In this paper, the effect of thermal-induced phase transformation in Inconel 625 alloy on corrosion behavior in high-temperature molten NaCl-KCl-MgCl2 salt was investigated. The results showed that the corrosion behavior was effectively influenced by the redistribution of Cr induced by the thermal-induced phase transformation. The Cr-rich chain carbides at the grain boundary and the Cr-rich regions between the needle-like delta phases formed the continuous Cr-rich channels from the grain boundary to the grain interior, which aggravated the inhomogeneous distribution of Cr and promoted the corrosion process. On this basis, the corrosion process occurred with the selective dissolution of the Cr element and invasion of Mg and O, which led to surface corrosion products composed of MgO/MgCr2O4 and subsurface corrosion holes. The research results of this paper are useful for understanding the role of phase transformation in superalloys during high-temperature molten salt corrosion.

The nucleation, growth, and degeneration behaviors of MC carbides in the Ni-12Mo-7Cr-2Ti-0.06C alloy during the long-term thermal exposure at 650 degrees C - 850 degrees C have been investigated. Two kinds of MC carbides, namely the stacking-fault-precipitate (SFP) type ones and the flake-like ones, have been observed in the exposed specimens. The SFP-type MC carbides possess a semi-coherent interface of (111)(MC)//(111)(gamma) with the matrix by the cube-on-cube orientation relationship (OR), which show the excellent thermal stability at 650 degrees C and the rapid coarsening and degeneration at the higher temperature. The flake-like MC carbides possess a semi-coherent interface of (11 (1) over bar)(MC)//(002)(gamma) with the matrix by the rotated OR, which play a dominant role at the initial stage of exposure at 850 degrees C. All MC carbides contain Mo, Ti and a small number of Cr and Ni. According to the first principle calculation results, the doping of Mo can facilitate the nucleation of MC carbides by decreasing the chemical interface energy. Based on crystallographic analyses, the evolution mechanisms of MC carbides were discussed. At the initial stage, the dislocations form around the primary MC carbides and the growing secondary ones. The Ti segregation can lower the stacking fault energy at dislocations and promote the dissociation of dislocation to form the clean stacking faults (SFs). Then, the expansion of SFs and the formation of MC carbides go on simultaneously as described by the Silcock-Tunstall model. The dense distribution of MC carbides on SFs aggravates the rapid coarsening and degeneration. The flake-like MC carbides tend to deviate from the strict rotated OR to eliminate the lattice mismatching during the coarsening process. In this premise, the predicted well-matched interface should be along (11 (1) over bar)(gamma) and (111)(gamma) planes and possess the stepped morphology with a deviation angle of similar to 9 degrees from the (11 (1) over bar)(gamma) planes, which well agrees with the experiment observations.

Oxidative stress is the redox imbalance state of organisms that involves in a variety of biological processes of diseases. Limonium aureum (L.) Hill. is an excellent wild plant resource in northern China, which has potential application value for treating oxidative stress. However, there are few studies that focused on the antioxidant effect and related mechanism of L. aureum. Thus, the present study combining systematic network pharmacology and molecular biology aimed to investigate the antioxidant effects of L. aureum and explore its underlying anti-oxidation mechanisms. First, the antioxidant activity of L. aureum extracts was confirmed by in vitro and intracellular antioxidant assays. Then, a total of 11 bioactive compounds, 102 predicted targets, and 70 antioxidant-related targets were obtained from open source databases. For elucidating the molecular mechanisms of L. aureum, the PPI network and integrated visualization network based on bioinformatics assays were constructed to preliminarily understand the active compounds and related targets. The subsequent enrichment analysis results showed that L. aureum mainly affect the biological processes involving oxidation-reduction process, response to drug, etc., and the interference with these biological processes might be due to the simultaneous influence on multiple signaling pathways, including the HIF-1 and ERBB signaling pathways. Moreover, the mRNA levels of predicted hub genes were measured by qRT-PCR to verify the regulatory effect of L. aureum on them. Collectively, this finding lays a foundation for further elucidating the anti-oxidative damage mechanism of L. aureum and promotes the development of therapeutic drugs for oxidative stress.

