Multiple and spectrally robust photonic magic angles in reconfigurable α-MoO3 trilayers.

The emergence of a topological transition of the polaritonic dispersion in twisted bilayers of anisotropic van der Waals materials at a given twist angle-the photonic magic angle-results in the diffractionless propagation of polaritons with deep-subwavelength resolution. This type of propagation, generally referred to as canalization, holds promise for the control of light at the nanoscale. However, the existence of a single photonic magic angle hinders such control since the canalization direction in twisted bilayers is unique and fixed for each incident frequency. Here we overcome this limitation by demonstrating multiple spectrally robust photonic magic angles in reconfigurable twisted α-phase molybdenum trioxide (α-MoO3) trilayers. We show that canalization of polaritons can be programmed at will along any desired in-plane direction in a single device with broad spectral ranges. These findings open the door for nanophotonics applications where on-demand control is crucial, such as thermal management, nanoimaging or entanglement of quantum emitters.

[New morphometric criteria in the study of pathogenesis of normal-tension glaucoma]. / Novye morfometricheskie kriterii v izuchenii patogeneza glaukomy normal'nogo davleniya.

INTRODUCTION: Studying the factors that contribute to the disturbance of transmembrane pressure gradient is a topical task in the research of pathogenesis of normal-tension glaucoma (NTG). PURPOSE: To measure and compare the thickness and depth of lamina cribrosa (LCT and LCD), as well as optic nerve subarachnoid space width (ONSASW) in patients with NTG and healthy individuals. MATERIAL AND METHODS: The first group included 12 patients (23 eyes) aged from 58 to 74 years (average age 66.8±3.2 years) with NTG who all had normal intraocular pressure and arterial hypotension. The second (control) group consisted of 11 healthy individuals (22 eyes) aged from 51 to 69 years (average age 56.2±4.2 years). All patients underwent structural and functional assessment of the optic nerve head using OCT RTVue-100 (Optovue, USA), as well as Humphrey Visual Field Analyzer (HFA II 745i, Germany-USA) and our modification of Frequency Doubling Technology perimetry. In all subjects the central corneal thickness (CCT) was measured by Pentacam HR (Oculus, Germany), the LCT and LCD were measured by EDI (Enhanced Depth Imaging) mode of Topcon 3D OCT 2000 (Japan). To measure the ONSASW we used a cross-sectional image of the optic nerve taken 3 mm behind the eyeball with Magnetic Resonance Imaging (Siemens Magnetom Symphony 1.5 T, Germany). RESULTS: Statistically significant difference was found between the 1st and 2nd groups in the average LCT (217.60±36.92 and 345.86±33.29 µm respectively; p=0.0000), LCD (435.00±86.31 and 367.31±87.00 µm, respectively; p=0.014) and ONSASW (1.27±0.13 and 1.44±0.19 mm respectively; p=0.004); the difference wasn't significant in the average CCT (543.26±31.52 and 557.50±24.92 µm respectively; p=0.11). CONCLUSION: Patients with NTG had significantly higher value of the LCD with significantly lower values of the LCT and ONSASW compared with healthy individuals, which confirms the importance of these morphometric criteria in the study of NTG pathogenesis.

Dark Matter Search in Missing Energy Events with NA64.

A search for sub-GeV dark matter production mediated by a new vector boson A^{'}, called a dark photon, is performed by the NA64 experiment in missing energy events from 100 GeV electron interactions in an active beam dump at the CERN SPS. From the analysis of the data collected in the years 2016, 2017, and 2018 with 2.84×10^{11} electrons on target no evidence of such a process has been found. The most stringent constraints on the A^{'} mixing strength with photons and the parameter space for the scalar and fermionic dark matter in the mass range ≲0.2 GeV are derived, thus demonstrating the power of the active beam dump approach for the dark matter search.

Comparison of the Size and Properties of the Cytochrome c/Cardiolipin Nanospheres in a Sediment and Non-polar Medium.

