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This study aims to explore the role of graphene in enhancing the radiation resistance of epoxy resin (EP) composites. Through the resin transfer molding process, we prepared 0.3 wt% graphene oxide (GO) and Hummer's method reduced graphene oxide (Hh-RGO) reinforced EP composites, respectively. By comparing the microstructure, free radical content, thermal stability, and mechanical properties of EP, GO/EP, and Hh-RGO/EP composites before and after γ-ray irradiation, we found that GO and Hh-RGO can effectively reduce the generation of free radicals in EP during irradiation, thereby reducing chemical bond breakage and enhancing its radiation resistance. Particularly, GO demonstrated stronger radiation damage resistance. The results showed that after γ-ray irradiation, the glass transition temperature, nano-indentation depth, and hardness of GO/EP composites decreased by 20.32%, 416.3 nm, and 16.00%, respectively, whereas EP decreased by 30.34%, 502.1 nm, and 41.82% respectively. This is mainly attributed to the fact that the addition of graphene nanoparticles as a reinforcement reduces the free radical content in EP and reduces the damage of free radicals to the EP crosslinked network during irradiation, thereby improving the thermal stability and mechanical properties of the composites. In addition, the Π electrons formed by the hexagonal honeycomb structure of GO and the Π-Π stacking effect formed with free radicals can slow down the aging of epoxy resin in a high-energy radiation environment, thereby prolonging its service life. This study provides important references for further optimization and application of graphene-modified epoxy resin. [ABSTRACT FROM AUTHOR]

In order to study the relationship between nutrient pollutants and suspended sediments (SS) in the upper reaches of the Yangtze River and two tributaries, water samples were collected from September 1, 2010 to September 30, 2011 at the Zhutuo, Cuntang, Beibei, Wulong, Qingxichang, Wanxian, and Fengjie cross-sections. In the laboratory, the SS concentration and the concentration of SS whose particle size was smaller than 0.02 mm were measured. The phosphorus (P), nitrogen (N), and permanganate index (CODMn) concentrations in the natural water sample, the settled water sample, and two types of filtered water samples obtained through filter membranes with pore sizes of 0.02 mm and 0.45 μm were monitored synchronously. The results show that there are strong relationships between the P and CODMn concentrations and the SS concentration. P mainly exists in particulate form, while N mainly exists in dissolved form. SS whose particle size is smaller than 0.02 mm accounts for a high proportion of sediments in the Yangtze River and has a strong effect on water quality. At the seven cross-sections, the amounts of P, N, and CODMn in particulate form in the wet season are higher than in the dry season and the adsorption amounts of P, N, and CODMn per unit mass of sediment are higher in the dry season than in the wet season.

課程知識問題是學校教育永遠也無法繞開的一個基本的核心話題。二十一世紀初以來，隨著新課程改革深入推進，在中國教育領域展開的課程知識大討論，已導致了人們的課程知識觀認同危機。考察近幾年的相關研究，在方法論上體現為一種「外推式」，而非「內生式」研究。為此，當代課程知識觀的重構需要從兩條進路展開：即從課程與教學理論和實踐歷史發展的內部，去梳理課程知識觀發展演變的內在理路；以課程知識與教學活動中，兒童之間的現實關係為切入點，去考察課程知識觀重構的現實基礎。 The issue of curriculum knowledge is a basic topic which school education may not slide over for ever. The widely controversy in the field of education in china has lead to the crisis of identity about the view of curriculum knowledge from the beginning of 21 century, with the further development of New Curriculum Reform. We find the many researches about curriculum knowledge are not generated from the inner educational field, but inspired by related studies outside. Therefore, we argue the recontruction of the view of curriculum knowledge must be done from two approaches: heckleing the inner logic of the evolvement about the view of curriculum knowledge, and examinating the practical base of reconstruction of the curriculum knowledge view from the perspective of real relationship between curriculum knowledge and children.

