Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 37
Filter
Add more filters










Publication year range
1.
Phys Rev Lett ; 121(4): 042701, 2018 Jul 27.
Article in English | MEDLINE | ID: mdl-30095928

ABSTRACT

We report on the measurement of the ^{7}Be(n,p)^{7}Li cross section from thermal to approximately 325 keV neutron energy, performed in the high-flux experimental area (EAR2) of the n_TOF facility at CERN. This reaction plays a key role in the lithium yield of the big bang nucleosynthesis (BBN) for standard cosmology. The only two previous time-of-flight measurements performed on this reaction did not cover the energy window of interest for BBN, and they showed a large discrepancy between each other. The measurement was performed with a Si telescope and a high-purity sample produced by implantation of a ^{7}Be ion beam at the ISOLDE facility at CERN. While a significantly higher cross section is found at low energy, relative to current evaluations, in the region of BBN interest, the present results are consistent with the values inferred from the time-reversal ^{7}Li(p,n)^{7}Be reaction, thus yielding only a relatively minor improvement on the so-called cosmological lithium problem. The relevance of these results on the near-threshold neutron production in the p+^{7}Li reaction is also discussed.

2.
Environ Sci Pollut Res Int ; 21(21): 12223-32, 2014 Nov.
Article in English | MEDLINE | ID: mdl-24840359

ABSTRACT

The aim of our studies was to determine the efficiency of decomposition of non-ionic surfactant by the Fenton method in the presence of iron nanocompounds and to compare it with the classical Fenton method. The subject of studies was water solutions of non-ionic detergent Tergitol TMN-10 used in textile industry. Water solutions of the surfactant were subjected to treatment by the classical Fenton method and to treatment in the presence of iron nanocompounds. In the samples of liquid solutions containing the surfactant, chemical oxygen demand (COD) and total organic carbon (TOC) were determined. The Fenton process was optimized based on studies of the effect of compounds used in the treatment, doses of iron and nanoiron, hydrogen peroxide and pH of the solution on surfactant decomposition. Iron oxide nanopowder catalyzed the process of detergent decomposition, increasing its efficiency and the degree of mineralization. It was found that the efficiency of the surfactant decomposition in the process with the use of iron nanocompounds was by 10 to 30 % higher than that in the classical method. The amounts of formed deposits were also several times smaller.


Subject(s)
Ferric Compounds/chemistry , Hydrogen Peroxide/chemistry , Iron/chemistry , Nanoparticles/chemistry , Poloxalene/chemistry , Surface-Active Agents/chemistry , Water Pollutants, Chemical/chemistry , Water Purification/methods , Biological Oxygen Demand Analysis , Hydrogen-Ion Concentration , Textile Industry
3.
Rev Sci Instrum ; 85(4): 043303, 2014 Apr.
Article in English | MEDLINE | ID: mdl-24784598

ABSTRACT

The designed and constructed at the University of Lodz an electron spectrometer is devoted to "in-beam" measurements. The apparatus is characterized by high efficiency up to 9%, good energy resolution (FWHM = 5 keV at 482 keV) and, what is very important good suppression of delta electrons, positrons, and photons emitted by the targets. This achievement was obtained using a combination of magnetic field in two different layouts: perpendicular and parallel to the axis of the spectrometer being orthogonal to the beamline. The conversion-electron spectrometer coupled to the EAGLE array was successfully tested in an "in-beam" measurement.

