Deep brain implantable microelectrode arrays for detection and functional localization of the subthalamic nucleus in rats with Parkinson’s disease

The subthalamic nucleus(STN)is considered the best target for deep brain stimulation treatments of Parkinson’s disease(PD).It is difficult to localize the STN due to its small size and deep location.Multichannel microelectrode arrays(MEAs)can rapidly and precisely locate the STN,which is important for precise stimulation.In this paper,16-channel MEAs modified with multiwalled carbon nanotube/poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate)(MWCNT/PEDOT:PSS)nanocomposites were designed and fabricated,and the accurate and rapid identification of the STN in PD rats was performed using detection sites distributed at different brain depths.These results showed that nuclei in 6-hydroxydopamine hydrobromide(6-OHDA)-lesioned brains discharged more intensely than those in unlesioned brains.In addition,the MEA simultaneously acquired neural signals from both the STN and the upper or lower boundary nuclei of the STN.Moreover,higher values of spike firing rate,spike amplitude,local field potential(LFP)power,and beta oscillations were detected in the STN of the 6-OHDA-lesioned brain,and may therefore be biomarkers of STN localization.Compared with the STNs of unlesioned brains,the power spectral density of spikes and LFPs synchronously decreased in the delta band and increased in the beta band of 6-OHDA-lesioned brains.This may be a cause of sleep and motor disorders associated with PD.Overall,this work describes a new cellular-level localization and detection method and provides a tool for future studies of deep brain nuclei.

The diverse heterogeneity of molecular alterations in prostate cancer identified through next-generation sequencing

Prostate cancer is a leading cause of global cancer-related death but attempts to improve diagnoses and develop novel therapies have been confounded by significant patient heterogeneity. In recent years, the application of next-generation sequencing to hundreds of prostate tumours has defined novel molecular subtypes and characterized extensive genomic aberration underlying disease initiation and progression. It is now clear that the heterogeneity observed in the clinic is underpinned by a molecular landscape rife with complexity, where genomic rearrangements and rare mutations combine to amplify transcriptomic diversity. This review dissects our current understanding of prostate cancer ＇omics＇, including the sentinel role of copy number variation, the growing spectrum of oncogenic fusion genes, the potential influence of chromothripsis, and breakthroughs in defining mutation-associated subtypes. Increasing evidence suggests that genomic lesions frequently converge on specific cellular functions and signalling pathways, yet recurrent gene aberration appears rare. Therefore, it is critical that we continue to define individual tumour genomes, especially in the context of their expressed transcriptome. Only through improved characterisation of tumour to tumour variability can we advance to an age of precision therapy and personalized oncology.

Computer-aided ionic liquid design for alkane/cycloalkane extractive distillation process

A computer-aided ionic liquid design(CAILD) study is presented for the frequently encountered alkane/cycloalkane separations in petrochemical industry. Exhaustive experimental data are first collected to extend the UNIFAC-IL model for this system, where the proximity effect in alkanes and cycloalkanes is considered specifically by defining distinct groups. The thermodynamic performances of a large number of ILs for 4 different alkane/cycloalkane systems are then compared to select a representative example of such separations. By applying n-heptane/methylcyclohexane extractive distillation as a case study, the CAILD task is cast as a mixed-integer nonlinear programming(MINLP) problem based on the obtained task-specific UNIFAC-IL model and two semi-empirical models for IL physical properties. The top 5 IL candidates determined by solving the MINLP problem are subsequently introduced into Aspen Plus for process simulation and economic analysis, which finally identify 1-hexadecyl-methylpiperidinium tricyanomethane([C_(16)MPip][C(CN)_3]) as the best entrainer for this separation.

考虑腐蚀影响的老旧FPSO船体总纵强度研究

以在渤海服役20年的FPSO为研究对象,分别采用水动力分析软件MOSES和SESAM计算其静水载荷和波浪载荷,进而得到船体所受总纵外载荷。依据《海上浮式装置入级规范》中关于腐蚀速率的规定计算FPSO在计入腐蚀后的船体剖面模数,根据《钢质海船入级与建造规范》中的相关规定,对FPSO在运营不同年限后的总纵强度进行校核,同时提出了改造加强的建议。校核结果表明:该船目前的总纵强度满足规范要求。

Detection of neuronal defensive discharge information transmission and characteristics in periaqueductal gray double-subregions using PtNP/PEDOT:PSS modified microelectrode arrays

