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臭腹腺蝗肠道中共存的淀粉和纤维素消化酶的纯化、动力学和抑制研究(英文)

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昆虫学报 2015年第7期58卷 739-749页

作者： Tolulope Felix ADEDIRAN isaac olusanjo adewale Department of Biochemistry Obafemi Awolowo University

【目的】本研究旨在了解臭腹腺蝗Zonocerus variegatus中碳水化合物的消化。【方法】依次通过CM-Sepharose CL-6B阳离子交换、QAE Sephadex A-50阴离子交换以及Sephadex G-100凝胶过滤,对臭腹腺蝗中肠的酶粗提取液(其中α-淀粉酶和纤维... 详细信息

【目的】本研究旨在了解臭腹腺蝗Zonocerus variegatus中碳水化合物的消化。【方法】依次通过CM-Sepharose CL-6B阳离子交换、QAE Sephadex A-50阴离子交换以及Sephadex G-100凝胶过滤,对臭腹腺蝗中肠的酶粗提取液(其中α-淀粉酶和纤维素酶的比活性分别为283±1.72 U/mg和17±0.83 U/mg)进行了纯化。最后通过层析将共存的酶分离成α-淀粉酶和纤维素酶。【结果】这两种酶都是单体,α-淀粉酶分子量为38 k Da,纤维素酶分子量为21 k Da。α-淀粉酶对淀粉的Km值为13.8±1.29 mg/m L,Vmax为3 883±52.25 U/mg pro;而纤维素酶对羧甲基纤维素底物的Km值为5.03±0.57 mg/m L,Vmax为433.00±5.24 U/mg pro。臭腹腺蝗α-淀粉酶能以不同的效率水解原淀粉,纤维素酶也能不同程度水解各种纤维材料。α-淀粉酶的水解活性在p H 6和40℃下最高,而纤维素酶的水解高活性在p H 9和45℃下最高。【结论】从番木瓜Carica papaya种子中分离到蛋白类抑制剂,发现它们是这两种酶的有效抑制剂,说明这些蛋白抑制剂(Cp AI和Cp CI)如果在害虫取食的作物上过量表达,则可能有利于害虫防治。尽管纤维类和淀粉类物质可能都显著提供该害虫的能量需求,但是动力学分析表明臭腹腺蝗更偏向于淀粉类食物。

关键词：臭腹腺蝗 α-淀粉酶纤维素酶消化酶纯化蛋白类抑制剂

Classifying rockburst with confidence:A novel conformal prediction approach

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International Journal of Mining Science and Technology 2024年第1期34卷 51-64页

作者： Bemah Ibrahim isaac Ahenkorah University of South Australia UniSA STEMSA 5000Australia

The scientific community recognizes the seriousness of rockbursts and the need for effective mitigation *** literature reports various successful applications of machine learning(ML)models for rockburst assessment;however,a significant question remains unanswered:How reliable are these models,and at what confidence level are classifications made?Typically,ML models output single rockburst grade even in the face of intricate and out-of-distribution samples,without any associated confidence *** the susceptibility of ML models to errors,it becomes imperative to quantify their uncertainty to prevent consequential *** address this issue,we propose a conformal prediction(CP)framework built on traditional ML models(extreme gradient boosting and random forest)to generate valid classifications of rockburst while producing a measure of confidence for its *** proposed framework guarantees marginal coverage and,in most cases,conditional coverage on the test *** CP was evaluated on a rockburst case in the Sanshandao Gold Mine in China,where it achieved high coverage and efficiency at applicable confidence ***,the CP identified several“confident”classifications from the traditional ML model as unreliable,necessitating expert verification for informed *** proposed framework improves the reliability and accuracy of rockburst assessments,with the potential to bolster user confidence.

关键词： Rockburst Machine learning Uncertainty quantification Conformal prediction

Effect of functional composite coating developed via sulphate and chloride process parameter on the UNS G10150 steel for structural and wear mitigation in defence application

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Defence Technology（防务技术） 2018年第3期14卷 196-203页

作者： Ojo Sunday isaac Fayomi Department of Mechanical Engineering Covenant University Department of Chemical Metallurgical and Materials Engineering Tshwane University of Technology

