Sesquiterpenes are natural terpenes containing 15 carbon atoms. They are widely used in the perfume, pharmaceutical, and biofuel industries due to their remarkable biological activities. The traditional production of sesquiterpenes relies on chemical synthesis or plant extraction, which has the disadvantages of low yields and waste of resources. The construction of microbial cell factories for the efficient synthesis of sesquiterpenes by means of synthetic biology provides a new option. In recent years, with the development of metabolic engineering and synthetic biology, the heterologous synthesis of a variety of sesquiterpenes has been successfully achieved by metabolic engineering of the oleaginous yeast, Yarrowia lipolytica. In this paper, we review the research progress in the heterologous synthesis of different sesquiterpenes by Y. lipolytica, discuss the synthetic biology strategies commonly used in this field, and make an outlook on the research directions and engineering approaches to further enhance the sesquiterpene yield in this host. This paper provides a reference for strategies such as synergistic optimization of synthetic biology and metabolic engineering, enhanced precursors, and opens up new directions for the application of synthetic biology in green chemistry and sustainable production.
Yarrowia/genetics* ; Sesquiterpenes/metabolism* ; Metabolic Engineering/methods* ; Synthetic Biology/methods*

Objective To evaluate the application value of percutaneous angle positioning system based on augmented reality in improving the accuracy of liver puncture.Methods A canine liver with an embedded marking ring was used as the target for puncture.A skilled physician with over 5 years of experience in liver puncture and a novice physician with limited experience in liver puncture separately performed liver puncture using either the augmented reality-based percutaneous angle localization system(navigation)or CT-guided technique alone(non-navigation).The corresponding puncturing data of non-navigation skilled group(Group A),non-navigation non-skilled group(Group B),navigation skilled group(Group C),and navigation non-skilled group(Group D)were obtained.The differences in the evaluation indicators,including the number of CT scans,number of needle adjustment,time spent for operation,and distance of error,between Group A and Group B,between Group C and Group D,between Group A and Group C,and between Group B and Group D,were analyzed.Results Statistically significant differences in the number of CT scans,number of needle adjustment,time spent for operation,and distance of error existed between Group A and Group B,between Group A and Group C,and between Group B and Group D(all P＜0.0 5),while the differences in the number of CT scans,number of needle adjustment,time spent for operation,and distance of error between Group C and Group D were not statistically significant(all P＞0.05)Conclusion In performing liver puncture,the use of percutaneous angle localization system can reduce the number of CT scans,number of needle adjustment,time spent for operation and distance of error,and improve the puncture accuracy as well,which provides a basis for the clinical utilization of this system and the employment of this system-guided puncture technology in primary hospitals.(J Intervent Radiol,2024,33:507-511)

Objective:To reconstruct the three-dimensional (3D) dose distribution in radiotherapy based on the convolutional neural networks (CNN) through multi-perspective scintillation light processing.Methods:First, fluorescence images were captured from three orthogonal perspectives using a complementary metal-oxide-semiconductor (CMOS) imaging sensor. Then, the images were converted into 3D images, which were input to the trained CNN for dose reconstruction. Finally, the reconstructed doses in different fields were evaluated in terms of gamma pass rate, mean-square error (MSE), percentage depth dose (PDD), and cross beam profile (CBP). Additionally, as the CNN model, 3D-Unet was pre-trained on a virtual dataset.Results:With the 50% maximum dose of as the threshold and 3%/3 mm as the standard, the central-plane and stereo-mean gamma pass rates of all field reconstruction distributions were over 90%, with MSEs remained below 1%. Besides, the PDD and CBP curves showed MSEs below 1‰ and below 1%, respectively.Conclusions:The deep learning-based method for 3D dose reconstruction using scintillation light contributes to enhanced verification of instantaneous 3D relative dose based on plastic scintillation detectors.

Objective To study the changes of hippocampal caspase-3 and PSD-95 expression levels in the mice exposed to ketamine 30 mg/(kg·d)for three months. Methods Forty C57BL/6 mice were randomly divided into two groups,and the chronic ketamine addiction model was established by giving mice a three month course of daily intraperitoneal injections of ketamine. Immunohistochemical study and Western blot-ting were applied to observe the expression of caspase-3 and PSD-95 protein. Results There were more expression of caspase-3 and less of PSD-95 in ketamine group as detected by immuohistochemistry. Western blotting results showed caspase-3 active fragment level significantly increased com-pared to saline group,but PSD-95 protein level was decreased. Conclusion The increased level of caspase-3 protein and reduced expression of PSD-95 are observed after long-term ketamine administration. These findings may provide an evidence for the neurotoxicity in mouse hippocampus of chronic ketamine addition as a recreational drug.