Apoptosis, as the major type of programmed cell death, plays an important role in the organism renewal and removal of defective and transformed cells, including cancer cells. One of the earliest apoptotic events is lipid peroxidation in the inner mitochondrial membrane catalyzed by a complex of cytochrome c (CytC) with the mitochondrial phospholipid cardiolipin (CL). It was shown that mixing CytC and CL solutions results in the formation of CytC/CL complexes (Cyt-CL nanospheres) with a diameter of 11-12 nm composed of the molten globule protein molecule and a CL monolayer. Using the methods of dynamic light scattering for the Cyt-CL chloroform solution and small-angle X-ray scattering for the Cyt-CL sediment, it was found that in both cases, Cyt-CL formed nanospheres with a diameter of 8 and 11 nm, which corresponded to the earlier determined lipid/protein ratios of 13-14 and 35-50, respectively. These results showed that the Cyt-CL nanospheres can form not only during crystallization but also in a hydrophobic medium. CytC in the complex exists as a molten globule, as evidenced by the emergence of tryptophan and tyrosine fluorescence (absent in the native protein) due to the Förster resonance transfer of the electron excitation energy onto the heme. At the same time, the coordinate bond between the heme iron and the sulfur atom of methionine 80 in Cyt-CL is disrupted (the absorption band at ~700 nm disappears). Similar disruption of the iron-sulfur bond in Cyt-CL was observed in 50% methanol. These changes were reversible, which corroborates the conclusion on the CytC transition to the molten globule conformation in methanol-containing solutions.

Search for a Hypothetical 16.7 MeV Gauge Boson and Dark Photons in the NA64 Experiment at CERN.

We report the first results on a direct search for a new 16.7 MeV boson (X) which could explain the anomalous excess of e^{+}e^{-} pairs observed in the excited ^{8}Be^{*} nucleus decays. Because of its coupling to electrons, the X could be produced in the bremsstrahlung reaction e^{-}Z→e^{-}ZX by a 100 GeV e^{-} beam incident on an active target in the NA64 experiment at the CERN Super Proton Synchrotron and observed through the subsequent decay into a e^{+}e^{-} pair. With 5.4×10^{10} electrons on target, no evidence for such decays was found, allowing us to set first limits on the X-e^{-} coupling in the range 1.3×10^{-4}≲ε_{e}≲4.2×10^{-4} excluding part of the allowed parameter space. We also set new bounds on the mixing strength of photons with dark photons (A^{'}) from nonobservation of the decay A^{'}→e^{+}e^{-} of the bremsstrahlung A^{'} with a mass ≲23 MeV.

Structural Study of the Complex Formed by Ceruloplasmin and Macrophage Migration Inhibitory Factor.

Macrophage migration inhibitory factor (MIF) is a key proinflammatory cytokine. Inhibitors of tautomerase activity of MIF are perspective antiinflammatory compounds. Ceruloplasmin, the copper-containing ferroxidase of blood plasma, is a noncompetitive inhibitor of tautomerase activity of MIF in the reaction with p-hydroxyphenylpyruvate. Small-angle X-ray scattering established a model of the complex formed by MIF and ceruloplasmin. Crystallographic analysis of MIF with a modified active site supports the model. The stoichiometry of 3 CP/MIF trimer complex was established using gel filtration. Conformity of novel data concerning the interaction regions in the studied proteins with previous biochemical data is discussed.

Diagnostic utility of long-term remote ECG monitoring in compare with 24 hour Holter monitoring in patients with atrial fibrillation after catheter radiofrequency ablation in the early postoperative period.

