The plasmid pCRG1600 is a 52.9-kb self-transmissible plasmid coding for resistance to aminoglycoside and beta-lactam antibiotics in Staphylococcus aureus. When transferred by transduction, plasmid deletion mutants affecting one or more antibiotic-resistance genes were readily obtained. Of these, one derivative (pCRG1690) was found to exhibit a conjugal transfer frequency ca. 100-fold higher than that of the wild-type plasmid. A preliminary physical-genetic map of pCRG1600 located tra in a 14.6-kb region within the 16.9-kb XbaI-A fragment. An 8.5-kb deletion to the left of tra in pCRG1690 was specifically associated with the increased conjugal transferability of the plasmid. Thus, pCRG1690 appears similar to plasmids derepressed for conjugal transfer (drd) in gram-negative bacterial species.
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http://dx.doi.org/10.1016/0147-619x(84)90044-1 | DOI Listing |
Org Lett
January 2025
Department of Chemistry, Ben-Gurion University of the Negev, Beer-Sheva 8410501, Israel.
A novel class of bis-8-aryl-isoquinoline () bis-alkylamine iron complexes, Fe()(OTf) and Fe()(OTf) ( = dipyrrolidinyl or = ,'-dimethylcyclohexyl-diamine), for asymmetric oxidation reactions is reported. The scalable divergent synthesis of 8-aryl-3-formylisoquinolines (), the key intermediates in preparing these ligands, enables precise structural and electronic tuning around the metal center. The enantioselective epoxidation and hydroxy carbonylation of conjugated alkenes, mediated by the Fe() catalyst with HO as the oxidant, demonstrates the potential of these redox Fe[N] catalysts in inducing face selection in oxygen transfer transformations.
View Article and Find Full Text PDFMicrob Drug Resist
January 2025
NHC Key Laboratory of Assisted Circulation, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China.
is an important cause of pyogenic infections, bacteremia, and chronic maxillary sinusitis. Mobile genetic elements (MGEs) play a key role in lateral gene transfer, resulting in broad transfer of antibiotic resistance genes (ARGs). However, studies on ARG-associated MGEs in are still rare.
View Article and Find Full Text PDFInorg Chem
January 2025
Univ. Grenoble Alpes, CNRS, CEA, IRIG, LCBM (UMR 5249), Grenoble F-38000, France.
Lanthanide(III) complexes with two-photon absorbing antennas are attractive for microscopy imaging of live cells because they can be excited in the NIR. We describe the synthesis and luminescence and imaging properties of two Eu complexes, and , with (-carbazolyl)-aryl-alkynyl-picolinamide and (-carbazolyl)-aryl-picolinamide antennas, respectively, conjugated to the TAT cell-penetrating peptides. Contrary to what was previously observed with related Eu complexes with carbazole-based antennas in a mixture of water and organic solvents, these two complexes show very low emission quantum yield (Φ < 0.
View Article and Find Full Text PDFMetallomics
January 2025
Department of Nutritional Sciences, University of Wisconsin, Madison, WI 53706, USA.
We previously used high pressure liquid chromatography (HPLC) coupled with Se-specific inductively coupled plasma mass spectrometry (ICP-MS) and molecule specific (ESI Orbitrap MS/MS) detection to study the increase in liver Se in turkeys and rats supplemented as selenite in high-Se (5 µg Se/g diet) and adequate-Se diets. We found that far more Se is present as selenosugar (seleno-N-acetyl galactosamine) than is present as selenocysteine (Sec) in true selenoproteins. In high-Se liver, the increase in liver Se was due to low molecular weight (LMW) selenometabolites as glutathione-, cysteine- and methyl-conjugates of the selenosugar, but also as high molecular weight (HMW) species as selenosugars decorating general proteins via mixed-disulfide bonds.
View Article and Find Full Text PDFNatl Sci Rev
February 2025
School of Chemistry, South China Normal University, Guangzhou 510006, China.
High-voltage lithium-metal batteries (HVLMBs) are appealing candidates for next-generation high-energy rechargeable batteries, but their practical applications are still limited by the severe capacity degradation, attributed to the poor interfacial stability and compatibility between the electrode and the electrolyte. In this work, a 2D conjugated phthalocyanine framework (CPF) containing single atoms (SAs) of cobalt (CoSAs-CPF) is developed as a novel artificial solid-electrolyte interphase (SEI) in which a large amount of charge is transferred to the CPF skeleton due to the Lewis acid activity of the Co metal sites and the strong electron-absorbing property of the cyano group (-CN), greatly enhancing the adsorption of the Li and regulating the Li distribution toward dendrite-free LMBs, which are superior to most of the reported SEI membranes. As a result, the Li||Li symmetrical cell with CoSAs-CPF-modified Li anodes (CoSAs-CPF@Li) exhibits a low polarization with an area capacity of 1.
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