ABSTRACT
Using the canonical force field theory, expressions of quadratic, cubic, and quartic canonical force constants are obtained for XY3 (D3h) molecules in curvilinear redundant coordinates, i.e., simple valence internal coordinates (VICs), in terms of force constants in normal coordinates and in independent symmetry coordinates. To carry out this task, it was previously necessary to obtain for the first time the non-linear redundancy relation and the corresponding orthogonal projection onto the pure vibrational manifold for XY3 (D3h) molecules corresponding to a set of seven VICs. As an application, the quartic canonical force field in curvilinear redundant internal coordinates of BH3 is determined from ab initio force fields in normal coordinates calculated at the coupled-cluster singles and doubles level with perturbative treatment of the triples in conjunction with a triple- and quadruple-ζ size basis set. This anharmonic force field so obtained for the borane molecule, and in general for XY3 (D3h) molecules, is uniquely defined (therefore in an unambiguous form) and depending on the same number of parameters, i.e., force constants, when independent coordinates (natural or symmetry) are used in its description.
ABSTRACT
Introducción: la obesidad mórbida es una enfermedad crónica que se manifiesta en cualquier edad o sexo y tiene gran impacto social y económico. Su manejo a través de la cirugía bariátrica ha demostrado resultados favorables, logrando la pérdida de exceso de peso y controlando enfermedades metabólicas asociadas. Una de las alternativas quirúrgicas más promisorias es el sleeve gástrico. Se realizó la presente investigación para describir el efecto que produce la técnica en la reducción del peso. Métodos: estudio observacional descriptivo basado en el seguimiento de quince pacientes obesos intervenidos quirúrgicamente mediante sleeve gástrico laparoscópico, con la finalidad de controlar la obesidad mórbida. Resultados: antes de la cirugía todos los pacientes se encontraban con un índice de masa corporal comprendido entre 35 y 43, correspondientes con los estados severo a mórbido de la obesidad. Al cabo de un año de la cirugía se apreció un descenso promedio del peso de 36 %, calculado según pérdida sobrepeso programada al año. Conclusión: la cirugía bariátrica mediante sleeve gástrico laparoscópico produjo una importante reducción de peso, lo que además puede redundar en una mejor gestión del tiempo y ahorros económicos para el paciente y las instituciones de salud.
Introduction: Morbid obesity is a chronic disease that manifests in any age or sex, and has great social and economic impact. Its management through bariatric surgery has shown favorable results, achieving weight loss and controlling excess associated metabolic diseases, one of the most promising surgical alternative is the gastric sleeve. To describe the effect of the technique in reducing the weight of this research was conducted. Method: Descriptive observational study based on fifteen regular monitoring of patients operated on by "gastrectomy sleeve" laparoscopic, in order to control morbid obesity, achieving also decreased expression of the cronic diseases. Results: patients before bariatric surgery were a corporeal mass index (BMI) of between 35 and 43 corresponding to the severe state of morbid obesity, there is an average weight loss of 36 % after a year. Conclusion: Bariatric surgery by "gastrectomy sleeve" laparoscopic weight loss guarantees associated comorbidities improving and reducing early complications related to the surgical procedure, this represents effective time management and economy of effort.
ABSTRACT
Two novel bifunctional N-methylhydroxamate-isocyanate linkers 20 and 21 were prepared in good yield and high purity from the corresponding amine salts using a biphasic reaction with phosgene. The facile ring opening reaction of N-Boc lactams using the anion of O-benzylhydroxylamine gave the protected amino hydroxamates 6a and 6c in good yields. The selective methylation of the hydroxamate nitrogen in the presence of the N-Boc group in these intermediates could be readily accomplished. The utility of the linkers was clearly demonstrated by the synthesis of the carbamate-tethered trishydroxamic acid 27 and the urea-tethered 29.
