Pub Date : 2006-09-19DOI: 10.1002/qsar.19900090309
F. Darvas, Z. Darvas
s of publications related to QSAR Editor: Ferenc Darvas, Budapest Technical Editor: Zsuzsanna Darvas, Budapest
编辑:Ferenc Darvas，布达佩斯技术编辑:Zsuzsanna Darvas，布达佩斯
{"title":"Abstracts of publications related to QASR","authors":"F. Darvas, Z. Darvas","doi":"10.1002/qsar.19900090309","DOIUrl":"https://doi.org/10.1002/qsar.19900090309","url":null,"abstract":"s of publications related to QSAR Editor: Ferenc Darvas, Budapest Technical Editor: Zsuzsanna Darvas, Budapest","PeriodicalId":20818,"journal":{"name":"Quantitative Structure-activity Relationships","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2006-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83036809","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 mechanism of N-demethylation by P-450 was investigated using MO calculation of 4-substituted N,N-dimethylaniline. The reactivities of the compounds and their intermediates were examined using the energies of HOMO and SOMO, and frontier electron densities. QSAR analysis using these electronic parameters indicated that one-electron first transfers from nitrogen to P-450 and the resultant cation radical forms α-amino radical, followed by hydroxylation and N-demethylation.
{"title":"Mechanistic Study on N‐Demethylation Catalyzed with P450 by Quantitative Structure Activity Relationship using Electronic Properties of 4‐Substituted N,N‐Dimethylaniline","authors":"A. Nanbo, T. Nanbo","doi":"10.1002/QSAR.200290004","DOIUrl":"https://doi.org/10.1002/QSAR.200290004","url":null,"abstract":"The mechanism of N-demethylation by P-450 was investigated using MO calculation of 4-substituted N,N-dimethylaniline. The reactivities of the compounds and their intermediates were examined using the energies of HOMO and SOMO, and frontier electron densities. QSAR analysis using these electronic parameters indicated that one-electron first transfers from nitrogen to P-450 and the resultant cation radical forms α-amino radical, followed by hydroxylation and N-demethylation.","PeriodicalId":20818,"journal":{"name":"Quantitative Structure-activity Relationships","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75511369","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 main purpose of this study was the investigation of quantitative structure-activity relationships of serotonin transporter ligands with regard to the future development of potential new and selective PET radiotracers for the serotonin transporter. A heterogeneous data set of 19 selective and non-selective serotonin reuptake inhibitors was used. Affinity data for both the serotonin transporter and the norepinephrine transporter was available. As a necessary prerequisite for our 3D QSAR studies a reasonable alignment of the compounds was developed using GASP. It was based on an existing pharmacophore model. In addition to the widely used CoMFA method, the somewhat newer CoMSIA method was applied. Statistically reliable CoMFA models for both the serotonin transporter (q 2 =0.538) and the norepinephrine transporter (q 2 =0.445) were developed, further improving the internal predictability by applying region focusing for the serotonin transporter (q 2 =0.674). These models were compared with the CoMSIA models for the serotonin and the norepinephrine transporter that yielded comparable cross-validated correlation coefficients (q 2 =0.531 and q 2 =0.502, respectively). Certain structural features that are distinctive of each transporter and important for high binding affinity were identified. Highly comparable results were obtained for CoMFA and CoMSIA. Both methods were applied to elucidate structural requirements for serotonin transporter selectivity. The resulting CoMSIA map provides important information for lead optimization with respect to selectivity enhancement.
