Journal of environmental exposure assessment最新文献

{"title":"Ambient air concentrations and risk assessment of selected organochlorine pesticides (OCPs) across five Middle Eastern countries","authors":"B. Gevao, P. Kurt-Karakus, Askin Birgul, Karell Martinez-Guijarro, C. Sukhn, D. Krishnan, Smitha Rajagopalan, Mariam Hajeyah, M. Bahloul, H. Alshemmari, M. Orif","doi":"10.20517/jeea.2022.05","DOIUrl":"https://doi.org/10.20517/jeea.2022.05","url":null,"abstract":"This paper presents data obtained from concurrently deployed polyurethane foam disk passive samplers in Kuwait, Turkey, Lebanon, Saudi Arabia, and Oman between January and October 2018. The study’s main goal was to initiate a passive air sampling network across the Middle East to generate comparable data, which will help report obligations of the various countries and be used in protocol discussions. The ∑24OCP concentrations were highest in the samples collected from Kartaba in Lebanon (7780 pg·m-3), and the lowest concentration was recorded at the BUTAL site in the Bursa province of Turkey (7.27 pg·m-3). The mean ambient ∑24OCP concentrations on a country-specific basis over consecutive sampling campaigns were: Lebanon (1680 pg·m-3) > Bursa (Turkey) (78.7 pg·m-3) > Oman (55 pg·m-3) > Kuwait (42 pg·m-3) > Jeddah, Saudi Arabia (19.1 pg·m-3). The results show no cancer risk due to inhalation of organochlorine pesticides (OCPs) in ambient air. This study provides the first reliable measurements of the spatial variability in the atmospheric concentrations of OCPs across several Middle Eastern countries, providing a baseline for assessing time trends in air, one of the core matrices for the effectiveness evaluation of the Stockholm Convention on Persistent Organic Pollutants.","PeriodicalId":73738,"journal":{"name":"Journal of environmental exposure assessment","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67658004","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Waste streams as current sources of persistent organic pollutants and organophosphate esters in Africa - a critical review","authors":"O. Akinrinade, W. Stubbings","doi":"10.20517/jeea.2022.17","DOIUrl":"https://doi.org/10.20517/jeea.2022.17","url":null,"abstract":"Per- and polyfluoroalkyl substances, chlorinated paraffins, brominated flame retardants, polychlorinated biphenyls and mirex are regulated under the United Nations Environment Programme’s (UNEP’s) Stockholm Convention on Persistent Organic Pollutants (POPs) intended for the eradication of hazardous contaminants in the environment. There is also a major concern for organophosphate esters and specific alternative or novel brominated flame retardants. To date, no evidence exists that major producers of these chemicals occur on the African continent. They are understood to find their way into African environments through the import of commercial products, in particular products with second-hand value and short lifespans, which may enter waste streams in a relatively shorter period. To further understand the current levels of these selected contaminants in African waste streams, existing documents capturing various African waste stream compartments for the above outlined targeted contaminants were gathered from an exhaustive literature review. Key factors influencing the transfer of contaminants from waste or elevated concentrations of contaminants in African waste streams are associated with the nature and/or sources of contaminants, volume of contaminants or waste in relation to the capacity of treatment plants/landfills, condition or age of treatment plants/landfill geomembrane liner, model adopted for contaminants removal and treatment procedures for collected sludges or leachates. Evidence from the selected studies indicates substantial POP contamination in African landfills and dumpsites, wastewater effluents/sludge and human/biological samples around dumpsites and landfills. Unfortunately, the continent has inadequate infrastructural capacity to adequately handle POP in the waste streams. This review provides recommendations and suggestions for future studies.","PeriodicalId":73738,"journal":{"name":"Journal of environmental exposure assessment","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67657726","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Extraction and Pyrolysis-GC-MS analysis of polyethylene in samples with medium to high lipid content","authors":"C. Rauert, Yufei