Efficient degradation of polystyrene microplastic pollutants in soil by dielectric barrier discharge plasma.

In this study, the atmospheric dielectric barrier discharge (DBD) plasma was proposed for the degradation of polystyrene microplastics (PS-MPs) for the first time, due to its ability to generate reactive oxygen species (ROS). The local temperature in plasma was found to play a crucial role, as it enhanced the degradation reaction induced by ROS when it exceeded the melting temperature of PS-MPs. Factors including applied voltage, air flow rate, and PS-MPs concentration were investigated, and the degradation products were analyzed. High plasma energy and adequate supply of ROS were pivotal in promoting degradation. At 20.1 kV, the degradation efficiency of PS-MPs reached 98.7% after 60 min treatment, with gases (mainly COx, accounting for 96.4%) as the main degradation products. At a concentration of 1 wt%, the PS-MPs exhibited a remarkable conversion rate of 90.6% to COx, showcasing the degradation performance and oxidation degree of this technology. Finally, the degradation mechanism of PS-MPs combined with the detection results of ROS was suggested. This work demonstrates that DBD plasma is a promising strategy for PS-MPs degradation, with high energy efficiency (8.80 mg/kJ) and degradation performance (98.7% within 1 h), providing direct evidence for the rapid and comprehensive treatment of MP pollutants.

Dechlorination of waste polyvinyl chloride (PVC) through non-thermal plasma.

Dechlorination is essential for the chemical recycling of waste polyvinyl chloride (PVC) plastics. This study investigated the use of non-thermal plasma (NTP) for chlorine removal, with a focus on the effects of treatment time and discharge power on dechlorination efficiency. The results showed that longer treatment times and higher discharge powers led to better dechlorination performance. The maximum efficiency (98.25%) and HCl recovery yield (55.72%) were achieved at 180 W power after 40 min of treatment where 96.44% of Cl existed in the form of HCl gas, 1.44% in the liquid product, and 2.12% in the solid residue product. NTP at a discharge power of 150 W showed better dechlorination performance compared to traditional thermal pyrolysis treatment in temperatures ranging from 200 to 400 °C. The activation energy analysis of the chlorine removal showed that compared to pyrolysis-based dechlorination (137.09 kJ/mol), NTP-based dechlorination (23.62 kJ/mol) was more easily achievable. This work presents a practical method for the dechlorination of waste PVC plastic using a novel technology without requiring additional thermal and pressure input.

Dechlorination and fuel gas generation in chemical looping conversion of waste PVC over inherently Na/Ca/K-containing bauxite residue-based oxygen carriers.

The inert atmosphere in chemical looping (CL) technology can considerably inhibit the formation of polychlorinated dibenzo-p-dioxins and dibenzofurans during the thermal treatment of polyvinyl chloride plastic (PVC) waste. In this study, PVC was innovatively converted to dechlorinated fuel gas via CL gasification under a high reaction temperature (RT) and the inert atmosphere by applying an unmodified bauxite residue (BR) as both a dechlorination agent and oxygen carrier. The dechlorination efficiency reached 49.98% at an oxygen ratio of only 0.1. Furthermore, a moderate RT (750 °C in this study) and an increased oxygen ratio enhanced the dechlorination effect. The highest dechlorination efficiency (92.12%) was achieved at an oxygen ratio of 0.6. Iron oxides in BR improved the generation of syngas from CL reactions. The yields of the effective gases (CH4, H2, and CO) increased by 57.13% to 0.121 Nm3/kg with an increase in oxygen ratio from 0 to 0.6. A high RT improved the production of the effective gases (an 809.39% increase to 0.344 Nm3/kg from 600 to 900 °C). Energy-dispersive spectroscopy and X-ray diffraction were used to study the mechanism, and formation of NaCl and Fe3O4 was observed on the reacted BR, indicating the successful adsorption of Cl and its capability as an oxygen carrier. Therefore, BR eliminated Cl in situ and enhanced the generation of value-added syngas, thereby achieving efficient PVC conversion.

Dielectric barrier discharge plasma for the remediation of microplastic-contaminated soil from landfill.

