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Cadmium content in foodstuffs from the Greek market.

Determinations of the cadmium content of a wide variety of foodstuffs from the Greek market were carried out. The values detected ranged from <0.1 ng x g(-1) in alcoholic beverages to 1595.8 ng x g(-1) in large snails. The highest values were observed in molluscs and crustaceans (117.4 ng x g(-1)), followed by leafy vegetables (28.3 ng x g(-1)), potatoes (22.3 ng x g(-1)) and organs and offal (20.7 ng x g(-1)), whereas the other food categories had a lower cadmium content. The results are comparable with those from the rest of Europe. Preliminary analytical data on the cadmium content of food samples of organic cultivation showed significantly lower values compared with those of samples of conventional produce.

Animals↗

International legislation on trace elements as contaminants in food: a review.

Environmental contaminants such as trace elements may be present in all foods. Foods, raw materials and ingredients for food production are to an increasing extent traded across borders. Hence, there is a need for international legislation on trace elements as contaminants in food. In 1961, the FAO and WHO established the Codex Alimentarius to elaborate international food legislation. Contaminants in food are handled by the Codex Committee for Food Additives and Contaminants (CCFAC). The Codex Alimentarius system for developing legislation concerning trace elements as contaminants in food is based upon the Codex General Standard for Contaminants and Toxins in Food (GSCTF). By October 2001, the principles for setting maximum limits (MLs) for contaminants in food are agreed, and work is in progress on MLs for trace elements such as lead and cadmium in the various food categories. The status for the proposals is presented and discussed. The EU Regulation 466/2001 of 8 March 2001 sets MLs for lead and cadmium in various foods. This regulation will apply from 5 April 2002. The EU regulation is more detailed but similar to the Codex draft standards for lead and cadmium in food. In future, legislators and administrators in the Codex and EU and analytical chemists will discuss how to use more and better analytical data as risk-management tools to protect public health. Trace elements' speciation is an important aspect of this discussion.

European Union↗

Identification of Albizia gum exudates which are not permitted food additives.

Trees of the genus Albizia have frequently been confused with Acacia species. The genus Albizia has been recommended for more extensive arid zone development; its species are sources of tannins and gum exudates, which are not included in any of the regulatory lists of permitted food additives. Analytical data permitting their identification are therefore required to allow food law compliance to be monitored. This paper presents data which serve to characterize the gums from seven Albizia species, making a total of eleven Albizia species for which data are available. The presence of tannins, and high proportions of aluminium and heavy metals, indicates that gum importers and food processors must be vigilant to ensure that Albizia gums do not enter human food chains as adulterants or contaminants.

Amino Acids↗

Gum arabic (Acacia senegal): unambiguous identification by 13C-NMR spectroscopy as an adjunct to the Revised JECFA Specification, and the application of 13C-NMR spectra for regulatory/legislative purposes.

The JECFA Specification for gum arabic was revised in 1990 to reflect more closely the specification of the Test Article used in evaluations that led to its classification 'ADI not specified' in 1982/83. Some producers and traders have objected to the Revised Specification; in contrast, consumer-protection groups consider that it remains too lax to provide the degree of safety assurance expected. This paper presents analytical data that confirm the mean values previously established for nitrogen and the specific rotation of bulk commercial gum arabic from Acacia senegal. The data also establish that natural gum arabic imported into the USA and Europe in 1989/91 met the Revised Specification, but that a disturbingly high proportion of spray-dried, processed gums sold as 'gum arabic' did not. NMR spectroscopy has (a) indicated that some such samples are based on non-permitted gums and (b) confirmed that the 1983 Test Article represents not only typical 1990/91 shipments but also a wide range of reference gum arabic samples from other reputable sources. Details of a representative 13C-NMR spectrum, derived by averaging the relative intensities for the characteristic resonances of 35 gum arabic samples, are given for future regulatory/legislative purposes. Some limitations of the Revised Specification and its susceptibility to commercial exploitation are discussed.

Carbon Isotopes↗

Simultaneous-successive processing across the life-span: a cross-sectional examination of stability and proficiency.

A cross-sectional comparison of elderly (n = 70, M = 71.55 years) and young adults (n = 157, M = 22.85) was performed employing a battery of tests sensitive to simultaneous-successive cognitive processing as described by the Luria-Das model. Factor analytic data were supportive of the basic stability and generalizability of this model over the life-span, i.e., a two-factor solution for the various cognitive tasks was obtained for both groups. Differences in the salient factor loadings across the groups are discussed, as are quantitative deficits in performance by the elderly. Covarying age and education, analyses of placement differences within the elderly sample suggested a greater deficit in simultaneous processing scores as a function of restrictiveness of placement.