本试验以反硝化细菌和酵母菌为基础菌种,按一定比例制得复合微生物菌剂,在盐碱地进行土壤改良试验,检测结果表明,使用复合微生物菌剂后,土壤中总盐含量及pH值均有明显降低;土壤中氮含量、有机质含量、微生物菌落数等有明显上升;另外,由于微生物生长繁殖所必须磷、钾等元素,其含量有所降低.本试验证明此种复合微生物菌剂对降低土壤盐碱度、增加土壤肥力具有明显作用,为盐碱地改良提供参考.

Swainsonine (SW) is a substance with both animal neurotoxicity and natural anticancer activity produced by the metabolism of endophytic fungus Alternaria section Undifilum oxytropis of locoweed. This paper produced SW by fermentation of the endophytic fungus A. oxytropis of locoweed and obtained the optimal ultrasonic-assisted extraction process of SW by the response surface methodology. Meanwhile, four mutant strains with significant and stable SW-producing properties were screened out after the mutagenesis of A. oxytropis by heavy-ion irradiation. Of these, three were high-yielding stains and one was a low-yielding strain. In addition, through the analysis of metabolomics studies, it was speculated that the different SW production performance of the mutant might be related to the biosynthesis and utilization of L-lysine, L-2-aminoadipate-6-semialdehyde, etc. These results laid the foundation for the expansion of SW production, artificial construction of low-toxic locoweed and clarification of the SW biosynthesis pathway in A. oxytropis.

The catastrophic intergranular cracking had been observed in the low-Cr alloy components in the primary loop of molten salt reactor. Such cracking was related to the coupling effect of fission product tellurium (Te) and fuel salts, whose atomic-level mechanism has puzzled researchers for many decades. In this work, combining multi-scale characterization techniques and theoretical calculations, it was found that Te segregation at grain boundaries can reduce the diffusion barrier of active element along grain boundaries and cause the nano-voids, which further evolve into the intergranular cracking.

为进一步验证常山散的抗球虫效果以及效力试验用虫株的敏感性,在百球清为对照的基础上,对效力试验用虫株再次以三字球虫粉为对照进行试验.试验分为常山散组、三字球虫粉组、攻虫不给药组和不攻虫不给药组,分别从攻虫后24 h(球虫入侵)和72 h(裂殖发育)开始给药,攻虫后168 h停止给药,观察药物对鸡临床症状、血便排出、盲肠病变的影响,计算抗球虫指数.结果显示,常山散和三字球虫粉给药后鸡精神状态和饮食欲基本恢复正常,血便排出和盲肠病变明显减轻或消失.攻虫后24,72 h给药常山散的抗球虫指数分别为163.04和161.67,三字球虫粉的抗球虫指数分别为174.26和170.71,均明显高于攻虫不给药组(84.78和81.13);2种药物攻虫后24 h给药抗球虫指数高于攻虫后72 h给药.结果表明,常山散具有较好的抗球虫效果,早期给药治疗效果更好,试验所用的柔嫩艾美耳球虫(广东株)药物敏感性较好.

本研究旨在探索12C6+离子辐照茶树精油后,茶树精油活性成份的变化及其对口蹄疫病毒(foot-and-mouth disease virus,FMDV)的杀灭效果.采用50、100、150、200 Gy的12C6+离子束辐照茶树精油后,利用气相色谱-质谱联用仪(gas chromatography-mass spectrometer,GC-MS)法和红外色谱法分析辐照前后茶树精油主要成分变化及其质量沉积效应;检测茶树精油中松油烯-4-醇、1,8-桉叶素含量变化;将辐照前后茶树精油原液以及1 ∶ 2、1 ∶ 4辐照后稀释的精油注射50日龄成年鼠检测其临床用药的安全性;将稀释成1 ∶ 2、1 ∶ 4、1 ∶ 6、1 ∶ 8的辐照后茶树精油分别与等量的1∶ 500的O-FMDV强毒充分混匀,皮下注射4～5日龄乳鼠,连续观察7 d,观察小鼠有无FMDV感染症状.试验结果表明,以100 Gy的12C6+离子束辐照茶树精油后,松油烯-4-醇含量由37.90％升高到39.03％,1,8-桉叶素含量无明显变化,羟基化合物含量明显增高;辐照前后茶树精油原液以及稀释后精油注射未见不良反应,辐照后茶树精油临床用药安全;乳鼠感染混有不同浓度的O-FMDV后,1 ∶ 2、1 ∶ 4稀释倍数的茶树精油组感染O-FMDV的乳鼠未出现死亡,注射部位未见炎症、坏死等,阳性对照组全部死亡.结果表明,12C6+离子束辐照茶树精油最佳剂量为100 Gy,在乳鼠体内抗O-FMDV效果的最大稀释度为1 ∶ 4,12C6+离子束辐照可以提高茶树精油对FMDV的杀灭效果.

