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Burns cause a loss of skin barrier function, rendering it prone to infection. The prevention of infection comprises a focus on the treatment of patients with burns. Therefore, we analysed the results of microbiological tests of patients with severe and extremely severe burns to provide a basis for the prevention and treatment of infection in patients with burns. The results of microbiological tests of patients with severe and extremely severe burns admitted to our burn centre between 2009 and 2019 were retrospectively reviewed. The overall positive rate of microbial detection was 40.67% and did not significantly decline over the 10-year study period. The most common positive sites were wounds, sputum, and urine. The most common bacterial species causing the infections were Acinetobacter baumannii, Klebsiella pneumoniae, and Pseudomonas aeruginosa. Furthermore, the predictors of a positive detection, overall and at various sites, mainly included the burn area and depth, inhalation injury, and length of the hospital stay. Positive detection was an important predictor of the prognosis. In particular, a positive blood culture and Klebsiella pneumoniae had better predictive strength for mortality than other sites and strains. This study analysed the microbiological testing results at a single burn centre over a period of 10 years. The results provide information regarding the predictors of a positive detection and the influence of a positive detection on prognosis, and can be used as a basis for the development of clinical infection prevention and treatment strategies, as well as the selection of treatment measures.

Wax deposition on walls of oil pipes is a common occurrence in crude oil extraction and is one of the major impediments to oilfield production. The most common method of paraffin removal is superconducting car thermal washing. This study proposes a heat flow coupling model that can analyze the temperature of the tubing-casing annular space to solve the low efficiency problem caused by adjusting initial parameters empirically. Using the superconducting car thermal washing process at the test oil well in city of Daqing, Chine as research object, the real-time temperature of annulus under various initial conditions is acquired by the fully-distributed Raman optical fiber temperature monitoring system. Compared with the real time data, theoretical data has a maximum deviation of 5?C, this result verifies the accuracy of the model. Based on the model, the study investigates the optimal initial parameters of superconducting car thermal washing by taking effective depth as an optimization goal. The optimal parameters for oil wells with different working conditions are obtained to improve the effectiveness of paraffin removal and increase thermal efficiency. This study provides theoretical support and an inspection method to promote superconducting car thermal washing and paraffin removal as well as to improve productive efficiency.

PT-symmetric quantum mechanics is an alternative formulation of quantum mechanics in which the mathematical axiom of Hermiticity (transpose and complex conjugate) is replaced by the physically transparent condition of space-time reflection symmetry (PT-symmetry). A Hamiltonian H is said to be PT-symmetric if it commutes with the operator PT. The key point of PT-symmetric quantum theory is to build a new positive definite inner product on the given Hilbert space so that the given Hamiltonian is Hermitian with respect to the new inner product. The aim of this note is to give further mathematical discussions on this theory. Especially, concepts of PT-frames, CPT-frames on a Hilbert space and for a Hamiltonian are proposed, their existence and constructions are discussed.