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苹果丁冷冻-热风联合干燥体积收缩机制

农业工程学报 2024年第2期40卷 63-71页

作者：任广跃朱乐雯段续刘文超李格格卫新雨河南科技大学食品与生物工程学院洛阳471023 河南省农产品干燥装备工程技术研究中心洛阳471023

为降低冻干苹果能耗,同时获得具有良好外观的脱水产品,该研究将冷冻-热风联合干燥应用于苹果脱水加工,并从水分迁移角度探究此过程中产品的收缩机制。选取4个水分转换点(干基含水率分别为1.00、0.76、0.53和0.33 g/g)对苹果进行联合干... 详细信息

为降低冻干苹果能耗,同时获得具有良好外观的脱水产品,该研究将冷冻-热风联合干燥应用于苹果脱水加工,并从水分迁移角度探究此过程中产品的收缩机制。选取4个水分转换点(干基含水率分别为1.00、0.76、0.53和0.33 g/g)对苹果进行联合干燥处理,并对脱水产品的收缩率、质构特性、微观结构、孔隙分布及样品在热风干燥阶段的水分迁移与分布进行测定及分析。结果表明,联合干燥样品的收缩情况显著(P<0.05)优于单一热风干燥样品,且转换点对样品收缩率影响较大(收缩率6%~45%),当转换点干基含水率低于0.53 g/g时,联合干燥样品没有出现明显的体积收缩现象。随着转换点干基含水率的升高,样品的收缩程度增大,并出现不同程度的中心塌陷,且孔隙率逐渐减小,但相应能耗降低。产品收缩主要发生在热风干燥过程的升速阶段,在此阶段样品自由水含量大幅减少,结合水与不易流动水未发生明显改变,样品内部水分在湿度差的作用下向表面迁移,这是导致联合干燥样品发生体积收缩的关键机制。该研究结果可为冷冻-热风联合干燥高效生产良好外观的脱水苹果提供数据支撑及理论参考。

关键词：冷冻干燥热风干燥联合干燥收缩水分迁移微观结构

Endorepellin downregulation promotes angiogenesis after experimental traumatic brain injury

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Neural Regeneration Research 2024年第5期19卷 1092-1097页

作者： Qian Zhang Yao Jing Qiuyuan Gong Lin Cai Ren Wang Dianxu Yang Liping Wang Meijie Qu Hao Chen Yaohui Tang Hengli Tian Jun Ding Zhiming xu Department of Gerontology Shanghai Sixth People’s Hospital Affiliated to Shanghai Jiao Tong University School of MedicineShanghaiChina Department of Neurosurgery Shanghai Sixth People’s Hospital Affiliated to Shanghai Jiao Tong University School of MedicineShanghaiChina Department of Neurology Renji HospitalSchool of MedicineShanghai Jiao Tong UniversityShanghaiChina School of Biomedical Engineering and Med-X Research Institute Shanghai Jiao Tong UniversityShanghaiChina Department of Neurology Affiliated Hospital of Qingdao UniversityQingdaoShandong ProvinceChina

Endorepellin plays a key role in the regulation of angiogenesis,but its effects on angiogenesis after traumatic brain injury are *** study explored the effects of endorepellin on angiogenesis and neurobehavioral outcomes after traumatic brain injury in *** were randomly divided into four groups:sham,controlled cortical impact only,adeno-associated virus(AAV)-green fluorescent protein,and AAV-shEndorepellin-green fluorescent protein *** the controlled cortical impact model,the transduction of AAV-shEndorepellin-green fluorescent protein downregulated endorepellin while increasing the number of CD31+/Ki-67+proliferating endothelial cells and the functional microvessel density in mouse *** changes resulted in improved neurological function compared with controlled cortical impact *** blotting revealed increased expression of vascular endothelial growth factor and angiopoietin-1 in mice treated with AAV-shEndorepellin-green fluorescent *** radiation angiography showed that endorepellin downregulation promoted angiogenesis and increased cortical neovascularization,which may further improve neurobehavioral ***,an in vitro study showed that downregulation of endorepellin increased tube formation by human umbilical vein endothelial cells compared with a *** analysis found that endorepellin downregulation may mediate angiogenesis by activating vascular endothelial growth factor-and angiopoietin-1-related signaling pathways.

