3,943 research outputs found

    Tolerance of banana for fusarium wilt is associated with early H2O2 accumulation in the roots

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    Banana plants derived from a tissue culture process possess a high rate of random variations that were widely used as popular cultivars due to the new desired traits. In this study, two near-isogenic lines, one susceptible (parental Williams-8818) and the other resistant (somaclonal variation progeny Williams-8818-1 from Williams-8818) to Fusarium oxysporum f. sp. Cubense (Foc4), were inoculated with race 4 of F. oxysporum (Fox). Production of O2ā€¢āˆ’ , H2O2 and MDA, as well as changes in enzyme activities, and transcript levels of SOD and CAT in root extracts were monitored every 24 h over 4 days. The histochemical location of H2O2 was also detected. In the resistant iso-line, the accumulation of O2ā€¢āˆ’ and H2O2, and the activation of SOD occurred in the first 24 h, but activation of CAT reached its maximum only after 48 h. All changes were generally lower in the susceptible iso-line when compared to the resistant iso-line. SOD transcripts were further up-regulated until 72 h in the resistant iso-line, but not in the susceptible iso-line. CAT expression was not affected in any of the two iso-lines. This suggests that expressions of the two key genes in the antioxidant system are less suitable indicators for Foc resistance in banana. In contrast, the first ā€œoxidative burstā€ is a better indicator for different susceptibility of banana to Foc.Key words: Banana, Fusarium oxysporum, catalase, reactive oxygen species, somaclonal variation, disease resistance

    Construction and evaluation of ratsā€™ tolerogenic dendritic cells (DC) induced by NF-ĪŗB Decoy method

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    Aims: To construct and evaluate ratsā€™ tolerogenic dendritic cells (DC) through induction by NF-ĪŗB Decoy method.Methods: GM-CSF and IL-4 were used to transform ratsā€™s monocytes into DC, and DC were stimulated with LPS, NF-ĪŗB Decoy ODN, and loaded with Bovine Typeā…”Collagen. The following methods were employed to phenotype DC: 1) Observation of cell morphology; 2) Evaluation of cell viability using trypan blue staining; 3) Purity determination of DC through detection of specific markers OX-62; 4) Evaluation of mature state of DC via the determination of the expression of CD80 and CD86; 5) Determination of stimulation capability towards the proliferation of lymphocyte and the secretion of INF-r and IL-10.Results: The activity of DC was more than 92%, and the expression of OX-62 was more than 70%. Most of DC exhibited the phenotype of CD80+/CD86-. Compared with control group and LPS-stimulation group, the less mature adhered cells and hairlike DC were observed in NF-ĪŗB decoy group. Significant reduction (p<0.05) was observed for the positive expression and extension of CD80 and CD86 in cell surface. After loaded with calf type II collagen, the low expression of CD80 and CD86 remains to be existed. The stimulation capability of DC towards lymphocyte in NF-ĪŗB decoy group was lower than that in control group (p<0.05) and LPS stimulation group (p<0.05).Conclusion: NF-ĪŗB Decoy ODN method can be successfully applied for construct ratsā€™ tolerogenic dendritic cells (DC) with stable morphology and phenotype. The tolerogenic DC exhibited immature immune phenotype, and low capability to stimulate lymphocytes.Keywords: dendritic cells (DC), NF-ĪŗB Decoy ODN, calf type II collage

    Intermolecular Interactions and Thermodynamic Properties of 3,6-Diamino-1,2,4,5-tetrazine-1,4-dioxide Dimers: A Density Functional Theoretical Study

