24 research outputs found

    Investigations on finite ideal quantum gases

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    Recursion formulae of the N-particle partition function, the occupation numbers and its fluctuations are given using the single-particle partition function. Exact results are presented for fermions and bosons in a common one-dimensional harmonic oscillator potential, for the three-dimensional harmonic oscillator approximations are tested. Applications to excited nuclei and Bose-Einstein condensation are discussed.Comment: 13 pages, 7 postscript figures, uses 'epsfig.sty'. Submitted to Physica A. More information available at http://obelix.physik.uni-osnabrueck.de/~schnack

    Bose-Einstein condensation of atomic gases in a harmonic oscillator confining potential trap

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    We present a model which predicts the temperature of Bose-Einstein condensation in atomic alkali gases and find excellent agreement with recent experimental observations. A system of bosons confined by a harmonic oscillator potential is not characterized by a critical temperature in the same way as an identical system which is not confined. We discuss the problem of Bose-Einstein condensation in an isotropic harmonic oscillator potential analytically and numerically for a range of parameters of relevance to the study of low temperature gases of alkali metals.Comment: 11 pages latex with two postscript figure

    Bose-Einstein condensation in multilayers

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    The critical BEC temperature TcT_{c} of a non interacting boson gas in a layered structure like those of cuprate superconductors is shown to have a minimum Tc,mT_{c,m}, at a characteristic separation between planes ama_{m}. It is shown that for a<ama<a_{m}, TcT_{c} increases monotonically back up to the ideal Bose gas T0T_{0} suggesting that a reduction in the separation between planes, as happens when one increases the pressure in a cuprate, leads to an increase in the critical temperature. For finite plane separation and penetrability the specific heat as a function of temperature shows two novel crests connected by a ridge in addition to the well-known BEC peak at TcT_{c} associated with the 3D behavior of the gas. For completely impenetrable planes the model reduces to many disconnected infinite slabs for which just one hump survives becoming a peak only when the slab widths are infinite.Comment: Four pages, four figure

    Bose-Einstein Condensation on Product Manifolds

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    We investigate the phenomenon of Bose-Einstein condensation on manifolds constructed as a product of a three-dimensional Euclidian space and a general smooth, compact dd-dimensional manifold possibly with boundary. By using spectral ζ\zeta-function methods, we are able to explicitly provide thermodynamical quantities like the critical temperature and the specific heat when the gas of bosons is confined, in the three-dimensional manifold, by the experimentally relevant anisotropic harmonic oscillator potential.Comment: 9 pages, LaTe

    Effectiveness and safety of PCSK9 inhibitor therapy in patients with familial hypercholesterolemia within a therapeutic program in Poland: Preliminary multicenter data

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    Background: In Poland, treatment with proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors has become available free of charge in a therapeutic program. Assessed herein, is the efficacy and safety of alirocumab and evolocumab in patients with heterozygous familial hypercholesterolemia (FH).Methods: Data of 55 adult FH patients who participated in the program were analyzed upon meeting the criteria established by the Ministry of Health (low density lipoprotein cholesterol [LDL-C] above 160 mg/dL on max. tolerated statin dose and ezetimib). The efficacy of PCSK9 inhibitors in reducing LDL-C with drug administration every 2 weeks was assessed after 3 months and 1 year of therapy. A safety profile evaluation was performed at each visit. 48 patients completed the 3-month and 21 for the 1-year observation periods (34 patients treated with alirokumab and 14 with evolocumab).Results: The mean concentration of direct-measured LDL-C decreased from the initial level of 215.1 ± 74.5 mg/dL to 75.3 ± 64.1 mg/dL, i.e., by 65 ± 14% following 3 months of treatment. This effect was stable in 1-year observation (77.7 ± 72.8 mg/dL). Adverse effects were flu-like symptoms (13.0%), injection site reactions (11.1%), fatigue (5.6%) and musculoskeletal symptoms (5.6%). Seven patients failed to complete the 3-month treatment period due to side effects or non-compliance, and 1 patient failed to complete the 1-year treatment due to myalgia.Conclusions: This study confirmed high effectiveness of PCSK9 inhibitors in reducing LDL-C levels in patients with FH. Due to restrictive inclusion criteria with LDL-C threshold level &gt; 160 mg/dL (&gt; 4.1 mmol/L) required for participation in the therapeutic program, a relatively small number of FH patients were eligible for treatment

