932 research outputs found

    Statistical optimization of culture medium for production of exopolysaccharide from endophytic fungus Bionectria ochroleuca and its antitumor effect in vitro

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    Endophytic fungi have been recognized as possible useful sources of bioactive metabolites. However, exopolysaccharide (EPS) production from endophytic fungi and its antitumor activity have been less explored. In the present study, endophtic fungus Bionectria ochroleuca M21 was exploited for the production of EPS in submerged culture. Among tested medium components, glucose, yeast extract, MgSO4 and Tween80 were found to be effective and significant on EPS production. Response surface methodology (RSM) was employed to optimize medium composition. The results showed that the significant factors were glucose, yeast extract and Tween80. The optimal medium was observed at the composition of glucose 55.7 g/L, yeast extract 6.04 g/L, MgSO4 0.25g/L and Tween80 0.1 % (v/v). Using the optimized medium, EPS production was achieve at 2.65 ± 0.16 g/L after 4 days fermentation in a 5L bioreactor. Examination of cytotoxicity showed that the EPS from B. ochroleuca M21 did not have cytotoxic activity on human liver HL-7702 cells at concentration 0.025–1.6 mg/mL. In contrast, the EPS exhibited antiproliferative activities against cell lines of liver cancer (HepG2), gastric cancer (SGC-7901) and colon cancer (HT29) in a dose- and time-dependent manner in the concentration ranges of 0.1-0.45 mg/mL

    Genome-Wide Association Study for Plant Height and Grain Yield in Rice under Contrasting Moisture Regimes

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    Drought is one of the vitally critical environmental stresses affecting both growth and yield potential in rice. Drought resistance is a complicated quantitative trait that is regulated by numerous small effect loci and hundreds of genes controlling various morphological and physiological responses to drought. For this study, 270 rice landraces and cultivars were analyzed for their drought resistance. This was done via determination of changes in plant height and grain yield under contrasting water regimes, followed by detailed identification of the underlying genetic architecture via genome-wide association study (GWAS). We controlled population structure by setting top two eigenvectors and combining kinship matrix for GWAS in this study. Eighteen, five, and six associated loci were identified for plant height, grain yield per plant, and drought resistant coefficient, respectively. Nine known functional genes were identified, including five for plant height (OsGA2ox3, OsGH3-2, sd-1, OsGNA1 and OsSAP11/OsDOG), two for grain yield per plant (OsCYP51G3 and OsRRMh) and two for drought resistant coefficient (OsPYL2 and OsGA2ox9), implying very reliable results. A previous study reported OsGNA1 to regulate root development, but this study reports additional controlling of both plant height and root length. Moreover, OsRLK5 is a new drought resistant candidate gene discovered in this study. OsRLK5 mutants showed faster water loss rates in detached leaves. This gene plays an important role in the positive regulation of yield-related traits under drought conditions. We furthermore discovered several new loci contributing to the three investigated traits (plant height, grain yield, and drought resistance). These associated loci and genes significantly improve our knowledge of the genetic control of these traits in rice. In addition, many drought resistant cultivars screened in this study can be used as parental genotypes to improve drought resistance of rice by molecular breeding

    X-ray Astronomy in the Laboratory with a Miniature Compact Object Produced by Laser-Driven Implosion

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    Laboratory spectroscopy of non-thermal equilibrium plasmas photoionized by intense radiation is a key to understanding compact objects, such as black holes, based on astronomical observations. This paper describes an experiment to study photoionizing plasmas in laboratory under well-defined and genuine conditions. Photoionized plasma is here generated using a 0.5-keV Planckian x-ray source created by means of a laser-driven implosion. The measured x-ray spectrum from the photoionized silicon plasma resembles those observed from the binary stars Cygnus X-3 and Vela X-1 with the Chandra x-ray satellite. This demonstrates that an extreme radiation field was produced in the laboratory, however, the theoretical interpretation of the laboratory spectrum significantly contradicts the generally accepted explanations in x-ray astronomy. This model experiment offers a novel test bed for validation and verification of computational codes used in x-ray astronomy.Comment: 5 pages, 4 figures are included. This is the original submitted version of the manuscript to be published in Nature Physic

    Establishment of a multiplex qPCR assay for the detection of pathogens associated with bovine respiratory disease complex

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    IntroductionThe bovine respiratory disease complex poses a significant threat to the cattle industry, necessitating a multifaceted approach to address its occurrence. The syndrome is caused by various pathogens such as bovine respiratory syncytial virus (BRSV), bovine parainfluenza virus type 3 (BPIV3), bovine viral diarrhea virus (BVDV), bovine adenovirus type 3 (BAV3), Mycoplasma bovis (Mb), and infectious bovine rhinotracheitis virus (IBRV). The confluence of these pathogens causes substantial economic losses to the cattle industry. Although preventive and control measures have been implemented, containment of bovine respiratory diseases continues to present a formidable challenge, highlighting the need for innovative diagnostic and intervention strategies.MethodsIn this study, we designed specific primers targeting six conserved pathogen genes (N of BRSV, M of BPIV3, 5’UTR of BVDV, Hexon of BAV3, oppF of Mb, and gB of IBRV). Subsequently, we established a multiplexed fluorescent real-time quantitative PCR (qPCR) assay for simultaneous detection of these pathogens.ResultsThe developed method exhibited high specificity and sensitivity, with the lowest detection limits for plasmid DNA standards of BRSV, BPIV3, BVDV, BAV3, Mb, and IBRV being 70.1, 40.4, 15.1, 74.4, 69.6, and 4.99 copies/μL, respectively. The coefficients of variation determined by the assay established in this study were <4%, and the amplification efficiency was 93.84%–111.60%, which showed the reliability and stability of the method.DiscussionThe detection rates for BRSV, BPIV3, BVDV, BAV3, Mb, and IBRV were 7.59% (17/224), 11.61% (26/224), 8.04% (18/224), 22.32% (50/224), 27.23% (61/224), and 8.04% (18/224), respectively. All 224 cows were cases of natural disease. Fifty-six diseased cattle were infected with a mixture of two or more of the six pathogens at a mixed infection rate of 25% (56/224). Therefore, this study successfully developed a highly efficient, rapid, specific, and sensitive multiplex qPCR method to detect major pathogens associated with bovine respiratory diseases. This advancement is expected to significantly influence the future of the cattle industry and serve as a valuable reference for subsequent research in this field

    Alcohol, Stem Cells and Cancer.

