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Optical monitoring and intra-day variabilities of BL Lac Objects OJ 287

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Research in Astronomy and Astrophysics 2021年第6期21卷 263-275页

作者： Yu-Hai Yuan Jun-Hui Fan hong Wu Jing-Meng Hao Wei-Rong huang Xiao-Lan Liu hong-ren huang Center for Astrophysics Guangzhou UniversityGuangzhou 510006China Astronomy Science and Technology Research Laboratory of Department of Education of Guangdong Province Guangzhou 510006China Key Laboratory for Astronomical Observation and Technology of Guangzhou Guangzhou 510006China Key Laboratory of Optical Astronomy National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China

Using the 1.26 m National Astronomical Observatory-Guangzhou University Infrared/Optical Telescope(NGT),we monitor one BL Lac object,OJ *** this source,we obtain 15094 gri observations(4900 at g band,5184 at r band and 5010 at i band)in 155 nights from 2014 December 13 to 2019 *** on the upper observations,we obtain the following results.(1)The total variation amplitude is~2.3 mag.(2)There are intra-day variabilities(IDVs).The IDV timescales(△T)are in the range from 7.69 min(Δm=0.06±0.02 mag)to 371.09 min(Δm=0.26±0.04 mag).(3)There are strong correlations betweenΔT andΔm,△m=(2.91±0.66)×10^(-4)ΔT+(0.08±0.009),with r=0.52,p=5.33×10^(-5).(4)There are intra-day periods in this source,with the period P≈94 min on 2017 December *** we supplement the observations from the literature,we can obtain that the long-term period is about 12.02±0.41 yr.(5)The spectral properties of OJ 287 show the bluer-when-brighter behavior,whatever state the source is at.

关键词： quasars:individual(OJ 287) photometry

Effect of lanthanum on microstructure of a nickel-based single crystal superalloy

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China Foundry 2025年第1期22卷 55-64页

作者： hong Gao Kai Guan ren-jie Cui Jian-chao Qin Zi-han Zhao Zhao-hui huang Science and Technology on Advanced High Temperature Structural Materials Laboratory Beijing Institute of Aeronautical MaterialsBeijing 100095China

To enhance the high-temperature oxidation resistance and mechanical properties of a secondgeneration nickel-based superalloy,various concentrations of lanthanum(La)ranging from 5.0×10^(-5)wt.%to 3.4×10^(-4)wt.%are added to the *** microstructure of the nickel-based single crystal superalloy with trace of La was examined by means of SEM,EDS and *** show the addition of La decreases the segregation of elements and increases the amount ofγ/γ′eutectics of the as-cast alloy,and in the interdendritic region,the growth of eutectics is accompanied by the growth of strip clusters composed of Ni_(5)La and Ni_(3)*** the La content in the alloy increases,the proportion of Ni_(5)La in the cluster *** heat treatment,incipient melting occurs in the cluster regions,leading to an increase in microporosity compared to the original as-cast ***,the heat treatment alters the shape of the clusters from a strip morphology to an elliptical one,and it changes their composition from Ni_(5)La and Ni_(3)Ta to a combination of Ni_(5)La,Ni_(3)Ta,and MC carbides.

关键词： single crystal superalloy lanthanum microstructure heat-treatment precipitate phase

Total synthesis of(+)-taberdicatine B and(+)-tabernabovine B

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Chinese Chemical Letters 2025年第02期36卷 349-353页

作者： Tengfei Xuan Xinyu Zhang Wei Han Yidong huang Weiwu ren Molecular Synthesis Center&Key Laboratory of Marine Drugs Chinese Ministry of EducationSchool of Medicine and PharmacyOcean University of China Laboratory for Marine Drugs and Bioproducts Laoshan Laboratory

The first total synthesis of(+)-taberdicatine B and(+)-tabernabovine B has been accomplished in 10steps with 26.9% overall yield and 15 steps with 7.3% overall yield, respectively. The prominent features of this efficient synthetic strategy include the following:(1)(+)-Taberdicatine B and(+)-tabernabovine B were accessed from common advanced intermediates by varying the substituents;(2) A one-pot asymmetric bromocyclization/hydrolysis was explored to assemble HPI skeleton;(3) Dieckmann condensation to form β-keto ester for the assembly of seven-membered ring;(4) An ester reduction/amide semireduction/cyclization sequence was applied to form the cage-like framework.