关键词： angiogenesis controlled cortical impact endorepellin neurological function traumatic brain injury

纵向压力和加固钢板对隧道力学性能影响的解析解

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岩土力学 2024年第6期45卷 1623-1632页

作者：江学辉颜建伟罗文俊李佳宝徐长节华东交通大学轨道交通基础设施性能监测与保障国家重点实验室江西南昌330013

为快速准确地评估纵向压力和加固钢板对盾构隧道力学性能的影响,基于隧道衬砌接缝面建立考虑纵向压力、弯矩和加固钢板耦合作用下的应力平衡方程,推导出了隧道力学性能的解析解。通过与经典抗弯刚度理论和数值模拟的计算结果对比,验证... 详细信息

为快速准确地评估纵向压力和加固钢板对盾构隧道力学性能的影响,基于隧道衬砌接缝面建立考虑纵向压力、弯矩和加固钢板耦合作用下的应力平衡方程,推导出了隧道力学性能的解析解。通过与经典抗弯刚度理论和数值模拟的计算结果对比,验证了该方法的可靠性。研究表明:隧道中性轴随纵向压力、加固钢板厚度和弹性模量增加而减小;隧道抗弯刚度随弯矩增大而减小(最大和最小隧道抗弯刚度与弯矩大小无关),与纵向压力呈S曲线正相关,与加固钢板厚度和弹性模量呈非线性正相关。有加固钢板的隧道抗弯刚度是无加固钢板的6.58倍;弯矩承载力与纵向压力、加固钢板厚度和弹性模量呈非线性正相关;衬砌接缝张开量与纵向压力、加固钢板厚度和弹性模量呈非线性反相关,与弯矩呈非线性正相关。该计算方法解析地诠释了纵向压力与加固钢板对盾构隧道力学性能的影响机制。

关键词：隧道工程解析解纵向压力加固钢板抗弯刚度

Supramolecular systems for bioapplications:recent research progress in China

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Science China Chemistry 2024年第5期67卷 1397-1441页

作者： Yue-Yang Liu Xiao-Yong Yu Yu-Chen Pan Hang Yin Shuang Chao Yujie Li He Ma Minzan Zuo Kun-xu Teng Jun-Li Hou Yong Chen Dong-Sheng Guo Ruibing Wang Yuxin Pei Zhichao Pei Jiang-Fei xu Xiao-Yu Hu Chunju Li Qing-Zheng Yang Leyong Wang Yu Liu Zhan-Ting Li State Key Laboratory of Organometallic Chemistry Key Laboratory of Synthetic and Self-Assembly Chemistry for Organic Functional MoleculesShanghai Institute of Organic ChemistryChinese Academy of SciencesUniversity of Chinese Academy of SciencesShanghai 200032China Department of Chemistry Fudan UniversityShanghai 200438China College of Chemistry State Key Laboratory of Elemento-Organic ChemistryCollaborative Innovation Center of Chemical Science and EngineeringNankai UniversityTianjin 300071China State Key Laboratory of Quality Research in Chinese Medicine Institute of Chinese Medical SciencesUniversity of MacaoMacao 999078China College of Chemistry&Pharmacy Northwest A&F UniversityYangling 712100China Key Lab of Organic Optoelectronics&Molecular Engineering Department of ChemistryTsinghua UniversityBeijing 100084China College of Materials Science and Technology Nanjing University of Aeronautics and AstronauticsNanjing 211106China Key Laboratory of Radiopharmaceuticals Ministry of EducationCollege of ChemistryBeijing Normal UniversityBeijing 100875China Tianjin Key Laboratory of Structure and Performance for Functional Molecules College of ChemistryTianjin Normal UniversityTianjin 300387China State Key Laboratory of Analytical Chemistry for Life Science Jiangsu Key Laboratory of Advanced Organic MaterialsSchool of Chemistry and Chemical EngineeringNanjing UniversityNanjing 210023China

Supramolecular systems feature dynamic,reversible and stimuli-responsive characteristics,which are not easily achieved by molecular *** last decade has witnessed tremendous advances in the investigations of supramolecular systems for various bioapplications,which include drug delivery,anticancer therapy,antibacterial therapy,photodynamic therapy,photothermal therapy,combination therapy,antidotes for residual drugs or toxins,and bioimaging and ***-guest chemistry has played a key role in the development of such bioactive supramolecular systems,and natural macrocycles(such as cyclodextrins),synthetic macrocycles(such as calixarenes,cucurbit[n]urils,and pillararenes),and porous framework polymers(such as supramolecular organic frameworks and flexible organic frameworks)have been most successfully used as hosts to build different kinds of host-guest systems for attaining designed *** self-assembly of rationally designed amphiphilic molecules,macromolecules and polymers represent another important approach for the construction of supramolecular architectures with advanced *** this review,we summarize the important contributions made by Chinese researchers in this field,with emphasis on those reported in the past five years.

