Windblown sand hazards risk assessment along the highways based on GIS-game theory combination weight.

Windblown sand hazards seriously threaten the safe operation of highways in desert areas. Reasonable risk assessment can provide the basis for windblown sand hazards prevention and risk reduction. To facilitate the formulation of better windblown sand hazards prevention and reduction strategies, a new windblown sand hazards risk assessment model along the highways was proposed, in which seven evaluation indicators were selected from danger of the hazard-causing factors, vulnerability of the hazard-forming environment, and the vulnerability of the hazard-bearing body. The model was established based on the combination weighting method of game theory, and the risk map was generated based on the GIS platform. Finally, the model was applied to the windblown sand hazards risk assessment along the Wuhai-Maqin Highway. The result showed that the risk of the windblown sand hazards along the Wuhai-Maqin Highway is mainly medium, low, and very low. High and very high risk windblown sand hazards sections account for only 33% of the total length of the highway. The high and very high risk highway sections of the windblown sand hazards are mainly distributed in the hinterland of shifting dunes area and near the horizontal curve with a small radius in the flat sandy land area. By comparing with the real information of windblown sand hazards along the highway, correlation was up to 85.93%, which verified the accuracy of the model. The model can be applied to windblown sand hazards risk assessment along the highways.

Conductive imprinted polymeric interfacially modified electrochemical sensors based on covalently bonded layer-by-layer assembly of Gr/Au with flower-like morphology for sensitive detection of 2,4,6-TCP.

Polymeric membrane sensors based on molecular imprinted polymers (MIPs) have been attractive analytical tools for detecting organic species. However, the MIPs in electrochemical sensors developed so far are usually prepared by in situ polymerization of pre-polymers and non-covalent adsorption on the surface of the working electrode. Meanwhile, the MIPs in the electrochemical sensors developed are typically made of a non-conductive polymer film. This results in a relatively low current due to the lack of electron transfer. Additionally, the smoothness of the traditional electrochemical substrate results in a low specific surface area, which reduces the sensitivity of the electrochemical sensor. Here, we describe a novel electrochemical sensor with a conductive interface and MIPs modification. The electrochemical sensor was modified by covalent coupled layer by layer self-assembly with the imprinted polymer film. The incorporation of these two conductive functional materials improves the conductivity of the electrodes and provides interface support materials to obtain high specific surface area. By using 2,4,6-trichlorophenol as the model, the sensitivity of the developed conductive sensor was greatly improved compared to that of the traditional MIPs sensor. We believe that the proposed MIPs-based sensing strategy provides a general and convenient method for making sensitive and selective electrochemical sensors.

Identification and verification of PCDD/Fs indicators from four typical large-scale municipal solid waste incinerations with large sample size in China.

Monitoring PCDD/Fs emissions from municipal solid waste incinerations (MSWIs) is of paramount importance, yet it can be time-consuming and labor-intensive. Predictive models offer an alternative approach for estimating their levels. However, robust models specific to PCDD/Fs were lacking. In this study, we collected 190 PCDD/Fs samples from 4 large-scale MSWIs in China, with the average PCDD/Fs levels and TEQ levels of 0.987 ng/m3 and 0.030 ng TEQ/m3, respectively. We developed and evaluated predictive models, including traditional statistical methods, e.g., linear regression (LR) as well as machine learning models such as back propagation-artificial neural networks (BP ANN) and random forest (RF). Correlation analysis identified 2,3,4,7,8-PeCDF, 1,2,3,6,7,8-HxCDF, 2,3,4,6,7,8-HxCDF were better indicator congeners for PCDD/Fs estimation (R2 > 0.9, p < 0.001). The predictive results favored the RF model, exhibiting a high R2 value and low root mean square error (RMSE) and mean absolute error (MAE). Additionally, the RF model showed excellent prediction ability during external validation, with low absolute relative error (ARE) of 10.9 %-12.6 % for the three indicator congeners in the normal PCDD/F TEQ levels group (<0.1 ng TEQ/m3) and slightly higher ARE values (13.8 %-17.9 %) for the high PCDD/F TEQ levels group (>0.1 ng TEQ/m3). In conclusion, our findings strongly support the RF model's effectiveness in predicting PCDD/Fs TEQ emission from MSWIs.

