128 research outputs found

    KorszerƱ, önkenƑ mƱszaki mƱanyag kompozitok tribolĂłgiai kutatĂĄsa dinamikus mozgĂĄs Ă©s terhelĂ©si rendszerekben, dinamikus tribomĂ©ter modulrendszerƱ tovĂĄbbfejlesztĂ©se = Tribological research of up-to-date self-lubricating engineering polymer composites in dynamic sliding and loading system, further modular development of the dynamic tribometer

    Get PDF
    A kutatĂĄsi programot kĂ©t fƑ vonalon keresztĂŒl valĂłsĂ­tottuk meg. I. A legĂșjabb mƱszaki mƱanyagok Ă©s kompozitjaik sĂșrlĂłdĂĄsi Ă©s kopĂĄsi viselkedĂ©sĂ©t kutattuk acĂ©l Ă©s DLC felĂŒleteken, a tribolĂłgiai eredmĂ©nyeket összehasonlĂ­tottuk a mĂĄr ismert polimer anyagok jellemzƑivel. Ennek kapcsĂĄn: - Több mĂ©rĂ©si modellrendszerben, kis Ă©s nagymĂ©retƱ mintavizsgĂĄlatokat vĂ©geztĂŒnk abrazĂ­v Ă©s adhezĂ­v feltĂ©telek esetĂ©n. - Dinamikus modellezĂ©ssel egy Ășj mĂ©rnöki, tribolĂłgiai adatbĂĄzist hoztunk lĂ©tre. - KorrelĂĄciĂłkeresĂ©st vĂ©geztĂŒnk az egyes vizsgĂĄlati rendszerek között. - ValĂłs gĂ©pĂ©szeti rendszermodellezĂ©shez, dinamikus hatĂĄsok Ă©letszerƱ tribolĂłgiai vizsgĂĄlatĂĄhoz fogaskerekes mĂ©rƑrendszert terveztĂŒnk. - Kidolgoztuk a polimer Ă©s kompozit fogprofilikon a kapcsolĂłvonal mentĂ©n Ă©bredƑ sĂșrlĂłdĂĄs mĂ©rĂ©sĂ©nek elvĂ©t. II. ModulĂĄris rendszerben tovĂĄbbfejlesztettĂŒk Ă©s Ă©pĂ­tettĂŒk a dinamikus tribolĂłgiai anyagvizsgĂĄlĂł berendezĂ©sĂŒnket. - A "pin-on-cylinder" Ă©s a "pin-on-plate" modult fejlesztettĂŒk ki egyedi funkciĂłkkal. - Az alapgĂ©pre megterveztĂŒk Ă©s elkĂ©szĂ­tettĂŒk a polimer fogaskerĂ©k fogsĂșrlĂłdĂĄsmĂ©rƑ modult. Az eredmĂ©nyeket Ă©s tĂ©ziseket folyamatosan publikĂĄltuk Ă©s ĂĄtĂŒltettĂŒk a mĂ©rnöki gyakorlatba Ă©s oktatĂĄsba, segĂ­tve az aktĂ­v mĂ©rnököket egyetemi hallgatĂłkat. A kutatĂĄsi program rĂ©szeredmĂ©nyeibƑl 4 sikeres PhD (ebbƑl 2 MagyarorszĂĄgon) fokozatszerzĂ©s törtĂ©nt. A program vĂ©gsƑ szakaszĂĄban szĂŒletett egy bejelentett szabadalom. | The research program was carried out via two main ways. I. The up-to-date engineering polymers and composite materials were tested in different tribological systems and compared to the conventional engineering plastics. The friction, wear and deformation of the selected materials against steel and DLC surface layer were measured as it follows: - Small-scale and large-scale test specimens under adhesive and abrasive - New tribological data base built on dynamic modeling - Correlation between the different tribo systems was investigated - For better correlation to a working dynamic tribo-systems we developed a tests system for gearmesh measurements - We worked out the theoretical background of the friction measurements of gear teeth profile along the action line. II. In modular system we developed the dynamic tribotester with new units: - A 'pin-on-cylinder' and 'pin-on-plate' moduls with unique functions - New unit for gearmesh measurements The results of the project and thesis were published and disseminated in many ways to the industry and education sphere, too. The research program was carried out in an international co-operation with belgian and romanian partners. During the program internationally 4 PhD degree were succesfully defended. In the final step of the project a patent were submitted, regarding the wear resistance of modified polymer surfaces and tribotesting

    The potential and shortcomings of mitochondrial DNA analysis for cheetah conservation management

