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深度神经网络修复策略综述
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作者 梁震 刘万伟 +3 位作者 吴陶然 薛白 王戟 杨文婧 《软件学报》 EI CSCD 北大核心 2024年第3期1231-1256,共26页
随着智能信息时代的发展,深度神经网络在人类社会众多领域中的应用,尤其是在自动驾驶、军事国防等安全攸关系统中的部署,引起了学术界和工业界对神经网络模型可能表现出的错误行为的担忧.虽然神经网络验证和神经网络测试可以提供关于错... 随着智能信息时代的发展,深度神经网络在人类社会众多领域中的应用,尤其是在自动驾驶、军事国防等安全攸关系统中的部署,引起了学术界和工业界对神经网络模型可能表现出的错误行为的担忧.虽然神经网络验证和神经网络测试可以提供关于错误行为的定性或者定量结论,但这种事后分析并不能防止错误行为的发生,如何修复表现出错误行为的预训练神经网络模型依然是极具挑战性的问题.为此,深度神经网络修复这一领域应运而生,旨在消除有缺陷的神经网络产生的错误预测,使得神经网络满足特定的规约性质.目前为止,典型的神经网络修复范式有3种:重训练、无错误定位的微调和包含错误定位的微调.介绍深度神经网络的发展和神经网络修复的必要性;厘清相近概念;明确神经网络修复的挑战;详尽地调研目前已有的神经网络修复策略,并对内在联系与区别进行分析和比较;调研整理神经网络修复策略常用的评价指标和基准测试;展望未来神经网络修复领域研究中需要重点关注的可行方向. 展开更多
关键词 深度神经网络修复 错误行为 重训练 微调 错误定位
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Responses of growth performance,antioxidant function,small intestinal morphology and mRNA expression of jejunal tight junction protein to dietary iron in yellow-feathered broilers
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作者 Kaiwen Lei Hao Wu +4 位作者 Jerry W Spears Xi Lin Xi Wang xue bai Yanling Huang 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2024年第4期1329-1337,共9页
This study aimed to investigate the dose-effect of iron on growth performance,antioxidant function.intestinal morphology,and mRNA expression of jejunal tight junction protein in 1-to21-d-old yellow-feathered broilers.... This study aimed to investigate the dose-effect of iron on growth performance,antioxidant function.intestinal morphology,and mRNA expression of jejunal tight junction protein in 1-to21-d-old yellow-feathered broilers.A total of 7201-d-old yellow-feathered maleb roilers were allocated to 9 treatments with 8 replicate cages of 10 birds per cage.The dietary treatments were consisted of a basal diet(contained 79.6 mg Fe kg^(-1))supplemented with 0,20,40,60,80,160,320,640,and 1,280 mg Fe kg^(-1)in the form of FeSO_(4)·7H_(2)O.Compared with the birds in the control group,birds supplemented with 20mg Fe kg^(-1)had higher average daily gain(ADG)(P<0.0001).Adding 640 and 1,280 mg Fe kg^(-1)significantly decreased ADG(P<0.0001)and average daily feed intake(ADFI)(P<0.0001)compared with supplementation of 20mg Fe kg^(-1).Malondialdehyde(MDA)concentration in plasma and duodenum increased linearly(P<0.0001),but MDA concentration in liver and jejunum increased linearly(P<0.05)or quadratically(P<0.05)with increased dietary Fe concentration.The villus height(VH)in duodenum and jejunum,and the ratio of villus height to crypt depth(V/C)in duodenum decreased linearly(P?0.05)as dietary Feincreased.As dietary Fe increased,the jejunal relative mRNA abundance of claudin-1 decreased linearly(P=0.001),but the jejunal relative mRNA abundance of zona occludens-1(ZO-1)and occludin decreased linearly(P?0.05)or quadratically(P?0.05).Compared with the supplementation of 20 mg Fe kg^(-1),the supplementation of640 mg Fe kg^(-1)or higher increased(P?0.05)MDA concentrations in plasma,duodenum,and jejunum,decreased VH in the duodenum and jejunum,and the addition of 1,280 mg Fe kg^(-1)reduced(P?0.05)the jejunal tight junction protein(claudin-1,ZO-1,occludin)mRNA abundance.In summary,640 mg of supplemental Fe kg^(-1)or greater was associated with decreased growth performance,increased oxidative stress,disrupted intestinal morphology,and reduced mRNA expression of jejunal tight junction protein. 展开更多
关键词 IRON yellow-feathered broiler antioxidant function intestinal morphology tight junction protein
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Multifunctional interfacial molecular bridge enabled by an aggregation-induced emission strategy for enhancing efficiency and UV stability of perovskite solar cells
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作者 Shuhang Bian Yuqi Wang +13 位作者 Fancong Zeng Zhongqi Liu Bin Liu Yanjie Wu Long Shao Yongzhi Shao Huan Zhang Shuainan Liu Jin Liang xue bai Lin Xu Donglei Zhou Biao Dong Hongwei Song 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第8期588-595,I0013,共9页