Evaluation the binding of chlorogenic acid with bovine serum albumin: Spectroscopic methods, electrochemical and molecular docking.

Chlorogenic acid(CGA) is the common active phenolic acid in Chinese medicinal materials such as honeysuckle and eucommia. It is a class of small molecules with multiple activities such as antioxidant, inhibiting cancer cells, lowering blood sugar and lowering blood pressure. In this paper, UV-vis spectroscopy, fluorescence spectroscopy, circular dichroism, molecular dynamics simulation and cyclic voltammetry (CV) electrochemical analysis were used to investigate the mechanism about interaction between CGA and BSA. Based on fluorescence quenching analysis, CGA quenched the inherent fluorescence of BSA remarkably through a static mechanism. The obtained value of binding constant (Kb = 5.75 × 105 L·mol-1) revealed a high binding affinity between CGA and BSA. The simulated molecular docking showed that hydrophobic force were also involved in the interaction between BSA and CGA. This paper also investigate the effect of temperature and metal ions on the binding of CGA and BSA. When the temperature increased, the binding of BSA and CGA was destroyed. Metal ions affect both the structure of BSA and the combination of BSA and CGA. By studying the mechanism of CGA interaction with BSA, we elucidated the storage and transport mechanism of CGA in vivo under simulated human environment and temperature conditions.

A two-gene random forest model to diagnose osteoarthritis based on RNA-binding protein-related genes in knee cartilage tissue.

Osteoarthritis (OA) is one of the most common diseases in the orthopedic clinic, characterized by progressive cartilage degradation. RNA-binding proteins (RBPs) are capable of binding to RNAs at transcription and translation levels, playing an important role in the pathogenesis of OA. This study aims to investigate the diagnosis values of RBP-related genes in OA. The RBPs were collected from previous studies, and the GSE114007 dataset (control = 18, OA = 20) was downloaded from the Gene Expression Omnibus (GEO) as the training cohort. Through various bioinformatical and machine learning methods, including genomic difference detection, protein-protein interaction network analyses, Lasso regression, univariate logistic regression, Boruta algorithm, and SVM-RFE, RNMT and RBM24 were identified and then included into the random forest (RF) diagnosis model. GSE117999 dataset (control = 10, OA = 10) and clinical samples collected from local hospital (control = 10, OA = 11) were used for external validation. The RF model was a promising tool to diagnose OA in the training dataset (area under curve [AUC] = 1.000, 95% confidence interval [CI] = 1.000-1.000), the GSE117999 cohort (AUC = 0.900, 95% CI = 0.769-1.000), and local samples (AUC = 0.759, 95% CI = 0.568-0.951). Besides, qPCR and Western Blotting experiments showed that RNMT (P < 0.05) and RBM24 (P < 0.01) were both down-regulated in CHON-001 cells with IL-1ß treatment. In all, an RF model to diagnose OA based on RNMT and RBM24 in cartilage tissue was constructed, providing a promising clinical tool and possible cut-in points in molecular mechanism clarification.

Pan-Cancer analysis of TERT and Validation in Osteosarcoma Cell Lines.

PURPOSE: To investigate the possible functions of TERT in pan-cancer and OS. METHODS: First, differential TERT gene expression analysis was conducted using multi-omics data integrative analyses, including differential expression, prognosis, the correlation between infiltrating inflammatory immune cells, and mutation in pan-cancer. Furthermore, differential TERT gene expression analysis was conducted using mRNA expression profiles related to OS based on the GEO Datasets. Various differentially expressed genes were chosen based on a fitness threshold for further investigations. Finally, the function of the TERT gene was assessed in OS cells, including cellular proliferation, migration, and metastasis. RESULTS: Pan-cancer research demonstrated that variable expression of TERT was not only associated with numerous types of human cancer but was also intimately linked to DNA methylation. Bioinformatic investigation revealed a link between the differential expression of TERT with immune cell infiltration in the tumor microenvironment (TME). In vitro studies indicated that inhibition of TERT decreased OS cell proliferation, motility, and metastasis. CONCLUSION: TERT may serve as a useful genomic biomarker for the diagnosis and prediction of pan-cancer and as a prospective therapeutic target for the treatment of OS.

