14 research outputs found

    Asymmetric memory for birth language perception versus production in young international adoptees

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    Adults who as children were adopted into a different linguistic community retain knowledge of their birth language. The possession (without awareness) of such knowledge is known to facilitate the (re)learning of birth-language speech patterns; this perceptual learning predicts such adults' production success as well, indicating that the retained linguistic knowledge is abstract in nature. Adoptees' acquisition of their adopted language is fast and complete; birth-language mastery disappears rapidly, although this latter process has been little studied. Here, 46 international adoptees from China aged four to 10 years, with Dutch as their new language, plus 47 matched non-adopted Dutch-native controls and 40 matched non-adopted Chinese controls, undertook across a two-week period 10 blocks of training in perceptually identifying Chinese speech contrasts (one segmental, one tonal) which were unlike any Dutch contrasts. Chinese controls easily accomplished all these tasks. The same participants also provided speech production data in an imitation task. In perception, adoptees and Dutch controls scored equivalently poorly at the outset of training; with training, the adoptees significantly improved while the Dutch controls did not. In production, adoptees' imitations both before and after training could be better identified, and received higher goodness ratings, than those of Dutch controls. The perception results confirm that birth-language knowledge is stored and can facilitate re-learning in post-adoption childhood; the production results suggest that although processing of phonological category detail appears to depend on access to the stored knowledge, general articulatory dimensions can at this age also still be remembered, and may facilitate spoken imitation

    Effect of iron saturation of bovine lactoferrin on the inhibition of hepatitis B virus in vitro

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    Background Hepatitis B virus (HBV) infection poses a major public health problem worldwide. Bovine lactoferrin (bLf) is a natural product that can inhibit HBV, but the effect of iron saturation on its resistance to HBV is unknown. Aims The purpose of this study is to investigate the impact of iron saturation of bLf against HBV. Methods HepG2 cells were cultured in DMEM high glucose containing 10% inactivated fetal calf serum, at 37Ā Ā°C, in 5% CO2. MTT method was used to detect the cytotoxicity of bLf to HepG2 cells. Apo-bLf and holo-bLf were prepared from bLf. Iron saturation of these proteins was determined by atomic absorption spectrophotometry. Non-cytotoxic concentrations of candidate proteins were used in anti-HBV tests. Fluorescent quantitative polymerase chain reaction was used to detect HBV-DNA. Results The TC50 and TC0of bLf were 54.570Ā mg/ml and 1.997 mg/ml, respectively. The iron saturation of bLf, apo-bLf and holo-bLf were 10.29%, 8.42% and 85.32%, respectively. In this study, four non-cytotoxic concentrations of candidate proteins (1.5, 1.0, 0.5, and 0.1 mg/ml, respectively) were used to inhibit HBV in HepG2 cells. The results showed that 1.5 mg/ml bLf and 0.1 mg/ml holo-bLf effectively impaired the HBV-DNA amplification in HBV-infected HepG2 cells (P < 0.05). However, apo-bLf, and Fe3+ did not show the anti-HBV effects. Conclusion A total of 1.5 mg/ml bLf and 0.1 mg/ml holo-bLf could inhibit HBV-DNA in HepG2 cells. Complete bLf structure, appropriate concentration and iron saturation of bLf are necessary conditions for anti-HBV effects

    Early Development of Definitive Erythroblasts from Human Pluripotent Stem Cells Defined by Expression of Glycophorin A/CD235a, CD34, and CD36

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    The development of human erythroid cells has been mostly examined in models of adult hematopoiesis, while their early derivation during embryonic and fetal stages is largely unknown. We observed the development and maturation of erythroblasts derived from human pluripotent stem cells (hPSCs) by an efficient co-culture system. These hPSC-derived early erythroblasts initially showed definitive characteristics with a glycophorin A+ (GPA+) CD34lowCD36āˆ’ phenotype and were distinct from adult CD34+ cell-derived ones. After losing CD34 expression, early GPA+CD36āˆ’ erythroblasts matured into GPA+CD36low/+ stage as the latter expressed higher levels of Ī²-globin along with a gradual loss of mesodermal and endothelial properties, and terminally suppressed CD36. We establish a unique inĀ vitro model to trace the early development of hPSC-derived erythroblasts by serial expression of CD34, GPA, and CD36. Our findings may provide insight into the understanding of human early erythropoiesis and, ultimately, therapeutic potential

    Genome-wide comparative analysis of RNA-binding Glycine-rich protein family genes between Gossypium arboreum and Gossypium raimondii.

