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Affinity-induced covalent protein-protein ligation via the SpyCatcherSpyTag interaction

Green Carbon 2023年第1期1卷 33-42页

作者： Jacob O.Fierer omar e.tovar-herrera Jonathan Y.Weinstein Amaranta Kahn Sarah Moraïs Itzhak Mizrahi edward A.Bayer Department of Biomolecular Sciences the Weizmann Institute of ScienceRehovot 7610001Israel Department of Life Sciences Ben-Gurion University of the NegevBeer Sheva 84105Israel National Institute of Biotechnology in the Negev Ben-Gurion University of the NegevBe’er Sheva 84105Israel The Goldman Sonnenfeldt School of Sustainability and Climate Change Ben-Gurion University of the NegevBeer Sheva 84105Israel

Production of economically viable bioethanol is potentially an environmentally and financially worthwhile *** major source for fermentable sugars is ***,lignocellulosic biomass is difficult to degrade,owing to its inherent structural *** are complexes of cellulases and associated polysaccharide-degrading enzymes bound to a protein scaffold that can efficiently degrade *** of the enzyme subunits into the complex depends on intermodular cohesin-dockerin interactions,which are robust but nonetheless *** modular architecture of these complexes can be used to assemble artificial designer cellulosomes for advanced nanotechnological *** that promote lignocellulose degradation involve high temperatures and acidic or alkaline conditions that could dismember designer cellulosomes,thus requiring separation of reaction steps,thereby increasing overall process *** overcome these challenges,we developed a means of covalently locking cohesin-dockerin interactions by integrating the chemistry of SpyCatcher-SpyTag approach to target and secure the *** resultant cohesin-conjugated dockerin complex was resistant to high temperatures,SDS,and urea while high affinity and specificity of the interacting modular components were *** this approach,a covalently locked,bivalent designer cellulosome complex was produced and demonstrated to be enzymatically active on cellulosic *** combination of affinity systems with SpyCatcher-SpyTag chemistry may prove of general use for improving other types of protein ligation systems and creating unconventional,biologically active,covalently locked,affinity-based molecular architectures.

关键词： Synthetic Biology Protein Ligation Cellulosomes Cohesin Dockerin Protein engineering Cellulose Degradation

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Pressurized environments directly influence friction and wear of dry steel contacts—Investigations in a novel high fluid pressure tribometer

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Friction 2024年第7期12卷 1599-1617页

作者： Paul ReICHLe Jakob BARZ Georg UMLAUF Günter e.M.tovar Institute of Interfacial Process engineering and Plasma Technology(IGVP) University of StuttgartStuttgart 70569Germany Fraunhofer Institute for Interfacial engineering and Biotechnology(IGB) Stuttgart 70569Germany

To reduce the usage of classical lubricants in deep drawing,a new tribological system based on volatile lubricants was ***,a volatile medium is injected under high pressure into the interstice between drawing tool and sheet *** on temperature and pressure,the temporary lubricant may exist in its gaseous or liquid *** this study,a novel high fluid pressure tribometer was designed to investigate the friction and wear of dry steel contacts under comparable conditions like in dry deep ***,a new ball-on-disc tribometer was designed and integrated into a high-pressure *** specifically investigate the effects of different environments(technical air,liquid and gaseous carbon dioxide,nitrogen,argon)at atmospheric and high pressure(0.1 MPa,6 MPa)on tribology,the specimens and all components were operating *** the experiments,the friction was measured *** show that the highest friction occurs in air and the lowest in carbon dioxide *** to the experiments,the wear of the specimens was assessed along with changes in surface chemistry related to tribochemical ***,the tribology of the dry sliding contacts is correlated to changes of the surface *** differences as well as similarities regarding the different fluid environments are *** the results show,the differences between the media used are most pronounced at elevated ***,this work gives clear indications on the suitability of volatile lubricants in dry friction or rather gas lubrication,especially for dry deep drawing.

关键词： dry friction and dry wear gas lubrication carbon dioxide tribo-layer dry metal forming

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应对气候变化相关冲击的全球经济压力测试

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新金融 2022年第12期 42-49页

作者： Yeu Jin Jung Camilo e.tovar Yiqun Wu Tianxiao Zheng 唐成千(翻译) 田振(翻译) 国际货币基金组织不详

测试全球经济以应对与气候变化相关的大型互联经济体的极端冲击意义重大。这篇IMF的工作论文研究了易受气候变化相关冲击影响的大型互联经济体,估计了这些经济体因这些冲击而面临风险的外部融资需求,并使用全球网络模型量化分析其对全... 详细信息