The silanized graphene oxide (KH-GO) with different mass fractions was dispersed in epoxy resin by a solution blending method and resin transfer molding process. The nano indentation method was used to test the micromechanical properties of GO/epoxy composites with different mass fractions, and the effect of GO on the hardness of epoxy matrix composites was quantitatively determined, and the influence of adding KH-GO on the thermal mechanical and bending properties of epoxy resin was discussed by dynamic thermal mechanical and universal strength machine tests. The experimental results show that the thermal and mechanical properties of composites are improved with the increase of the amount of KH-GO. Especially, when the content of KH-GO was 0.3%, the bending strength (125.4 MPa), hardness (281.0 MPa), and glass transition temperature (99.6°C) of composites reached the highest. It was proved that the composites showed its excellent performance and the silane coupling agent was successfully grafted to the graphene oxide by covalent bond, which effectively improved the interface compatibility of the reinforcing body and the matrix and was related to good dispersibility in the epoxy resin. This method is simple and effective, providing a certain reference value for the enhancement of the mechanical properties of the next generation of nanocomposites. [ABSTRACT FROM AUTHOR]

Milk exosomal microRNAs (miRNAs) are important for postnatal growth and immune system maturation in newborn mammals. The functional hypothesis of milk exosomal miRNAs and their potential bioavailability in milk to newborn mammals were investigated. Briefly, 37 exosomal miRNAs were upregulated compared to miRNAs found outside the exosomes. Among these miRNAs, ssc-miR-193a-3p expression was upregulated 1467.35 times, while ssc-miR-423-5p, ssc-miR-551a, ssc-miR-138, ssc-miR-1 and ssc-miR-124a were highly concentrated and upregulated 13.58–30.06 times. Moreover, these miRNAs appeared to be relevant for cell development and basic physiological processes of the immune system. Following the analysis of target gene prediction and related signalling pathways, 9262 target genes were mainly concentrated in three signalling pathways: metabolic pathways, pathways in cancer, and phosphatidylinositol 3-kinase/protein kinase B (PI3K/Akt) signalling pathways. Among 9262 target genes, more than 20 miRNAs were enriched in exosomes, such as methyl CpG binding protein 2 (MECP2) and glycogen synthase 1 (GYS1). After determining the miRNA localization-, distribution- and function-related metabolism, we found that these exosomes were specifically concentrated miRNA target genes and they were interrelated with cell development and basic cell functions, such as metabolism and immunity. It is speculated that miRNAs in milk can influence offspring via milk exosomes. [ABSTRACT FROM AUTHOR]

A heterogeneous lattice material composed of different cells is proposed to improve the energy absorption capacity. The heterogeneous structure is formed by setting layers of body-centered XY rods (BCCxy) cells as the reinforcement in the body-centered cubic (GBCC) uniform lattice material. The heterogeneous lattice samples are designed and processed by additive manufacturing technology. The stress wave propagation and energy absorption properties of heterogeneous lattice materials under impact load are analyzed by finite element simulation (FES) and Hopkinson pressure bar (SHPB) experiments. The results show that, compared with the GBCC uniform lattice material, the spreading velocity of the stress of the (GBCC)3(BCCxy)2 heterogeneous lattice material is reduced by 18.1%, the impact time is prolonged 27.9%, the stress peak of the transmitted bar is reduced by 34.8%, and the strain energy peak is reduced by 29.7%. It indicates that the heterogeneous lattice materials are able to reduce the spreading velocity of stress and improve the energy absorption capacity. In addition, the number of layers of reinforcement is an important factor affecting the stress wave propagation and energy absorption properties. [ABSTRACT FROM AUTHOR]

The polygrammoids (Polypodiaceae) are the most species‐rich and diversified epiphytic fern lineages, and hold an important role to understand the deep diverging events and rapid adaptation to changing environments in the plant tree of life. Despite progress in the phylogeny of this group of ferns in previous multilocus phylogenetic studies, uncertainty remains especially in backbone relationships among closely related clades, and the phylogenetic placement of recalcitrant species or lineages. Here, we investigated the deep phylogenetic relationships within Polypodiaceae by sampling all major lineages and using 81 plastid genomes (plastomes), of which 70 plastomes were newly sequenced with high‐throughput sequencing technology. Based on parsimony, maximum‐likelihood, Bayesian and multispecies coalescent analyses of genome skimming data, we achieved a better resolution of the backbone phylogeny of Polypodiaceae. Using simulated data matrices, we detected that potential phylogenetic artefacts, such as long‐branch attraction and insufficient taxonomic sampling, may have a confounding impact on the incongruence of phylogenetic inferences. Furthermore, our phylogenetic analyses offer greater resolution than previous multilocus studies, providing a robust framework for future phylogenetic implications on the subfamilial taxonomy of Polypodiaceae. Our phylogenomic study not only demonstrates the advantage of a character‐rich plastome dataset for resolving the recalcitrant lineages that have undergone rapid radiation, but also sheds new light on integrative explorations understanding the evolutionary history of large fern groups in the genomic era. [ABSTRACT FROM AUTHOR]

