Selection of early-maturing sweet orange cultivars by performance indexes

The objective of this work was to select adequate early-maturing sweet orange cultivars for the fresh fruit market and for industrial processing using performance indexes. Performance indexes for citrus were established from data collected in an experiment carried out in the southwest region of the state of Sao Paulo, involving 12 early-maturing sweet orange cultivars. New results were obtained by identifying cultivars with superior characteristics. In a comparison with 'Hamlin' sweet orange, a standard early-maturing cultivar, 'Valencia 2' and 'Salustiana' were considered better materials for the fresh fruit market, whereas 'Westin' sweet orange was identified as a superior cultivar for orange juice processing.

Systematic Evaluation of Extraction Methods for Multiplatform-Based Metabotyping: Application to the Fasciola hepatica Metabolome

Combining data from multiple analytical platforms is essential for comprehensive study of the molecular phenotype (metabotype) of a given biological sample. The metabolite profiles generated are intrinsically dependent on the analytical platforms, each requiring optimization of instrumental parameters, separation conditions, and sample extraction to deliver maximal biological information. An in-depth evaluation of extraction protocols for characterizing the metabolome of the hepatobiliary fluke Fasciola hepatica, using ultra performance liquid chromatography and capillary electrophoresis coupled with mass spectroscopy is presented. The spectrometric methods were characterized by performance, and metrics of merit were established, including precision, mass accuracy, selectivity, sensitivity, and platform stability. Although a core group of molecules was common to all methods, each platform contributed a unique set, whereby 142 metabolites out of 14,724 features were identified. A mixture design revealed that the chloroform:methanol:water proportion of 15:59:26 was globally the best composition for metabolite extraction across UPLC-MS and CE-MS platforms accommodating different columns and ionization modes. Despite the general assumption of the necessity of platform-adapted protocols for achieving effective metabotype characterization, we show that an appropriately designed single extraction procedure is able to fit the requirements of all technologies. This may constitute a paradigm shift in developing efficient protocols for high-throughput metabolite profiling with more-general analytical applicability.

Prediction of culture performance of juvenile Litopenaeus vannamei by in vitro (pH-stat) degree of feed protein hydrolysis with species-specific enzymes

Rapid in vitro methods for measuring digestibility may be useful in analysing aqua feeds if the extent and limits of their application are clearly defined. The pH-stat protein digestibility routine with shrimp hepatopancreas enzymes was previously related to apparent protein digestibility with juvenile Litopenaeus vannamei fed diets containing different protein ingredients. The potential of the method to predict culture performance of shrimp fed six commercial feeds (T3, T4, T5, T6, T7 and T8) with 350 g kg(-1) declared crude-protein content was assessed. The consistency of results obtained using hepatopancreas enzyme extracts from either pond or clear water-raised shrimp was further verified in terms of reproducibility and possible diet history effects upon in vitro outputs. Shrimps were previously acclimated and then maintained over 56 days (initial mean weight 3.28 g) on each diet in 500-L tanks at 114 ind m(-2), clear water closed system with continuous renewal and mechanical filtering (50 mu m), with four replicates per treatment. Feeds were offered four times daily (six days a week) delivered in trays at feeding rates ranging from 4.0% to 7.0% of stocked shrimp biomass. Feed was accessible to shrimp 4 h daily for 1-h feeding period after which uneaten feed was recovered. Growth and survival were determined every 14 days from a sample of 16 individuals per tank. Water quality was monitored daily (pH, temperature and salinity) and managed by water back flushing filter cleaning every 7-10 days. Feeds were analysed for crude protein, gross energy, amino acids and pepsin digestibility. In vitro pH-stat degree of protein hydrolysis (DH%) was determined for each feed using hepatopancreas enzyme extracts from experimental (clear water) or pond-raised shrimp. Feeds resulted in significant differences in shrimp performance (P < 0.05) as seen by the differences in growth rates (0.56-0.98 g week(-1)), final weight and feed conversion ratio (FCR). Shrimp performance and in vitro DH% with pond-raised shrimp enzymes showed significant correlation (P < 0.05) for yield (R-2 = 0.72), growth rates (R-2 = 0.72-0.80) and FCR (R-2 = -0.67). Other feed attributes (protein : energy ratio, amino acids, true protein, non-protein nitrogen contents and in vitro pepsin digestibility) showed none or limited correlation with shrimp culture performance. Additional correlations were found between growth rates and methionine (R-2 = 0.73), FCR and histidine (R-2 = -0.60), and DH% and methionine or methionine+cystine feed contents (R-2 = 0.67-0.92). pH-stat assays with shrimp enzymes generated reproducible DH% results with either pond (CV <= 6.5%) or clear water (CV <= 8.5%) hepatopancreas enzyme sources. Moreover, correlations between shrimp growth rates and feed DH% were significant regardless of the enzyme origin (pond or clear water-raised shrimp) and showed consistent R-2 values. Results suggest the feasibility of using standardized hepatopancreas enzyme extracts for in vitro protein digestibility.

