Monomer model: an integrated characterization method of geometrical deviations for assembly accuracy analysis

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Binbin Zhao ◽  
Yunlong Wang ◽  
Qingchao Sun ◽  
Yuanliang Zhang ◽  
Xiao Liang ◽  
...  
Keyword(s):  
Weak Links ◽  
Small Displacement ◽  
Accuracy Analysis ◽  
Content Type ◽  
Assembly Accuracy ◽  
Rotor Assembly ◽  
Relationship Of ◽  
Assembly Deviation ◽  
First Time

Purpose Assembly accuracy is the guarantee of mechanical product performance, and the characterization of the part with geometrical deviations is the basis of assembly accuracy analysis. Design/methodology/approach The existed small displacement torsors (SDT) model cannot fully describe the part with multiple mating surfaces, which increases the difficulty of accuracy analysis. This paper proposed an integrated characterization method for accuracy analysis. By analyzing the internal coupling relationship of the different geometrical deviations in a single part, the Monomer Model was established. Findings The effectiveness of the Monomer Model is verified through an analysis of a simulated rotor assembly analysis, and the corresponding accuracy analysis method based on the model reasonably predicts the assembly deviation of the rotor. Originality/value The Monomer Model realizes the reverse calculation of assembly deformation for the first time, which can be used to identify the weak links that affect the assembly accuracy, thus support the accuracy improvement in the re-assembly stage.

scholarly journals Two Different Quinohemoprotein Amine Dehydrogenases Initiate Anaerobic Degradation of Aromatic Amines inAromatoleum aromaticumEbN1

2019 ◽  
Vol 201 (16) ◽  
Author(s):  
Georg Schmitt ◽  
Martin Saft ◽  
Fabian Arndt ◽  
Jörg Kahnt ◽  
Johann Heider
Keyword(s):  
Aromatic Amines ◽  
Catalytic Efficiency ◽  
Growth Conditions ◽  
Complete Replacement ◽  
Content Type ◽  
Enzyme Family ◽  
First Time ◽  
Α Subunits ◽  
Substrate Spectrum

ABSTRACTAromatic amines like 2-phenylethylamine (2-PEA) and benzylamine (BAm) have been identified as novel growth substrates of the betaproteobacteriumAromatoleum aromaticumEbN1, which degrades a wide variety of aromatic compounds in the absence of oxygen under denitrifying growth conditions. The catabolic pathway of these amines was identified, starting with their oxidative deamination to the corresponding aldehydes, which are then further degraded via the enzymes of the phenylalanine or benzyl alcohol metabolic pathways. Two different periplasmic quinohemoprotein amine dehydrogenases involved in 2-PEA or BAm metabolism were identified and characterized. Both enzymes consist of three subunits, contain two hemeccofactors in their α-subunits, and exhibit extensive processing of their γ-subunits, generating four intramolecular thioether bonds and a cysteine tryptophylquinone (CTQ) cofactor. One of the enzymes was present in cells grown with 2-PEA or other substrates, showed an α2β2γ2composition, and had a rather broad substrate spectrum, which included 2-PEA, BAm, tyramine, and 1-butylamine. In contrast, the other enzyme was specifically induced in BAm-grown cells, showing an αβγ composition and activity only with BAm and 2-PEA. Since the former enzyme showed the highest catalytic efficiency with 2-PEA and the latter with BAm, they were designated 2-PEADH and benzylamine dehydrogenase (BAmDH). The catalytic properties and inhibition patterns of 2-PEADH and BAmDH showed considerable differences and were compared to previously characterized quinohemoproteins of the same enzyme family.IMPORTANCEThe known substrate spectrum ofA. aromaticumEbN1 is expanded toward aromatic amines, which are metabolized as sole substrates coupled to denitrification. The characterization of the two quinohemoprotein isoenzymes involved in degrading either 2-PEA or BAm expands the knowledge of this enzyme family and establishes for the first time that the necessary maturation of their quinoid CTQ cofactors does not require the presence of molecular oxygen. Moreover, the study revealed a highly interesting regulatory phenomenon, suggesting that growth with BAm leads to a complete replacement of 2-PEADH by BAmDH, which has considerably different catalytic and inhibition properties.

