405 research outputs found
Exceptional Performance of Hierarchical Ni-Fe (hydr)oxide@NiCu Electrocatalysts for Water Splitting
Developing lowâcost bifunctional electrocatalysts with superior activity for both the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) is of great importance for the widespread application of the water splitting technique. In this work, using earthâabundant transition metals (i.e., nickel, iron, and copper), 3D hierarchical nanoarchitectures, consisting of ultrathin NiâFe layeredâdoubleâhydroxide (NiâFe LDH) nanosheets or porous NiâFe oxides (NiFeOx) assembled to a metallic NiCu alloy, are delicately constructed. In alkaline solution, the asâprepared NiâFe LDH@NiCu possesses outstanding OER activity, achieving a current density of 10 mA cmâ2 at an overpotential of 218 mV, which is smaller than that of RuO2 catalyst (249 mV). In contrast, the resulting NiFeOx@NiCu exhibits better HER activity, yielding a current density of 10 mA cmâ2 at an overpotential of 66 mV, which is slightly higher than that of Pt catalyst (53 mV) but superior to all other transition metal (hydr)oxideâbased electrocatalysts. The remarkable activity of the NiâFe LDH@NiCu and NiFeOx@NiCu is further demonstrated by a 1.5 V solarâpanelâpowered electrolyzer, resulting in current densities of 10 and 50 mA cmâ2 at overpotentials of 293 and 506 mV, respectively. Such performance renders the asâprepared materials as the best bifunctional electrocatalysts so far
Self-assembling peptide-based nanoparticles enhance anticancer effect of ellipticine in vitro and in vivo
Population genetics of foxtail millet and its wild ancestor
<p>Abstract</p> <p>Background</p> <p>Foxtail millet (<it>Setaria italica </it>(L.) P. Beauv.), one of the most ancient domesticated crops, is becoming a model system for studying biofuel crops and comparative genomics in the grasses. However, knowledge on the level of genetic diversity and linkage disequilibrium (LD) is very limited in this crop and its wild ancestor, green foxtail (<it>Setaria viridis </it>(L.) P. Beauv.). Such information would help us to understand the domestication process of cultivated species and will allow further research in these species, including association mapping and identification of agricultural significant genes involved in domestication.</p> <p>Results</p> <p>In this study, we surveyed DNA sequence for nine loci across 50 accessions of cultivated foxtail millet and 34 of its wild progenitor. We found a low level of genetic diversity in wild green foxtail (θ = 0.0059), θ means Watterson's estimator of θ. Despite of a 55% loss of its wild diversity, foxtail millet still harbored a considerable level of diversity (θ = 0.0027) when compared to rice and sorghum (θ = 0.0024 and 0.0034, respectively). The level of LD in the domesticated foxtail millet extends to 1 kb, while it decayed rapidly to a negligible level within 150 bp in wild green foxtail. Using coalescent simulation, we estimated the bottleneck severity at k = 0.6095 when Ď/θ = 1. These results indicated that the domestication bottleneck of foxtail millet was more severe than that of maize but slightly less pronounced than that of rice.</p> <p>Conclusions</p> <p>The results in this study establish a general framework for the domestication history of foxtail millet. The low level of genetic diversity and the increased level of LD in foxtail millet are mainly caused by a population bottleneck, although gene flow from foxtail millet to green foxtail is another factor that may have shaped the pattern of genetic diversity of these two related gene pools. The knowledge provided in this study will benefit future population based studies in foxtail millet.</p
Association of dietary patterns with depressive symptoms in Chinese adolescents: a cross-sectional study
