Article
Chemistry, Multidisciplinary
Melissa A. Reith, Irene De Franceschi, Matthieu Soete, Nezha Badi, Resat Aksakal, Filip E. Du Prez
Summary: The study proposes a robust strategy for the synthesis of sequence-defined, discrete star-shaped macromolecules. The iterative approach allows for the preparation of asymmetrically branched macromolecules with high purity and yields, enabling sequence definition, precise insertion of branching points, and orthogonal end-group functionalization.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Polymer Science
Wencheng Shi, Boyu Wu, Xiaofeng Guo, Anchao Feng, San H. Thang
Summary: Fluorescent end-functional mikto-arm star copolymers were synthesized using a novel method and the linear correlation between fluorescence intensity and polymer concentration was verified. This method enables the quantitative analysis of the arm components of star polymers, providing a new approach for the characterization of star polymers.
Article
Polymer Science
Ethan W. Kent, Evan M. Lewoczko, Bin Zhao
Summary: This article investigates the conformational behavior of binary heterografted three-arm star molecular bottlebrushes in aqueous solutions in response to pH changes and addition of salts, revealing different conformational transitions based on the side chain structures and the greater efficiency of superchaotropic anions in inducing shape changes.
Article
Polymer Science
Chulu Zhou, Cuiping Hou, Lijie Wang, Wei Chen, Jianhua Cheng
Summary: In this study, norbornene macromonomers with PS or PtBA side chains were synthesized using a combination of ATRP and click reactions. The resulting linear and star-shaped brush block copolymers showed the ability to self-assemble into spherical micelles in solution. Interestingly, star diblock copolymers exhibited more stable properties compared to linear analogues, with less sensitivity to changes in composition.
Article
Polymer Science
Peter J. Mons, Nora Fribiczer, Kathrin Kowalczuk, Purushottam Poudel, Sebastian Seiffert, Felix H. Schacher
Summary: In this study, we report the synthesis of a novel double hydrophilic star-shaped block copolymer and investigate its solution properties under different solution pH conditions. We find that even short stickers can enhance the aggregation tendency at low pH values, resulting in aggregate sizes beyond 1 μm.
Article
Polymer Science
Eleni Vlassi, Aristeidis Papagiannopoulos, Stergios Pispas
Summary: This study investigates the synthesis and self-assembly of amphiphilic mikto-arm star copolymers with mixed arms in aqueous media. The star copolymers organize into nanostructures, with the lower hydrophobic content star forming smaller aggregates with higher critical aggregation concentration. The ability of the synthesized mikto-arm stars to encapsulate curcumin while maintaining its fluorescence properties is demonstrated, with different responses observed depending on the hydrophobic content of the star copolymer.
JOURNAL OF POLYMER SCIENCE
(2021)
Article
Chemistry, Multidisciplinary
Nari Kang, Sangho Cho, Eric E. Leonhardt, Chun Liu, Stanislav V. Verkhoturov, William Henry Hunter Woodward, Michael J. Eller, Tianyu Yuan, Thomas C. Fitzgibbons, Yannick P. Borguet, Ashlee A. Jahnke, Anatoliy N. Sokolov, Travis McIntire, Carl Reinhardt, Lei Fang, Emile A. Schweikert, Liam Patrick Spencer, Guorong Sun, Guohua Xie, Peter Trefonas, Karen L. Wooley
Summary: By constructing brush-like polymers, the vertical alignment of polymer side chains in thin films was achieved, leading to an improvement in the efficiency of organic light-emitting diodes.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Polymer Science
Kevin Nixon, Rui Sun, Yossef A. Elabd
Summary: In this study, 3-, 4-, and 6-arm star poly(vinylbenzyl methylimidazolium chloride) were synthesized via reversible addition-fragmentation chain transfer (RAFT) polymerization with a core-first approach, resulting in uniform number and length of polymer arms. The effect of initial radical initiator concentration and number of functional groups per multifunctional RAFT agent on polymerization reaction kinetics was investigated. Increasing the initial radical initiator concentration led to faster monomer conversion, while decreasing the number of functional groups per multifunctional RAFT agent resulted in a decrease in the initial rate retardation in reaction kinetics. This work demonstrates a facile method for synthesizing ion-containing star polymers with uniform number and length of polymer arms, showing potential as a new material for electrochemical energy devices due to property enhancements associated with their star polymer architecture.
