Occurrence, distribution, potential sources, and risks of organophosphate esters in fresh snow on Urumqi Glacier No. 1, eastern Tien Shan, China.

Organophosphate esters (OPEs), extensively used as flame retardants, are widely detected in various regions and environments. The potential toxicity of OPEs has caused great concern in recent years. Based on the global distillation model, the Tien Shan glaciers, such as Urumqi Glacier No. 1, could be as a potential "sink" for OPEs. However, little is known about the concentration, distribution, potential sources, and ecological risks of OPEs in Tien Shan glaciers. In this study, fresh snow samples were collected at various altitudes on the Urumqi Glacier No. 1, eastern Tien Shan, China. The total concentrations of ten OPEs (Σ10OPEs) ranged from 116 to 152 ng/L. The most abundant OPE was tris-(2-chloroisopropyl) phosphate (TCIPP), contributing to 74 % of the total OPEs. Σ10OPEs, tri-n-butyl phosphate (TnBP), and TCIPP concentrations showed positive correlations with altitude, indicating the effect of cold condensation on OPEs deposition. Based on air mass back-trajectory analysis and principal component analysis, we found that emissions from both traffic and household products in indoor environment were the important sources, and OPEs on the Urumqi Glacier No. 1 might mainly originate from Europe. Our assessment also showed triphenyl phosphate (TPhP) posed a low ecological risk in snow. This is the first systematic study of OPEs on the Tien Shan glaciers.

Associations of Attitudes and Practice Toward Oral Health, Socioeconomic Status, Self-Rated Oral Health, Subjective Oral Symptoms, and Oral Health-Related Quality of Life Among Residents in Eastern China: A Structural Equation Modeling Approach.

Background and Purpose: The purpose of this study was to investigate the relationships among attitudes and practice about oral health, socioeconomic status, subjective oral symptoms, self-rated oral health, and oral health-related quality of life (OHRQoL) in a group of people from eastern China. Methods: Between January 2021 to February 2022, 2502 (87.4%) of the 2863 participants completed an online questionnaire. OHRQoL, Socio-demographics characteristics, attitudes and practice toward oral health, self-rated oral health and subjective oral symptoms were all covered by the questionnaires. Based on the hypothetical model, structural equation modeling with the bootstrap method was used to examine the interactions and the strength of the correlations between the measured variables. Results: The final model demonstrated acceptable data fit. Socioeconomic status (ß = -0.051), attitudes (ß = -0.100) and practice (ß = -0.127) toward oral health, self-rated oral health (ß = -0.493) and subjective oral symptoms (ß = 0.294) were all significantly correlated with OHRQoL. Socioeconomic status was directly linked to attitudes (ß = 0.046) and practice (ß =0.070) about oral health, and attitudes play the role of intermediary between practice and socioeconomic status (ß = 0.018). OHRQoL was indirectly linked with attitudes mediated by practice (ß = -0.092), practice mediated by subjective oral symptoms (ß = -0.107), subjective oral symptoms mediated by self-rated oral health (ß = 0.031). OHRQoL was correlated with income, educational level, and socioeconomic status. Self-rated oral health was related to educational level and socioeconomic status. Conclusion: In a sample of eastern China residents, OHRQoL was influenced by socioeconomic status, attitudes and practice toward oral health, subjective oral symptoms, and self-rated oral health.

[Application of personalized guide plate combined with real-time navigation in repairing mandibular defect using fibula muscle flap].

