Armoring the cathode with starch gel enables Shuttle-Free Zinc-Iodine batteries.

Zinc-iodine batteries (ZIBs) have been recognized as a promising energy storage device due to their high energy density, low cost and environmental friendliness. However, the development of ZIBs is hindered by the shuttle effect of polyiodides which results in capacity degradation and poor cycling performance. Inspired by the ability of starch to form inclusion compounds with iodine, we propose to use a starch gel on the cathode to suppress the shuttle of polyiodides. Herein, porous carbon is utilized as a host for iodine species and provides an excellent conductive network, while starch gel is used as another host to suppress polyiodides shuttle, resulting in improved battery performance. The test results demonstrate that the conversion between I-/I2/I3- in the cathode and the effective inclusion role of starch suppress the shuttle of polyiodides during the charging process. Meanwhile, based on the electrochemical tests and theoretical DFT calculations, it is found that starch has a stronger ability to adsorb polyiodides compared to carbon materials, which enables effective confinement of polyiodides. The ZIBs used the cathode with starch gel exhibit high coulombic efficiency (>95 % at 0.2 A/g) and low self-discharge (86.8 % after resting for 24 h). This strategy is characterized by its simplicity, low cost and high applicability, making it significant for the advancement of high-performance ZIBs.

The Influence of Cadmium on Fountain Grass Performance Correlates Closely with Metabolite Profiles.

The relationship between metabolite changes and biological endpoints in response to cadmium (Cd) stress remains unclear. Fountain grass has good Cd enrichment and tolerance abilities and is widely used in agriculture and landscaping. We analyzed the metabolic responses by detecting the metabolites through UPLC-MS and examined the relationships between metabolite changes and the characteristics of morphology and physiology to different Cd stress in fountain grass. Our results showed that under Cd stress, 102 differential metabolites in roots and 48 differential metabolites in leaves were detected, with 20 shared metabolites. Under Cd stress, most of the carbohydrates in leaves and roots decreased, which contributed to the lowered leaf/root length and fresh weight. In comparison, most of the differential amino acids and lipids decreased in the leaves but increased in the roots. Almost all the differential amino acids in the roots were negatively correlated with root length and root fresh weight, while they were positively correlated with malondialdehyde content. However, most of the differential amino acids in the leaves were positively correlated with leaf length and leaf fresh weight but negatively correlated with malondialdehyde content. Metabolic pathway analysis showed that Cd significantly affects seven and eight metabolic pathways in the leaves and roots, respectively, with only purine metabolism co-existing in the roots and leaves. Our study is the first statement on metabolic responses to Cd stress and the relationships between differential metabolites and biological endpoints in fountain grass. The coordination between various metabolic pathways in fountain grass enables plants to adapt to Cd stress. This study provides a comprehensive framework by explaining the metabolic plasticity and Cd tolerance mechanisms of plants.

Stress-Stabilized Crystalline Phases of Ultrahigh Molecular Weight Polyethylene under Tensile Stress.

Ultrahigh molecular weight polyethylene (UHMWPE) is a semicrystalline polymer renowned for its exceptional mechanical properties, making it a popular material in various high-tech fields. Its mechanical attributes are predominantly governed by its crystalline structures, which may experience alterations in the chain conformation and interchain packing during mechanical deformation. This phenomenon leads to the emergence of distinct polymorphs with unique lattice structures. The investigation of stress-stabilized crystal structures of UHMWPE under tensile stress currently poses challenges with certain aspects remaining unclear. To address this, in this study, time-resolved X-ray wide-angle scattering (TR-WAXS) experiments of biaxially stretched UHMWPE films under in situ tensile conditions were conducted. Experimental results revealed two distinct stress-stabilized crystal phases of UHMWPE that differed from those previously reported. These stress-stabilized phases have been identified as the stress-stabilized orthorhombic crystal phase and the stress-stabilized monoclinic crystal phase, and their corresponding lattice parameters have been accurately calculated through an ab initio computational method. These findings provide deeper insights into UHMWPE's behavior under mechanical strain, opening other avenues for further academic exploration and potential applications in cutting-edge fields.

Microstructure and Tensile Properties of Melt-Spun Filaments of Polybutene-1 and Butene-1/Ethylene Copolymer.