The interface defects between the electron transport layer(ETL)and the perovskite layer,as well as the low ultraviolet(UV)light utilization rate of the perovskite absorption layer,pose significant challenges for the c... The interface defects between the electron transport layer(ETL)and the perovskite layer,as well as the low ultraviolet(UV)light utilization rate of the perovskite absorption layer,pose significant challenges for the commercialization of perovskite solar cells(PSCs).To address this issue,this paper proposes an innovative multifunctional interface modulation strategy by introducing aggregation-induced emission(AIE)molecule 5-[4-[1,2,2-tri[4-(3,5-dicarboxyphenyl)phenyl]ethylene]phenyl]benzene-1,3-dicarboxylic acid(H_(8)ETTB)at the SnO_(2)ETL/perovskite interface.Firstly,the interaction of H_(8)ETTB with the SnO_(2)surface,facilitated by its carboxyl groups,is effective in passivating surface defects caused by noncoord inated Sn and O vacancies.This interaction enhances the conductivity of the SnO_(2)film and adjusts energy levels,leading to enhanced charge carrier transport.Simultaneously,H_(8)ETTB can passivate noncoord inated Pb^(2+)ions at the perovskite interface,promoting perovskite crystallization and reducing the interface energy barrier,resulting in a perovskite film with low defects and high crystalline quality.More importantly,the H_(8)ETTB molecule,can convert UV light into light absorbable by the perovskite,thereby reducing damage caused by UV light and improving the device's utilization of UV.Consequently,the champion PSC based on SnO_(2)-H_(8)ETTB achieves an impressing efficiency of 23.32%and significantly improved photostability compared with the control device after continuous exposure to intense UV radiation.In addition,the Cs_(0.05)(FA_(0.95)MA_(0.05))_(0.95)Pb(I_(0.95)Br_(0.05))_(3)based device can achieve maximum efficiency of 24.01%,demonstrating the effectiveness and universality of this strategy.Overall,this innovative interface bridging strategy effectively tackles interface defects and low UV light utilization in PSCs,presenting a promising approach for achieving highly efficient and stable PSCs. 展开更多
关键词 Perovskite solar cells Aggregation-induced emission Defect passivation EFFICIENCY UV stability
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食管癌新型生物学标志物的筛选以及外周血mRNA初步验证
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作者 薛白 陈平 +5 位作者 张玉领 邵启祥 许国莹 郝惠惠 李洪春 蔡伟莉 《临床检验杂志》 CAS 2024年第5期337-342,共6页
目的采用生物信息学和实时荧光定量PCR(qRT-PCR)筛选并验证对食管癌(ESCA)发生和发展起关键作用的基因,以期寻找ESCA的新型生物学标志物。方法检索TCGA数据库,利用韦恩图分析,初步确定ESCA样本中差异表达基因与对无病生存率(DFS)产生最... 目的采用生物信息学和实时荧光定量PCR(qRT-PCR)筛选并验证对食管癌(ESCA)发生和发展起关键作用的基因,以期寻找ESCA的新型生物学标志物。方法检索TCGA数据库,利用韦恩图分析,初步确定ESCA样本中差异表达基因与对无病生存率(DFS)产生最显著影响的基因之间的交叉基因。通过对重叠基因进行蛋白质-蛋白质互作(PPI)网络分析,并进行GO和KEGG功能分析,筛选出与ESCA发生、发展相关的关键潜在基因。利用qRT-PCR对ESCA患者外周血中关键基因mRNA的表达水平进行定量分析并结合患者临床病理参数进行统计学分析,以评估其作为ESCA新型生物学标志物的潜在价值。结果在TCGA数据库中筛选出的ESCA差异表达基因与无病生存基因交叉后,发现存在明显差异表达的基因59个,其中39个基因上调,20个基因下调,且上述基因均明显影响患者的DFS。经过PPI网络分析后,确定了15个核心互作的上调基因,而下调基因没有形成任何互作网络。进一步对这15个核心互作基因通过GO和KEGG富集分析,发现纤维连接蛋白1(FN1)可能是ESCA筛查的潜在生物学标志物。qRT-PCR结果显示,与健康人对照组相比,ESCA患者外周血中FN1 mRNA的表达水平显著升高。结合患者的临床病理参数分析,发现分化程度差、临床病理分期高的ESCA患者外周血FN1 mRNA水平明显升高,且证实FN1 mRNA水平模型能够有效区分食管癌患者和健康人。结论FN1 mRNA可作为ESCA潜在的非侵入性筛查生物学标志物。 展开更多
关键词 食管癌 纤维连接蛋白1 生物学标志物
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Optimization of Extraction Process for Total Flavonoids from Penthorum chinense Pursh and Comparison of Their Contents from Different Parts
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作者 Hongsheng LIU Jiqiang YAO +2 位作者 xue bai Jianying KANG Yefei YUAN 《Medicinal Plant》 2024年第2期10-14,共5页
[Objectives]This study was conducted to optimize the extraction process of total flavonoids from Penthorum chinense Pursh and compare their contents from different parts.[Methods]Single factor and orthogonal experimen... [Objectives]This study was conducted to optimize the extraction process of total flavonoids from Penthorum chinense Pursh and compare their contents from different parts.[Methods]Single factor and orthogonal experiments were designed to optimize the extraction process of total flavonoids from P.chinense Pursh with the volume fraction of ethanol,the ratio of material to liquid,heating reflux extraction time and extraction times as factors,and the content of total flavonoids as the index.A verification test was carried out.The optimized extraction process was adopted to compare the contents of total flavonoids from different parts of P.chinense Pursh.[Results]The best extraction process was extracting the powder of P.chinense Pursh for 2.0 h with 20 times of 55%ethanol by reflux twice.Under this condition,the contents of total flavonoids were 3.63%,8.90%,11.28%,and 4.36%from stems,leaves,flowers and whole grass of P.chinense Pursh,respectively.[Conclusions]The process is reasonable,feasible and stable,and can effectively extract total flavonoids from P.chinense Pursh.The contents of total flavonoids from different parts of P.chinense Pursh were quite different,and the value was higher in the leaves and flowers,so the proportions of leaves and flowers should be paid attention to in the industrial processing of P.chinense Pursh. 展开更多
