Existing vehicle experiment systems tend to focus on the research of vehicle dynamics by conducting performance tests on every system or some parts of the vehicle so as to improve the entire performance of the vehicle...Existing vehicle experiment systems tend to focus on the research of vehicle dynamics by conducting performance tests on every system or some parts of the vehicle so as to improve the entire performance of the vehicle. Virtual technology is widely utilized in various vehicle test-beds. These test-beds are mainly used to simulate the driving training, conduct the research on drivers＇ behaviors, or give virtual demonstrations of the transportation environment. However, the study on the active safety of the running vehicle in the virtual environment is still insufficient. A virtual scene including roads and vehicles is developed by using the software Creator and Vega, and radars and cameras are also simulated in the scene. Based on dSPACE＇s rapid prototyping simulation and its single board DS1103, a simulation model including vehicle control signals is set up in MATLAB/Simulink, the model is then built into C code, and the system defined file（SDF） is downloaded to the DS1103 board through the experiment debug software ControlDesk and is kept running. Programming is made by mixing Visual C＋＋ 6.0, MATLAB API and Vega API. Control signals are read out by invoking library function MLIB/MTRACE of dSPACE. All the input, output, and system state values are acquired by arithmetic and are dynamically associated with the running status of the virtual vehicle. An intelligent vehicle experiment system is thus developed by virtue of program and integration. The system has not only the demonstration function, such as general driving, cruise control, active avoiding collision, but also the function of virtual experiment. Parameters of the system can be set according to needs, and the virtual test results can be analyzed and studied and used for the comparison with the existing models. The system reflects the running of the intelligent vehicle in the virtual traffic environment, at the same time, the system is a new attempt performed on the intelligent vehicle travel research and provides also a new research method for the development of intelligent vehicles.展开更多
This paper used the virtual reality modeling language （VRML） to establish the 3D virtual experiment instrument model, and by using the visual programming language VB to design and develop a interactive virtual reali...This paper used the virtual reality modeling language （VRML） to establish the 3D virtual experiment instrument model, and by using the visual programming language VB to design and develop a interactive virtual realization experiment platform, the interface has friendly interface, stable operation, strong practicability like with the Windows style, is a kind of reform for the traditional physics experiment teaching mode. The system has practical use value, also has reference value for the reform and modernization of other experimental courses.展开更多
In the scenario of a steam generator tube rupture accident in a lead-cooled fast reactor,secondary circuit subcooled water under high pressure is injected into an ordinary-pressure primary vessel,where a molten lead-b...In the scenario of a steam generator tube rupture accident in a lead-cooled fast reactor,secondary circuit subcooled water under high pressure is injected into an ordinary-pressure primary vessel,where a molten lead-based alloy(typically pure lead or lead-bismuth eutectic(LBE))is used as the coolant.To clarify the pressure build-up characteristics under water-jet injection,this study conducted several experiments by injecting pressurized water into a molten LBE pool at Sun Yat-sen University.To obtain a further understanding,several new experimental parameters were adopted,including the melt temperature,water subcooling,injection pressure,injection duration,and nozzle diameter.Through detailed analyses,it was found that the pressure and temperature during the water-melt interaction exhibited a consistent variation trend with our previous water-droplet injection mode LBE experiment.Similarly,the existence of a steam explosion was confirmed,which typically results in a much stronger pressure build-up.For the non-explosion cases,increasing the injection pressure,melt-pool temperature,nozzle diameter,and water subcooling promoted pressure build-up in the melt pool.However,a limited enhancement effect was observed when increasing the injection duration,which may be owing to the continually rising pressure in the interaction vessel or the isolation effect of the generated steam cavity.Regardless of whether a steam explosion occurred,the calculated mechanical and kinetic energy conversion efficiencies of the melt were relatively small(not exceeding 4.1%and 0.7%,respectively).Moreover,the range of the conversion efficiency was similar to that of previous water-droplet experiments,although the upper limit of the jet mode was slightly lower.展开更多
The hybrid CO_(2) thermal technique has achieved considerable success globally in extracting residual heavy oil from reserves following a long-term steam stimulation process.Using microscopic visualization experiments...The hybrid CO_(2) thermal technique has achieved considerable success globally in extracting residual heavy oil from reserves following a long-term steam stimulation process.Using microscopic visualization experiments and molecular dynamics(MD)simulations,this study investigates the microscopic enhanced oil recovery(EOR)mechanisms underlying residual oil removal using hybrid CO_(2) thermal systems.Based on the experimental models for the occurrence of heavy oil,this study evaluates the performance of hybrid CO_(2) thermal systems under various conditions using MD simulations.The results demonstrate that introducing CO_(2) molecules into heavy oil can effectively penetrate and decompose dense aggregates that are originally formed on hydrophobic surfaces.A stable miscible hybrid CO_(2) thermal system,with a high effective distribution ratio of CO_(2),proficiently reduces the interaction energies between heavy oil and rock surfaces,as well as within heavy oil.A visualization analysis of the interactions reveals that strong van der Waals(vdW)attractions occur between CO_(2) and heavy oil molecules,effectively promoting the decomposition and swelling of heavy oil.This unlocks the residual oil on the hydrophobic surfaces.Considering the impacts of temperature and CO_(2) concentration,an optimal gas-to-steam injection ratio(here,the CO_(2):steam ratio)ranging between 1:6 and 1:9 is recommended.This study examines the microscopic mechanisms underlying the hybrid CO_(2) thermal technique at a molecular scale,providing a significant theoretical guide for its expanded application in EOR.展开更多
As the commercialization of the fifth gen-eration communication(5G)is sped up,its system testing scheme is vital for the successful deployment of 5G.Especially,5G relies on the scale-increased multiple-input-multiple ...As the commercialization of the fifth gen-eration communication(5G)is sped up,its system testing scheme is vital for the successful deployment of 5G.Especially,5G relies on the scale-increased multiple-input-multiple output(MIMO)technique to improve its capacity and coverage.Thus,testing new functions of the 5G MIMO system accurately and ef-ficiently,including beamforming(beam-tracking with movement)and multiple-user(MU)multiplexing,is a challenging task.This paper tries to construct a lab-oratorial hardware and conduct equipment-controlled field testing.Firstly,the testing scheme is presented,which is composed of the framework,the channel models and the validation methods.Then,the channel model principles are explained in detail due to its di-rect influence on the testing accuracy.Specifically,we utilize the spatial consistency and the multi-link cor-relation properties to emulate the high-speed dynamic time-varying(HDT)and the multiple-cell(MC)-MU-MIMO channels.Finally,the above testing scheme is verified in a Shanghai 5G field experiment with the practical commercial equipment and the channel em-ulator.The results show that the 5G new functions are tested accurately and efficiently by switching the channel emulation configurations.展开更多
