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Immobilization of

Xiaokai SONG,Zhongyi JIANG,Lin LI,Hong WU

《化学科学与工程前沿(英文)》 2014年 第8卷 第3期   页码 353-361 doi: 10.1007/s11705-014-1421-2

摘要: Mesoporous silica particles were prepared for efficient immobilization of the -glucuronidase (GUS) through a biomimetic mineralization process, in which the solution containing lysozyme and GUS were added into the prehydrolyzed tetraethoxysilane (TEOS) solution. The silica particles were formed in a way of biomineralization under the catalysis of lysozyme and GUS was immobilized into the silica particles simultaneously during the precipitation process. The average diameter of the silica particles is about 200 nm with a pore size of about 4 nm. All the enzyme molecules are tightly entrapped inside the biosilica nanoparticles without any leaching even under a high ionic strength condition. The immobilized GUS exhibits significantly higher thermal and pH stability as well as the storage and recycling stability compared with GUS in free form. No loss in the enzyme activity of the immobilized GUS was found after 30-day’s storage, and the initial activity could be well retained after 12 repeated cycles.

关键词: storage and recycling stability     silica nanoparticles     biocatalysis     biomimetic synthesis     β-glucuronidase encapsulation    

Enhanced production of

Shen Huang,Xudong Feng,Chun Li

《化学科学与工程前沿(英文)》 2015年 第9卷 第4期   页码 501-510 doi: 10.1007/s11705-015-1544-0

摘要: -Glucuronidase from Li-3 (PGUS) can efficiently hydrolyze glycyrrhizin into the more valuable glycyrrhetic acid monoglucuronide. However, a low productivity of PGUS and the lack of an effective separation strategy have significantly limited its industrial applications. Therefore, the production of PGUS has been improved by optimizing both the fermentation and purification strategies. A two-stage fermentation strategy was developed where PGUS was first grown with glucose and then PGUS was produced in the presence of glycyrrhizin as an inducer. By using this strategy, the biomass was increased 1.5 times and the PGUS activity increased 5.4 times compared to that when glycyrrhizin was used as the sole carbon source. The amount of PGUS produced was increased another 16.6% when the fermentation was expanded to a 15-L fermenter. An effective protocol was also established to purify the PGUS using a sequential combination of hydrophobic, strong anion-exchange and gel filtration chromatography. This protocol had a recovery yield of 6% and gave PGUS that was 39 times purer than the crude PGUS. The purified PGUS had a specific activity of 350 U·mg .

关键词: β-glucuronidase     glycyrrhetic acid monoglucuronide     cell disruption     purification     chromatography    

Construction of a CaHPO4-PGUS1 hybrid nanoflower through protein-inorganic self-assembly, and its application in glycyrrhetinic acid 3-O-mono-β-D-glucuronide preparation

Tian Jiang, Yuhui Hou, Tengjiang Zhang, Xudong Feng, Chun Li

《化学科学与工程前沿(英文)》 2019年 第13卷 第3期   页码 554-562 doi: 10.1007/s11705-019-1834-z

摘要: Glycyrrhetinic acid 3- -mono- -D-glucuronide (GAMG), an important pharmaceutical intermediate and functional sweetener, has broad applications in the food and medical industries. A green and cost-effective method for its preparation is highly desired. Using site-directed mutagenesis, we previously obtained a variant of -glucuronidase from Li-3 (PGUS1), which can specifically transform glycyrrhizin (GL) into GAMG. In this study, a facile method was established to prepare a CaHPO -PGUS1 hybrid nanoflower for enzyme immobilization, based on protein-inorganic hybrid self-assembly. Under optimal conditions, 1.2 mg of a CaHPO -PGUS1 hybrid nanoflower precipitate with 71.2% immobilization efficiency, 35.60 mg∙g loading capacity, and 118% relative activity was obtained. Confocal laser scanning microscope and scanning electron microscope results showed that the enzyme was encapsulated in the CaHPO -PGUS1 hybrid nanoflower. Moreover, the thermostability of the CaHPO -PGUS1 hybrid nanoflower at 55°C was improved, and its half-life increased by 1.3 folds. Additionally, the CaHPO -PGUS1 hybrid nanoflower was used for the preparation of GAMG through GL hydrolysis, with the conversion rate of 92% in 8 h, and after eight consecutive runs, it had 60% of its original activity.