Pan, E. Okoffo, J. O'Brien, K. Thomas","doi":"10.20517/jeea.2022.04","DOIUrl":"https://doi.org/10.20517/jeea.2022.04","url":null,"abstract":"While it is recognised that humans are constantly exposed to plastics, there are limitations in understanding the extent of this exposure, particularly dietary exposure. This lack of information is partly due to challenges with the analysis of complicated matrices. This study aimed to assess the impact of medium to high lipid content (> 3%) food samples on the accurate quantification of polyethylene (PE), using pyrolysis-gas chromatography mass spectrometry, and develop an alternative sample processing strategy. Analysis of saturated, monounsaturated and polyunsaturated fats was demonstrated to form the same pyrolysis products as PE, producing a significant interference hindering quantification. An extraction protocol was developed that involves enzyme digestion to break the lipids into smaller chain fatty acids, removal of these interferences with pressurised liquid extraction washes, before a final extraction of the PE by pressurised liquid extraction. This new method was validated through the analysis of three medium- to high-fat content foods: cow’s milk, eggs and lamb meat, where PE recoveries were acceptable (104% to 127%). Method detection limits were also significantly reduced from 1.9 to 0.05 µg/injection (380 to 10 µg/g) with the new protocol, through the removal of matrix background. PE traces were observed in the three food matrices of 72-240 µg/g, significantly reduced as compared to samples extracted with the old method where concentrations of 12-32 mg/g were calculated, demonstrating the potential for overestimation of dietary exposure. Finally, a simple protocol is reported for future studies to (i) determine if an interference is present and (ii) sample processing methods to remove identified interferences.","PeriodicalId":73738,"journal":{"name":"Journal of environmental exposure assessment","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67657993","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Extended characterization of the indoor dust chemical composition by retrospective suspect and non-target analysis of high resolution mass spectrometric data","authors":"Florian Dubocq, Thanh Wang","doi":"10.20517/jeea.2022.23","DOIUrl":"https://doi.org/10.20517/jeea.2022.23","url":null,"abstract":"With the recent improvements in high-resolution mass spectrometry (HRMS), retrospective chemical analysis has been increasingly used in environmental sciences. This enables new insights into the chemical content of previously analysed samples with new data analysis methods or new information about emerging contaminants. This study aimed to conduct an in-depth investigation into the chemical content of various indoor dust samples using retrospective analysis. The samples were previously extracted using liquid-solid extraction without clean-up to increase the chemical coverage and thereafter analysed both using liquid chromatography (positive and negative ionisations) and gas chromatography coupled with high-resolution mass spectrometry. A retrospective data processing workflow was conducted in this new study by using both suspect screening analysis and non-target analysis. Among 30 dust samples from four different indoor settings, 298 compounds were tentatively identified with an identification confidence level of ≥ 3. The discussion was conducted on both individual compounds as well as their chemical compound groups and functional uses. Main detected chemical groups were plant natural products (n = 57), personal care products (n = 44), pharmaceuticals (n = 44), food additives (n = 43), plasticisers (n = 43), flame retardants (n = 43), colourants (n = 42) and pesticides (n = 31). Although some detected compounds were already reported for the same samples in our previous study, this retrospective analysis enabled the tentative identification of compounds such as polyethylene glycols, per- and polyfluoroalkyl substances, pesticides, benzotriazoles, benzothiazoles, fragrances, colourants and UV stabilizers. This study showed the usefulness of retrospective analysis on indoor dust samples to further characterise the chemical content, which can help to better estimate the exposure risks of organic contaminants to humans in the indoor environment.","PeriodicalId":73738,"journal":{"name":"Journal of environmental exposure assessment","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67658330","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Characterizing