4.
Lett Appl Microbiol ; 59(1): 99-107, 2014 Jul.
Article in English | MEDLINE | ID: mdl-24635164

ABSTRACT

UNLABELLED: Lignans are a group of diphenolic compounds with anticancer and antioxidant properties which are present in various grains, although their effect on toxigenic fungi has been poorly examined to date. In this study, the impact of the plant lignans pinoresinol and secoisolariciresinol on growth and trichothecene biosynthesis by five Fusarium graminearum strains of different chemotypes was examined in vitro. Both tested lignans exhibited radial growth inhibition against the fungal strains. RT-qPCR analyses of tri4, tri5 and tri11 genes encoding the first steps of the trichothecene biosynthesis pathway revealed a decrease in tri mRNA levels in lignan-treated fungal cultures. Correspondingly, decreased accumulation of toxins in lignan-treated cultures was confirmed by GC-MS analysis. This is the first study to demonstrate the inhibitory effect of both pinoresinol and secoisolariciresinol on growth and trichothecene biosynthesis in F. graminearum. SIGNIFICANCE AND IMPACT OF THE STUDY: Knowledge of the regulation of trichothecene production in Fusarium graminearum by environmental cues is key to the design of novel strategies to reduce mycotoxin levels in grains. Here, we show that the lignans pinoresinol and secoisolariciresinol, which occur in wheat grains, inhibit radial growth and decrease trichothecene levels in five F. graminearum strains. RT-qPCR analysis reveals that the reduction in trichothecene level in lignan-treated fungal cultures is associated with decreased mRNA transcript levels for the tri4, tri5 and tri11 genes that are involved in the trichothecene biosynthesis pathway.


Subject(s)
Antifungal Agents/pharmacology , Butylene Glycols/pharmacology , Furans/pharmacology , Fusarium/growth & development , Lignans/pharmacology , Trichothecenes/biosynthesis , Edible Grain/chemistry , Edible Grain/microbiology , Fusarium/genetics , Fusarium/metabolism , Gene Expression/drug effects , Genes, Fungal , Microbial Sensitivity Tests , RNA, Messenger/genetics , RNA, Messenger/metabolism , Transcription, Genetic , Triticum/chemistry , Triticum/microbiology
5.
Poult Sci ; 89(11): 2491-3, 2010 Nov.
Article in English | MEDLINE | ID: mdl-20952713

ABSTRACT

Ergosterol (ERG) content, being an indicator of fungal biomass, was analyzed in samples of eggshell, egg white, and egg yolk from eggs from farms with intensive management systems of layer hens (i.e., cage and litter housing). Moreover, analogous samples were analyzed from eggs from farms in the western central part of Poland, where layer hens were kept in the organic system. In all samples, the highest ERG concentration was found in shells and the lowest in egg white, whereas ERG was not found in egg yolk. When comparing investigated housing systems, a higher concentration of the analyzed metabolite was detected in eggs from litter housing than in eggs from cage housing. Concentrations of ERG in samples of eggs from organic husbandry were highly varied, ranging from 2.44 to 42.67 mg/kg in shells and from 0.28 to 16.11 mg/kg in egg white.


Subject(s)
Eggs/microbiology , Ergosterol/analysis , Fungi/isolation & purification , Animal Husbandry/methods , Animal Husbandry/standards , Animals , Biomarkers/analysis , Chickens , Diet , Egg Shell/microbiology , Egg White/microbiology , Female , Humans
6.
Food Addit Contam ; 24(11): 1292-8, 2007 Nov.
Article in English | MEDLINE | ID: mdl-17852394

ABSTRACT

Concentrations of fungal metabolites were measured in 32 wheat grain samples from north-eastern Poland in 2003. The samples originated from fields cultivated conventionally (but varying in chemical protection level) or cultivated organically. Concentrations of Fusarium toxins (HT-2, DON, 3-AcDON, NIV), trichodiene, microbial biomass indicators (fungal ergosterol and general adenosine 5'-triphosphate (ATP)) and seed vigour were assessed. A large variation between samples was observed, depending on their origin. Seed from organic farms contained similar amounts of Fusarium toxins but more ergosterol and ATP than conventionally grown and chemically protected seed. The highest levels of toxins and ergosterol were detected in samples from conventional cultivation lacking chemical protection. Intensive agronomic practices (including complete chemical protection) significantly lowered the levels of ergosterol, ATP and trichodiene, as compared with other cultivation systems.


Subject(s)
Food Contamination/analysis , Fusarium/isolation & purification , Mycotoxins/analysis , Triticum/chemistry , Adenosine Triphosphate/analysis , Biomass , Cyclohexenes/analysis , Ergosterol/analysis , Food, Organic/analysis , Plant Diseases/microbiology , Poland , Seeds/chemistry , Seeds/microbiology , Sesquiterpenes/analysis , Trichothecenes/analysis , Triticum/microbiology
7.
Phys Rev Lett ; 98(13): 132503, 2007 Mar 30.
Article in English | MEDLINE | ID: mdl-17501196

ABSTRACT

A rotational band has been unambiguously observed in an odd-proton transfermium nucleus for the first time. An in-beam gamma-ray spectroscopic study of 101/251Md has been performed using the gamma-ray array JUROGAM combined with the gas-filled separator RITU and the focal plane device GREAT. The experimental results, compared to Hartree-Fock-Bogolyubov calculations, lead to the interpretation that the rotational band is built on the [521]1/2(-) Nilsson state.

