New method for quantification of dye sorption using SBA mesoporous silica as a target sorbent.

In this work, a new method for the quantification of methyl violet cationic dye sorption onto SBA-15 mesoporous silica was developed. This method related the intensity of coloration of SBA-15 samples (after reached equilibrium sorption) within dye concentration in aqueous solution using Image-Pro Plus software. The sorption process of methyl violet dye onto SBA-15 was analyzed varying different initial parameters (dye concentration, mass of sorbent, pH of dye solution, and contact sorption time). SBA-15 proved as efficient sorbent for removal of methyl violet dye in contact time of 5 min, with maximum percentage of dye removal 99% at pH 8. The results obtained from Image-Pro Plus showed to be in good agreement with the sorption parameters obtained by UV/Vis spectroscopy, which has been the most commonly used instrument for quantification of dye sorption. The image analysis method proved well prediction of dye concentrations with maximum relative error of 1.83%. The advantages of this method are low cost and reliable quantitative evaluation with minimum of time.

Autotransfusion in emergent operative trauma resuscitation.

PURPOSE: Autotransfusion of red cells is common in many surgical specialties. However, this technique is not uniformly used in abdominal trauma. The purpose of this paper is to study the outcomes of patients who were autotransfused during emergency trauma operations in which they sustained full-thickness hollow viscus injury (HVI). METHODS: A total of 179 patients in period 1999-2008 with penetrating and blunt abdominal trauma requiring intraoperative blood transfusion were evaluated. Recipients of autotransfusion and banked blood (autotransfused group) were compared with recipients of banked blood products only (control group). The t-test, Chi-squared, and Fisher's exact test were used to evaluate the data. Multivariate regression analysis evaluated the primary outcomes, survival and bloodstream infection (BSI). RESULTS: Of the 179 patients, 108 controls and 71 autotransfused patients were evaluated. The results showed no statistically significant difference between the control and autotransfusion groups regarding age, injury pattern/severity [Injury Severity Score (ISS)], length of stay, postoperative international normalized ratio (INR), and volume of banked blood products. Both groups were also proportional with colon injury. The estimated operative blood loss (EBL) was 2,472 ± 3,261 for controls and 4,056 ± 3,825 for the autotransfused group (p = 0.0001). The total volume of blood transfused was 2,792 and 5,513 for controls and patients in the autotransfusion group, respectively (p = 0.002). Ninety controls (84 %) and 53 autotransfused patients (76 %) survived to discharge (p = 0.21). Twenty controls (49 %) and 17 autotransfused patients (45 %) developed BSI (p = 0.72). Logistic regression analysis revealed that an ISS >25, systolic blood pressure <90, and EBL >2 L predicted mortality. There was also a trend towards decreased survival with age >50 years. CONCLUSION: We found no evidence that emergent autotransfusion worsens clinical outcomes in the setting of concomitant HVI.

Novel composite films based on amidated pectin for cationic dye adsorption.

Pectin, with its tendency to gel in the presence of metal ions has become a widely used material for capturing the metal ions from wastewaters. Its dye-capturing properties have been much less investigated, and this paper is the first to show how films based on amidated pectin can be used for cationic dye adsorption. In the present study amidated pectin/montmorillonite composite films were synthesized by membrane casting, and they are stable in aqueous solution both below and above pectin pKa. FTIR, thermogravimetry and SEM-EDAX have confirmed the presence of montmorillonite in the cast films and the interactions between the two constituents. In order to evaluate the cationic dye adsorption of these films Basic Yellow 28 was used, showing that the films have higher adsorption capacity compared to the others reported in the literature. The results were fitted into Langmuir, Freundlich and Temkin isotherms indicating an exothermic process and setting the optimum amount of montmorillonite in the films to 30% of pectin mass. According to the Langmuir isotherm the maximum adsorption capacity is 571.4 mg/g.

Characterization of chitosan/montmorillonite membranes as adsorbents for Bezactiv Orange V-3R dye.

The synthesis, characterization and environmental application of chitosan/montmorillonite membrane for adsorption Bezactiv Orange V-3R were investigated. Chitosan/montmorillonite membranes were synthesized in different ratios, containing 10-50% of montmorillonite (MMT) in membrane. These membranes were characterized by using Fourier transform infrared spectroscopy (FTIR), thermogravimetry (TG) and scanning electron microscopy (SEM). The adsorption kinetics were investigated using three different concentrations of Bezactiv Orange dye (30, 50 and 80 mg/L). The adsorption capacity increases with increasing amount of MMT in membranes. These membranes show the highest adsorption capacity when the initial dye concentration was 80 mg/L. The results show that the optimum condition for adsorption of Bezactiv Orange is pH 6. A comparison of kinetic models was evaluated for the pseudo-first and pseudo-second order and intra-particle diffusion. The experimental data were fitted to the pseudo-second order kinetic model, and also followed by intra-particle diffusion. Intra-particle diffusion is not the only rate-controlling step. The Langmuir and Freundlich adsorption isotherms were applied to experimental equilibrium data at different concentration of dye solution. The results indicated the competency of chitosan/MMT membranes adsorbent for Bezactiv Orange adsorption.

Complexation of amidated pectin with poly(itaconic acid) as a polycarboxylic polymer model compound.

