Exciton spectroscopy of hexagonal boron nitride using non-resonant x-ray Raman scattering

We report non-resonant x-ray Raman scattering (XRS) measurements from hexagonal boron nitride for transferred momentum from 2 to 9 $\mathrm{\AA}^{-1}$ along directions both in and out of the basal plane. A symmetry-based argument, together with real-space full multiple scattering calculations of the projected density of states in the spherical harmonics basis, reveals that a strong pre-edge feature is a dominantly $Y_{10}$-type Frenkel exciton with no other \textit{s}-, \textit{p}-, or \textit{d}- components. This conclusion is supported by a second, independent calculation of the \textbf{q}-dependent XRS cross-section based on the Bethe-Salpeter equation

Nefrologiset konsultaatiot Oulun yliopistollisessa sairaalassa 2006–2017

Tiivistelmä. Suomessa munuaissairauksien perusdiagnostiikkaa tehdään suurelta osin perusterveydenhuollossa, ja tarvittaessa voidaan konsultoida nefrologista yksikköä. Munuaistautipotilaiden hoidon porrastuksesta on olemassa alueellisia hoitoketjuja, jotka ohjaavat konsultaatioita. Nefrologisesta konsultaatiokäytännöstä Suomessa on vain vähän tutkimuksia. Aikaisemmin sitä on tutkittu mm. Kuopion Yliopistollisessa sairaalassa vuosien 1989–1995 konsultaatioiden osalta. Kansainvälisesti moni tutkimus on keskittynyt tutkimaan varhaisen ja myöhäisen konsultaation vaikutusta potilaan ennusteeseen. Varhaisen konsultaation on osoitettu vähentävän kuolleisuutta. Tämän tutkimuksen tarkoituksena on analysoida kaikki sähköiset nefrologiset konsultaatiot ja lähetteet vuoden 2006 alusta vuoden 2017 loppuun. Lisäksi tarkastellaan, onko munuaispotilaiden luonne ja konsultaatioiden rakenne muuttunut kyseisinä vuosina. Tutkimusaineisto kattaa kaikki sähköiset konsultaatiot ja lähetteet vuosina 2006–2017. Tutkimusaineisto kerättiin Esko-potilastietojärjestelmästä erilliseen Excel-taulukkoon ja tiedot analysoitiin SPSS-ohjelmalla. Vuosina 2006–2017 Oulun yliopistollisen sairaalan nefrologian poliklinikalle tuli yhteensä 3257 konsultaatiota tai lähetettä. Eniten konsultaatioita ja lähetteitä tuli vuonna 2017, jolloin niitä tuli 615. Potilaiden keski-ikä oli 63.3 vuotta. Potilaista miesten osuus oli 56.8%. Konsultaatioiden suhteellinen osuus kasvoi tarkastelujakson jälkimmäisellä puoliskolla, jolloin konsultaatioiden osuus oli 51.8%. Lähetteistä 28% muutettiin konsultaatiovastaukseksi. Yleisin konsultoiva taho oli terveyskeskus. Laboratoriokokeissa yleisin proteinurian mittari oli virtsan albumiini/kreatiniinisuhde, joka oli määritetty 1364 potilaalta. Keskiarvo vuosina 2006–2011 oli 101,5 mg/mmol, ja vuosina 2012–2017 108,2 mg/mmol. Oulun yliopistollisessa sairaalassa on ollut sähköinen konsultaatio käytössä vuodesta 2006 alkaen. Aikaisemmissa tutkimuksissa on tutkittu sähköistä konsultaatiota hoidon tehostamisessa. Sen avulla on voitu hoitaa potilaita ilman nefrologin tapaamista, ja siten vähentää turhia sairaalalähetteitä. Tässä tutkimuksessa nefrologisten konsultaatioiden (vs. lähetteet) suhteellinen osuus kasvoi. Lisäksi merkittävä osuus lähetteistä voitiin muuttaa konsultaatiovastauksiksi. Lähetteisiin ja konsultaatioihin pystyttiin myös vastaamaan nopeasti, ja vain pienessä osassa viive oli yli yhden viikon verran. Nämä kertovat omalta osaltaan toimivasta konsultaatiokäytännöstä. Yleisin ensikonsultaation syy oli kohonnut kreatiniiniarvo ja/ tai poikkeava virtsalöydös. Lähes yhtä yleinen konsultaation syy oli hematuria ja / tai proteinuria ilman kohonnutta kreatiniinia. Sähköistä konsultaatiokäytäntöä voidaan tutkimuksen perusteella pitää toimivana käytäntönä, joka edistää perusterveydenhuollon ja erikoissairaanhoidon välistä yhteistyötä

Anisotropic excitonic effects in the energy loss function of hexagonal boron nitride

We demonstrate that the valence energy-loss function of hexagonal boron nitride (hBN) displays a strong anisotropy in shape, excitation energy and dispersion for momentum transfer q parallel or perpendicular to the hBN layers. This is manifested by e.g. an energy shift of 0.7 eV that cannot be captured by single-particle approaches and is a demonstration of a strong anisotropy in the two-body electron-hole interaction. Furthermore, for in-plane directions of q we observe a splitting of the -plasmon in the M direction that is absent in the K direction and this can be traced back to band-structure effects.Comment: 10 pages, 4 figure

