Gut microbiota-derived short-chain fatty acids and depression:deep insight into biological mechanisms and potential

The gut microbiota is a complex and dynamic ecosystem known as the second brain'.Composing the microbiota-gut-brain axis,the gut microbiota and its metabolites regulate the central nervous system through neural,endocrine and immune pathways to ensure the normal functioning of the organism,tuning individuals'health and disease status.Short-chain fatty acids(SCFAs),the main bioactive metabolites of the gut microbiota,are involved in several neuropsychiatric disorders,including depression.SCFAs have essential effects on each component of the microbiota-gut-brain axis in depression.In the present review,the roles of major SCFAs(acetate,propionate and butyrate)in the pathophysiology of depression are summarised with respect to chronic cerebral hypoperfusion,neuroinflammation,host epigenome and neuroendocrine alterations.Concluding remarks on the biological mechanisms related to gut microbiota will hopefully address the clinical value of microbiota-related treatments for depression.

基于SQUID传感器的超导单通道磁力仪研制

针对地球物理勘探中高精度磁场信号测量与靶目标大小方位检测难题,本文基于SQUID传感器研制了一种超导单通道磁力仪。首先,介绍了超导磁力仪工作原理,重点设计了其总体结构框架、控制单元、XYZ单元、无磁杜瓦瓶和供电模块;然后,提出了自适应滤波算法用于抑制运动磁场噪声干扰,静磁学逆向求解算法用于反演靶目标大小及方位;最后,采用半径0.2 m的圆铁球和边长5 m的地表立方空洞体进行检测实验,实验结果表明:本文超导磁力仪稳定可靠并满足地下勘探要求。

RIP3/MLKL-mediated neuronal necroptosis induced by methamphetamine at 39℃

Methamphetamine is one of the most prevalent drugs abused in the world.Methamphetamine abusers usually present with hyperpyrexia (39℃),hallucination and other psychiatric symptoms.However,the detailed mechanism underlying its neurotoxic action remains elusive.This study investigated the effects of methamphetamine + 39℃ on primary cortical neurons from the cortex of embryonic Sprague-Dawley rats.Primary cortex neurons were exposed to 1 mM methamphetamine + 39℃.Propidium iodide staining and lactate dehydrogenase release detection showed that methamphetamine + 39℃ triggered obvious necrosis-like death in cultured primary cortical neurons,which could be partially inhibited by receptor-interacting protein-1 (RIP1) inhibitor Necrostatin-1 partially.Western blot assay results showed that there were increases in the expressions of receptor-interacting protein-3 (RIP3) and mixed lineage kinase domain-like protein (MLKL) in the primary cortical neurons treated with 1 mM methamphetamine + 39℃ for 3 hours.After pre-treatment with RIP3 inhibitor GSK’872,propidium iodide staining and lactate dehydrogenase release detection showed that neuronal necrosis rate was significantly decreased;RIP3 and MLKL protein expression significantly decreased.Immunohistochemistry staining results also showed that the expressions of RIP3 and MLKL were up-regulated in brain specimens from humans who had died of methamphetamine abuse.Taken together,the above results suggest that methamphetamine + 39℃ can induce RIP3/MLKL regulated necroptosis,thereby resulting in neurotoxicity.The study protocol was approved by the Medical Ethics Committee of the Third Xiangya Hospital of Central South University,China (approval numbers: 2017-S026 and 2017-S033) on March 7,2017.

