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Identification and characterization of camptothecin tailoring enzymes in Nothapodytes tomentosa

Journal of Integrative Plant Biology 2024年第6期66卷 1158-1169页

作者： Yin Chen Jian-Ping Huang Yong-Jiang Wang meng-ling tu Junheng Li Bingyan Xu Guoqing Peng Jing Yang Sheng-Xiong Huang State Key Laboratory of Phytochemistry and Plant Resources in West China and Yunnan Key Laboratory of Natural Medicinal Chemistry Kunming Institute of BotanyChinese Academy of SciencesKunming 650201China University of Chinese Academy of Sciences Beijing 100049China Key Laboratory for Economic Plants and Biotechnology Kunming Institute of BotanyChinese Academy of SciencesKunming 650201China

Camptothecin is a complex monoterpenoid indole alkaloid with remarkable antitumor *** that two C-10 modified camptothecin derivatives,topotecan and irinotecan,have been approved as potent anticancer agents,there is a critical need for methods to access other aromatic ringfunctionalized congeners(e.g.,C-9,C-10,etc.).However,contemporary methods for chemical oxidation are generally harsh and low-yielding when applied to the camptothecin scaffold,thereby limiting the development of modified *** herein,we have identified four tailoring enzymes responsible for C-9 modifications of camptothecin from Nothapodytes tomentosa,via metabolomic and transcriptomic *** consist of a cytochrome P450(Nt CPT9H)which catalyzes the regioselective oxidation of camptothecin to 9-hydroxycamptothecin,as well as two methyltransferases(Nt OMT1/2,converting 9-hydroxycamptothecin to 9-methoxycamptothecin),and a uridine diphosphate-glycosyltransferase(Nt UGT5,decorating 9-hydroxycamptothecin to9-β-D-glucosyloxycamptothecin).Importantly,the critical residues that contribute to the specific catalytic activity of Nt CPT9H have been elucidated through molecular docking and mutagenesis *** work provides a genetic basis for producing camptothecin derivatives through metabolic *** will hasten the discovery of novel C-9 modified camptothecin derivatives,with profound implications for pharmaceutical manufacture.

关键词： camptothecin biosynthesis enzymatic assay Nothapodytes tomentosa tailoring enzyme transcriptomic analysis

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Insulation Design Rule for a Spacer in SF_(6)/N_(2)-filled DC Gas Insulated Apparatus

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CSEE Journal of Power and Energy Systems 2024年第2期10卷 727-735页

作者： Hongyang Zhou Guoming Ma meng Zhang Cong Wang Youping tu Chengrong Li State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources and the Beijing Key Laboratory of High Voltage and EMC North China Electric Power UniversityBeijing 102206China

A recurring challenge of a DC SF_(6)/N_(2)-filled GIS/GIL apparatus is the charge accumulation at DC *** conventional design rules and knowledge of AC spacers may not be applicable for this new type of apparatus.A novel design rule is proposed considering the effect of accumulated charge on the threshold of electric field strength being resistant to the superposed voltage.A surface charge accumulation simulation model is introduced,and the key parameters in the simulation model are *** addition,an experimental platform for a 100 kV spacer flashover test is *** flashover tests under superimposed voltage with opposing polarities are carried out,and the withstanding voltage of the spacer is ***,based on the proposed model,the threshold of the surface electric field strength(tangential component)on the DC spacer in SF_(6)/N_(2) mixed gases is *** a reliable insulation design of a DC GIS/GIL apparatus filled with 0.7 MPa SF_(6)/N_(2),the threshold of surface electric field strength on the DC spacer is 12 kV/*** insulation design rule can be referenced in the design of a high-voltage DC SF_(6)/N_(2)-filled GIS/GIL apparatus.

关键词： Charge accumulation DC spacer flashover voltage SF_(6)/N_(2) threshold of surface electric field strength

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Vesicular drug delivery systems for oral absorption enhancement

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Chinese Chemical Letters 2024年第7期35卷 73-88页

作者： linghui Zou meng Cheng Kaili Hu Jianfang Feng Liangxing tu Jiangxi University of Chinese Medicine Nanchang 330006China Guangxi University of Chinese Medicine Nanning 530200China Shanghai University of Traditional Chinese Medicine Shanghai 201203China

