Observation of damage initiation for trans-laminar fracture using in situ fast synchrotron x-ray radiography and ex situ x-ray computed tomography

Trans-laminar fracture is an important topic for engineering composites. In this study, trans-laminar fracture initiation in quasi-isotropic carbon/epoxy laminates made of non-crimp fabrics was examined using in situ fast synchrotron X-ray radiography and ex situ X-ray computed tomography. The maximum split lengths were measured by in situ radiography and were compared with the predicted values in a detailed FE model using cohesive elements. Ex situ computed tomography scans were also conducted to confirm that no fibre breakage occurs before the final load drop in the experiments. In situ and ex situ observations are complementary for the understanding of damage initiation

Characterizing the tissue of apple air-dried and osmo-air-dried rings by X-CT and OCT and relationship with ring crispness and fruit maturity at harvest measured by TRS

Air-dried apple rings were prepared from ‘Golden Delicious’ apples selected at harvest as less mature and more mature according to the absorption coefficient measured at 670 nm by time-resolved reflectance spectroscopy (TRS), stored in air for 5 months, and subjected to air-drying with (OSMO) and without (noOSMO) osmodehydration pre-treatment (60% sucrose syrup). Selected rings were submitted to microstructural analysis by X-ray computed tomography (X-CT), to subsurface structure analysis by optical coherence tomography (OCT) and to texture and sound emission analysis by bending–snapping test. Higher crispness index, higher number of sound events and higher average sound pressure level (SPL) characterized the OSMO rings. Total porosity was related to SPLav 60, pore fragmentation index to fracturability and specific surface area to the work required to snap the ring. A differentiation of the drying treatments, as well as of the products according to the TRS maturity class at harvest was obtained analyzing by principal component analysis (PCA) microstructure parameters and texture and acoustic parameters. The differences in mechanical and acoustic characteristics between OSMO and noOSMO rings were due to the different subsurface structure as found with OCT analysis

Prospective of Innovative Technologies for Quality Supervision and Classification of Roasted Coffee Beans

Color sorting is the major procedure employed for establish roast degree of coffee beans. However, color-based procedures have been proven to be ineffective, since coffee beans roasted to different degrees can present the same average readings in light reflectance measurements with significant quality variations. Besides to color, other major changes in beans are volume (swell), mass, form, bean pop and density. Eight samples of arabica coffee from Colombia and Guatemala have been roasted under slightly different conditions of time and temperature in order to obtain the same color classification. Sample analysis of data from nuclear magnetic resonance relaxometry show differences between samples in T1 and T2 parameters at cellular and subcellular level, and image analysis carried out on X-ray μCT leading to microestruture images corroborate differences in porosity and fissures presence among them, proving the potentiality of these technological solutions for sensing the microstructure of coffee to provide tools to enhance the roasting process

Characterisation of ‘Braeburn’ browning disorder by means of X-ray micro-CT

Unfavourable gas conditions during controlled atmosphere storage may cause browning symptoms in ‘Braeburn’ apple fruit (‘Braeburn’ browning disorder or BBD). These symptoms are likely to reflect massive changes in the microstructure of the fruit tissue. In this study, individual cells, the internal air network and the 3-D distribution of pores inside ‘Braeburn’ apple tissue were examined using high resolution X-ray micro computed tomography. Different stages of BBD could be clearly resolved on the virtual cross-sections, granting a unique 3-D insight in tissue flooding and formation of cavities in ‘Braeburn’ tissue during the development of the disorder. Image analysis methods were applied to extract morphometric parameters such as porosity, anisotropy and connectivity to characterise microstructure. The discriminative power of these descriptors was proven by their ability to classify fruit tissue as healthy and disordered with a success rate of 97%. The observed distinct radial patterns of porosity, anisotropy and connectivity may help in explaining why ‘Braeburn’ is susceptible to BBD.status: publishe

The Functional Implications of Common Genetic Variation in CYP3A5 and ABCB1 in Human Proximal Tubule Cells

