108 research outputs found

    CO (J = 1–0) Observations toward Filamentary Molecular Clouds in the Galactic Region with l = [169.°75, 174.°75], b = [−0.°75, 0.°5]

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    We present observations of the CO isotopologues (12CO, 13CO, and C18O) toward the Galactic region with 169fdg75 ≤ l ≤ 174fdg75 and −0fdg75 ≤ b ≤ 0fdg5 using the Purple Mountain Observatory 13.7 m millimeter-wavelength telescope. Based on the 13CO (J = 1 − 0) data, we find five molecular clouds within the velocity range between −25 and 8 km s−1 that are all characterized by conspicuous filamentary structures. We have identified eight filaments with a length of 6.38–28.45 pc, a mean H2 column density of 0.70 × 1021–6.53 × 1021 cm−2, and a line mass of 20.24–161.91 M ☉ pc−1, assuming a distance of ~1.7 kpc. Gaussian fittings to the inner parts of the radial density profiles lead to a mean FWHM width of 1.13 ± 0.01 pc. The velocity structures of most filaments present continuous distributions with slight velocity gradients. We find that turbulence is the dominant internal pressure to support the fragmentation of filaments instead of thermal pressure. Most filaments have virial parameters smaller than 2; thus, they are gravitationally bound. Four filaments have an LTE line mass close to the virial line mass. We further extract dense clumps using the 13CO data and find that 64% of the clumps are associated with the filaments. According to the complementary IR data, most filaments have associated Class II young stellar objects. Class I objects are mainly found to be located in the filaments with a virial parameter close to 1. Within two virialized filaments, 12CO outflows have been detected, indicating ongoing star-forming activity therein.National Key Research & Development of China [2017YFA0402702]; European Unions Horizon 2020 research and innovation program [639459]; NSFC [11473069, 11503086, 11629302]This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

    Causal relationship between atrial fibrillation and cognitive impairment: a Mendelian randomization study

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    Objective·To investigate the causal relationship between atrial fibrillation (AF) and cognitive impairment.Methods·A two-sample Mendelian randomization (TSMR) analysis was used to assess the potential causality of AF on cognitive dysfunction. Single nucleotide polymorphisms (SNPs) strongly associated with AF were extracted as instrumental variables by using a dataset of a large-scale genome-wide association study (GWAS) on AF. The associations of SNPs with Alzheimer′s disease dementia, Parkinson′s disease dementia, vascular dementia, Lewy body dementia, frontotemporal dementia, undefined dementia, and overall cognitive function assessment were extracted separately from publicly available GWAS data on cognitive dysfunction. The inverse variance-weighted (IVW) method was used for the main analysis, and sensitivity analyses were conducted by using Cochran′s Q test, MR-Egger regression, and leave-one-out method. To verify the robustness of the results, replicate analyses and meta-analyses were performed by using different GWAS data.Results·In the initial analysis, 101 SNPs were extracted as instrumental variables from a meta-analysis of a genome-wide association study involving up to 1 030 836 individuals. The IVW analysis showed no evidence for causal associations between AF and dementia [dementia (OR=1.032; 95%CI 0.973‒1.094; P=0.290), Parkinson′s disease dementia (OR=1.004; 95%CI 0.780‒1.291; P=0.977), vascular dementia (OR=1.123; 95%CI 0.969‒1.301; P=0.125), or unspecified dementia (OR=1.013; 95%CI 0.910‒1.129; P=0.807)]. In the replication analysis, 27 SNPs were extracted as instrumental variables from the FinnGen AF GWAS data, and the IVW analysis were consistent with the initial analysis [cognitive function (OR=0.999; 95%CI 0.982‒1.016; P=0.874), Alzheimer′s disease dementia (OR=0.977; 95%CI 0.943‒1.012; P=0.193), Lewy body dementia (OR=1.014; 95%CI 0.898‒1.145; P=0.826), or frontotemporal dementia (OR=0.996; 95%CI 0.745‒1.333; P=0.980)]. Both Mendelian randomization analyses and meta-analyses showed no evidence of an association between genetically predicted AF and different types of dementia or overall cognitive function assessment. MR-Egger regression suggested no horizontal pleiotropy and leave-one-out analysis showed stable results after individually removing each SNP.Conclusion·No evidence of a causal relationship between AF and cognitive impairment was found. The associations observed in observational studies can be partially attributed to confounding factors such as shared biology or co-morbidities