Oral administration is the most acceptable route of drug delivery at this stage due to its convenience,safety,and ***,drugs given orally are exposed to a complex gastrointestinal environment,causing a tremendous challenge for their successful absorption into the *** the past decades,researchers have developed various novel pharmaceutical technologies to improve oral absorption,among which the vesicular drug delivery system(like liposomes,niosomes and transfersomes)has received extensive ***,there have been several investigations confirming the improved effect of vesicular drug delivery systems on oral drug ***,the clinical translation of oral vesicular drug delivery systems has been less impressive than implied by the positive results,and few vesicular formulations for oral use have been marketed *** this background,this article provides an overview of the current applications and challenges associated with the vesicular delivery systems available for oral drug delivery,specifically liposomes,niosomes,transfersomes,chitosomes and *** composition,formation mechanism,drug delivery advantages and application cases of these carriers in oral drug delivery are *** possible mechanisms by which vesicular carriers enhance oral drug absorption are analyzed in terms of the in vivo process of oral ***,the challenges that oral vesicular carriers now face,such as safety,undefined in vivo fate,and scale-up production,are summarized,while possible strategies to deal with them are *** reviewing the aforementioned,it can facilitate a more comprehensive knowledge of vesicular systems that can be used for oral drug delivery,providing a theoretical basis and reference for the design of oral formulations.

关键词： Vesicular Oral Mechanism Drug delivery Liposome Niosomes Transfersomes Chitosomes Bilosomes

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Adhesion property of AlCrNbSiTi high-entropy alloy coating on zirconium:experimental and theoretical studies

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Nuclear Science and Techniques 2024年第8期35卷 79-91页

作者： Bao‑Liang Zhang Wen‑Guan Liu meng‑He tu Can Fang Yan Liu Yu‑Hui Wang Yong Hu Hui Wang China Institute of Atomic Energy Beijing 102413China Sino‑French Institute of Nuclear Engineering and Technology Sun Yat-Sen UniversityZhuhai 519082China School of Power and Mechanical Engineering Wuhan UniversityWuhan 430072China

Experimental scratch tests and first-principles calculations were used to investigate the adhesion property of AlCrNbSiTi high-entropy alloy(HEA)coatings on zirconium *** HEA and Cr coatings were deposited on Zr alloy substrates using multi-arc ion plating technology,and scratch tests were subsequently conducted to estimate the adhesion property of the *** results indicated that Cr coatings had better adhesion strength than HEA coatings,and the HEA coatings showed *** special quasi-random structure approach was used to build HEA models,and Cr/Zr and HEA/Zr interface models were employed to investigate the cohesion between the coatings and Zr substrate using first-principles *** calculated interface energies showed that the cohesion between the Cr coating and the Zr substrate was stronger than that of the HEA coating with *** contrary to Al or Si in the HEA coating,Cr,Nb,and Ti atoms binded strongly with Zr *** on the calculated elastic constants,it was found that low Cr and high Al content decreased the mechanical performances of HEA ***,this study demonstrated the utilization of a combined approach involving first-principles calculations and experimental studies for future HEA coating development.

关键词： High-entropy alloy coating Cr coating Adhesion property Scratch test First-principles calculation

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Intracellular redox potential-driven live-cell synthesis of CdSe quantum dots in Staphylococcus aureus

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Science China Chemistry 2024年第3期67卷 990-999页

作者： Cai-Qin Wu An-An Liu Xu Li Jia-Wei tu Juan Kong ling-ling Yang Jian-Hong Jia Chuan Wang Bin Hu Zhi-Xiong Xie Dai-Wen Pang The Institute for Advanced Studies College of Chemistry and Molecular SciencesCollege of Life SciencesHubei Key Laboratory of Cell HomeostasisWuhan UniversityWuhan 430072China Research Center for Analytical Sciences College of ChemistryState Key Laboratory of Medicinal Chemical BiologyTianjin Key Laboratory of Biosensing and Molecular RecognitionFrontiers Science Center for New Organic MatterFrontiers Science Center for Cell Responsesand Haihe Laboratory of Sustainable Chemical TransformationsNankai UniversityTianjin 300071China

Biosynthesized semiconductor quantum dots(QDs) have bright fluorescence,adjustable particle sizes,and environmental friendliness,endowing them with convenience and potential for biological *** to the unclear mechanism of the cellular environment on the live-cell synthesis of QDs,it is still difficult to regulate their optical ***,the critical role of the intracellular redox environment in regulating the fluorescence properties of biosynthesized CdSe QDs in Staphylococcus aureus(***) has been *** glutathione peroxidase(GPx) activity directly affects the intracellular H_(2)O_(2) produced in the SeO_(3)^(2-) reduction,which further manipulates the glutathione redox cycle to determine the content of low-valence *** a result,the fluorescence intensity of the synthesized CdSe QDs increases by 60% in the GPx overexpressed *** cellular redox potential that is controlled by the GSH redox cycle provides the driving force for the reduction of SeO_(3)^(2-),facilitating the synthesis of CdSe QDs in *** *** proposed mechanism of the cellular redox state provides a new perspective for regulating the synthesis of semiconductor nanomaterials in live cells.

