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PetroChina lays off 10000 workers in first nine months 被引量:1
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《China Oil & Gas》 CAS 2000年第4期21-21,共1页
关键词 PetroChina lays off 10000 workers in first nine months
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An Analysis of Play It As It Lays from the Perspective of Fromm’s Alienation Theory
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作者 朱叶琴 《海外英语》 2021年第8期233-235,共3页
Joan Didion is an outstanding female writer who has achieved a distinctive position in contemporary literature.Her second novel,Play It As It Lays,is nominated for a National Book Award.Set in Hollywood and Las Vegas,... Joan Didion is an outstanding female writer who has achieved a distinctive position in contemporary literature.Her second novel,Play It As It Lays,is nominated for a National Book Award.Set in Hollywood and Las Vegas,it presents the alienated world through exquisite description of its protagonist Maria.Based on Erich Fromm’s Alienation Theory,this essay attempts to analyze the alienation in the novel from two aspects:first,the novel’s materialistic environment in the 1960s;second,the alienated relationship between spouses as well as between parents and children. 展开更多
关键词 Joan Didion Play It As It lays Erich Fromm Alienation Theory RELATIONSHIP
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Caffeic acid and chlorogenic acid mediate the ADPN-AMPK-PPARαpathway to improve fatty liver and production performance in laying hens 被引量:2
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作者 Wenjie Tian Gerard Bryan Gonzales +6 位作者 Hao Wang Youyou Yang Chaohua Tang Qingyu Zhao Junmin Zhang Huiyan Zhang Yuchang Qin 《Journal of Animal Science and Biotechnology》 2025年第4期1634-1655,共22页
Background Caffeic acid(CA)and its derivative,chlorogenic acid(CGA),have shown promise in preventing and alleviating fatty liver disease.CA,compared to CGA,has much lower production costs and higher bioavailability,ma... Background Caffeic acid(CA)and its derivative,chlorogenic acid(CGA),have shown promise in preventing and alleviating fatty liver disease.CA,compared to CGA,has much lower production costs and higher bioavailability,making it a potentially superior feed additive.However,the efficacy,mechanistic differences,and comparative impacts of CA and CGA on fatty liver disease in laying hens remain unclear.This study aimed to evaluate and compare the effects of CA and CGA on production performance,egg quality,and fatty liver disease in laying hens.Results A total of 1,44061-week-old Hyline Brown laying hens were randomly divided into 8 groups and fed diets supplemented with basal diet,25,50,100 and 200 mg/kg of CA,and 100,200 and 400 mg/kg of CGA(CON,CA25,CA50,CA100,CA200,CGA100,CGA200 and CGA400,respectively)for 12 weeks.Both CA and CGA improved production performance and egg quality,while reducing markers of hepatic damage and lipid accumulation.CA and CGA significantly decreased TG,TC,and LDL-C levels and increased T-SOD activity.Transcriptomic and proteomic analyses revealed that CA and CGA reduced hepatic lipid accumulation through downregulation of lipid biosynthesis-related genes(ACLY,ACACA,FASN,and SCD1)and enhanced lipid transport and oxidation genes(FABPs,CD36,CPT1A,ACOX1,and SCP2).Of note,low-dose CA25 exhibited equivalent efficacy to the higher dose CGA100 group in alleviating fatty liver conditions.Mechanistically,CA and CGA alleviated lipid accumulation via activation of the ADPN-AMPK-PPARαsignaling pathway.Conclusions This study demonstrates that dietary CA and CGA effectively improve laying performance,egg quality,and hepatic lipid metabolism in laying hens,with CA potentially being more economical and efficient.Transcriptomic and proteomic evidence highlight shared mechanisms between CA25 and CGA100.These findings provide a foundation for CA and CGA as therapeutic agents for fatty liver disease and related metabolic diseases in hens,and also offer insights into the targeted modification of CGA(including the isomer of CGA)into CA,thereby providing novel strategies for the efficient utilization of CGA.Highlights(1)Dietary CA and CGA improve fatty liver,laying performance and egg quality.(2)Lower dose of CA25 achieves the equivalent improvement as CGA100 or CGA200.(3)CA and CGA mediate the ADPN-AMPK-PPARαpathway to alleviate fatty liver. 展开更多
关键词 ABSORPTIVITY Caffeic acid Chlorogenic acid Fatty liver Laying hens
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Comparative genomics study between high and low laying goose breeds reveals the important role of ESR1 in laying ability 被引量:1
