regions,with the lowest abundance in the South China Sea(0.03 particles/m^(3))and highest abundance in the seamount area in the western Pacific Ocean(0.58 particles/m^(3)).This study provides baseline data and insights into the fate and transportation of microplastics in the western Pacific region.展开更多
In the application of high-pressure water jet assisted breaking of deep underground rock engineering,the influence mechanism of rock temperature on the rock fragmentation process under jet action is still unclear.Ther...In the application of high-pressure water jet assisted breaking of deep underground rock engineering,the influence mechanism of rock temperature on the rock fragmentation process under jet action is still unclear.Therefore,the fluid evolution characteristics and rock fracture behavior during jet impingement were studied.The results indicate that the breaking process of high-temperature rock by jet impact can be divided into four stages:initial fluid-solid contact stage,intense thermal exchange stage,perforation and fracturing stage,and crack propagation and penetration stage.With the increase of rock temperature,the jet reflection angles and the time required for complete cooling of the impact surface significantly decrease,while the number of cracks and crack propagation rate significantly increase,and the rock breaking critical time is shortened by up to 34.5%.Based on numerical simulation results,it was found that the center temperature of granite at 400℃ rapidly decreased from 390 to 260℃ within 0.7 s under jet impact.In addition,a critical temperature and critical heat flux prediction model considering the staged breaking of hot rocks was established.These findings provide valuable insights to guide the water jet technology assisted deep ground hot rock excavation project.展开更多
Understanding the reinforcement effect of the newly developed prestressed reinforcement components(PRCs)(a system composed of prestressed steel bars(PSBs),protective sleeves,lateral pressure plates(LPPs),and anchoring...Understanding the reinforcement effect of the newly developed prestressed reinforcement components(PRCs)(a system composed of prestressed steel bars(PSBs),protective sleeves,lateral pressure plates(LPPs),and anchoring elements)is technically significant for the rational design of prestressed subgrade.A three-dimensional finite element model was established and verified based on a novel static model test and utilized to systematically analyze the influence of prestress levels and reinforcement modes on the reinforcement effect of the subgrade.The results show that the PRCs provide additional confining pressure to the subgrade through the diffusion effect of the prestress,which can therefore effectively improve the service performance of the subgrade.Compared to the unreinforced conventional subgrades,the settlements of prestressreinforced subgrades are reduced.The settlement attenuation rate(Rs)near the LPPs is larger than that at the subgrade center,and increasing the prestress positively contributes to the stability of the subgrade structure.In the multi-row reinforcement mode,the reinforcement effect of PRCs can extend from the reinforced area to the unreinforced area.In addition,as the horizontal distance from the LPPs increases,the additional confining pressure converted by the PSBs and LPPs gradually diminishes when spreading to the core load bearing area of the subgrade,resulting in a decrease in the Rs.Under the singlerow reinforcement mode,PRCs can be strategically arranged according to the local areas where subgrade defects readily occurred or observed,to obtain the desired reinforcement effect.Moreover,excessive prestress should not be applied near the subgrade shoulder line to avoid the shear failure of the subgrade shoulder.PRCs can be flexibly used for preventing and treating various subgrade defects of newly constructed or existing railway lines,achieving targeted and classified prevention,and effectively improving the bearing performance and deformation resistance of the subgrade.The research results are instructive for further elucidating the prestress reinforcement effect of PRCs on railway subgrades.展开更多
Purpose–The precast concrete slab track(PST)has advantages of fewer maintenance frequencies,better smooth rides and structural stability,which has been widely applied in urban rail transit.Precise positioning of prec...Purpose–The precast concrete slab track(PST)has advantages of fewer maintenance frequencies,better smooth rides and structural stability,which has been widely applied in urban rail transit.Precise positioning of precast concrete slab(PCS)is vital for keeping the initial track regularity.However,the cast-in-place process of the self-compacting concrete(SCC)filling layer generally causes a large deformation of PCS due to the water-hammer effect of flowing SCC,even cracking of PCS.Currently,the buoyancy characteristic and influencing factors of PCS during the SCC casting process have not been thoroughly studied in urban rail transit.Design/methodology/approach–In this work,a Computational Fluid Dynamics(CFD)model is established to calculate the buoyancy of PCS caused by the flowing SCC.The main influencing factors,including the inlet speed and flowability of SCC,have been analyzed and discussed.A new structural optimization scheme has been proposed for PST to reduce the buoyancy caused by the flowing SCC.Findings–The simulation and field test results showed that the buoyancy and deformation of PCS decreased obviously after adopting the new scheme.Originality/value–The findings of this study can provide guidance for the control of the deformation of PCS during the SCC construction process.展开更多