关键词： Asymmetric dearomatization Hexahydropyrrolo[2,3-b]indole Taberdicatine B Tabernabovine B Total synthesis

On-line determination of selenium compounds in tea infusion by extractive electrospray ionization mass spectrometry combined with a heating reaction device

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Chinese Chemical Letters 2025年第1期36卷 496-500页

作者： Lu huang Jiang Wang hong Jiang Lanfang Chen Huanwen Chen Academician Workstation Jiangxi University of Chinese MedicineNanchang 330004China Suzhou Jingcheng Precision Instrument Technology Co. Ltd.Suzhou 215228China The First Affiliated Hospital of Nanchang University Nanchang 330006China

Selenium is one of the important trace elements in the human *** deficiency will directly affect human *** people's attention to health,the content of selenium in food has gradually attracted ***,detecting selenium compounds in complex samples remains a *** this work,we built an online heating-reaction *** device combines the electrospray extraction ionization mass spectrometry(EESI-MS)with the heating reaction device,which can simultaneously detect various selenium compounds in complex liquid *** acidic conditions,the sample was heated and catalyzed by a heating reaction device,so that the SeO~(2-)_(3)and O-phenylenediamine(OPD)could generate 1,3-dihydro-2,1,*** on the above reactions,we can detect organic selenium,inorganic selenium and other compounds in liquid samples by organic mass *** this experiment,we determined the content of three forms of selenium:selenomethionine(SeMet),l-selenocystine(SeCys(2)),and sodium *** calibration curves for SeMet,SeCys(2),and sodium selenite showed strong linearity within a range of 0.50-50.00μg/*** limits of detection(LOD)for the three compounds were 0.22,0.27,and 0.41μg/L,*** limits of quantification(LOQ)were 0.68,0.81,and 1.23μg/L,*** recoveries at three levels ranged from 98.8%to 106.1%.In addition,this method can simultaneously detect three selenium compounds and three other specific chemical components in tea infusion samples,providing a rapid and efficient method for identifying tea quality.

关键词： Heating reaction device Extractive electrospray ionization mass spectrometry Inorganic selenium Selenium compounds Tea infusion

Cobalamin-dependent radical S-adenosyl-L-methionine protein functions with a partner to successively methylate tricyclic indole alkaloid for chuangxinmycin maturation and derivatization

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Science China Chemistry 2025年第1期68卷 308-316页

作者： Sili Wang Jiancheng huang Yanan Du Wei huang Yufeng Xue Xiaokun Xu Guannan Zhong Yuanyuan Shi Bin hong Xiaoying Bian Wen Liu State Key Laboratory of Chemical Biology Shanghai Institute of Organic ChemistryUniversity of Chinese Academy of SciencesChinese Academy of SciencesShanghai 200032China State Key Laboratory of Microbial Technology Shandong UniversityQingdao 266237China National Health Commission(NHC)Key Laboratory of Biotechnology for Microbial Drugs Institute of Medicinal BiotechnologyChinese Academy of Medical Science&Peking Union Medical CollegeBeijing 100050China

Cobalamin(Cbl)-dependent radical S-adenosyl-L-methionine(SAM)proteins constitute the largest collection of the radical SAM superfamily that has hundreds of thousands of individual *** of these proteins are involved in the biosynthesis of pharmaceutically important natural products to catalyze chemically demanding *** the biosynthetic pathway of chuangxinmycin(CXM),a unique indole alkaloid antibiotic with potent anti-infective activity,functionalization of the characteristic thiopyrano[4,3,2-cd]indole scaffold by regio-and stereoselective C3-methylation is believed to rely on a Cbl-dependent radical process,which,however,remained to be reconstituted *** here report the dissection of this enzymatic process,which requires the incorporation of Cxm8,a Cbl-dependent radical SAM protein,with Cxm9,a DUF5825family protein that shares no homology to any proteins of known ***8 and Cxm9 function together by forming an unexpected heterodimeric complex that selectively catalyzes C3-methylation of the tricyclic indole-S-hetero ring system in a successive manner,achieving CXM and a recently identified,C3-dimethylated *** biochemical characterization,isotope labeling,structural simulation and bioinformatics analysis rationalized the catalysis of the Cxm8/Cxm9 complex and particularly the necessity of the DUF5825 protein for C3-methylase *** is the first example that a Cbl-dependent protein acts with a partner to exhibit radical SAM activity.

