International Journal of Mass Spectrometry最新文献

{"title":"Molecular simulation methods of evaporating electrosprayed droplets","authors":"Styliani Consta,&nbsp;Han Nguyen","doi":"10.1016/j.ijms.2024.117369","DOIUrl":"10.1016/j.ijms.2024.117369","url":null,"abstract":"<div><div>A robust methodology for molecular simulations of evaporating droplets that enables comparison between the dynamics of the process of interest and the solvent evaporation rate has already been developed (Oh and Consta, 2017). The competition of these dynamics will determine the mass spectrum. However, the success of the approach depends on the accurate and effective treatment of electrostatic forces. Often, in droplet simulations, bulk solution parametrized force-fields are used where the Coulomb forces are directly taken into account with a cut-off distance longer than the droplet diameter. On the one hand this approach is inefficient for large droplets because the computational cost increases as the square of the number of the atomic sites, and on the other hand the force field is slightly different from that has been parametrized for the bulk solution. The effect of this new force field in the conformations of macromolecules is still unknown. Multilevel summation method (MSM) has been developed (Hardy et al. 2015) for the efficient treatment of electrostatic forces in non-periodic and semi-periodic systems, charged or neutral. MSM maintains the same force field in droplets as in the bulk solution. We compare MSM with direct electrostatic treatment in droplets. The comparison shows free energy differences between conformations of short peptides along the radius of gyration order parameter that indicate the need for validation of the direct method. We demonstrate the usage of MSM to study Rayleigh jet formation and charge emission from droplets. We conclude that robust approaches for droplet simulations that can be used with a force field of any complexity are available and can be implemented within many of the available open-source molecular modeling softwares. In the near future, the presented approach may provide reliable reference mass spectra for experiments, where the deviations from the experimental data may reveal valuable information about the processes that take place within the instrument.</div></div>","PeriodicalId":338,"journal":{"name":"International Journal of Mass Spectrometry","volume":"508 ","pages":"Article 117369"},"PeriodicalIF":1.6,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142722425","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Reactivity of 2-hydroxyethylhydrazinium nitrate (HEHN) with atomic iridium on graphite","authors":"Benjamin R. Bilik ,&nbsp;Kathryn Foreman ,&nbsp;Moritz Blankenhorn ,&nbsp;Jerry A. Boatz ,&nbsp;Steven D. Chambreau ,&nbsp;Kit Bowen","doi":"10.1016/j.ijms.2024.117373","DOIUrl":"10.1016/j.ijms.2024.117373","url":null,"abstract":"<div><div>In order to develop chemical kinetics models for the ignition and combustion of ionic liquid-based fuels, identification of the elementary steps in the thermal and catalytic decomposition of components such as 2-hydroxyethylhydrazinium nitrate (HEHN) is needed but is currently not well understood. The first decomposition step in protic ionic liquids such as HEHN is typically the proton transfer from the cation to the anion, resulting in the formation of 2-hydroxyethylhydrazine (HEH) and HNO₃. In this investigation, temperature-programmed desorption mass spectrometry (TPD-MS) and x-ray photoelectron spectroscopy (XPS) are used to investigate the heterogeneous catalytic decomposition of HEHN with iridium. HEHN is introduced onto a highly-oriented pyrolytic graphite (HOPG) substrate (approx. 100 monolayers (ML)) and mass-selected iridium atoms (0–10 % ML) are deposited on the HOPG surface. The products can be identified by their masses, and product distributions are monitored as a function of surface temperature and Ir coverage. Formation of product species on the bare HOPG versus on the HOPG with increasing Ir coverage (5, 10 % Ir) indicates that the presence of iridium enhances various reactions. XPS confirms the presence of iridium on the surface and indicates the possible chemical bonding states involved. The products and their possible elementary reaction mechanisms are discussed.