Item does not contain fulltextBACKGROUND: Calcineurin inhibitors (CNIs) are the primary immunosuppressive drugs used in solid organ transplantation but are associated with the development of histological lesions leading to kidney failure. CNIs are metabolized by CYP3A and excreted by not only P-glycoprotein (P-gp) (ABCB1) in the gut and liver, but also by proximal tubule cells (PTCs) in the kidney. Multiple studies have demonstrated the importance of genetic variation in CYP3A5 and ABCB1 for CNI disposition and nephrotoxicity. The present study was designed to study the functional implication of variation in these two genes in human PTCs. METHODS: A technique was developed to culture cells from renal tissue obtained from renal graft recipients by routine kidney biopsy. Primary cells were immortalized, subcloned, and then characterized for specific PTC markers (AQP1, CD13, brush border morphology) and donor CYP3A5(rs776746)/ABCB1(rs1045642) genotype. We then selected specific sets of confirmed conditionally immortalized PTCs (ciPTC) according to different combinations of the aforementioned genetic variants. Quantitative real-time polymerase chain reaction, Western blot, and immunohistochemistry were performed for studying CYP3A5 and ABCB1 expression. CYP3A5 activity was assessed by differential midazolam (MDZ) hydroxylation and P-gp (ABCB1 product) activity by a calcein efflux assay. Differential drug metabolism between cell lines was assessed by tacrolimus disappearance over 24 h. RESULTS: Cell lines were generated from 27 out of 38 tissue samples. On the basis of genotype and PTC biomarkers, 11 subclones were selected. In vitro PTC morphology with brush border microvilli was confirmed. CYP3A5*1 carriers had increased 1-OH/4-OH MDZ formation versus homozygous *3 carriers (mean: 2.36 (95% CI:1.11-3.40) vs 0.88 (95% CI:0.48-1.27); p < 0.05). P-gp activity was confirmed by calcein accumulation (mean 38.6%; 95% CI:32.8-44.4%), which was higher in cell lines with the ABCB1 3435TT than the 3435CC/CT genotype (46.2% vs 35.5%; 95% CI:28.7-42.2%). Tacrolimus disappearance was about two-fold higher in cell lines with the combined CYP3A5*1/ABCB1 3435TT genotype versus other genotype combinations. CONCLUSION: Biopsy-derived and immortalized human PTC cell lines demonstrate functional expression of genes involved in CNI metabolism. Differences in functional expression were detected according to common genetic variants in CYP3A5 and ABCB1. The studied genetic variants had a significant impact on in vitro tacrolimus metabolism. In particular, ciPTC with the combined CYP3A5*1/ABCB1 3435TT genotype demonstrated higher tacrolimus disappearance versus ciPTCs with a different pharmacogenetic profile. This in vitro model stresses the importance of the incorporation of pharmacogenetic variation in studies involved in (renal) drug disposition

Increased human dermal microvascular endothelial cell survival induced by cysteamine

Item does not contain fulltextBACKGROUND: Cystinosis is an autosomal recessive disease caused by intralysosomal cystine accumulation, treated with cysteamine. Recently, new adverse effects of cysteamine were reported. Skin biopsies showed microvascular proliferation (angioendotheliomatosis). To examine the mechanism of angioendotheliomatosis associated with cysteamine toxicity, we examined the effect of cysteamine on human dermal microvascular endothelial cells (HDMVEC). METHODS: After cysteamine exposure (range 0-3.0 mM) during 24 h, cell viability was measured using water soluble tetrazolium salt-1 (WST-1) in both control HDMVEC and fibroblasts. Cell proliferation and apoptosis rate were measured in HDMVEC by bromodeoxyuridine (BrdU) incorporation and caspase 3 and caspase 7 activity, respectively. Intracellular glutathione (GSH) was measured in HDMVEC after cysteamine exposure of 0, 0.1 or 1.0 mM. Medium and cysteamine were refreshed every 6 h to mimic the in vivo situation. Next, cell viability in HDMVEC was measured after 24 h of GSH exposure (range 0-10.0 mM). RESULTS: HDMVEC viability and proliferation increased after cysteamine exposure 0.03-3.0 mM (p < 0.01) and 0.03-1.0 mM (p = 0.01) respectively; cell viability in fibroblasts was not affected by incubation with cysteamine. Apoptosis remained unaffected by incubation with 0-1.0 mM cysteamine, 3.0 mM caused increased apoptosis. Intracellular GSH was significantly increased after incubation with cysteamine 0.1 mM (p = 0.02) and 1.0 mM (p < 0.01). HDMVEC viability increased after exposure to GSH 1.0-5.0 mM (p < 0.01). CONCLUSION: Cysteamine concentrations, similar to those described in plasma of cystinosis patients, stimulate HDMVEC viability and proliferation and increase intracellular GSH content. We postulate that this mechanism might underlie angioendotheliomatosis induced by cysteamine

Structure design of 3D printed cookies in relation to texture

In order to develop a model that allows for a better understanding of the interaction between the properties of the solid matrix, the structure and the mechanical behaviour of the cookie, both mechanical and structural properties need to be taken into account. To this end, a finite element model (FEM) was developed that predicts the mechanical properties of the structured product based on the material properties of the solid material used. The solid material mechanical properties were measured using compression tests with a universal testing machine. A larger variation of structures was analysed by means of FEM simulations, varying the size and shape of the air spaces and wall thickness of the structure. Structural parameters such as porosity, pore size and wall thickness were correlated to the mechanical properties such as Young’s modulus. In a next step these structures validated by means of mechanical compression tests on actual printed structures (by means of fused deposition modelling) with different air space distributions based on the 3D FE design files. The structure of the printed cookies will also be verified by means of 3D micro-CT imaging. Using this final correlation model, microstructure of the products can be engineered to achieve desirable texture properties in silico and create dedicated print files for additive manufacturing of cookies.status: publishe

The Functional Implications of Common Genetic Variation in CYP3A5 and ABCB1 in Human Proximal Tubule Cells

Calcineurin inhibitors (CNIs) are the primary immunosuppressive drugs used in solid organ transplantation but are associated with the development of histological lesions leading to kidney failure. CNIs are metabolized by CYP3A and excreted by not only P-glycoprotein (P-gp) (ABCB1) in the gut and liver, but also by proximal tubule cells (PTCs) in the kidney. Multiple studies have demonstrated the importance of genetic variation in CYP3A5 and ABCB1 for CNI disposition and nephrotoxicity. The present study was designed to study the functional implication of variation in these two genes in human PTCs.status: publishe