The dynamic scattering of laser light by dissolved charged macromolecules or suspended colloid particles in the surface potential well near the solid/liquid boundary is examined theoretically. This surface potential well is a combination of the long-range attraction potential of the electric double layer (EDL) and the short-range repulsion van der Waals potential. The frequency spectrum of the scattered light recorded in the heterodyne regime should contain peaks with the Doppler frequency shifts corresponding to the velocities of particle electrophoresis in the EDL. The wave reflected from the boundary surface may be used as the reference wave necessary in the heterodyne regime, and the intensity of the scattered wave collinear with the reflected wave should be recorded. Since field strengths in the EDL are about 105 V cm–1 such a method should have extremely high resolution. The case of the equilibrium reversible ‘partition’ of particles between the liquid film, where no force is present, and the surface layer is examined. In this case, the ‘partition coefficient’ defining the ratio of the bulk and surface fractions of particles may be about one, if the liquid film is thin enough (≈10–3 cm). Also, in this case, the integral frequency spectrum should contain the bulk part corresponding to the particle diffusion and the surface part with the Doppler peaks, where electrophoresis of particles should be seen.
从理论上研究了固体/液体边界附近表面势阱中溶解的带电大分子或悬浮胶体粒子对激光的动态散射。该表面电势井是双电层(EDL)的远程吸引电势和短程排斥范德华电势的结合。在外差状态下记录的散射光的频谱应该包含与EDL中颗粒电泳速度相对应的多普勒频移的峰。从边界面反射的波可以作为外差区所需的参考波，并记录与反射波共线的散射波强度。由于EDL中的场强约为105 V cm-1，因此这种方法应该具有极高的分辨率。在不存在力的情况下，粒子在液体膜和表层之间的平衡可逆“分配”的情况被检查。在这种情况下，如果液膜足够薄(≈10-3 cm)，则定义颗粒体积分数和表面分数之比的“分配系数”可能约为1。同时，在这种情况下，积分频谱应该包含与颗粒扩散相对应的本体部分和具有多普勒峰的表面部分，其中应该可以看到颗粒的电泳。
{"title":"Laser electrophoresis in surface electric double layer","authors":"S. Semenov","doi":"10.1039/A807555G","DOIUrl":"https://doi.org/10.1039/A807555G","url":null,"abstract":"The dynamic scattering of laser light by dissolved charged macromolecules or suspended colloid particles in the surface potential well near the solid/liquid boundary is examined theoretically. This surface potential well is a combination of the long-range attraction potential of the electric double layer (EDL) and the short-range repulsion van der Waals potential. The frequency spectrum of the scattered light recorded in the heterodyne regime should contain peaks with the Doppler frequency shifts corresponding to the velocities of particle electrophoresis in the EDL. The wave reflected from the boundary surface may be used as the reference wave necessary in the heterodyne regime, and the intensity of the scattered wave collinear with the reflected wave should be recorded. Since field strengths in the EDL are about 105 V cm–1 such a method should have extremely high resolution. The case of the equilibrium reversible ‘partition’ of particles between the liquid film, where no force is present, and the surface layer is examined. In this case, the ‘partition coefficient’ defining the ratio of the bulk and surface fractions of particles may be about one, if the liquid film is thin enough (≈10–3 cm). Also, in this case, the integral frequency spectrum should contain the bulk part corresponding to the particle diffusion and the surface part with the Doppler peaks, where electrophoresis of particles should be seen.","PeriodicalId":7814,"journal":{"name":"Analytical Communications","volume":"55 1","pages":"369-372"},"PeriodicalIF":0.0,"publicationDate":"1998-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86933478","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}
An integrated on-capillary electrochemical detector for capillary electrophoresis is described. It consists of a gold tube permanently fixed onto the end of a capillary. This detector configuration eliminates the need for micromanipulators for electrode alignment. The large surface area of the gold tubular electrode results in better sensitivity for PAD detection than is attainable with a gold wire electrode. Application of this detector to the determination of glucose in serum by CE–PAD is described.