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作者 Qingyuan Ouyang Hengli Xie +8 位作者 Shenqiang Hu Cong Lan Mingxia Ran Jiwei Hu HuaHe Liang Li Hehe Liu Hao Qu Jiwen Wang 《Journal of Integrative Agriculture》 2025年第3期1167-1180,共14页
The low egg production of goose greatly limits the development of the industry.China possesses the most abundant goose breeds resources.In this study,genome resequencing data of swan goose(Anser cygnoides)and domestic... The low egg production of goose greatly limits the development of the industry.China possesses the most abundant goose breeds resources.In this study,genome resequencing data of swan goose(Anser cygnoides)and domesticated high and low laying goose breeds(Anser cygnoides domestiation)were used to identify key genes related to egg laying ability in geese and verify their functions.Selective sweep analyses revealed 416 genes that were specifically selected during the domestication process from swan geese to high laying geese.Furthermore,SNPs and Indels markers were used in GWAS analyses between high and low laying breed geese.The results showed that RTCB,BPIFC,SYN3,SYNE1,VIP,and ESR1 may be related to the differences in laying ability of geese.Notably,only ESR1 was identified simultaneously by GWAS and selective sweep analysis.The genotype of Indelchr3:54429172,located downstream of ESR1,was confirmed to affect the expression of ESR1 in the ovarian stroma and showed significant correlation with body weight at first egg and laying frequency of geese.CCK-8,EdU,and flow cytometry confirmed that ESR1 can promote the apoptosis of goose pre-hierarchical follicles ganulosa cells(phGCs)and inhibit their proliferation.Combined with transcriptome data,it was found ESR1 involved in the function of goose phGCs may be related to MAPK and TGF-beta signaling pathways.Overall,our study used genomic information from different goose breeds to identify an indel located in the downstream of ESR1 associated with goose laying ability.The main pathways and biological processes of ESR1 involved in the regulation of goose laying ability were identified by cell biology and transcriptomics methods.These results are helpful to further understand the laying ability characteristics of goose and improve the egg production of geese. 展开更多
关键词 GOOSE laying ability GENOME ESR1
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Heat stress and the chicken gastrointestinal microbiota:a systematic review
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作者 Chris Major Ncho 《Journal of Animal Science and Biotechnology》 2025年第5期1989-2007,共19页
Heat stress(HS)has become a significant challenge for poultry farming due to an increase in global temperatures.Existing literature suggests that the health effects of HS in chickens are related to its impact on the g... Heat stress(HS)has become a significant challenge for poultry farming due to an increase in global temperatures.Existing literature suggests that the health effects of HS in chickens are related to its impact on the gastrointestinal tract.While there is evidence of the detrimental consequences of HS on the gut structure,little is known about the effects of HS on the microbial population inhabiting this organ.Fortunately,recent advancements in"omics"technologies have made investigating the interaction between HS and the gut microbiota possible.Therefore,a systematic review was conducted to assess the effects of HS on chicken gut microbiota.In July 2024,a comprehensive literature search was performed across scientific repositories,including Scopus,PubMed,Science Direct,and Google Scholar.Eighteen studies met the eligibility criteria for inclusion and a qualitative synthesis of their results was conducted according to the PRISMA guidelines.Current evidence indicates that HS poses a significant challenge to the gastrointestinal system of chickens,resulting in a range of physiological reactions.These changes trigger fierce competition among beneficial microbial species for limited nutrients,promote microbial shifts from obligate to facultative anaerobes,and increase the abundance of microbial species with high resistance to elevated environmental temperatures.Furthermore,the proliferation of pathogens is exacerbated.Ultimately,gut microbiota profiling highlights changes in microbial diversity,alterations in the composition of microbial populations,disruptions in specific microbial functional pathways(tricarboxylic acid cycle,amino acid metabolism,antioxidant biosynthesis,and fatty acid degradation),and the breakdown of complex networks that govern microbial interactions.Understanding the complex relationship between HS and microbial shifts within the chicken gut can provide valuable insights for the development of sustainable mitigation strategies.Further research is needed to expand the current knowledge and employ more advanced literature synthesis techniques such as meta-analyses. 展开更多