In comparison with conventional experimental teaching methods,the implementation of the Motic digital microscope mutual system in the experimental teaching of medicinal botany has been demonstrated to be a highly effi...In comparison with conventional experimental teaching methods,the implementation of the Motic digital microscope mutual system in the experimental teaching of medicinal botany has been demonstrated to be a highly efficacious approach to enhance the teaching level of experimental courses in medicinal botany.The implementation of a digital microscope mutual system in experimental teaching not only enhances students practical skills in laboratory operations but also increases classroom efficiency.Furthermore,it supports personalized development among students while fostering innovative thinking,independent learning capabilities,and analysis and problem-solving skills.Additionally,this approach contributes to the enhancement of students scientific literacy.展开更多
Background:QiShenYiQi(QSYQ)is commonly accepted to treat ischemic stroke(IS)in clinical settings,yet the underlying mechanism of action of QSYQ is largely unknown.Methods:By combining systems pharmacology with experim...Background:QiShenYiQi(QSYQ)is commonly accepted to treat ischemic stroke(IS)in clinical settings,yet the underlying mechanism of action of QSYQ is largely unknown.Methods:By combining systems pharmacology with experimental assessment,we examined the key targets,bioactive components,and mechanisms of QSYQ against IS.Results:Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform predicted a total number of 254 targets that were potentially related to QSYQ,whereas 699 targets associated with IS were gathered from Therapeutic Target Database,Comparative Toxicogenomics Database,Gene Cards,Online Mendelian Inheritance in Man,and National Center for Biotechnology Information databases,and 83 of these targets overlap with QSYQ-related targets.Importantly,through the analysis of Gene Ontology functional annotation,Kyoto Encyclopedia of Genes and Genomes pathway enrichment,and protein-protein interaction network,we identified 20 related signaling pathways along with 4 hub genes.Subsequently,our molecular docking results revealed that QSYQ might interact with PTGS2,PTGS1,SCN5A,and HSP90AB1.We observed dose-dependent beneficial effects of QSYQ in significantly improving neurological function and alleviating histopathological damage in middle cerebral artery occlusion model,while decreasing infarct volume.Notablely,QSYQ markedly downregulates tumor necrosis factor-α,interleukin-6,and interleukin-1 beta.Overall,this study demonstrates the synergetic effects of QSYQ on regulating multi-targets in IS through inhibiting inflammatory processes and neuronal apoptosis,these findings may expand the understanding of QSYQ and provide guidance for its clinical application in treating IS.Conclusion:Current study reveals the protective roles of QSYQ against IS through modulating PTGS2/PTGS1/SCN5A/HSP90AB1 and TNF signaling pathways.展开更多
This study aimed to evaluate the feasibility,safety,and efficacy of a noveltranscatheter suture closure system(HaloStitch^(®))for patent foramen ovale(PFO)closure in a swine model.Methods:Thirteen swine underwent...This study aimed to evaluate the feasibility,safety,and efficacy of a noveltranscatheter suture closure system(HaloStitch^(®))for patent foramen ovale(PFO)closure in a swine model.Methods:Thirteen swine underwentexperimental PF0 model creation.All animals received implantationof the transcatheter suture closure system to evaluate procedural success.Comprehensive follow-up over sixmonths included serial ultrasound imaging,histopathological analysis,and gross anatomical exaninationof cardiac specimens.Results:Successful HaloStitch^(®)device implantation was adhieved in 11 of 13 swine.Gross anatomical examination confirrned secure positioning of all sutures in the atrial septum,with noredundancy or thrombus formation.Postoperative ultrasound demonstrated stable suture and staplepositions throughout follow-up,with no evidence of suture breakage,displacement,or thrombus.Stapleswere clearly visualized under ultrasound imaging,Both the atrial septal defect orifice diameter and residualseptal shunt flow velocity decreased significantly during the observation period.Histopathological analysisrevealed partially organized thrombi at the implant head and fibrous connective tissue encapsulation withlocalized inflammatory cell infiltration surrounding the polymer material.Conclsions:The transcathetersuture closure system(HaloStitch^(®))demonstrated feasibility,safety,and biocompatib ility for PFO closure ina swine model,supporting its potential for clinical translation.展开更多
Benchmark experiments are indispensable for the development of neutron nuclear data evaluation libraries.Given the lack of domestic benchmarking of nuclear data in the fission energy region,this study developed a neut...Benchmark experiments are indispensable for the development of neutron nuclear data evaluation libraries.Given the lack of domestic benchmarking of nuclear data in the fission energy region,this study developed a neutron leakage spectrum measurement system using a spherical sample based on the^(252)Cf spontaneous fission source.The EJ309 detector(for highenergy measurements)and CLYC detector(for low-energy measurements)were combined to measure the time-of-flight spectrum using theγtagging method.To assess the performance of the system,the time-of-flight spectrum without a sample was measured first.The experimental spectra were consistent with those simulated using the Monte Carlo method and the standard^(252)Cf spectrum from ISO:8529-1.This demonstrates that the system can effectively measure the neutron events in the 0.15-8.0 MeV range.Then,a spherical polyethylene sample was used as the standard to verify the accuracy of the system for the benchmark experiment.The simulation results were obtained using the Monte Carlo method with evaluated data from the ENDF/B-Ⅷ.0,CENDL-3.2,JEFF-3.3,and JENDL-5 libraries.The measured neutron leakage spectra were compared with the corresponding simulated results for the neutron spectrum shape and calculated C/E values.The results showed that the simulated spectra with different data libraries reproduced the experimental results well in the 0.15-8.0 MeV range.This study confirms that the leakage neutron spectrum measurement system based on the^(252)Cf source can perform benchmarking and provides a foundation for evaluating neutron nuclear data through benchmark experiments.展开更多
Powered by advanced information technology,more and more complex systems are exhibiting characteristics of the cyber-physical-social systems(CPSS).In this context,computational experiments method has emerged as a nove...Powered by advanced information technology,more and more complex systems are exhibiting characteristics of the cyber-physical-social systems(CPSS).In this context,computational experiments method has emerged as a novel approach for the design,analysis,management,control,and integration of CPSS,which can realize the causal analysis of complex systems by means of“algorithmization”of“counterfactuals”.However,because CPSS involve human and social factors(e.g.,autonomy,initiative,and sociality),it is difficult for traditional design of experiment(DOE)methods to achieve the generative explanation of system emergence.To address this challenge,this paper proposes an integrated approach to the design of computational experiments,incorporating three key modules:1)Descriptive module:Determining the influencing factors and response variables of the system by means of the modeling of an artificial society;2)Interpretative module:Selecting factorial experimental design solution to identify the relationship between influencing factors and macro phenomena;3)Predictive module:Building a meta-model that is equivalent to artificial society to explore its operating laws.Finally,a case study of crowd-sourcing platforms is presented to illustrate the application process and effectiveness of the proposed approach,which can reveal the social impact of algorithmic behavior on“rider race”.展开更多
