American Journal of Microbiological Research最新文献

{"title":"Cloning, Sequencing and Production of Recombinant Polyclonal Antibodies against Egyptian Staphylococcal Enterotoxin A","authors":"H. N. El-Din, M. N. A. El-Naga, M. E. El-Fouly, M. Ibrahim, E. EL-SHATOURY, H. Hussein","doi":"10.12691/AJMR-5-6-3","DOIUrl":"https://doi.org/10.12691/AJMR-5-6-3","url":null,"abstract":"Staphylococcus aureus (S.aureus) is the most common pathogen found in hospitals, community-acquired infections and colonizes up to 50% of humans, including mucous membranes and damaged skin. Some strains produce enterotoxins (Ent) as staphylococcal enterotoxin A (SEA) which is involved in 75% of food poisoning outbreaks. Few methods are sensitive and specific enough to confirm the diagnosis of staphylococcal food poisoning. In this study, a segment of Ent A-ORF with molecular weight 774 bp was amplified, cloned, sequenced and aligned with published Ent A-ORFs. Ent A-ORF was subcloned into bacterial expression vector (GST-PGEX4T1 vector) and expressed as a fusion protein with GST-tagged protein. A band size of 27 kDa of purified Ent A protein was cleaved from GST protein by thrombin. The expressed protein of Ent A was identified by strong reaction with commercialized polyclonal antibodies against Ent A. Antiserum against Egyptian recombinant Ent A protein was produced by immunization of Balb/c mice, the produced recombinant polyclonal antibodies had a titre of 1:2500 in direct ELISA. The produced recombinant polyclonal antibody was evaluated and reacted specifically in Western immunoblotting analysis and ELISA test. Finally from the obtained results, the produced recombinant protein of Ent A can be used successfully for production of recombinant polyclonal antibodies and used in large-scale detection of staphylococcal enterotoxin A.","PeriodicalId":7580,"journal":{"name":"American Journal of Microbiological Research","volume":"65 1","pages":"131-137"},"PeriodicalIF":0.0,"publicationDate":"2017-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80352853","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":"Profile and Antibiotic Resistance Genes of Escherichia c oli Strains Isolated from Ready-to-Eat Raw Mixed Vegetables Salads in Collective Catering in Abidjan, Côte D’Ivoire","authors":"E. Toe, A. Dadié, E. Dako, Y. C. Blé, A. Toty, G. Loukou, K. Djé","doi":"10.12691/AJMR-5-6-2","DOIUrl":"https://doi.org/10.12691/AJMR-5-6-2","url":null,"abstract":"In recent years many cases of food poisoning due to the consumption of vegetable salads contaminated with antibiotic-resistant strains of E. coli have been reported. The objective of the study was to detect the profile and the genetic factors of antibiotic resistance of Escherichia coli, isolated from ready-to-eat raw mixed vegetable salads, in catering. A total of 218 E. coli strains isolated from salads were confirmed by identification of iudA gene. Antibiotic resistance profile was determined by the agar diffusion method and by the detection of resistance genetic supports. Prevalence of E. coli resistant to antibiotics in vegetable salads was 70.2% with 28.4% of multi-resistant. Antibiotic resistance particularly concerned tetracycline (52.3%), streptomycin (38.5%) and to a lesser extent, nalidixic acid (15.6%). The genes aaa [3] -IV, CIMT, QnrA, tetA, tetB, cmlA and cat1 respectively conferring resistance to gentamicin, ampicillin, quinolones, tetracycline and chloramphenicol were highlighted. The study reveals that the risk of contamination by strains of E. coli resistant to antibiotics exist and require healthy control measures.","PeriodicalId":7580,"journal":{"name":"American Journal of Microbiological Research","volume":"16 1","pages":"124-130"},"PeriodicalIF":0.0,"publicationDate":"2017-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87508320","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":"Novel Vaccines against Streptococcus p neumoniae Based on the Immunoprotective B-cell Epitope Region of Pneumococcal Choline Binding Protein D and Salmonella Enteritidis Flagellin","authors":"Shirin Tarahomjoo, S. Ghaderi","doi":"10.12691/AJMR-5-6-1","DOIUrl":"https://doi.org/10.12691/AJMR-5-6-1","url":null,"abstract":"Pneumococcal conjugate vaccines (PCVs) were constructed through chemical conjugation of pneumococcal capsules to immunogenic carrier proteins. The PCVs implementation in