关键词: β-glucuronidase     enzyme-inorganic hybrid nanoflower     biotransformation     glycyrrhizin     glycyrrtinic acid 3-O-mono-β-D-glucuronide    

Enzyme@bismuth-ellagic acid: a versatile platform for enzyme immobilization with enhanced acid-base stability

《化学科学与工程前沿(英文)》 2023年 第17卷 第6期   页码 784-794 doi: 10.1007/s11705-022-2278-4

摘要: In situ encapsulation is an effective way to synthesize enzyme@metal–organic framework biocatalysts; however, it is limited by the conditions of metal–organic framework synthesis and its acid-base stability. Herein, a biocatalytic platform with improved acid-base stability was constructed via a one-pot method using bismuth-ellagic acid as the carrier. Bismuth-ellagic acid is a green phenol-based metal–organic framework whose organic precursor is extracted from natural plants. After encapsulation, the stability, especially the acid-base stability, of amyloglucosidases@bismuth-ellagic acid was enhanced, which remained stable over a wide pH range (2–12) and achieved multiple recycling. By selecting a suitable buffer, bismuth-ellagic acid can encapsulate different types of enzymes and enable interactions between the encapsulated enzymes and cofactors, as well as between multiple enzymes. The green precursor, simple and convenient preparation process provided a versatile strategy for enzymes encapsulation.

关键词: bismuth-ellagic acid     in situ encapsulation     enzyme@MOF biocomposites    

Development of a new method for RMR and Q classification method to optimize support system in tunneling

Asghar RAHMATI,Lohrasb FARAMARZI,Manouchehr SANEI

《结构与土木工程前沿(英文)》 2014年 第8卷 第4期   页码 448-455 doi: 10.1007/s11709-014-0262-x

摘要: Rock mass classification system is very suitable for various engineering design and stability analysis. classification method is confirmed by Japan Highway Public Corporation that this method can figure out either strength or deformability of rock mass, further appropriating the amount of rock bolts, thickness of shotcrete, and size of pitch of steel ribs just after the blasting procedure. Based on these advantages of method, in this study, according to data of five deep and long tunnels in Iran, two equations for estimating the value of method from and classification systems were developed. These equations as a new method were able to optimize the support system for and classification systems. From classification and its application in these case studies, it is pointed out that the method for the design of support systems in underground working is more reliable than the and classification systems.

关键词: JH classification     Q and RMR classification     new method    

抗白粉病基因 <i>Pm40i> 在我国“后 <i>Pm21i> 时代”小麦育种中的重要作用 Perspective

唐圣雯,胡玉亭,钟胜福,罗培高

《工程(英文)》 2018年 第4卷 第4期   页码 500-506 doi: 10.1016/j.eng.2018.06.004

摘要:

由小麦白粉菌[Blumeria graminis f. sp. triticiBgt)] 引起的小麦白粉病是一种重要的小麦叶部病害,对小麦的产量产生很大的影响。20 世纪80 年代,通过簇毛麦(Heuchera villosa)的6VS 染色体与小麦6AL 染色体易位将抗白粉病基因Pm21 转移到普通小麦中。最近,在一些地方发现了对Pm21 有毒的Bgt,虽然这些菌株的病理学特性还有待研究,但这一现象提醒小麦育种者应注意应用Pm21 的风险。来源于普通小麦与中间偃麦草(Thinopyrum intermedium)杂种后代的抗白粉病基因Pm40,被定位在小麦7BS 染色体上,对Bgt 具有广谱和持久的抗性。通过细胞学研究,并未在Pm40 的载体品种中发现大片段外缘染色体。过去几年的研究发现,Pm40 的载体品种具有优良的农艺性状。因此,我们相信在未来的育种工程中,Pm40 将会在Pm21 的抗性被克服之后起巨大的作用。另外,Pm21 Pm40 都来源于外缘物种,这暗示着外源基因的抗性可能比小麦本身的基因更为持久和有效。