{"title":"3D QSAR of Serotonin Transporter Ligands: CoMFA and CoMSIA Studies","authors":"Julia Wellsow, H. Machulla, K. Kovar","doi":"10.1002/QSAR.200290000","DOIUrl":"https://doi.org/10.1002/QSAR.200290000","url":null,"abstract":"The main purpose of this study was the investigation of quantitative structure-activity relationships of serotonin transporter ligands with regard to the future development of potential new and selective PET radiotracers for the serotonin transporter. A heterogeneous data set of 19 selective and non-selective serotonin reuptake inhibitors was used. Affinity data for both the serotonin transporter and the norepinephrine transporter was available. As a necessary prerequisite for our 3D QSAR studies a reasonable alignment of the compounds was developed using GASP. It was based on an existing pharmacophore model. In addition to the widely used CoMFA method, the somewhat newer CoMSIA method was applied. Statistically reliable CoMFA models for both the serotonin transporter (q 2 =0.538) and the norepinephrine transporter (q 2 =0.445) were developed, further improving the internal predictability by applying region focusing for the serotonin transporter (q 2 =0.674). These models were compared with the CoMSIA models for the serotonin and the norepinephrine transporter that yielded comparable cross-validated correlation coefficients (q 2 =0.531 and q 2 =0.502, respectively). Certain structural features that are distinctive of each transporter and important for high binding affinity were identified. Highly comparable results were obtained for CoMFA and CoMSIA. Both methods were applied to elucidate structural requirements for serotonin transporter selectivity. The resulting CoMSIA map provides important information for lead optimization with respect to selectivity enhancement.","PeriodicalId":20818,"journal":{"name":"Quantitative Structure-activity Relationships","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75521210","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}
Due to the importance of the O-H bond dissociation in the antioxidant mechanism of anti-inflammatory phenols, we studied the biradical process Ph-OH → PhO . +H . for 25 phenolic compounds using ah initio calculations. Enthalpies of reaction (ΔH r ), changes in the electron density at the O-H bond critical point (ρ O H ) and total atomic charges of ortho and para carbon atoms strongly correlate with the in vitro inhibition of cyclooxygenase activity by phenols. The most active compounds have large values of the electron density at the O-H bond (ρ O H ), thus favouring the O-H bond dissociation. In contrast, inactive compounds have small values of the electron density at the O-H bond (ρ O H ), thus reducing the hydrogen donation ability. These results are also supported by the representation of the molecular electrostatic potentials maps. The prediction of the cyclooxygenase inhibitory activity of the proposed QSAR equations is analysed using the multilineal (MLR) method. Finally, the differences in biological activity are examined by analysing the binding interactions of active compounds in the pocket site of human COX-2 enzyme structure derived from crystallographic X -ray data.
鉴于O-H键解离在抗炎酚类化合物抗氧化机制中的重要作用，我们研究了Ph-OH→PhO的双自由基过程。+ H。25种酚类化合物使用从头计算。反应焓(ΔH r)、O-H键临界点的电子密度变化(ρ O H)和邻位碳原子和对位碳原子的总电荷与酚类物质对环加氧酶活性的体外抑制密切相关。最活跃的化合物在O-H键处具有较大的电子密度(ρ O H)，因此有利于O-H键的解离。相反，非活性化合物在O-H键上的电子密度(ρ O H)值较小，从而降低了给氢能力。这些结果也得到了分子静电势图的支持。利用多线性(MLR)方法对所建立的QSAR方程的环加氧酶抑制活性进行了预测。最后，通过晶体X射线数据分析人类COX-2酶结构口袋部位活性化合物的结合相互作用，研究了生物活性的差异。
{"title":"Theoretical Prediction of the Phenoxyl Radical Formation Capacity and Cyclooxygenase Inhibition Relationships by Phenolic Compounds","authors":"J. Ruiz, R. Pouplana","doi":"10.1002/QSAR.200290003","DOIUrl":"https://doi.org/10.1002/QSAR.200290003","url":null,"abstract":"Due to the importance of the O-H bond dissociation in the antioxidant mechanism of anti-inflammatory phenols, we studied the biradical process Ph-OH → PhO . +H . for 25 phenolic compounds using ah initio calculations. Enthalpies of reaction (ΔH r ), changes in the electron density at the O-H bond critical point (ρ O H ) and total atomic charges of ortho and para carbon atoms strongly correlate with the in vitro inhibition of cyclooxygenase activity by phenols. The most active compounds have large values of the electron density at the O-H bond (ρ O H ), thus favouring the O-H bond dissociation. In contrast, inactive compounds have small values of the electron density at the O-H bond (ρ O H ), thus reducing the hydrogen donation ability. These results are also supported by the representation of the molecular electrostatic potentials maps. The prediction of the cyclooxygenase inhibitory activity of the proposed QSAR equations is analysed using the multilineal (MLR) method. Finally, the differences in biological activity are examined by analysing the binding interactions of active compounds in the pocket site of human COX-2 enzyme structure derived from crystallographic X -ray data.","PeriodicalId":20818,"journal":{"name":"Quantitative Structure-activity Relationships","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84926385","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}
M. Bohl, J. Dunbar, E. Gifford, D. Wild, P. Willett, D. Wilton
Rigid ring systems can be used to position receptor-binding functional groups in 3D space and they thus play an increasingly important role in the design of combinatorial libraries. This paper discusses the use of shape-similarity methods to identify ring systems that are structurally similar to, and aligned with, a user-defined target ring system. These systems can be used as alternative scaffolds for the construction of a combinatorial library.