8.
Phys Rev Lett ; 97(17): 172501, 2006 Oct 27.
Article in English | MEDLINE | ID: mdl-17155467

ABSTRACT

The results of the Doppler-shift attenuation method lifetime measurements in partner bands of 128Cs and 132La are presented. Experimental reduced transition probabilities in 128Cs are compared with theoretical calculations done in the frame of the core-quasiparticle coupling model. The electromagnetic properties, energy and spin of levels belonging to the partner bands show that 128Cs is the best known example revealing the chiral symmetry breaking phenomenon.

9.
Int J Food Microbiol ; 98(2): 113-23, 2005 Feb 01.
Article in English | MEDLINE | ID: mdl-15681039

ABSTRACT

Kernels of five wheat cultivars (Triticum aestivum) of different bread-making quality were examined. Grown under field conditions, heads of wheat were inoculated in the flowering stage with an aqueous suspension of Fusarium culmorum conidia. Wheat heads were collected from the control and inoculated plots at full maturity. Control (non-inoculated) kernels without any symptoms of disease and Fusarium damaged kernels (FDK) were examined under scanning electron microscopy (SEM). Examination of the FDK fraction confirmed localisation of Fusarium hyphae on the surface and inside the tissues of kernels. Observations of the endosperm from Fusarium infected kernels revealed presence of fungal hyphae in the endosperm and some characteristic structural changes in many of its regions, such as partial or complete lack of the protein matrix, damage to large and small starch granules caused by fungal amylolytic enzymes, disappearance of small starch granules as the colonisation progressed, complete disappearance of the starchy endosperm under severe infection. Fungal colonisation of the endosperm and structural changes in its area were highly variable traits within the FDK fraction of a given cultivar.


Subject(s)
Fusarium/pathogenicity , Triticum/microbiology , Triticum/ultrastructure , Food Contamination/analysis , Food Microbiology , Microscopy, Electron, Scanning/methods , Plant Diseases/microbiology
10.
Food Addit Contam ; 20(6): 572-8, 2003 Jun.
Article in English | MEDLINE | ID: mdl-12881131

ABSTRACT

Wheat, barley and oat grain samples naturally contaminated with Fusarium spp. were analysed for the presence of scirpentriol (STO). This toxin was detected in 1, 37 and 8% of 248 wheat, 32 barley and 99 oat grain samples, respectively, and the maximum concentration was 83 microg x kg(-1). Samples of wheat and oat grain with visible scab symptoms were also analysed, and STO (mean level 255 microg x kg(-1)) was detected only in oat samples infected with F. sporotrichioides and F. poae as the dominant species. We analysed 15 barley samples that were subdivided based on seed size into fractions of <2.5 and > 2.5 mm in diameter. The smaller kernels contained an average 94% of the STO in the samples (in kernel fraction > 2.5 mm 28 microg x kg(-1), <2.5 mm 297 microg x kg(-1)). In oats, STO levels were highest in the chaff, lower in the stalk's apical internode and lowest in the grain.


Subject(s)
Edible Grain/chemistry , Food Contamination/analysis , Mycotoxins/analysis , Plant Diseases/microbiology , T-2 Toxin/analogs & derivatives , T-2 Toxin/analysis , Edible Grain/microbiology , Food Analysis/methods , Food Microbiology , Fusarium , Gas Chromatography-Mass Spectrometry/methods , Humans
11.
Food Addit Contam ; 19(5): 478-82, 2002 May.
Article in English | MEDLINE | ID: mdl-12028647

ABSTRACT

Ninety-nine naturally contaminated oat grain samples were collected in 12 plant breeding stations in different parts of Poland. T-2 toxin, HT-2 toxin and diacetoxyscirpenol (DAS) levels were determined by gas chromatography with mass selective detection (GC-MS). HT-2 was the major toxin with an incidence of 24% and its average level in positive samples was 21 microg kg(-1). The incidence of T-2 and DAS was 15 and 12%, and their average levels were 60 and 23 microg kg(-1), respectively. The highest concentrations of HT-2, T-2 and DAS were 47, 703 and 111 microg kg(-1), respectively. Sixty-five samples were free of detectable amounts of the toxic metabolites analysed.


