130 research outputs found

    Perceptions of the family of origin in adolescent drug users

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    This paper sets out to present the research outcomes regarding the perceptions of various family environment aspects in adolescent drug users. The research project adheres to family systems theory in its understanding of the family and the suggestions for supporting it. Three research questions were explored: (1) Does family support and parental control in the study group differ significantly between the childhood period and the later “addiction” phase? (2) Do adolescent drug users differ in their respective perceptions of their fathers’ and mothers’ parental attitudes? (3) Do selected areas of family functioning in codependent families differ according to the type of drugs used by adolescents (hard or soft)? The study group (N = 55) consisted of adolescents between 14 and 18 years of age who began therapy in drug rehabilitation centers. Three measurement tools were used in the study FACES IV-SOR (adapted into Polish by Margasiński), Parental Attitude Scales(in the version designed for young people) by Plopa, and the My Family questionnaire developed by the author. The obtained outcomes demonstrate that family support is rated as higher in childhood than in later life. Adifference in the respective perceptions of fathers’ and mothers’ parental attitudes has been observed on two scales: acceptance-rejection (mothers are perceived as more understanding than fathers) and Overprotectiveness (mothers are more often perceived as overprotective). Two differences have been discovered in the functioning of codependent families: (1) young people addicted to hard drugs are less attached to their family then those who use soft drugs; (2) young people addicted to hard drugs are more likely to perceive their mothers as inconsistent

    Nickel alendronate

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    The title compound {sys­tematic name: bis(μ2-dihydrogen 4-aza­niumyl-1-hy­droxy­butane-1,1-di­phos­pho­n­ato)bis­[aqua­(dihydrogen 4-aza­nium­yl-1-hy­droxy­butane-1,1-diphospho­n­ato)nickel(II)] dihydrate}, [Ni2(C4H12NO7P2)4(H2O)2]·2H2O, was synthesiized under hydro­thermal conditions. Its structure is isotypic with the CoII analogue. The crystal structure is built up from centrosymmetric dinuclear complex mol­ecules and the structure is reinforced by a net of inter­molecular O—H⋯O and N—H⋯O hydrogen bonds. One water mol­ecule is bound to the NiII atom in the octahedral coordination sphere, while the second is part of the inter­molecular hydrogen-bond system

    Predicted Studies of Branched and Cross-Linked Polyurethanes Based on Polyhydroxybutyrate with Polycaprolactone Triol in Soft Segments

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    The number of cross-links in the non-linear polyurethane structure is the basic factor affecting its properties. Selected properties of aliphatic polyurethanes with soft segments made of different amounts of polycaprolactonetriol, polycaprolactonediol and synthetic, telechelic poly([R,S]-3-hydroxybutyrate) were determined. On the basis of changes in polyurethane properties, the correlation between these properties and the construction of soft segments was found. The structure of polyurethanes, their morphology, hydrophilicity, thermal and mechanical properties were examined. These properties were changed linearly up to 15% content of polycaprolactonetriol in soft segments. A further increase in the amount of triol causes that these properties are mainly determined by the high number of cross-links.This research was founded by the National Science Center Miniatura 2 project no. 2018/02/X/ST5/02005 and partially by the UMG research project no. WPiT/2020/PZ/01

    Degradability of Polyurethanes and Their Blends with Polylactide, Chitosan and Starch

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    One of the methods of making traditional polymers more environmentally friendly is to modify them with natural materials or their biodegradable, synthetic equivalents. It was assumed that blends with polylactide (PLA), polysaccharides: chitosan (Ch) and starch (St) of branched polyurethane (PUR) based on synthetic poly([R,S]-3-hydroxybutyrate) (R,S-PHB) would degrade faster in the processes of hydrolysis and oxidation than pure PUR. For the sake of simplicity in the publication, all three modifiers: commercial PLA, Ch created by chemical modification of chitin and St are called bioadditives. The samples were incubated in a hydrolytic and oxidizing environment for 36 weeks and 11 weeks, respectively. The degradation process was assessed by observation of the chemical structure as well as the change in the mass of the samples, their molecular weight, surface morphology and thermal properties. It was found that the PUR samples with the highest amount of R,S-PHB and the lowest amount of polycaprolactone triol (PCLtriol) were degraded the most. Moreover, blending with St had the greatest impact on the susceptibility to degradation of PUR. However, the rate of weight loss of the samples was low, and after 36 weeks of incubation in the hydrolytic solution, it did not exceed 7% by weight. The weight loss of Ch and PLA blends was even smaller. However, a significant reduction in molecular weight, changes in morphology and changes in thermal properties indicated that the degradation of the samples should occur quickly after this time. Therefore, when using these polyurethanes and their blends, it should be taken into account that they should decompose slowly in their initial life. In summary, this process can be modified by changing the amount of R,S-PHB, the degree of cross-linking, and the type and amount of second blend component added (bioadditives).This research was founded by the National Science Center Poland Miniatura 2 project no. 2018/02/X/ST5/02005 and partially by the UMG research project no. WZNJ/2021/PZ/02

