Heuristic Expanding Disconnected Graph:A Rapid Path Planning Method for Mobile Robots

Existing mobile robots mostly use graph search algorithms for path planning,which suffer from relatively low planning efficiency owing to high redundancy and large computational complexity.Due to the limitations of the neighborhood search strategy,the robots could hardly obtain the most optimal global path.A global path planning algorithm,denoted as EDG*,is proposed by expanding nodes using a well-designed expanding disconnected graph operator(EDG)in this paper.Firstly,all obstacles are marked and their corners are located through the map pre-processing.Then,the EDG operator is designed to find points in non-obstruction areas to complete the rapid expansion of disconnected nodes.Finally,the EDG*heuristic iterative algorithm is proposed.It selects the candidate node through a specific valuation function and realizes the node expansion while avoiding collision with a minimum offset.Path planning experiments were conducted in a typical indoor environment and on the public dataset CSM.The result shows that the proposed EDG*reduced the planning time by more than 90%and total length of paths reduced by more than 4.6%.Compared to A*,Dijkstra and JPS,EDG*does not show an exponential explosion effect in map size.The EDG*showed better performance in terms of path smoothness,and collision avoidance.This shows that the EDG*algorithm proposed in this paper can improve the efficiency of path planning and enhance path quality.

Fundamentals and applications of photonic waveguides with bound states in the continuum

Photonic waveguides are the most fundamental element for photonic integrated circuits(PICs).Waveguide properties,such as propagation loss,modal areas,nonlinear coefficients,etc.,directly determine the functionalities and performance of PICs.Recently,the emerging waveguides with bound states in the continuum(BICs)have opened new opportunities for PICs because of their special properties in resonance and radiation.Here,we review the recent progress of PICs composed of waveguides with BICs.First,fundamentals including background physics and design rules of a BIC-based waveguide will be introduced.Next,two types of BIC-based waveguide structures,including shallowly etched dielectric and hybrid waveguides,will be presented.Lastly,the challenges and opportunities of PICs with BICs will be discussed.

华南杂交稻主要不育系品质性状特点及基因分析

将广东、广西选育推广的三系不育系分成3种类型:早期高产类型、中期优质类型和后期优质高产类型。早期高产类型不育系包括博A、Y华农A、天丰A和五丰A等;中期优质类型不育系包括粤丰A、野香A、泰丰A和广8A等;后期优质高产类型不育系包括贵A、香禾A、耕香A等。归纳分析3种类型不育系的品质性状,并对各不育系的品质基因进行检测,以期提高这些不育系的育种应用。结果表明,高产不育系的直链淀粉含量在22.4%~26.9%之间,多数不育系籽粒长宽比≤3.0,透明度≥2级,多携带不利品质的基因ALK、Chalk5、Wx-a、GS3等。优质不育系的直链淀粉含量在12.0%~18.0%之间,长宽比绝大多数在3.6~4.3之间,胶稠度≥62 mm,透明度≤2级,具有优质品质基因Wx-b、fgr、GW5、GL7、GW8等。优质高产不育系的直链淀粉含量在13.0%~16.0%之间,长宽比在3.3~3.6之间,胶稠度≥60 mm,垩白度在0~1.5%间,具有优质基因Wx-b和GW5,且产量较高。

感温型高产两系杂交稻隆两优305的选育及制种技术

隆两优305是广东省农业科学院水稻研究所、湖南亚华种业科学研究院、安徽隆平高科(新桥)种业有限公司共同选育的感温型两系杂交稻新组合,该组合具有产量高、丰产性好、抗稻瘟病、耐逆性较好等特点。2021年通过广东省农作物品种审定委员会审定,适宜广东省粤北以外稻作区早、晚造种植。介绍了隆两优305的选育过程、特征特性、高产栽培及制种技术等。

Overexpression and characterization of a thermostable β-agarase producing neoagarotetraose from a marine isolate Microbulbifer sp.AG1

An agarase gene containing 1 302 bp was cloned from Microbulbifer sp. AG1. It encoded a mature protein of 413 amino acids plus a 20-residue signal peptide. The recombinant enzyme without the signal peptide was expressed and purified from Escherichia coli BL21(DE3). When agarose was used as a substrate, the optimal temperature and pH for the enzyme were 60℃ and 7.5, respectively. The recombinant agarase showed excellent thermostability with 67% and 19% of residual activities after incubation at 50℃ and 60℃ for 1 h, respectively.Except SDS, the recombinant agarase had a relatively good resistance against the detected inhibitors, detergents and urea denaturant. Thin layer chromatography analysis and enzyme assay using p-nitrophenyl-α/β-Dgalactopyranoside revealed that the recombinant agarase was a β-agarase that degraded agarose into neoagarotetraose as the main end product. The enzymatic hydrolysis products with different degree of polymerization exhibited the antioxidant activities.