关键词： host-guest chemistry drug delivery anticancer and antibacterial photodynamic therapy photothermal therapy antidote transmembrane channel bioimaging and biosensing

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Mapk7 deletion in chondrocytes causes vertebral defects by reducing MEF2C/PTEN/AKT signaling

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Genes & Diseases 2024年第2期11卷 964-977页

作者： Chengzhi Wu Hengyu Liu Dongmei Zhong Xiaoming Yang Zhiheng Liao Yuyu Chen Shun Zhang Deying Su Baolin Zhang Chuan Li Liru Tian Caixia xu Peiqiang Su Guangdong Provincial Key Laboratory of Orthopedics and Traumatology Department of Spine SurgeryThe First Affiliated Hospital of Sun Yat-sen UniversityGuangzhouGuangdong 510080China Research Center for Translational Medicine The First Affiliated Hospital of Sun Yat-sen UniversityGuangzhouGuangdong 510080China Precision Medicine Institute The First Affiliated Hospital of Sun Yat-sen UniversityGuangzhouGuangdong 510080China Department of Orthopedics Renmin Hospital of Wuhan UniversityWuhanHubei 430060China Guangdong Provincial Key Laboratory of Proteomics and State Key Laboratory of Organ Failure Research School of Basic Medical SciencesSouthern Medical UniversityGuangzhouGuangdong 510515China

Mutation of the MAPK7 gene was related to human ***7 regulated the development of limb bones and skulls in ***,the role of MAPK7 in vertebral development is still *** this study,we constructed Col2a1-cre;Mapk7 f/f transgenic mouse model to delete Mapk7 in cartilage,which displayed kyphosis and ***,Mapk7 loss decreased MEF2C expression and thus activated PTEN to oppose PI3K/AKT signaling in vertebral growth plate chondrocytes,which impaired chondrocyte hypertrophy and attenuated vertebral *** vivo,systemic pharmacological activation of AKT rescued impaired chondrocyte hypertrophy and alleviated mouse vertebral defects caused by Mapk7 *** study firstly clarified the mechanism by which MAPK7 was involved in vertebral development,which might contribute to understanding the pathology of spinal deformity and provide a basis for the treatment of developmental disorders of the spine.

关键词： Chondrocyte hypertrophy Growth plate Kyphosis MAPK7 MEF2C Osteopenia PI3K/AKT PTEN

Reduction of the oxidative damage to H_(2)O_(2)-induced HepG2 cells via the Nrf2 signalling pathway by plant flavonoids Quercetin and Hyperoside

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Food Science and Human Wellness 2024年第4期13卷 1864-1876页

作者： Meijing Zhang Gaoshuai Zhang Xiangxing Meng xinxin Wang Jiao Xie Shaoshu Wang Biao Wang Jilite Wang Suwen Liu Qun Huang xu Yang Jing Li Hao Wang State Key Laboratory of Food Nutrition and Safety Tianjin University of Science and Technology(TUST)Tianjin 300457China Key Laboratory of Environmental Pollution Monitoring and Disease Control Ministry of EducationGuizhou Medical UniversityGuiyang 550025China College of Chemical Engineering and Materials Science Tianjin University of Science and Technology(TUST)Tianjin 300457China Department of Agriculture Hetao CollegeBayannur 015000China College of Food Science&Technology Hebei Normal University of Science and TechnologyQinhuangdao 066004China National Center of Supervision and Inspection for Processed Food Quality Tianjin Institute for Food Safety Inspection TechnologyTianjin 300457China

