Transfer bond stresses generated between FRP tendons and concrete

There is a growing interest in the use of new materials in construction. Materials such as fibre-reinforced plastics (FRPs) are lightweight, strong, and, for the most part, non-corrodible. Hence, the use of FRPs as prestressing tendons for concrete represents a viable, durable alternative to conventional practice using prestressing steel. This paper addresses the nature of the bond between an FRP tendon and concrete in the transfer zone of a pretensions concrete beam. In particular, two different types of aramid fibre-reinforced plastics (AFRPs) are considers. In the experimental investigation, the tendon pull-in behaviour during detensioning of a number of small-scale (100 X 200 X 2800 mm) pretensions concrete beams was monitored. These results were then used to make inferences about the bond stress distribution through the transfer zone. Both a constant and a non-linear relationship between the bond shear stress and the tendon slip were considers and the transfer behaviour of the two types of AFRP and steel were compared. It was found that by assuming a non-uniform bond stress distribution some interesting results about the distinctly different natures of the bond behaviour of the three materials were obtained. Teijin Ltd., Mitsui Construction Co., Natural Sciences and Engineering Research Council of Canada

Variations on fetal heart rate variability.

This is the final version of the article. It first appeared from Wiley via http://dx.doi.org/10.1113/JP27071

Inadequacies of micronutrient intake in normal weight and overweight young adults aged 18-25 years: a cross-sectional study

Objectives: This study aims to assess adequacy in micronutrient intake in comparison with reference nutrient intakes (RNI) and to identify differences in intakes between normal weight and overweight individuals. Study design: A sample of 542 university students (18e25 years), normal weight (N ¼ 369) and overweight (N ¼ 173), was included in a cross-sectional study. Methods: A three-day diet diary was used to assess energy and nutrient intake. BMI and waist circumference were measured. Results: Mean dietary vitamin D intake was lower than RNI in both men (4.44 mg) and women (5.04 mg). Mean intakes of calcium (597.44 mg), iron (8.62 mg) and folate (171.29 mg) were also lower than recommendations in women. Weight status (normal weight versus overweight) was significantly associated with micronutrient intake, and a trend towards a decrease in vitamin and mineral intake with increasing weight was noted. Conclusions: Results suggest the need to increase the intake of some micronutrients to meet the RNI, to ensure optimal health. This study provides a helpful tool to reinforce recommendations and potential health promotion and intervention strategies in university settings and could influence manufacturers involved in new food product development targeted to this young population

Active immunization with myelin-derived altered peptide ligand reduces mechanical pain hypersensitivity following peripheral nerve injury

BACKGROUND: T cells have been implicated in neuropathic pain that is caused by peripheral nerve injury. Immunogenic myelin basic protein (MBP) peptides have been shown to initiate mechanical allodynia in a T cell-dependent manner. Antagonistic altered peptide ligands (APLs) are peptides with substitutions in amino acid residues at T cell receptor contact sites and can inhibit T cell function and modulate inflammatory responses. In the present study, we studied the effects of immunization with MBP-derived APL on pain behavior and neuroinflammation in an animal model of peripheral nerve injury. METHODS: Lewis rats were immunized subcutaneously at the base of the tail with either a weakly encephalitogenic peptide of MBP (cyclo-MBP(87-99)) or APL (cyclo-(87-99)[A(91),A(96)]MBP(87-99)) in complete Freund’s adjuvant (CFA) or CFA only (control), following chronic constriction injury (CCI) of the left sciatic nerve. Pain hypersensitivity was tested by measurements of paw withdrawal threshold to mechanical stimuli, regulatory T cells in spleen and lymph nodes were analyzed by flow cytometry, and immune cell infiltration into the nervous system was assessed by immunohistochemistry (days 10 and 30 post-CCI). Cytokines were measured in serum and nervous tissue of nerve-injured rats (day 10 post-CCI). RESULTS: Rats immunized with the APL cyclo-(87-99)[A(91),A(96)]MBP(87-99) had significantly reduced mechanical pain hypersensitivity in the ipsilateral hindpaw compared to cyclo-MBP(87-99)-treated and control rats. This was associated with significantly decreased infiltration of T cells and ED1+ macrophages in the injured nerve of APL-treated animals. The percentage of anti-inflammatory (M2) macrophages was significantly upregulated in the APL-treated rats on day 30 post-CCI. Compared to the control rats, microglial activation in the ipsilateral lumbar spinal cord was significantly increased in the MBP-treated rats, but was not altered in the rats immunized with the MBP-derived APL. In addition, immunization with the APL significantly increased splenic regulatory T cells. Several cytokines were significantly altered after CCI, but no significant difference was observed between the APL-treated and control rats. CONCLUSIONS: These results suggest that immune deviation by active immunization with a non-encephalitogenic MBP-derived APL mediates an analgesic effect in animals with peripheral nerve injury. Thus, T cell immunomodulation warrants further investigation as a possible therapeutic strategy for the treatment of peripheral neuropathic pain

