P J Müller, G Haubold, M Menner, H H Grosse, J H Ozegowski, H Bocker
The results present evidence for the important role of phosphate-mediated regulation of the nourseothricin biosynthesis by the processes of phosphate limitation and release of phosphate. Also, higher initial concentrations of phosphate were found to have a strong inhibitory effect on the biosynthesis of nourseothricin. It is concluded that the initial phosphate concentration was the primary target for the biometrical optimization of the fermentation medium. The presence of zinc ions neutralized the negative effect of high initial concentrations of phosphate which was also strongly influenced by the regime of sterilization.
{"title":"Effect of phosphate on the biosynthesis of nourseothricin by Streptomyces noursei JA 3890b.","authors":"P J Müller, G Haubold, M Menner, H H Grosse, J H Ozegowski, H Bocker","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>The results present evidence for the important role of phosphate-mediated regulation of the nourseothricin biosynthesis by the processes of phosphate limitation and release of phosphate. Also, higher initial concentrations of phosphate were found to have a strong inhibitory effect on the biosynthesis of nourseothricin. It is concluded that the initial phosphate concentration was the primary target for the biometrical optimization of the fermentation medium. The presence of zinc ions neutralized the negative effect of high initial concentrations of phosphate which was also strongly influenced by the regime of sterilization.</p>","PeriodicalId":23874,"journal":{"name":"Zeitschrift fur allgemeine Mikrobiologie","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1984-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"17162514","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}
L-Tryptophan did not exert any influence on peptide alkaloid formation in an ergotamine and in an ergosine-accumulating C. purpurea strain. A different picture was observed in a series of related C. purpurea strains. Tryptophan showed a slight stimulatory effect on the ergotoxine producer Pepty 695/S. A blocked mutant of it, designated as Pepty 695/ch which was able to accumulate secoclavines gave similar results. In a high-yielding elymoclavine strain Pepty 695/e, the progeny of the former one, tryptophan up to a concentration of 25 mM stimulated remarkably clavine biosynthesis. Furthermore, tryptophan could overcome the block of synthesis by inorganic phosphate. Increased specific activities of chanoclavine cyclase but not DMAT synthetase were observed in cultures of strain Pepty 695/e supplemented with tryptophan. 5-Methyltryptophan and bioisosteres of tryptophan were ineffective in alkaloid stimulation. These results are compared with those obtained with the grass ergot strain SD 58 and discussed with the relation to other induction phenomena.
l -色氨酸对麦角胺和麦角素积累菌株中肽生物碱的形成没有任何影响。在一系列相关的紫红色葡萄球菌菌株中观察到不同的情况。色氨酸对麦角毒素产生酶Pepty 695/S有轻微的刺激作用。它的一个被阻断的突变体,被命名为Pepty 695/ch,它能够积累二级键,也给出了类似的结果。在一个高产的elymoclavine菌株Pepty 695/e中,色氨酸高达25 mM的浓度显著地刺激了clavine的生物合成。此外,色氨酸可以克服无机磷酸盐合成的障碍。在添加色氨酸的菌株Pepty 695/e的培养中,粗链环化酶的比活性增加,但dat合成酶的比活性没有增加。5-甲基色氨酸和色氨酸的生物同分异构体对生物碱刺激无效。将这些结果与草麦角菌株SD 58的结果进行了比较,并讨论了与其他诱导现象的关系。
{"title":"Influence of tryptophan and related compounds on ergot alkaloid formation in Claviceps purpurea (FR.) Tul.","authors":"D Erge, B Schumann, D Gröger","doi":"10.1002/jobm.3630241002","DOIUrl":"https://doi.org/10.1002/jobm.3630241002","url":null,"abstract":"<p><p>L-Tryptophan did not exert any influence on peptide alkaloid formation in an ergotamine and in an ergosine-accumulating C. purpurea strain. A different picture was observed in a series of related C. purpurea strains. Tryptophan showed a slight stimulatory effect on the ergotoxine producer Pepty 695/S. A blocked mutant of it, designated as Pepty 695/ch which was able to accumulate secoclavines gave similar results. In a high-yielding elymoclavine strain Pepty 695/e, the progeny of the former one, tryptophan up to a concentration of 25 mM stimulated remarkably clavine biosynthesis. Furthermore, tryptophan could overcome the block of synthesis by inorganic phosphate. Increased specific activities of chanoclavine cyclase but not DMAT synthetase were observed in cultures of strain Pepty 695/e supplemented with tryptophan. 