Simulation Training for Laparoscopic Surgery Can Improve Minimally Invasive Surgical Techniques for Interns and Probationers

Objective: The clinical clerkship and practice stage plays a pivotal role in the transition of medical students from theoretical knowledge to practical application, bridging the gap between classroom learning and real-life clinical experience. In order to improve the teaching quality of interns and probationers, we try to let them practice the skills of laparoscopic surgery in the early stage, and summed up a set of evaluation methods that can be widely used in medical education. Methods: From September 2019 to December 2019, a total of 54 interns and 72 trainees were selected as research objects. They were assigned to training sessions and their proficiency was assessed before and after the training. The change in proficiency is compared to determine whether the training course is valuable. Results: Before the operation training, the interns scores were BP 17.3 3.1, CC 17.9 3.4, KT 16.4 3.4, LS 16.7 3.3. The results of probationers were BP 16.9 2.7, CC 16.8 2.8, KT 15.2 1.6, and LS 14.8 2.2. After completing the operations training, the results of interns were BP 21.1 1.9, CC 20.6 2.7, KT 19.6 3.0, and LS 20.9 1.4. The probationers scores were BP 19.3 3.2, CC 19.6 3.5, KT 19.6 2.6, and LS 20.0 2.4. After the operation training, the performance of the intern group was better than that before the training (P < 0.05). The same is true of the probationer group. The time-consuming intern examinations were BP 147.9 38.5 s, CC 123.2 28.7 s, KT 82.6 24.1 s and LS 162.5 31.1 s. The examination time of probationers were BP 179.9 46.4 s, CC 132.1 24.3 s, KT 109.3 27.5 s and LS 210.0 58.8 s. Conclusion: Simulation training for laparoscopic surgery can improve minimally invasive surgical techniques for interns and probationers.

On simulation of precise orbit determination of HY-2 with centimeter precision based on satellite-borne GPS technique

The HY-2 satellite carrying a satellite-borne GPS receiver is the first Chinese radar altimeter satellite, whose radial orbit determination precision must reach the centimeter level. Now HY-2 is in the test phase so that the observations are not openly released. In order to study the precise orbit determination precision and procedure for HY-2 based on the satellite- borne GPS technique, the satellite-borne GPS data are simulated in this paper. The HY-2 satellite-borne GPS antenna can receive at least seven GPS satellites each epoch, which can validate the GPS receiver and antenna design. What＇s more, the precise orbit determination processing flow is given and precise orbit determination experiments are conducted using the HY-2-borne GPS data with both the reduced-dynamic method and the kinematic geometry method. With the 1 and 3 mm phase data random errors, the radial orbit determination precision can achieve the centimeter level using these two methods and the kinematic orbit accuracy is slightly lower than that of the reduced-dynamic orbit. The earth gravity field model is an important factor which seriously affects the precise orbit determination of altimeter satellites. The reduced-dynamic orbit determination experiments are made with different earth gravity field models, such as EIGEN2, EGM96, TEG4, and GEMT3. Using a large number of high precision satellite-bome GPS data, the HY-2 precise orbit determination can reach the centimeter level with commonly used earth gravity field models up to above 50 degrees and orders.

Application of the Computer Simulation Technique to Developing EFI Engine

The application of computer simulation technique to electronic controlled fuel injection(EFI) engine was studied to increase the development speed and improve the overall performance of the engine and car. On the basis of an EFI system developed by ourselves, the simulation model of the initial control data and engine operation points during a driving cycle and the car performance pridiction model were established. This method was applied to a mini car. The experiment showed that the simulated control data has good accuracy; and the engine test points and car performances obtained by simulation are useful for the matching of EFI system with gasoline engine and the development speed is increased.

