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Concise Synthesis of Lactococcus garvieae Lipoteichoic Acids Through an Additive-Modulated Preactivation Protocol and the Immunological Studies

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CCS Chemistry 2024年第2期6卷 403-414页

作者： Tianlu Li Tong Li Yue Yang Haoru Zhuang Jianwu Lv Ning Zhou Miaomiao Zhang Fengshan Wang Yiqun Geng Richard R.schmidt Peng Peng National Glycoengineering Research Center Shandong Key Laboratory of Carbohydrate Chemistry and GlycobiologyNMPA Key Laboratory for Quality Research and Evaluation of Carbohydrate Based MedicineShandong UniversityQingdao 266237 State Key Laboratory of Bioactive Substance and Function of Natural Medicines Institute of Materia MedicaChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijing 100050 Department of Chemistry University of KonstanzD-78457 Konstanz

Lipoteichoic acids(LTAs)are macroamphiphiles composed of alditol,lipid,phosphate,and carbohydrate *** to their inherent complexity,it is a severe challenge to access LTAs with structural integrity from natural sources for biological or immunological ***,we describe the first total synthesis of Lactococcus garvieae LTA(type II LTA),containing five distinct 1,2-cis gluco/galactopyranosidic linkages,via a novel additive-modulated o-glycosyl trichloroacetimidate preactivation glycosidation *** strategy features(1)high glycosidation yields and excellent 1,2-cis stereoselectivities independent of the donor anomeric configuration,(2)common and inexpensive reagents as promoters and additives,(3)application to standard glycosyl imidate donors without resorting to participating protection,and(4)general application to reactive and less reactive glycosyl ***,via the precise stereocontrolled construction of three galactopyranosidic and two glucopyranosidic bonds on a multigram scale,a series of structurally well-defined LTA molecules were successfully *** evaluation of these type II synthetic LTAs showed a structure–activity relationship in the stimulation of a proinflammatory response.

关键词： 1,2-cis glycosidation stereoselectivity lipoteichoic acid total synthesis additive-modulated trichloroacetimidate glycosidation immune response

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Newly Launched Satellite Seeks to Keep Methane Emitters Honest

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Engineering 2024年第10期41卷 1-3页

作者： Sean o’Neill Senior Technology Writer

on 4 March 2024,a new methane-observing satellite,MethaneSAT,was launched atop a SpaceX Falcon 9 rocket and successfully placed in orbit[1].Developed by the New York City,NY,USA-headquartered Environmental Defense Fund(EDF)in partnership with the New Zealand Space Agency and funded by multiple philanthropic donors including the Bezos Earth Fund,the spacecraft promises to greatly improve scientists’ability to pinpoint and monitor methane emissions,particularly those related to the oil and gas industry.

关键词： funded Methane methane

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Influence of railway wheel tread damage on wheel-rail impact loads and the durability of wheelsets

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Railway Engineering Science 2024年第1期32卷 20-35页

作者： Michele Maglio Tore Vernersson Jens C.o.Nielsen Anders Ekberg Elena Kabo CHARMEC Department of Mechanical and Maritime SciencesChalmers University of TechnologySE‑41296 GothenburgSweden

Dynamic wheel-rail contact forces induced by a severe form of wheel tread damage have been measured by a wheel impact load detector during full-scale field tests at different vehicle *** on laser scanning,the measured three-dimensional damage geometry is employed in simulations of dynamic vehicle-track interaction to calibrate and verify a simulation *** relation between the magnitude of the impact load and various operational parameters,such as vehicle speed,lateral position of wheel-rail contact,track stiffness and position of impact within a sleeper bay,is *** calibrated model is later employed in simulations featuring other forms of tread damage;their effects on impact load and subsequent fatigue impact on bearings,wheel webs and subsurface initiated rolling contact fatigue of the wheel tread are *** results quantify the effects of wheel tread defects and are valuable in a shift towards condition-based maintenance of running gear,and for general assessment of the severity of different types of railway wheel tread damage.

关键词： Wheel tread damage Rolling contact fatigue cluster Field measurements Dynamic vehicle-track interaction Wheel-rail impact load Wheelset durability

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Are dogs not susceptible to retroviral infections?