关键词: 小麦     白粉病     <i>Pm21i>     <i>Pm40i>     外源基因     内源抗性    

NiFeRuO<i>xi> nanosheets on Ni foam as an electrocatalyst for efficient

《化学科学与工程前沿(英文)》 2023年 第17卷 第11期   页码 1698-1706 doi: 10.1007/s11705-023-2334-8

摘要: The electrocatalyst NiFeRuOx/NF, comprised of NiFeRuOx nanosheets grown on Ni foam, was synthesized using a hydrothermal process followed by thermal annealing. NiFeRuOx/NF displays high electrocatalytic activity and stability for overall alkaline seawater splitting: 98 mV@ 10 mA∙cm−2 in hydrogen evolution reaction, 318 mV@ 50 mA∙cm−2 in oxygen evolution reaction, and a cell voltage of 1.53 V@ 10 mA∙cm−2, as well as 20 h of durability. A solar-driven system containing such a bifunctional NiFeRuOx/NF has an almost 100% Faradaic efficiency. The NiFeRuOx coating around Ni foam is an anti-corrosion layer and also a critical factor for enhancement of bifunctional performances.

关键词: NiFeRuOx nanosheets     Ni foam     electrocatalysis     overall seawater splitting     solar-driven system    

2014—2016年食品动物源RE-<i>cmeABCi>阳性弯曲菌流行与耐药性现状 Article

刘德俊, 刘蔚雯, 李星, 姚红, 沈张奇, 汪洋, 沈建忠

《工程(英文)》 2020年 第6卷 第1期   页码 34-39 doi: 10.1016/j.eng.2019.10.013

摘要:

弯曲菌是引起人类胃肠炎的一类重要食源性致病菌。RE-CmeABC是近年来弯曲菌中新发现的一种增强型耐药外排泵,可介导对兽医和人医临床治疗弯曲菌感染的重要药物,如氟喹诺酮类、酰胺醇类、大环内酯类及四环素类等药物的高水平耐药,而目前尚未有对该外排泵的大范围流行病学调查。因此,本研究调查了2014—2016年连续三年间我国山东、上海和广东等三个重点养殖区食品动物源RE-cmeABC阳性弯曲菌的流行与耐药性现状。结果显示,在1088株弯曲菌(931株结肠弯曲菌与157株空肠弯曲菌)中共检测出122株(11.2%)RE-cmeABC阳性菌株,包括111株(70.7%)空肠弯曲菌与11株(1.2%)结肠弯曲菌,空肠弯曲菌中RE-cmeABC的阳性率显著高于结肠弯曲菌。111株RE-cmeABC阳性空肠弯曲菌与46株RE-cmeABC阴性空肠弯曲菌相比在氟苯尼考、克林霉素和红霉素的耐药率上具有显著差异(P < 0.05),而在环丙沙星、四环素和庆大霉素的耐药率上无显著差异。然而,携带RE-cmeABC的菌株可以使环丙沙星与四环素对弯曲菌的MIC值分布趋于更高水平范围。脉冲场凝胶电泳分型(PFGE)结果显示RE-cmeABC阳性菌株在上海和广东地区以水平传播为主,在山东地区以克隆传播为主;三株分离于上海和广东的阳性菌为同一克隆型,4株分离于上海和山东的阳性菌为同一克隆型。本研究表明RE-cmeABC已在我国食品动物源弯曲菌中广泛流行,对公共卫生安全具有潜在威胁。

关键词: RE- <i> cmeABC i>     弯曲菌     环丙沙星     氟苯尼考    

A highly efficient methodology for the preparation of

Yongxin Zhang, Shucheng Wang, Yaodong Huang

《化学科学与工程前沿(英文)》 2021年 第15卷 第3期   页码 679-686 doi: 10.1007/s11705-020-1979-9

摘要: A convenient and highly efficient method is described for the synthesis of -methoxycarbazole derivatives, including those with sterically demanding, benzannulated, or strongly electron-donating or -withdrawing substituents. Various -methoxycarbazole derivatives were directly prepared in good-to-moderate yields by the Pd (dba) CHCl /9,9-dimethyl-4,5-bis(diphenylphosphino)xanthene-catalyzed reactions of the corresponding dibromobiphenyl compounds and methoxya-mine. Based on this methodology, the first total synthesis of 3,3′-[oxybis(methylene)]bis(9-methoxy-9 -carbazole), an antimicrobial dimeric carbazole alkaloid previously isolated from the stem bark of , was achieved in 18% yield over seven steps from 1,2-dibromobenzene.

