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Scalable, Green Chain Transfer Agent for Cationic RAFT Polymerizations

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Chinese Journal of Chemistry 2023年第4期41卷 399-404页

作者： Scott W.Spring Chloe S.Cerione Jesse H.Hsu Shelby L.Shankel Brett P.Fors Department of Chemistry and Chemical Biology Cornell UniversityIthacaNew York14853 United States

Cationic polymerizations of vinyl ethers have gained recent attention due to their ability to produce robust,biorenewable *** developments have been largely enabled by the advent of cationic reversible addition−fragmentation chain-transfer(RAFT)polymerization;however,the scalability and sustainability of this method are hindered by current chain-transfer agents(CTAs),which exist as viscous,colored oils requiring complex syntheses and solvent-intensive ***,we produce a solid,colorless CTA through a green synthetic route in 83%yield on a 50-gram *** investigate the utility of this CTA in chemical,electrochemical,photochemical,and acid-initiated methods,revealing that it achieves efficient polymerization with excellent control over molecular weight,low dispersity values,high chain end fidelity,and temporal control in cationic RAFT polymerizations.

关键词： Vinyl ethers CTA Cationic polymerization Green RAFT

Determining number of sites on ceria stabilizing single atoms via metal nanoparticle redispersion

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Chinese Journal of Catalysis 2020年第6期41卷 998-1005页

作者： Aisulu Aitbekova Cody JWrasman Andrew RRiscoe Larissa YKunz Matteo Cargnello Department of Chemical Engineering and SUNCAT Center for Interface Science and Catalysis Stanford UniversityStanfordCalifornia 94305United States

Single atom catalysts have recently attracted interest due to their maximization of the utilization of expensive noble metals as well as their unique catalytic properties. Based on its surface atomic properties, CeO2 is one of the most common supports for stabilizing single metal atoms. Many single atom catalysts are limited in their metal contents by the formation of metal nanoparticles once the catalyst support capacity for single atoms has been exceeded. Currently, there are no direct measurements to determine the capacity of a support to stabilize single atoms. In this work we develop a nanoparticle-based technique that allows for quantification of that capacity by redispersing Ru nanoparticles into single atoms and taking advantage of the different catalytic properties of Ru single atoms and nanoparticles in the CO2 hydrogenation reaction. This method avoids complications in metal loading caused by counterions in incipient wetness impregnation and can eventually be applied to a variety of different metals. Results using this technique follow trends in oxygen vacancy concentration and surface oxygen content and show promise as a new method for quantifying support single atom stabilization capacity.

关键词： Ceria Single-atom catalyst Oxygen vacancies CO2 hydrogenation Redispersion

A tri-layer approach to controlling nanopore formation in oxide supports

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Nano Research 2019年第6期12卷 1223-1228页

作者： Abha A.Gosavi James L.Hedrick Peng-Cheng Chen Justin M.Notestein Chad A.Mirkin Department of Chemical and Biological Engineering Northwestern University2145 Sheridan RoadEvanstonIllinois 60208USA International Institute for Nanotechnology Northwestern University2145 Sheridan RoadEvanstonIllinois 60208USA Department of Materials Science and Engineering Northwestern University2145 Sheridan RoadEvanstonIllinois 60208USA Department of Chemistry Northwestern University2145 Sheridan RoadEvanstonIllinois 60208USA

A novel tri-layer approach for immobilizing metal nanoparticles in SiO2 supports is *** this work,we show that under rapid heating to temperatures of approximately 1,000 ℃,metal nanoparticles less than 15 nm in size will entrench in the SiO2 layer on a silicon wafer to create pores as deep as 250 *** studied and characterized this entrenching behavior and subsequent nanopore formation for a wide variety of metal nanoparticles,including Au,Ag,Pt,Pd,and *** also demonstrate that an Al2O3 layer acts as a barrier to such pore ***,by creating a tri-layer architecture consisting of SiO2 on Al2O3 on silicon wafers,we can control the depth to which nanoparticles entrench between 3-5 *** small range allows one to entrench particles for the purpose of immobilization but still present them above the *** two advances of moving into the sub-15 nm size regime and of controlled particle immobilization through entrenchment have important implications in studying site-isolated and stabilized metal nanoparticles for applications in sensing,separations,and catalysis.