Polybutene-1 with form I crystals exhibits excellent creep resistance and environmental stress crack resistance. The filaments of polybutene-1 and its random copolymer with 4 mol% ethylene co-units were produced via extrusion melt spinning, which are expected to be in form I states and show outstanding mechanical properties. The variances in microstructure, crystallization-melting behavior, and mechanical properties between homopolymer and copolymer filaments were analyzed using SEM, SAXS/WAXD, DSC, and tensile tests. The crystallization of form II and subsequent phase transition into form I finished after the melt-spinning process in the copolymer sample while small amounts of form II crystals remained in homopolymer filaments. Surprisingly, copolymer filaments exhibited higher tensile strength and Young's modulus than homopolymer filaments, while the homopolymer films showed better mechanical properties than copolymer films. The high degree of orientation and long fibrous crystals play a critical role in the superior properties of copolymer filaments. The results indicate that the existence of ethylene increases the chain flexibility and benefits the formation of intercrystalline links during spinning, which contributes to an enhancement of mechanical properties. The structure-property correlation of melt-spun PB-1 filaments provides a reference for the development of polymer fibers with excellent creep resistance.

Design and Synthesis of Low Dielectric Poly(aryl ether ketone) from Incorporation Bulky Fluorene Groups and Regular Hydroquinone Structure.

To decrease the dipole polarization rate and reduce the dielectric constant of poly(aryl ether ketone) (PAEK) resin, 1,4-di(4-fluorobenzoyl) cyclohexane (DFBCH), a weakly polarizing cyclohexane-based monomer, was designed and synthesized as the primary reactant. The bulky fluorene group was incorporated to increase the free volume of the resin, further reducing the dielectric constant. Additionally, hydroquinone with a symmetric and regular structure was utilized to enhance the molecular chain's regularity and reduce dipole relaxation, further lowering the resin's dielectric constant and dielectric loss. The PFQEKs series resins exhibited excellent thermal stability with glass transition temperature (Tg) ranging from 222 to 239 °C and 5% weight loss (Td5%) ranging from 458 to 463 °C, with different monomer ratios. As the hydroquinone content increased, the dielectric constant (Dk) and dielectric loss (Df) of the resin decreased significantly, with Dk ranging from 2.92 to 2.77 and Df ranging from 0.011 to 0.008 at 10 GHz.

Unveiling Superior Capacitive Behaviors of One-Pot Molten Salt-Engineered B, N Co-Doped Porous Carbon Sheets.

Heteroatom-doped porous carbon materials with distinctive surface properties and capacitive behavior have been accepted as promising candidates for supercapacitor electrodes. Currently, the researches mainly focus on developing facile synthetic method and unveiling the structure-activity relationship to further elevate their capacitive performance. Here, the B, N co-doped porous carbon sheet (BN-PCS) is constructed by one-pot pyrolysis of agar in KCl/KHCO3 molten salt system. In this process, the urea acts as directing agent to guide the formation of 2D sheet morphology, and the decomposition of KHCO3 and boric acid creates rich micro- and mesopores in the carbon framework. The specific capacitance of optimized BN-PCS reaches 361.1 F g-1 at a current density of 0.5 A g-1 in an aqueous KOH electrolyte. Impressively, the fabricated symmetrical supercapacitor affords a maximum energy density of 43.5 Wh kg-1 at the power density of 375.0 W kg-1 in 1.0 mol L-1 TEABF4 /AN electrolyte. It also achieves excellent long-term stability with capacitance retention of 91.1% and Columbic efficiency of 100% over 10 000 cycles. This study indicates one-pot molten salt method is effective in engineering advanced carbon materials for high-performance energy storage devices.

Hydrogel/ß-FeOOH-Coated Poly(vinylidene fluoride) Membranes with Superhydrophilicity/Underwater Superoleophobicity Facilely Fabricated via an Aqueous Approach for Multifunctional Applications.