关键词 Penthorum chinense Pursh Total flavonoids Orthogonal experiments Extraction process Content determination
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Sources of dissolved inorganic carbon in rivers from the Changbaishan area, an active volcanic zone in North Eastern China 被引量:2
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作者 xue bai Benjamin Chetelat Yilong Song 《Acta Geochimica》 EI CAS CSCD 2017年第3期410-415,共6页
Major elements and carbon isotopes of dissolved inorganic carbon(DIC)have been measured in the waters of Changbaishan mountain,a volcanic area in northeastern China,between June and September 2016 to decipher the orig... Major elements and carbon isotopes of dissolved inorganic carbon(DIC)have been measured in the waters of Changbaishan mountain,a volcanic area in northeastern China,between June and September 2016 to decipher the origin of the CO_2 involved in chemical weathering reactions.Spatial variations of major elements ratios measured in water samples can be explained by a change of the chemical composition of the volcanic rocks between the volcanic cone(trachytes)and the basaltic shield as evidenced by the variations in the composition of these rocks.Hence,DIC results from the neutralization of CO_2 by silicate rocks.DIC concentrations vary from 0.3 to 2.5 mmol/L and carbon isotopic compositions of DIC measured in rivers vary from-14.2‰to 3.5‰.At a first order,the DIC transported by rivers is derived from the chemical weathering’s consumption of CO_2 with a magmatic origin,enriched in^(13)C(-5%)and biogenic soil CO_2 with lower isotopic compositions.The highest δ^(13)C values likely result from C isotopes fractionation during CO_2 degassing in rivers.A mass balance based on carbon isotopes suggest that the contribution of magmatic CO_2 varied from less than 20%to more than 70%.Uncertainties in this calculation associated with CO_2 degassing in rivers are difficult to quantify,and the consequence of CO_2 degassing would be an overestimation of the contribution of DIC derived from the neutralization of magmatic CO_2 by silicate rocks. 展开更多
关键词 溶解无机碳 无机碳源 火山区 东北部 河流 中国 土壤CO2 硅酸盐岩石
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The therapeutic efficacy and safety of Gongxuening capsule in dysfunctional uterine bleeding:a systematic review and meta-analysis
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作者 xue bai Yan-Ru Zhang +1 位作者 Feng-Qin Zhang Hai-Zhu Zhang 《Medical Data Mining》 2020年第4期152-165,共14页
Background:Gongxuening capsule is a Chinese patent medicine for treating the dysfunctional uterine bleeding.We report a meta-analysis of the combination efficacy between conventional medicines with Chinese patent drug... Background:Gongxuening capsule is a Chinese patent medicine for treating the dysfunctional uterine bleeding.We report a meta-analysis of the combination efficacy between conventional medicines with Chinese patent drug Gongxuening in the treatment of dysfunctional uterine bleeding.Materials and methods:Seven databases were used to retrieve the relevant research of Chinese patent drug Gongxuening treatment for dysfunctional uterine bleeding from the databases establishment to 2020.The data were extracted independently by 2 researchers according to the described selection research.The meta-analysis was performed using RevMan5.3 software.Results:This study included 23 randomized trials,with a total of 1,836 dysfunctional uterine bleeding patients.Chinese patent drug Gongxuening could significantly improve the effective rate,and reduce endometrial thickness,control bleeding time,complete hemostasis time and sex hormone level,and no serious adverse events.Based on sensitivity analysis and subgroup analysis,the heterogeneity sources of endometrial thickness,complete hemostasis time and sex hormone level were found.In follicle stimulating hormone and luteinizing hormone,there was no significant difference between the two groups when Chinese patent drug Gongxuening combined with desogestrel ethinylestradiol.Conclusion:Conventional medicines combined with Chinese patent drug Gongxuening can make patients with dysfunctional uterine bleeding achieve better effective rate,and no serious adverse events occurred. 展开更多
