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Flexible and ultrathin dopamine modified MXene and cellulose nanofiber composite films with alternating multilayer structure for superior electromagnetic interference shielding performance

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Frontiers of physics 2023年第3期18卷 155-166页

作者： Qiugang Liao Hao Liu Ziqiang Chen Yinggan Zhang Rui Xiong Zhou Cui Cuilian Wen Baisheng Sa Multiscale Computational Materials Facility and Key Laboratory of Eco-materials Advanced TechnologyCollege of Materials Science and EngineeringFuzhou UniversityFuzhou 350100China College of Materials Fujian Provincial Key Laboratory of Theoretical and Computational ChemistryXiamen UniversityXiamen 361005China

With the development of modern electronics,especially the next generation of wearable electromagnetic interference(EMI)shielding materials requires flexibility,ultrathin,lightweight and robustness to protect electronic devices from radiation pollution.In this work,the flexible and ultrathin dopamine modified MXene@cellulose nanofiber(DM@CNF)composite films with alternate multilayer structure have been developed by a facile vacuum filtration induced self-assembly approach.The multilayered DM@CNF composite films exhibit improved mechanical properties compared with the homogeneous DM/CNF film.By adjusting the layer number,the multilayered DM3@CNF2 composite film exhibits a tensile strength of 48.14 MPa and a toughness of 5.28 MJ·m^(–3) with a thickness about 19μm.Interestingly that,the DM@CNF film with annealing treatment achieves significant improvement in conductivity(up to 17264 S·m^(–1))and EMI properties(SE of 41.90 dB and SSE/t of 10169 dB·cm^(2)·g–1),which still maintains relatively high mechanical properties.It is highlighted that the ultrathin multilayered DM@CNF film exhibits superior EMI shielding performance compared with most of the metal-based,carbon-based and MXene-based shielding materials reported in the literature.These results will offer an appealing strategy to develop the ultrathin and flexible MXene-based materials with excellent EMI shielding performance for the next generation intelligent protection devices.

关键词： MXene dopamine cellulose nanofibers electromagnetic interference shielding performance mechanical properties

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Mercury's ring current and Mercury's magnetic storms

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Science China(Technological Sciences) 2022年第5期65卷 1210-1212页

作者： FU SuiYan ZONG qiugang Institute of Space Physics and Applied Technology Peking UniversityBeijing100871China

A magnetic storm is a temporal magnetic disturbance caused by solar wind interaction with the Earth’s magnetosphere.A geomagnetic storm on the scale of the year 1859 event[1] would cause trillions of dollars loss to modern technology,e.***.spacecraft,power lines and communication system.Chapman and Ferraro[2],first proposed that the ring current.

关键词： storm Earth Mercury

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Dietary supplementation of porcine bile acids improves laying performance,serum lipid metabolism and cecal microbiota in latephase laying hens

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Animal Nutrition 2022年第4期11卷 283-292页

作者： Bowen Yang Shimeng Huang Guoxian Zhao qiugang Ma State Key Laboratory of Animal Nutrition College of Animal Science and TechnologyChina Agricultural UniversityBeijingChina College of Animal Science and Technology Hebei Agricultural UniversityBaodingChina