关键词 BROILER Climate change Laying hens MICROBIOME POULTRY WELFARE
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Comprehensive metabolic profiling of dioxin-like compounds exposure in laying hens:Implications for toxicity assessment
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作者 Xiaoxu Hu Tong Xu +12 位作者 Yangsheng Chen Qian Zhang Lijuan Tang Liping Zheng Chu Wang Pu Wang Shujun Dong Ruiguo Wang Su Zhang Qinghua Zhang Heidi Qunhui Xie Li Xu Bin Zhao 《Journal of Environmental Sciences》 2025年第2期107-115,共9页
The evaluation of toxicity related to polychlorinated dibenzo-p-dioxins and furans(PCDD/Fs)and dioxin-like polychlorinated biphenyls(DL-PCBs)is crucial for a comprehensive risk assessment in real-world exposure scenar... The evaluation of toxicity related to polychlorinated dibenzo-p-dioxins and furans(PCDD/Fs)and dioxin-like polychlorinated biphenyls(DL-PCBs)is crucial for a comprehensive risk assessment in real-world exposure scenarios.This study employed a controlled feeding experiment to investigate the metabolic effects of dioxin-like compounds(DLCs)on laying hens via feed exposure.Diets enriched with two concentrations(1.17 and 5.13 pg toxic equivalents(TEQ)/g dry weight(dw))were administered over 14 days,followed by 28 days of clean feed.Metabolomics analyses of blood samples revealed significant metabolic variations between PCDD/Fs and DL-PCBs exposed groups and controls,reflecting the induced metabolic disruption.Distinct changes were observed in sphingosine,palmitoleic acid,linoleate,linolenic acid,taurocholic acid,indole acrylic acid,and dibutyl phthalate levels,implying possible connections between PCDD/Fs and DL-PCBs toxic effects and energy-neuronal imbalances,along with lipid accumulation and anomalous amino acid metabolism,impacting taurine metabolism.Moreover,we identified three differential endogenous metabolites—L-tryptophan,indole-3-acetaldehyde,and indole acrylic acid—as potential ligands for the aryl hydrocarbon receptor(AhR),suggesting their role inmediating PCDD/Fs and DL-PCBs toxicity.This comprehensive investigation provides novel insights into the metabolic alterations induced by PCDD/Fs and DL-PCBs in laying hens,thereby enhancing our ability to assess risks associated with their exposure in human populations. 展开更多
关键词 Polychlorinated dibenzo-p-dioxins and furans Dioxin-like polychlorinated BIPHENYLS Laying hens METABOLOMIC
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Integrated analysis of microbiome and transcriptome reveals the mechanisms underlying the chlorogenic acid‑mediated attenuation of oxidative stress and systemic inflammatory responses via gut‑liver axis in post‑peaking laying hens
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作者 Zhaoying Hu Lianchi Wu +7 位作者 Yujie Lv Chaoyue Ge Xinyu Luo Shenao Zhan Weichen Huang Xinyu Shen Dongyou Yu Bing Liu 《Journal of Animal Science and Biotechnology》 2025年第5期2281-2301,共21页
Background Systemic inflammatory responses and oxidative stress occur in laying hens during the aging process,particularly during the post-peaking laying period,which generally result in multi-organ damages,leading to... Background Systemic inflammatory responses and oxidative stress occur in laying hens during the aging process,particularly during the post-peaking laying period,which generally result in multi-organ damages,leading to significant declines in egg performance and quality.Chlorogenic acid(CGA)-enriched extract from Eucommia ulmoides leaves has anti-inflammatory and antioxidant activities.However,the mechanisms underlying whether and how CGA alleviates systemic inflammatory responses and oxidative stress to improve egg performance and quality in postpeaking laying hens remain unclear.In this study,the potential regulatory mechanisms of CGA in alleviating inflammatory responses and oxidative stress along the gut-liver axis were investigated.A total of 36055-week-old Hy-line white-laying hens were randomly selected and divided into four groups.The hens in the four groups were fed a basal diet(CON)or basal diets supplemented with 200,400,and 800 mg/kg of CGA(CGA200,CGA400,and CGA800,respectively)for 10 weeks.Results The results demonstrated that CGA significantly alleviated intestinal and hepatic damages resulting from systemic