关键词 Gongxuening capsule Conventional medicines Dysfunctional uterine bleeding META-ANALYSIS Systematic review
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LPS对牦牛瘤胃上皮细胞补体C3激活和ATP生成代谢的影响 被引量:1
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作者 张祺琪 王俊梅 +9 位作者 岳子奇 郭逸芯 施丽媛 张晓红 邹华围 彭全辉 薛白 王立志 王之盛 胡瑞 《畜牧兽医学报》 CAS CSCD 北大核心 2023年第11期4664-4675,共12页
旨在通过脂多糖(LPS)诱导牦牛瘤胃上皮细胞建立炎症模型,考察瘤胃上皮细胞作为非免疫细胞是否存在细胞内补体C3激活,及其对细胞三磷酸腺苷(ATP)生成的影响,为瘤胃健康营养调控技术提供试验依据。用不同浓度的LPS处理牦牛瘤胃上皮细胞系... 旨在通过脂多糖(LPS)诱导牦牛瘤胃上皮细胞建立炎症模型,考察瘤胃上皮细胞作为非免疫细胞是否存在细胞内补体C3激活,及其对细胞三磷酸腺苷(ATP)生成的影响,为瘤胃健康营养调控技术提供试验依据。用不同浓度的LPS处理牦牛瘤胃上皮细胞系,采用CCK-8法测定细胞活力;ELISA试剂盒测定细胞内补体C3激活产物C3a、C3b浓度以及培养基中白细胞介素-1β(IL-1β)、白细胞介素-6(IL-6)、肿瘤坏死因子α(TNF-α)浓度;化学法检测细胞内ATP浓度,线粒体红色荧光探针和流式细胞仪检测线粒体数量及膜电位;qPCR检测细胞IL-1β、IL-6、TNF-α,补体C3及其激活关键酶组织蛋白酶B(CTSB)和组织蛋白酶L(CTSL),以及ATP合成酶亚基(ATP 5A和ATP 5C1)等基因相对表达量。结果发现:1)不同浓度LPS处理后,牦牛瘤胃上皮细胞活力极显著下调(P<0.01),TNF-α、IL-1β和IL-6等促炎因子的基因表达量和浓度极显著上调(P<0.01),在LPS浓度为10μg·mL^(-1)时,牦牛瘤胃上皮细胞炎症模型构建成功;2)炎症下,牦牛瘤胃上皮细胞内补体C3及其激活关键酶CTSB的基因表达量极显著升高(P<0.01),激活产物补体片段C3a和C3b浓度极显著升高(P<0.01);3)炎症下,牦牛瘤胃上皮细胞ATP含量极显著下降(P<0.01),线粒体膜电位显著降低(P<0.05),ATP合成酶亚基ATP 5A和ATP 5C1的基因表达量随着LPS处理浓度升高显著下调(P<0.01)。综上,利用LPS诱导建立了牦牛瘤胃上皮细胞炎症模型。在LPS刺激下,牦牛瘤胃上皮细胞可发生细胞内补体C3激活过程,并抑制线粒体ATP合成酶亚基ATP 5A、ATP 5C1和有氧呼吸关键酶ME 1的基因表达,线粒体膜电位降低,抑制ATP生成。因此,LPS诱导炎症可抑制瘤胃上皮细胞ATP生成,从而导致瘤胃健康问题。 展开更多
关键词 牦牛 瘤胃上皮细胞 免疫炎症 补体C3 ATP
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用于氧还原反应的双原子钴-铁催化剂 被引量:1
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作者 唐甜蜜 王寅 +5 位作者 韩憬怡 张巧巧 白雪 牛效迪 王振旅 管景奇 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 2023年第3期48-55,共8页
金属-空气电池因其高效率和便携性受到广泛关注.然而,氧还原反应(ORR)的高能垒和缓慢的动力学导致其输出功率低.尽管贵金属铂基材料具有较高的ORR活性,但其在工业上的大规模应用受到高成本的制约.因此,迫切需要以储量丰富的非贵金属为原... 金属-空气电池因其高效率和便携性受到广泛关注.然而,氧还原反应(ORR)的高能垒和缓慢的动力学导致其输出功率低.尽管贵金属铂基材料具有较高的ORR活性,但其在工业上的大规模应用受到高成本的制约.因此,迫切需要以储量丰富的非贵金属为原料,开发具有低成本、高性能和耐用性的催化剂.近年来,单原子过渡金属与氮共掺杂碳材料(M-N-C)成为替代贵金属催化剂的理想材料.理论模拟和实验结果均表明,单原子Fe/Co-N-C催化剂具有良好的ORR活性,其中FeN_(4)和CoN_(4)构型被认为是主要活性位点.此外,含有相邻金属位点的双金属单原子催化剂具有加速ORR动力学的巨大潜力.通过对ORR中间体的桥式-顺式吸附,双金属位点可以促进O-O键的裂解,从而提高催化活性.除固有活性外,双金属位点可减少ORR过程中含氧中间体对M-N键的攻击,提高M-N-C对ORR的耐久性和工业应用潜力.因此,近年来,研究者开始探索双金属单原子催化剂的合成和电催化性能,发现Fe-Co, Fe-Mn, Fe-Cu, Co-Zn和Co-Pt双位点可以有效催化ORR.为进一步提高ORR活性,需要合理调节双原子结构,并引入更多的双金属位点.本文在氮掺杂石墨烯纳米片上构建了一种含FeN_(3)-CoN_(3)位点的新型双原子催化剂(CoFe-NG),该催化剂具有较好的ORR催化活性,半波电位为0.917 V, Tafel斜率为46 mV dec^(-1),远远优于单原子Fe-NG、单原子Co-NG和Pt/C催化剂.Koutecky-Levich曲线和H_(2)O_(2)产率揭示了CoFe-NG具有高效的四电子ORR过程,不仅表现出高电流密度,而且对氧还原为OH-(而不是过氧化氢)更具选择性.计时安培测试结果表明, CoFe-NG对甲醇和一氧化碳中毒具有较高的耐受性.KSCN中毒实验结果表明, SCN^(-)离子与Fe和Co位点发生强配位作用并使活性位点中毒.以CoFe-NG为空气电极组装的锌-空气电池,开路电压为1.47 V,峰值功率密度高达230 mW cm^(-2),具有良好的充放电循环稳定性,可以为一个小灯泡供电,并且在5 mA cm^(-2)条件下持续充放电250 h,输出电压几乎不变.理论计算表明,掺氮石墨烯上的FeN_(3)-CoN_(3)位点比FeN_(4)和CoN_(4)位点具有更低的ORR能垒, FeN_(3)-CoN_(3)位点上的速控步是^(*)OH中间体向H_(2)O的转化,与单位点FeN_(4)和CoN_(4)不同.综上,本文为可控合成高性能双金属单原子催化剂及进一步深入分析其电催化氧还原反应机理提供参考. 展开更多
关键词 双原子催化剂 M-N-C 氧还原反应 理论计算 锌-空气电池
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3D打印尼龙1212的无氧老化机理 被引量:1
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作者 郭荣哲 薛白 +1 位作者 谢兰 梁寅 《塑料工业》 CAS CSCD 北大核心 2023年第6期115-121,共7页
尼龙材料是3D打印的主要材料之一,其老化行为大大降低了循环使用率,造成材料的浪费。为了深入了解3D打印过程中尼龙粉末的变化情况,以尼龙1212(PA1212)粉末为原料,通过人工加速烧结模拟实验,以不同老化时间的粉末为研究对象,采用理论与... 尼龙材料是3D打印的主要材料之一,其老化行为大大降低了循环使用率,造成材料的浪费。为了深入了解3D打印过程中尼龙粉末的变化情况,以尼龙1212(PA1212)粉末为原料,通过人工加速烧结模拟实验,以不同老化时间的粉末为研究对象,采用理论与分析相结合的方式,探究尼龙无氧热老化机理。通过扫描电子显微镜(SEM)、X射线光电子能谱(XPS)、凝胶渗透色谱(GPC)、傅里叶红外光谱(FTIR)等测试,分析3D打印过程中粉料的无氧热老化行为。粉末吸收热量,导致球形尺寸增大,表面缺陷突增,黏度增加等。尼龙材料的无氧热老化过程伴随复杂的重排交联反应,酰胺键的C=O双键损耗,分子间作用力减弱,导致熔融和结晶等发生偏移,半结晶材料的尼龙结晶能力下降。此研究为尼龙材料在3D打印领域的发展提供了理论基础。 展开更多
关键词 尼龙1212 无氧老化 选择性激光烧结
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亮氨酸对黄牛皮下脂肪细胞棕色化的影响
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作者 郭逸芯 王之盛 +9 位作者 胡瑞 王俊梅 王森 施丽媛 张晓红 邹华围 左家学 彭全辉 薛白 王立志 《畜牧兽医学报》 CAS CSCD 北大核心 2023年第8期3286-3298,共13页
旨在分离黄牛皮下前体脂肪细胞,探究亮氨酸对白色脂肪细胞棕色化以及脂质代谢的影响。本研究采取4头3岁的健康雄性黄牛((351.7±42.5)kg)皮下脂肪组织分离前体脂肪细胞,混合后于细胞分化D 6-D 9添加不同浓度亮氨酸(0、0.5、1、2、4... 旨在分离黄牛皮下前体脂肪细胞,探究亮氨酸对白色脂肪细胞棕色化以及脂质代谢的影响。本研究采取4头3岁的健康雄性黄牛((351.7±42.5)kg)皮下脂肪组织分离前体脂肪细胞,混合后于细胞分化D 6-D 9添加不同浓度亮氨酸(0、0.5、1、2、4、8 mmol·L^(-1))(n=6)。RT-PCR检测棕色化标志基因,筛选亮氨酸诱导脂肪细胞棕色化的浓度,后续试验分为对照组(CON)和最佳浓度亮氨酸添加组(Leu)(n=6)。RT-PCR检测线粒体生物合成关键基因表达、mtDNA拷贝数以及脂质代谢相关基因的表达,Western Blot检测棕色化关键蛋白以及信号通路蛋白表达。Mito-tracker Green染色和油红O染色分别检测细胞内线粒体含量和脂滴形态的变化。结果表明,成功分离得到黄牛皮下前体脂肪细胞并诱导为成熟脂肪细胞。4 mmol·L^(-1)亮氨酸显著提高脂肪细胞中棕色化标志因子UCP1、PRDM 16和TMEM 26的mRNA相对表达量,线粒体生物合成关键基因SIRT1、TFAM和NRF 1/2的mRNA相对表达量,上调关键蛋白UCP1、CD137和SIRT1的表达量(P<0.01)。亮氨酸显著提高细胞中mtDNA拷贝数和线粒体含量(P<0.01),降低细胞内ATP含量(P<0.05),促使细胞脂滴由单房大脂滴向多房小脂滴转变,并降低细胞内甘油三酯的含量(P<0.01)。亮氨酸抑制脂肪合成基因ACC、FAS表达,促进脂肪分解基因ATGL、HSL和脂肪酸β氧化基因PPARα、CPT1、ACOX表达(P<0.01)。添加亮氨酸极显著上调p-AMPKα/AMPKα和PGC1α的蛋白表达量(P<0.01)。综上所述,亮氨酸能促进黄牛脂肪细胞棕色化和线粒体生物合成,促进脂肪分解抑制脂肪合成,减少细胞内脂质沉积,并上调p-AMPKα/AMPKα和PGC1α的蛋白表达量。 展开更多