{"title":"Scaffold Searching: Automated Identification of Similar Ring Systems for the Design of Combinatorial Libraries","authors":"M. Bohl, J. Dunbar, E. Gifford, D. Wild, P. Willett, D. Wilton","doi":"10.1002/QSAR.200290001","DOIUrl":"https://doi.org/10.1002/QSAR.200290001","url":null,"abstract":"Rigid ring systems can be used to position receptor-binding functional groups in 3D space and they thus play an increasingly important role in the design of combinatorial libraries. This paper discusses the use of shape-similarity methods to identify ring systems that are structurally similar to, and aligned with, a user-defined target ring system. These systems can be used as alternative scaffolds for the construction of a combinatorial library.","PeriodicalId":20818,"journal":{"name":"Quantitative Structure-activity Relationships","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77368297","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}
Mark Ashton, J. Barnard, F. Casset, M. Charlton, G. Downs, D. Gorse, J. Holliday, R. Lahana, P. Willett
This paper reports a comparison of calculated molecular properties and of 2D fragment bit-strings when used for the selection of structurally diverse subsets of a file of 44295 compounds. MaxMin dissimilarity-based selection and k-means cluster-based selection are used to select subsets containing between 1% and 20% of the file. Investigation of the numbers of bioactive molecules in the selected subsets suggest: that the MaxMin subsets are noticeably superior to the k-means subsets; that the property-based descriptors are marginally superior to the fragment-based descriptors; and that both approaches are noticeably superior to random selection.
{"title":"Identification of diverse database subsets using property-based and fragment-based molecular descriptions","authors":"Mark Ashton, J. Barnard, F. Casset, M. Charlton, G. Downs, D. Gorse, J. Holliday, R. Lahana, P. Willett","doi":"10.1002/QSAR.200290002","DOIUrl":"https://doi.org/10.1002/QSAR.200290002","url":null,"abstract":"This paper reports a comparison of calculated molecular properties and of 2D fragment bit-strings when used for the selection of structurally diverse subsets of a file of 44295 compounds. MaxMin dissimilarity-based selection and k-means cluster-based selection are used to select subsets containing between 1% and 20% of the file. Investigation of the numbers of bioactive molecules in the selected subsets suggest: that the MaxMin subsets are noticeably superior to the k-means subsets; that the property-based descriptors are marginally superior to the fragment-based descriptors; and that both approaches are noticeably superior to random selection.","PeriodicalId":20818,"journal":{"name":"Quantitative Structure-activity Relationships","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85064527","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}
Pub Date : 2002-11-01DOI: 10.1002/1521-3838(200211)21:5<507::AID-QSAR507>3.0.CO;2-L
K. Baumann
A novel translationally and rotationally invariant structure descriptor based on the distribution of 3D-atom pairs is described. The new Distance Profiles (DiP) descriptor was applied to two data sets which were previously studied with various 3D-QSAR techniques. DiP compares favorably to the other descriptors for these two data sets and obtains better models in both cases. Since DiP is used in combination with variable selection to achieve interpretability, special emphasize was put on validating the derived models. Avoiding overfitted models was accomplished by constraining the maximum number of variables allowed to select, and by using leave-50%-out cross-validation instead of leave-one-out cross-validation as objective function in variable selection. Furthermore, the derived models were validated with a permutation test where the entire variable selection procedure is repeated each time the response data are scrambled.