A tracking stability control problem for the vertical electric stabilization system of moving tank based on adaptive robust servo control is addressed.This paper mainly focuses on two types of possibly fast timevaryin...A tracking stability control problem for the vertical electric stabilization system of moving tank based on adaptive robust servo control is addressed.This paper mainly focuses on two types of possibly fast timevarying but bounded uncertainty within the vertical electric stabilization system:model parameter uncertainty and uncertain nonlinearity.First,the vertical electric stabilization system is constructed as an uncertain nonlinear dynamic system that can reflect the practical mechanics transfer process of the system.Second,the dynamical equation in the form of state space is established by designing the angular tracking error.Third,the comprehensive parameter of system uncertainty is designed to estimate the most conservative effects of uncertainty.Finally,an adaptive robust servo control which can effectively handle the combined effects of complex nonlinearity and uncertainty is proposed.The feasibility of the proposed control strategy under the practical physical condition is validated through the tests on the experimental platform.This paper pioneers the introduction of the internal nonlinearity and uncertainty of the vertical electric stabilization system into the settlement of the tracking stability control problem,and validates the advanced servo control strategy through experiment for the first time.展开更多
OBJECTIVE:To systematically evaluate the role of electroacupuncture in maintaining brain plasticity in ischemic stroke mediated brain damage.METHODS:We searched for all relevant trials published through Oct 7,2022 fro...OBJECTIVE:To systematically evaluate the role of electroacupuncture in maintaining brain plasticity in ischemic stroke mediated brain damage.METHODS:We searched for all relevant trials published through Oct 7,2022 from seven databases.Methodological quality was assessed using the CAMARADES Risk of Bias Tool.A Meta-analysis of comparative effects was performed using Review Manager v.5.3 software.RESULTS:A total of 101 studies involving 2148 animals were included.For most studies,primary outcomes results of the Meta-analysis indicate that EA significantly improved ischemic stroke rat's postsynaptic density thickness[Standardized Mean Difference(SMD)=1.41,95%confidence interval(CI)(0.59,2.23),P=0.0008],numerical density of synapses[SMD=1.55,95%CI(0.48,2.63),P=0.005]compared with non-EA-treated.Similarly,EA could improve parts of biomarkers of synapses,neurogenesis,angiogenesis and neurotrophin activity than the control group(P<0.05).CONCLUSION:The existing evidence suggests EA regulating ischemic stroke may be through brain plasticity.More rigorous and high quality studies should be conducted in the future.展开更多
In this paper,the mission and the thermal environment of the Solar Close Observations and Proximity Experiments(SCOPE)spacecraft are analyzed,and an advanced thermal management system(ATMS)is designed for it.The relat...In this paper,the mission and the thermal environment of the Solar Close Observations and Proximity Experiments(SCOPE)spacecraft are analyzed,and an advanced thermal management system(ATMS)is designed for it.The relationship and functions of the integrated database,the intelligent thermal control system and the efficient liquid cooling system in the ATMS are elaborated upon.For the complex thermal field regulation system and extreme space thermal environment,a modular simulation and thermal field planning method are proposed,and the feasibility of the planning algorithm is verified by numerical simulation.A solar array liquid cooling system is developed,and the system simulation results indicate that the temperatures of the solar arrays meet the requirements as the spacecraft flies by perihelion and aphelion.The advanced thermal management study supports the development of the SCOPE program and provides a reference for the thermal management in other deep-space exploration programs.展开更多
With the acceleration of marine construction in China,the exploitation and utilization of resources from islands and reefs are necessary.To prevent and dissipate waves in the process of resource exploitation and utili...With the acceleration of marine construction in China,the exploitation and utilization of resources from islands and reefs are necessary.To prevent and dissipate waves in the process of resource exploitation and utilization,a more effective method is to install floating breakwaters near the terrain of islands and reefs.The terrain around islands and reefs is complex,and waves undergo a series of changes due to the impact of the complex terrain in transmission.It is important to find a suitable location for floating breakwater systems on islands and reefs and investigate how the terrain affects the system’s hydrodynamic performance.This paper introduces a three-cylinder floating breakwater design.The breakwater system consists of 8 units connected by elastic structures and secured by a slack mooring system.To evaluate its effectiveness,a 3D model experiment was conducted in a wave basin.During the experiment,a model resembling the islands and reefs terrain was created on the basis of the water depth map of a specific region in the East China Sea.The transmission coefficients and motion responses of the three-cylinder floating breakwater system were then measured.This was done both in the middle of and behind the islands and reefs terrain.According to the experimental results,the three-cylinder floating breakwater system performs better in terms of hydrodynamics when it is placed behind the terrain of islands and reefs than in the middle of the same terrain.展开更多
The responses of ecosystem nitrogen (N) and phosphorus (P) to drought are an important component of globalchange studies. However, previous studies were more often based on site-specific experiments, introducing a sig...The responses of ecosystem nitrogen (N) and phosphorus (P) to drought are an important component of globalchange studies. However, previous studies were more often based on site-specific experiments, introducing a significantuncertainty to synthesis and site comparisons. We investigated the responses of vegetation and soil nutrientsto drought using a network experiment of temperate grasslands in Northern China. Drought treatment (66%reduction in growing season precipitation) was imposed by erecting rainout shelters, respectively, at the driest,intermediate, and wettest sites. We found that vegetation nutrient concentrations increased but soil nutrient concentrationsdecreased along the aridity gradient. Differential responses were observed under experimentaldrought among the three grassland sites. Specifically, the experimental drought did not change vegetation andsoil nutrient status at the driest site, while strongly reduced vegetation but increased soil nutrient concentrationsat the site with intermediate precipitation. On the contrary, experimental drought increased vegetation N concentrationsbut did not change vegetation P and soil nutrient concentrations at the wettest site. In general, the differentialeffects of drought on ecosystem nutrients were observed between manipulative and observationalexperiments as well as between sites. Our research findings suggest that conducting large-scale, consistent, andcontrolled network experiments is essential to accurately evaluate the effects of global climate change on terrestrialecosystem bio-geochemistry.展开更多
We report on the theoretical and experimental investigations of the transition of a typical quantum system with mixed regular-integrable classical dynamics to one with violated time-reversal(T)invariance.The measureme...We report on the theoretical and experimental investigations of the transition of a typical quantum system with mixed regular-integrable classical dynamics to one with violated time-reversal(T)invariance.The measurements are performed with a flat superconducting microwave resonator with circular shape in which chaoticity is induced by using either long antennas or inserting two circular disks into the cavity,and by magnetizing a ferrite disk placed at its center,which leads to violation of T invariance.We propose an extension of the Rosenzweig-Porter(RP)model,which interpolates between mixed regular-chaotic instead of integrable dynamics and fully chaotic dynamics with violated T-invariance,and derive a Wigner-surmise like analytical expression for the corresponding nearest-neighbor spacing distribution.We propose a procedure involving this result and those for the RP model to determine the size of T-invariance violation and chaoticity and validate it employing the experimental eigenfrequency spectra.展开更多
