106 research outputs found

    Structural phase transitions and their influence on Cu+ mobility in superionic ferroelastic Cu6PS5I single crystals

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    The structural origin of Cu+ ions conductivity in Cu6PS5I single crystals is described in terms of structural phase transitions studied by X-ray diffraction, polarizing microscope and calorimetric measurements. Below the phase transition at Tc=(144-169) K Cu6PS5I belongs to monoclinic, ferroelastic phase, space group Cc. Above Tc crystal changes the symmetry to cubic superstructure, space group F-43c (a=19.528); finally at 274K disordering of the Cu+ ions increases the symmetry to F-43m, (a=9.794). The phase transition at 274K coincides well with a strong anomaly in electrical conductivity observed in the Arrhenius plot. Diffusion paths for Cu+ ions are evidenced by means of the atomic displacement factors and split model. Influence of the copper stechiometry on the Tc is also discussed.Comment: conference pape

    Ferroelectric Phase Transitions in Films with Depletion Charge

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    We consider ferroelectric phase transitions in both short-circuited and biased ferroelectric-semiconductor films with a space (depletion) charge which leads to some unusual behavior. It is shown that in the presence of the charge the polarization separates into `switchable' and `non-switchable' parts. The electric field, appearing due to the space charge, does not wash out the phase transition, which remains second order but takes place at somewhat reduced temperature. At the same time, it leads to a suppression of the ferroelectricity in a near-electrode layer. This conclusion is valid for materials with both second and first order phase transitions in pure bulk samples. Influence of the depletion charge on thermodynamic coercive field reduces mainly to the lowering of the phase transition temperature, and its effect is negligible. The depletion charge can, however, facilitate an appearance of the domain structure which would be detrimental for device performance (fatigue). We discuss some issues of conceptual character, which are generally known but were overlooked in previous works. The present results have general implications for small systems with depletion charge.Comment: 11 pages, REVTeX 3.1, five eps-figures included in the text. Minor clarifications in the text. To appear in Phys. Rev. B 61, Apr 1 (2000

    Effect of total arterial grafting in the Arterial Revascularization Trial

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    Objectives The Arterial Revascularization Trial (ART) was designed to compare 10-year survival in bilateral versus single internal thoracic artery grafts. The intention-to-treat analysis has showed comparable outcomes between the 2 groups but an explanatory analysis suggested that those receiving 2 or more arterial grafts had better survival. Whether the exclusive use of arterial grafts provide further benefit is unclear. Methods We performed an exploratory analysis of the ART based on conduits actually received (as-treated principle). From ART cohort, only patients receiving at least 3 grafts were included. The final population consisted of 1084, 1010, and 390 patients in the single arterial graft (SAG) group, in the multiple arterial graft (MAG) group (2 or more arterial grafts with additional saphenous veins) and total arterial graft (TAG) group (3 or more arterial grafts only) respectively. Inverse probability of treatment weighting was used for comparison. Results When compared with the SAG group, there was a significant trend toward a reduction of 10-year mortality in the MAG and TAG group (test for trend P = .02). The TAG group was associated with the lowest risk of late mortality (hazard ratio, 0.68; 95% confidence interval, 0.48-0.96; P = .03) and with a significant risk reduction of the composite of death/myocardial infarction/stroke and repeat revascularization (hazard ratio, 0.71; 95% confidence interval, 0.53-0.94; P = .02). Conclusions When compared with SAG, both MAG and TAG represent valuable strategies to improve clinical outcomes following coronary artery bypass grafting but TAG can potentially provide further benefit.</p

    Assessment and prevalence of depression in women 45–55 years of age visiting gynecological clinics in Poland

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    ¶The aims of the Polish survey were to assess efficacy of screening for depression in gynecological practice and to estimate prevalence of depressive disorders in midlife women visiting gynecologists. The study included 2262 female outpatients aged 45–55, who were screened by 120 gynecologists throughout Poland. Patients completed the Beck’s Depression Inventory (BDI) and were assessed by gynecologists to verify the presence of symptoms of a current Depressive Episode according to ICD-10 diagnostic criteria. Patients who obtained a score of 12 points or more on the BDI were referred for psychiatric evaluation, including the modified version of Mini International Neuropsychiatric Interview (MINI). The study showed that gynecologists in Poland are able to perform screenings for depression effectively in outpatient settings. Results also suggested that about 19% of women aged 45 to 55 years visiting gynecologists may suffer from depressive disorders.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/41736/1/737_2003_Article_019.pd