关键词 亮氨酸 黄牛 原代脂肪细胞 棕色化 线粒体生物合成
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β-胡萝卜素对母犏牛营养物质表观消化率、瘤胃发酵特征及微生物区系的影响
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作者 李宁 岳双明 +4 位作者 李梦雅 王之盛 薛白 王立志 彭全辉 《动物营养学报》 CAS CSCD 北大核心 2023年第1期350-359,共10页
本试验旨在探究β-胡萝卜素对母犏牛营养物质表观消化率、瘤胃发酵特征及微生物区系的影响。选取12头健康、体重[(285.96±12.38) kg]相近的15月龄母犏牛(黄牛♂×牦牛♀),随机分为2个组,每组6个重复,每个重复1头牛。对照组饲... 本试验旨在探究β-胡萝卜素对母犏牛营养物质表观消化率、瘤胃发酵特征及微生物区系的影响。选取12头健康、体重[(285.96±12.38) kg]相近的15月龄母犏牛(黄牛♂×牦牛♀),随机分为2个组,每组6个重复,每个重复1头牛。对照组饲喂基础饲粮,试验组在对照组的基础上每头牛每天额外添加1 200 mgβ-胡萝卜素。试验预试期10 d,正试期85 d。结果表明:1)与对照组相比,试验组酸性洗涤纤维和中性洗涤纤维表观消化率显著提高(P<0.05)。2)与对照组相比,试验组瘤胃微生物蛋白和丙酸含量显著提高(P<0.05),瘤胃乙酸/丙酸值显著降低(P<0.05)。3)在门水平上,试验组拟杆菌门(Bacteroidetes)相对丰度显著高于对照组(P<0.05),互养菌门(Synergistetes)、放线菌门(Actinobacteria)、髌骨细菌门(Patescibacteria)、绿弯菌门(Chloroflexi)和芽单胞菌门(Gemmatimonadetes)相对丰度显著低于对照组(P<0.05)。在属水平上,试验组普雷沃氏菌属1(Prevotella 1)、鼠杆菌科(Muribaculaceae)和瘤胃球菌科UCG-014(Ruminococcaceae UCG-014)相对丰度显著高于对照组(P<0.05),甲烷短杆菌属(Methanobrevibacter)相对丰度显著低于对照组(P<0.05)。综上所述,饲粮添加β-胡萝卜素可以改变母犏牛瘤胃微生物区系和发酵模式,提高其对纤维的消化能力。 展开更多
关键词 胡萝卜素 母犏牛 营养物质表观消化率 瘤胃发酵 瘤胃微生物区系
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双杂原子配位提高单原子锰位点的析氧活性
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作者 白雪 韩璟怡 +2 位作者 陈思雨 牛效迪 管景奇 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 2023年第11期212-219,共8页
可再生能源的储存和转化可以增加能源利用的可及性,是目前能源发展的主要方向.析氧反应(OER)是电解水与可充电锌-空气电池的重要半反应,然而其较高的反应势垒降低了能源利用效率.因此,开发高效和稳定的OER催化剂是提升能源利用的关键.... 可再生能源的储存和转化可以增加能源利用的可及性,是目前能源发展的主要方向.析氧反应(OER)是电解水与可充电锌-空气电池的重要半反应,然而其较高的反应势垒降低了能源利用效率.因此,开发高效和稳定的OER催化剂是提升能源利用的关键.由于具有低成本和高原子利用率的优势,非贵金属基单原子催化剂已被广泛应用于电催化析氧反应.研究表明,单原子催化剂的OER活性与其电子结构密切相关.改变配位原子的种类和配位数可以调节单金属原子的d电子结构和自旋状态,进一步优化反应中间体的吸附.锰(Mn)是自然界光合作用系统的析氧中心,近年来模拟Mn结构以最大程度激发催化活性受到了广泛的关注.本文采用双杂原子配位方法来调节孤立锰位点的电子结构从而提升其OER性能.以氧化石墨烯、氯化锰和硫粉为前驱体,合成了双杂原子配位的单原子锰催化剂Mn-SG-500(退火温度为500℃),其中单锰原子与两个硫原子和两个氧原子配位.能谱分析(EDS)和X射线衍射(XRD)谱图中均未观察到锰基纳米粒子,高角环形暗场-扫描透射电子显微镜(HAADF-STEM)图像显示均匀分散的亮点,表明锰以单原子形式负载在石墨烯上.Mn的扩展X射线吸收精细结构(EXAFS)光谱结果表明,Mn-SG-500中的Mn表现出接近+2的化合价,且不存在Mn-Mn键,进一步说明Mn以单原子形式存在.拟合结果显示,Mn-S键长为2.34±0.07?,配位数为1.7±0.4;Mn-O键长为1.94±0.05?,配位数为1.8±0.4.电化学测试结果表明,在碱性条件下,Mn-SG-500在电流密度为10 mA cm^(-2)时的过电位为332 mV,Tafel斜率为56 mV dec-1.与无硫掺杂样品Mn-G-500相比,其过电位(η10)降低了59 mV.根据Arrhenius公式计算,S/O和Mn共配位降低了OER活化能.此外,在1.6 V(vs.RHE)电压下,Mn-SG-500连续运行25 h仍可保持电流密度在10 mA cm^(-2)以上.差分脉冲伏安(DPV)结果表明,在OER过程中,锰的价态由+2变为+4,说明四价锰是析氧反应的关键物种.反应后的Mn 2p XPS谱图也证实了Mn(Ⅳ)的生成.此外,硫的加入使Mn4+到MN_(2)+的还原电位从1.39 V降至1.348 V,提高了OER活性.通过理论计算进一步揭示Mn-SG-500上OER催化活性中心为Mn-S2O_(2),速率控步为*O氧化成*OOH,其理论过电位为0.9 V,远小于硫或氧单独配位的Mn-S4和Mn-O4.综上所述,催化剂Mn-SG-500的析氧活性提高是由于S和O的共配位引起了Mn电荷的重新分配和优化,这对其它过渡金属基催化剂的进一步结构设计和性能优化具有参考意义,也为相关催化领域的研究提供借鉴. 展开更多
关键词 双杂原子配体 原位拉曼 析氧反应 单原子催化剂 理论计算
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Promoting amorphization of commercial TiO_(2) upon sodiation to boost the sodium storage performance
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作者 Tao Li Ling-Yun Kong +2 位作者 xue bai Yan-Xiang Wang Yong-Xin Qi 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2023年第6期379-388,I0009,共11页
Anatase TiO_(2) is a promising anode material for sodium-ion batteries,yet the low electronic and ionic conductivities are the main obstacles for its practical application.Even though the amorphization of TiO_(2) upon... Anatase TiO_(2) is a promising anode material for sodium-ion batteries,yet the low electronic and ionic conductivities are the main obstacles for its practical application.Even though the amorphization of TiO_(2) upon sodiation has already been observed,its underneath mechanisms are not fully elucidated.Herein,a low-cost nitrogen-containing carbon source of polyacrylonitrile is adopted to modify commercial anatase TiO_(2) by a convenient and nontoxic ball-milling technique combined with subsequent annealing treatment.In particular,the employment of a nitrogen-doping approach accompanied by nitrogendoped carbon coating,results in a greatly improved conductivity,overall leading to a high reversible capacity of about 260 m A h g^(-1)at 25 m A g^(-1),superior rate capabilities,and an ultra-stable capacity of about 186 m A h g^(-1)after 1600 cycles at 500 m A g^(-1).Detailed characterizations denote that the improved conductivity as well as the small size of the synthesized TiO_(2) grains play a key role in the TiO_(2) amorphization upon sodiation,with the TiO_(2)/C nanocomposite undergoing a complete amorphization in just few cycles.Finally,the irreversible amorphization of TiO_(2) is confirmed to be a crucial ingredient facilitating the Na+diffusion kinetics and pseudocapacitive behavior,thus boosting the sodium storage performance. 展开更多