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    Dosage, gender, and genetic susceptibility to the effects of alcohol remained only partially elucidated. In this review, we summarize the current knowledge of the mechanisms underlying the role of alcohol in liver and gastrointestinal cancers. In addition, two recent pathways- DNA repair and TGF-β signaling which provide new insights into alcohol in the regulation of cancers and stem cells are also discussed here

    Morphology and metabolism of storage substances contribution to alkali stress responses in two contrasting barley cultivars during germination stage

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    Abstract: Barley (Hordeum vulgare L.) is a globally significant crop and serves as a pioneer crop for improving saline-alkaline soils due to its salt-alkali tolerant properties. However, the response mechanism of barley to alkali stress remains unclear. In this study, two barley genotypes with contrasting performance under alkali stress were selected: the alkali-tolerant SCMS and the alkali-sensitive QT9919. The morphological and physiological mechanisms of these two barley cultivars in response to alkali stress were elucidated. Results showed that alkali stress inhibited germination in QT9919, leading to significant decreases in germination vigor, plant height and root length. On the other hand, SCMS presented stronger water absorbing capacity than QT9919 under all circumstances. Furthermore, starch degradation and sugar metabolism were suppressed by alkali stress in both barley cultivars through down-regulation of genes expression and reduction of enzymes activities involved in the processes of EMP (Embden-Meyerhof-Parnas), tricarboxylic acid cycle (TCA), and pentose phosphate pathway (PPP). Notably, enzyme activity of hexokinase (HK) and malic dehydrogenase (MDH) showed significant changes under alkali stress between the two barley genotypes. This study provides insights into screening barley germplasm with strong alkali-tolerance and holds significant implications for improving and utilizing of saline-alkaline soils

    Wavefront improvement in an injection-seeded soft x-ray laser based on a solid-target plasma amplifier

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    Includes bibliographical references (page 4013).The wavefront of an injection-seeded soft x-ray laser beam generated by amplification of high-harmonic pulses in a λ=18.9 nm molybdenum plasma amplifier was measured by a Hartmann wavefront sensor with an accuracy of λ/32 root mean square (rms). A significant improvement in wavefront aberrations of 0.51±0.03λ rms to 0.23±0.01λ rms was observed as a function of plasma column length. The variation of wavefront characteristic as a function time delay between the injection of the seed and peak of soft x-ray amplifier pump was studied. The measurements were used to reconstruct the soft x-ray source and confirm its high peak brightness

    Synthesis, biological evaluation, and physicochemical property assessment of 4-substituted 2-phenylaminoquinazolines as Mer tyrosine kinase inhibitors

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    Current results identified 4-substituted 2-phenylaminoquinazoline compounds as novel Mer tyrosine kinase (Mer TK) inhibitors with a new scaffold. Twenty-one 2,4-disubstituted quinazolines (series 4-7) were designed, synthesized, and evaluated against Mer TK and a panel of human tumor cell lines aimed at exploring new Mer TK inhibitors as novel potential antitumor agents. A new lead, 4b, was discovered with a good balance between high potency (IC50 0.68μM) in the Mer TK assay and antiproliferative activity against MV4-11 (GI50 8.54μM), as well as other human tumor cell lines (GI50<20μM), and a desirable druglike property profile with low logP value (2.54) and high aqueous solubility (95.6μg/mL). Molecular modeling elucidated an expected binding mode of 4b with Mer TK and necessary interactions between them, thus supporting the hypothesis that Mer TK might be a biologic target of this kind of new active compound

    Macrophage Migration Inhibitory Factor Interacting with Th17 Cells May Be Involved in the Pathogenesis of Autoimmune Damage in Hashimoto’s Thyroiditis

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    Purpose. To explore the possible role of MIF and Th17 cells in the thyroid-specific autoimmune damage of Hashimoto’s thyroiditis (HT). Material and Methods. We enrolled 40 HT patients and 30 healthy controls and divided HT patients into euthyroid subset (n=22) and subclinical or overt hypothyroidism subset (n=18). The percentages of Th17 cells and expressions of MIF, interleukin 17A (IL-17A) mRNA in PBMCs, as well as serum concentrations of MIF, and IL-17A, and thyroid functions, and thyroid-specific autoantibodies (TPOAb, TgAb) were detected by flow cytometry, real-time RT-PCR, ELISA, and ECLIA in all subjects. Results. MIF mRNA, IL-17A mRNA expressions and Th17 cells percentages, serum MIF, and IL-17A protein levels were all significantly higher in HT patients, even in euthyroid subgroup. Additionally, the differences became more obvious in dysfunction subgroup. Importantly, both MIF levels and Th17 cells percentage were positively correlated with serum TPOAb, TgAb, and thyrotropin (TSH) levels in HT patients. Conclusions. These data suggest that MIF and Th17 cells increased dynamically and positively correlated with the markers of thyroid autoimmune damage, which indicated that interaction between MIF and Th17 cells may participate in the pathogenesis and development of thyroid-specific autoimmunity in HT
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