Indentation induced plastic zone size was studied using electron channelling contrast imaging in polycrystalline Fe. Nanoindentation tests were carried out in samples that were compressed to different degrees of thickness reduction. Both strain hardening and residual stresses induced by the compression contributed to significant hardness elevations at all levels of thickness reduction. By comparing between the un-deformed and pre deformed samples, texture and strain hardening effect were found to contribute to the differences between stresses at micro and macro scales. A correction for texture effects applied to average micro-stresses brought their values close to the macro-stresses. For each sample, a linear relationship was found between the cube of the plastic zone size measured and the inverse of the hardness. The slope of the linear trend line was shown to increase with increased compressive macro-stress level as determined by X-ray diffraction (XRD). This newly discovered empirical relationship demonstrated the potential of predicting macro-scale residual stress levels from nanoindentation experiments.

The magnetic properties of non-oriented electrical steels are determined by a combination of several metallurgical variables, including crystal orientation, misorientation (the orientation difference between two crystal orientations), and the amount of residual stress associated with plastic deformation. These variables are influenced by cold rolling and annealing. In order to study these relationships, samples in the semi-processed condition were subjected to an additional cold roll and a subsequent annealing at different temperatures, and then characterized using electron backscatter diffraction and nanoindentation. The process routing for these samples was not intended to be representative of real-world manufacturing; the purpose was to produce a spread in the metallurgical variables being investigated. Although some trends were observed involving orientation and misorientation, when present, deformation observed close to grain boundaries appeared to be the most influential variable on the magnetic properties.

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To produce the magnetic core of electric motors, nonoriented electrical steels (NOESs) are used with an electrically insulating coating applied to the surface. Residual stress is induced during the coating process, which will alter the hardness and magnetic domain structure of the NOES. In this study, the effect of the coating is examined, specifically, its role in creating a residual stress near the coating/steel interface. This stress was investigated by the nanoindentation technique. With this method, a ∼30 µm deep affected area was observed for NOES along both the rolling and transverse cross section directions, when in the presence of the coating. A biaxial tensile stress of ∼200 MPa was calculated from the measured hardness values in the NOES, which was linked to variations in the magnetic domain structure near the interface. The observed magnetic domain structure was simplified by the reduction of supplemental domain structure near the coating/steel interface.

Core loss is a significant source of energy loss in electric motor steel laminates. Therefore, there is interest in monitoring the quality and consistency of laminates at various stages of manufacturing. The purpose of this study was to investigate the feasibility of using surface magnetic Barkhausen noise for the evaluation of AC core loss, and further, to examine potential origins of magnetic loss in non-oriented electrical steel. Core loss values were measured by a single sheet tester and Barkhausen noise measurements were performed using pole flux control on eight laminates with various grain size, texture and composition. Magnetocrystalline energy was calculated from X-ray diffraction data to quantify texture. Results demonstrated higher surface Barkhausen emissions for samples with lower core loss. Barkhausen noise analyses were used to examine the interplay among core loss, grain size, magnetocrystalline energy and B–H characteristics. The inverse correlation between core loss and Barkhausen noise emissions was qualitatively explained in terms of the orthogonal vector contribution of microscopic eddy currents to losses associated with bulk currents arising in the sample during magnetization.

Indentation is a mature technique that has been widely used in materials science to investigate the mechanical properties of metals and thin films. The indentation technique provides accurate modulus and hardness values of materials over many length scales and can target specific microstructures within heterogeneous materials. A more traditional engineering approach for mechanical properties is three point bend testing which provides an indication of the general fracture performance of the material. The breaking force and toughness results determined are based on the materials overall structure and composition. However, for both techniques, the testing specimen requires certain degree of process. This study evaluated a new indentation technique, which is able to penetrate biological tissues, apply compressive loads on the bone surface and record the resulting displacement, using wild type rats fed with a standard diet. In this study, both femurs from the same animal were tested followed by the three point bending to reach structural failure. We found a correlation between the two techniques and the properties of the bone in the animal model.

Interleukin (IL)-10 has important effects in immunoregulation and inflammation, and previous studies have provided evidence for the involvement of IL-10 in the pathogenesis of Crohn's disease (CD). In this study, we investigated whether genetic variants of the IL-10 gene were associated with CD in a New Zealand population. Three single nucleotide polymorphisms (SNPs) in the promoter region of IL-10 (rs1800871, rs1800872, and rs1800896) and a flanking SNP, rs3024505, were genotyped in a well-characterized New Zealand dataset consisting of 342 CD cases and 610 controls. Furthermore, we measured serum IL-10 levels in a number of the CD patients and controls and examined whether a relationship existed between these polymorphisms and serum IL-10 levels. We demonstrated an association with CD for SNPs rs3024505 and rs1800896, and phenotypic analysis indicated an association of rs3024505 with an early age at first diagnosis, stricturing CD behavior, and requirement for bowel resection. We also observed that IL-10 concentration was significantly higher in CD patients than in the controls and that the T allele of rs1800896, the A allele of rs1800871, and the T allele of rs1800872 were associated with increased serum IL-10 levels.

