179 research outputs found

    Stability and convergence of the two parameter cubic spline collocation method for delay differential equations

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    AbstractIn this paper, we propose the cubic spline collocation method with two parameters for solving delay differential equations (DDEs). Some results of the local truncation error and the convergence of the spline collocation method are given. We also obtain some results of the linear stability and the nonlinear stability of the method for DDEs. In particular, we design an algorithm to obtain the ranges of the two parameters α,β which are necessary for the P-stability of the collocation method. Some illustrative examples successfully verify our theoretical results

    Poly[bis­[μ-1,4-bis­(1H-imidazol-5-yl)benzene-κ2 N 3:N 3′]diformatomanganese(II)]

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    In the title compound, [Mn(CHO2)2(C12H10N4)2]n, the MnII atom and the benzene ring of the ligand lie on an inversion centers. The MnII atom has an octa­hedral coordination environment composed of four N atoms from two different symmetry-related N-heterocyclic ligands forming the basal plane, and two O atoms from symmetry-related formate anions occupying the apical positions. The title compound forms a two-dimensional (4,4) net parallel to (100) with all the MnII atoms lying on a plane. The crystal structure is consolidated by inter­molecular N—H⋯O hydrogen bonds.

    2,5-Dibenzoyl­benzene-1,4-diaminium dichloride

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    The asymmetric unit of the title compound, C20H18N2O2 2+·2Cl−, is composed of one-half of the 2,5-dibenzoyl­benzene-1,4-diaminium dication, located on a centre of inversion, and one Cl− ion. The dihedral angle between the central benzene ring and the benzoyl phenyl ring is 53.3 (2)°. In the crystal structure, ions are linked to form a two-dimensional network parallel to the (10) plane by N—H⋯Cl hydrogen bonds

    Interferon-γ inhibits gastric carcinogenesis by inducing epithelial cell autophagy and T cell apoptosis

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    Author Manuscript 2012 June 15.IFN-γ mediates responses to bacterial infection and autoimmune disease, but it is also an important tumor suppressor. It is upregulated in the gastric mucosa by chronic Helicobacter infection; however, whether it plays a positive or negative role in inflammation-associated gastric carcinogenesis is unexplored. To study this question, we generated an H[superscript +]/K[superscript +]-ATPase-IFN-γ transgenic mouse that overexpresses murine IFN-γ in the stomach mucosa. In contrast to the expected proinflammatory role during infection, we found that IFN-γ overexpression failed to induce gastritis and instead inhibited gastric carcinogenesis induced by interleukin-1beta (IL-1β) and/or Helicobacter infection. Helper T cell (Th) 1 and Th17 immune responses were inhibited by IFN-γ through Fas induction and apoptosis in CD4 T cells. IFN-γ also induced autophagy in gastric epithelial cells through increased expression of Beclin-1. Finally, in the gastric epithelium, IFN-γ also inhibited IL-1β- and Helicobacter-induced epithelial apoptosis, proliferation, and Dckl1[superscript +] cell expansion. Taken together, our results suggest that IFN-γ coordinately inhibits bacterial infection and carcinogenesis in the gastric mucosa by suppressing putative gastric progenitor cell expansion and reducing epithelial cell apoptosis via induction of an autophagic program. Cancer Res; 71(12); 4247–59

    Clinicopathological characteristics and survival outcomes in Paget disease: a SEER populationâ based study

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    The objective of this study was to investigate the clinicopathological characteristics and survival outcomes of Paget disease (PD), Paget disease concomitant infiltrating duct carcinoma (PDâ IDC), and Paget disease concomitant intraductal carcinoma (PDâ DCIS). We identified 501,631 female patients from 2000 to 2013 in the Surveillance, Epidemiology, and End Results (SEER) database. These identified patients included patients with PD (n = 469), patients with PDâ IDC (n = 1832), and patients with PDâ DCIS (n = 1130) and infiltrating ductal carcinoma (IDC) (n = 498,076). Then, we compared the clinical characteristics of these patients with those who were diagnosed with IDC during the same period. The outcomes of these subtypes of breast carcinoma were different. Based on the overall survival, the patients with PDâ IDC had the worst prognosis (5â year survival rate = 84.1%). The PDâ DCIS had the best prognosis (5â year survival rate = 97.5%). Besides, among patients with Paget disease, the one who was married had a better prognosis than who were not. And, according to our research, the marital status was associated with the hormone receptor status in patients with PDâ IDC. Among three subtypes of Paget disease, patients with PDâ IDC had the worst prognosis. Besides, patients who were unmarried had worse outcomes. And the marital status of patients with PDâ IDC is associated with hormone status. The observation underscores the importance of individualized treatment.Patients with PDâ IDC have the worst prognosis. And the marital status of PDâ IDC patients is associated with hormone status and HER2 status. The observation underscores the importance of individualized treatment.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/144702/1/cam41475.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/144702/2/cam41475_am.pd

