"Visualization" Gas-Gas Sensors Based on High Performance Novel MXenes Materials.

The detection of toxic, harmful, explosive, and volatile gases cannot be separated from gas sensors, and gas sensors are also used to monitor the greenhouse effect and air pollution. However, existing gas sensors remain with many drawbacks, such as lower sensitivity, lower selectivity, and unstable room temperature detection. Thus, there is an imperative need to find more suitable sensing materials. The emergence of a new 2D layered material MXenes has brought dawn to solve this problem. The multiple advantages of MXenes, namely high specific surface area, enriched terminal functionality groups, hydrophilicity, and good electrical conductivity, make them among the most prolific gas-sensing materials. Therefore, this review paper describes the current main synthesis methods of MXenes materials, and focuses on summarizing and organizing the latest research results of MXenes in gas sensing applications. It also introduces the possible gas sensing mechanisms of MXenes materials on NH3 , NO2 , CH3 , and volatile organic compounds (VOCs). In conclusion, it provides insight into the problems and upcoming challenges of MXenes materials for gas sensing.

Computer-assisted tooth preparation template and predesigned restoration: a digital workflow.

This article introduces a new, fully digital workflow for the preparation of a guiding template and the procedure of the clinical operation in which it is put to use. A step-by-step technique is described including the virtual CAD of the preparation, the design of the template, the restoration based on the contours of the virtual preparation, the tooth preparation guided by the template, and the bonding of the predesigned restoration. The design and manufacture of all the templates and restorations are completed before the clinical operation.

Control strategies for carbapenemase-producing Enterobacteriaceae at different levels of the healthcare system.

There has been a rapid increase in recent years in the incidence of infection and colonization by carbapenemase-producing Enterobacteriaceae (CPE). A number of clusters and outbreaks have been reported, some of which have been contained, providing evidence that these clusters and outbreaks can be managed effectively when the appropriate control measures are implemented. This review outlines strategies recommended to control CPE dissemination both at the healthcare facility level (acute and long-term care) and from the public health point of view. A dedicated prepared plan should be required to prevent the spread of CPE at the hospital level. At the front line, activities should include management of patients at admission and new cases, active surveillance culturing and definition of high-risk groups. High compliance with standard precautions for all patients and full or modified contact precautions for defined categories of patients should be implemented. Long-term care facilities are areas where dissemination can also take place but more importantly they can become a reservoir as patients are admitted and released to other Health care facilities. From the public health point of view, surveillance must be tailored to identify regional spread and interfacility transmission to prevent further dissemination. Finally, a comprehensive set of activities at various levels is necessary to prevent further spread of these bacteria in the community.

Preparation Scheme Optimization of Thermosetting Polyurethane Modified Asphalt.

To solve the issue of the poor temperature stability of conventional modified asphalt, polyurethane (PU) was used as a modifier with its corresponding curing agent (CA) to prepare thermosetting PU asphalt. First, the modifying effects of the different types of PU modifiers were evaluated, and the optimal PU modifier was then selected. Second, a three-factor and three-level L9 (33) orthogonal experiment table was designed based on the preparation technology, PU dosage, and CA dosage to prepare the thermosetting PU asphalt and asphalt mixture. Further, the effect of PU dosage, CA dosage, and preparation technology on the 3d, 5d, and 7d splitting tensile strength, freeze-thaw splitting strength, and tensile strength ratio (TSR) of the PU asphalt mixture was analyzed, and a PU-modified asphalt preparation plan was recommended. Finally, a tension test was conducted on the PU-modified asphalt and a split tensile test was performed on the PU asphalt mixture to analyze their mechanical properties. The results show that the content of PU has a significant effect on the splitting tensile strength of PU asphalt mixtures. When the content of the PU modifier is 56.64% and the content of CA is 3.58%, the performance of the PU-modified asphalt and mixture is better when prepared by the prefabricated method. The PU-modified asphalt and mixture have high strength and plastic deformation ability. The modified asphalt mixture has excellent tensile performance, low-temperature performance, and water stability, which meets the requirements of epoxy asphalt and the mixture standards.