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Síntese química de poli(3,4-etilenodioxitiofeno) (PEDOT): novas arquiteturas para diferentes aplicações; Chemical synthesis of poly(3,4-ethylenedioxythiophene) (PEDOT): new archictetures for different aplications

Augusto, Tatiana
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 19/12/2012 PT
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Este trabalho apresenta estudos sobre a síntese química do PEDOT com o objetivo de desenvolver diferentes arquiteturas e propriedades para melhorar a taxa de degradabilidade deste polímero. As estratégias foram as preparações de uma blenda, um copolímero e um nanocompósito. O estudo foi iniciado pela síntese química oxidativa do PEDOT (poli (3,4- etilenodioxitiofeno)) em microestruturas utilizando condições brandas e ambientalmente amigáveis, porém o material obtido não apresentou solubilidade e boas condições de se produzir um filme. Então foi sintetizado quimicamente o PEDOT dopado com PSS (poli estireno sulfonado) (PEDOT:PSS), o mesmo foi usado para preparar blendas com o PLGA (poli (ácido láctico-co-glicólico), para melhorar sua degradabilidade. Foi possível produzir um filme fino e nanoestruturado através de deposição eletrostática camada por camada (LBL) que pode ser utilizado para modificação de eletrodos ou de suportes tridimensionais para engenharia celular. Para garantir a degradabilidade do material, foi realizada a síntese de copolímeros de PEDOT e PLLA (poli(lactídeo)) em que foi variada a proporção de PEDOT na cadeia polimérica. Os copolímeros foram caracterizados por IV, RMN, UV, análises térmicas e submetidos a testes de degradabilidade e de viabilidade celular...

Low-temperature synthesis of nanosized bismuth ferrite by the soft chemical method

Aguiar, E. C.; Ramirez, M. A.; Moura, F.; Varela, José Arana; Longo, Elson; Simões, A. Z.
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 13-20
ENG
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This paper describes research on a simple low-temperature synthesis route to prepare bismuth ferrite nanopowders by the polymeric precursor method using bismuth and iron nitrates. BiFeO 3 (BFO) nanopowders were characterized by means of X-ray diffraction analyses, (XRD), Fourier transform infrared (FT-IR) spectroscopy, Raman spectroscopy (Raman), thermogravimnetric analyses (TG-DTA), ultra-violet/vis (UV/Vis) and field emission scanning electron microscopy (FE-SEM). XRD patterns confirmed that a pure perovskite BiFeO 3 structure with a rhombohedral distorted perovskite structure was obtained by heating at 850 °C for 4 hours. Typical FT-IR spectra for BFO powders revealed the formation of a perovskite structure at high temperatures due to a metal-oxygen bond while Raman modes indicated oxygen octahedral tilts induced by structural distortion. A homogeneous size distribution of BFO powders obtained at 850 °C for 4 hours was verified by FE-SEM analyses. © 2012 Elsevier Ltd and Techna Group S.r.l.

Accelerated chemical synthesis of peptides and small proteins

Miranda, Les P.; Alewood, Paul F.
Fonte: The National Academy of Sciences Publicador: The National Academy of Sciences
Tipo: Artigo de Revista Científica
Publicado em 16/02/1999 EN
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The chemical synthesis of peptides and small proteins is a powerful complementary strategy to recombinant protein overexpression and is widely used in structural biology, immunology, protein engineering, and biomedical research. Despite considerable improvements in the fidelity of peptide chain assembly, side-chain protection, and postsynthesis analysis, a limiting factor in accessing polypeptides containing greater than 50 residues remains the time taken for chain assembly. The ultimate goal of this work is to establish highly efficient chemical procedures that achieve chain-assembly rates of approximately 10–15 residues per hour, thus underpinning the rapid chemical synthesis of long polypeptides and proteins, including cytokines, growth factors, protein domains, and small enzymes. Here we report Boc chemistry that employs O-(7-azabenzotriazol-1-yl)-N,N,N′,N′-tetramethyluronium hexafluorophosphate (HATU)/dimethyl sulfoxide in situ neutralization as the coupling agent and incorporates a protected amino acid residue every 5 min to produce peptides of good quality. This rapid coupling chemistry was successfully demonstrated by synthesizing several small to medium peptides, including the “difficult” C-terminal sequence of HIV-1 proteinase (residues 81–99); fragment 65–74 of the acyl carrier protein; conotoxin PnIA(A10L)...