Due to the exceptional laying performance of hens,the demand on lipid metabolism and oxidation in vivo is vigorous,resulting in excessive lipid accumulation in late-phase hens,which lowers the production performance.Bile acids regulate lipid metabolism and gut microbiota in humans and animals.However,the effect of porcine bile acids on lipid metabolism and cecal microbiota in laying hens in the late phase is still unclear.A total of 360 healthy 45-week-old laying hens were chosen for a 24-week feeding trial,where 0,30,60 and 90 mg/kg porcine bile acids were added to a basal diet,respectively.The results showed that dietary supplementation of 60 mg/kg bile acids increased egg production and feed conversion(P<0.05).Also,60 and 90 mg/kg porcine bile acids reduced abdominal fat percentage and body weight(P<0.05).The levels of serum total cholesterol,triglyceride,and low-density lipoprotein cholesterol of hens decreased(P<0.05)in bile acids supplement groups.As for cecal microbiota,bile acids supplementation did not affect the alpha diversity of cecal microbiota at the genus level.Moreover,dietary supplementation of 90 mg/kg bile acids resulted in an increase in the abundance of beneficial bacteria in the cecum,such as Lactobacillus,Bifidobacterium and Turicibacter.The changes in the cecal microbiota caused by bile acids supplementation correlated with serum lipid indexes.According to KEGG pathway analysis,dietary supplementation of 60 and 90 mg/kg bile acids promoted structural transformation of the cecal microbiota to down-regulate steroid biosynthesis,up-regulate fatty acid degradation and up-regulate unsaturated fatty acid biosynthesis.Meanwhile,bile acids bioisomerization function of cecal microbiota was enhanced in 60 and 90 mg/kg bile acids treatment,and the short-chain fatty acid metabolism was also affected.In conclusion,the present study revealed dietary supplementation of porcine bile acids enriched probiotics in the gut and improved serum lipid metabolism of laying hens.These findings demonstrate that porc

关键词： Porcine bile acids Lipid metabolism Gut microbiota Laying hens 16S rRNA

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The effect of non-storm time substorms on the ring current dynamics

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Earth and Planetary Physics 2021年第3期5卷 251-258页

作者： EunJin Jang Chao Yue qiugang Zong SuiYan Fu HaoBo Fu Institute of Space Physics and Applied Technology Peking UniversityBeijing 100871China

During geomagnetically active times such as geomagnetic storms,large amounts of energy can be released into the Earth’s magnetosphere and change the ring current intensity.Previous studies showed that significant enhancement of the ring current was related to geomagnetic storms,while few studies have examined substorm effects on ring current dynamics.In this study,we examine the ring current variation during non-storm time(SYM-H>−50 nT)substorms,especially during super-substorms(AE>1000 nT).We perform a statistical analysis of ring current plasma pressure and number flux of various ion species under different substorm conditions,based on Van Allen Probe observations.The plasma pressure and ion fluxes of the ring current increased dramatically during supersubstorms,while little change was observed for substorms with AE<1000 nT.The results shown in this study indicate that a non-storm time super-substorm may also have a significant contribution to the ring current.

关键词： super-substorms ring current ion fluxes

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Zearalenone toxicosis on reproduction as estrogen receptor selective modulator and alleviation of zearalenone biodegradative agent in pregnant sows

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Journal of Animal Science and Biotechnology 2022年第4期13卷 1222-1232页

作者： Jianchuan Zhou Lihong Zhao Shimeng Huang Qingxiu Liu Xiang Ao Yuanpei Lei Cheng Ji qiugang Ma State Key Laboratory of Animal Nutrition College of Animal Science and TechnologyChina Agricultural UniversityBeijing 100193China Sichuan tieqilishi Food Co. LtdMianyang 610000Sichuan provinceChina.

