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Nomenclatura Unesco > (23) Química

Mostrando recursos 141 - 160 de 42,074

141. cLaboratorio de Síntesis Orgánica, Facultad de Química, - Ramón Carrasco; A Juan A. Padrón; B Rol; O Pérez; Hortensia Rodríguez; C Margarita Suárez; C Carmen; Adept Química; Centro De Química Farmacéutica; Facultad De Química
Abstract Purpose. The recently defined molar-refractivity-partition index was applied to a family of 1,3,5- thiadiazin-2-thione derivatives in order to establish quantitative structure-antitumoral models. The goal of this effort is to establish the relationships between the structure and biological response of these compounds. Method. After the splitting of the sample in two sets, their indices were correlated against the measured biological activity. The combined use of our index with others had been able to describe not only the topologic but also the London dispersive forces of any fragment in relation to the biological response of the sets. Results. The obtained models...

142. 3Instituto de Química, Universidade Federal do Rio de Janeiro - Mila Pontes-buarque; Ana C. Tessis; José A. P. Bonapace; Marisa B. M. Monte; Fernando De Souza-barros; Adalberto Vieyra
contributed by Adalberto Vieyra∗∗ There exists an extensive literature on the possible roles of minerals in the prebiotic stages of the chemical

143. RESUMEN* - Problemas Relacionados Con Medicamentos; Martha Bibiana; Oñate Química-farmacéutica Grupo
(PRM), los define como problemas de salud, entendidos como resultados clínicos negativos, derivados de la farmacoterapia que, producidos por diversas causas, conducen a la no consecución del objetivo terapéutico o a la aparición de efectos no deseados. En este Consenso se recoge la definición de problema de salud de la WONCA, como “cualquier queja, observación o hecho que el paciente y / o el médico perciben como una desviación de la normalidad que ha afectado, puede afectar o afecta a la capacidad funcional del paciente”. El objeto de este artículo es definir PRM y riesgo de PRM a partir de...

144. Fused Cyclic Carbodiphosphorane: Carbodiphosphorane- diphosphinocarbene Thermal Interconversion - Sebastien Marrot; Tsuyoshi Kato; O P. Cossío; Gornitzka Antoine Baceiredo; Orgánica I; Vasco-euskal Herriko Unibertsitatea; Facultad De Química
All manipulations were performed under an inert atmosphere of argon using standard Schlenk techniques. Dry, oxygen-free solvents were employed. 1H, 13C, 31P NMR spectra were recorded on Bruker AC200, WM250 or Avance 300 spectrometers. IR spectra were recorded on a Perkin-Elmer 1600. 1H, 13C NMR chemical shift were reported in ppm relative to Me4Si as external standard. 31P NMR downfield chemical shift are expressed with a positive sign, in ppm, relative to standard of 85 % H3PO4. Carbodiphosphorane 1a was prepared by the previously reported method.[1] 2a: A benzene solution (1 mL) of 1a (0.05 g, 0.1 mmol) was heated...

145. Plasmonic nanoengineering in hollow metal nanostructures: an electron energy-loss spectroscopy study - Genç, Aziz
Resumen en Español Las nanoestructuras metálicas están siendo objeto de gran atención dada su capacidad para generar resonancias plasmónicas, que son oscilaciones colectivas de electrones alojados en la banda de conducción en un metal excitado por efecto de un campo electromagnético. El creciente interés entorno a las nanoestructuras metálicas como fuentes de plasmones, ha resultado en el desarrollo de un nuevo campo, la plasmónica, definida como la ciencia y tecnología de la generación, control y manipulación de las excitaciones resultantes de las interaciones de la luz con la materia. Las nanoestructuras plasmónicas encuentran aplicaciones en diversos campos que cubren biología, física,...

146. Aplicación de la ultra alta presión de homogenización (UHPH) en la elaboración de licuados vegetales de almendra de alta calidad - Valencia Flores, Dora Cecilia
La bebida de almendra ha experimentado en los últimos años un notable aumento en su consumo, y por tanto, se ha expandido el área de comercialización de este producto, en casi todo el mundo. Esta bebida, además de ser una alternativa a la leche (aunque no son comparables) para personas con intolerancia a los productos lácteos, se demanda por sus cualidades funcionales que pueden contribuir a reducir o prevenir enfermedades, que aquejan en la actualidad a la sociedad; esto debido principalmente al contenido de ácidos grasos poliinsaturados y monoinsaturados, y a las fracciones con propiedades antioxidantes, como vitamina E, compuestos fenólicos, flavonoides y poliaminas. El principal propósito de...