武陵山区4种块根类淀粉的糊化特性和冲调性质分析

目的:探究葛根、蕨根、百合、凉薯4种块根类植物淀粉的糊化特性与冲调特性。方法:采用扫描电子显微镜(SEM)、快速黏度分析仪(RVA)、差式量热扫描仪(DSC)等分析淀粉的微观形态和糊化特性;对4种淀粉进行冲泡,并分析淀粉糊的透明度和表观形态等。结果:葛根、蕨根、凉薯淀粉的颗粒形态较为相似,大多为球形;百合淀粉颗粒较大,且形态为纺锤形。糊化特性表明,百合淀粉的峰值黏度最高,为(7.00±0.03) Pa·s;葛根和百合淀粉的回生值较大,表明其易于回生。热力学特性表明,蕨根淀粉的起始糊化温度最低,为59.4℃,表明其容易糊化;百合淀粉的糊化焓值最高,为15.64 J/g,表明其糊化时需要更多的热量。冲调特性表明,葛根淀粉糊的透明度最好,其透光率为29.11%;而百合淀粉糊的透光率仅为12.25%;冲调后,葛根淀粉糊和百合淀粉糊易于形成凝胶,但流动性较差;蕨根淀粉糊和凉薯淀粉糊凝胶能力较差,易于流动。结论:百合淀粉和葛根淀粉的冲调性质相似,具有冲调类食品的开发潜力;蕨根淀粉和凉薯淀粉回生值较低,糊的流动性较好,可用于抑制食品的回生。

SQUID二阶磁梯度计标定系统的空间位置优化

超导量子干涉器件(SQUID)是利用磁通量子化与约瑟夫森效应这两种特性而形成的超导器件,可以分辨极微弱磁场变化,在磁信号灵敏探测方面应用广泛。因此,为确保其输出映射的准确性与使用质量,对使用过程中其进行定期校准至关重要。本文针对SQUID二阶磁梯度计在使用过程中的标定系统优化问题展开讨论,以标定线圈圆心为中心点建立笛卡尔坐标系,固定Y轴方向的相对位置,首先从Z轴方向移动标定线圈找到电流灵敏度最大位置范围,之后进一步精确标定位置,在X轴方向找到对Z轴方向移动最不敏感的相对位置,为标定中可能出现的人为误差提供更大的容错范围。并通过解析模型与有限元仿真模型相互验证,为后续实验提供了理论依据与先行性。利用解析模型与有限元模型及实测数据确定SQUID二阶磁梯度计在使用中的校准系数均为1.107,并对所提出的标定方法所产生的不确定度进行分析,为梯度计在低噪声环境条件下进行标定提供了更大的鲁棒性。

A New Generation of Intelligent Mapping and Remote Sensing Scientific Test Satellite Luojia-301

With the continuous improvement of the performance and the increasing variety of optical mapping and remote sensing satellites,they have become an important support for obtaining global accurate surveying and mapping remote sensing information.At present,optical mapping and remote sensing satellites already have sub-meter spatial resolution capabilities,but there is a serious lag problem in mapping and remote sensing information services.It is urgent to develop intelligent mapping and remote sensing satellites to promote the transformation and upgrading to real-time intelligent services.Firstly,based on the three imaging systems of the optical mapping and remote sensing satellites and their realization methods and application characteristics,this paper analyzes the applicable system of the intelligent mapping and remote sensing satellites.Further,according to the application requirements of real-time,intelligence,and popularization,puts forward the design concept of integrated intelligent remote sensing satellite integrating communication,navigation,and remote sensing and focuses on the service mode and integrated function composition of intelligent remote sensing satellite.Then expounds on the performance and characteristics of the Luojia-301 satellite,a new generation of intelligent surveying and mapping remote sensing scientific test satellite.And finally summarizes and prospects the development and mission of intelligent mapping remote sensing satellites.Luojia-301 satellite integrates remote sensing and communication functions.It explores an efficient and intelligent service mode of mapping and remote sensing information from data acquisition to the application terminal and provides a real service verification platform for on-orbit processing and real-time transmission of remote sensing data based on space-ground internet,which is of great significance to the construction of China’s spatial information network.

