127 research outputs found
ΠΠ½ΠΎΠ³ΠΎΡΠ»ΠΎΠΉΠ½ΡΠ΅ ΠΊΠΎΠΌΠΏΠΎΠ·ΠΈΡΠΈΠΎΠ½Π½ΡΠ΅ ΠΏΠ»Π°Π·ΠΌΠ΅Π½Π½ΡΠ΅ ΠΏΠΎΠΊΡΡΡΠΈΡ Π½Π° ΠΎΡΠ½ΠΎΠ²Π΅ ΠΎΠΊΡΠΈΠ΄Π½ΠΎΠΉ ΠΊΠ΅ΡΠ°ΠΌΠΈΠΊΠΈ ΠΈ ΠΌ-ΠΊΡΠΎΠ»Π΅ΠΉ
The paper considers the influence of the parameters of the plasma spraying process on the technological characteristics of multilayer coatings based on nickel-chromium, nickel-chromium-aluminum-yttrium materials, oxide ceramics, Β intended for operation at high temperature and additional dynamic loads. The design of plasma coatings during their application (with subsequent high-energy processing) under such conditions requires a comprehensive solution β both the use Β of high-quality powder ingredients and the optimization of technological parameters. The plasma process of applying powder materials has been improved to obtain the maximum values of their utilization factors. The technological characteristics that affect the properties of plasma coatings are optimized, namely: the flow rates of the plasma-forming and materials-transporting gases, the flow rate ofΒ supplied powder materials, the current and voltage of the electric arc of the plasma torch, the distance from the plasma torch nozzle exit to the substrate. The paper presents the results of studies of the structure Β of coatings, performed using scanning electron microscopy. Their analysis has made it possible to form general regularities obtained by the action of radiation of compression plasma flows on coatings formed by air plasma. The considered structures are created using the processes of melting, compaction and high-speed cooling of plasma coatings. The main optimization indicators are the maximum local compaction and spillage of the obtained compositions with the absence of defects and Β destruction from the impact of compression plasma flows. The main effect during the action of radiation of a compression plasma flow on previously formed coatings is thermal. It contributes heating of the near-surface layer. When the coating Β is exposed to radiation of compression plasma flows, a remelted layer of oxides with a thickness of about 12β15 Β΅m is created, smoothing the relief of the formed surface and creating a network of cracks on the surface, diverging into the depth of the coating. The liquid-phase processes occurring in the molten phase of the near-surface layers after exposure to compression plasma radiation change the structure of the layers and contribute to the modification of their mechanical properties. Β By smoothing the surface, increasing the density of the surface crystallized layer andΒ minimizing macro-defects β pores Β or macrocracks β the mechanical characteristics of the coatings increase.Π Π°ΡΡΠΌΠΎΡΡΠ΅Π½ΠΎ Π²Π»ΠΈΡΠ½ΠΈΠ΅ ΠΏΠ°ΡΠ°ΠΌΠ΅ΡΡΠΎΠ² ΠΏΡΠΎΡΠ΅ΡΡΠ° ΠΏΠ»Π°Π·ΠΌΠ΅Π½Π½ΠΎΠ³ΠΎ Π½Π°ΠΏΡΠ»Π΅Π½ΠΈΡ Π½Π° ΡΠ΅Ρ