早熟籼型杂交水稻五优3号及栽培制种技术

五优3号是广东省农业科学院水稻研究所和安康市农业科学研究院合作利用不育系五丰A与恢复系广恢3号配组育成的早熟籼型优质杂交水稻新组合,具有综合农艺性状优良、丰产稳产、矮秆抗倒等特性。2020年10月通过陕西省农作物品种审定委员会审定,适宜在陕南海拔60m以下稻区作直播稻品种种植。

Timing analysis of the black hole candidate EXO 1846–031 with Insight-HXMT monitoring

We present the observational results from a detailed timing analysis of the black hole candidate EXO 1846-031 during its outburst in 2019 with the observations of Insight-HXMT,NICER and MAXI.This outburst can be classified roughly into four different states.Type-C quasi-periodic oscillations(QPOs)observed by NICER(about 0.1-6 Hz)and Insight-HXMT(about 0.7-8 Hz)are also reported in this work.Meanwhile,we study various physical quantities related to QPO frequency.The QPO rms-frequency relationship in the energy band 1-10 keV indicates that there is a turning pointing in frequency around2 Hz,which is similar to that of GRS 1915+105.A possible hypothesis for the relationship above may be related to the inclination of the source,which may require a high inclination to explain it.The relationships between QPO frequency and QPO rms,hardness,total fractional rms and count rate have also been found in other transient sources,which can indicate that the origin of type-C QPOs is non-thermal.

水稻粒型调控基因功能研究进展

水稻是世界上的重要谷类粮食作物之一,其产量和品质一直都是育种学家关注的重点,关系到全球粮食安全和人类健康。水稻粒型主要包括粒长、粒宽、粒厚等,是受多基因控制的重要数量性状,不仅直接影响水稻产量,还与水稻品质密切相关。深入了解水稻粒型的形成与调控机理将有助于进一步提升水稻单株产量、改善稻米品质。分子生物学的发展和基因组学的研究为探究水稻内部调控机制带来了新的变革。大量水稻粒型的数量性状遗传位点(Quantitative trait locus,QTL)成功被鉴定与解析,并验证了与之有关的基因功能。目前,已有几条调控粒型的通路得到鉴定,如泛素-蛋白酶体降解途径、G蛋白信号途径、丝裂原活化蛋白激酶途径、转录因子调控途径、植物激素途径以及表观遗传途径等。然而,粒型调控网络极其复杂,多数基因上下游的调控组件作用机制尚不清楚,甚至影响粒型的各条通路间均存在一定的交叉互作。本文综述了影响水稻粒型的不同信号通路相关基因研究进展及关键粒型基因间的互作关系,总结了近年来粒型基因在育种上的应用情况,并提出结合多组学解析水稻粒型的调控机理研究,以期更好地服务于分子设计育种,为开发新的高产优质稻育种提供支撑。

水稻溶血磷脂酸酰基转移酶基因(LPAT)家族生物信息学分析及在籽粒油脂合成中的作用

【目的】挖掘水稻溶血磷脂酸酰基转移酶(Lysophosphatidic acid acyltransferase,LPAT)基因家族成员信息,分析其生物信息学特征及在水稻籽粒油脂合成中的作用。【方法】通过生物信息学分析,对OsLPAT基因家族进行基因结构、系统进化树、组织表达谱以及激素和逆境表达谱等分析。利用比较代谢组和转录组学的方法,分析OsLPAT家族各成员在水稻籽粒油脂合成中的作用。【结果】水稻基因组中LPAT家族包含5个成员,分别命名为OsLPAT1~OsLPAT5。除OsLPAT1外,其他成员均含有4~6个外显子,且各成员均包含Acyltransferase C-terminus(PF01553)结构域;进化分析显示,LPAT基因在单子叶植物中较为保守;OsLPAT2的表达受多种逆境条件及激素诱导,OsLPAT3和OsLPAT5的表达受到脱落酸(Abscisic acid,ABA)的强烈诱导,而OsLPAT4则特异性地受到渗透胁迫的诱导;比较代谢组和转录组学分析显示,OsLPAT家族各成员分别在籽粒发育的不同阶段发挥功能,从而促进油脂(Triacylglycerol,TAG)合成。【结论】水稻基因组中存在5个LPAT基因,其表达受到不同激素的诱导,可能在水稻激素响应过程中发挥作用。该家族成员参与了不同发育阶段籽粒中的油脂前体磷脂酸(Phosphatidic acid,PA)的合成,从而正调控籽粒中的油脂合成。