Chemical synthesis and spontaneous folding of a multidomain protein: Anticoagulant microprotein S

Hackeng, Tilman M.; Fernández, José A.; Dawson, Philip E.; Kent, Stephen B. H.; Griffin, John H.
Fonte: The National Academy of Sciences Publicador: The National Academy of Sciences
Tipo: Artigo de Revista Científica
EN
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Because of recent high-yield native ligation techniques, chemical synthesis of larger multidomain bioactive proteins is rapidly coming within reach. Here we describe the total chemical synthesis of a designed “microprotein S,” comprising the γ-carboxyglutamic acid-rich module, the thrombin-sensitive module, and the first epidermal growth factor-like module of human plasma protein S (residues 1–116). Synthetic microprotein S expressed anticoagulant cofactor activity for activated protein C in the down-regulation of blood coagulation, and the anticoagulant activity of microprotein S was not neutralized by C4b-binding protein, a natural inhibitor of native protein S in plasma. The correct folding of this complex multidomain protein was enhanced compared with individual modules because the γ-carboxyglutamic acid-rich module and the thrombin-sensitive module markedly facilitated correct folding of the first epidermal growth factor-like module compared with folding of the first epidermal growth factor-like module alone. These results demonstrate that total chemical synthesis of proteins offers an effective way to generate multidomain biologically active proteins.

Total chemical synthesis of enzymatically active human type II secretory phospholipase A2

Hackeng, Tilman M.; Mounier, Carine M.; Bon, Cassian; Dawson, Philip E.; Griffin, John H.; Kent, Stephen B. H.
Fonte: The National Academy of Sciences of the USA Publicador: The National Academy of Sciences of the USA
Tipo: Artigo de Revista Científica
Publicado em 22/07/1997 EN
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Human group II secretory phospholipase A2 (sPLA2) is an enzyme found in the α granules of platelets and at inflammatory sites. Although its physiological function is unclear, sPLA2 can inhibit blood coagulation reactions independent of its lipolytic action. To study the molecular basis of PLA2 activities, we developed a total chemical synthesis of sPLA2 by chemical ligation of large unprotected peptides. The synthetic segments PLA2-(1–58)-αCOSCH2COOH and PLA2-(59–124) were prepared by stepwise solid-phase peptide synthesis and ligated to yield a peptide bond between Gly58 and Cys59. The 124-residue polypeptide product (mass: 13,920 ± 2 Da) was folded to yield one major product (mass: 13,905 ± 1 Da), the loss of 15 ± 3 Da reflecting the formation of seven disulfide bonds. Circular dichroism studies of synthetic sPLA2 showed α-helix, β-structure, and random coil contents consistent with those found in the crystal structure of sPLA2. Synthetic sPLA2 had kcat and Km values identical to those of recombinant sPLA2 for hydrolysis of 1,2-bis(heptanoylthio)-phosphatidylcholine. Synthetic sPLA2, like recombinant sPLA2, inhibited thrombin generation from prothrombinase complex (factors Xa, V, II, Ca2+, and phospholipids). In the absence of phospholipids...

Total chemical synthesis of human matrix Gla protein

Hackeng, Tilman M.; Rosing, Jan; Spronk, Henri M.H.; Vermeer, Cees
Fonte: Cold Spring Harbor Laboratory Press Publicador: Cold Spring Harbor Laboratory Press
Tipo: Artigo de Revista Científica
Publicado em /04/2001 EN
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Human matrix Gla protein (MGP) is a vitamin K–dependent extracellular matrix protein that binds Ca2+ ions and that is involved in the prevention of vascular calcification. MGP is a 10.6-kD protein (84 amino acids) containing five γ-carboxyglutamic acid (Gla) residues and one disulfide bond. Studies of the mechanism by which MGP prevents calcification of the arterial media are hampered by the low solubility of the protein (<10 μg/mL). Because of solubility problems, processing of a recombinantly expressed MGP-fusion protein chimera to obtain MGP was unsuccessful. Here we describe the total chemical synthesis of MGP by tBoc solid-phase peptide synthesis (SPPS) and native chemical ligation. Peptide Tyr1-Ala53 was synthesized on a derivatized resin yielding a C-terminal thioester group. Peptide Cys54-Lys84 was synthesized on Lys-PAM resin yielding a C-terminal carboxylic acid. Subsequent native chemical ligation of the two peptides resulted in the formation of a native peptide bond between Ala53 and Cys54. Folding of the 1–84-polypeptide chain in 3 M guanidine (pH 8) resulted in a decrease of molecular mass from 10,605 to 10,603 (ESI-MS), representing the loss of two protons because of the formation of the Cys54-Cys60 internal disulfide bond. Like native MGP...