Subject(s)
Avena/chemistry , Food Contamination/analysis , Mycotoxins/analysis , T-2 Toxin/analogs & derivatives , Trichothecenes/analysis , Chromatography, Gas , Gas Chromatography-Mass Spectrometry , Humans , Poland , T-2 Toxin/analysis
12.
Ann Agric Environ Med ; 8(2): 269-74, 2001.
Article in English | MEDLINE | ID: mdl-11748887

ABSTRACT

Ten samples of stored wheat grain and 10 samples of settled grain dust released during machine threshing of wheat grain were collected on 10 farms located in Lublin province (eastern Poland). The samples were examined for the concentration of total microfungi, Fusarium species, fusariotoxins (moniliformin, deoxynivalenol, nivalenol), and ochratoxin. Microfungi able to grow on malt agar were present in 30% of grain samples (median for all examined samples = 0, range 0-227.5 x 10(3) cfu/g) and in all samples of grain dust (median = 977.5 x 10(3) cfu/g, range 115.0-16,700.0 x 10(3) cfu/g). Fusarium species (F. avenaceum) were found only in 10% of grain samples (median = 0, range 0-800.0 x 10(3) cfu/g), but in 90% of grain dust samples (median = 1,150 x 10(3) cfu/g, range 5.5-10,060.0 x 10(3) cfu/g). The species F. avenaceum, F. culmorum, F. graminearum, F. poae and F. sporotrichioides were isolated respectively from 50%, 10%, 20%, 40% and 20% of examined grain dust samples. The presence of the mycotoxins produced by Fusarium (moniliformin, deoxynivalenol, and nivalenol) was found altogether in 70% of wheat grain samples (median = 0.1275 microg/g, range 0-1.480 microg/g) and in 90% of grain dust samples (median = 0.350 microg/g, range 0-1.090 microg/g). Moniliformin (MON), deoxynivalenol (DON), and nivalenol (NIV) were each detected in 40% of grain samples, and respectively in 80%, 40%, and 40% of grain dust samples. Ochratoxin A (OTA) was detected in 60% of grain samples and in 60% of grain dust samples (median in both cases was 0.0005 microg/g). The concentrations of F. poae (p<0.05) and of total Fusarium species (p<0.01) in grain samples, and the concentrations of F. culmorum and F. graminearum (p<0.05) in grain dust samples were significantly correlated with the concentration of deoxynivalenol. The concentrations of F. poae (p<0.05) and of total Fusarium species (p<0.01) in grain dust samples were significantly correlated with the concentration of total fusariotoxins. Moreover, the concentration of total Fusarium species in grain dust samples was significantly correlated with the concentration of nivalenol (p<0.05). In conclusion, the majority of samples of wheat grain and grain threshing dust collected on farms in eastern Poland contained notable quantities of fusaria and/or fusariotoxins. This fact poses a potential risk of mycotoxicoses to agricultural workers exposed to grain dust when handling wheat during threshing, unloading, shuffling, and other farm occupations.


Subject(s)
Agricultural Workers' Diseases/etiology , Dust/analysis , Fungi/isolation & purification , Mycoses/etiology , Mycotoxins/analysis , Triticum/microbiology , Agricultural Workers' Diseases/epidemiology , Air Microbiology , Colony Count, Microbial , Cyclobutanes/analysis , Food Contamination , Food Microbiology , Fungi/metabolism , Fusarium/isolation & purification , Fusarium/metabolism , Humans , Mycoses/epidemiology , Occupational Exposure , Poland , Trichothecenes/analysis , Triticum/chemistry
13.
J Appl Genet ; 41(4): 237-46, 2000.
Article in English | MEDLINE | ID: mdl-14564070