关键词： nanopore formation nanoparticle entrenchment nanoparticle stabilization atomic force microscopy Au nanoparticles

Plasma-polymerized pericyte patches improve healing of murine wounds through increased angiogenesis and reduced inflammation

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Regenerative Biomaterials 2021年第4期8卷 21-32页

作者： Hannah M.Thomas Parinaz Ahangar Robert Fitridge Giles T.S.Kirby Stuart J.Mills Allison J.Cowin Future Industries Institute University of South AustraliaMawson Lakes SA 5095Australia Cell Therapy Manufacturing Cooperative Research Centre Adelaide SA 5000Australia Faculty of Health and Medical Sciences University of AdelaideAdelaide SA 5005Australia

Pericytes have the potential to be developed as a cell therapy for the treatment of wounds;however,the efficacy of any cell therapy relies on the successful delivery of intact and functioning ***,the effect of delivering pericytes on wound repair was assessed alongside the development of a surface-functionalized pericyte *** polymerization(PP)was used to functionalize the surface of silicone patches with heptylamine(HA)or acrylic acid(AA)*** pericytes were subsequently delivered to murine excisional wounds by intradermal injection or using the pericyte-laden patches and the comparative effects on wound healing,inflammation and revascularization *** AA surface provided the superior transfer of the cells to de-epidermized *** murine wounds treated either with pericytes injected directly into the wound or with the pericyte-laden AA patches showed improved healing with decreased neutrophil infiltration and reduced numbers of macrophages in the *** delivery also enhanced angiogenesis through a mechanism independent of VEGF ***,when delivered to wounds,improved healing responses by dampening inflammation and promoting *** of pericytes using PP-AA-functionalized patches was equally as effective as direct injection of pericytes into ***-functionalized dressings may therefore be a clinically relevant approach for the treatment of wounds.

关键词： pericytes cell therapy wound healing plasma polymerization advanced surfaces

Modeling measles transmission in adults and children:Implications to vaccination for eradication

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Infectious Disease Modelling 2024年第4期9卷 1007-1026页

作者： Anjana Pokharel Khagendra Adhikari Ramesh Gautam Kedar Nath Uprety Naveen K.Vaidya Padma Kanya Multiple Campus Tribhuvan UniversityKathmanduNepal Mathematical Biology Research Center KathmanduNepal Amrit Campus Tribhuvan UniversityKathmanduNepal Ratna Rajya Laxmi Campus Tribhuvan UniversityKathmanduNepal Central Department of Mathematics Tribhuvan UniversityKathmanduNepal Department of Mathematics and Statistics San Diego State UniversitySan DiegoCAUSA Computational Science Research Center San Diego State UniversitySan DiegoCAUSA Viral Information Institute San Diego State UniversitySan DiegoCAUSA

Despite the availability of successful vaccines,measles outbreaks have occurred frequently in recent years,presumably due to the lack of proper vaccination ***,measles cases in adult groups,albeit small in number,indicate that the previously neglected adult group may need to be brought into vaccine coverage to achieve WHO's goal of measles eradication from the *** this study,we develop a novel transmission dynamics model to describe measles cases in adults and children to evaluate the role of adult infection in persistent measles cases and vaccination programs for *** of our model,validated by measles cases from outbreaks in Nepal,provides the vaccination reproduction number(conditions for measles eradication or persistence)and the role of contact network *** results highlight that while children are primary targets for measles outbreaks,a small number of infections in adults may act as a reservoir for measles,causing obstacles to ***,our model analysis shows that while impactful controls can be achieved by children-focused vaccines,a combined adult-child vaccination program may help assert eradication of the disease.