Hydrogel coatings that can endow various substrates with superior properties (e.g., biocompatibility, hydrophilicity, and lubricity) have wide applications in the fields of oil/water separation, antifouling, anti-bioadhesion, etc. Currently, the engineering of multifunctional hydrogel-coated materials with superwettability and water purification property using a simple and sustainable strategy is still largely uninvestigated but has a beneficial effect on the world. Herein, we successfully prepared poly(2-acrylamido-2-methyl-1-propanesulfonic acid) hydrogel/ß-FeOOH-coated poly(vinylidene fluoride) (PVDF/PAMPS/ß-FeOOH) membrane through free-radical polymerization and the in situ mineralization process. In this work, owing to the combination of hydrophilic PAMPS hydrogel coating and ß-FeOOH nanorods anchored onto PVDF membrane, the resultant PVDF/PAMPS/ß-FeOOH membrane achieved outstanding superhydrophilicity/underwater superoleophobicity. Moreover, the membrane not only effectively separated surfactant-stabilized oil/water emulsions, but also possessed a long-term use capacity. In addition, excellent photocatalytic activity against organic pollutants was demonstrated so that the PVDF/PAMPS/ß-FeOOH membrane could be utilized to deal with wastewater. It is envisioned that these hydrogel/ß-FeOOH-coated PVDF membranes have versatile applications in the fields of oil/water separation and wastewater purification.

Non-Coplanar Diphenyl Fluorene and Weakly Polarized Cyclohexyl Can Effectively Improve the Solubility and Reduce the Dielectric Constant of Poly (Aryl Ether Ketone) Resin.

With the rapid development of high-frequency communication and large-scale integrated circuits, insulating dielectric materials require a low dielectric constant and dielectric loss. Poly (aryl ether ketone) resins (PAEK) have garnered considerable attention as an intriguing class of engineering thermoplastics possessing excellent chemical and thermal properties. However, the high permittivity of PAEK becomes an obstacle to its application in the field of high-frequency communication and large-scale integrated circuits. Therefore, reducing the dielectric constant and dielectric loss of PAEK while maintaining its excellent performance is critical to expanding the PAEK applications mentioned above. This study synthesized a series of poly (aryl ether ketone) resins that are low dielectric, highly thermally resistant, and soluble, containing cyclohexyl and diphenyl fluorene. The effects of cyclohexyl contents on the properties of a PAEK resin were studied systematically. The results showed that weakly-polarized cyclohexyl could reduce the molecular polarization of PAEK, resulting in low permittivity and high transmittance. The permittivity of PAEK is 2.95-3.26@10GHz, and the transmittance is 65-85%. In addition, the resin has excellent solubility and can be dissolved in NMP, DMF, DMAc, and other solvents at room temperature. Furthermore, cyclohexyl provided PAEK with excellent thermal properties, including a glass transition temperature of 239-245 °C and a 5% thermogravimetric temperature, under a nitrogen atmosphere of 469-534 °C. This makes it a promising candidate for use in high-frequency communications and large-scale integrated circuits.

The functional specificity of ERECTA-family receptors in Arabidopsis stomatal development is ensured by molecular chaperones in the endoplasmic reticulum.

Stomata are epidermal pores that control gas exchange between plants and the atmosphere. In Arabidopsis, the ERECTA family (ERECTAf) receptors, including ERECTA, ERECTA-LIKE 1 (ERL1) and ERL2, redundantly play pivotal roles in enforcing the 'one-cell-spacing' rule. Accumulating evidence has demonstrated that the functional specificities of receptors are likely associated with their differential subcellular dynamics. The endoplasmic reticulum (ER)-resident chaperone complex SDF2-ERdj3B-BiP functions in many aspects of plant development. We employed pharmacological treatments combined with cell biological and biochemical approaches to demonstrate that the abundance of ERECTA was reduced in the erdj3b-1 mutant, but the localization and dynamics of ERECTA were not noticeably affected. By contrast, the erdj3b mutation caused the retention of ERL1/ERL2 in the ER. Furthermore, we found that the function of SDF2-ERdj3B-BiP is implicated with the distinct roles of ERECTAf receptors. Our findings establish that the ERECTAf receptor-mediated signaling in stomatal development is ensured by the activities of the ER quality control system, which preferentially maintains the protein abundance of ERECTA and proper subcellular dynamics of ERL1/ERL2, prior to the receptors reaching their destination - the plasma membrane - to execute their functions.

Combining Metabolic Analysis With Biological Endpoints Provides a View Into the Drought Resistance Mechanism of Carex breviculmis.