Article
Chemistry, Physical
Marco Krummenacher, Martin O. O. Steinhauser
Summary: In this study, molecular dynamics computer simulations were used to investigate the complexation and clustering of branched polymers, focusing on star and bottle-brush polymers. The results provide insights into the factors governing the formation of polymer clusters and offer guidance for designing and preparing various types of polymer clusters. The study highlights the role of the hydrophobic parts of polymers in the self-assembly process.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Polymer Science
Kristin M. Fuller, Deztany Clay, Sarah R. Almahdali, Anastasia Paterson, Claire M. Barratt, Victor Desyatkin, Valentin O. Rodionov
Summary: A general method for the arm-first synthesis of star polymers is introduced, which involves a formal A2 + B3 step-growth process. The technique utilizes copper-catalyzed azide-alkyne cycloaddition (CuAAC) reaction between N3-C(CR2)C-N3 macromonomers and a trifunctional alkyne crosslinker. By systematically evaluating various synthetic conditions, the effects of macromonomer size and feed ratio on the product structures have been investigated. The broad scope of this methodology, enabled by the functional group tolerance of CuAAC, allows for its extension to other macromonomers.
EUROPEAN POLYMER JOURNAL
(2023)
Article
Chemistry, Multidisciplinary
Petra Bacova, Emmanouil Glynos, Spiros H. Anastasiadis, Vagelis Harmandaris
Summary: This study investigates the behavior of amphiphilic mikto-arm star copolymers in a selective polymer host through atomistic molecular dynamics simulations. The number of arms influences the self-assembly of the mikto-arm stars into cylindrical-like objects or a percolated network within the host matrix. The segmental dynamics of the stars is mainly controlled by their architecture and the heterogeneous local environment formed by intra- and intermolecular nanosegregation.
Article
Polymer Science
Fannie Burgevin, Alexia Hapeshi, Ji-Inn Song, Marta Omedes-Pujol, Annette Christie, Christopher Lindsay, Sebastien Perrier
Summary: Cationic polymers can be synthesized and used as vectors for efficient transportation and protection of nucleic acids. The structure and architecture of the polymers have an influence on the hydrolysis of the polymer side chains and the transfection efficiency. The stars, with a high number of well-defined arms, showed better transfection efficiency compared to the corresponding arm structures.
Article
Polymer Science
Aliaksei Aliakseyeu, Raman Hlushko, Svetlana A. Sukhishvili
Summary: We report the synthesis of a temperature-responsive polymer and study its phase transition behavior and interactions with molecules in water solutions. The results show that the molecular structure of the polymer has minimal effect on its phase transition temperature, while the presence of hydrogen-bond acceptors can suppress the transition temperature. In addition, star-shaped polymers have a higher ability to capture drug molecules and can be used for controlled release by adjusting the temperature.
Article
Polymer Science
Paulina Teper, Anna Celny, Agnieszka Kowalczuk, Barbara Mendrek
Summary: In this study, nanostructures composed of star-shaped polycations were used to prepare antibacterial materials. It was found that two different modes of star nanoparticles were observed in water, regardless of the quaternizing agent used. Comparison of the quaternary reaction in solution and on the surface showed that the reaction in solution is influenced by the alkyl chain length of the quaternary agent, while this relationship is not observed on the surface. The nanolayers quaternized with shorter alkyl bromide exhibited the best antibacterial properties, with 100% growth inhibition of E. coli and B. subtilis observed after 24 hours of contact.
Article
Polymer Science
Chengmeng Wang, Yibo Wu, Yihui Zhu, Hongbing Ma, Mingzu Zhang, GengXin Liu, Jinlin He, Peihong Ni
Summary: This study focuses on investigating eight-arm tapered star copolymers. The microstructures of tapered copolymers were confirmed using various techniques, and the properties of tapered and diblock copolymers were compared. The ratio of soft and hard segments greatly affects the thermal and mechanical properties of the tapered copolymers. Introduction of the star-shaped structure increases the thermal stability of the copolymers.
Article
Dentistry, Oral Surgery & Medicine
Huy Van Nguyen, Diep Hong Ha, An Thi Minh Dao, Rebecca K. Golley, Jane A. Scott, John Spencer, Lucinda Bell, Gemma Devenish-Coleman, Loc Giang Do
Summary: This study compared three approaches to managing missing data and found that each approach identified three trajectories of children's free sugars intake. The findings were consistent across the different approaches, suggesting the use of pairwise approach in future analyses to optimize sample size and statistical power.
