European Journal of Mass Spectrometry最新文献

筛选
英文 中文
BeerMIMS: Exploring the Use of Membrane-Inlet Mass Spectrometry (MIMS) Coupled to KNIME for the Characterization of Danish Beers. BeerMIMS:探索使用膜入口质谱(MIMS)耦合KNIME对丹麦啤酒的表征。
IF 1.3 4区 化学
European Journal of Mass Spectrometry Pub Date : 2021-12-01 Epub Date: 2022-01-06 DOI: 10.1177/14690667211073317
Sean Sebastian Hughes, Marcus M K Nielsen, Rasmus Voersaa Jonsbo, Carsten Uhd Nielsen, Frants Roager Lauritsen, Bala Krishna Prabhala
{"title":"BeerMIMS: Exploring the Use of Membrane-Inlet Mass Spectrometry (MIMS) Coupled to KNIME for the Characterization of Danish Beers.","authors":"Sean Sebastian Hughes,&nbsp;Marcus M K Nielsen,&nbsp;Rasmus Voersaa Jonsbo,&nbsp;Carsten Uhd Nielsen,&nbsp;Frants Roager Lauritsen,&nbsp;Bala Krishna Prabhala","doi":"10.1177/14690667211073317","DOIUrl":"https://doi.org/10.1177/14690667211073317","url":null,"abstract":"<p><p>Beer is a complex mix of more than 7700 compounds, around 800 of which are volatile. While GC-MS has been actively employed in the analysis of the volatome of beer, this method is challenged by the complex nature of the sample. Herein, we explored the possible of using membrane-inlet mass spectrometry (MIMS) coupled to KNIME to characterize local Danish beers. KNIME stands for Konstanz Information Miner and is a free open-source data processing software which comes with several prebuilt nodes, that, when organized, result in data processing workflows allowing swift analysis of data with outputs that can be visualized in the desired format. KNIME has been shown to be promising in automation of large datasets and requires very little computing power. In fact, most of the computations can be carried out on a regular PC. Herein, we have utilized a KNIME workflow for data visualization of MIMS data to understand the global volatome of beers. Feature identification was not possible as of now but with a combination of MIMS and a KNIME workflow, we were able to distinguish beers from different micro-breweries located in Denmark, laying the foundation for the use of MIMS in future analysis of the beer volatome.</p>","PeriodicalId":12007,"journal":{"name":"European Journal of Mass Spectrometry","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2021-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39650291","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 5
Discovery of metabolomic biomarkers for discriminating platinum-sensitive and platinum-resistant ovarian cancer by using GC-MS. GC-MS鉴别铂敏感和铂耐药卵巢癌代谢组学标志物的发现
IF 1.3 4区 化学
European Journal of Mass Spectrometry Pub Date : 2021-12-01 Epub Date: 2021-11-22 DOI: 10.1177/14690667211057996
Evren C Eroglu, Sule Tunug, Omer Faruk Geckil, Umran Kucukgoz Gulec, Mehmet Ali Vardar, Semra Paydas
{"title":"Discovery of metabolomic biomarkers for discriminating platinum-sensitive and platinum-resistant ovarian cancer by using GC-MS.","authors":"Evren C Eroglu,&nbsp;Sule Tunug,&nbsp;Omer Faruk Geckil,&nbsp;Umran Kucukgoz Gulec,&nbsp;Mehmet Ali Vardar,&nbsp;Semra Paydas","doi":"10.1177/14690667211057996","DOIUrl":"https://doi.org/10.1177/14690667211057996","url":null,"abstract":"<p><p>This study aims to determine ovarian cancer (OC) patients with platinum resistance for alternative treatment protocols by using metabolomic methodologies. Urine and serum samples of platinum-resistant and platinum-sensitive OC were analyzed using GC-MS. After data processing of GC-MS raw data, multivariate analyses were performed to interpret complex data for biologically meaningful information and to identify the biomarkers that cause differences between two groups. The biomarkers were verified after univariate, multivariate, and ROC analysis. Finally, metabolomic pathways related to group separations were specified. The results of biomarker analysis showed that 3,4-dihydroxyphenylacetic acid, 4-hydroxybutyric