[Pollution Characteristics and Emission Factors of PCDD/Fs from Iron and Steel Industry].

The pollution level, emission characteristics, and emission factors of PCDD/Fs from a number of steel plants were investigated in a particular province of China. The results showed that the concentration of PCDD/Fs was at a low level and decreased by 1-2 orders of magnitude compared with that in 2005-2019. In detail, the concentrations of PCDD/Fs ranged from 0.003-0.557 ng·m-3(I-TEQ), and the mean value was 0.165 ng·m-3 for the sintering process. Moreover, the concentrations of PCDD/Fs ranged from 0.006 to 0.057 ng·m-3, and the mean value was 0.025 ng·m-3 for the electric furnace process. In addition, the concentration of PCDD/Fs in the iron and steel industry from 2005 to 2020 increased first and then decreased, especially after the implementation of the new emission standard and the ultra-low emission control of conventional pollutants such as smoke, showing a significant decline. The results of fingerprint analysis showed that 2,3,7,8-TCDF was the largest congener contributing to the mass concentration, and lower chlorinated PCDFs were increased. This result differed from those of previous studies in which highly chlorinated PCDFs and PCDDs dominated, indicating that the generation source of PCDD/Fs had changed. The congener and isomer profiles of PCDD/Fs in flue gas from the sintering process were similar to those in the flue gas from the electric furnace process. Additionally, showing the characteristics of the typical high-temperature thermal process, the de novo synthesis may be the dominant mechanism of formation of PCDD/Fs in the sintering process and electric furnace process. The emission factor was 0.003-0.5 µg·t-1 (I-TEQ), and the average emission factor was (0.18±0.22) µg·t-1 for the sintering process. The emission factor was 0.04-0.5 µg·t-1, and the average emission factor was (0.27±0.23) µg·t-1 for the electric furnace process. These values were far lower than those of the standard toolkit for identification and quantification of dioxin and furan emissions released by UNEP in 2013 and the emission factors in the dioxin emission inventory of China in 2004. It is suggested that the emission factors of PCDD/Fs in the iron and steel industry of China should be studied and updated.

Farrerol alleviates collagenase-induced tendinopathy by inhibiting ferroptosis in rats.

Tendinopathy is mainly characterized by local pain, functional limitation and decreased athletic ability, which seriously affects the quality of life of patients and the career of athletes. Farrerol (FA), one of the main active compounds extracted from Rhododendron and plants in the Rhododendron family, has a wide range of pharmacological activities, such as immunomodulatory, anti-inflammatory and antiviral effects. However, the effect of FA on tendinopathy is unclear. Here, we investigated the pharmacological effect and mechanism of FA in tendon injury through collagenase-induced tendinopathy in vivo and RSL3-induced tenocytes injury in vitro. The results showed that FA alleviated the infiltration of inflammatory cells, promoted tenogenesis and improved mechanical properties of the Achilles tendon in rats. In addition, ferroptosis inducer RSL3 inhibits the tenogenesis in vitro and in vivo, which accelerates the progression of tendinopathy. Moreover, FA effectively inhibited iron accumulation and alleviated ferroptosis in the Achilles tendon. Using in vitro experiments, we found that FA antagonized ferroptosis by reducing lipid peroxidation and iron accumulation in tenocytes. Finally, we found that glutathione peroxidase 4 silencing could block the protective effect of FA on ferroptosis of tenocytes. Therefore, the results of this study suggest that FA can relieve collagenase-induced tendinopathy by inhibiting ferroptosis, and reveal that FA may be a potentially effective drug for the treatment of tendinopathy in the future.

Amplification of fluorescence polarization signal based on specific recognition of aptamers combined with quantum quenching effect for ultrasensitive and simple detection of PCB-77.

