ANALYSES OF MULTIVITAMINS IN NUTRACEUTICALS BY REVERSE PHASE HPLC WITH DAD, ELSD AND MS

ABSTRACT Vitamins are essential to human beings and support long-term healthy lifestyle. They exist widely in food, but in small amount. Hence, dietary supplements and fortified food products are more and more popular in the nutritional markets. According to the Infant Formula Act of 1980, the range of each of the nutrients should fall within a specific range or above the required minimum, so there is an increasing interest of accurate measurement of vitamins, particularly the B-group vitamins. However, traditional methods for vitamin B analyses are time-consuming and often in poor accuracy. As a result, rapid and reliable analytical methods for simultaneous determination of water-soluble vitamins in multivitamin and supplemented foods are important, indispensible and needed by food and nutraceutical industries for quality control during production, and for accurate evaluation of data and label clams. Due to low concentrations of B8 and B9 in nature, there is a critical need for preconcentration to facilitate their isolation and purification from a complex matrix like food. In order to minimize the consumption of solvents, solid phase extraction (SPE) has been introduced for sample preparation. In this study, two types of SPE, i.e., reversed-phase C18 and strong anion-exchange phase, were used for sample clean-up and pre-concentration. The average recoveries for vitamin B3, B5, B7 and B9 were 101.3%, 102.9%, 92.8% and 102.6%, respectively, by using C18 SPE. In contrast, the strong anion-exchange SPE provided the average recoveries of B3, B5, B7 and B9 in 91.5%, 93.0%, 109.1% and 106.7%, respectively. Furthermore, simultaneous determination of water-soluble vitamins was developed by a HPLC system installed with a ZORBAX Eclipse XDB-C18 (250mm x 4.6mm, 5 μm particle size, Aglient Technologies, Inc., Loveland, CO, USA) with a guard column (12.5mm x 4.6mm, 5 μm particle size), and compared by three detectors, including DAD, ELSD and MS. The B-complex supplement, multivitamin/multimineral tablets and powder and vitamin drink were tested to verify HPLC method. According to the results, LC-MS is the best to do the simultaneous determination of the B-group vitamins in lights of its analytical accuracy, precision, sensitivity and versatility

Taiwan Internet Diffusion: An Empirical Study of Internet Interactive Effects

The primary objects of this research were applying the innovation diffusion model to internet hosts and internet subscribers . The results of this study may be a useful reference to the further concept building of the relationship of innovative and adopters

Modeling Turbidity Currents Using the Multiple-state Discrete-time Markov Chain Approach

Source: ICHE Conference Archive - https://mdi-de.baw.de/icheArchive

Conservation genetics and phylogeography of endangered and endemic shrub Tetraena mongolica (Zygophyllaceae) in Inner Mongolia, China

<p>Abstract</p> <p>Background</p> <p><it>Tetraena mongolica </it>(Zygophyllaceae), an endangered endemic species in western Inner Mongolia, China. For endemic species with a limited geographical range and declining populations, historical patterns of demography and hierarchical genetic structure are important for determining population structure, and also provide information for developing effective and sustainable management plans. In this study, we assess genetic variation, population structure, and phylogeography of <it>T. mongolica </it>from eight populations. Furthermore, we evaluate the conservation and management units to provide the information for conservation.</p> <p>Results</p> <p>Sequence variation and spatial apportionment of the <it>atp</it>B-<it>rbc</it>L noncoding spacer region of the chloroplast DNA were used to reconstruct the phylogeography of <it>T. mongolica</it>. A total of 880 bp was sequenced from eight extant populations throughout the whole range of its distribution. At the cpDNA locus, high levels of genetic differentiation among populations and low levels of genetic variation within populations were detected, indicating that most seed dispersal was restricted within populations.</p> <p>Conclusions</p> <p>Demographic fluctuations, which led to random losses of genetic polymorphisms from populations, due to frequent flooding of the Yellow River and human disturbance were indicated by the analysis of BEAST skyline plot. Nested clade analysis revealed that restricted gene flow with isolation by distance plus occasional long distance dispersal is the main evolutionary factor affecting the phylogeography and population structure of <it>T</it>. <it>mongolica</it>. For setting a conservation management plan, each population of <it>T</it>. <it>mongolica </it>should be recognized as a conservation unit.</p

