Application of genetic algorithm for extraction of the parameters from powder EPR spectra

The application of the stochastic genetic algorithm in tandem with the deterministic Powell method to automated extraction of the magnetic parameters from powder EPR spectra was described. The efficiency and robustness of such hybrid approach were investigated as a function of the uncertainty range of the parameters, using simulated data sets. The discussed results demonstrate superior performance of the hybrid genetic algorithm in fitting of complex spectra in comparison to the common Monte Carlo method joint with the Powell refinement

Interaction of diatomic molecules with nickel ions inside the channels of high silica zeolites : an EPR and DFT study

Interaction of CO, NO, and O-2 diatomics with Ni-II and ions dispersed in ZSM-5 zeolite was investigated by electron paramagnetic resonance (EPR) spectroscopy and density functional theory (DFT) modelling. The resulting adducts Ni-I-CO, Ni-II-NO, and Ni-I-O-2 were identified based on g-tensor parameters, obtained by computer fitting of the powder EPR spectra, and next ascertained by parallel relativistic DFT calculations of the corresponding g-tensor values. The structures of the Ni-I-CO, Ni-II-NO, and Ni-I-O-2 complexes were obtained by geometry optimization with the Kohn-Sham method. Binding of the diatomics was discussed in terms of the spin-pairing and electron density transfer events. Interaction of CO with Ni-I cations led to the pronounced change in the coordination and electronic structure of the Ni-I center, however, no redox processes were observed in agreement with the "innocent" nature of CO as a ligand. On the contrary, strong electron and spin density redistribution was observed upon NO and O-2 interaction ("non-innocent ligands") leading to the formation of the bound nitrosonium NO delta+ and superoxo O-2(-) species, respectively

The Electronic Component of Solid Fluoride Electrolytes

The solid electrolytes based on sodium cryolite are present in aluminium electrolysers as frozen crystals formed on the side walls of the carbon lining (side ledge). Their main task is to protect the lining from the effect of liquid electrolyte and ensure temperature stabilization during the process of electrolysis. On the other hand, being electrically conductive, they can reduce the current efficiency. In this study, the value of the electronic component of the total conductivity of the solidified electrolytes of different compositions was determined. It was found that the highest electronic conductivity is exhibited by electrolytes containing both aluminium and calcium fluoride. However, the electronic component of the total conductivity is not high and reaches 0.1-2.3 mS/cm. Its share in the total conductivity of the solid multi-component electrolytes varies and, depending on their composition, is in the range of 1 ÷ 10%

Is there an easier way to differentiate phases of Toxoplasma gondii infection in pregnant women?

Background Precise detection of the moment of infection with Toxoplasma gondii in a pregnant woman plays a key role in determining the risk of transmission to the foetus. Diagnostic examination for toxoplasmosis performed in a pregnant woman should be performed as soon as possible, best before the planned pregnancy and in the beginning of the 1st trimester. Sometimes the first toxoplasma screening is only done later in pregnancy or close to term, when even the lack of specific IgM and high IgG avidity using traditional immunodiagnostic methods with native antigen does not allow to exclude early T. gondii infection with 100% certainty. Furthermore, diagnosis of acute toxoplasma infection often requires collection of two blood samples in 2-3 week period and demonstration of significant rise in IgG titres. The aim of the study was to show the possibilities of using recomLineToxoplasma test based on recombinant antigens and immunoblot technique in detection of the time of infection in pregnant women, incl. the risk of the transmission to the foetus, and differentiation of acute vs. chronic or past infection. Materials/methods Patients analysed consisted of women between ages 26-35, in whom IgG, IgM presence/titers and IgG avidity was tested using ELISA-VIDITEST Toxo IgG/IgM (Vidia) and ELISA Avidity-TOXO (EUROIMMUNE). In each patient, presence of IgG and IgM was tested additionally for recombinant T. gondii antigens: ROP1c, MIC3, GRA7, GRA8, p30, MAG1, GRA1, rSAG1 and IgG avidity for p30, MAG1, GRA1, and rSAG1 using recomLine Toxoplasma test (Mikrogen). Results were read automatically and interpreted with BLOTrix-Leader and phases of infection (I, II, III, IV) were determined according to test producer’s instructions. To show the usefulness of the test we selected 3 different patients. Results In the first patient in her 32 week of pregnancy, standard ELISA testing showed border values for IgM (1.0), positive IgG (192 IU/ml) and high IgG avidity (87%). recomLine test results were as follows: positive IgM for ROP1c, high IgG avidity to p30 and GRA1 and low to rSAG1, and pointed to II phase of infection (last 3-6 months), which correlated to acute toxoplasmosis during pregnancy, having in mind the 32 hbd. In the second patient (30 hbd), standard ELISA testing showed IgG of 198 IU/ml, no IgM and IgG avidity of 80%. recomLine test showed high IgG avidity to p30, MAG1, GRA1 and rSAG1 as well as IgM, which confirmed chronic infection (IV phase of infection; > 12 months) and excluded toxoplasma infection in pregnancy. In the third patient (17 hbd), standard ELISA showed specific IgM (1.7), IgG (187 IU/ml) and borderline avidity of 47%. recomLine test results showed: positive IgM for ROP1c and GRA8 and low IgG avidity to p30 and GRA1, which in fact pointed to the I phase of infection (0-3 months since examination), and confirmed the risk of possible foetal transmission. Results are shown in Fig.1. Conclusion recomLine Toxoplasma test, which is based on recombinant antigens, facilitates differentiation of acute from chronic T. gondii infection and allows to determine the time since infection and the risk of transmission to the foetus, without the need to collect consecutive blood samples. It may be useful especially in pregnant women, who only have their first diagnostic toxoplasma screening done in the II or III trimester of pregnancy. Figure 1. Results of standard ELISA vs. recombinant antigen testing for Toxoplasma gondii in 3 pregnant patients. Legend: hbd (hebdomas), i.e. week of pregnancy