developing countries was prevented by their high manufacturing costs. This issue can be overcome by development of protein based vaccines against pneumococci. Antibody responses are necessary for protection against S. pneumoniae. Choline binding protein D (CBPD) was already identified as a pneumococcal surface protein able to elicit protection against S. pneumoniae and its most protective B-cell epitope region (MIBR) was determined. MIBR was highly conserved in common pneumococcal serotypes. Whole antigens are not as potent as epitope based vaccines and B-cell epitope based vaccines are more effective than whole antigen based vaccines in the prevention of infections. Bacterial flagellins are effective adjuvants that signal via Toll like receptor 5 (TLR5). The TLR5 binding site of flagellin located in the D1 domain and its proper conformation is critical for TLR5 recognition of flagellin. In the present study, therefore, we aim to design effective chimeric vaccines against pneumococci based on MIBR and flagellin of Salmonella Enteritidis (FliC) using bioinformatics tools. FliC was joined to MIBR at N-terminus (CFH), C-terminus (FCH) and the D3 domain (D3Gly202, D3Thr275). All of the constructs were immunoprotective regarding the VaxiJen score (0.8). The codon optimization for constructs was done using OPTIMIZER. Analysis of the mRNA secondary structures using Mfold tool revealed no stable hairpins at 5' ends of constructs and thus the antigens can be expressed appropriately. SCRATCH results indicated that the antigens can be expressed in the soluble form in Escherichia coli at more than 80% probability. The 3D models of antigens resulted from I-TASSER indicated the presence of alpha helix, beta sheet, turn, coil, and 310 helix as the protein structural elements. Superimposing 3D models of D1 domains of antigens with the D1 domain of FliC using FATCAT indicated no change in the D1 conformation. Therefore, FliC can exert its adjuvant effects in these constructs through TLR5 signaling. Inserting MIBR in Gly202 of FliC enhanced the protein beta sheet content remarkably, which can result in appropriate thermostability of the antigen. Our results, therefore, demonstrated that D3Gly202 is a suitable vaccine candidate, which can elicit protection against common S. pneumoniae serotypes causing invasive pneumococcal disease in children less than 5 years of age.","PeriodicalId":7580,"journal":{"name":"American Journal of Microbiological Research","volume":"40 1","pages":"118-123"},"PeriodicalIF":0.0,"publicationDate":"2017-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79275946","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":"Cefotaxime Combined Ellagic Acid in a Liposomal Form for More Stable and Antimicrobial Effective Formula","authors":"Hani Asfour","doi":"10.12691/AJMR-5-5-4","DOIUrl":"https://doi.org/10.12691/AJMR-5-5-4","url":null,"abstract":"The aim of this study is loading of cefotaxime (CXM) and ellagic acid (EA) in a liposomal formula to enhance CXM corneal permeability, stability and antimicrobial activity, thin film hydration method used to form CXM- EA liposomes, particle size, zeta potential, scan electron microscope image, CXM release, drug stability and antimicrobial activity were tested. CTX entrapped in CXM – EA liposomes was 42.1 ± 3.2%, ellagic acid content was 72.1 ± 3.1%, particle size was 251.7 ± 1.2 nm, and Zeta potential was 12.4 ± 3.1 mV with a polydispersity index of 0.34 ± 0.21.In concern to CXM released, it was a dramatic rapid diffusion of raw CXM (~88%) after 1 hour, however, CXM released from CXM –EA liposomes (~50 %), after 2 h, raw CXM was completely dissolved in the buffer medium, but it takes about 8 h to be completely released to the buffered medium. Stability study was carried out among 14 days at room and refrigerator temperatures, raw CXM was expired after 7 days while the formulated CXM content was (~93 %) and (~96 %) for room and refrigerator temperature respectively, finally, antimicrobial activity was carried out against two gram positive and two gram negative microorganisms, data revealed that ellagic acid potentiates the antimicrobial activity of CXM.","PeriodicalId":7580,"journal":{"name":"American Journal of Microbiological Research","volume":"65 1","pages":"113-117"},"PeriodicalIF":0.0,"publicationDate":"2017-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82086181","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":"Apple, Guava