The major engineering challenge of materials in defence technologies is the vulnerability of based metals to structural and wears deformation in service. In this paper, structural formation, mechanical and thermal stability behavior of developed composite coating of Zn-30 Al-7%Ti/Sn chloride bath and Zn-30 Al-7%Ti/Sn sulphate bath was investigated and compared to provide mitigation against failure. The thermal ageing property was done for 2 h at 600C via isothermal furnace. The structural, interfacial effect and stability behaviors of the co-deposited alloys were evaluated using scanning electron microscope equipped with energy dispersive spectrometer(SEM/EDS), atomic force microscope(AFM) and Xray diffractometer(XRD). The hardness and wear properties of the deposited coatings were examined with diamond base micro-hardness tester and reciprocating sliding tester respectively. The result shows that Zn-30 Al-7%Ti/Sn sulphate co-deposition contributed to increase hardness and wear resistance than Zn-30 Al-7%Ti/Sn chloride bath alloy. The stable crystal growth and significant performance of Zn-30 Al-7%Ti/Sn sulphate are link to the intermetallic phase hybrid of Zn Al, Zn4 Ti Al2, Zn3 Al Ti. Besides, it was observed that Zn-30 Al-7%Ti/Sn sulphate has excellent thermomechanical stability at harsh temperature,due to the deposition of Sn/Ti on steel; leading to formation of super-hard interface. However, it was established that co-deposition of mild steel with Zn-30 Al-7%Ti/Sn in sulphate bath significantly improved the structural and wear performance. It was shown that the hardness and wear of the developed composite Zn-30 Al-7%Ti/Sn is increased by about 80% compared to as received sample and about 25% compared with Zn-30 Al-7%Ti/Sn chloride coating developed. The improvement was proved to be an interference of zinc-composite growth. Thus, this work shows that sulphate induced Zn-30 Al-7%Ti/Sn via generation of controllable process parameter can provide significant improv

关键词：防卫技术硫酸盐氯化物低碳钢结构涂层合成 UNS

HyDeploy:The UK’s First Hydrogen Blending Deployment Project

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Clean Energy 2019年第2期3卷 114-125页

作者： Tommy isaac Principal Engineer Progressive Energy LtdSwan House-Bonds MillsStonehouseGloucestershire GL103RFUK

The HyDeploy project is the UK’s first practical project to demonstrate that hydrogen can be safely blended into the natural-gas distribution system without requiring changes to appliances and the associated *** project is funded under Ofgem’s Network Innovation Competition and is a collaboration between Cadent Gas,Northern Gas Networks,Progressive Energy Ltd,Keele University(Keele),Health&Safety Laboratory and ITM *** and Northern Gas Networks are the Gas Distribution Network sponsors of the *** University is the host site,providing the gas-distribution network,which will receive the hydrogen *** University is the largest campus university in the ***&Safety Laboratory provides the scientific laboratories and experimental *** Power provides the electrolyser that produces the *** Energy Ltd is the project developer and project *** is structured into three distinct *** first is an extensive technical programme to establish the necessary detailed evidence base in support of an application to the Health&Safety Executive for Exemption to Schedule 3 of the Gas Safety(Management)Regulations(GS(M)R)to permit the injection of hydrogen at 20 mol%.This is required to allow hydrogen to be blended into a natural-gas supply above the current British limit of 0.1 mol%.The second phase comprises the construction of the electrolyser and grid entry unit,along with the necessary piping and valves,to allow hydrogen to be mixed and injected into the Keele University gas-distribution network and to ensure all necessary training of operatives is conducted before *** third phase is the trial itself,which is due to start in the summer of 2019 and last around 10 *** trial phase also provides an opportunity to undertake further experimental activities related to the operational network to support the pathway to full deployment of blended *** outcome of HyDeploy is principally develo

关键词： HyDeploy hydrogen blending demonstration project

Design for a specified natural frequency of elastically constrained axially graded bars

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Acta Mechanica Sinica 2010年第2期26卷 313-316页

作者： isaac Elishakoff Jason Yost Department of Mechanical Engineering Florida Atlantic University

This study derives some closed-form analytic as well as numeric solutions for the axially graded elasticallyconstrained bar with polynomial varying modulus of elasticity, along the axial coordinate. The solutions allo... 详细信息

关键词： Graded bars Vibration Natural frequency

Lipopolysaccharide mouse models for Parkinson's disease research:a critical appraisal

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Neural Regeneration Research 2022年第11期17卷 2413-2417页

作者： isaac Deng Larisa Bobrovskaya Health and Biomedical Innovation Clinical and Health SciencesUniversity of South AustraliaAdelaideAustralia