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Animal Diseases 2024年第3期4卷 217-223页

作者： Jorge Casseb João Henrique Campos Luciano Rodrigo Lopes Laboratory of Investigation in Dermatology and Immunodefciencies Department of DermatologyUniversity of São Paulo Medical SchoolSão PauloSPBrazil Igen-Institute of Immunogenetics São PauloSPBrazil Bioinformatics and Biomedical Data Science Division Health Informatics DepartmentUniversidade Federal de São Paulo–UNIFESP.Rua Botucatu 862Prédio Leal PradotérreoVila ClementinoCEP 04023-062São PauloSPBrazil

Retroviruses have been proven to cause infections and diseases in a series of mammalian hosts but not in ***,this letter discussed the dog susceptibility to retrovirus infection,encompassing arguments to understand why dogs may have not been infected by retroviruses thus *** potential resistance of retrovirus in dogs enables this provocative short communication to discuss this question,looking at some evolutive *** lineage of canids has shown,throughout its evolutionary history,a smaller accumulation of retroviruses in canid genomes,classifed as endogenous *** this context,the genomes of canids seem to ofer obstacles,which have been evolutionarily conserved,in the face of retroviral infection.

关键词： Retrovirus dogs Endogenous retrovirus

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A hybrid solar-biogas system for post-CoVID-19 rural energy access

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Clean Energy 2024年第1期8卷 84-99页

作者： ochuko K.overen KeChrist obileke Edson L Meyer Golden Makaka oliver o.Apeh Fort Hare Institute of Technology University of Fort HarePrivate Bag X1314Alice 5700South Africa Department of Physics Renewable Energy Research CentreUniversity of Fort HarePrivate Bag X1314Alice 5700South Africa Department of Electrical and Electronic Engineering Science Faculty of Engineering and Build EnvironmentUniversity of JohannesburgAuckland Park 2006South Africa

Solar home systems for rural electrification are often designed with a limited energy supply,which presents a drawback for the ***,uncontrolled livestock faeces in rural communities constitute environmental sanitation and health *** excrement can be used through a biogas digester to supplement solar energy to provide adequate and sustainable elec-tricity access to underserved rural communities while achieving waste ***,this study presents a hybrid solar-biogas system for a more dynamic energy supply and waste management for post-Covid recovery plans in rural communities.A parametric research approach that involves the use of the Integrated Environment Solution Virtual Environment software application and mathematical models to design the desired household load and the hybrid system sizing is used in the *** findings show that the daily household energy consumption was 6.6 kWh,equivalent to 206.40 kWh/month.A 1.2-kWp and 1.2-m^(3)hybrid solar-biogas system was found to adequately power the ***,the total initial investment cost of the system was$5777.20 with a net present value of$6566.78,net profit of$4443.6,a payback period of 14 years and 8 months,and a levelized cost of energy of$0.21/kWh;these include a 60%initial investment and maintenance costs *** performance contracting and energy-as-a-service were recommended to effectively run and operate the *** study successfully revealed the design,specifications and upscaling mechanism of the proposed hybrid solar-biogas *** research is required to unveil the efficacy of the system,the performance gap and the perception of the technology by the beneficiaries.

关键词： energy access sustainable rural development clean energy waste management post-CoVID-19 recovery plan

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optimization of bio-oil production parameters from the pyrolysis of elephant grass (Pennisetum purpureum) using response surface methodology

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Clean Energy 2024年第5期8卷 241-251页

作者： Sunday C.Ikpeseni Samuel o.Sada Ufuoma J.Efetobor Henry o.orugba Mathias Ekpu Hilary I.owamah Jeremiah L.Chukwuneke Solomon oyebisi Uche P.onochie Department of Mechanical Engineering Delta State UniversityP.M.B.1AbrakaNigeria Department of Mechanical Engineering Delta State PolytechnicP.M.B.3Otefe-OgharaNigeria Department of Chemical Engineering Delta State UniversityP.M.B.1AbrakaNigeria Department of Civil Engineering Delta State UniversityP.M.B.1AbrakaNigeria Department of Mechanical Engineering Nnamdi Azikiwe UniversityP.M.B.2025AwkaNigeria Department of Civil Engineering Covenant UniversityP.M.B.1023OttaNigeria Department of Civil Engineering The University of the South PacificP.M.B.9072SuvaFiji Department of Mechanical Engineering Delta State University of Science and TechnologyP.M.B.5OzoroNigeria