{"title":"Development and characterization of an integrated on-capillary tubular electrode for capillary electrophoresis/electrochemistry","authors":"S. Lunte, M. Zhong","doi":"10.1039/A803356K","DOIUrl":"https://doi.org/10.1039/A803356K","url":null,"abstract":"An integrated on-capillary electrochemical detector for capillary electrophoresis is described. It consists of a gold tube permanently fixed onto the end of a capillary. This detector configuration eliminates the need for micromanipulators for electrode alignment. The large surface area of the gold tubular electrode results in better sensitivity for PAD detection than is attainable with a gold wire electrode. Application of this detector to the determination of glucose in serum by CE–PAD is described.","PeriodicalId":7814,"journal":{"name":"Analytical Communications","volume":"15 1","pages":"209-212"},"PeriodicalIF":0.0,"publicationDate":"1998-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87583314","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 molecularly imprinted polymer capable of spectroscopic change based upon molecular recognition was prepared using a metalloporphyrin-based functional monomer. The effectiveness of the metalloporphyrin functional monomer was demonstrated on molecular imprinting of a nucleobase derivative, 9-ethyladenine (9-EA). When the concentration of 9-EA was increased, the visible absorbance spectra of the polymer dispersed in chloroform showed a red shift and the degree of the shift was dependent upon the concentration change. This readable molecular recognition phenomenon suggests a potential application of the molecularly imprinted polymer as optical sensor materials.
{"title":"Molecularly imprinted receptor having metalloporphyrin-based signaling binding site","authors":"J. Matsui","doi":"10.1039/A803404D","DOIUrl":"https://doi.org/10.1039/A803404D","url":null,"abstract":"A molecularly imprinted polymer capable of spectroscopic change based upon molecular recognition was prepared using a metalloporphyrin-based functional monomer. The effectiveness of the metalloporphyrin functional monomer was demonstrated on molecular imprinting of a nucleobase derivative, 9-ethyladenine (9-EA). When the concentration of 9-EA was increased, the visible absorbance spectra of the polymer dispersed in chloroform showed a red shift and the degree of the shift was dependent upon the concentration change. This readable molecular recognition phenomenon suggests a potential application of the molecularly imprinted polymer as optical sensor materials.","PeriodicalId":7814,"journal":{"name":"Analytical Communications","volume":"32 1","pages":"225-227"},"PeriodicalIF":0.0,"publicationDate":"1998-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91286876","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}
We demonstrate that the ligand cross-reactivities of molecularly imprinted polymers can be beneficially employed for the simultaneous separation of different stereoisomeric structures. In this study, a limited molecularly imprinted polymer combinatorial library has been prepared and used for the simultaneous separation of a mixture of N-tert-butyloxycarbonyl-L-phenylalanine, N-tert-butyloxycarbonyl-D-phenylalanine, N-acetyl-L-phenylalaninyl-L-tryptophanyl methyl ester, N-acetyl-D-phenylalaninyl-D- tryptophanyl methyl ester, yohimbine and corynanthine.
我们证明了分子印迹聚合物的配体交叉反应性可以很好地用于不同立体异构体结构的同时分离。本研究制备了一个有限分子印迹聚合物组合文库，用于同时分离n -叔丁基氧羰基- l-苯丙氨酸、n -叔丁基氧羰基- d -苯丙氨酸、n -乙酰基- l-苯丙氨酸- l-色氨酸甲酯、n -乙酰基- d -苯丙氨酸- d -色氨酸甲酯、育亨宾和鸟角氨酸的混合物。
{"title":"Molecularly imprinted polymer combinatorial libraries for multiple simultaneous chiral separations","authors":"L. Sabourin, R. Ansell, K. Mosbach, I. Nicholls","doi":"10.1039/A806195E","DOIUrl":"https://doi.org/10.1039/A806195E","url":null,"abstract":"We demonstrate that the ligand cross-reactivities of molecularly imprinted polymers can be beneficially employed for the simultaneous separation of different stereoisomeric structures. In this study, a limited molecularly imprinted polymer combinatorial library has been prepared and used for the simultaneous separation of a mixture of N-tert-butyloxycarbonyl-L-phenylalanine, N-tert-butyloxycarbonyl-D-phenylalanine, N-acetyl-L-phenylalaninyl-L-tryptophanyl methyl ester, N-acetyl-D-phenylalaninyl-D- tryptophanyl methyl ester, yohimbine and corynanthine.","PeriodicalId":7814,"journal":{"name":"Analytical Communications","volume":"1 1","pages":"285-287"},"PeriodicalIF":0.0,"publicationDate":"1998-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78506005","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 procedure for the determination of zirconium using Xylenol Orange has been developed from a conventional spectrophotometric one. An acidic medium of sulfuric rather than perchloric acid has been adopted, to achieve a fast reaction rate and greater sensitivity. Under optimised conditions, calibrations were found to be linear over a range of at least up to 10 ppm of zirconium. The detection limit was found to be 0.08 ppm and precisions (RSDs) at the 1, 3 and 5 ppm levels were 2.3, 1.9 and 0.2%, respectively. The procedure has been shown to be free of interferences from species which are present in the eluate from a technetium-99m generator, and has been applied to the determination of zirconium in such an eluate.