关键词: N-methoxyl carbazole     dimeric N-methoxyl carbazole     alkaloid     total synthesis     double N-arylation of methoxyamine    

通过<i> B i>位Ta置换对<i> AB i> O4型EuNbO4的热学和力学性质进行优化 Article

陈琳, 冯晶

《工程(英文)》 2020年 第6卷 第2期   页码 177-184 doi: 10.1016/j.eng.2019.12.006

摘要:

铁弹性的ABO4型RETaO4陶瓷和RENbO4陶瓷(RE表示稀土)是具有潜在应用价值的热障涂层(TBC)材料,研究人员正在对其进行大量研究。结果显示, RETaO4陶瓷的力学性质优于RENbO4陶瓷的力学性质。在本研究中,我们通过B位钽(Ta)置换对利用固相法(SSR)制备的EuNbO4陶瓷的热学和力学性质进行优化。我们使用X射线衍射(XRD)法和拉曼光谱技术对所制备的晶体结构进行确认,并利用扫描电子显微镜(SEM)对结构表面的微观形貌进行观察。结果表明,通过B位Ta置换可以有效提高EuNbO4陶瓷的杨氏模量和热膨胀系数(TEC),且其最大值分别为169 GPa和1.12×10−5 K−1(1200 ℃); EuNbO4陶瓷的热导率被降低至1.52 W·K–1·m–1(700 ℃),且材料的抗热辐射能力得到了改善。我们建立了声子热扩散系数与温度之间的关系,用以通过消除热辐射效应来确定声子本征热导率。研究结果表明,通过B位Ta置换能够有效优化EuNbO4的热学和力学性质,从而使得此种材料在将来可成为一种高温结构陶瓷材料。

关键词: 热障涂层,稀土铌酸盐,置换,热导率,热膨胀系数,杨氏模量    

Traces and echoes of <i>De Architecturai> by Marcus Vitruvius Pollio in the work of Xu Guangqi in 17th

Michela CIGOLA,Yibing FANG

《机械工程前沿(英文)》 2016年 第11卷 第1期   页码 3-11 doi: 10.1007/s11465-015-0359-5

摘要:

This study aims to investigate the role played by Xu Guangqi (1562–1633), minister of the Ming Dynasty, in the development of European scientific and technical knowledge in China between the 16th and 17th centuries by analyzing a book of Western technology that he wrote, namely, Taixi Shuifa (On Western Hydraulics). Several Western books related to machine knowledge are searched to trace the source of the illustrations in Taixi Shuifa. We found that Archimedes’ screw and Ctesibius’ machine, which are included in Vitruvius’ De Architectura volumes, also appear in the work of Xu Guangqi.

关键词: Vitruvius’ De Architectura     Xu Guangqi’s Taixi Shuifa     Jesuit missionaries     Italian Renaissance     drawing     representation    

Accounting for the uncertainties in the estimation of average shear wave velocity using – correlations

