Acoustofluidic one-step production of plasmonic Ag nanoparticles for portable paper-based ultrasensitive SERS detection of bactericides.

SERS measurements for monitoring bactericides in dairy products are highly desired for food safety problems. However, the complicated preparation process of SERS substrates greatly impedes the promotion of SERS. Here, we propose acoustofluidic one-step synthesis of Ag nanoparticles on paper substrates for SERS detection. Our method is economical, fast, simple, and eco-friendly. We adopted laser cutting to cut out appropriate paper shapes, and aldehydes were simultaneously produced at the cutting edge in the pyrolysis of cellulose by laser which were leveraged as the reducing reagent. In the synthesis, only 5 µL of Ag precursor was added to complete the reaction, and no reducing agent was used. Our recently developed acoustofluidic device was employed to intensely mix Ag+ ions and aldehydes and spread the reduced Ag nanoparticles over the substrate. The SERS substrate was fabricated in 1 step and 3 min. The standard R6G solution measurement demonstrated the excellent signal and prominent uniformity of the fabricated SERS substrates. SERS detection of the safe concentration of three bactericides, including tetracycline hydrochloride, thiabendazole, and malachite green, from food samples can be achieved using fabricated substrates. We take the least cost, time, reagents, and steps to fabricate the SERS substrate with satisfying performance. Our work has an extraodinary meaning for the green preparation and large-scale application of SERS.

Acoustofluidics-Assisted Multifunctional Paper-Based Analytical Devices.

Microfluidic paper-based analytical devices (µPADs) feature an economic and sensitive nature, while acoustofluidics displays contactless and versatile virtue, and both of them gained tremendous interest in the past decades. Integrating µPADs with acoustofluidic techniques provides great potential to overcome the inherent shortcomings and make appealing achievements. Here, we present acoustofluidics-assisted multifunctional paper-based analytical devices that leverage bulk acoustic waves to realize multiple applications on paper substrates, including uniform colorimetric detection, microparticle/cell enrichment, fluorescence amplification, homogeneous mixing, and nanomaterial synthesis. The glucose detection in the range of 5-15 mM was conducted to perform uniform colorimetric detection. Various types (brass powder, copper powder, diamond powder, and yeast cells) and sizes (5-200 µm) of solid particles and biological cells can be enriched on paper in a few seconds or minutes; thus, fluorescence amplification by 3 times was realized with the enrichment. The high-throughput and homogeneous mixing of two fluids can be achieved, and based on the mixing, nanomaterials (ZnO nanosheets) were synthesized on paper. We analyzed the underlying mechanisms of these applications in the devices, which are attributed to Faraday waves and Chladni patterns. With their simple fabrication and prominent effectiveness, the devices open up new possibilities for paper-based microfluidic devices.

Emission and capture characteristics of Chinese cooking-related fine particles.

Cooking can emit high concentrations of particles and gaseous pollutants. Cooking has contributed to the major source of indoor air pollutants, especially for particle pollutants in residential buildings. Many studies already analyzed the emission characteristics of Chinese cooking-related UFPs and PM2.5, while less for the fine particle size distributions. Currently, the fine particle emission characteristics of Chinese cooking need to be further investigated, since the mass size distribution of Chinese cooking is dominated by fine particles. This study determined the emission characteristics of PM1 and fine particles from three Chinese cooking methods. The capture efficiencies of particles were also measured by a modified indirect approach, including the impact of particle decay. The results showed that stir-fried vegetable and pan-fried meat dishes generated more fine particles at 0.542-1.5 µm. Besides, pan-fried and deep-fried meat dishes produce a higher generation of PM1. The fine particles (0.542-10 µm) number-based and volume-based size distributions of six dishes both presented a monodisperse behavior. The cooking methods are not a sensitive factor to the volume frequency of fine particle ranging from 0.542 to 10 µm. The averaged volume median and mode diameter for six typical Chinese dishes are 2.5 µm and 3.3 µm, respectively. The Sauter and DeBroukere mean diameter is 4.7 µm and 5.6 µm, respectively. The decay of fine particles increases with the particle diameter. The impact of particle decay on capture efficiency for 2-3 µm particles is about 5%. The capture efficiencies of pan-fried and deep-fried meat dishes are lower than that of vegetable dishes. In contrast, the capture efficiency for stir-fried meat dishes is higher than that of vegetable dishes. The capture efficiency for PM1 and 0.542-5 µm particles from six typical Chinese dishes were 60-90% on the IEC recommended exhaust flowrate.

The value of single-channel endoscopic traction and kiss suture technique in closing wounds caused by endoscopic resection of gastrointestinal muscularis propria tumors.

BACKGROUND: To investigate the value of single forceps endoscopic traction stapling suture technique (SFETSST) in closing wounds caused by endoscopic resection of gastrointestinal muscularis propria tumor (GMPT). METHODS: Consecutive patients who underwent submucosal tumor excavation (ESE) and endoscopic full-thickness resection (EFR) for GMPT in the Second Affiliated Hospital of Xiamen Medical College from January 2015 to January 2022 were retrospectively collected. They were divided into the SFETSST group and the standard group (patients who receive single forceps traction-free endoscopic suture technique). The healing effects were compared between the two groups. RESULTS: Seventy-seven patients were included in our study with 50 patients included in SFETSST group. The baseline characteristics had no significant difference between the two groups. The technical success rate of wound suture in SFETSST cluster was significantly upper than that within standard cluster (100% vs. 88.89%, P = 0.04). The wound suture time in SFETSST cluster was significantly lower than that within standard cluster (33.19 ± 10.64 min, P < 0.001). Moreover, the incidence rates of intra-operative and postoperative complications in SFETSST cluster were lower than standard cluster (0 vs. 7.41%, P = 0.051 and 0 vs. 11.11%, P = 0.016). Interestingly, the SFETSST cluster had lower cost of consumables (2485.40 ± 591.78 vs. 4098.52 ± 1903.06 Yuan, P = 0.01) and shorter hospital stay (4.96 ± 0.90 vs. 7.19 ± 2.45, P < 0.001) than standard cluster. CONCLUSION: Our study showed that to fully closure the full-thickness defects of digestive tract, SFETSST was effective, safe, and economical, which was worth popularizing.

Acoustics-Actuated Microrobots.

Microrobots can operate in tiny areas that traditional bulk robots cannot reach. The combination of acoustic actuation with microrobots extensively expands the application areas of microrobots due to their desirable miniaturization, flexibility, and biocompatibility features. Herein, an overview of the research and development of acoustics-actuated microrobots is provided. We first introduce the currently established manufacturing methods (3D printing and photolithography). Then, according to their different working principles, we divide acoustics-actuated microrobots into three categories including bubble propulsion, sharp-edge propulsion, and in-situ microrotor. Next, we summarize their established applications from targeted drug delivery to microfluidics operation to microsurgery. Finally, we illustrate current challenges and future perspectives to guide research in this field. This work not only gives a comprehensive overview of the latest technology of acoustics-actuated microrobots, but also provides an in-depth understanding of acoustic actuation for inspiring the next generation of advanced robotic devices.