42 research outputs found

    Cobalt-Catalyzed Biaryl Couplings via C–F Bond Activation in the Absence of Phosphine or NHC Ligands

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    A highly general and selective Co-catalyzed biaryl coupling through C–F cleavage under phosphine or NHC-free conditions was described. A broad range of aryl fluorides including unactivated fluorides as well as those with sensitive functionalities could couple with various Ti­(OEt)<sub>4</sub>-mediated aryl Grignard reagents with high selectivity under the catalysis of CoCl<sub>2</sub>/DMPU. Importantly, selective C–F bond activation couplings between two types of fluorines (difluorinated aromatics and on two different coupling partners) and in the presence of C–Cl or C–Br bonds could also be achieved

    Data_Sheet_1_Research on the influence mechanism of privacy invasion experiences with privacy protection intentions in social media contexts: Regulatory focus as the moderator.ZIP

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    IntroductionIn recent years, there have been numerous online privacy violation incidents caused by the leakage of personal information of social media users, yet there seems to be a tendency for users to burn out when it comes to privacy protection, which leads to more privacy invasions and forms a vicious circle. Few studies have examined the impact of social media users' privacy invasion experiences on their privacy protection intention. Protection motivation theory has often been applied to privacy protection research. However, it has been suggested that the theory could be improved by introducing individual emotional factors, and empirical research in this area is lacking.MethodsTo fill these gaps, the current study constructs a moderated chain mediation model based on protection motivation theory and regulatory focus theory, and introduces privacy fatigue as an emotional variable.Results and discussionAn analysis of a sample of 4800 from China finds that: (1) Social media users' previous privacy invasion experiences can increase their privacy protection intention. This process is mediated by response costs and privacy fatigue. (2) Privacy fatigue plays a masking effect, i.e., increased privacy invasion experiences and response costs will raise individuals' privacy fatigue, and the feeling of privacy fatigue significantly reduces individuals' willingness to protect their privacy. (3) Promotion-focus individuals are less likely to experience privacy fatigue than those with prevention-focus. In summary, this trend of “lie flat” on social media users' privacy protection is caused by the key factor of “privacy fatigue”, and the psychological trait of regulatory focus can be used to interfere with the development of privacy fatigue. This study extends the scope of research on privacy protection and regulatory focus theory, refines the theory of protection motivation, and expands the empirical study of privacy fatigue; the findings also inform the practical governance of social network privacy.</p

    Image_1_A Novel Strategy for Predicting 72-h Mortality After Admission in Patients With Polytrauma: A Study on the Development and Validation of a Web-Based Calculator.tif

    No full text
    BackgroundEarly and accessible screening of patients with polytrauma at a high risk of hospital death is essential. The purpose of this research was to seek an accurate and convenient solution to predict deaths occurring within 72 h after admission of these patients.MethodsA secondary analysis was conducted on 3,075 patients with polytrauma from the Dryad database. We imputed missing values in eligible individuals with the k-nearest neighbor algorithm and then randomly stratified them into the training group (n = 2,461) and the validation group (n = 614) based on a proportion of 8:2. The restricted cubic spline, univariate, backward stepwise, and multivariate logistic regression methods were employed to determine the suitable predictors. Calibration and receiver operating characteristic (ROC) curves were applied to assess the calibration and discrimination of the obtained model. The decision curve analysis was then chosen as the measure to examine the clinical usage.ResultsAge, the Glasgow Coma Scale score, the Injury Severity Score, base excess, and the initial lactate level were inferred as independent prognostic factors related to mortality. These factors were then integrated and applied to construct a model. The performance of calibration plots, ROC curves, and decision curve analysis indicated that the model had satisfactory predictive power for 72-h mortality after admission of patients with polytrauma. Moreover, we developed a nomogram for visualization and a web-based calculator for convenient application (https://songandwen.shinyapps.io/DynNomapp/).ConclusionsA convenient web-based calculator was constructed to robustly estimate the risk of death in patients with polytrauma within 72 h after admission, which may aid in further rationalization of clinical decision-making and accurate individual treatment.</p

    Characterization of Glutamine Deamidation by Long-Length Electrostatic Repulsion-Hydrophilic Interaction Chromatography-Tandem Mass Spectrometry (LERLIC-MS/MS) in Shotgun Proteomics

