170 research outputs found
Effect of CORONA treatment on finishing processes of linen fabrics
Application of CORONA technology for finishing processes of cellulosic fabric is an innovation in European textile industry.
A CORONA discharge is created between two electrodes with high voltage and a frequency of 20 – 40 kHz affecting the surface of a fabric running continuously at ambience pressure and temperature. The paper presents the newest results of research refer to linen fabrics properties without and after CORONA treatment. Fabrics after Corona get new better properties, what makes finishing processes much easier. Quality of fabrics after Corona can be highly improved in important aspects concerning safety of users. Corona treatment improves significantly wettability of cellulosic fabrics. New stage – CORONA treatment – apply in finishing process in line allows for eliminating initial washing without detriment to quality of finished fabric. Instead of washing applied, CORONA ensures good results in bleaching and evenness of dyeing by some kinds of dyes. Corona gives a chance to get better end properties at lower costs and less environmental aggressio
Structural changes in CORONA discharged cotton submitted to mercerization
The cleaning and swelling operations in cotton’s pré-treatmemt make it prepared for posterior dyeing and finishing. From those, mercerization is the one able to confer a major increase in overall quality of the fibrous material and consists of a very strong alkaline treatment of the material, which is kept under controlled tension. The properties are changed in the sense of a more intense luster, higher mechanical resistance, higher dyeability, higher obsorption of liquids and finishing compounds and a better dimensional stability. Changes in supramolecular organization namely in the type of cristallinity occur, as well as a morphological variation concerning the circularity of the transversal section of the fibre.
The present study proposes new conditions for mercerization assuming that a CORONA plasmatic discharge previously made is able to provide stronger effects by means of a more intense and faster reaction between the alkali and the cellulose.
CORONA treatment consists on the application of an electrical discharge of high voltage (around 10.000V) through air between two electrodes, using frequencies around 40 kHz, at normal atmospheric temperature and pressure, on dry cotton fabric. Structural changes analysis was made using FT-IR technique, microscopic studies, dyeing tests and determination of barium activity number for evaluation of mercerization degree.
Results show an important improvement of mercerization level meaning the possibility of a lower ecological impact and lower costs of processing
Developments in preparation and dyeing of CORONA discharged cellulosic materials
The preparation and dyeing of cellulosic fabrics hás important problems such as uniformity of aspect, cleaning efficiency, level of bleaching, conformity and fastness of colours, and ecological impact.
Combination of preparation processes can give optimal solutions, regarding economy and ecology, especially if superior quality items are achieved in final products. In fact, high standards concerning whiteness, starch removal and hidrophilicity are considered a good basis for leveled, cleaner and intense dyeing. A better white basis, escellent hidrophilicity and enough removal of impurities are obtained if desizing is omitted and a CORONA discharge is made over dry grey material.
Exhaustion dyeings with different classes of direct dyes show similar behavior concerning the positive influence of the discharge in the intensity of colours and their fastness. Good penetration of dyes in coronised cotton materials is assured and consequently a good fastness is abtained
Quality improvement and shortcut of preparation of CORONA discharged cotton fabrics
Textile industry has an important impact in world economy and consequently on environmental quality of life.
Textile processing uses huge amount of water, chemicals and energy and it is quite easy to conclude about the enormous meaning of pollution control and rationalization of energetic demands.
CORONA treatment in the wet processing of cotton textile materials has a great potential concerning the improvement of all the operations included in it, namely in preparation, dyeing, printing or final finishing.
Physical and chemical surface changes in cotton structure are noticed after CORONA discharge. The increase in oxidation potential and the creation of channels through cuticle are referred as responsible for the variation in cotton properties after plasmatic discharge, specially concerning absorption of water and treatment baths.
Advantages as the use of less chemicals, namely alkalis, oxidants and other auxiliaries, the reduction of times and temperatures, less damages in the materials surely can have a strong impact in economical and ecological aspects of the process. Complete hidrophilization of cellulosic materials renders very easy the access of baths and consequently conditions to more efficient operations are found.
Bleaching processes aim to give textile materials the adequate whiteness degree, the removal of sizing agents, the increase of hidrophility and cleaning by extraction of seeds, husks and waxes. The use of hydrogen peroxide in alkaline medium is a flexible and more ecological process when compared with methods based in chlorinated compounds.