测试全球经济以应对与气候变化相关的大型互联经济体的极端冲击意义重大。这篇IMF的工作论文研究了易受气候变化相关冲击影响的大型互联经济体,估计了这些经济体因这些冲击而面临风险的外部融资需求,并使用全球网络模型量化分析其对全球经济的溢出效应。研究结果表明,易受气候变化影响的大型互联经济体可能导致1.8万亿美元的国际储备流失(占2019年全球GDP的2%),国内和国际多边宏观经济政策可以帮助将这些全球损失减少到约0.8万亿美元,该情景强调了在评估气候变化相关冲击的影响时考虑全球溢出效应的重要性。本刊编译此篇论文,以期为读者带来思考和启发。

关键词：气候变化溢出效应外部融资需求多层网络模型

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True grit: ingestion of small stone particles by hummingbirds in West Mexico

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Avian Research 2021年第4期12卷 739-749页

作者： omar Maya-García Mauricio Ortega-Flores Jorge e.Schondube Posgrado en Ciencias Biológicas Unidad de PosgradoCoordinación del Posgrado en Ciencias BiológicasUniversidad Nacional Autónoma de MéxicoEdificio D1er pisoCircuito de PosgradosCiudad UniversitariaDel.CoyoacánC.P.04510 México D.F.Mexico Laboratorio de ecología Funcional Instituto de Investigaciones en Ecosistemas y SustentabilidadUniversidad Nacional Autónoma de MéxicoAntigua Carretera a Pátzcuaro No.8701Col.Ex Hacienda de San Joséde la HuertaC.P.58190 MoreliaMichoacánMexico

Background: Grit is used by birds mainly for grinding hard food items but can also serve a nutritional role as a source of minerals. Ingestion of grit by birds has been documented primarily in species that feed on seeds and *** feeding mainly on nectar and small arthropods, hummingbirds also ingest grit, but why they do so is unclear. We quantified the number of grit particles in the stomachs of six species of hummingbirds during an annual cycle in a seasonal ecosystem of West ***: We compared the number of grit particles in the stomachs of different hummingbird species(Mexican Violetear Colibri thalassinus, Amethyst-throated Mountaingem Lampornis amethystinus, White-eared Hummingbird Basilinna leucotis, Rivoli's Hummingbird eugenes fulgens, Broad-tailed Hummingbird Selasphorus platycercus, and Rufous Hummingbird S. rufus), and between sex and age categories during the different seasons of a year. To deter-mine if grit was used to grind ingested arthropods, we examined the relationships between the number of grit parti-cles, the biomass of arthropods ingested, and their chitin ***: Although species did not differ in the number of grit particles in their stomachs, we found that grit was mostly ingested by female individuals, with only one male of one species(Mexican Violetear) presenting grit in its stomach. We also found that female hummingbirds had grit in their stomachs during the rainy and the cold-dry season(June-February) but not during the warm-dry season(March-May). Our analyses revealed no relationship between the number of grit particles and the amount of ingested arthropods and arthropod chitin content. However,high grit consumption was related to wasp ingestion on Mexican ***: Our results indicate that grit is used mainly by female hummingbirds. The seasonal variation in the ingestion of grit by female individuals suggests that it can be used to meet mineral requirements related to breed-ing;how

关键词： Arthropod chitin content Arthropod digestion Breeding season Mineral nutritional requirements

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enabling data-driven anomaly detection by design in cyber-physical production systems

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Cybersecurity 2022年第3期5卷 34-51页

作者： Rui Pinto Gil Goncalves Jerker Delsing eduardo tovar Department of Informatics engineering Faculty of EngineeringUniversity of PortoPortoPortugal eISLAB Lulea University of TechnologyLuleaSweden Research Centre in Real-Time and embedded Computing Systems Polytechnic of Porto-School of EngineeringPortoPortugal

Designing and developing distributed cyber-physical production systems(CPPS)is a time-consuming,complex,and error-prone *** systems are typically heterogeneous,i.e.,they consist of multiple components implemented with different languages and development *** of the main problems nowadays in CPPS implementation is enabling security mechanisms by design while reducing the complexity and increasing the system’s *** the IeC 61499 standard is an excellent approach to tackle these challenges by enabling the design,deployment,and management of CPPS in a model-based engineering *** propose a method for CPPS design based on the IeC 61499 *** method allows designers to embed a bio-inspired anomaly-based host intrusion detection system(A-HIDS)in edge *** A-HIDS is based on the incremental Dendritic Cell Algorithm(iDCA)and can analyze OPC UA network data exchanged between the edge devices and detect attacks that target the CPPS’edge *** study’s findings have practical implications on the industrial security community by making novel contributions to the intrusion detection problem in CPPS considering immune-inspired solutions,and cost-effective security by design system *** to the experimental data,the proposed solution can dramatically reduce design and code complexity while improving application maintainability and successfully detecting network attacks without negatively impacting the performance of the CPPS edge devices.

