26 research outputs found

    Resolving co-eluting chromatographic patterns by means of dissimilarity analysis in iterative target transformation factor analysis

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    The initialization of concentration vector for iterative target transformation factor analysis (ITTFA) and identification of pure or key variables are the important issue in MCR. In this study, dissimilarity analysis and evolving factor analysis (EFA) are combined to find the selective or key variables and subsequently obtain initial estimates of the concentration vectors for resolution of gas chromatography/mass spectrometry (GC/MS) data by ITTFA. For systems containing components with highly similar mass spectra, a new constraint setting the elements out of elution window to 0 is used to improve convergence rate and accuracy of results. Tested by standard mixture of two wax esters and real GC/MS data of gasoline 97#, dissimilarity based ITTFA could obtain accurate results (average Dot product of concentration vectors, average deviation of peak area ratio and average similarity of mass spectra are 0.9929, 0.0228 and 981.0, respectively). (C) 2011 Elsevier B.V. All rights reserved

    Neutral losses: A type of important variables in prediction of branching degree for acyclic alkenes from mass spectra

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    Neutral losses are a type of important variables in mass spectral interpretation. Since it is hard to calculate or extract neutral losses from mass spectra, they are usually discarded. In this study, dissimilarity analysis was employed to extract mass spectral characteristics for predicting branching degree of acyclic alkenes. The relationships between branching degree and neutral loss were constructed under direction of experimental observation and mass spectral fragmentations. A branching degree predictor of acyclic alkenes was subsequently built based on the above relationships. After tested by the experimental data in previous studies, the predictor could correctly provide the branching degree from abundant ions of mass spectra. More importantly, this predictor was able to point out which acyclic alkenes could be predicted correctly or not. (C) 2012 Published by Elsevier B.V

    Grape-seed Polyphenols Play a Protective Role in Elastase-induced Abdominal Aortic Aneurysm in Mice

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    Abstract Abdominal aortic aneurysm (AAA) is a kind of disease characterized by aortic dilation, whose pathogenesis is linked to inflammation. This study aimed to determine whether grape-seed polyphenols (GSP) has anti-AAA effects and what mechanism is involved, thus to find a way to prevent occurrence and inhibit expansion of small AAA. In our study, AAA was induced by incubating the abdominal aorta of the mice with elastase, and GSP was administrated to the mice by gavage at different doses beginning on the day of the AAA inducement. In in vivo experiments, 800 mg/kg GSP could significantly reduce the incidence of AAA, the dilatation of aorta and elastin degradation in media, and dramatically decrease macrophage infiltration and activation and expression of matrix metalloproteinase (MMP) −2 and MMP-9 in the aorta, compared to the AAA model group. Meanwhile, 400 mg/kg GSP could also but not completely inhibit the occurrence and development of AAA. In in vitro experiments, GSP dose-dependently inhibited mRNA expression of interleukin (IL)-1β, IL-6 and monocyte chemoattractant protein-1 (MCP-1), and significantly inhibited expression and activity of MMP-2 and MMP-9, thus prevented elastin from degradation. In conclusion, GSP showed great anti-AAA effects and its mechanisms were related to inhibition of inflammation

    Quantitative Structure-Activity Relationship Study of Antioxidant Tripeptides Based on Model Population Analysis

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    Due to their beneficial effects on human health, antioxidant peptides have attracted much attention from researchers. However, the structure-activity relationships of antioxidant peptides have not been fully understood. In this paper, quantitative structure-activity relationships (QSAR) models were built on two datasets, i.e., the ferric thiocyanate (FTC) dataset and ferric-reducing antioxidant power (FRAP) dataset, containing 214 and 172 unique antioxidant tripeptides, respectively. Sixteen amino acid descriptors were used and model population analysis (MPA) was then applied to improve the QSAR models for better prediction performance. The results showed that, by applying MPA, the cross-validated coefficient of determination (Q2) was increased from 0.6170 to 0.7471 for the FTC dataset and from 0.4878 to 0.6088 for the FRAP dataset, respectively. These findings indicate that the integration of different amino acid descriptors provide additional information for model building and MPA can efficiently extract the information for better prediction performance

    Sociodemographic disparities in gastric cancer and the gastric precancerous cascade: A population-based study

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    Background: Gastric carcinogenesis is a multistep process initiating with chronic gastritis and progressing through atrophy, intestinal metaplasia, and dysplasia to carcinoma. This study aims to comprehensively investigate sociodemographic disparities in each stage of gastric carcinogenesis and estimate to what extent the inequalities could be ascribed to risk factors of gastric cancer (GC). Methods: We used the baseline data from a community-based study in China's high-risk areas, totalling 27094 participants. Gastric mucosa status was ascertained by endoscopy and biopsies. An overall socioeconomic status (SES) variable was generated by latent class analysis. We calculated relative risks (RRs) and 95% confidence intervals (CIs) using modified Poisson regression to assess associations of sociodemographic factors with each cascade stage. We estimated the percentage of the excess risk for neoplastic lesions among vulnerable populations that can be explained by established risk factors. Results: Age and sex showed associations with all gastric lesions, whose RRs increased with lesion progressing. Compared with individuals without schooling, the RRs of neoplastic lesions for people with primary, secondary, and post-secondary education were 0·86 (95% CI 0·76–0·97), 1·00 (95% CI 0·88–1·13), and 0·70 (95% CI 0·47–1·03), respectively. Participants with medium SES had a lower risk of neoplastic lesions than people in the low SES group (RR 0·83, 95% CI 0·74–0·93). GC risk factors could explain 33·6% of the excess risk of neoplastic lesions among men and a small proportion of the disparities among SES groups. Interpretation: Age and sex were essential sociodemographic factors for GC and precursor diseases. Individuals with low educational levels or SES were more likely to have neoplastic lesions. About one-third of the sex difference and a slight fraction of the socioeconomic inequalities could be attributed to included risk factors. Funding: Sanming Project of Medicine in Shenzhen, National Natural Science Foundation, and Special Project of Bejing-Tianjin-Hebei Basic Research Cooperation

