158 research outputs found
Compression and strength behaviour of viscose/polypropylene nonwoven fabrics
Compression and strength properties of viscose/polypropylene nonwoven fabrics has been studied. Compressionbehavior of the nonwoven samples (sample compressibility, sample thickness loss & sample compressive resilience) havebeen analyzed considering the magnitude of applied pressure, fabric weight, fabric thickness, and the porosity of thesamples. Based on the calculated porosity of the samples, pore compression behavior (pore compressibility, porosity loss &pore compressive resilience) are determined. Equations for the determination of pore compressibility, porosity loss, and porecompressive resilience, are established. Tensile strength and elongation as well as bursting strength and ball traverseelongation are also determined. The results show that the sample compression behavior as well as pore compressionbehavior depend on the magnitude of applied pressure. At the high level of applied pressure, a sample with highercompressibility has the lower sample compressive resilience. Differences in pore compressibility and porosity loss betweeninvestigated samples have also been registered, except in pore compressive resilience. Sample with the higher fabric weight,higher thickness, and lower porosity shows the lower sample compressibility, pore compressibility, sample thickness loss,porosity loss, and tensile elongation, but the higher tensile strength, bursting strength, and ball traverse elongation
Quality of clothing fabrics in terms of their comfort properties
Quality of various clothing woven fabrics with respect to their comfort properties, such as electro-physical properties, air permeability, and compression properties has been studied. Fabrics are produced from cotton and cotton/polyester fibre blends in plain, twill, satin and basket weave. Results show that cotton fabrics have lower values of the volume resistivity, air permeability and compressive resilience but higher values of effective relative dielectric permeability and compressibility as compared to fabrics that have been produced from cotton/PES fibre blends. Regression analysis shows a strong linear correlative relationship between the air permeability and the porosity of the woven fabrics with very high coefficient of linear correlation (0.9807). It is also observed that comfort properties are determined by the structure of woven fabrics (raw material composition, type of weave) as well as by the fabrics surface condition. Findings of the studies have been used for estimating the quality of woven fabrics in terms of their comfort properties by the application of ranking method. It is concluded that the group of cotton fabrics exhibits better quality of comfort as compared to the group of cotton/PES blend fabrics.
Derangement of Ras-Guanine Nucleotide-Releasing Factor 1 (Ras-GRF1) and Extracellular Signal-Regulated Kinase (ERK) Dependent Striatal Plasticity in L-DOPA-Induced Dyskinesia
BACKGROUND: Bidirectional long-term plasticity at the corticostriatal synapse has been proposed as a central cellular mechanism governing dopamine-mediated behavioral adaptations in the basal ganglia system. Balanced activity of medium spiny neurons (MSNs) in the direct and the indirect pathways is essential for normal striatal function. This balance is disrupted in Parkinson's disease and in L-3,4-dihydroxyphenylalanine (L-DOPA)-induced dyskinesia (LID), a common motor complication of current pharmacotherapy of Parkinson's disease.
METHODS: Electrophysiological recordings were performed in mouse cortico-striatal slice preparation. Synaptic plasticity, such as long-term potentiation (LTP) and depotentiation, was investigated. Specific pharmacological inhibitors or genetic manipulations were used to modulate the Ras-extracellular signal-regulated kinase (Ras-ERK) pathway, a signal transduction cascade implicated in behavioral plasticity, and synaptic activity in different subpopulations of striatal neurons was measured.
RESULTS: We found that the Ras-ERK pathway, is not only essential for long-term potentiation induced with a high frequency stimulation protocol (HFS-LTP) in the dorsal striatum, but also for its reversal, synaptic depotentiation. Ablation of Ras-guanine nucleotide-releasing factor 1 (Ras-GRF1), a neuronal activator of Ras proteins, causes a specific loss of HFS-LTP in the medium spiny neurons in the direct pathway without affecting LTP in the indirect pathway. Analysis of LTP in animals with unilateral 6-hydroxydopamine lesions (6-OHDA) rendered dyskinetic with chronic L-DOPA treatment reveals a complex, Ras-GRF1 and pathway-independent, apparently stochastic involvement of ERK.