基于心磁信号的电流密度分析方法研究

电流密度向量分析是心磁图仪临床应用中的关键诊断技术,其重构与分类效果将直接影响心脏疾病筛查的准确度。研究一种电流密度分析方法,包括电流密度重构逆向算法,并提出一种电流密度自动分类新算法。将该电流密度分析方法应用于27例健康志愿者和75例心肌缺血患者的临床验证:首先,使用四通道心磁图仪SQUID传感器采集36个测量点位心磁信号源数据,采用标准Ⅱ导联心电数据同步化心磁信号源数据;其次,应用基于傅里叶变换的逆向求解算法,重构每例受试者电流密度分布,自动计算3项电流密度分类参数CDI、IPCD、ERT,并通过多元线性回归模型确定自动分类算法中健康组和心肌缺血组的线性判别函数;最后,借助基于KL熵值计算和线性判别函数的自动分类新算法,对重构后的电流密度进行自动分类。结果表明:健康组与心肌缺血组间3项分类参数CDI、IPCD、ERT显著性差异分别为2.0×10^-11、2.7×10^-5和3.0×10^-4;CDI、IPCD、ERT诊断心肌缺血的敏感性分别为73%、81%和60%,特异性分别为100%、65%和73%;自动分类结果的敏感性、真阳性率、特异性、假阳性率和真阴性率分别为89.33%、100%、100%、0%和76.47%。实验说明,所述电流密度分析方法可靠、准确度高,可用于临床心肌缺血诊断。

食管异物252例临床分析

目的探讨食管异物的临床特点及相应的治疗方法。方法收集2010年6月-2018年6月该院收治的252例食管异物患者的临床资料。其中,男114例,女138例,年龄1~87岁,中位年龄52岁。所有患者均有明确的误吞或自食异物病史,并伴有吞咽困难及吞咽疼痛等症状,均行胸部X线、CT或食管钡剂检查以确诊。结果成人异物种类以植物性最多见,枣核为67.06%;其次为动物性,骨头为15.87%。小儿异物绝大部分为硬币,占8.33%。异物停留部位最多为食管上段(93.25%),其次为食管中段,占4.76%,食管下段极其少见。行硬性食管镜取出异物者占绝大多数(92.85%),所有患者中出现严重并发症者13例。结论食管异物为耳鼻咽喉科常见的急诊之一,多见于老年人及儿童,应及时就诊,延误治疗可引起一系列并发症。

Schistosoma japonicum egg antigen up-regulates fibrogenesis and inhibits proliferation in primary hepatic stellate cells in a concentration-dependent manner

AIM:To investigate the effects of different concentrations of Schistosoma japonicum(S.japonicum) egg antigen on fibrogenesis and apoptosis in primary hepatic stellate cells(HSCs).METHODS:A mouse model of schistosomiasis-associated liver fibrosis(SSLF) was established by infecting mice with schistosomal cercaria via the abdomen.HSCs were isolated from SSLF mice by discontinuous density gradient centrifugation,and their identity was confirmed by immunofluorescence double staining of α-smooth muscle actin(α-SMA) and desmin.The growth inhibitory effect and 50% inhibitory concentration(IC50) of S.japonicum egg antigen for primary HSCs(24 h) were determined using a cell counting kit-8(CCK-8) assay.The expression levels of α-SMA,matrix metalloproteinase-9(MMOL/LP-9) and tissue inhibitor of metalloproteinases-1(TIMP-1) in HSCs in response to different concentrations of S.japonicum egg antigen were detected by Western blotting and real-time reverse transcription-polymerase chain reaction.The levels of phospho-P38(P-P38),phospho-Jun N-terminal kinase(P-JNK) and phospho-Akt(P-AKT) in HSCs were detected by Western blotting.RESULTS:An SSLF mouse model was established,and primary HSCs were successfully isolated and cultured.S.japonicum egg antigen inhibited HSC proliferation in a concentration-dependent manner.The IC50 of the S.japonicum egg antigen was 244.53 ± 35.26 μg/mL.S.japonicum egg antigen enhanced α-SMA expression at both the mRNA and protein levels and enhanced TIMP-1 expression at the mRNA level in HSCs(P < 0.05),whereas the expression of MMOL/LP-9 was attenuated at both the mRNA and protein levels in a concentration-dependent manner(P < 0.05).A high concentration of S.japonicum egg antigen enhanced P-P38,P-JNK and P-AKT activation(P < 0.05).The changes in α-SMA and MMOL/LP-9 expression induced by S.japonicum egg antigen were closely correlated with P-P38 and P-JNK activation(P < 0.05).The attenuation of MMOL/LP-9 was also correlated with P-AKT activation(P < 0.05),but the increase in α-SMA expression was not.TIMP-1 expression was not correlated with P-P38,P-JNK or P-AKT activation.CONCLUSION:S.japonicum egg antigen promotes fibrogenesis,activates the P38/JNK mitogen-activated protein kinase and AKT/PI3K signaling pathways and inhibits proliferation in primary HSCs isolated from SSLF mice in a concentration-dependent manner.