Metabolomics is an effective tool to test the response of plants to environmental stress; however, the relationships between metabolites and biological endpoints remained obscure in response to drought stress. Carex breviculmis is widely used in forage production, turf management, and landscape application and it is particularly resistant to drought stress. We investigated the metabolomic responses of C. breviculmis to drought stress by imposing a 22-day natural soil water loss. The results showed that water-deficit restrained plant growth, reducing plant height, leaf fresh weight, and total weight, however, increasing soluble protein content and malondialdehyde content. In total, 129 differential metabolites in the leaves were detected between drought and control using the Ultrahigh Performance Liquid Chromatography-Mass Spectrometer (UPLC-MS) method. Drought enhanced most of the primary and secondary metabolites in the differential metabolites. Almost all the sugars, amino acids, organic acids, phytohormones, nucleotides, phenylpropanoids and polyketides in the differential metabolites were negatively correlated with plant height and leaf fresh weight, while they were positively correlated with soluble protein content and malondialdehyde content. Metabolic pathway analysis showed that drought stress significantly affected aminoacyl-tRNA biosynthesis, TCA cycling, starch and sucrose metabolism. Our study is the first statement on metabolomic responses to drought stress in the drought-enduring plant C. breviculmis. According to the result, the coordination between diverse metabolic pathways in C. breviculmis enables the plant to adapt to a drought environment. This study will provide a systematic framework for explaining the metabolic plasticity and drought tolerance mechanisms of C. breviculmis under drought stress.

Carbon Nanotubes Grown on the Carbon Fibers to Enhance the Photothermal Conversion toward Solar-Driven Applications.

Photothermal conversion is a directly, sustainable, and green path to use solar energy and the one of the most important keys is the photothermal conversion material. How to obtain the durable and effective material for photothermal conversion with low cost and facile preparation is still a great challenge. In this work, the carbon nanotubes (CNTs) are grown on the carbon fibers (CFs) via the catalysis of trapped Fe and Co. The absorption of the as-prepared CFs/CNTs illustrate the enhancement from the visible light to the near-infrared light range. The photothermal conversion characterization shows the grown CNTs promoting the higher surface temperature and the highest temperature reaches to about 325 °C under 10 sun irradiations. The water evaporation on the CFs/CNTs is measured 1.40 ± 0.03 kg·cm-2·h-1 under 1 sun irradiation and the water evaporation rate is also found depending on the irradiation density. The photothermal conversion applications and the water evaporation under natural irradiation also reveal the suitable candidate of the CFs/CNTs for photothermal conversion application. This work provides a facile path to obtain effective carbon-based materials for photothermal application.

Transcriptomic analysis reveals the role of FOUR LIPS in response to salt stress in rice.

KEY MESSAGE: An R2R3-MYB transcription factor FOUR LIPS associated with B-type Cyclin-Dependent Kinase 1;1 confers salt tolerance in rice. The Arabidopsis FOUR LIPS (AtFLP), an R2R3 MYB transcription factor, acts as an important stomatal development regulator. Only one orthologue protein of AtFLP, Oryza sativa FLP (OsFLP), was identified in rice. However, the function of OsFLP is largely unknown. In this study, we conducted RNA-seq and ChIP-seq to investigate the potential role of OsFLP in rice. Our results reveal that OsFLP is probably a multiple functional regulator involved in many biological processes in growth development and stress responses in rice. However, we mainly focus on the role of OsFLP in salt stress response. Consistently, phenotypic analysis under salt stress conditions showed that osflp exhibited significant sensitivity to salt stress, while OsFLP over-expression lines displayed obvious salt tolerance. Additionally, Yeast one-hybrid assay and electrophoretic mobility shift assay (EMSA) showed that OsFLP directly bound to the promoter region of Oryza sativa B-type Cyclin-Dependent Kinase 1;1 (OsCDKB1;1), and the expression of OsCDKB1;1 was repressed in osflp. Disturbing the expression of OsCDKB1;1 remarkably enhanced the tolerance to salt stress. Taken together, our findings reveal a crucial function of OsFLP regulating OsCDKB1;1 in salt tolerance and largely extend the knowledge about the role of OsFLP in rice.

Detecting subtle yet fast skeletal muscle contractions with ultrasoft and durable graphene-based cellular materials.

Human bodily movements are primarily controlled by the contractions of skeletal muscles. Unlike joint or skeletal movements that are generally performed in the large displacement range, the contractions of the skeletal muscles that underpin these movements are subtle in intensity yet high in frequency. This subtlety of movement makes it a formidable challenge to develop wearable and durable soft materials to electrically monitor such motions with high fidelity for the purpose of, for example, muscle/neuromuscular disease diagnosis. Here we report that an intrinsically fragile ultralow-density graphene-based cellular monolith sandwiched between silicone rubbers can exhibit a highly effective stress and strain transfer mechanism at its interface with the rubber, with a remarkable improvement in stretchability (>100%). In particular, this hybrid also exhibits a highly sensitive, broadband-frequency electrical response (up to 180 Hz) for a wide range of strains. By correlating the mechanical signal of muscle movements obtained from this hybrid material with electromyography, we demonstrate that the strain sensor based on this hybrid material may provide a new, soft and wearable mechanomyography approach for real-time monitoring of complex neuromuscular-skeletal interactions in a broad range of healthcare and human-machine interface applications. This work also provides a new architecture-enabled functional soft material platform for wearable electronics.