inflammatory responses and oxidative stress,thereby improving the laying performance and egg quality of post-peaking laying hens.CGA reduced systemic inflammation by improving intestinal barrier function and modulating inflammation-associated microbiota(Blautia and Megamonas),thus inhibiting endotoxin translocation.CGA can also reduce oxidative stress by upregulating the NRF-2 pathway-related genes and increasing antioxidant enzyme activities in the liver.The results of transcriptome sequencing revealed that CGA promoted lipid metabolism by regulating hepatic adipocytokine pathway-related genes/protein and reduced the inflammatory responses and apoptosis in liver by regulating PI3K/AKT pathway-related genes/proteins,which was also verified by qPCR and western blotting.Conclusion CGA alleviated multi-organ damages and dysfunction by suppressing the systemic inflammatory responses and oxidative stress in post-peaking laying hens,thereby improving egg performance and quality.The optimal dose of CGA is 400 mg/kg in this experiment.These results provide a sound theoretical basis for the application of CGA as an exogenous animal feed additive for laying hens. 展开更多
关键词 Chlorogenic acid Gut-liver axis Inflammation Laying hen Oxidative stress
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Supplementation of serine in low-gossypol cottonseed meal-based diet improved egg white gelling and rheological properties by regulating ovomucin synthesis and magnum physiological function in laying hens
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作者 Jianmin Zhou Yu Fu +5 位作者 Uchechukwu Edna Obianwuna Jing Wang Haijun Zhang Xiubo Li Guanghai Qi Shugeng Wu 《Journal of Integrative Agriculture》 2025年第3期1152-1166,共15页
This study examined the effect of dietary serine(Ser)on egg white quality,ovomucin content of laying hens fed low-gossypol cottonseed meal(LCSM)-based diet and sought to explore the regulatory mechanism underlying the... This study examined the effect of dietary serine(Ser)on egg white quality,ovomucin content of laying hens fed low-gossypol cottonseed meal(LCSM)-based diet and sought to explore the regulatory mechanism underlying the effects.A total of 288 Hy-Line Brown layers were randomly assigned into 3 treatments and respectively offered soybean meal(SBM)-based diet,LCSM-based diet,and LCSM-based diet supplemented with 0.435%L-Ser.Dietary Ser supplementation reversed the decrease in quality indices of albumen,including the proportion of thick albumen(P<0.05),thick-to-thin ratio(P<0.05),albumen height(P<0.05),Haugh unit(P<0.05),and apparent viscosity that were caused by LCSM intake.Also,dietary Ser supplementation mitigated the LCSM-induced reduction in ovomucin content of the albumen(P<0.05).FT-IR analysis of ovomucin revealed differences in second derivative spectra at 1,200-800 cm^(-1) between birds received SBM-and LCSM-based diets,meanwhile,the α-helix of ovomucin was decreased by LCSM but increased by Ser addition(P<0.05).Furthermore,Ser addition up-regulated the mRNA expression of β-ovomucin in magnum mucosa at 2 and 7.5 h post-oviposition(P<0.05).Ser mitigated the LCSMinduced impairment of magnum epithelium,increased goblet cell counts(P<0.05),and up-regulated the expression of occludin,mucin 2,and the relevant glycosyltransferases for O-glycosylation in magnum mucosa(P<0.05).Conclusively,the alleviating effect of Ser on declining albumen quality due to dietary LCSM,could be explained by the efficacy of Ser in regulating ovomucin synthesis.This regulation occurred at the levels of transcription and posttranscriptional O-glycosylation modification ofβ-ovomucin,while positive effect on magnum morphology and barrier function could also in part account for the ovomucin content.This would provide a promising research direction on the adoption of nutritional interventions for manipulation of egg white quality from perspectives of albumen protein synthesis. 展开更多
关键词 egg white quality low-gossypol cottonseed meal laying hen OVOMUCIN SERINE
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Comparative effects of selenium-enriched lactobacilli and selenium-enriched yeast on performance,egg selenium enrichment,antioxidant capacity,and ileal microbiota in laying hens
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作者 Jianmin Zhou Uchechukwu Edna Obianwuna +6 位作者 Longfei Zhang Yongli Liu Haijun Zhang Kai Qiu Jing Wang Guanghai Qi Shugeng Wu 《Journal of Animal Science and Biotechnology》 2025年第3期1399-1415,共17页