Adolescent↗

Regulatory off-gas analysis from the evaporation of Hanford simulated waste spiked with organic compounds.

After strontium/transuranics removal by precipitation followed by cesium/technetium removal by ion exchange, the remaining low-activity waste in the Hanford River Protection Project Waste Treatment Plant is to be concentrated by evaporation before being mixed with glass formers and vitrified. To provide a technical basis to permit the waste treatment facility, a relatively organic-rich Hanford Tank 241-AN-107 waste simulant was spiked with 14 target volatile, semi-volatile, and pesticide compounds and evaporated under vacuum in a bench-scale natural circulation evaporator fitted with an industrial stack off-gas sampler at the Savannah River National Laboratory. An evaporator material balance for the target organics was calculated by combining liquid stream mass and analytical data with off-gas emissions estimates obtained using U.S. Environmental Protection Agency (EPA) SW-846 Methods. Volatile and light semi-volatile organic compounds (<220 degrees C BP, >1 mm Hg vapor pressure) in the waste simulant were found to largely exit through the condenser vent, while heavier semi-volatiles and pesticides generally remain in the evaporator concentrate. An OLI Environmental Simulation Program (licensed by OLI Systems, Inc.) evaporator model successfully predicted operating conditions and the experimental distribution of the fed target organics exiting in the concentrate, condensate, and off-gas streams, with the exception of a few semi-volatile and pesticide compounds. Comparison with Henry's Law predictions suggests the OLI Environmental Simulation Program model is constrained by available literature data.

Air Pollutants↗

Contamination is a frequent confounding factor in toxicology studies with anthraquinone and related compounds.

Anthraquinone (AQ) (9,10-anthracenedione) is an important compound in commerce. Many structurally related AQ derivatives are medicinal natural plant products. Examples include 1-hydroxyanthraquinone (1-OH-AQ) and 2-hydroxyanthraquinone (2-OH-AQ), which are also metabolites of AQ. Some commercial AQ is produced by the oxidation of anthracene (AQ-OX). In the recent past, the anthracene used was distilled from coal tar and different lots of derived AQ often contained polycyclic aromatic hydrocarbon contaminants, particularly 9-nitroanthracene (9-NA). Many toxicology studies on AQ used contaminated anthracene-derived AQ-OX, including a National Toxicology Program (NTP) 2-year cancer bioassay that reported a weak to modest increase in tumors in the kidney and bladder of male and female F344/N rats and in the livers of male and female B6C3F1 mice. The AQ-OX used in that bioassay was mutagenic and contained 9-NA and other contaminants. In contrast, purified AQ is not genotoxic. The purpose of this paper is to provide additional information to help iterpret the NTP cancer bioassay. This paper describes a quantitative analytical study of the NTP anthracene-derived AQ-OX test material, and presents the results of mutagenicity studies with the 1-OH-AQ and 2-OH-AQ metabolites and the primary contaminant 9-NA. Purified 1-OH-AQ and 2-OH-AQ exhibited only weak mutagenic activity in selected strains of tester bacteria and required S9. Literature reports of potent mutagenic activity for 1-OH-AQ and 2-OH-AQ in bacteria minus S9 are, once again, very likely the result of the presence of contaminants in the test samples. Weak activity and limited production of the 1-OH-AQ and 2-OH-AQ metabolites are possible reasons that AQ fails to exhibit activity in numerous genotoxicity assays. 9-NA was mutagenic in tester strains TA98 and TA100 minus S9. This pattern of activity is consistent with that seen with the contaminated AQ-OX used in the NTP bioassay. Analysis of all the mutagenicity and analytical data, however, indicates that the mutagenic contamination in the NTP bioassay probably resides with compounds in addition to 9-NA. 9-NA exhibited potent mutagenic activity in the L5178Y mammalian cell mutagenicity assay in the presence of S9. The positive response was primarily associated with an increase in small colony mutants suggesting a predominance of a clastogenic mechanism. Quantitative mutagenicity and carcinogenicity potency estimates indicate that it is plausible that the contaminants alone in the NTP AQ-OX bioassay could have been responsible for all of the observed carcinogenic activity. Although AQ-OX is no longer commercially used in the United States, many of the reported genotoxicity and carcinogenicity results in the literature for AQ and AQ derivative compounds must be viewed with caution.

Animals↗

The contributions of behavioural genetic studies to attachment theory.

This review considers the ways in which the methods and theories of behavioural genetics and attachment theory are mutually informative. Four issues are discussed. First, the benefits of the adoptive and twin research designs for testing attachment theory proposals are examined. Second, the ways in which attachment research may elucidate the behavioural genetic concepts of 'shared' and 'non-shared' environment are assessed. Third, the methods use to clarify the role of child effects on child-parent attachment quality are addressed. Finally, the limitations and data analytic considerations of synthesizing behavioural genetic and attachment research are outlined.