Increased numbers of adherent invasive Escherichia coli (AIEC) have been found in Crohn's disease (CD) patients. In this report, we investigate the potential of the probiotic Escherichia coli Nissle 1917 (EcN) to reduce features associated with AIEC pathogenicity in an already established infection with AIEC reference strain LF82.

Leptin, a major hormonal product of the adipocyte, regulates appetite and reproductive function through its hypothalamic receptors. The leptin receptor is present in osteoblasts and chondrocytes, and previously we have shown leptin to be an anabolic bone factor in vitro, stimulating osteoblast proliferation and inhibiting osteoclastogenesis. Leptin increases bone mass and reduces bone fragility when administered peripherally but also can indirectly reduce bone mass when administered into the central nervous system. However, data from animal models deficient in either leptin (ob/ob) or its receptor (db/db) remain contradictory. We compared the bone phenotype of leptin receptor–deficient (db/db) and wild‐type mice using micro–computed tomographic (µCT) analysis of the proximal tibias and vertebrae. In the tibia, db/db mice had reduced percent trabecular bone volume (13.0 ± 1.62% in wild‐type versus 6.01 ± 0.601% in db/db mice, p = .002) and cortical bone volume (411 ± 21.5 µm3 versus 316 ± 3.53 µm3, p = .0014), trabecular thickness (48.4 ± 001.07 µm versus 45.1 ± 0.929 µm, p = .041) and trabecular number (2.68 ± 0.319 mm−1 versus 1.34 ± 0.148 mm−1, p = .0034). In the fifth lumbar vertebral body, the trabecular thickness and cortical thickness were decreased in the db/db versus wild‐type mice (0.053 ± 0.0011 mm versus 0.047 ± 0.0013 mm, p = .0002 and 0.062 ± 0.00054 mm versus 0.056 ± 0.0009 mm, p = .0001), respectively, whereas the trabecular and cortical percent bone volume and trabecular number did not reach significance. The total (endosteal and periosteal) cortical perimeter (12.2 ± 0.19 mm versus 13.2 ± 0.30 mm, p = .01) was increased. The serum osteocalcin levels were reduced in the db/db mice, suggesting that bone formation rates are decreased. The material properties of db/db femurs were determined by three‐point bending and nanoindentation, showing decreased bone strength (13.3 ± 0.280 N versus 7.99 ± 0.984 N, p = .0074) and material stiffness (28.5 ± 0.280 GPa versus 25.8 ± 0.281 GPa, p < .0001). These results demonstrate that bone mass and strength are reduced in the absence of leptin signaling, indicating that leptin acts in vivo as an anabolic bone factor. This concurs with results of in vitro studies and of peripheral leptin administration in vivo and suggests that leptin's direct effects on bone cells are likely to override its actions via the central nervous system. © 2011 American Society for Bone and Mineral Research

Histone deacetylase (HDAC) inhibitors regulate many biological responses, including anti-inflammatory and anti-cancer effects. We sought to identify novel classes of HDAC inhibitors from in-house compound libraries. Initially, compounds from 26 different structural classes that showed anti-inflammatory effects in a pre-screen in HEK293T cells were tested in vitro for HDAC inhibition, using a commercial fluorescence assay. The known HDAC inhibitors suberoylanilide hydroxamic acid (SAHA) and trichostatin A (TSA) were used as positive controls. Examples of three different structural classes (anilinoacridines, phenylpyrrolocarbazoles and benzofurylquinazolines) showed significant inhibition in the HDAC assay, and small subsets of these were also evaluated, seeking initial structure-activity relationships (SAR) for each class. Several of the most effective compounds from this HDAC screen were evaluated for their effects on the expression of the pro-inflammatory gene, IL1-alpha, and the cancer-related genes, p53, p21, E-cadherin and C-MYC. While the benzofurylquinazolines increased the expression level of the pro-inflammatory gene IL1-alpha as well as p21 and p53 in the PC3 cell line, a phenylpyrrolocarbazole had the converse effect on p53 expression. Several of the compounds showed in vitro HDAC inhibition ability in PC3, HCT116 and NIH-3T3 cell lines comparable to that of SAHA.