Objective: To explore the application of personalized guide plate combined with intraoperative real-time navigation in repairing of mandibular defect using fibula muscle flap, providing the basis for the precise repair and reconstruction of mandible. Methods: The clinical data of 12 patients (9 males and 3 females) aged from 23 to 71 years (mean, 55.5 years) between July 2019 and December 2021 were recorded. These patients were diagnosed as benign or malignant mandibular tumors, including 2 cases of ameloblastoma, 6 cases of squamous cell carcinoma, 2 cases of osteosarcoma, 1 case of adenoid cystic carcinoma, and 1 case of squamous carcinoma. All patients were treated with mandibular amputation, and then repaired by double-stacked three-segment fibula muscle flap. Preoperative virtual design scheme and guide plate were performed. During the operation, personalized guide plate combined with real-time navigation was used for fibular osteotomy and shaping. Thin-slice CT examination was performed at 2-3 weeks after operation, and was fitted with the preoperative virtual design scheme. The difference between the distance of bilateral mandibular angles relative to the reference plane in three-dimensional directions (left-right, vertical, and anterior-posterior) and the difference of the medial angle of the lower edge of the mandible reconstructed by fibula were measured, and the mean error of chromatographic fitting degree was calculated. Results: The guide plate and navigation were applied well, and the fibula shaping and positioning were accurate. The fibula muscle flap survived, the incision healed well, and the occlusal relationship was good. All 12 patients were followed up 1-29 months, with an average of 17 months. There was no significant difference on the distance of bilateral mandibular angles relative to the reference plane in the left-right [(-0.24±1.35) mm; t=-0.618, P=0.549], vertical [-0.85 (-1.35, 1.40) mm; Z=-0.079, P=0.937], and anterior-posterior [(-0.46±0.78) mm; t=-2.036, P=0.067] directions. The difference of the medial angle of the lower edge of the mandible reconstructed by fibula was also not significant [(-1.35±4.34)°; t=-1.081, P=0.303)]. Postoperative CT and preoperative virtual design fitting verified that there was no significant difference in the change of the mandibular angle on both sides, and the average error was (0.47±1.39) mm. Conclusion: The personalized guide combined with intraoperative real-time navigation improves the accuracy of peroneal muscle flap reconstruction of the mandible, reduces the complications, and provides a preliminary basis for the application of visual intraoperative navigation in fibula muscle flap reconstruction of the mandible.

The first detection of organophosphate esters (OPEs) of a high altitude fresh snowfall in the northeastern Tibetan Plateau.

Due to the gradual phase-out of brominated flame retardants, the consumption of organophosphate esters (OPEs) as suitable alternatives has increased in recent years. These compounds could be trapped and accumulate in the widely developed glaciers such as Laohugou Glacier No. 12 in the Tibetan Plateau (TP), as snow is an effective scavenger of organic pollutants in the atmosphere. However, large gaps in knowledge still exist regarding the occurrence, distribution, and source analysis of OPEs in TP glaciers. In this study, eight surface snow samples collected at different altitudes on Laohugou Glacier No. 12 on the northeastern edge of the TP in order to investigate sources and distribution of OPEs. The results showed that the concentrations of ∑7OPEs varied from 54.53 ng/L to 169.15 ng/L, with a mean of 99.84 ng/L. ∑Chlorinated-OPEs (Cl-OPEs) were dominant in these samples, accounting for 83% of the total OPE concentrations. ∑OPEs concentration increases with altitude on Laohugou Glacier No. 12, implying an altitudinal magnification effect on OPEs deposition. Principal component analysis suggests that OPEs primarily originated from traffic emissions and their variations were largely driven by dust transport. Analyses of backward trajectories of air masses and the wind field indicate that these OPEs might have come from urban emissions northwest of Laohugou Glacier No. 12. This study provides the first valuable insight into the environmental behavior of OPEs in Tibetan glaciers.

Clinical effects of elective neck dissection on 5-year survival rate of patients with early oral squamous cell carcinoma / 口腔疾病防治

Objective@#To investigate the effect of elective neck dissection on the 5-year survival rate of patients with early oral squamous cell carcinoma.@*Methods@#The data of 100 patients with early oral squamous cell carcinoma (cT1-2N0M0) were retrospectively analyzed. In 61 cases, the primary tumor was subjected to elective neck dissection (END). Neck observation and follow-up (NOF) were performed in 39 cases with enlarged resection of primary lesions. Clinicopathological data such as pT staging, pathology classification,the rate of cervical lymph node metastasis and the 5-year survival rate of the patients were statistically analyzed.@*Results@#The 5-year survival rates of the END and NOF groups were 86.9% and 69.2%, respectively, and the difference was statistically significant (P=0.028). END treatment was significantly better than NOF in controlling cervical lymph node metastasis in early oral squamous cell carcinoma (P=0.009). After stratified analysis of histopathological features, the 5-year survival rate of patients with pathological T2 (pT2) stage OSCC in the END group was significantly higher than that in the NOF group (P=0.020). The 5-year survival rate of patients with moderate and poorly differentiated pathological grade OSCC in the END group was significantly higher than that in the NOF group (P=0.013). @*Conclusion @# END is effective for the management of the cervical lymph node metastasis rate in early OSCC patients. For patients with pT2 stage or low differentiation pathological grade, active END can significantly improve the 5-year survival rate.

