102 research outputs found

    Inorganic salts: one of the controlling factors of reaction mechanism and complex compound formation

    Get PDF
    Abstract -Many chemical reactions, besides the main product, yield also an inorganic salt , e.g MgC12 or AlCl

    Morphology and surficial sediments of the Waldemar River confined outwash fan (Kaffiøyra, Svalbard)

    Get PDF
    The development and evolution of confined outwash fans in high Arctic regions depend on the rate of meltwater discharge which is directly related to the glacier ablation rate associated with climate conditions. Another factor controlling outwash fan morphology (e.g. distributive channels depth and width) are processes of fluvial erosion, transport and sediments deposition. All these factors have not previously been considered in relation to the evolution of confined outwash fans incised into the top of permafrost which commonly occur in the forefield of a subpolar glacier and mountains in the high Arctic regions. Morphology and surficial sediments of a confined outwash fan of the Waldemar River (NW Spitsbergen, Svalbard) were analysed on the basis of geomorphological and sedimentological researches. Results of our investigations show multiple relations between the depth and width of distributary channels, fan slope and textural features of glaciofluvial surficial sediments supplied into the fluvial system from glacier and as a result of lateral fluvial erosion of permafrost

    Short-term changes in thermal conditions and active layer thickness in the tundra of the Kaffiøyra region, NW Spitsbergen

    Get PDF
    This article describes and discusses the results of observations concerning short-term changes in the thermal conditions and the thickness of the active layer in a test field located in the tundra of the Kaffiøyra (NW Spitsbergen) during the summer season of 2015. One of the objectives was to find a correlation between the dynamic of the changes and the local topography. In recent years, thawing of the active layer in the Kaffiøyra region has been considerably varied in individual summer seasons. The test field area was 100 square meters, comprised 36 measurement points and was situated at approximately 3 m a.s.l. in the tundra. The measurements of the thickness and temperature of the active layer were carried out in July, August and early September of 2015. The greatest thickness of the active layer in the tundra was found near the moraine, in the area with the sharpest slope (156 cm to 212 cm). Ground temperatures were observed to follow the prevailing weather conditions with a delay, which amounted to about 24 h at a depth of 25 cm, and as much as 48 h at a depth of 75 cm. A greater thickness of the active layer was found in the western part of the test field, in the vicinity of a tidal channel, and in the eastern part of the field, bordering on the foot of the Aavatsmarkbreen’s moraine. A considerable sloping of the land, combined with increased surface runoff and infiltration at the time of precipitation, makes the water penetrating into the active layer increase its temperature. This demonstrates that the local land forms (tidal channels and terminal moraines) have a substantial influence on the extent and rate of changes which occur in the active layer.

    Just do it? When to do what you judge you ought to do

    Get PDF
    While it is generally believed that justification is a fallible guide to the truth, there might be interesting exceptions to this general rule. In recent work on bridge-principles, an increasing number of authors have argued that truths about what a subject ought to do are truths we stand in some privileged epistemic relation to and that our justified normative beliefs are beliefs that will not lead us astray. If these bridge-principles hold, it suggests that justification might play an interesting role in our normative theories. In turn, this might help us understand the value of justification, a value that's notoriously difficult to understand if we think of justification as but a fallible means to a desired end. We will argue that these bridge-principles will be incredibly difficult to defend. While we do not think that normative facts necessarily stand in any interesting relationship to our justified beliefs about them, there might well be a way of defending the idea that our justified beliefs about what to do won't lead us astray. In turn, this might help us understand the value of justification, but this way of thinking about justification and its value comes with costs few would be willing to pay

    (Bio)degradable polymeric materials for sustainable future—Part 3: Degradation studies of the PHA/wood flour-based composites and preliminary tests of antimicrobial activity