Background Organic selenium(Se)has gained recognition in poultry nutrition as a feed additive to boost production and Se deposition in eggs and tissues,owing to its high bioavailability,efficient tissue accumulation a... Background Organic selenium(Se)has gained recognition in poultry nutrition as a feed additive to boost production and Se deposition in eggs and tissues,owing to its high bioavailability,efficient tissue accumulation and minimal toxicity.Selenium-enriched yeast(SeY)is a well-established source,while selenium-enriched lactobacilli(SeL),a newer alternative,offers the added benefits of probiotics.This study examined the effects of SeY and SeL on egg quality,antioxidant capacity,Se deposition,and gut health in laying hens.After a two-week pre-treatment with a Sedeficient diet(SeD),450 Hy-Line Brown laying hens(30-week-old)were assigned into five dietary groups with six replicates of 15 hens each.The groups included a SeD,SeD supplemented with 1.5 mg Se/kg from SeY(SeY15),or 1.5,3.0,and 6.0 mg Se/kg from SeL(SeL15,SeL30,SeL60).The feeding trial lasted for 12 weeks.Results SeY15 and SeL15 improved the feed-to-egg ratio(P<0.05)in the latter stages.Haugh units were significantly increased(P<0.05)in the SeY15 and SeL30 groups,while darker yolk color(P<0.05)was observed in the SeY15,SeL15,and SeL60 groups.All Se-supplemented diets increased Se content in whole eggs,albumen,and yolk(P<0.05),while SeL groups showed a dose-dependent effect.Antioxidant enzyme activities increased,and MDA content decreased in the serum(P<0.05),with SeY15 showing the highest GSH-Px levels(P<0.05).SeL60 increased serum alkaline phosphatase and aspartate transaminase,and distorted the liver architecture(P<0.05).Se-diets reduced concentrations of reactive oxygen species(ROS)in the ileum and liver(P<0.05).SeL15 improved the ileal villus height-tocrypt depth ratio(P<0.05).SeY15 and/or SeL15 up-regulated TXNRD1 and SEPHS1 mRNA while down-regulating SCLY expression in the liver.SeY15 altered ileal microbiota by increasing both beneficial and pathogenic bacteria,whereas SeL15 predominantly boosted beneficial bacteria.Conclusion SeL integrates the antioxidant properties of organic Se with the probiotic benefits on gut health,resulting in a performance-enhancing effect comparable to that of SeY.However,high SeL level(6.0 mg Se/kg)compromised productivity and metabolic functions while enhancing Se deposition. 展开更多
关键词 Antioxidant capacity Egg selenium Feed efficiency Gut microbiota Laying hen Selenium-enriched lactobacilli Selenium-enriched yeast
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The impact of climatic conditions in wintering and breeding quarters on long-term breeding success in the Common Swift
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作者 Marco Cucco Giovanni Boano +4 位作者 Carlo Ciani Mauro Ferri Luciano Gelfi Fausto Minelli Irene Pellegrino 《Avian Research》 2025年第2期129-137,共9页
Climate change can affect rainfall and temperature worldwide,and the ability of birds to react to these changes can be mirrored by studying population phenology and their breeding success.Some European species have ad... Climate change can affect rainfall and temperature worldwide,and the ability of birds to react to these changes can be mirrored by studying population phenology and their breeding success.Some European species have advanced arrival and breeding dates in response to local spring advancement,but conditions experienced during winter seasons may also affect arrival dates and subsequent breeding success.We utilized data collected from 1983 to 2020 in four colonies of Common Swift(Apus apus)in Northern Italy(5486 breeding attempts)to examine the variations of laying date and breeding success in relation to non-breeding conditions(previous winter in Africa)and local conditions in breeding period(spring).Climatic conditions were monitored using the North Atlantic Oscillation(NAO)and El Nino Southern Oscillation(ENSO)indices to describe conditions experienced in winter quarters and the local temperature and rainfall conditions of the breeding area.Common Swifts laid their eggs earlier in warmer springs,and this in turn had a positive effect on breeding success.We did not find evidence for any effects of African winter conditions on laying date nor on breeding success.However,because studies made in the same area have demonstrated a relationship of winter conditions(NAO)on individual survival,our data highlight the importance of considering environmental variables across the annual life cycle to understand variation in Common Swift populations. 展开更多
关键词 Apus apus Breeding adaptation Climate change El nino southern oscillation Laying date North atlantic oscillation