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    Deamidation of glutamine (Gln) residues is a spontaneous or enzymatic process with significant implications in aging and human pathology. Although some methods are available to identify the γ/α-glutamyl products of deamidation, none of these methods allows the characterization of this post-translational modification (PTM) from complex biological samples by shotgun proteomics. Here we present LERLIC-MS/MS, a chromatographic strategy that uses a long (50 cm) anion-exchange capillary column operating in the electrostatic repulsion-hydrophilic interaction mode (ERLIC) and coupled directly to tandem mass spectrometry (MS/MS) for proteome analysis in a single injection. Profiling of soluble extracts of brain tissues by LERLIC-MS/MS distinguished for the first time γ/α-glutamyl isomers of deamidation, encountering a 1.7 γ/α-glutamyl ratio for most Gln deamidation products. A detailed analysis of any deviation from that observed ratio allowed the identification of transglutaminase-mediated γ-glutamyl isomers as intermediate products of transamidation. Furthermore, LERLIC-MS/MS was able to simultaneously separate Gln and asparagine (Asn) deamidation products even for those peptides showing multiple deamidated proteoforms. The characterization of Asn deamidated residues by LERLIC-MS/MS also uncovered novel PIMT (protein L-isoaspartyl methyltransferase) substrate proteins in human brain tissues that deviated from the expected 3:1 isoAsp/Asp ratio. Taken together, our results demonstrate that LERLIC-MS/MS can be used to perform an in-depth study of protein deamidation on a global proteome scale. This new strategy should help to elucidate the biological implications of deamidation in aging and disease conditions

    Characterization of Glutamine Deamidation by Long-Length Electrostatic Repulsion-Hydrophilic Interaction Chromatography-Tandem Mass Spectrometry (LERLIC-MS/MS) in Shotgun Proteomics

    No full text
    Deamidation of glutamine (Gln) residues is a spontaneous or enzymatic process with significant implications in aging and human pathology. Although some methods are available to identify the γ/α-glutamyl products of deamidation, none of these methods allows the characterization of this post-translational modification (PTM) from complex biological samples by shotgun proteomics. Here we present LERLIC-MS/MS, a chromatographic strategy that uses a long (50 cm) anion-exchange capillary column operating in the electrostatic repulsion-hydrophilic interaction mode (ERLIC) and coupled directly to tandem mass spectrometry (MS/MS) for proteome analysis in a single injection. Profiling of soluble extracts of brain tissues by LERLIC-MS/MS distinguished for the first time γ/α-glutamyl isomers of deamidation, encountering a 1.7 γ/α-glutamyl ratio for most Gln deamidation products. A detailed analysis of any deviation from that observed ratio allowed the identification of transglutaminase-mediated γ-glutamyl isomers as intermediate products of transamidation. Furthermore, LERLIC-MS/MS was able to simultaneously separate Gln and asparagine (Asn) deamidation products even for those peptides showing multiple deamidated proteoforms. The characterization of Asn deamidated residues by LERLIC-MS/MS also uncovered novel PIMT (protein L-isoaspartyl methyltransferase) substrate proteins in human brain tissues that deviated from the expected 3:1 isoAsp/Asp ratio. Taken together, our results demonstrate that LERLIC-MS/MS can be used to perform an in-depth study of protein deamidation on a global proteome scale. This new strategy should help to elucidate the biological implications of deamidation in aging and disease conditions

    Characterization of Glutamine Deamidation by Long-Length Electrostatic Repulsion-Hydrophilic Interaction Chromatography-Tandem Mass Spectrometry (LERLIC-MS/MS) in Shotgun Proteomics

    No full text
    Deamidation of glutamine (Gln) residues is a spontaneous or enzymatic process with significant implications in aging and human pathology. Although some methods are available to identify the γ/α-glutamyl products of deamidation, none of these methods allows the characterization of this post-translational modification (PTM) from complex biological samples by shotgun proteomics. Here we present LERLIC-MS/MS, a chromatographic strategy that uses a long (50 cm) anion-exchange capillary column operating in the electrostatic repulsion-hydrophilic interaction mode (ERLIC) and coupled directly to tandem mass spectrometry (MS/MS) for proteome analysis in a single injection. Profiling of soluble extracts of brain tissues by LERLIC-MS/MS distinguished for the first time γ/α-glutamyl isomers of deamidation, encountering a 1.7 γ/α-glutamyl ratio for most Gln deamidation products. A detailed analysis of any deviation from that observed ratio allowed the identification of transglutaminase-mediated γ-glutamyl isomers as intermediate products of transamidation. Furthermore, LERLIC-MS/MS was able to simultaneously separate Gln and asparagine (Asn) deamidation products even for those peptides showing multiple deamidated proteoforms. The characterization of Asn deamidated residues by LERLIC-MS/MS also uncovered novel PIMT (protein L-isoaspartyl methyltransferase) substrate proteins in human brain tissues that deviated from the expected 3:1 isoAsp/Asp ratio. Taken together, our results demonstrate that LERLIC-MS/MS can be used to perform an in-depth study of protein deamidation on a global proteome scale. This new strategy should help to elucidate the biological implications of deamidation in aging and disease conditions