关键词： Measles eradication Measles reservoir Adult-child vaccination Adults and children groups Nepal

Agent-based models reveal limits of mark-release-recapture estimates for the rare butterfly, Bhutanitis thaidina (Lepidoptera: Papilionidae)

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Insect Science 2022年第2期29卷 550-566页

作者： Zhengyang Wang Yuanheng Li Anuj Jain Naomi E.Pierce Department of Organismic and Evolutionary Biology and Museum of Comparative Zoology Harvard UniversityCambridgeMA 02138 USA

Insect diversity and abundance are in drastic decline worldwide,but quantifying insect populations to better conserve them is a difficult ***-release-recapture(MRR)is widely used as an ecological indicator for insect populations,but the accuracy of MRR estimates can vary with factors such as spatial scale,sampling effort and models of *** conducted a 3-year MRR study of *** in Yanzigou valley,*** but failed to obtain sufficient data for a robust population *** prompted us to integrate *** life history information to parameterize agent-based models and evaluate the conditions under which successful MRR studies could be *** evaluated:(1)the performance of MRR models under different landscape types,and(2)the influence of experimental design on the accuracy and variance of MRR-based *** simulations revealed systematic underestimates of true population parameters by MRR models when sampling effort was *** a total of 2772 simulations,subjective decisions in sampling protocol(e.g.,frequency,number of sampling locations,use of spatially explicit models,type of estimands)accounted for nearly half of the variation in *** conclude that MRR-based estimates could be improved with the addition of more field-specific parameters.

关键词： agent-based simulation Aristolochia moupinensis habitat hostplant landscape Mt.Gongga program MARK spatially explicit capture-recapture(SECR)

Jointly Optimized Spatial Histogram UNET Architecture(JOSHUA)for Adipose Tissue Segmentation

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Biomedical Engineering Frontiers 2022年第1期3卷 248-261页

作者： Joshua K.Peeples Julie F.Jameson Nisha M.Kotta Jonathan M.Grasman Whitney L.Stoppe Alina Zare Department of Electrical and Computer Engineering University of FloridaGainesvilleFL 32611USA Department of Chemical Engineering University of FloridaGainesvilleFL 32611USA J.Crayton Pruitt Family Department of Biomedical Engineering University of FloridaGainesvilleFL 32611USA Department of Biomedical Engineering New Jersey Institute of TechnologyUniversity HeightsNewarkNJ 07102USA

*** aim to develop a machine learning algorithm to quantify adipose tissue deposition at surgical sites as a function of biomaterial *** *** our knowledge,this study is the first investigation to apply convolutional neural network(CNN)models to identify and segment adipose tissue in histological images from silk fibroin biomaterial *** designing biomaterials for the treatment of various soft tissue injuries and diseases,one must consider the extent of adipose tissue *** this work,we analyzed adipose tissue accumulation in histological images of sectioned silk fibroin-based biomaterials excised from rodents following subcutaneous implantation for 1,2,4,or 8 *** strategies for quantifying adipose tissue after biomaterial implantation are often tedious and prone to human bias during *** used CNN models with novel spatial histogram layer(s)that can more accurately identify and segment regions of adipose tissue in hematoxylin and eosin(H&E)and Masson’s trichrome stained images,allowing for determination of the optimal biomaterial *** compared the method,Jointly Optimized Spatial Histogram UNET Architecture(JOSHUA),to the baseline UNET model and an extension of the baseline model,attention UNET,as well as to versions of the models with a supplemental attention-inspired mechanism(JOSHUA+and UNET+).*** inclusion of histogram layer(s)in our models shows improved performance through qualitative and quantitative *** results demonstrate that the proposed methods,JOSHUA and JOSHUA+,are highly beneficial for adipose tissue identification and *** new histological dataset and code used in our experiments are publicly available.