scholarly journals Construction and Application of a Functional Library of Cytochrome P450 Monooxygenases from the Filamentous Fungus Aspergillus oryzae

2011 ◽  
Vol 77 (9) ◽  
pp. 3147-3150 ◽  
Author(s):  
K. H. M. Nazmul Hussain Nazir ◽  
Hirofumi Ichinose ◽  
Hiroyuki Wariishi
Keyword(s):  
Cytochrome P450 ◽  
Aspergillus Oryzae ◽  
Cytochrome P450 Monooxygenases ◽  
Functional Screening ◽  
Content Type ◽  
P450 Monooxygenases ◽  
Rapid Characterization ◽  
Catalytic Functions ◽  
First Time

ABSTRACTA functional library of cytochrome P450 monooxygenases fromAspergillus oryzae(AoCYPs) was constructed in which 121 isoforms were coexpressed with yeast NADPH-cytochrome P450 oxidoreductase inSaccharomyces cerevisiae. Using this functional library, novel catalytic functions of AoCYPs, such as catalytic potentials of CYP57B3 against genistein, were elucidated for the first time. Comprehensive functional screening promises rapid characterization of catalytic potentials and utility of AoCYPs.

scholarly journals Fulminant Cryptosporidiosis after Near-Drowning: a Human Cryptosporidium parvum Strain Implicated in Invasive Gastrointestinal Adenocarcinoma and Cholangiocarcinoma in an Experimental Model

2012 ◽  
Vol 78 (6) ◽  
pp. 1746-1751 ◽  
Author(s):  
Gabriela Certad ◽  
Sadia Benamrouz ◽  
Karine Guyot ◽  
Anthony Mouray ◽  
Thierry Chassat ◽  
...  
Keyword(s):  
Stem Cell ◽  
Stem Cell Transplantation ◽  
Cryptosporidium Parvum ◽  
Severe Infection ◽  
Digestive Cancer ◽  
Content Type ◽  
Near Drowning ◽  
Neoplastic Process ◽  
First Time

ABSTRACTIn the present work, we report the characterization of aCryptosporidium parvumstrain isolated from a patient who nearly drowned in the Deule River (Lille, France) after being discharged from the hospital where he had undergone allogeneic stem cell transplantation. After being rescued and readmitted to the hospital, he developed fulminant cryptosporidiosis. The strain isolated from the patient's stools was identified asC. parvumII2A15G2R1 (subtype linked to zoonotic exposure) and inoculated into SCID mice. In this host, this virulentC. parvumisolate induced not only severe infection but also invasive gastrointestinal and biliary adenocarcinoma. The observation of adenocarcinomas that progressed through all layers of the digestive tract to the subserosa and spread via blood vessels confirmed the invasive nature of the neoplastic process. These results indicate for the first time that a human-derivedC. parvumisolate is able to induce digestive cancer. This study is of special interest considering the exposure of a large number of humans and animals to this waterborne protozoan, which is highly tumorigenic when inoculated in a rodent model.

scholarly journals Molecular characterization of a novel bla CTX-M-3-carrying Tn6741 transposon in Morganella morganii isolated from swine

2020 ◽  
Vol 69 (8) ◽  
pp. 1089-1094
Author(s):  
Xingwei Luo ◽  
Yajun Zhai ◽  
Dandan He ◽  
Xiaodie Cui ◽  
Yingying Yang ◽  
...  
Keyword(s):  
Type Species ◽  
Susceptibility Testing ◽  
Morganella Morganii ◽  
Ionization Time ◽  
Content Type ◽  
Genetic Environment ◽  
Link Type ◽  
Flight Mass Spectrometry ◽  
First Time

