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Ma L, Ma J, Tian Y, Li X, Tai B, Xing F. Fus3 Interacts with Gal83, Revealing the MAPK Crosstalk to Snf1/AMPK to Regulate Secondary Metabolic Substrates in Aspergillus flavus. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2024; 72:10065-10075. [PMID: 38634532 DOI: 10.1021/acs.jafc.4c01229] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/19/2024]
Abstract
Aflatoxins (AFs), highly carcinogenic natural products, are produced by the secondary metabolism of fungi such as Aspergillus flavus. Essential for the fungi to respond to environmental changes and aflatoxin synthesis, the pheromone mitogen-activated protein kinase (MAPK) is a potential regulator of aflatoxin biosynthesis. However, the mechanism by which pheromone MAPK regulates aflatoxin biosynthesis is not clear. Here, we showed Gal83, a new target of Fus3, and identified the pheromone Fus3-MAPK signaling pathway as a regulator of the Snf1/AMPK energy-sensing pathway modulating aflatoxins synthesis substrates. The screening for Fus3 target proteins identified the β subunit of Snf1/AMPK complexes using tandem affinity purification and multiomics. This subunit physically interacted with Fus3 both in vivo and in vitro and received phosphorylation from Fus3. Although the transcript levels of aflatoxin synthesis genes were not noticeably downregulated in both gal83 and fus3 deletion mutant strains, the levels of aflatoxin B1 and its synthesis substrates and gene expression levels of primary metabolizing enzymes were significantly reduced. This suggests that both the Fus3-MAPK and Snf1/AMPK pathways respond to energy signals. In conclusion, all the evidence unlocks a novel pathway of Fus3-MAPK to regulate AFs synthesis substrates by cross-talking with the Snf1/AMPK complexes.
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Affiliation(s)
- Longxue Ma
- Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences / Key Laboratory of Agro-products Quality and Safety Control in Storage and Transport Process, Ministry of Agriculture and Rural Affairs, Beijing 100193, P. R. China
| | - Junning Ma
- Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences / Key Laboratory of Agro-products Quality and Safety Control in Storage and Transport Process, Ministry of Agriculture and Rural Affairs, Beijing 100193, P. R. China
| | - Yuanyuan Tian
- Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences / Key Laboratory of Agro-products Quality and Safety Control in Storage and Transport Process, Ministry of Agriculture and Rural Affairs, Beijing 100193, P. R. China
| | - Xu Li
- Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences / Key Laboratory of Agro-products Quality and Safety Control in Storage and Transport Process, Ministry of Agriculture and Rural Affairs, Beijing 100193, P. R. China
| | - Bowen Tai
- Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences / Key Laboratory of Agro-products Quality and Safety Control in Storage and Transport Process, Ministry of Agriculture and Rural Affairs, Beijing 100193, P. R. China
| | - Fuguo Xing
- Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences / Key Laboratory of Agro-products Quality and Safety Control in Storage and Transport Process, Ministry of Agriculture and Rural Affairs, Beijing 100193, P. R. China
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Wei S, Zhang Y, Wu M, Lv Y, Zhang S, Zhai H, Hu Y. Mechanisms of methyl 2-methylbutyrate suppression on Aspergillus flavus growth and aflatoxin B1 biosynthesis. Int J Food Microbiol 2024; 409:110462. [PMID: 37918192 DOI: 10.1016/j.ijfoodmicro.2023.110462] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Revised: 10/17/2023] [Accepted: 10/26/2023] [Indexed: 11/04/2023]
Abstract
Aspergillus flavus and subsequently produced carcinogenic aflatoxins frequently contaminate postharvest food crops, resulting in a threat to global food safety. Chemical preservatives are currently the main antifungal agents. However, fungal resistance effect, biological toxicity, and environmental contamination limit their practical applications. The application of natural volatile organic compounds has great potential for controlling fungal and mycotoxin contamination of postharvest food crops. This study therefore investigated the antifungal and anti-aflatoxigenic activities of the volatile compound, methyl 2-methylbutyrate (M2M), against Aspergillus flavus and its potential mechanisms. M2M effectively inhibited A. flavus mycelia growth, with a minimum inhibitory concentration of 2.0 μL/mL. Moreover, M2M also suppressed aflatoxin production, sclerotia production, and the pathogenicity on peanut and corn flour. RNA-Seq results showed that 2899 differentially expressed genes (DEGs), and DEGs involved in ergosterol synthesis, cell wall structure, glycolysis, citric acid cycle, mitogen activated protein kinase signaling pathway, DNA replication, and aflatoxin biosynthesis, were down-regulated in A. flavus. Further studies showed that M2M strongly damaged the cell membrane and cell wall integrity, reduced ATP levels, and induced reactive oxygen species (ROS) accumulation and DNA damage. Notably, a GATA type zinc finger transcription factor, AfSreA (AFLA_132440), which is essential for A. flavus growth and aflatoxin production, was identified. The growth and aflatoxin yield in the ΔAfSreA strain decreased by 94.94 % and 71.82 %, respectively. Additionally, deletion of AfSreA destroyed cell wall integrity and decreased expressions of genes involved in aflatoxin biosynthesis. Taken together, our results identified the antifungal and anti-aflatoxigenic mechanisms of M2M against A. flavus, and confirmed the potential of M2M in protecting peanut and corn from fungal contamination.