Masquelet technique using an allogeneic cortical bone graft for a large bone defect:A case report

BACKGROUND The induced-membrane technique was initially described by Masquelet as an effective treatment for large bone defects,especially those caused by infection.Here,we report a case of chronic osteomyelitis of the radius associated with a 9 cm bone defect,which was filled with a large allogeneic cortical bone graft from a bone bank.Complete bony union was achieved after 14 months of follow-up.Previous studies have used autogenous bone as the primary bone source for the Masquelet technique;in our case,the exclusive use of allografts is as successful as the use of autologous bone grafts.With the advent of bone banks,it is possible to obtain an unlimited amount of allograft,and the Masquelet technique may be further improved based on this new way of bone grafting.CASE SUMMARY In this study,we reported a case of repair of a long bone defect in a 40-year-old male patient,which was characterized by the utilization of allograft cortical bone combined with the Masquelet technique for the treatment of the patient's long bone defect in the forearm.The patient's results of functional recovery of the forearm were surprising,which further deepens the scope of application of Masquelet technique and helps to strengthen the efficacy of Masquelet technique in the treatment of long bones indeed.CONCLUSION Allograft cortical bone combined with the Masquelet technique provides a new method of treatment to large bone defect.

An Enhanced Lung Cancer Detection Approach Using Dual-Model Deep Learning Technique

Lung cancer continues to be a leading cause of cancer-related deaths worldwide,emphasizing the critical need for improved diagnostic techniques.Early detection of lung tumors significantly increases the chances of successful treatment and survival.However,current diagnostic methods often fail to detect tumors at an early stage or to accurately pinpoint their location within the lung tissue.Single-model deep learning technologies for lung cancer detection,while beneficial,cannot capture the full range of features present in medical imaging data,leading to incomplete or inaccurate detection.Furthermore,it may not be robust enough to handle the wide variability in medical images due to different imaging conditions,patient anatomy,and tumor characteristics.To overcome these disadvantages,dual-model or multi-model approaches can be employed.This research focuses on enhancing the detection of lung cancer by utilizing a combination of two learning models:a Convolutional Neural Network(CNN)for categorization and the You Only Look Once(YOLOv8)architecture for real-time identification and pinpointing of tumors.CNNs automatically learn to extract hierarchical features from raw image data,capturing patterns such as edges,textures,and complex structures that are crucial for identifying lung cancer.YOLOv8 incorporates multiscale feature extraction,enabling the detection of tumors of varying sizes and scales within a single image.This is particularly beneficial for identifying small or irregularly shaped tumors that may be challenging to detect.Furthermore,through the utilization of cutting-edge data augmentation methods,such as Deep Convolutional Generative Adversarial Networks(DCGAN),the suggested approach can handle the issue of limited data and boost the models’ability to learn from diverse and comprehensive datasets.The combined method not only improved accuracy and localization but also ensured efficient real-time processing,which is crucial for practical clinical applications.The CNN achieved an accuracy of 97.67%in classifying lung tissues into healthy and cancerous categories.The YOLOv8 model achieved an Intersection over Union(IoU)score of 0.85 for tumor localization,reflecting high precision in detecting and marking tumor boundaries within the images.Finally,the incorporation of synthetic images generated by DCGAN led to a 10%improvement in both the CNN classification accuracy and YOLOv8 detection performance.

基于Plant Simulation仿真技术的装配生产线优化研究

【目的】优化装备生产线,缩短产品交付周期。【方法】基于Plant Simulation仿真技术,对装配生产线进行建模、编程、仿真、分析和优化,有效计算产品产量和成本,识别并优化装配生产线的瓶颈工位。【结果】优化后的三维产线仿真模型产量增幅接近10%,生产效率明显提升。【结论】通过将智能制造技能竞赛和科研教学活动相结合,能够凝练总结竞赛内容,促使教师紧盯前沿知识,创新改革教学内容,实现以赛促教、以赛促学、以赛促改、以赛促建的多重目标。

Analysis of Micromechanical Properties at the Interface of Pre-wet SBS Modified Asphalt Mixture Based on Molecular Simulation Technology