and quantifying chemical ingredient use in consumer products between two separate databases and implications for environmental and human health exposure","authors":"T. Gouin","doi":"10.20517/jeea.2022.14","DOIUrl":"https://doi.org/10.20517/jeea.2022.14","url":null,"abstract":"Assessing chemical exposure in home and personal care products (HPCPs) represents an important data need. Key challenges to the assessment are related to limited knowledge in quantifying and characterizing the weight-fraction inclusion level and functionality of chemicals in HPCPs. Publicly available tools have been developed to address these challenges, such as the Chemical and Products database (CPDat). This study aims to evaluate the relative performance of CPDat by comparing estimates of weight-fraction inclusion level and functionality to other relevant data sources. Specifically, estimates obtained from CPDat are evaluated and compared with estimates obtained from marketing analytic data, using Euromonitor Passport for 31 commonly used chemicals found in HPCPs. The results obtained from this exercise suggest relatively good agreement between each of the methods for 10 chemicals (ρ = 0.92; P-value =0.02). When considering all 31 chemical ingredients, however, the correlation observed is generally poor (ρ = 0.46; P-value = 0.1), which is attributed to differences in how the underlying data are obtained for each method. With an emphasis on obtaining data based on mining datasheets for individual products, the application of CPDat is suggested to be useful for higher tiers of assessment, with data obtained from marketing analytics providing valuable input to exposure-based screening models. The insight gained from this study can be used to help guide the appropriate use of data obtained from different sources within a tiered exposure assessment.","PeriodicalId":73738,"journal":{"name":"Journal of environmental exposure assessment","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67657654","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"First insights into the occurrence of pesticide residues in edible insects from sub-Saharan African countries","authors":"Giulia Poma, Shanshan Yin, B. T. Folarin, Alicia Macan Schönleben, Jasper Bombeke, J. C. Altamirano, G. Ssepuuya, D. Nakimbugwe, T. Oluseyi, A. Covaci","doi":"10.20517/jeea.2022.25","DOIUrl":"https://doi.org/10.20517/jeea.2022.25","url":null,"abstract":"Pesticide use is a common practice worldwide, especially in Sub-Saharan African (SSA) countries, where ongoing agriculture intensification and the need for disease vector control make it essential. The population can thus be exposed to variable amounts of pesticides through the diet. Edible insects are a highly regarded food source in SSA. However, they are still mostly harvested from the wild, where chemical applications are not necessarily controlled, representing a major cause of concern for consumers. We investigated residues of legacy (OCPs) and current-use pesticides (CUPs) in selected edible insects commonly consumed in Uganda and Nigeria, and evaluated the eventual health risk for the adult population associated with their consumption. Targeted OCPs were < LOQ in all analysed edible insects, except for hexachlorobenzene (up to 0.87 ng/g dw), while several CUPs were present at notable levels. Cypermethrin showed the highest median concentration (17 ng/g dw), while the Nigerian cricket Brachytrupes membranaceus was the most contaminated sample, with concentrations of aldicarb, propoxur, chlorpyrifos, dichlorvos and paclobutrazol reaching 118 ng/g dw, 327 ng/g dw, 156 ng/g dw, 26 ng/dw, and 14 ng/g dw, respectively. The concentrations of pesticides were generally well below the available maximum residue levels (MRLs), and the dietary risk assessment did not indicate health threats for the adult population. However, we suggest that the monitoring of the chemical safety of edible insects in SSA should be further investigated and insects should be integrated into more extensive dietary studies.","PeriodicalId":73738,"journal":{"name":"Journal of environmental exposure assessment","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67658408","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Tobacco-specific and combustion pollutants in settled house dust in Malta.","authors":"Noel J Aquilina,&nbsp;Christopher M Havel,&nbsp;Neal L Benowitz,&nbsp;Peyton Jacob","doi":"10.20517/jeea.2021.09","DOIUrl":"https://doi.org/10.20517/jeea.2021.09","url":null,"abstract":"<p><strong>Aim: </strong>Most of the carcinogenic pollutants coming from tobacco smoking or other combustion processes tend to accumulate in settled house dust (SHD) over time. This study evaluated the load of these pollutants in smokers and non-smokers' houses from relatively fresh SHD collected in five different districts on the island of Malta.