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Integrated mRNA-seq and miRNA-seq analysis reveals miR-210a-5p regulates uterine aging in laying hens by targeting the RASL11B/Raf/MAPK pathway
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作者 Xiyu Zhao Xinyan Li +7 位作者 Wenxin Zhang Mingyue Gao Conghao Zhong Boxuan Zhang Congjiao Sun Yao Zhang Shunshun Han Huadong Yin 《Journal of Animal Science and Biotechnology》 2025年第6期2658-2677,共20页
Background Uterine aging is a key factor contributing to the deterioration of egg quality and reproductive performance in laying hens.Despite its importance,the molecular mechanisms underlying uterine aging remain poo... Background Uterine aging is a key factor contributing to the deterioration of egg quality and reproductive performance in laying hens.Despite its importance,the molecular mechanisms underlying uterine aging remain poorly defined.This study aimed to characterize gene expression and regulatory changes associated with uterine aging in hens at different life stages.Results Transcriptomic Analysis of uterine tissue from hens aged 350,500,And 700 d revealed dynamic changes in gene expression patterns during aging.A significant upregulation of genes involved in cellular senescence was observed,including increased expression of the p53 signaling pathway And markers associated with inflammation And cell cycle arrest.The most notable changes occurred between 350 And 500 d of age,suggesting this as a critical window for the onset of uterine aging.MicroRNA sequencing identified miR-210a-5p as significantly reduced with age.Target prediction and experimental validation showed that miR-210a-5p directly suppresses the expression of RASL11B,a Ras-like small GTPase that activates the MAPK signaling pathway.In primary uterine epithelial cells,reduced miR-210a-5p levels led to elevated RASL11B expression,increased activation of B-Raf,MEK,and ERK proteins,and enhanced expression of aging-related genes and inflammatory factors.In contrast,overexpression of miR-210a-5p or inhibition of the MAPK pathway delayed senescence and reduced inflammatory signaling.RASL11B overexpression was sufficient to induce aging phenotypes,confirming its central role in promoting uterine cellular aging.Conclusions This study identifies a novel regulatory pathway in which miR-210a-5p modulates uterine aging through the RASL11B-MAPK signaling cascade.The findings provide mechanistic insight into age-related reproductive decline in hens and suggest that targeting this pathway may offer new strategies for maintaining uterine function and extending reproductive lifespan in poultry. 展开更多
关键词 Epithelial senescence Laying hen MAPK pathway MiR-210a-5p RASL11B Uterine aging
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Florfenicol-induced dysbiosis impairs intestinal homeostasis and host immune system in laying hens
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作者 Keesun Yu Inhwan Choi +10 位作者 Minseong Kim Young Jin Pyung Jin-Sun Lee Youbin Choi Sohyoung Won Younghoon Kim Byung-Chul Park Seung Hyun Han Tae Sub Park Tina Sorensen Dalgaard Cheol-Heui Yun 《Journal of Animal Science and Biotechnology》 2025年第3期1176-1193,共18页
Background Despite growing concerns about the adverse effects of antibiotics in farm animals,there has been little investigation of the effects of florfenicol in laying hens.This study examined the effect of florfenic... Background Despite growing concerns about the adverse effects of antibiotics in farm animals,there has been little investigation of the effects of florfenicol in laying hens.This study examined the effect of florfenicol on the intestinal homeostasis,immune system,and pathogen susceptibility of laying hens.Results The oral administration of florfenicol at field-relevant levels for 5 d resulted in a decrease in the gut microbiota genera Lactobacillus,Bacillus,and Bacteroides,indicating the development of intestinal dysbiosis.The dysbiosis led to decreased mRNA levels of key regulators peroxisome proliferator-activated receptor gamma(PPAR-γ)and hypoxia-inducible factor-1α(HIF-1α),compromising intestinal hypoxia.Intestinal homeostasis was also disrupted,with decreased expression of Occludin and Mucin 2(Muc2)genes combined with increased gut epithelial permeability.The breakdown in intestinal homeostasis and immune function provided a favorable environment for opportunistic bacteria like avian pathogenic Escherichia coli(APEC),culminating in systemic infection.Immunologically,florfenicol treatment resulted in increased proportion and absolute number of MRC1L-B^(+)monocytes/macrophages in the spleen,indicating an exacerbated