106 research outputs found

    Surface and bulk components of electrical conductivity in the (presumably special topological) Kondo insulator SmB6 at lowest temperatures

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    Samarium hexaboride (SmB6) has recently been considered to be a topological Kondo insulator (TKI), the first strongly correlated electron system to exhibit topological surface conduction states. In this contribution, results of electrical resistivity measurements between 80 K and 0.08 K of various SmB6 single crystalline samples are presented, analyzed and discussed. The received results imply that the residual conductivity of SmB6 below about 4 K is of non-activated (metallic-like) nature. It is shown that this metallic-like behavior can be attributed both to surface (2D) conduction states, as may be expected in case of a topological insulator, as well as to the highly correlated many-body (3D) bulk ground state which is formed within the gap of this compound. From this it follows that in SmB6, where surface conductivity states are clearly present, there is in parallel also a bulk contribution to residual electrical conductivity originating from the strongly correlated electron system with valence fluctuations. This raises the question whether SmB6 does not form a new / special type of topological insulator in which in the energy gap besides the surface conduction states, there is also a conducting narrow in-gap band originating from the bulk strongly correlated electron system.Comment: 9 pages, 5 figure

    Pregled tehnika recikliranja litij-ionskih baterija

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    This paper presents a literature review on the processing of used lithium-ion batteries in both industry and research. On an industrial scale, lithium-ion batteries are primarily processed through pyrometallurgical methods, leading to incomplete utilisation of lithium cells. On the other hand, the hydrometallurgical route of recycling lithium-ion batteries poses challenges, such as large-scale discharging or inert gas pretreatment, largely due to explosion hazards. Modern methods of lithium-ion battery recycling are oriented toward refining the leach liquor through solvent extraction methods using D2EHPA and Cyanex 272, to recover Co, Mn, and Ni. The final Li product is obtained through Na2CO3 precipitation.Ovaj rad predstavlja pregled literature o obradi rabljenih litij-ionskih baterija u industriji i istraĆŸivanju. U industrijskoj razini, litij-ionske baterije ponajprije se obrađuju pirometalurĆĄkim metodama, ĆĄto dovodi do nepotpunog iskoriĆĄtenja litijevih ćelija. S druge strane, hidrometalurĆĄki put recikliranja litij-ionskih baterija predstavlja izazove kao ĆĄto su veliko praĆŸnjenje ili predobrada inertnim plinom, uglavnom zbog opasnosti od eksplozije. Suvremene metode recikliranja litij-ionskih baterija usmjerene su na rafiniranje tekućine za ispiranje metodama ekstrakcije pomoću D2EHPA i Cyanex 272, da bi se dobili Co, Mn i Ni. Konačni produkt, Li, dobiva se taloĆŸenjem s Na2CO3

    Differences between the Italian and Slovak legal systems with respect to animal protection

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    This paper provides a comparative analysis of the legal content of animal protection legislation in the Slovak Republic with that of Italian legislation. Firstly, we compare the legal systems in the Slovak Republic and Italy with respect to the animal protection laws, especially criminal law in both countries. This comparison of the two different legislations allows detection of identical or different characteristics in the area of animal protection, which could be used later as an inspiration for lawmakers in both countries

    Alternative splicing variant of the hypoxia marker carbonic anhydrase IX expressed independently of hypoxia and tumour phenotype

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    CA IX is a hypoxia-induced, cancer-associated carbonic anhydrase isoform with functional involvement in pH control and cell adhesion. Here we describe an alternative splicing variant of the CA9 mRNA, which does not contain exons 8–9 and is expressed in tumour cells independently of hypoxia. It is also detectable in normal tissues in the absence of the full-length transcript and can therefore produce false-positive data in prognostic studies based on the detection of the hypoxia- and cancer-related CA9 expression. The splicing variant encodes a truncated CA IX protein lacking the C-terminal part of the catalytic domain. It shows diminished catalytic activity and is intracellular or secreted. When overexpressed, it reduces the capacity of the full-length CA IX protein to acidify extracellular pH of hypoxic cells and to bind carbonic anhydrase inhibitor. HeLa cells transfected with the splicing variant cDNA generate spheroids that do not form compact cores, suggesting that they fail to adapt to hypoxic stress. Our data indicate that the splicing variant can functionally interfere with the full-length CA IX. This might be relevant particularly under conditions of mild hypoxia, when the cells do not suffer from severe acidosis and do not need excessive pH control

