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Relationship between genotype and phenotype of flagellin C in Salmonella

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World Journal of Gastroenterology 2001年第6期7卷 864-867页

作者： Wan-Sheng Ji~1 jia-lu Hu~1 Jun-Wen Qiu~1 Bo-Rong Pan~1 Dao-Rong Peng~2 Bing-Long Shi~1 Shao-Juan Zhou~1 Kai-Chun Wu~1 Dai-Ming Fan~1 1 Chinese PLA Institute of Digestive Diseases2 Department of Bacteriology,Xijing Hospital,Fourth Military Medical University,Xi’an 710032,Shaanxi Province,China Chinese PLA Institute of Digestive Diseases Xijing Hospital Fourth Military Medical University Xi'an 710032 Shaanxi Province China.

AIM: To discover the relationship between the genotype and antigen serotype of flagellin C among Salmonella strains. METHODS: Fragment of Salmonella flagellin C in plasmid pLS408 was cloned, sequenced and compared with the corresponding sequence in other strains. Salmonella strains including two typhi strains, one paratyphoid strain, one enteritidis and one typhimurium strain were isolated from outpatients. Genome DNA was purified respectively from these clinical isolates, then the corresponding flagellin C fragment was amplified by polymerase chain reaction,and the amplification products were analyzed by agarose gel electrophoresis. RESULTS: The cloned fragment includes 582 nucleotides encoding the variable region and partial conservative region of Salmonella flagellin C in plasmid pLS408. With comparison to the corresponding sequences reported previously, there is only a little difference from other strains with the same flagellar serotype in both nucleotide and amino acid level. Specific PCR products were amplified in Salmonella strains with flagellar serotype H-1-d including S. muenchen, typhi and typhimurium, but not in S. paratyphoid C or S. enteritidis strains. CONCluSION: In this experiment, the specificity of nucleotide sequence could be found in flagellin C central variable regions as it exists in flagellar serotypes in Salmonella. It may be helpful to developing a rapid, sensitive, accurate and PCR-based method to detect Salmonella strains with serotype H-1-d.

关键词： Amino Acid Sequence Base Sequence Flagellin Genotype Molecular Sequence Data Phenotype Protein Isoforms Salmonella Species Specificity

Cutting Temperature and Tool Wear of Hard Turning Hardened Bearing Steel

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厦门大学学报（自然科学版） 2002年第S1期41卷 128-129页

作者： LIU Xian-li 1, WEN Dong-hui 2, LI Zhen-jia 1, XIAO lu 1, YAN Fu-gang 1 (1. Dept of Mechanical Engineering, Harbin University of Science and Technology, Harbin 150080, China 2. Dept of Precision Instrunmetns & Mechanol ogy, Tsinghua University, Beijing 100084, China)

A study was undertaken to investigate the performan ce of PCBN tool in the finish turning GCr15 bearing steel with different hardness between 30～64 HRC. The natural thermocouple was used to measure the cutting tem p erature, tool life and cutting temperature were investigated and compared. The m aterial can be heated by this instrument which using low voltage and high elec trical current, while PCBN can’t be heated by electrifying directly, so the ke ntanium layer coating over the PCBN is heated, so the PCBN is heated and its th ermoelectric property is got by this method. [TPP129,+60mm88mm,Y,PZ#] Fig.1 Effect of cutting depth and workpiec hardness on. the cutting temperatureThe objective was to determine the influence of the workpiece hardness on change s in cutting temperature and tool wear characterize. It can be found from Fig.1 that the cutting temperature show an increasing tendency with the improvement of workpiece hardness within the cutting speed scope when the workpiece hardness i s under HRC50. And on the other hand, it is found that the cutting temperature s how the downtrend with the improvement of workpiece hardness when the workpiece hardness is over HRC50. According to experimental results, the critical hard ness when turning hardened GCr15 bearing steel with PCBN tool is about HRC50. Th e wear causes of PCBN tool have been found out through taking photos on the micr o-shape of PCBN poly-laminate initial surface as well as face and flank of wea r tool and analysis on chemical elements. It is discovered that the PCBN tools a re not suitable for cutting the workpiece at nearly critical hardness, because n ear the critical hardness, PCBN wear at the highest speed. For researching the w ear rule of PCBN tool, the tool wear experiments have been carried on by using b earing steel GCr15 at hardness HRC40 and HRC60 with changing cutting speed. The indexes of tool life equations is gained under two kinds of conditions w hich are bigger than 0.6, so the effec