147. © International Society for Tropical Ecology - Contrasting Central Amazonian Rainforests; Katrin Vohland; Karin Furch; Joachim Adis
Abstract: The chemical composition of the cuticle of two closely related detritivorous polydesmid millipedes, inhabitants of contrasting forest habitats, was compared for their respective bioelement content (calcium, magnesium, potassium, silicon). No differences were found for the absolute amount of bioelements, but the relative amount was higher in Pycnotropis tida (Diplopoda, Polydesmida, Aphelidesmidae) from the inundation forest. P. sigma from the upland forest had a higher weight and higher fraction of organic compounds. That might be explained by a substitution of calcium with proteins. Both millipede species strongly accumulated calcium, so that differences in calcium contents of the different trophic levels...

148. MODELING AND CONTROL OF AN AUTOREFRIGERATED CSTR POLYMERIZATION REACTOR: IMPACT OF THE NON-CONDENSABLE GASES - E. C. Vasco De Toledoa; R. Maciel Filhoa; Faculdade De Engenharia Química; Cidade Universitária; Bairro Barão Geraldo; Campinas São Paulo
The concept of process intensification is applied to a CSTR polymerization reactor, where bulk reactions take place via styrene free-radicals, connected to a semi-flooded horizontal condenser; the aim is to operate the system in a safe and efficient way. The results obtained show that the developed model was able to reproduce the major dynamic characteristics, even with the presence of non-condensable gases. The existence of such gases prevents the reactor from ever reaching a steady-state, as they accumulate in the system, increasing the condenser pressure and the reactor temperature and reducing the contact area and the mass of liquid in...

149. Historia de la Química - Claudia De La Paz; Antonio Muñoz; Esteban Burgos; J. Esteban Rodríguez; Y Lucía Salazar Coria; Andrea C. López; María T. Plata; Eusebio Del Cueto; Hermilo Leal; María De Los A. Valdivia; Aníbal Bascuñán Blaset
Comportamiento de las partículas suspendidas y polen en la atmósfera de la región norte de la zona metropolitana de la Ciudad de México

150. aDepartamento de Química, Universidade Federal de Viçosa - Elson Santiago De Alvarengaa; John Mannb
Ácido orselínico é benzilado e 4-benziloxi-2-hidroxi-6-metilbenzoato de benzila (7) é então convertido no composto desejado (2), o qual é o constituinte aromático de calicheamicin g1I. Orsellinic acid (6) was benzylated, and the benzyl 4-benzyloxy-2-hydroxy-6-methylbenzoate (7) was then elaborated into the title compound (2), which is the aromatic constituent of calicheami-cin g1I.

151. MODELLING THE CARBON DIOXIDE SOLUBILITY WITH CPA EOS - Ana Rute Marques; Modelação Da; Solubilidade Do; Dióxido De; Carbono Com; A Equação; De Estado Cubic; Ana Rute Marques; Modelação Da; Solubilidade Do; Dióxido De; Carbono Com; A Equação; De Estado Cubic
requisitos necessários à obtenção do grau de Mestre em Engenharia Química,

152. p-Phenyleneethynylene Molecular Wires: Influence of Structure on - Photoinduced Electron-transfer Properties; Nazario Martín[b D; Facultad De Ciencias Químicas
Molecular Modelling: Calculations were performed using the program packages Gaussian03 [35] and VAMP 10.0.[36] Molecular properties in the electronic ground state were computed using density functional theory at the B3LYP/6-31G * (/6-311G**) and the B3PW91/6-31G * (/6-311G**) levels and the restricted Hartree-Fock formalism with the semi-empirical AM1 * Hamiltonian.[S1] Excited-state calculations used a singles-only configuration interaction (CIS) expansion with an active window of the three to six highest occupied and lowest unoccupied molecular orbitals and the AM1 Hamiltonian.[S2] Test calculations with a singles only CI with up to 30 active orbitals suggested that this level of theory is adequate for...