The huge amount of plastic waste accumulated in landfills has caused serious microplastic (MP) pollution to the soil environment, which has become an urgent issue in recent years. It is challenging to deal with the non-biodegradable MP pollutants in actual soil from landfills. In this study, a coaxial dielectric barrier discharge (DBD) system was proposed to remediate actual MP-contaminated landfill soil due to its strong oxidation capacity. The influence of carrier gas type, applied voltage, and air flow rate was investigated, and the possible degradation pathways of MP pollutants were suggested. Results showed the landfill soil samples contained four common MP pollutants, including polyethylene (PE), polypropylene (PP), polystyrene (PS), and polyvinyl chloride (PVC) with sizes ranging from 50 to 1500 µm. The MP pollutants in the soil were rapidly removed under the action of reactive oxygen species (ROS) generated by DBD plasma. Under the air flow rate of 1500 mL min-1, the maximum remediation efficiency represented by mass loss reached 96.5% after 30 min treatment. Compared with nitrogen, when air was used as the carrier gas, the remediation efficiency increased from 41.4% to 81.6%. The increased applied voltage from 17.5 to 24.1 kV could also promote the removal of MP contaminants. Sufficient air supply was conducive to thorough removal. However, when the air flow rate reached 1500 mL min-1 and continued to rise, the final remediation efficiency would be reduced due to the shortened residence time of ROS. The DBD plasma treatment proposed in this study showed high energy efficiency (19.03 mg kJ-1) and remediation performance (96.5%). The results are instructive for solving MP pollution in the soil environment.

Lower expression of KAI1 as a biomarker of poor survival prognosis of melanoma combined with colorectal cancer metastasis.

OBJECTIVE: This study aimed to investigate the correlation between KAI1 (CD82) and miR-633 expression and prognosis and survival time of patients with melanoma combined with colorectal cancer (CRC). METHODS: Clinical and follow-up data of melanoma and CRC patients were recorded, and the expression levels of KAI1 and miR-633 were detected. Pearson chi-square tests and Spearman correlation coefficient were used to analyze the relationship between prognosis and related parameters in these patients. Cox proportional risk regression and receiver operating characteristic curve analyses were used. RESULTS: Overall, 195 patients were included. KAI1 and miR-633 expression levels were significantly correlated with the prognosis of patients with melanoma combined with CRC. Spearman correlation analysis showed that the expression levels of KAI1 and miR-633 were significantly correlated with the prognosis of patients. Multivariate Cox regression analysis suggested that low expression levels of KAI1 and high expression levels of miR-633 indicated shorter survival time for patients. CONCLUSIONS: KAI1 expression was significantly correlated with melanoma and CRC patient prognosis. When KAI1 expression levels were low, the patient survival time was poor.

Host metabolic shift during systemic Salmonella infection revealed by comparative proteomics.

Salmonella enterica serovar Typhimurium (S. Typhimurium) is a food-borne bacterium that causes acute gastroenteritis in humans and typhoid fever in mice. Salmonella pathogenicity island II (SPI-2) is an important virulence gene cluster responsible for Salmonella survival and replication within host cells, leading to systemic infection. Previous studies have suggested that SPI-2 function to modulate host vesicle trafficking and immune response to promote systemic infection. However, the molecular mechanism and the host responses triggered by SPI-2 remain largely unknown. To assess the roles of SPI-2, we used a differential proteomic approach to analyse host proteins levels during systemic infections in mice. Our results showed that infection by WT S. Typhimurium triggered the reprogramming of host cell metabolism and inflammatory response. Salmonella systemic infection induces an up-regulation of glycolytic process and a repression of the tricarboxylic acid (TCA) cycle. WT-infected tissues prefer to produce adenosine 5'-triphosphate (ATP) through aerobic glycolysis rather than relying on oxidative phosphorylation to generate energy. Moreover, our data also revealed that infected macrophages may undergo both M1 and M2 polarization. In addition, our results further suggest that SPI-2 is involved in altering actin cytoskeleton to facilitate the Salmonella-containing vacuole (SCV) biogenesis and perhaps even the release of bacteria later in the infection process. Results from our study provide valuable insights into the roles of SPI-2 during systemic Salmonella infection and will guide future studies to dissect the molecular mechanisms of how SPI-2 functions in vivo.

Association between dynamic obesity and mortality in patients with first-ever ischemic stroke: A hospital-based prospective study.

