Development of diffusive gradients in thin-films technique for monitoring polycyclic aromatic hydrocarbons in coastal waters.

Addressing the challenge of accurately monitoring polycyclic aromatic hydrocarbons (PAHs) in aquatic systems, this study employed diffusive gradients in thin-films (DGT) technique to achieve methods detection limits as low as 0.02 ng L-1 to 0.05 ng L-1 through in situ preconcentration and determination of time-integrated concentrations. The efficacy of the developed DGT samplers was validated under diverse environmental conditions, demonstrating independence from factors such as pH (5.03-9.01), dissolved organic matter (0-20 mg L-1), and ionic strength (0.0001-0.6 M). Notably, the introduction of a novel theoretical approach to calculate diffusion coefficients based on solvent-accessible volume tailored for PAHs significantly enhanced the method's applicability, particularly for organic pollutants with low solubility. Field deployments in coastal zones validated the DGT method against traditional grab sampling, with findings advocating a 4 to 7-day optimal deployment duration for balancing sensitivity and mitigating lag time effects. These results provide a sophisticated, efficient solution to the persistent challenge of monitoring hydrophobic organic pollutants in aquatic environments, broadening the scope and applicability of DGT in environmental science and providing a robust tool for researchers.

Wearable and Recyclable Water-Toleration Sensor Derived from Lipoic Acid.

Flexible wearable sensors recently have made significant progress in human motion detection and health monitoring. However, most sensors still face challenges in terms of single detection targets, single application environments, and non-recyclability. Lipoic acid (LA) shows a great application prospect in soft materials due to its unique properties. Herein, ionic conducting elastomers (ICEs) based on polymerizable deep eutectic solvents consisting of LA and choline chloride are prepared. In addition to the good mechanical strength, high transparency, ionic conductivity, and self-healing efficiency, the ICEs exhibit swelling-strengthening behavior and enhanced adhesion strength in underwater environments due to the moisture-induced association of poly(LA) hydrophobic chains, thus making it possible for underwater sensing applications, such as underwater communication. As a strain sensor, it exhibits highly sensitive strain response with repeatability and durability, enabling the monitoring of both large and fine human motions, including joint movements, facial expressions, and pulse waves. Furthermore, due to the enhancement of ion mobility at higher temperatures, it also possesses excellent temperature-sensing performance. Notably, the ICEs can be fully recycled and reused as a new strain/temperature sensor through heating. This study provides a novel strategy for enhancing the mechanical strength of poly(LA) and the fabrication of multifunctional sensors.

Heavy metals in the sediments of Laoshan Bay, China: Distribution and contamination assessment.

We analyzed total organic carbon (TOC), total nitrogen (TN), and heavy metals in 58 sediment samples from the Laoshan Bay, China. TOC and TN results identified marine primary production as the dominant source for organic matter, and the weak correlations between TOC, TN, and heavy metals indicated the terrestrial origin of heavy metals. Cd showed insignificant correlations with other metals, which suggests that agriculture production is the main anthropogenic activity affecting the distribution of Cd. Pb contamination in past 50 years was likely to have occurred because of fossil fuel combustion. Despite 210Pb dating, it was still difficult to trace the contamination condition over interannual variations. Nonetheless, these results provide data for monitoring Pb contamination. As Laoshan Bay is an important economic area, it would be beneficial to conduct further studies to determine the sources and degree of contamination for each heavy metal.

Specific size distributions of elemental and organic carbon, and polycyclic aromatic hydrocarbons emitted from petrol engine using two fuel grades.

The most common commercial oils in the Chinese market are two petrol types with octane levels of 93 and 97. To determine the source spectrum of air pollutant emissions, we herein investigated the specific emission sizes of the total suspended particles (TSP), total carbon (TC), elemental carbon (EC), organic carbon (OC), and polycyclic aromatic hydrocarbons (PAHs) from a petrol engine fueled with 93# and 97# petrol in 2016 (based on Chinese national IV gasoline standard). We found that while 93# emitted a higher TSP content, 97# emitted greater TC, EC, OC, and PAHs. The highest carbon contents were found in the < 0.25 µm and 0.44-1.0 µm size fractions for the 93# and 97# petrol, respectively. OC content showed a significant positive correlation with EC, and EC2 (at 740 ℃) was the main carbon fragment in both petrol exhausts. The highest PAH content occurred in the 0.25-0.44 µm size-bin, differing from the results for TC, EC, and OC, and medium molecular weight (4 rings) PAHs were the primary component in the emissions. These results indicate that fuel composition and octane sensitivity have a prominent effect on the size distributions of TC (including EC, OC, and PAHs). Thus, more studies on the carbon content at specific emission sizes in petrol exhaust should be conducted to clarify the main factors impacting these variations.

Minimally Invasive Transforaminal Lumbar Interbody Fusion and Unilateral Fixation for Degenerative Lumbar Disease.

OBJECTIVE: To evaluate the clinical effect of the minimally invasive transforaminal lumbar interbody fusion combined with posterolateral fusion and unilateral fixation using a tubular retractor in the management of degenerative lumbar disease. METHODS: A retrospective analysis was conducted to analyze the clinical outcome of 58 degenerative lumbar disease patients who were treated with minimally invasive transforaminal lumbar interbody fusion combined with posterolateral fusion and unilateral fixation during December 2012 to January 2015. The spine was unilaterally approached through a 3.0-cm skin incision centered on the disc space, located 2.5 cm lateral to the midline, and the multifidus muscles and longissimus dorsi were stripped off. After transforaminal lumbar interbody fusion and posterolateral fusion the unilateral pedicle screw fixation was performed. The visual analogue scale (VAS) for back and leg pain, the Oswestry disability index (ODI), and the MacNab score were applied to evaluate clinical effects. The operation time, peri-operative bleeding, postoperative time in bed, hospitalization costs, and the change in the intervertebral height were analyzed. Radiological fusion based on the Bridwell grading system was also assessed at the last follow-up. The quality of life of the patients before and after the operation was assessed using the short form-36 scale (SF-36). RESULTS: Fifty-eight operations were successfully performed, and no nerve root injury or dural tear occurred. The average operation time was 138 ± 33 min, intraoperative blood loss was 126 ± 50 mL, the duration from surgery to getting out of bed was 46 ± 8 h, and hospitalization cost was 1.6 ± 0.2 ten thousand yuan. All of the 58 patients were followed up for 7-31 months, with an average of 14.6 months. The postoperative VAS scores and ODI score were significantly improved compared with preoperative data (P < 0.05). The evaluation of the MacNab score was excellent in 41 patients, good in 15, and fair in 2, suggesting an effective rate of 96.6%. The intervertebral height had reduced 0.2 ± 1.2 mm by the last follow-up, and there were 55 Grade I and II cases based on the Bridwell evaluation criterion. The fusion rate was 94.8%, and no screw breakage and loosening occurred. The scores of physical pain, general health, social, and emotional functioning were significantly increased at the last follow-up. CONCLUSION: Minimally invasive transforaminal lumbar interbody fusion combined with posterolateral fusion and unilateral fixation provide a new choice for degenerative lumbar disease, and the short-term clinical outcome is satisfactory.