Floating breakwaters(FBs)are commonly employed for the protection of coastal installations.In this work,a convextype floating breakwater(FB)is proposed,and its hydrodynamic characteristics are studied through systemat...Floating breakwaters(FBs)are commonly employed for the protection of coastal installations.In this work,a convextype floating breakwater(FB)is proposed,and its hydrodynamic characteristics are studied through systematic laboratory experiments.Two different deck widths and two different mooring systems are set in the experiment.The transmission coefficients,reflection coefficients,motion responses and mooring forces of convex-type FBs are obtained in experiments.The influences of the deck width and mooring system on the hydrodynamic characteristics of the proposed FB are analyzed and compared.The experimental results show that the reflection coefficient and mooring force of the convex-type FB with a cross-mooring system are significantly larger than those of the convextype FB with a parallel-mooring system.A convex-type FB with a larger deck width has a higher reflection coefficient.The convex-type FBs with cross-and parallel-mooring systems have similar surge and heave motions,but the cross-mooring results in small roll motion.In addition,reliable prediction formulas for the transmission coefficient of convex-type FBs with different mooring systems have been developed,which are important for engineering design.展开更多
文摘Uveal and conjunctival melanomas are relatively rare tumors;nonetheless,they pose a significant risk of mortality for a large number of affected individuals.The pathogenesis of melanoma at different sites is very similar,however,the prognosis for patients with ocular melanoma remains unfavourable,primarily due to its distinctive genetic profile and tumor microenvironment.Regardless of considerable advances in understanding the genetic characteristics and biological behaviour,the treatment of uveal and conjunctival melanoma remains a formidable challenge.To enhance the prospect of success,collaborative efforts involving medical professionals and researchers in thefields of ocular biology and oncology are essential.Current data show a lack of well-designed randomized clinical trials and limited benefits in current forms of treatment for these tumors.Despite advancements in the development of effective melanoma therapeutic strategies,all current treatments for uveal melanoma(UM)and conjunctival melanoma(CoM)remain unsatisfactory,resulting in a poor long-term prognosis.Ongoing trials offer hope for positive outcomes in advanced and metastatic tumors.A more comprehensive understanding of the genetic and molecular abnormalities involved in the development and progression of ocular melanomas opens the way for the development of personalized therapy,with various potential therapeutic targets currently under consideration.Increased comprehension of the molecular pathogenesis of UM and CoM and their specificities may aid in the development of new and more effective systemic therapeutic agents,with the hope of improving the prognosis for patients with metastatic disease.
基金Funded by the National Natural Science Foundation of Hunan Province,Chinal(No.2021JJ60012)。
文摘To prepare a conductive polymer actuator with decent performance,a self-built experimental platform for the preparation of polypyrrole film is employed.One of the essential goals is to examine the mechanical characteristics of the actuator in the presence of various combinations of process parameters,combined with the orthogonal test method of"four factors and three levels".The bending and sensing characteristics of actuators of various sizes are methodically examined using a self-made bending polypyrrole actuator.The functional relationship between the bending displacement and the output voltage signal is established by studying the characteristics of the actuator sensor subjected to various degrees of bending.The experimental results reveal that the bending displacement of the actuator tip almost exhibits a linear variation as a function of length and width.When the voltage reaches 0.8 V,the bending speed of the actuator tends to be stable.Finally,the mechanical properties of the self-assembled polypyrrole actuator are verified by the design and fabrication of the microgripper.
