Abstract
In this first paper in the SUPER GOODS series on powerfully star-forming galaxies in the two GOODS fields, we present a deep SCUBA-2 survey of the GOODS-N at both 850 and 450
μ
m (central ...rms noise of 0.28 mJy and 2.6 mJy, respectively). In the central region, the 850
μ
m observations cover the GOODS-N to near the confusion limit of ∼1.65 mJy, while over a wider 450 arcmin
2
region—well complemented by
Herschel
far-infrared imaging—they have a median
limit of 3.5 mJy. We present
catalogs of 186 850
μ
m and 31 450
μ
m selected sources. We use interferometric observations from the Submillimeter Array (SMA) and the Karl G. Jansky Very Large Array (VLA) to obtain precise positions for 114 SCUBA-2 sources (28 from the SMA, all of which are also VLA sources). We present new spectroscopic redshifts and include all existing spectroscopic or photometric redshifts. We also compare redshifts estimated using the 20 cm/850
μ
m and the 250 cm/850
μ
m flux ratios. We show that the redshift distribution increases with increasing flux, and we parameterize the dependence. We compute the star formation history and the star formation rate (SFR) density distribution functions in various redshift intervals, finding that they reach a peak at
before dropping to higher redshifts. We show that the number density per unit volume of
galaxies measured from the SCUBA-2 sample does not change much relative to that of lower SFR galaxies from UV selected samples over
, suggesting that, apart from changes in the normalization, the shape in the number density as a function of SFR is invariant over this redshift interval.
Abstract
We present a three-dimensional (3D) extinction analysis in the region towards the supernova remnant (SNR) S147 (G180.0–1.7) using multiband photometric data from the Xuyi Schmidt Telescope ...Photometric Survey of the Galactic Anticentre (XSTPS-GAC), 2MASS and WISE. We isolate a previously unrecognized dust structure likely to be associated with SNR S147. The structure, which we term as ‘S147 dust cloud’, is estimated to have a distance d = 1.22 ± 0.21 kpc, consistent with the conjecture that S147 is associated with pulsar PSR J0538 + 2817. The cloud includes several dense clumps of relatively high extinction that locate on the radio shell of S147 and coincide spatially with the CO and gamma-ray emission features. We conclude that the usage of CO measurements to trace the SNR associated MCs is unavoidably limited by the detection threshold, dust depletion and the difficulty of distance estimates in the outer Galaxy. 3D dust extinction mapping may provide a better way to identify and study SNR–MC interactions.
Background and Objective: Short‐chain fatty acids, such as butyric acid and propionic acid, are metabolic by‐products generated by periodontal microflora such as Porphyromonas gingivalis, and ...contribute to the pathogenesis of periodontitis. However, the effects of butyrate on the biological activities of gingival fibroblasts (GFs) are not well elucidated.
Material and Methods: Human GFs were exposed to various concentrations of butyrate (0.5–16 mm) for 24 h. Viable cells that excluded trypan blue were counted. Cell cycle distribution of GFs was analyzed by propidium iodide‐staining flow cytometry. Cellular reactive oxygen species (ROS) production was measured by flow cytometry using 2’,7’‐dichlorofluorescein (DCF). Total RNA and protein lysates were isolated and subjected to RT‐PCR using specific primers or to western blotting using specific antibodies, respectively.
Results: Butyrate inhibited the growth of GFs, as indicated by a decrease in the number of viable cells. This event was associated with an induction of G0/G1 and G2/M cell cycle arrest by butyrate (4–16 mm) in GFs. However, no marked apoptosis of GFs was noted in this experimental condition. Butyrate (> 2 mm) inhibited the expression of cdc2, cdc25C and cyclinB1 mRNAs and reduced the levels of Cdc2, Cdc25C and cyclinB1 proteins in GFs, as determined using RT‐PCR and western blotting, respectively. This toxic effect of butyrate was associated with the production of ROS.
Conclusion: These results suggest that butyrate generated by periodontal pathogens may be involved in the pathogenesis of periodontal diseases via the induction of ROS production and the impairment of cell growth, cell cycle progression and expression of cell cycle‐related genes in GFs. These events are important in the initiation and prolongation of inflammatory processes in periodontal diseases.