    Get PDF
    There are only about 7,100 adolescent and adult cheetahs (Acinonyx jubatus) remaining in the wild. With the majority occurring outside protected areas, their numbers are rapidly declining. Evidence-based conservation measures are essential for the survival of this species. Genetic data is routinely used to inform conservation strategies, e.g., by establishing conservation units (CU). A commonly used marker in conservation genetics is mitochondrial DNA (mtDNA). Here, we investigated the cheetah’s phylogeography using a large-scale mtDNA data set to refine subspecies distributions and better assign individuals to CUs. Our dataset mostly consisted of historic samples to cover the cheetah’s whole range as the species has been extinct in most of its former distribution. While our genetic data largely agree with geography-based subspecies assignments, several geographic regions show conflicting mtDNA signals. Our analyses support previous findings that evolutionary forces such as incomplete lineage sorting or mitochondrial capture likely confound the mitochondrial phylogeography of this species, especially in East and, to some extent, in Northeast Africa. We caution that subspecies assignments solely based on mtDNA should be treated carefully and argue for an additional standardized nuclear single nucleotide polymorphism (SNP) marker set for subspecies identification and monitoring. However, the detection of the A. j. soemmeringii specific haplogroup by a newly designed Amplification-Refractory Mutation System (ARMS) can already provide support for conservation measures.info:eu-repo/semantics/publishedVersio

    Incidence of erythropoietin antibody-mediated pure red cell aplasia: the Prospective Immunogenicity Surveillance Registry (PRIMS)

    Get PDF
    Background: Subcutaneous administration of Eprex(Âź) (epoetin alfa) in patients with chronic kidney disease (CKD) was contraindicated in the European Union between 2002 and 2006 after increased reports of anti-erythropoietin antibody-mediated pure red cell aplasia (PRCA). The Prospective Immunogenicity Surveillance Registry (PRIMS) was conducted to estimate the incidence of antibody-mediated PRCA with subcutaneous administration of a new coated-stopper syringe presentation of Eprex(Âź) and to compare this with the PRCA incidence with subcutaneous NeoRecormon(Âź) (epoetin beta) and Aranesp(Âź) (darbepoetin alfa). Methods: PRIMS was a multicentre, multinational, non-interventional, parallel-group, immunogenicity surveillance registry. Adults with CKD receiving or about to initiate subcutaneous Eprex(Âź), NeoRecormon(Âź) or Aranesp(Âź) for anaemia were enrolled and followed for up to 3 years. Unexplained loss or lack of effect (LOE), including suspected PRCA, was reported, with antibody testing for confirmation of PRCA. Results: Of the 15 333 patients enrolled, 5948 received Eprex(Âź) (8377 patient-years) and 9356 received NeoRecormon(Âź)/Aranesp(Âź) (14 286 patient-years). No treatment data were available for 29 patients. Among 23 patients with LOE, five cases of PRCA were confirmed (Eprex(Âź), n = 3; NeoRecormon(Âź), n = 1; Aranesp(Âź), n = 1). Based on exposed time, PRCA incidence was 35.8/100 000 patient-years (95% CI 7.4-104.7) for Eprex(Âź) versus 14.0/100 000 patient-years (95% CI 1.7-50.6) for NeoRecormon(Âź)/Aranesp(Âź). The incidence of PRCA with Eprex(Âź) was not significantly different versus comparator ESAs (rate ratio: 2.56; 95% CI 0.43-15.31). An analysis based on observed time produced similar findings. Conclusion: This large, prospective registry demonstrates that PRCA is rare with subcutaneous administration of either the new coated-stopper syringe presentation of Eprex(Âź), or NeoRecormon(Âź) or Aranesp(Âź).This study was funded by Janssen, Pharmaceutical Companies of Johnson & Johnson

    A study of the metal binding capacity of saccharinic acids formed during the alkali catalysed decomposition of cellulosic materials: nickel complexation by glucoisosaccharinic acids and xyloisosaccharinic acids

    Get PDF
    The stoichiometry of the metal complexes formed between nickel and the ligand ÎČ-glucoisosaccharinic acid (ÎČ-GISA) and a racemic mixture of enantiomers of xyloisosaccharinic acid (XISA) has been determined at both neutral and alkaline pHs. Bjerrum plots, Job's plots and conductance measurements indicated that for each of the systems one to one Ni(ligand) complexes were formed at near neutral pHs (13) sparingly soluble Ni2(ligand)(OH)4 complexes were formed. The stability constants for the Ni(ÎČ-GISA), Ni(α-GISA) and Ni(XISA) complexes formed at neutral pH were determined under identical conditions using polarographic studies. The measured stability constants for Ni(ÎČ-GISA) (log10 ÎČ = 1.94 ± 0.15) and for Ni(α-GISA)(log10 ÎČ = 2.07 ± 0.13) are very similar; the value measured for the Ni(XISA) complex (log10 ÎČ = 0.83) was an order of magnitude smaller. The stability constants for the Ni2(Ligand)(OH)4 complexes formed at highly alkaline pHs were determined using the Schubert method. The measured stability constant for Ni2(ÎČ-GISA)(OH)4 (log10 ÎČ = 30.6 ± 0.5) was an order of magnitude bigger than the value for Ni2(α-GISA)(OH)4 (log10 ÎČ = 29.0 ± 0.5) measured under identical conditions. Attempts to measure the stability constant for Ni2(XISA)(OH)4 were unsuccessful; Ni2(XISA)(OH)4 complexes were not present in significant amounts at high pH to allow the log10ÎČ value to be determined by the Schubert method

    Genomic Analyses Show Extremely Perilous Conservation Status of African and Asiatic cheetahs (Acinonyx jubatus).

