Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 7 de 7
Filter
Add more filters










Database
Language
Publication year range
1.
J Sep Sci ; 40(12): 2612-2619, 2017 Jun.
Article in English | MEDLINE | ID: mdl-28463409

ABSTRACT

Fabric-phase sorptive extraction has already been recognized as a simple and green alternative to the conventional sorbent-based sorptive microextraction techniques, using hybrid organic-inorganic sorbent coatings chemically bonded to a flexible fabric surface. Herein, we have investigated the synergistic combination of the advanced material properties offered by sol-gel graphene sorbent and the simplicity of Fabric phase sorptive extraction approach in selectively extracting bisphenol A and residual monomers including bisphenol A glycerolatedimethacrylate, urethane dimethacrylate, and triethylene glycol dimethacrylate derived dental restorative materials from cow and human breast milk samples. Different coatings were evaluated. Final method development employed sol-gel graphene coated media. The main experimental parameters influencing extraction of the compounds, such as sorbent chemistry used, sample loading conditions, elution solvent, sorption stirring time, elution time, impact of protein precipitation, amount of sample, and matrix effect, were investigated and optimized. Absolute recovery values from standard solutions were 50% for bisphenol A, 78% for T triethylene glycol dimethacrylate, 110% for urethane dimethacrylate, and 103% for bisphenol A glycerolatedimethacrylate, while respective absolute recovery values from milk were 30, 52, 104, and 42%. Method validation was performed according to European Decision 657/2002/EC in terms of selectivity, sensitivity, linearity, accuracy, and precision.


Subject(s)
Benzhydryl Compounds/analysis , Dental Materials/analysis , Milk, Human/chemistry , Milk/chemistry , Phenols/analysis , Animals , Cattle , Chromatography, High Pressure Liquid , Female , Graphite , Humans
2.
J Chromatogr A ; 1479: 20-31, 2017 Jan 06.
Article in English | MEDLINE | ID: mdl-27939021

ABSTRACT

In the present study, the impregnation of a micro - meso porous activated carbon with magnetite (Fe3O4) was successfully achieved by sonication and the magnetic activated carbon prepared (Bmi) was evaluated as a new adsorbent for ultrasonic assisted magnetic solid phase dispersive extraction of Bisphenol A (BPA) from cow milk and human breast milk samples, prior to the determination by HPLC with UV detection. The prepared Bmi was characterized by X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy and scanning electron microscopy (SEM). The effect of pH on adsorption, initial concentration, contact time and desorption were studied. The main experimental parameters influencing extraction efficiency of BPA, such as type and amount of the adsorbent, sample amount, type of desorption solvent, time of adsorption and desorption, type of precipitation solvent, were investigated and optimized. Under the optimal extraction conditions the absolute recovery of BPA was 81% and 95% in cow milk and human breast milk samples, respectively. Good linearity was observed in the investigated concentration range of 2.5µgkg-1-5000µgkg-1 (R2=0.9997). Limit of detection (LOD) was 0.75µgL-1, which is in accordance with the specific migration limit (SML) established by the European Union, and limit of quantification (LOQ) was 2.5µgL-1. Within-day and between-day recoveries ranged from 91.4% to 98.6% and 89.1% to 99.4% respectively and the RSDs were less than 3.7%. Due to the excellent magnetic behavior of Bmi the proposed method was shown to be simple and rapid. Besides these, this method is sensitive, low cost, efficient and environmentally friendly.


Subject(s)
Benzhydryl Compounds/isolation & purification , Charcoal/chemistry , Chemistry Techniques, Analytical/methods , Chromatography, High Pressure Liquid , Magnetics , Milk/chemistry , Phenols/isolation & purification , Solid Phase Extraction , Adsorption , Animals , Cattle , Ferrosoferric Oxide/chemistry , Humans , Limit of Detection , Microscopy, Electron, Scanning , Spectroscopy, Fourier Transform Infrared , Ultrasonics , Ultraviolet Rays , X-Ray Diffraction
3.
Article in English | MEDLINE | ID: mdl-27623110

ABSTRACT

Sample preparation is considered to be the most challenging step of the analytical procedure, since it has an effect on the whole analytical methodology, therefore it contributes significantly to the greenness or lack of it of the entire process. The elimination of the sample treatment steps, pursuing at the same time the reduction of the amount of the sample, strong reductions in consumption of hazardous reagents and energy also maximizing safety for operators and environment, the avoidance of the use of big amount of organic solvents, form the basis for greening sample preparation and analytical methods. In the last decade, the development and utilization of greener and sustainable microextraction techniques is an alternative to classical sample preparation procedures. In this review, the main green microextraction techniques (solid phase microextraction, stir bar sorptive extraction, hollow-fiber liquid phase microextraction, dispersive liquid - liquid microextraction, etc.) will be presented, with special attention to bioanalytical applications of these environment-friendly sample preparation techniques which comply with the green analytical chemistry principles.