CONCLUSIONS: These data not only demonstrate a central role for Ras-ERK signaling in striatal LTP, depotentiation, and LTP restored after L-DOPA treatment but also disclose multifaceted synaptic adaptations occurring in response to dopaminergic denervation and pulsatile administration of L-DOPA
TGFβR signalling determines CD103<sup>+</sup>CD11b<sup>+</sup> dendritic cell development in the intestine
CD103+CD11b+ dendritic cells (DCs) are unique to the intestine, but the factors governing their differentiation are unclear. Here we show that transforming growth factor receptor 1 (TGFβR1) has an indispensable, cell intrinsic role in the development of these cells. Deletion of Tgfbr1 results in markedly fewer intestinal CD103+CD11b+ DCs and a reciprocal increase in the CD103−CD11b+ dendritic cell subset. Transcriptional profiling identifies markers that define the CD103+CD11b+ DC lineage, including CD101, TREM1 and Siglec-F, and shows that the absence of CD103+CD11b+ DCs in CD11c-Cre.Tgfbr1fl/fl mice reflects defective differentiation from CD103−CD11b+ intermediaries, rather than an isolated loss of CD103 expression. The defect in CD103+CD11b+ DCs is accompanied by reduced generation of antigen-specific, inducible FoxP3+ regulatory T cells in vitro and in vivo, and by reduced numbers of endogenous Th17 cells in the intestinal mucosa. Thus, TGFβR1-mediated signalling may explain the tissue-specific development of these unique DCs
Increased S-nitrosylation and proteasomal degradation of caspase-3 during infection contribute to the persistence of adherent invasive escherichia coli (AIEC) in immune cells
Adherent invasive Escherichia coli (AIEC) have been implicated as a causative agent of Crohn's disease (CD) due to their isolation from the intestines of CD sufferers and their ability to persist in macrophages inducing granulomas. The rapid intracellular multiplication of AIEC sets it apart from other enteric pathogens such as Salmonella Typhimurium which after limited replication induce programmed cell death (PCD). Understanding the response of infected cells to the increased AIEC bacterial load and associated metabolic stress may offer insights into AIEC pathogenesis and its association with CD. Here we show that AIEC persistence within macrophages and dendritic cells is facilitated by increased proteasomal degradation of caspase-3. In addition S-nitrosylation of pro- and active forms of caspase-3, which can inhibit the enzymes activity, is increased in AIEC infected macrophages. This S-nitrosylated caspase-3 was seen to accumulate upon inhibition of the proteasome indicating an additional role for S-nitrosylation in inducing caspase-3 degradation in a manner independent of ubiquitination. In addition to the autophagic genetic defects that are linked to CD, this delay in apoptosis mediated in AIEC infected cells through increased degradation of caspase-3, may be an essential factor in its prolonged persistence in CD patients
Potential of a multiparametric optical sensor for determining in situ the maturity components of red and white vitis vinifera wine grapes
A non-destructive fluorescence-based technique for evaluating Vitis vinifera L. grape maturity using a portable sensor (Multiplex ®) is presented. It provides indices of anthocyanins and chlorophyll in Cabernet Sauvignon, Merlot and Sangiovese red grapes and of flavonols and chlorophyll in Vermentino white grapes. The good exponential relationship between the anthocyanin index and the actual anthocyanin content determined by wet chemistry was used to estimate grape anthocyanins from in field sensor data during ripening. Marked differences were found in the kinetics and the amount of anthocyanins between cultivars and between seasons. A sensor-driven mapping of the anthocyanin content in the grapes, expressed as g/kg fresh weight, was performed on a 7-ha vineyard planted with Sangiovese. In the Vermentino, the flavonol index was favorably correlated to the actual content of berry skin flavonols determined by means of HPLC analysis of skin extracts. It was used to make a non-destructive estimate of the evolution in the flavonol concentration in grape berry samplings. The chlorophyll index was inversely correlated in linear manner to the total soluble solids (°Brix): it could, therefore, be used as a new index of technological maturity. The fluorescence sensor (Multiplex) possesses a high potential for representing an important innovative tool for controlling grape maturity in precision viticulture
To respond or not to respond - a personal perspective of intestinal tolerance
For many years, the intestine was one of the poor relations of the immunology world, being a realm inhabited mostly by specialists and those interested in unusual phenomena. However, this has changed dramatically in recent years with the realization of how important the microbiota is in shaping immune function throughout the body, and almost every major immunology institution now includes the intestine as an area of interest. One of the most important aspects of the intestinal immune system is how it discriminates carefully between harmless and harmful antigens, in particular, its ability to generate active tolerance to materials such as commensal bacteria and food proteins. This phenomenon has been recognized for more than 100 years, and it is essential for preventing inflammatory disease in the intestine, but its basis remains enigmatic. Here, I discuss the progress that has been made in understanding oral tolerance during my 40 years in the field and highlight the topics that will be the focus of future research
Yersinia pseudotuberculosis supports Th17 differentiation and limits de novo regulatory T cell induction by directly interfering with T cell receptor signaling
Lymph-borne CD8α+ dendritic cells are uniquely able to cross-prime CD8+ T cells with antigen acquired from intestinal epithelial cells
Cross-presentation of cellular antigens is crucial for priming CD8<sup>+</sup> T cells, and generating immunity to intracellular pathogens—particularly viruses. It is unclear which intestinal phagocytes perform this function in vivo. To address this, we examined dendritic cells (DCs) from the intestinal lymph of IFABP-tOVA 232-4 mice, which express ovalbumin in small intestinal epithelial cells (IECs). Among lymph DCs (LDCs) only CD103<sup>+</sup> CD11b<sup>−</sup> CD8α<sup>+</sup> DCs cross-present IEC-derived ovalbumin to CD8<sup>+</sup> OT-I T cells. Similarly, in the mesenteric lymph nodes (MLNs), cross-presentation of IEC–ovalbumin was limited to the CD11c<sup>+</sup> MHCII<sup>hi</sup> CD8α<sup>+</sup> migratory DCs, but absent from all other subsets, including the resident CD8α<sup>hi</sup> DCs. Crucially, delivery of purified CD8α<sup>+</sup> LDCs, but not other LDC subsets, into the MLN subcapsular lymphatic sinus induced proliferation of ovalbumin-specific, gut-tropic CD8<sup>+</sup> T cells <i>in vivo</i>. Finally, in 232-4 mice treated with R848, CD8α<sup>+</sup> LDCs were uniquely able to cross-prime interferon γ-producing CD8<sup>+</sup>T cells and drive their migration to the intestine. Our results clearly demonstrate that migrating CD8α<sup>+</sup> intestinal DCs are indispensable for cross-presentation of cellular antigens and, in conditions of inflammation, for the initial differentiation of effector CD8<sup>+</sup> T cells. They may therefore represent an important target for the development of antiviral vaccinations
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