Publications by authors named "Ivan Yakovlev"

Non-equidistant and non-parallel grooves of a diffraction grating distort the diffracted wavefront. For a fixed wavelength, a grating with an arbitrary groove pattern is equivalent to a grating with perfect grooves having an effective surface profile different from the geometric one. It is shown that the previously proposed method for measuring non-equidistance can be used for simultaneous measurement of non-parallelism, and the measurement error is determined without any a priori information and fitting parameters.

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Calpainopathy, or limb-girdle muscular dystrophy type R1/2A (LGMDR1/2A), is the most prevalent form of LGMD, comprising about 32% of all cases. The disease is caused by mutations in the gene, leading to dysfunction of the corresponding protein-an enzyme critical for muscle fiber cytoskeleton remodeling and protein signaling regulation through selective proteolysis. Clinical manifestations demonstrate significant phenotypic polymorphisms, ranging from oligosymptomatic forms to severe early-onset cases, with the loss of ambulation occurring 10-25 years after disease onset.

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Dysferlinopathy is a phenotypically heterogeneous, inherited, progressive muscular dystrophy caused by mutations in the gene. Dysferlinopathy is marked by elevated serum creatine kinase (CK) and can in some cases manifest as hyperCKemia in asymptomatic or low-symptom states. Here, we describe the clinical signs and symptoms and laboratory and imaging results with quantitative MRI analysis of eight pediatric patients at asymptomatic and oligosymptomatic states of dysferlinopathy (aged 3-14 years).

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A new nitro-nitrosyl complex [RuNO(Phen)(NO)OH] (1) was synthesized and characterized by X-ray diffraction, where Phen = 1,10-phenanthroline. The complex was crystallized in two different modifications without (1) and with a solvent molecule of DMF (1a). The photolysis process together with the determination of the quantum yield of NO release was investigated in acetonitrile solution using a special flow-through system for the simultaneous registration of infrared (IR) and optical absorption (UV-vis) spectra under irradiation with 450 nm light.

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The DYSF gene encoding dysferlin protein is one of the largest and has many transcripts. Pathogenic variants in the gene can lead to various types of myopathies, which makes it a good object for studying the events occurring in it during genome editing by the CRISPR/Cas method. In this study, we evaluated the possibility of permanent skipping of exons 3-4, and 26-27 which deletion does not violate the reading frame and allows to eliminate truncated variants within exons.

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Dysferlinopathy treatment is an active area of investigation. Gene therapy is one potential approach. We studied muscle regeneration and inflammatory response after injection of an AAV-9 with a codon-optimized DYSF gene.

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Article Synopsis
  • - The study focused on dysferlinopathy in an isolated Avar population in Dagestan, examining the prevalence of a specific pathological DYSF gene variant linked to muscular dystrophy, using genetic screenings of 746 individuals.
  • - Findings revealed a high allele frequency of 14%, with a notable 3.8% of individuals homozygous for the variant, leading to two phenotypes: limb-girdle muscular dystrophy and Miyoshi muscular dystrophy.
  • - The research concluded that inbreeding contributed to the population's significant burden of dysferlinopathy, indicated by a low number of heterozygotes and a specific fixation index value.
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Analytical expressions for the spatial spectrum of fluence fluctuations of a laser pulse propagating in a medium with Kerr nonlinearity have been obtained. It is shown that inhomogeneities with a spatial scale much larger than the critical scale of self-focusing grow insignificantly even at large values of the B-integral. Experiments using BK7 glass and a KDP crystal as a nonlinear medium confirm the obtained theoretical results.

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MnGe epitaxial thin films previously grown mainly on Ge substrate have been synthesized on Si(111) using the co-deposition of Mn and Ge at a temperature of 390 °C. RMS roughness decreases by almost a factor of two in the transition from a completely polycrystalline to a highly ordered growth mode. This mode has been stabilized by changing the ratio of the Mn and Ge evaporation rate from the stoichiometric in the buffer layer.

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The use of the post-compression technique ensures gain in laser pulse peak power but at the same time degrades beam focusability due to the nonlinear wavefront distortions caused by a spatially nonuniform beam profile. In this paper a substantial focusability improvement of a post-compressed laser pulse by means of adaptive optics was demonstrated experimentally. The Strehl ratio increase from 0.

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Three-layer iron-rich FeSi/Ge/FeSi (0.2 < < 0.64) heterostructures on a Si(111) surface with Ge thicknesses of 4 nm and 7 nm were grown by molecular beam epitaxy.

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The PEARL laser output pulse with a duration of 60-70 fs was compressed to 11 fs after passing through a 5-mm thick silica plate and reflecting from two chirping mirrors with a total dispersion of -250 fs. The experiments were carried out for the B-integral values up to 19 without damage of the optical elements, which indicates that small-scale self-focusing was suppressed. The results obtained show the possibility of further nonlinear compression scaling to multipetawatt power in pulses with duration commensurate with the field period.

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The synthetic approaches for the preparation of (NO,OH)-(NO,NO)-[RuNO(L)(NO)OH], where L = ethyl nicotinate (I) and methyl nicotinate (II), are reported. The structures of the complexes are characterized by X-ray diffraction and analyzed by Hirshfeld surface analysis. Both compounds show a nitric oxide release reaction under 445 or 532 nm irradiation of dimethyl sulfoxide (DMSO) solutions, which is studied by combined ultraviolet-visible- (UV-vis), infrared- (IR), and electron paramagnetic resonance (EPR) spectroscopy and density functional theory (DFT) calculations.

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Plectinopathies are orphan diseases caused by gene mutations. is encoding the protein plectin, playing a role in linking cytoskeleton components in various tissues. In this study, we describe the clinical case of a 26-year-old patient with an early onset plectinopathy variant "limb-girdle muscle dystrophy type 2Q," report histopathological and ultrastructural findings in m.

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Limb-girdle muscular dystrophy type 2 (LGMD2B) is a mild form of dysferlinopathy, characterized by limb weakness and wasting. It is an autosomal recessive disease, with currently 140 mutations in the LGMD2B gene identified. Lack of functional dysferlin inhibits muscle fiber regeneration in voluntary muscles, the main pathological finding in LGMD2B patients.

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To date, over 30 genes with mutations causing limb-girdle muscle dystrophy have been described. Dysferlinopathies are a form of limb-girdle muscle dystrophy type 2B with an incidence ranging from 1:1,300 to 1:200,000 in different populations. In 1996, Dr.

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We report a method for ultrashort pulse reconstruction based only on the pulse spectrum and two self-phase modulated (SPM) spectra measured after pulse propagation through thin media with a Kerr nonlinearity. The advantage of this method is that it is a simple and very effective tool for characterization of complex signals. We have developed a new retrieval algorithm that was verified by reconstructing numerically generated fields, such as a complex electric field of double pulses and few-cycle pulses with noises, pedestals and dips down to zero spectral intensity, which is challenging for commonly used techniques.

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We discuss the theoretical and experimental investigation of acousto-optic dispersive tunable filters, based on quasi-collinear geometry of light-sound interaction in a tellurium dioxide single crystal. The geometry uses the effect of strong acoustic anisotropy in the paratellurite as well as peculiarities of acoustic wave reflections at the free boundary of the crystal. A mathematical concept for determination of optical, electrical, and constructional parameters of the filters is developed.

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