The need to increase bio-oil yield from biomass and enhance its fuel properties has driven research into optimizing the pyrolysis *** study investigated the influence of three key process parameters—temperature,heating rate,and nitrogen flow rate—on the pyrolysis of elephant grass(Pennisetum purpureum)in a fixed-bed *** surface methodology was used to study the im-pact of the aforementioned variables on bio-oil yield to improve its production *** analysis of the biomass revealed 79.24 wt%volatile matter,14.22 wt%fixed carbon,and 5.86%ash,with ultimate analysis showing 45.44%carbon,5.59%hydrogen,and 40.95%*** high volatile matter content and favourable carbon and hydrogen percentages indicate that elephant grass is a vi-able energy source due to its potential for high bio-oil yield and energy *** resulting bio-oil exhibited a higher heating value of 20.9 MJ/kg,indicating its suitability for various heating applications.A second-order regression model was developed for bio-oil yield,with optimal conditions identified as a temperature of 550°C,a heating rate of 17°C/min,and a nitrogen flow rate of 6 ml/*** study achieved an optimal bio-oil yield of 59.03 wt%,and the model’s high R²value of 0.8683 from analysis of variance analysis confirmed its predictive *** research highlights elephant grass as a sustainable feedstock for bio-oil production,offering valuable insights into optimizing pyrolysis conditions to enhance bio-oil yield,thus advancing biofuel technology.

关键词： renewable energy biomass sustainable feedstock regression model fixed-bed reactor

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A decomposition of light’s spin angular momentum density

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Light(Science & Applications) 2024年第8期13卷 1578-1589页

作者： Alex J.Vernon Sebastian Golat Claire Rigouzzo Eugene A.Lim Francisco J.Rodríguez-Fortuño Department of Physics King’s College LondonStrandLondon WC2R 2LSUK London Centre for Nanotechnology LondonUK

Light carries intrinsic spin angular momentum(SAM)when the electric or magnetic field vector rotates over time.A familiar vector equation calculates the direction of light’s SAM density using the right-hand rule with reference to the electric and magnetic polarisation *** Maxwell’s equations,this vector equation can be decomposed into a sum of two distinct terms,akin to the well-known Poynting vector decomposition into orbital and spin *** present the first general study of this spin decomposition,showing that the two terms,which we call canonical and Poynting spin,are chiral analogies to the canonical and spin momenta of light in its interaction with *** canonical momentum,canonical spin is directly *** canonical and Poynting spin incorporate spatial variation of the electric and magnetic fields and are influenced by optical *** decomposition allows us to show that a linearly polarised vortex beam,which has no total SAM,can nevertheless exert longitudinal chiral pressure due to equal and opposite canonical and Poynting spins.

关键词： canonical momentum angular

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Elucidating the Degradation Pathways of Human Insulin in the Solid State

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Journal of Analysis and Testing 2024年第3期8卷 288-299页

作者： Andrew Fagan Lorraine M.Bateman Joseph P.o'Shea Abina M.Crean SSPC the SFI Centre for Pharmaceutical Research School of Pharmacy University College Cork School of Pharmacy University College Cork Analytical and Biological Chemistry Research Facility (ABCRF) University College Cork School of Chemistry University College Cork

While there have been significant advances in the development of peptide oral dosage forms in recent years, highlighted by the clinical and commercial success of approved peptides such as Rybelsus?, there remain several barriers in the way of broad range applicability of this approach to peptide delivery. one such barrier includes the poor physical and chemical stability inherent to their structures, which persists in the solid state although degradation typically occurs at different rates and via different pathways in comparison to the solution state. Using insulin as a model peptide, this work sought to contribute to the development of analytical techniques for investigating common insulin degradation pathways. Chemically denatured,deamidated and aggregated samples were prepared and used to benchmark circular dichroism spectroscopy, reverse phase HPLC and size exclusion chromatography methods for the investigation of unfolding, chemical modifications and covalent aggregation of the insulin molecule respectively. Solid state degraded samples were prepared by heating insulin powder at 60 °C and 75% relative humidity for 1, 3, 5 and 7 d, and the degradation profiles of the samples were evaluated and compared with those observed in solution. While no unfolding was observed to occur, significant deamidation and covalent aggregation were detected. Reductive disulfide bond cleavage using dithiothreitol allowed for separation of the insulin A-and B-chains,offering a facile yet novel means of assessing the mechanisms of deamidation and covalent aggregation occurring in the solid state.