ObjectiveDepression is highly prevalent in adolescents and may have adverse social and health consequences. To investigate the effect of diet on the occurrence of depression in adolescents, this study examined the correlation between dietary patterns and depression in adolescents.MethodsA total of 853 participants were recruited in September to October 2022 in Taizhou, Zhejiang, China. The Chinese version of the Patient Health Questionnaire-9 was used to assess the subjectsâ depressive symptoms in the past 2âweeks. Relevant dietary information was obtained through a food frequency questionnaire. The associations between dietary patterns and the risk of depression were assessed using a logistic regression model.ResultsFour dietary patterns were identified by factor analysis, including the modern pattern, the snack-aquatic pattern, the traditional pattern, and the vegetarian pattern. The risk of mild depression among adolescents was higher in the Q2 and Q3 groups of the modern model than in the Q1 group of this type, and the risk of mild depression was higher in the Q4 group of the snack-aquatic model than in the Q1 group of this type; while the risk of moderate depressive symptoms was lower in the Q3 group of the vegetarian model compared with the Q1 group.ConclusionModern and snack-aquatic patterns are associated with an increased risk of depression in Chinese adolescents, and vegetarian patterns are associated with a reduced risk of depression. The current findings emphasize the importance of adolescents consuming moderate amounts of rice flour, adequate vegetables and fruits, and reducing snack intake
Uniform Exponential Stability of Discrete Evolution Families on Space of p
We prove that the discrete system Îśn+1=AnÎśn is uniformly exponentially stable if and only if the unique solution of the Cauchy problem Îśn+1=AnÎśn+eiθn+1zn+1,  nâZ+, Îś0=0, is bounded for any real number θ and any p-periodic sequence z(n) with z(0)=0. Here, An is a sequence of bounded linear operators on Banach space X
13.4 % Efficiency from All-Small-Molecule Organic Solar Cells Based on a Crystalline Donor with Chlorine and Trialkylsilyl Substitutions
How to simultaneously achieve both high open-circuit voltage (Voc) and high short-circuit current density (Jsc) is a big challenge for realising high power conversion efficiency (PCE) in all-small-molecule organic solar cells (all-SM OSCs). Herein, a novel small molecule (SM)-donor, namely FYSMâSiCl, with trialkylsilyl and chlorine substitutions was designed and synthesized. Compared to the original SM-donor FYSMâH, FYSMâSi with trialkylsilyl substitution showed a decreased crystallinity and lower highest occupied molecular orbital (HOMO) level, while FYSMâSiCl had an improved crystallinity, more ordered packing arrangement, significantly lower HOMO level, and predominant âface-onâ orientation. Matched with a SM-acceptor Y6, the FYSMâSiCl-based all-SM OSCs exhibited both high Voc of 0.85 V and high Jsc of 23.7 mA cmâ2, which is rare for all-SM OSCs and could be attributed to the low HOMO level of FYSMâSiCl donor and the delicate balance between high crystallinity and suitable blend morphology. As a result, FYSMâSiCl achieved a high PCE of 13.4 % in all-SM OSCs, which was much higher than those of the FYSMâH- (10.9 %) and FYSMâSi-based devices (12.2 %). This work demonstrated a promising method for the design of efficient SM-donors by a side-chain engineering strategy via the introduction of trialkylsilyl and chlorine substitutions
Fabrication of micro/nanometer-channel by Near-Field ElectroSpinning
Direct-written polymer micro/nanofiber from Near- Field ElectroSpinning (NFES) was utilized as shadow-mask to fabricate uniform micro/nanometer-channel. Both Single straight microfiber (line-width 2~10?? m) and nanofiber (diameter 200~800nm) were direct-written on the substrate with the NFES setup, and then 2-nm-thick titanium adhesive layer and 10-nm- thick gold layer were sputtered on the substrate successively. By the ultrasonication process in acetone and de-ionized water, the polymer fiber was removed and micro/nanometer-channel with gap width ranging from 7?? m to 700nm was formed. The fabrication process and related technical issues were also outlined in this work. The experimental results revealed that the micro/nanometer channel had a good uniformity, above 90% of the gap length value lied within the deviation range of Âą3%. This simple and facile method can be used to define the uniform micro/nano channel for organic thin film transistors. submicron-gap electrode by using an electrospun single fiber as shadow-mask. This is a simple and cost-effective method, yet the nanofiber used as shadow-mask was obtained through the post-stretching process, which increased the complexity and uncertainty of fabrication process. In this paper, Direct-write (DW) technology (9) based on Near-Field ElectroSpinning (NFES) (10) was utilized to obtain single straight micro/nanofiber directly, and used as shadow- mask to fabricate micro/nanometer-channel. The gap length of micro/nanometer-channel was in the range of 700nm to 7?? m. The fabrication process and related technical issues were described, and then the uniformity of micro/nanometer-channel was also evaluated and discussed