Threatened animals respond with appropriate defensive behaviors to survive.It has been accepted that midbrain periaqueductal gray(PAG)plays an essential role in the circuitry system and organizes defensive behavioral responses.However,the role and correlation of different PAG subregions in the expression of different defensive behaviors remain largely unexplored.Here,we designed and manufactured a microelectrode array(MEA)to simultaneously detect the activities of dPAG and vPAG neurons in freely behaving rats.To improve the detection performance of the MEAs,PtNP/PEDOT:PSS nanocomposites were modified onto the MEAs.Subsequently,the predator odor was used to induce the rat’s innate fear,and the changes and information transmission in neuronal activities were detected in the dPAG and vPAG.Our results showed that the dPAG and vPAG participated in innate fear,but the activation degree was distinct in different defense behaviors.During flight,neuronal responses were stronger and earlier in the dPAG than the vPAG,while vPAG neurons responded more strongly during freezing.By applying high-performance MEA,it was revealed that neural information spread from the activated dPAG to the weakly activated vPAG.Our research also revealed that dPAG and vPAG neurons exhibited different defensive discharge characteristics,and dPAG neurons participated in the regulation of defense responses with burst-firing patterns.The slow activation and continuous firing of vPAG neurons cooresponded with the regulation of long-term freezing responses.The results demonstrated the important role of PAG neuronal activities in controlling different aspects of defensive behaviors and provided novel insights for investigating defense from the electrophysiological perspective.

深吃水半潜式储油生产平台立管支撑结构分析

以陵水17-2深吃水半潜式储油生产平台为例,介绍立管支撑结构的分析流程与方法。立管支撑结构一端与平台下浮体相连,另一端与立管接头接收装置相连。计算分析中,为了准确模拟立管支撑结构及相连结构的受力情况,计算模型截取整段下浮体、并模拟立管接头接收装置的结构。立管载荷作用点准确按照立管接头的实际中心点进行施加。通过计算最大应力分析立管支撑结构的强度,通过S-N曲线和应力幅分析立管支撑结构的疲劳。

A Deep Learning Application for Building Damage Assessment Using Ultra-High-Resolution Remote Sensing Imagery in Turkey Earthquake

Rapid building damage assessment following an earthquake is important for humanitarian relief and disaster emergency responses.In February 2023,two magnitude-7.8 earthquakes struck Turkey in quick succession,impacting over 30 major cities across nearly 300 km.A quick and comprehensive understanding of the distribution of building damage is essential for e fficiently deploying rescue forces during critical rescue periods.This article presents the training of a two-stage convolutional neural network called BDANet that integrated image features captured before and after the disaster to evaluate the extent of building damage in Islahiye.Based on high-resolution remote sensing data from WorldView2,BDANet used predisaster imagery to extract building outlines;the image features before and after the disaster were then combined to conduct building damage assessment.We optimized these results to improve the accuracy of building edges and analyzed the damage to each building,and used population distribution information to estimate the population count and urgency of rescue at different disaster levels.The results indicate that the building area in the Islahiye region was 156.92 ha,with an affected area of 26.60 ha.Severely damaged buildings accounted for 15.67%of the total building area in the affected areas.WorldPop population distribution data indicated approximately 253,297,and 1,246 people in the collapsed,severely damaged,and lightly damaged areas,respectively.Accuracy verification showed that the BDANet model exhibited good performance in handling high-resolution images and can be used to directly assess building damage and provide rapid information for rescue operations in future disasters using model weights.

新一代水文水资源监测卫星SWOT数据特征、应用与展望

水文水资源监测是对地观测系统的重要任务之一,是支撑新时代水利高质量发展、满足“三水”共治需求和践行“十六字”治水策略的直接有效途径,而卫星遥感技术提供了一种大范围、快速和高精度的数据获取渠道。但是现有卫星遥感在水文水资源应用上存在多星同步观测难、应急响应能力差和易受天气影响等问题,因此美国国家航空航天局于2022年12月发射了地表水和海洋地形卫星(SWOT),这是全球第一颗通过多传感器协同观测全球陆地和海洋水资源的卫星,预期将极大提升水文水资源监测的时空分辨率和精度。系统梳理了水文水资源监测卫星发展现状、应用和技术难点等概况,并分析了SWOT卫星的参数、科学任务、算法流程和应用产品等内容,对我国后续卫星设计规划和数据处理关键技术有一定的参考价值。

Cu-optimized long-range interaction between Co nanoparticles and Co single atoms:Improved Fenton-like reaction activity