{"title":"Distance Profiles (DiP): A translationally and rotationally invariant 3D structure descriptor capturing steric properties of molecules","authors":"K. Baumann","doi":"10.1002/1521-3838(200211)21:5<507::AID-QSAR507>3.0.CO;2-L","DOIUrl":"https://doi.org/10.1002/1521-3838(200211)21:5<507::AID-QSAR507>3.0.CO;2-L","url":null,"abstract":"A novel translationally and rotationally invariant structure descriptor based on the distribution of 3D-atom pairs is described. The new Distance Profiles (DiP) descriptor was applied to two data sets which were previously studied with various 3D-QSAR techniques. DiP compares favorably to the other descriptors for these two data sets and obtains better models in both cases. Since DiP is used in combination with variable selection to achieve interpretability, special emphasize was put on validating the derived models. Avoiding overfitted models was accomplished by constraining the maximum number of variables allowed to select, and by using leave-50%-out cross-validation instead of leave-one-out cross-validation as objective function in variable selection. Furthermore, the derived models were validated with a permutation test where the entire variable selection procedure is repeated each time the response data are scrambled.","PeriodicalId":20818,"journal":{"name":"Quantitative Structure-activity Relationships","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90858340","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}
Pub Date : 2002-11-01DOI: 10.1002/1521-3838(200211)21:5<493::AID-QSAR493>3.0.CO;2-5
E. Deretey, M. Feher, Jonathan M. Schmidt
This work describes the modeling of human intestinal absorption using one- and two-descriptor nonlinear models. Molecules with known transport mechanisms other than passive transport were removed from the dataset. The human intestinal absorption data were fitted to symmetric and asymmetric sigmoidal curves and surfaces that were based on the arctangent function. The descriptors employed in the models are the sum of hydrogen bond donors and acceptors and the calculated SlogP octanol-water partition coefficient. Despite the simplicity of the model, the quality of fits and predictions is comparable to more complex approaches. As descriptors and predicted values can be calculated rapidly, the method is ideally suited for qualitative predictions for large virtual libraries and the results from de novo design.
{"title":"Rapid Prediction of Human Intestinal Absorption","authors":"E. Deretey, M. Feher, Jonathan M. Schmidt","doi":"10.1002/1521-3838(200211)21:5<493::AID-QSAR493>3.0.CO;2-5","DOIUrl":"https://doi.org/10.1002/1521-3838(200211)21:5<493::AID-QSAR493>3.0.CO;2-5","url":null,"abstract":"This work describes the modeling of human intestinal absorption using one- and two-descriptor nonlinear models. Molecules with known transport mechanisms other than passive transport were removed from the dataset. The human intestinal absorption data were fitted to symmetric and asymmetric sigmoidal curves and surfaces that were based on the arctangent function. The descriptors employed in the models are the sum of hydrogen bond donors and acceptors and the calculated SlogP octanol-water partition coefficient. Despite the simplicity of the model, the quality of fits and predictions is comparable to more complex approaches. As descriptors and predicted values can be calculated rapidly, the method is ideally suited for qualitative predictions for large virtual libraries and the results from de novo design.","PeriodicalId":20818,"journal":{"name":"Quantitative Structure-activity Relationships","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74549197","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}
Pub Date : 2002-11-01DOI: 10.1002/1521-3838(200211)21:5<457::AID-QSAR457>3.0.CO;2-5
B. Tehan, E. J. Lloyd, M. Wong, W. Pitt, J. Montana, D. Manallack, E. Gancia
The electronic properties of small molecules can be calculated quickly and with a reasonable degree of accuracy using semiempirical QM methods. In this study a set of QM properties derived from frontier electron theory have been used to produce a predictive model of the dissociation constants of phenols, benzoic acids and aliphatic carboxylic acids. The pK a values and structures of nearly 500 compounds were extracted from the Physprop database for this purpose. Multiple linear regression was used to search for relationships between pK a and the calculated QM properties. In most cases only a single independent variable, electrophilic superdelocalisability, was needed to produce a good model of pK a . The advantages of our approach are in the speed of calculation and the simplicity of the resultant models. The merits of using semiempirical methods to predict pK a are discussed in relation to previous studies.