关键词： cutting temperature tool wear hard turning pol ycrystalline cubic boron nitride (PCBN) hardened bearing steel

Neuropeptide Y receptor Y8b(npy8br)regulates feeding and digestion in Japanese medaka(Oryzias latipes)larvae:evidence from gene knockout

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2024年第7期25卷 605-616页

作者： Xiaodan jia Ke lu Xufang LIANG College of Fisheries Chinese Perch Research CenterHuazhong Agricultural UniversityWuhan 430070China Engineering Research Center of Green Development for Conventional Aquatic Biological Industry in the Yangtze River Economic Belt Ministry of EducationWuhan 430070China

Neuropeptide Y receptor Y8(NPY8R)is a fish-specific receptor with two subtypes,NPY8AR and *** in expression levels during physiological processes or in vivo regulation after ventricular injection suggest that NPY8BR plays an important role in feeding regulation;this has been found in only a few fish,at *** order to better understand the physiological function of npy8br,especially in digestion,we used clustered regularly interspaced short palindromic repeats(CRISPR)/CRISPR-associated protein 9(Cas9)technology to generate npy8br-/-japanese medaka(Oryzias latipes).We found that the deletion of npy8br in medaka larvae affected their feeding and digestion ability,ultimately affecting their ***,npy8br deficiency in medaka larvae resulted in decreased feed intake and decreased expression levels of orexigenic genes(npy and agrp).npy8br-/-medaka larvae fed for 10 d(10th day of feeding)still had incompletely digested brine shrimp(Artemia nauplii)in the digestive tract 8 h after feeding,the messenger RNA(mRNA)expression levels of digestion-related genes(amy,lpl,ctra,and ctrb)were significantly decreased,and the activity of amylase,trypsin,and lipase also significantly *** deletion of npy8br in medaka larvae inhibited the growth and significantly decreased the expression of growth-related genes(gh and igf1).Hematoxylin and eosin(H&E)sections of intestinal tissue showed that npy8br-/-medaka larvae had damaged intestine,thinned intestinal wall,and shortened intestinal *** far,this is the first npy8br gene knockout model established in fish and the first demonstration that npy8br plays an important role in digestion.

关键词： Neuropeptide Y receptor Y8b(npy8br) Japanese medaka(Oryzias latipes) Knockout Feeding Digestion

Experimental Study on Hard Turning Hardened GCr15 Steel with PCBN Tool

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厦门大学学报（自然科学版） 2002年第S1期41卷 125-126页

作者： LIU Xian-li 1, WEN Dong-hui 2, LI Zhen-jia 1, XIAO lu 1, YAN Fu-gang 1 (1. Dept. of Mechanical Engineering, Harbin University of Science and Technology, Harbin 150080, China 2. Dept. of Precision Instrunments & Mechano logy, Tsinghua University, Beijing 100084, China)

This paper discusses experimental results of turnin g experiments on GCr15 bearing steel hardened to 60～64 HRC. The objective was to d etermine the effect of the cutting parameters on cutting force, chip morphology and resultant workpiece surface quality, more specifically surface texture, micr ostructure alterations, changes in microhardness and residual stresses distribut ion. The changing rules of the main cutting force was shown in this paper which feature a increasing tendency with the improvement of the workpiece hardness wit hin the cutting parameter scope. The rule of cutting force changing with the wor kpiece hardness is accord to the traditional metal cutting theory. Stress value decrease with increasing cutting speed and workpiece hardness. The comparison of the machined surface roughness and harden layer depth of machined surface for d ifferent hardness is shown in Fig.1. The machined surface roughness is the worst when the workpiece hardness is around 50HRC. When the workpiece hardness is ove r 50HRC, the surface roughness value shows a descending tendency with the additi on hardness. The machined superficial harden layer depth shows an increasing ten dency with the improvement of the workpiece hardness. When the workpiece hardnes s is 50HRC the machined superficial harden layer depth is tiptop. When the workp iece hardness is over 50HRC the depth changes little with the addition of workpi ece hardness. The remnant stress status of the machined surface is shown in Fig. 2, which is press stress status both in surface and in base for less cutting par ameters under two kinds of cutting condition. But experiment results show that t ensile stress can be produced under uncomfortable cutting conditions. The deform ation created by the chip formation is reduced whereduce with [TPP126A,+35mm77mm,Z,PY#]Depth from surface (μm) ■ v=200m/min,f=0.24mm/r,ap=0.8mm,60HRC ● v=200m/min,f=0.15mm/r,ap=0.5mm,60HRC Fig.1 The subsurface residual stress between the two experime

