2 research outputs found
Transient anosmia and dysgeusia in COVID-19 disease: a cross sectional study
Objective: This study aims to explore the prevalence of anosmia and dysgeusia and their impact on COVID-19 patients.
Methods: This is a cross-sectional study. Patients diagnosed with COVID-19 between 1st October 2020 and 30th June 2021 were randomly selected from a national COVID-19 registry. COVID-19 cases were diagnosed using molecular testing method which measured the viral E gene. The Anosmia Reporting Tool, and a brief version of the questionnaire on olfactory disorders were used to measure the outcomes via telephone interviews. Data were analysed using SPSS 27 statistics software.
Results: A total of 405 COVID-19 adults were included in this study, 220 (54.3%) were males and 185 (45.8%) were females. The mean±SD age of participants was 38.2 ± 11.3 years. Alterations in the sense of smell and taste were reported by 206 (50.9%), and 195 (48.1%) of the patients, respectively. Sex and nationality of participants were significantly associated with anosmia and dysgeusia (p
Conclusion: Anosmia and dysgeusia are prevalent symptoms of COVID-19 disease, especially among females. Although transient, anosmia and dysgeusia had considerable impact on patient's life. Neuropsychological implications of COVID-19 in acute infection phase and prognosis of anosmia and dysgeusia in COVID-19 are areas for further exploration.</p
Mapping the Reactivity and Selectivity of 2‑Azidofucosyl Donors for the Assembly of <i>N</i>‑Acetylfucosamine-Containing Bacterial Oligosaccharides
The synthesis of complex oligosaccharides
is often hindered by
a lack of knowledge on the reactivity and selectivity of their constituent
building blocks. We investigated the reactivity and selectivity of
2-azidofucosyl (FucN<sub>3</sub>) donors, valuable synthons in the
synthesis of 2-acetamido-2-deoxyfucose (FucNAc) containing oligosaccharides.
Six FucN<sub>3</sub> donors, bearing benzyl, benzoyl, or <i>tert</i>-butyldimethylsilyl protecting groups at the C3-<i>O</i> and C4-<i>O</i> positions, were synthesized, and their
reactivity was assessed in a series of glycosylations using acceptors
of varying nucleophilicity and size. It was found that more reactive
nucleophiles and electron-withdrawing benzoyl groups on the donor
favor the formation of β-glycosides, while poorly reactive nucleophiles
and electron-donating protecting groups on the donor favor α-glycosidic
bond formation. Low-temperature NMR activation studies of Bn- and
Bz-protected donors revealed the formation of covalent FucN<sub>3</sub> triflates and oxosulfonium triflates. From these results, a mechanistic
explanation is offered in which more reactive acceptors preferentially
react via an S<sub>N</sub>2-like pathway, while less reactive acceptors
react via an S<sub>N</sub>1-like pathway. The knowledge obtained in
this reactivity study was then applied in the construction of α-FucN<sub>3</sub> linkages relevant to bacterial saccharides. Finally, a modular
synthesis of the <i>Staphylococcus aureus</i> type 5 capsular
polysaccharide repeating unit, a trisaccharide consisting of two FucNAc
units, is described