Although obesity is an established risk factor of primary stroke, the association between obesity and post-stroke mortality remains unclear. The aim of this study was to investigate the association between dynamic obesity status and mortality in survivors of their first stroke in China.Of 775 patients with first-ever ischemic stroke included in a longitudinal study, 754 patients were included in this study and categorized into 4 categories of body mass index (BMI) (underweight, normal weight, overweight, and obese) and 2 categories of waist circumference (WC) (normal WC and abdominal obesity) according to standard Chinese criteria. The mortality information and obesity status were obtained via telephone follow-up every 3 months, beginning in 2010 through 2016. Time-dependent Cox proportional hazards models were used to estimate the unadjusted and adjusted hazard ratios (HRs) for the relationship between all-cause mortality and dynamic obesity status.Of 754 patients, 60.87% were male, and the overall mean age was 61.45 years. After adjusting for possible confounders, significant inverse associations were identified between BMI and WC and all-cause mortality. Compared with those with normal BMI or WC, those with abdominal obesity or overweight had a significantly lower risk of all-cause mortality (HR and 95% confidence intervals [CIs]: .521 [.303-.897] and 0.545 [.352-.845], respectively), whereas patients with underweight had the highest risk and those with obesity had lower risk of mortality, though it was not statistically significant (1.241 [.691-2.226] and .486 [.192-1.231], respectively).Overweight and abdominal obesity were paradoxically associated with reduced risk of mortality in patients who survived their first-ever ischemic stroke in China. Future prospective studies must look at evaluating the role of obesity in different stroke subtypes and devise appropriate weight-management strategies for optimal prognoses in secondary prevention in these survivors.

Seizure description accuracy and seizure classification results from patient histories.

OBJECTIVES: To study the influence of inaccurate histories on the seizure classification results and explore the characteristics of the inaccurate descriptions from the relatives of people with epilepsy (PWE). METHODS: Fifty-four individuals from our multi-disciplinary meeting (MDM) were included. Their histories were collected. The relatives of the individuals answered a questionnaire regarding habitual seizures. Experienced epileptologists reviewed ictal videos, classified habitual seizures based on histories and videos separately with short term EEGs and brain MRIs, and answered the same questionnaire. With the answers from the epileptologists as references, the overall mistake rate for each relative was calculated. Mistake rate, kappa value, and other indicators were also calculated for each item of the questionnaire. Furthermore, seizure-related and socioeconomic factors were included in a multivariable logistic regression model to determine their roles in the overall mistake rates. RESULTS: The inconsistency of classifications from the histories is 25.93 %, with 18.52 % missing focal onset descriptions. The average overall mistake rate of the questionnaire was 28.92 %. Answers to most items were in moderate agreement with the epileptologists. Relatives were not good at reporting eye, face and head movements; asymmetrical postures; and time estimations. Movements of the limbs were likely to be detected. Younger individuals as well as relatives with higher educational levels were related to higher overall mistake rates (P = 0.012 and P = 0.031, respectively). CONCLUSIONS: The potential inaccuracy in histories didn't lead to a large deviation on seizure classifications. There is a certain space for improvement, the importance of detecting focal signs, subtle movements, and asymmetrical postures during seizures should be stressed.

Modified paediatric preoperative risk prediction score to predict postoperative ICU admission in children: a retrospective cohort study.

