Characteristics of the pyrolytic products and the pollutant emissions at different operating stages from a pilot waste tire pyrolysis furnace.

Pyrolysis is considered a highly practical, cost-effective, and environment-friendly technology for waste tires disposal. In this study, pyrolysis processes of waste tires were conducted in a pilot scale furnace feeding at 30 kg/h. The properties of pyrolytic products and the distribution patterns of pollutants generated in different operating stages (start-up, steady, and shut-down) were investigated. The pyrolytic gas in the steady state had a high caloric value of 10799 kJ/Nm3, valuable as heating source for pyrolysis. The elements of sulfur and zinc were effectively fixed as ZnS in the pyrolytic carbon. The basic properties of pyrolytic oil were in line with commercial diesel oil except for the lower flash point. Heavy metals were mainly concentrated in the pyrolytic carbon, with slightly higher concentrations in the steady state. Moreover, polycyclic aromatic hydrocarbons (PAHs) and polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) were mainly concentrated in the pyrolytic oil, with predominated low-ring PAHs and high chlorinated PCDD/Fs. The concentrations of PAHs and PCDD/Fs in the gas phase were higher during the start-up stage due to the memory effect, whereas were effectively reduced during the steady stage. The concentration of PAHs in the solid phase was highest during the furnace start-up and lowest in the shut-down stage. In contrast to PAHs, the PCDD/Fs in the solid phase reached their highest concentration during the shut-down stage, which was mainly affected by temperature. The results provide guidance for the reducing of pollutant emissions and the recycling of pyrolytic products.

Formation behavior of PAHs during pyrolysis of waste tires.

Polycyclic aromatic hydrocarbons (PAHs) formation from the pyrolysis of waste tires is inevitable because of the complexity of tire formulations and the addition of certain chemicals. In this study, the formation behavior and distribution of PAHs in three-phases were investigated from waste tires under pyrolysis conditions. The influencing factors including the temperature, heating rate, holding time, particle size, catalyzer, and atmosphere, were systematically evaluated. The results showed that PAHs were mainly concentrated in pyrolysis oil (94.59-99.03%), followed by the gas phase (0.96-5.34%), and their content was very low in the solid phase (0.01-0.99%). A higher temperature and slower heating rate lead to partial PAHs decomposition, thus reducing their emissions. The overall formation of PAHs can be inhibited when pyrolyzing coarse-grained tire powder. Furthermore, the PAHs formation mechanisms in waste tires were determined through reaction molecular dynamics, electron paramagnetic resonance, and intermediate products. Tires were mainly decomposed into benzene series, *C2H3, and *CH3; therefore, it was determined that PAHs were formed by the joint action of the hydrogen abstraction, and vinyl radical addition and methyl addition cyclization mechanisms. Among them, low and middle-ring PAHs were formed more easily, particularly naphthalene. The generation of PAHs can be inhibited by reducing the concentration of hydrocarbons and monocyclic benzene series. Regarding the distribution law and generation pathways of PAHs, our results provide guidance for reducing PAHs formation and emissions.

Dioxin emission and distribution from cement kiln co-processing of hazardous solid waste.

Cement kiln collaborative disposal technology can not only dispose of hazardous waste but also provide energy for the cement industry. However, the addition of hazardous waste may promote the formation of dioxins in cement kilns. In this study, typical hazardous solid wastes, such as solidified fly ash, electroplating sludge, and industrial residue, were co-processed in a cement kiln with different feeding positions and different feeding amounts. The concentrations of dioxins in the flue gas, clinker, and precalciner furnace slag were investigated. The effect of adding mixed hazardous solid waste on the formation of dioxin was also studied. The results showed that the concentration of dioxin in the flue gas without added hazardous waste was 1.57 ng/m3, and the concentration varied from 1.03 to 6.49 ng/m3 after the addition of hazardous waste. In addition, the concentration of dioxin in the flue gas and solid samples increased substantially when the co-processing ratio doubled. The large amount of Cu in solidified fly ash promoted the formation of dioxins, while the higher S content in the electroplating sludge suppressed the formation of dioxins. Compared with the addition of single hazardous waste, the concentration of dioxin in precalciner furnace slag increases by about 300%. Furthermore, the distributions of isomers in the clinker and precalciner furnace slag were similar. 1,2,3,4,6,7,8-HpCDD and OCDD accounted for a large proportion of the mass concentration, and the contribution rate ranged from 48.7 to 82.0%. Most importantly, correlation analysis showed that the concentration of dioxin was closely related to the copper content, hazardous waste types and additive proportion, with correlation coefficients of 0.79, 0.83, and 0.89, respectively. This study provides a basis for exploring the high environmental benefits of disposing of hazardous solid waste by co-processing in cement kilns.

