RESUMEN
Bio-based industries need efficient downstream solutions to process complex streams. This was addressed through a technology integration approach, where expanded-bed adsorption (EBA) is integrated with simulated moving-bed (SMB) technology. Current work involved adaptation of an SMB apparatus and control principle to implement expanded-bed level control. As an outcome, EBA-SMB technology was successfully applied for purification of γ-aminobutyric acid (GABA). This resulted in two-fold increase in productivity and a GABA purity ≥ 92 % in one step from unclarified fermentation broth, compared to ≥ 93 % purity in case of clarified broth and packed-bed SMB. These results proved that EBA-SMB technology is able to enhance process efficiency and economics of bioprocesses.
RESUMEN
Complex streams in bio-based industries require efficient downstream processing units. Simulated moving-bed (SMB) chromatography is known to improve process efficiency by reducing resin and buffer requirement, but it can be further enhanced by technology hybridization. In the current experiments, an SMB system has been integrated with a bipolar electrodialysis (BPED) system. SMB purified γ-aminobutyric acid (GABA) from a clarified fermentation broth while BPED processed the product-containing eluent stream into recyclable eluent and purified product streams. The continuous operation did not result in any impurity accumulation.
RESUMEN
Expanded-bed adsorption (EBA) is an efficient downstream technology that enhances the techno-economic potential of bio-based industries. However, application of EBA for bulk biochemicals requires the use of industrial resins. Therefore, two cation exchangers, namely, gel-type CS16GC and porous IRC747, were tested to purify γ-aminobutyric acid (GABA) from unclarified E. coli fermentation broth. Experiments compared the impact of gel-type and macroporous resin properties on the EBA process performance. As an outcome, the gel-type resin exhibited higher GABA binding capacity of compared to that of macroporous resin. This was due to improved hydrodynamics and uniform flow distribution in the case of gel-type resin. Further, CS16GC effectively removed ≥ 99 % of impurities and achieved ≥ 97 % GABA yield.
RESUMEN
OBJECTIVE: Personality characteristics are assumed to underlie health behaviors and, thus, a variety of health outcomes. Our aim was to examine prospectively whether personality traits predict short- and long-term weight loss after laparoscopic adjustable gastric banding. RESEARCH METHODS AND PROCEDURES: Of patients undergoing laparoscopic adjustable gastric banding, 168 (143 women, 25 men, 18 to 58 years old, mean 37 years, preoperative BMI 45.9 +/- 5.6 kg/m(2)) completed the Dutch Personality Questionnaire on average 1.5 years before the operation. The relationship between preoperative personality and short- and long-term postoperative weight loss was determined using multilevel regression analysis. RESULTS: The average weight loss of patients progressively increased to 10 BMI points until 18 months after surgery and stabilized thereafter. A lower baseline BMI, being a man, and a higher educational level were associated with a lower weight loss. None of the personality variables was associated with weight outcome at short-term follow-up. Six of seven personality variables did not predict long-term weight outcome. Egoism was associated with less weight loss in the long-term postoperative period. The effect sizes of the significant predictions were small. DISCUSSION: None of the personality variables predicted short-term weight outcome, and only one variable showed a small and unexpected association with long-term weight outcome that needs confirmation. This suggests that personality assessment as intake psychological screening is of little use for the prediction of a poor or successful weight outcome after bariatric surgery.
Asunto(s)
Gastroplastia , Obesidad Mórbida/cirugía , Personalidad , Pérdida de Peso , Adolescente , Adulto , Índice de Masa Corporal , Peso Corporal , Escolaridad , Femenino , Derivación Gástrica , Humanos , Laparoscopía , Masculino , Persona de Mediana Edad , Periodo Posoperatorio , Análisis de Regresión , Caracteres Sexuales , Encuestas y Cuestionarios , Resultado del TratamientoRESUMEN
BACKGROUND: The aim of this cross-sectional study was to examine short and long-term physical, mental and, particularly, social quality of life (QoL) of patients with severe obesity after laparoscopic adjustable gastric banding (LAGB). METHODS: 250 patients (221 female, 29 male, mean age 39.6 years, age range 22-61) filled out questionnaires to evaluate several aspects of QoL: 93 patients before LAGB, 48 with a follow-up duration of 8 through 24 months, and 109 patients 25 through 68 months after LAGB. RESULTS: Compared with patients before surgery, patients after surgery, in both follow-up groups, had lower weight and co-morbidity, felt and functioned better on physical and psychological dimensions of QoL, and on most aspects of social QoL. No significant differences emerged between the two postoperative groups. On average, the postoperative QoL was still lower than the age norm group. Mutual correlations between QoL and weight outcome were very low up to 2 years after surgery, but more strongly associated >2 years after surgery. CONCLUSION: LAGB could be a long-term solution to morbid obesity with regard to both weight and QoL outcome. The findings of our study emphasize the importance of including social QoL variables in outcome research. They further suggest that when the follow-up duration increases, especially in patients who are single, intervention and consultation should be simultaneously directed at weight and psychosocial variables.