AIM: To evaluate the diagnostic utility of long-term remote monitoring of ECG compared with 24 hour Holter monitoring for the detection of cardiac arrhythmias and conduction disturbance in patients with atrial fibrillation (AF) after catheter radiofrequency ablation (RFA; isolation) of the pulmonary veins. MATERIALS AND METHODS: The study included 62 patients aged 58.5±11.1 years, with paroxysmal or persistent AF, after catheter RFA (pulmonary veins isolation). Patients underwent long-term remote ECG monitoring, 24 hour Holter monitoring and transthoracic echocardiogram. RESULTS: After 24 hour Holter monitoring of 62 patients with AF after RFA in 21 of them (33.9%) was detected early recurrence of AF. Remote ECG monitoring of 18 patients, detected AF in 7 patients (39%), 2 of them were asymptomatic AF recurrence. 24 hour Holter monitoring of the same 18 patients AF recurrence was not detected at all (0%). CONCLUSION: Both of devices, long-term remote monitoring of ECG and 24 hour Holter monitoring detected 45.2% of recurrence of AF. Over the wearing of both devises 24 hour Holter and long-term remote monitor the last detected more events among 18 patients (33% vs 0%). Two evens of AF recurrence were asymptomatic.

[The recovering of breeding achievements of Populus × leningradensis bogd. and Populus × newensis bogd. Based on microsatellite analysis].

The genotyping of 75 trees from poplar plantations in St. Petersburg and Leningrad oblast was conducted with microsatellite markers to identify the elite clonal varieties developed by P.L. Bogdanov in the period of 1938­1965. The information about the varieties was lost. The authentic herbarium specimens of poplar clonal varieties preserved at the St. Petersburg State Forest Technical University were used as reference genotypes. According to the results of DNA fingerprinting, we identified the clonal plantations of Populus × newesis Bogd. and Populus × leningradensis Bogd. from the Kartashevskii forest district and the arboretum of the St. Petersburg State Forest Technical University. The identified elite poplar hybrids have a higher frost resistant and a higher growth rate. They are recommended for plantation cultivation in the northwest of Russia.

[Electrocardiographic aspects of morphogenesis of neuroleptic cardiopathy].

Neuroleptic cardiomyopathy (NCMP) is a consequence of cardiotoxic side effect of antipsychotic drugs. Changes of ECG associated with this condition are poorly known. Aim: To elucidate dynamics of ECG at different clinical stages of NCMP and evaluate its diagnostic value. Methods. We determined the frequency and informative values of 8 different ECG signs includingQTinterval corrected based at theBazettformula (QTc). Their informative value was estimated from the Kullback formula. The data obtained were analyzed by parametric and non-parametric statistics methods. Results: Pathological changes of ECG parameters associated with NCM Preflect processes of structural rearrangement in the heart at different levels of its organization. The analysis of the available information showed that almost all ECG parameters have high diagnostic value listed in the following rank order (frequency/informativeness): rhythm disorder - 1/8, prolongation of the QTc interval - 4/3, conduction disorder - 2/2, diffuse muscular changes - 3/1, right heart overload - 5/6, left ventricular hypertrophy - 7-8/5, impaired electrical activity of myocardium - 7-8/5, deviation of the electrical axis to the left - 6/4. It seems appropriate to distinguish the following three maximally informative (and therefore most important) ECG signs indicative of developing NCMP: diffuse muscular changes, conduction disorder, and prolongation of the QTc interval. Conclusion: The analysis of the available information provides a new insight into dynamics of ECG signs associated with NCMP and permits to estimate the diagnostic value of pathological changes for its earlier detection.

[About the Spatial Organization of Double-stranded DNA Molecules in the Cholesteric Liquid-crystalline Phase and Dispersion Particles of this Phase].

The answer to a question on the organization of molecules in a cholesteric phase is well enough proved in case of low molecular mass compounds. However, in case of double-stranded nucleic acids molecules the unequivocal answer to such question is a subject of discussions. In this work an attempt to generalize the well known literary data on the structure of the cholesteric phase formed by double-stranded DNA molecules was undertaken. Besides the experimental results of authors describing the packing of these molecules in the cholesteric liquid-crystalline dispersion particles are added to these data. Comparison of the results obtained offers the possibility to come out with an assumption of high probability of the existence of both the short-range positional and long-range orientational order in arrangement of double-stranded DNA molecules in a liquid-crystalline phase, and in the particles of dispersions of this phase generated under certain conditions. The occurrence of the orientational order, i.e. rotation of 'quasinematic' layers of double-stranded DNA molecules by a small angle, defines the formation of spatially twisted (cholesteric) structure with characteristic for it physical and chemical properties.