acid, L-threonine, D- mannose, and sorbitol metabolites were potential biomarkers in urine samples. In serum samples, L-arginine, linoleic acid, L-glutamine, and hypoxanthine were identified as important biomarkers. R2Y, Q2, AUC, sensitivity and specificity values of platinum-resistant and sensitive OC patients' urine and serum samples were 0.85, 0.545, 0.844, 91.30%, 81.08 and 0.570, 0.206, 0.743, 77.78%, 74.28%, respectively. In metabolic pathway analysis of urine samples, tyrosine metabolism and fructose and mannose metabolism were found to be statistically significant (p < 0.05) for the discrimination of the two groups. While 3,4-dihydroxyphenylacetic acid, L-tyrosine, and fumaric acid metabolites were effective in tyrosine metabolism. D-sorbitol and D-mannose metabolites were significantly important in fructose and mannose metabolism. However, seven metabolomic pathways were significant (p < 0.05) in serum samples. In terms of <i>p-</i>value, L-glutamine in the nitrogen metabolic pathway from the first three pathways; L-glutamine and pyroglutamic acid metabolites in D-glutamine and D-glutamate metabolism. In the arginine and proline metabolic pathway, L-arginine, L-proline, and L-ornithine metabolites differed significantly between the two groups.</p>","PeriodicalId":12007,"journal":{"name":"European Journal of Mass Spectrometry","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2021-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39913230","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 3
Evaluation of an integrative Bayesian peptide detection approach on a combinatorial peptide library. 基于组合肽库的综合贝叶斯肽检测方法的评价。
IF 1.3 4区 化学
European Journal of Mass Spectrometry Pub Date : 2021-12-01 Epub Date: 2022-01-06 DOI: 10.1177/14690667211066725
Miroslav Hruska, Dusan Holub
{"title":"Evaluation of an integrative Bayesian peptide detection approach on a combinatorial peptide library.","authors":"Miroslav Hruska,&nbsp;Dusan Holub","doi":"10.1177/14690667211066725","DOIUrl":"https://doi.org/10.1177/14690667211066725","url":null,"abstract":"<p><p>Detection of peptides lies at the core of bottom-up proteomics analyses. We examined a Bayesian approach to peptide detection, integrating match-based models (fragments, retention time, isotopic distribution, and precursor mass) and peptide prior probability models under a unified probabilistic framework. To assess the relevance of these models and their various combinations, we employed a complete- and a tail-complete search of a low-precursor-mass synthetic peptide library based on oncogenic KRAS peptides. The fragment match was by far the most informative match-based model, while the retention time match was the only remaining such model with an appreciable impact--increasing correct detections by around 8 %. A peptide prior probability model built from a reference proteome greatly improved the detection over a uniform prior, essentially transforming <i>de novo</i> sequencing into a reference-guided search. The knowledge of a correct sequence tag in advance to peptide-spectrum matching had only a moderate impact on peptide detection unless the tag was long and of high certainty. The approach also derived more precise error rates on the analyzed combinatorial peptide library than those estimated using PeptideProphet and Percolator, showing its potential applicability for the detection of homologous peptides. Although the approach requires further computational developments for routine data analysis, it illustrates the value of peptide prior probabilities and presents a Bayesian approach for their incorporation into peptide detection.</p>","PeriodicalId":12007,"journal":{"name":"European Journal of Mass Spectrometry","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2021-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39790849","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Theoretical description of electric fields in three-dimensional multipole ion traps. 三维多极离子阱中电场的理论描述。
