LR-0
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Nuclear data evaluations are periodically updated to render state of the art of knowledge, and the independent validation experiments are still of interest of the community. Current work describes validation of selected capture reactions used for monitoring of thermal neutrons in mixed fields, as well as reactions responsible for activation of components exposed to neutron flux. The validation was performed also for reaction 50Cr (n,γ), which is very important reaction directly affecting criticality safety, because chromium is essential component of stainless steel used as structural component of the core baffle closely adjoining to nuclear fuel. Described experiments were performed in reference neutron field of the LR-0 reactor. The activation rate was derived by gamma spectrometry using well-characterized HPGe detector. It was found that the capture cross sections for the dosimetry reactions 23Na (n,γ), 58Fe (n,γ), and 59Co (n,γ) agreed well within 10 % with calculations in thermal and epithermal region, but larger discrepancy was found for the isotopes of tin.
- Publikační typ
- časopisecké články MeSH
The work presents a detailed comparison of calculated and experimentally determined net peak areas of selected fission products gamma lines. The fission products were induced during a 2.5 h irradiation on the power level of 9.5 W in selected fuel pins of the VVER-1000 Mock-Up. The calculations were done with deterministic and stochastic (Monte Carlo) methods. The effects of different nuclear data libraries used for calculations are discussed as well. The Net Peak Area (NPA) may be used for the determination of fission density across the mock-up. This fission density is practically identical to power density.
The paper is intended to show the effect of a biological shielding simulator on fast neutron and photon transport in its vicinity. The fast neutron and photon fluxes were measured by means of scintillation spectroscopy using a 45×45 mm(2) and a 10×10 mm(2) cylindrical stilbene detector. The neutron spectrum was measured in the range of 0.6-10 MeV and the photon spectrum in 0.2-9 MeV. The results of the experiment are compared with calculations. The calculations were performed with various nuclear data libraries.
... gramatiky 206 -- 5.2 LR(0) gramatiky 220 -- Rozšiřující část -- 5.3 Vztah LR(0) gramatik a deterministických ... ... jazyků 236 -- 5.4 LR(k) gramatiky 242 -- 5.5 LR jazyky a deterministické jazyky 249 -- 5.6 LL(lc) gramatiky ... ... Algoritmicky neřešitelné problémy 260 -- Základní část -- 6.1 Turingovy stroje a jazyky typu 0 260 -- ... ... 6.2 Algoritmicky neřešitelné problémy 268 -- Rozšiřující část -- 6.3 Nerozhodnutelnost příslušnosti k LR ...
Matematický seminář ; 19
1. vyd. 331 s.
- Klíčová slova
- Kybernetika,
- MeSH
- kybernetika MeSH
- programovací jazyk MeSH
- software MeSH
- Publikační typ
- příručky MeSH
- Konspekt
- Počítačová věda. Výpočetní technika. Informační technologie
- NLK Obory
- technika
A protocol for high-pressure freezing and LR White embedding of mammalian cells suitable for fine ultrastructural studies in combination with immunogold labelling is presented. HeLa S3 cells enclosed in low-temperature gelling agarose were high-pressure frozen, freeze-substituted in acetone, and embedded in LR White at 0 degrees C. The morphology of such cells and the preservation of nuclear antigens were excellent in comparison with chemically fixed cells embedded in the same resin. The immunolabelling signal for different nuclear antigens was 4-to-13 times higher in high-pressure frozen than in chemically fixed cells. We conclude that one can successfully use high-pressure freezing/freeze-substitution and LR White embedding as an alternative of Lowicryl resins.
- MeSH
- akrylové pryskyřice MeSH
- antigeny jaderné analýza MeSH
- buněčné jádro imunologie ultrastruktura MeSH
- financování organizované MeSH
- HeLa buňky MeSH
- imunohistochemie MeSH
- kryoprezervace metody MeSH
- lidé MeSH
- mrazová substituce MeSH
- tlak MeSH
- transmisní elektronová mikroskopie MeSH
- zalévání tkání plastickou hmotou metody MeSH
- Check Tag
- lidé MeSH
... Substantial agreement -- .61-.80 Moderate agreement -- .41-.60 Fair agreement -- .11-.40 Slight agreement -- .0- ... ... .10 No agreement -- 1 1 + LR Interpretation -LR -- >10 Large <1 -- 5.0-10.0 Moderate .1-.2 -- 2.0-5.0 ...
