Structural and textural evolution of zirconia nanocrystals induced by thermal treatment

Nanometric tetragonal and monoclinic zirconia was synthesized from zirconyl chloride by the modified forced hydrolysis method. Phase transitions and morphological changes accompanying zirconia calcination in the temperaure range 600–1000 °C were studied by XRD, HR-TEM techniques and N2-porosimetry. Ageing of the amorphous hydrous zirconia at 100 °C for 48 h in the mother solution and its subsequent calcination at 600 °C for 6 h strongly favoured formation of single-phase tetragonal ZrO2 of the thermal stability enhanced by 250 °C. Influence of the calcination temperature on phase composition, grain size, grain boundaries and pore structure of the resultant ZrO2 material was analyzed

Metabolism of ticagrelor in patients with acute coronary syndromes.

© The Author(s) 2018Ticagrelor is a state-of-the-art antiplatelet agent used for the treatment of patients with acute coronary syndromes (ACS). Unlike remaining oral P2Y12 receptor inhibitors ticagrelor does not require metabolic activation to exert its antiplatelet action. Still, ticagrelor is extensively metabolized by hepatic CYP3A enzymes, and AR-C124910XX is its only active metabolite. A post hoc analysis of patient-level (n = 117) pharmacokinetic data pooled from two prospective studies was performed to identify clinical characteristics affecting the degree of AR-C124910XX formation during the first six hours after 180 mg ticagrelor loading dose in the setting of ACS. Both linear and multiple regression analyses indicated that ACS patients presenting with ST-elevation myocardial infarction or suffering from diabetes mellitus are more likely to have decreased rate of ticagrelor metabolism during the acute phase of ACS. Administration of morphine during ACS was found to negatively influence transformation of ticagrelor into AR-C124910XX when assessed with linear regression analysis, but not with multiple regression analysis. On the other hand, smoking appears to increase the degree of ticagrelor transformation in ACS patients. Mechanisms underlying our findings and their clinical significance warrant further research.Peer reviewedFinal Published versio

Montessori's mediation of meaning: a social semiotic perspective

The distinctive objects designed by Dr Maria Montessori as the centrepiece of her approach to pedagogy are the topic of this study. The Montessori approach to pedagogy, celebrating its centenary in 2007, continues to be used in classrooms throughout the world. Despite such widespread and enduring use, there has been little analysis of the Montessori objects to evaluate or understand their pedagogic impact. This study begins by outlining the provenance of the Montessori objects, reaching the conclusion that the tendency to interpret them from the perspective of the progressive education movement of the early twentieth century fails to provide insights into the developmental potential embodied in the objects. In order to appreciate that potential more fully, the study explores the design of the objects, specifically, the way in which the semiotic qualities embodied in their design orient children to the meanings of educational knowledge. A meta-analytic framework comprising three components is used to analyse the semiotic potential of the Montessori objects as educational artefacts. First, Vygotsky’s model of development is used to analyse the objects as external mediational means and to recognise the objects as complexes of signs materialising educational knowledge. In order to understand how the objects capture, in the form of concrete analogues, the linguistic meanings which construe educational knowledge, systemic functional linguistics, the second component of the framework, is used to achieve a rich and detailed social semiotic analysis of these relations, in particular, material and linguistic representations of abstract educational meanings. Finally, the pedagogic device, a central feature of Bernstein’s sociology of pedagogy, is used to analyse how the Montessori objects re-contextualise educational knowledge as developmental pedagogy. Particular attention is paid to the Montessori literacy pedagogy, in which the study of grammar plays a central role. The study reveals a central design principle which distinguishes the Montessori objects. This principle is the redundant representation of educational knowledge across multiple semiotic modes. Each representation holds constant the underlying meaning relations which construe quanta of educational knowledge, giving children the freedom to engage with this knowledge playfully, independently and successfully. The conclusion drawn from this study is that the design of the Montessori objects represents valuable educational potential which deserves continued investigation, as well as wider recognition and application. To initiate this process, the findings in this study may provide insights which can be used to develop tools for evaluating and enhancing the implementation of Montessori pedagogy in Montessori schools. The findings may also be used to adapt Montessori design principles for the benefit of educators working in non-Montessori contexts, in particular, those educators concerned with developing pedagogies which promote equitable access to educational knowledge

Infection control : point prevalence study versus incidence study in Polish long-term care facilities in 2009-2010 in the Małopolska Region