Water-lubricated single-screw compressors (WSSCs) have developed rapidly in recent years because they can supply oil-free compressed air at considerably low costs. However, a major technical obstacle is that the conventional bearing arrangement of a star wheel shaft is prone to wear failure, which makes it difficult for WSSCs to run properly for long periods of time. To solve this problem, a star wheel thrust bearing with new liquid groove was proposed in this paper. Pulsating forces (i.e., bearing forces) acting on a star wheel shaft by compressing air were calculated through the dynamic analysis of the star wheel shaft system. A mathematical model of hydraulic water films in the bearing sliding clearance was established to describe the influence of water injection pressure on water film pressure distribution and its bearing capacity. Lubrication characteristics were compared between two types of hydrostatic thrust bearings (HTBs) with different grooves to illustrate that the new structure is more suitable for WSSCs. The reasonability of the proposed model and simulation results were verified using an axial thrust bearing test rig developed by the authors. In addition, variation parameters of hydrostatic film thickness between the sliding surfaces of the star wheel axial thrust bearing were measured. The results show that the instability of the water film thickness and axial vibration of the star wheel were suppressed, thereby avoiding the contact of solid materials between the end face of the axial thrust bearing. This study provides a structural optimization pattern of star wheel axial thrust bearings used in water-lubricated single-screw compressors. [ABSTRACT FROM AUTHOR]

Fatty acid composition is an important aspect of meat quality in ruminants. Improving the beneficial fatty acid level in cashmere goat meat is important to its economic value. To investigate microRNAs (miRNAs) and mRNAs that regulate or coregulate polyunsaturated fatty acid (PUFA) synthesis and metabolism in the Inner Mongolia cashmere goat, we used longissimus dorsi muscle (WLM) and biceps femoris muscle (WBM) for transcript-level sequencing. RT-qPCR was used to evaluate the expression of mRNAs and miRNAs associated with PUFA synthesis and metabolism. The total PUFA content in the WBM was significantly higher than that in the WLM (P < 0.05). Our study is the first to systematically report miRNAs in cashmere goat meat. At the mRNA level, 20,375 genes were identified. ACSL1 , CD36 and TECRL were at the center of a gene regulatory network and contributed significantly to the accumulation and metabolic regulation of fatty acids. At the miRNA level, 426 known miRNAs and 30 novel miRNAs were identified. KEGG analysis revealed that the miRNA target genes were involved mainly in the PPAR signaling pathway. The mRNA-miRNA coregulation analysis showed that ACSL1 was negatively targeted by nine miRNAs: chi-miR-10a-5p, chi-miR-10b-5p, chi-miR-130b-5p, chi-miR-15a-5p_R-1, chi-miR-15b-5p, chi-miR-16a-5p, chi-miR-16b-5p, chi-miR-181c-5p_R+1, and chi-miR-26b-5p. Finally, we speculated that the simultaneous silencing of ACSL1 by one or more of these nine miRNAs through PPAR signaling led to low ACSL1 expression in the WLM and, ultimately to high PUFA content in the WBM. Our study helps elucidate the metabolic regulation of fatty acids in Inner Mongolia cashmere goats. [ABSTRACT FROM AUTHOR]

The fern genus Lepisorus represents one of the most complicated and controversial lineages in Polypodiaceae, with about 80 species which have been classified into several separate genera, and is notorious for its taxonomic difficulty. Despite progress in recent phylogenetic studies of the family Polypodiaceae involving Lepisorus and its allies, the deep phylogenetic relationship within this group of ferns is still unresolved, and no formal infrageneric classification has been proposed. This contribution presents the most comprehensive phylogenetic analysis of the genus, with 72% species sampled, using a total‐evidence approach based on eight plastid markers and ≤25 morphological characters for each species. The analyses resolve the backbone relationship and yield the most robust phylogenetic framework to date. Congruent with previous studies but with new findings, the results herein show that Lepisorus is monophyletic when Neolepisorus, Lemmaphyllum, Tricholepidium, Neocheiropteris and Lepidomicrosorium are included, as well as Lepisorus jakonensis and Paragramma. Furthermore, 17 well‐resolved clades are found in the phylogenetic topology, which can be characterized by morphological synapomorphies from traits of rhizome scales, laminae, sori and paraphyses. Based on molecular and morphological evidence, a new infrageneric classification system of Lepisorus is proposed which subdivided Lepisorus into 17 sections. [ABSTRACT FROM AUTHOR]