Ultrathin Nanosheets of Oxoâfunctionalized Graphene Inhibit the Ion Migration in Perovskite Solar Cells
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Comparison and evaluation of the methods for measuring hemolytic activity of <i>Stomolophus meleagris</i> jellyfish tentacle extract
Hemolytic activity assessment is a widely used method to evaluate the toxicity of marine organisms, including jellyfish. However, there are some challenges associated with testing hemolytic activity. In this study, four methods were employed to compare the hemolytic activity of jellyfish tentacle extract (TE). Firstly, a microplate reader was used to compare the mouse hemoglobin solution at three different wavelengths (415 nm, 541 nm, and 576 nm), and the most sensitive wavelength was selected for further experiments. Secondly, photomicrograph counting was used to determine the number of complete red blood cells in the field of view. Thirdly, a microplate reader was used to test hemolytic activity in a 96-well plate at 415 nm. Fourthly, a Bicinchoninic Acid (BCA) kit was used to test the concentration of hemoglobin in the solution. Finally, a UV-Vis Spectrophotometer was used to test hemolytic activity at 415 nm. Among the three wavelengths tested, the absorption value was most sensitive at 415 nm. The photomicrograph counting method was able to reflect changes in the shape of Red Blood Cells (RBCs). The microplate reader method may exhibit deviations when the solution concentration is high, while external factors could influence the BCA kit when the toxin concentration in the experimental group is low. The spectrophotometer method was found to be relatively accurate and sensitive to changes. When optimizing the method, it is important to consider the applicability of the Beer-Lambert law and the concentration of solutions
Food-specific IgG4-guided diet elimination improves allergy symptoms in children
Allergic diseases in children are major public health concerns due to their widespread and rising prevalence. Food-specific immunoglobulin G4(FS-IgG4) has been detected in patients with allergic diseases, but its clinical significance is still debated. In the present study, 407 children with allergic diseases were recruited and categorized into three groups according to the different systems involved: the respiratory system group, the skin system group, and a multiple system group, with the collection of clinical symptoms and serum antibodies, including total immunoglobulin E (IgE), house dust mite (HDM) IgE, food-specific IgE (FS-IgE), and FS-IgG4. Part of these patients were followed up with the intervention of FS-IgG4-guided diet elimination with or without add-on probiotics supplement. The analysis at baseline revealed distinct serum levels of different antibodies. The positive rate of FS-IgG4 in all groups was more than 80%, and the proportion of total IgE and FS-IgG4 both positive in the multi-system group was the highest (p=0.039). Egg and milk were the foods with the highest positive rate of FS-IgG4 in all groups. After diet elimination for more than 3 months, serum FS-IgG4 in children significantly decreased (P<0.05) along with the improvement of clinical symptoms, regardless of the add-on of probiotics. However, the intervention did not impact the serum levels of total IgE, FS-IgE, and HDM IgE. There was no further decrease of serum FS-IgG4 level in children followed up for more than 1 year, which may be related to noncompliance with diet elimination. Multivariate regression analysis revealed that the decline of serum FS-IgG4 was an independent predictable factor for the improvement of clinical symptoms (adjusted OR:1.412,95%CI 1.017â1.96, p=0.039). The add-on of probiotics showed less efficiency in reducing the FS-IgG4 level in more patients with relief of clinical symptoms. Our results confirmed the correlation between FS-IgG4 and allergic diseases, and the decreased FS-IgG4 could be a useful predictor for the improvement of allergic symptoms. FS-IgG4-guided diet elimination is an efficient treatment for allergic diseases. Our study adds solid data to the clinical significance of FS-IgG4 in allergic diseases
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