Subject(s)
Green Chemistry Technology , Liquid-Liquid Extraction , Solid Phase Extraction
4.
Pediatr Crit Care Med ; 7(1): 56-62, 2006 Jan.
Article in English | MEDLINE | ID: mdl-16395076

ABSTRACT

OBJECTIVE: To analyze the effect of an immune enhancing (IE) diet on infection and metabolic indices in children with severe head injury fed either an IE or a regular formula. DESIGN: : Randomized, blinded, controlled study. SETTING: Pediatric intensive care unit in a university hospital. PATIENTS: A total of 40 mechanically ventilated children with severe head injury. INTERVENTIONS: Within 12 hrs of pediatric intensive care unit admission, patients were randomized to receive a masked formula: either IE or regular formula. Feedings were advanced to a target volume of energy intake equal to 0.50%, 100%, 125%, 150%, and 150% of the predicted basal metabolic rate on days 1-5. MEASUREMENTS AND MAIN RESULTS: Nutritional and metabolic indices; interleukins-1beta, -6, and -8; tumor necrosis factor-alpha; and outcome end points (survival, length of stay, length of mechanical ventilation) were compared between the two groups. Only interleukin-8 levels were lower in the IE group compared with the regular formula group by day 5 (23.6 +/- 1.5 vs. 35.5 +/- 4 pg/mL, p < .04). In multivariate regression analysis, interleukin-8 was also independently negatively correlated with immunonutrition (p < .04). Nitrogen balance became positive in 30.8% of patients in the regular formula group and in 69.2% of patients in the IE group by day 5 (p < .05). Less gastric cultures were positive in the IE group compared with the regular formula group (26.7% vs. 71.4%, p < .02). Nosocomial infections (15% vs. 25%), length of stay (16.7 vs. 12.2 days), length of mechanical ventilation (11 vs. 8 days), and survival (80% vs. 95%) did not differ between groups. CONCLUSIONS: Although immunonutrition might decrease interleukin-8 and gastric colonization in children with severe head injury, it might not be associated with additional advantage over the one demonstrated by regular early enteral nutrition.


Subject(s)
Adjuvants, Immunologic/therapeutic use , Brain Injuries/therapy , Enteral Nutrition , Food, Formulated , Brain Injuries/immunology , Brain Injuries/metabolism , Child , Cross Infection , Cytokines/metabolism , Double-Blind Method , Female , Humans , Male , Multivariate Analysis , Nitrogen/metabolism , Prospective Studies , Respiration, Artificial
5.
J Crit Care ; 20(2): 139-46, 2005 Jun.
Article in English | MEDLINE | ID: mdl-16139154

ABSTRACT

PURPOSE: To determine the impact of resource use on the nurse/patient ratio in a pediatric intensive care unit (PICU). To examine the longitudinal influence of chronic or genetically influenced diseases on this interrelation. MATERIALS AND METHODS: Overall, 1586 patients admitted to the PICU through various modes of admission during a 5-year period were prospectively studied. RESULTS: The mean daily number of bed use increased from 5 to 8.1, leading to a significant skew from the ideal nurse/patient ratio of 1:1, to an overloaded one of 1:3-5. An increasing longitudinal trend of patients with metabolic diseases (P < .0001) or with genetic influence (62.8% in 1997, 70.7% in 2001) was noted. More patients with a genetic influence died than those without (13.8% vs 8.5%, P < .001), and more patients supported by mechanical ventilation suffered from a genetically influenced disease (64% vs 36%, P < .03). The mortality rate showed a trend for longitudinal reduction from 12.6% to 12%. CONCLUSIONS: The increasing trend of occupation of PICU bed and ventilator days by patients with chronic diseases may be related to the increasing trend of hospitalization of patients with recognized genetic influence. Although this new trend does not influence mortality, it significantly increases resource use and has a large impact on the staffing needs.