Π½ΠΎΠ»ΠΎΠ³ΠΈΡΠ΅ΡΠΊΠΈΠ΅ Ρ
Π°ΡΠ°ΠΊΡΠ΅ΡΠΈΡΡΠΈΠΊΠΈ ΠΌΠ½ΠΎΠ³ΠΎΡΠ»ΠΎΠΉΠ½ΡΡ
ΠΏΠΎΠΊΡΡΡΠΈΠΉ Π½Π° Π±Π°Π·Π΅ ΠΌΠ°ΡΠ΅ΡΠΈΠ°Π»ΠΎΠ² Π½ΠΈΠΊΠ΅Π»Ρ-Ρ
ΡΠΎΠΌ ΠΈ Π½ΠΈΠΊΠ΅Π»Ρ-Ρ
ΡΠΎΠΌ-Π°Π»ΡΠΌΠΈΠ½ΠΈΠΉ-ΠΈΡΡΡΠΈΠΉ, ΠΎΠΊΡΠΈΠ΄Π½ΠΎΠΉ ΠΊΠ΅ΡΠ°ΠΌΠΈΠΊΠΈ, ΠΏΡΠ΅Π΄Π½Π°Π·Π½Π°ΡΠ΅Π½Π½ΡΡ
Π΄Π»Ρ ΡΠΊΡΠΏΠ»ΡΠ°ΡΠ°ΡΠΈΠΈ ΠΏΡΠΈ Π²ΡΡΠΎΠΊΠΈΡ
ΡΠ΅ΠΌΠΏΠ΅ΡΠ°ΡΡΡΠ½ΡΡ
ΠΈ Π΄ΠΎΠΏΠΎΠ»Π½ΠΈΡΠ΅Π»ΡΠ½ΡΡ
Π΄ΠΈΠ½Π°ΠΌΠΈΡΠ΅ΡΠΊΠΈΡ
Π½Π°Π³ΡΡΠ·ΠΊΠ°Ρ
. ΠΠΎΠ½ΡΡΡΡΠΈΡΠΎΠ²Π°Π½ΠΈΠ΅ ΠΏΠ»Π°Π·ΠΌΠ΅Π½Π½ΡΡ
ΠΏΠΎΠΊΡΡΡΠΈΠΉ ΠΏΡΠΈ ΠΈΡ
Π½Π°Π½Π΅ΡΠ΅Π½ΠΈΠΈ (Ρ ΠΏΠΎΡΠ»Π΅Π΄ΡΡΡΠ΅ΠΉ Π²ΡΡΠΎΠΊΠΎΡΠ½Π΅ΡΠ³Π΅ΡΠΈΡΠ΅ΡΠΊΠΎΠΉ ΠΎΠ±ΡΠ°Π±ΠΎΡΠΊΠΎΠΉ) Π² ΡΠ°ΠΊΠΈΡ
ΡΡΠ»ΠΎΠ²ΠΈΡΡ
ΡΡΠ΅Π±ΡΠ΅Ρ ΠΊΠΎΠΌΠΏΠ»Π΅ΠΊΡΠ½ΠΎΠ³ΠΎ ΡΠ΅ΡΠ΅Π½ΠΈΡ β ΠΊΠ°ΠΊ ΠΏΡΠΈΠΌΠ΅Π½Π΅Π½ΠΈΡ ΠΊΠ°ΡΠ΅ΡΡΠ²Π΅Π½Π½ΡΡ
ΠΏΠΎΡΠΎΡΠΊΠΎΠ²ΡΡ
ΠΈΠ½Π³ΡΠ΅Π΄ΠΈΠ΅Π½ΡΠΎΠ², ΡΠ°ΠΊ ΠΈ ΠΎΠΏΡΠΈΠΌΠΈΠ·Π°ΡΠΈΠΈ ΡΠ΅Ρ
Π½ΠΎΠ»ΠΎΠ³ΠΈΡΠ΅ΡΠΊΠΈΡ
ΠΏΠ°ΡΠ°ΠΌΠ΅ΡΡΠΎΠ². Π£ΡΠΎΠ²Π΅ΡΡΠ΅Π½ΡΡΠ²ΠΎΠ²Π°Π½ ΠΏΠ»Π°Π·ΠΌΠ΅Π½Π½ΡΠΉ ΠΏΡΠΎΡΠ΅ΡΡ Π½Π°Π½Π΅ΡΠ΅Π½ΠΈΡ ΠΏΠΎΡΠΎΡΠΊΠΎΠ²ΡΡ
ΠΌΠ°ΡΠ΅ΡΠΈΠ°Π»ΠΎΠ² Π΄Π»Ρ ΠΏΠΎΠ»ΡΡΠ΅Π½ΠΈΡ ΠΌΠ°ΠΊΡΠΈΠΌΠ°Π»ΡΠ½ΡΡ
Π·Π½Π°ΡΠ΅Π½ΠΈΠΉ ΠΈΡ
ΠΊΠΎΡΡΡΠΈΡΠΈΠ΅Π½ΡΠΎΠ² ΠΈΡΠΏΠΎΠ»ΡΠ·ΠΎΠ²Π°Π½ΠΈΡ. ΠΠΏΡΠΈΠΌΠΈΠ·ΠΈΡΠΎΠ²Π°Π½Ρ ΡΠ΅Ρ
Π½ΠΎΠ»ΠΎΠ³ΠΈΡΠ΅ΡΠΊΠΈΠ΅ Ρ
Π°ΡΠ°ΠΊΡΠ΅ΡΠΈΡΡΠΈΠΊΠΈ, ΠΎΠΊΠ°Π·ΡΠ²Π°ΡΡΠΈΠ΅ Π²Π»ΠΈΡΠ½ΠΈΠ΅ Π½Π° ΡΠ²ΠΎΠΉΡΡΠ²Π° ΠΏΠ»Π°Π·ΠΌΠ΅Π½Π½ΡΡ
ΠΏΠΎΠΊΡΡΡΠΈΠΉ, Π° ΠΈΠΌΠ΅Π½Π½ΠΎ: Π²Π΅Π»ΠΈΡΠΈΠ½Ρ ΡΠ°ΡΡ
ΠΎΠ΄ΠΎΠ² ΠΏΠ»Π°Π·ΠΌΠΎΠΎΠ±ΡΠ°Π·ΡΡΡΠ΅Π³ΠΎ ΠΈ ΡΡΠ°Π½ΡΠΏΠΎΡΡΠΈΡΡΡΡΠ΅Π³ΠΎ ΠΌΠ°ΡΠ΅ΡΠΈΠ°Π»Ρ Π³Π°Π·ΠΎΠ², ΡΠ°ΡΡ
ΠΎΠ΄ ΠΏΠΎΠ΄Π°Π²Π°Π΅ΠΌΡΡ
ΠΏΠΎΡΠΎΡΠΊΠΎΠ²ΡΡ
ΠΌΠ°ΡΠ΅ΡΠΈΠ°Π»ΠΎΠ², ΡΠΎΠΊ ΠΈ Π½Π°ΠΏΡΡΠΆΠ΅Π½ΠΈΠ΅ ΡΠ»Π΅ΠΊΡΡΠΈΡΠ΅ΡΠΊΠΎΠΉ Π΄ΡΠ³ΠΈ ΠΏΠ»Π°Π·ΠΌΠ΅Π½Π½ΠΎΠΉ Π³ΠΎΡΠ΅Π»ΠΊΠΈ, ΡΠ°ΡΡΡΠΎΡΠ½ΠΈΠ΅ Β ΠΎΡ ΡΡΠ΅Π·Π° ΡΠΎΠΏΠ»Π° ΠΏΠ»Π°Π·ΠΌΠΎΡΡΠΎΠ½Π° Π΄ΠΎ ΠΏΠΎΠ΄Π»ΠΎΠΆΠΊΠΈ. Π ΡΡΠ°ΡΡΠ΅ ΠΏΡΠΈΠ²Π΅Π΄Π΅Π½Ρ ΡΠ΅Π·ΡΠ»ΡΡΠ°ΡΡ ΠΈΡΡΠ»Π΅Π΄ΠΎΠ²Π°Π½ΠΈΠΉ ΡΡΡΡΠΊΡΡΡΡ ΠΏΠΎΠΊΡΡΡΠΈΠΉ, Π²ΡΠΏΠΎΠ»Π½Π΅Π½Π½ΡΡ
Ρ ΠΏΡΠΈΠΌΠ΅Π½Π΅Π½ΠΈΠ΅ΠΌ ΡΠ°ΡΡΡΠΎΠ²ΠΎΠΉ ΡΠ»Π΅ΠΊΡΡΠΎΠ½Π½ΠΎΠΉ ΠΌΠΈΠΊΡΠΎΡΠΊΠΎΠΏΠΈΠΈ. ΠΡ
Π°Π½Π°Π»ΠΈΠ· ΠΏΠΎΠ·Π²ΠΎΠ»ΠΈΠ» ΡΡΠΎΡΠΌΠΈΡΠΎΠ²Π°ΡΡ ΠΎΠ±ΡΠΈΠ΅ Π·Π°ΠΊΠΎΠ½ΠΎΠΌΠ΅ΡΠ½ΠΎΡΡΠΈ, ΠΏΠΎΠ»ΡΡΠ°Π΅ΠΌΡΠ΅ ΠΏΡΠΈ Π²ΠΎΠ·Π΄Π΅ΠΉΡΡΠ²ΠΈΠΈ ΠΈΠ·Π»ΡΡΠ΅Π½ΠΈΡ ΠΊΠΎΠΌΠΏΡΠ΅ΡΡΠΈΠΎΠ½Π½ΡΡ
ΠΏΠ»Π°Π·ΠΌΠ΅Π½Π½ΡΡ
ΠΏΠΎΡΠΎΠΊΠΎΠ² Π½Π° ΡΡΠΎΡΠΌΠΈΡΠΎΠ²Π°Π½Π½ΡΠ΅ Π²ΠΎΠ·Π΄ΡΡΠ½ΠΎΠΉ ΠΏΠ»Π°Π·ΠΌΠΎΠΉ ΠΏΠΎΠΊΡΡΡΠΈΡ. Π Π°ΡΡΠΌΠΎΡΡΠ΅Π½Π½ΡΠ΅ ΡΡΡΡΠΊΡΡΡΡ ΡΠΎΠ·Π΄Π°Π½Ρ ΠΏΡΠΈ ΠΏΠΎΠΌΠΎΡΠΈ ΠΏΡΠΎΡΠ΅ΡΡΠΎΠ² ΠΏΠ»Π°Π²Π»Π΅Π½ΠΈΡ, ΡΠΏΠ»ΠΎΡΠ½Π΅Π½ΠΈΡ ΠΈ Π²ΡΡΠΎΠΊΠΎΡΠΊΠΎΡΠΎΡΡΠ½ΠΎΠ³ΠΎ ΠΎΡ
Π»Π°ΠΆΠ΄Π΅Π½ΠΈΡ ΠΏΠ»Π°Π·ΠΌΠ΅Π½Π½ΡΡ
ΠΏΠΎΠΊΡΡΡΠΈΠΉ. ΠΡΠ½ΠΎΠ²Π½ΡΠ΅ ΠΏΠΎΠΊΠ°Π·Π°ΡΠ΅Π»ΠΈ ΠΎΠΏΡΠΈΠΌΠΈΠ·Π°ΡΠΈΠΈ β ΠΌΠ°ΠΊΡΠΈΠΌΠ°Π»ΡΠ½ΠΎΠ΅ Π»ΠΎΠΊΠ°Π»ΡΠ½ΠΎΠ΅ ΡΠΏΠ»ΠΎΡΠ½Π΅Π½ΠΈΠ΅ ΠΈ ΠΏΡΠΎΠΏΠ»Π°Π²Π»Π΅Π½ΠΈΠ΅ ΠΏΠΎΠ»ΡΡΠ΅Π½Π½ΡΡ
