Evan R. McCarney, Kenneth A. Kristoffersen, Kathryn E. Anderssen
{"title":"Quantitative at-line monitoring of enzymatic hydrolysis using benchtop diffusion nuclear magnetic resonance spectroscopy","authors":"Evan R. McCarney, Kenneth A. Kristoffersen, Kathryn E. Anderssen","doi":"10.1002/mrc.5427","DOIUrl":"10.1002/mrc.5427","url":null,"abstract":"<p>Benchtop diffusion nuclear magnetic resonance (NMR) spectroscopy was used to perform quantitative monitoring of enzymatic hydrolysis. The study aimed to test the feasibility of the technology to characterize enzymatic hydrolysis processes in real time. Diffusion ordered spectroscopy (DOSY) was used to measure the signal intensity and apparent self-diffusion constant of solubilized protein in hydrolysate. The NMR technique was tested on an enzymatic hydrolysis reaction of red cod, a lean white fish, by the endopeptidase alcalase at 50°C. Hydrolysate samples were manually transferred from the reaction vessel to the NMR equipment. Measurement time was approximately 3 min per time point. The signal intensity from the DOSY experiment was used to measure protein concentration and the apparent self-diffusion constant was converted into an average molecular weight and an estimated degree of hydrolysis. These values were plotted as a function of time and both the rate of solubilization and the rate of protein breakdown could be calculated. In addition to being rapid and noninvasive, DOSY using benchtop NMR spectroscopy has an advantage compared with other enzymatic hydrolysis characterization methods as it gives a direct measure of average protein size; many functional properties of proteins are strongly influenced by protein size. Therefore, a method to give protein concentration and average size in real time will allow operators to more tightly control production from enzymatic hydrolysis. Although only one type of material was tested, it is anticipated that the method should be applicable to a broad variety of enzymatic hydrolysis feedstocks.</p>","PeriodicalId":18142,"journal":{"name":"Magnetic Resonance in Chemistry","volume":"62 6","pages":"452-462"},"PeriodicalIF":2.0,"publicationDate":"2024-01-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/mrc.5427","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139490918","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":"NMR characterization of uniformly 13C- and/or 15N-labeled, unsulfated chondroitins with high molecular weights","authors":"Megumi Ichikawa, Yuya Otsuka, Toshikazu Minamisawa, Noriyoshi Manabe, Yoshiki Yamaguchi","doi":"10.1002/mrc.5426","DOIUrl":"10.1002/mrc.5426","url":null,"abstract":"<p>Solution nuclear magnetic resonance (NMR) analysis of polysaccharides can provide valuable information not only on their primary structures but also on their conformation, dynamics, and interactions under physiological conditions. One of the main problems is that non-anomeric <sup>1</sup>H signals typically overlap, and this often hinders detailed NMR analysis. Isotope enrichment, such as with <sup>13</sup>C and <sup>15</sup>N, will add a new dimension to the NMR spectra of polysaccharides, and spectral analysis can be performed with enhanced sensitivity using isolated peaks. For this purpose, here we have prepared uniformly <sup>13</sup>C- and/or <sup>15</sup>N-labeled chondroitin polysaccharides –4)-β-D-glucuronopyranosyl-(1–3)-2-acetamido-2-deoxy-β-D-galactopyranosyl-(1– with molecular weights in the range from 310 to 460 k by bacterial fermentation. The enrichment ratios for <sup>13</sup>C and <sup>15</sup>N were 98.9 and 99.8%, respectively, based on the mass spectrometric analysis of the constituent chondroitin disaccharides. <sup>1</sup>H and <sup>13</sup>C NMR signals were assigned mainly based on HSQC and <sup>13</sup>C-detection experiments including INADEQUATE, HETCOR, and HETCOR-TOCSY. The carbonyl carbon signal of the <i>N</i>-acetyl-β-D-galactosamine residue was unambiguously distinguished from the C6 carbon of the β-D-glucuronic acid residue by the observation of <sup>13</sup>C peak splitting due to <sup>1</sup><i>J</i><sub>CN</sub> coupling in <sup>13</sup>C- and <sup>15</sup>N-labeled chondroitin. The <i>T</i><sub>2</sub>* and <i>T</i><sub>1</sub> were measured and indicate that both rigid and mobile sites are present in the long sequence of chondroitin. The conformation, dynamics, and interactions of chondroitin and its derivatives will be further analyzed based on the results obtained in this study.</p>","PeriodicalId":18142,"journal":{"name":"Magnetic Resonance in Chemistry","volume":"62 6","pages":"439-451"},"PeriodicalIF":2.0,"publicationDate":"2024-01-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139484262","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}