Structural analysis of neutral tetracycline using anharmonicity of delocalized vibrations.

While tetracyclines are in active medical use, their bioactive atomic compositions are still questionable. Here, we investigate the structural properties of neutral tetracycline in dimethyl sulfoxide - the environment used often to mimic the environment in vivo. We compare the measured linear and nonlinear infrared spectra to those calculated for a collection of stable and energetically plausible tautomers, and describe the structurally sensitive off-diagonal peaks using anharmonicities of the normal modes. The comparison of experimental and theoretical 2DIR spectra is consistent with the numerical predictions of statistical thermodynamics on the relative weights of possible tautomers. In result, we provide the systematic account of the structural realizations of neutral tetracycline in DMSO.

[Tanning lamp radiation-induced photochemical retinal damage].

On the basis of original clinical research a rare case of bilateral retinal damage due to tanning lamp radiation exposure is presented. Along with significant decrease of visual acuity and light sensitivity of central visual field as well as color vision impairment, bilateral macular dystrophy was found during an ophthalmoscopy and confirmed by optical coherent tomography and fluorescent angiography. Intensive retinoprotective, vascular, and antioxidant therapy was effective and led to functional improvement and stabilization of the pathologic process associated with photochemical retinal damage. A brief review of literature compares mechanisms of retinal damage by either short or long-wave near visible radiation.

SERS analysis of single cells and subcellular components: A review.

SERS is a rapidly advancing and non-destructive technique that has been proven to be more reliable and convenient than other traditional analytical methods. Due to its sensitivity and specificity, this technique is earning its place as a routine and powerful tool in biological and medical studies, especially for the analysis of living cells and subcellular components. This paper reviewed the research progress of single-cell SERS that has been made in the last few years and discussed challenges and future perspectives of this technique. The reviewed SERS platforms have been categorized according to their nature into the following types: (1) colloid-based, substrate-based, or hybrid; (2) ligand-based or ligand-free, and (3) label-based or label-free. The advantages and disadvantages of each type and their potential applications in various fields are thoroughly discussed.

Targosomes: Anti-HER2 PLGA nanocarriers for bioimaging, chemotherapy and local photothermal treatment of tumors and remote metastases.

Developing combined cancer therapy strategies is of utmost importance as it can enhance treatment efficacy, overcome drug resistance, and ultimately improve patient outcomes by targeting multiple pathways and mechanisms involved in cancer growth and progression. Specifically, the potential of developing a combination chemo&photothermal therapy using targeted polymer nanoparticles as nanocarriers offers a promising approach for synergistic cancer treatment by combining the benefits of both therapies, such as targeted drug delivery and localized hyperthermia. Here, we report the first targeted anti-HER2 PLGA nanocarriers, called targosomes, that simultaneously possess photothermal, chemotherapeutic and diagnostic properties using only molecular payloads. Biocompatible poly(lactic-co-glycolic acid), PLGA, nanoparticles were loaded with photosensitizer phthalocyanine, diagnostic dye Nile Blue, and chemotherapeutic drug irinotecan, which was chosen as a result of screening a panel of theragnostic nanoparticles. The targeted delivery to cell surface oncomarker HER2 was ensured by nanoparticle modification with the anti-HER2 monoclonal antibody, trastuzumab, using the one-pot synthesis method without chemical conjugation. The irradiation tests revealed prominent photothermal properties of nanoparticles, namely heating by 35 °C in 10 min. Nanoparticles exhibited a 7-fold increase in binding and nearly an 18-fold increase in cytotoxicity for HER2-overexpressing cells compared to cells lacking HER2 expression. This enhancement of cytotoxicity was further amplified by >20-fold under NIR light irradiation. In vivo studies proved the efficacy of nanoparticles for bioimaging of primary tumor and metastasis sites and demonstrated 93% tumor growth inhibition, making these nanoparticles excellent candidates for translation into theragnostic applications.

