Multi-ASV Collision Avoidance for Point-to-Point Transitions Based on Heading-Constrained Control Barrier Functions With Experiment

Dear Editor, Collision avoidance is critical for safe operations of multiple autonomous surface vehicles(ASVs). It is a challenging task to design collision-free control laws to ensure safety, especially in a crowded sea environment. This letter presents a collision-free pointto-point transition strategy for multiple ASVs subject to static obstacles, dynamic obstacles and neighboring ASVs based on control barrier functions(CBFs).

智能时代中小学教师人工智能伦理培养策略研究——基于科尔伯格道德发展理论

人工智能为中小学教育带来无限可能的同时,也引发了一系列的伦理道德风险和挑战。中小学生正处于伦理认知发展的重要阶段,因此,提升中小学教师人工智能伦理对于中小学生、教师自身、学校乃至中小学教育的发展都具有关键作用。但是,现阶段关于中小学教师群体人工智能伦理的研究相对较少且缺乏明确的理论指导。在综述中小学教师面临的人工智能伦理挑战的基础上,基于科尔伯格三水平六阶段伦理发展框架,有针对性地提出不同阶段中小学教师人工智能伦理的培养策略。这些伦理培养策略由低水平到高水平、初级阶段到高级阶段演进,包括培养中小学教师人工智能伦理意识、推动中小学教师自身建构人工智能伦理知识、发展中小学教师社会化协同构建、构建中小学教师人工智能伦理外部约束机制、构建民主化的人工智能伦理决策机制、培养中小学教师共同体的人工智能伦理责任。

Benchmark for establishment of organoids from gastrointestinal epithelium and cancer based on available consumables and reagents

Gastrointestinal cancers are a public health problem that threatens the lives of human being. A good experimental model is a powerful tool to promote the uncovering pathogenesis and establish novel treatment methods. High-quality biomedical research requires experimental models to recapitulate the physiological and pathological states of their parental tissues as much as possible. Organoids are such experimental models. Organoids refer to small organlike cellular clusters formed by the expansion and passaging of living tissues in 3D culture medium in vitro.Organoids are highly similar to the original tissues in terms of cellular composition, cell functions, and genomic profiling. Organoids have many advantages, such as short preparation cycles, long-term storage based on cryopreservation, and reusability. In recent years, researchers carried out the establishment of organoids from gastrointestinal mucosa and cancer tissues, and accumulated valuable experiences. In order to promote effective usage and further development of organoid-related technologies in the research of gastrointestinal diseases, this study proposes a benchmark based on utilization of available experimental consumables and reagents, which are involved in the key steps such as collection and pretreatment of biospecimen, organoid construction, organoid cryopreservation and recovery, growth status evaluation, and organoid quality control. We believe that the standard for the construction and preservation of organoids derived from human gastrointestinal epithelium and cancer tissues can provide an important reference for the majority of scientific researchers.

Time-Series Characteristics of Wind Power and Its Impact on Jilin Power Grid

With the rapid development of wind power, the large-scale wind power integration brings a new range of issues in dispatching operation. In order to gain a better grasp of the influence caused by wind power combined to the grid, the paper first establishes the impact characteristic indexes, and then analyzes the regularity of wind power time series in different spatial and temporal scales. At last, according to the analysis results, this paper assesses the impact of time-series characteristics of wind power on power grid, such as the frequency regulation, peak load regulation, which can provide the reference for wind power optimal dispatching of Jilin Power Grid.

槲皮素对人肺癌细胞株A549化疗药物增敏作用的实验研究(英文)