Adoption↗

Unsymmetrical 1,1'-disubstituted ferrocenes: synthesis of Co(ii), Cu(ii), Ni(ii) and Zn(ii) chelates of ferrocenyl -1-thiadiazolo-1'-tetrazole, -1-thiadiazolo-1'-triazole and -1-tetrazolo-1'-triazole with antimicrobial properties.

Condensation reactions of 1,1''-diacetylferrocene with different heteroaromatic amines such as, 2-amino-1,3,4-thiadiazole, 5-aminotetrazole and 3-amino-1,2,4-triazole to form unsymmetrically 1,1'-disubstituted ferrocenes have been studied. The obtained compounds have been further investigated for their liganding and biological properties upon chelation with Co(II), Cu(II), Ni(II) and Zn(II) metal ions. The synthesized compounds have been characterized by physical, spectral and analytical data and have been screened against pathogenic bacterial strains e.g., Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus, showing moderate activity as antibacterials in vitro.

Anti-Bacterial Agents↗

Antibacterial cobalt(II), nickel(II) and zinc(II) complexes of nicotinic acid-derived Schiff-bases.

Nicotinic acid derived Schiff bases and their transition metal [cobalt(II), nickel(II) and zinc(II)] complexes have been prepared and characterized by physical, spectral and analytical data. The Schiff bases act as deprotonated tridentate ligands for the complexation of the above mentioned metal ions. These complexes, possessing the general formula [M(L)2] [where M = Co(II), Ni(II) and Zn(II) and L = HL1-HL4] showed an octahedral geometry of the metal ions. For determining the effect of metal ions upon chelation, the Schiff bases and their complexes have been screened for antibacterial activity against several pathogenic strains of Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa. The new metal derivatives reported here were more bactericidal against one or more bacterial species as compared to the uncomplexed Schiff bases.

Anti-Bacterial Agents↗

Antibacterial Co(II), Cu(II), Ni(II) and Zn(II) complexes of thiadiazole derived furanyl, thiophenyl and pyrrolyl Schiff bases.

2-Amino-1,3,4-thiadiazole undergoes a condensation reaction with furane-, thiophene- and pyrrole-2-carboxaldehyde to form tridentate NNO, NNS and NNN donor Schiff bases. These Schiff bases were further used to obtain complexes of the type [M(L)2]X, where M = Co(II), Cu(II), Ni(II) or Zn(II), L = L1, L2 or L3 and X = Cl2. The new compounds described here have been characterized by their physical, spectral and analytical data, and have been screened for antibacterial activity against several bacterial strains such as Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa. The antibacterial potency of the Schiff bases increased upon chelation/complexation in comparison to the uncomplexed Schiff bases against the tested bacterial species thus, opening new approaches to find new ways in the fight against antibiotic-resistant strains.

Anti-Bacterial Agents↗

Transition metal acetylsalicylates and their anti-inflammatory activity.

Mononuclear and binuclear transition metal [Co(II), Cu(II), Ni(II) and Zn(II)] acetylsalicylates of the type [M(L)2], [M(L)2Cl2] and [(M)2(L)4] have been prepared and characterized on the basis of their physical, spectral and analytical data. The complexes have been investigated in an in vivo animal model for anti-inflammatory activity and show a better effect and a more potent action than acetylsalicylic acid.

Anti-Inflammatory Agents, Non-Steroidal↗

Zinc complexes of benzothiazole-derived Schiff bases with antibacterial activity.

Reaction of 2-acetamidobenzaldehyde with 2-amino-, 2-amino-4-methyl-, 2-amino-4-methoxy-, 2-amino-4-chloro-, 2-amino-6-nitro- and 2-amino-6-methylsufonylbenzothiazole afforded a series of Schiff bases. These compounds have been used for complexation reactions to obtain Zn(II) chelates having the same metal ion but different anions of the type [Zn(L)2]Xn [L = Schiff base derivative, X = SO4, NO3, C2O4 and CH3CO2 and n = 1 or 2] These complexes (Table I) have been characterized by physical, spectral, and analytical data. The Schiff bases act tridentately and their metal complexes were proposed to possess an octahedral geometry. To evaluate the antibacterial role of the anion, these compounds have been screened for antibacterial properties against pathogenic strains such as Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa.

Anti-Bacterial Agents↗

Oxovanadium(IV) complexes of hydrazides: potential antifungal agents.

