972 resultados para Retenção em prótese total
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The unnatural threo-6-acetoxy-5-hexadecanolide and the natural mosquito oviposition pheromone erythro-6-acetoxy-5-hexadecanolide were synthesized in a diastereodivergent fashion in 44% and 33% overall yield respectively from 5-bromovaleric acid and undecanal. The key step utilized a chemoenzymatic epoxidation-lactonization of a naturally available fatty acid to form the 6-hydroxy-5-hexadecanolide core.17 The epoxidation strategy was later adapted to allow for an asymmetric synthesis. Shi epoxidation afforded highly enantioenriched (5R, 6R)-6-hydroxyhexadecanolide (er = 10) in 70 % overall yield. Other derivatives of the chiral ketone catalyst were also screened. Finally, attempts were made to obtain the correct stereochemistry at C(6) of the target with a dynamic kinetic transformation using lipase and a transfer hydrogenation catalyst. Epimerization of the lactol with the transfer hydrogenation catalyst was successful, but lipase mediated reactions halted at <10 % conversion.
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This thesis describes the chemoenzymatic synthesis of three morphine alkaloids. The total synthesis of dihydrocodeine and hydrocodone was accomplished starting from bromobenzene in 16 and 17 steps, respectively. The key steps included a microbial oxidation of bromobenzene by E. coli JM109 (pDTG601A), a Kazmaier-Claisen rearrangement of glycinate ester to generate C-9 and C-14 stereo centers, a Johnson-Claisen rearrangement to set the C-13 quaternary center, and a C-10/C-11 ring closure via a Friedel-Crafts reaction. In addition, the total synthesis of ent-hydromorphone starting from β-bromoethylbenzene in 12 steps is also described. The key reactions included the enzymatic dihydroxylation of β-bromoethylbenzene to the corresponding cis-cyclohexadienediol, a Mitsunobu reaction, and an oxidative dearomatization followed by an intramolecular [4+2] cycloaddition.
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Letter of estimate sent to S.D. Woodruff for the total cost of construction and equipment of the extension of the line to Port Colborne [this is unsigned]. There is an envelope with this letter that suggests that it is from Mr. Shanly, Mar. 12, 1857.
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Letter to S.D. Woodruff stating the total quantity of timber plank in the Port Robinson Bridge at Chippawa. This is signed by Fred Holmes, Oct. 6, 1857.
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Chart of station 2, crop sections of the old back ditch on the south side of the feeder, station 45, station 118 and the total length from the culvert to lot no. 5. This is signed by Fred Holmes, April 13, 1857.
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List entitled “Total amount of ½ September paid” includes tax and supplies prices, n.d.
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Letter (2 letters contained in one with a total of 2 pages) addressed to Henry Nelles. The first part is from Gilles Moffatt and he says that there is a balance of 277 pounds and 13 shillings in their favour. This is dated Jan. 10, 1831. The second part is addressed to Henry Nelles from R. Gillespie and it says that he intends to go to London district before paying Mr. Nelles a visit in Grimsby. The second page of this letter is stained and missing a section. Text is slightly affected, Jan. 29, 1831.
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Tesis (Maestría en Administración de Empresas con Especialidad en Organización General) UANL
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Tesis (Maestría en Ciencias de la Administración con Especialidad en Relaciones Industriales) UANL
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Tesis (Maestría en Ciencias de la Administración con Especialidaden Producción y Calidad) UANL
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Tesis (Maestría en Psicologia Laboral) UANL.
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Tesis (Maestría en Ciencias de la Administración) U.A.N.L.
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Tesis (Maestría en Ciencias de la Administración con Especialidad en Producción y Calidad) - U.A.N.L, 1994
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Tesis (Lic. en Nutrición) U.A.N.L.
Conceptos básicos para la aplicación del control total de calidad [por] Juan Felipe Garza Villanueva
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Tesis (Maestría en Ciencias de la Administración, con especialidad en Producción) U.A.N.L.