•Pervaporation was applied for the separation of real mixtures in the process of beer production.•Novel thin-film composite pervaporation membranes are characterised.•The influence of the structural ...features of the polyimide in the coating layer on transport properties is discussed.•The influence of the main technological parameters on the process performance is discussed.
Thin-film composite pervaporation membranes with selective layer from pyromellitic dianhydride -4,4′ oxydianiline polyimide on porous poly(amide-imide) support (Romakon™-PM) for treatment of water/ethanol mixtures with exceeding water content (>50 wt% water) are characterised by the use of scanning electron microscopy, atomic force microscopy and X-ray diffraction. Membranes showed high values of flux, separation factor and PSI (up to 774) in the selected feed mixture composition range. The influence of the support and structural features of the polyimide in the coating layer on the transport properties is discussed. The membranes are successfully tested in terms of pervaporation dehydration of beer. The influence of the permeate temperature on the separation process performance is discussed.
The influence of the type of crosslinking agent for poly(vinyl alcohol) (PVA) (glutaraldehyde or epichlorohydrin) on the structure, morphology, thermal stability, and electrochemical properties of ...composite membranes based on the domestic perfluorinated sulfonic acid copolymer LSC, an analog of Nafion®, has been studied. The introduction of hydrophilic PVA has led to an increase in the moisture content of the membranes, which, taking into account the structural features, affects the proton conductivity. The presence of up to 5 wt % of cross-linked PVA in the composite membrane has not significantly changed the initial structure of LSC. The degree of crystallinity of the composite membranes upon the introduction of PVA has been slightly increased as compared to the original LSC membrane. With an increase in the amount of PVA in the composite, a domain surface morphology has appeared, its roughness being clearly increased. The increase in the PVA content in the LSC-PVA-GA samples has led to a noticeable increase in the temperature of thermal decomposition of sulfonic acid groups, while it has remained almost unchanged for the LSC-PVA-ECH samples.
The surface morphology, structural organization, and transport properties of composite membranes based on Russian Nafion-type perfluorinated copolymers filled with zirconium dioxide nanoparticles are ...studied using atomic force and scanning electron microscopy, X-ray structural analysis, and thermal analysis. A relationship between the morphology of the free surface and the “substrate” surface of Nafion-LSC-1 proton-conductive film membranes and the concentration of zirconium-dioxide nanoparticles (ZrO
2
) is found. Atomic force and scanning electron microscopy reveals a gradient in the concentration of zirconium-dioxide nanoparticles, with the highest concentration on the substrate side of the membrane. The free surface is characterized by the presence of two phases alternating over the surface area of the membrane, which may be due to the presence of hydrophilic and hydrophobic regions. Zirconium nanoparticles form associates with sizes up to 300 nm. Wide-angle X-ray diffraction data suggest that Nafion-LSC-1 composite membranes have a mesomorphic structure when the concentration of zirconium-dioxide nanoparticles is 1.6 wt %, while the precursors of these membranes are characterized by a crystalline structure. The samples of Nafion-LSC-1 and composite membranes filled with 0.53, 1.12, and 1.61 wt % of nanoparticles are characterized by moisture content, proton conductivity, and heat resistance.
Glioblastoma is the most aggressive type of brain tumors resistant to a number of antitumor drugs. The problem of therapy and drug treatment course is complicated by extremely high heterogeneity in ...the benign cell populations, the random arrangement of tumor cells, and polymorphism of their nuclei. The pathogenesis of gliomas needs to be studied using modern cellular technologies, genome- and transcriptome-wide technologies of high-throughput sequencing, analysis of gene expression on microarrays, and methods of modern bioinformatics to find new therapy targets. Functional annotation of genes related to the disease could be retrieved based on genetic databases and cross-validated by integrating complementary experimental data. Gene network reconstruction for a set of genes (proteins) proved to be effective approach to study mechanisms underlying disease progression. We used online bioinformatics tools for annotation of gene list for glioma, reconstruction of gene network and comparative analysis of gene ontology categories. The available tools and the databases for glioblastoma gene analysis are discussed together with the recent progress in this field.
Phase equilibria in the NaVO
3
–Na
2
WO
4
two-component system and in the NaCl–NaVO
3
–Na
2
EO
4
(E = Mo or W) three-component system were studied. The phase assemblages of the NaCl–NaVO
3
–Na
2
EO
4
...(E = Mo or W) three-component systems were analyzed. Differential thermal analysis (DTA) showed that the binary system is a eutectic system and the three-component systems are partitioned by the compound Na
3
ClEO
4
into two secondary triangles, in each of which eutectics were found. The percentages of the components in the ternary eutectics and their melting points were determined. Phase equilibria were described for all elements of the phase diagrams studied in this work. The Na
2
WO
4
crystallization field is represented by α, β, and γ phases, and the Na
2
MoO
4
crystallization field, by δ, γ, and β phases. The smallest crystallization field in the ternary systems belongs to low-melting NaVO
3
.