</div></div>","PeriodicalId":338,"journal":{"name":"International Journal of Mass Spectrometry","volume":"508 ","pages":"Article 117373"},"PeriodicalIF":1.6,"publicationDate":"2024-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142722339","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Identification of isomeric glucuronides by electronic excitation dissociation tandem mass spectrometry","authors":"Yang Tang ,&nbsp;Zhengwei Chen ,&nbsp;Liuxi Chen ,&nbsp;Xiaorong Liang ,&nbsp;Brian Dean ,&nbsp;Donglu Zhang","doi":"10.1016/j.ijms.2024.117372","DOIUrl":"10.1016/j.ijms.2024.117372","url":null,"abstract":"<div><div>Glucuronidation is a key phase II metabolic pathway for many drugs and xenobiotics. In pharmaceutical research, performing comprehensive structural analysis to differentiate isomeric glucuronides is critical for understanding the metabolism and reactivity of a drug. However, distinguishing glucuronide isomers using collision-induced dissociation (CID) methods has been challenging, since the glucuronyl moiety is typically lost under collision, leaving no information of the glucuronidation linkage. In this study, we introduce a radical-induced fragmentation method known as electronic excitation dissociation (EED) and has demonstrated its ability to characterize glucuronide structures at the MS² level without requiring additional derivatizations. We showed EED can generate extensive MS/MS fragments, including several unique fragments that could be relied on to distinguish isomers. Here, we present our results of successfully applying EED for analysis of three common types of isomeric glucuronides, including acyl-, <em>N</em>-, and <em>O</em>-glucuronides. The LC-EED-MS/MS workflow we introduced has great potential for high-throughput analysis of glucuronide mixtures in metabolite identification.</div></div>","PeriodicalId":338,"journal":{"name":"International Journal of Mass Spectrometry","volume":"508 ","pages":"Article 117372"},"PeriodicalIF":1.6,"publicationDate":"2024-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142722424","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Improving methods for sample preparation of biological fluids by inductively coupled plasma mass spectrometry","authors":"T.K. Nurubeyli ,&nbsp;N. Sh. Jafar ,&nbsp;G.N. Mammadova","doi":"10.1016/j.ijms.2024.117355","DOIUrl":"10.1016/j.ijms.2024.117355","url":null,"abstract":"<div><div>This study presents the results of analyzing biological fluids using Inductively Coupled Plasma Mass Spectrometry (ICP-MS) after applying various sample preparation methods. Optimal conditions for preparing biological fluids have been identified, which help minimize matrix effects and improve measurement accuracy. The most effective methods were selected considering the specifics of matrices and their interactions with analytical equipment. The study evaluated the contributions of spectral interferences to the analytical signal when using ICP-MS. It was found that the physical properties of acid solutions, such as viscosity, surface tension, density, and volatility, significantly affect the analysis results, introducing additional interferences and data distortions. The use of internal standards to eliminate spectral interferences was investigated. Criteria for choosing internal standards were established based on proximity to ionization potentials and mass characteristics, which allows for more accurate result correction and minimizes interference effects. Additionally, it was discovered that polyatomic ions play a significant role in enhancing analyte signals. This influence is due not to the background levels of elements in the samples or reagents, but to ions formed from matrix components in the samples. The study demonstrated that isobaric interferences caused by polyatomic ions significantly impact analytical accuracy. These findings contribute to improving sample preparation and analysis methods for biological fluids using ICP-MS, leading to more reliable and accurate measurements of element concentrations.