Satellite observations of coastal upwelling in the northern Arafura Sea

Coastal upwelling is significant for marine ecosystems by lifting nutrient-rich deep waters into the euphotic zone,thereby increasing primary and secondary productivity.The satellite observations show that the northern Arafura Sea(NAS),especially in the coastal region,features high chlorophyll-a(chl-a)concentrations,implying a strong coastal upwelling.However,coastal upwelling in the NAS has not received much attention.Based on a semi-automatic image processing technology,the seasonal and interannual variability of coastal upwelling in the NAS are investigated in this study using satellite-observed sea surface temperature(SST)and wind data.The results suggest that there are seasonal coastal upwelling events in the NAS modulated by upwelling-favorable southeast monsoon(SEM).The annual mean days,mean area,and annual mean intensity of coastal upwelling events during the SEM season are 92 days,6514 km^(2),and-5.31×10^(5),respectively,while the corresponding values during the northwest monsoon(NWM)season are 32 days,5569 km^(2),and-1.41×10^(5).It is also found that the SEM coastal upwelling in the NAS displays prominent interannual variability.The strong upwelling events are found in 2010,2013,2016,and 2017 when the southeast monsoon winds were weaker.Further analysis suggests that at the interannual scale,the upwelling index(UI)averaged in the SEM season is negatively correlated with that of three upwelling indicators.This can be attributed to the limitation of onshore geostrophic flow which is evidenced by the negative correlation between the UI and the alongshore difference in sea surface height.This study highlights the important role of the southeast monsoon in the temporal variability of coastal upwelling in the NAS.

A Quick Calculation Method for Radiation Pattern of Submillimeter Telescope with Deformation and Displacement

Radiation pattern captures the electromagnetic performance of reflector antennas,which is significantly affected by the deformation of the primary reflector due to gravity and the displacement of the secondary reflector.During the design process of large reflector antennas,a substantial amount of time is often dedicated to iteratively adjusting structural parameters and validating electromagnetic performance.To improve the efficiency of the design process,we first propose an approximate calculation method of optical path difference(OPD)for the deformation of the primary reflector under gravity and the displacement of the secondary reflector.Then an OPD fitting function based on the modified Zernike polynomials is proposed to capture the phase difference of radiation over the aperture plane,based on which the radiation pattern will be obtained quickly by the aperture field integration method.Numerical experiments demonstrate the effectiveness of the proposed quick calculation method for analyzing the radiation pattern of a 10.4 m submillimeter telescope antenna at its highest operating frequency of 856 GHz.In comparison with the numerical simulation method based on GRASP(which is an antenna electromagnetic analysis tool combining physical optics(PO)and physical theory of diffraction(PTD)),the quick calculation method reduces the time for radiation pattern analysis from more than one hour to less than two minutes.Furthermore,the quick calculation method exhibits excellent accuracy for the figure of merit(FOM)of the radiation pattern.Therefore,the proposed quick calculation method can obtain the radiation pattern with high speed and accuracy.Compared to the time-consuming numerical simulation method(PO and PTD),it can be employed for quick analysis of the radiation pattern for the lateral displacement of the secondary reflector and the deformation of the primary reflector under gravity in the design process of a reflector antenna.

Current status and prospects of research on safety situation awareness of high speed railway operation environment

Purpose–The safety of high-speed rail operation environments is an important guarantee for the safe operation of high-speed rail.The operating environment of the high-speed rail is complex,and the main factors affecting the safety of high-speed rail operating environment include meteorological disasters,perimeter intrusion and external environmental hazards.The purpose of the paper is to elaborate on the current research status and team research progress on the perception of safety situation in high-speed rail operation environment and to propose directions for further research in the future.Design/methodology/approach–In terms of the mechanism and spatio-temporal evolution law of the main influencing factors on the safety of high-speed rail operation environments,the research status is elaborated,and the latest research progress and achievements of the team are introduced.This paper elaborates on the research status and introduces the latest research progress and achievements of the team in terms of meteorological,perimeter and external environmental situation perception methods for high-speed rail operation.Findings–Based on the technical route of“situational awareness evaluation warning active control,”a technical system for monitoring the safety of high-speed train operation environments has been formed.Relevant theoretical and technical research and application have been carried out around the impact of meteorological disasters,perimeter intrusion and the external environment on high-speed rail safety.These works strongly support the improvement of China’s railway environmental safety guarantee technology.Originality/value–With the operation of CR450 high-speed trains with a speed of 400 kmper hour and the application of high-speed train autonomous driving technology in the future,new and higher requirements have been put forward for the safety of high-speed rail operation environments.The following five aspects of work are urgently needed:(1)Research the single factor disaster mechanism of wind,rain,snow,lightning,etc.for high-speed railways with a speed of 400 kms per hour,and based on this,study the evolution characteristics of multiple safety factors and the correlation between the high-speed driving safety environment,revealing the coupling disastermechanism ofmultiple influencing factors;(2)Research covers multi-source data fusion methods and associated features such as disaster monitoring data,meteorological information,route characteristics and terrain and landforms,studying the spatio-temporal evolution laws of meteorological disasters,perimeter intrusions and external environmental hazards;(3)In terms of meteorological disaster situation awareness,research high-precision prediction methods for meteorological information time series along high-speed rail lines and study the realization of small-scale real-time dynamic and accurate prediction of meteorological disasters along high-speed rail lines;(4)In terms of perimeter intrusion,research amulti-modal fusion perception method for typical scenarios of high-speed rail operation in all time,all weather and all coverage and combine artificial intelligence technology to achieve comprehensive and accurate perception of perimeter security risks along the high-speed rail line and(5)In terms of external environment,based on the existing general network framework for change detection,we will carry out research on change detection and algorithms in the surrounding environment of highspeed rail.

