SUMMARY: Thoracic disc herniation (TDH) has high technical difficulty and serious complications, and the clinical anatomy of thoracic intervertebral foramen is less. Collecting 10 adult male cadavers, measuring the longitudinal diameter of the dorsal root ganglion (D1), the transverse diameter of the dorsal root ganglion (D2), horizontal sagittal diameter of the upper edge of the intervertebral disc (S1), the high of intervertebral foramen (H1), the height of articulationes costovertebrales (H2), the height of intervertebral disk (H3), the angel of the dorsal root ganglion (a). The aim of this study is to explore the safe area of middle and lower thoracic section and provide anatomical basis for the selection of operative cannula. Mastering the certain rules of the anatomical structure of the middle and lower thoracic segments, and referring to the above parameters in clinical, is conducive to the selection of the working casing during surgery.
RESUMEN: La hernia de disco torácico (TDH) tiene una alta dificultad técnica y complicaciones graves, y la anatomía clínica del agujero intervertebral torácico es menor. Recolectando 10 cadáveres machos adultos, midiendo el diámetro longitudinal del ganglio de la raíz dorsal (D1), el diámetro transversal del ganglio de la raíz dorsal (D2), el diámetro sagital horizontal del borde superior del disco intervertebral (S1), el colmo del intervertebral agujero (H1), la altura de las articulaciones costovertebrales (H2), la altura del disco intervertebral (H3), el ángel del ganglio de la raíz dorsal (α). El objetivo de este estudio es explorar el área segura de la sección torácica media y baja y proporcionar una base anatómica para la selección de la cánula operatoria. Dominar ciertas reglas de la estructura anatómica de los segmentos torácicos medio e inferior, y referirse a los parámetros anteriores en clínica, es propicio para la selección de la carcasa de trabajo durante la cirugía.
OBJECTIVES: This study investigated whether tissue Doppler imaging parameters, especially the peak systolic velocity of the left ventricular lead-implanted segment (Ss), affect cardiac resynchronization therapy response. METHODS: In this case-control study, 110 enrolled patients were divided into cases (responder group, n=65) and controls (nonresponder group, n=45) based on whether their left ventricular end-systolic volume was reduced by ≥15% at 6 months after surgery. Preoperative clinical and echocardiographic data were collected. Multivariate logistic regression models were used to analyze the factors affecting the response to cardiac resynchronization therapy, and receiver operating characteristic curves were plotted to evaluate their diagnostic values. RESULTS: The proportion of patients with left bundle branch block in the case group was higher than that in the control group. The control group showed a higher left atrial volume index, E/A ratio and E/Em ratio but lower Ss than that of the case group. A multivariate regression analysis showed that left bundle branch block, Ss, and an E/Em ratio>14 were independent risk factors affecting the response to cardiac resynchronization therapy. Ss=4.1 cm/s was the best diagnostic threshold according to the receiver operating characteristic curve. CONCLUSIONS: Ss is an important factor affecting the response to cardiac resynchronization therapy. Patients with heart failure associated with Ss<4.1 cm/s have a higher risk of nonresponse.
Abstract A spiral case with its steel spiral case (SSC) being embedded in reinforced concrete under a pressurized condition is called a preloaded filling spiral case structure (PFSCS) in a hydropower plant. As a steel-concrete composite structure, a PFSCS is designed to work reliably. The non-uniform gap and contact nonlinearity between the SSC and the surrounding mass concrete have a great effect on the bearing mechanism of the composite structure. However, the description of the gap and contact nonlinearity in a PFSCS is a tough work. With the aim of efficiently describing the evolution process of the non-uniform gap and contact nonlinearity, we performed an experimental investigation and proposed a novel numerical simulation technique for structural finite element analyses (FEA) of PFSCSs. In the technique, the gap and contact nonlinearity as well as the construction process and operation process of a PFSCS are taken into account. A friction-contact model is used to simulate the sliding of the SSC against the concrete. A plasticity damage model is employed to describe the concrete. The development of the gap, contact status between the steel liner and the surrounding concrete, stresses of the steel liner and the steel bars, as well as the concrete cracking time and crack pattern, are presented in this work. The FEA results agree well with the experimental results. The agreement provides evidence that the applicability and competence of the proposed technique are valid and satisfactory.
The effect of heat treatment on the microstructures and tensile properties of a powder metallurgical (PM) TiAl based alloy has been investigated in this paper. The near gamma (NG) microstructure is transformed to a full lamellar (FL) microstructure with an average grain size of 100 μm by heat treatments. The lamellar spacing of FL structure decreases with the increase of cooling rate. For cooling rates of 5, 10 and 50 °C/min, the lamellar spacing is 1.9, 1.0 and 0.8 μm respectively. The room temperature tensile properties exhibit an increasing trend with decrease of lamellar spacing.