Publications by authors named "L Grant"

662 Publications

Designing and managing distributed learning: we're all in this together.

Rural Remote Health 2021 Jun 11;21(2):6171. Epub 2021 Jun 11.

CenMEDIC, 27 Church Street, Hampton, Middlesex TW12 2EB, UK

View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.22605/RRH6171DOI Listing
June 2021

1,2-Addition and cycloaddition reactions of niobium bis(imido) and oxo imido complexes.

Chem Sci 2020 Oct 9;11(42):11613-11632. Epub 2020 Oct 9.

Department of Chemistry, University of California Berkeley CA 94720 USA

The bis(imido) complexes (BDI)Nb(N Bu) and (BDI)Nb(N Bu)(NAr) (BDI = ,'-bis(2,6-diisopropylphenyl)-3,5-dimethyl-β-diketiminate; Ar = 2,6-diisopropylphenyl) were shown to engage in 1,2-addition and [2 + 2] cycloaddition reactions with a wide variety of substrates. Reaction of the bis(imido) complexes with dihydrogen, silanes, and boranes yielded hydrido-amido-imido complexes 1,2-addition across Nb-imido π-bonds; some of these complexes were shown to further react insertion of carbon dioxide to give formate-amido-imido products. Similarly, reaction of (BDI)Nb(N Bu) with -butylacetylene yielded an acetylide-amido-imido complex. In contrast to these results, many related mono(imido) Nb BDI complexes do not exhibit 1,2-addition reactivity, suggesting that π-loading plays an important role in activating the Nb-N π-bonds toward addition. The same bis(imido) complexes were also shown to engage in [2 + 2] cycloaddition reactions with oxygen- and sulfur-containing heteroallenes to give carbamate- and thiocarbamate-imido complexes: some of these complexes readily dimerized to give bis-μ-sulfido, bis-μ-iminodicarboxylate, and bis-μ-carbonate complexes. The mononuclear carbamate imido complex (BDI)Nb(NAr)(N( Bu)CO) () could be induced to eject -butylisocyanate to generate a four-coordinate terminal oxo imido intermediate, which could be trapped as the five-coordinate pyridine or DMAP adduct. The DMAP adducted oxo imido complex (BDI)NbO(NAr)(DMAP) () was shown to engage in 1,2-addition of silanes across the Nb-oxo π-bond; this represents a new reaction pathway in group 5 chemistry.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1039/d0sc03489dDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8162998PMC
October 2020

Does influenza vaccination attenuate the severity of breakthrough infections? A narrative review and recommendations for further research.

Vaccine 2021 Jun 2. Epub 2021 Jun 2.

Influenza Division, Centers for Disease Control and Prevention, Atlanta, GA, United States.

The effect of influenza vaccination on influenza severity remains uncertain. We reviewed the literature for evidence to inform the question of whether influenza illness is less severe among individuals who received influenza vaccination compared with individuals with influenza illness who were unvaccinated prior to their illnesses. We conducted a narrative review to identify published findings comparing severity of influenza outcomes by vaccination status among community-dwelling adults and children ≥ 6 months of age with laboratory-confirmed influenza illness. When at least four effect estimates of the same type (e.g., odds ratio) were available for a specific outcome and age category (children versus adults), data were pooled with meta-analysis to generate a summary effect estimate. We identified 38 published articles reporting ≥ 1 association between influenza vaccination status and one of 21 indicators of severity of influenza illness among individuals with laboratory-confirmed influenza. Study methodologies and effect estimates were highly heterogenous, with only five severity indicators meeting criteria for calculating a combined effect. Among eight studies, influenza vaccination was associated with 26% reduction in odds of ICU admission among adults with influenza-associated hospitalization (OR = 0.74, 95% CI 0.58, 0.93). Among five studies of adults with influenza-associated hospitalization, vaccinated patients had 31% reduced risk of death compared with unvaccinated patients (OR = 0.69, 95% CI 0.52, 0.92). Among four studies of children with influenza virus infection, vaccination was associated with an estimated 45% reduction in the odds of manifesting fever (OR = 0.55, 95% CI 0.42, 0.71). Vaccination was not significantly associated with receiving a clinical diagnosis of pneumonia among adults hospitalized with influenza (OR = 0.92, 95% CI 0.82, 1.04) or with risk of hospitalization following outpatient influenza illness among adults (OR = 0.60, 95% CI 0.28, 1.28). Overall, our findings support the hypothesis that influenza vaccination may attenuate the course of disease among individuals with breakthrough influenza virus infection.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.vaccine.2021.05.011DOI Listing
June 2021

