14 research outputs found

    Shielding features, to non-ionizing and ionizing photons, of FeCr-based composites

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    PubMed:33059194WOS:000596040000031This paper has been focused on the a detail study on non-ionizing and ionizing electromagnetic (EM) shielding features and build-up factors of reinforced with ferrochrome (FeCr) composites. The non-inozing electromagnetic shielding performance quantities of composites have been determined in the frequency range between 12.4 and 18.0 GHz. Also, the experimental mass attenuation coefficients (MAC) have been estimated using gamma spectrometer and various radioactive point, and compared to those of theoretical and simulation (MCNPX) results. With help of the obtained linear attenuation coefficients, several attenuation quantities, i.e., effective atomic number (Zeff), half value layer (HVL), and mean free path (MFP) have been discussed. In addition, buildup factors (EBF and EABF) values have been estimated utilizing the G-P fitting method. The results showed that composite encoded FeCr(15%) is superior shielding attenuation properties among the investigated samples. © 2020 Elsevier Lt

    Is muscle glycogenolysis impaired in X-linked phosphorylase b kinase deficiency?

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    Contains fulltext : 69600.pdf (publisher's version ) (Closed access)OBJECTIVE: It is unclear to what extent muscle phosphorylase b kinase (PHK) deficiency is associated with exercise-related symptoms and impaired muscle metabolism, because 1) only four patients have been characterized at the molecular level, 2) reported symptoms have been nonspecific, and 3) lactate responses to ischemic handgrip exercise have been normal. METHODS: We studied a 50-year-old man with X-linked PHK deficiency using ischemic forearm and cycle ergometry exercise tests to define the derangement of muscle metabolism. We compared our findings with those in patients with McArdle disease and in healthy subjects. RESULTS: Sequencing of PHKA1 showed a novel pathogenic mutation (c.831G>A) in exon 7. There was a normal increase of plasma lactate during forearm ischemic exercise, but lactate did not change during dynamic, submaximal exercise in contrast to the fourfold increase in healthy subjects. Constant workload elicited a second wind in all patients with McArdle disease, but not in the patient with PHK deficiency. IV glucose administration appeared to improve exercise tolerance in the patient with PHK deficiency, but not to the same extent as in the patients with McArdle disease. Lipolysis was higher in the patient with PHK deficiency than in controls. CONCLUSION: These findings demonstrate that X-linked PHK deficiency causes a mild metabolic myopathy with blunted muscle glycogen breakdown and impaired lactate production during dynamic exercise, which impairs oxidative capacity only marginally. The different response of lactate to submaximal and maximal exercise is likely related to differential activation mechanisms for myophosphorylase

    Placental Involvement in Glycogen Storage Disease Type IV

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    Glycogen storage disease type IV (GSD IV) is a rare autosomal recessive disorder caused by glycogen branching enzyme (GBE) deficiency and resulting in the storage of abnormal glycogen (polyglucosan). Prenatal diagnosis is based on biochemical assay of GBE activity or on mutation analysis, but polyglucosan can also be identified histologically in fetal tissues. We document placental involvement at 25 and 35 weeks of gestation in two cases with genetically confirmed GSD IV. Intracellular inclusions were seen mainly in the extravillous trophoblast. Our findings suggest the possibility of prenatal diagnosis by histological evaluation of placental biopsies. © 2008 Elsevier Ltd. All rights reserved

    Fhl1 W122S causes loss of protein function and late-onset mild myopathy

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    A member of the four-and-a-half-LIM (FHL) domain protein family, FHL1, is highly expressed in human adult skeletal and cardiac muscle. Mutations in FHL1 have been associated with diverse X-linked muscle diseases: scapuloperoneal (SP) myopathy, reducing body myopathy, X-linked myopathy with postural muscle atrophy, rigid spine syndrome (RSS) and Emery-Dreifuss muscular dystrophy. In 2008, we identified a missense mutation in the second LIM domain of FHL1 (c.365 G>C, p.W122S) in a family with SP myopathy. We generated a knock-in mouse model harboring the c.365 G>C Fhl1 mutation and investigated the effects of this mutation at three time points (3-5 months, 7-10 months and 18-20 months) in hemizygous male and heterozygous female mice. Survival was comparable in mutant and wild-type animals. We observed decreased forelimb strength and exercise capacity in adult hemizygous male mice starting from 7 to 10 months of age. Western blot analysis showed absence of Fhl1 in muscle at later stages. Thus, adult hemizygous male, but not heterozygous female, mice showed a slowly progressive phenotype similar to human patients with late-onset muscle weakness. In contrast to SP myopathy patients with the FHL1 W122S mutation, mutant mice did not manifest cytoplasmic inclusions (reducing bodies) in muscle. Because muscle weakness was evident prior to loss of Fhl1 protein and without reducing bodies, our findings indicate that loss of function is responsible for the myopathy in the Fhl1 W122S knock-in mice

    Macrocytic anemia and mitochondriopathy resulting from a defect in sideroflexin 4.

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    We used exome sequencing to identify mutations in sideroflexin 4 (SFXN4) in two children with mitochondrial disease (the more severe case also presented with macrocytic anemia). SFXN4 is an uncharacterized mitochondrial protein that localizes to the mitochondrial inner membrane. sfxn4 knockdown in zebrafish recapitulated the mitochondrial respiratory defect observed in both individuals and the macrocytic anemia with megaloblastic features of the more severe case. In vitro and in vivo complementation studies with fibroblasts from the affected individuals and zebrafish demonstrated the requirement of SFXN4 for mitochondrial respiratory homeostasis and erythropoiesis. Our findings establish mutations in SFXN4 as a cause of mitochondriopathy and macrocytic anemia

    Macrocytic anemia and mitochondriopathy resulting from a defect in sideroflexin 4

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    We used exome sequencing to identify mutations in sideroflexin 4 (SFXN4) in two children with mitochondrial disease (the more severe case also presented with macrocytic anemia). SFXN4 is an uncharacterized mitochondrial protein that localizes to the mitochondrial inner membrane. sfxn4 knockdown in zebrafish recapitulated the mitochondrial respiratory defect observed in both individuals and the macrocytic anemia with megaloblastic features of the more severe case. In vitro and in vivo complementation studies with fibroblasts from the affected individuals and zebrafish demonstrated the requirement of SFXN4 for mitochondrial respiratory homeostasis and erythropoiesis. Our findings establish mutations in SFXN4 as a cause of mitochondriopathy and macrocytic anemia. \ua9 2013 by The American Society of Human Genetics. All rights reserved
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