What Has Been Neglected in the Green Revolution? Developing Crop Poly-Genotype Varieties for Improving (Intra-Variety) Genetic Diversity in Agriculture

Modern agriculture, based on the improved single-genotype crop varieties and the intensive and monocultural managements, has contributed tremendously to the world’s food supply. However, it is also challenged by stagnant yield growth, increasingly high input, mounting environmental pollution and pressing sustainability of development. In comparison, old agriculture of 100 years ago, based on the traditional multi-genotype landraces and low-input cultivation, prevailed thousands of years and still exists now in subsistence farming in marginal areas in spite of its low productivity. Crop multi-genotype breeding, which combines the advantages of both old and modern agriculture at the high level of productivity, will give us a promising strategy to break the predicament of modern agriculture. The concept, necessity, principle, technical tactics and characteristics of crop multi-genotype breeding are first elucidated in detail here. Two successful cases of application in rice and cotton are presented. Firstly, rice multi-genotype inbred varieties (colony variety) have commercialized using MAGIC lines. In cotton, a multi-genotype hybrid variety Jing-Mi 1 revealed superiority in seeded cotton and lint yields over the check variety in regional trial. Multigenotype variety could be maintained and recover the genetic diversity in production system. In their progenies of the MAGIC lines, most of them could be transmitted to the multi-genotype varieties, implying that the genetic diversity of agro-ecosystem could be effectively restored by crop multi-genotype varieties. We believe crop multi-genotype breeding will make a substantial contribution to restoring genetic diversity of agro-ecosystem, preventing the exacerbation of vulnerable environment and promoting the sustainable development of agriculture. We call for ever-increasing efforts to develop and apply the crop multi-genotype breeding in agriculture.

On-orbit Geometric Calibration of Linear Push-broom Optical Satellite Based on Sparse GCPs

The paper presents a geometric calibration method based on the sparse ground control points (GCPs), aiming to the linear push-broom optical satellite. This method can achieve the optimal estimate of internal and external parameters with two overlapped image pair along the charge-coupled device (CCD), and sparse GCPs in the image region, further get rid of the dependence on the expensive calibration site data. With the calibrated parameters, the line of sight (LOS) of all CCD detectors can be recovered. This paper firstly establishes the rigorous imaging model of linear push-broom optical satellite based on its imaging mechanism. And then the calibration model is constructed by improving the internal sensor model with a viewing-angle model after an analysis on systematic errors existing in the imaging model is performed. A step-wise solution is applied aiming to the optimal estimate of external and internal parameters. At last, we conduct a set of experiments on the ZY-3 NAD camera and verify the accuracy and effectiveness of the presented method by comparison.

Stream-computing of High Accuracy On-board Real-time Cloud Detection for High Resolution Optical Satellite Imagery

This paper focuses on the time efficiency for machine vision and intelligent photogrammetry, especially high accuracy on-board real-time cloud detection method. With the development of technology, the data acquisition ability is growing continuously and the volume of raw data is increasing explosively. Meanwhile, because of the higher requirement of data accuracy, the computation load is also becoming heavier. This situation makes time efficiency extremely important. Moreover, the cloud cover rate of optical satellite imagery is up to approximately 50%, which is seriously restricting the applications of on-board intelligent photogrammetry services. To meet the on-board cloud detection requirements and offer valid input data to subsequent processing, this paper presents a stream-computing of high accuracy on-board real-time cloud detection solution which follows the “bottom-up” understanding strategy of machine vision and uses multiple embedded GPU with significant potential to be applied on-board. Without external memory, the data parallel pipeline system based on multiple processing modules of this solution could afford the “stream-in, processing, stream-out” real-time stream computing. In experiments, images of GF-2 satellite are used to validate the accuracy and performance of this approach, and the experimental results show that this solution could not only bring up cloud detection accuracy, but also match the on-board real-time processing requirements.