5-Methyltryptophan and bioisosteres of tryptophan were ineffective in alkaloid stimulation. These results are compared with those obtained with the grass ergot strain SD 58 and discussed with the relation to other induction phenomena.</p>","PeriodicalId":23874,"journal":{"name":"Zeitschrift fur allgemeine Mikrobiologie","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1984-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"17582464","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}
W Ihn, C Wagner, W F Fleck, D Tresselt, I Eritt, P Sedmera
Various blocked mutants were isolated from three leukaemomycin-(daunomycin-)producing strains IMET JA 3933, IMET JA 5142 and IMET JA 5570 of Streptomyces griseus by NTG and UV treatments. Among them, one class of four mutants ZIMET 43707/1P, IMET JA 5570/3P, IMET JA 5570/10P and IMET JA 5142/01P1 produced new blue and red pigments. Two red compounds designated 1PI and 1PII are the main components of the pigment complex produced by culture of the blocked mutant ZIMET 43707/1P. This paper describes the isolation of 1PI and IPII; furthermore, the spectral and physicochemical properties of these anthracyclinones and the elucidation of their structures are reported.
通过NTG和UV处理,从灰色链霉菌的3株产白霉素(道诺霉素)菌株IMET JA 3933、IMET JA 5142和IMET JA 5570中分离出多种阻断突变体。其中,一类4个突变体ZIMET 43707/1P、IMET JA 5570/3P、IMET JA 5570/10P和IMET JA 5142/01P1产生了新的蓝色和红色色素。两种被命名为1PI和1PII的红色化合物是阻断突变体ZIMET 43707/1P培养产生的色素复合物的主要成分。本文介绍了1PI和IPII的分离;此外,还报道了这些蒽环类化合物的光谱和理化性质,并对它们的结构进行了说明。
{"title":"[Leukemomycin-blocked mutants of Streptomyces griseus and their pigments. II. New 7-hydroxy-bisnahydro-rhodomycinones from the mutant ZIMET 41707/1P].","authors":"W Ihn, C Wagner, W F Fleck, D Tresselt, I Eritt, P Sedmera","doi":"10.1002/jobm.3630240805","DOIUrl":"https://doi.org/10.1002/jobm.3630240805","url":null,"abstract":"<p><p>Various blocked mutants were isolated from three leukaemomycin-(daunomycin-)producing strains IMET JA 3933, IMET JA 5142 and IMET JA 5570 of Streptomyces griseus by NTG and UV treatments. Among them, one class of four mutants ZIMET 43707/1P, IMET JA 5570/3P, IMET JA 5570/10P and IMET JA 5142/01P1 produced new blue and red pigments. Two red compounds designated 1PI and 1PII are the main components of the pigment complex produced by culture of the blocked mutant ZIMET 43707/1P. This paper describes the isolation of 1PI and IPII; furthermore, the spectral and physicochemical properties of these anthracyclinones and the elucidation of their structures are reported.</p>","PeriodicalId":23874,"journal":{"name":"Zeitschrift fur allgemeine Mikrobiologie","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1984-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"17498370","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}
The mixed culture kinetics of stringent and relaxed Escherichia coli cells were investigated in a glucose-limited chemostat at different dilution rates. Independent of the dilution rate the stringent cells competed out the relaxed cells. But the number of generations necessary for displaying the relaxed cells by the stringent ones increased with increasing dilution rate. The results are discussed as a consequence of the regulatory role of guanosine-5'-diphosphate-3'-diphosphate (ppGpp) which is known to be present at different concentrations in stringent and relaxed cells under conditions of nutrient limitation. In addition, it is postulated that the coefficient of the maintenance metabolism according to PIRT (1965) is slower in stringent cells than in relaxed cells of E. coli.
