Publications

Embedded steel column bases are normally idealized as fixed boundary condition in the analysis of steel frameworks. In practice, the embedded column bases sometimes have embedded depth notably smaller than that recommended by the structural design codes. In such a case, the fixed boundary assumption may overestimate the stiffness of the bases to a large extent. In light of this, this paper proposes a theoretical model for the accurate prediction of the rotational stiffness of the shallow embedded steel column bases, with the combined effects of key influencing factors, including the axial load in the column, the shear deformation of the embedded column, the rotational constraint provided by the column end plate, and the stiffness contribution from the anchor bolts. To achieve this, the calculation of the rotational stiffness of the base plate is refined in this paper based on previous study, which can consider the contribution from the anchor bolts, and incorporated in the Winkler foundation beam model, giving the expression of the initial rotational stiffness of the embedded column base. The proposed model is validated by the experimental and finite element simulation results.

No abstract is provided for this article.

Coronary artery calcium score (CACS) is an established marker of coronary artery disease (CAD) and has been extensively used to stratify risk in asymptomatic individuals. However, the value of CACS in predicting plaque morphology in patients with advanced CAD is less established. The present analysis aims to assess the association between CACS and plaque characteristics detected by near-infrared spectroscopy-intravascular ultrasound (NIRS-IVUS) imaging in patients with obstructive CAD.

We studied the safety and feasibility of intracoronary sonotherapy (IST) and its effect on the coronary vessel at 6 months. Thirty‐seven patients with stable or unstable angina were included (40 lesions). The indication was de novo lesion (n = 26), restenosis (n = 2), in‐stent restenosis (n = 11), and a total occlusion of a venous bypass graft. After successful angioplasty, IST was performed using a 5 Fr catheter with three serial ultrasound transducers operating at 1 MHz. IST was successfully performed in 36 lesions (success rate, 90%). IST exposure time per lesion was 718 ± 127 sec. During hospital stay, one patient died due to a bleeding complication. At 6‐month follow‐up, one patient experienced acute myocardial infarction, eight patients underwent repeat PTCA. No patient underwent CABG. Late lumen loss was 1.05 ± 0.70 mm with a restenosis rate of 25%. IVUS analysis revealed a neointima burden of 25% ± 11%. IST can be applied safely and with high acute procedural success. Sonotherapy‐related major adverse events were not observed. Late lumen loss and neointimal growth were similar to conventional PTCA approaches. These results justify the initiation of randomized clinical efficacy studies. Catheter Cardiovasc Interv 2003;60:9–17. © 2003 Wiley–Liss, Inc.

There is paucity of information on how lung physiology and cellular inflammation differs between non-smoking-COPD (NS-COPD) and smoking-COPD (S-COPD). Aim: To evaluate and compare physiological and induced sputum cellular inflammatory profiles of NS-COPD and S-COPD. Methods: 47 NS-COPD and 39 S-COPD subjects underwent spirometry, Impulse-oscillometry (IOS), body plethysmography and lung-diffusion (single breath), and sputum-induction to measure the cellular-inflammatory profile. Normally distributed and non-normally distributed data were compared using means (SD) and medians (IQR), using parametric and non-parametric tests respectively. Results: There were no differences in % predicted values for FEV1, FVC, FEF25-75/FVC, SRaw, SGaw, RV, TLC, RV/TLC, ITGV, FRC, R5Hz, R20Hz, and DLCO SB and DLCO/VA between NS-COPD and S-COPD (all p values>0.05). The only physiological difference observed was in median % predicted X5Hz values on IOS; S-COPD had higher X5 compared to NS-COPD [1908.3Hz (1308.3, 2987.5), vs 983.3Hz (461.1, 2091.7), p=0.002]. S-COPD had greater median total inflammatory cells/gm sputum and absolute neutrophils/gm sputum compared to NS-COPD [7.2(3.6, 10.3)x106/gm vs 4.1(2.3, 6.9)x106/gm, p=0.01] and [5.5(2.8, 8.7)x106/gm vs 2.8(1.6, 6.0)x106/gm, p=0.01] respectively. No differences were observed between numbers of lymphocytes, eosinophils and macrophages in S-COPD and NS-COPD (all p values>0.05). Conclusion: S-COPD and NS-COPD show similar lung function derangements as measured by lung volumes, airway resistance and lung-diffusion, apart from an increased airway reactance and greater total and neutrophil cell counts in the induced sputum in S-COPD compared to NS-COPD.

No abstract is provided for this article.

The introduction of coronary balloon angioplasty in the late 1970s by Andreas Gruentzig provided an innovative, less invasive method for revascularization of patients with coronary artery disease. This has subsequently led to a rapid development of new percutaneous devices to treat atherosclerotic vasculopathies. Following its success in the initial studies, the expanded use of angioplasty in the clinic has shown that the arteries could react to angioplasty by a proliferative process similar to wound healing, a process known as restenosis. Defined as a renarrowing of the treated vessel area that equals or exceeds 50% of the lumen in the adjacent normal segment of the artery, restenosis severely limited the success of percutaneous coronary intervention. Together with the high prevalence of this vasculopathy, which ranges from 30% to 60% of lesions treated, an intensive search was prompted for interventional techniques that could minimize the risk of restenosis.

No abstract is provided for this article.