Using a sample of nearly 140,000 primary red-clump stars selected from the LAMOST and Gaia surveys, we have identified a large sample of "young" /Fe-enhanced stars with stellar ages younger than 6.0 ...Gyr and /Fe ratios greater than 0.15 dex. The stellar ages and /Fe ratios are measured from LAMOST spectra, using a machine-learning method trained with common stars in the LAMOST-APOGEE fields (for /Fe) and in the LAMOST-Kepler fields (for stellar age). The existence of these "young" /Fe-enhanced stars is not expected from the classical Galactic chemical evolution models. To explore their possible origins, we have analyzed the spatial distribution, and the chemical and kinematic properties of those stars and compared the results with those of the chemically thin and thick disk populations. We find that those "young" /Fe-enhanced stars have distributions in number density, metallicity, C/N abundance ratio, velocity dispersion, and orbital eccentricity that are essentially the same as those of the chemically thick disk population. Our results clearly show those so-called "young" /Fe-enhanced stars are not really young but genuinely old. Although other alternative explanations can not be fully ruled out, our results suggest that the most possible origin of these old stars is the result of stellar mergers or mass transfer.
This review focuses on various synthesis strategies of anion‐exchange membranes (AEMs) for fuel cells, diverse methodologies of AEM‐forming, together with relationship between structures and ...properties. AEMs are discussed from seven categories, including (1) AEMs derived from Nafion precursors with sulfonyl fluoride groups, which display excellent stability and well‐developed morphologies that similar to Nafion, but has potentially high costs. (2) AEMs prepared by grafting technologies, such as chemical grafting technique, ATRP technique, plasma grafting technique and radiation grafting technique. (3) AEMs based on functionalized commercial polymers, including PVA, SEBS, CPP, PEEK, PES, PEI, PPO, and so on. (4) AEMs prepared by newly‐synthesized polymers, in which the most interesting approach is to synthesize alkaline multi‐block copolymers with enough long hydrophilic/hydrophobic blocks. (5) AEMs containing heterogeneous composition, which mainly prepared by blending and sol‐gel methods, reinforced or pore‐filling AEMs and IPN or s‐IPN. (6) AEMs with functional groups different from quaternary ammonium, which includes the studies of new type of AEMs with highly chemical stability in alkaline solution. (7) Hybrid membranes combining AEM with PEM, in which new configuration results in different performances. At last, conclusions and perspectives for the future researches of AEMs are presented.
Refractory high-entropy alloys hold the potential for high-temperature applications beyond the capability of the state-of-the-art Ni-based superalloys, and thus, it is important to study their solid ...solution formation characteristics and mechanical properties. In this study, designed by CALPHAD method, formation of as-cast arc-melted body-centered cubic MoNbTaTiV was experimentally verified using X-ray diffraction and scanning electron microscopy. The measured density and lattice parameter for MoNbTaTiV are 9.29g/cm3 and 3.224 Å, which obey the rule of mixtures (ROM). The alloy exhibits high hardness at 443 Hv, high yield strength at 1.4 GPa, and good compressive fracture strength at 2.45 GPa with a fracture strain of ∼30% at room temperature. The yield strength and hardness values of this alloy, and other single-phase refractory high-entropy alloys, are estimated using a simple model of solid solution strengthening. Reasonable agreement between modeling prediction and experiments is obtained. In addition, first-principles density functional theory calculations predict an enthalpy of formation of −0.865 kJ/mol for the MoNbTaTiV alloy, with calculated atomic volume and elastic properties (e.g., bulk and elastic moduli) obeying the ROM.
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•MoNbTaTiV exhibits the BCC structure, agreeing with CALPHAD calculations.•Predicted solid solution strengthening agrees well with experiments.•Hardness of BCC high entropy alloys is about three times the yield strength.•Calculated atomic volume and bulk and shear moduli obey the rule of mixtures.
Although electron cryo-microscopy (cryo-EM) single-particle analysis has become an important tool for structural biology of large and flexible macro-molecular assemblies, the technique has not yet ...reached its full potential. Besides fundamental limits imposed by radiation damage, poor detectors and beam-induced sample movement have been shown to degrade attainable resolutions. A new generation of direct electron detectors may ameliorate both effects. Apart from exhibiting improved signal-to-noise performance, these cameras are also fast enough to follow particle movements during electron irradiation. Here, we assess the potentials of this technology for cryo-EM structure determination. Using a newly developed statistical movie processing approach to compensate for beam-induced movement, we show that ribosome reconstructions with unprecedented resolutions may be calculated from almost two orders of magnitude fewer particles than used previously. Therefore, this methodology may expand the scope of high-resolution cryo-EM to a broad range of biological specimens.DOI:http://dx.doi.org/10.7554/eLife.00461.001.