Chemical synthesis and biotinylation of the thrombospondin domain TSR2

Tiefenbrunn, Theresa K; Dawson, Philip E
Fonte: Wiley Subscription Services, Inc., A Wiley Company Publicador: Wiley Subscription Services, Inc., A Wiley Company
Tipo: Artigo de Revista Científica
EN
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The type 1 repeat domain from thrombospondin has potent antiangiogenic activity and a structurally interesting fold, making it an attractive target for protein engineering. Chemical synthesis is an attractive approach for studying protein domains because it enables the use of unnatural amino acids for site-specific labeling and detailed structure-function analysis. Here, we demonstrate the first total chemical synthesis of the thrombospondin type 1 repeat domain by native chemical ligation. In addition to the natural domain, five sites for side chain modification were evaluated and two were found to be compatible with oxidative folding. Several challenges were encountered during peptide synthesis due to the functional complexity of the domain. These challenges were overcome by the use of new solid supports, scavengers, and the testing of multiple ligation sites. We also describe an unusual sequence-specific protecting group migration observed during cleavage resulting in +90 Da and +194 Da adducts. Synthetic access to this domain enables the synthesis of a number of variants that can be used to further our understanding of the biochemical interaction network of thrombospondin and provide insight into the structure and function of this important antitumorogenic protein domain.

Chemical Synthesis of Proteins

Nilsson, Bradley L.; Soellner, Matthew B.; Raines, Ronald T.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em //2005 EN
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Proteins have become accessible targets for chemical synthesis. The basic strategy is to use native chemical ligation, Staudinger ligation, or other orthogonal chemical reactions to couple synthetic peptides. The ligation reactions are compatible with a variety of solvents and proceed in solution or on a solid support. Chemical synthesis enables a level of control on protein composition that greatly exceeds that attainable with ribosome-mediated biosynthesis. Accordingly, the chemical synthesis of proteins is providing previously unattainable insight into the structure and function of proteins.

Silica mesocellular foam and carbon nanofoam for fine chemical synthesis and separation

Lancaster, Thomas M. (Thomas Michael), 1977-
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 103 leaves; 4657248 bytes; 4657056 bytes; application/pdf; application/pdf
ENG
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In chromatography, the selective separation for large molecules, polymers, and proteins is of particular interest. To achieve quality separations, the stationary phase should exhibit pore diameters greater than 10 nm to facilitate the diffusion of large analytes throughout the stationary phase. In packed-bed applications, narrow particle and pore size distributions and uniform particle shape would lead to improved separations. Thus, spherical stationary phase particles are often preferred, but the challenge has been to combine spherical particle morphologies, high surface areas, large mesopores, and narrow pore size distributions. We have successfully created a new three-step synthesis of spherical MCF (S- MCF) particles utilizing sodium fluoride as a condensation catalyst. The approach allowed for independent control over S-MCF particle and pore size, and was extended to other non-ordered porous silicas. The S-MCF particles were engineered into a reverse- phase chromatographic column and achieved good separation ability for a mixture of aryl ketones. By relating chromatographic performance to S-MCF surface silanol chemistry, an improved S-MCF chromatographic support was realized, which rivaled the separation capability of a commercially available chromatographic support. The asymmetric Diels-Alder (ADA) reaction is very useful in building complex chiral molecules through the formation of chiral carbon ring structures...

5.33 Advanced Chemical Experimentation and Instrumentation, Fall 2002; Advanced Chemical Experimentation and Instrumentation

Gheorghiu, Mircea D.
Fonte: MIT - Massachusetts Institute of Technology Publicador: MIT - Massachusetts Institute of Technology
EN-US
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Advanced experimentation, with particular emphasis on chemical synthesis and the fundamentals of quantum chemistry illustrated through molecular spectroscopy. Instruction and practice in the written and oral presentation of experimental results.

