| 1. |
- Makarov, Sergey, et al.
(författare)
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Soft X-ray diffraction patterns measured by a LiF detector with sub-micrometre resolution and an ultimate dynamic range
- 2020
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Ingår i: Journal of Synchrotron Radiation. - 0909-0495. ; 27, s. 625-632
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Tidskriftsartikel (refereegranskat)abstract
- The unique diagnostic possibilities of X-ray diffraction, small X-ray scattering and phase-contrast imaging techniques applied with high-intensity coherent X-ray synchrotron and X-ray free-electron laser radiation can only be fully realized if a sufficient dynamic range and/or spatial resolution of the detector is available. In this work, it is demonstrated that the use of lithium fluoride (LiF) as a photoluminescence (PL) imaging detector allows measuring of an X-ray diffraction image with a dynamic range of ∼107 within the sub-micrometre spatial resolution. At the PETRA III facility, the diffraction pattern created behind a circular aperture with a diameter of 5μm irradiated by a beam with a photon energy of 500eV was recorded on a LiF crystal. In the diffraction pattern, the accumulated dose was varied from 1.7 × 105Jcm-3 in the central maximum to 2 × 10-2Jcm-3 in the 16th maximum of diffraction fringes. The period of the last fringe was measured with 0.8μm width. The PL response of the LiF crystal being used as a detector on the irradiation dose of 500eV photons was evaluated. For the particular model of laser-scanning confocal microscope Carl Zeiss LSM700, used for the readout of the PL signal, the calibration dependencies on the intensity of photopumping (excitation) radiation (λ = 488nm) and the gain have been obtained.
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| 2. |
- Kharintsev, Sergey S., et al.
(författare)
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Light-Controlled Multiphase Structuring of Perovskite Crystal Enabled by Thermoplasmonic Metasurface
- 2023
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Ingår i: ACS Nano. - : American Chemical Society (ACS). - 1936-0851 .- 1936-086X. ; 17:10, s. 9235-9244
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Tidskriftsartikel (refereegranskat)abstract
- Halide perovskites belong to an important family of semiconducting materials with electronic properties that enable a myriad of applications, especially in photovoltaics and optoelectronics. Their optical properties, including photoluminescence quantum yield, are affected and notably enhanced at crystal imperfections where the symmetry is broken and the density of states increases. These lattice distortions can be introduced through structural phase transitions, allowing charge gradients to appear near the interfaces between phase structures. In this work, we demonstrate controlled multiphase structuring in a single perovskite crystal. The concept uses cesium lead bromine (CsPbBr3) placed on a thermoplasmonic TiN/Si metasurface and enables single-, double-, and triple-phase structures to form on demand above room temperature. This approach promises application horizons of dynamically controlled heterostructures with distinctive electronic and enhanced optical properties.
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| 3. |
- Rodin, Sergey, et al.
(författare)
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Aberrant interactions between amyloid-beta and alpha5 laminins as possible driver of neuronal disfunction in Alzheimer's disease
- 2020
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Ingår i: Biochimie. - : Elsevier. - 0300-9084 .- 1638-6183. ; 174, s. 44-48
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Forskningsöversikt (refereegranskat)abstract
- It has been widely accepted that laminins are involved in pathogenesis of Alzheimer's disease (AD). Amyloid plaques in AD patients are associated with immunostaining using antibodies raised against laminin-111, and laminin-111 has been shown to prevent aggregation of amyloid peptides. Although numerous articles describe small peptides from laminin-111 that are capable to disaggregate amyloid buildups and reduce neurotoxicity in in vitro and in vivo models, there is no approved laminin-111-based therapeutic approaches for treatment of AD. Also, it has been shown that immunoreactivity to laminin111 appears late in development of cerebral amyloidosis. Based on the published data, we hypothesize that aberrant interaction between amyloid-beta and alpha 5-laminins such as laminin-511 prevents the necessary laminin signaling into neurons leading to neurodegeneration and contributing to the early development of AD. Laminin-511 is the key extracellular protein that protects neurons from anoikis, inhibits excitoxicity and provides signaling that stabilizes dendritic spines and synapses in the developed brain. Absence of the signaling from laminin-511 leads to behavioral defects in mice. Laminin-511 and hippocampal neurons are in direct contact and accumulation of amyloid-beta that has been shown to avidly bind laminin-511 may physically decouple the interaction between alpha 5-laminins and the neuronal membrane receptors inhibiting the signaling. Under this hypothesis, protein domains and peptides from laminin alpha 5 chain may have a therapeutic potential in treatment of AD and the appearance of laminin-111 in the amyloid plaques is simply a consequence of the disease.
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| 4. |
- Moiseev, Sergey, et al.