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Affiliation(s)
- Shan Wei
- College of Bioengineering, Henan University of Technology, Zhengzhou 450001, PR China
| | - Yige Zhang
- College of Bioengineering, Henan University of Technology, Zhengzhou 450001, PR China
| | - Menghan Wu
- College of Bioengineering, Henan University of Technology, Zhengzhou 450001, PR China
| | - Yangyong Lv
- College of Bioengineering, Henan University of Technology, Zhengzhou 450001, PR China
| | - Shuaibing Zhang
- College of Bioengineering, Henan University of Technology, Zhengzhou 450001, PR China
| | - Huanchen Zhai
- College of Bioengineering, Henan University of Technology, Zhengzhou 450001, PR China
| | - Yuansen Hu
- College of Bioengineering, Henan University of Technology, Zhengzhou 450001, PR China; Food Laboratory of Zhongyuan, Henan University of Technology, Luohe 462300, PR China.
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Liang L, Wang X, Lan H, Wei S, Lei Y, Zhang S, Zhai H, Hu Y, Lv Y. Comprehensive analysis of aflatoxin B 1 biosynthesis in Aspergillus flavus via transcriptome-wide m 6A methylome response to cycloleucine. JOURNAL OF HAZARDOUS MATERIALS 2024; 461:132677. [PMID: 37797576 DOI: 10.1016/j.jhazmat.2023.132677] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Revised: 09/22/2023] [Accepted: 09/28/2023] [Indexed: 10/07/2023]
Abstract
Aspergillus flavus and its toxic aflatoxins secondary metabolites contaminate food and grains, posing a severe threat to human health and leading to liver cancer. Here, we demonstrated that cycloleucine blocked aflatoxin B1 synthesis by inhibiting N6-methyladenosine (m6A) methylation modification of messenger RNA (mRNA). m6A Methylation Immunoprecipitation Sequencing (m6A MeRIP-Seq)-based comprehensive transcriptome-wide m6A profiling identified 102 differentially expressed genes that underwent m6A modification, of which 22 hypermethylated genes were downregulated and 49 hypomethylated genes were upregulated, suggesting a negative correlation between m6A methylation and gene expression. Notably, cycloleucine inhibited aflatoxin B1 production via multiple targets. The m6A sites of several key genes involved in the aflatoxin B1 biosynthesis pathway were significantly enriched in the coding sequence and around the stop codon, resulting in their downregulation. Furthermore, m6A methylation on genes related to the aflatoxin B1 biosynthesis pathway led to reduced mRNA stability. Cycloleucine inhibition of aflatoxin B1 production highlights its potential as an agent for removing mycotoxins in environmental pollution. ENVIRONMENTAL IMPLICATION: Aflatoxins, highly carcinogenic secondary metabolites produced by Aspergillus flavus, frequently contaminate crops such as peanut, corn, wheat and sesame leading to irreversible loss in the quality and yield of agricultural products and posing serious threats to food safety. Aflatoxins has also been linked to developmental delays and liver cancer in humans. In our study, 'monitoring aflatoxin concentrations and its bioaccumulation in organisms' has been conducted. The results demonstrated that aflatoxin production in A. flavus was completely blocked after cycloleucine treatment. Additionally, we demonstrated that inhibition of aflatoxin was linked to N6-methyladenosine methylation of multiple genes in aflatoxin biosynthesis pathway.