    Bioassay-guided isolation of three new alkaloids from Suillus bovinus and preliminary mechanism against ginseng root rot

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    In order to control the occurrence of ginseng root rot caused by Fusarium solani (Mart.) Sacc., the antifungal compounds of the mushroom Suillus bovinus were investigated. And three new alkaloids (1–3), named bovinalkaloid A–C, along with one known analog (4), were isolated and identified by bioassay-guided isolation and spectroscopic analyses. Compound 1 strongly inhibited the mycelial growth and spore germination of F. solani with minimum inhibitory concentration of 2.08 mM. Increases in electrical conductivity, nucleic acid, and protein contents, and decreases in lipid content showed that the membrane permeability and integrity were damaged by compound 1. Compound 1 also increased the contents of malondialdehyde and hydrogen peroxide and the activities of antioxidant enzymes, indicating that lipid peroxidation had taken place in F. solani. Compound 1 may serve as a natural alternative to synthetic fungicides for the control of ginseng root rot

    Role of ε-Poly-lysine in mixed surimi gel: concentration, underlying mechanism, and application

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    The effects of different concentrations of ε-Poly-lysine (ε-PL: 0.005%, 0.01%, 0.02%, 0.04%, and 0.06%) on the marine fish-egg white protein compound gels, treated with 0.4% TGase induced cross-linking were systematically investigated under low salt and phosphorus-free conditions (0.5% NaCl). The results showed the combination of ε-PL and TGase had a synergistic effect on improving sectional gel properties of composite surimi samples. Wherein the rheological, LF-NMR, and SEM results confirmed that the addition of ε-PL based on 0.4% TGase significantly improved the gel strength (to the highest value: 781.63 g·cm), apparent viscosity, and G 'value of the composite surimi sample, as well as reduced the internal water fluidity of surimi, accompanied by the emergence of a more dense and uniform gel network structure. Notably, ε-PL treatment significantly inhibited fat oxidation in the compound surimi gel and the degree of inhibition was proportional to its addition (decreased from 2.03 to 1.67 mg·kg−1). However, the addition of a small amount (0.005%) or an excessive amount (0.06%) of ε-PL on the gel properties of composite surimi samples witnessed the negative effects of the changes in the internal water distribution state and the cooking loss. To sum up, moderate ε-PL (0.04%) treatment combined with TGase induction can maximize the performance of mixed surimi gel and inhibit fat oxidation. The research results supply a diverse perspective and theoretical basis for the development of 'low salt and no phosphorus' surimi product ingredients

    Experimental and numerical investigation of rubber damping ring and its application in multi-span shafting

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    A new approach for establishing the mechanical model of the rubber damping ring was studied numerically and experimentally. Firstly, parameters of Mooney–Rivlin and Prony series models of the rubber material were identified based on ISIGHT integrating with ANSYS and MATLAB, in which the rubber damping ring’s hysteresis loop was obtained by vibration experiment and ANSYS simulation, respectively; meanwhile, the dynamic stiffness and damping were calculated simultaneously by a parameter separation and identification method. Subsequently, the accuracy of the constitutive model parameters was verified experimentally. In the light of this, based on the experimental design and the approximate model method of the joint simulation platform, a mechanical model of dynamic stiffness and damping of the rubber damping ring was established. Finally, the rubber damping ring’s mathematical model was employed to perform a vibration reduction analysis in a multi-span shafting, where the numerical and experimental investigation was conducted, respectively. The results show that the theoretical and experimental error of vibration reduction rate is less than 17%, which verifies the accuracy of the mechanical model of the rubber damping ring

    Morphological quantification of proliferation-to-invasion transition in tumor spheroids