IF 1.3 4区 化学
European Journal of Mass Spectrometry Pub Date : 2021-10-01 Epub Date: 2021-10-28 DOI: 10.1177/14690667211047918
Maxim Vasilyev, Semyon Rudyi, Yuri Rozhdestvensky
{"title":"Theoretical description of electric fields in three-dimensional multipole ion traps.","authors":"Maxim Vasilyev,&nbsp;Semyon Rudyi,&nbsp;Yuri Rozhdestvensky","doi":"10.1177/14690667211047918","DOIUrl":"https://doi.org/10.1177/14690667211047918","url":null,"abstract":"<p><p>In this paper, the principle of forming the spatial distribution of the potential in multipole three-dimensional ion traps of a general type is considered. A matrix method for describing the electric fields in ion traps for the <math><mi>n</mi></math>th order of multipole is proposed. Typical electrode geometries for hexapole and octupole traps are considered.</p>","PeriodicalId":12007,"journal":{"name":"European Journal of Mass Spectrometry","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2021-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39570583","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 3
Poly(2-vinylpyridine) as a reference compound for mass calibration in positive-ion matrix-assisted laser desorption/ionization-mass spectrometry on different instrumental platforms. 聚(2-乙烯基吡啶)作为正离子基质辅助激光解吸/电离-质谱法在不同仪器平台上的质量校准参考化合物。
IF 1.3 4区 化学
European Journal of Mass Spectrometry Pub Date : 2021-10-01 Epub Date: 2021-11-05 DOI: 10.1177/14690667211055701
Jürgen H Gross
{"title":"Poly(2-vinylpyridine) as a reference compound for mass calibration in positive-ion matrix-assisted laser desorption/ionization-mass spectrometry on different instrumental platforms.","authors":"Jürgen H Gross","doi":"10.1177/14690667211055701","DOIUrl":"https://doi.org/10.1177/14690667211055701","url":null,"abstract":"<p><p>Butyl-terminated poly(2-vinylpyridine) (P2VP), C<sub>4</sub>H<sub>9</sub>(C<sub>7</sub>H<sub>7</sub>N)<i><sub>n</sub></i>H, is evaluated for use as an external and internal mass calibrant in positive-ion matrix-assisted laser desorption/ionization-mass spectrometry (MALDI-MS). P2VP oligomers covering the <i>m/z</i> 450-4500 range are employed to calibrate a time-of-flight (TOF) mass spectrometer in linear and reflector mode, an ion mobility-quadrupole-time-of-flight (IM-Q-TOF) mass spectrometer, and a Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometer. The proton affinity of P2VPs introduced by the numerous pyridyl groups leads to the almost exclusive formation of [M + H]<sup>+</sup> ions with common acidic matrices like α-cyano-4-hydroxycinnamic acid (CHCA) and 2,5-dihydroxybenzoic acid (DHB) as well as with the non-acidic and aprotic matrices 1,8-dihydroxy-10<i>H</i>-anthracen-9-on (dithranol) and 2-[(2<i>E</i>)-3-(4-<i>tert</i>-butylphenyl)-2-methylprop-2-enylidene]malonitrile (DCTB). This prevalence of [M + H]<sup>+</sup> ions evenly spaced at Δ(<i>m/z</i>) = 105.0578 renders butyl-terminated P2VP oligomers as convenient mass calibrants. The mass accuracies achieved across various <i>m/z</i> ranges with different mass analyzers and modes of operation are evaluated by using established standard compounds. Results as obtained by internal or external calibration are presented. Further, the compilation of mass reference lists tailored to suit the respective analyzer modes is discussed and those reference files are provided.</p>","PeriodicalId":12007,"journal":{"name":"European Journal of Mass Spectrometry","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2021-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8586192/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39592845","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Joseph John Thomson investigates the paranormal. 约瑟夫·约翰·汤姆森调查超自然现象。
IF 1.3 4区 化学
