6,117 results match your criteria mma


Investigating Nanoparticle Organization in Polymer Matrices during Reaction-Induced Phase Transitions and Material Processing.

ACS Appl Mater Interfaces 2021 Sep 25;13(35):42104-42113. Epub 2021 Aug 25.

Department of Chemical and Biomolecular Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States.

Controlling nanoparticle organization in polymer matrices has been and is still a long-standing issue and directly impacts the performance of the materials. In the majority of instances, simply mixing nanoparticles and polymers leads to macroscale aggregation, resulting in deleterious effects. An alternative method to physically blending independent components such as nanoparticle and polymers is to conduct polymerizations in one-phase monomer/nanoparticle mixtures. Read More

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September 2021

Profiling Combat Sports Athletes: Competitive History and Outcomes According to Sports Type and Current Level of Competition.

Sports Med Open 2021 Aug 25;7(1):63. Epub 2021 Aug 25.

School of Arts and Humanities, Psychology and Criminology, Edith Cowan University, Joondalup, WA, Australia.

Background: This study aimed to investigate the competitive history (the age when training and competing started), training habits and patterns of winning and losing of competitive combat sports athletes across different combat sports as well as the level of competition (e.g. amateurs, state-level and elite). Read More

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Molecular Mirror Technology Facilitates High-Throughput, Accurate SARS-CoV-2 Testing.

Microbiol Spectr 2021 09 25;9(1):e0039221. Epub 2021 Aug 25.

Department of Pathology, University of California, San Diegogrid.266100.3, La Jolla, California, USA.

Tests to diagnose acute SARS-CoV-2 infection are at the center of controlling the COVID-19 pandemic. Rapid tests benefit from providing quick results but suffer from lower sensitivity, while PCR tests usually take longer to provide more reliable results and can be difficult to scale to meet population needs. We evaluated the diagnostic efficacy of a Molecular Mirror assay (MMA) using nucleic acid extraction and a nucleic acid extraction-free method to determine its ability to identify SARS-CoV-2 in nasal specimens from individuals suspected of having SARS-CoV-2. Read More

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September 2021

Long-term mortality in patients with moyamoya angiopathy according to stroke presentation type in South Korea.

Acta Neurochir (Wien) 2021 Aug 24. Epub 2021 Aug 24.

Department of Biostatistics, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.

Background: Incidence, prevalence, and long-term survival outcomes in patients with moyamoya angiopathy (MMA) according to stroke presentation type and age group have not been clearly elucidated.

Methods: We investigated mortality in patients with MMA (moyamoya disease, probable moyamoya disease, moyamoya syndrome) of whose International Classification Disease 10 code was I67.5 from 2006 to 2015 using the Korean National Health Insurance database. Read More

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Cobalamin and folate status in women during early pregnancy in Bhaktapur, Nepal.

J Nutr Sci 2021;10:e57. Epub 2021 Aug 9.

Centre for Intervention Science in Maternal and Child Health, Centre for International Health, Department of Global Public Health and Primary Care, University of Bergen, Bergen, Norway.

The demand for cobalamin (vitamin B12) and folate is increased during pregnancy, and deficiency during pregnancy may lead to complications and adverse outcomes. Yet, the status of these micronutrients is unknown in many populations. We assessed the concentration of cobalamin, folate and their functional biomarkers, total homocysteine (tHcy) and methylmalonic acid (MMA), in 561 pregnant women enrolled in a community-based randomised controlled trial in Bhaktapur, Nepal. Read More

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Laser performance and investigation of the optimal density functional and the dependence of the basis sets for (E, E)-2,5-bis (3,4-dimethoxystyryl) pyrazine (BDP) molecule.

J Mol Model 2021 Aug 20;27(9):256. Epub 2021 Aug 20.

Chemistry Department, Faculty of Science, Tanta University, Tanta, Egypt.

This manuscript includes some photophysical parameters and some optical properties such as absorption and emission spectra of the (E, E)-2,5-bis (3,4-dimethoxystyryl) pyrazine (BDP) by applying sol-gel and copolymer matrices. The BDP molecular structure is incorporated in sol-gel matrix and copolymer of methyl methacrylate (MMA) and 2-hydroxyethyl methacrylate (HEMA). In case of sol-gel matrix, the BDP molecular structure has higher quantum yield in addition to photostability maxima. Read More

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Organic Persistent Luminescent Materials: Ultralong Room-Temperature Phosphorescence and Multicolor-Tunable Afterglow.

ACS Appl Mater Interfaces 2021 Sep 19;13(34):41131-41139. Epub 2021 Aug 19.