    Get PDF
    We live in a world characterized by biodiversity loss and global environmental change. The extinction of large carnivores can have ramifying effects on ecosystems like an uncontrolled increase in wild herbivores, which in turn can have knock-on impacts on vegetation regeneration and communities. Cheetahs (Acinonyx jubatus) serve important ecosystem functions as apex predators; yet, they are quickly heading towards an uncertain future. Threatened by habitat loss, human-wildlife conflict and illegal trafficking, there are only approximately 7100 individuals remaining in nature. We present the most comprehensive genome-wide analysis of cheetah phylogeography and conservation genomics to date, assembling samples from nearly the entire current and past species' range. We show that their phylogeography is more complex than previously thought, and that East African cheetahs (A. j. raineyi) are genetically distinct from Southern African individuals (A. j. jubatus), warranting their recognition as a distinct subspecies. We found strong genetic differentiation between all classically recognized subspecies, thus refuting earlier findings that cheetahs show only little differentiation. The strongest differentiation was observed between the Asiatic and all the African subspecies. We detected high inbreeding in the Critically Endangered Iranian (A. j. venaticus) and North-western (A. j. hecki) subspecies, and show that overall cheetahs, along with snow leopards, have the lowest genome-wide heterozygosity of all the big cats. This further emphasizes the cheetah's perilous conservation status. Our results provide novel and important information on cheetah phylogeography that can support evidence-based conservation policy decisions to help protect this species. This is especially relevant in light of ongoing and proposed translocations across subspecies boundaries, and the increasing threats of illegal trafficking

    The role of the right inferior frontal gyrus in the pathogenesis of post-stroke psychosis.

    Get PDF
    Psychotic symptoms have previously been reported following right hemisphere brain injury. We sought to identify the specific neuroanatomical basis of delusions following stroke by studying a series of patients with post-stroke psychosis. Lesion overlap analysis was conducted on three individuals with delusions following right hemisphere stroke. These cases were compared with a control group of patients with similar anatomical damage. The main outcome measures were presence of delusions and presence of behavioural susceptibility. The right inferior frontal gyrus and underlying white matter, including the superior longitudinal fasciculus and anterior corona radiata, were involved in all three cases. All three had a preexisting untreated psychiatric disorder. In contrast, only one of nine control cases with equivalent lesions had evidence of previous psychiatric disorder (p = 0.0182, Fisher’s exact test), and this was being treated at the time of stroke. We provide clinical evidence from patients with structural brain lesions implicating damage to the right inferior frontal lobe in the generation of persistent psychosis following stroke. We suggest that preexisting psychiatric disease provided a behavioural susceptibility to develop delusions in these individuals. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s00415-014-7242-x) contains supplementary material, which is available to authorized users

    Fluxes of dissolved organic carbon in stand throughfall and percolation water in 12 boreal coniferous stands on mineral soils in Finland

    Get PDF
    Predictors for glucose intolerance postpartum were evaluated in women with gestational diabetes mellitus (GDM) based on the 2013 World Health Organization (WHO) criteria. 1841 women were tested for GDM in a prospective cohort study. A postpartum 75g oral glucose tolerance test (OGTT) was performed in women with GDM at 14 ± 4.1 weeks. Of all 231 mothers with GDM, 83.1% (192) had a postpartum OGTT of which 18.2% (35) had glucose intolerance. Women with glucose intolerance were more often of Asian origin [15.1% vs. 3.7%, OR 4.64 (1.26–17.12)], had more often a recurrent history of GDM [41.7% vs. 26.7%, OR 3.68 (1.37–9.87)], higher fasting glycaemia (FPG) [5.1 (4.5–5.3) vs. 4.6 (4.3–5.1) mmol/L, OR 1.05 (1.01–1.09)], higher HbA1c [33 (31–36) vs. 32 (30–33) mmol/mol, OR 4.89 (1.61–14.82)], and higher triglycerides [2.2 (1.9–2.8) vs. 2.0 (1.6–2.5) mmol/L, OR 1.00 (1.00–1.01)]. Sensitivity of glucose challenge test (GCT) ≄7.2 mmol/l for glucose intolerance postpartum was 80% (63.1%–91.6%). The area under the curve to predict glucose intolerance was 0.76 (0.65–0.87) for FPG, 0.54 (0.43–0.65) for HbA1c and 0.75 (0.64–0.86) for both combined. In conclusion, nearly one-fifth of women with GDM have glucose intolerance postpartum. A GCT ≄7.2 mmol/L identifies a high risk population for glucose intolerance postpartum
    • 

    corecore