Digital Eddy Current Detection Method Based on High-Speed Sampling with STM32.

The electromagnetic eddy current non-destructive testing system enables the non-destructive analysis of surface defect information on tested materials. Based on the principles of eddy current detection, this paper presents a digital eddy current detection method using high-speed sampling based on STM32. A differential eddy current coil is used as the detection probe, and the combination of a differential bridge and a differential amplifier circuit helps to reduce common-mode noise interference. The detection signal is collected via an STM32-based acquisition circuit and transmitted to the host computer through Ethernet for digital demodulation processing. The host computer performs operations such as smoothing averaging, sinusoidal fitting, and outlier removal to extract the amplitude and phase of the detection signal. The system also visually displays the condition of the tested object's surface in real time through graphical visualization. Testing showed that this system can operate at frequencies up to 8.84 MHz and clearly identify defects as narrow as 1 mm on the surface of the tested steel plate.

Treatment of cutaneous Rosai-Dorfman disease with ALA-PDT combined with low-dose oral corticosteroids: A case report.

Cutaneous Rosai-Dorfman Disease (CRDD), a rare form of Rosai-Dorfman Disease (RDD), lacks established treatment guidelines. In this case report, we detailed a successful case of CRDD management in a 50-year-old woman with facial lesions. Our treatment included 5-aminolevulinic acid photodynamic therapy (ALA-PDT) and low-dose oral corticosteroids. Remarkable improvement was evident after six ALA-PDT courses, and a one-year follow-up confirmed sustained remission. This case highlights the potential of combining ALA-PDT with low-dose corticosteroids as a promising therapeutic strategy for CRDD. Further research is necessary to fully elucidate its mechanisms and effectiveness.

Histological analysis of different types of port-wine stains to guide clinical decision making: A retrospective study.

BACKGROUND AND OBJECTIVES: Port-wine stains are defined as congenital benign vascular lesions. The treatment of port-wine stains remains a challenge, worldwide. This study aimed to analyze the histological characteristics in different types of port-wine stains and provide guidance for clinical decision-making. METHODS AND MATERIALS: Biopsies were from the hospital from 2015 to 2021. H&E staining, Immunofluorescence staining, Masson's trichrome staining and Weigert staining were performed on the tissues. RESULTS: A total of 35 port-wine stains patients were included in the study of four distinct types, namely red port-wine stains (11 cases), purple port-wine stains (seven cases), hypertrophic port-wine stains (nine cases) and nodular port-wine stains (eight cases). The mean vessel diameter of the different types was 38.7 ± 5.9 µm, 93.5 ± 9.7 µm, 155.6 ± 21.8 µm and 155.6 ± 29.54 µm, respectively. Mean vessel depth was 396.4 ± 31 µm, 944.2 ± 105.4 µm, 2,971 ± 161.3 µm and 3,594 ± 364.6 µm, respectively. The vessels in red port-wine stains, purple port-wine stains and hypertrophic port-wine stains were mainly composed of capillary and venous malformations, whereas those in nodular port-wine stains were venous or arteriovenous malformations. LIMITATION: The main limitation of the current study was the small number of patients. CONCLUSION: As the disease progresses, vessel diameters become larger, the vessel wall becomes thicker and vessels were found in a greater depth. A treatment plan should be scientifically formulated keeping in mind the histological characteristics of port-wine stains.

Synthesis, Characterization, and Properties of BN-Fluoranthenes.

Boron/nitrogen-doped fluoranthenes, a new class of BN-doped cyclopenta-fused polycyclic aromatic hydrocarbons, were synthesized via pyrrolic-type nitrogen directed C-H borylation. Regioselective bromination of BN-fluoranthene (3a) gave mono- and dibrominated BN-fluoranthenes. The halogenated BN-fluoranthene (3b) can undergo various of further cross-coupling reactions to deliver a series of BN-fluoranthenes. Moreover, incorporating BN unit in to fluoranthene resulted in a wider HOMO-LUMO energy gaps. The aromaticities of the BN-fluoranthene (3a) were quantified by experimental and computational studies.

Defect Width Assessment Based on the Near-Field Magnetic Flux Leakage Method.

Magnetic flux leakage (MFL) testing has been widely used as a non-destructive testing method for various materials. However, it is difficult to separate the influences of the defect geometrical parameters such as depth, width, and length on the received leakage signals. In this paper, a "near-field" MFL method is proposed to quantify defect widths. Both the finite element modelling (FEM) and experimental studies are carried out to investigate the performance of the proposed method. It is found that that the distance between two peaks of the "near-field" MFL is strongly related to the defect width and lift-off value, whereas it is slightly affected by the defect depth. Based on this phenomenon, a defect width assessment relying on the "near-field" MFL method is proposed. Results show that relative judging errors are less than 5%. In addition, the analytical expression of the "near-field" MFL is also developed.