239 research outputs found

    Augmented Arnoldi-Tikhonov Regularization Methods for Solving Large-Scale Linear Ill-Posed Systems

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    We propose an augmented Arnoldi-Tikhonov regularization method for the solution of large-scale linear ill-posed systems. This method augments the Krylov subspace by a user-supplied low-dimensional subspace, which contains a rough approximation of the desired solution. The augmentation is implemented by a modified Arnoldi process. Some useful results are also presented. Numerical experiments illustrate that the augmented method outperforms the corresponding method without augmentation on some real-world examples

    Identification of QTL and candidate genes for Pb accumulation in maize at maturity stage

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    Pb stress.which were located on chromosome 2 and 6 respectively. The two genes were dramatically up-regulated during led to the identiļ¬cation of two Pb-responsive genes from those QTLs, GRMZM2G137161 and GRMZM2G132995, in different tissues, including roots, stems, leaves, and kernels. Furthermore, RNA-seq data and qRT-PCR analysis correlated with stems. A total of 20 QTLs at logarithm of odds (LOD) ratio ā‰„3 were detected for Pb concentration tissues of maize were roots > leaves > stems > kernels. The Pb concentration of kernels was higher signiļ¬cantly stems and leaves ( P < 0.01). The present study has demonstrated that the trend of Pb concentration in different tissues and all the DH lines (P < 0.01). Pb concentration of kernels displayed signiļ¬cant positive relationships with leaves, and kernels were measured. There was a wide distribution of Pb concentration among the mentioned four ). Pb concentrations in roots, stems, -1 solution (500 mg kg2)3ļ¬lled up with soil which was stressed with a Pb(NOidentiļ¬ed using 207 IBM10 DH at maturity stage. The IBM10 DH and parents were planted in pots which were important insights for protecting the environment. Quantitative trait loci (QTL) for Pb accumulation in maize were L) may provide Zea maysthe genetic basis for the underlying mechanism of tolerance for lead responses in maize (Lead (Pb) has become one of the most abundant heavy metal pollutants of the environment. Understandin

    Ligustrazine Inhibits the Migration and Invasion of Renal Cell Carcinoma

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    Ligustrazine is a Chinese herb (Chuanxiong)Ā approved for use as a medical drug in China. Recent evidence suggests that ligustrazine has promising antitumor properties. Our preliminary results showed that ligustrazine could inhibit the growth of human renal cell carcinoma (RCC) cell lines. However, the complicated molecular mechanism has not been fully revealed. Therefore, the purpose of this study to investigate the mechanism of ligustrazine resistance in human RCC cells. Cell proliferation, migration, invasion, and colony-formation ability of RCC cells A498 were detected by MTT assay, clonal formation rates, and transwell chamber assay inĀ vitro. The expression of epithelialā€“mesenchymal transition (EMT)ā€“related proteins were analyzed using western blot test. The effect of ligustrazine on the growth of A498 cells in nude mice was investigated inĀ vivo. Our results showed that ligustrazine could significantly inhibit the proliferation, migration, and invasion of A498 both inĀ vivoĀ andĀ vitro. Western blot analysis showed that the expressions of EMT-related, N-cadherin, snail, and slug proteins were significantly decreased in A498 in the ligustrazine treatment group. This study indicated that ligustrazine could significantly inhibit the malignant biological behaviors of RCC cell lines, possibly by inhibiting the EMT process

    Dietary inflammatory index, and depression and mortality risk associations in U.S. adults, with a special focus on cancer survivors

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    IntroductionA higher risk for depression and mortality is associated with the inflammatory potential of diet measured through the Dietary Inflammatory Index (DII). The roles of DII in the risk of depression and death in cancer survivors were unclear. We aimed to examine the association between energy-adjusted DII (E-DII) score and risk of depression, and mortality using data from the 2007ā€“2018 National Health and Nutrition Examination Survey (NHANES), with a special focus on cancer survivors.MethodsThe 24-h dietary recall interview was used as a basis to calculate the E-DII score and the Patient Health Questionnaire-9 (PHQ-9) was used to measure the depressive outcomes. Logistic regression analyses were performed to determine the association between quartiles of E-DII score and depression. Cox proportional hazard regression and competing risk analyses were used to estimate the risks of quartiles of E-DII score or depression on mortality.ResultsA total of 27,447 participants were included; including 24,694 subjects without cancer and 2,753 cancer survivors. The E-DII score and depression were not distributed differently between the two groups. However, the E-DII scores were positively associated with within each groupā€™s depression (all P trend &lt; 0.001) and participants with higher E-DII scores had a higher risk of depression (subjects without cancer: ORQ4vsQ1: 2.17, 95% CI: 1.75ā€“2.70; cancer survivors: ORQ4vsQ1: 1.78, 95% CI: 1.09ā€“2.92). The median follow-up time were 87 person-months, a total of 1,701 (4.8%) and 570 (15.2%) all-cause deaths in subjects without cancer and cancer survivors were identified by the end of 2019. The highest E-DII scores quartile was associated with the highest risk of all-cause (HRQ4vsQ1: 1.90, 95% CI: 1.54ā€“2.35) and cardiovascular disease (CVD) cause death (HRQ4vsQ1: 2.50, 95% CI: 1.69ā€“2.3.7) in the subjects without cancer. Moreover, participants with depressive symptoms had higher all-cause mortality (HR: 1.29, 95% CI: 1.04ā€“1.59). No significant correlation was found for E-DII scores or depression with all-cause, cancer-cause or CVD-cause mortality in cancer survivors.ConclusionOur findings demonstrate that E-DII score was positively associated with depression risk. A higher E-DII score or depressive symptom may increase the risks of all-cause and CVD-cause mortality only among general subjects