Clinical characteristics and prognosis of takotsubo syndrome patients in single center

Takotsubo syndrome(TTS)is a clinical syndr-ome that frequently occurs in postmenopausal women,mostly induced by stress factors.It is characterized by chest pain,ST-segment elevation,and/or T-wave changes in electrocardiogram,along with my-ocardial troponin elevation.[1]TTS can be easily misdia-gnosed as myocardial infarction,and improper treatme-nt may lead to serious consequences.There are few re-ports and research on this disease.[2]

共享经济背景下共享平台差异化和专业化研究

通过多期动态分析找出影响因素和机制,研究共享平台的差异化和专业化程度问题。在共享平台中前期,从成本中区别出资源所有者时间成本后,中低收入者及其闲置资源最早加入平台;同时,产品替代性促进专业化,但是运营成本、需求碎片化和产品定位限制专业化。所以在中前期平台服务以横向差异和非专业服务为主。另外,在不同发展阶段,对共享经济的扶持补贴,有不同的社会福利影响。

Linking fatty liver diseases to hepatocellular carcinoma by hepatic stellate cells

Hepatic stellate cells(HSCs),a distinct category of non-parenchymal cells in the liver,are critical for liver homeostasis.In healthy livers,HSCs remain non-proliferative and quiescent.However,under conditions of acute or chronic liver damage,HSCs are activated and participate in the progression and regulation of liver diseases such as liver fibrosis,cirrhosis,and liver cancer.Fatty liver diseases(FLD),including nonalcoholic(NAFLD)and alcoholrelated(ALD),are common chronic inflammatory conditions of the liver.These diseases,often resulting from multiple metabolic disorders,can progress through a sequence of inflammation,fibrosis,and ultimately,cancer.In this review,we focused on the activation and regulatory mechanism of HSCs in the context of FLD.We summarized the molecular pathways of activated HSCs(aHSCs)in mediating FLD and their role in promoting liver tumor development from the perspectives of cell proliferation,invasion,metastasis,angiogenesis,immunosuppression,and chemo-resistance.We aimed to offer an in-depth discussion on the reciprocal regulatory interactions between FLD and HSC activation,providing new insights for researchers in this field.

医教协同背景下成人护理教育“互联网+”翻转课堂教学模式的构建

在医教协同的背景下构建一个完善、优质的成人护理教育"互联网+"翻转课堂教学模式,培养学生自主学习和终生学习的能力,提高护理人才培养质量至关重要。文章重点探讨了如何在互联网背景下下构建适合成人学习者特点的线上线下翻转课堂教学模式。

基于果蝇优化算法和DWT-SVD的数字水印方法

针对嵌入水印强度的不确定性,提出了一种利用果蝇优化算法并结合小波变换与奇异值分解的数字图像水印嵌入算法。首先,利用小波变换对载体图像进行二级小波分解,然后对LL2子带进行4×4分块并进行奇异值分解以提高嵌入水印的稳定性,最终将水印信息以一定的强度嵌入到分解的最大奇异值中。果蝇优化算法综合考虑水印嵌入算法的鲁棒性与不可见性之间的矛盾,并结合水印嵌入方案确定最佳嵌入强度,首先根据影响水印性能的指标定义适应度函数,并对该函数的参数进行优化,确定了最佳的适应度函数,然后再应用果蝇优化算法寻找嵌入水印强度的最优解。最后通过仿真实验对该水印方案的性能进行测试与分析,实验结果表明,当嵌入水印图像的峰值信噪比达到40 dB时,提取水印的平均NC值能达到0.98以上。