关键词 Commercial TiO_(2) Anode material Amorphization Nitrogen doping Sodium-ion battery
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Simultaneous bottom-up double-layer synergistic engineering by multifunctional natural molecules for efficient and stable SnO2-based planar perovskite solar cells
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作者 Yue Liu Yanbo Gao +11 位作者 Tingting Li Xinyu Bao Zehua Xu Fujun Zhang Min Lu Zhennan Wu Yanjie Wu Guang Sun xue bai Zhifeng Shi Junhua Hu Yu Zhang 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2023年第5期40-47,I0002,共9页
The performance and stability of perovskite solar cells(PSCs)is limited by detrimental defects,mostly distributed at the grain boundary(GB)of bulk perovskite film and interface,which induce serious carrier non-radiati... The performance and stability of perovskite solar cells(PSCs)is limited by detrimental defects,mostly distributed at the grain boundary(GB)of bulk perovskite film and interface,which induce serious carrier non-radiative recombination.Therefore,there is particularly urgent to realize simultaneous passivation of bulk defects and interfacial defects.In this work,a simple,low-cost and effective multifunctional modification strategy is developed by introducing theλ-Carrageenan(λ-C)as the interfacial layer of SnO_(2)/perovskite.The sulfate groups ofλ-C not only play a positive role in passivating the Sn4+from SnO_(2)film,resulting in high conductivity,but also effectively passivate the defects at the SnO_(2)/perovskite interface.Meanwhile,λ-C can effectively passivate the defects in the perovskite film due to the strong binding force between the high content of sulfate groups and PbI2.The synergistic effect ofλ-C simultaneously achieves interfacial defects and bulk defects passivation,better crystalline quality,suppressed charge recombination,released interfacial stress and more favorable interfacial energy level alignment.Based on the above efficient synergy,theλ-C-modified device achieves a high efficiency of 23.81%,which is~24.53%higher than the control device(19.12%).To our best knowledge,23.81%of power conversion efficiency(PCE)is the highest reported PCE value of PSCs employing green natural additives.Moreover,long-term and thermal stabilities are significantly improved after interface modification.Thus,this work provides an idea for developing multifunctional natural materials towards the attainment of the efficient and stable PSCs. 展开更多
关键词 Perovskite solar cells γ-Carrageenan Interfacial modification Stability Defect passivation
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A review of the etched terminal structure of a 4H-SiC PiN diode
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作者 Hang Zhou Jingrong Yan +8 位作者 Jialin Li Huan Ge Tao Zhu Bingke Zhang Shucheng Chang Junmin Sun xue bai Xiaoguang Wei Fei Yang 《Journal of Semiconductors》 EI CAS CSCD 2023年第11期69-78,共10页
The comparison of domestic and foreign studies has been utilized to extensively employ junction termination extension(JTE)structures for power devices.However,achieving a gradual doping concentration change in the lat... The comparison of domestic and foreign studies has been utilized to extensively employ junction termination extension(JTE)structures for power devices.However,achieving a gradual doping concentration change in the lateral direction is difficult for SiC devices since the diffusion constants of the implanted aluminum ions in SiC are much less than silicon.Many previously reported studies adopted many new structures to solve this problem.Additionally,the JTE structure is strongly sensitive to the ion implantation dose.Thus,GA-JTE,double-zone etched JTE structures,and SM-JTE with modulation spacing were reported to overcome the above shortcomings of the JTE structure and effectively increase the breakdown voltage.They provided a theoretical basis for fabricating terminal structures of 4H-SiC PiN diodes.This paper summarized the effects of different terminal structures on the electrical properties of SiC devices at home and abroad.Presently,the continuous development and breakthrough of terminal technology have significantly improved the breakdown voltage and terminal efficiency of 4H-SiC PiN power diodes. 展开更多