A polyaniline-modified electrode surface for boosting the electrocatalysis towards the hydrogen evolution reaction and ethanol oxidation reaction.

Here, polyaniline (PANI) is reported loaded on carbon paper to modify the carbon paper-PANI-Pt electrode surface, tailoring the electrocatalytic capability towards the hydrogen evolution reaction and ethanol oxidation reaction. The reasons for the enhancement by the PANI layer are attributed to the hydrophilic electrode surface, uniform dispersion of Pt, and large electrochemical active surface.

Heat-Resistant and High-Performance Solid-State Supercapacitors Based on Poly(para-phenylene terephthalamide) Fibers via Polymer-Assisted Metal Deposition.

Heat-resistant supercapacitors with excellent mechanical strength are highly required for flexible and wearable electronics in our daily life. Here, high-performance and heat-resistant solid-state supercapacitors based on poly(para-phenylene terephthalamide) fibers/Ag/poly(3,4-ethylenedioxythiophene)/polystyrene sulfonate (PEDOT:PSS)&carbon nanotubes (PPTA/Ag/PCNTs) have been fabricated for the first time. Due to the toughness of the PPTA fibers and the excellent electroconductivity of the composite fiber, the PPTA/Ag/PCNTs-based supercapacitor exhibits good electrochemical performance together with brilliant mechanical strength and bending durability. Moreover, the heat resistance of tough PPTA/Ag/PCNTs fiber and ionic liquid gel electrolyte endow the supercapacitor with stability at temperatures as high as 80 °C and the capacitance can return to more than 80% after the heat treatment. The power density or energy density of the supercapacitor assembled on PPTA/Ag/PCNTs fiber electrodes is higher than that of any other polymer fiber-related supercapacitor. This work adds to the study of high-performance supercapacitors based on polymer fibers and provides the possibility to apply PPTA fiber for energy storage devices with flexibility and heat resistance.

Biomimetic Porous Nanofiber-Based Oil Pump for Spontaneous Oil Directional Transport and Collection.

Directional transport and manipulation of liquid substances have drawn wide attention owing to their crucial applications from microfluid to large-area water harvesting. Spontaneous oil directional transport, especially having the prospect of large-scale manufacturing, plays a huge role in marine oil cleanup, but is exposed to the limitations such as low efficiency and transport velocity. Here, we report a biomimetic porous nanofiber-based oil pump from cosolvent electrospinning, endowed with the parenchyma cellular structure of plants. These tightly packed and uniform nanoporous structures of nanofibers are capable of self-pumping oil upward with an ultrahigh pumping rate of 21.12 g g-1 h-1, which has been proposed as an explicit mechanism. Following oil directional transport, it can obtain an efficient oil collection of 127.52 g g-1. We anticipate that our designed oil pump will provide a versatile platform for spontaneous oil directional transport and collection with potential applications in the fields of laboratory-on-a-chip, microreaction devices, chemical engineering, and the petrochemical industry.

Metabolomic analysis of the egg yolk during the embryonic development of broilers.