ΠΊΠΎΠΌΠΏΠΎΠ·ΠΈΡΠΈΠΉ Ρ ΠΎΡΡΡΡΡΡΠ²ΠΈΠ΅ΠΌ Π΄Π΅ΡΠ΅ΠΊΡΠΎΠ² ΠΈ ΡΠ°Π·ΡΡΡΠ΅Π½ΠΈΠΉ ΠΎΡ Π²ΠΎΠ·Π΄Π΅ΠΉΡΡΠ²ΠΈΡ ΠΏΠΎΡΠΎΠΊΠΎΠ² ΠΊΠΎΠΌΠΏΡΠ΅ΡΡΠΈΠΎΠ½Π½ΠΎΠΉ ΠΏΠ»Π°Π·ΠΌΡ. ΠΠ»Π°Π²Π½ΡΠΉ ΡΡΡΠ΅ΠΊΡ ΠΏΡΠΈ Π²ΠΎΠ·Π΄Π΅ΠΉΡΡΠ²ΠΈΠΈ ΠΈΠ·Π»ΡΡΠ΅Π½ΠΈΡ ΠΊΠΎΠΌΠΏΡΠ΅ΡΡΠΈΠΎΠ½Π½ΠΎΠ³ΠΎ ΠΏΠ»Π°Π·ΠΌΠ΅Π½Π½ΠΎΠ³ΠΎ ΠΏΠΎΡΠΎΠΊΠ° Π½Π° ΡΠ°Π½Π΅Π΅ ΡΡΠΎΡΠΌΠΈΡΠΎΠ²Π°Π½Π½ΡΠ΅ ΠΏΠΎΠΊΡΡΡΠΈΡ β ΡΠ΅ΠΏΠ»ΠΎΠ²ΠΎΠΉ. Β ΠΠ½ ΡΠΏΠΎΡΠΎΠ±ΡΡΠ²ΡΠ΅Ρ Π½Π°Π³ΡΠ΅Π²Ρ ΠΏΡΠΈΠΏΠΎΠ²Π΅ΡΡ
Π½ΠΎΡΡΠ½ΠΎΠ³ΠΎ ΡΠ»ΠΎΡ. ΠΡΠΈ Π΄Π΅ΠΉΡΡΠ²ΠΈΠΈ Π½Π° ΠΏΠΎΠΊΡΡΡΠΈΡ ΠΈΠ·Π»ΡΡΠ΅Π½ΠΈΡ ΠΊΠΎΠΌΠΏΡΠ΅ΡΡΠΈΠΎΠ½Π½ΡΡ
ΠΏΠ»Π°Π·ΠΌΠ΅Π½Π½ΡΡ
ΠΏΠΎΡΠΎΠΊΠΎΠ² ΡΠΎΠ·Π΄Π°Π΅ΡΡΡ ΠΏΠ΅ΡΠ΅ΠΏΠ»Π°Π²Π»Π΅Π½Π½ΡΠΉ ΡΠ»ΠΎΠΉ ΠΎΠΊΡΠΈΠ΄ΠΎΠ² ΡΠΎΠ»ΡΠΈΠ½ΠΎΠΉ ΠΏΠΎΡΡΠ΄ΠΊΠ° 12β15 ΠΌΠΊΠΌ, ΡΠ³Π»Π°ΠΆΠΈΠ²Π°ΡΡΠΈΠΉ ΡΠ΅Π»ΡΠ΅Ρ ΡΡΠΎΡΠΌΠΈΡΠΎΠ²Π°Π½Π½ΠΎΠΉ ΠΏΠΎΠ²Π΅ΡΡ
Π½ΠΎΡΡΠΈ ΠΈ ΡΠΎΠ·Π΄Π°ΡΡΠΈΠΉ Π½Π° ΠΏΠΎΠ²Π΅ΡΡ
Π½ΠΎΡΡΠΈ ΡΠ΅ΡΠΊΡ ΡΡΠ΅ΡΠΈΠ½, ΡΠ°ΡΡ
ΠΎΠ΄ΡΡΠΈΡ
ΡΡ Π² Π³Π»ΡΠ±ΠΈΠ½Ρ ΠΏΠΎΠΊΡΡΡΠΈΡ. ΠΡΠΎΠΈΡΡ
ΠΎΠ΄ΡΡΠΈΠ΅ Π² ΡΠ°ΡΠΏΠ»Π°Π²Π»Π΅Π½Π½ΠΎΠΉ ΡΠ°Π·Π΅ ΠΏΡΠΈΠΏΠΎΠ²Π΅ΡΡ
Π½ΠΎΡΡΠ½ΡΡ
ΡΠ»ΠΎΠ΅Π² ΠΆΠΈΠ΄ΠΊΠΎΡΠ°Π·Π½ΡΠ΅ ΠΏΡΠΎΡΠ΅ΡΡΡ ΠΏΠΎΡΠ»Π΅ Π²ΠΎΠ·Π΄Π΅ΠΉΡΡΠ²ΠΈΡ ΠΈΠ·Π»ΡΡΠ΅Π½ΠΈΡ ΠΊΠΎΠΌΠΏΡΠ΅ΡΡΠΈΠΎΠ½Π½ΠΎΠΉ ΠΏΠ»Π°Π·ΠΌΡ ΠΈΠ·ΠΌΠ΅Π½ΡΡΡ ΡΡΡΡΠΊΡΡΡΡ ΡΠ»ΠΎΠ΅Π² ΠΈ ΡΠΏΠΎΡΠΎΠ±ΡΡΠ²ΡΡΡ ΠΌΠΎΠ΄ΠΈΡΠΈΠΊΠ°ΡΠΈΠΈ ΠΈΡ
ΠΌΠ΅Ρ
Π°Π½ΠΈΡΠ΅ΡΠΊΠΈΡ
ΡΠ²ΠΎΠΉΡΡΠ². ΠΠ»Π°Π³ΠΎΠ΄Π°ΡΡ ΡΠ³Π»Π°ΠΆΠΈΠ²Π°Π½ΠΈΡ ΠΏΠΎΠ²Π΅ΡΡ
Π½ΠΎΡΡΠΈ, ΡΠ²Π΅Π»ΠΈΡΠ΅Π½ΠΈΡ ΠΏΠ»ΠΎΡΠ½ΠΎΡΡΠΈ ΠΏΠΎΠ²Π΅ΡΡ
Π½ΠΎΡΡΠ½ΠΎΠ³ΠΎ Π·Π°ΠΊΡΠΈΡΡΠ°Π»Π»ΠΈΠ·ΠΎΠ²Π°Π½Π½ΠΎΠ³ΠΎ ΡΠ»ΠΎΡ ΠΈ ΠΌΠΈΠ½ΠΈΠΌΠΈΠ·Π°ΡΠΈΠΈ ΠΌΠ°ΠΊΡΠΎΠ΄Π΅ΡΠ΅ΠΊΡΠΎΠ² β ΠΏΠΎΡ ΠΈΠ»ΠΈ ΠΌΠ°ΠΊΡΠΎΡΡΠ΅ΡΠΈΠ½ β ΠΏΠΎΠ²ΡΡΠ°ΡΡΡΡ ΠΌΠ΅Ρ
Π°Π½ΠΈΡΠ΅ΡΠΊΠΈΠ΅ Ρ
Π°ΡΠ°ΠΊΡΠ΅ΡΠΈΡΡΠΈΠΊΠΈ ΠΏΠΎΠΊΡΡΡΠΈΠΉ
Computer Aided Autism Diagnosis Using Diffusion Tensor Imaging
Β© 2013 IEEE. Autism Spectrum Disorder (ASD), commonly known as autism, is a lifelong developmental disorder associated with a broad range of symptoms including difficulties in social interaction, communication skills, and restricted and repetitive behaviors. In autism spectrum disorder, numerous studies suggest abnormal development of neural networks that manifest itself as abnormalities of brain shape, functionality, and/ or connectivity. The aim of this work is to present our automated computer aided diagnostic (CAD) system for accurate identification of autism spectrum disorder based on the connectivity of the white matter (WM) tracts. To achieve this goal, two levels of analysis are provided for local and global scores using diffusion tensor imaging (DTI) data. A local analysis using the Johns Hopkins WM atlas is exploited for DTI atlas-based segmentation. Furthermore, WM integrity is examined by extracting the most notable features representing WM connectivity from DTI. Interactions of WM features between different areas in the brain, demonstrating correlations