</div></div>","PeriodicalId":338,"journal":{"name":"International Journal of Mass Spectrometry","volume":"507 ","pages":"Article 117355"},"PeriodicalIF":1.6,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142652335","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A super-resolution coded aperture miniature mass spectrometer proof-of-concept for planetary science","authors":"Tanouir Aloui ,&nbsp;Rafael Bento Serpa ,&nbsp;Daniel Ross ,&nbsp;Scarlett Francini ,&nbsp;Chris Wu ,&nbsp;Kevin Lee ,&nbsp;Kathleen Masse ,&nbsp;Justin A. Keogh ,&nbsp;Robert Kingston ,&nbsp;Heeju Choi ,&nbsp;Charles B. Parker ,&nbsp;Jennifer C. Stern ,&nbsp;M. Bonner Denton ,&nbsp;Jeffrey T. Glass ,&nbsp;Michael E. Gehm ,&nbsp;Jason J. Amsden","doi":"10.1016/j.ijms.2024.117368","DOIUrl":"10.1016/j.ijms.2024.117368","url":null,"abstract":"<div><div>Mass spectrometers are essential instruments for <em>in situ</em> analysis of planetary materials. Ideally, a space flight mass spectrometer would have a mass range from ∼10 u to at least 500 u to enable analysis of organic molecules to aid in searching for the requirements for life; capability for high precision isotope ratios of carbon, nitrogen, oxygen, sulfur, and noble gases to understand solar system evolution and functioning; and ability to resolve isobaric interferences at low <em>m/z</em> such as CO and N₂ to study planetary atmospheres. Despite the considerable progress in flight mass spectrometry since the 1970s, no single flight mass spectrometer has all these ideal characteristics. In this paper, we present a proof-of-concept super-resolution coded aperture cycloidal miniature mass spectrometer (SR-CAMMS) for planetary science. Design considerations and preliminary results are presented including: a mass range of 10–260 u with resolution of 0.5 u or better; the ability to resolve the isobaric interference between CO and N₂ at <em>m/z</em> = 28 u using sampling-super resolution; and the ability to acquire isotope ratios with Poisson statistics limited precision. Thus, the instrument met all design considerations except mass range, which was expected to be 10–500 u; reasons for this discrepancy are discussed in the paper.</div></div>","PeriodicalId":338,"journal":{"name":"International Journal of Mass Spectrometry","volume":"507 ","pages":"Article 117368"},"PeriodicalIF":1.6,"publicationDate":"2024-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142652242","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Richard A. J. O'Hair – A mass spectrometrist who is showing that gas-phase ion chemistry is not just a science but an art","authors":"Gavin E. Reid PhD.,&nbsp;Victor Ryzhov Ph.D.","doi":"10.1016/j.ijms.2024.117367","DOIUrl":"10.1016/j.ijms.2024.117367","url":null,"abstract":"","PeriodicalId":338,"journal":{"name":"International Journal of Mass Spectrometry","volume":"507 ","pages":"Article 117367"},"PeriodicalIF":1.6,"publicationDate":"2024-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142703826","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Can OPAH ions be a source of CO and HCO in the interstellar medium? Lessons learned from the unimolecular dissociation of dibenzofuran and dibenz[b,f]oxepin radical cations","authors":"Nicholas Zinck ,&nbsp;Andras Bodi ,&nbsp;Paul M. Mayer","doi":"10.1016/j.ijms.2024.117366","DOIUrl":"10.1016/j.ijms.2024.117366","url":null,"abstract":"<div><div>Unlike polycyclic aromatic hydrocarbons (PAHs), which are recognized to be key players in interstellar and astrochemistry, less is known about the astrochemical relevance of oxygen-containing PAHs (OPAHs). Small O-containing molecules such as CO and HCO are ubiquitous in the interstellar medium and understanding how OPAHs may be a source for these critical small molecules is important. To this end, we have studied the unimolecular reactions of two ionized OPAHs, dibenzofuran (<strong>1</strong>^{<strong>+•</strong>}) and dibenz[b,f]oxepin (<strong>2</strong>^{<strong>+•</strong>}) with tandem mass spectrometry (collision-energy resolved dissociation) and imaging photoelectron photoion coincidence spectroscopy (iPEPICO). Collision-induced dissociation (CID) results show the competition between the loss of carbon monoxide (CO) and loss of 29 Da (either the formyl radical (HCO) or sequential H loss), with the latter being the dominant reaction. Rice–Ramsperger–Kassel–Marcus (RRKM) modeling of the iPEPICO data, on the other hand, is consistent with the loss of CO from the parent ion at the dissociative ionization onset, and, in the case of <strong>2</strong>^{<strong>+•</strong>}, sequential H-atom loss from this product. There is significant difference between the two structurally similar systems. In <strong>1</strong>^{<strong>+•</strong>}, dissociation requires around 4 eV of ion internal energy, while only 2.5 eV internal energy is required for <strong>2</strong>^{<strong>+•</strong>} to fragment. Calculations at the CAM-B3LYP/6–311++G(d,p) level of theory were used to examine the reaction pathways. For CO loss in <strong>1</strong>^{<strong>+•</strong>}, the reaction is initiated by a ring expansion followed by contraction of the central ring forming an ion–molecule complex between protonated cyclopenta[3,4]cyclobuta[1,2]benzene and CO. HCO loss is preceded by H migration to a bridging carbon vicinal to the oxygen atom and subsequent ring re-organization to form a low energy cyclopenta[c][1]benzopyran cation. This channel is higher enough in energy to preclude its participation near threshold, but not at higher internal energies reached in the CID experiment, which could therefore involve both sequential H loss and HCO loss. In <strong>2</strong>^{<strong>+•</strong>}, the reaction starts with an opening of the central O-containing ring, lowering the energy demand relative to <strong>1</strong>^{<strong>+•</strong>}.</div></div>","PeriodicalId":338,"journal":{"name":"International Journal of Mass Spectrometry","volume":"507 ","pages":"Article 117366"},"PeriodicalIF":1.6,"publicationDate":"2024-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142652243","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Complexation of diserinol isophthalamide with phosphorylated biomolecules in electrospray ionization mass spectrometry","authors":"Madeline Schultz,&nbsp;Neil A. Ellis,&nbsp;Nwanne D. Banor,&nbsp;Daniel A. Thomas","doi":"10.1016/j.ijms.2024.117364","DOIUrl":"10.1016/j.ijms.2024.117364","url":null,"abstract":"<div><div>Electrospray ionization (ESI) enables gentle transfer of biomolecules from solution to vacuum, facilitating the study of biomolecular structure under highly controlled conditions. However, biomolecules are desolvated during the ESI process, and the loss of ionic hydrogen bonds to solvent molecules can drive structural rearrangement, most prominently at solvent-exposed charge sites. Microsolvation reagents can bind to these bare charge sites in ESI mass spectrometry (ESI–MS) experiments, providing alternative intermolecular interaction partners. Previously, 18-crown-6 was shown to be an effective reagent for binding to cationic monoalkylammonium residues. More recently, diserinol isophthalamide (DIP) was reported as an analogous anionic microsolvation reagent, primarily for carboxylate residues of small model peptides. Herein, we expand upon this work to examine the complexation of DIP, 1,1’-(1,2-phenylene)bis(3-phenylurea) (PBP), and triclocarban (TCC) with molecules featuring a terminal or linking phosphate moiety. Specifically, using ESI–MS, we assess the binding of these reagents with dimethyl phosphate (DMP), cyclic adenosine monophosphate (cAMP), dibutyryl cAMP, RNA dinucleotides ApU and CpG, and angiotensin II phosphate (DRVpYIHPF). For DMP, the smallest target molecule, reagents TCC, PBP and DIP showed favorable adduction. However, for larger systems, PBP and TCC showed reduced complexation, which was attributed to steric hindrance from the terminal aromatic moieties of PBP and the limited hydrogen bonding network of TCC. Overall, of the three reagents, DIP showed the most consistent performance for anionic microsolvation of phosphate groups, facilitating future studies of gas-phase biomolecular structure and the effects of microsolvation.