This study aims to elucidate the dynamic evolution mechanism of the fracturing fracture system during the exploration and development of complex oil and gas reservoirs.By integrating methods of rock mechanical testing...This study aims to elucidate the dynamic evolution mechanism of the fracturing fracture system during the exploration and development of complex oil and gas reservoirs.By integrating methods of rock mechanical testing,logging calculation,and seismic inversion technology,we obtained the current insitu stress characteristics of a single well and rock mechanical parameters.Simultaneously,significant controlling factors of rock mechanical properties were analyzed.Subsequently,by coupling hydraulic fracturing physical experiments with finite element numerical simulation,three different fracturing models were configured:single-cluster,double-cluster,and triple-cluster perforations.Combined with acoustic emission technology,the fracture initiation mode and evolution characteristics during the loading process were determined.The results indicate the following findings:(1)The extension direction and length of the fracture are significantly controlled by the direction of the maximum horizontal principal stress.(2)Areas with poor cementation and compactness exhibit complex fracture morphology,prone to generating network fractures.(3)The interlayer development of fracturing fractures is controlled by the strata occurrence.(4)Increasing the displacement of fracturing fluid enlarges the fracturing fracture length and height.This research provides theoretical support and effective guidance for hydraulic fracturing design in tight oil and gas reservoirs.展开更多
Although many studies based on naturally deformed samples have been carried out to investigate the pore-crack characteristics of shales,studies based on high temperature(T)and high pressure(P)deformation experiments,w...Although many studies based on naturally deformed samples have been carried out to investigate the pore-crack characteristics of shales,studies based on high temperature(T)and high pressure(P)deformation experiments,which can exclude sample heterogeneity factors,simulate deep T-P conditions,and generate a continuous deformation sequence,are still rare.In this study,shales with different deformation levels are generated by triaxial compression experiments,and methods including scanning electron microscopy,mercury injection,and gas sorption are utilized to characterize their influence factors and pore-crack characteristics.Results indicate that T is the primary factor influencing shale deformation when P is low,while P is dominant under high P conditions.At T<90℃ and P<60 MPa,shales undergo brittle deformation and their macropores decrease due to the compaction of primary pores,while mesopores increase because of the interconnection of micropores.At 90℃<T<200℃ and 60 MPa<P<110 MPa,shales experience brittle-ductile transitional deformation,and their macro-and micropores increase because of the extension of open cracks and the plastic deformation of clay flakes respectively,while mesopores decrease dramatically.At T>200℃ and P>110 MPa,shales are subjected to ductile deformation,and their micro-and mesopores drop significantly due to the intense compaction in the matrix while macropores continuously increase with crack expansion.The permeability of shale increases with the degree of deformation and ductile material contents are predicted to be a key factor determining whether open microcracks can be preserved after ductile deformation.To account for these experimental results,an ideal model of micro pore-crack system evolution in deformed shales is further proposed,which can provide guidance for the exploration of shale gas resources in the deep or structurally complex zones.展开更多
Both straw incorporation and irrigation practices affect biological nitrogen(N)fixation(BNF),but it is still unclear how straw incorporation impacts BNF under continuous(CFI)or intermittent(IFI)flooding irrigation in ...Both straw incorporation and irrigation practices affect biological nitrogen(N)fixation(BNF),but it is still unclear how straw incorporation impacts BNF under continuous(CFI)or intermittent(IFI)flooding irrigation in a rice cropping system.A15N2-labeling chamber system was placed in a rice field to evaluate BNF with straw incorporation under CFI or IFI for 90 d.The nif H(gene encoding the nitrogenase reductase subunit)DNA and c DNA in soil were amplified using real-time quantitative polymerase chain reaction,and high-throughput sequencing was applied to the nif H gene.The total fixed N in the straw incorporation treatment was 14.3 kg ha^(-1)under CFI,being 116%higher than that under IFI(6.62 kg ha^(-1)).Straw incorporation and CFI showed significant interactive effects on the total fixed N and abundances of nif H DNA and c DNA.The increase in BNF was mainly due to the increase in the abundances of heterotrophic diazotrophs such as Desulfovibrio,Azonexus,and Azotobacter.These results indicated that straw incorporation stimulated BNF under CFI relative to IFI,which might ultimately lead to a rapid enhancement of soil fertility.展开更多
BACKGROUND Anastomotic leaks remain one of the most dreaded complications in gastrointestinal surgery causing significant morbidity,that negatively affect the patients’quality of life.Experimental studies play an imp...BACKGROUND Anastomotic leaks remain one of the most dreaded complications in gastrointestinal surgery causing significant morbidity,that negatively affect the patients’quality of life.Experimental studies play an important role in understanding the pathophysiological background of anastomotic healing and there are still many fields that require further investigation.Knowledge drawn from these studies can lead to interventions or techniques that can reduce the risk of anastomotic leak in patients with high-risk features.Despite the advances in experimental protocols and techniques,designing a high-quality study is still challenging for the investigators as there is a plethora of different models used.AIM To review current state of the art for experimental protocols in high-risk anastomosis in rats.METHODS This systematic review was performed according to The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines.To identify eligible studies,a comprehensive literature search was performed in the electronic databases PubMed(MEDLINE)and Scopus,covering the period from conception until 18 October 2023.RESULTS From our search strategy 102 studies were included and were categorized based on the mechanism used to create a high-risk anastomosis.Methods of assessing anastomotic healing were extracted and were individually appraised.CONCLUSION Anastomotic healing studies have evolved over the last decades,but the findings are yet to be translated into human studies.There is a need for high-quality,well-designed studies that will help to the better understanding of the pathophysiology of anastomotic healing and the effects of various interventions.展开更多
基金supported by Specialized Research Fund for the Doctoral Program of Higher Education of China (Grant No. 20070006011)
文摘Existing vehicle experiment systems tend to focus on the research of vehicle dynamics by conducting performance tests on every system or some parts of the vehicle so as to improve the entire performance of the vehicle. Virtual technology is widely utilized in various vehicle test-beds. These test-beds are mainly used to simulate the driving training, conduct the research on drivers＇ behaviors, or give virtual demonstrations of the transportation environment. However, the study on the active safety of the running vehicle in the virtual environment is still insufficient. A virtual scene including roads and vehicles is developed by using the software Creator and Vega, and radars and cameras are also simulated in the scene. Based on dSPACE＇s rapid prototyping simulation and its single board DS1103, a simulation model including vehicle control signals is set up in MATLAB/Simulink, the model is then built into C code, and the system defined file（SDF） is downloaded to the DS1103 board through the experiment debug software ControlDesk and is kept running. Programming is made by mixing Visual C＋＋ 6.0, MATLAB API and Vega API. Control signals are read out by invoking library function MLIB/MTRACE of dSPACE. All the input, output, and system state values are acquired by arithmetic and are dynamically associated with the running status of the virtual vehicle. An intelligent vehicle experiment system is thus developed by virtue of program and integration. The system has not only the demonstration function, such as general driving, cruise control, active avoiding collision, but also the function of virtual experiment. Parameters of the system can be set according to needs, and the virtual test results can be analyzed and studied and used for the comparison with the existing models. The system reflects the running of the intelligent vehicle in the virtual traffic environment, at the same time, the system is a new attempt performed on the intelligent vehicle travel research and provides also a new research method for the development of intelligent vehicles.