Objective: The present study was designed to investigate whether quercetin exerts increasing chemosensitivity on human lung adenocarcinoma cells when quercetin combined with cisplatin (DDP) and vincristine (VCR) in vitro respectively and its possible antitumor mechanism. To provide experimental proof for clinical combination application. Methods: Using intermittent administration of high dose VCR, human lung adenocarcinoma sensitive cell line (A549/S) was induced to VCR-resistant human lung adenocarcinoma cell line (A549/VCR). MTT assay was adapted for examing the 50% inhibition (IC50) value of DDP and VCR on A549/S and A549/VCR when quercetin combined with DDP and VCR respectively. Results: IC50 of DDP on A549/S and A549/VCR was 10.18 and 12.35 mg/L, and the IC50 of VCR on the two cell lines was 1.21 and 12.77 mg/L, respectively. The resistance fold of A549/VCR on VCR and DDP was 10.55 and 1.21, respectively. When quercetin at concentration of 50, 100 and 200 μmol/L in combination with DDP and VCR respectively, the IC50 of DDP and VCR on A549/S and A549/VCR were obvious decreased (P < 0.05 - P < 0.01). Conclusion: The experiment results suggested that quercetin could increase the chemosensitivity and partly revise the resistance of A549/VCR.

Finite Control Set Model Predictive Torque Control Using Sliding Model Control for Induction Motors

Finite control set model predictive torque control(FCS-MPTC)has become increasingly prevalent for induction motors(IM)owing to its simple concept,easy incorporation of constraints and strong flexibility.In traditional FCS-MPTC speed controller design,a classical proportional integral(PI)controller is typically chosen to generate the torque reference.However,the PI controller is dependent on system parameters and sensitive to the load torque variation,which seriously affects control performance.In this paper,a model predictive torque control using sliding mode control(MPTC+SMC)for IM is proposed to enhance the robust performance of the drive system.First,the influence of the parameter mismatches for FCS-MPTC is analyzed.Second,the shortcomings of traditional PI controller are derived.Then,the proposed MPTC+SMC method is designed,and the MPTC+PI and MPTC+SMC are compared theoretically.Finally,experimental results demonstrate the correctness and effectiveness of the proposed MPTC+SMC.In comparison with MPTC+PI,MPTC+SMC has the better dynamic performance and stronger robust performance against parameter variations and load disturbance.

A Clustering Analysis Method for Massive Music Data

Clustering analysis plays a very important role in the field of data mining,image segmentation and pattern recognition.The method of cluster analysis is introduced to analyze NetEYun music data.In addition,different types of music data are clustered to find the commonness among the same kind of music.A music data-oriented clustering analysis method is proposed:Firstly,the audio beat period is calculated by reading the audio file data,and the emotional features of the audio are extracted;Secondly,the audio beat period is calculated by Fourier transform.Finally,a clustering algorithm is designed to obtain the clustering results of music data.

新型冠状病毒灭活疫苗不影响免疫性血栓相关自身抗体水平,不增加血栓形成的风险:一项前瞻性中国人群队列研究

新型冠状病毒感染的患者凝血功能异常与体内存在抗磷脂抗体相关并可导致血栓等不良预后事件.近期,有研究报道腺病毒载体新冠疫苗接种后,诱导产生的抗血小板因子4(PF4)抗体与接种者血栓事件及血小板减少相关.目前,新型冠状病毒灭活疫苗在中国广泛接种,其是否影响免疫性血栓相关自身抗体的产生和增加血栓事件已成为迫切需要探索的问题.本项前瞻性研究共招募了406名接种两剂新型冠状病毒灭活疫苗(BBIBP-Cor V,北京生物)的医务工作者,分别在接种前和接种第二剂后4周采集外周血样本,检测抗心磷脂(anti-cardiolipin antibody, aCL)抗体、抗β2糖蛋白I(anti-β2 glycoprotein I antibody, aβ2GP1)抗体、抗磷脂酰丝氨酸/凝血酶原(anti-phosphatidylserine/prothrombin antibody, aPS/PT)抗体和抗PF4-肝素复合物(anti-platelet factor 4-heparin antibody, aPF4-heparin)抗体.入组者接种第二剂疫苗4周后SARS-CoV-2抗体血清转化率为95.81%(389/406),自身抗体的阳性率及抗体水平在接种前后采集的样本中没有显著差异.在最少8周的随访期内,所有受试者均未出现血栓事件及血小板减少.综上所述,新型冠状病毒灭活疫苗不影响抗磷脂抗体和抗PF4-肝素抗体的水平,同时未增加血栓形成的风险.

