95 research outputs found

    Ocena raportowania społecznego banków w Polsce

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    Banks, as institutions of public trust with a dual role in society (commercial and benevolent), should base their activities on ethical behavior towards society and respect for the natural environment. The modern economy presents new business challenges and one of them is the need for greater transparency. The way to communicate the effects of the adopted social responsibility strategy is to create and publish social reports. The aim of this publication is to present the issues of social reporting as well as to evaluate social reports prepared by banks in Poland. The research hypotheses are: reporting on social responsibility is important for banks and reporting on the social responsibility of banks varies in terms of form and content. The analysis of reporting in the Polish banking sector has proved that banks are well aware of the potential to communicate the concept of social responsibility. However, the study also exposed the imperfections of reporting of Polish banks.Banki, jako instytucje zaufania publicznego o podwójnej roli w życiu społecznym (komercyjnej i służebnej), powinny opierać swoją działalność na etycznym postępowaniu względem społeczeństwa i środowiska. Współczesna gospodarka stawia nowe wymagania biznesowe, a jednym z nich jest potrzeba większej transparentności strategii społecznej odpowiedzialności. Sposobem informowania o tym jest tworzenie i publikowanie raportów społecznych. Celem artykułu jest przedstawienie problematyki raportowania społecznego, a także ocena stanu raportowania społecznego banków w Polsce w latach 2015–2016. Na potrzeby niniejszej pracy przyjęto hipotezę badawczą, iż raportowanie w zakresie społecznej odpowiedzialności jest ważne dla banków. Założono także, że raportowanie pozafinansowe jest zróżnicowane co do form i treści. Analiza raportowania w polskim sektorze bankowym udowodniła, iż banki doskonale zdają sobie sprawę z potencjału komunikowania koncepcji społecznej odpowiedzialności. Badanie obnażyło również niedoskonałości raportowania polskich banków

    Mesoporous Silica-Based Materials for Electronics-Oriented Applications

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    International audienceElectronics, and nanoelectronics in particular, represent one of the most promising branches of technology. The search for novel and more efficient materials seems to be natural here. Thus far, silicon-based devices have been monopolizing this domain. Indeed, it is justified since it allows for significant miniaturization of electronic elements by their densification in integrated circuits. Nevertheless, silicon has some restrictions. Since this material is applied in the bulk form, the miniaturization limit seems to be already reached. Moreover, smaller silicon-based elements (mainly processors) need much more energy and generate significantly more heat than their larger counterparts. In our opinion, the future belongs to nanostructured materials where a proper structure is obtained by means of bottom-up nanotechnology. A great example of a material utilizing nanostructuring is mesoporous silica, which, due to its outstanding properties, can find numerous applications in electronic devices. This focused review is devoted to the application of porous silica-based materials in electronics. We guide the reader through the development and most crucial findings of porous silica from its first synthesis in 1992 to the present. The article describes constant struggle of researchers to find better solutions to supercapacitors, lower the k value or redox-active hybrids while maintaining robust mechanical properties. Finally, the last section refers to ultra-modern applications of silica such as molecular artificial neural networks or super-dense magnetic memory storage

    Synthesis in silica nanoreactor: Copper pyrophosphate quantum dots and silver oxide nanocrystallites inside silica mezochannels

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    The synthesis routes are presented for the preparation of nanocomposites composed of nanocrystals placed inside SBA-15 silica pores. The procedures assume treating the silica channels as nanoreactors, where nanocrystals are created as a result of thermal decomposition of internal functional units. Its sizes and chemical composition can be modified by the change of functional group types and density inside silica channels. The procedure is demonstrated by the example of copper pyrophosphate quantum dots and silver oxide nanoparticles inside silica mezochannels. The method can be easily adopted to other types of nanocrystals that can be synthesized inside silica nanoreactors

    The performance of triglyceride to high-density lipoprotein cholesterol ratio in acute coronary syndromes using a diagnostic decision tree