Parkinson's disease,the most common movement disorder,has a strong neuroinflammatory *** is evident by increased pro-inflammatory cytokines in the serum,and the presence of activated microglial cells,and inflammatory cytokines in the substantia nigra of post-mortem brains as well as cerebrospinal fluid of Parkinson's disease *** central and peripheral neuroinflammatory aspects of Parkinson's disease can be investigated in vivo via administration of the inflammagen lipopolysaccharide,a component of the cell wall of gram-negative *** this mini-review,we will critically evaluate different routes of lipopolysaccharide administration(including intranasal systemic and ste reotasic),their relevance to clinical Parkinson's disease as well as the recent findings in lipopolysaccharide mouse *** will also share our own expe riences with systemic and intrastriatal lipopolysaccharide models in C57BL/6 mice and will discuss the usefulness of lipopolysaccharide mouse models for future research in the field.

关键词： C57BL/6 mice intranasal models lipopolysaccharide models neuroinflammation Parkinson's disease stereotaxic models substantia nigra systemic models

Infection,Pain,and Itch

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Neuroscience Bulletin 2018年第1期34卷 109-119页

作者： isaac M.Chiu Department of Microbiology and Immunobiology Division of Immunology Harvard Medical School

Pain and itch are unpleasant sensations that often accompany infections caused by viral, bacterial, parasitic, and fungal pathogens. Recent studies show that sensory neurons are able to directly detect pathogens to mediate pain and itch. Nociceptor and pruriceptor neurons respond to pathogen-associated molecular patterns, including Toll-like receptor ligands, N-formyl peptides, and bacterial toxins. Other pathogens are able to silence neuronal activity to produce analgesia during infection. Pain and itch could lead to neuronal modulation of the immune system or behavioral avoidance of future patho- gen exposure. Conversely, pathogens could modulate neuronal signaling to potentiate their pathogenesis and facilitate their spread to other hosts. Defining how pathogens modulate pain and itch has critical implications for sensory neurobiology and our understanding of host- microbe interactions.

关键词： Pain Itch Bacteria Pathogens Infection Inflammation Viruses

Seeing invisible objects with intelligent optics isaacNape&AndrewForbes

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Light(Science & Applications) 2024年第10期13卷 1995-1996页

作者： isaac Nape Andrew Forbes School of Physics University of the WitwatersrandJohannesburgSouth Africa

Transparent objects are invisible to traditional cameras because they can only detect intensity fluctuations,necessitating the need for interferometry followed by computationally intensive digital image *** it is shown that the necessary transformations can be performed optically by combining machine learning and diffractive optics,for a direct in-situ measurement of transparent objects with conventional cameras.

关键词： optics visible interferometry

Modulation of mitochondrial bioenergetics as a therapeutic strategy in Alzheimer＇s disease

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Neural Regeneration Research 2018年第1期13卷 19-25页

作者： isaac G. Onyango Gertcia Biotechnology Charlottesville VA USA

Alzheimer’s disease （AD） is an increasingly pressing worldwide public-health, social, political and economic concern. Despite significant investment in multiple traditional therapeutic strategies that have achieved success in preclinical models addressing the pathological hallmarks of the disease, these efforts have not translated into any effective disease-modifying therapies. This could be because interventions are being tested too late in the disease process. While existing therapies provide symptomatic and clinical benefit, they do not fully address the molecular abnormalities that occur in AD neurons. The pathophysiology of AD is complex; mitochondrial bioenergetic deficits and brain hypometabolism coupled with increased mitochondrial oxidative stress are antecedent and potentially play a causal role in the disease pathogenesis. Dysfunctional mitochondria accumulate from the combination of impaired mitophagy, which can also induce injurious inflammatory responses, and inadequate neuronal mitochondrial biogenesis. Altering the metabolic capacity of the brain by modulating/potentiating its mitochondrial bioenergetics may be a strategy for disease prevention and treatment. We present insights into the mechanisms of mitochondrial dysfunction in AD brain as well as an overview of emerging treatments with the potential to prevent, delay or reverse the neurodegenerative process by targeting mitochondria.

关键词： Alzheimer's disease mitochondria bioenergetics mitochondrial DNA neuroinflammation mitohormesis caloric restriction hypometabolism mitophagy mitochondrial biogenesis recombinant-human mitochondrial transcription factor A antioxidants proteasome mitochondrial transcription activator-like effector nucleases clustered regularly interspaced short palindromic repeats/associated protein 9 (CRISPR/Cas9) caloric restriction stem cells