Modification of activated carbon using urea to enhance the adsorption of dioxins.

Activated carbon is commonly used to remove dioxins from flue gas via adsorption. Improving the targeted adsorption capacity of activated carbon for dioxins can reduce the consumption of adsorbents and help achieve emission standards for target pollutants. Here, commercial coal-based activated carbon was used as a raw material and modified by urea impregnation along with treatment at high temperature under a nitrogen atmosphere. It was found that modification with urea effectively improved the pore structure of activated carbon while incorporating a certain amount of nitrogen. The best modification effect was achieved at a modification temperature of 600 °C, an impregnation ratio of urea to activated carbon of 1:1, and with high-temperature treatment for 2 h. The mesopore volume of the modified activated carbon (AC600) reached 0.38 cm3/g, accounting for 57.58% of the total pore volume. With an impregnation ratio of urea to activated carbon of 1:1, high-temperature treatment for 2 h, and a modification temperature of 800 °C, a certain amount of nitrogen was introduced into the carbon rings to form a modified activated carbon (AC800) rich in pyridine and pyrrole groups (atomic percentage = 4.84%). The activated carbon modified by urea and the unmodified activated carbon were subsequently selected for dioxin adsorption experiments using a dioxin generation and adsorption system. AC600 showed the highest adsorption efficiency for dioxins, reaching 97.65%, based on toxicity equivalents. Although AC800 has poor pore properties, it has more pyridine and pyrrole groups than AC600. Consequently, the efficiency of AC800 at adsorbing low-concentration dioxins reached 85.24% based on toxicity equivalents. Overall, this study describes two mechanisms for effectively modifying activated carbon with urea based on (1) optimizing the pore structure of activated carbon and (2) incorporating nitrogen.

Pulsed Electromagnetic Field Attenuates Osteoarthritis Progression in a Murine Destabilization-Induced Model through Inhibition of TNF-α and IL-6 Signaling.

OBJECTIVE: To investigate the anti-inflammatory effects and mechanisms of pulsed electromagnetic field (PEMF) in the treatment of osteoarthritis (OA) in the destabilization of the medial meniscus (DMM) mice. DESIGN: Ten-week-old male wild-type (WT), interleukin (IL)-6-/- and tumor necrosis factor (TNF)-α-/- mice undergoing DMM surgery were randomly divided into 2 groups (n = 10 each): mice with PEMF exposure and mice with sham PEMF exposure. PEMF (75 Hz, 3.8 mT, 1 h/day) or sham PEMF was applied for 4 weeks. Pain behavior of mice, histological assessment of cartilage and synovium, micro-CT (computed tomography) analysis of bone, real-time polymerase chain reaction, and immunohistochemical staining of cartilage were performed. RESULTS: After DMM surgery, PEMF had a beneficial effect on pain, cartilage degeneration, synovitis, and trabecular bone microarchitecture in WT mice; these protective effects were reduced in IL-6-/- and TNF-α-/- mice. In addition, PEMF downregulated IL-6 and TNF-α expression in cartilage. PEMF also ameliorated cartilage matrix, chondrocyte apoptosis, and autophagy, while deletion of IL-6 or TNF-α suppressed the effects. CONCLUSIONS: PEMF attenuates structural and functional progression of OA through inhibition of TNF-α and IL-6 signaling. The protective effects of PEMF on chondrocyte apoptosis and autophagy are regulated by TNF-α and IL-6 signaling.

Application of neural network model in assisting device fitting for low vision patients.

BACKGROUND: To explore the application of neural network models in artificial intelligence (AI)-aided devices fitting for low vision patients. METHODS: The data of 836 visually impaired people were collected in southwestern Fujian from May 2014 to May 2017. After a full eye examination, 629 low vision patients were selected from this group. Based on the visual functions, rehabilitation needs, and living quality scores of the selected patients, the professionals chose assistive devices that were the best fit for the patients. The data of these three factors were then subjected to the quantitative analysis, and the results were digitized and labeled. The final datasets were used to train a fully connected deep neural networks to obtain an AI-aided model for assistive device fitting. RESULTS: In this study, the main causes of low vision in southwestern Fujian were congenital diseases, among which congenital cataract was the most common. During the low vision AI-aided devices fitting, we found that the intermediate distance magnifier was suitable for the largest number of patients. Through quantitative analysis of the research results, it was found that AI-aided devices fitting was closely related to visual function, rehabilitation needs and quality of life. If this complex relationship can be mapped into the neural network model, AI-aided device fitting can be realized. We built a fully connected neural network model for AI-aided device fitting. The input of the model was the characteristic data of low vision patients, and the output was the forecast of suitable devices. When the threshold of the model was 0.4, the accuracy was about 80% and the F1 value was about 0.31. This threshold can be used as the classification judgment threshold of the model. CONCLUSIONS: Low vision AI-aided device fitting is closely related to visual function, rehabilitation needs, and quality of life scores. The neural network model based on full connection can achieve high accuracy in AI-aided devices fitting. It has a great impact on clinical application.

