Higher Values In Samples Research Articles

Evolution of the volatile compounds of ripened sausages as a function of both storage time and composition of packaging atmosphere

An experimental investigation was carried out to study the evolution of the volatile compounds of ripened sausages as a function of both storage time (time) and composition of packaging atmosphere (MAP). Ripened sausages, prepared at an industrial plant, were packed applying three different atmosphere compositions and were stored for three months. The obtained data evinced that the evolution of the volatile compounds was significantly related to the variable time more than to the variable MAP. The main volatile compounds were those derived from spices. Among them, Δ3-carene was the most abundant and a significant decrease was observed during storage (p<0.05). The volatile compounds derived from lipid autoxidation showed generally a significant increase during storage, suggesting the raise of lipid oxidation also at low oxygen concentration. Moreover, octanal and nonanal were significantly influenced by the atmosphere composition, with the highest values in samples packed at the lowest CO2 concentration.

Discrimination between diffuse and point sources of arsenic at Zimapán, Hidalgo state, Mexico

There are two principal sources of arsenic in Zimapán. Point sources are linked to mining and smelting activities and especially to mine tailings. Diffuse sources are not well defined and are linked to regional flow systems in carbonate rocks. Both sources are caused by the oxidation of arsenic-rich sulfidic mineralization. Point sources are characterized by Ca-SO(4)-HCO(3) ground water type and relatively enriched values of deltaD, delta(18)O, and delta(34)S(SO(4)). Diffuse sources are characterized by Ca-Na-HCO(3) type of ground water and more depleted values of deltaD, delta(18)O, and delta(34)S(SO(4)). Values of deltaD and delta(18)O indicate similar altitude of recharge for both arsenic sources and stronger impact of evaporation for point sources in mine tailings. There are also different values of delta(34)S(SO(4)) for both sources, presumably due to different types of mineralization or isotopic zonality in deposits. In Principal Component Analysis (PCA), the principal component 1 (PC1), which describes the impact of sulfide oxidation and neutralization by the dissolution of carbonates, has higher values in samples from point sources. In spite of similar concentrations of As in ground water affected by diffuse sources and point sources (mean values 0.21 mg L(-1) and 0.31 mg L(-1), respectively, in the years from 2003 to 2008), the diffuse sources have more impact on the health of population in Zimapán. This is caused by the extraction of ground water from wells tapping regional flow system. In contrast, wells located in the proximity of mine tailings are not generally used for water supply.

Usage of the standard and modified comet assay in assessment of DNA damage in human lymphocytes after exposure to ionizing radiation

Usage of the standard and modified comet assay in assessment of DNA damage in human lymphocytes after exposure to ionizing radiationBackground. Human organisms are extremely sensitive to ionizing radiation, which has the strong genotoxic effect on the DNA molecule. The aim of the present study was to detect the type of DNA damage and cell death caused by ionizing radiation as well as the sensitivity of the standard and modified comet assay.Methods. The effect of gamma radiation (0.1 Gy and 4 Gy) on human lymphocytes was observed using the standard alkaline and Fpg-modified comet assay with ability to detect oxidized purines as well as with the DNA diffusion test.Results. Parameters of the standard comet assay showed significantly higher values in samples exposed to 4 Gy than in samples exposed to radiation dose of 0.1 Gy and control sample. The Fpg-modified comet assay showed significantly higher values already at dose of 0.1 Gy as the result of oxidative DNA damage. The DNA diffusion test showed that gamma rays lead to apoptosis more often than to necrosis.Conclusions. This observation suggests that the standard alkaline and Fpg-modified comet assays as well as the DNA diffusion test are reliable techniques for estimation of DNA

Metal levels in tissues of Eurasian otters ( Lutra lutra) from Hungary: Variation with sex, age, condition and location

Liver samples of Eurasian otters from various parts of Hungary were analysed for mercury, copper, zinc, lead and cadmium. Only zinc concentration was significantly higher in females. Higher mercury and cadmium concentrations in adults and higher zinc values in immature otters were measured. Accumulation of mercury, copper and zinc in tissues increased with the declining condition of animals. Mercury and copper were detected with higher values in samples from large rivers.