COMMUNITY DENTISTRY AND ORAL EPIDEMIOLOGY
(2023)
Article
Chemistry, Multidisciplinary
Runze Liu, Zehao Sun, Hejin Huang, Jeremiah A. Johnson, Alfredo Alexander-Katz, Caroline A. Ross
Summary: Diblock Janus-type A-branch-B bottlebrush copolymers (di-JBBCPs) consist of a backbone with alternating A and B side chains, allowing for microphase separation perpendicular to the backbone. The self-assembly of di-JBBCPs was theoretically investigated using a reparametrized dissipative particle dynamics (DPD) model, and the results were compared with experimental data. The model showed good correspondence with the experimentally observed cylinder, gyroid, and lamellar morphologies, and predicted additional spherical phases, indicating the diversity of morphologies achievable with complex BCP molecular architectures.
Article
Environmental Sciences
Truong X. Ngo, Ha Pham, Hieu D. T. Phan, Anh T. N. Nguyen, Hien T. To, Thanh T. N. Nguyen
Summary: This article introduces an approach to estimate daily PM2.5 concentration in Vietnam from 2012 to 2020. The approach utilizes ground PM2.5 measurements, satellite aerosol optical depth, meteorological and land use maps, and applies a mixed effect model (MEM) to account for cloudy conditions. The resulting dataset provides the first long-term, comprehensive, and high-quality PM2.5 dataset for Vietnam, and has been used in various studies and applications in the environment and public health.
SCIENCE OF THE TOTAL ENVIRONMENT
(2023)
Article
Biology
Abby Sarkar, Yinhua Jin, Brian C. DeFelice, Catriona Y. Logan, Yan Yang, Teni Anbarchian, Peng Wu, Maurizio Morri, Norma F. Neff, Huy Nguyen, Eric Rulifson, Matthew Fish, Avi Gurion Kaye, Azalia M. Martinez Jaimes, Roel Nusse, Pramod Mistry
Summary: Intermittent fasting promotes rapid hepatocyte proliferation and maintains liver homeostasis. This study challenges the widely held view that liver tissue is mostly quiescent and provides the first example of dietary influence on adult hepatocyte proliferation.
Article
Chemistry, Multidisciplinary
Keith E. L. Husted, Abraham Herzog-Arbeitman, Denise Kleinschmidt, Wenxu Zhang, Zehao Sun, Alyssa J. Fielitz, An N. Le, Mingjiang Zhong, Jeremiah A. Johnson
Summary: Graft copolymers provide a versatile platform for designing self-assembling materials, but controlling their thermomechanical and morphological properties has been challenging. In this study, a strategy for controlling these properties by varying pendant groups was discovered. This strategy allows for the design of a wide range of materials with different properties. The study also simplifies graft copolymer synthesis and provides access to a diverse family of silicone-based materials.
ACS CENTRAL SCIENCE
(2023)
Article
Chemistry, Multidisciplinary
Gabriel Bradford, Jeffrey Lopez, Jurgis Ruza, Michael A. Stolberg, Richard Osterude, Jeremiah A. Johnson, Rafael Gomez-Bombarelli, Yang Shao-Horn
Summary: Solid polymer electrolytes (SPEs) have the potential to improve lithium-ion batteries by enhancing safety and enabling higher energy densities. A chemistry-informed machine learning model was developed to predict ionic conductivity of SPEs, using data from hundreds of experimental publications. The model encodes the Arrhenius equation into the readout layer of a neural network and has improved accuracy in predicting ionic conductivity.
ACS CENTRAL SCIENCE
(2023)
Article
Chemistry, Physical
Matthew A. Pearson, Sachin Bhagchandani, Mircea Dinca, Jeremiah A. Johnson
Summary: A strategy of mixing multivalent polymer ligands with MOF-forming linkers and free linkers is investigated to alter the degree of polymer incorporation in polyMOFs and tune their properties, resulting in polyMOFs with superior N-2 and CO2 uptake. The mixed ligand approach is further extended to create multivariate (MTV)-polyMOFs without the addition of small molecule components.
MOLECULAR SYSTEMS DESIGN & ENGINEERING
(2023)
Article
Chemistry, Multidisciplinary
Herbert Wakefield, Ilia Kevlishvili, Kelsie E. Wentz, Yunxin Yao, Tatiana B. Kouznetsova, Sophia J. Melvin, Em G. Ambrosius, Abraham Herzog-Arbeitman, Maxime A. Siegler, Jeremiah A. Johnson, Stephen L. Craig, Heather J. Kulik, Rebekka S. Klausen
Summary: The cis- and trans-isomers of a silacycloheptene were selectively synthesized using a silyl dianion, providing a novel method for studying strained cycloalkenes. Quantum chemical calculations and crystallographic signatures confirmed that the trans-isomer is more strained than the cis isomer. The trans-isomer also exhibited unique reactivity in ring-opening metathesis polymerization (ROMP) and showed increased molecular compliance compared to carbon-based analogues.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Polymer Science
Haley K. Beech, Jeremiah A. Johnson, Bradley D. Olsen
Summary: Small angle neutron scattering was used to measure the single chain radii of gyration of end-linked polymer gels before and after cross-linking. The prestrain, which is the ratio of the average chain size in a cross-linked network to that of a free chain in solution, increased as gel synthesis concentration decreased near the overlap concentration. Dilute gels with higher loop fractions were found to be spatially homogeneous. The results provide a reference for network theories that rely on prestrain for the calculation of mechanical properties.