between WM areas were used, and feature selection among those associations were made. Finally, a leave-one-subject-out classifier is employed to yield a final per-subject decision. The proposed system was tested on a large dataset of 263 subjects from the National Database of Autism Research (NDAR) with their Autism Diagnostic Observation Schedule (ADOS) scores and diagnosis (139 typically developed: 66 males, and 73 females, and 124 autistics: 66 males, and 58 females), with ages ranging from 96 to 215 months, achieving an overall accuracy of 73%. In addition to this achieved global accuracy, diagnostically-important brain areas were identified, allowing for a better understanding of ASD-related brain abnormalities, which is considered as an essential step towards developing early personalized treatment plans for children with autism spectrum disorder
Mutations in the latent TGF-beta binding protein 3 (LTBP3) gene cause brachyolmia with amelogenesis imperfecta
Inherited dental malformations constitute a clinically and genetically heterogeneous group of disorders. Here, we report on four families, three of them consanguineous, with an identical phenotype, characterized by significant short stature with brachyolmia and hypoplastic amelogenesis imperfecta (AI) with almost absent enamel. This phenotype was first described in 1996 by Verloes et al. as an autosomal recessive form of brachyolmia associated with AI. Whole-exome sequencing resulted in the identification of recessive hypomorphic mutations including deletion, nonsense and splice mutations, in the LTBP3 gene, which is involved in the TGF-beta signaling pathway. We further investigated gene expression during mouse development and tooth formation. Differentiated ameloblasts synthesizing enamel matrix proteins and odontoblasts expressed the gene. Study of an available knockout mouse model showed that the mutant mice displayed very thin to absent enamel in both incisors and molars, hereby recapitulating the AI phenotype in the human disorder
Does size matter for horny beetles? A geometric morphometric analysis of interspecific and intersexual size and shape variation in Colophon haughtoni Barnard, 1929, and C. kawaii Mizukami, 1997 (Coleoptera: Lucanidae)