    Familial hypercholesterolaemia in children and adolescents from 48 countries: a cross-sectional study

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    Background Approximately 450 000 children are born with familial hypercholesterolaemia worldwide every year, yet only 2·1% of adults with familial hypercholesterolaemia were diagnosed before age 18 years via current diagnostic approaches, which are derived from observations in adults. We aimed to characterise children and adolescents with heterozygous familial hypercholesterolaemia (HeFH) and understand current approaches to the identification and management of familial hypercholesterolaemia to inform future public health strategies. Methods For this cross-sectional study, we assessed children and adolescents younger than 18 years with a clinical or genetic diagnosis of HeFH at the time of entry into the Familial Hypercholesterolaemia Studies Collaboration (FHSC) registry between Oct 1, 2015, and Jan 31, 2021. Data in the registry were collected from 55 regional or national registries in 48 countries. Diagnoses relying on self-reported history of familial hypercholesterolaemia and suspected secondary hypercholesterolaemia were excluded from the registry; people with untreated LDL cholesterol (LDL-C) of at least 13·0 mmol/L were excluded from this study. Data were assessed overall and by WHO region, World Bank country income status, age, diagnostic criteria, and index-case status. The main outcome of this study was to assess current identification and management of children and adolescents with familial hypercholesterolaemia. Findings Of 63 093 individuals in the FHSC registry, 11 848 (18·8%) were children or adolescents younger than 18 years with HeFH and were included in this study; 5756 (50·2%) of 11 476 included individuals were female and 5720 (49·8%) were male. Sex data were missing for 372 (3·1%) of 11 848 individuals. Median age at registry entry was 9·6 years (IQR 5·8–13·2). 10 099 (89·9%) of 11 235 included individuals had a final genetically confirmed diagnosis of familial hypercholesterolaemia and 1136 (10·1%) had a clinical diagnosis. Genetically confirmed diagnosis data or clinical diagnosis data were missing for 613 (5·2%) of 11 848 individuals. Genetic diagnosis was more common in children and adolescents from high-income countries (9427 [92·4%] of 10 202) than in children and adolescents from non-high-income countries (199 [48·0%] of 415). 3414 (31·6%) of 10 804 children or adolescents were index cases. Familial-hypercholesterolaemia-related physical signs, cardiovascular risk factors, and cardiovascular disease were uncommon, but were more common in non-high-income countries. 7557 (72·4%) of 10 428 included children or adolescents were not taking lipid-lowering medication (LLM) and had a median LDL-C of 5·00 mmol/L (IQR 4·05–6·08). Compared with genetic diagnosis, the use of unadapted clinical criteria intended for use in adults and reliant on more extreme phenotypes could result in 50–75% of children and adolescents with familial hypercholesterolaemia not being identified. Interpretation Clinical characteristics observed in adults with familial hypercholesterolaemia are uncommon in children and adolescents with familial hypercholesterolaemia, hence detection in this age group relies on measurement of LDL-C and genetic confirmation. Where genetic testing is unavailable, increased availability and use of LDL-C measurements in the first few years of life could help reduce the current gap between prevalence and detection, enabling increased use of combination LLM to reach recommended LDL-C targets early in life. Funding Pfizer, Amgen, Merck Sharp & Dohme, Sanofi–Aventis, Daiichi Sankyo, and Regeneron

    Familial hypercholesterolaemia in children and adolescents from 48 countries: a cross-sectional study

