Disintegration Kinetics of Microbial Cells

Results of the disintegration of yeast Saccharomyces cerevisiae in the bead mill with a multi disk impeller are presented. The degree of disintegration was specified on the basis of absorbency measurements at the wavelength 260 nm. The process was investigated by two integrated methods. The experimental values of maximum absorbency Am2 appeared to be smaller than theoretical ones Am1, which resulted from searching for the highest values of correlation coefficient between variables t and ln[Am1 / (Am1 – A)]. A significant increase of the process rate constant was observed when the slurry concentration increased in the range from 0.05 to 0.20 g d.m./cm3. This phenomenon was explained by an additional mechanism of cell destruction, which was induced by fragments of ground walls. The rate constant changed during the process due to a change of inner process conditions, and not directly as a result of a changing number of microbial cells. Modeling of the process in which the first-order differential equation is used to describe the kinetics is correct, with the process rate constant being a function of parameters that describe inner conditions changing during the process

Zróżnicowanie poziomu płac w Polsce w układzie przestrzennym

Zadanie pt. „Digitalizacja i udostępnienie w Cyfrowym Repozytorium Uniwersytetu Łódzkiego kolekcji czasopism naukowych wydawanych przez Uniwersytet Łódzki” nr 885/P-DUN/2014 zostało dofinansowane ze środków MNiSW w ramach działalności upowszechniającej nauk

Predictors of eating disorders outcomes in Polish teenage patients

Aim of the study. The aim of this study was to assess factors associated with the outcome of eating disorders in Polish teenage patients. Material and methods. Analyses covered the data of 47 patients diagnosed with any of the eating disorders according to DSM IV consulted for the first time in the outpatients clinic of the Child and Adolescent Psychiatry Unit between 2002/2004 in Krakow (DGN1), Poland and then followed up between 2009/2011 (DGN2). The influence of the number of variables collected at DGN1 on outcomes was analysed. Results. The outcomes of anorexia nervosa and bulimia nervosa are influenced by some aspects of clinical picture, patients’ objective family situation, their self-image and the perception they have of their family relations. The co-occurrence of depressive symptoms and younger age of parents proved to be the most clinically important negative outcome predictors in the whole group of eating disorders. Discussion. The small size of group in the follow-up study is the most important limitating factor. Conclusion. Outcomes in eating disorders are affected by several psycho-bio-social factors common to all patients and specific for the diagnosis type they initially present

Outcome of Polish teenage patients with eating disorders

аim of the study. The aim of the study was to assess outcome of patients with eating disorders in a Polish socio-cultural context. Material and methods. Re-assessed after 6.72 years (SD 0.99 years, min 4.58 years, max 8.81 years), 47 of 112 patients consulted initially in the outpatient clinic of the Child and Adolescent Psychiatry Unit between 2002/2004 in Krakow, Poland with one of the eating disorders. Results. Complete remission (absence of symptoms for three months) took place in 55% of patients from the restrictive anorexia nervosa group and in 27.3% of patients from the bulimia nervosa group. A full range of symptoms was observed in 10% of patients from the restrictive anorexia nervosa group and in 36.4% of patients from the bulimia nervosa group. In both groups, the longer the follow-up study, the worse outcome observed. Discussion. Small size of group in the follow-up study caused a significant limitation. Conclusion. The remission rates indices for restrictive anorexia nervosa are similar to those presented in other follow-up studies. In the case of bulimia nervosa, they are lower than average. An analysis of diagnosis variability between the initial and the follow up assessment indicates low crossover rate from anorexia nervosa to the bulimia nervosa group

The Rietveld refinement studies of pyromorphite-vanadinite and mimetite-vanadinite solid solution series

Mimetite Pb 5 (PO 4 ) 3 Cl, vanadinite Pb 5 (VO 4 ) 3 Cl and pyromorphite Pb 5 (PO 4 ) 3 Cl belong to the apatite supergroup. They form in oxidation zones of lead ore deposits. These minerals have high thermal stability (Dong et al. 2002) and low solubility (Flis et al. 2011) thus they have many applications. Pyromorphite and mimetite are especially used to immobilize lead in contaminated soils and hazardous industrial wastes (Ma et al. 1993, Kim et al. 2005, Bajda et al. 2007), it is therefore important to know the impact of various factors on their properties. Crystal structure of apatites corresponds to the general formula M 5 (TO 4 ) 3 X, where M are bi - valent cations distributed on two distinct crystallographic sites, TO 4 is a trivalent oxyanion and X is a monovalent anion. The structure and chemistry of apatite allow for numerous substitutions of metal cation and anionic complexes (Hughes & Rakovan 2002, Pan & Fleet 2002). It was found that substitutions cause variations in the unit cell parameters and chemical properties of these minerals (Botto et al. 1997), but there are no articles presenting variations in the whole series. Therefore, these researches present changes of lattice parameters for pyromorphite-vanadinite and mimetite-vanadinite solid solution series. Pyromorphite, mimetite and vanadinite crystallize in hexagonal symmetry (the space group P6 3 /m) (Dong et al. 2002, Pan & Fleet 2002). They form continuous isomorphic series. The aim of study was to examine how lattice parameters of pyromorphite-vanadinite and mimetite-vanadinite solid solutions series change with increasing vanadium content and characterize these pheno mena. Crystallographic studies were conducted on synthetic pyromorphite, mimetite and vanadinite and minerals with intermediate compositions Pb 5 (TO 4 ) 3 Cl, where T = P + V or As + V, of various P/V or As/V ratios. Samples were analyzed by X-Ray diffraction (XRD) using RIGAKU Smartlab X-Ray diffractometer with Cu radiation in a 10° to 110° 2Θ range at a step size of 0.02 2Θ and a rate of 2 s per step. The phase identification was carried out using the X’Rayan computer program and X-ray standard patterns in the form of ICDD files (card 19-0701, 19-0683 and 43-1461). The unit-cell refinement and Rietveld structure refinement were made using the FullProf Suite computer program package (Rodriguez-Carvajal 1993). The Rietveld refinement has shown systematic changes in unit cell parameters of studied samples depending on their chemical composition. Dimensions of unit cell parameters of pyromorphite-vanadinite solid solution series increase linearly with the substitution of vanadate ions in the structure of pyromorphite. Lattice parameter “a” increase in the range of 9.987–10.325 Å, while lattice parameter “c” increase in the range of 7.33–7.343 Å. In case of the mimetite-vanadinite solid solution series, lattice parameter “a” increase (10.251–10.325 Å range), whereas lattice parameter “c” decrease (7.442–7.343 Å range) linearly with the substitution of vanadate ions in the structure of mimetite. This situation indicates the equivalent position of the tetrahedral TO 4 in the structure of lead apatite