Ryan Toomey, Jacob Powell, Jacob Cheever, James K. Harper
{"title":"Distinguishing between COOH, COO−, and hydrogen disordered COOH sites in solids with 13C chemical shift anisotropy and T1 measurements","authors":"Ryan Toomey, Jacob Powell, Jacob Cheever, James K. Harper","doi":"10.1002/mrc.5425","DOIUrl":"10.1002/mrc.5425","url":null,"abstract":"<p>Since 1993, it has been known that <sup>13</sup>C chemical shift tensor (i.e., δ<sub>11</sub>, δ<sub>22</sub>, and δ<sub>33</sub>) provides information sufficient to distinguish between COOH and COO<sup>−</sup> sites. Herein, four previously unreported metrics are proposed for differentiating COOH/COO<sup>−</sup> moieties. A new relationship is also introduced that correlates the asymmetry (i.e., δ<sub>11</sub>–δ<sub>22</sub>) of COOH sites to the proximity of hydrogen bond donating partners within 2.6 Å with high accuracy (±0.05 Å). Conversely, a limitation to all proposed metrics is that they fail to distinguish between COO<sup>−</sup> and hydrogen disordered COOH sites. To reconcile this omission, a new approach is proposed based on <i>T</i><sub>1</sub> measurements of both <sup>1</sup>H and <sup>13</sup>C. The <sup>13</sup>C <i>T</i><sub>1</sub> values are particularly sensitive with the <i>T</i><sub>1</sub> for hydrogen disordered COOH moieties found to be nearly six times smaller than <i>T</i><sub>1</sub>'s from COO<sup>−</sup> sites.</p>","PeriodicalId":18142,"journal":{"name":"Magnetic Resonance in Chemistry","volume":"62 3","pages":"190-197"},"PeriodicalIF":2.0,"publicationDate":"2024-01-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139490481","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}
Amy Jenne, Ronald Soong, Katelyn Downey, Rajshree Ghosh Biswas, Venita Decker, Falko Busse, Benjamin Goerling, Agnes Haber, Myrna J. Simpson, Andre J. Simpson
{"title":"Brewing alcohol 101: An undergraduate experiment utilizing benchtop NMR for quantification and process monitoring","authors":"Amy Jenne, Ronald Soong, Katelyn Downey, Rajshree Ghosh Biswas, Venita Decker, Falko Busse, Benjamin Goerling, Agnes Haber, Myrna J. Simpson, Andre J. Simpson","doi":"10.1002/mrc.5428","DOIUrl":"10.1002/mrc.5428","url":null,"abstract":"<p>In recent years there has been a renewed interest in benchtop NMR. Given their lower cost of ownership, smaller footprint, and ease of use, they are especially suited as an educational tool. Here, a new experiment targeted at upper-year undergraduates and first-year graduate students follows the conversion of D-glucose into ethanol at low-field. First, high and low-field data on D-glucose are compared and students learn both the Hz and ppm scales and how J-coupling is field-independent. The students then acquire their own quantitative NMR datasets and perform the quantification using an Electronic Reference To Access In Vivo Concentration (ERETIC) technique. To our knowledge ERETIC is not currently taught at the undergraduate level, but has an advantage in that internal standards are not required; ideal for following processes or with future use in flow-based benchtop monitoring. Using this quantitative data, students can relate a simple chemical process (fermentation) back to more complex topics such as reaction kinetics, bridging the gaps between analytical and physical chemistry. When asked to reflect on the experiment, students had an overwhelmingly positive experience, citing agreement with learning objectives, ease of understanding the protocol, and enjoyment. Each of the respondents recommended this experiment as a learning tool for others. This experiment has been outlined for other instructors to utilize in their own courses across institutions, with the hope that a continued expansion of low-field NMR will increase accessibility and learning opportunities at the undergraduate level.</p>","PeriodicalId":18142,"journal":{"name":"Magnetic Resonance in Chemistry","volume":"62 6","pages":"429-438"},"PeriodicalIF":2.0,"publicationDate":"2024-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/mrc.5428","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139478772","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}