《结构与土木工程前沿(英文)》 2021年 第15卷 第5期   页码 1199-1208 doi: 10.1007/s11709-021-0749-1

摘要: Site-specific seismic hazard analysis is crucial for designing earthquake resistance structures, particularly in seismically active regions. Shear wave velocity ( V S) is a key parameter in such analysis, although the economy and other factors restrict its direct field measurement in many cases. Various V S–SPT– N correlations are routinely incorporated in seismic hazard analysis to estimate the value of V S. However, many uncertainties question the reliability of these estimated V S values. This paper comes up with a statistical approach to take care of such uncertainties involved in V S calculations. The measured SPT– N values from all the critical boreholes were converted into statistical parameters and passed through various correlations to estimate V S at different depths. The effect of different soil layers in the boreholes on the Vs estimation was also taken into account. Further, the average shear wave velocity of the top 30 m soil cover ( V S30) is estimated after accounting for various epistemic and aleatoric uncertainties. The scattering nature of the V S values estimated using different V SN correlations was reduced significantly with the application of the methodology. Study results further clearly demonstrated the potential of the approach to eliminate various uncertainties involved in the estimation of V S30 using general and soil-specific correlations.

关键词: uncertainties     V SN correlations     V S30     SPT data     statistical methodology    

<i>RR1i> and <i>RR2i> gene deletion affects the immunogenicity of a live attenuated pseudorabies

Shijun YAN,He YAN,Chaolin ZHANG,Tongyan WANG,Qingyuan YANG,Zhe SUN,Yan XIAO,Feifei TAN,Xiangdong LI,Kegong TIAN

《农业科学与工程前沿(英文)》 2016年 第3卷 第1期   页码 81-86 doi: 10.15302/J-FASE-2016088

摘要: As virulence-determining genes, and encode the small subunit and large subunit of viral ribonucleotide reductase (RR) in pseudorabies virus which have been extensively studied in mice. However, their role in pigs has not been adequately investigated. In this study, we deleted and genes based on a / / triple gene-deleted pseudorabies virus and tested its efficacy in pigs as a vaccine candidate. The rescued virus showed similar growth properties and plaque size as its parent strain. In an animal study, the virus could elicit humoral immune responses shown by generation of gB-specific antibodies and virus neutralizing antibodies. However, vaccination could not provide protection against virulent pseudorabies virus challenge since vaccinated pigs showed clinical pseudorabies-specific syndromes. The deficiency in protection may due to the generation of late and low levels of gB antibodies and virus neutralizing antibodies.

关键词: pseudorabies virus     RR1 and RR2     ribonucleotide reductase     vaccine candidate    

Efficient acetoin production from pyruvate by engineered whole-cell biocatalysis

《化学科学与工程前沿(英文)》 2023年 第17卷 第4期   页码 425-436 doi: 10.1007/s11705-022-2229-0

摘要: Acetoin is an important platform chemical, which has a wide range of applications in many industries. Halomonas bluephagenesis, a chassis for next generation of industrial biotechnology, has advantages of fast growth and high tolerance to organic acid salts and alkaline environment. Here, α-acetolactate synthase and α-acetolactate decarboxylase from Bacillus subtilis 168 were co-expressed in H. bluephagenesis to produce acetoin from pyruvate. After reaction condition optimization and further increase of α-acetolactate decarboxylase expression, acetoin production and yield were significantly enhanced to 223.4 mmol·L–1 and 0.491 mol·mol–1 from 125.4 mmol·L–1 and 0.333 mol·mol–1, respectively. Finally, the highest titer of 974.3 mmol·L–1 (85.84 g·L–1) of acetoin was accumulated from 2143.4 mmol·L–1 (188.6 g·L–1) of pyruvic acid within 8 h in fed-batch bioconversion under optimal reaction conditions. Moreover, the reusability of the cell catalysis was also tested, and the result illustrated that the whole-cell catalysis obtained 433.3, 440.2, 379.0, 442.8 and 339.4 mmol·L–1 (38.2, 38.8, 33.4, 39.0 and 29.9 g·L–1) acetoin in five repeated cycles under the same conditions. This work therefore provided an efficient H. bluephagenesis whole-cell catalysis with a broad development prospect in biosynthesis of acetoin.