基金Supported by National Natural Science Foundation of China(12101482)Postdoctoral Science Foundation of China(2022M722604)+2 种基金General Project of Science and Technology of Shaanxi Province(2023-YBSF-372)The Natural Science Foundation of Shaan Xi Province(2023-JCQN-0016)Shannxi Mathmatical Basic Science Research Project(23JSQ042)。
文摘In order to better describe the phenomenon of biological invasion,this paper introduces a free boundary model of biological invasion.Firstly,the right free boundary is added to the equation with logistic terms.Secondly,the existence and uniqueness of local solutions are proved by the Sobolev embedding theorem and the comparison principle.Finally,according to the relevant research data and contents of red fire ants,the diffusion area and nest number of red fire ants were simulated without external disturbance.This paper mainly simulates the early diffusion process of red fire ants.In the early diffusion stage,red fire ants grow slowly and then spread over a large area after reaching a certain number.
文摘BACKGROUND Mild cognitive impairment(MCI)has a high risk of progression to Alzheimer’s disease.The disease is often accompanied by sleep disorders,and whether sleep disorders have an effect on brain function in patients with MCI is unclear.AIM To explore the near-infrared brain function characteristics of MCI with sleep disorders.METHODS A total of 120 patients with MCI(MCI group)and 50 healthy subjects(control group)were selected.All subjects underwent the functional near-infrared spec-troscopy test.Collect baseline data,Mini-Mental State Examination,Montreal Cognitive Assessment scale,fatigue severity scale(FSS)score,sleep parameter,and oxyhemoglobin(Oxy-Hb)concentration and peak time of functional near-infrared spectroscopy test during the task period.The relationship between Oxy-RESULTS Compared with the control group,the FSS score of the MCI group was higher(t=11.310),and the scores of Pittsburgh sleep quality index,sleep time,sleep efficiency,nocturnal sleep disturbance,and daytime dysfunction were higher(Z=-10.518,-10.368,-9.035,-10.661,-10.088).Subjective sleep quality and total sleep time scores were lower(Z=-11.592,-9.924).The sleep efficiency of the MCI group was lower,and the awakening frequency,rem sleep latency period,total sleep time,and oxygen desaturation index were higher(t=5.969,5.829,2.887,3.003,5.937).The Oxy-Hb concentration at T0,T1,and T2 in the MCI group was lower(t=14.940,11.280,5.721),and the peak time was higher(t=18.800,13.350,9.827).In MCI patients,the concentration of Oxy-Hb during T0 was negatively correlated with the scores of Pittsburgh sleep quality index,sleep time,total sleep time,and sleep efficiency(r=-0.611,-0.388,-0.563,-0.356).It was positively correlated with sleep efficiency and total sleep time(r=0.754,0.650),and negatively correlated with oxygen desaturation index(r=-0.561)and FSS score(r=-0.526).All comparisons were P<0.05.CONCLUSION Patients with MCI and sleep disorders have lower near-infrared brain function than normal people,which is related to sleep quality.Clinically,a comprehensive assessment of the near-infrared brain function of patients should be carried out to guide targeted treatment and improve curative effect.
基金supported by Major Project of Science and Technology Department of Yunnan Province(202002AA100005,202102AE090027-2)National Natural Science Foundation of China(82260703)+1 种基金Cassava Industrial Technology System of China(CARS11-YNTY)Yunnan Province Ten Thousand Plan Industrial Technology Talents Project(YNWR-CYJS-2020-010)。
文摘Moringa oleifera Lam.is a Moringa genus in the Moringaceae family that is high in nutrients and has a wide range of applications.Phenolic compounds are widely found in plants and have various health benefits for the human body.With its high content and wide variety of phenolic compounds,M.oleifera Lam.has been widely studied for its health benefits.The phenolic compounds in M.oleifera Lam.(MOPCs)can be a potential source of functional food ingredients in pharmaceutical and industrial applications.Numerous studies have shown that MOPCs have antioxidant,anti-obesity,anti-diabetic,and antibacterial effects.Although the research on MOPCs has been gradually increasing,the extraction,isolation,identification,biological activities,and comprehensive application of MOPCs need a more systematic summary and generalization.Therefore,this paper reviews the isolation and extraction methods,structure identification,biological activities,and comprehensive applications to provide a further reference for the research and application of MOPCs.