The chicken egg yolk, which is abundant with lipids, proteins, and minerals, is the major nutrient resource for the embryonic development. In fact, the magnitude and type of yolk nutrients are dynamically changed during the chicken embryogenesis to meet the developmental and nutritional requests at different stages. The yolk nutrients are metabolized and absorbed by the yolk sac membrane and then used by the embryo or other extraembryonic tissues. Thus, understanding the metabolites in the yolk helps to unveil the developmental nutritional requirements for the chicken embryo. In this study, we performed ultra high performance liquid chromatography/tandem mass spectrometry (UHPLC-MS/MS) analysis to investigate the change of metabolites in the egg yolk at embryonic (E) 07, E09, E11, E15, E17, and E19. The results showed that 1) the egg yolk metabolites at E07 and E09 were approximately similar, but E09, E11, E15, E17, and E19 were different from each other, indicating the developmental and metabolic change of the egg yolk; and 2) most of the metabolites were annotated in amino acid metabolism pathways from E11 to E15 and E17 to E19. Especially, arginine, lysine, cysteine, and histidine were continuously increased during the embryonic development, probably because of their effects on the growth promotion and oxidative stress amelioration of the embryo. Interestingly, the ferroptosis was found as one of major processes occurred from E15 to E17 and E17 to E19. Owing to the upregulated expression of acyl-CoA synthetase long-chain family member 4 detected in the yolk sac, we assumed that the ferroptosis of the yolk sac was perhaps caused by the accumulation of reactive oxygen species, which was induced by the large amount of polyunsaturated fatty acids and influx of iron in the yolk. Our findings might offer a novel understanding of embryonic nutrition of broilers according to the developmental changes of metabolites in the egg yolk and may provide new ideas to improve the health and nutrition for prehatch broiler chickens.

Feasibility of Predicting Static Dielectric Constants of Polymer Materials: A Density Functional Theory Method.

The rapid development of electronic devices with high integration levels, a light weight, and a multifunctional performance has fostered the design of novel polymer materials with low dielectric constants, which is crucial for the electronic packaging and encapsulation of these electronic components. Theoretical studies are more efficient and cost-effective for screening potential polymer materials with low dielectric constants than experimental investigations. In this study, we used a molecular density functional theory (DFT) approach combined with the B3LYP functional at the 6-31+G(d, p) basis set to validate the feasibility of predicting static dielectric constants of the polymer materials. First, we assessed the influence of the basis sets on the polarizability. Furthermore, the changes of polarizability, polarizability per monomer unit, and differences in polarizability between the consecutive polymer chains as a function of the number of monomers were summarized and discussed. We outlined a similar behavior for the volume of the polymers as well. Finally, we simulated dielectric constants of three typical polymer materials, polyethylene (PE), polytetrafluoroethylene (PTFE), and polystyrene (PS), by combining with the Clausius-Mossotti equation. The simulated results showed excellent agreement with experimental data from the literature, suggesting that this theoretical DFT method has great potential for the molecular design and development of novel polymer materials with low dielectric constants.

Developmental Change of Yolk Microbiota and Its Role on Early Colonization of Intestinal Microbiota in Chicken Embryo.

Although the fertilized eggs were found to contain microbes in early studies, the detailed composition of yolk microbiota and its influence on embryo intestinal microbiota have not been satisfactorily examined yet. In this study, the yolk microbiota was explored by using 16s rRNA sequencing at different developmental stages of the broiler embryo. The results showed that the relative abundance of yolk microbiota was barely changed during embryogenesis. According to the KEGG analysis, the yolk microbiota were functionally related to amino acid, carbohydrate, and lipid metabolisms during chicken embryogenesis. The yolk microbiota influences the embryonic intestinal microbiota through increasing the colonization of Proteobacteria, Firmicutes, and Bacteroidetes in the intestine, particularly. The intestinal microbes of neonatal chicks showed higher proportions of Faecalibacterium, Blautia, Coprococcus, Dorea, and Roseburia compared to the embryonic intestinal microbiota. Our findings might give a better understanding of the composition and developmental change of yolk microbiota and its roles in shaping the intestinal microbiota.

The Sexual Effect of Chicken Embryos on the Yolk Metabolites and Liver Lipid Metabolism.

The metabolic processes of animals are usually affected by sex. Egg yolk is the major nutrient utilized for the growth and development of a chicken embryo. In this study, we explored the differences of yolk metabolites in male and female chicken embryos by LC-MS/MS. Furthermore, we investigated the mRNA expression of lipoprotein lipase (LPL) and fatty acid synthase (FAS) in chicken embryo liver with different sexes in different embryonic stages. The results showed that the nutrient metabolites in the yolk of female chickens were mainly related to lipid metabolism and amino acid metabolism in the early embryonic stage, and vitamin metabolism in the late embryonic stage. The male yolk metabolites were mainly associated with lipid metabolism and nucleic acid metabolism in the early developmental stage, and amino acids metabolism in the late embryonic stage. There was no significant difference in the expression of LPL or FAS in livers of male and female chicken embryos at different embryonic stages. Our results may lead to a better understanding of the sexual effect on yolk nutrient metabolism during chicken embryonic development.