Somatostatin-Positive Neurons in the Rostral Zona Incerta Modulate Innate Fear-Induced Defensive Response in Mice

Defensive behaviors induced by innate fear or Pavlovian fear conditioning are crucial for animals to avoid threats and ensure survival.The zona incerta(ZI)has been demonstrated to play important roles in fear learning and fear memory,as well as modulating auditory-induced innate defensive behavior.However,whether the neuronal subtypes in the ZI and specific circuits can mediate the innate fear response is largely unknown.Here,we found that somatostatin(SST)-positive neurons in the rostral ZI of mice were activated by a visual innate fear stimulus.Optogenetic inhibition of SST-positive neurons in the rostral ZI resulted in reduced flight responses to an overhead looming stimulus.Optogenetic activation of SST-positive neurons in the rostral ZI induced fear-like defensive behavior including increased immobility and bradycardia.In addition,we demonstrated that manipulation of the GABAergic projections from SST-positive neurons in the rostral ZI to the downstream nucleus reuniens(Re)mediated fear-like defensive behavior.Retrograde trans-synaptic tracing also revealed looming stimulus-activated neurons in the superior colliculus(SC)that projected to the Re-projecting SST-positive neurons in the rostral ZI(SC-ZIrSST-Re pathway).Together,our study elucidates the function of SST-positive neurons in the rostral ZI and the SC-ZIrSST-Re tri-synaptic circuit in mediating the innate fear response.

Biologically inspired anthraquinone redox centers and biomass graphene for renewable colloidal gels toward ultrahigh-performance flexible micro-supercapacitors

Biomass carbon and small redox biomolecules are attractive materials for green,sustainable energy storage devices owing to their environmentally friendly,low-cost,scalable,and novel sources.However,most devices manufactured using these materials have low specific capacitance,poor cycle stability,short lifetime,complexity,and low precision of device fabrication.Herein,we report the directed self-assembly of mononuclear anthraquinone(MAQ)derivatives and porous lignin-based graphene oxide(PLGO)into a renewable colloidal gel through noncovalent interactions.These self-assembled gel electrode materials exhibited high capacitance(484.8 F g^(−1) at a current density of 1 A g^(−1))and could be further printed as flexible micro-supercapacitors(FMSCs)with arbitrary patterns and a relatively high resolution on specific substrates.The FMSCs exhibited excellent areal capacitance(43.6 mF cm^(−2)),energy and power densities(6.1μWh cm^(−2) and 50μW cm^(−2),respectively),and cycle stability(>10,000 cycles).Furthermore,the printed FMSCs and integrated FMSC arrays exhibited remarkable flexibility while maintaining a stable capacitance.The proposed approach can be applied to other quinone biomolecules and biomass-based carbon materials.This study provides a basis for fabricating green and sustainable energy storage device architectures with high capacitance,long-term cycling,high scalability,and high precision.

Experimental tomographic methods for analysing flow dynamics of gas-oil- water flows in horizontal pipeline

Gas-oil-water three phase flow is of practical significance in oil and gas industries. An insight into the dynamics of such multiphase flows is significantly valuable to obtain optimal design parameters and operational conditions. Since flow patterns are sensitive to pipe geometry, flow conditions and thermophysical properties of fluid, it is extremely challenging to provide a universal solution for visualisation of three phase horizontal flows. This study deals with a fully developed, turbulent three phase flow and presents the outcomes of electrical tomographic imaging techniques to visualise gas-oil-water flows in a horizontal pipeline.

Experimental and Numerical Investigation on Strain Rate-Dependent Tensile Behavior of ZrB2–SiC Ceramic Composite

In this study,the strain rate-dependent dynamic tensile behavior of ZrB2-20%SiC ceramic composite was investigated using experimental and numerical approaches.The split Hopkinson pressure bar apparatus was used to measure the dynamic splitting tensile response at strain rates of 17-67 s^(−1).The experiment results demonstrate a significant strain rate dependence of the dynamic tensile behavior of the ZrB2-SiC ceramic composite.The dynamic tensile strength increased linearly with the strain rate,from 288 MPa at 17 s^(−1)to 654 MPa at 67 s^(−1).Moreover,a strain rate-dependent tensile strength was introduced into a modified JH-2 model to describe the dynamic tensile behavior and fracture process of ZrB2-SiC ceramics.The numerical results of dynamic tensile strength agree well with the experimental result.Moreover,the fracture process of ZrB2-SiC ceramics under dynamic tension was further studied by combining high-speed images and numerical results.The effect of strain rate on the fracture process and failure patterns of the ZrB2-SiC ceramic composite could be verified by the modified JH-2 model.