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    Background: Approximately 450 000 children are born with familial hypercholesterolaemia worldwide every year, yet only 2·1% of adults with familial hypercholesterolaemia were diagnosed before age 18 years via current diagnostic approaches, which are derived from observations in adults. We aimed to characterise children and adolescents with heterozygous familial hypercholesterolaemia (HeFH) and understand current approaches to the identification and management of familial hypercholesterolaemia to inform future public health strategies. Methods: For this cross-sectional study, we assessed children and adolescents younger than 18 years with a clinical or genetic diagnosis of HeFH at the time of entry into the Familial Hypercholesterolaemia Studies Collaboration (FHSC) registry between Oct 1, 2015, and Jan 31, 2021. Data in the registry were collected from 55 regional or national registries in 48 countries. Diagnoses relying on self-reported history of familial hypercholesterolaemia and suspected secondary hypercholesterolaemia were excluded from the registry; people with untreated LDL cholesterol (LDL-C) of at least 13·0 mmol/L were excluded from this study. Data were assessed overall and by WHO region, World Bank country income status, age, diagnostic criteria, and index-case status. The main outcome of this study was to assess current identification and management of children and adolescents with familial hypercholesterolaemia. Findings: Of 63 093 individuals in the FHSC registry, 11 848 (18·8%) were children or adolescents younger than 18 years with HeFH and were included in this study; 5756 (50·2%) of 11 476 included individuals were female and 5720 (49·8%) were male. Sex data were missing for 372 (3·1%) of 11 848 individuals. Median age at registry entry was 9·6 years (IQR 5·8-13·2). 10 099 (89·9%) of 11 235 included individuals had a final genetically confirmed diagnosis of familial hypercholesterolaemia and 1136 (10·1%) had a clinical diagnosis. Genetically confirmed diagnosis data or clinical diagnosis data were missing for 613 (5·2%) of 11 848 individuals. Genetic diagnosis was more common in children and adolescents from high-income countries (9427 [92·4%] of 10 202) than in children and adolescents from non-high-income countries (199 [48·0%] of 415). 3414 (31·6%) of 10 804 children or adolescents were index cases. Familial-hypercholesterolaemia-related physical signs, cardiovascular risk factors, and cardiovascular disease were uncommon, but were more common in non-high-income countries. 7557 (72·4%) of 10 428 included children or adolescents were not taking lipid-lowering medication (LLM) and had a median LDL-C of 5·00 mmol/L (IQR 4·05-6·08). Compared with genetic diagnosis, the use of unadapted clinical criteria intended for use in adults and reliant on more extreme phenotypes could result in 50-75% of children and adolescents with familial hypercholesterolaemia not being identified. Interpretation: Clinical characteristics observed in adults with familial hypercholesterolaemia are uncommon in children and adolescents with familial hypercholesterolaemia, hence detection in this age group relies on measurement of LDL-C and genetic confirmation. Where genetic testing is unavailable, increased availability and use of LDL-C measurements in the first few years of life could help reduce the current gap between prevalence and detection, enabling increased use of combination LLM to reach recommended LDL-C targets early in life

    Zastosowanie pomiaru fluorescencji NADH w ocenie mikrokrążenia

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    There is compelling evidence for a link between microvascular and endothelial dysfunction and the pathogenesis of cardiovascular disease. Endothelial dysfunction is a globalized systemic disease process consisting of attenuated vasodilation and augmented vasoconstriction. Till now the assessment of microvascular endothelial function was mainly based on perfusion methods perform in response to various stimuli. Recently, there is a new method to assess NADH fluorescence that allows to follow metabolic changes depending on the blood flow.Zgromadzono przekonujące dowody na istnienie związku między zaburzeniami mikrokrążenia oraz funkcji śródbłonka a patogenezą chorób układu sercowo-naczyniowego. Dysfunkcja śródbłonka to ogólnoustrojowy proces chorobowy, w którym dochodzi do osłabienia potencjału wazodylatacyjnego i wzmożenia wazokonstrykcji. Podstawą dotychczasowych badań funkcji śródbłonka mikrokrążenia były głównie metody służące ocenie zmiany przepływu krwi w odpowiedzi na różne bodźce. Obecnie dostępna metoda oceny fluorescencji NADH pozwala badać zmiany na poziomie metabolicznym, które są zależne od przepływu krwi
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