关键词： injuries implantation Spatial

The origin and biosynthesis of the naphthalenoid moiety of juglone in black walnut

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Horticulture Research 2018年第1期5卷 159-169页

作者： Rachel M.McCoy Sagar M.Utturkar Joseph W.Crook Jyothi Thimmapuram Joshua R.Widhalm Department of Horticulture and Landscape Architecture Purdue University625 Agriculture Mall DriveWest LafayetteIN47907USA Purdue Center for Plant Biology Purdue UniversityWest LafayetteIN47907USA Bioinformatics Core Purdue University155 South Grant StreetWest LafayetteIN47907USA

Several members of the Juglandaceae family produce juglone,a specialized 1,4-naphthoquinone(1,4-NQ)natural product that is responsible for the notorious allelopathic effects of black walnut(Juglans nigra).Despite its documented ecological roles and potential for being developed as a novel natural product-based herbicide,none of the genes involved in synthesizing juglone have been *** on classical labeling studies,we hypothesized that biosynthesis of juglone’s naphthalenoid moiety is shared with biochemical steps of the phylloquinone ***,using comparative transcriptomics in combination with targeted metabolic profiling of 1,4-NQs in various black walnut organs,we provide evidence that phylloquinone pathway genes involved in 1,4-dihydroxynaphthoic acid(DHNA)formation are expressed in roots for synthesis of a compound other than *** experiments using axenic black walnut root cultures revealed that stable isotopically labeled L-glutamate incorporates into juglone resulting in the same mass shift as that expected for labeling of the quinone ring in *** together,these results indicate that in planta,an intermediate from the phylloquinone pathway provides the naphthalenoid moiety of ***,this work shows that juglone can be de novo synthesized in roots without the contribution of immediate precursors translocated from aerial *** present study illuminates all genes involved in synthesizing the juglone naphthoquinone ring and provides RNA-sequencing datasets that can be used with functional screening studies to elucidate the remaining juglone pathway *** of the generated knowledge is expected to inform future metabolic engineering strategies for harnessing juglone as a novel natural product-based herbicide.

关键词： moiety roots synthesizing

Million-scale data integrated deep neural network for phonon properties of heuslers spanning the periodic table

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npj Computational Materials 2023年第1期9卷 2155-2166页

作者： Alejandro Rodriguez Changpeng Lin Hongao Yang Mohammed Al-Fahdi Chen Shen Kamal Choudhary Yong Zhao Jianjun Hu Bingyang Cao Hongbin Zhang Ming Hu Department of Mechanical Engineering University of South CarolinaColumbiaSC 29208USA Theory and Simulation of Materials(THEOS) École Polytechnique Fédérale de LausanneCH-1015 LausanneSwitzerland Key Laboratory for Thermal Science and Power Engineering of Ministry of Education Department of Engineering MechanicsTsinghua UniversityBeijing 100084China Institute of Materials Science Technical University of DarmstadtDarmstadt 64287Germany Materials Science and Engineering Division National Institute of Standards and TechnologyGaithersburgMD 20899USA Department of Computer Science and Engineering University of South CarolinaColumbiaSC 29208USA

Existing machine learning potentials for predicting phonon properties of crystals are typically limited on a material-to-materialbasis, primarily due to the exponential scaling of model complexity with the number of atomic species. We address this bottleneckwith the developed Elemental Spatial Density Neural Network Force Field, namely Elemental-SDNNFF. The effectiveness andprecision of our Elemental-SDNNFF approach are demonstrated on 11,866 full, half, and quaternary Heusler structures spanning 55elements in the periodic table by prediction of complete phonon properties. Self-improvement schemes including active learningand data augmentation techniques provide an abundant 9.4 million atomic data for training. Deep insight into predicted ultralowlattice thermal conductivity (<1 Wm^(−1) K^(−1)) of 774 Heusler structures is gained by p–d orbital hybridization analysis. Additionally, aclass of two-band charge-2 Weyl points, referred to as “double Weyl points”, are found in 68% and 87% of 1662 half and 1550quaternary Heuslers, respectively.

关键词： properties phonon spanning