    Degradability of cross-linked polyurethanes/chitosan composites

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    Polyurethanes with synthetic poly([R,S]-3-hydroxybutyrate) in the soft segment and with polycaprolactone triol as cross-linker were blended with chitosan and degraded in hydrolytic and oxidative solutions. Progress of the degradation of the samples was evaluated by changes in their weight, surface topography and thermal properties. Increasing the poly([R,S]-3-hydroxybutyrate) content in soft segment as well as blending with chitosan resulted in an increase in degradability of cross-linked polyurethanes in both solutions.Centre of Polymer and Carbon Materials, Polish Academy of Sciences, University of Wolverhampton, University of the Basque Country (UPV/EHU), Gdynia Maritime Universit

    High performance size-exclusion chromatography analysis of polar compounds applied to refined, mild deodorized, extra virgin olive oils and their blends: An approach to their differentiation

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    An investigation was carried out to evaluate the use of High Performance Size-Exclusion Chromatography (HPSEC) of polar compounds of refined, mild deodorized, extra virgin olive oils as well as of their blends, in attempting to reveal significant differences in the amounts of the substance classes constituting polar compounds among these oils. Two sets of blends were prepared by mixing an extra virgin olive oil with both refined and mild deodorized olive oils in increasing amounts. The obtained data highlighted that the triacylglycerol oligopolymers were absent or present in traces in the extra virgin olive oil, while their mean amount was equal to 0.04. g/100. g and 0.72. g/100. g in mild deodorized and refined olive oils, respectively. Oxidized triacylglycerols and diacylglycerols were more abundant in mild deodorized oil and refined oil than in extra virgin olive oil. The Factorial Discriminant Analysis of the data showed that the HPSEC analysis could reveal the presence of refined/mild deodorized oils in extra virgin olive oils. In particular, the classification functions obtained allowed designation of mixtures containing at least 30. g/100. g of mild deodorized oil and all those containing refined olive oil as deodorized oil, therefore as oils subjected to at least a mild refining treatment. © 2011 Elsevier Ltd

    Branched polyurethanes based on synthetic polyhydroxybutyrate with tunable structure and properties

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    Branched, aliphatic polyurethanes (PURs) were synthesized and compared to linear analogues. The influence of polycaprolactonetriol and synthetic poly([R,S]-3-hydroxybutyrate) (R,S-PHB) in soft segments on structure, thermal and sorptive properties of PURs was determined. Using FTIR and Raman spectroscopies it was found that increasing the R,S-PHB amount in the structure of branched PURs reduced a tendency of urethane groups to hydrogen bonding. Melting enthalpies (on DSC thermograms) of both soft and hard segments of linear PURs were higher than branched PURs, suggesting that linear PURs were more crystalline. Oil sorption by samples of linear and branched PURs, containing only polycaprolactone chains in soft segments, was higher than in the case of samples with R,S-PHB in their structure. Branched PUR without R,S-PHB absorbed the highest amount of oil. Introducing R,S-PHB into the PUR structure increased water sorption. Thus, by operating the number of branching and the amount of poly([R,S]-3-hydroxybutyrate) in soft segments thermal and sorptive properties of aliphatic PURs could be controlled

    Transcriptional activation of the human brain-derived neurotrophic factor gene promoter III by dopamine signaling in NT2/N neurons

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    We have identified a functional cAMP-response element (CRE) in the human brain-derived neurotrophic factor (BDNF) gene promoter III and established that it participated in the modulation of BDNF expression in NT2/N neurons via downstream signaling from the D1 class of dopamine (DA) receptors. The up-regulation of BDNF expression, in turn, produced neuroprotective signals through receptor tyrosine kinase B (TrkB) and promoted cell survival under the conditions of oxygen and glucose deprivation. To our knowledge this is the first evidence showing the presence of a functional CRE in the human BDNF gene and the role of DA signaling in establishing transcriptional competence of CRE in post-mitotic NT2/N neurons. This ability of DA to regulate the expression of the BDNF survival factor has a profound significance for the nigrostriatal pathway, because it indicates the existence of a feedback loop between the neutrophin, which promotes both the maturation and survival of dopaminergic neurons, and the neurotransmitter, which the mature neurons ultimately produce and release

    Color and Luminescence stability of selected dental materials in vitro

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    To study luminescence, reflectance, and color stability of dental composites and ceramics. Materials and Methods: IPS e.max, IPS Classic, Gradia, and Sinfony materials were tested, both unpolished (as-cast) and polished specimens. Coffee, tea, red wine, and distilled water (control) were used as staining drinks. Disk-shaped specimens were soaked in the staining drinks for up to 5 days. Color was measured by a colorimeter. Fluorescence was recorded using a spectrofluorometer, in the front-face geometry. Time-resolved fluorescence spectra were recorded using a laser nanosecond spectrofluorometer. Results: The exposure of the examined dental materials to staining drinks caused changes in color of the composites and ceramics, with the polished specimens exhibiting significantly lower color changes as compared to unpolished specimens. Composites exhibited lower color stability as compared to ceramic materials. Water also caused perceptible color changes in most materials. The materials tested demonstrated significantly different initial luminescence intensities. Upon exposure to staining drinks, luminescence became weaker by up to 40%, dependent on the drink and the material. Time-resolved luminescence spectra exhibited some red shift of the emission band at longer times, with the lifetimes in the range of tens of nanoseconds. Conclusions: Unpolished specimens with a more developed surface have lower color stability. Specimens stored in water develop some changes in their visual appearance. The presently proposed methods are effective in evaluating the luminescence of dental materials. Luminescence needs to be tested in addition to color, as the two characteristics are uncorrelated. It is important to further improve the color and luminescence stability of dental materials
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