(författare)
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Association of venous thromboembolic events with skin, pulmonary and kidney involvement in ANCA-associated vasculitis : A multinational study
- 2021
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Ingår i: Rheumatology. - : Oxford University Press (OUP). - 1462-0332 .- 1462-0324. ; 60:10, s. 4654-4661
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Tidskriftsartikel (refereegranskat)abstract
- Objective: To investigate the occurrence of venous thromboembolic events (VTE) in a large cohort of patients with antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) across the European Union, Turkey, Russia, UK and North America. Methods: Patients with a definite diagnosis of AAV who were followed for at least 3 months and had sufficient documentation were included. Data on VTE, including either deep vein thrombosis or pulmonary embolism, were collected retrospectively from tertiary vasculitis centres. Univariate and multivariate regression models were used to estimate odds ratios (ORs) and 95% CIs. Results: Over a median follow-up of 63 (interquartile range: 29, 101) months, VTE occurred in 278 (9.7%) of 2869 AAV patients with a similar frequency across different countries (from 6.3% to 13.7%), and AAV subtype [granulomatosis with polyangiitis: 9.8% (95% CI: 8.3, 11.6%); microscopic polyangiitis: 9.6% (95% CI: 7.9, 11.4%); and eosinophilic granulomatosis with polyangiitis: 9.8% (95% CI: 7.0, 13.3%)]. Most VTE (65.6%) were reported in the first-year post-diagnosis. Multiple factor logistic regression analysis adjusted for sex and age showed that skin (OR 1.71, 95% CI: 1.01, 2.92), pulmonary (OR 1.78, 95% CI: 1.04, 3.14) and kidney [eGFR 15-60 ml/min/1.73 m2, OR 2.86 (95% CI: 1.27, 6.47); eGFR <15 ml/min/1.73 m2, OR 6.71 (95% CI: 2.94, 15.33)] involvement were independent variables associated with a higher occurrence of VTE. Conclusion: Two-thirds of VTE occurred during the initial phase of active disease. We confirmed previous findings from smaller studies that a decrease in kidney function, skin involvement and pulmonary disease are independently associated with VTE.
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| 5. |
- Moiseev, Sergey, et al.
(författare)
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Traditional and Disease-Specific Risk Factors for Cardiovascular Events in Antineutrophil Cytoplasmic Antibody-Associated Vasculitis : A Multinational Retrospective Study
- 2023
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Ingår i: Journal of Rheumatology. - : The Journal of Rheumatology. - 0315-162X .- 1499-2752. ; 50:9, s. 1145-1151
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Tidskriftsartikel (refereegranskat)abstract
- Objective. To investigate the occurrence of cardiovascular events (CVEs) in a large cohort of patients with antineutrophil cytoplasmic antibody (ANCA)-Associated vasculitis (AAV) across the European Union, China, Turkey, Russia, the United Kingdom, and the USA. Methods. Patients with a definite diagnosis of AAV who were followed for ? 3 months and had sufficient documentation were included. Data on myocardial infarction (MI) and stroke were collected retrospectively from tertiary vasculitis centers. Univariate and multivariate Cox regression models were used to estimate hazard ratios (HRs) and 95% CIs. Results. Over a median follow-up of 62.0 months (IQR 22.6-100.0), CVEs (mostly MIs) occurred in 245 (10.7%) of 2286 patients with AAV, with a higher frequency in China and the UK. On multivariate regression analysis, older age (55-64.9 yrs, HR 2.93, 95% CI 1.99-4.31), smoking (HR 1.98, 95% CI 1.48-2.64), Chinese origin (HR 4.24, 95% CI 3.07-5.85), and pulmonary (HR 1.50, 95% CI 1.09-2.06) and kidney (HR 3.02, 95% CI 2.08-4.37) involvement were independent variables associated with a higher occurrence of CVEs. Conclusion. We showed that geographic region and both traditional and disease-specific (kidney involvement in particular) factors were independently associated with CVEs. Proper assessment and management of modifiable cardiovascular (CV) risk factors are essential for prevention of CV morbidity in patients with AAV.
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| 6. |
- Tiguntseva, Ekaterina, et al.
(författare)
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Room-Temperature Lasing from Mie-Resonant Nonplasmonic Nanoparticles
- 2020
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Ingår i: ACS Nano. - : American Chemical Society (ACS). - 1936-086X .- 1936-0851. ; 14:7, s. 8149-8156
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Tidskriftsartikel (refereegranskat)abstract
- Subwavelength particles supporting Mie resonances underpin a strategy in nanophotonics for efficient control and manipulation of light by employing both an electric and a magnetic optically induced multipolar resonant response. Here, we demonstrate that monolithic dielectric nanoparticles made of CsPbBr3 halide perovskites can exhibit both efficient Mie-resonant lasing and structural coloring in the visible and near-IR frequency ranges. We employ a simple chemical synthesis with nearly epitaxial quality for fabricating subwavelength cubes with high optical gain and demonstrate single-mode lasing governed by the Mie resonances from nanocubes as small as 310 nm by the side length. These active nanoantennas represent the most compact room-temperature nonplasmonic nanolasers demonstrated until now.
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| 7. |
- Zograf, Georgii, 1994, et al.
(författare)
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Dielectric materials
- 2023
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Ingår i: All-Dielectric Nanophotonics. - 9780323951951 ; , s. 49-69
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- In this chapter, we review the main materials for all-dielectric nanophotonics, including various metal-oxides, standard semiconductors (II-VI and III-V), 2D materials (transition-metal dichalcogenides), and halide perovskites. We focus on their linear and nonlinear responses as well as discuss their structural properties. This part can be useful for those who would like to design novel advanced all-dielectric nanophotonic structures for a broad range of applications.
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