    The population-level economic burden of liver cancer in China, 2019–2030: prevalence-based estimations from a societal perspective

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    Abstract Background Benchmark data on the population-level economic burden are critical to inform policymakers about liver cancer control. However, comprehensive data in China are currently limited. Methods A prevalence-based approach from a societal perspective was used to quantify the annual economic burden of liver cancer in China from 2019 to 2030. Detailed per-case data on medical/non-medical expenditure and work-loss days were extracted from a multicenter survey. The numbers/rates of new/prevalent cases and deaths, survival, and population-related parameters were extracted from the Global Burden of Disease 2019 and the literature. All expenditure data were reported in both 2019 Chinese Yuan (CNY) and United States dollar (US,for mainestimations).ResultTheoveralleconomicburdenoflivercancerwasestimatedatCNY76.7/US, for main estimations). Result The overall economic burden of liver cancer was estimated at CNY76.7/US11.1 billion in China in 2019 (0.047% of the local GDP). The direct expenditure was CNY21.6/US3.1billion,includingCNY19.7/US3.1 billion, including CNY19.7/US2.9 billion for medical expenditure and CNY1.9/US0.3billionfornon−medicalexpenditure.TheindirectcostwasCNY55.1/US0.3 billion for non-medical expenditure. The indirect cost was CNY55.1/US8.0 billion (71.8% of the overall burden), including CNY3.0/US0.4billionduetodisabilityandCNY52.0/US0.4 billion due to disability and CNY52.0/US7.5 billion due to premature death. The total burden would increase to CNY84.2/US12.2billion,CNY141.7/US12.2 billion, CNY141.7/US20.5 billion, and CNY234.3/US34.0billionin2020,2025,and2030,accountingfor0.10234.0 billion in 2020, 2025, and 2030, accounting for 0.102%, 0.138%, and 0.192% of China's GDP, respectively. However, if China achieves the goals of Healthy China 2030 or the United Nations' Sustainable Development Goals for non-communicable diseases, the burden in 2030 would be < CNY144.4/US20.9 billion. Conclusions The population-level economic burden of liver cancer in China is currently substantial and will consistently increase in the future. Sustainable efforts in primary and secondary interventions for liver cancer need to be further strengthened

    Cadaveric cardiosphere-derived cells can maintain regenerative capacity and improve the heart function of cardiomyopathy

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    <p><b>Objective</b>: Cardiosphere-derived cells (CDCs) improve cardiac function and attenuate remodeling in ischemic and non-ischemic cardiomyopathy, and are currently obtained through myocardial biopsy. However, there is not any study on whether functional CDCs may be obtained through cadaveric autopsy with similar benefits in non-ischemic cardiomyopathy. <b>Methods</b>: Cardiac tissues from human or mouse cadavers were harvested, plated at 4°C, and removed at varying time points to culture human CDCs (CLH-EDCs) and mouse CDCs (CM-CDCs). The differentiation and paracrine effects of CDCs were also assessed. Furthermore, intramyocardial injection of cadaveric CM-CDCs was performed in an induced dilated cardiomyopathy (DCM) model. <b>Results</b>: With the extension of post mortem hours, the number of CLH-EDCs and CM-CDCs harvested from autopsy specimens decreased. The expressions of von Willebrand factor (VWF) and smooth muscle actin (SMA) on CDCs were gradually reduced, however, cardiac troponin I (TNI) expression increased in the 24 h group compared to the 0 h group. CLH-EDCs were also found to have similar paracrine function in the 24 h group compared to 0 h group. 8 weeks after CM-CDCs transplantion to the injured heart, mean left ventricular ejection fraction increased in both 0 h (64.99 ± 3.4%) and 24 h (62.99 ± 2.8%) CM-CDCs-treated groups as compared to the PBS treated group (53.64 ± 5.6 cm), with a decrease in left ventricular internal diastolic diameter (0.29 ± 0.08 cm and 0.32 ± 0.04 cm in 0 h and 24 h groups, vs. 0.41 ± 0.05 cm in PBS group). <b>Conclusion</b>: CDCs from cadaveric autopsy are highly proliferative and differentiative, and may be used as a source for allograft transplantation, in order to decrease myocardial fibrosis, attenuate left ventricular remodeling, and improve heart function in doxorubicin-induced non-ischemic cardiomyopathy.</p
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