文摘Introduction: Diabetes remains a real public health problem today, due to its associated morbidity and mortality. It induces numerous metabolic, biochemical, hematological, and immunological changes, responsible for multiple complications. The objective of this study was to characterize clinically and biologically type 2 diabetic patients followed at the National Center for Diabetology and Arterial Hypertension of the Central Hospital of Yaoundé. Method: This prospective, cross-sectional, and analytical study took place from April 5 to July 31, 2023 (4 months) on 100 diabetic patients of both sexes (61 women and 39 men), aged from 31 to 88 years. Body Mass Index, systolic and diastolic blood pressure, and cardiac frequency were measured on each of the patients. Subsequently, blood was collected from the patients for the determination of the complete blood count, HBA1c, lipid profile, serum albumin, TNF-α, and IL-6 levels. The data were analyzed using SPSS 17.0 software. Results: The age average of our population was 56.99 ± 11.51 years, the population was primarily female (61%) and primarily between the ages of 55 and 88. 67% of respondents were married. 59% went to secondary school. 73% of them lived in urban areas. 30% were obese and 40% were overweight, with an average BMI of 28.75 kg/m2. 76% of patients took oral antidiabetic medications. HbA1c level average was 8.65%, with 60% having readings above 6.5%. Low hemoglobin and hypochromia were among the abnormalities of red blood cells observed. Lipid profiles revealed low HDL-cholesterol and high triglycerides and cholesterol. Elevated levels of TNF-α and IL-6 indicated inflammation and cardiovascular risk. Conclusion: These results indicate the necessity of focused diabetic care and management on diabetic patients attending the central hospital of Yaoundé, Cameroon.
文摘A spice formulation study in Burkina Faso was carried out using local ingredients for the benefit of households. The objective of this study was to propose some spice formulations based on local ingredients in order to reduce the use of chemical spices in the preparation of different dishes. The Design of Experiments (DOE) methodology was used for the formulation of the spices and their physicochemical, nutritional and sensory characteristics were evaluated by standardized and standard methods. The results obtained showed lipid contents (g/100 g DM) ranging from 10.41 ± 0.26 to 15.64 ± 0.68, total sugars from 4.39 ± 0.32 to 5.46 ± 0.31, protein from 3.65 ± 0.17 to 12.04 ± 0.35 and ash from 5.83 ± 0.01 to 7.02 ± 0.01. The polyphenol content ranged from 9.09 ± 1.60 to 11.33 ± 0.90, and the flavonoid content ranged from 0.65 ± 0.03 to 1.08 ± 0.13. The sensory analysis carried out showed that the spices have generally satisfactory organoleptic characteristics. These results constitute new information in the diet of populations and are an alternative to the chemical spices used in their cooking.
文摘In this paper,we present a modeling of the soil-water characteristic curve for residual and sedimentary soils of Bom Brinquedo Hill’s,located in Antonina,Brazil.This mountain range region is characterized as a natural disaster risk area,requiring continuous research related to the stability of the area.To obtain the soil-water characteristic curve,undisturbed samples of residual and sedimentary soil were collected,followed by suction testing using the filter paper method.Considering the bimodal characteristic presented by the soil,LABFIT software was employed for curve fitting using the generic formulation“Harris+C”.The results of the tests indicated that the phenomenon of hysteresis had a greater influence in situations with higher suction levels.When comparing the residual moisture values of the macropores between residual soil and sedimentary soil,the former exhibited the lower value.This suggests that the residual soil has a coarser grain size and larger pores,which facilitates the release of water retained in the soil’s macropores.
