融合前车轨迹预测的改进人工势场轨迹规划研究

人工势场算法在移动场景中的避撞路径规划很少考虑其与前车未来轨迹的时序耦合影响,基本将每个规划周期内的前车视为静态,通过不同规划周期滚动更新的方式进行准动态路径规划,导致规划路径不够合理、一致性差。本文针对性提出通过时序耦合关联,将前车预测轨迹融入智能汽车路径规划过程。首先构建了改进人工势场算法的引力场及斥力场模型,提出在每个规划周期内,将前车位置在斥力场中根据其预测值进行动态更新;而后提出了基于驾驶意图聚类识别及离散优化结合的前车轨迹长时间预测算法,以及基于运动学模型聚类识别与无迹卡尔曼滤波算法结合的前车轨迹短时间预测算法,再经S函数进行加权融合完成前车轨迹的最终预测。高速驶出及邻车切入等场景下的仿真分析表明,相比于传统的人工势场算法,所提出的改进人工势场动态轨迹规划算法能获得更加合理和一致性更优的规划结果。

原位还原制备磺酸型水性聚氨酯/纳米银复合材料及其表征

使用水溶性聚酯多元醇(BY3301)和磺酸盐扩链剂氨基磺酸钠(A95)与四甲基苯二甲基二异氰酸酯(TMXDI)合成了磺酸型水性聚氨酯(SWPU)。在SWPU中原位还原纳米银(AgNPs)制备了磺酸型水性聚氨酯/纳米银(SWPU/AgNPs)复合乳液。涂膜之后测试了复合材料的力学性能、热性能和粘接性能的变化。同时使用动态光散射(DLS)和透射电镜(TEM)测试了乳液的粒径分布以及AgNPs的尺寸。结果表明,原位还原引入的AgNPs可以提高复合材料的力学性能和热性能,对于SWPU的粘接性能影响不大。SWPU在复合材料中还起到了稳定剂的作用,有效避免了AgNPs的团聚。TEM的研究显示复合材料中的AgNPs的形状为球形,粒径范围在5~40 nm。

Drivers’ EEG Responses to Different Distraction Tasks

Driver distraction has been deemed a major cause of traffic accidents.However,drivers’brain response activities to different distraction types have not been well investigated.The purpose of this study is to investigate the response of electroencephalography(EEG)activities to different distraction tasks.In the conducted simulation tests,three secondary tasks(i.e.,a clock task,a 2-back task,and a navigation task)are designed to induce different types of driver distractions.Twenty-four participants are recruited for the designed tests,and differences in drivers’brain response activities concerning distraction types are investigated.The results show that the differences in comprehensive distraction are more significant than that in single cognitive distraction.Friedman test and post hoc two-tailed Nemenyi test are conducted to further identify the differences in band activities among brain regions.The results show that the theta energy in the frontal lobe is significantly higher than that in other brain regions in distracted driving,whereas the alpha energy in the temporal lobe significantly decreases compared to other brain regions.These results provide theoretical references for the development of distraction detection systems based on EEG signals.

DZNep inhibits the proliferation of colon cancer HCT116 cells by inducing senescence and apoptosis

EZH2 is over-expressed in human colon cancer and is closely associated with tumor proliferation,metastasis and poor prognosis.Targeting and inhibiting EZH2 may be an effective therapeutic strategy for colon cancer.3-Deazaneplanocin A(DZNep),as an EZH2 inhibitor,can suppress cancer cell growth.However,the anti-cancer role of DZNep in colon cancer cells has been rarely studied.In this study,we demonstrate that DZNep can inhibit the growth and survival of colon cancer HCT116 cells by inducing cellular senescence and apoptosis.The study provides a novel view of anti-cancer mechanisms of DZNep in human colon cancer cells.

Gut Microbiome Alterations in COVID-19

Since the outset of the coronavirus disease 2019(COVID-19)pandemic,the gut microbiome in COVID-19 has garnered substantial interest,given its significant roles in human health and pathophysiology.Accumulating evidence is unveiling that the gut microbiome is broadly altered in COVID-19,including the bacterial microbiome,mycobiome,and virome.Overall,the gut microbial ecological network is significantly weakened and becomes sparse in patients with COVID-19,together with a decrease in gut microbiome diversity.Beyond the existence of severe acute respiratory syndrome coronavirus type 2(SARS-CoV-2),the gut microbiome of patients with COVID-19 is also characterized by enrichment of opportunistic bacteria,fungi,and eukaryotic viruses,which are also associated with disease severity and presentation.Meanwhile,a multitude of symbiotic bacteria and bacteriophages are decreased in abundance in patients with COVID-19.Such gut microbiome features persist in a significant subset of patients with COVID-19 even after disease resolution,coinciding with‘long COVID’(also known as postacute sequelae of COVID-19).The broadly-altered gut microbiome is largely a consequence of SARS-CoV-2 infection and its downstream detrimental effects on the systemic host immunity and the gut milieu.The impaired host immunity and distorted gut microbial ecology,particularly loss of low-abundance beneficial bacteria and blooms of opportunistic fungi including Candida,may hinder the reassembly of the gut microbiome post COVID-19.Future investigation is necessary to fully understand the role of the gut microbiome in host immunity against SARS-CoV-2 infection,as well as the long-term effect of COVID-19 on the gut microbiome in relation to the host health after the pandemic.