Clearance of Circulating Epstein‐Barr Virus DNA in Children with Acute Malaria after Antimalaria Treatment

Children living in malaria-endemic regions have a high incidence of Burkitt lymphoma (BL), the etiology of which involves Plasmodium falciparum malaria and Epstein-Barr virus (EBV) infections. In the present study, we compared EBV DNA loads in plasma and saliva samples from Ugandan children with acute malaria (M+) at the time of diagnosis and 14 days after antimalaria treatment, children without malaria (M-), and children with BL. EBV DNA was detected, by real-time polymerase chain reaction, in 31% of the plasma and in 79% of the saliva samples from children in the M+ group. Antimalaria treatment led to clearance of plasma viral load in 85% of the cases but did not affect the levels in saliva. There was a significant difference in plasma EBV loads across the groups. The lowest levels were detected in samples from the M- group, increased levels were detected in samples from the M+ group, and levels reached the highest values in samples from children with BL. The same trend was evident in the frequency and levels of anti-BZLF1 antibodies, which is indicative of viral reactivation. In the M+ group, the positive plasma samples clustered around 7-9 years of age, the peak incidence of BL. The clearance of circulating EBV after antimalaria treatment suggests a direct relationship between active malaria infection and viral reactivation.

IrO 2 -based thick-film resistors

IrO 2 -based thick-film resistors were prepared and their microstructure/electrical property relationship was studied as a function of the firing temperature Tf and composition. The resistor microstructure exhibits a notable change, from a strongly segregated structure for Tf=750 °C, to a quasihomogeneous one when the firing temperature increases to Tf=850 °C. Likewise, a substantial change is observed in the sheet resistance (Rs) dependence on the volume fraction (v) of the conductive phase. For resistors prepared at Tf=750 °C the percolation power law Rs≈(v−vc)−t (where vc and t are the critical volume fraction and exponent, respectively) is observed, while samples fired at Tf⩾850 °C follow the relation ln Rs≈a(v−v0) where a and v0 are proper constants. In addition, the slope of plot a is affected by the firing temperature Tf as well as by the measuring temperature at T&amp;lt;50 K. Very high temperature coefficients of resistance are measured at cryogenic temperatures. The longitudinal gauge factor values are in the range from 3 to 12.4 according to the resistor composition and firing temperature, with the highest values in samples fired at 950 °C with sheet resistance in the range from 104 to 107 Ω/□.

Variation in the Quantitation of Prostate-specific Antigen in Reference Material: Differences in Commercial Immunoassays,

Prostate-specific antigen (PSA) is a widely used biochemical marker for prostate cancer (1). PSA, a serine protease, forms complexes with serine protease inhibitors such as α2-macroglobulin and α1-antichymotrypsin (ACT) (2). The major immunoreactive forms of serum PSA are PSA-ACT complex and free PSA. PSA complexed to α2-macroglobulin is not measured by current immunoassays (3). Because the proportion of PSA complexed to ACT is higher in men with prostate cancer than in men with benign prostatic hyperplasia (BPH) (3)(4), the use of a ratio of free-to-total PSA may improve discrimination between men with BPH and prostate cancer (5)(6). Results obtained with different PSA immunoassays are not interchangeable (7)(8)(9)(10). The variation among immunoassays reflects, in large part, the specificity of different PSA antibodies (7). To a lesser extent, the composition of the calibrator, the PSA values assigned to the calibrator, the test diluent, and the physical design of the immunoassays contribute to intermethod differences (6)(7). Assays using a monoclonal-monoclonal sandwich format yield, in general, an equimolar response to free and ACT-complexed PSA, whereas monoclonal-polyclonal formats tend to yield higher values for samples containing greater proportions of free PSA (8). We have recently described the Bayer Immuno 1TM PSA Assay (Bayer Corporation), which uses a monoclonal-polyclonal antibody format that yields an equimolar response to varying proportions of free and complexed PSA (11). This has now been found to be a result of the unique binding properties of the monoclonal antibody used for the capture of PSA (manuscript in submission). Proficiency testing among clinical laboratories has indicated large intermethod variability in the quantitation of total PSA (12). The aim of this study was to determine the magnitude and cause of this intermethod variation. Here we report our multi-site analysis of …