文摘In order to contribute to a better understanding of the biodiversity of local chicken populations, this study focused on the description of the essential qualitative parameters in the phenotypic characterization of local species. Conducted in 6 localities in the Far North Region of Cameroon (Doukoula, Yagoua, Guidiguis, Dziguilao, Maroua 3rd and Méri), a population of 240 local chickens, including 172 hens and 68 cocks were characterized in family farms. The choice of localities was made on the basis of their strong potential local chicken flocks in the region. To this end, each animal was the subject of a qualitative description based on the identification of the sex of the animal, the description of the colorations of the plumage and extremities, and the description of the types of format, plumage and crests. All observations were made with the naked eye and in daylight and then photographed. The main results show that the plumage colors are multiple and dominated by the White-Pied-Black (21.7%) and the Mille-fleur (20.8%);the wattles are dominated by the red (60%) and the pink (35.4%);the tarsi are dominated by the white (43.8%) and the black (32.08%);the white skin (92.5%) dominates over the pink skin (7.5%);the “Smooth-uniform” feather is dominant (97.08%), followed by the smooth-crested type (2.08%) and the fries type (0.82%);the medium size of the chickens is dominant (86.66%), followed by the dwarf size (9.58%) and the large size (3.75%). The results of this study demonstrate that there is a strong phenotypic diversity within the local chicken population. This diversity can serve as a basis for the development of selection, conservation and genetic potential improvement programs based on rational exploitation of the local chicken.
文摘Addressing the existing gap in ethical research surrounding distinct technical characteristics of Robotic Process Automation enhanced with Artificial Intelligence (AI-RPA), this analysis examines the unique ethical dimensions by positioning AI-RPA as a distinct technological subdivision. From an analytical perspective, this study highlights key characteristics such as minimal reliance on programming, rapid development cycles, and restricted algorithmic control, which differentiate AI-RPA from traditional AI systems. These characteristics underscore the need for tailored ethical considerations, to identify ethical perils within AI-RPA’s technological origins. By positioning AI-RPA as a distinct subdivision and examining its unique characteristics alongside their emerging ethical challenges, this paper enriches the evolving discourse on AI ethics, providing valuable insights for researchers, policymakers, and organizations implementing AI-RPA technologies.
文摘Production of this crop is experiencing significant challenges, resulting in a decline in seed and fiber quality. To address this challenge, generations of high-performance cotton plants of the Gossypium hirsutum L. species have been developed and are currently being commercialized. This study evaluated the impact of gin types on the agro-industrial quality of cotton in Côte d’Ivoire. To this end, cotton from the G3, R1, and R2 generations was harvested, sampled, and ginned on machines with 10 and 170 saws in the localities of Ouangolodougou, Ferkessédougou, Korhogo, M’Bengué, Boundiali, Séguéla, and Mankono, as well as at the Centre National de Recherche Agronomique CNRA) in Bouaké. The results demonstrated that cotton fibers obtained from ginning on 10-saw machines exhibited superior quality compared to those from 170-saw machines. Fiber length, fiber length uniformity, and short fiber rate exhibited the highest deviations according to gin type. The use of 170-saw gins resulted in a notable decline in quality. Conversely, micronaire index, fiber tenacity and elongation, and reflectance remained consistent across machine types. These results will enable us to more effectively regulate and advise cotton-processing factories, which primarily utilize 170-saw gins to enhance agro-industrial quality in Côte d’Ivoire. Furthermore, these results will assist breeders in incorporating them into their processes to enhance the quality of the varieties they offer to farmers.