Continuous flow separation techniques for microchemical synthesis

Kralj, Jason G
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 153 leaves
ENG
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Performing multistep microchemical synthesis requires many techniques from combining micromixers in series to the development of continuous microfluidic separation tools. Safety, high heat and mass transfer rates, and cost savings all continue to motivate microreactor development as a research tool, but many reactions generate a variety of (by)products including solid particles, immiscible fluids (gas and liquid), and miscible components requiring purification. We have endeavored to develop microfluidic systems which compliment existing microreactor technology, using forces that grow stronger with decreasing length scales such as electric fields and interfacial phenomena, and to use straightforward microfluidic mixers for kinetic studies of energetic material synthesis. Dielectrophoresis was used to study the continuous separation of polystyrene particles based on size. Essentially, a microfluidic particle "ratchet" was created using a soft-lithography microchannel and slanted interdigitated electrodes which provide a transverse force component on the particles. Experimental behavior agreed well with the model predictions, and 4 & 6 micron particles were continuously separated. Liquid-liquid extraction is another useful tool for microchemical synthesis and well-suited to small length scales because high mass transfer rates can be attained.; (cont.) However...

Design and operation of microchemical systems for multistep chemical syntheses

Sahoo, Hemantkumar
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 184 leaves
ENG
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This thesis focused on advancing the microchemical field from single device based demonstrations to systems that can perform multi-step series and parallel synthesis. Few examples of micro-separators and micro-pumps suited for miniaturized lab-on-a-chip systems for organic syntheses exist, so the first half of this thesis developed systems for these micro-unit-operations, while the second half demonstrated multistep microchemical operations enabled by these systems. In-line continuous separation devices are developed that enabled removal of unreacted reagents/byproducts, making it possible to realize a series of reactions without leaving the microreactor environment. Differences in surface forces and preferential wettability characteristics of fluoropolymers are used for phase separation. Such microseparators are used to demonstrate 100% separation of two phase flows of hexane and water, toluene and water, dichloromethane and water, and hexane and methanol. Integrated liquid-liquid extraction devices are microfabricated that performed two -phase contacting by segmented flow, followed by separation - resulting in single stage extraction. Single stage extraction of N,N-dimethylformamide from dichloromethane to water, and from diethyl ether to water is demonstrated. The development of separators allows microreactors to be connected to microseparators to form microreactor networks enabling reactions and separations in succession. The starting reagents are loaded in syringes and syringe pumps push fluid through the train of microdevices. However...

Nanocompartmentalization of soft materials with three mutually immiscible solvents: synthesis and self-assembly of three-arm star-polyphiles

de Campo, Liliana; Moghaddam, Minoo J.; Varslot, Trond; Kirby, Nigel; Mittelbach, Rainer; Sawkins, Tim; Hyde, Stephen T.
Fonte: American Chemical Society Publicador: American Chemical Society
Tipo: Artigo de Revista Científica Formato: 10 pages
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We report synthesis, thermotropic, and lyotropic mesomorphism of a family of novel “star-polyphiles”: small star-shaped molecules bearing three mutually immiscible arms, hydrophilic (oligoethylene glycol), oleophilic (alkanes), and fluorophilic (perfluorinated alkanes), attached to a central 1,3,5-trihydroxybenzene core. A facile, flexible multistep synthesis giving high-purity yields of 14 distinct members of the family is described, with variable arm lengths, forming crystalline, or various mesostructured gel phases in their neat state at room temperature. Furthermore, we show that specific members of these star-polyphiles can be simultaneously loaded with up to three mutually immiscible solvents, dodecane, perfluoro-nonane, and water, to form liquid crystals and microemulsions with multiple chemically distinct mesoscale compartments. The mesoscale chemical polyfunctionality of these polyphiles, coupled with thermotropic and lyotropic polymorphism, make them promising potential soft materials for a variety of applications, including host matrices for multiple mutually immiscible chemicals and drug delivery; We acknowledge support from the Australian Research Council’s Discovery grant scheme.