Fluorine in Asturian coals

Concentrations of fluorine in Asturian bituminous coals and anthracites have been determined. Fluorine analysis has been carried out by comparing oxygen bomb combustion and pyrohydrolysis methods. Pyrohydrolysis revealed higher values in samples whose ash contents were greater than 25 wt%, which in turn was related to fluorine contents higher than 100 ppm. Good correlation between fluorine and ash content suggests that fluorine is present in these coals in mineral species, and is not probably associated with organic matter. The association of fluorine with phosphorus is also discussed. An excess of fluorine concentration versus phosphorus, corresponding to fluorapatite, has been found.

The establishment of provisional quality assurance guidelines for assessing the hygienic adequacy of the lamb carcass cooling process

The hygienic consequence of a lamb carcass cooling process can be assessed by evaluating the product's time-temperature history at a site within the carcass cavity adjacent to the 5th and 6th lumbar vertebrae. From these data, a numerical value, the process hygiene index, is generated which reflects the amount of potential bacterial growth the process allows and is proposed as an alternative quality assurance tool for assessing lamb cooling processes. Two hygienically acceptable lamb cooling processes, one producing carcasses destined for freezing and the other producing carcasses destined for chilled processing, were monitored. Acceptable cooling processes can be conveniently described in terms of a three class sampling plan where the maximum acceptable value (M) is the highest value obtained and the target value (m) is determined as the 80th percentile value of the pooled data from acceptable runs. The number (c), the proportion of sample values that may lie between (m) and (M), is determined from the acceptable run with the highest sample values. For the process yielding carcasses destined for freezing M = 15, m = 14 and c = 20% while for that producing carcasses for chilled processing M = 9, m = 6 and c = 60%. For both processes a minimum of five samples was tested per process run. Based on these values, provisional processing guidelines for the hygienic cooling of lamb carcasses are suggested.

Fluorine in Asturian coals

Abstract Concentrations of fluorine in Asturian bituminous coals and anthracites have been determined. Fluorine analysis has been carried out by comparing oxygen bomb combustion and pyrohydrolysis methods. Pyrohydrolysis revealed higher values in samples whose ash contents were greater than 25 wt%, which in turn was related to fluorine contents higher than 100 ppm. Good correlation between fluorine and ash content suggests that fluorine is present in these coals in mineral species, and is not probably associated with organic matter. The association of fluorine with phosphorus is also discussed. An excess of fluorine concentration versus phosphorus, corresponding to fluorapatite, has been found.

Changes in a fractional site occupancy as an effect of an oxygen ordering on the basal CuO plane in YBa2Cu3Ox

X-ray diffraction and thermogravimetric (TGA) studies have been carried out on orthorhombic YBa2Cu3Ox samples obtained by the reoxygenation of tetragonal samples. Thermogravimetric measurements performed in 100% oxygen provided data for the oxygen content (x) on the CuO basal planes. At fixed x higher than 6.8, samples obtained by different final heat treatments show different amounts of orthorhombic distortion (higher values for samples with higher degree of ordering). The orthorhombic distortion and oxygen content data have been used for the estimation of fractional site occupancy of O(1) and O(5) sites∗∗The site notation is the same as in Jorgensen's et al.2 paper. of YBa2Cu3Ox on the basis of Bakker's et al. 8theory. Differences in fractional site occupancy are obtained for samples with different degree of ordering.