文摘This paper used the virtual reality modeling language （VRML） to establish the 3D virtual experiment instrument model, and by using the visual programming language VB to design and develop a interactive virtual realization experiment platform, the interface has friendly interface, stable operation, strong practicability like with the Windows style, is a kind of reform for the traditional physics experiment teaching mode. The system has practical use value, also has reference value for the reform and modernization of other experimental courses.
基金supported by Basic and Applied Basic research foundation of Guangdong province(Nos.2021A1515010343 and 2022A1515011582)the Science and Technology Program of Guangdong Province(Nos.2021A0505030026 and 2022A0505050029).
文摘In the scenario of a steam generator tube rupture accident in a lead-cooled fast reactor,secondary circuit subcooled water under high pressure is injected into an ordinary-pressure primary vessel,where a molten lead-based alloy(typically pure lead or lead-bismuth eutectic(LBE))is used as the coolant.To clarify the pressure build-up characteristics under water-jet injection,this study conducted several experiments by injecting pressurized water into a molten LBE pool at Sun Yat-sen University.To obtain a further understanding,several new experimental parameters were adopted,including the melt temperature,water subcooling,injection pressure,injection duration,and nozzle diameter.Through detailed analyses,it was found that the pressure and temperature during the water-melt interaction exhibited a consistent variation trend with our previous water-droplet injection mode LBE experiment.Similarly,the existence of a steam explosion was confirmed,which typically results in a much stronger pressure build-up.For the non-explosion cases,increasing the injection pressure,melt-pool temperature,nozzle diameter,and water subcooling promoted pressure build-up in the melt pool.However,a limited enhancement effect was observed when increasing the injection duration,which may be owing to the continually rising pressure in the interaction vessel or the isolation effect of the generated steam cavity.Regardless of whether a steam explosion occurred,the calculated mechanical and kinetic energy conversion efficiencies of the melt were relatively small(not exceeding 4.1%and 0.7%,respectively).Moreover,the range of the conversion efficiency was similar to that of previous water-droplet experiments,although the upper limit of the jet mode was slightly lower.
基金financially supported by the National Natural Science Foundation of China(No.U20B6003)the China Scholarship Council(No.202306440015)a project of the China Petroleum&Chemical Corporation(No.P22174)。
文摘The hybrid CO_(2) thermal technique has achieved considerable success globally in extracting residual heavy oil from reserves following a long-term steam stimulation process.Using microscopic visualization experiments and molecular dynamics(MD)simulations,this study investigates the microscopic enhanced oil recovery(EOR)mechanisms underlying residual oil removal using hybrid CO_(2) thermal systems.Based on the experimental models for the occurrence of heavy oil,this study evaluates the performance of hybrid CO_(2) thermal systems under various conditions using MD simulations.The results demonstrate that introducing CO_(2) molecules into heavy oil can effectively penetrate and decompose dense aggregates that are originally formed on hydrophobic surfaces.A stable miscible hybrid CO_(2) thermal system,with a high effective distribution ratio of CO_(2),proficiently reduces the interaction energies between heavy oil and rock surfaces,as well as within heavy oil.A visualization analysis of the interactions reveals that strong van der Waals(vdW)attractions occur between CO_(2) and heavy oil molecules,effectively promoting the decomposition and swelling of heavy oil.This unlocks the residual oil on the hydrophobic surfaces.Considering the impacts of temperature and CO_(2) concentration,an optimal gas-to-steam injection ratio(here,the CO_(2):steam ratio)ranging between 1:6 and 1:9 is recommended.This study examines the microscopic mechanisms underlying the hybrid CO_(2) thermal technique at a molecular scale,providing a significant theoretical guide for its expanded application in EOR.
基金supported in part by National Natural Science Foundation of China under Grant 62201087,Grant 62525101,in part by the National Key R&D Program of China under Grant 2023YFB2904803in part by the Guangdong Major Project of Basic and Applied Basic Research under Grant 2023B0303000001+1 种基金in part by the Natural Science Foundation of Beijing-Xiaomi Innovation Joint Foundation under Grant L243002in part by the Beijing University of Posts and Telecommunications-China Mobile Research Institute Joint Institute.
文摘As the commercialization of the fifth gen-eration communication(5G)is sped up,its system testing scheme is vital for the successful deployment of 5G.Especially,5G relies on the scale-increased multiple-input-multiple output(MIMO)technique to improve its capacity and coverage.Thus,testing new functions of the 5G MIMO system accurately and ef-ficiently,including beamforming(beam-tracking with movement)and multiple-user(MU)multiplexing,is a challenging task.This paper tries to construct a lab-oratorial hardware and conduct equipment-controlled field testing.Firstly,the testing scheme is presented,which is composed of the framework,the channel models and the validation methods.Then,the channel model principles are explained in detail due to its di-rect influence on the testing accuracy.Specifically,we utilize the spatial consistency and the multi-link cor-relation properties to emulate the high-speed dynamic time-varying(HDT)and the multiple-cell(MC)-MU-MIMO channels.Finally,the above testing scheme is verified in a Shanghai 5G field experiment with the practical commercial equipment and the channel em-ulator.The results show that the 5G new functions are tested accurately and efficiently by switching the channel emulation configurations.
