A5079860724- Chemical Reaction Mechanisms
- Chemical Synthesis and Analysis
- Inorganic and Organometallic Chemistry
- Chemical Synthesis and Reactions
- HIV, Drug Use, Sexual Risk
- HIV/AIDS Research and Interventions
- Analytical Chemistry and Chromatography
- Chemical Reactions and Mechanisms
- Enzyme Catalysis and Immobilization
- Chemical Reactions and Isotopes
- Photochemistry and Electron Transfer Studies
- Organic and Inorganic Chemical Reactions
- Asymmetric Synthesis and Catalysis
- Mass Spectrometry Techniques and Applications
- LGBTQ Health, Identity, and Policy
- Sex work and related issues
- DNA and Nucleic Acid Chemistry
- Enzyme function and inhibition
- Organophosphorus compounds synthesis
- Various Chemistry Research Topics
- Spectroscopy and Quantum Chemical Studies
- Molecular spectroscopy and chirality
- Coordination Chemistry and Organometallics
- Adolescent Sexual and Reproductive Health
- Synthesis and Biological Evaluation
Cardiff University
2020-2025
Southmead Hospital
2024
Royal Veterinary College
2008
University of Kent
1981-2002
In-Q-Tel
1993
Northern Hospital
1984
Royal College of Surgeons of England
1984
Shell (United Kingdom)
1981
University of Oxford
1965
Dyson (United Kingdom)
1965
Research Article| July 01 1965 DIRECT EVIDENCE FOR AN ACYLATED THIOL AS INTERMEDIATE IN PAPAIN- AND FICIN-CATALYSED HYDROLYSES G LOWE; LOWE Search for other works by this author on: This Site PubMed Google Scholar A WILLIAMS Biochem J (1965) 96 (1): 189–193. https://doi.org/10.1042/bj0960189 Views Icon Article contents Figures & tables Video Audio Supplementary Data Peer Review Share MailTo Twitter LinkedIn Cite Get Permissions Citation LOWE, WILLIAMS; HYDROLYSES. 1 1965; doi: Download...
1. The Michaelis-Menten parameters for the papain-catalysed hydrolysis of a number alkyl, aryl and alkyl-thiol esters hippuric acid have been determined. 2. For all most alkyl studied, catalytic constant, k(0), is 2-3sec.(-1) probably represents deacylation common intermediate, hippuryl-papain. 3. Two hippurylamide, however, rate constants, less than 2-3sec.(-1). It possible to interpret available kinetic data in terms three-step mechanism which an enzyme-substrate complex first formed,...
ABSTRACT Introduction HIV prevention methods, such as pre‐exposure prophylaxis (PrEP), have been a significant contributing factor to global decline in transmission. PrEP has available through the NHS Wales since 2017. However, access is exclusively via sexual health clinics, and those accessing do not reflect being diagnosed with HIV. Widening beyond clinics may be one approach encourage more equitable uptake, there growing interest offering services community pharmacies. We, therefore,...
Book Review| August 01 1980 Enzymic and Non-enzymic Catalysis Catalysis. P. DUNNILL, A. WISEMAN, N. BLAKEBOROUGH. Ellis HorwoodChichester 1979 pp. 249, £19.75 WILLIAMS Search for other works by this author on: This Site PubMed Google Scholar Biochem Soc Trans (1980) 8 (4): 470–471. https://doi.org/10.1042/bst0080470a Views Icon Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Twitter LinkedIn Cite Get Permissions Citation WILLIAMS; 1 1980; doi: Download...
1. The self-catalysed hydrolyses of the thiol esters, S-hippurylthioglycollic acid and S-ethyl monothiolsuccinate, have been shown to be slower than deacylation step for papain-catalysed hydrolysis hippuric by a factor approx. 10(5). This difference in rate constants largely reflects activation energy, which together with other evidence drawn from literature make it unlikely that carboxylate ion could nucleophile responsible acyl-papain. 2. imidazole-catalysed ethyl thiolacetate energies...
We examined PrEP use, condomless anal sex (CAS), and adherence among men who have with (MSM) attending sexual health clinics in Wales, UK. In addition, we explored the association between introduction of measures to control transmission SARS-CoV-2 on these outcomes. conducted an ecological momentary assessment study individuals receipt Wales. Participants used electronic medication cap record use completed weekly behaviour surveys. defined daily as percentage CAS episodes covered by...