Prognostic Nomogram for Patients with Hepatitis E Virus-related Acute Liver Failure:A Multicenter Study in China

Background and Aims:Timely and effective assessment scoring systems for predicting the mortality of patients with hepatitis E virus-related acute liver failure(HEV-ALF)are urgently needed.The present study aimed to establish an effective nomogram for predicting the mortality of HEV-ALF patients.Methods:The nomogram was based on a cross-sectional set of 404 HEV-ALF patients who were identified and enrolled from a cohort of 650 patients with liver failure.To compare the performance with that of the model for end-stage liver disease(MELD)scoring and CLIF-Consortiumacute-on-chronic liver failure score(CLIF-C-ACLFs)models,we assessed the predictive accuracy of the nomogram using the concordance index(C-index),and its discriminative ability using time-dependent receiver operating characteristics(td-ROC)analysis,respectively.Results:Multivariate logistic regression analysis of the development set carried out to predict mortality revealed that γ-glutamyl transpeptidase,albumin,total bilirubin,urea nitrogen,creatinine,international normalized ratio,and neutrophil-to-lymphocyte ratio were independent factors,all of which were incorporated into the new nomogram to predict the mortality of HEV-ALF patients.The area under the curve of this nomogram for mortality prediction was 0.671(95%confidence interval:0.602-0.740),which was higher than that of the MELD and CLIF-C-ACLFs models.Moreover,the td-ROC and decision curves analysis showed that both discriminative ability and threshold probabilities of the nomogram were superior to those of the MELD and CLIF-C-ACLFs models.A similar trend was observed in the validation set.Conclusions:The novel nomogram is an accurate and efficient mortality prediction method for HEV-ALF patients.

Preparation and Determination of Immunological Activities of Anti-HBV Egg Yolk Extraction

To prepare an effective immune preparation to treat hepatitis B, hens were immunized with hepatitis B vaccines, and then anti-HBV egg yolk extraction （anti-HBV EYE） was refined from egg yolk by a dialyzable method. Its chemical characteristics were identified by ultraviolet spectrum, HPLC, Lowry analysis and pharmacopocia-raleted methods. The specific immunological activity was examined by leukocyte adherence inhibition （LAI） in vitro and delayed type hypersensitivity （DTH） in vivo. Anti-HBV EYE was a small dialyzable substance with molecular weight less than 12 kD containing 18 kinds of amino acids. The preparation could obviously inhibit LAI and DTH which was similar to hepatitis B virus-specific transfer factor of pig spleen. However, there were no similar effects observed in the nonspecific transfer factor （NTF） group, control egg yolk extraction （CEYE） group and hepatitis A virus （HAV） group. The results suggested that anti-HBV EYE contained hepatitis B virus-specific transfer factor （STF） and had the antigen-specific cell immune activity similar to PSHBV-TF. The STF obtained from egg yolk of the hens immunized with specific antigen, might be a potential candidate for immunoregulation in hepatitis B prevention and treatment.

Octahedral silver oxide nanoparticles enabling remarkable SERS activity for detecting circulating tumor cells

The detection of circulating tumor cells(CTCs)is a crucial tool for early cancer diagnosis,prognosis,and postoperative evaluation.However,detection sensitivity remains a major challenge because CTCs are extremely rare in peripheral blood.To effectively detect CTCs,octahedral Ag_(2)O nanoparticles(NPs)with high dispersibility,good biocompatibility,remarkable surface-enhanced Raman scattering(SERS)enhancement,and obvious enhancement selectivity are designed as an SERS platform.Ag_(2)O NPs with many oxygen vacancy defects are successfully synthesized,which exhibit an ultra-high SERS enhancement factor(1.98×10^(6))for 4-mercaptopyridine molecules.The remarkable SERS activity of octahedral Ag_(2)O NPs is derived from the synergistic effect of the surface defect-promoted photo-induced charge transfer(PICT)process and strong vibration coupling resonance in the Ag_(2)O-molecule SERS complex,greatly amplifying the molecular Raman scattering crosssection.The promoted PICT process is confirmed using ultraviolet-visible(UV-Vis)absorption spectroscopy,demonstrating that obvious PICT resonance occurs in Ag_(2)O SERS system under visible light.An additional growth step of SERS bioprobe is proposed by modifying the Raman signal molecules and functional biological molecules on Ag_(2)O NPs for CTC detection.The Ag_(2)O-based SERS bioprobe exhibits excellent detection specificity for different cancer cells in rabbit blood.Importantly,the high-sensitivity Ag_(2)O-based SERS bioprobe satisfies the requirement for rare CTC detection in the peripheral blood of cancer patients,and the detection limit can reach 1 cell per m L.To our knowledge,this study is the first time that a semiconductor SERS substrate has been successfully utilized in CTC detection.This work provides new insights into CTC detection and the development of novel semiconductor-based SERS platforms for cancer diagnosis.