Colophon is an understudied, rare and endangered stag beetle genus with all species endemic to isolated mountain peaks in South Africaβs Western Cape. Geometric morphometrics was used to analyse intersexual and interspecific variation of size and shape in the mandibles, heads, pronota and elytra of two sympatric species: Colophon haughtoni and Colophon kawaii. All measured structures showed significant sexual dimorphism, which may result from male-male competition for females. Female mandibles were too small and featureless for analysis, but male Colophon beetles possess large, ornate mandibles for fighting. Males had significantly larger heads and pronota that demonstrated shape changes which may relate to resource diversion to the mandibles and their supporting structures. Females are indistinguishable across species, but males were accurately identified using mandibles, heads and pronota. Male C. kawaii were significantly larger than C. haughtoni for all structures. These results support the species status of C. kawaii, which is currently in doubt due to its hybridisation with C. haughtoni. We also demonstrate the value of geometric morphometrics as a tool which may aid Colophon conservation by providing biological and phylogenetic insights and enabling species identification
The role of tissue transglutaminase (TG2) in regulating the tumour progression of the mouse colon carcinoma CT26
The multifunctional enzyme tissue transglutaminase (TG2) is reported to both mediate and inhibit tumour progression. To elucidate these different roles of TG2, we established a series of stable-transfected mouse colon carcinoma CT26 cells expressing a catalytically active (wild type) and a transamidating-inactive TG2 (Cys277Ser) mutant. Comparison of the TG2-transfected cells with the empty vector control indicated no differences in cell proliferation, apoptosis and susceptibility to doxorubicin, which correlated with no detectable changes in the activation of the transcription factor NF-?B. TG2-transfected cells showed increased expression of integrin Γ3, and were more adherent and less migratory on fibronectin than control cells. Direct interaction of TG2 with Γ3 integrins was demonstrated by immunoprecipitation, suggesting that TG2 acts as a coreceptor for fibronectin with Γ3 integrins. All cells expressed the same level of TGFΓ receptors I and II, but only cells transfected with active TG2 had increased levels of TGFΓ1 and matrix-deposited fibronectin, which could be inhibited by TG2 site-directed inhibitors. Moreover, only cells transfected with active TG2 were capable of inhibiting tumour growth when compared to the empty vector controls. We conclude that in this colon carcinoma model increased levels of active TG2 are unfavourable to tumour growth due to their role in activation of TGFΓ1 and increased matrix deposition, which in turn favours increased cell adhesion and a lowered migratory and invasive behaviour
