Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 20 of 22 for “"Beta lactams"”.
-
Chromatographic Separation of Enantiomers of Some Physiologically Active Types of Compounds on Chiral Stationary Phases (Benzodiazepinones, Beta-Lactams, Beta-Aminoacids)
… enantiomers and enantiomers of aryl substituted (beta)-lactams can be separated directly on amino acid derived chiral stationary phases, whereas (beta)-amino acid enantiomers can be separated, after conversion to the dinitrobenzamide esters, on amide or N-aryl amino acid derived chiral stationary …
-
Enantioenriched Homoaldol Products, Beta-Substituted Ketones, Isoxazolines, and Beta-Lactams Through Elaboration of Allylamine Asymmetric Homoenolate Equivalents: Synthesis and Elucidation of Reaction Pathways
… was converted into an enantiomerically pure beta-lactam via a beta-amino alcohol and a beta-amino acid in six synthetic steps in 25% overall yield.
-
Exploring and enhancing context-dependent beta-lactam antibiotic efficacy
Antibiotics, such as beta-lactams, are essential medical tools for the treatment of bacterial infections. Unfortunately, clinical treatment efficacy is declining over time as bacteria adapt to and evade antibiotic treatment through mechanisms called antibiotic resistance, tolerance, and …
-
Molecular methods for the detection of TEM- and SHV-related beta lactamase genes in members of the Enterobacteriaceae
… is a common and important clinical problem. Beta lactam resistance in Gram negative bacilli is mediated predominantly by beta lactamases, enzymes able to hydrolyse the beta lactam ring. The commonest plasmid mediated beta lactamases in the Enterobacteriaceae are those related to either TEM-1 …
-
Synthetic applications of the aza-Achmatowicz rearrangement
… izidinie alkaloid systems, $\beta$-lactams, and unusual amino acids.
-
Improved synthesis and application of planar-chiral nucleophilic catalysts in asymmetric reactions and copper-catalyzed enantioselective N-H insertion reactions
… the first asymmetric synthesis of trans P-lactams, and Chapter 3 describes the asymmetric synthesis of tertiary a-chloroesters. In the chapter describing the asymmetric synthesis of trans [beta]-lactams, we present mechanistic data supporting a novel mechanism, in which the N-triflylimine, …
-
Antibiotic Tolerance and Heteroresistance: Associated Fitness Costs and Potential in Evading Antibiotic Killing
… to a variety of antibiotic treatments, including beta-lactams, macrolides, and fluoroquinolones.</p> <p>In the first chapter, we focused on fluoroquinolone resistance in S. pneumoniae. Fluoroquinolones are one of the most frequently prescribed antibiotics, yet fluoroquinolone resistance in S. …
-
Phenotypic and molecular characterization of coagulase negative staphylococci from pigs and humans in Lusaka province, Zambia.
… prevalence of multidrug resistance at 60.7% to beta-lactams, tetracyclines, phenicols, sulfonamides, lincosamides and aminoglycosides. While, Methicillin Resistant-CoNS were prevalent when tested using phenotypic methods, none of the MR-CoNS tested positive for the mecA gene using PCR, …
-
Phenotypic and molecular characterization of coagulase negative staphylococci from pigs and humans in Lusaka province, Zambia.
… prevalence of multidrug resistance at 60.7% to beta-lactams, tetracyclines, phenicols, sulfonamides, lincosamides and aminoglycosides. While, Methicillin Resistant-CoNS were prevalent when tested using phenotypic methods, none of the MR-CoNS tested positive for the mecA gene using PCR, …
-
Molecular Mechanisms of Antimicrobial Resistance In Multi-Drug Resistant Enterococci
… resistant to valuable antibiotics, like beta-lactams, or evolve resistance to all existing antimicrobials. The LiaFSR system regulates resistance to cell membrane (CM) stressors like daptomycin (DAP), a front-line drug for multi-drug resistant infections. DAP resistance (DAP-R) in <em>E. …
-
Characterization of Metronidazole- and Vancomycin-Resistant Clinical Isolates of Clostridium Difficile
… to antibiotics such as fluoroquinolones and beta lactams, which has made the treatment of CDI very challenging. Currently, metronidazole and vancomycin are the most commonly used drugs for the treatment of primary CDI. Metronidazole is used for the treatment of mild to non-severe cases of CDI …
-
Improving antibiotic therapy for Mycobacterium tuberculosis
… the potential of specific combinations, such as beta-lactams with aminoglycosides or clofazimine, to enhance Mtb killing, while also identifying combinations that may reduce treatment efficacy due to antagonistic effects. I also analysed the metabolism of antibiotics within Mtb and examined how …
-
Defining the Aetiology and Antimicrobial Susceptibility Patterns of the Predominant Bacteria Associated with Bloodstream Infections at the Hospital for Tropical Diseases in Ho Chi Minh City, Vietnam
… genes. These genes include extended spectrum Beta lactamases (ESBLs) and AmpC lactamases in the Enterobacteriaceae, methicillin-resistance genes in <i>Staphylococcus aureus</i>, carbapenemase-resistance genes in Gram-negative bacilli and vancomycin-resistance genes in enterococcus. Asian …
-
Cargo delivery into gram-negative bacteria via enterobactin uptake machinery
… enterobactin-antibiotic conjugates, where the [beta]-lactam antibiotics ampicillin (Amp) and amoxicillin (Amx) are linked to a monofunctionalized enterobactin scaffold via a stable polyethyleneglycol linker are reported. Under conditions of iron limitation, these siderophore-modified antibiotics …
-
Investigating and engineering the post-translational modifications in RiPP natural product biosynthesis (I) Thiopeptides (II) Sactipeptides
… including well-known antibiotics such as the beta-lactams, tetracyclines, macrolides, and glycopeptides. With the rising resistance to these proven antibiotic classes, alternative sources of antibiotics must be discovered. The ribosomally synthesized and post-translationally modified peptides …
-
Photoassisted Generation of Complex N, O, S Polyheterocycles
… that contained the biologically relevant beta-lactam fragment.</p> <p>A summation of engineering work is also included to detail the development and implementation of several new LED irradiators. These irradiators are key to the photochemistry that will be discussed, and their development …
-
A general catalytic β-C–H carbonylation of aliphatic amines to β-lactams
Carbonyl compounds are of central importance to organic chemistry and their reactions have been described as the ‘backbone of organic synthesis’. Over recent decades, palladium-catalysed C–H carbonylation reactions have emerged as a powerful means of introducing carbonyl motifs to organic …
-
Nasopharyngeal colonization dynamics with Streptococcus pneumoniae and associated antimicrobial resistance in a South African birth cohort
… in the pbp1a and pbp2x genes, known to confer beta-lactam resistance, were identified in penicillin nonsusceptible ST705215B/15C isolates. A total of 329 antimicrobial resistance (AMR) genes were detected in 64% (125/196) of the sequenced samples, including 36 non-redundant genes ranging from 1 …
-
Studying the riboregulatory role of Hfq in Klebsiella pneumoniae using CLASH (crosslinking, ligation and sequencing of hybrids)
In nature, microorganisms are frequently exposed to different types of stresses, such as temperature fluctuations, osmotic pressure, pH variations, nutrient availability changes, attack by host immunity, exposure to free radicals and antibiotics. In response, microorganisms employ various …
Page 1 of 2