    Image_2_A Novel Strategy for Predicting 72-h Mortality After Admission in Patients With Polytrauma: A Study on the Development and Validation of a Web-Based Calculator.tif

    No full text
    BackgroundEarly and accessible screening of patients with polytrauma at a high risk of hospital death is essential. The purpose of this research was to seek an accurate and convenient solution to predict deaths occurring within 72 h after admission of these patients.MethodsA secondary analysis was conducted on 3,075 patients with polytrauma from the Dryad database. We imputed missing values in eligible individuals with the k-nearest neighbor algorithm and then randomly stratified them into the training group (n = 2,461) and the validation group (n = 614) based on a proportion of 8:2. The restricted cubic spline, univariate, backward stepwise, and multivariate logistic regression methods were employed to determine the suitable predictors. Calibration and receiver operating characteristic (ROC) curves were applied to assess the calibration and discrimination of the obtained model. The decision curve analysis was then chosen as the measure to examine the clinical usage.ResultsAge, the Glasgow Coma Scale score, the Injury Severity Score, base excess, and the initial lactate level were inferred as independent prognostic factors related to mortality. These factors were then integrated and applied to construct a model. The performance of calibration plots, ROC curves, and decision curve analysis indicated that the model had satisfactory predictive power for 72-h mortality after admission of patients with polytrauma. Moreover, we developed a nomogram for visualization and a web-based calculator for convenient application (https://songandwen.shinyapps.io/DynNomapp/).ConclusionsA convenient web-based calculator was constructed to robustly estimate the risk of death in patients with polytrauma within 72 h after admission, which may aid in further rationalization of clinical decision-making and accurate individual treatment.</p

    d‑α-tocopheryl Polyethylene Glycol 1000 Succinate: A View from FTICR MS and Tandem MS

    No full text
    d-α-tocopheryl polyethylene glycol 1000 succinate (TPGS) is an important polymeric excipient frequently used in drug formulation. However, differing compositions of the TPGS samples between batches are believed to result in variable performance of the formulated product. Herein, a high performance method using Fourier-transform ion cyclotron resonance (FTICR) mass spectrometry (MS) and tandem mass spectrometry (MS/MS) to analyze the composition of TPGS samples and the structure of TPGS was established. Aided by high mass accuracy and high resolution, the full MS overview of TPGS is able to provide composition information, and diagnostic fragments from collisionally activated dissociation (CAD) and electron capture dissociation (ECD) MS/MS can be used for the identification of the TPGS structure. ECD and CAD show different preferences in bond cleavage, and an interesting cross-ring cleavage was generated by CAD. Fragmentation information from ECD/ECD MS3 is useful for providing confidence in the results. The influence of different ionization agents (Na+, Li+, and Ag+) on fragmentation of TPGS was investigated with the silver adduct providing different fragments. In addition to the methodology study, the MS and MS/MS results from four batches of TPGS samples from two manufacturers were compared. This method can be utilized for the composition and structure study of many other polymeric compounds. FTICR MS/MS demonstrated its promising role as a structural characterization tool complementary to traditional spectroscopy techniques

    Data_Sheet_1_A Novel Strategy for Predicting 72-h Mortality After Admission in Patients With Polytrauma: A Study on the Development and Validation of a Web-Based Calculator.docx

    No full text
    BackgroundEarly and accessible screening of patients with polytrauma at a high risk of hospital death is essential. The purpose of this research was to seek an accurate and convenient solution to predict deaths occurring within 72 h after admission of these patients.MethodsA secondary analysis was conducted on 3,075 patients with polytrauma from the Dryad database. We imputed missing values in eligible individuals with the k-nearest neighbor algorithm and then randomly stratified them into the training group (n = 2,461) and the validation group (n = 614) based on a proportion of 8:2. The restricted cubic spline, univariate, backward stepwise, and multivariate logistic regression methods were employed to determine the suitable predictors. Calibration and receiver operating characteristic (ROC) curves were applied to assess the calibration and discrimination of the obtained model. The decision curve analysis was then chosen as the measure to examine the clinical usage.ResultsAge, the Glasgow Coma Scale score, the Injury Severity Score, base excess, and the initial lactate level were inferred as independent prognostic factors related to mortality. These factors were then integrated and applied to construct a model. The performance of calibration plots, ROC curves, and decision curve analysis indicated that the model had satisfactory predictive power for 72-h mortality after admission of patients with polytrauma. Moreover, we developed a nomogram for visualization and a web-based calculator for convenient application (https://songandwen.shinyapps.io/DynNomapp/).ConclusionsA convenient web-based calculator was constructed to robustly estimate the risk of death in patients with polytrauma within 72 h after admission, which may aid in further rationalization of clinical decision-making and accurate individual treatment.</p
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