Structural and vibrational behaviour of pyromorphite-vanadinite solid solution series

Pyromorphite Pb5(PO4)3Cl and vanadinite Pb5(VO4)3Cl belong to the apatite supergroup. They are secondary minerals formed in the oxidation zones of lead ore deposits. Both crystallize in hexagonal symmetry with the space group P63/m (Dong et al. 2002). The crystal structure of these two minerals allows to accommodate both metal cations and anionic complexes. It is the reason, why pyromorphite and vanadinite forms solid solution series. Isovalent replacement of P with V is one of the most common anionic substitution. Lead apatites are one of the least soluble along apatites group minerals and characterized by high thermal stability (Dong et al. 2002, Flis et al. 2011). Characteristic properties of apatite structure cause that these minerals are successfully used in many fields, especially for the immobilization of toxic waste and lead-contaminated soil (Ma et al. 1993, Chen et al. 1997, Dong et al. 2002, Kim et al. 2005). So far, pyromorphite and mimetite are the most known and used for the immobilization of lead. Pyromorphite and mimetite are isostructural with vanadinite, therefore it has been predicted that this mineral is also important for the environment. Accordingly, the aim of this study was to characterize of the pyromorphite-vanadinite solid solution series. This research present systematic changes in the structure of these minerals. Pure pyromorphite and vanadinite and minerals with intermediate compositions Pb5(TO4)3Cl, where T = P + V, of various P/V ratios were synthesized  from aqueous solutions at 298 K and pH = 3.5. Synthetic solids were analyzed by X-Ray diffraction (XRD), infrared absorption spectroscopy (FTIR) and Raman spectroscopy. Based on the X-Ray analysis, it was found that synthetic precipitates represent homogeneous phases of pyromorphite and vanadinite, which have intermediate chemical composition. Diffraction peaks of pyromorphite-vanadinite solid solution series were shifted due to replacement of PO4 by VO4. Replacement of PO4 by VO4 anions is causing changes in the structure of apatite and hence these shifts. Unit cell parameters of studied solid solutions show a linear variation. In the FTIR and Raman spectra of pyromorphite-vanadinite solid solutions series, the bands which are characteristic for vibrations of P-O bonds of the PO4 tetrahedra as well as vibrations of V-O bonds of the VO4 tetrahedra appeared. Analysis of Mid-IR spectra and Raman spectra also allowed to observe correlation between the band positions and the extent of the anionic substitution among the studied series. The structure of pyromorphite and vanadinite is generally similar, although they vary in chemical composition. Causes of variability are probably connected with the properties of individual ions.The project was financed with resources of the National Science Centre, Poland, granted based on decision no. DEC-2013/09/N/ST10/00677

Use of the far infrared spectroscopy for NaCl and KCl minerals characterization : a case study of halides from Kłodawa in Poland

The paper presents research on chloride minerals of natural origin from Kłodawa (Poland), i.e., colorless, blue and purple halite as well as colorless sylvite. Selected samples of minerals were studied by chemical analysis (ICP-OES, ICP-MS, titration methods) and crystallographic measurements. Then, for the tested halides, research was carried out using far-infrared spectroscopy. Spectroscopic studies confirmed the simple way of distinguishing NaCl and KCl minerals using far-infrared spectroscopy, known in the literature. The novelty is that the article presents for the first time the experimental far infrared spectra of natural blue and purple halite. It was observed that the blue (178 cm−1) and purple (176 cm−1) halites have the strongest infrared band slightly shifted towards higher wavenumbers compared to colorless halite (174 cm−1). As part of the work, the infrared spectra of the crystal structure models of sodium and potassium chloride were calculated for the first time using the density functional theory (with the B3LYP functional and the 6-31G* basis set, 125-atom model). The proposed approach can be used not only as a powerful method differentiating NaCl and KCl minerals, but it can also help with understanding of different defects in crystal lattices for naturally occurring halides and crystals of other minerals