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    Abstract(#br)Background(#br)Metastasis determines the lethality of cancer. In most clinical cases, patients are able to live with tumor proliferation before metastasis. Thus, the transition from tumor proliferation to metastasis/invasion is essential. However, the mechanism is still unclear and especially, the proliferation-to-metastasis/invasion transition point has not been well defined. Therefore, quantitative characterization of this transition is urgently needed.(#br)Methods(#br)We have successfully developed a home-built living-cell incubation system combined with an inverted optical microscope, and a systematic, quantitative approach to describing the major characteristic morphological parameters for the identification of the critical transition points for tumor-cell spheroids in a collagen fiber scaffold.(#br)Results(#br)The system focuses on in vitro tumor modeling, e.g. the development of tumor-cell spheroids in a collagen fiber scaffold and the monitoring of cell transition from proliferation to invasion. By applying this approach to multiple tumor spheroid models, such as U87 (glioma tumor), H1299 (lung cancer), and MDA-MB-231 (breast cancer) cells, we have obtained quantitative morphological references to evaluate the proliferation-to-invasion transition time, as well as differentiating the invasion potential of tumor cells upon environmental changes, i.e. drug application.(#br)Conclusions(#br)Our quantitative approach provides a feasible clarification for the proliferation-to-invasion transition of in vitro tumor models (spheroids). Moreover, the transition time is a useful reference for the invasive potential of tumor cells.(#br)General significance(#br)This quantitative approach is potentially applicable to primary tumor cells, and thus has potential applications in the fields of cancer metastasis investigations and clinical diagnostics

    Therapeutic Effects of Glutamic Acid in Piglets Challenged with Deoxynivalenol

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    The mycotoxin deoxynivalenol (DON), one of the most common food contaminants, primarily targets the gastrointestinal tract to affect animal and human health. This study was conducted to examine the protective function of glutamic acid on intestinal injury and oxidative stress caused by DON in piglets. Twenty-eight piglets were assigned randomly into 4 dietary treatments (7 pigs/treatment): 1) uncontaminated control diet (NC), 2) NC+DON at 4 mg/kg (DON), 3) NC+2% glutamic acid (GLU), and 4) NC+2% glutamic acid + DON at 4 mg/kg (DG). At day 15, 30 and 37, blood samples were collected to determine serum concentrations of CAT (catalase), T-AOC (total antioxidant capacity), H2O2 (hydrogen peroxide), NO (nitric oxide), MDA (maleic dialdehyde), DAO (diamine oxidase) and D-lactate. Intestinal morphology, and the activation of Akt/mTOR/4EBP1 signal pathway, as well as the concentrations of H2O2, MDA, and DAO in kidney, liver and small intestine, were analyzed at day 37. Results showed that DON significantly (P<0.05) induced oxidative stress in piglets, while this stress was remarkably reduced with glutamic acid supplementation according to the change of oxidative parameters in blood and tissues. Meanwhile, DON caused obvious intestinal injury from microscopic observations and permeability indicators, which was alleviated by glutamic acid supplementation. Moreover, the inhibition of DON on Akt/mTOR/4EBP1 signal pathway was reduced by glutamic acid supplementation. Collectively, these data suggest that glutamic acid may be a useful nutritional regulator for DON-induced damage manifested as oxidative stress, intestinal injury and signaling inhibition

    Addressing Individual Perception: Extending the Technology Acceptance Model to the Interim Payment Method in Construction Projects

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    An increasing trend in late payment and nonpayment of construction projects would hinder the sustainable development of projects by impeding progress or causing disputes. Although the interim payment method is a good practice to solve payment-related problems of construction projects, its acceptance rate is low, and studies on it are few. Therefore, this research aims to extend the Technology Acceptance Model (TAM) to understand practitioners’ acceptance behavior toward the interim payment method. By adopting TAM, this study established an acceptance model of the interim payment method, which consists of four constructs and 25 indicators, and validated it through 131 survey data collected in Jiangsu Province, China. The results showed that the adoption rate for public projects (17%) was much lower than that of private projects (44.8%). The results revealed that environmental factors, perceived usefulness, and attitude increase practitioners’ acceptance, while the perceived ease of use impedes practitioners’ acceptance. In addition, the settlement process and pricing method impact the ease of use the most and could be breakthrough points for improvement in the future. Moreover, the perceived usefulness significantly affects practitioners’ attitudes but does not affect behavioral intention. This study contributes to the body of knowledge of project management by identifying the key causes of the low acceptance of the interim payment method and provides strategies for further improvement. The findings would help to inform the decision-making in policies, strategies, and incentive schemes to increase practitioners’ acceptance in China and worldwide
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