Search

This study presents a methodology to make a simple equivalent model of frequency-dependent impedance functions of soil-structure interactions using a frequency-independent spring and dashpot, together with a proposed element called 'gyromass.' The gyromass is frequency independent and is defined as a unit system that generates a reaction force due to the relative acceleration of the nodes between which the gyromass is placed. It is found that a model consisting of a spring, dashpot, and gyromass may generate various types of frequency-dependent impedance characteristics. This study proposes two types of simple models that express typical frequency-independent impedance functions of soil-structure interactions by using the gyromass. The advantage of these models is that the frequency-dependent characteristics can easily be expressed by a small number of elements and degrees of freedom. Moreover, they can be applied directly to conventional time-history analyses, even beyond the elastic region of the structural members. An example in which a simple model is applied to the time-history analysis of a soil-pile-superstructure system with an inelastic structural member when subjected to an earthquake wave is illustrated. DOI: 10.1061/(ASCE)0733-9399(2007)133:10(1101) CE Database subject headings: Soil-structure interaction; Elastic foundations; Soil-pile interaction; Dynamic analysis; Embedded foundations; Frequency.

This study focuses on how to determine an optimal radius minimizing the bending strains of vertical, cylindrical fixed-head piles embedded in a homogeneous elastic stratum in soil-pile-structure systems where the kinematic interaction dominates. In order to determine the appropriate radius, closed form formulae for the bending strains at the head of the piles are derived based on three-dimensional wave propagation theory. A general expression of the closed form formulae can be obtained by normalizing the bending strains with respect to a mean shear strain of the soil medium. The normalized bending strains can be expressed by the radius to height ratio of the piles, the ratio of soil to pile stiffness, and a factor representing the relative amplitude and the phase lag between the loading at the head of the piles and the deformation of the ground. The results of parametric analyses reveal the presence of an optimal radius that locally minimizes the bending strains of the piles. Criteria for determining the optimal radius of soil-pile-structure systems are presented. DOI: 10.1061/(ASCE) 1090-0241 (2005) 131:10(1243) CE Database subject headings: Soil-structure interaction; Elastic foundations; Soil-pile interaction; Dynamic analysis; Embedded foundations; Bending; Kinematics.

This paper presents a detailed investigation of the influence on the rocking impedance of flexible sidewalls in embedded foundations. The study focuses on vertical and cylindrical foundations embedded in a homogeneous elastic stratum. In order to anticipate the effects of the flexibility, closed-form formulae for rocking impedance are derived based on three-dimensional wave propagation theory and superposition of both the rocking and flexural movements on a single model by assuming complete bonding conditions between the soil and foundations. A function representing the effect of the flexibility is identified from the closed-form formulae, in terms of the height to radius ratio of the foundations and the ratio of the stiffnesses of the ground and foundations. The rocking impedance for a flexible sidewall differs from those evaluated under the assumption of a rigid sidewall. The applicable range of rocking impedance evaluated under the assumption of a rigid sidewall is assessed, and contours to assist in the estimation of the dynamic response of deeply embedded foundations are presented. DOI: 10.1061/(ASCE)1090-0241(2004)130:4(438) CE Database subject headings: Impedance; Flexibility; Soil-structure interaction; Elastic foundations; Soil-pile interaction; Dynamic analysis; Damping; Embedded foundations.

Subvalvular aortic stenosis typically manifests at a young age and rarely presents in adulthood. It may cause left ventricular outflow tract stenosis, which requires surgical treatment in severe cases. The coexistence of discrete subvalvular aortic stenosis and quadricuspid aortic valve is a highly unusual finding. We present a case of a patient with coexisting discrete subvalvular aortic stenosis and quadricuspid aortic valve, who underwent aortic valve plasty and subvalvular aortic stenotomy. A 63-year-old woman with a history of shortness of breath on exertion was referred to our hospital after being diagnosed with discrete subvalvular aortic stenosis and quadricuspid aortic valve at another hospital. Echocardiography revealed membranous tissue below the aortic valve and a quadricuspid aortic valve. Dobutamine stress echocardiography showed a mean pressure gradient of 75 mmHg and Vmax of 5.9 m/s in the subaortic membranous area. The subaortic valve membranous structures were first resected during surgery to release the subaortic stenosis. The aortic valve had four cusps with an accessory cusp between the right and left coronary cusps. Next, the right coronary cusp was sutured to the accessory cusp and converted to a single valve. Intraoperative transesophageal echocardiography showed trivial aortic regurgitation. The intraoperatively resected subvalvular tissue contained fibrous connective tissue with fibrous thickening and mucinous degeneration. At one-year postoperative follow-up, there is no subvalvular aortic stenosis and aortic regurgitation recurrence, and the patient is doing well. Long-term outcomes of aortic valvuloplasty for quadricuspid aortic valves are not well-characterized in the literature. Owing to the high relapse rate of subvalvular aortic stenosis, rigorous follow-up with echocardiography every six to twelve months is essential to evaluate the long-term success of aortic valve plasty., Competing Interests: Human subjects: Consent for treatment and open access publication was obtained or waived by all participants in this study. Research ethics review committee of ayase heart hospital issued approval Approval No. 2024-0002-1. This study was approved by the Research Ethics Review Committee of Ayase heart hospital in Japan (Approval No. 2024-0002-1). Written informed consent was obtained from patient. . Conflicts of interest: In compliance with the ICMJE uniform disclosure form, all authors declare the following: Payment/services info: All authors have declared that no financial support was received from any organization for the submitted work. Financial relationships: All authors have declared that they have no financial relationships at present or within the previous three years with any organizations that might have an interest in the submitted work. Other relationships: All authors have declared that there are no other relationships or activities that could appear to have influenced the submitted work., (Copyright © 2024, Saitoh et al.)

Genetically encoded calcium indicators (GECIs) are suitable for long-term imaging studies. In this study, we employed a highly sensitive GECI, G-GECO, and achieved efficient gene delivery with an adenoviral vector. The adenoviral vector allowed us to express G-GECO in more than 80% of cells. More than 80% of G-GECO-expressing cells showed an ATP-induced increase in fluorescence intensity due to Ca 2+ release from intracellular stores and subsequent Ca 2+ entry. The fluorescence intensity of these cells was increased more than 2-fold by stimulation with 10 μM ATP. We applied long-term imaging (for ~10 h) to monitor Ca 2+ responses in SF2, a rat dental epithelial cell line, in culture conditions. SF2 cells showed intermittent rises in the intracellular Ca 2+ concentration in the presence of 100 nM 1,25-dihydroxyvitamin D 3 . Many of these Ca 2+ responses began at a specific location in the cytoplasm and spread throughout the entire cytoplasm. The combination of efficient gene delivery with an adenoviral vector and long-term imaging with a highly sensitive GECI enabled detection of intermittent Ca 2+ responses that occur only 3-10 times/h/100 cells. This method could be useful to study the effects of Ca 2+ responses for regulating longterm processes, such as gene expression, cell migration, and cell division, in many cell types.