关键词： cbl-dependent radical SAM protein biosynthesis chuangxinmycin stereoselective methylation

PD-YOLO:Colon Polyp Detection Model Based on Enhanced Small-Target Feature Extraction

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Computers, Materials & Continua 2025年第1期82卷 913-928页

作者： Yicong Yu Kaixin Lin Jiajun hong Rong-Guei Tsai Yuanzhi huang New Engineering Industry College Putian UniversityPutian351100China Engineering Research Center of Big Data Application in Private Health Medicine(Putian University) Fujian Province UniversityPutian351100China Computer College Guangdong University of Science&TechnologyDongguan523668China

In recent years,the number of patientswith colon disease has increased *** polyps are the precursor lesions of colon *** not diagnosed in time,they can easily develop into colon cancer,posing a serious threat to patients’lives and health.A colonoscopy is an important means of detecting colon ***,in polyp imaging,due to the large differences and diverse types of polyps in size,shape,color,etc.,traditional detection methods face the problem of high false positive rates,which creates problems for doctors during the diagnosis *** order to improve the accuracy and efficiency of colon polyp detection,this question proposes a network model suitable for colon polyp detection(PD-YOLO).This method introduces the self-attention mechanism CBAM(Convolutional Block Attention Module)in the backbone layer based on YOLOv7,allowing themodel to adaptively focus on key information and ignore the unimportant *** help themodel do a better job of polyp localization and bounding box regression,add the SPD-Conv(Symmetric Positive Definite Convolution)module to the neck layer and use deconvolution instead of *** results indicate that the PD-YOLO algorithm demonstrates strong robustness in colon polyp *** to the original YOLOv7,on the Kvasir-SEG dataset,PD-YOLO has shown an increase of 5.44 percentage points in AP@0.5,showcasing significant advantages over other mainstream methods.

关键词： Polyp detection YOLOv7 SPD-Conv CBAM deconvolution

Effect of two-pass rolling of textured roll and polished roll on surface topography and mechanical properties of 316L stainless steel ultra-thin strip

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Journal of Iron and Steel Research International 2025年第1期32卷 186-197页

作者： Zeng-qiang Zhang Xi Liao Zhong-kai ren Zhen-hua Wang Ya-xing Liu Tao Wang Qing-xue huang College of Mechanical and Vehicle Engineering Taiyuan University of TechnologyTaiyuan030024ShanxiChina Engineering Research Center of Advanced Metal Composites Forming Technology and Equipment of Ministry of Education Taiyuan University of TechnologyTaiyuan030024ShanxiChina National Key Laboratory of Metal Forming Technology and Heavy Equipment Taiyuan University of TechnologyTaiyuan030024ShanxiChina Shanxi TISCO Stainless Steel Precision Strip Co. Ltd.Taiyuan030032ShanxiChina

The textured roll and polished roll were applied instead of the ground roll in a 20-high mill to conduct two-pass rolling of 316L stainless steel strip with thickness of 0.027 *** the two-pass rolling with the textured roll and polished roll(TPR),the surface roughness of the strip is dramatically reduced,and the surface topographical anisotropy index is diminished to 30.9%of the initial *** with the strip rolled using the ground roll in both passes(GGR),the elongation of TPR rolled strip is obviously improved,and the mechanical property anisotropy is greatly *** anisotropy index of tensile strength and elongation are 42.58%and 52.59%of that of GGR rolled strip,which is mainly attributed to the significant decrease of the texture intensity of the strip by TPR *** results indicate that TPR process can obtain the stainless steel ultra-thin strip with smooth and uniform surface topography and good mechanical properties.