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    Background. Modern modeling techniques, including decision trees, may potentially provide accurate prediction and classification of outcomes, and support the process of clinical decision making. The objective of our study was to evaluate the performance of triglyceride to high-density lipoprotein (TG:HDL-C) ratio in acute coronary syndromes (ACS) presented using a decision tree analysis. Methods. The initial study group consisted of 220 consecutive patients admitted to hospital within the first 6 hours from the onset of chest pain. All these patients met clinical criteria of ACS and were compared with 116 healthy volunteers in a case-control study. Serum was assayed on admission for cardiac troponin I, C-reactive protein, apolipoproteins ApoAI and ApoB, and lipid parameters. Atherogenic lipid ratios: TC:HDL:C, LDL-C:HDL:C and TG:HDL-C were calculated. Results. ACS patients showed almost twice as high median values of TG:HDL-C as controls [2.77 (1.88–4.08) vs. 1.47 (0.99–2.08); p < 0.0001]. The TG:HDL-C ratio was significantly related to the positive history of coronary artery disease, age and lipid parameters, except for LDL-C. The TG:HDL-C ratio was, after age, the most powerful independent predictor and classifier of the occurrence of ACS with the optimal cutoff being 2.28. The performance of TG:HDL-C was superior to other lipid parameters and ratios, and enabled identification of the additional 6 subjects with ACS. Conclusion. The TG:HDL-C ratio is a useful risk marker of the ACS occurrence. Further prospective studies are needed to confirm our findings and clarify the interaction between TG and HDL-C concentrations in ACS patients

    Magnetic behaviour of Mn12-stearate single-molecule magnets Immobilized on the surface of 300 nm spherical silica nanoparticles

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    The magnetic behaviour of Mn 12 -stearate single-molecule magnets (SMMs) ([ Mn12O12 (CH3(CH2)16CO2)16]⋅2CH3COOH⋅4H2O ) on the surface of 300 nm spherical silica nanoparticles were investigated. The SMMs were bonded at the silica surface with the assumed number of anchoring points, which influenced on their degree of freedom and distribution. In order to check the properties of Mn 12 -stearate molecules separated on the silica surface, and check their interactions, the samples containing four different concentration of spacers per single anchoring unit and variously bonded Mn 12 -stearate particles were prepared. The materials have been examined using Raman spectroscopy, transmission electron microscopy, and SQUID magnetometry. The results of magnetic measurements showed a correlation between the way of single-molecule magnets immobilization onto the silica spheres and the magnetic properties of the obtained hybrid materials

    Iron Doped SBA-15 Mesoporous Silica Studied by Mössbauer Spectroscopy

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    Mesoporous silica SBA-15 containing propyl-iron-phosphonate groups were considered to confirm their molecular structure. To detect the iron-containing group configuration the Mössbauer spectroscopy was used. Both mesoporous silica SBA-15 containing propyl-iron-phosphonate groups and pure doping agent (iron acetylacetate) were investigated using Mössbauer spectroscopy. The parameters such as isomer shift, quadrupole splitting, and asymmetry in 57Fe Mössbauer spectra were analyzed. The differences in Mössbauer spectra were explained assuming different local surroundings of Fe nuclei. On this base we were able to conclude about activation of phosphonate units by iron ions and determinate the oxidation state of the metal ion. To examine bonding between iron atoms and phosphonic units the resonance Raman spectroscopy was applied. The density functional theory (DFT) approach was used to make adequate calculations. The distribution of active units inside silica matrix was estimated by comparison of calculated vibrational spectra with the experimental ones. Analysis of both Mössbauer and resonance Raman spectra seems to confirm the correctness of the synthesis procedure. Also EDX elemental analysis confirms our conclusions

    New Class of Antimicrobial Agents: SBA-15 Silica Containing Anchored Copper Ions

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    The paper is about a new class of antimicrobial functional nanomaterials. Proposed compounds are based on SBA-15 porous silica matrices and contain anchored copper ions. Thanks to the immobilization of functional groups the compounds are safer for environment than commonly used disinfectant agents. We prepared and examined silica based materials containing two concentrations of copper-containing groups: 10 and 5%. For the reference we prepared samples containing free-standing CuO molecules in the structure and checked their antimicrobial properties. Antibacterial effect of considered SBA-15-Cu material was tested on Escherichia coli bacteria. Antimicrobial tests were applied for the pure form of the material and as modifying agents for plastics. The obtained results showed that the sample with lower concentration of active copper-containing groups has stronger antimicrobial properties than the one with higher concentration of copper. Interestingly, silica containing free-standing CuO molecules has no antimicrobial properties. Considering the obtained results, we can conclude that the most probable antimicrobial mechanism in this case is an oxidation stress. When a plastic modifier is applied the material is enriched with bacterial inhibitory properties. It seems that SBA-15 silica containing low concentration of anchored copper ions is promising in terms of its antibacterial property and biomaterial potential for commercial use