Quantitation of malondialdehyde in gingival crevicular fluid by a high-performance liquid chromatography-based method

Lipid peroxidation (LPO) has been associated with periodontal disease, and the evaluation of malondialdehyde (MDA) in the gingival crevicular fluid (GCF), an inflammatory exudate from the surrounding tissue of the periodontium, may be useful to clarify the role of LPO in the pathogenesis of periodontal disease. We describe the validation of a method to measure MDA in the GCF using high-performance liquid chromatography. MDA calibration curves were prepared with phosphate-buffered solution spiked with increasing known concentrations of MDA. Healthy and diseased GCF samples were collected from the same patient to avoid interindividual variability. MDA response was linear in the range measured, and excellent agreement was observed between added and detected concentrations of MDA. Samples' intra- and interday coefficients of variation were below 6.3% and 12.4%, respectively. The limit of quantitation (signal/noise = 5) was 0.03 mu M. When the validated method was applied to the GCF, excellent agreement was observed in the MDA quantitation from healthy and diseased sites, and diseased sites presented more MDA than healthy sites (P < 0.05). In this study, a validated method for MDA quantitation in GCF was established with satisfactory sensitivity, precision, and accuracy. (C) 2012 Elsevier Inc. All rights reserved.

DEVELOPMENT AND VALIDATION OF AN ANALYTICAL METHOD FOR QUANTITATION OF THE DRUG BEVACIZUMAB BY HIGH PERFORMANCE LIQUID CHROMATOGRAPHY

DEVELOPMENT AND VALIDATION OF AN ANALYTICAL METHOD FOR QUANTITATION OF THE DRUG BEVACIZUMAB BY HIGH PERFORMANCE LIQUID CHROMATOGRAPHY. In this study, an analytical method was developed and validated for quantitation of the drug bevacizumab (Avastin (R)) by high performance liquid chromatography (HPLC). The HPLC column was a BioSuite 250 (R) HR SEC, 300 x 7.8 mm x 5 mu m (Waters, USA). The mobile phase consisted of phosphate buffered saline (PBS). The results revealed that the method was specific, precise. accurate, robust and linear (r(2) = 0.998) from 5 to 75 mu g mL(-1). Therefore, this method can be used in drug release studies or in quality control ampoules of the drug.

Is early manual preference in infants defined by intermanual performance asymmetry in reaching?

In the present study we evaluated the relationship between manual preference and intermanual performance asymmetry in reaching of 5-month-old infants. Manual preference was assessed through frequency of reaches toward toys presented at midline, left or right in egocentric coordinates. Intermanual performance asymmetry was evaluated through kinematic analysis. Results showed that performance was predominantly symmetric between hands. Lateral toy positions induced predominance of ipsilateral reaching, while the midline position led to equivalent distribution between right and left handed reaches. No significant correlation between manual preference and intermanual performance asymmetry was observed. These results converge against the notion that manual preference derives from a genetically determined advantage of movement control favoring the right hand. (C) 2012 Elsevier Inc. All rights reserved.