{"title":"Mixed culture kinetics of stringent and relaxed Escherichia coli cells in glucose-limited chemostat.","authors":"D Riesenberg, F Bergter","doi":"10.1002/jobm.3630240210","DOIUrl":"https://doi.org/10.1002/jobm.3630240210","url":null,"abstract":"<p><p>The mixed culture kinetics of stringent and relaxed Escherichia coli cells were investigated in a glucose-limited chemostat at different dilution rates. Independent of the dilution rate the stringent cells competed out the relaxed cells. But the number of generations necessary for displaying the relaxed cells by the stringent ones increased with increasing dilution rate. The results are discussed as a consequence of the regulatory role of guanosine-5'-diphosphate-3'-diphosphate (ppGpp) which is known to be present at different concentrations in stringent and relaxed cells under conditions of nutrient limitation. In addition, it is postulated that the coefficient of the maintenance metabolism according to PIRT (1965) is slower in stringent cells than in relaxed cells of E. coli.</p>","PeriodicalId":23874,"journal":{"name":"Zeitschrift fur allgemeine Mikrobiologie","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1984-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"17432513","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}
Escherichia coli K12 strains containing the plasmid pBR322 often show varying contents of plasmid oligomers, in which the monomer units are arranged in tandem. When the concentration of the plasmid-selective antibiotic tetracycline in the medium becomes increased selection of cells containing largely higher oligomers occurs. The number of monomer units organized in the oligomers increases with tetracycline concentration. recA- mutants are unable to generate oligomers under the same conditions and show lower tetracycline resistance. This observations suggest a selective advantage of oligomer containing cells in the presence of tetracycline as a result of higher gene dosage. But E. coli cells transformed with monomers, dimers, trimers, as well as tetramers of pBR322 are characterized by roughly the same plasmid DNA content as well as plasmid coded beta-lactamase and resistance to tetracycline.
{"title":"[Formation of plasmid pBR322 oligomers as depending on a tetracycline concentration].","authors":"W Wiehle, M Hecker, B Reichstein, F Mach","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>Escherichia coli K12 strains containing the plasmid pBR322 often show varying contents of plasmid oligomers, in which the monomer units are arranged in tandem. When the concentration of the plasmid-selective antibiotic tetracycline in the medium becomes increased selection of cells containing largely higher oligomers occurs. The number of monomer units organized in the oligomers increases with tetracycline concentration. recA- mutants are unable to generate oligomers under the same conditions and show lower tetracycline resistance. This observations suggest a selective advantage of oligomer containing cells in the presence of tetracycline as a result of higher gene dosage. But E. coli cells transformed with monomers, dimers, trimers, as well as tetramers of pBR322 are characterized by roughly the same plasmid DNA content as well as plasmid coded beta-lactamase and resistance to tetracycline.</p>","PeriodicalId":23874,"journal":{"name":"Zeitschrift fur allgemeine Mikrobiologie","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1984-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"17432514","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}
Two series of aerial-mycelium-negative (Amy-), anthracycline-nonproducing (Ant-) mutants were obtained from ancestral Amy+Ant+ strains of S. griseus: a) derivatives represented by the met- strain 39 which could not differentiate although they were still producing both the butyrolactone-type autoregulator 1 and NADP-glycohydrolase, and b) mutants whose incapability to form spores and anthracycline pigments was apparently caused by the loss of autoregulator production. These latter mutants responded to the addition of 1 or the naturally occurring dihydro derivative 2 with complete or at least partial reconstitution of differentiation-associated functions. All of the b)-type mutant strains exhibited similar biochemical alterations in the presence of 1 or 2 regardless of the presence of additional genetic changes in the primary metabolism. Two mutants, however, displayed an altered pattern of secondary product formation. In submerged cultures the major biochemical changes observed in presence of 1 (or 2) were an increase of the lipid level in the mycelium, an alteration of the lipid composition, and a stimulation of neutral proteinase production. All of the blocked autoregulator-negative mutants were discernible from the ancestral strains and strain 39 by their lack of NADP-glycohydrolase production. This suggested the existance of a common genetic locus or a common pleiotropic regulator gene controling both gene functions. Present ideas concerning the role of butyrolactone-type autoregulator 1 as a pleiotropic effector molecule interacting with development of S. griseus are summarized in a hypothetical scheme.