Improved synthesis of biotinol-5'-AMP: implications for antibacterial discovery

Tieu, W.; Polyak, S.W.; Paparella, A.S.; Yap, M.Y.; Soares Da Costa, T.P.; Ng, B.; Wang, G.; Lumb, R.; Bell, J.M.; Turnidge, J.D.; Wilce, M.C.J.; Booker, G.W.; Abell, A.D.
Fonte: American Chemical Society Publicador: American Chemical Society
Tipo: Artigo de Revista Científica
Publicado em //2015 EN
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An improved synthesis of biotinol-5'-AMP, an acyl-AMP mimic of the natural reaction intermediate of biotin protein ligase (BPL), is reported. This compound was shown to be a pan inhibitor of BPLs from a series of clinically important bacteria, particularly Staphylococcus aureus and Mycobacterium tuberculosis, and kinetic analysis revealed it to be competitive against the substrate biotin. Biotinol-5'-AMP also exhibits antibacterial activity against a panel of clinical isolates of S. aureus and M. tuberculosis with MIC values of 1-8 and 0.5-2.5 μg/mL, respectively, while being devoid of cytotoxicity to human HepG2 cells.; William Tieu, Steven W. Polyak, Ashleigh S. Paparella, Min Y. Yap, Tatiana P. Soares da Costa, Belinda Ng, Geqing Wang, Richard Lumb, Jan M. Bell, John D. Turnidge, Matthew C. J. Wilce, Grant W. Booker, and Andrew D. Abell

A deeper understanding of the Diels–Alder reaction

Lording, William James
Fonte: Universidade Nacional da Austrália Publicador: Universidade Nacional da Austrália
Tipo: Thesis (PhD); Doctor of Philosophy (PhD)
EN_AU
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The Diels-Alder reaction was discovered in 1928 and has become the most efficient and practical method for the synthesis of six-membered carbocyclic and heterocyclic rings. This thesis comprises three chapters of results and discussion with the Diels-Alder reaction as a theme. Chapter 2 details an investigation of endo:exo selectivity in the Diels-Alder reactions of 1,3-butadiene. Chapter 3 explores aspects of the intramolecular Diels-Alder reactions of some substituted 1,3,8-nonatrienes, and Chapter 4 describes the domino Diels-Alder reactions of 1,4-diiodo-1,3-butadiene. The Diels-Alder reaction is powerful, general, and widely used in chemical synthesis, and it is well known that many Diels-Alder reactions exhibit endo selectivity, in accord with Alder’s empirical rule. The origins of endo:exo selectivity in the Diels-Alder reaction, however, are not completely understood and there is a dearth of experimental evidence concerning the Diels-Alder reactions of the archetypal 1,3-diene, 1,3- butadiene. Chapter 2 describes a study of the Diels-Alder reactions of an isotopically labelled 1,3-butadiene with a range of simple dienophiles, allowing the endo:exo selectivities of these important reactions to be determined for the first time. The experimental data shed light on the origins of endo:exo selectivity in the Diels-Alder reaction and will serve as an important reference for future computational investigations in this area. The intramolecular Diels-Alder reaction shares many of the virtues of its intermolecular counterpart...

Microfluidic approaches to the synthesis of complex polymeric particles

Dendukuri, Dhananjay, 1978-
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 128 p.
ENG
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The synthesis of micron-sized polymeric particles with precise control over shape, monodispersity and chemistry is a technologically important objective. Varied applications including medical diagnostics. designer fabrics and optical devices could benefit from the availability of geometrically complex and chemically inhomogeneous particles. Microfluidics has recently emerged as an important alternative route to the synthesis of such complex particles. This thesis presents three new approaches to complex particle and structure synthesis in microfluidic devices. In the first approach. droplets formed by shearing a curable photopolymer. using a continuous water phase at a T-junction, were constrained to adopt non-spherical shapes by confining them using appropriate microchannel geometries. The non-spherical shapes formed were permanently preserved by photopolymerizing the constrained droplets in situ using focused ultraviolet (UV) light from an inverted microscope. The second and more general method called Continuous Flow Lithography (CFL) is a one-phase, projection photolithography based process to continuously synthesize polymeric microparticles in any 2-D extruded shape down to the colloidal length scale.; (cont.) Polymerization was also performed across laminar. co-flowing streams to generate Janus particles containing different chemistries...