The pre-wetting of aggregate surface is a means to improve the interface performance of SBS modified asphalt and aggregate.The effect of pre-wetting technology on the interaction between SBS modified asphalt and aggregate was analyzed by molecular dynamics simulation.The diffusion coefficient and concentration distribution of SBS modified asphalt on aggregate surface are included.The simulation results show that the diffusion coefficient of the aggregate surface of SBS modified asphalt is increased by 47.6%and 70.5%respectively after 110#asphalt and 130#asphalt are pre-wetted.The concentration distribution of SBS modified asphalt on the aggregate surface after pre-wetting is more uniform.According to the results of interface energy calculation,the interface energy of SBS modified bitumen and aggregate can be increased by about 5%after pre-wetting.According to the results of molecular dynamics simulation,the pre-wetting technology can effectively improve the interface workability of SBS modified bitumen and aggregate,so as to improve the interface performance.

Molecular simulation study of the microstructures and properties of pyridinium ionic liquid[HPy][BF_(4)]mixed with acetonitrile

The microstructures and thermodynamic properties of mixed systems comprising pyridinium ionic liquid[HPy][BF_(4)]and acetonitrile at different mole fractions were studied using molecular dynamics simulation in this work.The following properties were determined:density,self-diffusion coefficient,excess molar volume,and radial distribution function.The results show that with an increase in the mole fraction of[HPy][BF_(4)],the self-diffusion coefficient decreases.Additionally,the excess molar volume initially decreases,reaches a minimum,and then increases.The rules of radial distribution functions(RDFs)of characteristic atoms are different.With increasing the mole fraction of[HPy][BF_(4)],the first peak of the RDFs of HA1-F decreases,while that of CT6-CT6 rises at first and then decreases.This indicates that the solvent molecules affect the polar and non-polar regions of[HPy][BF_(4)]differently.

Advancements and challenges in neuroimaging for the diagnosis of intracranial aneurysms:Addressing false positive diagnoses and emerging techniques

Despite advancements in neuroimaging,false positive diagnoses of intracranial aneurysms remain a significant concern.This article examines the causes,prevalence,and implications of such false-positive diagnoses.We discuss how conditions like arterial occlusion with vascular stump formation and infundibular widening can mimic aneurysms,particularly in the anterior circulation.The article compares various imaging modalities,including computer tomography angiogram,magnetic resonance imaging/angiography,and digital subtraction angiogram,highlighting their strengths and limitations.We emphasize the im-portance of accurate differentiation to avoid unnecessary surgical interventions.The potential of emerging technologies,such as high-resolution vessel wall ima-ging and deep neural networks for automated detection,is explored as promising avenues for improving diagnostic accuracy.This manuscript underscores the need for continued research and clinical vigilance in the diagnosis of intracranial aneurysms.

Hysteresis-Loop Criticality in Disordered Ferromagnets–A Comprehensive Review of Computational Techniques

Disordered ferromagnets with a domain structure that exhibit a hysteresis loop when driven by the external magnetic field are essential materials for modern technological applications.Therefore,the understanding and potential for controlling the hysteresis phenomenon in thesematerials,especially concerning the disorder-induced critical behavior on the hysteresis loop,have attracted significant experimental,theoretical,and numerical research efforts.We review the challenges of the numerical modeling of physical phenomena behind the hysteresis loop critical behavior in disordered ferromagnetic systems related to the non-equilibriumstochastic dynamics of domain walls driven by external fields.Specifically,using the extended Random Field Ising Model,we present different simulation approaches and advanced numerical techniques that adequately describe the hysteresis loop shapes and the collective nature of the magnetization fluctuations associated with the criticality of the hysteresis loop for different sample shapes and varied parameters of disorder and rate of change of the external field,as well as the influence of thermal fluctuations and demagnetizing fields.The studied examples demonstrate how these numerical approaches reveal newphysical insights,providing quantitativemeasures of pertinent variables extracted from the systems’simulated or experimentally measured Barkhausen noise signals.The described computational techniques using inherent scale-invariance can be applied to the analysis of various complex systems,both quantum and classical,exhibiting non-equilibrium dynamical critical point or self-organized criticality.