The interplay between multi-atom assembly configurations and single atoms(SAs)has been gaining attention in research.However,the effect of long-term range interactions between SAs and multi-atom assemblies on the orbital filling characteristics has yet to be investigated.In this context,we introduced copper(Cu)doping to strengthen the interaction between cobalt(Co)nanoparticles(NPs)and Co SAs by promoting the spontaneous formation of Co-Cu alloy NPs that tends toward aggregation owing to its negative cohesive energy(-0.06454),instead of forming Cu SAs.The incorporation of Cu within the Co-Cu alloy NPs,compared to the pure Co NPs,significantly expedites the kinetics of peroxymonosulfate(PMS)oxidation processes on Co SAs.Unlike Co NPs,Co-Cu NPs facilitate electron rearrangement in the d orbitals(especially dz^(2)and dxz)near the Fermi level in Co SAs,thereby optimizing the dz^(2)-O(PMS)and dxz-O(SO_(5)^(-))orbital interaction.Eventually,the Co-Cu alloy NPs embedded in nitrogen-doped carbon(CC@CNC)catalysts rapidly eliminated 80.67% of 20 mg L^(-1)carbamazepine(CBZ)within 5 min.This performance significantly surpasses that of catalysts consisting solely of Co NPs in a similar matrix(C@CNC),which achieved a 58.99% reduction in 5 min.The quasi in situ characterization suggested that PMS acts as an electron donor and will transfer electrons to Co SAs,generating^(1)O_(2)for contaminant abatement.This study offers valuable insights into the mechanisms by which composite active sites formed through multi-atom assembly interact at the atomic orbital level to achieve high-efficiency PMS-based advanced oxidation processes at the atomic orbital level.

Coupling WO_(3-x) dots-encapsulated metal-organic frameworks and template-free branched polymerization for dual signal-amplified electrochemiluminescence biosensing

Developing accurate and sensitive DNA methyltransferase(MTase) analysis methods is essential for early clinical diagnosis and development of antimicrobial drug targets. In this work, by coupling WO_(3-x) dotsencapsulated metal-organic frameworks(MOFs) as co-reactants and terminal deoxynucleotidyl transferase(Td T)-mediated template-free branched polymerization, a dual signal-amplified electrochemiluminescent(ECL) biosensor was constructed to detect DNA adenine methylation(Dam) MTase. The employment of WO_(3-x) dots-encapsulated MOFs(i.e., NH_(2)-UIO66@WO_(3-x) ) was not only beneficial for biomolecule conjugation because of the abundant amino groups but also led to a 7-fold enhanced ECL response due to the increased loading of WO_(3-x). Moreover, Td T-mediated template-free branched polymerization promoted the capture of ECL emitters on the electrode surface, achieving 20-fold enhanced signal amplification. The presented ECL biosensor demonstrated a low detection limit of 2.4 × 10^(-4)U/m L, and displayed high reliability for the detection of Dam MTase in both spiked human serum and E. coli cell samples, and for the screening of potential inhibitors. This study opens a new avenue for designing a dual signal amplificationbased ECL bioassay for Dam MTase and screening inhibitors in the fields of clinical diagnosis and drug development.

Impaired Spatial Firing Representations of Neurons in the Medial Entorhinal Cortex of the Epileptic Rat Using Microelectrode Arrays

Epilepsy severely impairs the cognitive behavior of patients.It remains unclear whether epilepsy-induced cognitive impairment is associated with neuronal activities in the medial entorhinal cortex(MEC),a region known for its involvement in spatial cognition.To explore this neural mechanism,we recorded the spikes and local field potentials from MEC neurons in lithium-pilocarpine-induced epileptic rats using self-designed microelectrode arrays.Through the open field test,we identified spatial cells exhibiting spatially selective firing properties and assessed their spatial representations in relation to the progression of epilepsy.Meanwhile,we analyzed theta oscillations and theta modulation in both excitatory and inhibitory neurons.Furthermore,we used a novel object recognition test to evaluate changes in spatial cognitive ability of epileptic rats.After the epilepsy modeling,the spatial tuning of various types of spatial cells had suffered a rapid and pronounced damage during the latent period(1 to 5 d).Subsequently,the firing characteristics and theta oscillations were impaired.In the chronic period(>10 d),the performance in the novel object experiment deteriorated.In conclusion,our study demonstrates the detrimental effect on spatial representations and electrophysiological properties of MEC neurons in the epileptic latency,suggesting the potential use of these changes as a"functional biomarker"for predicting cognitive impairment caused by epilepsy.