OBJECTIVE: To integrate intrinsic surgical risk into the paediatric preoperative risk prediction score (PRPS) model to construct a more comprehensive risk scoring system (modified PRPS) and improve the prediction accuracy of postoperative intensive care unit (ICU) admission in paediatric patients. DESIGN: This was a retrospective study conducted between 1 January and 30 December 2016. Data on age, American Society of Anaesthesiology physical status (ASA-PS), oxygen saturation, prematurity, non-fasted status, severity of surgery and immediate transfer to the ICU after surgery were collected. The modified PRPS was developed by logistic regression in the derivation cohort; it was tested and compared with the paediatric PRPS and ASA-PS by the Hosmer-Lemeshow test, the receiver operating characteristic (ROC) curve and Kappa analysis in the validation cohort. SETTING: Hospital-based study in China. PARTICIPANTS: Paediatric patients (≤14 years) who underwent surgery under general anaesthesia were included, and those who needed reoperation due to surgical complications or stayed in the ICU preoperatively were excluded. MAIN OUTCOME MEASURE: ICU admission rate, defined as any patients' direct disposition from the operating room to the ICU immediately after the surgery. RESULTS: A total of 9261 paediatric patients were included in this study, with 418 patients admitted to the ICU. In the validation cohort, the modified PRPS model fit the test data well (deciles of risk goodness-of-fit χ2=6.84, p=0.077). The area under the ROC curve of the modified PRPS, paediatric PRPS and ASA-PS were 0.963, 0.941 and 0.870, respectively (p<0.05), and the Kappa values were 0.620, 0.286 and 0.267. Analyses in the cohort indicated that the modified PRPS was superior to the paediatric PRPS and ASA-PS. CONCLUSIONS: The modified PRPS integrating intrinsic surgical risk shows better prediction accuracy than the previous PRPS.

[Relative Survival of Patients with Ischemic Stroke].

OBJECTIVE: To estimate the relative survival ratio of patients with ischemic stroke and its risk factors. METHODS: Lifetable and Ederer Ⅱ methods were used to estimate the relative survival ratio of patients with ischemic stroke. The Poission error structure model was adopted to determine the risk factors associated with survival. RESULTS: The patients had 99%, 98%, 98% and 99% relative survival ratio 1 year, 3 years, 5 years and 7 years after stroke, respectively. The relative excess risk of death increased with age [53-62 yr. vs. <53 yr., relative excess risk (RER=26.975, 95%CI: 1.668-410.90, P=0.020 1], higher mRS scores (≥3 vs. <3 points, RER=14.700, 95%CI: 1.05-206.45, P=0.047 3), and under body mass (vs. normal body mass, RER=10.082, 95%CI: 2.076-48.958, P=0.004 2). CONCLUSION: Ischemic stroke patients have a good prognosis, with slightly lower survival rates than the matched general populations. Those who are older, under body mass, and have a higher mRS score have lower survival rates.

Comparison of the flexible parametric survival model and Cox model in estimating Markov transition probabilities using real-world data.

BACKGROUND AND OBJECTIVE: Markov micro-simulation models are being increasingly used in health economic evaluations. An important feature of the Markov micro-simulation model is its ability to consider transition probabilities of heterogeneous subgroups with different risk profiles. A survival analysis is generally performed to accurately estimate the transition probabilities associated with the risk profiles. This study aimed to apply a flexible parametric survival model (FPSM) to estimate individual transition probabilities. MATERIALS AND METHODS: The data were obtained from a cohort study investigating ischemic stroke outcomes in Western China. In total, 585 subjects were included in the analysis. To explore the goodness of fit of the FPSM, we compared the estimated hazard ratios and baseline cumulative hazards, both of which are necessary to the calculate individual transition probabilities, and the Markov micro-simulation models constructed using the FPSM and Cox model to determine the validity of the two Markov micro-simulation models and cost-effectiveness results. RESULTS: The flexible parametric proportional hazards model produced hazard ratio and baseline cumulative hazard estimates that were similar to those obtained using the Cox proportional hazards model. The simulated cumulative incidence of recurrent ischemic stroke and 5-years cost-effectiveness of Incremental cost-effectiveness Ratios (ICERs) were also similar using the two approaches. A discrepancy in the results was evident between the 5-years cost-effectiveness and the 10-years cost-effectiveness of ICERs, which were approximately 0.9 million (China Yuan) and 0.5 million (China Yuan), respectively. CONCLUSIONS: The flexible parametric survival model represents a good approach for estimating individual transition probabilities for a Markov micro-simulation model.

[Health Utility of Patients with Stroke Measured by EQ-5D and SF-6D].

