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The stages of development of molecular photonics at Tomsk State University are presented. It was A. N. Terenin's student, N. A. Prilezhaeva, who pioneered the Russian photochemistry and fostered the development of a Tomsk school of spectroscopists, at that time the only research team in the Asian part of Russia. In 1950, the research in the field of molecular spectroscopy and quantum chemistry of complex molecules was initiated by a Prilezhaeva's student, V. I. Danilova, who became a TSU Professor at a later date. Fundamental problems were posed and solved, which related the spectra and the electron shell structure with the physical-chemical properties of several classes of complex organic molecules. The generalizations made by Danilova were quite valuable for the theory of molecular spectra and helped forming her own scientific school in 1970-80s.

The absorption and fluorescence spectra of charged anionic and cationic forms of bisphenol A (BPA) have been studied. The nature of electronically excited states and the photolysis of the BPA molecule have been interpreted based on results of quantum chemical calculations. The BPA spectra in an aqueous solution are compared during transition from the neutral to the ionic form. Results of calculations have shown that the small value of the fluorescence quantum yield in all examined molecular structures is determined by the high efficiency of the singlet-triplet conversion. In the anionic BPA form, a decrease in the efficiency of radiation decay channel by two orders of magnitude has been recorded caused by a change in the orbital nature of the fluorescent state compared to the neutral and cationic forms. It is shown that the probability of photolysis of the molecule under study increases due to the overlap of the absorption spectra of the anionic form in an aqueous solution under exposure to sunlight.

Context. Puppis A is a medium-age supernova remnant (SNR), which is visible as a very bright extended X-ray source. While numerous studies have investigated individual features of the SNR, at this time, no comprehensive study of the entirety of its X-ray emission exists. Aims. Using field-scan data acquired by the SRG/eROSITA telescope during its calibration and performance verification phase, we aim to investigate the physical conditions of shocked plasma and the distribution of elements throughout Puppis A. Methods. Using broad- and narrow-band imaging, we investigate the large-scale distribution of absorption and plasma temperature as well as typical emission lines. This approach is complemented by spatially resolved spectral analysis of the shocked plasma in Puppis A, for which we divide the SNR into around 700 distinct regions, resulting in maps of key physical quantities over its extent. Results. We find a strong peak of foreground absorption in the southwest quadrant, which in conjunction with high temperatures at the northeast rim creates the well-known strip of hard emission crossing Puppis A. Furthermore, using the observed distribution of ionization ages, we attempt to reconstruct the age of the shock in the individual regions. We find a quite recent shock interaction for the prominent northeast filament and ejecta knot, as well as for the outer edge of the bright eastern knot. Finally, elemental abundance maps reveal only a single clear enhancement of the plasma with ejecta material, consistent with a previously identified region, and no obvious ejecta enrichment in the remainder of the SNR. Within this region, we confirm the spatial separation of silicon-rich ejecta from those dominated by lighter elements., 20+5 pages, 10+5 figures; Accepted by A&A for the Special Issue: The Early Data Release of eROSITA and Mikhail Pavlinsky ART-XC on the SRG Mission; Abstract abridged

Context. Central compact objects (CCOs) are a peculiar class of neutron stars, primarily encountered close to the center of young supernova remnants (SNRs) and characterized by thermal X-ray emission. Aims. Our goal is to perform a systematic study of the proper motion of all known CCOs with appropriate data available. In addition, we aim to measure the expansion of three SNRs within our sample to obtain a direct handle on their kinematics and age. Methods. We analyze multiple archival Chandra data sets, consisting of HRC and ACIS observations separated by temporal baselines between 8 and 15 years. In order to correct for systematic astrometric uncertainties, we establish a reference frame using X-ray detected sources in Gaia DR2, to provide accurate proper motion estimates for our target CCOs. Complementarily, we use our coaligned data sets to trace the expansion of three SNRs by directly measuring the spatial offset of various filaments and ejecta clumps between different epochs. Results. In total, we present new proper motion measurements for six CCOs, among which we do not find any indication of a hypervelocity object. We tentatively identify direct signatures of expansion for the SNRs G15.9+0.2 and Kes 79, at estimated significance of $2.5\sigma$ and $2\sigma$, respectively. Moreover, we confirm recent results by Borkowski et al., measuring the rapid expansion of G350.1$-$0.3 at almost $6000\,{\rm km\,s^{-1}}$, which places its maximal age at $600-700$ years. The observed expansion, combined with the rather small proper motion of its CCO, implies the need for a very inhomogeneous circumstellar medium to explain the highly asymmetric appearance of the SNR. Finally, for the SNR RX J1713.7$-$3946, we combine previously published expansion measurements with our measurement of the CCO's proper motion to obtain a constraining upper limit of $1700$ years on the system's age., Comment: 22+8 pages, 16+3 figures. Accepted for publication in Astronomy & Astrophysics

