Evaluation on production trend, compositions, and impact of plastic waste in Chengdu, southwestern China.

Based on statistical data from 2005 to 2019, we used the back propagation (BP) neural network model to predict the production amount of plastic waste in Chengdu. In addition to the amount of waste produced we wanted to achieve an understanding of its composition and environmental impacts. Compositions of plastic waste were analyzed by sampling. Particulate matter in the air and greenhouse gas emissions (GHGs) from plastic waste incineration, bisphenol A (BPA) from plastic waste landfills, were also evaluated. Results indicated that (a) economic development, urban construction level, and residents' consumption were pusitively correlated to different degrees to plastic waste production; (b) the production of plastic waste in Chengdu in 2025 and 2030 will reach 865.3 and 931 kilotons (Kt), respectively; (c) high density polyethylene (HDPE) and polypropylene (PP) are the two main components of plastic waste in Chengdu and accounted for 40.17% and 24.96%, respectively; (d) different degrees of environmental impacts occurred during plastic waste incineration and landfill (taking 2019 as an example, the incineration of plastic waste in Chengdu produced between 2874.82 and 4711.73 tons of inhalable particulate matter (PM) and emitted between 725.4 and 867.4 Kt of CO2, and between 65.02 and 910.27 kg of bisphenol A (BPA) leached from sanitary landfills); (e) positive policies and measures from the beginning to the end-of-life of plastics should be carried out in the future, which would improve the level of plastic waste management in Chengdu and mitigate the side-impacts from plastic waste treatment and disposal.Implications: The implications of this article are Generation trends of plastic waste were revealed by a BP neural network model, which provided essential data for authorities to make decisions on waste management.Influencing factors affecting plastic waste generation were analyzed, which will strongly support policy considerations regarding plastic waste control.This investigation first explored and reported the compositions of plastic waste mixed with municipal solid waste (MSW), which yielded valuable information concerning plastic waste and details concerning the impacts of plastic waste disposal processes.Those results of this investigation, being published here for the first time, will guide plastic waste management in Chengdu and could also provide useful information to other cities regarding that issue.

Successful treatment of a critically ill patient with acute respiratory distress syndrome from COVID-19 using mechanical ventilation strategy with low levels of positive end-expiratory pressure: A CARE-compliant case report.

INTRODUCTION: Acute respiratory distress syndrome (ARDS) secondary to COVID-19 is different from the ARDS caused by other infections. Conventional mechanical ventilation strategies using high levels of PEEP may not be beneficial and can even be harmful to patient with ARDS from COVID-19. So the ventilation strategies should be adjusted in order to improve the pulmonary ventilation function and oxygenation status, and outcomes of the patient. PATIENT CONCERNS: Herein, we present a 76-year-old male patient with ARDS secondary to COVID-19. We describe our experience with mechanical ventilation strategy and the changes in respiratory mechanics in the patient during treatment. DIAGNOSIS: The patient had tested positive for coronavirus (COVID-19) in nucleic acid test. Chest CT showed multiple ground glass shadows in both lungs. INTERVENTIONS: The patient received mechanical ventilation with low tidal volume and low PEEP. OUTCOMES: After treatment, the patients condition, as well as oxygenation status was improved, and he tested negative for the coronavirus several times. CONCLUSION: This case demonstrated that the low tidal volume with low levels of PEEP ventilation strategy may be more suitable for ARDS from COVID-19.

[Inventory and environmental impact of VOCs emission from the typical anthropogenic sources in Sichuan province].