    Characterization of condensed tannins from purple prairie clover (Dalea purpurea Vent.) conserved as either freeze-dried forage, sun-cured hay or silage

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    Conservation methods have been shown to affect forage nutrient composition and value, but little information is available about the effect of forage conservation on plant condensed tannins (CT). The objective of this study was to assess the effects of conservation method on the concentration, chemical composition and biological activity of CT. Whole-plant purple prairie clover (PPC, Dalea purpurea Vent.) was harvested at full flower and conserved as freeze-dried forage (FD), hay (HAY) or silage (SIL). Concentration of CT in conserved PPC was determined by the butanol-HCl-acetone method. Structural composition, protein-precipitation capacity and anti-bacterial activity of CT isolated from conserved forage were determined by in situ thiolytic degradation followed by HPLC-MS analysis, a protein precipitation assay using bovine serum albumin and ribulose 1,5-disphosphate carboxylase as model proteins and by an Escherichia coli (E. coli) growth test, respectively. Conservation method had no effect on concentration of total CT, but ensiling decreased (p HAY > SIL. E. coli growth n M9 medium was inhibited by 25-100 Āµg/mL of CT isolated from FD, HAY and SIL (p < 0.05), but preservation method had no effect on the ability of CT to inhibit bacterial growth. The results demonstrated that ensiling decreased the extractability and protein-precipitating capacity of CT by increasing the proportions of PC. Purple prairie clover conserved as hay retained more biologically active CT than if it was conserved as silage

    Ecological risk of microplastic toxicity to earthworms in soil: A bibliometric analysis

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    Accumulation of microplastics (MPs) in soil is a serious environmental concern. Addition of exogenous MPs can alter structure and physicochemical properties of and material transport in soil. MPs are particularly toxic to earthworms, which are soil ecosystem engineers, and exacerbate ecological risks; however, there is a lack of comprehensive and in-depth analyses of how MPs exhibit toxicity to/towards earthworms. In this study, we report a bibliometric analysis of 77 peer-reviewed papers published before December 2021 to systematically analyze how the addition of exogenous MPs contributes to earthworm toxicity and clarify the historical development and research hotspots in this field. We found that first, polyethylene and polystyrene are the most common materials used to study the toxic effects of MPs on earthworms. Second, the toxic mechanisms of MPs on earthworms mainly involve histopathological damage and oxidative stress, as well as serving as carriers of complex pollutants (e.g., heavy metals and organic pollutants) through combined adsorptionā€“desorption. Third, oxidative stress is the typical reaction process of MPs toxicity in earthworms. When the content of MPs in soil exceeds 0.1%, earthworm growth is affected, and oxidative stress is induced, resulting in neural and DNA damage. Based on published studies, the prospects for future research on the ecological risks posed by MPs to earthworms have also been discussed. Overall, our findings help clarify the ecological risk of soil MPs toxicity to earthworms, reveal the mechanism of their toxic effects, and provide a theoretical basis for future studies focusing on establishing a healthy and ecologically sustainable soil environment

