Micro- and nanoplastics are considered one of the top pollutants that threaten the environment, aquatic life, and mammalian (including human) health. Unfortunately, the development of uncomplicated but reliable analytical methods that are sensitive to individual microplastic particles, with sizes smaller than 1 μm, remains incomplete. Here, we demonstrate the detection and identification of (single) micro- and nanoplastics by using surface-enhanced Raman spectroscopy (SERS) with Klarite substrates. Klarite is an exceptional SERS substrate; it is shaped as a dense grid of inverted pyramidal cavities made of gold. Numerical simulations demonstrate that these cavities (or pits) strongly focus incident light into intense hotspots. We show that Klarite has the potential to facilitate the detection and identification of synthesized and atmospheric/aquatic microplastic (single) particles, with sizes down to 360 nm. We find enhancement factors of up to 2 orders of magnitude for polystyrene analytes. In addition, we detect and identify microplastics with sizes down to 450 nm on Klarite, with samples extracted from ambient, airborne particles. Moreover, we demonstrate Raman mapping as a fast detection technique for submicron microplastic particles. The results show that SERS with Klarite is a facile technique that has the potential to detect and systematically measure nanoplastics in the environment. This research is an important step toward detecting nanoscale plastic particles that may cause toxic effects to mammalian and aquatic life when present in high concentrations.

Aims We hypothesized that the wide-awake local anaesthesia with no tourniquet (WALANT) technique is cost-effective, easy to use, safe, and reproducible, with a low learning curve towards mastery, having a high patient satisfaction rate. Furthermore, WALANT would be a suitable alternative for the austere and developing nation environments where lack of funds and resources are a common issue. Methods This was a randomized control trial of 169 patients who required surgery for closed isolated distal radius fractures. The study was performed between March 2016 and April 2019 at a public sector level 1 trauma centre. General anaesthesia was used in 56 patients, Bier’s block in 58 patients, and WALANT in 55 patients. Data were collected on pre-, peri-, and postoperative parameters, clinical outcome, hospital costs, and patient satisfaction. One-way analysis of variance (ANOVA) was used with a p-value of 0.05 being significant. Results Operations with WALANT proceeded sooner, and patients recovered faster, resulting in mean fewer missed working days (7.8 (SD 1.67)) compared with general anaesthesia (20.1 (SD 7.37)) or Bier’s block (14.1 (SD 7.65)) (p < 0.001). The WALANT patients did not develop complications, while the other patients did (p < 0.04). Clinical outcomes did not differ, nor did surgeon qualification affect clinical outcomes. Mean hospital costs were lower for WALANT ($428.50 (SD 77.71)) than for general anaesthesia ($630.63 (SD 114.77)) or Bier’s block ($734.00 (SD 37.54)) (p < 0.001). Patient satisfaction was also higher (p < 0.001). Conclusion WALANT for distal radius fractures results in a faster recovery, is more cost-effective, has similar clinical outcomes, and has fewer complications than general anaesthesia or Bier's block. This makes WALANT an attractive technique in any setting, but especially in middle- and low-income countries. Cite this article: Bone Joint Res 2020;9(7):429–439.

In recent years, bioanalytical surface-enhanced Raman spectroscopy (SERS) has blossomed into a fast-growing research area. We present here a review on SERS-based assays with focus on early bacterial infection detection and chronic disease diagnosis.

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