关键词： Artificial immune systems Cyber-physical production systems IeC 61499 Function blocks Industrial Internet of Things Anomaly-based host intrusion detection system Model-based engineering

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evaluation of the 8th AJCC staging system for pathologically versus clinically staged pancreatic adenocarcinoma: A time to revisit a dogma?

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Hepatobiliary & Pancreatic Diseases International 2018年第1期17卷 64-69页

作者： omar Abdel-Rahman Clinical Oncology Department Faculty of Medicine Ain Shams University

Background: The 8 th edition of the American Joint Committee on Cancer(AJCC) staging system for pancreatic exocrine adenocarcinoma has been released. The current study seeks to assess the 7 th and 8 th editions among patients registered within the surveillance, epidemiology and end results(SeeR) ***: SeeR database(2010–2013) has been accessed through SeeR*Stat program and AJCC 8 th edition stages were reconstructed utilizing the collaborative stage descriptions. Kaplan–Meier analysis of overall survival and pancreatic cancer-specific survival analyses(according to both 7 th and 8 th editions and according to whether pathological or clinical staging were conducted) has been performed. Multivariate analysis of factors affecting pancreatic cancer-specific survival was also conducted through a Cox proportional hazard ***: A total of 18 948 patients with pancreatic adenocarcinoma were identified in the period from 2010–2013. Pancreatic cancer-specific survival among pathologically staged patients and according to the 8 th edition showed significant differences for all pair wise comparisons among different stages(P except for the comparison between stage IA and stage IB(P = 0.307) and the comparison between stage IB and stage IIA(P = 0.116). Moreover, P value for stage IA vs IIA was 0.014; while pancreatic cancer-specific survival according to the 7 th edition among pathologically staged patients showed significant differences for all pair wise comparisons among different stages(P except for the comparison between IA and IB(P = 0.072), the comparison between stage IIA and stage IIB(P = 0.065), the comparison between stage IIA and stage Ⅲ(P = 0.059) and the comparison between IIB and Ⅲ(P = 0.595).Among clinically staged patients(i.e. those who did not undergo initial radical surgery), the prognostic performance of both 7 th and 8 th stages for both overall survival and pancreatic cancer-specific survival was ***: Th

关键词： Pancreatic cancer AJCC SeeR Prognosis

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Bone marrow-derived mesenchymal stem cells ameliorate sodium nitrite-induced hypoxic brain injury in a rat model

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Neural Regeneration Research 2017年第12期12卷 1990-1999页

作者： elham H.A.Ali omar A.Ahmed-Farid Amany A.e.Osman Faculty of Women for Art Sciences and Education Ain Shams University Cairo Egypt National Organization for Drug Control and Research (NODCAR) Giza Egypt

Sodium nitrite（Na NO2） is an inorganic salt used broadly in chemical industry. Na NO2 is highly reactive with hemoglobin causing hypoxia. Mesenchymal stem cells（MSCs） are capable of differentiating into a variety of tissue specific cells and MSC therapy is a potential method for improving brain functions. This work aims to investigate the possible therapeutic role of bone marrow-derived MSCs against Na NO2 induced hypoxic brain injury. Rats were divided into control group（treated for 3 or 6 weeks）, hypoxic（HP） group（subcutaneous injection of 35 mg/kg Na NO2 for 3 weeks to induce hypoxic brain injury）, HP recovery groups N-2 w R and N-3 w R（treated with the same dose of Na NO2 for 2 and 3 weeks respectively, followed by 4-week or 3-week self-recovery respectively）, and MSCs treated groups N-2 w SC and N-3 w SC（treated with the same dose of Na NO2 for 2 and 3 weeks respectively, followed by one injection of 2 × 106 MSCs via the tail vein in combination with 4 week self-recovery or intravenous injection of Na NO2 for 1 week in combination with 3 week self-recovery）. The levels of neurotransmitters（norepinephrine, dopamine, serotonin）, energy substances（adenosine monophosphate, adenosine diphosphate, adenosine triphosphate）, and oxidative stress markers（malondialdehyde, nitric oxide, 8-hydroxy-2′-deoxyguanosine, glutathione reduced form, and oxidized glutathione） in the frontal cortex and midbrain were measured using high performance liquid chromatography. At the same time, hematoxylin-eosin staining was performed to observe the pathological change of the injured brain tissue. Compared with HP group, pathological change of brain tissue was milder, the levels of malondialdehyde, nitric oxide, oxidized glutathione, 8-hydroxy-2′-deoxyguanosine, norepinephrine, serotonin, glutathione reduced form, and adenosine triphosphate in the frontal cortex and midbrain were significantly decreased, and glutathione reduced form/oxidized glutathione and adenosine monophosphate/adenosine

关键词： nerve regeneration hypoxia bone marrow-derived mesenchymal stem cells sodium nitrite monoamine neurotransmitter cell energy neural regeneration

