94 research outputs found

    Low-temperature synthesis of two-dimensional nanostructured Co3O4 and improved electrochemical properties for lithium-ion batteries

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    Urea as a cheap reagent is very useful in preparation two-dimensional metal oxides with tunable crystal morphologies, while refluxing method is a simple route to control the decomposition of urea. Here, a low temperature refluxing in the presence of urea is developed to prepare porous Co3O4 as anode material for lithium-ion batteries. The self-assembly cobalt hydrotalcite-like compounds (Co-HLC) is firstly synthesized through refluxing the mixture of cobaltous nitrate and urea. After pyrolysis, the flower-like morphology of Co-HLC is successfully maintained in the final product of Co3O4. The ordered two-dimensional Co3O4 nanosheets provide good contact with electrolyte and stable porous structure during lithiation/delithiation. Co3O4-120 synthesized under refluxing temperature of 120 °C shows the initial charge capacities of 722 and 741 mAh g−1 at the 2nd and 100th cycle under 100 mA g−1. Moreover, Co3O4-120 as electrode for a supercapacitor presents excellent capacitance, 167 F g−1 after 3000 cycles at 1 A g−1. Under 5, 10 and 20 A g−1, Co3O4-120 electrode delivers 128, 104 and 90 F g−1, respectively. The porous structure in Co3O4 with enhanced electrochemical performance indicates low temperature refluxing preparation is an applicable and energy-saved method to synthesize transitional metal oxide with tunable crystal morphologies

    Habitual intake of flavonoid subclasses and risk of colorectal cancer in two large prospective cohorts

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    Background: Flavonoids inhibit the growth of colon cancer cells in vitro. In a secondary analysis of a randomized controlled trial, the Polyp Prevention Trial, a higher intake of one sub-class, flavonols, was significantly associated with reduced risk of recurrent advanced adenoma. Most previous prospective studies on colorectal cancer evaluated only a limited number of flavonoid sub-classes and intake ranges, yielding inconsistent results.  Objective: To examine whether higher habitual dietary intakes of flavonoid subclasses (flavonols, flavones, flavanones, flavan-3-ols and anthocyanins) are associated with lower risk of colorectal cancer.  Design: Using data from validated food frequency questionnaires administered every four years and an updated flavonoid food composition database flavonoid intakes were calculated for 42,478 male participants from the Health Professionals Follow-up Study and for 76,364 female participants from the Nurses’ Health Study.  Results: During up to 26 years of follow-up, 2,519 colorectal cancer cases (1,061 in men, 1,458 in women) were documented. Intakes of flavonoid subclasses were not associated with risk of colorectal cancer in either cohort. Pooled multivariable adjusted relative risks (95% confidence interval) comparing the highest with the lowest quintile were 1.04 (0.91, 1.18) for flavonols; 1.01 (0.89, 1.15) for flavones; 0.96 (0.84, 1.10) for flavanones; 1.07 (0.95, 1.21) for flavan-3-ols; and 0.98 (0.81, 1.19) for anthocyanins (all p-values for heterogeneity by sex >0.19). In subsite analyses, flavonoid intake was also not associated with colon or rectal cancer risk.  Conclusion: Our findings do not support the hypothesis that a higher habitual intake of any flavonoid sub-class decreases the risk of colorectal cancer

    The Different Effects of Skeletal Muscle and Fat Mass on Height Increment in Children and Adolescents Aged 6–11 Years: A Cohort Study From China

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    ObjectiveThis study aimed to investigate the contribution of body composition including skeletal muscle mass (SMM) and body fat mass (BFM) to longitudinal growth among children and adolescents aged 6–11 years old.MethodsThis cohort study was conducted from the annual health examination between 2019 and 2020. Annual height gain and weight gain and changes in SMM and BFM were calculated and compared between sexes, different nutritional status, and growth curve shifting mode. Spearman analyses and multiple linear regression analysis were performed to identify the impact of SMM, BFM, or body mass index (BMI) on height gain.ResultsOf the 584 subjects, the annual height gains of boys (4.76 cm in the 6–9-year group and 4.63 cm in the 10–11-year group) were significantly lower than those of girls (5.48 and 5.74 cm, respectively). Spearman analysis showed that SMM gain and height gain were positively and significantly correlated in each examination of all children (r = 0.535 for boys and 0.734 for girls, p < 0.001). Conversely, BFM and height gains were negatively (r = -0.5240 for boys and -0.232 for girls, p < 0.001) correlated. Multiple linear regression analysis identified SMM gain as an independent predictor (95% CI: 1.20,1.44) of height gain after adjusting for age, gender, BMI, BFM gain, and percentage of body fat (PBF).ConclusionSMM gains, rather than BFM gains, were associated with height gains in children and adolescents aged 6–11 years. Monitoring SMM changes in routine healthcare might motivate children and adolescents to achieve dietary and exercise recommendations, thereby growing taller without gaining excessive weight