基金Supported by Major Project of School-level Teaching Reform and Research of Guangxi University of Chinese Medicine(2022A006)。
文摘In comparison with conventional experimental teaching methods,the implementation of the Motic digital microscope mutual system in the experimental teaching of medicinal botany has been demonstrated to be a highly efficacious approach to enhance the teaching level of experimental courses in medicinal botany.The implementation of a digital microscope mutual system in experimental teaching not only enhances students practical skills in laboratory operations but also increases classroom efficiency.Furthermore,it supports personalized development among students while fostering innovative thinking,independent learning capabilities,and analysis and problem-solving skills.Additionally,this approach contributes to the enhancement of students scientific literacy.
基金supported by the National Natural Science Foundation of China(No.82274313)Projects of Shaanxi Administration of Traditional Chinese Medicine(2022-SLRH-YQ-010)Key Laboratory of Traditional Chinese Medicine and Pharmacology.
文摘Background:QiShenYiQi(QSYQ)is commonly accepted to treat ischemic stroke(IS)in clinical settings,yet the underlying mechanism of action of QSYQ is largely unknown.Methods:By combining systems pharmacology with experimental assessment,we examined the key targets,bioactive components,and mechanisms of QSYQ against IS.Results:Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform predicted a total number of 254 targets that were potentially related to QSYQ,whereas 699 targets associated with IS were gathered from Therapeutic Target Database,Comparative Toxicogenomics Database,Gene Cards,Online Mendelian Inheritance in Man,and National Center for Biotechnology Information databases,and 83 of these targets overlap with QSYQ-related targets.Importantly,through the analysis of Gene Ontology functional annotation,Kyoto Encyclopedia of Genes and Genomes pathway enrichment,and protein-protein interaction network,we identified 20 related signaling pathways along with 4 hub genes.Subsequently,our molecular docking results revealed that QSYQ might interact with PTGS2,PTGS1,SCN5A,and HSP90AB1.We observed dose-dependent beneficial effects of QSYQ in significantly improving neurological function and alleviating histopathological damage in middle cerebral artery occlusion model,while decreasing infarct volume.Notablely,QSYQ markedly downregulates tumor necrosis factor-α,interleukin-6,and interleukin-1 beta.Overall,this study demonstrates the synergetic effects of QSYQ on regulating multi-targets in IS through inhibiting inflammatory processes and neuronal apoptosis,these findings may expand the understanding of QSYQ and provide guidance for its clinical application in treating IS.Conclusion:Current study reveals the protective roles of QSYQ against IS through modulating PTGS2/PTGS1/SCN5A/HSP90AB1 and TNF signaling pathways.
基金supported by grants from National High-Level Hospital Clinical Research Funding(2023-GSP-RC-04).
文摘This study aimed to evaluate the feasibility,safety,and efficacy of a noveltranscatheter suture closure system(HaloStitch^(®))for patent foramen ovale(PFO)closure in a swine model.Methods:Thirteen swine underwentexperimental PF0 model creation.All animals received implantationof the transcatheter suture closure system to evaluate procedural success.Comprehensive follow-up over sixmonths included serial ultrasound imaging,histopathological analysis,and gross anatomical exaninationof cardiac specimens.Results:Successful HaloStitch^(®)device implantation was adhieved in 11 of 13 swine.Gross anatomical examination confirrned secure positioning of all sutures in the atrial septum,with noredundancy or thrombus formation.Postoperative ultrasound demonstrated stable suture and staplepositions throughout follow-up,with no evidence of suture breakage,displacement,or thrombus.Stapleswere clearly visualized under ultrasound imaging,Both the atrial septal defect orifice diameter and residualseptal shunt flow velocity decreased significantly during the observation period.Histopathological analysisrevealed partially organized thrombi at the implant head and fibrous connective tissue encapsulation withlocalized inflammatory cell infiltration surrounding the polymer material.Conclsions:The transcathetersuture closure system(HaloStitch^(®))demonstrated feasibility,safety,and biocompatib ility for PFO closure ina swine model,supporting its potential for clinical translation.
基金supported by the National Natural Science Foundation of China(No.U2067205)。
文摘Benchmark experiments are indispensable for the development of neutron nuclear data evaluation libraries.Given the lack of domestic benchmarking of nuclear data in the fission energy region,this study developed a neutron leakage spectrum measurement system using a spherical sample based on the^(252)Cf spontaneous fission source.The EJ309 detector(for highenergy measurements)and CLYC detector(for low-energy measurements)were combined to measure the time-of-flight spectrum using theγtagging method.To assess the performance of the system,the time-of-flight spectrum without a sample was measured first.The experimental spectra were consistent with those simulated using the Monte Carlo method and the standard^(252)Cf spectrum from ISO:8529-1.This demonstrates that the system can effectively measure the neutron events in the 0.15-8.0 MeV range.Then,a spherical polyethylene sample was used as the standard to verify the accuracy of the system for the benchmark experiment.The simulation results were obtained using the Monte Carlo method with evaluated data from the ENDF/B-Ⅷ.0,CENDL-3.2,JEFF-3.3,and JENDL-5 libraries.The measured neutron leakage spectra were compared with the corresponding simulated results for the neutron spectrum shape and calculated C/E values.The results showed that the simulated spectra with different data libraries reproduced the experimental results well in the 0.15-8.0 MeV range.This study confirms that the leakage neutron spectrum measurement system based on the^(252)Cf source can perform benchmarking and provides a foundation for evaluating neutron nuclear data through benchmark experiments.
基金the National Key Research and Development Program of China(2021YFF0900800)the National Natural Science Foundation of China(61972276,62206116,62032016)+2 种基金the New Liberal Arts Reform and Practice Project of National Ministry of Education(2021170002)the Open Research Fund of the State Key Laboratory for Management and Control of Complex Systems(20210101)Tianjin University Talent Innovation Reward Program for Literature and Science Graduate Student(C1-2022-010)。
文摘Powered by advanced information technology,more and more complex systems are exhibiting characteristics of the cyber-physical-social systems(CPSS).In this context,computational experiments method has emerged as a novel approach for the design,analysis,management,control,and integration of CPSS,which can realize the causal analysis of complex systems by means of“algorithmization”of“counterfactuals”.However,because CPSS involve human and social factors(e.g.,autonomy,initiative,and sociality),it is difficult for traditional design of experiment(DOE)methods to achieve the generative explanation of system emergence.To address this challenge,this paper proposes an integrated approach to the design of computational experiments,incorporating three key modules:1)Descriptive module:Determining the influencing factors and response variables of the system by means of the modeling of an artificial society;2)Interpretative module:Selecting factorial experimental design solution to identify the relationship between influencing factors and macro phenomena;3)Predictive module:Building a meta-model that is equivalent to artificial society to explore its operating laws.Finally,a case study of crowd-sourcing platforms is presented to illustrate the application process and effectiveness of the proposed approach,which can reveal the social impact of algorithmic behavior on“rider race”.