{"title":"Modification by genetic changes of the pleiotropic interference of butyrolactone-type autoregulators with differentiation of Streptomyces griseus.","authors":"U Gräfe, I Eritt, G Reinhardt, D Krebs, W F Fleck","doi":"10.1002/jobm.3630240803","DOIUrl":"https://doi.org/10.1002/jobm.3630240803","url":null,"abstract":"<p><p>Two series of aerial-mycelium-negative (Amy-), anthracycline-nonproducing (Ant-) mutants were obtained from ancestral Amy+Ant+ strains of S. griseus: a) derivatives represented by the met- strain 39 which could not differentiate although they were still producing both the butyrolactone-type autoregulator 1 and NADP-glycohydrolase, and b) mutants whose incapability to form spores and anthracycline pigments was apparently caused by the loss of autoregulator production. These latter mutants responded to the addition of 1 or the naturally occurring dihydro derivative 2 with complete or at least partial reconstitution of differentiation-associated functions. All of the b)-type mutant strains exhibited similar biochemical alterations in the presence of 1 or 2 regardless of the presence of additional genetic changes in the primary metabolism. Two mutants, however, displayed an altered pattern of secondary product formation. In submerged cultures the major biochemical changes observed in presence of 1 (or 2) were an increase of the lipid level in the mycelium, an alteration of the lipid composition, and a stimulation of neutral proteinase production. All of the blocked autoregulator-negative mutants were discernible from the ancestral strains and strain 39 by their lack of NADP-glycohydrolase production. This suggested the existance of a common genetic locus or a common pleiotropic regulator gene controling both gene functions. Present ideas concerning the role of butyrolactone-type autoregulator 1 as a pleiotropic effector molecule interacting with development of S. griseus are summarized in a hypothetical scheme.</p>","PeriodicalId":23874,"journal":{"name":"Zeitschrift fur allgemeine Mikrobiologie","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1984-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"17498369","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}
A Streptomyces griseus strain deficient in the formation of aerial mycelium and arthrospore development (Amy-) was studied by electron microscopy and compared with the sporulating parental strain (Amy+). The investigations were performed with colonies grown on solid medium. The substructural characteristics of the essential events of sporogenesis could clearly been demonstrated in the aerial mycelium of the Amy+ colonies. The mycelium of the surface region of the Amy- colonies showed altered features. The most pronounced alteration was the absence of the surface sheath, normally present on the aerial hyphae of the parental strain. The cross wall type II, characteristic of sporogeneous hyphae, was not discernible in the Amy- hyphae. Some substructural features resembling the essential events of normal sporogenesis were evident in the Amy- strain, albeit diminished and interfered with by abnormalities. The resulting propagative cells were of different size and feature.