    Get PDF
    © 2020 The Authors. Published by MDPI. This is an open access article available under a Creative Commons licence. The published version can be accessed at the following link on the publisher’s website: https://doi.org/10.3390/ma13092200The need for a cost reduction of the materials derived from (bio)degradable polymers forces research development into the formation of biocomposites with cheaper fillers. As additives can be made using the post-consumer wood, generated during wood products processing, re-use of recycled waste materials in the production of biocomposites can be an environmentally friendly way to minimalize and/or utilize the amount of the solid waste. Also, bioactive materials, which possess small amounts of antimicrobial additives belong to a very attractive packaging industry solution. This paper presents a study into the biodegradation, under laboratory composting conditions, of the composites that consist of poly[(R)-3-hydroxybutyrate-co-4-hydroxybutyrate)] and wood flour as a polymer matrix and natural filler, respectively. Thermogravimetric analysis, differential scanning calorimetry and scanning electron microscopy were used to evaluate the degradation progress of the obtained composites with different amounts of wood flour. The degradation products were characterized by multistage electrospray ionization mass spectrometry. Also, preliminary tests of the antimicrobial activity of selected materials with the addition of nisin were performed. The obtained results suggest that the different amount of filler has a significant influence on the degradation profile.Published onlin

    Skutecznośći bezpieczeństwo trombolizy dożylnej za pomocą alteplazy w leczeniu udaru niedokrwiennego mózgu w szpitalu w regionie rolniczym

    Get PDF
    Background and purpose Ongoing evaluation of the results of thrombolytic therapy in patients with ischaemic stroke (IS) in regions with different health care organization is absolutely crucial for making this method of treatment safer and efficient. The aim of this study was to analyse the efficacy and safety of treatment with intravenous alteplase in patients with acute IS in a rural hospital. Material and methods Between 2006 and 2011, 1392 patients with IS were treated (including 200 patients treated with alteplase; 14.37%). In patients treated with alteplase, we analysed the influence of several variables on the functional status after 3 months according to the modified Rankin Scale (mRS), case-fatality rate during 3 months after onset and symptomatic intracerebral haemorrhage (SICH). Results In the studied population, good outcome (mRS 0–2) at 3 months was related to younger age (p = 0.001), male sex (p = 0.02) and low scores (< 15 points) on the National Institutes of Health Stroke Scale (NIHSS) (p < 0.0001). Deaths within 3 months were related to older age (p = 0.027), female sex (p = 0.004), severity of stroke measured by NIHSS score (p < 0.0001) and presence of radiological signs of previous stroke in baseline computed tomography (CT) (p = 0.002). Patients with SICH had higher mean age (p = 0.014) and higher severity of neurological deficit measured on the NIHSS scale (p = 0.03). Conclusions The indications for intravenous thrombolysis in patients with IS should be strictly analysed so that the treatment is effective and safe especially in older patients, patients with greater severity of neurological symptoms and patients with old post-stroke lesions in baseline CT.Wstęp i cel pracy Prowadzenie ciągłej oceny wyników leczenia trombolitycznego chorych na udar niedokrwienny mózgu (UNM) w regionach różniących się organizacją ochrony zdrowia ma duże znaczenie dla skuteczniejszego oraz bezpieczniejszego stosowania tej metody. Celem pracy była analiza skuteczności i bezpieczeństwa leczenia podawaną dożylnie alteplazą u chorych na UNM w szpitalu w regionie rolniczym. Materiał i metody W latach 2006–2011 autorzy leczyli 1392 chorych na UNM – alteplazę otrzymało 200 pacjentów (14,37%). W grupie chorych leczonych alteplazą przeanalizowano wpływ wielu czynników na stan funkcjonalny po 3 miesiącach, uwzględniając punktację w zmodyfikowanej skali Rankina (mRS), częstość zgonów w ciągu 3 miesięcy od zachorowania oraz częstość objawowych krwotoków śródmózgowych (SICH). Wyniki W badanej populacji dobry wynik leczenia (mRS 0–2) po 3 miesiącach wiązał się z młodszym wiekiem chorych (p = 0,001), płcią męską (p = 0,02) i małą (< 15 pkt) punktacją w Skali Udarowej Narodowych Instytutów Zdrowia (NIHSS) (p < 0,0001). Zgony w ciągu 3 miesięcy były istotnie częstsze wśród osób starszych (p = 0,027), kobiet (p = 0,004), osób z dużym nasileniem ubytkowych objawów neurologicznych w skali NIHSS (p < 0,0001) i u osób z objawami przebytego udaru w wyjściowej tomografii komputerowej (TK) (p = 0,002). Grupa chorych z SICH cechowała się większą średnią wieku (p = 0,014) i większym nasileniem objawów neurologicznych mierzonych skalą NIHSS (p = 0,03). Wnioski Należy ściśle analizować wskazania do dożylnej trombolizy u chorych na UNM, aby leczenie było skuteczne i bezpieczne, w szczególności u chorych starszych, chorych ze znacznym nasileniem objawów neurologicznych i chorych z obecnością starych ognisk poudarowych w wyjściowej TK