    Tobacco Smoke Exposure During Pregnancy Increases Maternal Blood Lead Levels Affecting Neonate Birth Weight

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    To assess the effect of lead exposure from cigarette smoke on fetal growth, blood lead concentrations were measured using inductively coupled plasma mass spectrometry in 150 healthy pregnant women. Mean lead concentrations in plasma and whole blood were significantly higher in the smoking group compared with the nonsmoking group in each trimester of pregnancy (p < 0.001). Logistic regression analysis showed the highest impact of the number of cigarettes smoked per day for serum lead concentration (β = 0.238; p < 0.05), while in whole blood, it was duration of smoking before conception (β = 0.297; p < 0.001). Birth weight of the smoking mothers' infants was significantly lower (mean ± SEM, 3,192 ± 50.8 and 3,569 ± 49.6 g, respectively; p < 0.001) and negatively correlated with lead levels in plasma (r = −0.38; p < 0.001) and in whole blood (r = −0.27; p < 0.001). Therefore, it is suggested that smoking during pregnancy increases lead concentrations in maternal blood. Fetal exposure to low doses of lead in utero may be a serious risk factor causing lower birth weight

    Functionalised Anodised Aluminium Oxide as a Biocidal Agent

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    In this article, we describe the antimicrobial properties of a new composite based on anodic aluminium oxide (AAO) membranes containing propyl-copper-phosphonate units arranged at a predetermined density inside the AAO channels. The samples were prepared with four concentrations of copper ions and tested as antimicrobial drug on four different strains of Escherichia coli (K12, R2, R3 and R4). For comparison, the same strains were tested with three types of antibiotics using the minimal inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) tests. Moreover, DNA was isolated from the analysed bacteria which was additionally digested with formamidopyrimidine-DNA glycosylase (Fpg) protein from the group of repair glycosases. These enzymes are markers of modified oxidised bases in nucleic acids produced during oxidative stress in cells. Preliminary cellular studies, MIC and MBC tests and digestion with Fpg protein after modification of bacterial DNA suggest that these compounds may have greater potential as antibacterial agents than antibiotics such as ciprofloxacin, bleomycin and cloxacillin. The described composites are highly specific for the analysed model Escherichia coli strains and may be used in the future as new substitutes for commonly used antibiotics in clinical and nosocomial infections in the progressing pandemic era. The results show much stronger antibacterial properties of the functionalised membranes on the action of bacterial membranes in comparison to the antibiotics in the Fpg digestion experiment. This is most likely due to the strong induction of oxidative stress in the cell through the breakdown of the analysed bacterial DNA. We have also observed that the intermolecular distances between the functional units play an important role for the antimicrobial properties of the used material. Hence, we utilised the idea of the 2D solvent to tailor them

    Spherical silica functionalized by 2-naphthalene methanol luminophores as a phosphorescence sensor

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    Photoluminescence is known to have huge potential for applications in studying biological systems. In that respect, phosphorescent dye molecules open the possibility to study the local slow solvent dynamics close to hard and soft surfaces and interfaces using the triplet state (TSD: triplet state solvation dynamics). However, for that purpose, probe molecules with efficient phosphorescence features are required with a fixed location on the surface. In this article, a potential TSD probe is presented in the form of a nanocomposite: we synthesize spherical silica particles with 2-naphthalene methanol molecules attached to the surface with a predefined surface density. The synthesis procedure is described in detail, and the obtained materials are characterized employing transmission electron microscopy imaging, Raman, and X-ray photoelectron spectroscopy. Finally, TSD experiments are carried out in order to confirm the phosphorescence properties of the obtained materials and the route to develop phosphorescent sensors at silica surfaces based on the presented results is discussed
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