{"title":"Substructural study of sporogenesis in Streptomyces griseus.","authors":"C Strunk","doi":"10.1002/jobm.3630240813","DOIUrl":"https://doi.org/10.1002/jobm.3630240813","url":null,"abstract":"<p><p>A Streptomyces griseus strain deficient in the formation of aerial mycelium and arthrospore development (Amy-) was studied by electron microscopy and compared with the sporulating parental strain (Amy+). The investigations were performed with colonies grown on solid medium. The substructural characteristics of the essential events of sporogenesis could clearly been demonstrated in the aerial mycelium of the Amy+ colonies. The mycelium of the surface region of the Amy- colonies showed altered features. The most pronounced alteration was the absence of the surface sheath, normally present on the aerial hyphae of the parental strain. The cross wall type II, characteristic of sporogeneous hyphae, was not discernible in the Amy- hyphae. Some substructural features resembling the essential events of normal sporogenesis were evident in the Amy- strain, albeit diminished and interfered with by abnormalities. The resulting propagative cells were of different size and feature.</p>","PeriodicalId":23874,"journal":{"name":"Zeitschrift fur allgemeine Mikrobiologie","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1984-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"17498371","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}
The virulence of Pasteurella multocida strains in experimental infections of mice has been shown to depend on the iron contents of the cultivation media. Frequent passages of bacteria on iron-deficient growth media result in drastic decrease of virulence. In the case of one strain also immunogenicity was lowered. The results with nutritional media differing in their iron contents show that iron probably exhibits a regulatory effect on the production of a not yet identified virulence.
{"title":"[Modification of virulence and immunogenicity of Pasteurella multocida by iron in vitro].","authors":"K D Flossmann, H Rosner, U Grünke, N Miosga","doi":"10.1002/jobm.3630240404","DOIUrl":"https://doi.org/10.1002/jobm.3630240404","url":null,"abstract":"<p><p>The virulence of Pasteurella multocida strains in experimental infections of mice has been shown to depend on the iron contents of the cultivation media. Frequent passages of bacteria on iron-deficient growth media result in drastic decrease of virulence. In the case of one strain also immunogenicity was lowered. The results with nutritional media differing in their iron contents show that iron probably exhibits a regulatory effect on the production of a not yet identified virulence.</p>","PeriodicalId":23874,"journal":{"name":"Zeitschrift fur allgemeine Mikrobiologie","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1984-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"17794298","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}
The significance of the sequential processes of phosphate limitation and of phosphate release from medium constituents is demonstrated in technical streptomycin fermentations. The phosphate limitation initiated the streptomycin synthesis as well as the formation of phosphatases and protease. In later periods of the process the phosphate release influences especially the enzyme formation.
{"title":"Sequential processes of phosphate limitation and of phosphate release in streptomycin fermentations.","authors":"P J Müller, A Christner, J H Ozegowski","doi":"10.1002/jobm.3630230408","DOIUrl":"https://doi.org/10.1002/jobm.3630230408","url":null,"abstract":"<p><p>The significance of the sequential processes of phosphate limitation and of phosphate release from medium constituents is demonstrated in technical streptomycin fermentations. The phosphate limitation initiated the streptomycin synthesis as well as the formation of phosphatases and protease. In later periods of the process the phosphate release influences especially the enzyme formation.</p>","PeriodicalId":23874,"journal":{"name":"Zeitschrift fur allgemeine Mikrobiologie","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1983-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"17472740","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}
Results furnish evidence for a partial uncoupling of respiration at conditions of phosphate limitation in turimycin fermentations. The uncoupling was primarily caused by the high intracellular ATP hydrolase activity and probably also by the CN-resistant respiration. The results support the idea that high dephoshorylating enzyme activities may have a regulatory effect on the secondary product biosynthesis.
{"title":"Uncoupling of respiration in turimycin fermentations.","authors":"W Effenberger, P J Müller, H Bocker","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>Results furnish evidence for a partial uncoupling of respiration at conditions of phosphate limitation in turimycin fermentations. The uncoupling was primarily caused by the high intracellular ATP hydrolase activity and probably also by the CN-resistant respiration. The results support the idea that high dephoshorylating enzyme activities may have a regulatory effect on the secondary product biosynthesis.</p>","PeriodicalId":23874,"journal":{"name":"Zeitschrift fur allgemeine Mikrobiologie","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1983-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"17725471","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}