OBJECTIVE: To compare EQ-5D and SF-6D for measuring health utility of stroke patients in health economic evaluation studies. METHODS: A prospective cohort study was conducted on 596 stroke patients in the West China Hospital of Sichuan University from 2010 to 2016. Data were collected at baseline through face to face interviews and at the follow-up stages through telephone interviews with a three-month interval. EQ-5D and SF-6D were used for measuring health utility scores of the participants. The consistency of the two instruments was assessed using Bland-Altman plot and Intraclass correlation coefficient (ICC) . Logistic regression models were established to identify predictors of health utility. RESULTS: The participants had a mean utility score of 0.78 (95% confidence interval:0.76, 0.80) in EQ-5D,compared with 0.74 (95% confidence interval: 0.73, 0.76) in SF-6D,and a median (interquartile range) of 0.86 (0.68, 1.00) in EQ-5D and 0.73 (0.62, 0.86) in SF-6D. The 95% limits of agreement between the two instruments ranged from -0.28 to 0.35,with an ICC of 0.67 (95% confidence interval: 0.62,0.71). EQ-5D had a higher ceiling effect. The health utility score of stroke patients changed there rapidly in acute phase (less than 3 months) but barely changed there after.Severity of stroke was a major predictor of health utility scores. CONCLUSION: The two instruments generate inconsistent results in health utility. SF-6D is better for measuring health utility in patients with stroke in China.

Exercise and quality of life after first-ever ischaemic stroke: a two-year follow-up study.

BACKGROUND: Quality of life (QoL) post-stroke is an important health outcome. Physical deconditioning and physical inactivity are highly prevalent in stroke survivors. This study aimed to assess the long-term trends in QoL and to explore the effect of exercise on the QoL of ischaemic stroke patients. METHODS: Data for this prospective study were collected at baseline using face-to-face interviews, and telephone follow-ups were completed every three months from 2010 through 2014. QoL was evaluated with the 12-item Short-Form Health Survey (SF-12). The relationship between changes in exercise and QoL changes was analysed with a multi-level model. RESULTS: Exercise and QoL generally increased during the study period. After adjusting for covariates, the SF-12 Physical Component Summary (PCS) scores increased by 0.60 on average for each unit increase in exercise frequency and by 0.52 for each hour increase in weekly exercise time. For weekly exercise times ≤ 22.73 h, the PCS scores continued to increase with increasing exercise time. The Mental Component Summary scores increased by 0.51 on average for each unit increase in exercise frequency and by 0.35 for each hour increase in weekly exercise time. Furthermore, the standard deviations of exercise frequency and exercise time were inversely associated with changes in the PCS score. CONCLUSIONS: Exercise is an important modifiable behaviour. Long-term regular mild exercise should be recommended to improve QoL among stroke survivors.

[Application of Competing Risks Model in Predicting Smoking Relapse Following Ischemic Stroke].

OBJECTIVE: To determine factors associated with smoking relapse in men who survived from their first stroke. METHODS: Data were collected through face to face interviews with stroke patients in the hospital, and then repeated every three months via telephone over the period from 2010 to 2014. Kaplan-Meier method and competing risk model were adopted to estimate and predict smoking relapse rates. RESULTS: The Kaplan-Meier method estimated a higher relapse rate than the competing risk model. The four-year relapse rate was 43.1% after adjustment of competing risk. Exposure to environmental tobacco smoking outside of home and workplace (such as bars and restaurants) (P=0.01), single (P<0.01), and prior history of smoking at least 20 cigarettes per day (P=0.02) were significant predictors of smoking relapse. CONCLUSION: When competing risks exist, competing risks model should be used in data analyses. Smoking interventions should give priorities to those without a spouse and those with a heavy smoking history. Smoking ban in public settings can reduce smoking relapse in stroke patients.

[Sample Size Calculation using SAS for Phaseâ ¡in Two-stage Clinical Trials of Anti-tumor Drugs].

OBJECTIVE: To compare Gehan two-stage design and Simon two-stage design in sample size calculations for phase Ⅱ clinical trials of anti-tumor drugs. METHODS: We explained the sample size calculation methods with a single-stage design, Gehan two-stage design, and Simon optimal two-stage and minimax two-stage designs in line with the principle of exact binomial probability. By setting up different parameters in SAS macro program, the advantages and disadvantages of these designs were compared. RESULTS: The minimax two-stage design does not increase the maximum sample size compared with the single-stage design. Compared with the Gehan two-stage design, the Simon two-stage design has the advantage of being able to determine an early termination of trials when no or low anti-tumor activities are evident. CONCLUSION: Simon two-stage design is better than single-stage design and Gehan two-stage design. The minimax design is more popular than the optimal design.

