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Diamond has an extremely high thermal conductivity, making it to have a great potential as a heat dissipation material. Based on the hot filament chemical vapor deposition (HFCVD) technique, diamond thick films were deposited on silicon carbide substrates by using the multi-step method in this paper. The scanning electron microscopy (SEM) and Raman spectroscopy were adopted for characterizing the samples. The influences of filament power, carbon concentration, and reactive pressure on the growth rate and quality of the diamond films were systematically studied. It is found that the diamond film with the best quality is synthesized by adopting a filament power of 1 600 W, a methane/hydrogen flux ratio of 18/300 (nucleation stage) and 14/300 (growth stage), and a reactive pressure of 4 kPa. The corresponding growth rate is 1.4 μm/h.

Isolation of circulating tumor cells (CTCs) from blood samples has important prognostic and therapeutic implications for cancer treatments, but the process is very challenging due to the low concentration of CTCs. In this study, we report a novel 3D printed microfluidic device functionalized with anti-EpCAM (epithelial cell adhesion molecule) antibodies to isolate CTCs from human blood samples. A 3D printing technology was utilized with specially designed interior structures to fabricate a microfluidic device with high surface area and fluid flow manipulation, increasing capture efficiency of tumor cells. These devices with the optimal flow rate (1 mL/h) and channel length (2 cm) were demonstrated to test three kinds of EpCAM positive cancer cell lines (MCF-7 breast cancer, SW480 colon cancer, and PC3 prostate cancer), and one kind of EpCAM negative cancer cell line (293T kidney cancer). Experimentally, the capture efficiency higher than 90% has been achieved, and the isolation of MCF-7 tumor cells from spiked human blood samples has also been demonstrated. Combined with DNA-based detection (e.g. polymerase chain reaction or DNA sequencing), the detection and analysis of released DNAs from captured tumor cells could be another future direction for clinical diagnosis and cancer treatment.

Electromagnetic exploration, characterized by its low cost, wide applicability, and high operational efficiency, finds extensive applications in fields such as oil and gas exploration, mineral prospecting, and engineering geology. Traditional controlled-source electromagnetic detection methods are typically confined to operating frequencies below 250 kHz, resulting in insufficient detection accuracy for applications such as shallow and intermediate-depth exploration, thereby constraining their performance in high-resolution imaging. To address these challenges, we propose a controlled-source ultra-audio frequency electromagnetic receive system based on the Internet of Things (IoT). We investigate cascaded digital filtering and sampling techniques to extend the receiver's sampling rate range, thereby elevating the operating frequency of controlled-source electromagnetic acquisition from the conventional maximum of 250 kHz to 1 MHz. The receiver achieves a sampling rate of up to 2.5 MHz, comprising three magnetic field measurement channels and two electric field measurement channels. The instrument is compact, lightweight, capable of real-time data storage locally, and real-time data transmission to an upper computer. Additionally, IoT technology is introduced, leading to the design of a cloud-based real-time remote control and data acquisition scheme. Experimental results demonstrate the stability of the instrument, meeting the requirements of field exploration. [ABSTRACT FROM AUTHOR]