基金supported in part by the Nation Natural Science Foundation of China under Grant No.52175099China Postdoctoral Science Foundation under Grant No.2020M671494Jiangsu Planned Projects for Postdoctoral Research Funds under Grant No.2020Z179。
文摘A tracking stability control problem for the vertical electric stabilization system of moving tank based on adaptive robust servo control is addressed.This paper mainly focuses on two types of possibly fast timevarying but bounded uncertainty within the vertical electric stabilization system:model parameter uncertainty and uncertain nonlinearity.First,the vertical electric stabilization system is constructed as an uncertain nonlinear dynamic system that can reflect the practical mechanics transfer process of the system.Second,the dynamical equation in the form of state space is established by designing the angular tracking error.Third,the comprehensive parameter of system uncertainty is designed to estimate the most conservative effects of uncertainty.Finally,an adaptive robust servo control which can effectively handle the combined effects of complex nonlinearity and uncertainty is proposed.The feasibility of the proposed control strategy under the practical physical condition is validated through the tests on the experimental platform.This paper pioneers the introduction of the internal nonlinearity and uncertainty of the vertical electric stabilization system into the settlement of the tracking stability control problem,and validates the advanced servo control strategy through experiment for the first time.
基金National Natural Science Foundation of China Project:Electroacupuncture Prevents Ferroptosis in Ischemic Stroke Through Regulating Ubiquitin Ligase NEDD4-like E3 and Inhibiting Ferritinophagy Pathway(No.82104978)Scientific Research of Shaanxi Provincial Department of Education of China Project:Mechanism of Acupuncture on Microglia Activation in Mice with Cerebral Ischemia-Reperfusion(No.23JK0410)。
文摘OBJECTIVE:To systematically evaluate the role of electroacupuncture in maintaining brain plasticity in ischemic stroke mediated brain damage.METHODS:We searched for all relevant trials published through Oct 7,2022 from seven databases.Methodological quality was assessed using the CAMARADES Risk of Bias Tool.A Meta-analysis of comparative effects was performed using Review Manager v.5.3 software.RESULTS:A total of 101 studies involving 2148 animals were included.For most studies,primary outcomes results of the Meta-analysis indicate that EA significantly improved ischemic stroke rat's postsynaptic density thickness[Standardized Mean Difference(SMD)=1.41,95%confidence interval(CI)(0.59,2.23),P=0.0008],numerical density of synapses[SMD=1.55,95%CI(0.48,2.63),P=0.005]compared with non-EA-treated.Similarly,EA could improve parts of biomarkers of synapses,neurogenesis,angiogenesis and neurotrophin activity than the control group(P<0.05).CONCLUSION:The existing evidence suggests EA regulating ischemic stroke may be through brain plasticity.More rigorous and high quality studies should be conducted in the future.
文摘In this paper,the mission and the thermal environment of the Solar Close Observations and Proximity Experiments(SCOPE)spacecraft are analyzed,and an advanced thermal management system(ATMS)is designed for it.The relationship and functions of the integrated database,the intelligent thermal control system and the efficient liquid cooling system in the ATMS are elaborated upon.For the complex thermal field regulation system and extreme space thermal environment,a modular simulation and thermal field planning method are proposed,and the feasibility of the planning algorithm is verified by numerical simulation.A solar array liquid cooling system is developed,and the system simulation results indicate that the temperatures of the solar arrays meet the requirements as the spacecraft flies by perihelion and aphelion.The advanced thermal management study supports the development of the SCOPE program and provides a reference for the thermal management in other deep-space exploration programs.
基金financially supported by the China National Funds for Distinguished Young Scientists(Grant No.52025112).
文摘With the acceleration of marine construction in China,the exploitation and utilization of resources from islands and reefs are necessary.To prevent and dissipate waves in the process of resource exploitation and utilization,a more effective method is to install floating breakwaters near the terrain of islands and reefs.The terrain around islands and reefs is complex,and waves undergo a series of changes due to the impact of the complex terrain in transmission.It is important to find a suitable location for floating breakwater systems on islands and reefs and investigate how the terrain affects the system’s hydrodynamic performance.This paper introduces a three-cylinder floating breakwater design.The breakwater system consists of 8 units connected by elastic structures and secured by a slack mooring system.To evaluate its effectiveness,a 3D model experiment was conducted in a wave basin.During the experiment,a model resembling the islands and reefs terrain was created on the basis of the water depth map of a specific region in the East China Sea.The transmission coefficients and motion responses of the three-cylinder floating breakwater system were then measured.This was done both in the middle of and behind the islands and reefs terrain.According to the experimental results,the three-cylinder floating breakwater system performs better in terms of hydrodynamics when it is placed behind the terrain of islands and reefs than in the middle of the same terrain.
基金the National Key Research and Development Program of China(2019YFE0117000)the National Natural Science Foundation of China(32171549 and 31971465)and the Youth Innovation Promotion Association CAS(2020199).
文摘The responses of ecosystem nitrogen (N) and phosphorus (P) to drought are an important component of globalchange studies. However, previous studies were more often based on site-specific experiments, introducing a significantuncertainty to synthesis and site comparisons. We investigated the responses of vegetation and soil nutrientsto drought using a network experiment of temperate grasslands in Northern China. Drought treatment (66%reduction in growing season precipitation) was imposed by erecting rainout shelters, respectively, at the driest,intermediate, and wettest sites. We found that vegetation nutrient concentrations increased but soil nutrient concentrationsdecreased along the aridity gradient. Differential responses were observed under experimentaldrought among the three grassland sites. Specifically, the experimental drought did not change vegetation andsoil nutrient status at the driest site, while strongly reduced vegetation but increased soil nutrient concentrationsat the site with intermediate precipitation. On the contrary, experimental drought increased vegetation N concentrationsbut did not change vegetation P and soil nutrient concentrations at the wettest site. In general, the differentialeffects of drought on ecosystem nutrients were observed between manipulative and observationalexperiments as well as between sites. Our research findings suggest that conducting large-scale, consistent, andcontrolled network experiments is essential to accurately evaluate the effects of global climate change on terrestrialecosystem bio-geochemistry.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11775100,12247101,and 11961131009)the financial support from the China Scholarship Council(Grant No.CSC202306180087)the financial support from the Institute for Basic Science in Korea(Grant No.IBS-R024-D1)。
文摘We report on the theoretical and experimental investigations of the transition of a typical quantum system with mixed regular-integrable classical dynamics to one with violated time-reversal(T)invariance.The measurements are performed with a flat superconducting microwave resonator with circular shape in which chaoticity is induced by using either long antennas or inserting two circular disks into the cavity,and by magnetizing a ferrite disk placed at its center,which leads to violation of T invariance.We propose an extension of the Rosenzweig-Porter(RP)model,which interpolates between mixed regular-chaotic instead of integrable dynamics and fully chaotic dynamics with violated T-invariance,and derive a Wigner-surmise like analytical expression for the corresponding nearest-neighbor spacing distribution.We propose a procedure involving this result and those for the RP model to determine the size of T-invariance violation and chaoticity and validate it employing the experimental eigenfrequency spectra.