During the past years, the VLTI-instrument GRAVITY has made spectacular discoveries with phase-referenced interferometric imaging with milliarcsecond resolution and ten microarcsecond astrometry. Here, we report on the upgrade of the GRAVITY science spectrometer with two new grisms in October 2019, increasing the instrument throughput by a factor > 2. This improvement was made possible by using a high refractive index Germanium substrate, which reduces the grism and groove angles, and by successfully applying an anti-reflection coating to the ruled surface to overcome Fresnel losses. We present the design, manufacturing, and laboratory testing of the new grisms, as well as the results from the re-commissioning on sky.

Spectral-luminescent properties and photolysis of charged forms (cation and anion) of bisphenol A are studied experimentally and by methods of quantum chemistry. The calculations and the experiment demonstrate that no new absorption bands appear in the absorption spectra of charged forms in the region of 200–600 nm as compared to a neutral molecule. The polar solvent (water) shifts the absorption spectrum bands of the ionic forms to the region of low energies. In this case, the shift of cation absorption spectrum is insignificant, while the shift of anion absorption spectrum is significant as the intensity of absorption bands increases. The low quantum yield of f luorescence of ionic forms is explained by the predominance of singlet-triplet conversion efficiency over the efficiency of the radiation channel of f luorescent state decay. The low quantum yield of f luorescence of the anion form is due not only to the effective singlet-triplet conversion, but also to the low efficiency of the radiation decay of the f luorescent state of the anion caused by a change in its orbital nature. Calculations demonstrate that the potential curves of the excited states of bisphenol A and its ionic forms have a significant potential barrier for photolysis. An increase in the potential reaction barrier in the cation decreases the efficiency of its photolysis. The increase in the photodissociation efficiency of the bisphenol A anion is caused by a noticeable decrease in the potential barrier and an increase in the overlap between the absorption spectra of the bisphenol A anion and the solar radiation.

Background: There is little information regarding the safety of intravenous tissue plasminogen activator (IV-tPA) in patients with stroke and COVID-19. Methods: This multicenter study included consecutive stroke patients with and without COVID-19 treated with IV-tPA between February 18, 2019, to December 31, 2020, at 9 centers participating in the CASCADE initiative. Clinical outcomes included modified Rankin Scale (mRS) at hospital discharge, in-hospital mortality, the rate of hemorrhagic transformation. Using Bayesian multiple regression and after adjusting for variables with significant value in univariable analysis, we reported the posterior adjusted odds ratio (OR, with 95% Credible Intervals [CrI]) of the main outcomes. Results: A total of 545 stroke patients, including 101 patients with COVID-19 were evaluated. Patients with COVID-19 had a more severe stroke at admission. In the study cohort, 85 (15.9%) patients had a hemorrhagic transformation, and 72 (13.1%) died in the hospital. After adjustment for confounding variables, discharge mRS score >2 (OR: 0.73, 95% CrI: 0.16, 3.05), in-hospital mortality (OR: 2.06, 95% CrI: 0.76, 5.53), and hemorrhagic transformation (OR: 1.514, 95% CrI: 0.66, 3.31) were similar in COVID-19 and non COVID-19 patients. High -sensitivity C reactive protein level was a predictor of hemorrhagic transformation in all cases (OR:1.01, 95%CI: 1.0026, 1.018), including those with COVID-19 (OR:1.024, 95%CI:1.002, 1.054). Conclusion: IV-tPA treatment in patients with acute ischemic stroke and COVID-19 was not associated with an increased risk of disability, mortality, and hemorrhagic transformation compared to those without COVID-19. IVtPA should continue to be considered as the standard of care in patients with hyper acute stroke and COVID-19.

The planes occurring at convex corners during anisotropic etching of (100)-silicon in aqueous KOH were identified as (411)-planes with the help of an especially developed measuring technique. The etching rate of these planes in relation to the rate of the (100)-planes declines with increasing potassium hydroxide concentration. In contrast, the temperature dependence of this etch rate ratio is neglectable in the relevant range between 60 degree C and 100 degree C. Based on these results, special structures suited for the compensation of the undercutting in the case of very narrow contures were developed. With the help of these structures it is feasible to realize, for instance, bent V-grooves or structures with a very low ratio between lateral expansion and etching depth, e.g. a descrete pyramid-trunk with minimum dimensions on the wafer surface. This offers access to completely new applications, among others spiral channels with double-sided anisotropic etching for micromechanical heat exchangers, corrugated diaphragms stiffened in two dimensions with low thermal resistance and arbitrary wall thickness, bellow structures for decoupling mechanical stresses between micromechanical devices and their packaging. Furthermore, this technology paves the way for designing novel types of accelerometers and inclination sensors with external seismic mass.