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    RB-GRP (RNA-binding Glycine-rich protein gene) family belongs to the fourth subfamily of the GRP (Glycine-rich protein gene) superfamily, which plays a great role in plant growth and development, as well as in abiotic stresses response, while it has not been identified in cotton. Here, we identified 37 and 32 RB-GRPs from two cotton species (Gossypium arboreum and Gossypium raimondii, respectively), which were divided into four distinct subfamilies based on the presence of additional motifs and the arrangement of the glycine repeats. The distribution of RB-GRPs was nonrandom and uneven among the chromosomes both in two cotton species. The expansion of RB-GRP gene family between two cultivars was mainly attributed to segmental and tandem duplication events indicated by synteny analysis, and the tandem duplicated genes were mapped into homologous collinear blocks, indicated that they shared a common ancestral gene in both species. Furthermore, most RB-GRPs in two cotton species undergone stronger negative selective pressure by evolutionary analysis of RB-GRP orthologous genes. Meanwhile, RB-GRPs participated in different abiotic stresses (Abscisic acid, salt and Polyethylene glycol) responses and tissues at different developmental stages between two cotton species were showed by gene expression analysis. This research would provide insight into the evolution and function of the RB-GRPs in Gossypium species

    Cholesteryl-Modification of a Glucomannan from Bletilla striata and Its Hydrogel Properties

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    A glucomannan-type polysaccharide, named BSP, was obtained from the tubers of Bletilla striata by ultrasonic-assisted extraction, ethanol precipitation, deproteination and gel-permeation chromatography. HPLC analysis revealed that BSP contained mannose and glucose in the molar ratio of 3.5:1. Its molecular weight (Mw) was estimated to be 20 kDa. Methylation analysis, FT-IR and NMR analyses indicated that BSP consisted of (1ā†’4)-linked Ī²-D-glucopyranosyl residues and (1ā†’4)-linked Ī²-D-mannopyranosyl residues. Cholesteryl succinate was linked to BSP to make it more amphiphilic and the degree of substitution of cholesteryl succinate-BSP was 3.2%. The critical micelle concentration of modified BSP was 0.001 mg/mL, suggesting it could self-assemble into nanoparticles in aqueous solution

    Highly Durable Na<sub>2</sub>V<sub>6</sub>O<sub>16</sub>Ā·1.63H<sub>2</sub>O Nanowire Cathode for Aqueous Zinc-Ion Battery

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    Rechargeable aqueous zinc-ion batteries are highly desirable for grid-scale applications due to their low cost and high safety; however, the poor cycling stability hinders their widespread application. Herein, a highly durable zinc-ion battery system with a Na<sub>2</sub>V<sub>6</sub>O<sub>16</sub>Ā·1.63H<sub>2</sub>O nanowire cathode and an aqueous ZnĀ­(CF<sub>3</sub>SO<sub>3</sub>)<sub>2</sub> electrolyte has been developed. The Na<sub>2</sub>V<sub>6</sub>O<sub>16</sub>Ā·1.63H<sub>2</sub>O nanowires deliver a high specific capacity of 352 mAh g<sup>ā€“1</sup> at 50 mA g<sup>ā€“1</sup> and exhibit a capacity retention of 90% over 6000 cycles at 5000 mA g<sup>ā€“1</sup>, which represents the best cycling performance compared with all previous reports. In contrast, the NaV<sub>3</sub>O<sub>8</sub> nanowires maintain only 17% of the initial capacity after 4000 cycles at 5000 mA g<sup>ā€“1</sup>. A single-nanowire-based zinc-ion battery is assembled, which reveals the intrinsic Zn<sup>2+</sup> storage mechanism at nanoscale. The remarkable electrochemical performance especially the long-term cycling stability makes Na<sub>2</sub>V<sub>6</sub>O<sub>16</sub>Ā·1.63H<sub>2</sub>O a promising cathode for a low-cost and safe aqueous zinc-ion battery
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