[Dilated cardiomyopathy in patients with schizophrenia].

AIM: To study the frequency of pathoanatomic and some clinical signs of dilated cardiomyopathy (DCM) in schizophrenic patients (SPs). SUBJECTS AND METHODS: Autopsy records were studied in 838 SPs treated at a psychiatric hospital in 1952 to 2007. The records were used to select DCM cases (n = 74) and sudden deaths (n = 101) and to examine 339 electrocardiograms (ECG). The 2006-2007 information obtained in the dissecting rooms of three Tver hospitals (1413 sections) was analyzed. RESULTS: DCM was absent (neuroleptics were not used) before 1956. With the application of neuroleptics, the diagnosis of DCM cases significantly increased and its rate was 14.2% among the dead SPs. DCM might be a cause of sudden death in 21.8% of SPs. The rate of pathological ECG signs noticeably increased with the longer use of neuroleptics. In the hospital-wide network, the detection rate for DCM was 0.5% of the autopsies. CONCLUSION: The use of neuroleptics, in SPs in particular, may lead to the development of DCM.

[Regarding the so called posterior approach for posterior eye wall foreign body removal].

Disadvantages of the posterior approach for the optic nerve head foreign body removal, especially with associated intraocular hemorrhage, have been analyzed. In such circumstances the transvitreal approach is of an evident benefit since it also allows removing the intraocular hemorrhage which is a potential source of severe vitreoretinal proliferation.

The Rurikids: The First Experience of Reconstructing the Genetic Portrait of the Ruling Family of Medieval Rus' Based on Paleogenomic Data.

The Rurikids were the reigning house of Rus', its principalities and, ultimately the Tsardom of Russia, for seven centuries: from the IX to the end of the XVI century. According to the Primary Chronicle (the Tale of Bygone Years), the main chronicle of Rus', the Rurik dynasty was founded by the Varangian prince Rurik, invited to reign in Novgorod in 862, but still there is no direct genetic evidence of the origin of the early Rurikids. This research, for the first time, provides a genome-wide paleogenetic analysis of bone remains belonging to one of the Rurikids, Prince Dmitry Alexandrovich (?-1294), the son of the Grand Prince of Vladimir Alexander Yaroslavich Nevsky (1221-1263). It has been established that his Y chromosome belongs to the N1a haplogroup. Most of the modern Rurikids, according to their genealogies, belonging to the N1a haplogroup, have the most similar variants of Y chromosomes to each other, as well as to the Y chromosome of Prince Dmitry Alexandrovich. Genome-wide data of the medieval and modern Rurikids unequivocally indicates that they belong to the N1a haplogroup of the Y chromosome, starting at least from the XI century (since the time of Prince Yaroslav the Wise). All the other alleged Rurikids, both ancient and modern, being carriers of other haplogroups (R1a, I2a), possess high heterogeneity of the sequence of Y chromosomes, meaning that we cannot confirm their common ancestry. The most probable ancestors of Prince Dmitry Alexandrovich in the male line were the men who left the burial ground Bolshoy Oleny Island on the coast of the Kola Peninsula about 3,600 years ago. The reconstruction of the genome of Prince Dmitry Alexandrovich indicates the contribution of three ancestral components to his origin: (1) the early medieval population of the east of Scandinavia from the island of Oland, (2) representatives of the steppe nomadic peoples of the Eurasian steppes of the Iron Age or the early medieval population of central Europe (steppe nomads from the territory of Hungary), and (3) the ancient East-Eurasian component. Reliable statistics were also obtained when the Scandinavians were replaced with the Medieval Russian Slavic populations of the XI century. Thus, for the first time, we have shown the complex nature of interethnic interactions in the formation of the nobility of medieval Rus' on the example of the ancient Rurikid.