An Algorithm for Cloud-based Web Service Combination Optimization Through Plant Growth Simulation

In order to improve the efficiency of cloud-based web services,an improved plant growth simulation algorithm scheduling model.This model first used mathematical methods to describe the relationships between cloud-based web services and the constraints of system resources.Then,a light-induced plant growth simulation algorithm was established.The performance of the algorithm was compared through several plant types,and the best plant model was selected as the setting for the system.Experimental results show that when the number of test cloud-based web services reaches 2048,the model being 2.14 times faster than PSO,2.8 times faster than the ant colony algorithm,2.9 times faster than the bee colony algorithm,and a remarkable 8.38 times faster than the genetic algorithm.

SolarDesign:An online photovoltaic device simulation and design platform

Solar Design(https://solardesign.cn/)is an online photovoltaic device simulation and design platform that provides engineering modeling analysis for crystalline silicon solar cells,as well as emerging high-efficiency solar cells such as organic,perovskite,and tandem cells.The platform offers user-updatable libraries of basic photovoltaic materials and devices,device-level multi-physics simulations involving optical–electrical–thermal interactions,and circuit-level compact model simulations based on detailed balance theory.Employing internationally advanced numerical methods,the platform accurately,rapidly,and efficiently solves optical absorption,electrical transport,and compact circuit models.It achieves multi-level photovoltaic simulation technology from“materials to devices to circuits”with fully independent intellectual property rights.Compared to commercial softwares,the platform achieves high accuracy and improves speed by more than an order of magnitude.Additionally,it can simulate unique electrical transport processes in emerging solar cells,such as quantum tunneling,exciton dissociation,and ion migration.

Femtosecond laser small incision lenticule extraction on binocularity for myopia with glasses-free 3D technique

AIM:To evaluate the effect of femtosecond laser small incision lenticule extraction(SMILE)on the binocular visual function in myopic patients with glasses-free threedimensional(3D)technique.METHODS:Totally 50 myopic patients(39 females and 11 males)with SMILE were enrolled in this prospective study.The glasses-free 3D technique was used to evaluate the binocular visual function in these subjects including static stereopsis,dynamic stereopsis,foveal suppression,and binocular balance point of signal to noise ratio(s/n ratio).All subjects received measurements in 1d before operation,and 1d,1wk,and 1mo postoperatively.RESULTS:Both static and dynamic stereopsis showed no significant difference after SMILE.The foveal suppression improved significantly 1wk and 1mo after SMILE(P=0.005 and P=0.007 respectively).The binocular balance point of signal to noise ratio showed a significant improvement 1d,1wk and 1mo after SMILE for both eyes(P<0.001 for each eye respectively).CONCLUSION:Glasses-free 3D technique can be used to evaluate the effect of SMILE on the binocular visual function in myopic patients perceptively,and SMILE can improve both foveal suppression and binocular imbalance in these patients.

Numerical Simulation of Flow and Temperature Distribution in a Bottom-Blown Copper Bath

Smelting with oxygen bottom blowing is one of the main methods used in the frame of copper pyrometallurgy.With this approach,feed materials and oxygen-enriched air are introduced in reversed order to enhance multiphaseflow within the furnace.Understanding the flow structure and temperature distribution in this setup is crucial foroptimizing production.In this study,gas-liquid interactions,and temperature profiles under varying air-injectionconditions are examined by means of numerical simulation for a 3.2 m×20 m furnace.The results indicate that thehigh-velocity regions are essentially distributed near the lance within the reaction region and the flue gas outlet,while low-velocity regions are located close to the furnace walls on both side of the reaction region.Dead regionsappear in the sedimentation region,with gas velocities surpassing those of the molten phase.As the injection rateincreases from 0.50 to 0.80 Nm3/s,the stabilization time of the average liquid surface velocity decreases from 2.6 sto 1.9 s,exhibiting a similar trend to the gas holdup.During stabilization,the average liquid surface velocity risesfrom 0.505 to 0.702 m/s.The average turbulent kinetic energy(TKE)of the fluid in the molten bath increases from0.095 to 0.162 m^(2)/s^(2).The proportion of the area distribution with TKE greater than 0.10 m^(2)/s^(2) and the gas holdupat steady state both rise with an increase in the injection quantity.The maximum splashing height of the melt growsfrom approximately 0.756 to 1.154 m,with the affected area expanding from 14.239 to 20.498 m^(2).Under differentworking conditions with varying injection quantities,the average temperature changes in melt zone and flue gaszone of the furnace are small.The temperature in the melt and in the flue-gas zone spans the interval 1200℃–1257℃,and 1073℃–1121℃,respectively.The temperature distribution of the melt and flue gas reveals a patterncharacterized by elevated temperatures in the reaction zone,gradually transitioning to lower temperatures in thesedimentation region.