Glass Recognition and Map Optimization Method for Mobile Robot Based on Boundary Guidance

Current research on autonomous mobile robots focuses primarily on perceptual accuracy and autonomous performance.In commercial and domestic constructions,concrete,wood,and glass are typically used.Laser and visual mapping or planning algorithms are highly accurate in mapping wood panels and concrete walls.However,indoor and outdoor glass curtain walls may fail to perceive these transparent materials.In this study,a novel indoor glass recognition and map optimization method based on boundary guidance is proposed.First,the status of glass recognition techniques is analyzed comprehensively.Next,a glass image segmentation network based on boundary data guidance and the optimization of a planning map based on depth repair are proposed.Finally,map optimization and path-planning tests are conducted and compared using different algorithms.The results confirm the favorable adaptability of the proposed method to indoor transparent plates and glass curtain walls.Using the proposed method,the recognition accuracy of a public test set increases to 94.1%.After adding the planning map,incorrect coverage redundancies for two test scenes reduce by 59.84%and 55.7%.Herein,a glass recognition and map optimization method is proposed that offers sufficient capacity in perceiving indoor glass materials and recognizing indoor no-entry regions.

Förster resonance energy transfer reveals phillygenin and swertiamarin concurrently target AKT on different binding domains to increase the anti-inflammatory effect

The clinical benefit of combination therapy is significant,but it is not easy to define the mechanism of complexity and diversity.Previous studies illustrate that phillygenin(Phi)binds in the allosteric inhibit pocket of protein kinase B(AKT),and swertiamarin(Swe)acts on the pleckstrin homology(PH)domain of AKT.However,the combined synergistic effect of relieving the inflammatory response has yet to be elucidated.Based on high sensitivity,specificity and fast-responsibility fluorescent sensors,the Förster resonance energy transfer(FRET)technique offers a route to provide clear insights into physiological and pathological processes.In the study,molecular docking,the fluorescent probes of Phi and Swe for FRET were designed and synthesized.FRET analysis shown that Swe and Phi concurrently acted on the PH domain and allosterically inhibited pocket of AKT,respectively.The combination of Swe and Phi significantly increased the heat stability of AKT and decreased protease-induced degeneration.In lipopolysaccharides(LPS)-induced mice and cells,the combination arrested AKT activation,nuclear factor kappa-B(NF-κB)phosphorylation,and the expression of tumor necrosis factor-α(TNF-α),interleukin(IL)-6 and IL-8.In conclusion,FRET revealed Phi and Swe concurrently targeted AKT on different domains and the combination of Phi and Swe enhanced the anti-inflammatory effect.

Acoustic Purcell effect induced by quasibound state in the continuum

We study theoretically and experimentally the acoustic Purcell effect induced by quasi-bound states in the continuum(quasiBICs).A theoretical framework describing the acoustic Purcell effect of a resonant system is developed based on the system’s radiative and dissipative factors,which reveals the critical emission condition for achieving optimum Purcell factors.We show that the quasiBICs contribute to highly confined acoustic field and bring about greatly enhanced acoustic emission,leading to strong Purcell effect.Our concept is demonstrated via two coupled resonators supporting a Friedrich-Wintgen quasiBIC,and the theoretical results are validated by the experiments observing emission enhancement of the sound source by nearly two orders of magnitude.Our work bridges the gap between the acoustic Purcell effect and acoustic BICs essential for enhanced wave-matter interaction and acoustic emission,which may contribute to the research of high-intensity sound sources,high-quality-factor acoustic devices and nonlinear acoustics.

The mechanisms of enhanced thickness-dependent DC breakdown strength of EP/MWCNTs nanocomposites

Owing to advanced power electronic and electrical applications developing towards miniaturisation and integration,the thickness-dependent DC breakdown mechanism of epoxy/multiwall-carbon-nanotube nanocomposites is under investigation.The results indicate that the breakdown strength of nanocomposites containing 0.05 wt%multiwall-carbon-nanotubes rises by~18%,and the breakdown strength falls exponentially with increasing thickness.To clarify the microscopic mechanism,a simulation model of DC breakdown,including carriers transport and segmental dynamics,is developed,and the accordant simulation results with experimental results indicate that the thickness-dependent DC breakdown of epoxy/multiwall-carbon-nanotube nanocomposites is determined both by segment chain dynamics and charge transport.According to the breakdown model analysis,the effects of multiwall-carbon-nanotube on enhanced breakdown strength are caused by the increased amount of deep traps in the interfacial region,while the influence of thickness is attributed to the enlarged segment chain displacement and electric field distortion as the voltage raising time increases.