European Journal of Mass Spectrometry Pub Date : 2021-10-01 Epub Date: 2021-10-07 DOI: 10.1177/14690667211050599
Kevin M Downard
{"title":"Joseph John Thomson investigates the paranormal.","authors":"Kevin M Downard","doi":"10.1177/14690667211050599","DOIUrl":"https://doi.org/10.1177/14690667211050599","url":null,"abstract":"<p><p>Joseph John Thomson is best known for detecting two isotopes of neon within cathode ray tubes that lay the foundation of the field of mass spectrometry. He was awarded the 1906 Nobel Prize in Physics for the discovery of the electron and for his work on the conduction of electricity in gases in the same devices. He is less known for his strong religious beliefs and his interest in psychical research and the paranormal. Thomson served as a member of the Society for Psychical Research for over 50 years and even became its Vice President. During this time, he attended a number of séances and demonstrations by professed psychics and mediums. This article traces those who influenced his interest in the paranormal, from Balfour Stewart to Lord Rayleigh and William Crookes. It reports and illustrates his beliefs and experiences investigating the paranormal in his own words.</p>","PeriodicalId":12007,"journal":{"name":"European Journal of Mass Spectrometry","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2021-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39493740","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Vacuum ultraviolet photoionization and dissociative photoionization of toluene: Experimental and theoretical insights. 真空紫外光电离和解离光电离的甲苯:实验和理论见解。
IF 1.3 4区 化学
European Journal of Mass Spectrometry Pub Date : 2021-10-01 Epub Date: 2021-10-06 DOI: 10.1177/14690667211042707
Yujie Zhao, Pei Huang, Li Li, Yousheng Zhan, Ke Wang, Haohang Yang, Jianhui Jin, Yuqian Chen, Yibao Liu, Liusi Sheng, Jun Chen, Maoqi Cao
{"title":"Vacuum ultraviolet photoionization and dissociative photoionization of toluene: Experimental and theoretical insights.","authors":"Yujie Zhao,&nbsp;Pei Huang,&nbsp;Li Li,&nbsp;Yousheng Zhan,&nbsp;Ke Wang,&nbsp;Haohang Yang,&nbsp;Jianhui Jin,&nbsp;Yuqian Chen,&nbsp;Yibao Liu,&nbsp;Liusi Sheng,&nbsp;Jun Chen,&nbsp;Maoqi Cao","doi":"10.1177/14690667211042707","DOIUrl":"https://doi.org/10.1177/14690667211042707","url":null,"abstract":"<p><p>The photoionization and dissociative photoionization of toluene have been studied using synchrotron radiation vacuum ultraviolet light with photon energy in the range of 8.50-25.50 eV. The ionization energies (8.82 eV) and double ionization energies (23.80 eV) of toluene as well as the appearance energies for its major fragments C<sub>7</sub>H<sub>7</sub><sup>+</sup> (11.17/10.71 eV), C<sub>6</sub>H<sub>5</sub><sup>+</sup> (13.73 eV), C<sub>5</sub>H<sub>6</sub><sup>+</sup> (13.58/12.50 eV), C<sub>5</sub>H<sub>5</sub><sup>+</sup> (16.23 eV), C<sub>4</sub>H<sub>5</sub><sup>+</sup> (15.64 eV), C<sub>4</sub>H<sub>4</sub><sup>+</sup> (16.10 eV) and C<sub>4</sub>H<sub>3</sub><sup>+</sup> (17.11 eV) are determined, respectively by using photoionization efficiency spectrometry. With the help of experimental and theoretical results, seven dissociative photoionization channels have been proposed: C<sub>7</sub>H<sub>7</sub><sup>+</sup> + H, C<sub>6</sub>H<sub>5</sub><sup>+</sup> + CH<sub>3</sub>, C<sub>5</sub>H<sub>6</sub><sup>+</sup> + C<sub>2</sub>H<sub>2</sub>, C<sub>5</sub>H<sub>5</sub><sup>+</sup> + C<sub>2</sub>H<sub>2</sub> + H, C<sub>4</sub>H<sub>5</sub><sup>+</sup> + C<sub>3</sub>H<sub>3</sub>, C<sub>4</sub>H<sub>4</sub><sup>+</sup> + C<sub>3</sub>H<sub>4</sub> and C<sub>4</sub>H<sub>3</sub><sup>+</sup> + C<sub>3</sub>H<sub>4</sub> + H. In addition, the geometries of the intermediates, transition states and products involved in these photoionization and dissociative photoionization processes have been performed at the B3LYP/6-311++G(d, p) level. The mechanisms of dissociative