Background:Zearalenone(ZEA)is a resorcylic acid lactone derivative derived from various Fusarium species that are widely found in food and feeds.The molecular structure of ZEA resembles that of the mammalian hormone 17β-oestradiol,thus zearalenone and its metabolites are known to compete with endogenous hormones for estrogen receptors binding sites and to activate transcription of oestrogen-responsive genes.However,the effect of long-term low-dose ZEA exposure on the reproductive response to Bacillus subtilis ANSB01G culture for first-parity gilts has not yet been investigated.This study was conducted to investigate the toxic effects of ZEA as an estrogen receptor selective modulator and the alleviating effects of Bacillus subtilis ANSB01G cultures as ZEA biodegraders in pregnant sows during their first parity.Results:A total of 80 first-parity gilts(Yorkshire×Landrace)were randomly assigned to four dietary treatments during gestation:CO(positive control);MO(negative control,246μg ZEA/kg diet);COA(CO+B.subtilis ANSB01G culture with 2×10^(9)CFU/kg diet);MOA(MO+B.subtilis ANSB01G culture with 2×10^(9)CFU/kg diet).There were 20 replications per treatment with one gilt per replicate.Feeding low-dose ZEA naturally contaminated diets disordered most of reproductive hormones secretion and affected estrogen receptor-αand estrogen receptor-βconcentrations in serum and specific organs and led to moderate histopathological changes of gilts,but did not cause significant detrimental effects on reproductive performance.The addition of Bacillus subtilis ANSB01G culture to the diet can effectively relieve the competence of ZEA to estrogen receptor and the disturbance of reproductive hormones secretion,and then ameliorate toxicosis of ZEA in gilts.Conclusions:Collectively,our study investigated the effects of feeding low-dose ZEA on reproduction in pregnant sows during their first parity.Feeding low-dose ZEA could modulate estrogen receptor-αand-βconcentrations in specific organs,cause disturbance of reproductive hormones and vul

关键词： Bacillus subtilis ANSB01G Estrogen receptor Mycotoxin biodegradation Pregnant sows Reproductive performance ZEA

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Bacillus subtilis ANSB01G culture alleviates oxidative stress and cell apoptosis induced by dietary zearalenone in first-parity gestation sows

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Animal Nutrition 2020年第3期6卷 372-378页

作者： Jianchuan Zhou Xiang Ao Yuanpei Lei Cheng Ji qiugang Ma State Key Laboratory of Animal Nutrition China Agricultural UniversityBeijing100193China

This study was conducted to evaluate the alleviation of Bacillus subtilis ANSB01G culture as zearalenone(ZEA)biodegradation agent on oxidative stress,cell apoptosis and fecal ZEA residue in the first parity gestation sows during the gestation.A total of 80 first-parity gilts(Yorkshire×Landrace)were randomly allocated to 4 dietary treatments with 20 replications per treatment and one gilt per replicate.The dietary treatments were as follows:CO(positive control);MO(negative control,ZEA level at 246μg/kg diet);COA(CO+B.subtilis ANSB01G culture with 2×10^9 CFU/kg diet);MOA(MO+ZEA level at 260μg/kg diet+B.subtilis ANSB01G culture with 2×10^9 CFU/kg diet).The experiment lasted for the whole gestation period of sows.Results showed that feeding the diet naturally contaminated with low-dose ZEA caused an increase of cell apoptosis in organ and the residual ZEA in feces as well as a decrease of antioxidant function in serum.The addition of B.subtilis ANSB01G culture in the diets can effectively alleviate the status of oxidative stress and cell apoptosis induced by ZEA in diets of gestation sows,as well as decrease the content of residual ZEA in feces.

关键词： Zearalenone Gestation sow Bacillus subtilis ANSB01G culture Mycotoxin biodegradation agent Oxidative stress Cell apoptosis

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Vitamin K alleviates bone calcium loss caused by Salmonella Enteritidis through carboxylation of osteocalcin

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Journal of Animal Science and Biotechnology 2021年第4期12卷 1572-1581页

作者： Yaojun Liu Rainer Mosenthin Lihong Zhao Jianyun Zhang Cheng Ji qiugang Ma State Key Laboratory of Animal Nutrition College of Animal Science and TechnologyChina Agricultural UniversityBeijing 100193China Institute of Animal Science University of Hohenheim70593 StuttgartGermany