    3, 4-dihydroxyl-phenyl lactic acid restores NADH dehydrogenase 1 α subunit 10 to ameliorate cardiac reperfusion injury.

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    The present study aimed to detect the role of 3, 4-dihydroxyl-phenyl lactic acid (DLA) during ischemia/reperfusion (I/R) induced myocardial injury with emphasis on the underlying mechanism of DLA antioxidant. Male Spragu-Dawley (SD) rats were subjected to left descending artery occlusion followed by reperfusion. Treatment with DLA ameliorated myocardial structure and function disorder, blunted the impairment of Complex I activity and mitochondrial function after I/R. The results of 2-D fluorescence difference gel electrophoresis revealed that DLA prevented the decrease in NDUFA10 expression, one of the subunits of Complex I. To find the target of DLA, the binding affinity of Sirtuin 1 (SIRT1) to DLA and DLA derivatives with replaced two phenolic hydroxyls was detected using surface plasmon resonance and bilayer interferometry. The results showed that DLA could activate SIRT1 after I/R probably by binding to this protein, depending on phenolic hydroxyl. Moreover, the importance of SIRT1 to DLA effectiveness was confirmed through siRNA transfection in vitro. These results demonstrated that DLA was able to prevent I/R induced decrease in NDUFA10 expression, improve Complex I activity and mitochondrial function, eventually attenuate cardiac structure and function injury after I/R, which was possibly related to its ability of binding to and activating SIRT1

    Compositions of Organic Acids in PM10 Emission Sources in Xiamen Urban Atmosphere

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    对厦门城区大气颗粒物PM10中有机酸的可能来源,如烹调油烟、生物质燃烧颗粒、汽车尾气和土壤/路面扬尘等4种不同排放源,采用再悬浮混合箱得到PM10样品.采用BF3/正丁醇衍生-GC/MS分析方法,测定了包括二元羧酸、脂肪酸和芳香酸共15种有机酸.结果表明,烹调油烟中有机酸的含量远高于其它颗粒物,最高可达53%,其中亚油酸和油酸的含量最高,为24%±14%;而汽车尾气颗粒物中乙二酸的含量最高,其次为邻苯二甲酸Ph;汽油燃烧颗粒物中己二酸与壬二酸的比值显著高于其它样品,可用于环境大气中二元羧酸的人为和生物来源的定性判断.除发电机排放样品外,其它样品中丙二酸与丁二酸的比值(0.07~0.44)远低于环境样品中该比值范围(0.61~3.93),表明丙二酸与丁二酸的比值可用于环境大气中二元羧酸的一次/二次来源的定性判断。Abstract:The possible organic acid emission sources in PM10 in Xiamen urban atmosphere such as cooking,biomass burning,vehicle exhaust and soil /dust were obtained using a re-suspension test chamber. A total of 15 organic acids including dicarboxylic acids,fatty acids and aromatic acids were determined using GC/MS after derivatization with BF3 /n-butanol. The results showed that the highest total concentration of 15 organic acids ( 53%) was found in cooking emission and the average concentration of the sum of linoleic acid and oleic acid was 24% ± 14%. However,oxalic acid was the most abundant species followed by phthalic acid in gasoline vehicle exhaust. The ratios of adipic to azelaic acid in gasoline combustion emissions were significantly higher than those in other emission sources,which can be used to qualitatively differentiate anthropogenic and biological source of dicarboxylic acids in atmospheric samples. The ratios of malonic to succinic acid in source emissions ( except gasoline generator emissions) were lower ( 0. 07-0. 44) than ambient PM10 samples ( 0. 61-3. 93) ,which can be used to qualitatively differentiate the primary source and the secondary source of dicarboxylic acids in urban PM10 .国家自然科学基金项目(40971257,41171365);环境保护公益性行业科研专项(201009004);福建省自然科学基金计划项目(2009J05106