Numerical Simulation of Blood Flow Dynamics in a Stenosed Artery Enhanced by Copper and Alumina Nanoparticles

Nanotechnology holds immense importance in the biomedical field due to its ability to revolutionize healthcare on a molecular scale.Motivated by the imperative of enhancing patient outcomes,a comprehensive numerical simulation study on the dynamics of blood flow in a stenosed artery,focusing on the effects of copper and alumina nanoparticles,is conducted.The study employs a 2-dimensional Newtonian blood flow model infused with copper and alumina nanoparticles,considering the influence of a magnetic field,thermal radiation,and various flow parameters.The governing differential equations are first non-dimensionalized to facilitate analysis and subsequently solved using the 4th order collocation method,bvp4c module in MATLAB.This approach obtains velocity and temperature profiles,revealing the impact of relevant parameters crucial in the biomedical field.The findings of this study underscore the significance of understanding blood flow dynamics in stenosed arteries and the potential benefits of utilizing copper and alumina nanoparticles in treatment strategies.The incorporation of nanoparticles introduces novel avenues for enhancing therapeutic interventions,particularly in mitigating the effects of stenosis.The elucidation of velocity and temperature profiles provides valuable insights into the behavior of blood flow under different conditions,thereby informing the development of targeted biomedical applications.The arterial curvature flow parameter influences temperature profiles,with increased parameters promoting more efficient heat dissipation.The elevated values of Prandtl number and thermal radiation parameter showcase the diminished temperature profiles,indicating stronger dominance of momentum diffusion over thermal diffusion and radiative heat transfer mechanism.Sensitivity analysis of the pertinent physical parameters reveals that the Prandtl number has the most significant impact on blood flow dynamics.A statistical analysis of the present results and existing literature has also been included in the study.Overall,this research contributes to advancing our understanding of vascular health and lays the groundwork for innovative approaches in stenosis treatment and related biomedical fields.

Plastic deformation mechanism of γ-phase U–Mo alloy studied by molecular dynamics simulations

Uranium–molybdenum(U–Mo) alloys are critical for nuclear power generation and propulsion because of their superior thermal conductivity, irradiation stability, and anti-swelling properties. This study explores the plastic deformation mechanisms of γ-phase U–Mo alloys using molecular dynamics(MD) simulations. In the slip model, the generalized stacking fault energy(GSFE) and the modified Peierls–Nabarro(P–N) model are used to determine the competitive relationships among different slip systems. In the twinning model, the generalized plane fault energy(GPFE) is assessed to evaluate the competition between slip and twinning. The findings reveal that among the three slip systems, the {110}<111>slip system is preferentially activated, while in the {112}<111> system, twinning is favored over slip, as confirmed by MD tensile simulations conducted in various directions. Additionally, the impact of Mo content on deformation behavior is emphasized. Insights are provided for optimizing process conditions to avoid γ → α′′ transitions, thereby maintaining a higher proportion of γ-phase U–Mo alloys for practical applications.

