Cytotoxicity of albebetin oligomers depends on cross-β-sheet formation

AbstractPrefibrillar cytotoxicity was suggested as a common amyloid characteristic. We showed two types of albebetin prefibrillar oligomers are formed during incubation at pH 7.3. Initial round-shaped oligomers consist of 10–15 molecules determined by atomic force microscopy, do not bind thioflavin-T and do not affect viability of granular neurons and SH-SY5Y cells. They are converted into ca. 30–40-mers possessing cross-β-sheet and reducing viability of neuronal cells. Neither monomers nor fibrils possess cytotoxicity. We suggest that oligomeric size is important for stabilising cross-β-sheet core critical for cytotoxicity. As albebetin was used as a carrier-protein for drug delivery, examination of amyloidogenicity is required prior polypeptide biomedical applications

Comparison of QG-Induced Dispersion with Standard Physics Effects

One of the predictions of quantum gravity phenomenology is that, in situations where Planck-scale physics and the notion of a quantum spacetime are relevant, field propagation will be described by a modified set of laws. Descriptions of the underlying mechanism differ from model to model, but a general feature is that electromagnetic waves will have non-trivial dispersion relations. A physical phenomenon that offers the possibility of experimentally testing these ideas in the foreseeable future is the propagation of high-energy gamma rays from GRB's at cosmological distances. With the observation of non-standard dispersion relations within experimental reach, it is thus important to find out whether there are competing effects that could either mask or be mistaken for this one. In this letter, we consider possible effects from standard physics, due to electromagnetic interactions, classical as well as quantum, and coupling to classical geometry. Our results indicate that, for currently observed gamma-ray energies and estimates of cosmological parameter values, those effects are much smaller than the quantum gravity one if the latter is first-order in the energy; some corrections are comparable in magnitude with the second-order quantum gravity ones, but they have a very different energy dependence.Comment: 8 pages; Version to be published in CQG as a letter; Includes some new comments and references, but no changes in the result

May Measurement Month 2017: an analysis of blood pressure screening results in Armenia-Europe

Elevated blood pressure (BP) is a growing burden worldwide, leading to over 10 million deaths each year. May Measurement Month (MMM) is a global initiative aimed at raising awareness of high BP and to act as a temporary solution to the lack of screening programmes worldwide. An opportunistic cross-sectional survey of volunteers aged ≥18 was carried out in May 2017. Blood pressure measurement, the definition of hypertension and statistical analysis followed the standard MMM protocol. The study was conducted in public areas (14 sites in Yerevan and 18 in regions), both indoor and outdoor, as well as in 42 primary care centres. A total of 9199 individuals were screened during MMM17 of which 9186 had three BP measurements available. The mean age of screened individuals was 50 ± 16.7 years, 57.3% was female. At the time of screening 17.9% were on antihypertensive medication. After imputation, a percentage of participants with hypertension was 33.9%, and 52.9% of them were on treatment. Of those treated, 77.0% had uncontrolled BP. MMM17 was the largest BP screening campaign undertaken in Armenia. We found that in Armenia, untreated hypertension is common, as is not adequately treated hypertension

An analysis of blood pressure screening of 21 112 participants in Armenia: May Measurement Month 2018.

Elevated blood pressure (BP) is a growing burden worldwide and is the leading cause of mortality and disability-adjusted life years all over the world. May Measurement Month (MMM) is a global initiative aimed to raise awareness of high BP and to act as a temporary solution to the lack of screening programmes worldwide. An opportunistic cross-sectional survey of volunteers aged ≥18 was carried out in May to July 2018. Blood pressure measurement, the definition of hypertension (HTN) and statistical analysis followed the standard MMM protocol. The study was conducted in public areas (17 sites in Yerevan and 22 in regions), both indoor and outdoor, as well as in 78 primary care centres. A total of 21 112 individuals were screened during MMM18, of which 20 732 had three BP measurements available. The mean age of screened individuals was 46.2 ± 17.3 years, 57.8% were female. At the time of screening, 26.1% were on antihypertensive medication. After imputation, the percentage of participants with HTN was 38.7%, and 76.7% of them were aware of their high BP. Of participants receiving treatment, 47.1% had a controlled BP. MMM18 was the largest BP screening campaign undertaken in Armenia. We found that the proportion of HTN is substantial in Armenia, which may be a vital contributor to the growing burden of non-communicable diseases. Our results also suggest that untreated HTN is common and when treated still not adequately controlled in Armenia. The current situation, with an insufficient control rate of HTN, must be changed as soon as possible

Beam-helicity asymmetries for single-hadron production in semi-inclusive deep-inelastic scattering from unpolarized hydrogen and deuterium targets

A measurement of beam-helicity asymmetries for single-hadron production in deep-inelastic scattering is presented. Data from the scattering of 27.6 GeV electrons and positrons off gaseous hydrogen and deuterium targets were collected by the HERMES experiment. The asymmetries are presented separately as a function of the Bjorken scaling variable, the hadron transverse momentum, and the fractional energy for charged pions and kaons as well as for protons and anti-protons. These asymmetries are also presented as a function of the three aforementioned kinematic variables simultaneously

Transverse-target-spin asymmetry in exclusive ω\omega-meson electroproduction

Hard exclusive electroproduction of $\omega$ mesons is studied with the HERMES spectrometer at the DESY laboratory by scattering 27.6 GeV positron and electron beams off a transversely polarized hydrogen target. The amplitudes of five azimuthal modulations of the single-spin asymmetry of the cross section with respect to the transverse proton polarization are measured. They are determined in the entire kinematic region as well as for two bins in photon virtuality and momentum transfer to the nucleon. Also, a separation of asymmetry amplitudes into longitudinal and transverse components is done. These results are compared to a phenomenological model that includes the pion pole contribution. Within this model, the data favor a positive $\pi\omega$ transition form factor.Comment: DESY Report 15-14

Gamma spectrometry in the ITWG CMX-4 exercise

Low enriched uranium samples of unknown origin were analyzed by 16 laboratories in the context of a Collaborative Materials Exercise (CMX), organized by the Nuclear Forensics International Technical Working Group (ITWG). The purpose was to compare and prioritize nuclear forensic methods and techniques, and to evaluate attribution capabilities among participants. This paper gives a snapshot of the gamma spectrometric capabilities of the participating laboratories and summarizes the results achieved by gamma spectrometry

Longitudinal double-spin asymmetries in semi-inclusive deep-inelastic scattering of electrons and positrons by protons and deuterons

A comprehensive collection of results on longitudinal double-spin asymmetries is presented for charged pions and kaons produced in semi-inclusive deep-inelastic scattering of electrons and positrons on the proton and deuteron, based on the full HERMES data set. The dependence of the asymmetries on hadron transverse momentum and azimuthal angle extends the sensitivity to the flavor structure of the nucleon beyond the distribution functions accessible in the collinear framework. No strong dependence on those variables is observed. In addition, the hadron charge-difference asymmetry is presented, which under certain model assumptions provides access to the helicity distributions of valence quarks