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Pharmacological strategies in extracorporeal membrane oxygenation weaning failure: a call to action

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emergency and Critical Care Medicine 2023年第2期3卷 43-45页

作者： Francisco J.González-Ruiz Francisco M.Baranda-tovar Luis A.Baeza-herrera JoséD.Utrilla-Álvarez Ricardo e.Quirázco-Cordova Gustavo Rojas-Velasco Department of Cardiovascular Critical Care National Institute of Cardiology“Dr.Ignacio Chávez”Mexico CityMexico National Institute of Cardiology.Juan Badiano 1 Belisario Dominguez Secc 16Tlalpan14080Mexico CityMexico

extracorporeal membrane oxygenation has emerged as a viable alternative for stabilizing and improving critically ill patients in acute cardiovascular ***,the weaning stage has been associated with a high morbidity and mortality *** makes searching for strategies that reduce failure in this final process *** a new approach must be tried and included in our protocols,seeking the patient’s well-being at all *** this article,the authors discuss their point of view regarding potential pharmacological alternatives and the mechanism of action involved,which could decrease the mortality associated with this therapeutic.

关键词： β-Blockers extracorporeal membrane oxygenation Inodilators Mechanical circulatory support Pharmacological strategies

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GReeN SYNTHeSIS OF ANTIBACTeRIAL CHITOSAN FILMS LOADeD WITH SILVeR NANOPARTICLeS

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Chinese Journal of Polymer Science 2013年第7期31卷 984-993页

作者： Neama A. Reiad omar e. Abdel Salam ehab F. Abadir Farid A. Harraz Sanitary & environmental engineering Department Housing & Building National Research Center Department of Chemical engineering Faculty of EngineeringCairo University Advanced Materials Technology Department Central Metallurgical R & D Institute

An eco-friendly chemical reduction method was successfully used for the preparation of chitosan （CTS） composite films loaded with silver nanoparticles （AgNPs） by self assembly method using poly（ethylene glycol） as both reducing and stabilizing agent. UV-Vis spectra of the prepared chitosan loaded silver nanoparticles （CTSLAg） films reveal that full reduction of silver ions to silver nanoparticles takes place at 90 ℃. The effect of reaction conditions on the silver nanoparticles formation was investigated using UV-Vis spectrophotometer. The morphology of the films was tested by scanning electron microscopy （SeM）. The DSC curves showed that the CTSLAg film had a favorable compatibility and heat stability. AgNPs were confirmed by XRD and UV-Vis spectroscopy. The TeM findings revealed that the silver nanoparticles synthesized were spherical in shape with uniform dispersal, and by increasing CTS：PeG ratio larger silver nanoparticles could be obtained. The results of antibacterial study reveal that the prepared nanoeomposite films exhibited potential inhibition.

关键词： Chitosan Silver nanoparticles Antibacterial activity.

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Adsorptive removal of iron and manganese ions from aqueous solutions with microporous chitosan/polyethylene glycol blend membrane

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Journal of environmental Sciences 2012年第8期24卷 1425-1432页

作者： Neama A.Reiad omar e.Abdel Salam ehab F.Abadir Farid A.Harraz Sanitary&environmental Department Housing&Building National Research Center87 el Tahrir st.DokkiEgypt Department of Chemical engineering Faculty of EngineeringCairo UniversityGizaEgypt Advanced Materials Technology Department Central Metallurgical R&D InstituteHelwanEgypt

Microporous chitosan （CS） membranes were directly prepared by extraction of poly（ethylene glycol）（PeG） from CS/PeG blend membrane and were examined for iron and manganese ions removal from aqueous solutions. The different variables affecting the adsorption capacity of the membranes such as contact time, pH of the sorption medium, and initial metal ion concentration in the feed solution were investigated on a batch adsorption basis. The affinity of CS/PeG blend membrane to adsorb Fe（II） ions is higher than that of Mn（II） ions, with adsorption equilibrium achieved after 60 min for Fe（II） and Mn（II） ions. By increasing CS]PeG ratio in the blend membrane the adsorption capacity of metal ions increased. Among all parameters, pH has the most significant effect on the adsorption capacity, particularly in the range of 2.9-5.9. The increase in CS/PeG ratio was found to enhance the adsorption capacity of the membranes. The effects of initial concentration of metal ions on the extent of metal ions removal were investigated in detail. The experimental data were better fitted to Freundlich equation than Langmuir. In addition, it was found that the iron and manganese ions adsorbed on the membranes can be effectively desorbed in 0.1 mol/L HCl solution （up to 98% desorption efficiency） and the blend membranes can be reused almost without loss of the adsorption capacity for iron and manganese ions.

关键词： chitosan blend membrane iron and manganese ions adsorption

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