关键词： redox H_(2)O_(2) peroxidase quantum dot Staphylococcus aureus

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In situ synthesis of porous Pt-Pd bimetallic structures for sweat glucose biosensing using dynamic hydrogen bubble template method

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Rare Metals 2024年第7期43卷 3408-3414页

作者： Yi-Wen Guo Qian-Hui Wei Fei Wei Hao Liu Hong-Bin Zhao Dong Wang Hai-ling tu State Key Laboratory of Advanced Materials for Smart Sensing China GRINM Group Co.Ltd.Beijing 100088China Department of Advanced Electronic Materials GRIMAT Engineering Institute Co.Ltd.Beijing 101407China General Research Institute for Nonferrous Metals Beijing 100088China GRINM(Guangdong)Institute for Advanced Materials and Technology Foshan 528000China School of Chemical Engineering Northeast Electric Power UniversityJilin 132012China

For the practical application of sweat glucose biosensors,it is crucial to develop a method for modifying the working electrode with noble metals that ensures strong *** this study,we synthesized porous Pt-Pd bimetall... 详细信息

关键词： method bubble porous

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Single-cell transcriptomics reveals tumor landscape in ovarian carcinosarcoma

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2024年第8期25卷 686-699页

作者： Junfen XU mengyan tu Department of Gynecologic Oncology Women’s HospitalZhejiang University School of MedicineHangzhou 310006China Zhejiang Provincial Clinical Research Center for Obstetrics and Gynecology Hangzhou 310006China

Objective:The present study used single-cell RNA sequencing(scRNA-seq)to characterize the cellular composition of ovarian carcinosarcoma(OCS)and identify its molecular ***:scRNA-seq was performed in resected primary OCS for an in-depth analysis of tumor cells and the tumor *** staining was used for *** scRNA-seq data of OCS were compared with those of high-grade serous ovarian carcinoma(HGSOC)tumors and other OCS ***:Both malignant epithelial and malignant mesenchymal cells were observed in the OCS patient of this *** identified four epithelial cell subclusters with different biological *** them,epithelial subcluster 4 presented high levels of breast cancer type 1 susceptibility protein homolog(BRCA1)and DNA topoisomerase 2-α(TOP2A)expression and was related to drug resistance and cell *** analyzed the interaction between epithelial and mesenchymal cells and found that fibroblast growth factor(FGF)and pleiotrophin(PTN)signalings were the main pathways contributing to communication between these ***,we compared the malignant epithelial and mesenchymal cells of this OCS tumor with our previous published HGSOC scRNA-seq data and OCS *** the epithelial subclusters in the OCS tumor could be found in the HGSOC ***,the mesenchymal subcluster C14 exhibited specific expression patterns in the OCS tumor,characterized by elevated expression of cytochrome P450 family 24 subfamily A member 1(CYP24A1),collagen type XXIIIα1 chain(COL23A1),cholecystokinin(CCK),bone morphogenetic protein 7(BMP7),PTN,Wnt inhibitory factor 1(WIF1),and insulin-like growth factor 2(IGF2).Moreover,this subcluster showed distinct characteristics when compared with both another previously published OCS tumor and normal ovarian ***:This study provides the single-cell transcriptomics signature of human OCS,which constitutes a new resource for elucidating OCS diversity.