Sean T. Holmes, Cameron M. Boley, Angelika Dewicki, Zachary T. Gardner, Cameron S. Vojvodin, Robbie J. Iuliucci, Robert W. Schurko
{"title":"Carbon-13 chemical shift tensor measurements for nitrogen-dense compounds","authors":"Sean T. Holmes, Cameron M. Boley, Angelika Dewicki, Zachary T. Gardner, Cameron S. Vojvodin, Robbie J. Iuliucci, Robert W. Schurko","doi":"10.1002/mrc.5422","DOIUrl":"10.1002/mrc.5422","url":null,"abstract":"<p>This paper reports the principal values of the <sup>13</sup>C chemical shift tensors for five nitrogen-dense compounds (i.e., cytosine, uracil, imidazole, guanidine hydrochloride, and aminoguanidine hydrochloride). Although these are all fundamentally important compounds, the majority do not have <sup>13</sup>C chemical shift tensors reported in the literature. The chemical shift tensors are obtained from <sup>1</sup>H→<sup>13</sup>C cross-polarization magic-angle spinning (CP/MAS) experiments that were conducted at a high field of 18.8 T to suppress the effects of <sup>14</sup>N-<sup>13</sup>C residual dipolar coupling. Quantum chemical calculations using density functional theory are used to obtain the <sup>13</sup>C magnetic shielding tensors for these compounds. The best agreement with experiment arises from calculations using the hybrid functional PBE0 or the double-hybrid functional PBE0-DH, along with the triple-zeta basis sets TZ2P or pc-3, respectively, and intermolecular effects modeled using large clusters of molecules with electrostatic embedding through the COSMO approach. These measurements are part of an ongoing effort to expand the catalog of accurate <sup>13</sup>C chemical shift tensor measurements, with the aim of creating a database that may be useful for benchmarking the accuracy of quantum chemical calculations, developing nuclear magnetic resonance (NMR) crystallography protocols, or aiding in applications involving machine learning or data mining. This work was conducted at the National High Magnetic Field Laboratory as part of a 2-week school for introducing undergraduate students to practical laboratory experience that will prepare them for scientific careers or postgraduate studies.</p>","PeriodicalId":18142,"journal":{"name":"Magnetic Resonance in Chemistry","volume":"62 3","pages":"179-189"},"PeriodicalIF":2.0,"publicationDate":"2024-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139478773","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}
James Daley, Joseph Siciliano, Vincent Ferraro, Elodie Sutter, Adam Lounsbery, Nicholas Whiting
{"title":"Temperature lowering of liquid nitrogen via injection of helium gas bubbles improves the generation of parahydrogen-enriched gas","authors":"James Daley, Joseph Siciliano, Vincent Ferraro, Elodie Sutter, Adam Lounsbery, Nicholas Whiting","doi":"10.1002/mrc.5423","DOIUrl":"10.1002/mrc.5423","url":null,"abstract":"<p>The para spin isomer of hydrogen gas possesses high nuclear spin order that can enhance the NMR signals of a variety of molecular species. Hydrogen is routinely enriched in the para spin state by lowering the gas temperature while flowing through a catalyst. Although parahydrogen enrichments approaching 100% are achievable near the H<sub>2</sub> liquefaction temperature of 20 K, many experimentalists operate at liquid nitrogen temperatures (77 K) due to the lower associated costs and overall simplicity of the parahydrogen generator. Parahydrogen that is generated at 77 K provides an enrichment value of ~51% of the para spin isomer; while useful, there are many applications that can benefit from low-cost access to higher parahydrogen enrichments. Here, we introduce a method of improving parahydrogen enrichment values using a liquid nitrogen-cooled generator that operates at temperatures less than 77 K. The boiling temperature of liquid nitrogen is lowered through internal evaporation into helium gas bubbles that are injected into the liquid. Changes to liquid nitrogen temperatures and parahydrogen enrichment values were monitored as a function of helium gas flow rate. The injected helium bubbles lowered the liquid nitrogen temperature to ~65.5 K, and parahydrogen enrichments of up to ~59% were achieved; this represents an ~16% improvement compared with the expected parahydrogen fraction at 77 K. This technique is simple to implement in standard liquid nitrogen-cooled parahydrogen generators and may be of interest to a wide range of scientists that require a cost-effective approach to improving parahydrogen enrichment values.