Microfluidic synthesis of colloidal nanomaterials

Khan, Saif A
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 184 leaves
ENG
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This thesis focuses on microfluidics based approaches for synthesis and surface-engineering of colloidal particles. Bottom-up assembly through colloidal nucleation and growth is a popular route to the controlled synthesis of nanomaterials. Standard bench-scale synthetic chemistry techniques often involve non-uniform spatial and temporal distributions of concentration and temperature, and are not readily scalable. Photolithography-based microfabrication enables the application of classical techniques of chemical reaction engineering to design chemical reactors that cannot be realized easily at the macroscale, and that closely approach theoretical 'idealized' reactor configurations. In addition, the microfluidic format allows precisely controlled reaction conditions such as rapid mixing, and concentration and temperature uniformity. The goal of this thesis was to design microfluidic reactors for synthesis of core-shell colloidal particles with tunable sizes. Microscale segmented gas-liquid flows overcome the large axial dispersion effects associated with single-phase laminar flows. Microchannel devices that yielded uniform, stable gas-liquid segmented flows over three orders of magnitude in flow velocity were first developed.; (cont.) Extensive experimental studies of the transport...

2D molecular magnets with weak topological invariant magnetic moments: Mathematical prediction of targets for chemical synthesis

Packwood, Daniel M.; Reaves, Kelley T.; Federici, Filippo Leonida; Katzgraber, Helmut G.; Teizer, Winfried
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
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An open problem in applied mathematics is to predict interesting molecules which are realistic targets for chemical synthesis. In this paper, we use a spin Hamiltonian-type model to predict molecular magnets (MMs) with magnetic moments that are intrinsically robust under random shape deformations to the molecule. Using the concept of convergence in probability, we show that for MMs in which all spin centers lie in-plane and all spin center interactions are ferromagnetic, the total spin of the molecule is a `weak topological invariant' when the number of spin centers is sufficiently large. By weak topological invariant, we mean that the total spin of the molecule only depends upon the arrangement of spin centers in the molecule, and is unlikely to change under shape deformations to the molecule. Our calculations show that only between 20 and 50 spin centers are necessary for the total spin of these MMs to be a weak topological invariant. The robustness effect is particularly enhanced for 2D ferromagnetic MMs that possess a small number of spin rings in the structure.; Comment: 21 pages, 5 figures

Heterocyclic nucleosides: Chemical synthesis and biological properties

Merino, Pedro
Fonte: Bentham Science Publishers Publicador: Bentham Science Publishers
Tipo: Artículo Formato: 259768 bytes; application/pdf
ENG
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7 pages.; This update covers the literature for 2002 and 2003 dealing with the main topic of the previous review entitled Heterocyclic nucleosides. Chemical synthesis and biological properties and published in Curr. Med. Chem.-AIA, 2002, 1, 389. As in the first review, the papers in this survey are grouped by the type of the heterocyclic system that acts as a spacer between the hydroxymethyl group and the base moiety.; Peer reviewed

Microreactors: New Opportunities in Chemical Synthesis; Micro Reatores: Novas Oportunidades em Síntese Química

Angelo Henrique L. Machado; Univeridade de Brasília; Omar Pandoli; Pontifícia Universidade Católica; Leandro S. de Mariz e Miranda; Universidade Federal do Rio de Janeiro; Rodrigo Octavio M. A. de Souza; Universidade Federal do Rio de Janeiro
Fonte: Revista Virtual de Química Publicador: Revista Virtual de Química
Tipo: ; Formato: binary/octet-stream
Publicado em 27/06/2014 PT
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The implementation of chemical reactions in continuous mode under microfluidic conditions by the use of microreactors is a very attractive alternative to the traditional batch and semi-batch mode currently used for chemical synthesis. The fine control of the stoichiometry, kinetics and thermal exchange of the reaction, as well as the easy scale up, low physical space demand for installation/operation and the easy implementation of in-line analysis techniques for in process controls approach the laboratory development to a reproducible, robust, safe, cost-competitive and environmentally sustainable chemical process.  DOI: 10.5935/1984-6835.20140068; A execução de reações químicas em modo contínuo de operação sob condições microfluídicas em micro reatores é uma alternativa muito atraente às condições em batelada e semi batelada tradicionalmente empregadas para a síntese química. O fino controle da estequiometria, cinética e troca térmica da reação em execução, bem como a facilidade na ampliação de escala de produção, baixa demanda por espaço físico para sua instalação/operação e viabilidade na implementação de técnicas de análise em linha para os controles em processo, aproximam o desenvolvimento laboratorial da implementação de um processo químico reprodutível...