Centrifuge modelling of building response to tunnel excavation

Understanding the building response to tunnelling-induced settlements is an important aspect of urban tunnelling in soft ground. Previous centrifuge modelling research demonstrated significant potential to study this tunnel–soil–structure interaction problem. However, these recent studies were limited by simplified building models, which might result in uncertainties when interpreting the building performance to tunnelling subsidence. This paper presents an experimental modelling procedure and the results of a series of centrifuge tests, involving relatively complex surface structures subjected to tunnelling in sand. Powder-based three-dimensional (3D) printing was adopted to fabricate building models with realistic layouts, facade openings and foundations. The 3D printed material had a Young's modulus and a brittle response similar to historic masonry. Modelling effects and boundary conditions are quantified. The good agreement between the experimentally obtained results and previous research demonstrates that the soil–structure interaction during tunnel excavation is well replicated. The experimental procedure provides a framework to quantify how building features affect the response of buildings to tunnelling subsidence.The authors are grateful to EPSRC grant EP/K018221/1 and Crossrail for the financial support

Stepped wedge cluster randomized controlled trial designs: a review of reporting quality and design features

Background The stepped wedge (SW) cluster randomized controlled trial (CRCT) design is being used with increasing frequency. However, there is limited published research on the quality of reporting of SW-CRCTs. We address this issue by conducting a literature review. Methods Medline, Ovid, Web of Knowledge, the Cochrane Library, PsycINFO, the ISRCTN registry, and ClinicalTrials.gov were searched to identify investigations employing the SW-CRCT design up to February 2015. For each included completed study, information was extracted on a selection of criteria, based on the CONSORT extension to CRCTs, to assess the quality of reporting. Results A total of 123 studies were included in our review, of which 39 were completed trial reports. The standard of reporting of SW-CRCTs varied in quality. The percentage of trials reporting each criterion varied to as low as 15.4%, with a median of 66.7%. Conclusions There is much room for improvement in the quality of reporting of SW-CRCTs. This is consistent with recent findings for CRCTs. A CONSORT extension for SW-CRCTs is warranted to standardize the reporting of SW-CRCTs.This work was supported by the Wellcome Trust (grant number 099770/Z/12/Z to MJG); the Medical Research Council (grant number MC_UP_1302/2 to APM) and the National Institute for Health Research Cambridge Biomedical Research Centre (MC_UP_1302/4 to JMSW)

Comparison of ANS binding property of SOD1 in the presence and absence of both Asc and DNA in 20 mM Tris-HCl buffer (pH 7.4).

<p>A) Fluorescence spectra of 20 µM ANS added into the mixtures containing 4 µM SOD1, 4 µM SOD1 and 7.5 µM ctDNA, or 4 µM SOD1, 7.5 µM ctDNA and 2 mM Asc. B) Change in the emission of 20 µM ANS added into the mixtures containing 4 µM SOD1 and 7.5 µM ctDNA with Asc dose. C) Change in the emission of 20 µM ANS added into the mixtures containing 4 µM SOD1, 2 mM Asc, and 7.5 µM ctDNA with incubation time. Reactions were first incubated at 37°C for 2 h (A and B) or 0–72 h (C), and then re-incubated for 10 min at 37°C after addition of 20 µM ANS prior to measurement.</p

Dependences of DNA-triggered aggregation of oxidized SOD1 proteins on reaction conditions in 20 mM Tris-HCl buffer (pH 7.4).

<p>A) Reactions without stirring were incubated at 37°C for 0–120 min after addition of 7.5 µM ctDNA into the mixtures containing 4 µM SOD1 and 2 mM Asc. B) For DNA dose dependence, 0–75 µM ctDNA were added into the mixtures containing 4 µM SOD1 and 2 mM Asc were incubated at 37°C for 2 h. C) SOD1 dose dependence was observed by incubating reactions consisted of 0–16 µM SOD1, 2 mM Asc, and 7.5 µM ctDNA at 37°C for 2 h.</p

Inhibition of DNA-triggered aggregation of oxidized SOD1 proteins in 20 mM Tris-HCl buffer (pH 7.4).