OBJECTIVE: The objective of this study was to evaluate the epidemiology of infection in Polish long-term care facilities (LTCFs) and to analyse the capabilities and legitimacy of implementing continuous targeted surveillance. METHODS: The study investigated the relationship between the presence of infection and health status, tested using a point prevalence study (PPS) and incidence study. A 1-day PPS was carried out in October 2009, with prospective continuous surveillance between December 2009 and November 2010. Infections were defined according to McGeer’s criteria. RESULTS: The surveillance encompassed 193 people. The prevalence was 14.0 % in residential homes (RHs) and 18.7 % in the nursing home (NH). Various types of infections (in the PPS) were observed significantly more frequently in patients with asthma, wounds, atherosclerosis of lower extremities, tracheotomy tubes and conditions in patients hospitalised in intensive care units (ICUs) up to 1 year before the PPS day. The incidence rate was 2.7/1,000 patient days (pds). CONCLUSIONS: The factors determined to be important for the risk of infection (in the continuous study) include the general status of patients, expressed using Barthel, abbreviated mental and Katz scales, as well as limited physical activity, stool incontinence and urinary catheterisation. In the PPS study, only a slight relationship was shown between the general status of residents and the risk of infection. None of the general status scales used clinically were shown to be helpful in estimating that risk, similarly to the five-point physical activity scale. Prospective continuous surveillance shows a possibility of limiting the range of infection control in the LTCFs within targeted surveillance in a population of patients that requires intensive nursing procedures. As a marker, one could point to the low score in the Barthel or Katz scales or low physical activity/bedridden persons

The Relationship Between Grain Hardness, Dough Mixing Parameters and Bread-Making Quality in Winter Wheat

The influence of grain hardness, determined by using molecular markers and physical methods (near-infrared (NIR) technique and particle size index—PSI) on dough characteristics, which in turn were determined with the use of a farinograph and reomixer, as well as bread-making properties were studied. The material covered 24 winter wheat genotypes differing in grain hardness. The field experiment was conducted at standard and increased levels of nitrogen fertilization. Results of molecular analyses were in agreement with those obtained by the use of physical methods for soft-grained lines. Some lines classified as hard (by physical methods) appeared to have the wild-type Pina and Pinb alleles, similar to soft lines. Differences in dough and bread-making properties between lines classified as hard and soft on the basis of molecular data appeared to be of less significance than the differences between lines classified as hard and soft on the basis of physical analyses of grain texture. Values of relative grain hardness at the increased nitrogen fertilization level were significantly higher. At both fertilization levels the NIR parameter determining grain hardness was significantly positively correlated with the wet gluten and sedimentation values, with most of the rheological parameters and bread yield. Values of this parameter correlated with quality characteristics in a higher degree than values of particle size index

Infections and risk-adjusted length of stay and hospital mortality in Polish Neonatology Intensive Care Units

Background: The objectives of this study were to analyze the impact of infections on prolonging hospital stay with consideration of underlying risk factors and determining the mortality rates and its association with infections. Methods: An electronic database developed from a continuous prospective targeted infection surveillance program was used in the study. Data were collected from 2009 to 2012 in five Polish tertiary academic neonatal intensive care units (NICUs). The length of stay (LOS) of 2,003 very low birth weight (VLBW) neonates was calculated as the sum of the number of days since birth until death or until reaching a weight of 1,800 g. Results: The median LOS for neonates with infections was twice as high as for neonates without infection. LOS was significantly affected by the overall general condition of the neonate, as expressed by both gestational age and birth weight as well as by the Clinical Risk Index for Babies (CRIB) score; another independent factor was presence of at least one infection. Risk of in-hospital mortality was significantly increased by male sex and vaginal birth and was lower among breastfed neonates. Deaths were significantly more frequent in neonates without infection. Conclusions: The general condition of VLBW infants statistically increase both their risk of mortality and LOS; this is in contrast to the presence of infection, which significantly prolonged LOS only

Impact of mild therapeutic hypothermia on bioavailability of ticagrelor in patients with acute myocardial infarction after out-of-hospital cardiac arrest

Background: Out-of-hospital cardiac arrest (OHCA) frequently occurs in the early phase of acute myocardial infarction (MI). Survivors require percutaneous coronary intervention (PCI) with concomitantdual antiplatelet therapy. Target temperature management, including mild therapeutic hypothermia (MTH), should be applied in comatose patients after resuscitation. However, an increased risk of stent thrombosis in patients undergoing hypothermia is observed. The aim of this study was to assess the impact of MTH on pharmacokinetics of ticagrelor in cardiac arrest survivors with MI treated with MTH and PCI.Methods: In a prospective, observational, single-center study pharmacokinetics of ticagrelor were evaluated in 41 MI patients, including 11 patients after OHCA undergoing MTH (MTH group) and 30 MI patients without OHCA and MTH (no-MTH group). Blood samples were drawn before administration of a 180 mg ticagrelor loading dose, and 30 min, 1, 2, 4, 6, 12, and 24 h after the loading dose.Results: In patients treated with MTH total exposure to ticagrelor during the first 12 h after the loading dose and maximal plasma concentration of ticagrelor were significantly lower than in the no-MTH group (AUC(0–12): 3403 ± 2879 vs. 8746 ± 5596 ng·h/mL, difference: 61%, p = 0.01; Cmax: 475 ± 353 vs. 1568 ± 784 ng/mL, p = 0.0002). Time to achieve maximal ticagrelor plasma concentration was also delayed in the MTH group (tmax for ticagrelor: 12 [6–24] vs. 4 [2–12] h, p = 0.01).Conclusions: Bioavailability of ticagrelor was substantially decreased and delayed in MI patients treated with MTH after OHCA. Trial registration: ClinicalTrials.gov Identifier: NCT0261193