医教协同背景下成人护理教育“互联网+”翻转课堂教学模式的构建

在医教协同背景下构建一个完善、优质的成人护理教育“互联网+”翻转课堂教学模式,培养学生自主学习和终身学习的能力,提高护理人才培养质量至关重要。文章重点探讨了如何在互联网背景下构建适合成人学习者特点的线上线下翻转课堂教学模式。

浮动油封O形圈黏弹性行为研究及结构优化设计

通过(实验)力学理论计算和有限元模拟的方法,研究了浮动油封结构中O形橡胶密封圈的黏弹性行为。结果表明:松弛过程中密封压力随着时间增加逐渐减小,蠕变过程中蠕变位移随着时间增加逐渐增大,均可能导致浮动油封结构的漏油失效。建立的理论计算模型与有限元分析结果一致,证明该有限元分析方法可用于预测浮动油封O形圈在松弛和蠕变过程中的载荷和位移变化。同时考虑到浮动油封由于O形圈的结构松弛和其与浮动油封座摩擦损伤可能导致的浮动油封结构漏油失效,提出了一种包含PTFE垫圈和恒压弹簧的浮动油封新结构。

新工科背景下的流体力学实验教学改革创新

在新工科背景下,针对流体力学实验内容欠丰富、大都是验证性的实验、教学方法及模式尚未突破等现状,开展了流体力学实验教学改革创新研究,主要通过改进实验内容和教学方法、增设虚拟实验平台与新型实验装置、开启创新性人才培养模式等方式,培养学生独立解决问题的能力,改变其依赖性,激发学生对流体力学实验的兴趣。将流体力学理论知识和实验紧密结合,对提高学生工程素养、培养自主创新能力具有积极意义。

冠心病PCI术后住院病人健康商数与治疗依从性的相关性研究

[目的]了解冠心病经皮冠状动脉介入治疗(PCI)术后病人健康商数及治疗依从性现状,探讨二者之间的关系。[方法]便利抽样法选取衡阳市三级甲等医院心内科共192例冠心病PCI术后病人,采用一般资料调查问卷、简要健康商数指数测评20题问卷、冠状动脉介入术后病人治疗依从性问卷进行调查。[结果]192例冠心病PCI术后病人健康商数得分(59.92±10.55)分;40.1%的病人服药依从性好,79.2%的病人没有按要求复查冠状动脉造影,48.4%的病人没有按要求进行运动试验,生活方式依从性中,67.7%的病人仍未控制高脂饮食的摄入,53.6%的病人未控制好体重,79.2%的病人运动依从性差;相关性分析显示健康商数与治疗依从性的3个维度呈正相关。[结论]冠心病PCI术后病人健康商数水平低,从而治疗依从性差,需进一步制定干预方案提高病人健康商数,从而促进病人的治疗依从性。

Modified model for end-stage liver disease improves shortterm prognosis of hepatitis B virus-related acute-on-chronic liver failure

AIM To investigate whether the short-term prognosis of hepatitis B virus(HBV)-related acute-on-chronic liver failure(ACLF) could be improved by using a modified model for end-stage liver disease(MELD) including serum lactate.METHODS This clinical study was conducted at the First Affiliated Hospital, Fujian Medicine University, China. From 2009 to 2015, 236 patients diagnosed with HBV-related ACLF at our center were recruited for this 3-month followup study. Demographic data and serum lactate levels were collected from the patients. The MELD scores with or without serum lactate levels from survival and nonsurvival groups were recorded and compared.RESULTS Two hundred and thirty-six patients with HBV-ACLF were divided into two groups: survival group(S) andnon-survival group(NS). Compared with the NS group, the patients in survival the S group had a significantly lower level of serum lactate(3.11 ± 1.98 vs 4.67 ± 2.43, t = 5.43, P < 0.001) and MELD score(23.33 ± 5.42 vs 30.37 ± 6.58, t = 9.01, P = 0.023). Furthermore, serum lactate level was positively correlated with MELD score(r = 0.315, P < 0.001). Therefore, a modified MELD including serum lactate was developed by logistic regression analysis(0.314 × lactate + 0.172 × MELD-5.923). In predicting 3-month mortality using the MELD-LAC model, the patients from the S group had significantly lower baseline scores(-0.930 ± 1.34) when compared with those from the NS group(0.771 ± 1.32, t = 9.735, P < 0.001). The area under the receiver operating characteristic curve(AUROC) was 0.859 calculated by using the MELD-LAC model, which was significantly higher than that calculated by using the lactate level(0.790) or MELD alone(0.818). When the cutoff value was set at-0.4741, the sensitivity, specificity, positive predictive value and negative predictive value for predicting short-term mortality were 91.5%, 80.10%, 94.34% and 74.62%, respectively. When the MELD-LAC scores at baseline level were set at-0.5561 and 0.6879, the corresponding mortality rates within three months were 75% and 90%, respectively.CONCLUSION The short-term prognosis of HBV-related ACLF was improved by using a modified MELD including serum lactate from the present 6-year clinical study.