关键词： hard turning surface integrity PCBN tool harde ned bearing steel

Origin and evolution of false brinelling and fretting corrosion under rolling conditions

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Friction 2024年第4期12卷 618-631页

作者： Xin jia lu HUANG Miao SUN Wenbin LI National Institute of Metrology Beijing 100029China Yantai Tiancheng Machinery Co. Ltd.Yantai 264006China

Rolling bearings working in oscillating applications often suffer from false brinelling and fretting corrosion that limit their service *** present,the study of oscillation-induced failures is primarily dominated by a large number of sliding and bench ***,most of the previous work are not able to fully describe the two closely related but different failure *** this study,the origin and evolution of the two failures are thoroughly investigated under strictly controlled oscillating rolling *** results show that failure evolves from false brinelling to fretting corrosion under dry friction conditions regardless of the oscillation *** process is accompanied by a large area peeling and serious oxidation,and the oxygen content increases from 2.50 wt%to 21.22 wt%.Oxidation is a crucial factor in the evolution of false brinelling into fretting ***,the distribution of microwear and oxygen content depend on the oscillation *** lubrication conditions,the friction coefficient(COF)is smaller in the initial stage and led to local slip or transient instability of rolling ***,the size of the wear marks and COF increased and appeared to be larger than those under a dry friction ***,grease can separate the contact surfaces,only surface deformation owing to false brinelling and slight damage at the roughness level *** evolution of false brinelling and fretting corrosion is also closely related to residual *** brinelling often occurrs with residual stress accomulation,meanwhile,the residual stress increases from 120 to 300 *** peeling occurs,residual stress is *** failure pattern transformed from false brinelling to fretting corrosion and is accompanied by *** far,none of investigation is able to show satisfactory evolution of oscillating-induced failures,this study may contribute to more scientific understanding of rolling bearings against long-

关键词： oscillating false brinelling fretting corrosion wear residual stress

Changes of lipid metabolism in plasma,liver and bile during cholesterol gallstone formation in rabbit model

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World Journal of Gastroenterology 1998年第4期4卷 65-67页

作者： ZHAO JiChun1, XIAO lujia1, ZHU Hong2, SHU Ye1 and CHENG NanSheng1Keywords cholelithiasis lipids/metabolism cholesterol/metabolism apolipoproteins/metabolism triglycerides/metabolism rabbits diseases models, animal