关键词: acetoin     pyruvate     α-acetolactate synthetase     α-acetolactate decarboxylase     Halomonas bluephagenesis     whole-cell biocatalysis    

High frequency of alternative splicing variants of the oncogene in neuroendocrine tumors of the pancreas and breast

《医学前沿(英文)》   页码 907-923 doi: 10.1007/s11684-023-1009-7

摘要: The characteristic genetic abnormality of neuroendocrine neoplasms (NENs), a heterogeneous group of tumors found in various organs, remains to be identified. Here, based on the analysis of the splicing variants of an oncogene Focal Adhesion Kinase (FAK) in The Cancer Genome Atlas datasets that contain 9193 patients of 33 cancer subtypes, we found that Box 6/Box 7-containing FAK variants (FAK6/7) were observed in 7 (87.5%) of 8 pancreatic neuroendocrine carcinomas and 20 (11.76%) of 170 pancreatic ductal adenocarcinomas (PDACs). We tested FAK variants in 157 tumor samples collected from Chinese patients with pancreatic tumors, and found that FAK6/7 was positive in 34 (75.6%) of 45 pancreatic NENs, 19 (47.5%) of 40 pancreatic solid pseudopapillary neoplasms, and 2 (2.9%) of 69 PDACs. We further tested FAK splicing variants in breast neuroendocrine carcinoma (BrNECs), and found that FAK6/7 was positive in 14 (93.3%) of 15 BrNECs but 0 in 23 non-NEC breast cancers. We explored the underlying mechanisms and found that a splicing factor serine/arginine repetitive matrix protein 4 (SRRM4) was overexpressed in FAK6/7-positive pancreatic tumors and breast tumors, which promoted the formation of FAK6/7 in cells. These results suggested that FAK6/7 could be a biomarker of NENs and represent a potential therapeutic target for these orphan diseases.

关键词: FAK6/7     SRRM4     neuroendocrine neoplasms     pancreas     breast    

标题 作者 时间 类型 操作

Immobilization of

Xiaokai SONG,Zhongyi JIANG,Lin LI,Hong WU

期刊论文

Enhanced production of

Shen Huang,Xudong Feng,Chun Li

期刊论文

Construction of a CaHPO4-PGUS1 hybrid nanoflower through protein-inorganic self-assembly, and its application in glycyrrhetinic acid 3-O-mono-β-D-glucuronide preparation

Tian Jiang, Yuhui Hou, Tengjiang Zhang, Xudong Feng, Chun Li

期刊论文

Enzyme@bismuth-ellagic acid: a versatile platform for enzyme immobilization with enhanced acid-base stability

期刊论文

Development of a new method for RMR and Q classification method to optimize support system in tunneling

Asghar RAHMATI,Lohrasb FARAMARZI,Manouchehr SANEI

期刊论文

抗白粉病基因 <i>Pm40i> 在我国“后 <i>Pm21i> 时代”小麦育种中的重要作用

唐圣雯,胡玉亭,钟胜福,罗培高

期刊论文

NiFeRuO<i>xi> nanosheets on Ni foam as an electrocatalyst for efficient

期刊论文

2014—2016年食品动物源RE-<i>cmeABCi>阳性弯曲菌流行与耐药性现状

刘德俊, 刘蔚雯, 李星, 姚红, 沈张奇, 汪洋, 沈建忠

期刊论文

A highly efficient methodology for the preparation of

Yongxin Zhang, Shucheng Wang, Yaodong Huang

期刊论文

通过<i> B i>位Ta置换对<i> AB i> O4型EuNbO4的热学和力学性质进行优化

陈琳, 冯晶

期刊论文

Traces and echoes of <i>De Architecturai> by Marcus Vitruvius Pollio in the work of Xu Guangqi in 17th

Michela CIGOLA,Yibing FANG

期刊论文

Accounting for the uncertainties in the estimation of average shear wave velocity using – correlations

期刊论文

<i>RR1i> and <i>RR2i> gene deletion affects the immunogenicity of a live attenuated pseudorabies

Shijun YAN,He YAN,Chaolin ZHANG,Tongyan WANG,Qingyuan YANG,Zhe SUN,Yan XIAO,Feifei TAN,Xiangdong LI,Kegong TIAN

期刊论文

Efficient acetoin production from pyruvate by engineered whole-cell biocatalysis

期刊论文

High frequency of alternative splicing variants of the oncogene in neuroendocrine tumors of the pancreas and breast

期刊论文