Causes of vision loss at China's largest blind school during a period of significant economic growth: 2008-2016.

PURPOSE: To investigate the different causes of vision loss and school-based treatment regimens at Quanzhou Blind School (QBS), China's largest blind school, in 2008 and 2016. METHODS: In 2008, 144 students received comprehensive eye examinations along with a complete family and ophthalmic history; in 2016, 125 students were examined. Vision loss was categorized into visual impairment and blindness classifications based on WHO guidelines. The etiologies of impairment and blindness in 2008 were compared to those in 2016 using the Fisher exact test. The prevalence and type of visual aids were also analyzed during this period. RESULTS: The leading cause of visual impairment significantly shifted from corneal scarring in 2008 to retinopathy of prematurity (ROP) in 2016 (P = 0.020). Congenital cataracts remained the leading cause of blindness in 2008 and 2016. In 2016 there was a significant increase in the use of visual aids, with 63.2% of students using them in 2016 compared to 8.3% in 2008 (P = 0.0001). CONCLUSIONS: Between 2008 and 2016, the leading cause of visual impairment shifted from corneal scarring to ROP, while congenital cataracts remained the leading cause of blindness.

Pulsed Electromagnetic Field Versus Whole Body Vibration on Cartilage and Subchondral Trabecular Bone in Mice With Knee Osteoarthritis.

Pulsed electromagnetic field (PEMF) and whole body vibration (WBV) interventions are expected to be important strategies for management of osteoarthritis (OA). The aim of the study was to investigate the comparative effectiveness of PEMF versus WBV on cartilage and subchondral trabecular bone in mice with knee OA (KOA) induced by surgical destabilization of the medial meniscus (DMM). Forty 12-week-old male C57/BL mice were randomly divided into four groups (n = 10): Control, OA, PEMF, and WBV. OA was induced (OA, PEMF, and WBV groups) by surgical DMM of right knee joint. Mice in PEMF group received 1 h/day PEMF exposure with 75 Hz, 1.6 mT for 4 weeks, and the WBV group was exposed to WBV for 20 min/day with 5 Hz, 4 mm, 0.3 g peak acceleration for 4 weeks. Micro-computed tomography (micro-CT), histology, and immunohistochemistry analyses were performed to evaluate the changes in cartilage and microstructure of trabecular bone. The bone volume fraction (BV/TV), trabecular thickness (Tb.Th), and trabecular number (Tb.N) increased, and bone surface/bone volume (BS/BV) decreased by micro-CT analysis in PEMF and WBV groups. The Osteoarthritis Research Society International (OARSI) scores in PEMF and WBV groups were significantly lower than in the OA group. Immunohistochemical results showed that PEMF and WBV promoted expressions of Aggrecan, and inhibited expressions of IL-1ß, ADAMTS4, and MMP13. Superior results are seen in PEMF group compared with WBV group. Both PEMF and WBV were effective, could delay cartilage degeneration and preserve subchondral trabecular bone microarchitecture, and PEMF was found to be superior to WBV. Bioelectromagnetics. 2020;41:298-307 © 2020 Bioelectromagnetics Society.

Effects of Pulsed Electromagnetic Field Therapy on Pain, Stiffness, Physical Function, and Quality of Life in Patients With Osteoarthritis: A Systematic Review and Meta-Analysis of Randomized Placebo-Controlled Trials.

