The relative reactivity of a systematic series of simple aliphatic acetate esters has been measured. Exposure of pairs of esters of increasing remote steric hindrance (by altering the degree of branching of the ester alkyl group) to a methanolic solution of CsCO proved to be a reliable (and general) method for quantitating the rate differences in these base-catalyzed transesterification reactions. The trends in relative rates are in accordance with the qualitative "Rule of Six" put forward by Melvin S. Newman in 1950, as deduced then from interpretation of earlier reports of ease of Fischer esterification reactions.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1021/acs.joc.4c01673 | DOI Listing |
Otolaryngol Head Neck Surg
January 2025
Department of Otolaryngology-Head and Neck Surgery, Thomas Jefferson University Hospital, Philadelphia, Pennsylvania, USA.
Objective: We aim to explore the differences in complication rates in endoscopic versus open transcervical treatment of Zenker diverticulum.
Study Design: Retrospective Cohort Study from January 1, 2015 to December 31, 2023.
Setting: Queries of the TriNetX database's United States Collaborative Network.
Biomol Biomed
December 2024
Department of General Surgery, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, China.
Severe acute pancreatitis (SAP) is one of the leading causes of hospital admissions for gastrointestinal diseases, with a rising incidence worldwide. Intestinal microbiota dysbiosis caused by SAP exacerbates systemic inflammatory response syndrome and organ dysfunction. Fecal microbiota transplantation (FMT) has emerged as a promising therapeutic option for gastrointestinal diseases.
View Article and Find Full Text PDFJ Clin Tuberc Other Mycobact Dis
December 2024
Department of Microbiology and Virology, School of Medicine, Jiroft University of Medical Sciences, Jiroft, Iran.
Background: Leprosy is a chronic infectious disease caused by () However, the emergence of drug-resistant strains of this bacterium, especially multidrug-resistant (MDR) strains, is a serious concern. This study aimed to evaluate the global prevalence of MDR and its implications.
Methods: Using PRISMA guidelines, we systematically reviewed ISI Web of Science, MEDLINE, and EMBASE up to August 2023 to assess the prevalence of MDR .
Front Microbiol
December 2024
College of Biology, Hunan University, Changsha, China.
Introduction: Dengue viruses (DENVs), the causative agents of dengue hemorrhagic fever and dengue shock syndrome, undergo genetic mutations that result in new strains and lead to ongoing global re-infections.
Objectives: To address the growing complexity of identifying and tracking biological samples, this study screened RNA barcode segments for the four DENV serotypes, ensuring high specificity and recall rates for DENV identification using segments.
Results: Through analyzing complete genome sequences of DENVs, we screened eight barcode segments for DENV, DENV-1, DENV-2, DENV-3, and DENV-4 identification.
Front Microbiol
December 2024
Department of Earth Sciences, University of Southern California, Los Angeles, CA, United States.
Microbial activity in the deep continental subsurface is difficult to measure due to low cell densities, low energy fluxes, cryptic elemental cycles and enigmatic metabolisms. Nonetheless, direct access to rare sample sites and sensitive laboratory measurements can be used to better understand the variables that govern microbial life underground. In this study, we sampled fluids from six boreholes at depths ranging from 244 m to 1,478 m below ground at the Sanford Underground Research Facility (SURF), a former goldmine in South Dakota, United States.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!