文摘BACKGROUND Autoimmune hepatitis(AIH)is typically treated with immunomodulators and steroids.However,some patients are refractory to these treatments,necessitating alternative approaches.Biological therapies have recently been explored for these difficult cases.AIM To assess the efficacy and safety of biologics in AIH,focusing on patients unresponsive to standard treatments and evaluating outcomes such as serological markers and histological remission.METHODS A case-based systematic review was performed following the PRISMA protocol to evaluate the efficacy and safety of biological therapies in AIH.The primary focus was on serological improvement and histological remission.The secondary focus was on assessing therapy safety and additional outcomes.A standardized search command was applied to MEDLINE,EMBASE,and Cochrane Library databases to identify relevant studies.Inclusion criteria encompassed adult AIH patients treated with biologics.Data were analyzed based on demographics,prior treatments,and therapy-related outcomes.A narrative synthesis was employed to address biases and provide a comprehensive overview of the evidence.RESULTS A total of 352 studies were reviewed,with 30 selected for detailed analysis.Key findings revealed that Belimumab led to a favourable response in five out of eight AIH patients across two studies.Rituximab demonstrated high efficacy,with 41 out of 45 patients showing significant improvement across six studies.Basiliximab was assessed in a single study,where the sole patient treated experienced a beneficial outcome.Additionally,a notable number of AIH cases were induced by anti-tumor necrosis factor(TNF)medications,including 16 cases associated with infliximab and four cases with adalimumab.All these cases showed improvement upon withdrawal of the biologic agent.CONCLUSION Belimumab and Rituximab show promise as effective alternatives for managing refractory AIH,demonstrating significant improvements in clinical outcomes and liver function.However,the variability in patient responses to different therapies highlights the need for personalized treatment strategies.The risk of AIH induced by anti-TNF therapies underscores the need for vigilant monitoring and prompt symptom recognition.These findings support the incorporation of biologic agents into AIH treatment protocols,particularly for patients who do not respond to conventional therapies.
基金the funding support from the National Natural Science Foundation of China(Grant No.52308340)Chongqing Talent Innovation and Entrepreneurship Demonstration Team Project(Grant No.cstc2024ycjh-bgzxm0012)the Science and Technology Projects supported by China Coal Technology and Engineering Chongqing Design and Research Institute(Group)Co.,Ltd..(Grant No.H20230317)。
文摘Influenced by complex external factors,the displacement-time curve of reservoir landslides demonstrates both short-term and long-term diversity and dynamic complexity.It is difficult for existing methods,including Regression models and Neural network models,to perform multi-characteristic coupled displacement prediction because they fail to consider landslide creep characteristics.This paper integrates the creep characteristics of landslides with non-linear intelligent algorithms and proposes a dynamic intelligent landslide displacement prediction method based on a combination of the Biological Growth model(BG),Convolutional Neural Network(CNN),and Long ShortTerm Memory Network(LSTM).This prediction approach improves three different biological growth models,thereby effectively extracting landslide creep characteristic parameters.Simultaneously,it integrates external factors(rainfall and reservoir water level)to construct an internal and external comprehensive dataset for data augmentation,which is input into the improved CNN-LSTM model.Thereafter,harnessing the robust feature extraction capabilities and spatial translation invariance of CNN,the model autonomously captures short-term local fluctuation characteristics of landslide displacement,and combines LSTM's efficient handling of long-term nonlinear temporal data to improve prediction performance.An evaluation of the Liangshuijing landslide in the Three Gorges Reservoir Area indicates that BG-CNN-LSTM exhibits high prediction accuracy,excellent generalization capabilities when dealing with various types of landslides.The research provides an innovative approach to achieving the whole-process,realtime,high-precision displacement predictions for multicharacteristic coupled landslides.
基金Project supported by the National Key Research and Development Program of China(Grant Nos.2022YFE0136000 and 2024YFC3013100)the Joint Meteorological Fund(Grant No.U2342211)+1 种基金the Joint Research Project for Meteorological Capacity Improvement(Grant No.22NLTSZ004)the National Meteorological Information Center(Grant No.NMICJY202301)。
文摘Using complex network methods,we construct undirected and directed heatwave networks to systematically analyze heatwave events over China from 1961 to 2023,exploring their spatiotemporal evolution patterns in different regions.The findings reveal a significant increase in heatwaves since the 2000s,with the average occurrence rising from approximately 3 to 5 times,and their duration increasing from 15 to around 30 days,nearly doubling.An increasing trend of“early onset and late withdrawal”of heatwaves has become more pronounced each year.In particular,eastern regions experience heatwaves that typically start earlier and tend to persist into September,exhibiting greater interannual variability compared to western areas.The middle and lower reaches of the Yangtze River and Xinjiang are identified as high-frequency heatwave areas.Complex network analysis reveals the dynamics of heatwave propagation,with degree centrality and synchronization distance indicating that the middle and lower reaches of the Yangtze River,Northeast China,and Xinjiang are key nodes in heatwave spread.Additionally,network divergence analysis shows that Xinjiang acts as a“source”area for heatwaves,exporting heat to surrounding regions,while the central region functions as a major“sink,”receiving more heatwave events.Further analysis from 1994 to 2023 indicates that heatwave events exhibit stronger network centrality and more complex synchronization patterns.These results suggest that complex networks provide a refined framework for depicting the spatiotemporal dynamics of heatwave propagation,offering new avenues for studying their occurrence and development patterns.