关键词 PiN diode terminal structure mesa-JTE reverse breakdown voltage etching process
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Identification of biomarkers associated with the feed efficiency by metabolomics profiling:results from the broiler lines divergent for high or low abdominal fat content
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作者 Zhiyong Su xue bai +7 位作者 Haoyu Wang Shouzhi Wang Chong Chen Fan Xiao Huaishun Guo Haihe Gao Li Leng Hui Li 《Journal of Animal Science and Biotechnology》 SCIE CAS CSCD 2023年第1期33-46,共14页
Background:Improving feed efficiency(FE)is one of the main objectives in broiler breeding.It is difficult to directly measure FE traits,and breeders hence have been trying to identify biomarkers for the indirect selec... Background:Improving feed efficiency(FE)is one of the main objectives in broiler breeding.It is difficult to directly measure FE traits,and breeders hence have been trying to identify biomarkers for the indirect selection and improvement of FE traits.Metabolome is the"bridge"between genome and phenome.The metabolites may potentially account for more of the phenotypic variation and can suitably serve as biomarkers for selecting FE traits.This study aimed to identify plasma metabolite markers for selecting high-FE broilers.A total of 441 birds from Northeast Agricultural University broiler lines divergently selected for abdominal fat content were used to analyze plasma metabolome and estimate the genetic parameters of differentially expressed metabolites.Results:The results identified 124 differentially expressed plasma metabolites(P<0.05)between the lean line(highFE birds)and the fat line(low-FE birds).Among these differentially expressed plasma metabolites,44 were found to have higher positive or negative genetic correlations with FE traits(|r_g|≥0.30).Of these 44 metabolites,14 were found to display moderate to high heritability estimates(h~2≥0.20).However,among the 14 metabolites,4 metabolites whose physiological functions have not been reported were excluded.Ultimately,10 metabolites were suggested to serve as the potential biomarkers for breeding the high-FE broilers.Based on the physiological functions of these metabolites,reducing inflammatory and improving immunity were proposed to improve FE and increase production efficiency.Conclusions:According to the pipeline for the selection of the metabolite markers established in this study,it was suggested that 10 metabolites including 7-ketocholesterol,dimethyl sulfone,epsilon-(gamma-glutamyl)-lysine,gamma-glutamyltyrosine,2-oxoadipic acid,L-homoarginine,testosterone,adenosine 5'-monophosphate,adrenic acid,and calcitriol could be used as the potential biomarkers for breeding the"food-saving broilers". 展开更多
关键词 BIOMARKER BROILER Feed efficiency Metabolomics
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Global simulation of plasma series resonance effect in radio frequency capacitively coupled Ar/O_(2) plasma
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作者 白雪 徐海文 +3 位作者 田崇彪 董婉 宋远红 王友年 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第12期422-429,共8页
Radio frequency capacitively coupled plasmas(RF CCPs)play a pivotal role in various applications in etching and deposition processes on a microscopic scale in semiconductor manufacturing.In the discharge process,the p... Radio frequency capacitively coupled plasmas(RF CCPs)play a pivotal role in various applications in etching and deposition processes on a microscopic scale in semiconductor manufacturing.In the discharge process,the plasma series resonance(PSR)effect is easily observed in electrically asymmetric and geometrically asymmetric discharges,which could largely influence the power absorption,ionization rate,etc.In this work,the PSR effect arising from geometrically and electrically asymmetric discharge in argon-oxygen mixture gas is mainly investigated by using a plasma equivalent circuit model coupled with a global model.At relatively low pressures,as Ar content(α)increases,the inductance of the bulk is