Plastics are widely used in human daily life, which bring great convenience. Nevertheless, the disposal of a large amount of plastic wastes also brings great pressure to the environment. Polyethylene terephthalate (PET) is a polymer thermoplastic material produced from petroleum. It has become one of the most commonly used plastics in the world due to its durability, high transparency, light weight and other characteristics. PET can exist in nature for a long time due to its complex structure and the difficulty in degradation, which causes serious pollution to the global ecological environment, and threatens human health. The degradation of PET wastes has since become one of the global challenges. Compared with physical and chemical methods, biodegradation is the greenest way for treating PET wastes. This review summarizes the recent advances on PET biodegradation including microbial and enzymatic degradation of PET, biodegradation pathway, biodegradation mechanisms, and molecular modification of PET-degrading enzymes. In addition, the prospect for achieveing efficient degradation of PET, searching and improving microorganisms or enzymes that can degrade PET of high crystallinity are presented, with the aimto facilitate the development, application and molecular modification of PET biodegradation microorganisms or enzymes.
Humans ; Polyethylene Terephthalates/metabolism* ; Polymers ; Biodegradation, Environmental ; Petroleum

Since the outbreak of COVID-19, the hospital is faced with such challenges as sustained input in patient screening, referral and rescue, supportive medical supplies including the management of personal protective supplies and the maintenance of medical equipment. In the face of increasing workload, the medical materials support team of the hospital took the following measures in the principles of " discovering new sources of supplies and minimizing consumption" . These measures taken include proactive supply procurement strategy, prioritizing allocations based on risk exposure, uniform distribution of supplies based on inventory and usage, and traceable management for donated supplies; optimal and central deployment of equipments, emergency installation, pre-maintenance and emergency repairs for equipments; efficient and safe sterilization of reusable materials and equipments using sterilizers; enhanced personnel training and management to keep updating the medical supplies capacity of the team. All these efforts have contributed significantly to the orderly work of epidemic control.

The modifications of slices, flip angle, SAR mode and TR time are required when the SAR exceeds the limits. The scan time and image quality are affected by those. This study analyzes the SAR from the basic side. With the principle diagram of SIEMENS 1.5 T AVANTO and 3.0 T VERIO MRIS, the trouble shooting procedure of SAR problem is reached both in application and problem sides.
Algorithms ; Image Enhancement

3D printing technology is a kind of manufacturing technology for increasing materials. Based on its advantages of rapid prototyping, digitalization and customization, it can effectively meet the needs of personalized and accurate medical treatment, and has been widely studied and applied in the medical field. This paper introduces the principle, technology and materials of 3D printing technology, and describes the research and application status of the technology in medical field. Meanwhile, some problems of 3D printing technology existing in the current development and its future application prospects also will be discussed.
Medicine ; trends ; Printing, Three-Dimensional ; Research ; trends

Ramping-up is the magnet current injection procedure which is under the control of resistance, voltage, current lead temperature, magnet pressure, temperature and so on. In this procedure, the factors related to the stability of the magnet such as, magnet temperature, pressure and currents are constantly changing. This procedure is the main step which the magnet-quench occurs in. This study uses the data collected during 7 years and SIMENS MRI ramping-up theory, in order to help engineers understand the key factors to reduce the magnet quench during the ramping up procedure.
Magnets ; Temperature

In order to solve the problem of continuous monitoring and automatic regulation of patient airbag pressure in intensive care unit, the study designed an intelligent management system of artificial airway airbag pressure. It can realize real-time monitoring and automatic control of airbag pressure. Its pressure data was sent to the PC in real time by the serial port. It can realize the display, store, review and analysis of pressure data. Its clinical application effect was discussed. Experiments showed that the system can monitor airbag pressure in real time and control the pressure to stabilize at 25~30 cmH
Air Bags ; Critical Care ; Humans ; Intensive Care Units ; Monitoring, Physiologic