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Affiliation(s)
- Liuke Liang
- College of biological engineering, Henan University of Technology, Zhengzhou 450001, China
| | - Xiaoyan Wang
- College of biological engineering, Henan University of Technology, Zhengzhou 450001, China
| | - Haier Lan
- College of biological engineering, Henan University of Technology, Zhengzhou 450001, China
| | - Shan Wei
- College of biological engineering, Henan University of Technology, Zhengzhou 450001, China
| | - Yang Lei
- College of biological engineering, Henan University of Technology, Zhengzhou 450001, China
| | - Shuaibing Zhang
- College of biological engineering, Henan University of Technology, Zhengzhou 450001, China
| | - Huanchen Zhai
- College of biological engineering, Henan University of Technology, Zhengzhou 450001, China
| | - Yuansen Hu
- College of biological engineering, Henan University of Technology, Zhengzhou 450001, China
| | - Yangyong Lv
- College of biological engineering, Henan University of Technology, Zhengzhou 450001, China.
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Xie M, Bai N, Yang X, Liu Y, Zhang KQ, Yang J. Fus3 regulates asexual development and trap morphogenesis in the nematode-trapping fungus Arthrobotrys oligospora. iScience 2023; 26:107404. [PMID: 37609635 PMCID: PMC10440713 DOI: 10.1016/j.isci.2023.107404] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2022] [Revised: 04/07/2023] [Accepted: 07/12/2023] [Indexed: 08/24/2023] Open
Abstract
Mitogen-activated protein kinase (MAPK) Fus3 is an essential regulator of cell differentiation and virulence in fungal pathogens of plants and animals. However, the function and regulatory mechanism of MAPK signaling in nematode-trapping (NT) fungi remain largely unknown. NT fungi can specialize in the formation of "traps", an important indicator of transition from a saprophytic to a predatory lifestyle. Here, we characterized an orthologous Fus3 in a typical NT fungus Arthrobotrys oligospora using multi-phenotypic analysis and multi-omics approaches. Our results showed that Fus3 plays an important role in asexual growth and development, conidiation, stress response, DNA damage, autophagy, and secondary metabolism. Importantly, Fus3 plays an indispensable role in hyphal fusion, trap morphogenesis, and nematode predation. Moreover, we constructed the regulatory networks of Fus3 by means of transcriptomic and yeast two-hybrid techniques. This study provides insights into the mechanism of MAPK signaling in asexual development and pathogenicity of NT fungi.
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Affiliation(s)
- Meihua Xie
- State Key Laboratory for Conservation and Utilization of Bio-Resources, Key Laboratory for Microbial Resources of the Ministry of Education, School of Life Sciences, Yunnan University, Kunming 650091, P.R. China
- School of Resource, Environment and Chemistry, Chuxiong Normal University, Chuxiong 675000, P.R. China
| | - Na Bai
- State Key Laboratory for Conservation and Utilization of Bio-Resources, Key Laboratory for Microbial Resources of the Ministry of Education, School of Life Sciences, Yunnan University, Kunming 650091, P.R. China
| | - Xuewei Yang
- State Key Laboratory for Conservation and Utilization of Bio-Resources, Key Laboratory for Microbial Resources of the Ministry of Education, School of Life Sciences, Yunnan University, Kunming 650091, P.R. China
| | - Yankun Liu
- State Key Laboratory for Conservation and Utilization of Bio-Resources, Key Laboratory for Microbial Resources of the Ministry of Education, School of Life Sciences, Yunnan University, Kunming 650091, P.R. China
| | - Ke-Qin Zhang
- State Key Laboratory for Conservation and Utilization of Bio-Resources, Key Laboratory for Microbial Resources of the Ministry of Education, School of Life Sciences, Yunnan University, Kunming 650091, P.R. China
| | - Jinkui Yang
- State Key Laboratory for Conservation and Utilization of Bio-Resources, Key Laboratory for Microbial Resources of the Ministry of Education, School of Life Sciences, Yunnan University, Kunming 650091, P.R. China
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Si P, Wang G, Wu W, Hussain S, Guo L, Wu W, Yang Q, Xing F. SakA Regulates Morphological Development, Ochratoxin A Biosynthesis and Pathogenicity of Aspergillus westerdijkiae and the Response to Different Environmental Stresses. Toxins (Basel) 2023; 15:toxins15040292. [PMID: 37104230 PMCID: PMC10141874 DOI: 10.3390/toxins15040292] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 04/05/2023] [Accepted: 04/14/2023] [Indexed: 04/28/2023] Open
Abstract