The fruits of Ailanthus altissima Swingle (AS) possess a variety of pharmacological activities. Its antioxidant activity and the potential mode of action have not yet been investigated. In in vitro studies, AS revealed the strong reducing power and DPPH scavenging effect, but hydroxyl radical scavenging activity and ferrous ions-chelating ability were not strong. Meanwhile, the oxidative stress RAW264.7 cell injury model was established, the low and medium-doses of AS showed significant protective effects on the viability of H2O2-treated cells by CCK-8 method. Besides, three doses of AS all increased the activities of SOD, CAT, and GSH-Px and decreased the MDA level compared with the H2O2 group, suggesting it significantly relieved oxidative stress of cells. The active ingredients and related targets of AS were collected by HERB and Swiss Target Prediction database, the common targets of drugs and diseases database were conducted by GeneCards database platform and the Venny platform. We screened the core targets of AS like threonine kinase1 (AKT1), mitogen-activated protein kinase 1 (MAPK1), sirtuin-1 (SIRT1), mechanistic target of rapamycin kinase (MTOR) by STRING database, and the key pathways involved PI3K-AKT and FoxO signaling pathway by KEGG pathway enrichment analysis. Besides, qRT-PCR revealed AS preconditioning significantly up-regulated the expression level of AKT1, SIRT1, MAPK1, and MTOR in model cells, and the effect was related to the regulation of FoxO and PI3K/AKT signaling pathway. In summary, AS showed significant antioxidant activity and its potential mechanism was regulating FoxO and PI3K/AKT signaling pathway.

The effects of W/Mo ratio on the microstructures of as-cast Nb-modified Hastelloy N alloys have been investigated systematically in this study. It was found that the dendritic morphologies are independent on W/Mo ratio, but the microsegregation behaviors and the primary precipitates in the interdendritic regions are greatly affected. The electron probe microanalyses revealed that W segregates to dendrite core regions, while Mo, Cr, Nb and C to the interdendritic regions. The microsegregation of elements becomes more severe with the W/Mo ratio increasing. The primary precipitates in the interdendritic regions were identified as MC/γ eutectic phases in all alloys, and the MC carbide lamellae in the eutectic phases can be categorized into two types, namely thin (Nb, Mo)C ones in the three Mo-contained alloys and thick NbC ones in the Mo-free alloy. The sizes of MC/γ eutectic phases change with the W/Mo ratio in the same manner as the solidification temperature region, and their number densities gradually increase with the W/Mo ratio increasing. Based on the thermodynamic calculations and solidification theory, the influencing mechanism of W/Mo ratio on the microstructures of as-cast Nb-modified Hastelloy N alloys was briefly discussed.

为红茂草药物的进一步开发和利用,本试验以甘肃平凉地区野生药用植物红茂草为研究对象,采用水蒸气提取、蒸馏萃取(SDE)提取、超临界CO2萃取等3种方法,分别提取红茂草中的精油成分;以GC-MS对其精油进行化学成分分析,并将超临界CO2萃取的红茂草精油采用平板菌落计数法对金黄色葡萄球菌、大肠杆菌和绿脓杆菌进行抑菌活性测定.结果 显示,三种提取方法中,水蒸气提取法和蒸馏萃取提取法所得精油为橙黄色,有浑浊,超临界CO2萃取法所得精油为淡黄色,澄清液体.3种方法所得精油均含有24种共同成分,以超临界CO2萃取法最优,其提取率为2.1220％,水蒸气提取法最低,提取率为1.7870％;将超临界CO2萃取的红茂草精油作用于3种供试菌,测定其最小抑菌浓度(MIC)分别为:金黄色葡萄球菌0.2500 g/mL、大肠杆菌0.3000 g/mL,绿脓杆菌0.2600 g/mL,抑菌效果显著.研究结果表明,超临界CO2萃取是提取红茂草精油的最佳方法,通过超临界CO2萃取法提取的红茂草精油对金黄色葡萄球菌、大肠杆菌和绿脓杆菌具有良好的抑菌效果.