</p>","PeriodicalId":18142,"journal":{"name":"Magnetic Resonance in Chemistry","volume":"62 2","pages":"94-100"},"PeriodicalIF":2.0,"publicationDate":"2024-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139087444","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}
Tristan Maschmeyer, Breanna Conklin, Thomas C. Malig, David J. Russell, Kenji L. Kurita, Jason E. Hein, José G. Napolitano
{"title":"A reliable external calibration method for reaction monitoring with benchtop NMR","authors":"Tristan Maschmeyer, Breanna Conklin, Thomas C. Malig, David J. Russell, Kenji L. Kurita, Jason E. Hein, José G. Napolitano","doi":"10.1002/mrc.5421","DOIUrl":"10.1002/mrc.5421","url":null,"abstract":"<p>Nuclear magnetic resonance (NMR) spectroscopy is a powerful analytical technique with the ability to acquire both quantitative and structurally insightful data for multiple components in a test sample. This makes NMR spectroscopy a desirable tool to understand, monitor, and optimize chemical transformations. While quantitative NMR (qNMR) approaches relying on internal standards are well-established, using an absolute external calibration scheme is beneficial for reaction monitoring as resonance overlap complications from an added reference material to the sample can be avoided. Particularly, this type of qNMR technique is of interest with benchtop NMR spectrometers as the likelihood of resonance overlap is only enhanced with the lower magnetic field strengths of the used permanent magnets. The included study describes a simple yet robust methodology to determine concentration conversion factors for NMR systems using single- and multi-analyte linear regression models. This approach is leveraged to investigate a pharmaceutically relevant amide coupling batch reaction. An <i>on-line</i> stopped-flow (<i>i.e.</i>, interrupted-flow or paused-flow) benchtop NMR system was used to monitor both the 1,1′-carbonyldiimidazole (CDI) promoted acid activation and the amide coupling. The results highlight how quantitative measurements in benchtop NMR systems can provide valuable information and enable analysts to make decisions in real time.</p>","PeriodicalId":18142,"journal":{"name":"Magnetic Resonance in Chemistry","volume":"62 3","pages":"169-178"},"PeriodicalIF":2.0,"publicationDate":"2023-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/mrc.5421","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138799996","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}
Stefan Kuhn, Heinz Kolshorn, Christoph Steinbeck, Nils Schlörer
{"title":"Twenty years of nmrshiftdb2: A case study of an open database for analytical chemistry","authors":"Stefan Kuhn, Heinz Kolshorn, Christoph Steinbeck, Nils Schlörer","doi":"10.1002/mrc.5418","DOIUrl":"10.1002/mrc.5418","url":null,"abstract":"<p>In October 2003, 20 years ago, the open-source and open-content database NMRshiftDB was announced. Since then, the database, renamed as nmrshiftdb2 later, has been continuously available and is one of the longer-running projects in the field of open data in chemistry. After 20 years, we evaluate the success of the project and present lessons learnt for similar projects.