A series of planar chiral iodoarenes based on [2.2]paracyclophane was synthesized. An efficient asymmetric intramolecular oxidative lactonization of naphthols enabled by a combination of these chiral iodoarenes and m CPBA as oxidant is reported. This reaction proceeds under mild conditions, allowing the formation of spirolactones bearing a tetrasubstituted stereocenter in moderate yields and good enantioselectivity. [ABSTRACT FROM AUTHOR]

Objective: The etiology of cardiovascular disease (CVD) is complex owing to the interactions of genetic variance with environmental factors. Inflammatory processes are now being increasingly implicated in the pathogenesis of CVD. This meta-analysis investigated the potential role of interleukin-6 (IL-6) as a risk factor for CVD development in healthy individuals. Methods: Literature search was carried out in multiple electronic databases, and study selection followed a priori eligibility criteria. Meta-analyses of standardized mean differences were carried out to determine an overall effect size of the difference in IL-6 levels between CVD cases and non-CVD matched controls. Meta-regression analyses were performed to examine the relationship between the IL-6 levels in CVD cases and several explanatory variables. Results: Seventeen studies enrolling 288738 healthy individuals with an average follow-up duration of 7.4 ± 4.1 years were found eligible. Overall, data of 5400 CVD cases and 14607 matched non-CVD controls are used in the present meta-analysis. Baseline IL-6 levels were significantly higher in CVD cases than in non-CVD controls (standardized mean difference [95% confidence interval]) of 0.14 [0.09, 0.20]/mean difference of 0.36 [0.28, 0.44] picogram per milliliter). Total cholesterol, LDL-cholesterol, and triglyceride levels were also significantly higher, and HDL-cholesterol levels were significantly lower in CVD cases in comparison with the controls. Systolic blood pressure and total cholesterol levels had a significantly positive relationship, whereas triglyceride levels had a significantly inverse relationship with the levels of IL-6. Conclusion: Higher IL-6 levels in healthy individuals are associated with CVD risk, which is co-associated with hypertension and hypercholesterolemia. [ABSTRACT FROM AUTHOR]

Here, we publish Lepisorus sect. Paragramma (Blume) C.F. Zhao, R. Wei & X.C. Zhang as a combinatio nova to replace the section name in Zhao et al. (2020), which was published as a status nova and turned out to be an invalid name, because we cited an incorrect basionym. A revised infrageneric classification of Lepisorus also is proposed. [ABSTRACT FROM AUTHOR]

Lepisorus waltonii (Ching) S. L. Yu is a typical alpine fern species in the Qinghai-Tibet Plateau and Hengduan Mountain Regions. Here, we described the complete chloroplast genome of L. waltonii using Illumina paired-end sequencing. The chloroplast genome length is 157,148 bp, containing two inverted repeats (IR, 27,110 bp each) regions, separated by a large single-copy (LSC, 81,243 bp), and a small single-copy (SSC, 21,685 bp) regions, respectively. The genome contains 118 functional genes, including 85 protein-coding genes, 29 tRNA genes, and four rRNA genes. The total GC content of the chloroplast genome is 41.8%. ML phylogenetic analysis revealed that L. waltonii was closest related to Lepisorus clathratus. [ABSTRACT FROM AUTHOR]

• A real-time displacement measurement technique based on all-fiber Fabry–Perot interferometer. • The quadrature detection algorithm can significantly simplify the data processing process. • Two Fabry-Perot interference signals with a phase shift of π / 2 can be obtained directly. • The object displacement can be reconstructed directly by the quadrature demodulation algorithm. • The structure of the system is simple and compact. A real-time displacement reconstruction method based on an all-fiber Fabry–Perot interferometer (FPI) is proposed, utilizing the fiber end face and the object surface to form an extrinsic FPI. Using the constant phase difference of 90° between the two output ports of the 2 × 2 coupler, two-phase orthogonal FPI signals carrying the object motion information can be detected by two invisible photodetectors, and real-time displacement reconstruction can be realized by adopting inverse tangent and unwrapping processing procedures. Results show that the absolute errors of the experiment are below 80 nm. [ABSTRACT FROM AUTHOR]