Here, we report a novel aptasensor based on decahedral silver nanoparticles (Ag10NPs) enhanced fluorescence polarization (FP) for detecting PCB-77. Using aptamer modified Ag10NPs hybridized with DNA sequence labeled fluorescent group as an analytical probe, polychlorinated biphenyls (PCB-77) could be detected with high sensitivity and selectivity. The linear range of determination was 0.02 ng/L to 390 ng/L and the limit of detection was 5 pg/L. In addition, through the optimization of the experiment condition and signal probe DNA (pDNA), we found that the maximum FP signal could be generated when the distance between fluorescein and the surface of Ag10NPs was 3 nm. When the aptamer was immobilized on the surface of Ag10NPs could be strengthened the anti-interference performance of aptamer nanoprobe and further improved the detection ability. At the same time, we also compared the detection performance of the traditional FP signal enhancer streptavidin (SA) analysis system. The fluorescence polarization aptasensor could detect PCB-77 samples efficiently in complex environmental water, which shows a good application prospect.

Evaluation the effect of nanoparticles on the structure of aptamers by analyzing the recognition dynamics of aptamer functionalized nanoparticles.

Aptamer-functionalized nanoparticles have been widely studied as targeted probes in biomedical applications for targeted therapy and imaging. The rigidity of the nanoparticle could stabilized the spatial structure of the aptamer, ensuring the selectivity and affinity for target recognition in the complex environment. The main aim of this article study was to explore the effect of the spatial structure of aptamer in the interaction between aptamer nanoprobes and receptors. We designed and synthesized aptamer functionalized nanoparticle systems with different derivation lengths, and developed a unique kinetic analysis to quantify affinity interactions. The system used silver decahedral nanoparticles (Ag10NPs), which was then chemically functionalized with thrombin (or IgE) aptamers of different tail lengths to produced different nanoprobes, and employed thrombin (or IgE) as target on a surface plasmon resonance (SPR) biosensor to evaluate the binding of these nanoprobes. Kinetic analysis of the SPR binding curve was performed to evaluated the affinity between nanoprobes and targets. Under the premise of eliminating multivalent interactions, we found that the distance between aptamer and nanoparticle could affect the affinity between nanoprobe and target. Furthermore, we found that keeping a certain distance between aptamer and nanoparticle could effectively improved the recognition efficiency of the aptamer nanoprobe and target. It shows that the rigidity of nanomaterials could maintain the spatial structure of the aptamer.

Mineralization crust field experiment for desert sand solidification based on enzymatic calcification.

Sandstorms have been recognized as severe natural disasters worldwide and it is of great significance to propose an effective and environmentally friendly method to combat sandstorm. In this study, the enzymatic calcification (EC) treatment technology was used for mineralization crust and desert sand solidification. Both laboratory experiments and field site tests were conducted to demonstrate the feasibility of EC treatment to improve wind-erosion resistance and rainfall-erosion resistance. Results showed that with the concentration of reactants higher than 0.25 M or the ratio of urease solution to the cementation solution above 0.8, the improvement effects of wind-erosion resistance and rainfall-erosion resistance decreased. Therefore, the 0.25 M of reagent concentration and 0.8 of ratio of urease solution to the cementation solution were chosen for subsequent field site test. The two test sites had similar CaCO3 contents, thus obtaining a similar increasing range of surface strength. However, the test site one had larger surface strengths due to thicker cemented crust layers. Both the two test sites had sufficient wind-erosion resistance because of crust layer. Moreover, rainfalls decreased surface strength; the surface strength recovered to a high level after water evaporation. In addition, the effect of rainfall on thickness of crust layer and CaCO3 was small. The EC treatment had good ecological compatibility, and the combined EC and grass seed treatment was effective for mitigation of desertification. The results demonstrated that EC treatment significantly improved both wind-erosion and rainfall-erosion resistance, which presents promising potential for anti-desertification.

Photocatalytic behavior of biochar-modified carbon nitride with enriched visible-light reactivity.