MUC1 immunotherapy against a metastatic mammary adenocarcinoma model: Importance of IFN-gamma

Abstract Immunotherapy using mucin 1 (MUC1) linked to oxidised mannan (MFP) was investigated in an aggressive MUC1+ metastatic tumour, DA3-MUC1 because, unlike many MUC1+ tumour models, DA3-MUC1 is not spontaneously rejected in mice making it an alternative model for immunotherapy studies. Further, DA3-MUC1 cells are resistant to lysis by anti-MUC1 cytotoxic T cells (CTLs). The inability of DA3-MUC1 tumours to be rejected in naïve mice as well as vaccination to MUC1 was attributed to a deficiency of expression of MHC class I molecules on the tumour cell surface. In vitro and in vivo analysis of subcutaneous tumours and lung metastases demonstrated that DA3-MUC1 tumour cells have a low expression (&lt; 6%) of MHC class I which can be upregulated (&gt; 90%) following culturing with IFN-γ. Results from flow cytometry analysis and immunoperoxidase staining indicated that the in vitro up-regulation of MHC class I could be maintained for up to seven days in vivo, without affecting the expression levels of MUC1 antigen. Interestingly, MUC1-specific CTL that lyse DA3-MUC1 targets in vitro were induced in MFP immunised mice but failed to protect mice from a DA3-MUC1 tumour challenge. These results highlight the importance of MHC class I molecules in the induction of anti-tumour immunity and the MFP immune response.</jats:p

Quantitating skill acquisition with optical ultrasound simulation

Objective To investigate and compare the effect of simulator training on quantitative scores for ultrasound‐related skills for trainees with novice level ultrasound experience and expert ultrasound operators. Methods Three novice (comprising of 11, 32, 23 participants) and one expert (10 participants) subgroups undertook an ultrasound simulation training session. Pre‐ and post‐training test scores were collected for each subgroup. Outcome measures were as follows: mean accuracy score for obtaining the correct anatomical plane, percentage of correctly acquired target planes, mean number of movements, time to achieve image, distance travelled by probe and accumulated angling of the probe. Results The novices showed improvement in image acquisition after completion of the simulation training session with an improvement in the rate of correctly acquired target planes from 28–57% to 39–83%. This was not replicated in the experts. The novice’s individual ratios based on pre‐ vs. post‐training metrics improved between 1.7‐ and 4.3‐fold for number of movements, 1.9‐ and 6.7‐fold for distance, 2.0‐ and 5.2‐fold for time taken and 1.8‐ and 7.3‐fold for accumulated angling. Among the experts, there was no relationship between pre‐training simulator metrics and years of ultrasound experience. Conclusions The individual simulation metrics suggest the sessions were delivered at an appropriate level for basic training as novice trainees were able to show demonstrable improvements in both efficiency and accuracy on the simulator. Experts did not improve after the simulation modules, and the novice scores post‐training were similar to those of experts, suggesting the exercises were valid in testing ultrasound skills at novice but not expert level