The Monofunctional Catalase KatE of Xanthomonas axonopodis pv. citri Is Required for Full Virulence in Citrus Plants
BACKGROUND: Xanthomonas axonopodis pv. citri (Xac) is an obligate aerobic phytopathogen constantly exposed to hydrogen peroxide produced by normal aerobic respiration and by the plant defense response during plant-pathogen interactions. Four putative catalase genes have been identified in silico in the Xac genome, designated as katE, catB, srpA (monofunctional catalases) and katG (bifunctional catalase). METHODOLOGY/PRINCIPAL FINDINGS: Xac catalase activity was analyzed using native gel electrophoresis and semi-quantitative RT-PCR. We demonstrated that the catalase activity pattern was regulated in different growth stages displaying the highest levels during the stationary phase. KatE was the most active catalase in this phase of growth. At this stage cells were more resistant to hydrogen peroxide as was determined by the analysis of CFU after the exposition to different H(2)O(2) concentrations. In addition, Xac exhibited an adaptive response to hydrogen peroxide, displaying higher levels of catalase activity and H(2)O(2) resistance after treatment with sub-lethal concentrations of the oxidant. In the plant-like medium XVM2 the expression of KatE was strongly induced and in this medium Xac was more resistant to H(2)O(2). A XackatE mutant strain was constructed by insertional mutagenesis. We observed that catalase induction in stationary phase was lost meanwhile the adaptive response to peroxide was maintained in this mutant. Finally, the XackatE strain was assayed in planta during host plant interaction rendering a less aggressive phenotype with a minor canker formation. CONCLUSIONS: Our results confirmed that in contrast to other Xanthomonas species, Xac catalase-specific activity is induced during the stationary phase of growth in parallel with the bacterial resistance to peroxide challenge. Moreover, Xac catalases expression pattern is modified in response to any stimuli associated with the plant or the microenvironment it provides. The catalase KatE has been shown to have an important function for the colonization and survival of the bacterium in the citrus plant during the pathogenic process. Our work provides the first genetic evidence to support a monofunctional catalase as a virulence factor in Xac
Clinical oxidative stress during leprosy multidrug therapy:impact of dapsone oxidation