<p>A) Effect of ionic strength was observed by incubating reactions containing 4 µM SOD1, 2 mM Asc, and 7.5 µM ctDNA at 37°C for 2 h in the presence of 0–800 mM NaCl. Here, the inhibition degree of aggregation is expressed by [(RALS)₀– (RALS)_NaCl]/(RALS)₀×100%, (RALS)₀ and (RALS)_NaCl represent RALS values in the absence and in the presence of NaCl at each concentration, respectively. B) The inhibitory effect of GdmCl was monitored by RALS measurements. Reactions containing 4 µM SOD1, 2 mM Asc, and 7.5 µM ctDNA were incubated at 37°C for 2 h in the presence of 0–6 M GdmCl. The disaggregation degree of aggregation is expressed as (A). C) The disaggregation and inhibition of aggregates was monitored by agarose gel electrophoresis. The aggregates were produced by incubating reactions containing 4 µM SOD1, 2 mM Asc, and 15 µM pBR322 DNA for 24 h at 37°C, and re-incubated for 1 min with 0–6 M GdmCl before loading onto gels. D) The inhibition of aggregation caused by EDTA was monitored by agarose gel electrophoresis. 4 µM SOD1 and 2 mM ascorbate were incubated for 2 h at 37°C with 15 µM pBR322 DNA in the presence of 0–100 mM EDTA before loading onto gels.</p

Regulation of Both the Reactive Oxygen Species Level and Antioxidant Enzyme Activity in Drought-Stressed Rice Organs by Benzimidazolate-Based SOD1 Mimics

In the study, three benzimidazolate-based Cu²⁺ complexes were identified as SOD1 mimics to explore their effects on the levels of reactive oxygen species (ROS) and activities of antioxidant enzymes in drought-stressed rice organs. Superoxide dismutase (SOD) activity of the mimics was found to be controlled by unsaturated coordination, auxiliary ligands, and counter-anions. In comparison to the control, SOD1 mimic treatment for rice seeds significantly reduced ROS (O₂^• ^–, H₂O₂, and •OH) levels in the rice leaf and root while notably increased activities of antioxidant enzymes, including SOD1 and catalase. It can enhance the tolerance of plant organs to drought stress and, thus, has a practical potency of application in rice production on arid land

Visualization of aggregate and control samples under TEM.

<p>The controls were 7.5 µM λDNA (A) and 4 µM SOD1 (B) and incubated for 2 h at 37°C in the buffer (pH 7.4) containing 2 mM Asc prior to observation. C) Aggregate monomers were produced by incubating reactions containing 4 µM SOD1, 2 mM Asc and 7.5 µM λDNA for 2 h at 37°C.</p

ITC analysis of oxidized SOD1 proteins binding to ssDNA.

<p>A) The upper panel shows the raw calorimetric data of the titration of ssDNA (40 µM) into WT SOD1 (5 µM) at 25°C in the 20 mM Tris-HCl buffer (pH 7.4) containing 4 mM Asc, and the lower panel shows the corresponding integrated injection heats, corrected for the heat of dilution. B) ITC data of the titration of ssDNA (40 µM) into SOD1 (5 µM) at 25°C in the 20 mM Tris-HCl buffer (pH 7.4) without Asc. All samples were incubated for 2 h at 37°C prior to titration under the identical conditions. The curve in the lower figure represents the best least-squares fits to the one-site binding model.</p

Observations of Asc-mediated WT SOD1 oxidation by one- and two-dimensional gel electrophoresis.

<p>A) Non-reducing SDS-PAGE gels for observation of Asc dose-dependent SOD1 oxidation. 10 µM SOD1 was incubated at 37°C for 2 h with 0–8 mM Asc. B) 2-DE gels for observation of p<i>I</i> and molecular mass of the SOD1 protein treated with Asc. 10 µM SOD1 was incubated with 4 mM Asc at 37°C for 2 h.</p

Determination of cellular uptake pathways of DNA condensates.

<p>Here, the DNA condensates were prepared as in Cell Transfection Experiments. Cellular uptake pathways of the DNA condensates were determined by the reduction in the luciferase activity of the cells treated by the specific inhibitors. n ≥ 3, **<i>P</i> = 0.01, ***<i>P</i> = 0.00.</p