Introduction. The bla CTX-M-3 gene has rarely been reported in Morganella morganii strains and its genetic environment has not yet been investigated. Aim. To identify the bla CTX-M-3 gene in M. morganii isolated from swine and characterize its genetic environment. Methodology. A M. morganii isolate (named MM1L5) from a deceased swine was identified using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) and subjected to antimicrobial susceptibility testing. The bla genes were detected and then the genetic location and environment of bla CTX-M-3 were investigated by Southern blot and PCR mapping, respectively. The M. morganii bla CTX-M-3 gene was cloned and expressed in Escherichia coli . Results. Isolate MM1L5 harboured the bla CTX-M-3 and bla TEM-1 genes. The bla CTX-M-3 gene, located on the chromosome, was co-carried with an IS26 and bla TEM-1 gene by a novel 6361 bp IS26-flanked composite transposon, designated Tn6741. This transposon consisted of a novel bla CTX-M-3-containing module, IS26-ΔISEcp1-bla CTX-M-3-Δorf477-IS26 (named Tn6710), and a bla TEM-1-containing module, IS26-Δorf477-bla TEM-1-tnpR-IS26, differing from previous reports. Phylogenetic analysis showed a significant variation based on the sequence of Tn6741, as compared to those of other related transposons. Interestingly, although the cloned bla CTX-M-3 gene could confer resistance to ceftiofur, cefquinome, ceftriaxone and cefotaxime, one amino acid substitution (Ile-142-Thr) resulted in a significant reduction of resistance to these antimicrobials. Conclusion. This is the first time that bla CTX-M-3 has been identified on a chromosome from a M. morganii isolate. Furthermore, the bla CTX-M-3 gene was located with an IS26 element and bla TEM-1 gene on a novel IS26-flanked composite transposon, Tn6741, suggesting that Tn6741 might act as a reservoir for the bla CTX-M-3 and bla TEM-1 genes and may become an important vehicle for their dissemination among M. morganii .

Preparation and characterization of novel Yellow-Green fluorescent polymerizable dye and its copolymer with application of highly selective sensor for cations iron

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Hanieh Shaki
Keyword(s):  
Metal Ions ◽  
Covalent Bond ◽  
Analytical Techniques ◽  
Side Chain ◽  
Content Type ◽  
Photo Induced Electron Transfer ◽  
Green Fluorescent ◽  
First Time ◽  
Acrylonitrile Polymer

Purpose In this work, A new 4–(2-aminoethylene) amino-N-(2-hydroxyethyl)-1,8-naphthalimide with intense green fluorescent was synthesized. This low molecular weight compound was immobilized by forming a covalent-bond with an acrylonitrile polymer containing carboxylic acid groups. The new prepared dye and self-coloured polymer were characterized by analytical techniques. Design/methodology/approach The synthesized compounds were characterized by TLC, DSC, FTIR, 1HNMR, 13CNMR, GPC, UV–visible and Fluorometery. The photophysical characteristics of the dye and polymer containing naphthalimide moiety in the side chain, were measured both in the absence and in the presence of Ag+, Cd+2, Co+2, Cr+3, Cu+2, Fe+3, Hg+2, Ni+2, Pb+2 and Zn+2 cations. Findings The results showed that the characterization of the synthesized dye and its polymer verified their structural correctness. It is shown that dye and polymer are photo-induced electron transfer (PET) fluorescent sensors which exhibit fluorescence quenching in the presence of metal ions. Among the various metal ions, both dye and polymer are more sensitive to Fe+3 cations. Originality/value This study is original. A 4–(2-aminoethylene) amino-N-(2-hydroxyethyl)-1,8-naphthalimide and its self-coloured polymer were synthesized for the first time, successfully.

Cost efficiency and service effectiveness for university e-libraries in Taiwan

2014 ◽  
Vol 32 (3) ◽  
pp. 308-321 ◽  
Author(s):  
Ling-Feng Hsieh ◽  
Jiung-Bin Chin ◽  
Mu-Chen Wu
Keyword(s):  
Cost Efficiency ◽  
Assessment Model ◽  
Content Type ◽  
Service Effectiveness ◽  
Related Data ◽  
The Cost ◽  
The University ◽  
Relationship Of ◽  
First Time

Purpose – The aim of this paper is to construct a model of cost efficiency and service effectiveness for a university e-library to allocate e-resources cost and to attain quality of service enhancement and cater to the needs of readers with existing e-resources. Design/methodology/approach – The paper establishes an assessment model for the cost efficiency and service effectiveness of a university e-library in Taiwan. It then proceeds with an empirical study and analysis of related data collected from e-libraries of 16 universities. A discussion of the results of the study and suggestions for the adjustment of the university e-libraries follows. Findings – The paper combines two models of cost efficiency and service effectiveness for the first time to analyze and consider the output results created by the input cost of university e-libraries in Taiwan and their utilization by readers. Originality/value – The paper builds a figure for the relationship of e-library cost efficiency and service effectiveness at 16 universities in Taiwan and then divides it into four types.