Experimental investigation on the deformation characteristics of locking-steel-pipe(LSP)pile retaining structure during excavation in sand

Locking-steel-pipe(LSP)piles connect with adjacent joints to form a pile row enclosure structure.Due to the advantages of quick construction,efficiency in installation,and recycle utilization,the connected LSP piles are frequently used as retaining structure in deep excavation.However,systematic studies of the deformation mechanism of the LSP pile retaining structure are rarely reported,and it still lack of experimental evidence to optimize the design.In this study,a braced supported excavation experimental model test in sand was designed and conducted to investigate the deformation characteristics of LSP pile retaining structure.Three dimensional(3D)printing technique was creatively applied to manufacture LSP model piles.The experimental results show that,a“S”shaped distribution of bending moments is observed along pile shaft when excavation is executed;the deflection of pile shaft develops deep-seated movements toward the excavation side as excavation went deeper,resulting in a“bowl”ground settlement.With the deflection of LSP piles,a rotating trend was occurred between pairs of locking joint,and the severe open deformation of locking joint arose on excavation side.There was a gradual reduction in earth pressure behind the LSP pile retaining wall with excavation depth.The earth pressure between two struts level had no obvious changing,owing to the supported effect of inner struts.

Neoadjuvant therapy followed by local excision and two-stage total mesorectal excision:a new strategy for sphincter preservation in locally advanced ultra-low rectal cancer

Background:With the increased usage of neoadjuvant chemoradiotherapy,improved surgical technique and stapling devices,sphincter-preserving resection has become more frequent for patients with rectal cancer.However,as for locally advanced ultra-low rectal cancer,sphincter-preservation is still facing an enormous challenge.Objective:To introduce an NLT strategy of sphincter-preservation-neoadjuvant therapy(NT)followed by local excision(LE)and two-stage total mesorectal excision(TME)-into the treatment of locally advanced ultra-low rectal cancer(lesions with anal sphincter invasion).Methods:From October 2010 to October 2011,nine patients with locally advanced rectal cancer located less than 3 cm from the anal verge were treated by the NLT strategy.All patients had shown good clinical response to NT.The LE procedure was carried transanally 6-8 weeks after completion of the NT.TME was performed to dissect mesorectal lymph nodes 4-6 weeks after LE.Results:Of the nine patients,the lesion was assessed as T2 in two,T3 in five,and T4 in two before NT,and lymph node metastasis was detected in five patients.The median distance from the tumor to the anal verge was 2.5 cm(range:1-3 cm).The median follow-up was 27 months(range:24-34 months).No distant metastasis was detected.Only one patient(11.1%)developed local recurrence at 12 months post-operatively and then underwent abdomino-perineal resection.The remaining eight patients had preserved long-term continence and the median Wexner score at two years post-operation was 4(range:2-6).Conclusion:The new NLT strategy can achieve sphincter-preservation in some patients with ultra-low rectal cancer,with favorable oncological outcome and preservation of normal anal sphincter function.

术前低蛋白血症会增加克罗恩病一期肠吻合术后腹腔内感染性并发症的发生风险

目的:本研究旨在探讨术前低蛋白血症对克罗恩病(CD)患者一期肠吻合术后发生腹腔内感染性并发症(IASCs)的影响。方法:2007-2015年期间所有行肠切除一期肠吻合手术的CD患者纳入研究。采用单因素和多因素分析评估术前低蛋白血症(白蛋白<30 g/L)与术后IASCs发生风险的关系。结果:共计124例患者纳入研究,其中117例(94.4%)可以获得术前白蛋白水平的数据。13例(11.7%)患者术前合并低蛋白血症。相较之下,术前低蛋白血症患者CD诊断至手术的间期更长(P=0.012),术前服用5氨基水杨酸的比例更高(P=0.013),术中发现小肠梗阻的比例更高(P=0.015)。共有24例(19.4%)患者术后出现IASCs。单因素分析显示,术前低蛋白血症患者术后IASCs风险更高(P=0.012)。多因素分析证实,术前低蛋白血症是术后IASCs的独立危险因素(OR=4.67,95%CI:1.28–17.04,P=0.02)。将术前白蛋白水平作为一个连续型变量进行多因素分析,亦可得到相同的结果(P=0.019)。结论:对于行肠切除一期肠吻合的CD患者,术前低蛋白血症提示术后IASCs发生风险增高。改善术前营养状态或可降低术后IASCs的发生风险。

ARTICLE OPEN Mutant KRAS triggers functional reprogramming of tumor-associated macrophages in colorectal cancer

