139 research outputs found

    Dual Clustering Co-teaching with Consistent Sample Mining for Unsupervised Person Re-Identification

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    In unsupervised person Re-ID, peer-teaching strategy leveraging two networks to facilitate training has been proven to be an effective method to deal with the pseudo label noise. However, training two networks with a set of noisy pseudo labels reduces the complementarity of the two networks and results in label noise accumulation. To handle this issue, this paper proposes a novel Dual Clustering Co-teaching (DCCT) approach. DCCT mainly exploits the features extracted by two networks to generate two sets of pseudo labels separately by clustering with different parameters. Each network is trained with the pseudo labels generated by its peer network, which can increase the complementarity of the two networks to reduce the impact of noises. Furthermore, we propose dual clustering with dynamic parameters (DCDP) to make the network adaptive and robust to dynamically changing clustering parameters. Moreover, Consistent Sample Mining (CSM) is proposed to find the samples with unchanged pseudo labels during training for potential noisy sample removal. Extensive experiments demonstrate the effectiveness of the proposed method, which outperforms the state-of-the-art unsupervised person Re-ID methods by a considerable margin and surpasses most methods utilizing camera information

    IMECE2010-40121 The Entropy Analysis on NH 3 /CO 2 Cascade Refrigeration Cycle

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    ABSTRACT This paper introduces a cascade refrigeration cycle that uses natural refrigerants of CO 2 and NH 3 at low temperature. It introduces the character of CO 2 and NH 3 , besides analyzes the cascade refrigeration cycle. The optimal intermediate temperature of NH 3 /CO 2 cascade refrigeration cycle is determined by the entropy production minimization method.We analyze the four processes entropy production in both CO 2 cycle(LT side)and NH 3 cycle(HT side) and research how the total entropy production changes in the conditions of different T 0 ,different T CL and different △T. We also find that in order to enhance the efficiency of NH 3 /CO 2 cascade refrigeration cycle,it is necessary to reduce △T. It can be concluded that NH 3 /CO 2 cascade refrigeration cycle has a good future

    Dissecting the causal relationship between neuroticism and osteoarthritis: a univariable and multivariable Mendelian randomization study

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    BackgroundMental health has been found to be associated with risk of osteoarthritis (OA), but the causal relationship was not fully clarified.MethodsTwo-sample Mendelian randomization (MR) study was conducted to investigate the causal relationship between neuroticism (n = 329,821) and the two most frequently affected parts of osteoarthritis (OA) (knee OA: case/control =24,955/378,169; hip OA: case/control = 15,704/378,169) using large scale summary genome-wide association study (GWAS) data. Inverse variance weighted (IVW), weighted median, and MR-Egger were used to estimate the causal effects. Multiple sensitivity analyses were conducted to examine the robustness of the causal estimates. Multivariable MR analysis was used to estimate the direct effects of neuroticism on OA after accounting for the other OA risk factors. Two-step MR approach was employed to explore the potential mediators of the causal relationship.ResultsUnivariable MR analysis indicated that 1-SD increase in genetically predicted neuroticism score was associated with an increased risk of knee OA (IVW: OR, 1.17; 95% CI, 1.087–1.26; p = 2.72E−05) but not with hip OA. The causal effects remained significant after accounting for the effects of BMI, alcohol drinking, and vigorous physical activity but were attenuated with adjustment of smoking. Further mediation analysis revealed that smoking initiation mediated a significant proportion of the causal effects of neuroticism on knee OA (proportion of mediation effects in total effects: 22.3%; 95% CI, 5.9%–38.6%; p = 7.60E−03).ConclusionsNeuroticism has significant causal effects on knee OA risk. Smoking might partly mediate the causal relationship. Further studies were warranted to explore the underlying mechanisms and potential use of neuroticism management for OA treatment

    A T7 exonuclease-assisted cyclic enzymatic amplification method coupled with rolling circle amplification: a dual-amplification strategy for sensitive and selective microRNA detection

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    National Basic Research Program of China [2010CB732402, 2013CB933703]; National Science Foundation of China [21205100, 21275122, 21075104]; National Instrumentation Program [2011YQ03012412]; Fundamental Research Funds for the Central Universities [2012121025]; Natural Science Foundation of Fujian Province for Distinguished Young Scholars [2010J06004]A T7 exonuclease-assisted cyclic enzymatic amplification method (CEAM) was combined with rolling circle amplification (RCA) to develop a RCA-CEAM dual amplification method for ultrasensitive detection of microRNA with excellent selectivity

    High-Efficiency Amorphous Silicon Solar Cell on a Periodic Nanocone Back Reflector

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    An amorphous silicon solar cell on a periodic nanocone back reflector with a high 9.7% initial conversion efficiency is presented. The optimized back-reflector morphology provides powerful light trapping and enables excellent electrical cell performance. Up-scaling to industrial production of large-area modules should be possible using nanoimprint lithography