</p><p><strong>Methods: </strong>An improved, efficient extraction method to obtain three fractions from a 200 mg of SHD was developed. It was validated for the analysis of nicotine and polycyclic aromatic hydrocarbons (PAH) by GC-MS/MS and nicotelline and TSNA by LC-MS/MS. Kruskal-Wallis H tests were used to evaluate differences across districts, while a Mann-Whitney <i>U</i> test was used to check differences between smokers and non-smokers' houses. Diagnostic ratios were used to evaluate the carcinogenicity of PAH in SHD in Malta.</p><p><strong>Results: </strong>For all analytes, no statistical difference was observed across different districts, but, in smokers' houses, 97.9% of the total concentration of all target analytes found in SHD is nicotine, 0.1% is TSNA, and 2.0% is PAH. In non-smokers' houses, nicotine represents 16.8% of the load, while 0.4% and 82.8% are TSNA and PAH, respectively. The carcinogenicity of the PAH mixture in Maltese SHD, expressed as the mean benzo(a)pyrene equivalent (BaP_eq) is 371 ng/g.</p><p><strong>Conclusion: </strong>Indoor activities, ventilation practices, and infiltration of outdoor pollutants contribute to a complex SHD composition. Although the BaP_eq is on the lower end of carcinogenicity, the effects of a mixture including tobacco-related potent carcinogens in SHD are largely unknown. In view of indoor, continuous exposure to SHD through several pathways, further research is warranted.</p>","PeriodicalId":73738,"journal":{"name":"Journal of environmental exposure assessment","volume":"1 ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9056077/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10302786","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Species-specific dechlorane plus isomer fractionation during bioaccumulation: phenomenon and potential mechanisms","authors":"Ke-Lan Guan, Hong-Ying Liu, Xiaojun Luo","doi":"10.20517/jeea.2022.07","DOIUrl":"https://doi.org/10.20517/jeea.2022.07","url":null,"abstract":"The occurrence and behavior of dechlorane plus (DP), an additive chlorinated flame retardant, have been intensively studied since it was identified in 2006. The commercial products of DP are a mixture of two stereoisomers: syn-DP and anti-DP. Stereoselective bioaccumulation of DP isomers in biota was reported in field monitoring and laboratory experiments. This review summarizes stereoselective bioaccumulation of DP in biota samples and provides the potential mechanisms for this stereoselective bioaccumulation. Stereoselective enrichment of syn-DP was widely observed in fish, whereas selective enrichment of anti-DP was mainly found in some birds. This species-specific stereoselective enrichment of DP might reflect that two different types of DP isomer fractionation occurred in bioaccumulation between ectotherms and endotherms. Anti-DP is more readily metabolized through biotransformation in all animals. However, a preferential excretion of anti-DP in fish and syn-DP in birds was observed based on the available data. Both processes determine the DP isomer fractionation in bioaccumulation. A direct comparison in DP composition between biological samples and commercial products was conducted for most studies to determine the occurrence of stereoselective DP enrichment, which may lead to underestimating the potential stereoselective enrichment of DP in organisms. The factors which affected the DP isomer composition in organisms included the tissues or organs used, DP concentration, organisms’ trophic levels occupied, and sex. Inconsistent results were obtained considering the effects of these influence factors. The underlying cause of these inconsistent results is unclear based on present data. Further research on DP biotransformation and interactions between DP and biomacromolecule is needed.","PeriodicalId":73738,"journal":{"name":"Journal of environmental exposure assessment","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67657584","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Concentrations and human exposure to hexabromocyclododecane and tetrabromobisphenol A from the indoor