Impact of Hymenoptera venom allergy and the effects of specific venom immunotherapy on mast cell metabolites in sensitized children

Introduction and objective. Mast cells (MC) are effector cells during severe systemic reactions (SR) to Hymenoptera stings. Venom specific immunotherapy (VIT) is the treatment of choice for prevention of SR to stings. Tryptase and prostaglandin D2 metabolites (PGD2 ) are the markers of MC activation. The study design was to 1. compare baseline values of serum tryptase concentration (BST) and PGD2 metabolites in children with/without venom sensitization, 2. to evaluate an influence of rush VIT on MC markers in treated children. Materials and methods. Sensitized group: 25 children with SR to Hymenoptera sting. Control group: 19 healthy children. Active treatment: 5-day-rush-VIT. BST was evaluated by ImmunoCAP, PGD2 metabolites in blood and urine by GC-NICI-MS. Results. The baseline blood levels of MC markers were significantly higher, while urinary concentration of 9α,11β-PGF2 was significantly lower in the whole group of venom-sensitized children compared to controls. Severity of SR showed negative correlation with urinary PGD2 metabolites, while positive with plasma 9α,11β-PGF2 and BST concentration The highest sensitivity was obtained for plasma 9α,11β-PGF2 whereas the highest specificity for urinary PGD-M. Conclusions. In children with IgE-mediated SR to Hymenoptera stings, elevation of baseline values of PGD2 metabolites in blood is accompanied by decreased excretion of its urinary metabolites. Assessment of stable PGD2 metabolites might serve as an independent MC marker to identify allergic children. There is an association between urinary PGD2 metabolites and severity of the SR to Hymenoptera stings

Development of children's hymenoptera venom allergy quality of life scale (CHVAQoLS)

BACKGROUND: Venom allergy is a rare but life-threatening disease and may have a considerable impact on the health-related quality of life (HRQoL) of patients, especially children. This paper presents development of the HRQoL scale for children and adolescents with Hymenoptera venom allergy (HVA). METHODS: The study sample consisted of 71 children, born between 1992 and 2000, who presented with a history of insect sting reaction when referred for consultation in the allergy center of Polish-American Children’s Hospital, Krakow, Poland, during the period from 2000 to 2010. The initial pool of 60 items - divided into 6 domains - was prepared. The items with intercorrelations higher than 0.7 were removed from each domain and then principal component analysis was conducted for each domain separately, to provide a one-dimensional subscale for each domain. Reliability of the subscales was assessed using Cronbach alpha coefficient in terms of Classical Test Theory and with rho coefficient in terms of Item Response Theory. The multidimensionality of the scale was tested using multi-trait scaling. RESULTS: Three to four items from each domain were subsequently selected to constitute six subscales. Rho coefficients for all the subscales reached 0.8, similar results were achieved with the Cronbach alpha coefficients. Multi-trait method showed that the majority of the items indicated stronger correlations with their own subscales than with other subscales, which proves that our constructed subscales measure different dimensions of HRQoL. CONCLUSIONS: The presented scale comprises high validity and reliability subscales measuring six dimensions of HRQoL related to Hymenoptera venom allergy in children and adolescents. Such information may be useful in everyday clinical practice

Comparison of methods for isolation of bacterial and fungal DNA from human blood

The study aimed at optimization of DNA isolation from blood of representatives of four microbial groups causing sepsis, i.e., Gram negative: Escherichia coli, Gram positive: Staphylococcus aureus, yeast: Candida albicans, and filamentous fungus: Aspergillus fumigatus. Additionally, the five commercial kits for microbial DNA isolation from the blood were tested. The developed procedure of DNA isolation consisted of three consecutive steps, i.e., mechanical disruption, chemical lysis, and thermal lysis. Afterward, DNA was isolated from the previously prepared samples (erythrocyte lysis) with the use of five commercial kits for DNA isolation. They were compared paying heed to detection limit, concentration, DNA purity, and heme concentration in samples. The isolation of DNA without preliminary erythrocyte lysis resulted in far higher heme concentration than when lysis was applied. In the variant with erythrocyte lysis, two of the commercial kits were most effective in purifying the DNA extract from heme. Designed procedure allowed obtaining microbial DNA from all four groups of pathogens under study in the amount sufficient to conduct the rtPCR reaction, which aimed at detecting them in the blood

The cytotoxic effect of copper (II) complexes with halogenated 1,3-disubstituted arylthioureas on cancer and bacterial cells

A series of eight copper (II) complexes with 3-(4-chloro-3-nitrophenyl)thiourea were designed and synthesized. The cytotoxic activity of all compounds was assessed in three human cancer cell lines (SW480, SW620, PC3) and human normal keratinocytes (HaCaT). The complexes 1, 3, 5, 7 and 8 were cytotoxic to the studied tumor cells in the low micromolar range, without affecting the normal cells. The complexes 1, 3, 7 and 8 induced lactate dehydrogenase (LDH) release in all cancer cell lines, but not in the HaCaT cells. They provoked early apoptosis in pathological cells, especially in SW480 and PC3 cells. The ability of compounds 1, 3, 7 and 8 to diminish interleukin-6 (IL-6) concentration in a cell was established. For the first time, the influence of the most promising Cu (II) complexes on intensities of detoxifying and reactive oxygen species (ROS) scavenging the enzymes of tumor cells was studied. The cytotoxic effect of all copper (II) conjugates against standard and hospital bacterial strains was also proved