关键词： Biopharmaceutical analysis Covalent aggregation Deamidation Disulfide cleavage Insulin Solid state Stability

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Evaluation of Mechanical Properties and Surface Quality of Wood from Bosnia and Herzegovina Exposed to outdoor Conditions

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Journal of Renewable Materials 2024年第8期12卷 1417-1431页

作者： Redžo Hasanagić UmejrŠljivo Leila Fathi Pallavi Gautam Mohsen Bahmani Miha Humar Department of Wood Science and Technology Faculty of Technical EngineeringUniversity of BihaćBihać77000Bosnia and Herzegovina Department of Wood and Furniture Industry Engineering Faculty of Resources and Earth ScienceShahrekord UniversityShahrekord64165478Iran Department of Botany Institute of ScienceBanaras Hindu UniversityVaranasiUttar Pradesh221005India Biotechnical Faculty Department of Wood ScienceUniversity of LjubljanaLjubljana1501Slovenia

This study investigated the mechanical properties of beech(Fagus sylvatica L.)and fir(Abies alba)wood from Bosnia and Herzegovina under outdoor *** were exposed for 3-month exposure to assess bending strength,color changes,and surface *** showed outdoor exposure negatively affected mechanical properties,particularly in samples with extended finger joints,causing significant surface cracks in uncoated *** wood exhibited notable color changes under exposure,with approximately 50%darkening without coating compared to 25%under covered *** samples displayed minimal color changes,affirming the efficacy of surface *** wood exhibited a roughness of 8.264μm,while beechwood average roughness increased from 6.767 to 13.916μm after exposure,with micro-pore development affecting water *** analysis identified prevalent fungal colonies,including Penicillium,Aureobasidium,Sclerophoma,and Chaetomium,underscoring their role in organic matter *** study highlights the importance of wood exposure and treatment selection for various applications.

关键词： Mechanical properties outdoor conditions cracks wood species

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Deep Weighted Fusion Learning(DWFL)-based multi-sensor fusion model for accurate building occupancy detection

Energy and AI

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Energy and AI 2024年第3期17卷 542-554页

作者： MdRumman Rafi Fei Hu Shuhui Li Aijun Song Xingli Zhang Zheng o’Neill Department of Electrical and Computer Engineering The University of AlabamaTuscaloosaALUSA Mechanical Engineering Texas A&M UniversityTXUSA

With the advancement of artificial intelligence,the dominance of deep learning(DL)models over ordinary machine learning(ML)algorithms has become a reality in recent years due to its capability of handling complex pattern recognition without manual feature *** the growing demands for power savings,building energy loss reduction could benefit from DL *** buildings/rooms with the varying number of occupants,heating,ventilation,and air conditioning(HVAC)systems are often found in operations without much *** reduce the building’s energy loss,accurate occupancy detection/prediction(oDP)results could be used to control the proper operations of ***,oDP is a challenging issue due to multiple reasons,such as improper selection/deployment of sensors,inefficient learning algorithms for pattern recognition,varying room conditions,*** overcome the above challenges,we propose a DL-based framework,i.e.,Deep Weighted Fusion Learning(DWFL),to detect and predict occupancy counts with optimal multi-sensor fusion *** fuses the extracted features from multiple types of sensors with the priority/weight assignment to each *** weight assignment considers different room conditions and the pros/cons of each type of *** evaluate DWFL model in terms of occupancy prediction accuracy,we have set up an experimental testbed with low-cost cameras,carbon dioxide(Co_(2)),and passive infrared(PIR)*** the recently proposed occupancy detection models,DeepFusion utilized deep learning model on heterogeneous sensor data and achieved 88%accuracy in occupancy count estimation(Xue et al.,2019).Another deep learning-based model MI-PIR achieved 91%accuracy on raw analog data from PIR sensors(Andrews et al.,2020).our research outcome is 94%.Therefore,the experiment results show that our DWFL scheme outperforms the state-of-the-art oDP methods by 3%.

关键词： Building energy saving Convolutional neural network(CNN) occupancy detection Deep learning Multi-sensor fusion Wavelet transform

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