{"title":"Determination of zirconium with Xylenol Orange by flow injection spectrophotometry: application to eluates from technetium-99m generators","authors":"K. Grudpan, Mayuree Utamong, C. Taylor","doi":"10.1039/A708836A","DOIUrl":"https://doi.org/10.1039/A708836A","url":null,"abstract":"A procedure for the determination of zirconium using Xylenol Orange has been developed from a conventional spectrophotometric one. An acidic medium of sulfuric rather than perchloric acid has been adopted, to achieve a fast reaction rate and greater sensitivity. Under optimised conditions, calibrations were found to be linear over a range of at least up to 10 ppm of zirconium. The detection limit was found to be 0.08 ppm and precisions (RSDs) at the 1, 3 and 5 ppm levels were 2.3, 1.9 and 0.2%, respectively. The procedure has been shown to be free of interferences from species which are present in the eluate from a technetium-99m generator, and has been applied to the determination of zirconium in such an eluate.","PeriodicalId":7814,"journal":{"name":"Analytical Communications","volume":"40 1","pages":"107-108"},"PeriodicalIF":0.0,"publicationDate":"1998-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74816044","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 method for the determination of phosphine using packed column isothermal gas chromatography has been developed and validated. The limit of detection is 0.01 ng ml–1 and response is linear over the ranges 0.1–1.0 and 2.5–25 ng ml–1. Reproducibility at 0.1 ng ml–1 was found to be 12.1% RSD. The method has been used to establish that phosphine is outgassed by newly fabricated semi-conductor devices containing phosphide compounds as dopants and is present in flatus of human origin.
建立了用填充柱等温气相色谱法测定磷化氢的方法并进行了验证。检测限为0.01 ng ml-1，在0.1 ~ 1.0和2.5 ~ 25 ng ml-1范围内呈线性关系。0.1 ng ml-1的重现性RSD为12.1%。该方法已被用来确定磷化氢是由含有磷化化合物作为掺杂剂的新制造的半导体器件排出的，并且存在于人类来源的排气中。
{"title":"Determination of phosphine by packed column gas chromatography with alkali flame ionisation detection","authors":"M. Chughtai, J. Pridham","doi":"10.1039/A801070F","DOIUrl":"https://doi.org/10.1039/A801070F","url":null,"abstract":"A method for the determination of phosphine using packed column isothermal gas chromatography has been developed and validated. The limit of detection is 0.01 ng ml–1 and response is linear over the ranges 0.1–1.0 and 2.5–25 ng ml–1. Reproducibility at 0.1 ng ml–1 was found to be 12.1% RSD. The method has been used to establish that phosphine is outgassed by newly fabricated semi-conductor devices containing phosphide compounds as dopants and is present in flatus of human origin.","PeriodicalId":7814,"journal":{"name":"Analytical Communications","volume":"85 1","pages":"109-111"},"PeriodicalIF":0.0,"publicationDate":"1998-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79282075","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}
R. Neubert, K. Raith, Steve Raudenkolb, S. Wartewig
The degradation of ceramides type IV induced by thermal treatment up to 140 °C was studied by using electrospray mass spectrometry, Fourier transform infrared photoacoustic spectroscopy and Fourier transform Raman spectrocopy. At temperatures above 125 °C structural changes such as cleavage of the CC bond, destruction of the amide structure and variations of the hydrogen bonds were observed in the head group of ceramides type IV. The mass spectrometry studies revealed the formation of free α-hydroxy fatty acids due to heat treatment. Degradation of ceramide III was not evident in the temperature range studied.