Ultra-thin layered structures and modified bandgaps are two efficient strategies to increase the photocatalytic performance of various materials for the semiconductor industry. In the present study, we combined both strategies in one material to form carbon-doped graphitic carbon nitride (g-C3N4) nano-layered structures by the method of melamine thermal condensation, in the presence of different mass ratios of biochar. The characterization showed that the composite with the best ratio retained the g-C3N4 polymeric framework and the bond with g-C3N4. The biochar was established via π-π stacking interactions and ether bond bridges. The π-conjugated electron systems provided from biochar can elevate charge separation efficiency. The ultra-thin structure also curtailed the distance of photogenerated electrons migrating to the surface and enlarge specific surface area of materials. The presence of carbon narrowed the bandgap and increased light absorption at a wider range of wavelengths of g-C3N4. The biochar/melamine ratio of 1:15 presented the best performance, 2.8 and 5 times faster than g-C3N4 degradating Rhodamine and Methyl Orange, respectively. Moreover, the catalyst presented a good stability for 4 cycles. In addition to that, biochar from waste biomass can be considered a sustainable, cost-effective, and efficient option to modify g-C3N4-based photocatalysts.

Leonurine inhibits IL-1ß induced inflammation in murine chondrocytes and ameliorates murine osteoarthritis.

Osteoarthritis (OA) is a chronic degenerative joint disease characterized by cartilage degradation, subchondral bone sclerosis and synovitis. Leonurine, an active component extracted from the leaves of Herba leonuri, has been reported to possess various potent biological effects such as anti-oxidant, anti-apoptosis, and anti-inflammatory. However, the therapeutic benefits of leonurine on OA have not been reported. This study aimed to evaluate the therapeutic effect of leonurine on chondrocytes and in murine OA models. Murine chondrocytes were pre-treated with leonurine (5, 10, and 20 µM) for 2 h and then stimulated with IL-1ß for 24 h. Production of NO, PGE2, IL-6, TNF-α, MMP-3, MMP-13, and ADAMTS-5 was assessed with the Griess reagent and ELISAs. The mRNA expression of COX-2, iNOS, MMP-3, MMP-13, ADAMTS-5, aggrecan, and collagen-II was tested with real-time polymerase chain reaction. The protein expression of iNOS, COX-2 and NF-κB-related signaling molecules was measured with western blotting. In this study, leonurine visibly inhibited the IL-1ß-induced production of NO, PGE2, IL-6 and TNF-α; and decreased the expression of iNOS, COX-2, MMP-3, MMP-13 and ADAMTS-5 in chondrocytes. Furthermore, leonurine significantly suppressed IL-1ß-stimulated NF-κB activation. In addition, treatment with leonurine not only prevented cartilage destruction and subchondral bone thickening, but also alleviated synovitis in a murine OA model. Taken together, these results suggest that leonurine may be a potential therapeutic agent in OA treatment.

[Discussion of Emissions and Health Risk of Polycyclic Aromatic Hydrocarbons (PAHs) from the Retreading Process of Waste Tires].

The emissions characteristics of 16 kinds of polycyclic aromatic hydrocarbons (PAHs) in ambient air during the waste tire retreading process (open-air storage, mixing, vulcanization, and grinding processes) and in workers' dormitory were analyzed. In addition, the occupational health risk of the workers was evaluated. Results showed that PAHs were detected in all retreading processes and in the workers' dormitory. The highest concentration site was the mixing process, followed by open-air storage and vulcanization process. The lowest concentration point was in the grinding process. The average concentration of PAHs in the workers' dormitory was 11.1 ng·m-3. The PAHs at all sampling points were largely phenanthrene (Phe), fluoranthene (Flu), anthracene (Ant), and pyrene (Pry), which also had a stronger linear correlation with the total PAH concentration. An analysis of the benzene rings showed that three ring and four ring were the majority, while two ring, five ring, and six ring components accounted for less than 10%. Results of the possible influencing factors of the PAHs revealed that the open-air storage and dormitory might be affected by a combustion source, but the mixing, vulcanization, and grinding processes might be affected by rubber oil. The principal component analysis (PCA) and cluster analysis showed that the spatial location of all sites would significantly influence the distribution of PAHs during the tire retreading process. The health risk assessment showed that occupational workers had a lower risk of lifelong cancer, and there was little influence on life expectancy.