    Synthetic lethal targeting of oncogenic transcription factors in acute leukemia by PARP inhibitors

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    Acute myeloid leukemia (AML) is mostly driven by oncogenic transcription factors, which have been classically viewed as intractable targets using small molecule inhibitor approaches. Here, we demonstrate that AML driven by repressive transcription factors including AML1-ETO and PML-RARα are extremely sensitive to Poly (ADP-ribose) Polymerase (PARP) inhibitor (PARPi), in part due to their suppressed expression of key homologous recombination genes and thus compromised DNA damage response (DDR). In contrast, leukemia driven by MLL fusions with dominant transactivation ability is proficient in DDR and insensitive to PARP inhibition. Intriguing, depletion of an MLL downstream target, Hoxa9 that activates expression of various HR genes, impairs DDR and sensitizes MLL leukemia to PARPi. Conversely, Hoxa9 over-expression confers PARPi resistance to AML1-ETO and PML-RARα transformed cells. Together, these studies describe a potential utility of PARPi-induced synthetic lethality for leukemia treatment and reveal a novel molecular mechanism governing PARPi sensitivity in AML

    Filmer i historieundervisning

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    I kunskapsöversikten kommer vi att undersöka med hjÀlp av diverse teorier, perspektiv samt vetenskapliga artiklar om Àmnet filmer i historieundervisningen. Det som kom fram av undersökningen Àr att anvÀnda sig av media i historieundervisningen Àr gynnsamt och positivt, eftersom det gynnar eleverna samtidigt som det stimulerar deras lÀrande och utvecklar deras anvÀndning av de didaktiska förmÄgorna. Det Àr vÀsentligt att anvÀnda sig av relevanta filmer och filmklipp till undervisningsmomenten och att median bör vara den bÀsta möjliga att anvÀnda i klassrummet. Bred forskning finns inom detta Àmne men lÀrarutbildningen lÀgger inte stor vikt pÄ att förmedla kunskap till lÀrarstudenterna om de didaktiska valen inom film i historieundervisning

    Film som didaktiskt verktyg

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    VĂ„rt syfte Ă€r att ta reda pĂ„ hur lĂ€rare anvĂ€nder film som didaktiskt verktyg i klassrummet pĂ„ grundskolan 7–9. Film Ă€r sĂ„ pass populĂ€r och nĂ€rvarande i elevernas liv utanför skolan att den konkurrerar med skolan om uppmĂ€rksamhet. LĂ€rarna som vi intervjuade pratade om fördelar med att visa film i historieundervisningen. LĂ€rarna menade att de anvĂ€nder film som komplement eller redskap till undervisningen. Nackdelar med film som lĂ€rarna nĂ€mnde var bland annat tidsbegrĂ€nsning, bristen pĂ„ urval av film samt de praktiska bekymren. För att besvara vĂ„r frĂ„gestĂ€llning genomfördes kvalitativa intervjuer i form av semistrukturerade intervjufrĂ„gor. Denna metod omfattar Ă€ven mejlintervjuer. Den teoretiska utgĂ„ngspunkten som ligger till grund för vĂ„r analys av empirin Ă€r The Big Six frĂ„n Tom Morton och Peter Seixas. Vidare understöds The Big Six av Stephane Levesques teori om den historiska empatin.Resultatet av denna studie visar att samtliga lĂ€rare var eniga om att anvĂ€nda film pĂ„ olika sĂ€tt Ă€r ett bra redskap som komplement till historieundervisning. LĂ€rares svar överensstĂ€mmer om att det Ă€r arbetsomrĂ„det som styr hur ofta man visar film eller klipp. LĂ€rarna Ă€r överens om att de visar bĂ„de hela filmen och bitar av den beroende pĂ„ tidsbegrĂ€nsning, filmens svĂ„righetsnivĂ„ samt omrĂ„de man undervisar om. De frĂ€msta förmĂ„gorna som lĂ€rarna anser eleverna utvecklar under filmvisning Ă€r kĂ€llkritik och historiebruk. Dock finns det olika syften bakom varför och hur lĂ€rarna visar film i historieundervisning. Film kan tillföra djupare förstĂ„else för historiska sammanhang, nya perspektiv och levandegör undervisningen