Subject(s)
Intensive Care Units, Pediatric/statistics & numerical data , Nursing Care/statistics & numerical data , Adolescent , Adult , Child , Child, Preschool , Genetic Diseases, Inborn/nursing , Hospital Mortality , Humans , Infant , Length of Stay , Longitudinal Studies , Prospective Studies
6.
Nutrition ; 21(7-8): 799-807, 2005.
Article in English | MEDLINE | ID: mdl-15975487

ABSTRACT

OBJECTIVES: In a blinded, prospective, randomized, controlled clinical trial, we compared nitrogen balance (NB), nutritional indices, antioxidant catalysts, and outcome in critically ill children given an immune-enhancing formula (I) or conventional early enteral nutrition (C). METHODS: Fifty patients, 103 +/- 7 months old, with disorders prompting admission to the pediatric intensive care unit, including sepsis, respiratory failure, and severe head injury, were enrolled in the study. Within 12 h of admission, patients were randomized to receive I (n=25) or C (n=25). Caloric intake was aimed at meeting patient's predicted basal metabolic rate by day 2 and predicted energy expenditure by day 4, irrespective of group assignment. Outcome endpoints and complications were recorded; NB, transthyretin, retinol-binding protein, transferrin, zinc, copper, and metabolic indices were measured on days 1 and 5 and compared with clinical and nutritional characteristics within and between groups. RESULTS: Both diets achieved their initial targets of covering predicted basal metabolic rate by day 2 and predicted energy expenditure by day 4. Twenty four-hour NB became positive in 40% of patients in group C and occurred in 64% of patients in group I by day 5. Only in group I did the mean NB become positive by day 5 (0.07+/-0.07 g/kg versus -0.24+/-0.03 g/kg on day 1, P<0.001) compared with group C in which the mean NB remained negative (-0.06+/-0.04 g/kg versus -0.25+/-0.06 g/kg on day 1, P<0.001). By day 5, nutritional indices and antioxidant catalysts showed a higher increasing trend in group I compared with group C and higher osmolality (P<0.02), sodium (P<0.03), and urea (P<0.04). Diarrhea for group I (P<0.02) and gastric distention for group C (P<0.04) were the most frequently recorded complications. Mortality or length of stay did not differ between groups, but there was a trend for less gastric gram plus isolates (P<0.05) or for Candida species (P<0.04) and nosocomial infections in group I compared with group C. CONCLUSIONS: Although less well tolerated, immunonutrition is a feasible method of early enteral nutrition in the pediatric intensive care unit. It has a favorable effect on nutritional indices and antioxidant catalysts, but not on outcome hard endpoints. Although it poses a higher metabolic burden to the patient, it shows a trend to improve colonization and infection rates. Appropriate modifications for specific age populations might improve its tolerability and benefits among critically ill children.


Subject(s)
Critical Illness/therapy , Enteral Nutrition/methods , Food, Formulated/classification , Immunocompetence , Nitrogen/metabolism , Antioxidants/metabolism , Child , Critical Illness/mortality , Double-Blind Method , Energy Metabolism , Enteral Nutrition/adverse effects , Enteral Nutrition/standards , Female , Humans , Infections/epidemiology , Intensive Care Units, Pediatric , Length of Stay , Male , Nutritional Status , Prospective Studies , Treatment Outcome
7.
Intensive Care Med ; 31(6): 851-8, 2005 Jun.
Article in English | MEDLINE | ID: mdl-15834703

ABSTRACT

OBJECTIVE: To compare the effect of early enteral feeding using immune-enhancing (IE) vs. non-immune-enhancing (NIE) formulas on cytokines in children with septic shock. DESIGN AND SETTING: A single-center, randomized, blinded controlled trial in a pediatric intensive care unit of a university hospital. PATIENTS: We randomized 38 patients with septic shock to either IE or NIE. Feedings were advanced to a target volume of energy intake equal to 1/2, 1, 5/4, 6/4, and 6/4 of the predicted basal metabolic rate on days 1-5, respectively. MEASUREMENTS AND RESULTS: Interleukins (IL) 1beta, 6, and 8, tumor necrosis factor alpha, C-reactive protein, Pediatric Risk of Mortality (PRISM) score, survival, secondary infections, length of stay, and mechanical ventilation were compared within and between the two groups. Actual mean energy and protein intakes did not differ between the two groups and the caloric-protein balance was not correlated to cytokine levels. On day 5 IL-6 levels were significantly lower (11.8+/-2.4 vs. 38.3+/-3.6) and IL-8 significantly higher in the IE than in the NIE group (65.4+/-17 vs. 21+/-2.5). After 5 days of nutritional support a significant decrease in IL-6 levels was recorded only in group IE (mean of paired differences 39.4+/-3 pg/ml). In multivariate regression analysis the variation in cytokines was independently correlated only to PRISM (R(2)=-0.50), but pediatric intensive care unit outcome endpoints did not differ between the two groups. CONCLUSIONS: Early IE nutrition may modulate cytokines in children with septic shock, but there is no evidence that this immunomodulation has any impact on short-term outcome.


Subject(s)
Cytokines/blood , Enteral Nutrition/methods , Shock, Septic/therapy , Child , Food, Formulated , Humans , Interleukins/blood , Multivariate Analysis , Regression Analysis , Shock, Septic/immunology
SELECTION OF CITATIONS
SEARCH DETAIL
...