QUANTIFICATION OF TRYPTOPHAN IN PLASMA BY HIGH PERFORMANCE LIQUID CHROMATOGRAPHY

A simple, rapid and selective method using high-performance liquid chromatography with ultraviolet detection (267 nm) was applied for the determination of tryptophan in plasma. Separation was carried out on a C18 column (150 x 4.6 mm internal diameter) in 6 min. The mobile phase consisted of 5 mM the sodium acetate and acetonitrile (92:8, v/v). The method was shown to be precise and accurate, and good recovery of analyte was achieved, characterizing the method as efficient and reliable for use in laboratory analysis.

Stability-indicating methods for the enantioselective determination of dihydropyridines by high performance liquid chromatography and capillary electrophoresis

This paper presents simple, rapid, precise and accurate stability-indicating HPLC and CE methods, which were developed and validated for the determination of nitrendipine, nimodipine and nisoldipine. These drugs are calcium channel antagonists of the 1,4-dihydropyridine type which are used in the treatment of cardiovascular diseases. Experimental results showed a good linear correlation between the area and the concentration of drugs covering a relatively large domain of concentration in all cases. The linearity of the analytical procedures was in the range of 2.0-120.0 mu g mL-1 for nitrendipine, 1.0-100.0 mu g mL(-1) for nimodipine and 100.0-600.0 mu g mL(-1) for nisoldipine, the regression determination coefficient being higher than 0.99 in all cases. The proposed methods were found to have good precision and accuracy. The chemical stability of these drugs was determined under various conditions and the methods have shown adequate separation for their enantiomers and degradation products. In addition, degradation products produced as a result of stress studies did not interfere with the detection of the drugs' enantiomers and the assays can thus be considered stability-indicating.

Performance and selectivity of PtxSn/C electro-catalysts for ethanol oxidation prepared by reduction with different formic acid concentrations

Carbon supported Pt-Sn catalysts were prepared by reduction of Pt and Sn precursors with formic acid and characterized in terms of structure, morphology and surface properties. The electrocatalytic activity for ethanol oxidation was studied in a direct ethanol fuel cell (DEFC) at 70 degrees C and 90 degrees C. Electrochemical and physico-chemical data indicated that a proper balance of Pt and Sn species in the near surface region was necessary to maximize the reaction rate. The best atomic surface composition, in terms of electrochemical performance, was Pt:Sn 65:35 corresponding to a bulk composition 75:25 namely Pt3Sn1/C. The reaction products of ethanol electro-oxidation in single cell and their distribution as a function of the nature of catalyst were determined. Essentially, acetaldehyde and acetic acid were detected as the main reaction products; whereas, a lower content of CO2 was formed. The selectivity toward acetic acid vs. acetaldehyde increased with the increase of the Sn content and decreased by decreasing the concentration of the reducing agent used in the catalyst preparation. According to the recent literature, these results have been interpreted on the basis of ethanol adsorption characteristics and ligand effects occurring for Sn-rich electrocatalysts. (C) 2012 Elsevier Ltd. All rights reserved.

Ranking Configurations of Shading Devices by Its Thermal and Luminous Performance

This paper evaluates the thermal and luminous performance of different louver configurations on an office room model located in Maceió-AL (Brazil), ranking the alternatives in a way that leads to choices for alternatives with potential balanced performance. Parametric analyses were done, based on computer simulations on software Troplux 5 and DesignBuilder 2. The variables examined were number of slats, slat slope and slat reflectance, considering the window facing North, South, East and West and a fixed shading mask for each orientation. Results refer to internal average illuminance and solar heat gains through windows. It was observed that configurations of shading devices with the same shading mask may have different luminous and thermal performance. The alternatives were ranked, so the information here produced has the potential to support decisions on designing shading devices in practice.