and Pineapple Fruit Extracts as Antimicrobial Agents against Pathogenic Bacteria","authors":"S. Kabir, Sheikh Mehbish Jahan, Mahboob Hossain, Romana Siddique","doi":"10.12691/AJMR-5-5-2","DOIUrl":"https://doi.org/10.12691/AJMR-5-5-2","url":null,"abstract":"This investigation was conducted to compare the antimicrobial properties of alcohol fruit extracts from Apple (Malus pumila), Guava (Psidium guajava), and Pineapple (Ananas comosus) against eight bacteria: Staphylococcus aureus, Enteroaggregative E.coli (EAEC), Enterotoxigenic E.coli (ETEC), Enterobacter cloacae, Shigella flexineri, Enterococcus faecalis, Klebsiella, and Pseudomonas aeruginosa. All the fruits were bought fresh from the market, cut into small cubes, and sun dried to a crisp over 4-5 days. After being blended to a fine powder, 75g of each powder was passed through a Soxhlet apparatus containing 250 ml of 99% ethanol to obtain a crude extract. This process was repeated with 250 ml of methanol to obtain a methanolic crude extract. The antimicrobial properties of the extracts were tested using agar well diffusion, Norfloxacin used as positive control and water as negative control. The inhibition zones from each extract were measured and an activity index was calculated from the mean zone sizes. All fruits showed some degree of antimicrobial properties with the highest activity index (2.6) being from Pineapple ethanolic and methanolic extracts against EAEC. Both Apple ethanolic and methanolic extracts showed activity only against Staph. aureus and EAEC. Guava extracts were effective against all the strains except for ETEC. Pineapple extracts were strongly active against all the bacteria. The methanolic extracts of Apple and Guava showed slightly larger zones compared to their ethanolic extracts. For Pineapple, inhibition zones from the ethanolic extracts were slightly larger. The results of this investigation show great promise for potential antimicrobial drugs.","PeriodicalId":7580,"journal":{"name":"American Journal of Microbiological Research","volume":"7 1","pages":"101-106"},"PeriodicalIF":0.0,"publicationDate":"2017-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74973455","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":"Seroprevalence and Risk Factors of Brucellosis among Camels Belonging to Selected Districts of Afar, Ethiopia: Need for Public Awareness","authors":"Fikru Gizaw, Gizachew Fentahun, Semu Mersha, Hailegebriel Bedada, M. Pal, V. Kandi","doi":"10.12691/AJMR-5-5-1","DOIUrl":"https://doi.org/10.12691/AJMR-5-5-1","url":null,"abstract":"Brucellosis is a highly infectious bacterial disease of global significance, which affects humans as well as a wide variety of animals. A cross-sectional study was conducted in three selected districts of Afar region of Ethiopia to determine the seroprevalence of camel brucellosis. A total of 245 camels from selected districts were included in the study. All serum samples were tested and screened serologically using Rose Bengal plate test and confirmed using a complement fixation test. Associated risk factor analysis was also conducted using chi-square and logistic regression analysis. As a result, 30 (12.2%) were Rose Bengal plate test reactors in which 10 (4.1%) were confirmed to be positive using complement fixation test. The statistical analysis indicated that herd size (χ2=13.206; p=0.001 and OR=17.053; 95% CI=1.988-146.254), contact with other ruminants (χ2=13.524; p=0.00 and OR=12.774; 95% CI=1.560-104.625) and history of abortion (χ2=28.022; p=0.00 and OR=38.000; 95% CI=4.694-307.657) were statistically significant and the major risk factors for the presence and transmission of the disease between animals. But age, body condition score, physiological status, parity and geographical location were found statistically insignificant (P>0.05). Public awareness towards the diseases was interviewed with the structured questionnaire format and it was noted that most of the pastoralists had no knowledge about zoonotic disease transmission, consequences of consuming raw milk, and handling aborted animals without any protective material. In general, camel brucellosis is prevalent in this area of study and public awareness towards zoonotic importance is low. Therefore, fruitful and sustainable work is required