丽江野鼠鼠疫自然疫源地10年扩散趋势研究

目的通过更大范围内的自然疫源地调查,研究丽江野鼠鼠疫自然疫源地分布范围的变化扩散趋势,探讨其规律,为鼠疫防治工作提供科学依据。方法采用鼠疫间接血凝试验(IHA)检测鼠疫指示动物和鼠类血清中鼠疫F1抗体。结果通过近10年三轮更大范围内的系统性调查提示:自然疫源地的自然环境复杂,分布范围逐渐演变,由小而大,扩散速度较快,扩散趋势呈现一定的规律性,即由最初发现证实的面积大约210km^2,3个乡镇9个行政村35个自然村,逐步以黄山镇南溪村委会鹿子村为中心向周边扩散,2013年增加约250km^2,达到450km^2,阳性点覆盖面积增加了119.0%。2015年进一步扩散增加约180km^2,达到630km^2,阳性点覆盖面积再新增40.0%,累计调查明确的疫源地分布于玉龙、古城两县(区)的8个乡镇、14个行政村、65个村民小组。扩散方向以向东向北扩散为主,向北扩散趋势更为明显,致使疫源地中心点向东北方向偏移,即中心点不再是黄山镇南溪村委会的鹿子村,而是北移至太安乡吉子村委会汝南化,并有进一步扩散的趋势。尽管疫源地累计发现了7次鼠间鼠疫流行并成功处置,但历次疫源地调查中,区域危险人群、鼠血清、搜索的自毙动物、小型兽类等调查采集的标本均未检测到阳性信息。结论指示动物血清学证实,疫源地范围已经明显向北向东移,以向东北方向扩散为主。扩散趋势明显,扩散速度较快,疫情扩散的风险进一步增高。

PKP结合明胶海绵辅助利多卡因治疗胸腰椎骨折的疗效分析

目的探讨PKP手术中应用明胶海绵辅助利多卡因治疗胸腰椎骨折的临床疗效。方法将40例骨质疏松性胸腰椎压缩骨折患者随机分为两组,观察组采用PKP术中明胶海绵辅助利多卡因治疗,对照组采用传统局部麻醉下行PKP手术治疗,比较两组不同时间点的VAS疼痛评分、Cobb角及椎体高度。结果观察组术中的VAS评分显著高于对照组,差异有统计学意义(P<0.05),术后两组之间的VAS评分差异无统计学意义(P>0.05)。两组患者各时间点的椎体高度和Cobb角差异无统计学意义(P>0.05)。结论与传统PKP手术相比,PKP术中结合明胶海绵辅助利多卡因治疗胸腰椎骨折,可有效减轻术中疼痛,且对术后椎体高度、后凸畸形的矫正效果无不良影响。

桥接组合式内固定系统治疗Edinburgh ⅡB型锁骨骨折的疗效

目的探讨桥接组合式内固定系统治疗Edinburgh ⅡB型锁骨骨折的疗效。方法将40例Edinburgh ⅡB型锁骨骨折患者按照治疗方法不同分为观察组(20例,采用桥接组合式内固定系统)和对照组(20例,采用锁定钢板内固定系统)。比较两组治疗效果及术后并发症。结果两组患者均获得随访,时间6~12个月。术中出血量、骨折愈合时间观察组均少于对照组(P<0.01),手术时间对照组少于观察组(P<0.01)。术后12周根据Neer肩关节评分系统评价优良率:观察组为17/20,对照组为15/20,观察组优良率高于对照组,但差异无统计学意义(P>0.05)。术后并发症:两组术后均未发生切口感染,观察组1例出现内置物松动,对照组2例出现钢板断裂,差异无统计学意义(P>0.05)。结论桥接组合式内固定系统治疗Edinburgh ⅡB型锁骨骨折同锁定钢板一样能达到预期效果,但内固定断裂的发生率较锁定钢板低,肩关节功能恢复快。