{"title":"Thermal degradation of ceramides as studied by mass spectrometry and vibrational spectroscopy","authors":"R. Neubert, K. Raith, Steve Raudenkolb, S. Wartewig","doi":"10.1039/A801326H","DOIUrl":"https://doi.org/10.1039/A801326H","url":null,"abstract":"The degradation of ceramides type IV induced by thermal treatment up to 140 °C was studied by using electrospray mass spectrometry, Fourier transform infrared photoacoustic spectroscopy and Fourier transform Raman spectrocopy. At temperatures above 125 °C structural changes such as cleavage of the CC bond, destruction of the amide structure and variations of the hydrogen bonds were observed in the head group of ceramides type IV. The mass spectrometry studies revealed the formation of free α-hydroxy fatty acids due to heat treatment. Degradation of ceramide III was not evident in the temperature range studied.","PeriodicalId":7814,"journal":{"name":"Analytical Communications","volume":"42 1","pages":"161-164"},"PeriodicalIF":0.0,"publicationDate":"1998-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85402094","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}
An electrochemically-based submersible probe for in-situ monitoring of the total content of dissolved metal species is described. The flow-through sensor relies on the coupling of an internal on-line acidification of the collected samples with potentiometric stripping detection of the metals released from their complexes. The optimisation and characterisation of the new remote sensor have been carried out with trace measurements of cadmium and lead in the presence of EDTA and NTA. Elevated levels of these ligands (e.g. 0.05 and 1.0 mM EDTA and NTA, respectively) had no effect upon the cadmium and lead peaks, as compared to the complete disappearance of the response without the internal acid delivery. Such real-time measurements of the total form of dissolved heavy metals hold great promise for environmental and industrial monitoring. Other in-situ speciation sensing schemes are anticipated based on the versatility of the renewable-reagent flow probe.
{"title":"Electrochemical flow sensor for in-situ monitoring of total metal concentrations","authors":"Joseph Wang, B. Tian, Jianyang Wang","doi":"10.1039/A803525C","DOIUrl":"https://doi.org/10.1039/A803525C","url":null,"abstract":"An electrochemically-based submersible probe for in-situ monitoring of the total content of dissolved metal species is described. The flow-through sensor relies on the coupling of an internal on-line acidification of the collected samples with potentiometric stripping detection of the metals released from their complexes. The optimisation and characterisation of the new remote sensor have been carried out with trace measurements of cadmium and lead in the presence of EDTA and NTA. Elevated levels of these ligands (e.g. 0.05 and 1.0 mM EDTA and NTA, respectively) had no effect upon the cadmium and lead peaks, as compared to the complete disappearance of the response without the internal acid delivery. Such real-time measurements of the total form of dissolved heavy metals hold great promise for environmental and industrial monitoring. Other in-situ speciation sensing schemes are anticipated based on the versatility of the renewable-reagent flow probe.","PeriodicalId":7814,"journal":{"name":"Analytical Communications","volume":"102 1","pages":"241-243"},"PeriodicalIF":0.0,"publicationDate":"1998-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80630621","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 amount of sodium dodecyl sulfate (SDS) adsorbed on a reversed-phase octadecylsilica (ODS) stationary phase in micellar liquid chromatographic (MLC) separation has been measured. It was found that the weight percentage of SDS on the stationary phase (16.5%) was similar to the percentage ratio of C/Si (C/Si = 17.1%) of the original ODS stationary phase. This indicated that the octadecyl groups of the ODS packing were largely covered by adsorbed surfactants and the stationary phase in the MLC system could be considered to be the adsorbed surfactant. Accordingly, a new three-phase equilibrium model in which the adsorbed surfactant was assumed to be the stationary phase was proposed to illustrate the behaviour of analyte partitioning in MLC. The negative impact of the adsorbed surfactant on the efficiency of MLC was discussed in terms of this new model. With the three-phase model, the equilibrium constant (K3) for direct transfer of the analyte from the surfactant in the mobile phase to the surfactant on the stationary phase could be calculated. The results obtained for K3 using two model analytes showed that the mobile phase and stationary phase portions of the surfactant in MLC had similar but not identical abilities for binding the analyte. The effects and limitations of the use of organic modifiers in MLC are also discussed.