photoionization of toluene and the intermediates and transition states involved are discussed in detail. Generally speaking, the experimental results are in agreement with theoretical calculations in this work and published literature results. Especially the mechanisms of dissociative photoionization to C<sub>4</sub>H<sub>5</sub><sup>+</sup>, C<sub>4</sub>H<sub>4</sub><sup>+</sup> and C<sub>4</sub>H<sub>3</sub><sup>+</sup> were discussed for the first time in this work. This investigation may provide useful information on understanding the photoionization and dissociative photoionization of toluene.</p>","PeriodicalId":12007,"journal":{"name":"European Journal of Mass Spectrometry","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2021-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39512923","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
High-resolution mass spectrometry reveals a complex ganglioside pattern and novel polysialylated structures associated with the human motor cortex. 高分辨率质谱揭示了与人类运动皮层相关的复杂神经节苷脂模式和新型多唾液化结构。
IF 1.3 4区 化学
European Journal of Mass Spectrometry Pub Date : 2021-10-01 Epub Date: 2021-09-13 DOI: 10.1177/14690667211040912
Raluca Ica, Cristian Va Munteanu, Zeljka Vukelic, Alina D Zamfir
{"title":"High-resolution mass spectrometry reveals a complex ganglioside pattern and novel polysialylated structures associated with the human motor cortex.","authors":"Raluca Ica,&nbsp;Cristian Va Munteanu,&nbsp;Zeljka Vukelic,&nbsp;Alina D Zamfir","doi":"10.1177/14690667211040912","DOIUrl":"https://doi.org/10.1177/14690667211040912","url":null,"abstract":"<p><p>We have developed here a superior methodology based on high-resolution mass spectrometry for screening and fragmentation analysis of gangliosides extracted and purified from the human motor cortex . The experiments, conducted on a nanoelectrospray Orbitrap mass spectroscope in the negative ion mode, allowed the discrimination in the native mixture extracted from human motor cortex of no less than 83 different gangliosides, which represents the highest number of structures identified so far in this brain region. The spectral data, acquired in high-resolution mass spectrometry mode with a remarkable sensitivity and an average mass accuracy of 4.48 ppm, also show that the gangliosidome of motor cortex is generally characterized by species exhibiting a much higher degree of sialylation than previously known. Motor cortex was found dominated by complex structures with a sialylation degree ≥3, exhibiting long saccharide chains, in the G1 class. Fucogangliosides and species with the glycan chain elongated by either <i>O</i>-acetylation and/or acetate anion attachments were also detected; the later modification was for the first time discovered in this brain region. Of major significance is the identification of hepta and octasialylated species of GS1 and GO1 type, which are among the structures with the longest oligosaccharide chain discovered so far in the human brain. In the last stage of research, tandem mass spectrometry performed by higher energy collision dissociation provided structural data documenting the occurrence of GT1b (d18:1/20:0) isomer in the human motor cortex.</p>","PeriodicalId":12007,"journal":{"name":"European Journal of Mass Spectrometry","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2021-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39411933","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 1
Proximity Effects in Mass Spectra of Benzanilides. 苯甲酰苯胺质谱中的邻近效应。
IF 1.3 4区 化学
European Journal of Mass Spectrometry Pub Date : 2021-10-01 DOI: 10.1177/14690667211054152
Nathan W Fenwick, Amie Saidykhan, Yasser Nazir, Richard Telford, Binyaameen Masood, William H C Martin, Richard T Gallagher, Richard D Bowen