Key Lab of Environment-friendly Chemistry and Application in Ministry of Education, and Key Laboratory of Advanced Functional Polymer Materials of Colleges, Universities of Hunan Province and College of Chemistry, Xiangtan University, Xiangtan, Hunan 411105, China.

Organic persistent luminescent materials have attracted special attention due to their significant applications in optoelectronics, sensors, and security technology areas. In this work, a series of organic compounds (1-4) with twisted electron donor-acceptor structures are successfully designed and synthesized, and then the resultant compounds are dissolved in methyl methacrylate (MMA), and afterward, in situ polymerization realizes single-molecular organic room-temperature phosphorescent (RTP) materials (P1-P4). All RTP materials show long lifetime, especially P2 exhibits ultralong lifetime of 1. Read More

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September 2021

Cytotoxicity and cell response of preosteoblast in calcium sulfate-augmented PMMA bone cement.

Biomed Mater 2021 Aug 19;16(5). Epub 2021 Aug 19.

Department of Orthopedic Surgery, Chang Gung Memorial Hospital, Taoyuan, Taiwan.

Poly(methyl methacrylate) (PMMA) has been widely used in orthopedic applications, but bone ingrowth and toxic monomer release are drawback of this material. Particle reinforcement with osteoconductive substitute, such as calcium sulfate (CaSO), is one of the solutions used to modify PMMA bone cement. The current study investigated the mechanical, chemical and biological properties of CaSO-augmented bone cement. Read More

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Effects of ytterbium laser surface treatment on the bonding of two resin cements to zirconia.

Dent Mater J 2021 Aug 19. Epub 2021 Aug 19.

Division of Removable Prosthodontics, Department of Oral Rehabilitation, Fukuoka Dental College.

Monolithic zirconia crowns bonded to zirconia abutments have become more commonly used in the construction of cement-retained implant superstructures. The present study aimed to examine the effects of laser surface treatments on the bond strength of two resin cements to zirconia. Three types of surfaces were examined: untreated, alumina blasted, and ytterbium laser treated; and two types of resin cements: 4-META/MMA-TBB resin cement and composite resin cement. Read More

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Preparation of Polypropylene-Composite Particles by Dispersion Polymerization.

Langmuir 2021 Aug 19;37(34):10388-10393. Epub 2021 Aug 19.

Department of Chemical Science and Engineering, Graduate School of Engineering, Kobe University, Rokko, Nada, Kobe 657-8501, Japan.

Polypropylene (PP)/poly(benzyl methacrylate) (PBzMA) composite particles were prepared by dispersion polymerization of benzyl methacrylate (BzMA) in the presence of PP particles without a conventional dispersant. The polymerization process yielded a stable emulsion of composite particles with a "currant bun"-like morphology consisting of a PBzMA core and PP bumps, indicating that the PP particles operate as colloidal stabilizers. Conversely, when BzMA was replaced with styrene as the monomer, dispersion polymerization yielded a large amount of aggregates. Read More

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Climate survey development to assess the DEI gap across surgical specialties in an academic institution.

Am J Surg 2021 Aug 10. Epub 2021 Aug 10.

University of Alabama at Birmingham Medical Center, Department of Surgery, 1808 7th Ave S BDB 202, Birmingham, AL, 35233, USA; American College of Surgeons, Division of Research and Optimal Patient Care, 633 N St Clair St, Chicago, IL, 60611, USA. Electronic address:

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Topical mitomycin C application post endoscopic removal of antrochoanal polyp.

Laryngoscope Investig Otolaryngol 2021 Aug 28;6(4):619-622. Epub 2021 Jun 28.

Otorhinolaryngology Head and Neck Surgery Department, Faculty of Medicine Zagazig University Zagazig Egypt.

Objective: Assessment the effect of topical application of mitomycin-C (MMC) after endoscopic removal of antrochoanal polyp (ACP) on its recurrence rate.

Methods: This prospective study was done on patients with ACP. Endoscopic nasal surgery has been done to remove the polyp after wide middle meatal antrostomy. Read More

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Enantioseparation of mandelic acid and substituted derivatives by high-performance liquid chromatography with hydroxypropyl-β-cyclodextrin as chiral mobile additive and evaluation of inclusion complexes by molecular dynamics.

Chirality 2021 Oct 14;33(10):675-684. Epub 2021 Aug 14.

College of Pharmaceutical Science, Zhejiang University of Technology, Hangzhou, P.R. China.