    Vegetative Ecological Characteristics of Restored Reed (Phragmites australis) Wetlands in the Yellow River Delta, China

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    In this study, we compared ecological characteristics of wetland vegetation in a series of restoration projects that were carried out in the wetlands of Yellow River Delta. The investigated characteristics include plant composition structure, species diversity and community similarity in three kinds of Phragmites australis wetlands, i.e. restored P. australis wetlands (R1, R2, R3 and R4: restored in 2002, 2005, 2007 and 2009, respectively), natural P. australis wetland (N) and degraded P. australis wetland (D) to assess the process of wetlands restoration. The coverage of the R1 was 99%, which was similar to natural wetland. Among all studied wetlands, the highest and lowest stem density was observed in R1 and R2, respectively, Plant height and stem diameter show the same trend as N > R2 > R1 > R3 > D > R4. Species diversity of restored P. australis wetlands became closed to natural wetland. Both species richness and Shannon–Wiener index had similar tendency: increased first and then decreased with restored time. The highest species richness and species diversity were observed in R2, while the lowest values of those parameters were found in natural P. australis wetland. Similarity indexes between restored wetlands and natural wetland increased with the restoration time, but they were still less than 50%. The results indicate that the vegetation of P. australis wetlands has experienced a great improvement after several years’ restoration, and it is feasible to restored degraded P. australis wetlands by pouring fresh water into those wetlands in the Yellow River Delta. However, it is notable that costal degraded P. australis wetland in this region may take years to decades to reach the status of natural wetland

    Finishing the euchromatic sequence of the human genome

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    The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

    “mTOR Signaling Pathway”: A Potential Target of Curcumin in the Treatment of Spinal Cord Injury

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    The purpose of this review is to discuss the possibility of the treatment of spinal cord injury (SCI) with curcumin via regulating the mTOR signaling pathway, which may provide another strong support for curcumin to be a promising medicine applied to the treatment of SCI. Curcumin is termed as a multifunctional targeting therapy drug that regulates the mTOR signaling pathway in the treatment of numerous diseases. Previous research has already revealed that mTOR signaling pathway plays a vital role in prognosis, which involves the axon regeneration and autophagy. This review discusses a potential mechanism that curcumin suppresses the activation of this pathway and ameliorates the microenvironment of axons regeneration which would provide a new way that induces autophagy appropriately

    Research Progress in Rat Models of Intrauterine Adhesion

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    Intact endometrium and proper endometrial thickness are the necessary conditions for normal uterine reproductive function. Intrauterine adhesion (IUA) can cause recurrent abortion and infertility, which seriously affects the normal reproductive function of patients. At present, the treatment methods for IUA include surgery elimination and use of estrogen, but there are problems such as poor effectiveness, high rate of recurrence, and still with low pregnancy rate. The specific pathogenesis and developmental mechanism of IUA and the repair mechanism of damaged endometrium are still unclear. Establishing an appropriate animal model is conducive to the research of human IUA in all aspects. Here, we introduced the common rat models of IUA in recent years, including physical and mechanical damage method, chemical damage method, biological damage method and combined damage method, and described its application from the aspects of modeling rate, stability, and pathogenesis of IUA, and discussed the observation indexes to evaluate the success of modeling, in order to provide useful reference for selecting appropriate modeling methods. Generally, the combined model of repeated endometrial damage and infection of pregnant rats may be more suitable for the clinical IUA caused by multiple abortions and infections after curettage

    Thermal kinetics of montmorillonite nanoclay/maleic anhydride-modified polypropylene nanocomposites

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    Thermal kinetics of montmorillonite nanoclay (MMT)/maleic anhydride-modified polypropylene (MAH-PP) composites (PPCNs) is reported here in terms of thermal stability, decomposition, and crystallization kinetics. The effects of MMT nanoclay on the thermal stability of PP in MMT/MAH-PP composites have been examined at different heating rates by means of thermogravimetric (TG) analysis. Based on the TG results, the Ozawa method was applied to determine the activation energies of decomposition for MMT/MAH-PP composites and the results were then verified by the Kissinger method. It was found that the thermal stability of PP was significantly improved in the presence of MMT nanoclay. Differential scanning calorimetry (DSC) was used to study the melting and crystallization behaviors of MMT/MAH-PP composites under various thermal conditions. Using the data from DSC, the Kissinger method was applied to estimate the activation energies of PPCNs which were required during their non-isothermal crystallization. The activation energies of crystallization showed that MMT nanoclay served as a nucleating agent in the non-isothermal crystallization of PP in the PPCNs and as a result, the crystallinity of PP was greatly enhanced. Therefore, the presence of MMT nanoclay in MMT/MAH-PP composites effectively modified the thermal kinetics of PP
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