Understanding dilution effects on particle-containing pesticide droplets deposition on rice leaf via developing CFD-VOF-DPM model.

BACKGROUND: Pesticide dilution is one of the essential aspects of plant protection. However, the effect of dilution on the deposition characteristics of pesticide droplets containing particulate additives on crop leaf surfaces remains unclear and warrants further research. Herein, a validated computational fluid dynamics (CFD)-volume of fluid (VOF)-discrete phase model (DPM) numerical model was developed to analyze the influence of particle content on the deposition behavior of droplets on the leaf surface comparatively, taking into account the particle content of different diluted thifluzamide solutions. Additionally, the study aimed to analyze further the kinetic behavior of pesticide droplets landing on rice leaves across different dilution conditions. RESULTS: Pesticide droplets diluted 100-fold had a lower retraction rate during spreading than particle-free droplets, so the solution is more easily deposited in the leaves. Moreover, the low dilution (high concentration) increased the critical adhesion rate between droplets and rice leaves, inhibiting the bouncing of droplets on the leaf surface, thus promoting their effective deposition on the surface. In addition, low dilution (high concentration) is not conducive to spreading droplets when the impact velocity is high, and it also results in a large amount of pesticide use. CONCLUSION: The actual application process can be through understanding the dilution factor of the configured pesticide solution, and reasonable adjustment of the nozzle pressure can effectively improve the utilization rate of pesticides and reduce the pollution brought by pesticides to the environment. These results provide an essential reference for studying pesticide droplet deposition characteristics, including rice plant protection and spraying technology. © 2024 Society of Chemical Industry.

A virtual simulation system-based teaching method for the experimental course of oral local nerve block anesthesia / 中华医学教育探索杂志

Objective:To investigate the effect of the virtual simulation system-based teaching method for the experimental course of oral local nerve block anesthesia in improving the effect of traditional teaching methods.Methods:One hundred and eighteen undergraduate dental students were randomly divided into two groups, the experimental group was taught using a virtual simulation-based system, and the control group was taught using traditional teaching. The results of the teaching were comprehensively evaluated through course feedback questionnaires, analysis of theoretical test scores, evaluations of the trainees administering and receiving anesthesia on the current anesthesia, and faculty evaluations of the success of the anesthesia, and t-tests and chi-square tests were performed using SPSS 23.0.Results:There was no significant difference in baseline level between the two groups. The students in the experimental group thought that the learning was more vivid ( t=4.24, P=0.005) and had more self-confidence in local anesthesia ( t=4.99, P<0.001). The students in the experimental group felt less needle tip jitter during injection ( t=2.22, P=0.048) and better contact with the medial surface of the mandible ( t=2.22, P=0.020). The students who received anesthesia reported less pain during injection ( t=1.99, P=0.029) and better anesthesia of the inferior alveolar nerve ( t=3.36, P=0.039) in the experimental group. Teacher assessment revealed that the experimental group had a significantly lower failure rate of inferior alveolar nerve block than the control group ( χ2=4.40, P=0.036). Conclusions:The virtual simulation system can optimize the experimental teaching of oral local nerve block anesthesia and can achieve a satisfactory teaching effect.

Promotion effect of TGF-β-Zfp423-ApoD pathway on lip sensory recovery after nerve sacrifice caused by nerve collateral compensation / 国际口腔科学杂志·英文版

Resection of oral and maxillofacial tumors is often accompanied by the inferior alveolar nerve neurectomy, resulting in abnormal sensation in lower lip. It is generally believed that spontaneous sensory recovery in this nerve injury is difficult. However, during our follow-up, patients with inferior alveolar nerve sacrifice showed different degrees of lower lip sensory recovery. In this study, a prospective cohort study was conducted to demonstrate this phenomenon and analyze the factors influencing sensory recovery. A mental nerve transection model of Thy1-YFP mice and tissue clearing technique were used to explore possible mechanisms in this process. Gene silencing and overexpression experiments were then conducted to detect the changes in cell morphology and molecular markers. In our follow-up, 75% of patients with unilateral inferior alveolar nerve neurectomy had complete sensory recovery of the lower lip 12 months postoperatively. Patients with younger age, malignant tumors, and preservation of ipsilateral buccal and lingual nerves had a shorter recovery time. The buccal nerve collateral sprouting compensation was observed in the lower lip tissue of Thy1-YFP mice. ApoD was demonstrated to be involved in axon growth and peripheral nerve sensory recovery in the animal model. TGF-β inhibited the expression of STAT3 and the transcription of ApoD in Schwann cells through Zfp423. Overall, after sacrificing the inferior alveolar nerve, the collateral compensation of the ipsilateral buccal nerve could innervate the sensation. And this process was regulated by TGF-β-Zfp423-ApoD pathway.