Third edition xii, 650 stran : ilustrace ; 27 cm
- MeSH
- fyzikální vyšetření * metody MeSH
- medicína založená na důkazech MeSH
- muskuloskeletální nemoci * diagnóza MeSH
- techniky fyzikální terapie MeSH
- Publikační typ
- příručky MeSH
- Konspekt
- Ortopedie. Chirurgie. Oftalmologie
- NLK Obory
- ortopedie
The aim of this study is to obtain by Monte Carlo method the high energy photon flux due to neutron capture in the internals and vessel layers of the experimental reactor LR-0 located in REZ, Czech Republic, and loaded with VVER-1000 fuel. The calclated neutron, photon and photon to neutron flux ratio are compared with experimental measurements performed with a multi-parameter stilbene detector. The results show clear underestimation of photon flux in downcomer and some overestimation at vessel surface and 1/4 thickness but a good fitting for deeper points in vessel.
- MeSH
- analýza selhání vybavení MeSH
- dávka záření MeSH
- elektrárny přístrojové vybavení normy MeSH
- fotony * MeSH
- metoda Monte Carlo MeSH
- počítačová simulace MeSH
- radiační ochrana přístrojové vybavení metody MeSH
- radiační rozptyl MeSH
- radiometrie metody MeSH
- statistické modely * MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Česká republika MeSH
Celiac disease (CD) is a largely undiagnosed immune-mediated enteropathy. A point-of-care test (POCT) could represent a rapid and cost-effective tool on ruling out CD. The objective of this study is to evaluate retrospectively the performance of a POCT based on detection of IgA and IgG antibodies against deamidated gliadins peptides (DGP). The study was performed on 53 children presenting clinical suspicions of CD, all being investigated by intestinal biopsy and standard serology. The performance of POCT was compared to the diagnostic result obtained from the gold standard of histology and serology. 10 children were diagnosed as CD positive by the POCT. Among the 43 children identified as CD negatives, 37 were correctly identified by POCT and 6 were considered as false positives. No false negative results were observed. The POCT yields a sensitivity and a negative predictive value (NPV) of 100%, and a negative likelihood ratio (LR-) of 0 in this selected pediatric population. The high NPV and low LR- ratio indicate that this POCT could be an useful and discriminative tool for excluding CD. This study and the results published so far are promising but need to be confirmed in larger cohort.
- Klíčová slova
- point-of-care test, detekce protilátek proti deamidovaným gliadin peptidům, pravidlo-out CD, rychlý test,
- MeSH
- bezlepková dieta MeSH
- biopsie MeSH
- celiakie * diagnóza imunologie komplikace prevence a kontrola MeSH
- diagnostické techniky a postupy * MeSH
- dítě MeSH
- interpretace statistických dat MeSH
- kojenec MeSH
- lidé MeSH
- mladiství MeSH
- prediktivní hodnota testů MeSH
- předškolní dítě MeSH
- retrospektivní studie MeSH
- senzitivita a specificita * MeSH
- sérologické testy MeSH
- statistika jako téma metody normy organizace a řízení MeSH
- Check Tag
- dítě MeSH
- kojenec MeSH
- lidé MeSH
- mladiství MeSH
- mužské pohlaví MeSH
- předškolní dítě MeSH
- ženské pohlaví MeSH
The work presents a detailed comparison of calculated and experimentally determined net peak areas of longer-living fission products after 100 h irradiation on a reactor with power of ~630 W and several days cooling. Specifically the nuclides studied are (140)Ba, (103)Ru, (131)I, (141)Ce, (95)Zr. The good agreement between the calculated and measured net peak areas, which is better than in determination using short lived (92)Sr, is reported. The experiment was conducted on the VVER-1000 mock-up installed on the LR-0 reactor. The Monte Carlo approach has been used for calculations. The influence of different data libraries on results of calculation is discussed as well.