Oxovanadium(IV) -derived antifungals have been prepared by condensing equimolar amounts of vanadyl sulfate with hydrazides. All the synthesized ligands and their metal complexes were characterized by IR, UV-Visible and micro analytical data. These synthesized compounds were screened for their antifungal activity against Aspergillus flavus (A. flavus), Trichophyton longifusus (T. longifusus), Candida albicans (C. albicans), Microsporum canis (M. canis), Fusarium solani (F. solani) and Candida glaberata (C. glaberata) fungal strains. All complexes showed promising antifungal activity against different fungal strains with the exception of F. Solani and C. glaberata. Minimum Inhibitory Concentration (MIC) of different complexes and ligands are in the range of 250 to 400 microg/mL. Complex 7a and ligand 13 exhibit lowest MIC of 250 microg/mL whereas, complex 5a and ligands 2, 7 and 14 showed highest MIC of 400 microg/mL.

Antifungal Agents↗

Kinetic study on the irreversible thermal denaturation of lentil lectin.

The irreversible thermal denaturation of lentil lectin was investigated at pH 7.4 using different techniques including high-sensitivity differential scanning calorimetry, differential detergent solubility thermal gel analysis, intrinsic fluorescence and hemagglutinating activity assays. The shape of the transition, as well as its scan-rate dependence, can be explained by assuming that thermal denaturation takes place according to the kinetic scheme N k-->D, where k is a first-order kinetic constant that changes with temperature, as given by the Arrhenius equation, N the native state, and D the denatured one. On the basis of this model, the value of the rate constant as a function of temperature and the activation energy were calculated. The analytical data obtained with the other methods used in this work support the proposed two-state kinetic model.

Calorimetry, Differential Scanning↗

Spectroscopic characterization of the uptake of essential and xenobiotic metal cations in cells of the soil bacterium Azospirillum brasilense.

The results of flame (FAAS) or graphite furnace atomic absorption spectrometric (GFAAS) analyses are presented and discussed on the accumulation of essential metals (Mg, Ca, Mn and Fe contained in the cultivation medium) and traces of each one of the conventionally xenobiotic elements from the group V, Co, Ni, Cu, Zn or Pb, added to the medium in concentrations (0.2 mM) which do not essentially suppress growth of the bacterial culture, in cells of the plant root-associated nitrogen-fixing bacterium Azospirillum brasilense. Along with the essential cations assimilated by the bacterium, Zn and Cu were found to effectively accumulate in the biomass from the environment. The uptake of Co and Ni was significantly less pronounced, whereas Pb and V appeared to be present in cells in much lower concentrations than in the cultivation medium evidently showing no tendency to be assimilated by azospirilla. The effect of the above xenobiotics on the uptake level of the four essential elements provided evidence that they may compete for the formation of biologically active complexes with substances of both intracellular and extracellular localization. The analytical data obtained are compared with Fourier transform infrared (FTIR) spectra of intact vacuum-dried bacterial cells grown in a standard medium and under the conditions of an increased metal uptake.

Azospirillum brasilense↗

Sampling and analytical methods for the determination of monochloroacetic acid in air.

A personal sampling and analytical method has been developed for the determination of monochloroacetic acid (MCA) vapor in air. The sampling procedure is the collection of MCA with a solid sorbent sampling tube packed with silica gel. The MCA is leached from the exposed sorbent into distilled, deionized water and quantitated by ion chromatographic analysis. The method has been validated in the concentration range of 0.35 to 29 mg/m3 in 3-L air samples. The capacity of the silica gel is in the range of 3 to 4 mg of MCA per 100 mg of sorbent, which allows for up to 8 hr of sampling at concentrations greater than 40 mg/m3. There are no significant interferences from glycolic acid, acetic acid, dichloroacetic acid, trichloroacetic acid, fluoride and chloride compounds, or water vapor. The effects on the analytical data due to variations in the temperature and humidity of the test atmosphere, sample storage time and chromatographic parameters have been found to be minimal.

Acetates↗

A zonal rotor method for the preparation of microperoxisomes from epithelial cells of guinea pig small intestine.

A method is described for the preparation of catalase particles from homogenates made from suspensions of epithelial cells of the small intestine of the guinea pig. Electron microscope examination of the preparations revealed the presence of small diaminobenzidine-positive particles measuring 0.1-0.3 nm in diameter and resembling the microperoxisomes observed by Novikoff and Novikoff (1972. J. Cell Biol.53:532.). Analytical data upon which the method is based are presented. The technique consisted of a rate zonal separation of microperoxisomes from large particles followed by an isopycnic separation from less dense organelles. Application of the method yielded microperoxisomes purified between 20- and 30-fold.

Alkaline Phosphatase↗