Specific absorption rate of superparamagnetic nanoparticles with uniaxial magnetic anisotropy has been calculated both for dilute assembly and for assembly of nanoparticle clusters with various ...filling factors using numerical simulation. The optimal particle diameters at which the specific absorption rate of assembly reaches a maximum have been obtained depending on the value of the uniaxial anisotropy constant. The optimal particle diameters are found to shift to smaller values with an increase in the anisotropy constant. The range of optimal diameters decreases simultaneously. The specific absorption rate decreases also as a function of cluster filling factor, but the optimal particle diameters remain almost unchanged.
the current-voltage characteristics and photoelectric properties of semiconductor structures containing Pd nanoparticles in thin films synthesized by the sol-gel method on an
n
-InP substrate have ...been investigated. The experimental results show that in presence of hydrogen the cut-off voltage changes. The photovoltage and photocurrent upon illumination of the structure with an LED (λ = 0
.
9 µm) and pulsed exposure to hydrogen change, that was observed earlier for hydrogen-sensitive Pd/
n
-InP Schottky diodes. The prospects of using the structures under study as a sensitive element for hydrogen sensor are discussed.
Polymer film membranes are used to solve specific separation problems that dictate structural requirements. Structural and morphological parameters of film membranes based on glassy ...polyheteroarylenes can be controlled in the process of preparation from solutions that opens up prospects for obtaining structured membranes required for targeted separation. In the case of aromatic poly(amide-imide)s, the possibility of controlling film formation and structure virtually has not been studied. In the present work, a series of homologous co-poly(amide-imide)s differing in the number of repeating units with carboxyl-substituted aromatic fragments was synthesized by polycondensation. Comparative analysis of the processes of formation of membranes with different morphologies based on these polymers under equal conditions was performed. New information was obtained about the influence of the amounts of carboxyl groups and the residual solvent on structural properties of asymmetric membranes. The influence of these factors on transport properties of dense membranes under pervaporation conditions was studied. It was demonstrated that in the case of carboxyl-containing poly(amide-imide)s, the domains formed during film preparation had a significant effect on membrane properties.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Objective to describe the features of the ENT conditions and disorders in children with Hunter syndrome. Hunter syndrome, also known as mucopolysaccharidosis type II (MPS II), is a rare X-linked ...recessive disease. The MPS II is a hereditary metabolic disorder caused by accumulation of glycosaminoglycans (GAG) in organs and tissues due to mutations in the genes, which encode intralysosomal hydrolysis of macromolecules. Hunter syndrome is a progressive, multisystem disease. At the same time a child may have mental retardation and speech development delay, skeletal bone deformities, loss of vision, hearing loss.Patients and MethodsThe study included 17 boys aged from 2 to 12 years old with genetically confirmed Hunter syndrome. All patients underwent examination by otolaryngologist, also tympanometry, diagnostic nasopharyngolaryngoscopy, registration of otoacoustic emission, audiometry, cardiorespiratory monitoring were performed.ResultsThe accumulation of GAG leads to a gradual narrowing of the nasopharynx and larynx lumen, a thickening of the tongue and vocal folds, laryngeal cartilages deformation, an enlarged of pharyngeal, palatine and lingual tonsils.11 children (64.7%) had chronic inflammation of the nasal mucosa and pharyngeal tonsil with frequent exacerbations. Pharyngeal tonsil hypertrophy was detected in 10 patients (58.8%).14 children (82%) had a wide, thickened tongue. Hypertrophy of the tonsils was diagnosed in 8 children (47%).The voice had changed (hoarseness) in 16 children (94%). Deformation of the epiglottis was detected in 4 people (23.5%), tracheomalacia – in 1 child (5.8%).Among the complications acute sinusitis and exudative otitis media were detectable in 52.9% of patients. 10 children (58.8%) had obstructive sleep apnea (OSA) syndrome, two of them (11.7%) had a severe degree of the disease, which was an indication for adenotonsillectomy. Hearing loss was found in 10 boys (58.8%).In most patients (82%) a combined pathology of the ear, throat and nose was detected, 2 children (11.7%) had only adenoid hypertrophy, and only 1 child(5.8%) did not have any pathology of ENT organs.ConclusionFunctional disorders and diseases of the ear, throat and nose are found in most children with Hunter syndrome, which could be one of its early manifestations. An ENT specialist may suspect MPS type II according to the presence of an ENT pathology that is difficult to treat in a standard manner, combined with the pathology of other organs and systems.Early diagnosis and the possibility of enzyme replacement therapy can control the disease progression and avoid early disability.
The kinetics of changing in optical transmittance of palladium (Pd) nanolayers (about 10 nm thick, deposited on object glass substrates by thermal evaporation in vacuum) in hydrogen flow (100% H
2
) ...in the temperature range of 300–335 K are studied. It is shown that the rate of changing of palladium optical transmittance at hydrogen flow rises linearly with increasing the temperature due to sorption of hydrogen by Pd layer. The rate of changing in optical transmittance of Pd layer during sorption and desorption of hydrogen is established to rise by about one order with increasing the temperature from 300 to 335 K. The curves describing the changing in optical transmittance of palladium nanolayer during hydrogen desorption have two distinct sections: linear and nonlinear. The linear section of the curve weakly depends on temperature, while the nonlinear section sharply rises with increasing the temperature. Such the changing of the rate in optical transmittance can be associated with phase transition from β- to α-phase during hydrogen desorption from palladium.
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