{"title":"Estimation of pKa Using Semiempirical Molecular Orbital Methods. Part 1: Application to Phenols and Carboxylic Acids.","authors":"B. Tehan, E. J. Lloyd, M. Wong, W. Pitt, J. Montana, D. Manallack, E. Gancia","doi":"10.1002/1521-3838(200211)21:5<457::AID-QSAR457>3.0.CO;2-5","DOIUrl":"https://doi.org/10.1002/1521-3838(200211)21:5<457::AID-QSAR457>3.0.CO;2-5","url":null,"abstract":"The electronic properties of small molecules can be calculated quickly and with a reasonable degree of accuracy using semiempirical QM methods. In this study a set of QM properties derived from frontier electron theory have been used to produce a predictive model of the dissociation constants of phenols, benzoic acids and aliphatic carboxylic acids. The pK a values and structures of nearly 500 compounds were extracted from the Physprop database for this purpose. Multiple linear regression was used to search for relationships between pK a and the calculated QM properties. In most cases only a single independent variable, electrophilic superdelocalisability, was needed to produce a good model of pK a . The advantages of our approach are in the speed of calculation and the simplicity of the resultant models. The merits of using semiempirical methods to predict pK a are discussed in relation to previous studies.","PeriodicalId":20818,"journal":{"name":"Quantitative Structure-activity Relationships","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88567467","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}
Pub Date : 2002-11-01DOI: 10.1002/1521-3838(200211)21:5<473::AID-QSAR473>3.0.CO;2-D
B. Tehan, E. J. Lloyd, M. Wong, W. Pitt, E. Gancia, D. Manallack
The pK a of a compound directly influences its biopharmaceutical profile. This article describes the development of a method for estimating pK a values for a number of nitrogen containing chemical structures using semiempirical QM properties derived from frontier electron theory. Typically, the property giving the best correlation with pK d was the electrophilic superdelocalisability of the nitrogen atom resulting in regression equations with r 2 values up to 0.94. The advantages of this technique are in the simplicity of the models and the speed of calculation, suggesting that this method could be widely applied to the estimation of pK a values. The success of this approach is discussed in relation to other methods.
{"title":"Estimation of pKa Using Semiempirical Molecular Orbital Methods. Part 2: Application to Amines, Anilines and Various Nitrogen Containing Heterocyclic Compounds.","authors":"B. Tehan, E. J. Lloyd, M. Wong, W. Pitt, E. Gancia, D. Manallack","doi":"10.1002/1521-3838(200211)21:5<473::AID-QSAR473>3.0.CO;2-D","DOIUrl":"https://doi.org/10.1002/1521-3838(200211)21:5<473::AID-QSAR473>3.0.CO;2-D","url":null,"abstract":"The pK a of a compound directly influences its biopharmaceutical profile. This article describes the development of a method for estimating pK a values for a number of nitrogen containing chemical structures using semiempirical QM properties derived from frontier electron theory. Typically, the property giving the best correlation with pK d was the electrophilic superdelocalisability of the nitrogen atom resulting in regression equations with r 2 values up to 0.94. The advantages of this technique are in the simplicity of the models and the speed of calculation, suggesting that this method could be widely applied to the estimation of pK a values. The success of this approach is discussed in relation to other methods.","PeriodicalId":20818,"journal":{"name":"Quantitative Structure-activity Relationships","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75499482","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}
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