关键词： Textured roll Polished roll Surface topography Mechanical property Stainless steel ultra-thin strip

AZD1775 synergizes with SLC7A11 inhibition to promote ferroptosis

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Science China(Life Sciences) 2025年第1期68卷 204-218页

作者： Chen Xiong hong Ling Yingdan huang Hanzhi Dong Bangxiang Xie Qian Hao Xiang Zhou Fudan University Shanghai Cancer Center and Institutes of Biomedical Sciences Fudan UniversityShanghai 200032China Department of Oncology Shanghai Medical CollegeFudan UniversityShanghai 200032China Department of Breast Surgery Fudan University Shanghai Cancer CenterFudan UniversityShanghai 200032China Department of Oncology First Affiliated Hospital of Nanchang UniversityNanchang 330006China Beijing Institute of Hepatology Beijing Youan HospitalCapital Medical UniversityBeijing 100069China Beijing Engineering Research Center for Precision Medicine and Transformation of Hepatitis and Liver Cancer Beijing 100069China Key Laboratory of Breast Cancer in Shanghai Fudan University Shanghai Cancer CenterFudan UniversityShanghai 200032China Shanghai Key Laboratory of Medical Epigenetics International Co-laboratory of Medical Epigenetics and Metabolism(Ministry of Science and Technology)Institutes of Biomedical SciencesFudan UniversityShanghai 200032China

Tumor suppressor p53-mediated cell cycle arrest and DNA damage repair may exert cytoprotective effects against cancer therapies,including WEE1 *** that p53 activation can also lead to multiple types of cell death,the role of this tumor suppressor in WEE1 inhibitor-based therapies remains *** this study,we reported that nucleolar stress-mediated p53 activation enhanced the WEE1 inhibitor AZD1775-induced ferroptosis to suppress lung cancer *** findings showed that AZD1775 promoted ferroptosis by blocking cystine uptake,an action similar to that of ***,inhibition of WEE1 by the WEE1 inhibitors or siRNAs induced compensatory upregulation of SLC7A11,which conferred resistance to ***,AZD1775 prevented the enrichment of H3K9me3,a histone marker of transcriptional repression,on the SLC7A11 promoter by repressing the expression of the histone methyltransferase SETDB1,thereby enhancing NRF2-mediated SLC7A11 *** finding was also validated using the H3K9me3 inhibitor ***,we found that the nucleolar stress-inducing agent Actinomycin D(Act.D)inhibited SLC7A11 expression by activating p53,thus augmenting AZD1775-induced ***,the combination of AZD1775 and Act.D synergistically suppressed wild-type p53-harboring lung cancer cell growth both in vitro and in ***,our study demonstrates that AZD1775 promotes ferroptosis by targeting cystine uptake but also mediates the adaptive activation of SLC7A11 through the WEE1-SETDB1 cascade and NRF2-induced transcription,and inhibition of SLC7A11 by Act.D boosts the anti-tumor efficacy of AZD1775 by enhancing ferroptosis in cancers with wild-type p53.

关键词： p53 NRF2 SLC7A11 WEE1 AZD1775 ferroptosis nucleolar stress

Oscillatory flow reactor facilitates fast photochemical Wolff rearrangement toward synthesis of α-substituted amides in flow

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Chinese Chemical Letters 2025年第02期36卷 389-393页

作者： Huashan huang Jingze Chen Luyun Zhang hong Yan Siqi Li Fen-Er Chen Institute of Pharmaceutical Science and Technology College of Chemistry Fuzhou University Key Laboratory of Natural Medicines of the Changbai Mountain Ministry of Education Molecular Medicine Research Center College of Pharmacy Yanbian University Engineering Center of Catalysis and Synthesis for Chiral Molecules Department of Chemistry Fudan University Shanghai Engineering Center of Industrial Catalysis for Chiral Drugs

A visible light-promoted fast photochemical Wolff rearrangement was developed toward synthesis of α-substituted amides in continuous flow with the use of a photochemical oscillatory flow reactor(POFR).The control experiment indicates that a fast process of the Wolff rearrangement(<40 s) is involved. Notably, this protocol does not require excess use of any reactants, and the resulting α-substituted amides could be isolated by recrystallization in good to excellent yields.

关键词： Flow photochemistry Ketene Oscillatory flow reactor Wolff rearrangement α-Substituted amides