OBJECTIVE: Pulsed electromagnetic field (PEMF) therapy is a potentially useful treatment for osteoarthritis (OA), but its effectiveness is still controversial. This study aimed to examine the effects of PEMF therapy and PEMF parameters on symptoms and quality of life (QOL) in patients with OA. METHODS: Cochrane Central Register of Controlled Trials, PubMed, CINAHL, EMBASE, PEDro, clinical trial registers, and reference lists were searched until April 2019. This study examined randomized, placebo-controlled trials, patients with OA, symptom and/or QOL related outcomes, and articles published in English. Two authors extracted data and completed quality assessment. RESULTS: Sixteen studies were included in our systematic review, while 15 studies with complete data were included in the meta-analysis. Our primary outcome was the standardized mean difference, which was equal to the treatment effect in the PEMF group minus the treatment effect in the placebo group divided by the pooled standard deviation. For pain, the standardized mean difference was 1.06 (95% CI = 0.61 to 1.51), for stiffness 0.37 (95% CI = 0.07 to 0.67), for function 0.46 (95% CI = 0.14 to 0.78), and for QOL 1.49 (95% CI = -0.06 to 3.04). PEMF parameters did not influence symptoms. CONCLUSIONS: Compared with placebo, there was a beneficial effect of PEMF therapy on pain, stiffness, and physical function in patients with OA. Duration of treatment may not be a critical factor in pain management. Further studies are required to confirm the effects of PEMF therapy on QOL. IMPACT: Our study suggests that PEMF therapy has clinically significant effects on pain in patients with OA. The current evidence was limited to the short-term effects of PEMF therapy.

Effectiveness of Elastic Taping in Patients With Knee Osteoarthritis: A Systematic Review and Meta-Analysis.

OBJECTIVE: The aim of the study was to assess the effects of elastic taping on pain, physical function, range of motion, and muscle strength in patients with knee osteoarthritis. DESIGN: We searched the PubMed, the Cochrane Central Register of Controlled Trials, Web of Science, Physiotherapy Evidence Database, Scopus, EMBASE, OVID, CNKI, and WANFANG to identify relevant randomized controlled trials. The primary outcome measures were pain and physical function. The secondary outcome measures were range of motion and muscle strength. RESULTS: Eleven randomized controlled trials involving 490 patients with knee osteoarthritis were included. A statistically significant difference was detected in pain (standardized mean difference = -0.78, 95% confidence interval = 1.07 to -0.50, P < 0.00001), physical function (standardized mean difference = 0.73, 95% confidence interval = -1.03 to -0.43, P < 0.00001), range of motion (mean difference = 2.04, 95% confidence interval = 0.14 to 3.94, P = 0.04), and quadriceps muscle strength (mean difference = 2.42, 95% confidence interval = 1.09 to 3.74, P = 0.0004). No significant differences were found for the hamstring muscle strength. CONCLUSIONS: Elastic taping has significant effects on pain, physical function, range of motion, and quadriceps muscle strength in patients with knee osteoarthritis. The current evidence is insufficient to draw conclusions on the effects of elastic taping combined with other physiotherapy for knee osteoarthritis. Further studies are needed to investigate the long-term effects of elastic taping combined with other physiotherapy compared with elastic taping alone for knee osteoarthritis.

Effects of electromagnetic fields on osteoarthritis.

Osteoarthritis (OA), characterized by joint malfunction and chronic disability, is the most common form of arthritis. The pathogenesis of OA is unclear, yet studies have shown that it is due to an imbalance between the synthesis and decomposition of chondrocytes, cell matrices and subchondral bone, which leads to the degeneration of articular cartilage. Currently, there are many therapies that can be used to treat OA, including the use of pulsed electromagnetic fields (PEMFs). PEMFs stimulate proliferation of chondrocytes and exert a protective effect on the catabolic environment. Furthermore, this technique is beneficial for subchondral trabecular bone microarchitecture and the prevention of subchondral bone loss, ultimately blocking the progression of OA. However, it is still unknown whether PEMFs could be used to treat OA in the clinic. Furthermore, the deeper signaling pathways underlying the mechanism by which PEMFs influence OA remain unclear.

Fast determination of two atractylenolides in Rhizoma Atractylodis Macrocephalae by Fourier transform near-infrared spectroscopy with partial least squares.

Rhizoma Atractylodis Macrocephalae (RAM) is a commonly used food and traditional Chinese medicine (TCM), which traditionally strengthens the spleen, benefits vital energy, eliminates dampness, and promotes hidroschesis. Its primary effective constituents are polysaccharides and volatile oil, whose main components are atractylenolide I and III. Fourier transform near-infrared spectroscopy (FT-NIR) is widely used in TCM research. However, determination of atractylenolides in RAM using FT-NIR has not been described. In this study, a new method for the determination of atractylenolides I and III in RAM by NIR was established. The spectral characteristics of atractylenolides I and III were obtained by second derivative multiple scattering correction, and its chart to the original absorbance spectra. Additionally, in combination with the partial least squares (PLS) algorithm, the calibration process was performed for the quantitation of the samples. The root mean square error of cross-validation of the PLS models for atractylenolides I and III was 0.0387 and 0.0358, and the determination coefficient of quantitative models was 96.63 and 96.16, respectively. This study demonstrated that NIR spectroscopy can be used to analyze quickly and efficiently the contents of atractylenolides I and III in RAM.