Based on Sichuan province environmental statistical survey data and other relevant activity data, volatile organic compounds (VOCs) emissions from typical anthropogenic sources in Sichuan province were calculated for the year of 2011 by applying the emission factor method. Besides, ozone and secondary organic aerosol formation potentials of these typical anthropogenic sources were discussed. The total VOC emission from these sources was about 482 kt in Sichuan province, biomass burning, solvent utilization, industrial processes, storage and distribution of fuel, and fossil fuel combustion contributed 174 kt, 153 kt, 121 kt, 21 kt and 13 kt, respectively; architecture wall painting, furniture coating, wood decoration painting and artificial board were the major emission sectors of the solvent utilization; while for the industrial processes, 19.4% of VOCs emission was from the wine industry. Chengdu was the largest contributor compared to the other cities in Sichuan, whose VOCs emission from these typical anthropogenic sources in 2011 was 112 kt. OFP of these sources was 1,930 kt altogether. Solvent utilization contributed 50.5% of the total SOA formation potentials, biomass burning and industrial processes both contributed about 23% , with storage and distribution of fuel and fossil fuel combustion accounting for 1% and 1.4%, respectively.

[A pilot study of diaphragmatic function evaluated as predictors of weaning in chronic obstructive pulmonary disease patients].

OBJECTIVE: To evaluate the predictive performance of neuro-mechanical coupling (NMC) and neuro-ventilatory coupling (NVC) in the weaning outcome in patients with chronic obstructive pulmonary disease (COPD). METHODS: Sixteen patients were enrolled when the criteria for their first spontaneous breathing trial (SBT) was met. A 30-minute SBT was attempted, with the measurement of electrical activity of the diaphragm (Edi), NMC, NVC, NVC × NMC, index of rapid shallow breathing (f/Vt), airway occlusion pressure (P(0.1)) and f/Vt × P(0.1) at 0, 5 and 30 min. The receiver operating characteristic (ROC) curve was calculated to evaluate the predictive performance of each index. RESULTS: Successful weaning (S group) was observed in 6 patients while weaning failure (F group) in 10 patients. (1) The predictive capacity of Edi: at 30 min of SBT, Edi showed higher values in the F group (P < 0.05), the area under the ROC curves (AUC) was 0.817(P < 0.05). (2) The predictive capacity of NVC and NMC: at 5, 30 min of SBT, NVC and NMC showed higher values in the S group (P < 0.05); at 30 min of SBT NVC presented the largest AUC than any other time of SBT (0.822, P < 0.05), while the AUC of NMC was 0.800(P > 0.05). (3) The predictive capacity of NVC × NMC: at 30 min of SBT, the AUC of NVC × NMC was larger than NVC (0.864, P < 0.05), showing greater sensitivity (100.0%) and specificity (83.3%). (4) The predictive capacity of f/Vt and P(0.1): f/Vt and f/Vt × P(0.1) presented poor predictive performance in the failed patients. CONCLUSIONS: Edi, NVC and NVC × NMC were good predictor for the weaning outcome in patients with COPD.

[Operative treatment of supracondylar femoral fractures].

OBJECTIVE: Biomechanical properties between retrograde nail and condylar buttress plate for supracondylar femoral fracture were tested and compared. The functional operative results were also followed and analyzed. METHODS: (1) Six fresh adult moist cadaveric femoral specimens were used to create femoral supracondylar fracture models. Six specimens were divided into two groups. Group 1 was fixed with retrograde locking intramedullary nail and group 2 with condylar buttress plate. All specimens undergone biomechanical test and the data were analyzed using SPSS software. (2) From August 1995 to December 2000, 36 cases (37 limbs) of femoral supracondylar fracture were included. The follow-up period ranged from 2.1 years to 7.5 years. RESULTS: (1) Biomechanical tests showed: The stiffness of the condylar buttress plate in resisting axial compression force was smaller than that of the retrograde locking intramedullary nail. condylar buttress plate showed larger stiffness in resisting bending force than the retrograde locking intramedullary nail. (2) Clinical outcomes: According to Neer rating system, the functional scores were excellent in 26 cases, good in 8, fair in 1 and poor in 2. The excellent-good rate was 91.9%. The excellent-good rate of plating cases was 94.7% and retrograde nail was 93.3%. ROM of the knee joint ranges from 60 degrees to 135 degrees , with an average of 110 degrees. CONCLUSION: The excellent or good outcomes of femoral supracondylar fracture could be obtained through the operative treatment. The fixation of the retrograde locking and condylar buttress plate have their own advantages in biomechanical properties.