The enantioseparation and resolution mechanism of mandelic acid (MA), 4-methoxymandelic acid (MMA), and 4-propoxymandelic acid (PMA) were investigated by reversed-phase high-performance liquid chromatography (HPLC) with 2-hydroxypropyl-β-cyclodextrin (HP-β-CD) as a chiral mobile-phase additive and molecular dynamics simulation. The suitable chromatographic conditions for the enantioseparation of MA, MMA, and PMA were obtained. Under the selected chromatographic conditions, these enantiomers could achieve baseline separation. Read More

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October 2021

Phenotypic and genotypic analysis of children with methylmalonic academia: A single-center study in China and a recent literature review.

Clin Chim Acta 2021 Aug 10;522:14-22. Epub 2021 Aug 10.

Tianjin Pediatric Research Institute, Tianjin Children's Hospital (Children's Hospital of Tianjin University), Tianjin 300134, China; Tianjin Key Laboratory of Birth Defects for Prevention and Treatment, Tianjin 300134, China.

Background: Methylmalonic acidemia (MMA) is a rare inherited metabolic disease caused by methylmalonyl-CoA deficiency or cobalamin metabolism disorder. It is mainly inherited in autosomal recessive mode. According to whether combined with homocysteinemia and the causative genes, it can be divided into many different subtypes. Read More

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True terminal pentafurcation of the external carotid artery and terminal trifurcation of the contralateral one, occipitoauricular trunk, retropharyngeal internal carotid artery.

Surg Radiol Anat 2021 Aug 11. Epub 2021 Aug 11.

Department 11 of Plastic and Reconstructive Surgery and Pediatric Surgery, Faculty of Medicine, "Carol Davila" University of Medicine and Pharmacy, Bucharest, Romania.

The external carotid artery (ECA) commonly ascends in the retromandibular fossa and bifurcates posteromedial to the neck of the mandible into the maxillary (MA) and superficial temporal (STA) arteries. In its course in the neck, the ECA gives off the superior thyroid, lingual (LA), facial (FA), ascending pharyngeal (APA), occipital (OA) and posterior auricular (PAA) arteries. When the computed tomography angiograms of a 65-year-old male were evaluated, extremely rare anatomical variations of both ECAs were found. Read More

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Mechanistic Study of Membrane Disruption by Antimicrobial Methacrylate Random Copolymers by the Single Giant Vesicle Method.

Langmuir 2021 08 11;37(33):9982-9995. Epub 2021 Aug 11.

Division of Materials Science, Graduate School of Science and Technology, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara 6300192, Japan.

Cationic amphiphilic polymers have been a platform to create new antimicrobial materials that act by disrupting bacterial cell membranes. While activity characterization and chemical optimization have been done in numerous studies, there remains a gap in our knowledge on the antimicrobial mechanisms of the polymers, which is needed to connect their chemical structures and biological activities. To that end, we used a single giant unilamellar vesicle (GUV) method to identify the membrane-disrupting mechanism of methacrylate random copolymers. Read More

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Multimodal Analgesia in Head and Neck Free Flap Reconstruction: A Systematic Review.

Otolaryngol Head Neck Surg 2021 Aug 10:1945998211032910. Epub 2021 Aug 10.

Department of Otorhinolaryngology, University of Pennsylvania, Philadelphia, Pennsylvania, USA.

Objective: Postoperative pain after head and neck cancer surgery is commonly treated with opioids, which are associated with considerable side effects. The objective of this study is to analyze the safety and efficacy of using multimodal analgesia (MMA) for patients undergoing head and neck cancer surgery with free flap reconstruction.

Data Sources: A systematic search was conducted in PubMed, Cochrane, Embase, Scopus, and clinicaltrials. Read More

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Influence of Osmotic Pressure on Nanostructures in Thin Films of a Weakly-Segregated Block Copolymer and Its Blends with a Homopolymer.

Polymers (Basel) 2021 Jul 28;13(15). Epub 2021 Jul 28.

Department of Chemical and Materials Engineering, National Central University, Taoyuan 32001, Taiwan.

We studied the influence of osmotic pressure on nanostructures in thin films of a symmetric weakly-segregated polystyrene-block-poly (methyl methacrylate), P(S-b-MMA), block copolymer and its mixtures with a polystyrene (PS) homopolymer of various compositions. Thin films were deposited on substrates through surface neutralization. The surface neutralization results from the PS mats, which were oxidized and cross-linked by UV-light exposure. Read More

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Serum Methylmalonic Acid Mediates Aging-Related Cancer Aggressiveness.

Authors:

Cancer Discov 2020 Oct 28;10(10):1441. Epub 2020 Aug 28.

