A trace code pattern location measurement approach is proposed. It includes a method that can precisely extract the trace code pattern to identify the color laser printer or photocopier class. In this study, we collected 379 samples from 15 brands, including 129 models and 196 printers or photocopiers. The trace code pattern class is identified. Four class characteristics are used to identify the print source: (i) the relation between the pattern and print output direction; (ii) observation of the shape features from among the trace code pattern units; (iii) the feature arrangement from among the trace code pattern units; and (iv) the arrangement relation of the trace code pattern. Blind testing shows that the accuracy of the proposed method is approximately 96.9% for the Questioned Document Examiners, and 84.3% in the non‐Questioned Document Examiners. It is thus an effective technique for determining a print's color laser printer or photocopier source class.

In this study, the stability and specificity of a counterfeit protection system (CPS) code were determined. This research involved an analysis of a counterfeit protection system code unit over time using the pattern location measurement method. We collected 379 sample sheets from 196 printers or photocopiers, covering 14 original brands, including 129 models. There was an interval of at least two months between the collections of samples from each machine. Four types of characteristics were established: CPS pattern unit, distance of the CPS unit, position of dots, size and shape of the dot. Except for the partial changes in the Xerox brand, no other brand exhibited changes over time. This implies that the CPS characteristics are stable. Meanwhile, no correlation was noted between the combinations of the characteristic systems in the collected samples, which implied strong specificity.

Rationale The dried roots of Euphorbia kansui L., known as Kansui, are used to treat ascites and edema in traditional Chinese medicine. However, the toxicity of this herb has seriously restricted its clinical application. A unique vinegar‐processing method has been used to reduce its toxicity since the time of ancient China. However, the detoxification mechanism underlying such vinegar processing has not been fully revealed. To find the answer, the process‐induced changes in components should be carefully investigated. Methods We performed a systematic analysis of chemical components in raw and vinegar‐processed Kansui using ultrahigh‐performance liquid chromatography (UHPLC) diode array detection tandem mass spectrometry and UHPLC high‐resolution mass spectrometry. Thirty‐one chemical components in raw and vinegar‐processed Kansui were found, the chemical structures of 28 components among them were proposed and the process‐induced changes in components were then investigated. Results A comprehensive conclusion about the process‐induced chemical change was drawn. It was found that jatrophane‐type diterpenoids decreased markedly after vinegar processing, while ingenane‐type diterpenoids were retained during vinegar processing. In silico drug target identification gave hints that jatrophane‐type diterpenoids, which decreased markedly during vinegar processing, may have more intense toxicity involving cholinesterase and mitogen‐activated protein kinases, while ingenane‐type diterpenoids, which were retained during vinegar processing, may have a more intense therapeutic effect involving carbonic anhydrase. Conclusions The possible detoxification mechanism of vinegar‐processed Kansui is presented. The research has significance for the therapeutic/toxic chemical basis of Kansui. Also, it has significance for drug discovery from terpenoids within the herb.

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Defect and facet engineering are the two effective approaches to tune the surface reactivity of metal-oxide-based sensing materials. Here, oxygen vacancies defective of WO 3 nanosheets with exposed (002) crystal facet [D-WO 3 -(002)] were obtained by a simple hydrothermal−hydrogenation process. The results revealed that a D-WO 3 -( 002)-based acetone sensor exhibits excellent comprehensive gas sensitive performance: low limit of detection (0.5 ppm), wide range of 0.5−100 ppm (S = 2.8∼45.6), high selectivity, fast response−recovery, and excellent repeatability. The outstanding gas-sensing performance is attributed to the synergistic effects of the dominant (002) facet and the defect of oxygen vacancy structure, which effectively improved the surface reactivity of monoclinic WO 3 nanosheets. For highly sensitive and wide range sensing performance, this work demonstrates tremendous potential application prospect for environmental monitoring of acetone and non-invasive diagnosis of diabetes.