    Ligustrazine Inhibits the Migration and Invasion of Renal Cell Carcinoma

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    Ligustrazine is a Chinese herb (Chuanxiong) approved for use as a medical drug in China. Recent evidence suggests that ligustrazine has promising antitumor properties. Our preliminary results showed that ligustrazine could inhibit the growth of human renal cell carcinoma (RCC) cell lines. However, the complicated molecular mechanism has not been fully revealed. Therefore, the purpose of this study to investigate the mechanism of ligustrazine resistance in human RCC cells. Cell proliferation, migration, invasion, and colony-formation ability of RCC cells A498 were detected by MTT assay, clonal formation rates, and transwell chamber assay in vitro. The expression of epithelialā€“mesenchymal transition (EMT)ā€“related proteins were analyzed using western blot test. The effect of ligustrazine on the growth of A498 cells in nude mice was investigated in vivo. Our results showed that ligustrazine could significantly inhibit the proliferation, migration, and invasion of A498 both in vivo and vitro. Western blot analysis showed that the expressions of EMT-related, N-cadherin, snail, and slug proteins were significantly decreased in A498 in the ligustrazine treatment group. This study indicated that ligustrazine could significantly inhibit the malignant biological behaviors of RCC cell lines, possibly by inhibiting the EMT process

    Outbreak of COVID-19 and SARS in mainland China: a comparative study based on national surveillance data

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    Objective To compare the epidemiological characteristics and transmission dynamics in relation to interventions against the COVID-19 and severe acute respiratory syndrome (SARS) outbreak in mainland China. Design Comparative study based on a unique data set of COVID-19 and SARS. Setting Outbreak in mainland China. Participants The final database included 82 858 confirmed cases of COVID-19 and 5327 cases of SARS. Methods We brought together all existing data sources and integrated them into a comprehensive data set. Individual information on age, sex, occupation, residence location, date of illness onset, date of diagnosis and clinical outcome was extracted. Control measures deployed in mainland China were collected. We compared the epidemiological and spatial characteristics of COVID-19 and SARS. We estimated the effective reproduction number to explore differences in transmission dynamics and intervention effects. Results Compared with SARS, COVID-19 affected more extensive areas (1668 vs 230 counties) within a shorter time (101 vs 193 days) and had higher attack rate (61.8 vs 4.0 per million persons). The COVID-19 outbreak had only one epidemic peak and one epicentre (Hubei Province), while the SARS outbreak resulted in two peaks and two epicentres (Guangdong Province and Beijing). SARSCoV-2 was more likely to infect older people (median age of 52 years), while SARS-CoV tended to infect young adults (median age of 34 years). The case fatality rate (CFR) of either disease increased with age, but the CFR of COVID-19 was significantly lower than that of SARS (5.6% vs 6.4%). The trajectory of effective reproduction number dynamically changed in relation to interventions, which fell below 1 within 2 months for COVID-19 and within 5.5 months for SARS. Conclusions China has taken more prompt and effective responses to combat COVID-19 by learning lessons from SARS, providing us with some epidemiological clues to control the ongoing COVID-19 pandemic worldwid

    The influence of methotrexate-related transporter and metabolizing enzyme gene polymorphisms on peri-engraftment syndrome and graft-versus-host disease after haplo-hematopoietic stem cell transplantation in pediatric patients with malignant hematological diseases

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    BackgroundMethotrexate (MTX), utilized as a graft-versus-host disease (GvHD) prophylactic agent in allogeneic hematopoietic stem cell transplantation (allo-HSCT), has been proven to effectively decrease the occurrence of the peri-engraftment syndrome (Peri-ES) and acute GvHD (aGvHD). Changes in the pharmacodynamics of MTX are closely associated with gene polymorphisms in genes encoding drug-metabolizing enzymes and transporters. Nevertheless, the current studies mainly concentrate on leukemia or autoimmune diseases, and limited studies on allo-HSCT were reported.MethodsHere, we retrospectively assessed the relationship between MTX-related transporter and metabolizing enzyme gene polymorphisms, clinical characteristics, and outcomes in 57 pediatric patients who received haploid HSCT (haplo-HSCT) with malignant tumors at a single center.ResultsWe discovered all gene polymorphisms were in the Hardyā€“Weinberg equilibrium in our cohort. We discovered a significant correlation between platelet recovery time and ABCB1 (1236C&gt;T) (p = 0.042). Compared with patients with SLCO1B1 (1865+4846T&gt;C) TT, patients with SLCO1B1 (1865+4846T&gt;C) TC/CC had an increased incidence of Peri-ES (p = 0.030). Based on the multivariate Cox analysis, we discovered that SLCO1B1 (1865+4846T&gt;C) TT genotype was an independent protective factor for Peri-ES morbidity (hazard ratio (HR) = 0.464, p = 0.031), and the dose of mononuclear cells reinfused was significantly correlated with IIā€“IV aGvHD (HR = 2.604, p = 0.039).ConclusionIn summary, our findings prove that the hostā€™s genotypes might modify the risk of developing Peri-ES, contribute to a better understanding of the inter-individual difference in efficacy, and facilitate the development of individualized approaches to GvHD prophylaxis
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