采用滤纸片法、肉汤稀释法和点种法研究3种植物精油及其化学成分对5种病原菌的体外抑菌活性.用气相色谱-质谱联用技术(gas chromatography-mass spectrometer,GC-MS)最佳分析条件对化学活性成分进行鉴定,用峰面积归一法测定各化合物在挥发油中的相对百分含量.结果表明:9.5％的牛至、香茅、丁香精油可将白色葡萄球菌、白色念珠菌全部杀灭;4.75％的牛至、香茅、丁香精油可将金黄色葡萄球菌全部杀灭;4.75％牛至、丁香精油可将大肠埃希菌全部杀灭,但香茅精油杀灭浓度相对较弱;3种精油对铜绿假单胞菌的杀灭浓度均大于9.5％;GC-MS结果显示,牛至精油中主要含有双戊烯(33.93％)、百里香酚(19.12％)、4-萜品醇(14.92％)、α-蒎烯(10.87％);丁香精油主要成分为丁香酚(86.54％),1-石竹烯(10.41％);香茅精油主要包括香茅醛(31.38％)、香叶醇(18.43％);植物精油具有广谱的抑菌活性.

为了建立青蒿的 SRAP 最佳扩增体系，并筛选出 SRAP 多态性引物，本研究以青蒿叶片 DNA 为模板，采用正交试验设计，以 Mg 2 + 、 dNTP Mix 、 Taq DNA 聚合酶、引物和 DNA 模板 5 种因素 5 个水平，对青蒿 SRAP 反应体系进行研究。结果表明，青蒿 SRAP-PCR 最佳反应体系为：引物 0.6 μ mol / L 、 Mg 2 + 2.0 mmol / L 、模板 DNA 5.1 ng 、 Taq DNA 聚合酶 2.0 U 、 dNTPs 0.25 mmol / L ，总体积为 25 μ L 。各因素对扩增反应均有不同影响，其中引物浓度的影响最大， dNTPs 的影响最小。运用该体系对不同种质资源的青蒿进行验证，证明该体系稳定可靠，并在 30 个引物组合中筛选出了 25 对扩增条带清晰，多态性丰富的引物组合。这一结论为今后利用 SRAP 标记技术进行青蒿分子遗传学研究提供了科学依据。

目的:建立菘蓝新品种"中青一号"的质量标准.方法:采用薄层色谱法(thin layer chromato-graphy,TLC)进行定性鉴别;采用反向高效液相色谱法(RP-high performance liquid chromatography,RP-HPLC)测定(R,S)-告依春的含量;色谱柱:Waters XSELECT SSH-C18(4.6mmx 150mm,5.0 μm),流动相:乙腈-水(15:85),流速:1.0mL/min,检测波长:245nm.结果:TLC可检出特征斑点,阴性对照无干扰;RP-HPLC条件下(R,S)-告依春在0.058～1.740μg(r=0.9996)范围内呈良好线性关系,重复性及加样回收率的相对标准误差均小于2％.结论:所建立的定性定量鉴别方法准确性、专属性强,重现性有较好体现,且该方法快速简便,可作为中青一号的质量控制标准.

为评价常山散对靶动物鸡的安全性,将80只岭南黄羽肉鸡随机分为4组,每组20只.常山散按推荐剂量的1倍(0.1 g/kg)、3倍(0.3 g/kg)和5倍(0.5 g/kg)进行给药,连用7d,同时设置空白对照组.试验期间每日观察记录鸡的精神、采食、饮水、粪便等外观表现,测定给药7d后和休药7d后血常规指标、血液生化指标、脏器系数,并进行肝肾病理学观察.结果 显示,常山散各剂量组鸡的临床状态、饮食和粪便均正常.与空白对照组比较,给药7d后,常山散1倍和3倍剂量组鸡血常规指标、血液生化指标和脏器系数均无显著性变化(P＞0.05),解剖各脏器未发现肉眼可见病变;5倍剂量组的肝和肾出现轻度肿胀和淤血,肝系数显著降低(P＜0.05).休药7d后,除5倍剂量组鸡丙氨酸氨基转移酶显著降低外(P＜0.05),其他各项指标均无显著性变化(P＞0.05).空白对照组鸡临床表现和各项检测指标均正常.结果 表明,常山散按1倍和3倍推荐剂量给药对靶动物鸡无毒副作用,临床使用安全.