from the government, animal health professionals, and other stakeholders in the prevention and control of the disease. Improved public awareness is inevitable to reduce the prevalence and spread of the camel brucellosis.","PeriodicalId":7580,"journal":{"name":"American Journal of Microbiological Research","volume":"163 1","pages":"94-100"},"PeriodicalIF":0.0,"publicationDate":"2017-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82064268","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":"Antimicrobial Properties of Phenolic Extracts against Nosocomial Drug Resistant Organisms","authors":"Sambasivarao Yaragalla, Surya k krishnanbabu, J. Gopinath, Buvan G Gengadharan, Thanagam Brightline Mk, Harnell Madhurin","doi":"10.12691/AJMR-5-4-4","DOIUrl":"https://doi.org/10.12691/AJMR-5-4-4","url":null,"abstract":"Nosocomial Multi Drug resistance microbial infection is a global concern nowadays. Due to its multi-drug resistant nature, treatment with conventional antibiotics does not assure desired clinical outcomes. Therefore, there is a need to find new compounds and/or alternative methods to get arsenal against the pathogen. Combination therapies using conventional antibiotics and phytochemicals fulfill both requirements [1]. A variety of essential oils have been screened for their antimicrobial activity [15]. The antimicrobial activity of plant-derived essential oils is the basis of many applications, especially in food preservation, aromatherapy and medicine. This present study demonstrates the efficacy of phenolic-phytochemical extract combinations from pine, coconut and oatmeal colloidal solution against multidrug resistant organisms such as Staphylococcus aureus (ATCC 43300), Pseudomonas aeruginosa (ATCC 27853) and Candida albicans (ATCC 10231). The efficacy of the phytochemical combinations against these microbes were measured by estimating the inhibitory zone as produced by antibiotic sensitivity disc diffusion method on Mueller-Hinton agar. These results can be used as a support in doing further quantitative analysis in prevention and treatment of the common infectious diseases that is caused by these organisms [4].","PeriodicalId":7580,"journal":{"name":"American Journal of Microbiological Research","volume":"10 1","pages":"91-93"},"PeriodicalIF":0.0,"publicationDate":"2017-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74148341","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":"Production of Ethanol and Biomass from Rice Husk Using Cultures of Aspergillus flavus, Aspergillus eamarii and Saccharomyces cerevisiae","authors":"Onwuakor C.E, Hans-Anukam Uzunma, J. UzokweMunachi","doi":"10.12691/AJMR-5-4-3","DOIUrl":"https://doi.org/10.12691/AJMR-5-4-3","url":null,"abstract":"Microbial degradation/conversion of agricultural/industrial wastes to useful bio-products such as bioethanol has become increasingly a popular alternative to gasoline worldwide and has been proven to be useful in many industrial and pharmaceutical processes. In this work, microbial hydrolysis of rice husk into fermentable sugars using Aspergillus flavus and Aspergillus eamarii and subsequent fermentation of sugars to ethanol was achieved using Saccharomyces cerevisiae. The rice husks were ground to fine powder and microbially hydrolyzed by incubating with Aspergillus flavus and Aspergillus eamarii in peptone water for 7 days. Determination of reducing sugar using Fehlings’ reagents confirmed the presence of fermentable sugar in both media. Approximately 6.89° Brix in Aspergillus flavus medium was optimized to 24.41° Brix while 7.12° Brix in Aspergillus eamarii was optimized to 24.10° Brix by adding 300g of sucrose and then fermented to ethanol using Saccharomyces cerevisiae isolated from palm wine at room temperature. The results showed a reduction in pH (6.5-4.1 and 6.8-4.1), an increase in temperature (28-30°C and 28-30°C), increase in percentage titratable acidity (0.33-2.96% and 0.27-2.90%), significant increase in alcohol content (0.00-14.89% and 2.42-14.47%), increase in biomass (0.00-2.16g/l and 0.00-2.08g/l) and decrease in specific gravity (1.112-1.005 and 1.114-1.007) in Aspergillus flavus and Aspergillus eamarii media respectively over a period of 7 days of fermentation. Aspergillus flavus and Aspergillus eamarii hydrolysates yielded 14.89% and 14.47% ethanol respectively after distillation. The results of the