Systems analysis of drug-induced receptor tyrosine kinase reprogramming following targeted mono- and combination anti-cancer therapy

The receptor tyrosine kinases (RTKs) are key drivers of cancer progression and targets for drug therapy. A major challenge in anti-RTK treatment is the dependence of drug effectiveness on co-expression of multiple RTKs which defines resistance to single drug therapy. Reprogramming of the RTK network leading to alteration in RTK co-expression in response to drug intervention is a dynamic mechanism of acquired resistance to single drug therapy in many cancers. One route to overcome this resistance is combination therapy. We describe the results of a joint in silico, in vitro, and in vivo investigations on the efficacy of trastuzumab, pertuzumab and their combination to target the HER2 receptors. Computational modelling revealed that these two drugs alone and in combination differentially suppressed RTK network activation depending on RTK co-expression. Analyses of mRNA expression in SKOV3 ovarian tumour xenograft showed up-regulation of HER3 following treatment. Considering this in a computational model revealed that HER3 up-regulation reprograms RTK kinetics from HER2 homodimerisation to HER3/HER2 heterodimerisation. The results showed synergy of the trastuzumab and pertuzumab combination treatment of the HER2 overexpressing tumour can be due to an independence of the combination effect on HER3/HER2 composition when it changes due to drug-induced RTK reprogramming

Inelastic Scattering from Core-electrons: a Multiple Scattering Approach

The real-space multiple-scattering (RSMS) approach is applied to model non-resonant inelastic scattering from deep core electron levels over a broad energy spectrum. This approach is applicable to aperiodic or periodic systems alike and incorporates ab initio, self-consistent electronic structure and final state effects. The approach generalizes to finite momentum transfer a method used extensively to model x-ray absorption spectra (XAS), and includes both near edge spectra and extended fine structure. The calculations can be used to analyze experimental results of inelastic scattering from core-electrons using either x-ray photons (NRIXS) or electrons (EELS). In the low momentum transfer region (the dipole limit), these inelastic loss spectra are proportional to those from XAS. Thus their analysis can provide similar information about the electronic and structural properties of a system. Results for finite momentum transfer yield additional information concerning monopole, quadrupole, and higher couplings. Our results are compared both with experiment and with other theoretical calculations.Comment: 11 pages, 8 figures. Submitted to Phys. Rev.

Antibody responses to nasopharyngeal carriage of Streptococcus pneumoniae in adults: A longitudinal household study

Background. Natural immunity to Streptococcus pneumoniae is thought to be induced by exposure to S. pneumoniae or cross-reactive antigens. No longitudinal studies of carriage of and immune responses to S. pneumoniae have been conducted using sophisticated immunological laboratory techniques.Methods. We enrolled 121 families with young children into this study. Nasopharyngeal (NP) swabs were collected monthly for 10 months from all family members and were cultured in a standard fashion. Cultured S. pneumoniae isolates were serotyped. At the beginning (month 0) and end (month 10) of the study, venous blood was collected from family members 118 years old. Serotype-specific antipolysaccharide immunoglobulin G (IgG) and functional antibody and antibodies to pneumolysin, pneumococcal surface protein A (PspA), and pneumococcal surface antigen A (PsaA) were measured in paired serum samples.Results. Levels of anticapsular IgG increased significantly after carriage of serotypes 9V, 14, 18C, 19F, and 23F by an individual or family member. For serotype 14, a higher level of anticapsular IgG at the beginning of the study was associated with reduced odds of carriage (P = .0006). There was a small (similar to 20%) but significant increase in titers of antibodies to PsaA and pneumolysin but no change in titers of antibody to PspA.Conclusions. Adults respond to NP carriage by mounting anticapsular and weak antiprotein antibody responses, and naturally induced anticapsular IgG can prevent carriage

Biochem Soc Trans

Abnormal protein aggregation and intracellular or extracellular accumulation of misfolded and aggregated proteins are key events in the pathogenesis of different neurodegenerative diseases. Furthermore, endoplasmic reticulum stress and impairment of the ubiquitin-proteasome system probably contribute to neurodegeneration in these diseases. A characteristic feature of AD (Alzheimer's disease) is the abnormal accumulation of Abeta (amyloid beta-peptide) in the brain. Evidence shows that the AD-associated PS (presenilin) also forms aggregates under certain conditions and that another AD-associated protein, ubiquilin-1, controls protein aggregation and deposition of aggregated proteins. Here, we review the current knowledge of ubiquilin-1 and PS in protein aggregation and related events that potentially influence neurodegeneration

GINZBURG-LANDAU THEORY OF VORTICES IN dd-WAVE SUPERCONDUCTORS

Ginzburg-Landau theory is used to study the properties of single vortices and of the Abrikosov vortex lattice in a $d_{x^2-y^2}$ superconductor. For a single vortex, the $s$-wave order parameter has the expected four-lobe structure in a ring around the core and falls off like $1/r^2$ at large distances. The topological structure of the $s$-wave order parameter consists of one counter-rotating unit vortex, centered at the core, surrounded by four symmetrically placed positive unit vortices. The Abrikosov lattice is shown to have a triangular structure close to $T_c$ and an oblique structure at lower temperatures. Comparison is made to recent neutron scattering data.Comment: 4 pages, REVTeX, 3 figures available upon reques