    Hydrogeochemical processes of groundwater system and its mining-motivated effect in mining areas of Western China

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    The exploitation of coal resources will destroy the aquifer structure, disturb the groundwater system and produce a new water cycle model. As the focus of coal supply and production, the western mining area is short of water resources and fragile in ecology. High-intensity and large-scale mining aggravates this disturbance and makes the hydrochemical process such as water-rock interaction more intense. The coal mining-motivated effect of groundwater system hydrochemistry behind it is a key scientific problem related to the prediction accuracy of coal mine safety mining and the protection of groundwater environment in green mining. In view of this, taking the Caojiatan coal mine in western Yushen mining area as an example, using the principles and methods of hydrogeochemistry, from the perspective of ‘what it is’, ‘why it is’ and ‘how it changes’, the results of mining-motivated effect, the process of mining-motivated effect, and the evolution trend of hydrochemistry are systematically studied. The results show that the groundwater in the study area can be divided into five clusters. Cluster Ⅰ represents the shallow groundwater dominated by Quaternary and weathered bedrock aquifers in the west wing of the mine field after coal mining. Cluster Ⅱ represents the mixing of groundwater before and after mining. Cluster Ⅲ represents the groundwater before mining. Cluster Ⅳ and Cluster Ⅴ mainly represent the groundwater of Yan’an Formation after mining. After coal mining, the proportion of HCO3–Ca and HCO3–Mg in the groundwater samples of the fourth and fifth sections of Zhiluo Formation and Yan’an Formation increased, the shallow groundwater quality after mining in the west wing of the mine field was the best as a whole, and the water quality of each aquifer has a tendency to evolve well and is not sensitive to the response of coal mining. The groundwater in the study area is controlled by the ion exchange, and the groundwater in the fourth and above aquifers of Yan’an Formation before coal mining is controlled by the dissolution of carbonate and silicate rocks. The shallow groundwater in the west wing of the mine field after coal mining is controlled by the dissolution of carbonate rocks. The groundwater in the aquifers of the Zhiluo Formation and the fourth and fifth sections of the Yan’an Formation is mainly controlled by the dissolution of silicate rocks and the oxidation of FeS2. The groundwater in the aquifers of the third and lower sections of the Yan’an Formation is mainly controlled by the dissolution of evaporated salt. Coal mining accelerates the circulation speed of groundwater and the hydraulic connection between aquifers. The resulting dilution effect and the discharge measures after mine water treatment are the reasons for the hydrochemical characteristics and water quality evolution of the aquifers in the fourth section of Yan'an Formation and above. In the future, we should continue to do a good job in the discharge of mine water after treatment, and pay attention to the trend of groundwater characteristics in the fifth section of Zhiluo Formation and Yan’an Formation evolving to shallow groundwater, so as to avoid misjudgment of the results of water inrush sources

    Discovery and structural characterization of a therapeutic antibody against coxsackievirus A10

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    9月20日,《科学》子刊《科学•进展》(Science Advances)刊出了我校夏宁邵教授团队发表的题为“Discovery and structural characterization of a therapeutic antibody against coxsackievirus A10”的研究论文。该研究首次发现手足口病重要病原体柯萨奇病毒A组10型(CVA10)不同类型病毒颗粒共有的优势中和表位,揭示了病毒颗粒及其与优势中和抗体复合物的精确三维结构,阐明了中和抗体的功能与作用机制,为新型疫苗和治疗药物的研制提供了重要的理论基础。 该研究首次揭示并描绘了CVA10的病毒颗粒及其优势中和表位的精确特征,发现了具有良好应用潜能的治疗性中和抗体,为新型疫苗和特异性治疗药物的研究提供了关键基础。 我校夏宁邵教授、程通副教授和美国加州大学洛杉矶分校纳米系统研究所Z. Hong Zhou(周正洪)教授、美国加州大学圣地亚哥分校颜晓东博士为该论文的共同通讯作者。我校博士生朱瑞、徐龙发博士后、郑清炳工程师、李少伟教授和美国加州大学洛杉矶分校崔彦祥博士后为该论文共同第一作者。【Abstract】Coxsackievirus A10 (CVA10) recently emerged as a major pathogen of hand, foot, and mouth disease and herpangina in children worldwide, and lack of a vaccine or a cure against CVA10 infections has made therapeutic antibody identification a public health priority. By targeting a local isolate, CVA10-FJ-01, we obtained a potent antibody, 2G8, against all three capsid forms of CVA10. We show that 2G8 exhibited both 100% preventive and 100% therapeutic efficacy against CVA10 infection in mice. Comparisons of the near-atomic cryo–electron microscopy structures of the three forms of CVA10 capsid and their complexes with 2G8 Fab reveal that a single Fab binds a border region across the three capsid proteins (VP1 to VP3) and explain 2G8’s remarkable cross-reactivities against all three capsid forms. The atomic structures of this first neutralizing antibody of CVA10 should inform strategies for designing vaccines and therapeutics against CVA10 infections.This work was supported by grants from the National Science and Technology Major Projects for Major New Drugs Innovation and Development (2018ZX09711003-005-003), the National Science and Technology Major Project of Infectious Diseases (2017ZX10304402-002-003), the National Natural Science Foundation of China (31670933 and 81801646), and the National Institutes of Health (R37-GM33050, GM071940, DE025567, and AI094386). We acknowledge the use of instruments at the Electron Imaging Center for Nanomachines supported by the University of California, Los Angeles and by instrumentation grants from NIH (1S10RR23057 and 1U24GM116792) and NSF (DBI-1338135 and DMR-1548924). 该研究获得了国家自然科学基金、新药创制国家科技重大专项、传染病防治国家科技重大专项和美国国立卫生研究院基金的资助