卷积神经网络在心电逆问题中的应用

基于横跨膜电位分布的心电逆问题研究,即从身体表面电位无创重建心脏跨膜电位,可视为一种多输入多输出的回归问题(亦即多个体表电位分布输入重构多个心脏跨膜电位分布输出),而基于数据驱动的机器学习模型是解决回归问题的一种有效手段。通过使用深度卷动神经网络(CNN)构建深度学习模型,使用Caffe框架训练神经网络;此外,基于真实的心脏模型,使用ECGSim软件仿真了肯特束综合症心室激活情况的数据,用于训练和测试回归模型。实验结果表明,与极限学习机(ELM)和核化的极限学习机相比,CNN方法在心脏跨膜电位重构方面有更高的精度和泛化性能。

优质高产丝苗型不育系广8A的选育与应用

广8A是以含广东野生稻亲缘的优质早籼稻增城丝苗-8选为母本,与保持系1325B杂交制保后再与325A测交并回交转育而成的野败型优质高产丝苗型籼稻不育系。该不育系由广东省农业科学院水稻研究所选育而成,具备稻米品质优、配合力强、抗病性好、综合农艺性状优良的特点。自2010年通过广东省技术鉴定以来,以其为亲本配组并通过国家、省级审定或授权的水稻新品种已达44个,审定区域包括广东、广西、福建、云南、湖南、湖北和四川等省(区),这些品种均表现出优质、高产稳产、适应性强的特点,充分体现了广8A作为水稻“广东芯”的作用,并作为试验材料广泛应用于栽培、生理等基础理论研究。其中,以广8A配组选育的广8优165、广8优金占、广8优2168组合,在省级区试中均呈现丰、抗、优高度协调性,并连续4年被遴选为广东省农业主导品种,从2017年至今,在广东累计推广面积达到26万hm2以上,在华南地区和长江中下游地区具有极其重要的生产价值。

Isolation and initial characterization of GW5, a major QTL associated with rice grain width and weight

Grain weight is a major determinant of crop grain yield and is controlled by naturally occurring quantitative trait loci （QTLs）. We earlier identified a major QTL that controls rice grain width and weight, GW5, which was mapped to a recombination hotspot on rice chromosome 5. To gain a better understanding of how GW5 controls rice grain width, we conducted fine mapping of this locus and uncovered a 1 212-bp deletion associated with the increased grain width in the rice cultivar Asominori, in comparison with the slender grain rice IR24. In addition, genotyping analyses of 46 rice cultivars revealed that this deletion is highly correlated with the grain-width phenotype, suggesting that the GW5 deletion might have been selected during rice domestication. GW5 encodes a novel nuclear protein of 144 amino acids that is localized to the nucleus. Furthermore, we show that GW5 physically interacts with polyubiquitin in a yeast two-hybrid assay. Together, our results suggest that GW5 represents a major QTL underlying rice width and weight, and that it likely acts in the ubiquitin-proteasome pathway to regulate cell division during seed development. This study provides novel insights into the molecular mechanisms controlling rice grain development and suggests that GW5 could serve as a potential tool for high-yield breeding of crops.

细胞因子信号转导抑制分子1在胃癌中的表达及意义

目的分析细胞因子信号转导抑制分子1(SOCS1)在胃癌组织中的表达及其与患者临床病理参数间的关系,探讨其在胃癌患者预后中的意义。方法收集67例无术前放射治疗和化学治疗史的胃癌患者的胃癌及癌旁组织标本,建立组织芯片,通过免疫组织化学染色SP法检测组织中SOCS1蛋白的表达情况。采用χ2检验分析SOCS1蛋白表达与患者临床病理参数的关系,采用Kaplan-Meier生存曲线和log-rank检验分析SOCS1蛋白表达与患者生存的关系,采用Cox比例风险回归模型分析SOCS1蛋白表达与预后的关系。结果 SOCS1蛋白阳性表达率在胃癌组织中为80.6%(54/67),在癌旁组织中为61.2%(41/67),两组间差异有统计学意义(P<0.05)。SOCS1蛋白表达阳性患者的淋巴结转移率高于阴性表达患者[74.1%(40/54)vs 38.5(5/13),P<0.05]。Kaplan-Meier生存分析结果显示,SOCS1蛋白阳性表达患者的总生存率低于阴性表达患者(P<0.05)。Cox比例风险回归模型分析结果显示,SOCS1蛋白表达和肿瘤TNM分期是胃癌患者的独立预后因素。结论 SOCS1蛋白在胃癌中高表达,检测其表达情况有助于临床判断胃癌患者淋巴结转移及预测预后。