Article
Health Care Sciences & Services
Hung Manh Pham, Anh Phuong Nguyen, Huong Thi Thu Nguyen, Tam Ngoc Nguyen, Thanh Xuan Nguyen, Thu Thi Hoai Nguyen, Huong Thi Thanh Nguyen, Anh Trung Nguyen, Quang Ngoc Nguyen, Giang Song Tran, Huyen Thi Thanh Vu
Summary: The study aimed to explore the impact of frailty on in-hospital adverse outcomes and net adverse clinical events (NACE) in older patients with acute coronary syndrome. The results showed that over 30% of ACS older patients presented with frailty, which was associated with an increased risk of in-hospital adverse outcomes and NACE.
JOURNAL OF MULTIDISCIPLINARY HEALTHCARE
(2023)
Article
Health Care Sciences & Services
Britt Klein, Huy Nguyen, Suzanne McLaren, Brooke Andrews, Kerrie Shandley
Summary: This study aimed to explore the preliminary effectiveness and acceptability of a new fully automated self-help biopsychosocial transdiagnostic digital intervention called Life Flex. The results showed that Life Flex program had early support in reducing anxiety, depression, psychological distress, and emotional dysregulation, while improving emotional, social, and psychological well-being, optimism, and health-related quality of life.
JMIR FORMATIVE RESEARCH
(2023)
Article
Fisheries
Hans Stubbe Solgaard, Yingkui Yang, Thong Tien Nguyen
Summary: The welfare of farmed fish has become an important consideration for consumers when making purchasing decisions. This study aims to investigate consumers' preferences and willingness to pay for farmed fish welfare and also examines the influence of social desirability on their responses. An online survey was conducted among Danish consumers, using a discrete choice experiment to elicit their preferences and willingness to pay for fish welfare. The findings reveal that attributes such as fish form, labeling, price, and premium have an impact on consumers' choice of fish. The study also highlights the presence of consumer heterogeneity in preferences and willingness to pay, and the influence of social desirability bias on the valuation of fish welfare.
Article
Polymer Science
Tetsu Ouchi, Wencong Wang, Brooke E. E. Silverstein, Jeremiah A. A. Johnson, Stephen L. L. Craig
Summary: The influence of strand length on deformation and tension in a polymer network was studied using mechanophore force probes. It was found that the critical strain at which measurable mechanochromism is observed is correlated with the strain hardening of the matrix, but independent of the molecular length of the probes. The rate of decoloration during relaxation of the network was found to depend on the relaxing strain, indicating the effect of residual tension on the reversion reaction.
Article
Chemistry, Multidisciplinary
Keith E. L. Husted, Abraham Herzog-Arbeitman, Denise Kleinschmidt, Wenxu Zhang, Zehao Sun, Alyssa J. Fielitz, An N. Le, Mingjiang Zhong, Jeremiah A. Johnson
Summary: Based on experimental results from a library of 92 polynorbornene-graft-polydimethylsiloxane (PDMS) copolymers, a versatile backbone-pendant sequence-control strategy is discovered, which provides a simple method for precisely controlling the thermomechanical and morphological properties of graft copolymers. Small structural variations of pendant groups in small-molecule comonomers have significant impacts on various properties of silicone-based graft copolymers, resulting in a wide range of designable materials properties. This study reveals a new pendant-group-mediated self-assembly strategy that simplifies graft copolymer synthesis and enables the development of a diverse family of silicone-based materials with tailored performance specifications.
ACS CENTRAL SCIENCE
(2023)
Article
Psychology, Clinical
Britt Klein, Erin Oldenhof, Huy Nguyen, Peter Schattner, Kerrie Shandley
Summary: This study is a 6-week trial that aimed to evaluate the impact of a self-help digital intervention on reducing and stopping the use of BDZ medication. The results showed that participants reduced their BDZ use and reported less dependency during the intervention. Additionally, there were improvements in symptoms of anxiety, insomnia, depression, psychological distress, and emotional dysregulation, as well as overall mental wellbeing and quality of life.
JOURNAL OF BEHAVIORAL AND COGNITIVE THERAPY
(2023)