超导磁梯度张量探头结构优化方法研究

针对传统超导磁梯度张量探头中多个磁梯度计间的噪声互扰会降低系统灵敏度的问题,本文提出了一种基于二维傅里叶变换的磁梯度张量探头结构优化方法。通过二维傅里叶变换及逆变换将磁场矢量Z分量沿着Z轴方向的二阶空间导数Bzzz转换为磁场矢量的3个分量以及一阶磁梯度张量的5个独立元素,把通常至少需要6个SQUID一阶平面磁梯度计的探头结构简化为只需要1个二阶SQUID磁梯度计的探头结构,消除了磁梯度计之间的噪声干扰,系统灵敏度提高了1个数量级。实验结果表明该探头具有良好的探测能力,证明了这种优化方法的可行性。

糖尿病患者功能失调性态度与焦虑抑郁的关系分析

目的:探讨糖尿病患者功能失调性态度与焦虑、抑郁状况,并分析功能失调性态度与焦虑、抑郁的关系.方法:于2022年4月8-23日对湖南省15家医院的糖尿病住院患者,使用功能失调态度量表(DAS)、广泛性焦虑自评量表(GAD-7)和患者健康问卷抑郁症状群量表(PHQ-9),通过"问卷星"进行线上问卷调查;采用Pearson相关分析了解功能失调性态度与焦虑和抑郁相关性.结果:534例糖尿病患者中43.8%有抑郁情绪,34.1%存在焦虑问题;糖尿病患者的DAS总分为(130.20±30.83)分;DAS与GAD-7(r=0.498,P<0.01)、PHQ-9(r=0.516,P<0.01)评分均呈正相关.结论:糖尿病患者功能失调性态度处于低水平,功能失调性态度与焦虑、抑郁呈正相关;临床医务人员应对肥胖、情绪不良的糖尿病患者进行评估,并有针对性的对其加强健康教育及相关心理干预,以尽可能改善患者功能失调性态度水平及不良情绪,提高患者的生活质量.

基于SQUID磁梯度仪的金属未爆炸物探测方法研究

安全、准确又快速地探测金属未爆炸物是一个全球安全治理难题。磁法是当前未爆炸物探测的一个主要手段,超导量子干涉器(SQUID)作为新兴的磁探测设备具有巨大潜力。SQUID磁梯度的基本特点是灵敏度极高、噪声低,在弱磁场探测领域发挥重要作用。作者提出将SQUID应用于金属未爆炸物探测领域的方法,通过SQUID磁梯度仪样机对未爆炸物模型的测量实验和仿真计算,得出其测量结果准确可靠且反演结果与实验设置吻合,初步验证了SQUID应用于金属未爆炸物探测领域的可行性和研究价值。

China’s high-resolution optical remote sensing satellites and their mapping applications

Since the beginning of the twenty-first century,several countries have made great efforts to develop space remote sensing for building a high-resolution earth observation system.Under the great attention of the government and the guidance of the major scientific and technological project of the high-resolution earth observation system,China has made continuous breakthroughs and progress in high-resolution remote sensing imaging technology.The development of domestic high-resolution remote sensing satellites shows a vigorous trend,and consequently,a relatively stable and perfect high-resolution earth observation system has been formed.The development of high-resolution remote sensing satellites has greatly promoted and enriched modern mapping technologies and methods.In this paper,the development status,along with mapping modes and applications of China’s high-resolution remote sensing satellites are reviewed,and the development trend in high-resolution earth observation system for global and ground control-free mapping is discussed,providing a reference for the subsequent development of high-resolution remote sensing satellites in China.