The present work concerns the study of half bleaching process when this operation is preceded by a CORONA discharge made on dry grey fabrics. The influence in the whiteness degree, hidrophility, starch removal and uniformity of properties of the cellulosic material after preparation is studied
Influence of plasmatic CORONA discharge in dyeing of desized/mercerised fabrics
If a plasmatic CORONA discharge is applied in desized cotton fabrics, mercerisation is easily integrated in the chain of their wet preparation, meaning better whiteness and darker and cleaner colours in posterior direct dyeing, when compared with a mercerisation done in presence of an adequate wetting agent. This means that CORONA achieves fibre modifications which promote quicker penetration of the caustic soda inside the material. These results have great impact in the wet processing of cellulosic materials, meaning a reduction of pollution in the source, by eliminating the wetting agent, as well as an increase in mercerisation performance, with better whiteness and better dyeing effect in desized/mercerised materials
Alterations in peripheral blood memory B cells in patients with active rheumatoid arthritis are dependent on the action of tumour necrosis factor
INTRODUCTION: Disturbances in peripheral blood memory B cell subpopulations have been observed in various autoimmune diseases, but have not been fully delineated in rheumatoid arthritis (RA). Additionally, the possible role of tumour necrosis factor (TNF) in regulating changes in specific peripheral blood memory B cell subsets in RA is still unclear. METHODS: The frequency and distribution of B cell subsets in the peripheral blood and synovial membrane of active RA patients with long-standing disease have been analysed. Additionally, the possible role of TNF in causing disturbances in memory B cell subsets in RA patients was assessed in a clinical trial with the specific TNF-neutralising antibody, infliximab. RESULTS: RA patients, independent of disease duration, have a significantly lower frequency of peripheral blood pre-switch IgD+CD27+ memory B cells than healthy individuals, whereas post-switch IgD-CD27+ accumulate with increased disease duration. Notably, both pre-switch IgD+CD27+ and post-switch IgD-CD27+ memory B cells accumulate in the synovial membrane of RA patients. Finally, anti-TNF therapy increased the frequency of pre-switch IgD+CD27 memory B cells in the peripheral blood. CONCLUSIONS: The data suggest that decreases in peripheral blood IgD+CD27+ pre-switch memory B cells in RA reflect their accumulation in the synovial tissue. Moreover, the significant increase in the peripheral blood pre-switch memory B cells in patients who underwent specific TNF-blockade with infliximab indicates that trafficking of memory B cells into inflamed tissue in RA patients is regulated by TNF and can be corrected by neutralising TN
The bile acid TUDCA increases glucose-induced insulin secretion via the cAMP/PKA pathway in pancreatic beta cells
Objective
While bile acids are important for the digestion process, they also act as signaling molecules in many tissues, including the endocrine pancreas, which expresses specific bile acid receptors that regulate several cell functions. In this study, we investigated the effects of the conjugated bile acid TUDCA on glucose-stimulated insulin secretion (GSIS) from pancreatic β-cells.
Methods
Pancreatic islets were isolated from 90-day-old male mice. Insulin secretion was measured by radioimmunoassay, protein phosphorylation by western blot, Ca2 + signals by fluorescence microscopy and ATP-dependent K+ (KATP) channels by electrophysiology.
Results
TUDCA dose-dependently increased GSIS in fresh islets at stimulatory glucose concentrations but remained without effect at low glucose levels. This effect was not associated with changes in glucose metabolism, Ca2 + signals or KATP channel activity; however, it was lost in the presence of a cAMP competitor or a PKA inhibitor. Additionally, PKA and CREB phosphorylation were observed after 1-hour incubation with TUDCA. The potentiation of GSIS was blunted by the Gα stimulatory, G protein subunit-specific inhibitor NF449 and mimicked by the specific TGR5 agonist INT-777, pointing to the involvement of the bile acid G protein-coupled receptor TGR5.
Conclusion
Our data indicate that TUDCA potentiates GSIS through the cAMP/PKA pathway.This work was by grants from the Spanish Ministerio de Ciencia e Innovación (BFU2013-42789-P; BFU2011-28358)This work was supported by grants from Fundacão de Amparo á Pesquisa do Estado de São Paulo (FAPESP 2013/01318-4)This work was supported by grants from Conselho Nacional para o Desenvolvimento CientÃfico e Tecnológico (CNPq 200030/2014-0
Characterisation of surface-liquids interaction in textile materials
Interaction of textile materials with liquids is very important to predict products behavior in different situations going from processing to use conditions, such as aqueous and dry cleaning, tendency to soiling, absorption of sweat, penetration of treatment products, dyeing baths and printing pastes.
Cotton hydrophilic and hydrophobic surfaces are analyzed in order to compare the more important types of cotton substrates and illustrate different processing phases and final products: raw, desized, bleached, softened, printed and resin finished materials.
Surface modifications were induced by changing the type of products applied in finishing treatments, namely different types of softeners, resins and printing pastes and by CORONA irradiation of these substrates. Energetic superficial changes and its influence over wettability behavior, either for hydrophilic or hydrophobic cases, were evaluated
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