Numerical simulation of protection range in exploiting the upper protective layer with a bow pseudo-incline technique

The developing processes of stress and deformation fields of a protected layer after mining an upper-protective layer with a bow pseudo-incline technique were simulated to locate the protection region. The pressure relief of the protected layer was analyzed after mining the upper-protective layer. The pressure relief angle along the strike and incline were located according to the roles of protection of the deformation and stress pressure-relief of the protective layer after mining. This results show that the upper-protective layer with the bow pseudo-incline technique have an upper and downside pressure relief angle of 85 and 68 degrees respectively; the distribution of strike pressure relief angles along the pseudo-incline working face is uneven and their values range from 38.3 to 51 degrees. The pressure relief angle of the inclined middle location was the largest. The distribution of the protection region of the upper-protective layer with the bow pseudo-incline teelmique located by practical tests and numerical simulation is essentially consistent, compared with the results obtained by these methods.

Applications of scale-adaptive simulation technique based on one-equation turbulence model

A modified scale-adaptive simulation （SAS） technique based on the Spalart- Allmaras （SA） model is proposed. To clarify its capability in prediction of the complex turbulent flow, two typical cases are carried out, i.e., the subcritical flow past a circular cylinder and the transonic flow over a hemisphere cylinder. For comparison, the same cases are calculated by the detached-eddy simulation （DES）, the delayed-detached eddy simulation （DDES）, and the XY-SAS approaches. Some typical results including the mean pressure coefficient, velocity, and Reynolds stress profiles are obtained and compared with the experiments. Extensive calculations show that the proposed SAS technique can give better prediction of the massively separated flow and shock/turbulent-boundary-layer interaction than the DES and DDES methods. Furthermore, by the comparison of the XY-SAS model with the present SAS model, some improvements can be obtained.

Three-Dimensional Rigid-Plastic FEM Simulation of Bulk Forming Processes with New Contact and Remeshing Techniques

Some techniques such as die surface description, contact judgement algorithm and remeshing are proposed to improve the robustness of the numerical solution. Based on these techniques, a three-dimensional rigid-plastic FEM code has been developed. Isothermal forging process of a cylindrical housing has been simulated. The simulation results show that the given techniques and the FEM code are reasonable and feasible for three-dimensional bulk forming processes.

Land use/cover change and ecological network in Gansu Province,China during 2000-2020 and their simulations in 2050

Land use/cover change(LUCC)constitutes the spatial and temporal patterns of ecological security,and the construction of ecological networks is an effective way to ensure ecological security.Exploring the spatial and temporal change characteristics of ecological network and analyzing the integrated relationship between LUCC and ecological security are crucial for ensuring regional ecological security.Gansu is one of the provinces with fragile ecological environment in China,and rapid changes in land use patterns in recent decades have threatened ecological security.Therefore,taking Gansu Province as the study area,this study simulated its land use pattern in 2050 using patch-generating land use simulation(PLUS)model based on the LUCC trend from 2000 to 2020 and integrated the LUCC into morphological spatial pattern analysis(MSPA)to identify ecological sources and extract the ecological corridors to construct ecological network using circuit theory.The results revealed that,according to the prediction results in 2050,the areas of cultivated land,forest land,grassland,water body,construction land,and unused land would be 63,447.52,39,510.80,148,115.18,4605.21,8368.89,and 161,752.40 km^(2),respectively.The number of ecological sources in Gansu Province would increase to 80,with a total area of 99,927.18 km^(2).The number of ecological corridors would increase to 191,with an estimated total length of 6120.66 km.Both ecological sources and ecological corridors showed a sparse distribution in the northwest and dense distribution in the southeast of the province at the spatial scale.The number of ecological pinch points would reach 312 and the total area would expect to increase to 842.84 km^(2),with the most pronounced increase in the Longdong region.Compared with 2020,the number and area of ecological barriers in 2050 would decrease significantly by 63 and 370.71 km^(2),respectively.In general,based on the prediction results,the connectivity of ecological network of Gansu Province would increase in 2050.To achieve the predicted ecological network in 2050,emphasis should be placed on the protection of cultivated land and ecological land,the establishment of ecological sources in desert areas,the reinforcement of the protection for existing ecological sources,and the construction of ecological corridors to enhance the stability of ecological network.This study provides valuable theoretical support and references for the future construction of ecological networks and regional land resource management decision-making.