Evaluation and Modelling of the Material Properties for Analysis of Cold-formed Steel Sections

The results of two series of experimental investigations to evaluate the mechanical properties and the residual stresses of cold-formed steel (CFS) sections are reported in this paper. These investigations were performed on channel-shaped CFS sections manufactured using cold-roll forming technique. Tensile coupon tests were used to evaluate the mechanical properties at different positions of the channel sections. Electrical resistance strain gauges with an Electrical Discharge Machining cutting technique were used to establish the magnitudes and the distributions of residual stresses within the channel sections. Based on the experimental results, appropriate analysis models for the stress-strain relationship, the variation of the yield strength, and the residual stresses in CFS channel sections are established. These models are incorporated within a large deformation shell finite element to form a model for cold-formed steel sections. The finite element model is evaluated against experimental results of CFSsections in compression

Re-examination of steel frame office buildings in preventing collapse when subject to intense fires

The purpose of the paper is to investigate the extent to which present-day design of steel framed buildings is susceptible to total collapse when subjected to extreme fire events. We select a 50 storey structure in which 2 and 4 adjacent storeys located at different above-ground heights are, in separate scenarios engulfed in raging fires. A total of 8 scenarios are analyzed, employing Newtonian mechanics and realistic energy dissipating properties of H-shaped columns and normal concrete floor slabs possessing secondary (shrinkage and temperature) reinforcement alone. While the present Canadian building code is the basis for our column designs, other standards provide very similar specifications. Although fire proofing is required in virtually all high rise building construction, we are excluding such materials in order to simplify the analyses, but clearly do not advocate its omission – quite the opposite in fact. As well, attributes such as floor beams, partitions and furnishings of every description, all of which would in practice participate in absorbing the kinetic energy of a crush-down upper block are excluded. Despite such a vast array of conservative assumptions, it is shown that partial collapse may occur during crush-down, however, in no case will total collapse be the consequence. These results should provide some comfort to code writers that their requirements should indeed prevent the most catastrophic of failures due to fires

Adjunctive quetiapine for serotonin reuptake inhibitor-resistant obsessive-compulsive disorder: A meta-analysis of randomised controlled treatment trials

Small studies have shown positive effects from adding a variety of antipsychotic agents in patients with obsessive–compulsive disorder who are unresponsive to treatment with serotonin reuptake inhibitors. The evidence, however, is contradictory. This paper reports a meta-analysis of existing double-blind randomized placebo-controlled studies looking at the addition of the second-generation antipsychotic quetiapine in such cases. Three studies fulfilled the inclusion criteria. Altogether 102 individuals were subjected to analysis using Review Manager (4.2.7). The results showed evidence of efficacy for adjunctive quetiapine (< 400 mg/day) on the primary efficacy criterion, measured as changes from baseline in total Yale–Brown Obsessive Compulsive Scale scores (P = 0.008), the clinical significance of which was limited by between-study heterogeneity. The mechanism underlying the effect may involve serotonin and/or dopamine neurotransmission

The database of quantitative cellular signaling: management and analysis of chemical kinetic models of signaling networks

Motivation: Analysis of cellular signaling interactions is expected to pose an enormous informatics challenge, perhaps even larger than analyzing the genome. The complex networks arising from signaling processes are traditionally represented as block diagrams. A key step in the evolution toward a more quantitative understanding of signaling is to explicitly specify the kinetics of all chemical reaction steps in a pathway. Technical advances in proteomics and high-throughput protein interaction assays promise a flood of such quantitative data. While annotations, molecular information and pathway connectivity have been compiled in several databases, and there are several proposals for general cell model description languages, there is currently little experience with databases of chemical kinetics and reaction level models of signaling networks. Results: The Database of Quantitative Cellular Signaling is a repository of models of signaling pathways. It is intended both to serve the growing field of chemical-reaction level simulation of signaling networks, and to anticipate issues in large-scale data management for signaling chemistry

Comparative tolerance of Pinus radiata and microbial activity to copper and zinc in a soil treated with metal-amended biosolids