Oncogenic KRAS has been previously identified to act in a cell-intrinsic manner to modulate multiple biological functions of colorectal cancer(CRC).Here,we demonstrate a cell-extrinsic role of KRAS,where KRAS engages with the tumor microenvironment by functional reprogramming of tumor-associated macrophages(TAMs).In human CRC specimens,mutant KRAS positively correlates with the presence of TAMs.Mutationally activated KRAS in tumor cells reprograms macrophages to a TAM-like phenotype via a combination effect of tumor-derived CSF2 and lactate.In turn,KRAS-reprogrammed macrophages were shown to not only promote tumor progression but also induce the resistance of tumor cells to cetuximab therapy.Mechanistically,KRAS drives the production of CSF2 and lactate in tumor cells by stabilizing hypoxia-inducible factor-la(HIF-1a),a transcription factor that controls the expression of CSF2 and glycolytic genes.Mutant KRAS increased the production of reactive oxygen species,an inhibitor of prolyl hydroxylase activity which decreases HIF-1a hydroxylation,leading to enhanced HIF-1a stabilization.This cell-extrinsic mechanism awards KRAS a critical role in engineering a permissive microenvironment to promote tumor malignancy,and may present new insights on potential therapeutic defense strategies against mutant KRAS tumors.

Incidence and risk factors for incisional surgical site infection in patients with Crohn’s disease undergoing bowel resection

Background:Patients with Crohn’s disease(CD)are often reported to be at a high risk for incisional surgical site infection(SSI).The aim of this study was to identify the risk factors associated with post-operative incisional SSI in CD patients after bowel resection.Method:CD patients undergoing bowel resection between 2007 and 2015 were enrolled.Demographic and clinical features related to post-operative incisional SSI were analysed using both univariate and multivariate logistical analyses.Results:Of all eligible patients(n=159),123(77.4%)were male,with a mean age at surgery of 33.4611.8 years.A total of 35(22.0%)CD patients developed post-operative incisional SSI.Post-operative incisional SSI was more likely to happen in patients who had penetrating type of disease(P=0.018),underwent bowel resection for the indication of chronic fistula(P=0.005)and had an intra-operative finding of fistula(P=0.001).A greater proportion of patients with post-operative incisional SSI were found to have anemia(P=0.019)but elevated levels of white blood cells(P=0.027),neutrophils(P=0.006)as well as an elevated percentage of neutrophils(P=0.005).Multivariate logistic regression analysis showed that anemia(odds ratio[OR]:3.31,95%confidence interval[CI]:1.05-10.46,P=0.041),an elevated percentage of neutrophils(OR:2.85,95%CI:1.23-6.59,P=0.014)and an intra-operative finding of fistula(OR:3.76,95%CI:1.53-9.21,P=0.004)were significantly associated with the risk for post-operative incisional SSI.Conclusions:Anemia,elevated percentage of neutrophils and intra-operative finding of fistula are predictors for the development of post-operative incisional SSI in CD patients undergoing bowel resection.Favorable pre-operative nutrition status and low inflammatory status may lessen the incidence of post-operative incisional SSI.

Research on the improvement of the LaneGCN trajectory prediction algorithm

The LaneGCN proposed by Uber has achieved good performance in trajectory prediction, but it has shortcomings in capturing longrange information, expressing road information and modelling the strong and weak relationships of interaction between actors. Inthis paper, the LaneGCN is improved from three parts. Firstly, multi-scale long short-term memory is introduced to encode multiscaletrajectory information. Secondly, relative distance information is added to enhance the spatial expressive capacity of themodelin the process of road information encoding. Finally, we build a weighted interaction model based on Graph Attention Networksin the process of road information encoding. In order to verify the performance of the improved model, ablation and comparisonexperiments are designed in this paper. The results showed that all the evaluation metrics are lower than the LaneGCN and theoverall performance of the model is improved.

Spatio-temporal heuristic method:a trajectory planning for automatic parking considering obstacle behavior

Purpose–The purpose of this paper is to develop a real-time trajectory planner with optimal maneuver for autonomous vehicles to deal with dynamic obstacles during parallel parking.Design/methodology/approach–To deal with dynamic obstacles for autonomous vehicles during parking,a long-and short-term mixed trajectory planning algorithm is proposed in this paper.In long term,considering obstacle behavior,A-star algorithm was improved by RS curve and potential function via spatio-temporal map to obtain a safe and efficient initial trajectory.In short term,this paper proposes a nonlinear model predictive control trajectory optimizer to smooth and adjust the trajectory online based on the vehicle kinematic model.Moreover,the proposed method is simulated and verified in four common dynamic parking scenarios by ACADO Toolkit and QPOASE solver.Findings–Compared with the spline optimization method,the results show that the proposed method can generate efficient obstacle avoidance strategies,safe parking trajectories and control parameters such as the front wheel angle and velocity in high-efficient central processing units.Originality/value–It is aimed at improving the robustness of automatic parking system and providing a reference for decision-making in a dynamic environment.