scholarly journals Expression and Functional Characterization of the First Bacteriophage-Encoded Chaperonin

2012 ◽  
Vol 86 (18) ◽  
pp. 10103-10111 ◽  
Author(s):  
Lidia P. Kurochkina ◽  
Pavel I. Semenyuk ◽  
Victor N. Orlov ◽  
Johan Robben ◽  
Nina N. Sykilinda ◽  
...  
Keyword(s):  
Thermal Inactivation ◽  
Functional Characterization ◽  
Content Type ◽  
Chaperonin Groel ◽  
Phage Propagation ◽  
Physicochemical Methods ◽  
First Time

Chaperonins promote protein foldingin vivoand are ubiquitously found in bacteria, archaea, and eukaryotes. The first viral chaperonin GroEL ortholog, gene product 146 (gp146), whose gene was earlier identified in the genome of bacteriophage EL, has been shown to be synthesized during phage propagation inPseudomonas aeruginosacells. The recombinant gp146 has been expressed inEscherichia coliand characterized by different physicochemical methods for the first time. Using serum against the recombinant protein, gp146's native substrate, the phage endolysin gp188, has been immunoprecipitated from the lysate of EL-infected bacteria and identified by mass spectrometry.In vitroexperiments have shown that gp146 has a protective effect against endolysin thermal inactivation and aggregation, providing evidence of its chaperonin function. The phage chaperonin has been found to have the architecture and some properties similar to those of GroEL but not to require cochaperonin for its functional activity.

scholarly journals First Characterization of CTX-M-15-Producing Escherichia coli Strains Belonging to Sequence Type (ST) 410, ST224, and ST1284 from Commercial Swine in South America

2016 ◽  
Vol 60 (4) ◽  
pp. 2505-2508 ◽  
Author(s):  
Ketrin C. Silva ◽  
Marina Moreno ◽  
Carlos Cabrera ◽  
Beny Spira ◽  
Louise Cerdeira ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
South America ◽  
Insertion Sequence ◽  
Sequence Type ◽  
Content Type ◽  
First Time ◽  
Genetic Context ◽  
New Reservoir

ABSTRACTWe report for the first time the isolation of CTX-M-15-producingEscherichia colistrains belonging to sequence type (ST) 410, ST224, and ST1284 in commercial swine in Brazil. TheblaCTX-M-15gene was located on F-::A9::B1 and C1::A9::B1 IncF-type plasmids, surrounded by a new genetic context comprising the IS26insertion sequence truncated with the ISEcp1element upstream ofblaCTX-M-15. These results reveal that commercial swine have become a new reservoir of CTX-M-15-producing bacteria in South America.

scholarly journals Acetylacetone-cleaving enzyme Dke1: a novel C-C-bond-cleaving enzyme from Acinetobacter johnsonii

2003 ◽  
Vol 369 (3) ◽  
pp. 573-581 ◽  
Author(s):  
Grit D. STRAGANZ ◽  
Anton GLIEDER ◽  
Lothar BRECKER ◽  
Douglas W. RIBBONS ◽  
Walter STEINER
Keyword(s):  
Metabolic Pathway ◽  
Metabolic Pathways ◽  
Active Protein ◽  
Acinetobacter Johnsonii ◽  
High Affinity ◽  
Gene Coding ◽  
High Yields ◽  
Relationship Of ◽  
First Time