A study was conducted to evaluate the effects of elevated concentrations of copper (Cu) and zinc (Zn) in a soil treated with biosolids previously spiked with these metals on Pinus radiata during a 312-day glasshouse pot trial. The total soil metal concentrations in the treatments were 16, 48, 146 and 232 mg Cu/kg or 36, 141, 430 and 668 mg Zn/kg. Increased total soil Cu concentration increased the soil solution Cu concentration (0.03-0.54 mg/L) but had no effect on leaf and root dry matter production. Increased total soil Zn concentration also increased the soil solution Zn concentration (0.9-362 mg/L). Decreased leaf and root dry matter were recorded above the total soil Zn concentration of 141 mg/kg (soil solution Zn concentration, >4.4 mg/L). A lower percentage of Cu in the soil soluble + exchangeable fraction (5-12 %) and lower Cu2+ concentration in soil solution (0.001-0.06 μM) relative to Zn (soil soluble + exchangeable fraction, 12-66 %; soil solution Zn2+ concentration, 4.5-4,419 μM) indicated lower bioavailability of Cu. Soil dehydrogenase activity decreased with every successive level of Cu and Zn applied, but the reduction was higher for Zn than for Cu addition. Dehydrogenase activity was reduced by 40 % (EC40) at the total solution-phase and solid-phase soluble + exchangeable Cu concentrations of 0.5 mg/L and 14.5 mg/kg, respectively. For Zn the corresponding EC50 were 9 mg/L and 55 mg/kg, respectively. Based on our findings, we propose that current New Zealand soil guidelines values for Cu and Zn (100 mg/kg for Cu; 300 mg/kg for Zn) should be revised downwards based on apparent toxicity to soil biological activity (Cu and Zn) and radiata pine (Zn only) at the threshold concentration. © 2013 Springer-Verlag Berlin Heidelberg

Diagnostic accuracy of simplified ultrasound hand examination protocols for detection of inflammation and disease burden in patients with rheumatoid arthritis

Background: There is no consensus regarding the minimum number of joints that should be included in an ultrasound (US) scoring system to reliably assess for disease activity in rheumatoid arthritis (RA). / Purpose: To assess whether simplified US protocols for hand examination are as informative as the examination of 22 joints in patients with RA, and to correlate the US parameters with disease activity (DAS-28). / Material and Methods: This is a cross-sectional study of 224 RA patients stratified based on their DAS-28 scores and assessed using eight preselected US examination protocols, including 22, 18, 16, 14, ten, eight, and two different combinations of four joints, respectively. / Results: We found a significant difference between US hand scores regarding their ability to detect active inflammation and erosions. DAS-28 scores correlated very well with the power Doppler (PD) scores generated by all eight US examination protocols (r = 0.89–1, P < 0.05), irrespective of patients' disease activity. Simplified US scores missed information on presence of PD in 20.6–40.2% patients (P < 0.05) and misdiagnosed non-erosive hand RA in 12–38.4% patients (P < 0.05), depending on the number of joints excluded from US hand examination. / Conclusion: Preselected simplified US scores are less reliable in appreciating the disease burden when compared with an extended protocol for 22 joint US examination, raising clinicians' awareness regarding the need to comprehensively assess multiple hand joints to reliably rule out subclinical inflammation

Comparison between Several Ultrasound Hand Joint Scores and Conventional Radiography in Diagnosing Hand Osteoarthritis

This is the first study to investigate the usefulness of a standardized ultrasound (US) examination protocol in diagnosing hand osteoarthritis (OA). We conducted a cross-sectional study including 62 patients, ultimately diagnosed with hand OA based on imaging evidence of osteoarthritic changes with the particular distribution required for fulfilment of American College of Radiology diagnosis criteria. We compared a 32-joint US score (wrists, metacarpophalangeal [MCP], proximal interphalangeal [PIP] or distal interphalangeal [DIP] and carpometacarpal [CMC]-1 joints), with smaller, predefined joint scores, assessing 22 joints (wrists, MCPs and PIPs or PIPs, DIPs and CMC-1), 10 joints (MCP 2–3, PIP 2–3 and CMC-1 or PIP 2–3, DIP 2–3 and CMC-1) and 6 joints (DIP 2–3, CMC-1), respectively. The US findings were correlated with radiographic scores for erosions and osteophytes. Radiographic osteophyte scores correlated well with all the US scores mentioned earlier (R = 0.381 to 0.645, p < 0.05), despite low sensitivity for detection of osteophytes (43.5%) and erosions (28.9%), compared with the 32 joint US score. Both 10 joint US protocols (assessing MCP 2–3, PIP 2–3 and CMC-1 or PIP 2–3, DIP 2–3 and CMC-1 joints) performed better than conventional radiography, by identifying osteophytes in an additional 25.6% and 23.9% of patients, respectively. The conclusion of this study is that the US examination of 10 preselected hand joints is more sensitive than conventional radiography in diagnosing hand OA in patients who do not fulfill American College of Radiology clinical criteria, a finding likely to have practical implications for facilitating diagnosis of hand OA