Methylmalonic acid (MMA) from older donors' sera promoted cancer-cell invasiveness and metastasis. Read More

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October 2020

An atlas of metallome and metabolome interactions and associations with incident diabetes in the Strong Heart Family Study.

Environ Int 2021 Aug 5;157:106810. Epub 2021 Aug 5.

Department of Medicine, School of Medicine, Emory University, Atlanta, GA 30322, USA.

Background: Chronic exposure to certain metals plays a role in disease development. Integrating untargeted metabolomics with urinary metallome data may contribute to better understanding the pathophysiology of diseases and complex molecular interactions related to environmental metal exposures. To discover novel associations between urinary metal biomarkers and metabolism networks, we conducted an integrative metallome-metabolome analysis using a panel of urinary metals and untargeted blood metabolomic data from the Strong Heart Family Study (SHFS). Read More

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Controlled (Co)Polymerization of Methacrylates Using a Novel Symmetrical Trithiocarbonate RAFT Agent Bearing Diphenylmethyl Groups.

Molecules 2021 Jul 30;26(15). Epub 2021 Jul 30.

Centro de Investigación en Química Aplicada, Enrique Reyna Hermosillo, No. 140, Col. San José de los Cerritos, Saltillo 25294, Mexico.

Herein, we report a novel type of symmetrical trithiocarbonate chain transfer agent (CTA) based diphenylmethyl as R groups. The utilization of this CTA in the Reversible Addition-Fragmentation chain Transfer (RAFT) process reveals an efficient control in the polymerization of methacrylic monomers and the preparation of block copolymers. The latter are obtained by the (co)polymerization of styrene or butyl acrylate using a functionalized macro-CTA polymethyl methacrylate (PMMA) previously synthesized. Read More

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Influence of Fluorine-Containing Monomer Content on the Hydrophobic and Transparent Properties of Nanohybrid Silica Polyacrylate Coating Materials.

Materials (Basel) 2021 Jul 30;14(15). Epub 2021 Jul 30.

Department of Chemical and Materials Engineering, National Kaohsiung University of Science and Technology, Kaohsiung 807, Taiwan.

Nanosilica-modified, fluorine-containing polyacrylate hybrid coating materials, consisting of dodecafluoroheptyl methacrylate (DFMA), methyl methacrylate (MMA), 2-ethyl hexyl acrylate (2-EHA), 3-(trimethoxysilyl) propyl methacrylate (KH-570), and tetraethylorthosilicate (TEOS), are synthesized successfully by free radical polymerization and the sol-gel process. It is revealed that the content of the fluorine-containing polyacrylate hybrid coating materials from DFMA monomers significantly improves the properties of the films. The polyacrylate coating film prepared with a weight ratio of DFMA/MMA at 1:5 exhibits the largest water contact angle of 105. Read More

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MR Imaging of Cochlear Modiolus and Endolymphatic Hydrops in Patients With Menière's Disease.

Front Surg 2021 20;8:667248. Epub 2021 Jul 20.

Otorhinolaryngology Department, Centro Hospitalar Universitário Lisboa Norte, Lisbon, Portugal.

Menière's disease (MD) is an inner ear disorder characterized by recurrent episodes of spontaneous vertigo, unilateral low-frequency sensorineural hearing loss, tinnitus, and aural fullness. Current diagnosis still often has to rely on subjective and audiometric criteria only, although endolymphatic hydrops is recognized as the pathophysiological substrate of the disease, having been demonstrated in anatomical pathological studies and by magnetic resonance (MRI). The modiolus has a close functional and anatomical relationship with the cochlear nerve and membranous labyrinth and can be evaluated with MRI but no data exist on the modiolar size in MD. Read More

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Does the bonding effectiveness of a fiber post/resin composite benefit from mechanical or chemical treatment? Seven methods for saliva-contaminated surfaces.

J Prosthodont Res 2021 Aug 4. Epub 2021 Aug 4.

Department of Fixed Prosthodontics, Osaka University Graduate School of Dentistry, Osaka.

Purpose: This study examined four cleaning methods and three chemical treatments for artificial saliva-contaminated fiber posts in terms of bonding durability to resin composite core materials.