experiment conducted shows that rice husk and other cellulosic agricultural wastes could be potential substrates which can be exploited by industries for production of bioethanol and other biotechnological products.","PeriodicalId":7580,"journal":{"name":"American Journal of Microbiological Research","volume":"104 1","pages":"86-90"},"PeriodicalIF":0.0,"publicationDate":"2017-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76124096","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":"Comparative Antimicrobial Effectiveness of Two Medicated Soaps with Herbal Soap from Morinda morindoides (Rubiaceae) against Skin Pathogens","authors":"Touré Abdoulaye, M. Souleymane, Ouattara Howélé, S. Y. Réné, D. Joseph, Coulibaly Adama","doi":"10.12691/AJMR-5-4-1","DOIUrl":"https://doi.org/10.12691/AJMR-5-4-1","url":null,"abstract":"In present study two medicated soaps namely Pharmaderm and Micoderme and herbal soap Morinda formulated with fat extracted from leaves of Morinda morindoides (Rubiaceae) were investigated for their antimicrobial activities against some clinical strains for skin.diseases. The purpose of this study was to verify and compare their antimicrobial effectiveness. Agar broth dilution method with Sabouraud and Mueller-Hinton at serial concentrations of soaps ranging from 62.50 to 3.9 mg/ml and agar plate method were used to determine antimicrobial parameters. All strains tested were inhibited significantly (p T. mentagrophytes was most sensitive fungi whereas C. albicans was least strain in presence of tested soaps. S. aureus was the most resistant among testing bacteria. This study demonstrated that hence buttressing the information written on two medicated soaps labels they possess antimicrobial activity and fat of M. morindoides incorporated at 10 % on basic soap formulation gave an effective antimicrobial power to soap Morinda. Further investigation was to clarify the phytochemical groups of herbal fat responsible for antimicrobial power of soap Morinda.","PeriodicalId":7580,"journal":{"name":"American Journal of Microbiological Research","volume":"124 1","pages":"74-77"},"PeriodicalIF":0.0,"publicationDate":"2017-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73554266","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":"Identification of Newer Antimicrobial Agents: A Study of Invitro Antibacterial and Antifungal Activities of Leaf extracts of Medicinal Plant Aerva lanata (L.) Juss. ex Schult","authors":"Madhusudhan Kairamkonda, Vikram Godishala, V. Kandi","doi":"10.12691/AJMR-5-3-3","DOIUrl":"https://doi.org/10.12691/AJMR-5-3-3","url":null,"abstract":"In the era of presence and spread of infectious diseases caused by microorganisms demonstrating resistance against most antimicrobial agents routinely used in the treatment, there is a serious need of search for potential agents which can be used as antimicrobials. The plant extracts of Aerva lanata were collected and processed using standard procedures. Whatman filter papers were then impregnated with varied concentrations of plant extract and antimicrobial susceptibility testing was performed using Kirby-Bauer disk diffusion method for bacteria. The standard disk diffusion method was used to test antifungal drugs against yeasts, and non-dermatophyte filamentous fungal isolates.The ethanolic extract at a concentration of 600 µg/ mL and 900 µg/ mL showed increased antibacterial activities against Esherichia coli as compared to the standard drug tested at similar concentrations. The chloroform extracts and the ethanol extract revealed increased antibacterial activity against Klebsiella pneumoniae. The chloroform solvent extract showed similar antifungal activities as the standard drug against Candida albicans, and the H2O extract showed greater antifungal activity against Drechslera halodes as compared to the control drug tested. Antibacterial and antifungal properties of leaf extracts of Aerva lanata plant in comparison with the control drugs revealed either similar or increased activities signifying their potential for future candidates as antimicrobial agents.","PeriodicalId":7580,"journal":{"name":"American Journal of Microbiological Research","volume":"35 1","pages":"66-70"},"PeriodicalIF":0.0,"publicationDate":"2017-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83144001","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}