Background Atopic dermatitis (atopic eczema) is a chronic inflammatory skin disease that has reached epidemic proportions in children worldwide and is increasing in prevalence. Because of the ...significant socioeconomic effect of atopic dermatitis and its effect on the quality of life of children and families, there have been decades of research focused on disease prevention, with limited success. Recent advances in cutaneous biology suggest skin barrier defects might be key initiators of atopic dermatitis and possibly allergic sensitization. Objective Our objective was to test whether skin barrier enhancement from birth represents a feasible strategy for reducing the incidence of atopic dermatitis in high-risk neonates. Methods We performed a randomized controlled trial in the United States and United Kingdom of 124 neonates at high risk for atopic dermatitis. Parents in the intervention arm were instructed to apply full-body emollient therapy at least once per day starting within 3 weeks of birth. Parents in the control arm were asked to use no emollients. The primary feasibility outcome was the percentage of families willing to be randomized. The primary clinical outcome was the cumulative incidence of atopic dermatitis at 6 months, as assessed by a trained investigator. Results Forty-two percent of eligible families agreed to be randomized into the trial. All participating families in the intervention arm found the intervention acceptable. A statistically significant protective effect was found with the use of daily emollient on the cumulative incidence of atopic dermatitis with a relative risk reduction of 50% (relative risk, 0.50; 95% CI, 0.28-0.9; P = .017). There were no emollient-related adverse events and no differences in adverse events between groups. Conclusion The results of this trial demonstrate that emollient therapy from birth represents a feasible, safe, and effective approach for atopic dermatitis prevention. If confirmed in larger trials, emollient therapy from birth would be a simple and low-cost intervention that could reduce the global burden of allergic diseases.
Summary
Background
Data are limited regarding the effectiveness and safety of generic velpatasvir plus sofosbuvir (VEL/SOF) for hepatitis C virus (HCV) in patients with or without human ...immunodeficiency virus (HIV) coinfection.
Aim
To evaluate the effectiveness and safety of generic VEL/SOF‐based therapy for HCV infection in patients with or without HIV coinfection in Taiwan.
Methods
Sixty‐nine HIV/HCV‐coinfected and 159 HCV‐monoinfected patients receiving 12 weeks of generic VEL/SOF with or without ribavirin (RBV) for HCV were prospectively enrolled. The anti‐viral responses and the adverse events (AEs) were compared between the two groups. The characteristics potentially related to sustained virological response 12 weeks off therapy (SVR12) were analysed.
Results
The SVR12 was achieved in 67 HIV/HCV‐coinfected patients (97.1%; 95% CI: 90.0%‐99.2%) and in 156 HCV‐monoinfected patients (98.1%; 95% CI: 94.6%‐99.4%) receiving VEL/SOF‐based therapy, respectively. The SVR12 rates were comparable between HIV/HCV‐coinfected and HCV‐monoinfected patients, regardless of pre‐specified baseline characteristics. One hundred twenty‐two (53.5%) and seven (3.1%) patients had baseline resistance‐associated substitutions (RASs) in HCV NS5A and NS5B regions, but the SVR12 rates were not affected by the presence or absence of RASs. One (1.4%) and five (3.1%) patients in the HIV/HCV‐coinfected and HCV‐monoinfected groups had serious AEs. No patient died or discontinued treatment due to AEs. The eGFR remained stable throughout the course of treatment in HIV/HCV‐coinfected patients receiving anti‐retroviral therapy containing tenofovir disoproxil fumarate (TDF).
Conclusions
Generic VEL/SOF‐based therapy is well‐tolerated and provides comparably high SVR12 rates for HCV infection in patients with and without HIV coinfection.
Previous research has shown that patients with chronic obstructive pulmonary disease (COPD) tend to have a higher risk for cognitive impairment and dementia, a neurodegenerative disorder. The goal of ...this study was to examine what relationship, if any, exists between COPD and Parkinson's disease (PD), which is also a neurodegenerative disorder.
Our study analyzed medical data from the population of Taiwan from 1998 to 2008, with a follow-up period extending to the end of 2010. We identified patients with COPD by the Taiwan National Health Insurance Research Database (NHIRD). We selected a comparison cohort from the general population that was random frequency-matched by age (in 5-year increments), sex and index year, and further analyzed the risk of PD using Cox's regression model, including sex, age and comorbidities.
The study enrolled 20 728 COPD patients (71.1% male, mean age = 68.2 years) and 41 147 controls. The risk of developing PD was 1.37 times greater in patients with COPD compared with patients without COPD after adjusting for age, sex and comorbidities. A significantly increased risk of PD was also found in patients with COPD who had any comorbidity other than diabetes.
This nationwide retrospective cohort study demonstrates that PD risk is significantly increased in patients with COPD compared with those of the general population.
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