[Geochemical Characteristics of Lateral Hyporheic Zone Between the River Water and Groundwater, a Case Study of Maanxi in Chongqing].

The hyporheic zone is a place where river water and groundwater mutually exchange and mix. It plays an important role in protecting the ecology and water quality of river water and groundwater. In order to study the geochemical characteristics of lateral hyporheic zone in river and ground water, water temperature, dissolved oxygen, pH, electrical conductivity were measured automatically at the hyporheic zone of Maanxi in Chongqing. The concentrations of ions in water and elements in sediment within the hyporheic zone were also analyzed. The results showed that the hydrochemical species of lateral hyporheic zone in Maanxi was HCO3-Ca·Mg. Affected by the infiltration of river water, the coefficient variations of water temperature, dissolved oxygen, pH and electrical conductivity in the hyporheic zone were lower than those observed in the river under the buffer action. Along with the farther distance from the riverbank, an anoxia redox environment was formed in the hyporheic zone due to a physical, chemical and biological interactions. An acid and alkali environment was also formed with a decreasing pH trend near the riverbank and hyporheic zone. Under its influence, concentrations of K+, NH4+-N, NO3- and SO42- decreased. Mn, electrical conductivity, and the concentrations of Ca2+, Mg2+, Ba2+ and Sr2+ firstly increased and then decreased, while the concentrations of Fe, Al3+ were elevated. Affected by the long-time interaction of river water and groundwater, the elementary concentrations in the sediment were relatively high at the place of about 30 cm away from the riverbank. This consequently formed a hydrogeochemical gradient in the hyporheic zone. The boundary of the hyporheic zone was inferred at 30 to 50 cm away from the riverbank, whereas the boundary of shallow hyporheic zone was located at 10 cm away from the riverbank. In the process of river water recharging groudnwater, hyporheic zone of river and groundwater played an important role in the purification of water quality.

[Comparison on the Hydrogeochemical Characteristics of Typical Karst Groundwater System in Southwest China, a Case of Qingmuguan and Laolongdong in Chongqing].

To study the hydrogeochemical characteristics of southwestern typical karst underground river influenced by different land-use types and human activities, underground rivers of Qingmuguan and Laolongdong, which have similar geological background in Chongqing, were contrastively analyzed from the scale of monthly and rainfall event variation. By the means of independent t-test and principal component analysis(PCA), the results showed that ions of Ca2+, HCO3-, Mg2+, K+, NO3-, Na+, SO42-, Cl- and conductivity were distinctly different at the outlet of the two observed underground rivers, Jiangjia spring and Laolongdong. Compared with Laolongdong, Jiangjia spring showed larger monthly variation range and mean concentrations of K+, NO3-, but ions of Na+, SO42-, Cl- showed an opposite trend. Water-rock interaction played an important role in the hydrogeochemical characteristics and variations of two observed karst underground rivers. Qingmuguan underground river was mainly affected by agricultural activities, while Laolongdong underground river was dominantly influenced by urban and industrial activities. Owing to the difference in manner and intensity of human activities, the two observed karst underground river systems responded differently during a single rainfall event. The variation of water chemical indicators that highly corresponded to discharge at Jiangjia spring were relatively disordered at Laolongdong. It was shown that the hydrogeochemical characteristic of Qingmuguan was primarily influenced by soil erosion and agricultural activities, followed by water-rock interaction, while the hydrochemical characteristic of Laolongdong was dominantly influenced by water-rock interaction, followed by urban activities, industrial activities and soil erosion.