Role of the IL-33/ST2/p38 signaling pathway in the immune response of corneal epithelial cells to Aspergillus fumigatus infection

AIM: To investigate the expression of interleukin(IL)-33 in the cornea and human corneal epithelial cells(HCECs) exposed to Aspergillus fumigatus(A. fumigatus), and to determine the function of IL-33/ST2/p38 signaling pathway in the immune response of corneal epithelial cells to A. fumigatus infection.METHODS: The mRNA and protein expression of IL-33 in HCECs and mice corneas were examined by quantitative real-time reverse transcription polymerase chain reaction(q RT-PCR) and Western blot analysis, respectively. IL-33 expression was also detected in cornea samples from healthy donors and patients with fungal keratitis with immunohistochemistry. The cultured HCECs were treated with inactive A. fumigatus hyphae at various concentrations with or without recombinant human IL-33 protein, soluble recombinant ST2 protein, specific ST2 neutralizing antibody, or the mitogen-activated protein kinase(MAPK) p38 inhibitor SB203580 for evaluation of the expression and activation of IL-33/ST2/p38 signaling in the regulation of proinflammatory cytokines. The production levels of IL-6 and IL-1β were determined by qR T-PCR and enzymelinked immunosorbent assay(ELISA). The proliferation of HCECs was determined by a Cell Counting Kit-8(CCK8) assay and cell count.RESULTS: IL-33 expression levels increased in the corneal tissues of patients with fungal keratitis and in mice corneas of experimental A. fumigatus infection,as well as in HCECs with infection of A. fumigatus. A. fumigatus strongly stimulated HCECs-generated proinflammatory cytokine(IL-6 and IL-1β) production at both the mRNA and protein levels. This production of proinflammatory mediators stimulated by A. fumigatus was further stimulated by IL-33 and was prevented by soluble ST2 protein or ST2 neutralizing antibody. Moreover, IL-33 naturally promoted the p38 phosphorylation induced by A. fumigatus, which was suppressed by soluble ST2 protein. The MAPK p38 inhibitor SB203580 also inhibited the A. fumigatus-induced proinflammatory cytokine production. IL-33 administration for 48 h and 72 h promoted the proliferation of HCECs, which was attenuated by treatment with soluble recombinant human ST2 protein.CONCLUSION: A. fumigatus elevates IL-33 expression in human and mice corneas and HCECs. Thus, IL-33/ST2/p38 signaling may play an important role in amplifying the immune response of corneal epithelial cells to A. fumigatus infection. Besides, IL-33 promotes the cell proliferation of HCECs via its receptor ST2. These findings suggest a novel autocrine mechanism of amplification of the fungalinduced inflammatory response in the corneal epithelium, highlighting a potential therapeutic target for fungal keratitis.

安全配置策略自动生成与验证技术研究

针对网络信息系统安全设备体系需要快速响应、统一配置管理的需求,开展安全配置策略自动生成与验证技术研究,突破安全配置策略形式化描述、安全配置意图与策略映射模型构建及验证、安全配置策略自动转译、安全配置策略冲突检测及优化等关键技术,实现将网络安全配置意图准确快速转化为信息系统安全设备可识别执行的网络安全策略,提升大规模网络信息系统基础安全设施策略智能计算生成能力。

Wireless Relay Communication on High Speed Railway：Full Duplex or Half Duplex？

In this paper,we introduce one full-duplex(FD) relaying transmission scheme for high speed railway and compare its ergodic capacity and outage performance with half-duplex(HD) relaying scheme. Both decode-and-forward(DF) amplify-and-forward(AF) relay modes are considered. Moreover,the carriage penetration loss(CPL) and the self-interference(SI) cancellation ratio are investigated. We derive the closed-form expressions for the outage probability and ergodic capacity of both HD and FD relay transmission schemes. It is shown that when CPL is larger than a certain level,the FD relay can achieve better performance in terms of capacity and keep the outage probability in a low level. It is also found that three factors: AF or DF modes,CPL and SI cancellation ratio,can have impact on capacity performance,and that CPL is one decisive factor. Our results can provide theoretical supports for development and deployment of future wireless communication systems on high speed railways.