{"title":"Proximity Effects in Mass Spectra of Benzanilides.","authors":"Nathan W Fenwick,&nbsp;Amie Saidykhan,&nbsp;Yasser Nazir,&nbsp;Richard Telford,&nbsp;Binyaameen Masood,&nbsp;William H C Martin,&nbsp;Richard T Gallagher,&nbsp;Richard D Bowen","doi":"10.1177/14690667211054152","DOIUrl":"https://doi.org/10.1177/14690667211054152","url":null,"abstract":"<p><p>The analytical value of peaks arising by a proximity effect in the electron ionization mass spectra of benzanilides has been established by examining the spectra of numerous examples of general structure XC<sub>6</sub>H<sub>4</sub>NHCOC<sub>6</sub>H<sub>4</sub>Y. Significant [M-X]<sup>+</sup> signals are observed only when X = Cl, Br, I or CH<sub>3</sub>O in the 2-position. The presence of strong [M-X]<sup>+</sup> signals, but negligibly weak [M-Y]<sup>+</sup> peaks, even when the C-Y bond would be expected to break more readily than the C-X bond, indicates that these diagnostically useful signals do not arise by simple cleavage. Similarly, the presence of an appreciable [M-Cl]<sup>+</sup> signal, but no [M-Br]<sup>+</sup> signal, in the spectra of representative examples of 4-Br-2ClC<sub>6</sub>H<sub>3</sub>NHCOC<sub>6</sub>H<sub>4</sub>Y, reveals that loss of a substituent from the 2-position occurs much more rapidly than fission of a weaker bond to a substituent in the 4-position. These trends are interpreted in terms of cyclization of the ionized 2-substituted benzanilide, followed by elimination of the substituent originally in the 2-position, to form a protonated 2-arylbenzoxazole.</p>","PeriodicalId":12007,"journal":{"name":"European Journal of Mass Spectrometry","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2021-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ftp.ncbi.nlm.nih.gov/pub/pmc/oa_pdf/b1/ba/10.1177_14690667211054152.PMC8586190.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39699764","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 1
Certain Properties of a Generalized Class of Analytic Functions Involving Some Convolution Operator 一类包含卷积算子的广义解析函数的某些性质
IF 1.3 4区 化学
European Journal of Mass Spectrometry Pub Date : 2021-05-28 DOI: 10.34198/EJMS.7121.4976
F.S.A. Malik, Nusrat Ahmed Dar, Chitaranjan Sharma
{"title":"Certain Properties of a Generalized Class of Analytic Functions Involving Some Convolution Operator","authors":"F.S.A. Malik, Nusrat Ahmed Dar, Chitaranjan Sharma","doi":"10.34198/EJMS.7121.4976","DOIUrl":"https://doi.org/10.34198/EJMS.7121.4976","url":null,"abstract":"We use the concept of convolution to introduce and study the properties of a unified family \u0000 $mathcal{TUM}_gamma(g,b,k,alpha)$, \u0000 $(0leqgammaleq1,,kgeq0)$, \u0000 consisting of uniformly $k$-starlike and $k$-convex functions of \u0000 complex order $binmathbb{C}setminus{0}$ \u0000 and type $alphain[0,1)$.\u0000 The family $mathcal{TUM}_gamma(g,b,k,alpha)$ is a generalization of several other families of analytic functions available in literature.\u0000 Apart from discussing the coefficient bounds, sharp radii estimates, extreme points and the subordination theorem for this family, we settle down the Silverman's conjecture for integral means inequality. Moreover, invariance of this family under certain well-known integral operators is also established in this paper. Some previously known results are obtained as special cases.","PeriodicalId":12007,"journal":{"name":"European Journal of Mass Spectrometry","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2021-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49519356","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 1
0
×
引用
GB/T 7714-2015
复制
MLA
复制
APA
复制
导出至
BibTeX EndNote RefMan NoteFirst NoteExpress
×
提示
您的信息不完整,为了账户安全,请先补充。
现在去补充
×
提示
您因"违规操作"
具体请查看互助需知
我知道了
×
提示
确定
请完成安全验证×
相关产品
×
本文献相关产品
联系我们:info@booksci.cn Book学术提供免费学术资源搜索服务,方便国内外学者检索中英文文献。致力于提供最便捷和优质的服务体验。 Copyright © 2023 布克学术 All rights reserved.
京ICP备2023020795号-1
ghs 京公网安备 11010802042870号
Book学术文献互助
Book学术文献互助群
群 号:481959085
Book学术官方微信