Smoking prevalence and seizure control in Chinese males with epilepsy.

Smoking has a negative effect on most diseases, yet it is under-investigated in people with epilepsy; thus its role is not clear in the general population with epilepsy. We performed a retrospective pilot study on males with epilepsy to determine the smoking rate and its relationship with seizure control using univariate analysis to calculate odds ratios (ORs) and also used a multi-variate logistic regression model. The smoking rate in our sample of 278 individuals was 25.5%, which is lower than the general Chinese population smoking rate among males of 52.1%. We used two classifications: the first classified epilepsy as generalized, or by presumed topographic origin (temporal, frontal, parietal and occipital). The second classified the dominant seizure type of an individual as generalized tonic clonic seizure (GTCS), myoclonic seizure (MS), complex partial seizure (CPS), simple partial seizure (SPS), and secondary GTCS (sGTCS). The univariable analysis of satisfactory seizure control profile and smoking rate in both classifications showed a trend towards a beneficial effect of smoking although most were not statistically significant. Considering medication is an important confounding factor that would largely influence seizure control, we also conducted multi-variable analysis for both classifications with drug numbers and dosage. The result of our model also suggested that smoking is a protective factor. Our findings seem to suggest that smoking could have a potential role in seizure control although confounders need exploration particularly in view of the potential long term health effects. Replication in a much larger sample is needed as well as case control studies to elucidate this issue.

Long-term trends and predictors of smoking behaviors among men following first-ever ischemic stroke.

Continued smoking following stroke is associated with adverse outcomes including increased risk of mortality and secondary stroke. The aim of this study was to examine the long-term trends in smoking behaviors and factors associated with smoking relapse among men who survived their first-ever stroke. Data collection for this longitudinal study was conducted at baseline through face-to-face interviews and follow-up was completed every 3 months via telephone, beginning in 2010 and continuing through 2014. Cox proportional hazard regression models were used to identify predictors of smoking relapse behavior. At baseline, 372 male patients were recruited into the study. Totally, 155 (41.7%) of these patients stopped smoking for stroke, and 61 (39.3%) began smoking again within 57 months after discharge with an increasing trend in the number of cigarettes smoked per day. Exposure to environmental tobacco smoke at places outside of home and work (such as bars, restaurants) (HR, 2.34; 95% CI, 1.04-5.29, P=0.04), not having a spouse (HR, 0.12; 95% CI, 0.04-0.36; P=0.0002) and smoking at least 20 cigarettes per day before stroke (HR, 2.42; 95% CI, 1.14-5.14, P=0.02) were predictors of smoking relapse. It was concluded that environmental tobacco smoke is an important determinant of smoking relapse among men who survive their first stroke. Environmental tobacco smoke should be addressed by smoke-free policies in public places.

An Algorithm and R Program for Fitting and Simulation of Pharmacokinetic and Pharmacodynamic Data.

BACKGROUND AND OBJECTIVES: Pharmacokinetic/pharmacodynamic link models are widely used in dose-finding studies. By applying such models, the results of initial pharmacokinetic/pharmacodynamic studies can be used to predict the potential therapeutic dose range. This knowledge can improve the design of later comparative large-scale clinical trials by reducing the number of participants and saving time and resources. However, the modeling process can be challenging, time consuming, and costly, even when using cutting-edge, powerful pharmacological software. Here, we provide a freely available R program for expediently analyzing pharmacokinetic/pharmacodynamic data, including data importation, parameter estimation, simulation, and model diagnostics. METHODS: First, we explain the theory related to the establishment of the pharmacokinetic/pharmacodynamic link model. Subsequently, we present the algorithms used for parameter estimation and potential therapeutic dose computation. The implementation of the R program is illustrated by a clinical example. The software package is then validated by comparing the model parameters and the goodness-of-fit statistics generated by our R package with those generated by the widely used pharmacological software WinNonlin. RESULTS: The pharmacokinetic and pharmacodynamic parameters as well as the potential recommended therapeutic dose can be acquired with the R package. The validation process shows that the parameters estimated using our package are satisfactory. CONCLUSIONS: The R program developed and presented here provides pharmacokinetic researchers with a simple and easy-to-access tool for pharmacokinetic/pharmacodynamic analysis on personal computers.