</p>","PeriodicalId":18142,"journal":{"name":"Magnetic Resonance in Chemistry","volume":"62 2","pages":"74-83"},"PeriodicalIF":2.0,"publicationDate":"2023-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/mrc.5418","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138800096","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":"Predicting 51V nuclear magnetic resonance observables in molecular crystals","authors":"Joshua D. Hartman, Daniel Capistran","doi":"10.1002/mrc.5420","DOIUrl":"10.1002/mrc.5420","url":null,"abstract":"<p>Solid-state nuclear magnetic resonance (NMR) spectroscopy and quantum chemical density functional theory (DFT) calculations are widely used to characterize vanadium centers in biological and pharmaceutically relevant compounds. Several techniques have been recently developed to improve the accuracy of predicted NMR parameters obtained from DFT. Fragment-based and planewave-corrected methods employing hybrid density functionals are particularly effective tools for solid-state applications. A recent benchmark study involving molecular crystal compounds found that fragment-based NMR calculations using hybrid density functionals improve the accuracy of predicted <sup>51</sup>V chemical shieldings by 20% relative to traditional planewave methods. This work extends the previous study, including a careful analysis of <sup>51</sup>V chemical shift anisotropy, electric field gradient calculations, and a more extensive test set. The accuracy of planewave-corrected techniques and recently developed fragment-based methods using electrostatic embedding based on the polarized continuum model (PCM) are found to be highly competitive with previous methods. Planewave-corrected methods achieve a 34% improvement in the errors of predicted <sup>51</sup>V chemical shieldings relative to planewave. Additionally, planewave-corrected and fragment-based calculations were performed using PCM embedding, improving the accuracy of predicted <sup>51</sup>V chemical shielding (CS) tensor principal values by 30% and \u0000<span></span><math>\u0000 <msub>\u0000 <mrow>\u0000 <mi>C</mi>\u0000 </mrow>\u0000 <mrow>\u0000 <mi>q</mi>\u0000 </mrow>\u0000 </msub></math> values by 15% relative to traditional planewave methods. The performance of these methods is further examined using a redox-active oxovandium complex and a common <sup>51</sup>V NMR reference compound.</p>","PeriodicalId":18142,"journal":{"name":"Magnetic Resonance in Chemistry","volume":"62 6","pages":"416-428"},"PeriodicalIF":2.0,"publicationDate":"2023-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/mrc.5420","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138799984","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}
Johnnie Phuong, Zeno Romero, Hans Hasse, Kerstin Münnemann
{"title":"Polarization transfer methods for quantitative analysis of flowing mixtures with benchtop 13C NMR spectroscopy","authors":"Johnnie Phuong, Zeno Romero, Hans Hasse, Kerstin Münnemann","doi":"10.1002/mrc.5417","DOIUrl":"10.1002/mrc.5417","url":null,"abstract":"<p>Benchtop NMR spectroscopy is attractive for process monitoring; however, there are still drawbacks that often hamper its use, namely, the comparatively low spectral resolution in <sup>1</sup>H NMR, as well as the low signal intensities and problems with the premagnetization of flowing samples in <sup>13</sup>C NMR. We show here that all these problems can be overcome by using <sup>1</sup>H-<sup>13</sup>C polarization transfer methods. Two ternary test mixtures (one with overlapping peaks in the <sup>1</sup>H NMR spectrum and one with well-separated peaks, which was used as a reference) were studied with a 1 T benchtop NMR spectrometer using the polarization transfer sequence PENDANT (polarization enhancement that is nurtured during attached nucleus testing). The mixtures were analyzed quantitatively in stationary as well as in flow experiments by PENDANT enhanced <sup>13</sup>C NMR experiments, and the results were compared with those from the gravimetric sample preparation and from standard <sup>1</sup>H and <sup>13</sup>C NMR spectroscopy. Furthermore, as a proxy for a process monitoring application, continuous dilution experiments were carried out, and the composition of the mixture was monitored in a flow setup by <sup>13</sup>C NMR benchtop spectroscopy with PENDANT. The results demonstrate the high potential of polarization transfer methods for applications in quantitative process analysis with benchtop NMR instruments, in particular with flowing samples.</p>","PeriodicalId":18142,"journal":{"name":"Magnetic Resonance in Chemistry","volume":"62 5","pages":"398-411"},"PeriodicalIF":2.0,"publicationDate":"2023-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/mrc.5417","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138799997","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}