基金supported by the Major Scientific and Technological Projects of CNPC under grant ZD2019-183-006the National Science and Technology Major Project of China(2016ZX05014002-006)the National Natural Science Foundation of China(42072234)。
文摘This study aims to elucidate the dynamic evolution mechanism of the fracturing fracture system during the exploration and development of complex oil and gas reservoirs.By integrating methods of rock mechanical testing,logging calculation,and seismic inversion technology,we obtained the current insitu stress characteristics of a single well and rock mechanical parameters.Simultaneously,significant controlling factors of rock mechanical properties were analyzed.Subsequently,by coupling hydraulic fracturing physical experiments with finite element numerical simulation,three different fracturing models were configured:single-cluster,double-cluster,and triple-cluster perforations.Combined with acoustic emission technology,the fracture initiation mode and evolution characteristics during the loading process were determined.The results indicate the following findings:(1)The extension direction and length of the fracture are significantly controlled by the direction of the maximum horizontal principal stress.(2)Areas with poor cementation and compactness exhibit complex fracture morphology,prone to generating network fractures.(3)The interlayer development of fracturing fractures is controlled by the strata occurrence.(4)Increasing the displacement of fracturing fluid enlarges the fracturing fracture length and height.This research provides theoretical support and effective guidance for hydraulic fracturing design in tight oil and gas reservoirs.
基金supported by the National Natural Science Foundation of China(Grant Nos.42372153,41530315)the National Key Research and Development Program of China(Grant No.2023YFF0804300)+1 种基金the National Science and Technology Major Project of China(Grant Nos.2016ZX05066,2017ZX05064)the“Climate Change:Carbon Budget and Related Issues”Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDA05030100)。
文摘Although many studies based on naturally deformed samples have been carried out to investigate the pore-crack characteristics of shales,studies based on high temperature(T)and high pressure(P)deformation experiments,which can exclude sample heterogeneity factors,simulate deep T-P conditions,and generate a continuous deformation sequence,are still rare.In this study,shales with different deformation levels are generated by triaxial compression experiments,and methods including scanning electron microscopy,mercury injection,and gas sorption are utilized to characterize their influence factors and pore-crack characteristics.Results indicate that T is the primary factor influencing shale deformation when P is low,while P is dominant under high P conditions.At T<90℃ and P<60 MPa,shales undergo brittle deformation and their macropores decrease due to the compaction of primary pores,while mesopores increase because of the interconnection of micropores.At 90℃<T<200℃ and 60 MPa<P<110 MPa,shales experience brittle-ductile transitional deformation,and their macro-and micropores increase because of the extension of open cracks and the plastic deformation of clay flakes respectively,while mesopores decrease dramatically.At T>200℃ and P>110 MPa,shales are subjected to ductile deformation,and their micro-and mesopores drop significantly due to the intense compaction in the matrix while macropores continuously increase with crack expansion.The permeability of shale increases with the degree of deformation and ductile material contents are predicted to be a key factor determining whether open microcracks can be preserved after ductile deformation.To account for these experimental results,an ideal model of micro pore-crack system evolution in deformed shales is further proposed,which can provide guidance for the exploration of shale gas resources in the deep or structurally complex zones.
基金supported by the National Natural Science Foundation of China(Nos.42177333 and 31870500)the National Special Program for Key Basic Research of the Ministry of Science and Technology of China(No.2015FY110700)the Jiangsu Agriculture Science and Technology Innovation Fund,China(No.JASTIFCX(20)2003)。
文摘Both straw incorporation and irrigation practices affect biological nitrogen(N)fixation(BNF),but it is still unclear how straw incorporation impacts BNF under continuous(CFI)or intermittent(IFI)flooding irrigation in a rice cropping system.A15N2-labeling chamber system was placed in a rice field to evaluate BNF with straw incorporation under CFI or IFI for 90 d.The nif H(gene encoding the nitrogenase reductase subunit)DNA and c DNA in soil were amplified using real-time quantitative polymerase chain reaction,and high-throughput sequencing was applied to the nif H gene.The total fixed N in the straw incorporation treatment was 14.3 kg ha^(-1)under CFI,being 116%higher than that under IFI(6.62 kg ha^(-1)).Straw incorporation and CFI showed significant interactive effects on the total fixed N and abundances of nif H DNA and c DNA.The increase in BNF was mainly due to the increase in the abundances of heterotrophic diazotrophs such as Desulfovibrio,Azonexus,and Azotobacter.These results indicated that straw incorporation stimulated BNF under CFI relative to IFI,which might ultimately lead to a rapid enhancement of soil fertility.
文摘BACKGROUND Anastomotic leaks remain one of the most dreaded complications in gastrointestinal surgery causing significant morbidity,that negatively affect the patients’quality of life.Experimental studies play an important role in understanding the pathophysiological background of anastomotic healing and there are still many fields that require further investigation.Knowledge drawn from these studies can lead to interventions or techniques that can reduce the risk of anastomotic leak in patients with high-risk features.Despite the advances in experimental protocols and techniques,designing a high-quality study is still challenging for the investigators as there is a plethora of different models used.AIM To review current state of the art for experimental protocols in high-risk anastomosis in rats.METHODS This systematic review was performed according to The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines.To identify eligible studies,a comprehensive literature search was performed in the electronic databases PubMed(MEDLINE)and Scopus,covering the period from conception until 18 October 2023.RESULTS From our search strategy 102 studies were included and were categorized based on the mechanism used to create a high-risk anastomosis.Methods of assessing anastomotic healing were extracted and were individually appraised.CONCLUSION Anastomotic healing studies have evolved over the last decades,but the findings are yet to be translated into human studies.There is a need for high-quality,well-designed studies that will help to the better understanding of the pathophysiology of anastomotic healing and the effects of various interventions.
