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Nicholas A. Peppas

Bio: Nicholas A. Peppas is an academic researcher from University of Texas at Austin. The author has contributed to research in topics: Self-healing hydrogels & Drug delivery. The author has an hindex of 141, co-authored 825 publications receiving 90533 citations. Previous affiliations of Nicholas A. Peppas include National Technical University & University of Texas System.


Papers
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Journal ArticleDOI
15 Dec 2016-Nature
TL;DR: Design and test new polymers with clinical uses in mind, urge Nicholas A. Peppas and Ali Khademhosseini.
Abstract: Design and test new polymers with clinical uses in mind, urge Nicholas A. Peppas and Ali Khademhosseini.

30 citations

Journal ArticleDOI
TL;DR: In this paper, poly(methyl methacrylate and co-maleic anhydride) were prepared by free-radical, bulk polymerization using 0.005 mole % benzoyl peroxide as an initiator at 50 °C for 24 h.
Abstract: Poly(methyl methacrylate) and poly(methyl methacrylate–co‐maleic anhydride) were prepared by free‐radical, bulk polymerization using 0.005 mole % benzoyl peroxide as an initiator at 50 °C for 24 h. The resulting transparent cylinders were cut in a lathe into disks of 14‐mm diameter and 2.2‐mm thickness. Samples were also prepared in the form of thin slabs of 14×2×1 mm3. Subsequently, they were irradiated by γ rays at the level of 2–12 Mrad and their molecular weight distribution was determined by gel permeation chromatography. Changes in their structure before and after irradiation were determined by infrared spectroscopy. Their sensitivity values Gs and solubility characteristics in various solvents were determined. Planar and radial dissolution studies were performed in pure methyl ethyl ketone or ethanol at 26 °C. The positions of the solvent/gel and gel/glassy fronts were followed as functions of time. The results were correlated with the pseudosteady‐state solutions of a new mathematical model incorp...

30 citations

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TL;DR: In this article, the organic phase of bituminous coals is represented as a three-dimensional macromolecular network, with chains consisting of aromatic or heterocyclic clusters and smaller connecting bonds, usually of etheric, sulfidicor methylenic nature.
Abstract: The organic phase of bituminous coals may be represented as a three-dimensional macromolecular network, with chains consisting of aromatic or heterocyclic clusters and smaller connecting bonds, usually of etheric, sulfidicor methylenic nature. The crosslinks are covalently bonded bridges or hydrogen-bonded structures. The molecular weight between crosslinks, [Mbar]C, and other parameters of the crosslinked structure can be calculated using the results of various experiments and applying theories widely used for the analysis of polymeric networks, albeit with significant modifications.

30 citations

Journal ArticleDOI
TL;DR: In this article, the authors used magnetic resonance imaging (MRI) to study changing microstructure and molecular motion during dissolution of polyvinyl alcohol (PVA) in water, and measured one-dimensional water concentration profiles as a function of distance from the polymer−solvent interface.
Abstract: Magnetic resonance imaging is used to study changing microstructure and molecular motion during dissolution of poly(vinyl alcohol) (PVA) in water. One-dimensional water concentration profiles were measured as a function of distance from the polymer−solvent interface. Diffusion-weighted profiles were used to calculate the spatial variation of the self-diffusion coefficient of water. The results indicate that diffusion coefficient values decrease toward the glassy core of the polymer. Self-diffusion coefficient values within the dissolving polymer increase with increasing dissolution time, while those near the polymer−solvent interface remain fairly constant. The effect of PVA molecular weight on the dissolution mechanism was investigated, with Mn varying between 35 740 and 133 000. Comparisons were made with a mathematical model for polymer dissolution. The water concentration profiles predicted by the model are qualitatively consistent with the experimentally obtained profiles. In addition, the scaling l...

30 citations


Cited by
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28 Jul 2005
TL;DR: PfPMP1)与感染红细胞、树突状组胞以及胎盘的单个或多个受体作用,在黏附及免疫逃避中起关键的作�ly.
Abstract: 抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1(PfPMP1)与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用,在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员,通过启动转录不同的var基因变异体为抗原变异提供了分子基础。

18,940 citations

Journal Article
TL;DR: This book by a teacher of statistics (as well as a consultant for "experimenters") is a comprehensive study of the philosophical background for the statistical design of experiment.
Abstract: THE DESIGN AND ANALYSIS OF EXPERIMENTS. By Oscar Kempthorne. New York, John Wiley and Sons, Inc., 1952. 631 pp. $8.50. This book by a teacher of statistics (as well as a consultant for \"experimenters\") is a comprehensive study of the philosophical background for the statistical design of experiment. It is necessary to have some facility with algebraic notation and manipulation to be able to use the volume intelligently. The problems are presented from the theoretical point of view, without such practical examples as would be helpful for those not acquainted with mathematics. The mathematical justification for the techniques is given. As a somewhat advanced treatment of the design and analysis of experiments, this volume will be interesting and helpful for many who approach statistics theoretically as well as practically. With emphasis on the \"why,\" and with description given broadly, the author relates the subject matter to the general theory of statistics and to the general problem of experimental inference. MARGARET J. ROBERTSON

13,333 citations

Journal ArticleDOI
TL;DR: The 11th edition of Harrison's Principles of Internal Medicine welcomes Anthony Fauci to its editorial staff, in addition to more than 85 new contributors.
Abstract: The 11th edition of Harrison's Principles of Internal Medicine welcomes Anthony Fauci to its editorial staff, in addition to more than 85 new contributors. While the organization of the book is similar to previous editions, major emphasis has been placed on disorders that affect multiple organ systems. Important advances in genetics, immunology, and oncology are emphasized. Many chapters of the book have been rewritten and describe major advances in internal medicine. Subjects that received only a paragraph or two of attention in previous editions are now covered in entire chapters. Among the chapters that have been extensively revised are the chapters on infections in the compromised host, on skin rashes in infections, on many of the viral infections, including cytomegalovirus and Epstein-Barr virus, on sexually transmitted diseases, on diabetes mellitus, on disorders of bone and mineral metabolism, and on lymphadenopathy and splenomegaly. The major revisions in these chapters and many

6,968 citations

Journal ArticleDOI
TL;DR: This review discusses the synthetic chemistry, fluid stabilization and surface modification of superparamagnetic iron oxide nanoparticles, as well as their use for above biomedical applications.

6,207 citations

Journal ArticleDOI
TL;DR: Probing the various interfaces of nanoparticle/biological interfaces allows the development of predictive relationships between structure and activity that are determined by nanomaterial properties such as size, shape, surface chemistry, roughness and surface coatings.
Abstract: Rapid growth in nanotechnology is increasing the likelihood of engineered nanomaterials coming into contact with humans and the environment. Nanoparticles interacting with proteins, membranes, cells, DNA and organelles establish a series of nanoparticle/biological interfaces that depend on colloidal forces as well as dynamic biophysicochemical interactions. These interactions lead to the formation of protein coronas, particle wrapping, intracellular uptake and biocatalytic processes that could have biocompatible or bioadverse outcomes. For their part, the biomolecules may induce phase transformations, free energy releases, restructuring and dissolution at the nanomaterial surface. Probing these various interfaces allows the development of predictive relationships between structure and activity that are determined by nanomaterial properties such as size, shape, surface chemistry, roughness and surface coatings. This knowledge is important from the perspective of safe use of nanomaterials.

6,075 citations