weakened,which leads to a more obvious PSR phenomenon and a higher resonance frequency(ω_(psr)).When the Ar content is fixed,varying the pressure and gap distance could also have different effects on the PSR effect.With the increase of the pressure,the PSR frequency shifts towards the higher order,but in the case of much higher pressure,the PSR oscillation would be strongly damped by frequent electron-neutral collisions.With the increase of the gap distance,the PSR frequency becomes lower.In addition,electrically asymmetric waveforms applied to a geometrically asymmetric chamber may weaken or enhance the asymmetry of the discharge and regulate the PSR effect.In this work,the Ar/O_(2) electronegative mixture gas is introduced in a capacitive discharge to study the PSR effect under geometric asymmetry effect and electrical asymmetry effect,which can provide necessary guidance in laboratory research and current applications. 展开更多
关键词 capacitively coupled Ar/O_(2)plasma PSR effect plasma equivalent circuit model global model
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Danlu Tongdu tablets treat lumbar spinal stenosis through reducing reactive oxygen species and apoptosis by regulating CDK2/CDK4/CDKN1A expression
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作者 xue bai Ayesha Tasleem Tahir +3 位作者 Zheng-Heng Yu Wen-Bo Cheng Bo Zhang Jun Kang 《Traditional Medicine Research》 2023年第7期47-55,共9页
Lumbar spinal stenosis is caused by the compression of the nerve root or cauda equina nerve by stenosis of the lumbar spinal canal or intervertebral foramen,and is manifested as chronic low back and leg pain.Danlu Ton... Lumbar spinal stenosis is caused by the compression of the nerve root or cauda equina nerve by stenosis of the lumbar spinal canal or intervertebral foramen,and is manifested as chronic low back and leg pain.Danlu Tongdu(DLTD)tablets can relieve chronic pain caused by lumbar spinal stenosis,but the molecular mechanism remains largely unknown.In this study,the potential molecular mechanism of DLTD tablets in the treatment of lumbar spinal stenosis was first predicted by the network pharmacology method.Results showed that DLTD functions in regulating anti-oxidative,apoptosis,and inflammation signaling pathways.Furthermore,the flow cytometry results showed that DLTD tablets efficiently reduced reactive oxygen species content and inhibited rat neural stem cell apoptosis induced by hydrogen peroxide.DLTD also inhibited the mitochondrial membrane potential damage induced by hydrogen peroxide.Elisa analysis showed that DLTD induced cell cycle-related protein,CDK2 and CDK4,and reduced CDKN1A protein expression level.Taken together,our study provided new insights of DLTD in treating lumbar spinal stenosis through reducing reactive oxygen species content,decreasing apoptosis by inhibiting CDKN1A and promoting CDK2 and CDK4 expression levels. 展开更多
关键词 Danlu Tongdu lumbar spinal stenosis reactive oxygen species cell apoptosis
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Effects of Carbon Nanomaterials on Soil Enzyme Activity of Turfgrass
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作者 Ying XIONG xue bai +1 位作者 Shulan ZHAO Li'an DUO 《Agricultural Biotechnology》 CAS 2023年第1期76-77,83,共3页
[Objectives]This study was conducted to evaluate the effects of carbon nanomaterials on soil ecosystem and explore the ecological risks of environmental exposure of carbon nanomaterials. [Methods] The effects of carbo... [Objectives]This study was conducted to evaluate the effects of carbon nanomaterials on soil ecosystem and explore the ecological risks of environmental exposure of carbon nanomaterials. [Methods] The effects of carbon nanomaterials on soil enzyme activity was studied by adding graphene, graphene oxide and carbon nanotubes to turfgrass soil. [Results] Compared with the control(CK), the activity of soil protease, sucrase, alkaline phosphatase and catalase was not significantly affected by carbon nanomaterials. Under the treatment of carbon nanotubes, urease activity was significantly lower than that of graphene and graphene oxide, and dehydrogenase activity was significantly lower than that of the CK, graphene and graphene oxide. [Conclusions] This study provides a theoretical basis for the safe application of carbon nanomaterials. 展开更多
关键词 Carbon nanomaterials TURFGRASS Soil enzyme activity
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