254 research outputs found
Magnetic systems at criticality: different signatures of scaling
Different aspects of critical behaviour of magnetic materials are presented
and discussed. The scaling ideas are shown to arise in the context of purely
magnetic properties as well as in that of thermal properties as demonstrated by
magnetocaloric effect or combined scaling of excess entropy and order
parameter. Two non-standard approaches to scaling phenomena are described. The
presented concepts are exemplified by experimental data gathered on four
representatives of molecular magnets.Comment: 33 pages, 16 figure
Magnetic Properties of TbNi1 xAuxIn Compounds
Polycrystalline samples of for x = 0.1, 0.2, 0.4, 0.6 and 0.8 were prepared and studied by powder X-ray and neutron diffraction and ac magnetic susceptibility measurements. These compounds crystallize in the hexagonal ZrNiAl-type structure. With increasing Au content a change in the magnetic structure is observed. For x = 0.1, 0.2 and 0.4 the magnetic order is described by the propagation vector k = (1/2, 0, 1/2) while for x = 0.8 by k = (0, 0, 1/2). Between 1.5 K and the Néel temperature the magnetic order is stable
The spectral manifistation of the new luminescent styryl dyes photostability and phototoxic influence on the DNA
У роботі запропоновано методи спектральних досліджень фотостабільності та фото-
токсичного впливу люмінесціюючих зондів-барвників на ДНК. Досліджено спектри оптичного
поглинання, флюоресценції та фосфоресценції нових стирилових барвників та систем
ДНК+барвник. Спектри оптичного поглинання досліджуваних сполук реєструвалися під час
опромінювання зразків цих речовин видимим світлом. У роботі аналізуються результати цих
експериментів, проведені на низці барвників. Зафіксовано зміни оптичної густини D розчинів
систем ДНК+барвник на ділянці спектра 250+300 нм (що відповідає першому електронному
переходу в ДНК) та 370+650 нм (що відповідає першому електронному переходу в молекулах
барвників). Динаміка D(t) не є монотонною. Показано, що бавники Mn-Styr ma Di-Styr-30 є
фотохімічно безпечними для ДНК; ці барвники є більш фотостабільними у зв 'язаному з ДНК
стані, ніж: у вільному. Барвники Di-Styr-24 ma Dst-MdO, на відміну від попередніх, проявляють
невеликий фототоксичний вплив на ДНК. Пропонуються версії щодо можливих механізмів
фотогтокичності (та фотостабільності).The spectral investigation methods of the phenomena of luminescent dye probes photostability and
phototoxic influence on the DNA were proposed. The optical absorption, fluorescence and phosphorescence
spectra of the samples of the newest investigated styryl dyes and the systems DNA +dye were studied.
The optical absorption spectra of the samples of these compounds were measured under the irradiation
of these samples by visible light. The results of the investigations carried out on a number of dyes were
analyzed and discussed. The changes of optical density D value in wavelength regions 250+300 nm
(that corresponds to the DNA first electronic transition) and 370+650 nm (that corresponds to a dye
electronic transition) of the DNA+dye solutions were fixed. The dynamics ofD(t) was not monotonous.
It was shown the Mn-Styr and Di-Styr-30 dyes are photochemically safe for the DNA; these dyes bound
to the DNA are more photostable than in free state. The Di-Styr-24 and Dst-MdO dyes show slight phototoxic
effect on the DNA. The versions of possible phototoxicity (and photostability) mechanisms are
proposed
Prevalence of diabetes in the Republic of Ireland: results from the National Health Survey (SLAN) 2007
Background: Current estimates of diabetes prevalence in the Republic of Ireland (RoI) are based on UK epidemiological studies. This study uses Irish data to describe the prevalence of doctor-diagnosed diabetes amongst all adults aged 18+ years and undiagnosed diabetes amongst those aged 45+ years. Methods: The survey of lifestyle attitudes and nutrition (SLAN) 2007 is based on a nationally representative sample of Irish adults aged 18+ years (n = 10,364). Self-reported doctor-diagnosed diabetes was recorded for respondents in the full sample. Diabetes medication use, measured height and weight, and non-fasting blood samples were variously recorded in sub-samples of younger (n = 967) and older (n = 1,207) respondents. Results: The prevalence of doctor-diagnosed diabetes amongst adults aged 18+ years was 3.5% (95% CI 3.1% - 3.9%). After adjustment for other explanatory variables; the risk of self-reported doctor-diagnosed diabetes was significantly related to age (p < 0.0001), employment status (p = 0.0003) and obesity (p = 0.0003). Amongst adults aged 45+ years, the prevalence of doctor-diagnosed diabetes was 8.9% (95% CI 7.3% -10.5%) and undiagnosed diabetes was 2.8% (95% CI 1.4% - 4.1%). This represented 31.2% of diabetes cases in this age group. Conclusion: Notwithstanding methodological differences, these prevalence estimates are consistent with those in the UK and France. However, the percentage of undiagnosed cases amongst adults aged 45+ years appears to be higher in the RoI. Increased efforts to improve early detection and population level interventions to address adverse diet and lifestyle factors are urgently needed
Inclusive dielectron production in proton-proton collisions at 2.2 GeV beam energy
Data on inclusive dielectron production are presented for the reaction p+p at
2.2 GeV measured with the High Acceptance DiElectron Spectrometer (HADES). Our
results supplement data obtained earlier in this bombarding energy regime by
DLS and HADES. The comparison with the 2.09 GeV DLS data is discussed. The
reconstructed e+e- distributions are confronted with simulated pair cocktails,
revealing an excess yield at invariant masses around 0.5 GeV/c2. Inclusive
cross sections of neutral pion and eta production are obtained
Partial Wave Analysis of the Reaction to Search for the "" Bound State
Employing the Bonn-Gatchina partial wave analysis framework (PWA), we have
analyzed HADES data of the reaction . This
reaction might contain information about the kaonic cluster "" via its
decay into . Due to interference effects in our coherent description
of the data, a hypothetical (or, specifically "")
cluster signal must not necessarily show up as a pronounced feature (e.g. a
peak) in an invariant mass spectra like . Our PWA analysis includes a
variety of resonant and non-resonant intermediate states and delivers a good
description of our data (various angular distributions and two-hadron invariant
mass spectra) without a contribution of a cluster. At a
confidence level of CL=95\% such a cluster can not contribute more than
2-12\% to the total cross section with a final state, which
translates into a production cross-section between 0.7 and 4.2 ,
respectively. The range of the upper limit depends on the assumed cluster mass,
width and production process.Comment: 7 Pages, 5 Figure
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