environment in Bangkok metropolitan area, Thailand","authors":"Sonthinee Waiyarat, S. Boontanon, N. Boontanon, S. Harrad, M. Abdallah, D. Drage","doi":"10.20517/jeea.2022.06","DOIUrl":"https://doi.org/10.20517/jeea.2022.06","url":null,"abstract":"Aim: This study investigated hexabromocyclododecane (HBCDD) and tetrabromobisphenol A (TBBPA) concentrations in indoor dust from houses, offices, and cars and estimated toddler and adult exposure to HBCDD and TBBPA through dust ingestion. Methods: The concentrations of HBCDD and TBBPA were measured in 47 indoor dust samples collected from the Bangkok metropolitan area, Thailand. All samples were analyzed for HBCDD and TBBPA using LC-MS/MS. The estimated daily intake (EDI) through dust ingestion was calculated from the median and 95th percentile concentrations of HBCDD and TBBPA. Results: HBCDD was detected in 47% of samples, and TBBPA was detected in all samples. The median concentrations of HBCDD were 6.7 ng g-1, <0.7 ng g-1, and <0.7 ng g-1 in cars, houses, and offices, respectively. The isomer composition of ∑HBCDD in dust was: α-HBCDD (40%-54%), γ-HBCDD (19%-40%), and β-HBCDD (17%-28%). In contrast, TBBPA was observed at higher concentrations, with median values of 674, 67, and 22 ng g-1 in offices, houses, and cars, respectively. Under a median exposure scenario, toddlers were exposed to 0.05 ng kg-1 bw day-1 for HBCDD and 0.25 ng kg-1 bw day-1 for TBBPA, with adults exposed to 0.01 and 0.06 ng kg-1 bw day-1 for HBCDD and TBBPA respectively. Conclusion: Concentrations of HBCDD in dust from Thai cars, homes, and offices are lower than those of TBBPA following the listing of HBCDD in the Stockholm Convention on Persistent Organic Pollutants and limited use of HBCDD in Thailand in applications such as building insulation foam. Concentrations of TBBPA in office dust significantly exceeded (P < 0.05) those in house and car dust owing to the greater number of electronic appliances and poor natural ventilation in offices. EDIs for Thai toddlers exceeded those of adults under both median and high-end exposure scenarios. However, EDIs of HBCDD and TBBPA for the general Thai population were below the corresponding oral reference dose guidelines.","PeriodicalId":73738,"journal":{"name":"Journal of environmental exposure assessment","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67658041","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Regional deposited dose in the human respiratory tract using different particulate metrics","authors":"E. Chalvatzaki, S. Chatoutsidou, M. Lazaridis","doi":"10.20517/jeea.2022.16","DOIUrl":"https://doi.org/10.20517/jeea.2022.16","url":null,"abstract":"The objective of the current study was to calculate the deposited dose rate in the human respiratory tract arising from particle number (PN) and particle mass (PM) measurements. A main objective was the investigation of deposition pattern and characteristics of the two metrics in the human respiratory tract. The dose rate was estimated for residents at a suburban background location (Chania, Greece). The total dose rate showed two peaks, one in the morning (1.6 × 109 particles/h at 7:00-8:00) and the other one at night (2.1 × 109 particles/h at 21:00-22:00), during the warm period, while the cold period showed two peaks, morning (2.0 × 109 particles/h at 9:00-10:00) and afternoon (3.6 × 109 particles/h at 18:00-19:00). The peaks during the warm period were associated with traffic emissions, whereas the peaks during the cold period were associated with both heating and traffic emissions. A higher dose rate of PN10 was found in the alveolar region while for PM10 it was found in the extrathoracic region. These findings are linked with increased contribution of ultrafine and coarse particles to PN10 (65%-78% and 54%-62% for cold and warm periods, respectively) and PM10 (63% and 55% for cold and warm periods, respectively) concentrations, respectively. The current study showed the importance to use both number and mass aerosol metrics for determining the human exposure and regional dose and their related health effects. The novelty of the current study is the simultaneous measurements of the two particles metrics and the full particle size distributions to make accurate estimates of regional deposited dose.","PeriodicalId":73738,"journal":{"name":"Journal of environmental exposure assessment","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67657714","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}