Xuejun Zhao

Currently, millimeter-wave imaging system plays a central role in security detection systems. Existing concealed object detectors for millimeter-wave images can only detect pre-trained categories and fail when encountering new, unseen categories. Accurately identifying the increasingly diverse types and shapes of concealed objects is a pressing challenge. Therefore, this paper proposes a novel open vocabulary detection algorithm: Open-MMW, capable of recognizing more diverse and untrained objects. This is the first time that open vocabulary detection has been introduced into the task of millimeter-wave image detection. We improved the YOLO-World detector framework by designing Multi-Scale Convolution and Task-Integrated Block to optimize feature extraction and detection accuracy. Additionally, the Text-Image Interaction Module leverages attention mechanisms to address the challenge of feature alignment between millimeter-wave images and text. Extensive experiments conducted on public and private datasets demonstrate the effectiveness of Open-MMW. Compared to the baseline model, Open-MMW improves recall by 13.7%, precision by 13.9%, mAP@0.5 by 14.2%, and mAP@[0.5–0.95] by 10.3%.The performance improvements are even more significant compared to state-of-the-art multimodal interaction models, showcasing powerful zero-shot detection capabilities not present in traditional closed-set detection.

5F‐MDMB‐PICA, an indole‐type synthetic cannabinoid (SC), was classified illicit globally in 2020. Although the extensive metabolism of 5F‐MDMB‐PICA in the human body warrants the development of robust analytical methods for metabolite detection and quantification, a current lack of reference standards for characteristic metabolites hinders such method creation. This work described the synthesis of 18 reference standards for 5F‐MDMB‐PICA and its possible Phase I metabolites, including three hydroxylated positional isomers R14 to R16. All the compounds were systematic characterized via nuclear magnetic resonance, Fourier transform infrared spectroscopy, and high‐resolution mass spectrometry. Furthermore, two methods were developed for the simultaneous detection of all standards using liquid chromatography–tandem mass spectrometry and ultra‐performance liquid chromatography–quadrupole time‐of‐flight mass spectrometry. By comparison with authentic samples, R17 was identified as a suitable urine biomarker for 5F‐MDMB‐PICA uptake.

Cannabinoid metabolites have been reported to be more potent than their parent compounds. Among them, ajulemic acid (AJA) is a side-chain analog of Δ⁹-THC-11-oic acid, which would be a good template structure for the discovery of more potent analogues. Herein, we optimized the key allylic oxidation step to introduce the C-11 hydroxy group with a high yield. A series of compounds was prepared with this condition applied including HU-210, 11-nor-Δ⁸-tetrahydrocannabinol (THC)-carboxylic acid and Δ⁹-THC-carboxylic acid.

Cannabinoid metabolites have been reported to be more potent than the parent compounds. Among them, Ajulemic acid (AJA) is a synthetic analogue of Δ9-THC-11-oic which will be a good template structure for discovery of more potent analogues. Herein, we optimized the key allylic oxidation step to introduce the C-11 hydroxy group with high yield. And a series of compounds were prepared with this condition applied including HU-210, 11-Nor-Δ8-Tetrahydrocannabinol-9-carboxylic acid and Δ9-THC-COOH.