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Search Results: 1 - 10 of 187645 matches for " Manuel; de Leiva "
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Infecciones por el virus Coxsackie
Revista chilena de pediatría , 1953,
Qualidade do a?o inoxidável martensítico do tipo AISI-420 utilizado na confec??o de ferramentas cirúrgicas
Rodrigues, César Augusto Duarte;Enokibara, Fausto;Leiva, Tomaz Puga;Nunes, Ivani Aparecida;Rollo, Jo?o Manuel Domingos de Almeida;
Rem: Revista Escola de Minas , 2009, DOI: 10.1590/S0370-44672009000400010
Abstract: until now the martensitic stainless steel type aisi-420 is widely used in the manufacture of surgical implements. these implements present premature corrosion problems identified after cleaning, , sterilization and cutting edge loss and/or rupture during the surgical processes. this study evaluates the steel as to the chemical composition, hardness, microstructure and pitting corrosion resistance in a solution of enzyme detergent diluted in water by anodic cyclic polarization. this mixture is used in the cleaning of surgical implements that are submerged in this solution for 2 h before cleaning and sterilization. the results show steels with martensite microstructures in the ferrite phase, together wth impurities. these presented low pitting potential values in compariston to steels with a fully martensitic microstructure.
Intoxicaciones agudas en pediatría
Prado Vizcaíno,Yalena; Vizcaíno Londián,María de los ángeles; Abeledo García,Carlos Manuel; Prado Vizcaíno,Elisa; Leiva Peláez,Osney;
Revista Cubana de Pediatr?-a , 2011,
Abstract: introduction: the intoxications have been in past years a major cause of increase of morbidity and mortality in pediatric ages. objective: to determine the clinical behavior of acute intoxications from january, 2005 to december, 2009 in the "william soler" children hospital. methods: in above mentioned hospital the study was conducted. the medical records, acute intoxications registry and the coding cards of hospital discharges were reviewed due to intoxications of patients admitted at hospital in this period. results: in hospital 886 patients were admitted. the group with a greater frequency of intoxications was that aged 1 to 5 with predominance of male sex although without significant differences regarding female sex. the more frequent intoxications were due to drugs mainly the psychogenic drugs and antibiotics, followed by foods and by chemical products at home. the 30,2 % of cases were admitted. conclusions: these results make us to think in the need to be on the alert and to create actions aimed to protect or to prevent the intoxications in so vulnerable ages.
Diabetes autoinmune del adulto en diabéticos tipo 2: frecuencia y características
Cabrera-Rode,Eduardo; Perich Amador,Pedro; Díaz Horta,Oscar; Molina Matos,Gisela; Suárez Fonseca,Leonel; Tiberti,Claudio; Arranz Calzado,Celeste; Licea Puig,Manuel; Puig Domingo,Manuel; de Leiva,Alberto; Di Mario,Umberto;
Revista Cubana de Endocrinolog?-a , 2001,
Abstract: this paper was aimed at knowing the frequency, clinico-biochemical, immunologic and genetic characteristics of autoimmune diabetes in adults (lada) in 1 000 type 2 diabetic patients aged 35 or over with different times of duration of diabetes. glycemia, anti-pancreatic islet cell antibodies (ica), anti-gad65 antibodies, anti-ica512bdc/ia2 antibodies, anti-microsomal thyroid antibodies (amt), anti-gastric parietal antibodies (agp), antinuclear antibodies (an), microalbuminuria and peptide c during fasting were determined. these patients were surveyed and some clinical characteristics were registered. they were divided into 2 groups according to the presence of ica. all the type 2 + diabetics for anti-islet cell autoantibodies (ica and/or antigad65) were identified as lada. 3.4 % of type 2 ica + were detected. 22.0 % of type 2 ica - diabetics had anti-gad65 antibodies. it was found that type 2 ica + diabetics were younger, that their diabetes was shorter, that they had lower bmi, reduced levels of fasting peptide c, less dm2 history family (parents), lower values of diastolic and systolic arterial pressure, higher presence of anti-gad65 antibodies, amt and agp in comparison with type 2 ica - diabetics. it was observed that type 2 ica+ diabetics (lada) have specific characteristics that make them similar to type 1 diabetics, which would lead to important variations in their treatment and evolution as regards type 2 ica - diabetics. among the cuban type 2 diabetics it was detected a low frequency of ica and a high frequency of gad, which were different to those found in the caucasian populations. the anti-gad65 antibodies were higher than ica to detect lada. the clinical and immunological characteristics of these patients show the slow progression of the autoimmune destruction of b-cells with therapeutic implications.
Bridge effect of the C=C, C=N and N=N bonds on the long distance electronic charge transfer of para?substituted stilbenoid compounds
Manuel A. Leiva,Raul G. E. Morales
Spectroscopy: An International Journal , 2000, DOI: 10.1155/2000/895968
Abstract: By means of 13C?NMR spectroscopy and ab initio molecular orbital theory calculations, we have analyzed the bridge effect of the C=C, C=N and N=N bonds on the long distance charge transfer of 4?dimethylamino?4'?nitrostilbenoid compounds in the ground electronic state.
A Generalization of Cramer’s Rule  [PDF]
Hugo Leiva
Advances in Linear Algebra & Matrix Theory (ALAMT) , 2015, DOI: 10.4236/alamt.2015.54016