{"title":"New three-phase model for micellar liquid chromatography","authors":"Wenzhi Hu, P. Haddad","doi":"10.1039/A802244E","DOIUrl":"https://doi.org/10.1039/A802244E","url":null,"abstract":"The amount of sodium dodecyl sulfate (SDS) adsorbed on a reversed-phase octadecylsilica (ODS) stationary phase in micellar liquid chromatographic (MLC) separation has been measured. It was found that the weight percentage of SDS on the stationary phase (16.5%) was similar to the percentage ratio of C/Si (C/Si = 17.1%) of the original ODS stationary phase. This indicated that the octadecyl groups of the ODS packing were largely covered by adsorbed surfactants and the stationary phase in the MLC system could be considered to be the adsorbed surfactant. Accordingly, a new three-phase equilibrium model in which the adsorbed surfactant was assumed to be the stationary phase was proposed to illustrate the behaviour of analyte partitioning in MLC. The negative impact of the adsorbed surfactant on the efficiency of MLC was discussed in terms of this new model. With the three-phase model, the equilibrium constant (K3) for direct transfer of the analyte from the surfactant in the mobile phase to the surfactant on the stationary phase could be calculated. The results obtained for K3 using two model analytes showed that the mobile phase and stationary phase portions of the surfactant in MLC had similar but not identical abilities for binding the analyte. The effects and limitations of the use of organic modifiers in MLC are also discussed.","PeriodicalId":7814,"journal":{"name":"Analytical Communications","volume":"83 1","pages":"191-194"},"PeriodicalIF":0.0,"publicationDate":"1998-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80383591","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}
X. D. Wang, T. Cardwell, R. Cattrall, G. E. Jenkins
Pulsed flow chemistry (PFC) is described as a new approach to automated on-line analytical chemistry. In contrast to existing flow-based analytical chemistry methods, PFC is characterized by pulsed flow, turbulent mixing and low axial dispersion. The PFC system is fully computerized and all operations are under software control. Consequently, most flow analysis methods (e.g., flow injection, continuous flow, flow titration, etc.) can be selected with a simple click of the mouse. The system is easily miniaturized and portable which makes it particularly suited to field instrumentation. The system has been tested using several flow-based techniques including on-line titration for the determination of calcium in waters with potentiometric detection and a calcium ion sensor.
{"title":"Pulsed flow chemistry. A new approach to the generation of concentration profiles in flow analysis","authors":"X. D. Wang, T. Cardwell, R. Cattrall, G. E. Jenkins","doi":"10.1039/A708659H","DOIUrl":"https://doi.org/10.1039/A708659H","url":null,"abstract":"Pulsed flow chemistry (PFC) is described as a new approach to automated on-line analytical chemistry. In contrast to existing flow-based analytical chemistry methods, PFC is characterized by pulsed flow, turbulent mixing and low axial dispersion. The PFC system is fully computerized and all operations are under software control. Consequently, most flow analysis methods (e.g., flow injection, continuous flow, flow titration, etc.) can be selected with a simple click of the mouse. The system is easily miniaturized and portable which makes it particularly suited to field instrumentation. The system has been tested using several flow-based techniques including on-line titration for the determination of calcium in waters with potentiometric detection and a calcium ion sensor.","PeriodicalId":7814,"journal":{"name":"Analytical Communications","volume":"116 1","pages":"97-101"},"PeriodicalIF":0.0,"publicationDate":"1998-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87857572","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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