Abstract Background Researchers are increasingly seeking to use routinely collected data support clinical trials. This approach has the potential transform way trials conducted in future. The availability of for research, whether healthcare or administrative, increased, and infrastructure funding enabled much this. However, challenges remain at all stages a trial life cycle. study, COMORANT-UK, aimed systematically identify, with key stakeholders across UK, ongoing related that seek data....
Objectives To describe the early impact of COVID-19 and associated control measures on sexual behaviour pre-exposure prophylaxis (PrEP) users in Wales. Methods Data were obtained from an ecological momentary assessment study PrEP use behaviour. Participants individuals accessing through National Health Service (NHS) health clinics across four boards Weekly data documenting condomless sex preceding week analysed between 03/02/2020 10/05/2020. The introduction social distancing changes to...
P. Gray and A. Williams, Trans. Faraday Soc., 1959, 55, 760 DOI: 10.1039/TF9595500760
Abstract Background The COVID-19 pandemic and its associated restrictions stopped people freely engaging in sexual behaviour. We explored behaviour amongst men who have sex with (MSM) using mixed methods during the multiple lockdowns Wales. Methods An online survey was advertised on social media platforms (focusing Welsh LGBT groups), from June 2020 to July 2020. MSM over 16 years were invited take part if they resident Qualitative interviews undertaken as of a study examining knowledge...
Kinetic parameters for the hydrolysis of substituted phenyl acetates and hippurates catalysed by alcalase have been measured at 25° 0·1M ionic strength. The pH-dependencies k0/Km parameter 4-methoxy- 4-chloro-phenyl 4-nitrophenyl acetate are identical sigmoid in shape three substrates. Acylation is probably rate-limiting step methyl hippurate hydrolyses because value k0 less than essentially constant aryl benzyl esters. (k0/Km used as a measure) insensitive to σ (ρ= 0·35, r= 0·788) but more...
HIV pre-exposure prophylaxis (PrEP) involves the use of antiretroviral medication in HIV-negative individuals considered to be at risk acquiring HIV. It has been shown prevent and available Wales since July 2017. Measuring understanding adherence PrEP is complex as it relies on simultaneous both sexual activity. We aimed understand experiences men who have sex with (MSM) living initiating, implementing persisting PrEP.We conducted semistructured interviews MSM users participated a cohort...
The British Student Doctor Journal is a high quality, open access, biannual, peer-reviewed, general medical journal, which publishes articles written primarily by students. In addition to publishing original research and systematic reviews, we also provide platform students express thought reflections on clinical practice, student life education.All of our content fully available without subscription with no authorship charges. All published in go through rigorous peer-review process, led...
Stigma may influence the use of HIV pre-exposure prophylaxis (PrEP). However, there is an absence robust measures for PrEP-related stigma. We describe adaptation a stigma scale in PrEP users and experiences Wales (UK) with regards to A mixed methods study was conducted where completed questionnaire items about subset were interviewed their taking PrEP. adapted from assessed construct validity internal consistency. analysed interview data using framework approach, themes focussing on enacted...
P. Gray, Rathbone and A. Williams, J. Chem. Soc., 1961, 2620 DOI: 10.1039/JR9610002620
ABSTRACT Background HIV Pre‐Exposure Prophylaxis (PrEP) has been available in Wales since 2017. The coronavirus disease (COVID‐19) pandemic impacted UK sexual health services, leading to a reduction service provision. There is lack of research on the experiences PrEP users during this time. Objective We aimed explore following introduction COVID‐19 measures. Methods conducted secondary data analysis two prior interview studies (DO‐PrEP and UPrEP). Data collection was undertaken between May...
We investigated the determinants of daily PrEP use and coverage condomless anal sex (CAS) by among men who have with in Wales, UK. measured electronic monitors CAS secure online surveys. defined based on medication cap openings as episodes preceded ≥ 3 days followed 2 use. included 57 participants (5463 observations). An STI diagnosis was associated lower but also coverage. Older adults had higher A belief that other users took prescribed is an important cue for intervention, reflecting...