Clinical Characteristics and Risk Factors for Mortality in Patients with Meningitis Caused by Staphylococcus aureus and Vancomycin Minimal Inhibitory Concentrations Against These Isolates

Background/PurposeBacterial meningitis caused by Staphylococcus aureus is uncommon but has a high mortality rate. The aims of this study were to better understand the clinical manifestations of S. aureus meningitis, to identify the risk factors for mortality in the affected patients, and to determine the levels of vancomycin minimal inhibitory concentrations (MICs) against these pathogens.MethodsA retrospective study of patients with S. aureus meningitis hospitalized between December 2000 and December 2008 was made, and vancomycin MICs against S. aureus isolates was determined using Etest.ResultsAmong 37 patients with S. aureus meningitis, fever was most commonly observed. Twenty-six patients (70.3%) had received prior neurosurgery, and 24 (64.9%) patients were suffering from methicillin-resistant S. aureus (MRSA) infections. The vancomycin MIC of 2 μg/mL was found in 23 (74.2%) of 31 S. aureus isolates available for testing. Excluding three patients who did not receive antibiotics for their S. aureus meningitis the mortality rate was 35.3% in the 34 remaining patients, with concurrent infective endocarditis an independent risk factor for mortality (odds ratio = 21.00; 95% confidence interval, 1.834-240.515; p = 0.01).ConclusionPatients with S. aureus meningitis and concurrent infective endocarditis were at a higher risk of mortality. A vancomycin MIC of 2 μg/mL against a substantial number of S. aureus isolates that grew from the cerebrospinal fluid suggests the importance of obtaining trough vancomycin concentrations of 15-20 μg/mL for the treatment of MRSA meningitis

SAGITTAL AND FRONTAL LOWER LIMBS KINETICS DURING STEPPING DOWN IN TAICHI ELDERLY

The aim was to compare the kinetic characteristics of the beginning stance phase during stepping down in Taichi and normal elderly. Nine elderly taichi subjects and eleven matched controls participated in the study. Whole body kinematics and ground reaction forces (GRF) were recorded using 10 Vicon cameras (250Hz) and two Kistler force plates (1000Hz). Sagittal and frontal kinetic parameters were calculated by using Visual3D software. Differences in variables between groups were tested using t-test. The results indicated hip extensor / knee flexor / ankle plantarflexor / support moment and peak hip/knee/ankle power were greater in Taichi group. It was concluded that Taichi group has ability to translate forward movement (hip moment / power), to control body (knee moment /power) and to absorption energy (ankle moment / power) in sagittal plane

Separation Enhancement of Mechanical Filters by Adding Negative Air Ions

The purpose of this work is to combine negative air ions (NAIs) and mechanical filters for removal of indoor suspended particulates. Various factors, including aerosol size (0.05-0.45 μm), face velocity (10 and 20 cm/s), species of aerosol (potassium chloride and dioctyl phthalate), relative humidity (30% and 70%), and concentrations of NAIs (2 ´ 104, 1 ´ 105, and 2 ´ 105 NAIs/cm3) were considered to evaluate their effects on the aerosol collection characteristics of filters. Results show that the aerosol penetration through the mechanical filter is higher than that through the mechanical filters cooperated with NAIs. This finding implies that the aerosol removal efficiency of mechanical filters can be improved by NAIs. Furthermore, the aerosol penetration through the mechanical filters increased with the aerosol size when NAIs were added. That is due to that the aerosol is easier to be charged when its size gets larger. The results also indicate the aerosol penetration decreased with the NAIs concentration increased. Reversely, aerosol penetration through the mechanical filters increased with the face velocity under the influence of NAIs. The aerosol penetration through the filter with NAIs was no affected with relative humidity. Finally, The penetration through the filter with NAIs against solid aerosol was lower than that against liquid aerosol