    Cerebral thrombolysis in patients with ischemic stroke and heart failure

    Get PDF
    Background Heart failure (HF) is common among patients with ischemic stroke (IS), however its impact on outcome after iv-thrombolysis has not been fully determined. Moreover, definition of HF has been recently modified, but majority of stroke studies classified patients regarding an old HF criteria. Thus, the aim of our study was to evaluate the relationship between both, newly and formerly defined HF and the long-term outcome, mortality and the presence of hemorrhagic complications in patients with acute IS treated with iv-thrombolysis. Methods We retrospectively evaluated data from 328 Caucasian patients with IS consecutively treated with iv-thrombolysis. HF was defined according to old and new definition; long-term outcome was assessed with modified Rankin Scale (mRS) score and mortality rate on 90th days after IS. Results The incidence of HF did not differ between patients with favorable (mRS 0–2) and unfavorable (mRS 3–6) functional outcome respectively for the old and for the new definition (10.4% vs. 15.5, p = 0.17; 17.4% vs. 18.1%, p = 0.88) and between those who survived and died within 90 days after IS (11.7% vs. 20.0%, p = 0.27; 17.2% vs. 25.0%, p = 0.38, respectively). Multivariate analysis showed no impact of HF diagnosis on outcome (p = 0.94) or mortality (p = 0.64). Conclusion The presence of systolic HF, defined according to an old and a new definition, does not determine safety and efficacy of cerebral iv-thrombolysis in patients with IS

    State-of-the-art of transcatheter treatment of aortic valve stenosis and the overview of the InFlow project aiming at developing the first Polish TAVI system

    Get PDF
    Initial experience of transcatheter aortic valve implantation (TAVI) or replacement (TAVR) has ap-peared as a promising minimally invasive technology for patients disqualified from surgical treatment (SAVR). Safety and efficacy of TAVI has been analyzed and assessed through numerous registries and trials. Furthermore, results obtained from comparative TAVI vs. SAVR trials proved that both treat¬ments can be considered equal in terms of post-procedural mortality and morbidity in high-risk, as well as lower risk patients. However, there are still some issues that have to be addressed, such as higher chance of paravalvular leakage, vascular injuries, conduction disturbances, malpositioning and the yet unmet problem of insufficient biological valves durability. Recent technological developments along with the learning curve of operators prove a great potential for improvement of TAVI and a chance of surpassing SAVR in various groups of patients in the near future. In pursuit of finding new solutions, the CardValve Consortium consisting of leading scientific and research institutions in Poland has been created. Under the name of InFlow and financial support from the National Center for Research and Development, they have started a project with the aim to design, create and implement into clinical practice the first, Polish, low-profile TAVI valve system, utilizing not only biological but also artificial, polymeric-based prosthesis. This review focuses on current developments in TAVI technologies including the InFlow project
    corecore