145,222 research outputs found
UV-enhanced sacrificial layer stabilised graphene oxide hollow fibre membranes for nanofiltration
Graphene oxide (GO) membranes have demonstrated great potential in gas separation and liquid filtration. For upscale applications, GO membranes in a hollow fibre geometry are of particular interest due to the high-efficiency and easy-assembly features at module level. However, GO membranes were found unstable in dry state on ceramic hollow fibre substrates, mainly due to the drying-related shrinkage, which has limited the applications and post-treatments of GO membranes. We demonstrate here that GO hollow fibre membranes can be stabilised by using a porous poly(methyl methacrylate) (PMMA) sacrificial layer, which creates a space between the hollow fibre substrate and the GO membrane thus allowing stress-free shrinkage. Defect-free GO hollow fibre membrane was successfully determined and the membrane was stable in a long term (1200 hours) gas-tight stability test. Post-treatment of the GO membranes with UV light was also successfully accomplished in air, which induced the creation of controlled microstructural defects in the membrane and increased the roughness factor of the membrane surface. The permeability of the UV-treated GO membranes was greatly enhanced from 0.07 to 2.8 L m(−2) h(−1) bar(−1) for water, and 0.14 to 7.5 L m(−2) h(−1) bar(−1) for acetone, with an unchanged low molecular weight cut off (~250 Da)
Complementation between mouse Mfn1 and Mfn2 protects mitochondrial fusion defects caused by CMT2A disease mutations
Mfn2, an oligomeric mitochondrial protein important for mitochondrial fusion, is mutated in Charcot-Marie-Tooth disease (CMT) type 2A, a peripheral neuropathy characterized by axonal degeneration. In addition to homooligomeric complexes, Mfn2 also associates with Mfn1, but the functional significance of such heterooligomeric complexes is unknown. Also unknown is why Mfn2 mutations in CMT2A lead to cell type–specific defects given the widespread expression of Mfn2. In this study, we show that homooligomeric complexes formed by many Mfn2 disease mutants are nonfunctional for mitochondrial fusion. However, wild-type Mfn1 complements mutant Mfn2 through the formation of heterooligomeric complexes, including complexes that form in trans between mitochondria. Wild-type Mfn2 cannot complement the disease alleles. Our results highlight the functional importance of Mfn1–Mfn2 heterooligomeric complexes and the close interplay between the two mitofusins in the control of mitochondrial fusion. Furthermore, they suggest that tissues with low Mfn1 expression are vulnerable in CMT2A and that methods to increase Mfn1 expression in the peripheral nervous system would benefit CMT2A patients
A study of the growth in speech sound discrimination ability of kindergarten children
Thesis (Ed.M.)--Boston Universit
A survey of voice quality disorders among high school students of the eastern and western New England Dialect regions.
Thesis (Ed.M.)--Boston Universit
Mechanisms conferring sensitivity to low dose radiation exposure and consideration of potentially sensitivie individuals
No description supplie
A novel mutation in NDUFB11 unveils a new clinical phenotype associated with lactic acidosis and sideroblastic anemia
NDUFB11, a component of mitochondrial complex I, is a relatively small integral membrane protein, belonging to the 'supernumerary' group of subunits, but proved to be absolutely essential for the assembly of an active complex I. Mutations in in the X-linked nuclear encoded NDUFB11 gene have recently been discovered in association with two distinct phenotypes, i.e. microphthalmia with linear skin defects and histiocytoid cardiomyopathy. We report on a male with complex I deficiency, caused by a de novo mutation in NDUFB11 and displaying early onset sideroblastic anemia as the unique feature. This is the third report that describes a mutation in NDUFB11 but all are associated to a different phenotype. Our results further expand the molecular spectrum and associated clinical phenotype of NDUFB11 defects
New era of cystic fibrosis: full mutational analysis and personalized therapy
Despite its apparently simple genetics, cystic fibrosis (CF) is a rather complex genetic disease. A lot of variability in the steps of the path from the cystic fibrosis transmembrane conductance regulator (CFTR ) gene to the clinical manifestations originates an uncertain genotype - phenotype relationship. A major determinant of this uncertainty is the incomplete knowledge of the CFTR mutated genotypes, due to the high number of CFTR mutations and to the higher number of their combinations in trans and in cis. Also the very limited knowledge of functional effects of CFTR mutated alleles severely impairs our diagnostic and prognostic ability. The
final phenotypic modulation exerted by CFTR modifier genes and interactome further complicates the framework.
The next generation sequencing approach is a rapid, lowcost and high-throughput tool that allows a near complete structural characterization of CFTR mutated genotypes, as well as of genotypes of several other genes cooperating to the final CF clinical manifestations. This powerful method perfectly complements the new personalized therapeutic approach for CF. Drugs active on specific CFTR mutational classes are already available for CF patients or are in phase 3 trials. A complete genetic characterization has been becoming crucial for a correct personalized therapy. However, the need of a functional classification of each CFTR mutation potently arises. Future big efforts towards an ever more detailed knowledge of both structural and
functional CFTR defects, coupled to parallel personalized therapeutic interventions decisive for CF cure can be
foreseen
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