Twist-tunable polaritonic nanoresonators in a van der Waals crystal.

Optical nanoresonators are key building blocks in various nanotechnological applications (e.g., spectroscopy) due to their ability to effectively confine light at the nanoscale. Recently, nanoresonators based on phonon polaritons (PhPs)-light coupled to lattice vibrations-in polar crystals (e.g., SiC, or h-BN) have attracted much attention due to their strong field confinement, high quality factors, and their potential to enhance the photonic density of states at mid-infrared (mid-IR) frequencies, where numerous molecular vibrations reside. Here, we introduce a new class of mid-IR nanoresonators that not only exhibit the extraordinary properties previously reported, but also incorporate a new degree of freedom: twist tuning, i.e., the possibility of controlling their spectral response by simply rotating the constituent material. To achieve this result, we place a pristine slab of the van der Waals (vdW) α-MoO3 crystal, which supports in-plane hyperbolic PhPs, on an array of metallic ribbons. This sample design based on electromagnetic engineering, not only allows the definition of α-MoO3 nanoresonators with low losses (quality factors, Q, up to 200), but also enables a broad spectral tuning of the polaritonic resonances (up to 32 cm-1, i.e., up to ~6 times their full width at half maximum, FWHM ~5 cm-1) by a simple in-plane rotation of the same slab (from 0 to 45°). These results open the door to the development of tunable and low-loss IR nanotechnologies, fundamental requirements for their implementation in molecular sensing, emission or photodetection applications.

Hexagonal boron nitride nanophotonics: a record-breaking material for the ultraviolet and visible spectral ranges.

A global trend towards miniaturization and multiwavelength performance of nanophotonic devices drives research on novel phenomena, such as bound states in the continuum and Mietronics, as well as surveys for high-refractive index and strongly anisotropic materials and metasurfaces. Hexagonal boron nitride (hBN) is one of the promising materials for future nanophotonics owing to its inherent anisotropy and prospects of high-quality monocrystal growth with an atomically flat surface. Here, we present highly accurate optical constants of hBN in the broad wavelength range of 250-1700 nm combining imaging ellipsometry measurements, scanning near-field optical microscopy and first-principles quantum mechanical computations. hBN's high refractive index, up to 2.75 in the ultraviolet (UV) and visible range, broadband birefringence of ∼0.7, and negligible optical losses make it an outstanding material for UV and visible range photonics. Based on our measurement results, we propose and design novel optical elements: handedness-preserving mirrors and subwavelength waveguides with dimensions of 40 nm operating in the visible and UV ranges, respectively. Remarkably, our results offer a unique opportunity to bridge the size gap between photonics and electronics.

ATP-dependent DNA ligase from Thermococcus sp. 1519 displays a new arrangement of the OB-fold domain.

DNA ligases join single-strand breaks in double-stranded DNA by catalyzing the formation of a phosphodiester bond between adjacent 5'-phosphate and 3'-hydroxyl termini. Their function is essential for maintaining genome integrity in the replication, recombination and repair of DNA. High flexibility is important for the function of DNA ligase molecules. Two types of overall conformations of archaeal DNA ligase that depend on the relative position of the OB-fold domain have previously been revealed: closed and open extended conformations. The structure of ATP-dependent DNA ligase from Thermococcus sp. 1519 (LigTh1519) in the crystalline state determined at a resolution of 3.02 Šshows a new relative arrangement of the OB-fold domain which is intermediate between the positions of this domain in the closed and the open extended conformations of previously determined archaeal DNA ligases. However, small-angle X-ray scattering (SAXS) measurements indicate that in solution the LigTh1519 molecule adopts either an open extended conformation or both an intermediate and an open extended conformation with the open extended conformation being dominant.