ABSTRACT

The genetic determination of variability of barley doubled haploid (DH) lines in regard of their susceptibility to Fusarium head blight caused by Fusarium culmorum was studied. The susceptibility was evaluated in 3-year field experiment on the basis of reduction in yield traits and myotoxin accumulation in infected kernels. The following traits were analysed in inoculated and control plants: kernel number and weight per ear, 1000-kernel weight, percentage of plump kernels (>2.5 mm), deoxynivalenol (DON) content and nivalenol (NIV) content of kernels. On the basis of the obtained data, heritability coefficient (ratio of genotypic to phenotypic variance) was assessed, and genetic parameters as well as the number of effective factors were estimated. Heritability coefficients calculated from two-way analysis of variance, i.e.regarding the influence of years and year x genotype interaction, appeared to be exceptionally low and ranged from 5.2% for the reduction in plump kernels to 38.2% for the reduction in 1000-kernel weight. In the case of mycotoxin accumulation about 60% of the observed variability in NIV concentrations and 30% in DON concentration resulted form genetic differences among lines. Additive effects of genes were important for all the analysed traits. Significant effects of dominance and dominance x dominance were observed for 1000-kernel weight and percentage of plump kernels. Moreover, it was found that the observed variability in yield trait reduction resulted from segregation of 5-6 effective factors, DON contents from 4 factors, while NIV content from 5 factors.

14.
Nahrung ; 42(2): 81-3, 1998 Apr.
Article in English | MEDLINE | ID: mdl-9631371

ABSTRACT

Deoxynivalenol (DON) in concentration range 0.1-156.6 mg/kg, was found in 48 samples of barley kernels collected from heads with visible symptoms of head scab after inoculation in a field with Fusarium culmorum and Fusarium graminearum. Four fractions of the kernels were collected according to their size: > 2.8 mm (I); < or = 2.8-2.5 mm (II); > 2.5-2.2 mm (III) and < 2.2 mm (IV). In plants infected with Fusarium (when compared to the control) number of kernels in the fraction of the largest kernels (> 2.8 mm) decreased from 38% to 18%, while in small kernels (fractions < 2.5-2.2 mm and < 2.2 mm) numbers increased respectively from 16 to 22% and from 14 to 28%. Average level of DON concentration in these fractions was as follows: (I) 3.5 mg/kg--(4%); (II) 9.1 mg/kg--(16%); (III) 35.5 mg/kg--(29%) and (IV) 43.3 mg/kg--(51%). The highest DON accumulation was observed in fraction of small (< 2.5 mm) kernels. The fraction contributed from 77% up to 94% of total DON content in kernels with low (< 2 mg/kg) and high (> 100 mg/kg) contamination level, respectively. These results indicate that as well level of samples contamination with DON as human and animal health risk in consequence can be reduced by kernels selection (according their size) followed by rejection of the smallest kernels fraction.


Subject(s)
Fusarium/metabolism , Hordeum/chemistry , Mycotoxins/analysis , Plant Diseases/microbiology , Trichothecenes/analysis , Chromatography, Thin Layer , Seeds/chemistry , Seeds/microbiology
15.
Food Addit Contam ; 14(4): 321-5, 1997.
Article in English | MEDLINE | ID: mdl-9205559

ABSTRACT

Strains (10705) of microscopic fungi were isolated from spring barley heads in the region of Lublin (south-eastern Poland). Fusarium sporotrichioides Sherb was found in 418 (3.9%) of isolated strains. Group A trichothecene mycotoxins were detected in the collected barley kernels colonized by F. sporotrichioides, with Fusarium head blight symptoms. Among 24 samples analysed, 12 were T-2 toxin positive in a range of contamination from 0.02 to 2.40 micrograms/g (average 0.45), while in five samples HT-2 toxin ranged from 0.01 to 0.37 micrograms/g (average 0.23) and T-2 tetraol was detected in two samples in a range of 0.01-0.21 micrograms/g (average 0.11). Twelve samples were free of detectable amounts of the toxic metabolites analysed.