The toxicity of acetylacetone has been demonstrated in various studies. Little is known, however, about metabolic pathways for its detoxification or mineralization. Data presented here describe for the first time the microbial degradation of acetylacetone and the characterization of a novel enzyme that initiates the metabolic pathway. From an Acinetobacter johnsonii strain that grew with acetylacetone as the sole carbon source, an inducible acetylacetone-cleaving enzyme was purified to homogeneity. The corresponding gene, coding for a 153 amino acid sequence that does not show any significant relationship to other known protein sequences, was cloned and overexpressed in Escherichia coli and gave high yields of active enzyme. The enzyme cleaves acetylacetone to equimolar amounts of methylglyoxal and acetate, consuming one equivalent of molecular oxygen. No exogenous cofactor is required, but Fe2+ is bound to the active protein and essential for its catalytic activity. The enzyme has a high affinity for acetylacetone with a Km of 9.1μM and a kcat of 8.5s-1. A metabolic pathway for acetylacetone degradation and the putative relationship of this novel enzyme to previously described dioxygenases are discussed.

scholarly journals Detection of Five mcr-9-Carrying Enterobacterales Isolates in Four Czech Hospitals

mSphere ◽  
2020 ◽  
Vol 5 (6) ◽  
Author(s):  
Ibrahim Bitar ◽  
Costas C. Papagiannitsis ◽  
Lucie Kraftova ◽  
Katerina Chudejova ◽  
Vittoria Mattioni Marchetti ◽  
...  
Keyword(s):  
Resistance Genes ◽  
Resistance Mechanisms ◽  
Mobile Elements ◽  
Citrobacter Freundii ◽  
Colistin Resistance ◽  
Content Type ◽  
Resistance Determinants ◽  
Enterobacter Hormaechei ◽  
First Time

ABSTRACT The aim of this study was to report the characterization of the first mcr-positive Enterobacterales isolated from Czech hospitals. In 2019, one Citrobacter freundii and four Enterobacter isolates were recovered from Czech hospitals. The production of carbapenemases was examined by a matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF MS) imipenem hydrolysis assay. Additionally, bacteria were screened for the presence of carbapenemase-encoding genes and plasmid-mediated colistin resistance genes by PCR. To define the genetic units carrying mcr genes, the genomic DNAs of mcr-carrying clinical isolates were sequenced on the PacBio Sequel I platform. Results showed that all isolates carried blaVIM- and mcr-like genes. Analysis of whole-genome sequencing (WGS) data revealed that all isolates carried mcr-9-like alleles. Furthermore, the three sequence type 106 (ST106) Enterobacter hormaechei isolates harbored the blaVIM-1 gene, while the ST764 E. hormaechei and ST95 C. freundii included blaVIM-4. Analysis of plasmid sequences showed that, in all isolates, mcr-9 was carried on IncHI2 plasmids. Additionally, at least one multidrug resistance (MDR) region was identified in each mcr-9-carrying IncHI2 plasmid. The blaVIM-4 gene was found in the MDR regions of p48880_MCR_VIM and p51929_MCR_VIM. In the three remaining isolates, blaVIM-1 was localized on plasmids (∼55 kb) exhibiting repA-like sequences 99% identical to the respective gene of pKPC-CAV1193. In conclusion, to the best of our knowledge, these 5 isolates were the first mcr-9-positive bacteria of clinical origin identified in the Czech Republic. Additionally, the carriage of the blaVIM-1 on pKPC-CAV1193-like plasmids is described for the first time. Thus, our findings underline the ongoing evolution of mobile elements implicated in the dissemination of clinically important resistance determinants. IMPORTANCE Infections caused by carbapenemase-producing bacteria have led to the revival of polymyxins as the “last-resort” antibiotic. Since 2016, several reports describing the presence of plasmid-mediated colistin resistance genes, mcr, in different host species and geographic areas were published. Here, we report the first detection of Enterobacterales carrying mcr-9-like alleles isolated from Czech hospitals in 2019. Furthermore, the three ST106 Enterobacter hormaechei isolates harbored blaVIM-1, while the ST764 E. hormaechei and ST95 Citrobacter freundii isolates included blaVIM-4. Analysis of WGS data showed that, in all isolates, mcr-9 was carried on IncHI2 plasmids. blaVIM-4 was found in the MDR regions of IncHI2 plasmids, while blaVIM-1 was localized on pKPC-CAV1193-like plasmids, described here for the first time. These findings underline the ongoing evolution of mobile elements implicated in dissemination of clinically important resistance determinants. Thus, WGS characterization of MDR bacteria is crucial to unravel the mechanisms involved in dissemination of resistance mechanisms.

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