153. GERMINATION OF GRASS SEEDS SUBJECTED TO STATIONARY MAGNETIC FIELD - Mercedes Florez Garcia; Ph. D; Ingeniero Agronomo Profesor; Elvira Martinez Ramirez; Ph. D; Ciencias Quimicas; Profesor Titular; Maria Victoria; Carbonell Padrino; Ph. D; Ingeniero Agronomo; Profesor Titular
The objective of the present study is to determine and quantify the effect produced by a stationary magnetic field in germination of patrense seeds (Festuca arundinacea and Medicago sativa, L). Seeds were exposed to 250 mT during different periods of time: 10 minutes, 20 minutes, 1 hour, 24 hours or in a chronic way, doses (B1-B5). Parameters used were average germination time (AGT) and the necessary time for germination of 1, 10, 25, 50 and 75 % of seeds (T1- T7S). According to results obtained with alfalfa seeds, it can be said that the AGT is significant less in seeds...

154. potential remediation - Liliana Eugenia; Carmen Ciuffo; Facultad De Química; Bioquímica Y Farmacia; María Belli
Radioactive trace in semi natural grassland. Effect of 40K in soil and

155. 2Departamento de Clínica Odontológica, 3Departamento de Química Orgânica e Inorgânica, - Braz J Med Biol Res; M. O. Moraes; E. R. Silveira; M. A. S. Lima; F. J. M. Elmiro
180 by piplartine and piperine, two alkaloid amides from Piper 1Departamento de Fisiologia e Farmacologia,

156. RESUMEN* - Palabras Claves Seguimiento; Pedro Amariles; Químico Farmacéutico Magister En; Farmacia Clínica; Farmacoterapia Especialista Atención
Amariles P, Giraldo N. Método Dáder de seguimiento farmacoterapéutico a pacientes y problemas relacionados con la

157. Departamento de Química Orgânica, Instituto de Química, Universidade Federal do Rio Grande do Sul, 91501-970 Porto - Rossana Barcellos Friedrich; Marcia Camponogara Fontana; Ruy Carlos; R. Beck; Adriana Raffin Pohlmann; Alegre Rs; Silvia Stanisçuaski Guterres
ti go

158. Study of Analytical On-line Pyrolysis of Oils from Macauba Fruit (Acrocomia sclerocarpa M) via GC/MS - I. C. P. Fortesa; P. J. Baughb
Estudos pirolíticos dos óleos vegetais das partes (endocarpo mais mesocarpo e epicarpo) do fruto da Macauba (Acrocomia sclerocarpa M.) foram realizados sob atmosfera de hélio usando-se um pirolisador de filamento modelo Girdel 75-Py-1, conectado diretamente a um CG/EM. Os experimentos foram realizados em diferentes temperaturas e tempos de pirólise, para avaliar como estes parâmetros afetam o processo pirolítico de obtenção dos produtos bem como a sua reprodutibilidade. A pirólise dos óleos gerou grande número de compostos tais como hidrocarbonetos, aldeídos e ácidos carboxílicos, este último refletindo a composição original dos óleos. A identificação de alguns compostos foi feita com o...

159. Photosensitization by drugs* - Miguel A. Miranda; Tecnología Química Upv-csic
Abstract: Certain drugs are known to elicit photosensitivity side effects. A satisfactory under-standing of the involved mechanistic aspects is necessary to anticipate the photosensitizing potential. We have used tiaprofenic acid (TPA), a photosensitizing nonsteroidal antiinflam-matory drug, to illustrate the methodology followed to address this problem. After studying the photophysical and photochemical properties of TPA, the attention has been directed towards the reactivity of its lowest lying π−π * triplet with biomolecules. Photosensitized lipid peroxidation occurs by a mixed type I (radicals) and type II (singlet oxygen) mecha-nism. In the case of proteins, the photosensitized reactions include Tyr, Trp, and His...

160. Facultad de Quimica Simulation Study
Using the Brownian dynamics simulation technique, we studied the fracture process of ' DNA chains subjected to transient extensional flow>, letting the solution with DNA molecules pass through a very small orifice (radius = 0.0065 cm), thus experiencing extensional flow ofthe convergent (sinkj type. The DNA molecules were modeled us FENE bedspr ing chains with the springs obeying a modijied Warner force law, as proposed by Reese and Zimm. Thefracture yield was strongly dependent on flow rate and molecular weight, reaching, in our setup, a level of 100 % at aflow rate of around 0.001 cm3/s.for DNA with moleciilar weight...

 

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