•Few-Mode Fibers (FMF) and Multimode Fibers (MMF) can be used in Phase-Sensitive OTDR (PS-OTDR) to decrease influence of the nonlinear effects.•Application of FMFs and MMFs in PS-OTDR allows to ...increase signal-to-noise ratio at distances up to 50 km.•FMF supports longer propagation distances than MMF due to the lower attenuation.•FMF and MMF application is compatible with other techniques of OTDR range extension.
We discuss the possible advantages of using few-mode and multimode fibers in coherent optical time-domain reflectometry sensing systems. We show that the application of few-mode and multimode fibers decreases nonlinear effects and impedes modulation instability. In comparison to standard single-mode optical fiber, few-mode and multimode fibers may help to increase signal power at the receiver. We also show that few-mode fibers may potentially increase sensing distance.
The inherited neurodegenerative disease Friedreich's ataxia (FRDA) is caused by GAA⋅TTC triplet repeat hyperexpansions within the first intron of the
FXN gene, encoding the mitochondrial protein ...frataxin. Long GAA⋅TTC repeats cause heterochromatin-mediated gene silencing and loss of frataxin in affected individuals. We report the derivation of induced pluripotent stem cells (iPSCs) from FRDA patient fibroblasts by transcription factor reprogramming.
FXN gene repression is maintained in the iPSCs, as are the global gene expression signatures reflecting the human disease. GAA⋅TTC repeats uniquely in
FXN in the iPSCs exhibit repeat instability similar to patient families, where they expand and/or contract with discrete changes in length between generations. The mismatch repair enzyme MSH2, implicated in repeat instability in other triplet repeat diseases, is highly expressed in pluripotent cells and occupies
FXN intron 1, and shRNA silencing of
MSH2 impedes repeat expansion, providing a possible molecular explanation for repeat expansion in FRDA.
► FRDA iPSCs retain key molecular features characteristic of the human disease ► GAA•TTC repeat instability is observed in iPSCs in the disease-relevant
FXN gene ► Repeat instability is dependent on the mismatch repair enzyme MSH2
We report on the design of a novel flexible very large mode area photonic crystal fibre for short pulse high peak power fibre laser and beam delivery applications. This fibre has an extremely large ...mode area exceeding 2500 microm(2) when kept straight and over 1000 microm(2) when bent over a 10 cm radius at a wavelength of 1064 nm. In addition our fibre exhibits very small fundamental mode bending loss below 10(-2) dB/m. The large difference between the propagation loss levels of fundamental and higher order modes forces efficient single-mode guidance in the fibre core while bent. This allows using the fibre to build compact high power laser systems. The paper further explores the major features of this fibre including: the dependence of the mode field area on the fibre core shape, the influence of the bending radius and of the bending direction as well as the impact of manufacturing tolerances on the fibre specifications.
Friedreich's ataxia (FRDA) is a hereditary neuromuscular disorder. Cardiomyopathy is the leading cause of premature death in FRDA. FRDA cardiomyopathy is a complex and progressive disease with no ...cure or treatment to slow its progression. At the cellular level, cardiomyocyte hypertrophy, apoptosis and fibrosis contribute to the cardiac pathology. However, the heart is composed of multiple cell types and several clinical studies have reported the involvement of cardiac non-myocytes such as vascular cells, autonomic neurons, and inflammatory cells in the pathogenesis of FRDA cardiomyopathy. In fact, several of the cardiac pathologies associated with FRDA including cardiomyocyte necrosis, fibrosis, and arrhythmia, could be contributed to by a diseased vasculature and autonomic dysfunction. Here, we review available evidence regarding the current understanding of cellular mechanisms for, and the involvement of, cardiac non-myocytes in the pathogenesis of FRDA cardiomyopathy.
•This is a review article. Highlights only required for full research articles.
In this article we present an all-fiber vector bend sensor by means of a self-fabricated micro-structured multicore optical fiber. The reported solution is based on differential intensity variations ...of the light transmitted along the cores whose changes are influenced by the bending angle and orientation. The unique asymmetric structure of the air-holes in the optical fiber provides each core with different confinement losses of the fundamental mode depending on the bending radius and orientation, making each of the cores bend-sensitive in a range of at least 80°. It has been experimentally demonstrated that the reported sensor enables the bending angle and orientation to be detected in a full range of 360° without any dead-zones, and the possibility of end point detection with millimeter precision. Additionally, a reconstruction of the bending vector has been carried out theoretically, and a good match can be observed between the experimental and theoretical data.