[Possible Sources of PCDD/Fs in Atmosphere of a Certain District in Guangdong].

This paper analyzed 17 polychlorinated dibenzo-p-dioxins and dibenzofurans(PCDD/Fs) by HRGC/HRMS in the flue gas of a certain municipal solid waste incinerator(MSWI) and its surrounding air and other possible sources in Guangdong. It discussed the feature of homologs and main toxic monomers in all samples. It also investigated the relationship among surrounding area, MSWI and possible sources using principle component analysis (PCA) and cluster analysis. The results showed that the concentration of PCDD/Fs was higher in the flue gas than the ambient air, moreover non-effect suffered by prevailing wind direction. The possible sources might be tyre factory and open burning based on spot survey. The concentration of PCDD/Fs was lower in tyre factory than upwind station, but higher at open burning spot than outdrop monitoring station. The analysis of homologs showed that OCDD, 1,2,3,4,6,7,8-HpCDD and 1,2,3,4,6,7,8-HpCDF were the main materials in the flue gas and air, meanwhile OCDF was also found in atmosphere. There was similar feature of 17 PCDD/Fs between surrounding monitoring station and tyre factory, and the same between flue gas and open burning. The further analysis showed that the linearly dependent coefficients of 1,2,3,7,8-PeCDD and 2,3,4,6,7,8-HxCDF were 0.95 and 0.75, respectively. It showed the strong correlation of two monomers in all ambient air samples. The PCA and cluster analysis showed that MSWI influenced the surrounding air, tyre factory had an impact on upwind station, and open burning had a lower effect on outdrop monitoring station.

Airborne PCDD/Fs in two e-waste recycling regions after stricter environmental regulations.

Since the 2010s, the authorities of Guangdong province and local governments have enhanced law enforcement and environmental regulations to abolish open burning, acid washing, and other uncontrolled e-waste recycling activities. In this study, ambient air and indoor dust near different kinds of e-waste recycling processes were collected in Guiyu and Qingyuan to investigate the pollution status of particles and polychlorinated dibenzo-p-dioxins and furans (PCDD/Fs) after stricter environmental regulations. PM2.5 and PCDD/Fs both showed significantly reduced levels in the two regions compared with the documented data. The congener distribution and principal component analysis results also confirmed the significant differences between the current PCDD/Fs pollution characterizations and the historical ones. The estimated total intake doses via air inhalation and dust ingestion of children in the recycling region of Guiyu ranged from 10 to 32pgTEQ/(kg•day), which far exceeded the tolerable daily intake (TDI) limit (1-4pgTEQ/(kg•day). Although the measurements showed a significant reduction of the release of PCDD/Fs, the pollution status was still considered severe in Guiyu town after stricter regulations were implemented.

[Onset time and efficacy of sublingual immunotherapy with Dermatophagoides farinae drops in children with allergic rhinitis].

OBJECTIVE: To investigate the onset time and efficacy of sublingual immunotherapy (SLIT) with Dermatophagoides farinae drops in children with house dust mites (HDM)-induced allergic rhinitis (AR). METHODS: One hundred and forty three children with perennial moderate to severe HDM-induced AR were treated by SLIT with standardized Dermatophagoides farinae extract. One hundred children who finally completed two years treatment were divided into two groups according to the age: younger children group (aged 4-8 years, n = 52) and older children group (aged 9-14 years, n = 48). Respectively, Each children was assessed before and after 1st, 2nd, 3rd, 6th, 12th, 24th months of the treatment. Total nasal symptom score (TNSS), total medication score (TMS) and visual analogue scale (VAS) were evaluated at each visit. All clinical data were analyzed retrospectively with the SPSS 19.0 software. RESULTS: TNSS, TMS and VAS of two groups decreased significantly after three months of the treatment compared with before (younger children group: Z value was -3.843, -3.534, -3.940, older children group: Z value was -3.938, -3.405, -3.953, all P < 0.05). TNSS and VAS of younger children group decreased significantly after two months of the treatment compared with before (6.4 ± 1.6, 5.3 ± 1.4 vs 8.6 ± 1.2, 7.9 ± 1.6, Z value was -3.843, -3.940, both P < 0.05). Five children (5%) experienced local adverse events and 2 children (2%) experienced mild systemic adverse events. No severe adverse events happened during the treatment. CONCLUSIONS: SLIT with Dermatophagoides farinae drops is an efficient and safe treatment for children with HDM-induced AR. Its onset of action can be observed as early as 3 months after treatment.