    Thrombin inhibitory activity of some polyphenolic compounds

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    Thrombin, also known as an active plasma coagulation factor II, belongs to the family of serine proteases and plays a crucial role in blood coagulation process. The process of thrombin generation is the central event of the hemostatic process and regulates blood coagulant activity. For this reason, thrombin inhibition is key to successful novel antithrombotic pharmacotherapy. The aim of our present study was to examine the effects of the well-known polyphenolic compounds on the activity of thrombin, by characterization of its interaction with selected polyphenols using different biochemical methods and biosensor BIAcore analyses. Only six compounds, cyanidin, quercetin, silybin, cyanin, (+)-catechin and (−)-epicatechin, of all examined in this study polyphenols caused the inhibition of thrombin amidolytic activity. But only three of the six compounds (cyanidin, quercetin and silybin) changed thrombin proteolytic activity. BIAcore analyses demonstrated that cyanidin and quercetin caused a strong response in the interaction with immobilized thrombin, while cyanin and (−)-epicatechin induced a low response. Lineweaver–Burk curves show that used polyphenol aglycones act as competitive thrombin inhibitors. Our results suggest that polyphenolic compounds might be potential structural bases and source to find and project nature-based, safe, orally bioavailable direct thrombin inhibitors.This work was supported by Grant 545/485 and Grant 506/810 from the University of Lodz

    Constitutive modelling of skin ageing

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    The objective of this chapter is to review the main biomechanical and structural aspects associated with both intrinsic and extrinsic skin ageing, and to present potential research avenues to account for these effects in mathematical and computational models of the skin. This will be illustrated through recent work of the authors which provides a basis to those interested in developing mechanistic constitutive models capturing the mechanobiology of skin across the life course

    Rare variants in BNC2 are implicated in autosomal-dominant congenital lower urinary-tract obstruction

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    Congenital lower urinary-tract obstruction (LUTO) is caused by anatomical blockage of the bladder outflow tract or by functional impairment of urinary voiding. About three out of 10,000 pregnancies are affected. Although several monogenic causes of functional obstruction have been defined, it is unknown whether congenital LUTO caused by anatomical blockage has a monogenic cause. Exome sequencing in a family with four affected individuals with anatomical blockage of the urethra identified a rare nonsense variant (c.2557C>T [p.Arg853(∗)]) in BNC2, encoding basonuclin 2, tracking with LUTO over three generations. Re-sequencing BNC2 in 697 individuals with LUTO revealed three further independent missense variants in three unrelated families. In human and mouse embryogenesis, basonuclin 2 was detected in lower urinary-tract rudiments. In zebrafish embryos, bnc2 was expressed in the pronephric duct and cloaca, analogs of the mammalian lower urinary tract. Experimental knockdown of Bnc2 in zebrafish caused pronephric-outlet obstruction and cloacal dilatation, phenocopying human congenital LUTO. Collectively, these results support the conclusion that variants in BNC2 are strongly implicated in LUTO etiology as a result of anatomical blockage

    Profiling and imaging of forensic evidence – a pan-European forensic round robin study part 1: document forgery

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    The forensic scenario, on which the round robin study was based, simulated a suspected intentional manipulation of a real estate rental agreement consisting of a total of three pages. The aims of this study were to (i) establish the amount and reliability of information extractable from a single type of evidence and to (ii) provide suggestions on the most suitable combination of compatible techniques for a multi-modal imaging approach to forgery detection. To address these aims, seventeen laboratories from sixteen countries were invited to answer the following tasks questions: (i) which printing technique was used? (ii) were the three pages printed with the same printer? (iii) were the three pages made from the same paper? (iv) were the three pages originally stapled? (v) were the headings and signatures written with the same ink? and (vi) were headings and signatures of the same age on all pages? The methods used were classified into the following categories: Optical spectroscopy, including multispectral imaging, smartphone mapping, UV-luminescence and LIBS; Infrared spectroscopy, including Raman and FTIR (micro-)spectroscopy; X-ray spectroscopy, including SEM-EDX, PIXE and XPS; Mass spectrometry, including ICPMS, SIMS, MALDI and LDIMS; Electrostatic imaging, as well as non-imaging methods, such as non-multimodal visual inspection, (micro-)spectroscopy, physical testing and thin layer chromatography. The performance of the techniques was evaluated as the proportion of discriminated sample pairs to all possible sample pairs. For the undiscriminated sample pairs, a distinction was made between undecidability and false positive claims. It was found that none of the methods used were able to solve all tasks completely and/or correctly and that certain methods were a priori judged unsuitable by the laboratories for some tasks. Correct results were generally achieved for the discrimination of printer toners, whereas incorrect results in the discrimination of inks. For the discrimination of paper, solid state analytical methods proved to be superior to mass spectrometric methods. None of the participating laboratories deemed addressing ink age feasible. It was concluded that correct forensic statements can only be achieved by the complementary application of different methods and that the classical approach of round robin studies to send standardised subsamples to the participants is not feasible for a true multimodal approach if the techniques are not available at one location
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