AIM To find out the relationship between the disturbances of lipid metabolism and the formation of cholesterol gallstones by studying the changes of lipid metabolism in plasma, liver tissue and the *** Male and female white Japanese rabbits were divided randomly into a control group (Con) and four experimental groups of 10 rabbits each fed with a diet containing 1.2% cholesterol for one, two, three and four weeks (1wk, 2wk, 3wk and 4wk group). The measurement of plasma triglyceride (TG), total cholesterol (TC), high density lipoprotein cholesterol (HDL-C) and its subfractions (HDL2-C, HDL3-C), very low and low density lipoprotein cholesterol (VLDL-C, LDL-C) was taken with standard enzymatic techniques. Apolipoprotein (apo) concentrations in plasma were measured by radial immunodiffusion assay for apoA1, apoB100, aopCⅡ and apoCⅢ. Total cholesterol of liver was measured by the enzymatic procedure for each animal. Bile acids, mainly glycocholate (GCA) and glycodeoxycholate (GDCA) were detected by dual wavelength thin layer *** In all the experimental groups fed with dietary cholesterol, cholesterol crystal was found in the gallbladder in 2/10 cases of the 1wk group, 4/10 of the 2wk group, 6/10 of the 3wk group and 7/10 of the 4wk group respectively. The concentration of plasma total cholesterol (TC), triglyceride (TG), phospholipid (pl), VLDL-C, LDL-C, apoB100, apoCⅡ, apoCⅢ gradually increased (P＜0.05) with the prolonged feeding time of dietary cholesterol. High density lipoprotein cholesterol and its subfractions (HDL-C, HDL2-C, HDL3-C) showed a tendency to decrease, but without statistical significance (P＞ 0.05). ApoA1 was reduced with increased feeding time of dietary cholesterol (P ＜0.05). The hepatic and biliary cholesterol increased 1-1.5 times as compared with the control group (t=5.221 and 3.445, P＜0.05). The GCA gradually decreased beginning from the control group to the 4wk group (P＜0.05).CONCluSION Owing to the high cholesterol diet, the

关键词： metabolism rabbit lipid cholesterol

Expression of cyclin-dependent kinase 9 is positively correlated with the autophagy level in colon cancer

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World Journal of Gastrointestinal Oncology 2024年第2期16卷 314-330页

作者： Lei Zheng jia lu Da-lu Kong Department of Colorectal Cancer Surgery National Clinical Research Center for CancerKey Laboratory of Cancer Immunology and Biotherapy of TianjinTianjin Key Laboratory of Digestive CancerKey Laboratory of Cancer Prevention and Therapy of TianjinTianjin’s Clinical Research Center for CancerTianjin Medical University Cancer Institute and HospitalTianjin 300060China Department of Infection Management National Clinical Research Center for CancerKey Laboratory of Cancer Immunology and Biotherapy of TianjinTianjin Key Laboratory of Digestive CancerKey Laboratory of Cancer Prevention and Therapy of TianjinTianjin’s Clinical Research Center for CancerTianjin Medical University Cancer Institute and HospitalTianjin 300060China

BACKGROUND Cyclin-dependent kinase 9(CDK9)expression and autophagy in colorectal cancer(CRC)tissues has not been widely ***9,a key regulator of transcription,may influence the occurrence and progression of *** expression of auto-phagy-related genes BECN1 and drug resistance factor ABCG2 may also play a role in *** normal physiological conditions,autophagy can inhibit tumorigenesis,but once a tumor forms,autophagy may promote tumor ***,understanding the relationship between autophagy and cancer,partic-ularly how autophagy promotes tumor growth after its formation,is a key motivation for this *** To investigate the relationship between CDK9 expression and autophagy in CRC,assess differences in autophagy between left and right colon cancer,and analyze the associations of autophagy-related genes with clinical features and *** We collected tumor tissues and paracarcinoma tissues from colon cancer patients with liver metastasis to observe the level of autophagy in tissues with high levels of CDK9 and low levels of *** also collected primary tissue from left and right colon cancer patients with liver metastasis to compare the autophagy levels and the expression of BECN1 and ABCG2 in the tumor and paracarcinoma *** The incidence of autophagy and the expression of BECN1 and ABCG2 were different in left and right colon cancer,and autophagy might be involved in the occurrence of chemotherapy *** analysis of the rela-tionship between the expression of autophagy-related genes CDK9,ABCG2,and BECN1 and the clinical features and prognosis of colorectal cancer showed that the high expression of CDK9 indicated a poor prognosis in colorectal *** This study laid the foundation for further research on the combination of CDK9 inhibitors and autophagy inhibitors in the treatment of patients with CRC.