基金Supported by Undergraduate Training Programs for Innovation and Entrepreneurship of Guangdong Province(202310580005)Youth Project of Zhaoqing University(QN202443)China Agriculture Research System of MOF and MARA(CARS-26).
文摘This paper systematically introduces the extraction process of the active components from the essential oil of Melaleuca alternifolia,elucidates the biological functions of these active components,and summarizes their applications in agricultural pest control.Furthermore,the paper examines the future developmental directions of M.alternifolia essential oil in pest control,along with the current challenges associated with its application.The aim is to offer insights for future research on botanical essential oils,particularly regarding their biological functions and applications in agricultural pest control.
基金Supported by the National Key Research and Development Program(No.2016YFC1402201)the China Ocean Mineral Resources R&D Association Project(No.DY135-E2-2-04)。
文摘Microplastic contamination is considered a major threat to the marine environment.Although microplastic pollution in the Pacific Ocean has been studied,its abundance,distribution,composition,and origin in the western Pacific Ocean remain unclear.Here,we investigated the abundance and distribution characteristics of microplastics in surface waters of the western Pacific Ocean and analyzed their potential sources.Results show that microplastics were widespread in the western Pacific Ocean,with abundance ranging from 0.03 to 2.36 particles/m^(3)(average 0.37±0.47 particles/m^(3)).Fibers/filaments and fragments were the main shapes of microplastics(71.6%)and the most abundant microplastic size class was<1.0 mm(42.4%).Significant differences in microplastic abundance were observed in different regions,with the lowest abundance in the South China Sea(0.03 particles/m^(3))and highest abundance in the seamount area in the western Pacific Ocean(0.58 particles/m^(3)).This study provides baseline data and insights into the fate and transportation of microplastics in the western Pacific region.
基金supported by National Natural Science Foundation of China (No.U23A20597)National Major Science and Technology Project of China (No.2024ZD1003803)+1 种基金Chongqing Science Fund for Distinguished Young Scholars of Chongqing Municipality (No.CSTB2022NSCQ-JQX0028)Natural Science Foundation of Chongqing (No.CSTB2024NSCQ-MSX0503)。
文摘In the application of high-pressure water jet assisted breaking of deep underground rock engineering,the influence mechanism of rock temperature on the rock fragmentation process under jet action is still unclear.Therefore,the fluid evolution characteristics and rock fracture behavior during jet impingement were studied.The results indicate that the breaking process of high-temperature rock by jet impact can be divided into four stages:initial fluid-solid contact stage,intense thermal exchange stage,perforation and fracturing stage,and crack propagation and penetration stage.With the increase of rock temperature,the jet reflection angles and the time required for complete cooling of the impact surface significantly decrease,while the number of cracks and crack propagation rate significantly increase,and the rock breaking critical time is shortened by up to 34.5%.Based on numerical simulation results,it was found that the center temperature of granite at 400℃ rapidly decreased from 390 to 260℃ within 0.7 s under jet impact.In addition,a critical temperature and critical heat flux prediction model considering the staged breaking of hot rocks was established.These findings provide valuable insights to guide the water jet technology assisted deep ground hot rock excavation project.