    Animal welfare during transport: comparison of mortality during transport from farm to slaughter of different animal species and categories in the Czech Republic

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    Animals may be subjected to various stressors during transport, which may compromise their health and welfare as well as meat quality. In the chain of operations between a farm and a slaughterhouse, animal transport is probably the most stressful and injurious stage. Data on mortality is commonly collected at slaughterhouse as a retrospective indicator of animal welfare during transport. Ten-year prevalence of mortality of all the species and categories of animals (cattle, pigs, goats, sheep, poultry, rabbits and ostriches) regularly scheduled for slaughter in the Czech slaughterhouses was assessed as dead on arrival after road transport from 2010 to 2019. Among livestock, the highest mortality was found in pigs (0.065%); statistically higher compared to cattle (0.027%) and sheep (0.015%). In animals shipped in containers (rabbits, broiler chickens, end-of-lay hens, turkeys, geese and ducks), the highest prevalence was found in laying hens (0.507%), statistically higher compared to broiler chickens (0.425%) and rabbits (0.199%). The lowest prevalence was observed in geese (0.003%). There was a trend for decreasing death losses of pigs in more recent years and losses in broiler chickens and ducks increased. The results indicate that the current transport conditions should be re-evaluated for poultry. Emphasis should be put on the assessment of animal fitness before transport. This is especially important for animals at the end of their production cycle such as dairy cows, sows, and laying hens. They were more likely to die during the journey. Highlights Dead on arrival is an animal-based measure commonly applied at slaughterhouse as a retrospective indicator of animal welfare during transport. In a cross-species comparison, the highest prevalence was observed for animals transported in cages and for end of production cycle animals. To reduce mortality, several factors have to be considered by the meat industry other than the species-related ability to cope with transport

    Film som didaktiskt verktyg

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    VĂ„rt syfte Ă€r att ta reda pĂ„ hur lĂ€rare anvĂ€nder film som didaktiskt verktyg i klassrummet pĂ„ grundskolan 7–9. Film Ă€r sĂ„ pass populĂ€r och nĂ€rvarande i elevernas liv utanför skolan att den konkurrerar med skolan om uppmĂ€rksamhet. LĂ€rarna som vi intervjuade pratade om fördelar med att visa film i historieundervisningen. LĂ€rarna menade att de anvĂ€nder film som komplement eller redskap till undervisningen. Nackdelar med film som lĂ€rarna nĂ€mnde var bland annat tidsbegrĂ€nsning, bristen pĂ„ urval av film samt de praktiska bekymren. För att besvara vĂ„r frĂ„gestĂ€llning genomfördes kvalitativa intervjuer i form av semistrukturerade intervjufrĂ„gor. Denna metod omfattar Ă€ven mejlintervjuer. Den teoretiska utgĂ„ngspunkten som ligger till grund för vĂ„r analys av empirin Ă€r The Big Six frĂ„n Tom Morton och Peter Seixas. Vidare understöds The Big Six av Stephane Levesques teori om den historiska empatin.Resultatet av denna studie visar att samtliga lĂ€rare var eniga om att anvĂ€nda film pĂ„ olika sĂ€tt Ă€r ett bra redskap som komplement till historieundervisning. LĂ€rares svar överensstĂ€mmer om att det Ă€r arbetsomrĂ„det som styr hur ofta man visar film eller klipp. LĂ€rarna Ă€r överens om att de visar bĂ„de hela filmen och bitar av den beroende pĂ„ tidsbegrĂ€nsning, filmens svĂ„righetsnivĂ„ samt omrĂ„de man undervisar om. De frĂ€msta förmĂ„gorna som lĂ€rarna anser eleverna utvecklar under filmvisning Ă€r kĂ€llkritik och historiebruk. Dock finns det olika syften bakom varför och hur lĂ€rarna visar film i historieundervisning. Film kan tillföra djupare förstĂ„else för historiska sammanhang, nya perspektiv och levandegör undervisningen
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