This study aims to assess the oxidative stress in leprosy patients under multidrug therapy (MDT; dapsone, clofazimine and rifampicin), evaluating the nitric oxide (NO) concentration, catalase (CAT) and superoxide dismutase (SOD) activities, glutathione (GSH) levels, total antioxidant capacity, lipid peroxidation, and methemoglobin formation. For this, we analyzed 23 leprosy patients and 20 healthy individuals from the Amazon region, Brazil, aged between 20 and 45 years. Blood sampling enabled the evaluation of leprosy patients prior to starting multidrug therapy (called MDT 0) and until the third month of multidrug therapy (MDT 3). With regard to dapsone (DDS) plasma levels, we showed that there was no statistical difference in drug plasma levels between multibacillary (0.518Β±0.029 ΞΌg/mL) and paucibacillary (0.662Β±0.123 ΞΌg/mL) patients. The methemoglobin levels and numbers of Heinz bodies were significantly enhanced after the third MDTsupervised dose, but this treatment did not significantly change the lipid peroxidation and NO levels in these leprosy patients. In addition, CAT activity was significantly reduced in MDT-treated leprosy patients, while GSH content was increased in these patients. However, SOD and Trolox equivalent antioxidant capacity levels were similar in patients with and without treatment. These data suggest that MDT can reduce the activity of some antioxidant enzyme and influence ROS accumulation, which may induce hematological changes, such as methemoglobinemia in patients with leprosy. We also explored some redox mechanisms associated with DDS and its main oxidative metabolite DDS-NHOH and we explored the possible binding of DDS to the active site of CYP2C19 with the aid of molecular modeling software
Sex- and age-related differences in the management and outcomes of chronic heart failure: an analysis of patients from the ESC HFA EORP Heart Failure Long-Term Registry
Aims: This study aimed to assess age- and sex-related differences in management and 1-year risk for all-cause mortality and hospitalization in chronic heart failure (HF) patients. Methods and results: Of 16 354 patients included in the European Society of Cardiology Heart Failure Long-Term Registry, 9428 chronic HF patients were analysed [median age: 66 years; 28.5% women; mean left ventricular ejection fraction (LVEF) 37%]. Rates of use of guideline-directed medical therapy (GDMT) were high (angiotensin-converting enzyme inhibitors/angiotensin receptor blockers, beta-blockers and mineralocorticoid receptor antagonists: 85.7%, 88.7% and 58.8%, respectively). Crude GDMT utilization rates were lower in women than in men (all differences: P\ua0 64 0.001), and GDMT use became lower with ageing in both sexes, at baseline and at 1-year follow-up. Sex