Experimental Study of the Mechanical Properties of Full-Scale Rubber Bearings at 23 °C, 0 °C, and -20 °C

In this study, the effects of ambient temperature on the horizontal mechanical performance of isolated rubber bearings were investigated using high-speed reciprocating loading methods. A comprehensive series of 54 experimental trials are performed on the full-scale (900 mm-diameter) isolation rubber bearings, encompassing a range of temperatures (-20 °C, 0 °C, and 23 °C), shear pressures (50%, 100%, and 250%), and frequencies (0.20 Hz, 0.25 Hz, and 0.30 Hz). Because the compression-shear tests were conducted at high velocities and pressures (specifically, vertical compressive stress of 15 MPa), the equipment used in these tests was capable of generating substantial inertial and frictional forces. Appropriate correction methodologies for the precise determination of mechanical performance metrics for bearings are presented. Then, a comprehensive investigation of the effects of various loading conditions on the characteristic strength, post-yield stiffness, horizontal equivalent stiffness, and equivalent damping ratio of LRB900 (lead-core rubber bearings 900 mm-diameter) and LNR900 (linear natural rubber bearings 900 mm-diameter) is conducted. The empirical results show a discernible relationship between these characteristics and ambient temperature as the number of loading cycles increases, except for the equivalent damping ratio. Finally, empirical fitting formulations incorporating the influence of ambient temperature are presented for each performance indicator. These formulas are intended to assist designers in performing seismic design analyses by allowing them to take into consideration the effects of ambient temperature comprehensively.

Improving the aroma profile of inoculated fermented sausages by constructing a synthetic core microbial community

Commercial starter cultures play a critical role in the industrial production of fermented sausages. However, commercial starter cultures could not reproduce the metabolic actions of diverse microorganisms and the aroma profile of the traditional spontaneously fermented sausages. Identifying the core microbial community in spontaneously fermented sausages will facilitate the construction of a synthetic microbial community for reproducing metabolic actions and flavor compounds in spontaneously fermented sausages. This study aimed to reveal the core microbial community of spontaneously fermented sausages based on their relative abundance, flavor-producing ability, and co-occurrence performance. We identified five promising genera to construct the synthetic core microbial community, these were Lactobacillus, Staphylococcus, Macrococcus, Streptococcus, and Pediococcus. Sausages inoculated with a synthetic core microbial community presented higher quality of aroma profile than the fermented sausages inoculated with a commercial starter culture. Some important volatile flavor compounds of spontaneously fermented sausage, such as (-)-β-pinene, β-caryophyllene, 3-methyl-1-butanol, α-terpineol, ethyl 2-methylpropanoate, and ethyl 3-methylbutanoate which are associated with floral, fruity, sweet, and fresh aromas, were also detected in fermented sausage inoculated with synthetic microbial community. This indicated that the synthetic core microbial community efficiently reproduced flavor metabolism. Overall, this study provides a practical strategy to design a synthetic microbial community applicable to different scientific fields.

[Management of radiation-induced intestinal injury:from multi-disciplinary team team to holistic integrative management]

Radiation-induced intestinal injury is a radiation injury of the colon and rectum after radiotherapy for pelvic malignant tumors. This condition affects multiple organs in the pelvis, making treatment challenging. In clinical practice, the most effective protocol is often determined through discussion by a multi-disciplinary team (MDT). However, due to the severity and complexity of radiation enteritis, many patients still experience poor diagnosis and treatment outcomes. Holistic integrative management (HIM) is a rapidly developing concept that has greatly enhanced clinical medicine in recent years. It improves the level of diagnosis, treatment, prevention, and rehabilitation from multiple dimensions of prevention, screening, diagnosis, treatment, and rehabilitation. In the context of radiation-induced intestinal injury, HIM also calls for the implementation of an individualized management system that focuses on the patient as a whole within the healthcare team. From the perspective of HIM, this article introduces some of the latest progress of radiation-induced intestinal injury in recent years.