Changes in corneal innervation and pain responses in fungal keratitis

AIM: To characterize changes in the cornea nerve and pain responses in fungal keratitis(FK).METHODS: A retrospective analysis of in vivo confocal microscopy images of 11 FK corneas was performed, and the results were compared with those for 11 normal corneas. Subbasal corneal nerves were analyzed for total nerve number, main nerve trunk number, branching patterns and tortuosity. C57 BL/6 mice were infected with Aspergillus fumigatus. Disease severity was determined through clinical scoring and slit lamp photography. Corneas were harvested at 1, 3, 5, and 7 d post infection(p.i.) and assessed for β III tubulin. Corneal mechanical sensitivity thresholds were detected by von Frey test. β-endorphin(β-EP) and μ receptor protein expression was detected through Western blotting.RESULTS: Total nerve number, main nerve trunk number, and nerve branching were significantly lower in FK patients than in controls, but tortuosity was not significantly different. In infected mice, subbasal nerve density decreased from 1 d p.i., reaching a minimum at 5 d p.i. Clinical scores rose at 1 d p.i., peaked at 3 d p.i., and decreased at 5 d p.i. Mechanical sensitivity thresholds showed the same trends. β-EP and μ receptor protein expression increased after infection.CONCLUSION: Corneal nerve density is lower in FK patients and Aspergillus fumigatus-infected mice than in controls. Pain sensitivity decreases with postinfection corneal ulcer aggravation. β-EP and μ receptor proteins are both upregulated in infected mouse corneas.

Geographical inhomogeneity and temporal variability of mixing property and driving mechanism in the Arctic Ocean

Upper ocean mixing plays a key role in the atmosphere-ocean heat transfer and sea ice extent and thickness via modulating the upper ocean temperatures in the Arctic Ocean.Observations of diffusivities in the Arctic that directly indicate the ocean mixing properties are sparse.Therefore,the spatiotemporal pattern and magnitude of diapycnal diffusivities and kinetic energy dissipation rates in the upper Arctic Ocean are important for atmosphere-ocean heat transfers and sea ice changes.These were first estimated from the Ice-Tethered Profilers dataset(2005–2019)using a strain-based fine-scale parameterization.The resultant mixing properties showed signifi cant geographical inhomogeneity and temporal variability.Diapycnal diff usivities and dissipation rates in the Atlantic sector of the Arctic Ocean were stronger than those on the Pacific side.Mixing in the Atlantic sector increased significantly during the observation period;whereas in the Pacific sector,it weakened before 2011 and then strengthened.Potential impact factors include wind,sea ice,near inertial waves,and stratifi cation,while their relative contributions vary between the two sectors of the Arctic Ocean.In the Atlantic sector,turbulent mixing dominated,while in the Pacific sector,turbulent mixing was inhibited by strong stratification prior to 2011,and is able to overcome the stratifi cation gradually after 2014.The vertical turbulent heat fl ux constantly increased in the Atlantic sector year by year,while it decreased in the Pacific sector post 2010.The estimated heat flux variability induced by enhanced turbulent mixing is expected to continue to diminish sea ice in the near future.

DOA and Subarray-Interval Estimation for Arbitrarily Distributed UAV Swarm System

In this paper,DOA and subarray-interval estimation are considered and applied to arbitrarily distributed unmanned aerial vehicle(UAV)swarm system,in which multiple small UAVs containing uniform linear array(ULA)are divided by unknown intervals because of dynamic moving.Three parameters are taken to indicate the steering vector,namely,the direction of arrivals(DOAs)of target users,the intervals of UAVs,and the orientation angles of UAVs.The orientation angles are first estimated with an auxiliary user and the DOAs are obtained through a search free rooting method,despite the intervals among the UAVs.Afterwards,the intervals among UAVs can also be calculated via exhaustive when the number of target users are no less than three.We further develop a low-complex method to reduce the computational complexity during subarray-interval estimation.The deterministic Cramér-Rao bound(CRB)of the DOA,orientation angle and subarray-interval can be inferred in a closed form.Eventually,numerical instances are cited to verify the research results.

一种基于安全标签的单向身份认证技术

短波、超短波等窄带无线通信手段由于通信距离远、应用成本低仍然被广泛使用,针对窄带无线数据通信,提出了一种基于安全标签的单向身份认证技术,在为无线通信过程提供安全防护保障的同时,尽可能小地减少窄带无线信道带宽的占用,并通过实验评估安全认证功能对无线数据传输性能的影响。