infection.Furthermore,both the proportion and absolute number ofγδT cells in the lamina propria of the cecum decreased.Treatment with florfenicol reduced butyrate levels in the cecum.However,the administration of butyrate before and during florfenicol treatment restored factors associated with intestinal homeostasis,including PPAR-γ,Occludin,and Muc2,while partially restoring HIF-1α,normalized intestinal hypoxia and gut permeability,and reversed immune cell changes,suppressing APEC systemic infection.Conclusion The uncontrolled and widespread use of florfenicol can negatively affect intestinal health in chickens.Specifically,florfenicol was found to impair intestinal homeostasis and immune function in laying hens,including by reducing butyrate levels,thereby increasing their susceptibility to systemic APEC infection.The development of strategies for mitigating the adverse effects of florfenicol on gut health and pathogen susceptibility in laying hens is therefore essential. 展开更多
关键词 Antibiotics-induced dysbiosis Avian immunology Avian pathogenic Escherichia coli Gut homeostasis Laying hen Short chain fatty acids
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Multi-Area Vibration Precision Laying Process in Multi-Material 3D Sand Printing
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作者 Weifei Song Zhongde Shan +5 位作者 Haoqin Yang Yangyang Hu Dandan Yan Haoming Shi Jian Huang Yajun Yin 《Additive Manufacturing Frontiers》 2025年第3期134-146,共13页
Multi-material 3D sand printing has gained significant attention;however,research has mainly focused on materials and mechanisms,with limited exploration of optimizing the sand-laying process through numerical simulat... Multi-material 3D sand printing has gained significant attention;however,research has mainly focused on materials and mechanisms,with limited exploration of optimizing the sand-laying process through numerical simulations.In this study,we investigated the dynamic behavior of sand particles during a vibratory sand-laying process for multi-material additive manufacturing using discrete element simulations.The objective is to enable precise control over the amount and distribution of sand for multi-material printing.In this study,we combined experiments and simulations to calibrate the contact parameters of different sands and establish a relationship between the curing agent content and surface energy of sand particles.A model for the vibratory fall of multimaterial sand was developed to study the motion characteristics of sand particles.This allows for macro-control over the sand spreading flow and high-quality multi-material sand laying.The results show that the flow rate of falling sand increases with decreasing surface energy of the particles,wider spreader openings,and higher vibration frequencies.For silica and chromite sands,when their surface energy ranged from 0.15 to 25 J·m^(2)and0.01-0.03 J·m^(2),respectively,and the sand spreader opening was 6 mm with a vibration frequency of 500 Hz,the sand flow rates of both materials became nearly identical.However,a higher sand paving speed and height increased the scattering of sand particles outside the target area,thereby decreasing the paving quality.The results accomplished in this study enable precise and uniform sand particle deposition and offers guidelines for optimizing sand speed and height,thus expanding the application of multi-material sand 3D printing in complex and high-performance manufacturing. 展开更多
关键词 Multi-material sand 3D sand printing Discrete element Vibration precision laying
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LaY沸石中La离子定位的研究 被引量:12
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作者 潘晖华 何鸣元 +2 位作者 宋家庆 田辉平 朱玉霞 《石油学报(石油加工)》 EI CAS CSCD 北大核心 2007年第3期87-91,共5页
由二交二焙工艺及液-固工艺制备LaY沸石,采用多晶XRD结合Rietveld结构精修确定了La离子在Y沸石骨架外的分布。结果表明,进入方钠石笼的La离子定位于SⅠ’位置,与骨架O3形成配位,从而稳定沸石骨架,提高沸石水热稳定性。采用液-固工艺制备... 由二交二焙工艺及液-固工艺制备LaY沸石,采用多晶XRD结合Rietveld结构精修确定了La离子在Y沸石骨架外的分布。结果表明,进入方钠石笼的La离子定位于SⅠ’位置,与骨架O3形成配位,从而稳定沸石骨架,提高沸石水热稳定性。采用液-固工艺制备的LaY沸石中La离子与O3的距离比采用二交二焙工艺制备的LaY沸石中La离子与O3的距离要短。因此,前者La离子与O3的作用更强。采用液-固工艺制备的LaY沸石中,每个La离子除与3个O3配位外,还与2个羟基配位,La离子以[La(OH)2]+形式存在。2种工艺制备的样品中,均有少量Na+定位于六方柱笼SⅠ位置。采用二交二焙工艺制备的LaY沸石中,沸石骨架有轻微脱Al,有少量Al3+定位于SⅡ’位置。 展开更多
关键词 LaY沸石 稀土 结构精修 稀土离子位置
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柔性管Reel-lay铺管安装稳定性分析 被引量:6
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作者 白勇 唐继蔚 +2 位作者 余彬彬 阮伟东 闫会宾 《海洋工程》 CSCD 北大核心 2013年第6期22-29,共8页