Quantification of tryptophan in plasma by high performance liquid chromatography

A simple, rapid and selective method using high-performance liquid chromatography with ultraviolet detection (267 nm) was applied for the determination of tryptophan in plasma. Separation was carried out on a C18 column (150 x 4.6 mm internal diameter) in 6 min. The mobile phase consisted of 5 mM the sodium acetate and acetonitrile (92:8, v/v). The method was shown to be precise and accurate, and good recovery of analyte was achieved, characterizing the method as efficient and reliable for use in laboratory analysis.

Hydroxocobalamin quantification in human plasma by high-performance liquid chromatography coupled with electrospray tandem mass spectrometry in a pharmacokinetic study

A rapid, sensitive and specific method for quantifying hydroxocobalamin in human plasma using paracetamol as the internal standard (IS) is described. The analyte and the IS were extracted from plasma by liquid-liquid extraction using an organic solvent (ethanol 100%; -20°C). The extracts were analyzed by high performance liquid chromatography coupled with electrospray tandem mass spectrometry (HPLC-MS-MS). Chromatography was performed on Prevail C8 3 μm, analytical column (2.1×100 mm i.d.). The method had a chromatographic run time of 3.4 min and a linear calibration curve over the range 5-400 ng.mL-1 (r>0.9983). The limit of quantification was 5 ng.mL-1. The method was also validated without the use of the internal standard. The precision in the intra-batch validation with IS was 9.6%, 8.9%, 1.0% and 2.8% whereas without IS was 9.2%, 8.2%, 1.8% and 1.5% for 5, 15, 80 and 320 ng/mL, respectively. The accuracy in intra-batch validation with IS was 108.9%, 99.9%, 98.9% and 99.0% whereas without IS was 101.1%, 99.3%, 97.5% and 92.5% for 5, 15, 80 and 320 ng/mL, respectively. The precision in the inter-batch validation with IS was 9.4%, 6.9%, 4.6% and 5.5% whereas without IS was 10.9%, 6.4%, 5.0% and 6.2% for 5, 15, 80 and 320 ng/mL, respectively. The accuracy in inter-batch validation with IS was 101.9%, 104.1%, 103.2% and 99.7% whereas without IS was 94.4%, 101.2%, 101.6% and 96.0% for 5, 15, 80 and 320 ng/mL, respectively. This HPLC-MS-MS procedure was used to assess the pharmacokinetics of Hydroxo cobalamin following intramuscular injection 5000 μg in healthy volunteers of both sexes (10 males and 10 females). The volunteers had the following clinical characteristics (according to gender and expressed as mean ± SD [range]): males: age: 32.40 ± 8.00 y [23.00-46.00], height: 1.73 ± 0.07 m [1.62-1.85], body weight: 72.48 ± 10.22 Kg [60.20- 88.00]; females: age: 28.60 ± 9.54 y [18.00-44.00], height: 1.60 ± 0.05 m [1.54-1.70], body weight: 58.64 ± 6.09 Kg [51.70- 66.70]. The following pharmacokinetic parameters were obtained from the hydroxocobalamin plasma concentration vs. time curves: AUClast, T1/2, Tmax, Vd, Cl, Cmax and Clast. The pharmacokinetic parameters were 120 (± 25) ng/mL for Cmax, 2044 (± 641) ng.h/mL for AUClast, 8 (± 3.2) ng.mL-1 for Clast, 38 (± 15.8) hr for T1/2 and 2.5 (range 1-6) hr for Tmax. Female volunteers presented significant (p=0.0136) lower AUC (1706 ± 704) ng.h/mL) and larger (p=0.0205) clearance (2.91 ± 1.41 L/hr), as compared to male 2383 ± 343 ng.h/mL and 1.76 ± 0.23 L/hr, respectively. These pharmacokinetic differences could explain the higher prevalence of vitamin B12 deficiency in female patients. The method described validated well without the use of the internal standard and this approach should be investigated in other HPLC-MS-MS methods.