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    Three fully optimized structures of 3,6-diamino-1,2,4,5-tetrazine-1,4-dioxide (LAX-112) dimers have been obtained with theĀ density functional theory (DFT) method at the B3LYP/6-311++G level. Vibrational frequency calculations were carried out toĀ ascertain that each structure is a minimum (no imaginary frequencies). The intermolecular interaction energy is calculated withĀ the basis set superposition error (BSSE) correction and zero point energy (ZPE) correction. The greatest corrected binding energyĀ among the three dimers is ā€“42.38 kJ molā€“1. The charge redistribution mainly occurs on the adjacent O(N)ā€¦ā€¦H atoms betweenĀ submolecules and the charge transfer between two subsystems is very small. Natural bond orbital (NBO) analysis was performedĀ to reveal the origin of the interaction. Based on the vibrational analysis, the standard thermodynamic functions (heat capacitiesĀ (cop), entropies (Som ) and enthalpies (Hom)) and the changes of thermodynamic properties from the monomer to dimer with theĀ temperature ranging from 200.00 K to 800.00 K have been obtained using statistical thermodynamics. The results show that theĀ strong hydrogen bonds dominantly contribute to the dimers, while the bonding energies are not only determined by the hydrogenĀ bonding. The dimerization process of dimer II can occur spontaneously at room temperature.KEYWORDSĀ 3,6-Diamino-1,2,4,5-tetrazine-1,4-dioxide (LAX-112), intermolecular interaction, density functional theory (DFT), natural bondĀ orbital (NBO) analysis, thermodynamic properties

    Aberrant Neurovascular Coupling in Diabetic Retinopathy Using Arterial Spin Labeling (ASL) and Functional Magnetic Resonance Imaging (fMRI) methods

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    Yu-Lin Zhong,1,* Rui-Yang Hu,2,* Xin Huang1 1Department of Ophthalmology, Jiangxi Provincial Peopleā€™s Hospital, The First Affiliated Hospital of Nanchang Medical College, Nanchang, Jiangxi, 330006, Peopleā€™s Republic of China; 2School of Ophthalmology and Optometry, Jiangxi Medical College, Nanchang University, Nanchang, Jiangxi, 330006, Peopleā€™s Republic of China*These authors contributed equally to this workCorrespondence: Xin Huang, Department of Ophthalmology, Jiangxi Provincial Peopleā€™s Hospital, No. 152, Ai Guo Road, Dong Hu District, Nanchang, Jiangxi, 330006, Peopleā€™s Republic of China, Tel +86 15879215294, Email [email protected]: Previous imaging studies have demonstrated that diabetic retinopathy (DR) is linked to structural and functional abnormalities in the brain. However, the extent to which DR patients exhibit abnormal neurovascular coupling remains largely unknown.Methods: Thirty-one patients with DR and 31 sex- and age-matched healthy controls underwent resting-state functional magnetic resonance imaging (rs-fMRI) to calculate functional connectivity strength (FCS) and arterial spin-labeling imaging (ASL) to calculate cerebral blood flow (CBF). The study compared CBF-FCS coupling across the entire grey matter and CBF/FCS ratios (representing blood supply per unit of connectivity strength) per voxel between the two groups. Additionally, a support vector machine (SVM) method was employed to differentiate between diabetic retinopathy (DR) patients and healthy controls (HC).Results: In DRpatients compared to healthy controls, there was a reduction in CBF-FCS coupling across the entire grey matter. Specifically, DR patients exhibited elevated CBF/FCS ratios primarily in the primary visual cortex, including the right calcarine fissure and surrounding cortex. On the other hand, reduced CBF/FCS ratios were mainly observed in premotor and supplementary motor areas, including the left middle frontal gyrus.Conclusion: An elevated CBF/FCS ratio suggests that patients with DR may have a reduced volume of gray matter in the brain. A decrease in its ratio indicates a decrease in regional CBF in patients with DR. These findings suggest that neurovascular decoupling in the visual cortex, as well as in the supplementary motor and frontal gyrus, may represent a neuropathological mechanism in diabetic retinopathy.Keywords: neurovascular coupling, diabetic retinopathy, arterial spin labelling, cerebral blood flow, functional connectivity strength, resting-state, SV

    Design of three-dimensional fitted garment pieces in a virtual environment

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    2004-2005 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

    Design and Testing of Cesium Atomic Concentration Detection System Based on TDLAS

