420 research outputs found

    Urease activity in soybean meal products

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    Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141471/1/aocs0360.pd

    Comparison Between Diffusion-Weighted MRI and I-123-mIBG Uptake in Primary High-Risk Neuroblastoma

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    Background: High-risk neuroblastoma (HR-NB) has a variable response to preoperative chemotherapy. It is not possible to differentiate viable vs. nonviable residual tumor before surgery. Purpose: To explore the association between apparent diffusion coefficient (ADC) values from diffusion-weighted magnetic resonance imaging (DW-MRI), 123I-meta-iodobenzyl-guanidine (123I-mIBG) uptake, and histology before and after chemotherapy. Study Type: Retrospective. Subjects: Forty patients with HR-NB. Field Strength/Sequence: 1.5T axial DW-MRI (b = 0,1000 s/mm2 ) and T2-weighted sequences. 123I-mIBG scintigraphy planar imaging (all patients), with additional 123I-mIBG single-photon emission computed tomography / computerized tomography (SPECT/CT) imaging (15 patients). Assessment: ADC maps and 123I-mIBG SPECT/CT images were coregistered to the T2-weighted images. 123I-mIBG uptake was normalized with a tumor-to-liver count ratio (TLCR). Regions of interest (ROIs) for primary tumor volume and different intratumor subregions were drawn. The lower quartile ADC value (ADC25prc) was used over the entire tumor volume and the overall level of 123I-mIBG uptake was graded into avidity groups. Statistical Tests: Analysis of variance (ANOVA) and linear regression were used to compare ADC and MIBG values before and after treatment. Threshold values to classify tumors as viable/necrotic were obtained using ROC analysis of ADC and TLCR values. Results: No significant difference in whole-tumor ADC25prc values were found between different 123I-mIBG avidity groups pre- (P = 0.31) or postchemotherapy (P = 0.35). In the “intratumor” analysis, 5/15 patients (prechemotherapy) and 0/14 patients (postchemotherapy) showed a significant correlation between ADC and TLCR values (P < 0.05). Increased tumor shrinkage was associated with lower pretreatment tumor ADC25prc values (P < 0.001); no association was found with pretreatment 123I-mIBG avidity (P = 0.17). Completely nonviable tumors had significantly lower postchemotherapy ADC25prc values than tumors with >10% viable tumor (P < 0.05). Both pre- and posttreatment TLCR values were significantly higher in patients with >50% viable tumor than those with 10–50% viable tumor (P < 0.05). Data Conclusion: 123I-mIBG avidity and ADC values are complementary noninvasive biomarkers of therapeutic response in HR-NB. Level of Evidence: 4. Technical Efficacy Stage: 3

    Mid-IR spectroscopic instrumentation for point-of-care diagnosis using a hollow silica waveguide gas cell

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    Laser spectroscopy provides the basis of instrumentation developed for the diagnosis of infectious disease, via quantification of organic biomarkers that are produced by associated bacteria. The technology is centred on a multichannel pulsed quantum cascade laser system that allows multiple lasers with different wavelengths to be used simultaneously, each selected to monitor a different diagnostic biomarker. The instrument also utilizes a hollow silica waveguide (HSW) gas cell which has a very high ratio of interaction pathlength to internal volume. This allows sensitive detection of low volume gas species from small volume biological samples. The spectroscopic performance of a range of HSW gas cells with different lengths and bore diameters has been assessed using methane as a test gas and a best-case limit of detection of 0.26 ppm was determined. The response time of this cell was measured as a 1,000 sccm flow of methane passed through it and was found to be 0.75 s. These results are compared with those obtained using a multi-pass Herriot cell. A prototype instrument has been built and approved for clinical trials for detection of lung infection in acute-care patients via analysis of ventilator breath. Demonstration of the instrument for headspace gas analysis is made by monitoring the methane emission from bovine faeces. The manufacture of a hospital-ready device for monitoring biomarkers of infection in the exhaled breath of intensive care ventilator patients is also presented

    Regularization-independent study of renormalized non-perturbative quenched QED

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    A recently proposed regularization-independent method is used for the first time to solve the renormalized fermion Schwinger-Dyson equation numerically in quenched QED4_4. The Curtis-Pennington vertex is used to illustrate the technique and to facilitate comparison with previous calculations which used the alternative regularization schemes of modified ultraviolet cut-off and dimensional regularization. Our new results are in excellent numerical agreement with these, and so we can now conclude with confidence that there is no residual regularization dependence in these results. Moreover, from a computational point of view the regularization independent method has enormous advantages, since all integrals are absolutely convergent by construction, and so do not mix small and arbitrarily large momentum scales. We analytically predict power law behaviour in the asymptotic region, which is confirmed numerically with high precision. The successful demonstration of this efficient new technique opens the way for studies of unquenched QED to be undertaken in the near future.Comment: 20 pages,5 figure

    Sustained versus repetitive standing trunk extension results in greater spinal growth and pain improvement in back pain: A randomized clinical trial

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    Abstract BACKGROUND: McKenzie standing trunk extension exercises have been used for the management of low back pain (LBP). However, no study to date has investigated the effect of standing trunk extension postures on spinal height and clinical outcomes. OBJECTIVE: To evaluate in subjects with LBP following a period of trunk loading how spinal height, pain, symptoms’ centralization and function outcome measures respond to two standing postures interventions: (1) repetitive trunk extension (RTE) and (2) sustained trunk extension (STE). METHODS: A consecutive sample of convenience of people with LBP were recruited to participate in 2-session physical therapy using either RTE or STE in standing. RESULTS: Thirty participants (18 women) with a mean age of 53 ± 17.5 years completed the study. The first session resulted in spinal height increase (spinal growth) of 2.07 ± 1.32 mm for the RTE intervention and 4.54 ± 1.61 mm for the STE group (p < 0.001; ES = 1.67), while the second session (2-week following the first session) resulted in spinal growth of 2.39 ± 1.46 mm for the RTE group and 3.91 ± 2.06 mm for the STE group (p = 0.027; ES = 0.85). The STE group presented with the larger reduction in most pain from 6 to 2 as compared to the RTE group from 6 to 4 between Session 1 and Session 2 (p < 0.001). There was no difference between the groups in Modified Oswestry score and symptoms centralization (p = 0.88 and p = 0.77, respectively). CONCLUSION: People with LBP experienced greater spine growth and improvements of pain during standing STE as compared to RTE. People with LBP could use such postures and movements to alleviate their LBP and improve spine height while in a weight bearing position
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