    Fructose-1,6-bisphosphate and aldolase mediate glucose sensing by AMPK

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    葡萄糖是生物中最基本、最主要的营养物质,它不仅是机体能量的主要来源,也是生物质合成的主要原料。因此,葡萄糖的水平对于生物体是极其重要的。然而,在生活中,体内葡萄糖水平的波动是十分常见的,这是因为我们不可能每时每刻都在摄入葡萄糖:睡一大觉、剧烈运动几个小时或者太忙了没时间吃饭,都会引起葡萄糖水平的显著下降。这时,机体能够触发一套有效的过程应对这类“不利情况”,其中最为关键的就是激活“代谢的核心调节”——AMPK。在葡萄糖水平下降时,被激活的AMPK能够迅速启动脂肪、蛋白质的分解代谢,关闭它们的合成代谢,从而起到维持机体的能量和物质代谢的平衡,弥补机体因葡萄糖不足引起的胁迫压力。那么,机体如何感受葡萄糖水平下降,并“传递”给AMPK使其激活呢?林圣彩教授课题组的这项研究正是发现了生理状态下机体感受葡萄糖水平的机制。通过研究他们发现,无论在不含葡萄糖的细胞培养条件下,还是在饥饿的低血糖的动物体内,都不能观测到AMP水平的上升,这充分说明了机体有一套尚不为人知的、独立于AMP的感应葡萄糖水平的机制。在进一步的研究中他们揭示了这一完整过程:葡萄糖水平下降将引起的葡萄糖代谢中间物——果糖1,6-二磷酸(fructose-1,6-bisphosphate)水平的下降,该过程进一步地被糖酵解通路上的代谢酶——醛缩酶(aldolase)感应,因为醛缩酶正是将含有6个碳原子的果糖1,6-二磷酸裂解成三碳糖的酶,一旦醛缩酶“吃不到”由葡萄糖衍生的果糖1,6-二磷酸,它便“翻脸”,传递给也正是林圣彩教授课题组先前发现的溶酶体途径进而激活AMPK。该过程完全不涉及AMP水平,即能量水平的变化,是一条全新的、完全建立在实际的生理情况上的通路。林圣彩教授进一步地把葡萄糖水平总结为一种“状态信号”,以区别于传统的“能量信号”。据悉,该葡萄糖感知通路的发现对开发用于治疗肥胖症,乃至延长寿命的药物具有深远的意义。【Abstract】The major energy source for most cells is glucose, from which ATP is generated via glycolysis and/or oxidative metabolism. Glucose deprivation activates AMP-activated protein kinase (AMPK)1, but it is unclear whether this activation occurs solely via changes in AMP or ADP, the classical activators of AMPK2, 3, 4, 5. Here, we describe an AMP/ADP-independent mechanism that triggers AMPK activation by sensing the absence of fructose-1,6-bisphosphate (FBP), with AMPK being progressively activated as extracellular glucose and intracellular FBP decrease. When unoccupied by FBP, aldolases promote the formation of a lysosomal complex containing at least v-ATPase, ragulator, axin, liver kinase B1 (LKB1) and AMPK, which has previously been shown to be required for AMPK activation6, 7. Knockdown of aldolases activates AMPK even in cells with abundant glucose, whereas the catalysis-defective D34S aldolase mutant, which still binds FBP, blocks AMPK activation. Cell-free reconstitution assays show that addition of FBP disrupts the association of axin and LKB1 with v-ATPase and ragulator. Importantly, in some cell types AMP/ATP and ADP/ATP ratios remain unchanged during acute glucose starvation, and intact AMP-binding sites on AMPK are not required for AMPK activation. These results establish that aldolase, as well as being a glycolytic enzyme, is a sensor of glucose availability that regulates AMPK.D.G.H. was supported by an Investigator Award from the Wellcome Trust (097726) and a Programme Grant from Cancer Research UK (C37030/A15101). S.-C.L. was supported by grants from the National Key Research and Development Project of China (2016YFA0502001) and the National Natural Science Foundation of China (#31430094, #31690101, #31571214, #31601152 and #J1310027)
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