关键词： Autophagy Tumorigenesis Tumor tissue Paracarcinoma tissue Expression Left/right colon cancer

Intelligent geochemical interpretation of mass chromatograms:Based on convolution neural network

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Petroleum Science 2024年第2期21卷 752-764页

作者： Kai-Ming Su Jun-Gang lu jian Yu Zi-Xing lu Shi-jia Chen Hubei Key Laboratory of Petroleum Geochemistry and Environment Wuhan430100HubeiChina College of Resources and Environment Yangtze UniversityWuhan430100HubeiChina School of Geoscience and Technology Southwest Petroleum UniversityChengdu610500SichuanChina Changqing Oilfield Company PetroChinaXi'an710021ShaanxiChina

Gas chromatography-mass spectrometry(GC-MS)is an extremely important analytical technique that is widely used in organic *** is the only approach to capture biomarker features of organic matter and provides the key evidence for oil-source correlation and thermal maturity ***,the conventional way of processing and interpreting the mass chromatogram is both timeconsuming and labor-intensive,which increases the research cost and restrains extensive applications of this *** overcome this limitation,a correlation model is developed based on the convolution neural network(CNN)to link the mass chromatogram and biomarker features of samples from the Triassic Yanchang Formation,Ordos Basin,*** this way,the mass chromatogram can be automatically *** research first performs dimensionality reduction for 15 biomarker parameters via the factor analysis and then quantifies the biomarker features using two indexes(*** and PMI)that represent the organic matter thermal maturity and parent material type,***,training,interpretation,and validation are performed multiple times using different CNN models to optimize the model structure and hyper-parameter setting,with the mass chromatogram used as the input and the obtained MI and PMI values for supervision(label).The optimized model presents high accuracy in automatically interpreting the mass chromatogram,with R2values typically above 0.85 and0.80 for the thermal maturity and parent material interpretation results,*** significance of this research is twofold:(i)developing an efficient technique for geochemical research;(ii)more importantly,demonstrating the potential of artificial intelligence in organic geochemistry and providing vital references for future related studies.

关键词： Organic geochemistry Biomarker Mass chromatographic analysis Automated interpretation Convolution neural network Machine learning

Triple signal amplification electrochemical sensing platform for Hg^(2+) in water without direct modification of the working electrode

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Frontiers of Environmental Science & Engineering 2024年第7期18卷 157-167页

作者： Liuyin Hu jiahua Cui Tao lu Yalin Wang Jinping jia School of Environmental Science and Engineering Shanghai Jiao Tong UniversityShanghai 200240China School of Chemistry and Chemical Engineering Shanghai Jiao Tong UniversityShanghai 200240China International Copper Association Ltd.Shanghai 200020China

An ultrasensitive electrochemical biosensor to detect trace Hg^(2+)in environmental samples was developed utilizing nanogold-decorated magnetic reduced graphene oxide(MrGO-AuNPs),exonuclease III-assisted target cycle(Exo Ⅲ-ATC)and hybridization chain reaction(HCR)synergistic triple signal *** MrGO-AuNPs is a superior carrier for capture DNA(cDNA)and acts as magnetic media for automatic separation and *** innovative utilization of the magnetism and improved sensing efficiency obviates the need for direct modification and repeated polishing of the working ***,the three DNA hairpins(cDNA,methylene blue(MB)labeled HP1 and HP2)further contribute to biosensor specificity and *** cDNA captures Hgt,it activates Exo Ⅲ-ATC due to the formation of a sticky end in the DNA stem via thymine-Hig-thymidine(T-Hg^(2+)-T),this leads to the hydrolysis of self-folded DNA by Exo Ⅲ-ATC to form"key"DNA(kDNA).The kDNA subsequently initiates HCR,resulting in massive super-sandwich structures(kDNA-[HP1/HP2])carrying signaling molecules on MrGO-AuNPs,and this overall structure serves as a signal probe(SP).Leveraging magnetic adsorption,the SP was automatically adsorbed onto the magneto-glass carbon electrode(MGCE),generating an amplified *** biosensor's detection limit(LOD)was 3.14 pmol/L,far below the limit of 10 nmol/L for mercury in drinking water set by the US *** biosensor also showed excellent selectivity when challenged by interfering ions,and the results of its application in actual samples indicate that it has good potential for practical applications in environmental monitoring.

关键词： Electrochemical sensing Hg^(2+) Amplification Graphene Hybridization chain reaction Exonuclease Ⅲ