Oriental martial arts has millions of fans around the world. Successfully develop and cultivate all styles of martial arts from Chinese Wushu to full contact Muetai, Kyokushinkai karate, and many ...others. Kyokushinkai Karate is one of the most popular types of martial arts, cultivated by more than 16 million people in 140 countries, which has a well-established training system, one of the elements of which is the development of specialized kata complexes. This is a formalized sequence of movements, combined on the principles of a duel with imaginary one or more opponents. The purpose of the study is to improve the special training of qualified Kyokushinkai karate athletes in the competitive discipline of Kumite with the use of kata complexes. The following research methods were used: theoretical analysis and generalization of scientific and methodological literature; sociological methods (questionnaires); pedagogical observation; pedagogical testing, pedagogical experiment; medical and biological methods, and methods of mathematical statistics. The priority of the executioner "Sanchin" and "Tensho" as elements of special training and the significance of their impact on the physical condition of the athlete. The author's technique of training process with the use of kata complexes is developed and introduced, for the directed influence on separate indicators of the level of development of special physical qualities and functional state of karate. As a result of the use of kata in the preparation of qualified karate for Kumite in the athletes of the experimental group, there were significant positive changes in the level of development of special physical qualities and speed and strength indicators when performing many shock combinations. There was a statistically significant (p <0.05) increase in power and time parameters of complex, multi-stroke combinations "Shita Tsuki" - "Mavashi Tsuki" - 25.8%, "Shita Tsuki" - "Mavashi Tsuki" - "Mavashi Geri" - 28.4%).
Identifying biomarkers is important for assessment of disease progression, prediction of symptom development, and determination of treatment effectiveness. While unbiased analyses of differential ...gene expression using next-generation sequencing methods are now routinely conducted, proteomics studies are more challenging because of traditional methods predominantly being low throughput and offering a limited dynamic range for simultaneous detection of hundreds of proteins that drastically differ in their intracellular abundance. We utilized a sensitive and high-throughput proteomic technique, reverse phase protein array (RPPA), to attain protein expression profiles of primary fibroblasts obtained from patients with Friedreich's ataxia (FRDA) and unaffected controls (CTRLs). The RPPA was designed to detect 217 proteins or phosphorylated proteins by individual antibody, and the specificity of each antibody was validated prior to the experiment. Among 62 fibroblast samples (44 FRDA and 18 CTRLs) analyzed, 30 proteins/phosphoproteins were significantly changed in FRDA fibroblasts compared with CTRL cells (p < 0.05), mostly representing signaling molecules and metabolic enzymes. As expected, frataxin was significantly downregulated in FRDA samples, thus serving as an internal CTRL for assay integrity. Extensive bioinformatics analyses were conducted to correlate differentially expressed proteins with critical disease parameters (e.g., selected symptoms, age of onset, guanine–adenine–adenine sizes, frataxin levels, and Functional Assessment Rating Scale scores). Members of the integrin family of proteins specifically associated with hearing loss in FRDA. Also, RPPA data, combined with results of transcriptome profiling, uncovered defects in the retinoic acid metabolism pathway in FRDA samples. Moreover, expression of aldehyde dehydrogenase family 1 member A3 differed significantly between cardiomyopathy-positive and cardiomyopathy-negative FRDA cohorts, demonstrating that metabolites such as retinol, retinal, or retinoic acid could become potential predictive biomarkers of cardiac presentation in FRDA.
Display omitted
•RPPA analyzing Friedreich's ataxia cells reveals changed expression of 30 proteins.•Integrin expression correlates with hearing loss in Friedreich's ataxia samples.•Retinol levels are lower in serum of patients with Friedreich's ataxia than controls.
We conducted a sensitive and high-throughput reverse phase protein array to attain protein expression profiles of primary fibroblasts from patients with Friedreich's ataxia (FRDA) and unaffected controls using a pool of 217 validated antibodies. Our extensive bioinformatics analyses correlated differentially expressed (DE) proteins with critical disease parameters. Expression levels of several integrin proteins specifically associated with hearing loss in FRDA. Also, reverse phase protein array data integrated with transcriptome data uncovered defects in retinoic acid metabolism in FRDA samples.
Reduced expression of the mitochondrial protein Frataxin (FXN) is the underlying cause of Friedreich's ataxia. We propose a model of premature termination of FXN transcription induced by pathogenic ...expanded GAA repeats that links R-loop structures, antisense transcription, and heterochromatin formation as a novel mechanism of transcriptional repression in Friedreich's ataxia.
PDF