The hydrophilic bile acid ursodeoxycholic acid (UDCA), which in vivo is converted to its taurine conjugate tauroursodeoxycholic acid (TUDC), is a mainstay in the treatment of cholestatic liver disease. TUDC prevents bile acid-induced cholestasis and induces choleresis. Its beneficial effects involve an increased hepatobiliary secretion as well as cytoprotective and antiapoptotic effects. The choleretic effect of TUDC largely depends on a rapid targeting and insertion of intracellularly stored transport ATPases into the canalicular membrane, such as the bile salt export pump (Bsep) and multidrug resistance protein-2 (Mrp2) [1]. It was recently shown that the TUDC-induced signaling involves phosphorylation of the epidermal growth factor receptor (EGFR) at tyrosine 845 and 1173, but not Tyr1045. Tyr845, a known Src kinase target, triggers an activating autophosphorylation at Tyr1173 of the EGFR [2]. Furthermore, c-Src, focal adhesion kinase (FAK), phosphatidylinositol 3-kinase (PI3K) and Ras/Raf are activated within minutes by TUDC, which triggers downstream dual activation of extracellular signal-regulated kinases (Erks) and p38 mitogen-activated protein kinase (p38MAPK) [1-4]. Recent data indicate that integrins are a long-searched sensor for TUDC in the liver, because TUDC interacts with α5s1 integrins in the liver resulting in a conformational change with activation of s1 integrin and the initiation of downstream integrin signaling. In contrast to the previously reported s1 integrin activation in response to hypoosmolarity or insulin, TUDC-induced integrin activation occurs inside the hepatocyte and requires TUDC uptake via the basolateral Na+/taurocholate cotransporting polypeptide (Ntcp) [2]. However, other mechanisms of TUDC action may contribute to its choleretic effect under pathological cholestatic conditions. Hepatocyte apoptosis can be triggered by the retention of hydrophobic bile acids in hepatocytes by activation of ligand-independent death receptor pathways in vivo and in vitro. Toxic bile acids such as taurolithocholyl-3 sulfate (TLCS) and glycochenodeoxycholate (GCDC) have previously been shown to induce apoptosis in a CD95-dependent apoptosis, involving activation of the acidic sphingomyelinase, increased ceramide formation and activation of the protein kinase Cζ (PKCζ) followed by an oxidative stress response via serine phosphorylation of p47phox and NADPH oxidase activation. Putative inhibition of phosphatase activities by reactive oxygen species (ROS) triggers an activation of the Src family kinase Yes and activation of the c-Jun-N-terminal kinase-1/-2 (JNK). The activated Yes kinase associates with the EGFR resulting in a Yes-mediated EGFR transactivation. Activated EGFR then associates in a JNK-dependent way with CD95 and catalyzes CD95 tyrosine phosphorylation, which triggers CD95 membrane trafficking, death-inducing signaling complex (DISC) formation, i.e. association of Fas-associated death domain (FADD) and caspase 8 to the death receptor, followed by caspase 8-dependent mitochondrial amplification of pro-apoptotic signaling, which finally leads to apoptotic cell death [5]. Bile salt-induced apoptosis can be antagonized by TUDC. This cytoprotective effect of TUDC results from an inhibition of JNK activation and CD95 trafficking to the cell surface and activation of caspases 8 and 9 [6]. However, the molecular basis of TUDC-sensing with regard to anti-apoptosis is not yet settled, but may involve a TUDC-mediated inhibition of bile salt-induced phosphorylation of the MAP kinase kinase 4/7 (MKK4/7) upstream of JNK activation Furthermore, similar to cAMP, TUDC induced a protein kinase A (PKA)-sensitive serine/threonine phosphorylation of the CD95 in presence of GCDC, which was identified as an internalization signal for CD95. Inhibition of hepatocyte apoptosis by cAMP involves both PKA-dependent serine/threonine phosphorylation of the CD95 and inhibition of EGFR activation, which results in an inhibition of CD95 tyrosine phosphorylation, CD95 membrane targeting, and DISC formation. mRNA analyses show that the dual specificity MAP kinase phosphatase MKP-1, a transcriptionally regulated immediate early gene-encoded enzyme, is upregulated in response to TUDC after stimulation with GCDC for up to 60 min, which was already shown for cAMP [7]. Preliminary data suggest that TUDC-induced integrin activation is involved in mediating its anti-apoptotic effect.