Hyperoside and quercetin are similar in molecular *** this study,the antioxidant regulatory targets of hyperoside and quercetin are mainly in the nuclear factor(erythroid-2-derived)-related factor 2(Nrf2)pathway predicted by network *** the antioxidant effect and mechanism of hyperoside and quercetin were measured and compared in H_(2)O_(2)-induced Hep G2 cells and Caenorhabditis *** findings indicated that quercetin was more effective than hyperoside in reducing oxidative damage,which was proved by improved cell viability,decreased reactive oxygen species(ROS)production,decreased cellular apoptosis,and alleviated mitochondrial *** addition,quercetin was more efficient than hyperoside in enhancing the expression of Nrf2-associated m RNAs,increasing the activities of superoxide dismutase(SOD),glutathione peroxidase(GSH-Px),and catalase(CAT),and reducing the cellular malondialdehyde(MDA)*** was superior to hyperoside in prolonging the lifespan of worms,decreasing the accumulation of lipofuscin,inhibiting ROS production,and increasing the proportion of skn-1 in the *** the Nrf2 inhibitor ML385,we verified that quercetin and hyperoside primarily protected the cells against oxidative damage via the Nrf2 signalling ***,molecular docking and dynamics simulations demonstrated that the quercetin-Kelch-like ECH-associated protein 1(Keap1)complex was more stable than the hyperoside-Keap1 *** stable structure of the complex might hinder the binding of Nrf2 and Keap1 to release Nrf2 and facilitate its entry into the nucleus to play an antioxidant ***,quercetin had a better antioxidant than hyperoside.

关键词： Hyperoside Quercetin HepG2 cell Oxidative damage Nrf2 signalling pathway

平台经济发展下政府职能的优化与企业边界重塑

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中国流通经济 2024年第4期38卷 117-126页

作者：牛志伟刘肖楠许晨曦浙江工商大学经济学院浙江杭州310035 首都经济贸易大学会计学院北京市100070 中国人民大学商学院北京市100872

平台经济催生新的商业模式和价值链,同时也改变传统的企业边界和政府职能的定义。基于企业边界理论,对企业边界的影响因素进行分析,发现传统理论中强调的成本、专用性等因素可能不再是唯一或主要的影响因素;在数字经济条件下,新因素是... 详细信息

平台经济催生新的商业模式和价值链,同时也改变传统的企业边界和政府职能的定义。基于企业边界理论,对企业边界的影响因素进行分析,发现传统理论中强调的成本、专用性等因素可能不再是唯一或主要的影响因素;在数字经济条件下,新因素是由于数字的重要性而产生的权力因素。政府作为国家行政机关,拥有执法权,依法对国家和社会公共事务进行管理,是公共行政的本质表现。因此,基于政府职能理论,对政府的职能及其影响进行分析,并探讨平台经济在重塑企业边界和优化政府职能方面的中介作用,提出“政府利用平台影响企业边界,企业通过平台优化政府职能”的双向互动路径,为研究政企关系提供新的研究范式。研究表明,政府利用平台,实现与企业的信息交流,提高监管规范,促进合作协同,优化资源配置效率和公共服务水平,进而影响企业边界;企业通过平台实现跨界经营与异业合作,促进创新竞争,实现资产虚拟化和共享化,进行数据驱动经营和个性化服务,促进价格竞争与服务优化,进而优化政府职能。因此,政府应积极利用平台经济的优势,鼓励企业成立或加入平台,积极开展平台化转型,支持平台经济的发展和监管,维护市场秩序,保护消费者权益,支持创新发展,更好履行政府义务、实现政府职能。

关键词：企业边界政府职能平台经济中介作用

草氨酸钠通过抑制肺泡Ⅱ型上皮细胞衰老减轻小鼠矽肺纤维化

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环境与职业医学 2024年第7期41卷 760-767+779页

作者：刘文静毛娜李雅倩高学敏魏中秋朱莹徐洪靳馥宇华北理工大学公共卫生学院华北理工大学基础医学院华北理工大学医学部

[背景]肺泡Ⅱ型上皮细胞衰老是矽肺纤维化进展的重要驱动因素，草氨酸钠对肺泡Ⅱ型上皮细胞衰老的调节作用尚不清楚。[目的]探讨乳酸脱氢酶抑制剂草氨酸钠是否可通过抑制肺泡Ⅱ型上皮细胞衰老减轻小鼠矽肺纤维化。[方法]本研究分为体内... 详细信息