Ochratoxin A (OTA), as a common mycotoxin, has seriously harmful effects on agricultural products, livestock and humans. There are reports on the regulation of SakA in the MAPK pathway, which regulates the production of mycotoxins. However, the role of SakA in the regulation of Aspergillus westerdijkiae and OTA production is not clear. In this study, a SakA deletion mutant (ΔAwSakA) was constructed. The effects of different concentrations of D-sorbitol, NaCl, Congo red and H2O2 on the mycelia growth, conidia production and biosynthesis of OTA were investigated in A. westerdijkiae WT and ΔAwSakA. The results showed that 100 g/L NaCl and 3.6 M D-sorbitol significantly inhibited mycelium growth and that a concentration of 0.1% Congo red was sufficient to inhibit the mycelium growth. A reduction in mycelium development was observed in ΔAwSakA, especially in high concentrations of osmotic stress. A lack of AwSakA dramatically reduced OTA production by downregulating the expression of the biosynthetic genes otaA, otaY, otaB and otaD. However, otaC and the transcription factor otaR1 were slightly upregulated by 80 g/L NaCl and 2.4 M D-sorbitol, whereas they were downregulated by 0.1% Congo red and 2 mM H2O2. Furthermore, ΔAwSakA showed degenerative infection ability toward pears and grapes. These results suggest that AwSakA is involved in the regulation of fungal growth, OTA biosynthesis and the pathogenicity of A. westerdijkiae and could be influenced by specific environmental stresses.
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Affiliation(s)
- Peidong Si
- College of Food Science and Engineering, Qingdao Agricultural University, Qingdao 266109, China
- Key Laboratory of Agro-Products Quality and Safety Control in Storage and Transport Process, Ministry of Agriculture and Rural Affairs, Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Gang Wang
- Key Laboratory of Agro-Products Quality and Safety Control in Storage and Transport Process, Ministry of Agriculture and Rural Affairs, Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Wenqing Wu
- Key Laboratory of Agro-Products Quality and Safety Control in Storage and Transport Process, Ministry of Agriculture and Rural Affairs, Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Sarfaraz Hussain
- Key Laboratory of Agro-Products Quality and Safety Control in Storage and Transport Process, Ministry of Agriculture and Rural Affairs, Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Ling Guo
- Key Laboratory of Agro-Products Quality and Safety Control in Storage and Transport Process, Ministry of Agriculture and Rural Affairs, Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Wei Wu
- College of Food Science and Engineering, Qingdao Agricultural University, Qingdao 266109, China
| | - Qingli Yang
- College of Food Science and Engineering, Qingdao Agricultural University, Qingdao 266109, China
| | - Fuguo Xing
- Key Laboratory of Agro-Products Quality and Safety Control in Storage and Transport Process, Ministry of Agriculture and Rural Affairs, Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing 100193, China
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Schalamun M, Beier S, Hinterdobler W, Wanko N, Schinnerl J, Brecker L, Engl DE, Schmoll M. MAPkinases regulate secondary metabolism, sexual development and light dependent cellulase regulation in Trichoderma reesei. Sci Rep 2023; 13:1912. [PMID: 36732590 PMCID: PMC9894936 DOI: 10.1038/s41598-023-28938-w] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Accepted: 01/27/2023] [Indexed: 02/04/2023] Open
Abstract
The filamentous fungus Trichoderma reesei is a prolific producer of plant cell wall degrading enzymes, which are regulated in response to diverse environmental signals for optimal adaptation, but also produces a wide array of secondary metabolites. Available carbon source and light are the strongest cues currently known to impact secreted enzyme levels and an interplay with regulation of secondary metabolism became increasingly obvious in recent years. While cellulase regulation is already known to be modulated by different mitogen activated protein kinase (MAPK) pathways, the relevance of the light signal, which is transmitted by this pathway in other fungi as well, is still unknown in T. reesei as are interconnections to secondary metabolism and chemical communication under mating conditions. Here we show that MAPkinases differentially influence cellulase regulation in light and darkness and that the Hog1 homologue TMK3, but not TMK1 or TMK2 are required for the chemotropic response to glucose in T. reesei. Additionally, MAPkinases regulate production of specific secondary metabolites including trichodimerol and bisorbibutenolid, a bioactive compound with cytostatic effect on cancer cells and deterrent effect on larvae, under conditions facilitating mating, which reflects a defect in chemical communication. Strains lacking either of the MAPkinases become female sterile, indicating the conservation of the role of MAPkinases in sexual fertility also in T. reesei. In summary, our findings substantiate the previously detected interconnection of cellulase regulation with regulation of secondary metabolism as well as the involvement of MAPkinases in light dependent gene regulation of cellulase and secondary metabolite genes in fungi.