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    In order to better build the Neutral Beam Injector with Negative Ion Source (NNBI), the pre-research on key technologies has been carried out for the Comprehensive Research Facility for Fusion Technology (CRAFT). Cesium seeding into negative-ion sources is a prerequisite to obtain the required negative hydrogen ion. The performance of ion source largely depends on the cesium conditions in the source. It is very necessary to quantitatively measure the amount of cesium in the source during the plasma on and off periods (vacuum stage). This article uses the absorption peak of cesium atoms near 852.1nm to build a cesium atom concentration detection system based on Tunable Diode Laser Absorption Spectroscopy (TDLAS) technology. The test experiment based on the cesium cell is carried out, obtained the variation curve of cesium concentration at different temperatures. The experimental results indicate that: the system detection range is within 5*10E6-2.5*10E7 pieces/cm3 and the system resolution better than 1*10E6 pieces/cm3.Comment: 8 pages,7 figures, the 20th International Symposium on Laser-Aided Plasma Diagnostic

    Earth as a Proxy Exoplanet: Deconstructing and Reconstructing Spectrophotometric Light Curves

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    Point-source spectrophotometric (single-point) light curves of Earth-like planets contain a surprising amount of information about the spatial features of those worlds. Spatially resolving these light curves is important for assessing time-varying surface features and the existence of an atmosphere, which in turn is critical to life on Earth and significant for determining habitability on exoplanets. Given that Earth is the only celestial body confirmed to harbor life, treating it as a proxy exoplanet by analyzing time-resolved spectral images provides a benchmark in the search for habitable exoplanets. The Earth Polychromatic Imaging Camera (EPIC) on the Deep Space Climate Observatory (DSCOVR) provides such an opportunity, with observations of ~5000 full-disk sunlit Earth images each year at 10 wavelengths with high temporal frequency. We disk-integrate these spectral images to create single-point light curves and decompose them into principal components (PCs). Using machine-learning techniques to relate the PCs to six preselected spatial features, we find that the first and fourth PCs of the single-point light curves, contributing ~83.23% of the light-curve variability, contain information about low and high clouds, respectively. Surface information relevant to the contrast between land and ocean reflectance is contained in the second PC, while individual land subtypes are not easily distinguishable (<0.1% total light-curve variation). We build an Earth model by systematically altering the spatial features to derive causal relationships to the PCs. This model can serve as a baseline for analyzing Earth-like exoplanets and guide wavelength selection and sampling strategies for future observations

    Factors associated with health-seeking behavior among migrant workers in Beijing, China

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    <p>Abstract</p> <p>Background</p> <p>Migrant workers are a unique phenomenon in the process of China's economic transformation. The household registration system classifies them as temporary residents in cities, putting them in a vulnerable state with an unfair share of urban infrastructure and social public welfare. The amount of pressure inflicted by migrant workers in Beijing, as one of the major migration destinations, is currently at a threshold. This study was designed to assess the factors associated with health-seeking behavior and to explore feasible solutions to the obstacles migrant workers in China faced with when accessing health-care.</p> <p>Methods</p> <p>A sample of 2,478 migrant workers in Beijing was chosen by the multi-stage stratified cluster sampling method. A structured questionnaire survey was conducted via face-to-face interviews between investigators and subjects. The multilevel methodology (MLM) was used to demonstrate the independent effects of the explanatory variables on health seeking behavior in migrant workers.</p> <p>Results</p> <p>The medical visitation rate of migrant workers within the past two weeks was 4.8%, which only accounted for 36.4% of those who were ill. Nearly one-third of the migrant workers chose self-medication (33.3%) or no measures (30.3%) while ill within the past two weeks. 19.7% of the sick migrants who should have been hospitalized failed to receive medical treatment within the past year. According to self-reported reasons, the high cost of health service was a significant obstacle to health-care access for 40.5% of the migrant workers who became sick. However, 94.0% of the migrant workers didn't have any insurance coverage in Beijing. The multilevel model analysis indicates that health-seeking behavior among migrants is significantly associated with their insurance coverage. Meanwhile, such factors as household monthly income per capita and working hours per day also affect the medical visitation rate of the migrant workers in Beijing.</p> <p>Conclusion</p> <p>This study assesses the influence of socio-demographic characteristics on the migrant workers' decision to seek health care services when they fall ill, and it also indicates that the current health service system discourages migrant workers from seeking appropriate care of good quality. Relevant policies of public medical insurance and assistance program should be vigorously implemented for providing affordable health care services to the migrants. Feasible measures need to be taken to reduce the health risks associated with current hygiene practices and equity should be assured in access to health care services among migrant workers.</p
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