    Intratumoral Decorin Gene Delivery by AAV Vector Inhibits Brain Glioblastomas and Prolongs Survival of Animals by Inducing Cell Differentiation

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    Glioblastoma multiforme (GBM) is the most malignant cancer in the central nervous system with poor clinical prognosis. In this study, we investigated the therapeutic effect of an anti-cancer protein, decorin, by delivering it into a xenograft U87MG glioma tumor in the brain of nude mice through an adeno-associated viral (AAV2) gene delivery system. Decorin expression from the AAV vector in vitro inhibited cultured U87MG cell growth by induction of cell differentiation. Intracranial injection of AAV-decorin vector to the glioma-bearing nude mice in vivo significantly suppressed brain tumor growth and prolonged survival when compared to control non-treated mice bearing the same U87MG tumors. Proteomics analysis on protein expression profiles in the U87MG glioma cells after AAV-mediated decorin gene transfer revealed up- and down-regulation of important proteins. Differentially expressed proteins between control and AAV-decorin-transduced cells were identified through MALDI-TOF MS and database mining. We found that a number of important proteins that are involved in apoptosis, transcription, chemotherapy resistance, mitosis, and fatty acid metabolism have been altered as a result of decorin overexpression. These findings offer valuable insight into the mechanisms of the anti-glioblastoma effects of decorin. In addition, AAV-mediated decorin gene delivery warrants further investigation as a potential therapeutic approach for brain tumors

    Screening for low bone mass with quantitative ultrasonography in a community without dual-energy X-ray absorptiometry: population-based survey

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    BACKGROUND: Dual-energy x-ray absorptiometry (DXA) is the criterion standard to identify low bone mineral density (BMD), but access to axial DXA may be limited or cost prohibitive. We screened for low bone mass with quantitative ultrasonography (QUS) in a community without DXA, analyzed its reliability and obtained reference values and estimated the prevalence of low QUS values. METHODS: We enrolled 6493 residents of Kinmen, Taiwan, and a reference group (96 men and 70 women aged 20–29 years) for this cross-sectional, community-based study. All participants completed a questionnaire and underwent ultrasonographic measurements. Reliability and validity of QUS measurements were evaluated. Broadband ultrasound attenuation (BUA) values were obtained and statistically analyzed by age, sex and weight. Annual loss of BUA was determined. Trends in the prevalence of QUS scores were evaluated. RESULTS: Two QUS were used and had a correlation coefficient of 0.90 (p < 0.001). Calcaneal BUA was significantly correlated with BMD in the femoral neck (r = 0.67, p < 0.001) and BMD of the total lumbar spine (r = 0.59, p < 0.001). BUAs in the reference group were 92.72 ± 13.36 and 87.90 ± 10.68 dB/MHz for men and women, respectively. Estimated annual losses of calcaneal BUA were 0.83% per year for women, 0.27% per year for men, and 0.51% per year for the total population. The prevalence of severely low QUS values (T-score = -2.5) tended to increase with aging in both sexes (p < 0.001). Across age strata, moderately low QUS values (-2.5 < T-score < -1.0) were 31.6–41.0% in men and 23.7–38.1% in women; a significant trend with age was observed in men (p < 0.001). CONCLUSION: Age-related decreases in calcaneal ultrasonometry, which reflected the prevalence of low bone mass, were more obvious in women than in men

    Role of IKK/NF-κB Signaling in Extinction of Conditioned Place Aversion Memory in Rats

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    The inhibitor κB protein kinase/nuclear factor κB (IKK/NF-κB) signaling pathway is critical for synaptic plasticity. However, the role of IKK/NF-κB in drug withdrawal-associated conditioned place aversion (CPA) memory is unknown. Here, we showed that inhibition of IKK/NF-κB by sulphasalazine (SSZ; 10 mM, i.c.v.) selectively blocked the extinction but not acquisition or expression of morphine-induced CPA in rats. The blockade of CPA extinction induced by SSZ was abolished by sodium butyrate, an inhibitor of histone deacetylase. Thus, the IKK/NF-κB signaling pathway might play a critical role in the extinction of morphine-induced CPA in rats and might be a potential pharmacotherapy target for opiate addiction
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