Background:The present study aimed at evaluating the effect of vitamin K(VK)supplementation on bone health of laying hens challenged by Salmonella Enteritidis.Methods:A total of 8032-week-old double negative salmonella-free brown-egg laying hens were randomly assigned to 4 treatments with 20 replicates each(1 bird per replicate)according to a 2×2 factorial design with 2 dietary VK supplementation levels[0 mg/kg(VK0)vs 2 mg/kg VK(VK2)and 2 challenge treatments[Salmonella Enteritidis(SE)vs physiological saline solution(PS)].During the last 3 days of week 43 of age,birds of both VK treatments were either orally challenged with 1.0 mL suspension of 109 cfu/mL S.Enteritidis daily or received the same volume of PS.Results:The laying rate,daily egg mass,tibia strength,CT,cOC and cOC/(cOC+ucOC)of VK2 treatment increased(P<0.05)in contrast to VK0,however,the medullary area and ucOC of VK2 treatment decreased(P<0.05)in contrast to VK0.Mortality,medullary area,serum Ca content of SE treatments increased(P<0.05)in contrast to PS treatments.In both SE treatments,the decrease(P<0.05)in birds’tibia strength was associated with higher(P<0.05)Ca levels in serum.There is an interaction(P<0.05)between SE challenge and VK levels with regard to tibia strength and serum Ca levels.At week 42,serum CT was positively correlated with cOC(R=0.99,P=0.009);at week 44,tibia strength was positively correlated with BMD(R=0.95,P=0.045),but negatively correlated with medullary area(R=−0.98,P=0.018).Conclusions:VK(2 mg/kg)supplementation to diets of laying hens can enhance bone strength under challenge situations with Salmonella Enteritidis.Medullary area has proven to be a sensitive biomarker for bone calcium loss caused by SE infection.

关键词： Calcium Laying hen Salmonella Enteritidis Vitamin K

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Dietary ellagic acid ameliorated Clostridium perfringens-induced subclinical necrotic enteritis in broilers via regulating inflammation and cecal microbiota

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Journal of Animal Science and Biotechnology 2022年第5期13卷 1513-1530页

作者： Yu Tang Xinyue Zhang Yanan Wang Yongpeng Guo Peiqi Zhu Guiguan Li Jianyun Zhang qiugang Ma Lihong Zhao State Key Laboratory of Animal Nutrition Poultry Nutrition and Feed Technology Innovation TeamCollege of Animal Science and TechnologyChina Agricultural UniversityNo.2.West Road Yuanming yuanBeijing 100193People’s Republic of China Jiangsu Lihua animal husbandry Co. Ltd.No.500Hexi VillageLuxi Village CommitteeNiutang TownWujin DistrictChangzhou CityJiangsu Province 213168People’s Republic of China COFCO feed Co. Ltd4th FloorNo.6Nandaan HutongXicheng DistrictBeijing 100193People’s Republic of China

Background: Subclinical necrotic enteritis(SNE), a common intestinal disease of broiler caused by Clostridium perfringens, could reduce production performance of broilers by chronic intestinal damage and poor absorption of nutrients. Ellagic acid(EA) has been reported to present antioxidant and anti-inflammatory properties on human and animals in many aspects. This study was conducted to evaluate the effect and mechanism of EA in relieving SNE in broilers induced by C. perfringens.Results: C. perfringens challenge decreased body weight(BW), average daily gain(ADG), jejunal villi height/crypt depth(V/C) ratio, the activity of catalase(CAT) and the mRNA expression of zonula occludens 1(ZO-1) in jejunal mucosa of broilers. While feed conversion ratios(FCR), jejunal crypt depth(CD), the activities of myeloperoxidase(MPO) and diamine oxidase(DAO), as well as the concentrations of interleukin 6(IL-6), C-reactive protein(CRP) and procalcitonin(PCT) in serum, the activities of inducible nitric oxide synthase(iNOS) and lysozyme(LZM), the concentration of malondialdehyde(MDA), and the mRNA expressions of claudin-2, TNF-α, IL-1β, TLR-4, TLR-2, NF-κB,JAK3, STAT6 and iNOS in jejunal mucosa of broilers were increased by C. perfringens challenge. Dietary EA supplement relieved these adverse effects, and heightened jejunal villi height(VH), the concentration of D-xylose in plasma, activity of superoxide dismutase(SOD), and the mRNA expression of occludin in jejunal mucosa of broilers.The alpha diversity of cecal microbiota indicated that dietary EA supplement increased observed species and Shannon index. C. perfringens challenge increased the relative abundance of Firmicutes and decreased the relative abundance of Desulfobacterota in cecal microbiota. EA increased the relative abundance of Firmicutes in cecal microbiota. LEfSe analysis showed that C. perfringens challenge triggered the imbalance of cecal microbiota in broilers, dietary EA supplementation led to a small beneficial effect on microbiota, while the simultaneous effe