Dispersion Effects of High-Order-Mode Fiber on Temperature and Axial Strain Discrimination

在 high-order-mode 纤维(HOMF ) 利用分散的效果有效地在环境温度和轴的紧张区别变化的一条新途径被建议并且试验性地示威了。基于 HOMF 的纤维的试验性的描述有三明治纤维结构的形式的干涉仪与数字模拟结果展出优秀协议。在空间频率领域的 interferometry 的一个 Fourier 变换方法被采用区分模式在不同指导核心的模式之间联合。多重分散山峰的不同阶段敏感被采用一个新奇阶段解调计划认识到双参数的察觉到提取。

Carbonate dynamics in a tropical coastal system in the South China Sea featuring upwelling, river plumes and submarine groundwater discharge

This study examined carbonate dynamics in the northwestern South China Sea(NWSCS),an area jointly influenced by upwelling,river plumes and submarine groundwater discharge.Data were obtained from two cruises conducted in summer 2009 and 2012.In 2009,a high salinity-low temperature water mass occurred nearshore off northeastern Hainan Island,indicative of upwelling,commonly referred to as HNEU.A river plume fueled primarily by local rivers and characterized by low salinity and high temperature was observed in the NWSCS off the mainland roughly along the 30 m isobath.In 2012,coastal upwelling off northeastern Hainan Island was not detectable at the surface,but was observed at a different location off eastern Hainan Island(HEU).River plume waters in 2012 were patchily distributed,with a low salinity zone further westerly than that in 2009 and another on the mid-shelf of the NWSCS sourced from the Pearl River which reached out~250 km from the mouth of the Pearl River Estuary.In 2009,elevated dissolved inorganic carbon(DIC)and total alkalinity(TA)occurred in the coastal plume,where submarine groundwater discharge contributed DIC and TA additions of 38.9±20.5 and 42.5±22.3μmol kg^(−1),respectively,with a DIC/TA ratio of~0.92,which made a minor contribution to the variation of seawater partial pressure of CO_(2)(pCO_(2)),pH and the aragonite saturation state index(Ω_(arag)).Additionally,high surface phytoplankton production consumed DIC of 10.0±10.4μmol kg^(−1) but did not significantly affect TA,which dominated pCO_(2) drawdown in the coastal plume water and increased the pH andΩ_(arag) at surface.Submarine groundwater discharge was also observed in the region influenced by upwelling,but to a lesser degree than that impacted by coastal plume.Lower pH andΩ_(arag) and higher pCO_(2) values than in offshore waters were observed downstream of the upwelling system,attributable largely to organic matter remineralization with a DIC addition of 23.8±8.4μmol kg^(−1).In 2012,submarine groundwater discharge was not detected but high phytoplankton production dominated carbonate dynamics in the coastal plume water with a net DIC consumption of 104.2μmol kg^(−1),which markedly drew down sea surface pCO_(2) and increased pH andΩ_(arag).In the Pearl River Plume,the solubility-driven CO_(2) sink exceeded biological CO_(2) uptake,resulting in an additional decrease of pH andΩ_(arag) and increase of seawater pCO_(2).Taken together,this study demonstrated complex spatial and year-to-year variability,and the controls of the carbonate system under the joint modulations of upwelling,river plumes and submarine groundwater discharge.A first order estimate that considered the rise of atmospheric CO_(2) and seawater temperature further suggested a high risk of ocean acidification in this coastal area by the end of this century,which could be amplified under the stresses of river plumes,submarine groundwater discharge and organic matter remineralization.