Abstract The Continuous Strength Method (CSM) provides accurate cross‐section resistance predictions since allowance is made for the partial spread of plasticity and the beneficial effects of strain hardening. Although CSM design provisions for different loading conditions are available, the method was limited to the determination of cross‐sectional resistance until recent research by Arrayago et al. (2020) proposed a consistent new approach to the design of stainless steel hollow section members subjected to compression. Extension of the CSM to the design of stainless steel members subjected to combined compression and bending moment is presented in this paper. The analysis is based on numerical results generated in the current study and existing results collected from the literature on stainless steel hollow section members. The results demonstrate that the adoption of the CSM design equations to predict column strength considerably improves the accuracy of the calculated beam‐column capacities. The reliability of the proposed approach is demonstrated through statistical analyses performed in accordance with EN 1990.
In some parts of the world in recent years there has been an increase in morbidity of asthma and in deaths from the disease. The subject is a very complex one and carefully designed and conducted studies are needed to clarify the situation.
1. Opioid receptors have been localised on sensory fibres in the vagus nerve and opioids have previously been shown to inhibit non-adrenergic, non-cholinergic (NANC) neurotransmission in guinea-pig bronchi in vitro and in vivo. We have now investigated whether an inhibitory effect could be demonstrated on cholinergic neurotransmission. 2. Electrical field stimulation (EFS) (8 Hz, 0.5 ms, 40 V for 20 s) produced only a rapid, cholinergic response in the upper trachea but in the lower trachea and main bronchi a cholinergic response which was atropine-sensitive and a longer lasting NANC contraction that was atropine-insensitive was demonstrated. This slow contraction could be blocked by tetrodotoxin and capsaicin pretreatment. 3. [D-Ala2, NMePhe4, Gly-ol5]enkephalin (DAMGO), a selective mu-opioid receptor agonist, inhibited the cholinergic response to EFS at 8 Hz in a dose-dependent manner in main bronchi (IC50 = 113 nM with a maximal inhibition of 35.7 +/- 5.6% 10 microM, n = 5). In the lower trachea, DAMGO inhibited the cholinergic response to a similar extent (inhibition of 35.8 +/- 3.5% at 10 microM, n = 5). However, DAMGO had no effect on the contractile response to exogenously applied acetylcholine in the main bronchi. By contrast, opioids had no inhibitory effect on cholinergic neurotransmission in the upper trachea. DAMGO (1 microM) inhibited the cholinergic response to EFS in a frequency-dependent manner in the main bronchi with greater inhibition at lower frequencies of stimulation. 4. The delta-opioid receptor agonist [D-Pen2, D-Pen5]enkephalin (DPDPE) significantly inhibited the cholinergic component of the constrictor response to EFS at 8 Hz in the bronchi but at the highest dose used (10 microM). U-50,488H, a Kappa-receptor agonist, had no inhibitory effect on the cholinergic constrictor component in the main bronchi (10microM). 5. DAMGO also inhibited the NANC responses to EFS in the main bronchi in a dose-dependent manner (with an IC50 = 36 nm and a maximal inhibition of 63.4 + 8.3%, at 1 microM, n = 5). DAMGO had no effect on contractile responses to exogenously applied substance P (SP). DPDPE (10 microM) was less effective in inhibition of the NANC bronchoconstriction with a maximal inhibition of 29.2 + 4.2% (n = 7), and U-50,488H (1O microM) had no inhibitory effect. 6. After capsaicin pretreatment, which depleted sensory nerves of neuropeptides, the inhibitory effect of DAMGO (1 microM) on cholinergic constriction in main bronchi at 8 Hz was only 13.4 + 1.9% (n = 13) compared with 32.9 + 4.0% (n = 9) inhibition in vehicle-treated controls (P < 0.001). 7. Opioids may reduce the cholinergic neural responses in airways partly via an inhibitory action on excitatory NANC nerves and partly by a direct effect on cholinergic neurotransmission. The opioid receptor involved is of the mu-opioid receptor subtype.
Real-world evidence (RWE) has emerged as a resource to support regulatory decision-making when further assessing the efficacy/effectiveness and safety of therapies available in clinical practice [1...
Commentary on: Makikallio T, Holm NR, Lindsay M, et al . Percutaneous coronary angioplasty versus coronary artery bypass grafting in treatment of unprotected left main stenosis (NOBLE): a prospective, randomised, open-label, non-inferiority trial. Lancet 2016;388:2743–2752. An on-going debate is whether percutaneous coronary intervention (PCI) offers similar clinical results compared with coronary artery bypass grafting surgery (CABG) for patients with unprotected left main artery disease (ULMAD). Previously, the SYNergy between percutaneous coronary intervention with TAXus and cardiac surgery (SYNTAX) trial scrutinized the benefit of the first generation of drug-eluting stents in patients with multivessel disease and ULMAD. At 5 years, CABG was associated with improved clinical outcomes compared with PCI. Nonetheless, in patients with ULMAD and SYNTAX score <33, similar results were observed.1 The European and American guidelines agree upon the fact that in patients with ULMAD, CABG is the preferred treatment whereas PCI might be an alternative when the SYNTAX score …
Aluminum alloys are being increasingly used in a wide range of construction applications owing to their sound mechanical properties, lightness in weight, strong corrosion resistance, ability to be formed into complex and efficient cross-sectional shapes, and natural aesthetics. Aluminum alloys are characterized by a rounded stress–strain response, with no sharply defined yield point. Such behavior can be accurately represented using Ramberg–Osgood-type equations. In the present study, use of a two-stage Ramberg–Osgood model to describe the full-range stress–strain behavior of aluminum alloys is proposed and, following careful analysis of a comprehensive database of aluminum alloy coupon test data assembled from the literature, standardized values or predictive expressions for the required input parameters are derived. The experimental database includes over 700 engineering stress–strain curves obtained from 56 sources and covers five common aluminum alloy grades: 5052-H36, 6061-T6, 6063-T5, 6082-T6, and 7A04-T6. The developed model is shown to be more accurate in predicting the full-range stress–strain response of aluminum alloys than existing expressions, and is suitable for use in the analytical modeling, numerical simulation, and advanced design of aluminum alloy structures.
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