关键词： Broiler Clostridium perfringens Ellagic acid Intestinal microbiota Subclinical necrotic enteritis

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Magnetic storms in Mercury's magnetosphere

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Science China(Technological Sciences) 2022年第6期65卷 1427-1432页

作者： ZONG qiugang ZHAO JiuTong LIU JianJun FU SuiYan SUN WeiJie ZHANG Hui LE Guan RANKIN Robert WEI Yong Institute of Space Physics and Applied Technology Peking UniversityBeijing 100871 China Polar Research Institute of China Shanghai 2000136China Department of Climate and Space Sciences and Engineering University of MichiganAnn Arbor 48109USA Geophysical Institute University of Alaska FairbanksFairbanks 99775USA ITM Laboratory Heliophysics Science DivisionNASA Goddard Space Flight CenterGreenbelt 20771USA Department of Physics University of AlbertaEdmonton T6G2R3Canada Institute of Geology and Geophysics Chinese Academy of SciencesBeijing 100029China

We present evidence of geomagnetic storms in Mercury’s magnetosphere based on MESSENGER magnetic field observations made just before the probe impacted the planet.Our findings answer the question of whether geomagnetic storms can occur in other planetary magnetospheres.The interaction of the solar wind with Mercury’s magnetosphere is known to involve flux transfer events in the dayside magnetosphere,plasmoids and flux ropes in the magnetotail,and substorm-like processes,all of which occur morphologically similar to Earth but with significant differences.The significantly weaker magnetic field,smaller magnetosphere,and much faster timescale of processes around Mercury,when compared with Earth,enable charged particles to escape its magnetosphere more efficiently through magnetopause shadowing and direct bombard of the surface.Our analysis of MESSENGER’s data during a coronal mass ejection(CME)proves that,despite these substantial differences,a bifurcated ring current can form in Mercury’s magnetosphere that initiates magnetic storms under strong solar wind driving.

关键词： magnetic storm Mercury magnetosphere ring current

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Space physics and astronomy research from Chinese polar stations: current and future directions

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Advances in Polar Science 2023年第4期34卷 239-250页

作者： ZONG qiugang HU Zejun LIU Jianjun JIANG Peng DU Yang ZHANG Wei Key Laboratory of Polar Science MNRPolar Research Institute of ChinaShanghai 200136China Institute of Space Physics and Applied Technology Peking UniversityBeijing 100871China Shanghai Institute of Satellite Engineering Shanghai 201109China

Space weather has a remarkable effect on modern human activities,e.g.,communication,navigation,space exploration etc.Space physics study from polar stations is as an important part of the entire solar-terrestrial space,and conducts quantitative research from the perspective of overall space plasma behavior.One of the most important issues is to identify the dominant processes that transfer plasma and momentum from the solar wind to Earth’s magnetosphere.Thus,it is necessary to carry out research for combination the observations from polar ground stations and spacecraft observations in the space.Observations at polar regions can be as a window to the space for satellite traffic controls.The operation of the observation chain―Zhongshan-Taishan-Kunlun Station could monitor polar space debris in a large area with high temporal and spatial resolution.Also,night-time measurements of astronomical seeing at Dome A in Antarctica make it less challenging to locate a telescope above it,thereby giving greater access to the free atmosphere because of a thinner boundary layer.

关键词： Great Wall Station Zhongshan Station Yellow River Station Kjell Henriksen Observatory China-Iceland Arctic Science Observatory Dome A

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