Methods: Non-contaminated fiber posts (Tokuyama FR Post, Tokuyama Dental) and those contaminated (GC Fiber Post, GC) with artificial saliva (Saliveht Aerosol, Teijin Pharma) were used. Washing and drying (WD), alcohol cleaning (AlC), H3PO4 etching (P/WD), alumina blasting (B/D) for decontamination and silanization (Clearfil Ceramic Primer Plus, Kuraray Noritake Dental, Si), resin priming (HC Primer, Shofu, MMA), and bonding resin application (Clearfil Universal Bond Quick, Kuraray Noritake Dental, BR) for chemical treatment were performed. Read More

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Traumatic epidural hematoma treated with endovascular coil embolization.

Surg Neurol Int 2021 6;12:322. Epub 2021 Jul 6.

Department of Neurosurgery, National Brain Aneurysm and Tumor Center, Minneapolis, Minnesota, United States.

Background: Traumatic cerebrovascular injury may result in epidural hematoma (EDH) from laceration of the middle meningeal artery (MMA), which is a potentially life-threatening emergency. Treatment ranges from surgical evacuation to conservative management based on a variety of clinical and imaging factors.

Case Description: A 14-year-old male presented to our institution after falling from his bicycle with traumatic subarachnoid hemorrhage and a right frontotemporal EDH. Read More

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Multimodal Analgesic Management for Lumbar Decompression Surgery in the Ambulatory Setting: Clinical Case Series and Review of the Literature.

World Neurosurg 2021 Jul 31. Epub 2021 Jul 31.

Department of Orthopaedic Surgery, Rush University Medical Center, Chicago, IL, USA. Electronic address:

Background: Effective pain control is vital for successful surgery in the ambulatory setting. Our study aims to characterize a case series of patients who underwent lumbar decompression (LD) in the ambulatory surgical center (ASC) with the use of a multimodal analgesic (MMA) protocol.

Methods: A prospective surgical registry was retrospectively assessed for patients who underwent single or multilevel LD in an ASC using MMA from 2013 to 2019. Read More

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Determination of Cytokines and Oxidative Stress Biomarkers in Cognitive Impairment Induced by Methylmalonic Acidemia.

Neuroimmunomodulation 2021 2;28(3):178-186. Epub 2021 Aug 2.

Department of Medical Laboratory, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, Beijing, China.

Objective: Methylmalonic acidemia (MMA) is the most common organic acidemia in children. Many patients with MMA suffered from cognitive impairments. The aim of this study was to identify the significance of cytokines and oxidative stress biomarkers in MMA-induced cognitive impairment. Read More

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Rectus sheath block and emergency midline laparotomy at a hospital in Ethiopia: A prospective observational study.

Ann Med Surg (Lond) 2021 Aug 15;68:102572. Epub 2021 Jul 15.

Department of Anesthesia, College of Health Sciences, Debre Tabor University, Debre Tabor, Ethiopia.

Background: Midline laparotomy is associated with severe postoperative pain. Literature showed controversial results regarding the efficacy of the rectus sheath block.

Methods: This is a prospective cohort study that recruits 30 patients in the rectus sheath block (RSB) group and 30 patients in the multimodal analgesia (MMA) group who underwent emergency midline laparotomy. Read More

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Multi-omic profiling of plasma reveals molecular alterations in children with COVID-19.

Theranostics 2021 6;11(16):8008-8026. Epub 2021 Jul 6.

Guangzhou Institute of Pediatrics, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, 510120, China.

Children usually develop less severe symptoms responding to Coronavirus Disease 2019 (COVID-19) than adults. However, little is known about the molecular alterations and pathogenesis of COVID-19 in children. We conducted plasma proteomic and metabolomic profilings of the blood samples of a cohort containing 18 COVID-19-children with mild symptoms and 12 healthy children, which were enrolled from hospital admissions and outpatients, respectively. Read More

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How latex film formation and adhesion at the nanoscale correlate to performance of pressure sensitive adhesives with cellulose nanocrystals.

Philos Trans A Math Phys Eng Sci 2021 Sep 2;379(2206):20200330. Epub 2021 Aug 2.

Chemical Engineering Department, McMaster University, 1280 Main Street West, Hamilton, Ontario, Canada L8S 4L8.

Emulsion polymerized latex-based pressure-sensitive adhesives (PSAs) are more environmentally benign because they are synthesized in water but often underperform compared to their solution polymerized counterparts. Studies have shown a simultaneous improvement in the tack, and peel and shear strength of various acrylic PSAs upon the addition of cellulose nanocrystals (CNCs). This work uses atomic force microscopy (AFM) to examine the role of CNCs in (i) the coalescence of hydrophobic 2-ethyl hexyl acrylate/-butyl acrylate/methyl methacrylate (EHA/BA/MMA) latex films and (ii) as adhesion modifiers over multiple length scales. Read More

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September 2021