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Affiliation(s)
- Miriam Schalamun
- Center for Health and Bioresources, Bioresources Unit, AIT Austrian Institute of Technology GmbH, Konrad Lorenz Strasse 24, 3430, Tulln, Austria
| | - Sabrina Beier
- Center for Health and Bioresources, Bioresources Unit, AIT Austrian Institute of Technology GmbH, Konrad Lorenz Strasse 24, 3430, Tulln, Austria
| | - Wolfgang Hinterdobler
- Center for Health and Bioresources, Bioresources Unit, AIT Austrian Institute of Technology GmbH, Konrad Lorenz Strasse 24, 3430, Tulln, Austria
- MyPilz GmbH, Wienerbergstrasse 55/13-15, 1120, Vienna, Austria
| | - Nicole Wanko
- Center for Health and Bioresources, Bioresources Unit, AIT Austrian Institute of Technology GmbH, Konrad Lorenz Strasse 24, 3430, Tulln, Austria
| | - Johann Schinnerl
- Department of Botany and Biodiversity Research, University of Vienna, Rennweg 14, 1030, Vienna, Austria
| | - Lothar Brecker
- Department of Organic Chemistry, University of Vienna, Währinger Strasse 38, 1090, Vienna, Austria
| | - Dorothea Elisa Engl
- Department of Organic Chemistry, University of Vienna, Währinger Strasse 38, 1090, Vienna, Austria
| | - Monika Schmoll
- Center for Health and Bioresources, Bioresources Unit, AIT Austrian Institute of Technology GmbH, Konrad Lorenz Strasse 24, 3430, Tulln, Austria.
- Division of Terrestrial Ecosystem Research, Department of Microbiology and Ecosystem Science, University of Vienna, Djerassiplatz 1, 1030, Vienna, Austria.
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New insights into the persistent effect of transient cinnamaldehyde vapor treatment on the growth and aflatoxin synthesis of Aspergillus flavus. Food Res Int 2023; 163:112300. [PMID: 36596201 DOI: 10.1016/j.foodres.2022.112300] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Revised: 11/26/2022] [Accepted: 12/03/2022] [Indexed: 12/13/2022]
Abstract
The antimicrobial effects of continuous treatment with essential oils (EOs) in both liquid and gaseous phases have been intensively studied. Due to their rapid volatility, the effects of EOs on microorganisms after transient treatment are also worth exploring. In this work, the persistent effects of cinnamaldehyde (CA) vapor on Aspergillus flavus were detected by a series of biochemical analyses. Transcriptome analysis was also conducted to study the gene expression changes between recovered and normal A. flavus. When CA vapor was removed, biochemical analyses showed that the oxidative stress induced by the antimicrobial atmosphere was alleviated, and almost all the damaged functions were restored apart from mitochondrial function. Remarkably, the suppressed aflatoxin production intensified, which was confirmed by the up-regulation of most genes in the aflatoxin synthetic gene cluster, the velvet-related gene FluG and the aflatoxin precursor acetyl-CoA. Transcriptomic analysis also demonstrated significant changes in secondary metabolism, energy metabolism, oxidative stress, and amino acid metabolism in the recovery group. Taken together, these findings provide new insights into the mechanisms underlying the response of A. flavus to CA vapor treatment and will guide the rational application of EOs.
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Ferrara M, Perrone G, Gallo A. Recent advances in biosynthesis and regulatory mechanisms of principal mycotoxins. Curr Opin Food Sci 2022. [DOI: 10.1016/j.cofs.2022.100923] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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