[Emission of PCDD/Fs from Crematories and Its Influencing Factors].

To analysis the influencing factors for the emssions of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) as structure of crematory, air pollution control device (APCD) and funeral objects, etc, we collected and measured the PCDD/Fs emissions in flue gas from 13 crematories in China. Then we proposed some supervision suggestions on measures of pollution control and management. The results indicated that the emission levels of PCDD/Fs (as the toxic equivalent concentration, TEQ) was ranged in a large gap from 0.027 to 15.8 ng x m(-3), and the average was 3.2 ng x m(-3). Emissions factor of PCDD/Fs (as TEQ) from 13 crematories varied between 45.9 and 22 236 ng x body(-1), and the average was 4 738 ng x body(-1). The emissions of PCDD/Fs from flat incinerators were generally lower, whereas higher ratio up to the national discharge standard, than that of car type incinerators. Congener distribution of PCDD/Fs in flue gas from 13 crematories were different from each other. Since the emission of PCDD/Fs from some crematories remains in high level, it is necessary to control pollution from the source, improve the pollution control technology, and strengthen government supervision, by following measures: 11 cremating funeral objects separately from corpse; 22 adding one

[Clinical characteristics of benign paroxysmal positional vertigo secondary to sudden deafness].

OBJECTIVE: To retrospectively analyze the clinical characteristics of the benign paroxysmal positional vertigo (BPPV) secondary to the sudden deafness (SD) and to explore pathogenetic mechanism. METHOD: One hundred and seventy-eight cases of the SD in our department were retrospectively analyzed. They were all treated under the guidance of clinical guidelines. RESULT: (1) In all these patient's with SD, there were 31 cases with BPPV secondary to the SD. There were 26 cases of BPPV of posterior semicircular canal and 5 cases of BPPV of lateral BPPV semicircular canal. All patients with BPPV were diagnosed as the same ears as the SD, including 16 cases on left sides and 15 on right sides. (2) The interval between the onset of SD and BPPV was less than one week in 27 cases, between one week and one month in 3 cases, and between one and three months in 1 case. (3) All patients with BPPV secondary to the SD were cured with Epley maneuver or Barbecue roll maneuver. CONCLUSION: The occurrence of BPPV may follow SD, and the major of BPPV secondary to the SD occurs in the posterior semicircular canal. The canalith repositioning is an effective therapy to the secondary BPPV.

[Levels of PCDD/Fs and dioxin-like PCBs in soils near E-waste dismantling sites].

One hundred and fifty one soil samples from 125 sampling points were collected near E-waste dismantling sites and analyzed for polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and dioxin-like polychlorinated biphenyls (PCBs). Total concentration of PCDD/Fs in topsoil samples ranged from 280 pg x g(-1) to 7 010 pg x g(-1) dry weight with the mean value of 1 380 pg x g(-1) dry weight. The mean value of the second layer and the deepest layer is 63% and 38% of that of top soils, respectively. The toxic equivalent quantity (TEQ) of PCDD/Fs in top soils ranged from 1.4 pg x g(-1) to 94.8 pg x g(-1) (I-TEQ). According to the guidelines for TEQ concentrations established in Germany, 19 of 125 topsoil samples (15% of the total topsoil samples analyzed) could not be expected to pose human health hazards. The rest of 85% of top soils needs investigations of source identification. If the contribution of PCB to TEQ was considered, 98% of top soils need investigations of source identification. Principle component analysis (PCA) is used to identify the PCDD/Fs sources. The homologue profiles of PCDD/Fs showed that dismantling activities are the main emission resources of the PCDD/Fs from thermal processes, also are the main emission resources of the PCDD/Fs in soils of this area.