BACKGROUND: Unmet medical needs remain in patients with red blood cell transfusion-dependent (RBC-TD) lower-risk myelodysplastic syndromes (LR-MDS) who are not responding to or are ineligible for erythropoiesis-stimulating agents (ESAs). Imetelstat, a competitive telomerase inhibitor, showed promising results in a phase 2 trial. We aimed to compare the RBC transfusion independence (RBC-TI) rate with imetelstat versus placebo in patients with RBC-TD LR-MDS. METHODS: In phase 3 of IMerge, a double-blind, placebo-controlled trial conducted in 118 sites including university hospitals, cancer centres, and outpatient clinics in 17 countries, patients (aged ≥18 years) with ESA-relapsed, ESA-refractory, or ESA-ineligible LR-MDS (low or intermediate-1 risk disease as per International Prognostic Scoring System [IPSS] criteria) were randomly assigned via a computer-generated schedule (2:1) to receive imetelstat 7·5 mg/kg or placebo, administered as a 2-h intravenous infusion, every 4 weeks until disease progression, unacceptable toxic effects, or withdrawal of consent. Randomisation was stratified by previous RBC transfusion burden and IPSS risk group. Patients, investigators, and those analysing the data were masked to group assignment. The primary endpoint was 8-week RBC-TI, defined as the proportion of patients without RBC transfusions for at least 8 consecutive weeks starting on the day of randomisation until subsequent anti-cancer therapy, if any. Primary efficacy analyses were performed in the intention-to-treat population, and safety analyses were conducted in patients who received at least one dose of trial medication or placebo. This trial is registered with ClinicalTrials.gov (NCT02598661; substudy active and recruiting). FINDINGS: Between Sept 11, 2019, and Oct 13, 2021, 178 patients were enrolled and randomly assigned (118 to imetelstat and 60 to placebo). 111 (62%) were male and 67 (38%) were female. 91 (77%) of 118 patients had discontinued treatment by data cutoff in the imetelstat group versus 45 (75%) in the placebo group; a further one patient in the placebo group did not receive treatment. Median follow-up was 19·5 months (IQR 12·0-23·4) in the imetelstat group and 17·5 months (12·1-22·7) in the placebo group. In the imetelstat group, 47 (40% [95% CI 30·9-49·3]) patients had an RBC-TI of at least 8 weeks versus nine (15% [7·1-26·6]) in the placebo group (rate difference 25% [9·9 to 36·9]; p=0·0008). Overall, 107 (91%) of 118 patients receiving imetelstat and 28 (47%) of 59 patients receiving placebo had grade 3-4 treatment-emergent adverse events. The most common treatment-emergent grade 3-4 adverse events in patients taking imetelstat were neutropenia (80 [68%] patients who received imetelstat vs two [3%] who received placebo) and thrombocytopenia (73 [62%] vs five [8%]). No treatment-related deaths were reported. INTERPRETATION: Imetelstat offers a novel mechanism of action with durable transfusion independence (approximately 1 year) and disease-modifying activity for heavily transfused patients with LR-MDS who are not responding to or are ineligible for ESAs. FUNDING: Janssen Research & Development before April 18, 2019, and Geron Corporation thereafter.
- MeSH
- dospělí MeSH
- dvojitá slepá metoda MeSH
- erytropoéza MeSH
- lidé MeSH
- mladiství MeSH
- myelodysplastické syndromy * farmakoterapie MeSH
- oligonukleotidy * MeSH
- protokoly protinádorové kombinované chemoterapie MeSH
- trombocytopenie * farmakoterapie MeSH
- výsledek terapie MeSH
- Check Tag
- dospělí MeSH
- lidé MeSH
- mladiství MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- klinické zkoušky, fáze III MeSH
- randomizované kontrolované studie MeSH