关键词： Ovarian carcinosarcoma Single-cell RNA sequencing(scRNA-seq) tumor heterogeneity

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基于水化学和氢氧同位素的泰安城区岩溶地下水补给来源及演化过程

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环境科学 2024年第4期45卷 2096-2106页

作者：孟令华中化地质矿山总局山东地质勘查院泰安271000

泰安市城区岩溶地下水较丰富,是重要的地下水供水水源地.基于泰安城区岩溶水和地表水的水化学和氢氧同位素(δD、δ^(18)O和~3H)特征,结合Gibbs图解、主要离子比值,揭示岩溶地下水补给来源、补给年代、循环更新能力及主要的水-岩作用演... 详细信息

泰安市城区岩溶地下水较丰富,是重要的地下水供水水源地.基于泰安城区岩溶水和地表水的水化学和氢氧同位素(δD、δ^(18)O和~3H)特征,结合Gibbs图解、主要离子比值,揭示岩溶地下水补给来源、补给年代、循环更新能力及主要的水-岩作用演化过程.结果表明,区内岩溶地下水阳离子以Ca^(2+)和Na^(+)为主,阴离子以HCO_(3)^(-)和SO_(4)^(2-)为主,K^(+)、NO_(3)^(-)、Cl^(-)、Na^(+)和SO_(4)^(2-)的变异系数较大,空间差异性较强,Ca^(2+)和HCO_(3)^(-)的含量较稳定.水化学类型复杂多变,主要为HCO_(3)·SO_(4)-Ca型、HCO_(3)·Cl-Ca型和HCO_(3)-Ca型.大气降水是岩溶地下水和地表水的主要补给来源,地下水在径流过程中经历了一定的蒸发作用,但影响性相对较小;岩溶地下水~3H含量介于3.0~5.4 tu之间,与现代水(指1952年核爆以后)水力联系密切,循环更新能力较强,更容易遭受污染,在开发利用时应加强水资源保护.岩溶地下水水化学演化特征受岩石风化作用、阳离子交替吸附作用和人类活动的共同影响,水化学成分主要来源于碳酸盐矿物及少量硅铝酸盐矿物的风化溶解,其演化主要受方解石等贫镁矿物的溶解作用影响,白云岩风化溶解作用影响较小.

关键词：岩溶地下水水化学特征氢氧同位素水-岩作用泰安城区

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High-timing-precision detection of single X-ray photons by superconducting nanowires

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National Science Review 2024年第1期11卷 194-203页

作者： Shuya Guo Jingrou Tan Hengbin Zhang Jinguang Wang Tianhao Ji Labao Zhang Xiaolong Hu Jian Chen Jun Xie Kai Zou Yun meng Xiaomin Bei ling-An Wu Qi Chen Hao Wang Xuecou tu Xiaoqing Jia Qing-Yuan Zhao Lin Kang Peiheng Wu Research Institute of Superconductor Electronics Nanjing University Qian Xuesen Laboratory of Space Technology Beijing National Laboratory of Condensed Matter Physics Institute of Physics Chinese Academy of Sciences Hefei National Laboratory School of Precision Instrument and Optoelectronic Engineering Tianjin University Key Laboratory of Optoelectronic Information Science and Technology Ministry of Education

Precisely acquiring the timing information of individual X-ray photons is important in both fundamental research and practical applications. The timing precision of commonly used X-ray single-photon detectors remains in the range of one hundred picoseconds to microseconds. In this work, we report on high-timing-precision detection of single X-ray photons through the fast transition to the normal state from the superconductive state of superconducting nanowires. We successfully demonstrate a free-running X-ray single-photon detector with a timing resolution of 20.1 ps made of 100-nm-thick niobium nitride film with an active area of 50 μm by 50 μm. By using a repeated differential timing measurement on two adjacent X-ray single-photon detectors, we demonstrate a precision of 0.87 ps in the arrival-time difference of X-ray photon measurements. Therefore, our work significantly enhances the timing precision in X-ray photon counting, opening a new niche for ultrafast X-ray photonics and many associated applications.

关键词： single-photon detection timing precision superconductor ultrafast phenomenon pulsar X-ray navigation

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Equivalence between the internal observability and equation

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Applied Mathematics(A Journal of Chinese Universities) 2024年第1期39卷 89-97页

作者： LIU Wen-jun tu Zhi-yu School of Mathematics and Statistics Nanjing University of Information Science and TechnologyNanjing 210044China

This paper is concerned with a third order in time linear Moore-Gibson-Thompson equation which describes the acoustic velocity potential in ultrasound wave *** by the work of Kaltenbacher,Lasiecka and Marchand(Control Cybernet.2011,40:971-988),we establish an observability inequality of the conservative problem,and then discuss the equivalence between the exponential stabilization of a dissipative system and the internal observational inequality of the corresponding conservative system.

关键词： Moore-Gibson-Thompson equation internal observability exponential stability

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