Complexes based on amidated pectin (AP) and poly(itaconic acid) (PIA) were prepared by casting films from solutions of AP and PIA in different ratios with the pectin amount ranging from 10% to 90% by mass. The complexes were investigated by elemental analysis, Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and thermogravimetry (TG). In all investigated ratios of AP/PIA glassy transparent films with a uniform structure were obtained. The results of elemental analysis confirmed the composition of the complexes, and FTIR spectroscopy has shown carboxylic and amide peak shifting, indicating complex formation between AP and PIA. Comparison of thermograms of AP/PIA films with different ratios of AP indicated that the increase of the amount of AP increases the thermal stability of the films by retarding the onset of the main degradation processes.

The role of thyroid hormone administration in potential organ donors.

HYPOTHESIS: Levothyroxine sodium therapy should be used in brain-dead potential organ donors to reverse hemodynamic instability and to prevent cardiovascular collapse, leading to more available organs for transplantation. DESIGN: Prospective, before and after clinical study. SETTING: A surgical intensive care unit of an academic county hospital. PATIENTS: During a 12-month period (September 1, 1999, through August 31, 2000), we evaluated 19 hemodynamically unstable patients with traumatic and nontraumatic intracranial lesions, who were candidates for organ donation following brain death declaration. INTERVENTIONS: All patients were resuscitated aggressively for organ preservation by fluids, inotropic agents, and vasopressors. If, despite all measures, the patients remained hemodynamically unstable, a bolus of 1 ampule of 50% dextrose, 2 g of methylprednisolone sodium succinate, 20 U of insulin, and 20 microg of levothyroxine sodium was administered, followed by a continuous levothyroxine sodium infusion at 10 microg/h. RESULTS: There was a significant reduction in the total vasopressor requirement after levothyroxine therapy (mean +/- SD, 11.1 +/- 0.9 microg/kg per minute vs 6.4 +/- 1.4 microg/kg per minute, P =.02). Ten patients (53%) had complete discontinuation of vasopressors. There were no failures to reach organ donation due to cardiopulmonary arrest. CONCLUSIONS: Levothyroxine therapy plays an important role in the management of hemodynamically unstable potential organ donors by decreasing vasopressor requirements and preventing cardiovascular collapse. This may result in an increase in the quantity and quality of organs available for transplantation.

Old age as a criterion for trauma team activation.

BACKGROUND: Elderly trauma patients have been shown to have a worse prognosis than young patients. Age alone is not a criterion for trauma team activation (TTA). In the present study, we evaluated the role of age > or = 70 years as a criterion for TTA. METHODS: The present study was a trauma registry study that included injured patients 70 years of age or older. Patients who died in hospital, were admitted to the intensive care unit (ICU) within 24 hours, or had a non-orthopedic operation were assumed to benefit from TTA. RESULTS: During a 7.5-year period, 883 elderly (> or = 70 years) trauma patients meeting trauma center criteria were admitted to our center. Overall, 223 patients (25%) met at least one of the standard TTA criteria. The mortality in this group was 50%, the ICU admission rate was 39%, and a non-orthopedic operation was required in 35%. The remaining 660 patients (75%) did not meet standard TTA criteria. The mortality was 16%, the need for ICU admission was 24%, and non-orthopedic operations were required in 19%. Sixty-three percent of patients with severe injuries (Injury Severity Score > 15) and 25% of patients with critical injuries (Injury Severity Score > 30) did not have any of the standard hemodynamic criteria for TTA. CONCLUSION: Elderly trauma patients have a high mortality, even with fairly minor or moderately severe injuries. A significant number of elderly patients with severe injuries do not meet the standard criteria for TTA. It is suggested that age > or = 70 years alone should be a criterion for TTA.

TRISS methodology: an inappropriate tool for comparing outcomes between trauma centers.

BACKGROUND: The TRISS methodology has been used for comparison of survival outcomes between trauma centers. The purpose of this study was to evaluate the role of TRISS in comparing outcomes between a small and a large trauma center and evaluate its usefulness in various groups of patients. STUDY DESIGN: Trauma registry study that compared the survival outcomes between a large academic level I trauma center and a small community level II center. The comparison was made with the standard TRISS probability of survival, M value, and Z score. In the second part of the study the patients from the small center were matched for age, gender, injury severity score, Glasgow Coma Scale, head Abbreviated Injury Score, BP, prehospital respiratory assistance, and transport mode with an equal number of patients from the large center. The Z scores were calculated for each center. In the third part of the study the TRISS usefulness and limitations were evaluated in various subgroups of patients by calculating its sensitivity, specificity, positive predictive value, negative predictive value, and misclassification rate. RESULTS: The Z value of the large center (3,315 patients) was 2.24, indicating a considerably higher mortality than expected when compared with the Major Trauma Outcomes Study population. The Z value of the small center (331 patients) was -0.92, indicating fewer than the Major Trauma Outcomes Study expected deaths. In the second part of the study, 297 patients from the small center were matched with an equal number from the large center. The Z scores were -0.40 and -0.95, respectively, indicating slightly better outcomes than those of the Major Trauma Outcomes Study. Additional evaluation of the TRISS prediction of survival in various subgroups of patients showed a high misclassification rate in severe trauma, in some groups higher than 25%. CONCLUSIONS: The TRISS methodology is not a reliable tool for comparing outcomes between trauma centers and has an unacceptably high misclassification rate in patients with severe trauma.