Subject(s)
Food Contamination , Fusarium/isolation & purification , Hordeum/chemistry , Hordeum/microbiology , Trichothecenes/analysis , Chromatography, Gas , Chromatography, Thin Layer , Humans , Mass Spectrometry , Plant Diseases/microbiology , Poland
16.
Nat Toxins ; 4(5): 228-33, 1996.
Article in English | MEDLINE | ID: mdl-8946398

ABSTRACT

F. moniliforme and other species of Liseola section, F. culmorum, F. dlamini, and F. nygamai, were examined for their ability to produce gibberellic acid (GA3), fumonisins, trichothecenes, zearalenone, moniliformin, and bikaverin (TLC method). Gibberellic acid was produced by F. moniliforme strains in liquid medium and on rice kernels with a maximum concentration level of 470 mg/dm3 and 1 g/kg, respectively. No strain isolated in Poland produced GA3. High-yielding gibberellic acid strains produced neither trichothecenes and fumonisins nor other tested compounds. Also the rest of strains of examined species did not produce trichothecenes and other mycotoxins except for fumonisins which were found in rice cultures of F. moniliforme, F. proliferatum, and F. subglutinans. Bikaverin was produced by F. moniliforme always together with fumonisins. Filtrates of liquid cultures of gibberellin producing strains were tested for their toxicity to brine shrimps larvae (Artemia salina). It was found that GA3 presence does not increase toxicity of these filtrates.


Subject(s)
Fusarium/metabolism , Gibberellins/biosynthesis , Mycotoxins/biosynthesis , Xanthones , Animals , Artemia/drug effects , Mycotoxins/toxicity , Xanthenes/metabolism
17.
Mycotoxin Res ; 12(2): 67-72, 1996 Sep.
Article in English | MEDLINE | ID: mdl-23604653

ABSTRACT

Toxicity toA. salina, of the Fusarium metabolites: deoxynivalenol (DON), its acetylated derivatives (3- and 15-AcDON), zearalenone (ZON), neosolaniol (NEO), nivalenol (NIV), T-2, HT-2 toxins, has been examined and compared with toxicity of extracts of barley kernels (8 cultivars and 4 lines) inoculated withFusarium culmorum, F. graminearum andF. sporotrichioides respectively. Estimated LC50 values were expressed as relative toxicity (RT) in mg DON/kg for samples inoculated withF. culmorum, F. graminearum or in mg T-2/kg forF. sporotrichioides inoculations.Toxicity of extracts of the same genotype/line kernels was compared among different pathogens used for inoculation and differences in Fusarium head blight susceptibility of different genotypes/lines inoculated with the sameFusarium strain were found. Significant correlation between toxicity of extracts (LC50, RT) and toxic metabolites concentration was found ([Formula: see text]; P = 0.01).Bioassays withA. Salina offer a fast, easy and inexpensive method to examine cereal genotypes susceptibility to Fusarium head blight and mycotoxins accumulation in kernels.

18.
Mycotoxin Res ; 8(1): 27-30, 1992 Mar.
Article in English | MEDLINE | ID: mdl-23605940

ABSTRACT

The analysis of deoxynivalenol (DON) in naturally infected wheat samples, after having been separated into four fractions through laboratory sieves, showed very low levels of DON in the fraction of largest kernels >2.8 mm (0 up to 1 mg/kg). The highest concentration of DON was found in fractions 2.2 to 2.5 mm and <2.2mm with up to 14mg/kg and 15mg/kg DON, respectively. In two samples (fractions <2.2mm) nivalenol was detected in concentrations up to 1,4mg/kg.

19.
Mycotoxin Res ; 7 Suppl 1: 31-7, 1991 Mar.
Article in English | MEDLINE | ID: mdl-23605734

ABSTRACT

The yield of diacetoxyscirpenol (DAS) production by F. sambucinum strain No KF 735, isolated from potato tuber with dry rot symptoms, cultured on solid media and on liquid medium, has been examined.The amount of DAS produced within 28 days at 25°C in the cultures grown on solid media (wheat, rye, rice, oats, corn, barley, triticale and malt) reached 238mg/kg±9 to 789±16mg/kg (mean ± standard error; n=3), on potato cubes -55±3mg/kg and on the potato extract -147±5mg/dcm(3).The best substracts for crystalline compound production were malt and barley grain.

20.
Mycotoxin Res ; 7 Suppl 1: 91-6, 1991 Mar.
Article in English | MEDLINE | ID: mdl-23605745

ABSTRACT

The susceptibility of six winter wheat cultivars toFusarium head blight has beenstudied. The lowest infected plants intensity, mean degree of head damage and fusariosis index exhibited cultivar Grana which also cumulated the lowest amount of trichothecenes (DON and derivatives ). Possibility to produce NIV by Polish strains has been found.in F.graminearum.

SELECTION OF CITATIONS
SEARCH DETAIL
...