In this paper, we find two formulas for the solutions of the following linear equation \"\"\"\", where \"\" is a \"\" real matrix. This system has been well studied since the 1970s. It is known and simple proven that there is a solution for all \"\" if, and only if, the rows of A are linearly independent, and the minimum norm solution is given by the Moore-Penrose inverse formula, which is often denoted by \"\" ; in this case, this solution is given by \"\". Using this formula, Cramer’s Rule and Burgstahler’s Theorem (Theorem 2), we prove the following representation for this solution


\"\", where \"\" are the row vectors of the matrix A. To the best of our knowledge and looking in to many Linear Algebra books, there is not formula for this solution depending on determinants. Of course, this formula coincides with the one given by Cramer’s Rule when \"\".

A Characterization of Semilinear Surjective Operators and Applications to Control Problems  [PDF]
Edgar Iturriaga, Hugo Leiva
Applied Mathematics (AM) , 2010, DOI: 10.4236/am.2010.14033
Abstract: In this paper we characterize a broad class of semilinear surjective operators given by the following formula where Z are Hilbert spaces, and is a suitable nonlinear function. First, we give a necessary and sufficient condition for the linear operator to be surjective. Second, we prove the following statement: If and is a Lipschitz function with a Lipschitz constant small enough, then and for all the equation admits the following solution .We use these results to prove the exact controllability of the following semilinear evolution equation , , where , are Hilbert spaces, is the infinitesimal generator of strongly continuous semigroup in the control function belong to and is a suitable function. As a particular case we consider the semilinear damped wave equation, the model of vibrating plate equation, the integrodifferential wave equation with Delay, etc.
Evaluación de la eficacia del método de Sofropedagogía Obstétrica mediante el dosaje de Beta-Endorfinas
Manuele,Eduardo; Arca,Manuel; Arca,Francisco; Gorischnik,Margarita; Leiva,Carina; Schuler,Ema; Viera,Ma. Noelia;
Ciencia, docencia y tecnolog?-a , 2010,
Abstract: results of a study aimed to relate the serum levels of beta-endorphins with the degree of painful sensation perceived by women during delivery labor are presented. two groups of patients in identical obstetric conditions differentiated only by their sophropedagogic preparation for childbirth were compared. it was assumed that the prepared patients would have less painful sensations and therefore fewer requirements of endogenic analgesics. the results suggest the effectiveness of the method as well of its implementation.
A road traffic injury surveillance system using combined data sources in Peru
Medina,Yliana Rojas; Espitia-Hardeman,Victoria; Dellinger,Ann M.; Loayza,Manuel; Leiva,Rene; Cisneros,Gloria;
Revista Panamericana de Salud Pública , 2011, DOI: 10.1590/S1020-49892011000300007
Abstract: a national hospital-based nonfatal road traffic injury surveillance system was established at sentinel units across peru in 2007 under the leadership of the ministry of health. surveillance data are drawn from three different sources (hospital records, police reports, and vehicle insurance reports) and include nonfatal road traffic injuries initially attended at emergency rooms. a single data collection form is used to record information about the injured, event characteristics related to the driver of the vehicle(s), and the vehicle(s). data are analyzed periodically and disseminated to all surveillance system participants. results indicated young adult males (15-29 years old) were most affected by nonfatal road traffic injuries and were most often the drivers of the vehicles involved in the collision. four-wheeled vehicle occupants comprised one-half of cases in most regions of the country, and pedestrians injured in the event accounted for almost another half. the system established in peru could serve as a model for the use of multiple data sources in national nonfatal road traffic injury surveillance. based on this study, the challenges of this type of system include sustaining and increasing participation among sentinel units nationwide and identifying appropriate prevention interventions at the local level based on the resulting data.
Kinetics and Mechanism of the Thermal Decomposition Reaction of 3,3,6,6-tetramethyl-1,2,4,5-tetroxane in Methanol Solution
Laura C. Leiva,Maria G. Castellanos,Nelly L. Jorge,Manuel E. Gómez Vara
Revista de la Sociedad Química de México , 1998,
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