On-orbit geometric calibration of satellite laser altimeters using infrared detectors and corner-cube retroreflectors

After being launched into orbit,the geometric calibration of a satellite laser altimeter will reduce errors in laser pointing and ranging caused by satellite vibrations during launch,environmental changes,and thermal effects during long-term operation,which guarantees the accuracy of measurement data.In this study,a satellite laser geometric calibration method combining infrared detectors and corner-cube retroreflectors(CCRs)is proposed.First,a CCR-based laser ranging error calibration method was established,and then a laser pointing error calibration model was derived based on a single infrared detector array.Taking GaoFen-7(GF-7)satellite laser beam 2 as the experimental object,laser geometric calibration was realized using an infrared detector and CCR-measured data.Then,the accuracy of the proposed method was compared with that of other calibration methods,the CMLID and the CMSPR.The results show that the accuracy of the proposed calibration method is equivalent to that of the CMLID and higher than that of the CMSPR.Among them,the accuracy of the laser pointing after calibration using the proposed method is better than 0.8 arcsec,and the elevation accuracy of the laser on flat,sloping,and mountainous terrains is better than 0.11 m,0.30 m,and 1.80 m,respectively.

Built-in piezoelectric field improved photocatalytic performance of nanoflower-like Bi_(2)WO_(6) using low-power white LEDs

Photocatalysis technology has been proved to be a potential strategy for removal of organic dyes,however high-power light sources are generally necessary to initiate photocatalytic reaction.In this work,we employed an excellent photocatalyst of Bi_(2)WO_(6) with visible light harvest and meanwhile an intrinsic ferroelectricity,which realized the efficient degradation of organic dye via the synergetic photopiezocatalysis.Through coupling the illumination by a low-power(9 W)LED and the ultrasonic vibration(120 W)by an ultrasonic cleaner,the nano flower-like Bi_(2)WO_(6) composed of ultrathin nanosheets showed a much more enhanced photopiezocatalysis performance for purification of organic dye than the individual photocatalysis and piezocatalysis.Furthermore,the high mineralization efficiency and the good durability of the Bi_(2)WO_(6) catalyst were demonstrated.The possible mechanism of photopiezocatalysis was finally proposed,where the ultrasound-induced piezoelectric field in Bi_(2)WO_(6) drove photo-generated electrons and holes to diffuse along opposite directions,consequently promoting the separation efficiency of charge carriers.This work indicates that the synergetic photopiezocatalysis by coupling irradiation and ultrasonic vibration is a promising strategy to purify organic pollutants in wastewater.

Grid cell remapping under three-dimensional object and social landmarks detected by implantable microelectrode arrays for the medial entorhinal cortex

Grid cells with stable hexagonal firing patterns in the medial entorhinal cortex(MEC)carry the vital function of serving as a metric for the surrounding environment.Whether this mechanism processes only spatial information or involves nonspatial information remains elusive.Here,we fabricated an MEC-shaped microelectrode array(MEA)to detect the variation in neural spikes and local field potentials of the MEC when rats forage in a square enclosure with a planar,three-dimensional object and social landmarks in sequence.The results showed that grid cells exhibited rate remapping under social conditions in which spike firing fields closer to the social landmark had a higher firing rate.Furthermore,global remapping showed that hexagonal firing patterns were rotated and scaled when the planar landmark was replaced with object and social landmarks.In addition,when grid cells were activated,the local field potentials were dominated by the theta band(5–8 Hz),and spike phase locking was observed at troughs of theta oscillations.Our results suggest the pattern separation mechanism of grid cells in which the spatial firing structure and firing rate respond to spatial and social information,respectively,which may provide new insights into how the brain creates a cognitive map.

Carbides Evolution in 12Cr Martensitic Heat-resistant Steel with Life Depletion for Long-term Service

Evaluating the residual life of exposed components in power industry is a very important procedure inroutine examination. The microstructures of a series of X20CrMoV12.1 martensitic superheater tube samples in a boiler in different service periods were investigated extensively to extract a quantitative relationship. During long-term service from start to rupture, hardness decreased monotonically with life depletion, and the decrease of hardness in prior austenite grain boundary was steeper than that in the matrix. Microstructure observation showed obvious damage characteristics, including carbide coarsening and martensite decomposing, and the martensite structure decomposed completely in rupture state. The morphology, distribution and composition of the main precipitates M23 C6 varied distinctly. The aspect ratio of coarsened carbides along grain boundary increased several fold with respect to their original size. The composition of coarsened M23 C6 carbide shows the most regular trend of Cr enrichment and the statistical result of Cr enrichment in M23 C6 shows a linear correlation between the ratio of Cr to Fe and service time to the power of 3/2, which may be considered as an index of material degradation due to long-term service exposure.