[背景]肺泡Ⅱ型上皮细胞衰老是矽肺纤维化进展的重要驱动因素，草氨酸钠对肺泡Ⅱ型上皮细胞衰老的调节作用尚不清楚。[目的]探讨乳酸脱氢酶抑制剂草氨酸钠是否可通过抑制肺泡Ⅱ型上皮细胞衰老减轻小鼠矽肺纤维化。[方法]本研究分为体内实验和体外实验两部分。体内研究中将40只SPF级雄性C57BL/6J随机分为4组，每组10只，实验分组为对照组、矽肺模型组、草氨酸钠低剂量治疗组、草氨酸钠高剂量治疗组。采用一次性气管灌注SiO2悬浊液50μL(100 mg·mL-1)制备矽肺小鼠模型；采用腹腔注射草氨酸钠100μL(225 mmol·L-1和1 125 mmol·L-1)制备草氨酸钠治疗模型。体外研究中采用SiO2诱导MLE-12小鼠肺泡Ⅱ型上皮细胞，实验分组为（1）不同浓度SiO2诱导组：对照组、50μg·mL-1SiO2组、100μg·mL-1SiO2组和200μg·mL-1SiO2组；（2）草氨酸钠治疗组：对照组、SiO2组(100μg·mL-1)、草氨酸钠低剂量(25 mmol·L-1)治疗组和草氨酸钠高剂量(50 mmol·L-1)治疗组。采用苏木素-伊红（HE）染色观察肺组织病理学形态；天狼星红染色观察肺组织胶原蛋白沉积；采用免疫荧光染色观察表面活性蛋白C前体（Pro-SPC）和β-半乳糖苷酶（β-galactosidase）的阳性共表达；采用免疫荧光染色观察MLE-12细胞β-galactosidase的阳性表达；采用免疫印迹法检测I型胶原（CoL I）、纤维连接蛋白1（FN1）、己糖激酶2（HK2）、肌肉丙酮酸激酶同工酶2（PKM2）、乳酸脱氢酶A（LDHA）、磷酸化毛细血管扩张性共济失调（p-ATR）、细胞周期蛋白依靠性激酶抑制剂p21和p16的蛋白表达水平。[结果]与对照组相比较，矽肺模型组和SiO2诱导的MLE-12细胞中，HK2、PKM2、LDHA、p-ATR、p21和p16的蛋白表达水平均上调（P <0.05）。体内研究显示，与对照组相比较，矽肺模型组中，矽结节面积，胶原蛋白沉积面积，β-galactosidase阳性细胞数占比，CoL I、FN1、LDHA、p-ATR、p21和p16的蛋白表达水平均上调（P <0.05）；与矽肺模型组相比较，草氨酸钠治疗组中矽结节面积，胶原蛋白沉积面积，β-galactosidase阳性细胞数占比，CoL I、FN1、LDHA、p-ATR、p21和p16的蛋白表达水平均下调，且草氨酸钠高剂量治疗组效果优于草氨酸钠低剂量治疗组（P <0.05）。体外研究显示，与对照组相比较，SiO2诱导组中，β-galactosidase阳性细胞数占比、p-ATR、p21和p16的蛋白表达水平均上调（P <0.05）；与SiO2组相比较，草氨酸钠治疗组中β-galactosidase阳性细胞数占比、LDHA、p-ATR、p21和p16的蛋白表达水平均下调，且草氨酸钠高剂量治疗组效果优于草氨酸钠低剂量治疗组（P <0.05）。[结论]乳酸脱氢酶抑制剂草氨酸钠可通过抑制肺泡Ⅱ型上皮细胞衰老以减轻小鼠矽肺纤维化。

关键词：草氨酸钠肺泡Ⅱ型上皮细胞矽肺衰老 β-半乳糖苷酶

Low friction under ultrahigh contact pressure enabled by self-assembled fluorinated azobenzene layers

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Friction 2024年第7期12卷 1434-1448页

作者： Dandan xuE Zhi xu Linyuan GUO Wendi LUO Liran MA Yu TIAN Ming MA Qingdao ZENG Ke DENG Wenjing ZHANG Yichun XIA Shizhu WEN Jianbin LUO State Key Laboratory of Tribology in Advanced Equipment Tsinghua UniversityBeijing 100084China National Center for Nanoscience and Technology Beijing 100190China

Extensive efforts have been made to pursue a low-friction state with promising applications in many fields,such as mechanical and biomedical *** which,the load capacity of the low-friction state has been considered to be crucial for industrial ***,we report a low friction under ultrahigh contact pressure by building a novel self-assembled fluorinated azobenzene layer on an atomically smooth highly-oriented pyrolytic graphite(HOPG)*** friction coefficients could be as low as 0.0005 or even lower under a contact pressure of up to 4 *** demonstrates that the low friction under ultrahigh contact pressure is attributed to molecular *** fluorination leads to effective and robust lubrication between the tip and the self-assembled layer and enhances tighter rigidity which can reduce the stress concentration in the substrate,which was verified by density functional theory(DFT)and molecular dynamics(MD)*** work provides a new approach to avoid the failure of ultralow friction coefficient under relatively high contact pressure,which has promising potential application value in the future.

关键词： ultrahigh contact pressure self-assembled layer fluorination robust lubrication