基金supported by the National Natural Science Foundation of China(Grant Nos.51978672 and 52308335)the Natural Science Funding of Hunan Province(Grant No.2023JJ41054)the Natural Science Research Project of Anhui Educational Committee(Grant No.2023AH051170)。
文摘Understanding the reinforcement effect of the newly developed prestressed reinforcement components(PRCs)(a system composed of prestressed steel bars(PSBs),protective sleeves,lateral pressure plates(LPPs),and anchoring elements)is technically significant for the rational design of prestressed subgrade.A three-dimensional finite element model was established and verified based on a novel static model test and utilized to systematically analyze the influence of prestress levels and reinforcement modes on the reinforcement effect of the subgrade.The results show that the PRCs provide additional confining pressure to the subgrade through the diffusion effect of the prestress,which can therefore effectively improve the service performance of the subgrade.Compared to the unreinforced conventional subgrades,the settlements of prestressreinforced subgrades are reduced.The settlement attenuation rate(Rs)near the LPPs is larger than that at the subgrade center,and increasing the prestress positively contributes to the stability of the subgrade structure.In the multi-row reinforcement mode,the reinforcement effect of PRCs can extend from the reinforced area to the unreinforced area.In addition,as the horizontal distance from the LPPs increases,the additional confining pressure converted by the PSBs and LPPs gradually diminishes when spreading to the core load bearing area of the subgrade,resulting in a decrease in the Rs.Under the singlerow reinforcement mode,PRCs can be strategically arranged according to the local areas where subgrade defects readily occurred or observed,to obtain the desired reinforcement effect.Moreover,excessive prestress should not be applied near the subgrade shoulder line to avoid the shear failure of the subgrade shoulder.PRCs can be flexibly used for preventing and treating various subgrade defects of newly constructed or existing railway lines,achieving targeted and classified prevention,and effectively improving the bearing performance and deformation resistance of the subgrade.The research results are instructive for further elucidating the prestress reinforcement effect of PRCs on railway subgrades.
文摘Purpose–The precast concrete slab track(PST)has advantages of fewer maintenance frequencies,better smooth rides and structural stability,which has been widely applied in urban rail transit.Precise positioning of precast concrete slab(PCS)is vital for keeping the initial track regularity.However,the cast-in-place process of the self-compacting concrete(SCC)filling layer generally causes a large deformation of PCS due to the water-hammer effect of flowing SCC,even cracking of PCS.Currently,the buoyancy characteristic and influencing factors of PCS during the SCC casting process have not been thoroughly studied in urban rail transit.Design/methodology/approach–In this work,a Computational Fluid Dynamics(CFD)model is established to calculate the buoyancy of PCS caused by the flowing SCC.The main influencing factors,including the inlet speed and flowability of SCC,have been analyzed and discussed.A new structural optimization scheme has been proposed for PST to reduce the buoyancy caused by the flowing SCC.Findings–The simulation and field test results showed that the buoyancy and deformation of PCS decreased obviously after adopting the new scheme.Originality/value–The findings of this study can provide guidance for the control of the deformation of PCS during the SCC construction process.
基金financially supported by the National Natural Science Foundation of China(Grant No.52088102)New Cornerstone Science Foundation through the XPLORER PRIZE.
文摘Floating breakwaters(FBs)are commonly employed for the protection of coastal installations.In this work,a convextype floating breakwater(FB)is proposed,and its hydrodynamic characteristics are studied through systematic laboratory experiments.Two different deck widths and two different mooring systems are set in the experiment.The transmission coefficients,reflection coefficients,motion responses and mooring forces of convex-type FBs are obtained in experiments.The influences of the deck width and mooring system on the hydrodynamic characteristics of the proposed FB are analyzed and compared.The experimental results show that the reflection coefficient and mooring force of the convex-type FB with a cross-mooring system are significantly larger than those of the convextype FB with a parallel-mooring system.A convex-type FB with a larger deck width has a higher reflection coefficient.The convex-type FBs with cross-and parallel-mooring systems have similar surge and heave motions,but the cross-mooring results in small roll motion.In addition,reliable prediction formulas for the transmission coefficient of convex-type FBs with different mooring systems have been developed,which are important for engineering design.