The effects of Nb addition on the microstructures of Ni-12Mo-7Cr based superalloy have been systematically investigated in this study. If no Nb addition, the granular and thin rod-like M2C carbides distribute in the matrix and at the grain boundaries. In the alloy with 1 wt % Nb, the needle-like Mo-riched MC carbides and the granular Nb-containing M2C carbides form in the matrix and at the grain boundaries respectively. The needle-like MC carbides were found to grow along the {1 0 0} planes of the matrix and possess a cube-on-cube orientation relationship (OR) with the matrix. In the case of the alloy with 4 wt % Nb, the thick rod-like NbC carbides with few other metal elements were found to form in the matrix, which grow along the {1 1 1} planes and possess a twin-like OR with the matrix with a small-angle deviation. Based on the interface energy analyses, the morphology differences between MC and NbC carbides were found to result from their different ORs and interface structures. (c) 2020 Elsevier B.V. All rights reserved.

提高机体免疫力是中药抗球虫的重要途径之一.中药可以刺激鸡免疫器官的发育,增强免疫细胞活性、激活免疫细胞的增值,促进相关免疫分子的分泌等,从而达到抗球虫作用.对近年文献报道的中药抗球虫免疫学研究进行综述,旨在为中药科学防治鸡球虫病和抗球虫机理的阐明提供参考.

益生菌对于平衡动物胃肠道菌群有着重要影响,其在生长繁殖过程中会产生多种活性酶及其他代谢产物.中药经益生菌发酵后,其有效活性成分得到充分利用的同时还可促进动物生长、提高免疫力,具有无抗、低残留、绿色安全等优点,是替代抗生素的理想饲料添加剂,在畜牧业中的发展前景十分广阔.论文从益生菌发酵中药的作用机理、种类、特征、菌种选择及条件优化等方面分别进行了阐述,为研发新型饲料添加剂提供一定的参考.

为了研究肉桂、山苍子、迷迭香植物精油化学成分及体外抑菌活性,采用滤纸片法测定抑菌圈直径,通过肉汤稀释法和点种法测定其最小抑菌浓度(MIC)、最小杀菌浓度(MBC),并通过气相-质谱法(GC-MS)测定各植物精油的成分及含量.结果显示,肉桂精油浓度在1.118％时就可将5种病原菌全部杀灭;山苍子精油浓度在4.75％时可将S.albus、S.aureus、E.coli、C.albians杀灭,而对P.aeruginosa的杀灭浓度大于9.5％;迷迭香精油在浓度9.5％可将S.albus、S.aureus、C.albicans杀灭,而对E.coli、P.aeruginosa的杀灭浓度大于9.5％.GC-MS结果显示,肉桂精油主要组分为肉桂醛(83.57％)、2'-甲氧基肉桂醛(5.96％),香豆素(2.90％);山苍子精油包括柠檬醛(21.45％)、双戊烯(21.88％)、(Z)-3,7-二甲基-2,6-辛二烯醛(20.96％);迷迭香精油主要含有α-蒎烯(24.09％)、桉树脑(25.81％)、左旋樟脑(25.09％)、异龙脑(9.28％).结果表明,3种植物精油具有广谱的抑菌活性,能够为开发新型、绿色、安全、高效的抗生素替代品提供理论依据.

以茶树油中1,8-桉叶素和松油烯-4-醇的相对含量为指标,借助刮膜式分子蒸馏技术,在单因素试验基础上进行正交试验,并通过气相色谱法测定相对含量,得出在蒸馏温度38℃,蒸馏压力110 Pa,进料速率2.5 mL/min,刮膜转速450 r/min条件下,轻组分中1,8-桉叶素相对含量由2.674％提升至5.33％;在蒸馏温度38℃,蒸馏压力110 Pa,进料速率3 mL/min,刮膜转速450 r/min,重组分中松油烯-4-醇的相对含量由43.416％提升至65.17％.运用该技术,富集效果明显,能为挥发油类物质的工业化生产提供参考价值.