钢管的S-lay、J-lay铺管方法的应用研究已经非常深入,而柔性管的Reel-lay铺管法的应用研究则相对较少。由于管道本身的材料非线性、管土接触存在非线性以及环境的不确定性等问题过于复杂,因此通过类比J-lay铺管法,采用整管的力学性能、... 钢管的S-lay、J-lay铺管方法的应用研究已经非常深入,而柔性管的Reel-lay铺管法的应用研究则相对较少。由于管道本身的材料非线性、管土接触存在非线性以及环境的不确定性等问题过于复杂,因此通过类比J-lay铺管法,采用整管的力学性能、弹性海底模型及均匀流等方式对Reel-lay铺管的水下段稳定性问题进行了简化;根据悬链线理论和小变形梁理论,给出了柔性管Reel-lay铺管法的数值计算方法,并与有限元模拟的结果进行了对比分析。结果表明:随着铺设角度增大,管道受到的弯矩也随之增大,但管道顶部的拉力却随之减小;随着铺设水深的增加,管道悬浮段质量增加,管道顶部拉力明显增加,但弯矩明显减小;浮重对管道铺设很重要,应根据实际情况,选择合适的配重以满足管道稳定和铺设的要求。 展开更多
关键词 柔性管 Reel—lay铺管法 整体稳定性 理论模型 有限元模型
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微波辅助均相沉淀法制备(Y_(1-x-y),La_y)_2O_3∶xEu^(3+)红色荧光粉 被引量:2
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作者 曾青云 李青 +2 位作者 肖婷 王宗俊 肖培南 《有色金属科学与工程》 CAS 2017年第2期107-111,共5页
用微波辅助均相沉淀法制备了一系列(Y_(1-x-y),La_y)_2O_3∶xEu^(3+)(x=0.01~0.05,y=0.05~0.25)红色荧光粉.研究Eu^(3+)、La^(3+)的掺杂浓度和煅烧温度对荧光粉性能的影响.通过差热分析仪、红外光谱仪、XRD、SEM和荧光分光光度计,对前... 用微波辅助均相沉淀法制备了一系列(Y_(1-x-y),La_y)_2O_3∶xEu^(3+)(x=0.01~0.05,y=0.05~0.25)红色荧光粉.研究Eu^(3+)、La^(3+)的掺杂浓度和煅烧温度对荧光粉性能的影响.通过差热分析仪、红外光谱仪、XRD、SEM和荧光分光光度计,对前驱体热重曲线和FTIR曲线、样品的晶体结构、表面形貌及颗粒大小和荧光性能进行表征.结果表明:前驱体组成为(Y,La,Eu)OHCO_3·nH_2O;所制备样品为立方晶系;SEM显示荧光粉为均匀分散的球形颗粒,粒度为200 nm左右;较为适宜的焙烧温度为900℃;La^(3+)掺杂含量y=10%,Eu^(3+)掺杂含量x=3%时,样品荧光粉发光性能最好,最大发射波长为614 nm,对应的是Eu^(3+)的5D0→7F2跃迁;样品的色坐标为(0.654,0.346).所制备的(Y_(1-x-y),La_y)_2O_3∶xEu^(3+)荧光粉具备较好的发光强度与色纯度. 展开更多
关键词 (Y1-x-y Lay)2O3∶xEu3+ 微波 红色荧光粉 均相沉淀法
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La交换NaY分子筛中的离子定位和迁移规律 被引量:14
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作者 杜晓辉 张海涛 +3 位作者 李雪礼 谭争国 刘宏海 高雄厚 《催化学报》 SCIE EI CAS CSCD 北大核心 2013年第8期1599-1607,共9页
以NaY分子筛为原料, 采用二次交换二次焙烧工艺, 制得了LaNH4Y-1, LaY-1, LaNH4Y-2和LaY-2四种分子筛样品. 采用粉末X射线衍射结合Rietveld结构精修确定了La离子在分子筛中的分布. 结果表明, 在离子交换过程中, La离子首先定位于分子筛... 以NaY分子筛为原料, 采用二次交换二次焙烧工艺, 制得了LaNH4Y-1, LaY-1, LaNH4Y-2和LaY-2四种分子筛样品. 采用粉末X射线衍射结合Rietveld结构精修确定了La离子在分子筛中的分布. 结果表明, 在离子交换过程中, La离子首先定位于分子筛超笼里; 经焙烧脱水后, La离子迁移到分子筛方钠石笼并定位在SI′位置. T-O-T键角的变化表明, LaNH4Y-1表现出最大的骨架扭曲性和结构不稳定性. La离子定位在SI′位置与O3配位, 增加了T-O3的键长, 表明稀土离子不仅通过控制骨架脱铝抑制晶胞收缩, 还可能通过影响T-O3键长使晶胞增大. 在REY分子筛中, 稀土的主要作用是稳定分子筛结构, 从而调节其酸性和催化活性. 采用红外光谱和NH3程序升温脱附考察了La离子和NH4+对分子筛酸性的影响, 并总结了稀土离子稳定Y型分子筛的机理. 展开更多
关键词 LaY型分子筛 RIETVELD结构精修 镧离子迁移 骨架结构 热稳定性
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海底管道S-Lay铺设过程中的质量控制 被引量:3
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作者 焦冬梅 于文太 +1 位作者 杜永军 韩旭 《中国海洋平台》 2013年第3期23-26,共4页
海底管道作为最主要的海洋石油天然气的运输方式,对施工质量要求很高。在对S-Lay铺管船铺设海底管道的铺管工艺进行介绍的基础上,利用因果分析法,对铺管过程中的潜在风险因素进行了识别和分析,并针对这些问题,对铺管过程中各个环节的质... 海底管道作为最主要的海洋石油天然气的运输方式,对施工质量要求很高。在对S-Lay铺管船铺设海底管道的铺管工艺进行介绍的基础上,利用因果分析法,对铺管过程中的潜在风险因素进行了识别和分析,并针对这些问题,对铺管过程中各个环节的质量控制要点进行了阐述,对类似项目的质量管理有参考意义。 展开更多
关键词 海底管道 S—Lay铺管 因果分析 质量控制
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Correlation between Polymorphism of Neuropeptide Y Gene and Traits at First Laying of Wenchang Chicken
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作者 朱文奇 李慧芳 +5 位作者 吴蓉蓉 宋卫涛 徐文娟 于吉英 肖小君 陈宽维 《Animal Husbandry and Feed Science》 CAS 2009年第2期5-7,12,共4页
[ Objective] The paper presents the polymorphism of neuropeptide Y gene (NPY) and its relationship with traits at first laying in Wen- chang chicken in order to provide information for breeding of high-yielding Wenc... [ Objective] The paper presents the polymorphism of neuropeptide Y gene (NPY) and its relationship with traits at first laying in Wen- chang chicken in order to provide information for breeding of high-yielding Wenchang chicken. [Method] The polymorphism of NPYgene at Dra I site was detected by PCR-RFLP, and the genotypes and the genetic stability were determined. The correlation between the polymorphism and traits at first laying (age, body weight and egg weight) was also analyzed. [Result] There were three kinds of genotype of NPYgene at Dra I site in Wenchang chicken, designated as AA, AB and BB; the distribution of these genotypes was consistent with the Hardy -Weinberg law; age and egg weight were not significantly different among the three genotypes ( P 〉0.05), and body weight was extremely significantly different ( P 〈0.01 ). [ Conclusion] The NPYgene of Wenchang chicken is in Hardy -Weinberg equilibrium at Dra I site, and its genetic polymorphism affects body weight at first laying. 展开更多
关键词 Wenchang chicken NPY gene Traits at first laying
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EPON用单纤三向模块的设计
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作者 沈开贵 《光通信技术》 CSCD 北大核心 2007年第5期44-46,共3页
目前人们更为关注的EPON与GPON,它们都具有同时传输TDM、IP数据和视频广播的能力。对于视频广播,是通过扩展第三波长(1550nm)来实现的,称为RF overlay。文章介绍了RF overlay EPON系统对用户端单纤三向模块的性能要求,并分析了三向模块... 目前人们更为关注的EPON与GPON,它们都具有同时传输TDM、IP数据和视频广播的能力。对于视频广播,是通过扩展第三波长(1550nm)来实现的,称为RF overlay。文章介绍了RF overlay EPON系统对用户端单纤三向模块的性能要求,并分析了三向模块的基本原理以及设计中的要点。最后给出了样品的测试结果,结果表明该样品满足IEEE802.3ah建议要求,可以应用在EPON系统中。 展开更多
关键词 RF OVER LAY 三向模块 突发发射
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