</div></div>","PeriodicalId":338,"journal":{"name":"International Journal of Mass Spectrometry","volume":"507 ","pages":"Article 117364"},"PeriodicalIF":1.6,"publicationDate":"2024-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142652334","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Unravelling the favorability of radical-directed xn-H2O dissociation at serine and threonine","authors":"Evan E. Hubbard,&nbsp;Ryan R. Julian","doi":"10.1016/j.ijms.2024.117363","DOIUrl":"10.1016/j.ijms.2024.117363","url":null,"abstract":"<div><div>Among tandem-mass-spectrometry approaches, radical-directed dissociation (RDD) is uniquely sensitive to molecular structure because the location and types of cleavage observed are dictated by radical migration propensities. Although the underlying chemistry for many RDD fragmentation pathways has been previously explained, x_n-H₂O fragment ions that occur exclusively at serine and threonine residues, have not been examined in detail. Creation of this fragment type inherently requires two dissociation events, one to lose water and another to cleave the peptide backbone. Double dissociations are typically disfavored relative to pathways requiring a single cleavage, yet x_n-H₂O fragment ions are abundant in RDD spectra. To understand why this fragmentation pathway is favorable, we used a combination of computational chemistry and experiments on peptides with a variety of covalent modifications. Our results explore the energetics, location, and migration of the radical in each step of the mechanism, revealing that favorability can be attributed to the stability of the required radical intermediates and access to low-energy pathways connecting them. Ultimately, the abundant nature of x_n-H₂O ions and the selectivity associated with their exclusive generation at Ser/Thr provides high value sequence information in RDD experiments.</div></div>","PeriodicalId":338,"journal":{"name":"International Journal of Mass Spectrometry","volume":"507 ","pages":"Article 117363"},"PeriodicalIF":1.6,"publicationDate":"2024-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142586170","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Gas phase proton affinities of proline-containing peptides. 1: ProGly, ProAla, ProVal, ProLeu, ProIle, and ProPro","authors":"Henry Cardwell ,&nbsp;Paul Acoria ,&nbsp;Alexis Brender A Brandis ,&nbsp;Kathy Huynh ,&nbsp;Madeleine Lamb ,&nbsp;Sophie Messinger ,&nbsp;Daria Moody ,&nbsp;Laurel Nicks ,&nbsp;Hao Qian ,&nbsp;Marcus Quint ,&nbsp;Trinh Ton ,&nbsp;Anna Grace Towler ,&nbsp;Michael Valasquez ,&nbsp;Jennifer Poutsma ,&nbsp;John C. Poutsma","doi":"10.1016/j.ijms.2024.117352","DOIUrl":"10.1016/j.ijms.2024.117352","url":null,"abstract":"<div><div>The gas-phase proton affinities (PA) for a series of proline-containing dipeptides have been measured in an ESI triple quadrupole instrument using the extended kinetic method. Proton affinities for ProGly (<strong>1</strong>), ProAla (<strong>2</strong>), ProVal (<strong>3</strong>), ProLeu (<strong>4</strong>), ProIle (<strong>5</strong>), and ProPro (<strong>6</strong>) were determined to be 969.6 ± 7.8, 990.4 ± 7.7, 987.6 ± 7.9, 982.8 ± 8.0, 988.8 ± 10.1, and 996.5 ± 12.2 kJ/mol, respectively. Predictions for the proton affinities for <strong>1</strong>–<strong>6</strong> were also obtained through isodesmic calculations at the B3LYP/6-311++G(d,p)//B3LYP/6-31+G(d) level of theory. The predicted proton affinities for <strong>1</strong> and <strong>6</strong> of 966.9 and 991.0 kJ/mol are in agreement with the experimental values. However, the predicted proton affinities for <strong>2</strong>–<strong>5</strong> of 973.5, 975.9, 975.7, and 975.9 are between 8 and 15 kJ/mol lower than the experimental values. Additional calculations with a larger basis set (B3LYP/6-311++G(2df,2p), inclusion of dispersion (B3LYP-D3/6-311++G(d,p)), switching to second order perturbation theory (MP2/6-31++G(d,p) and MP2/6-311++G(2df,2p), or switching density functional (M06-2x/6-311++G(d,p) and M06-2x/6-311++G(2df,2p) show only modest changes in derived thermochemistry lending support to the original calculations. We recommend using the experimental proton affinities for ProGly and ProPro and using the calculated values for ProAla, ProVal, ProLeu, and ProIle with the experimental proton affinities as upper limits.</div></div>","PeriodicalId":338,"journal":{"name":"International Journal of Mass Spectrometry","volume":"507 ","pages":"Article 117352"},"PeriodicalIF":1.6,"publicationDate":"2024-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142552386","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}