was not an independent predictor of GDMT prescription; however, age >75 years was a significant predictor of GDMT underutilization. Rates of all-cause mortality were lower in women than in men (7.1% vs. 8.7%; P\ua0=\ua00.015), as were rates of all-cause hospitalization (21.9% vs. 27.3%; P\ua075 years. Conclusions: There was a decline in GDMT use with advanced age in both sexes. Sex was not an independent predictor of GDMT or adverse outcomes. However, age >75 years independently predicted lower GDMT use and higher all-cause mortality in patients with LVEF 6445%
A targeted next-generation sequencing assay for the molecular diagnosis of genetic disorders with orodental involvement.
BACKGROUND: Orodental diseases include several clinically and genetically heterogeneous disorders that can present in isolation or as part of a genetic syndrome. Due to the vast number of genes implicated in these disorders, establishing a molecular diagnosis can be challenging. We aimed to develop a targeted next-generation sequencing (NGS) assay to diagnose mutations and potentially identify novel genes mutated in this group of disorders. METHODS: We designed an NGS gene panel that targets 585 known and candidate genes in orodental disease. We screened a cohort of 101 unrelated patients without a molecular diagnosis referred to the Reference Centre for Oro-Dental Manifestations of Rare Diseases, Strasbourg, France, for a variety of orodental disorders including isolated and syndromic amelogenesis imperfecta (AI), isolated and syndromic selective tooth agenesis (STHAG), isolated and syndromic dentinogenesis imperfecta, isolated dentin dysplasia, otodental dysplasia and primary failure of tooth eruption. RESULTS: We discovered 21 novel pathogenic variants and identified the causative mutation in 39 unrelated patients in known genes (overall diagnostic rate: 39%). Among the largest subcohorts of patients with isolated AI (50 unrelated patients) and isolated STHAG (21 unrelated patients), we had a definitive diagnosis in 14 (27%) and 15 cases (71%), respectively. Surprisingly, COL17A1 mutations accounted for the majority of autosomal-dominant AI cases. CONCLUSIONS: We have developed a novel targeted NGS assay for the efficient molecular diagnosis of a wide variety of orodental diseases. Furthermore, our panel will contribute to better understanding the contribution of these genes to orodental disease. TRIAL REGISTRATION NUMBERS: NCT01746121 and NCT02397824.journal articleresearch support, non-u.s. gov't2016 Feb2015 10 26importe
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