COVID-19 Infection, Reinfection, and Vaccine Effectiveness in a Prospective Cohort of Arizona Frontline/Essential Workers: The AZ HEROES Research Protocol.

JMIR Res Protoc 2021 May 26. Epub 2021 May 26.

University of Arizona, Mel and Enid Zuckerman College of Public Health, Tucson, US.

Background: The Arizona Healthcare, Emergency Response, and Other Essential workers Study (AZ HEROES) aims to examine the epidemiology of SARS-CoV-2 infection and COVID-19 illness among adults with high occupational exposure risk.

Objective: Study objectives include estimating incidence of SARS-CoV-2 infection in essential workers by symptom presentation and demographic factors, determining independent effects of occupational and community exposures on incidence of SARS-CoV-2 infection, establishing molecular and immunologic characteristics of SARS-CoV-2 infection in essential workers, describing the duration and patterns of rRT-PCR-positivity, and examining post-vaccine immunologic response.

Methods: Eligible participants include Arizona residents aged 18-85 years who work at least 20 hours per week in an occupation involving regular direct contact (within three feet) with others. Recruitment goals are stratified by demographic characteristics (50% aged 40 or older, 50% women, and 50% Hispanic or American Indian), by occupation (40% healthcare personnel, 30% first responders, and 30% other essential workers), and by prior SARS-CoV-2 infection (with up to 50% seropositive at baseline). Information on sociodemographics, health and medical history, vaccination status, exposures to individuals with suspected or confirmed SARS-CoV-2 infection, use of personal protective equipment, and perceived risks are collected at enrollment and updated through quarterly surveys. Every week, participants complete active surveillance for COVID-19-like illness (CLI) and self-collect nasal swabs. Additional self-collected nasal swab and saliva specimens are collected in the event of CLI onset. Respiratory specimens are sent to Marshfield Laboratories and tested for SARS-CoV-2 by real-time reverse transcription polymerase chain reaction (rRT-PCR) assay. CLI symptoms and impact on work and productivity are followed through illness resolution. Serum specimens are collected every 3 months and additional sera are collected following incident rRT-PCR positivity and after each COVID-19 vaccine dose. Incidence of SARS-CoV-2 infections will be calculated by person-weeks at risk and compared by occupation and demographic characteristics and by seropositivity status and infection and vaccination history.

Results: The AZ HEROES study was funded by the Centers for Disease Control and Prevention. Enrollment began July 27, 2020 and as of May 1, 2021 a total of 3,165 participants have been enrolled in the study.

Conclusions: AZ HEROES is unique in aiming to recruit a diverse sample of essential workers and prospectively following strata of SARS-CoV-2 seronegative and seropositive adults. Survey results combined with active surveillance data on exposure, CLI, weekly molecular diagnostic testing, and periodic serology will be used to estimate the incidence of symptomatic and asymptomatic SARS-CoV-2 infection, assess the intensity and durability of immune responses to natural infection and COVID-19 vaccination, and contribute to the evaluation of COVID-19 vaccine effectiveness.

Clinicaltrial:

International Registered Report: DERR1-10.2196/28925.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.2196/28925DOI Listing
May 2021

Growth and renal function dynamics of renal oncocytomas on active surveillance.

BJU Int 2021 May 28. Epub 2021 May 28.

Division of Surgery and Interventional Science, University College London.

Objectives: To study the natural history of renal oncocytomas and address indications for intervention by determining how growth associates with renal function over time, the reasons for surgery and ablation, and disease-specific survival.

Patients And Methods: Retrospective cohort of consecutive patients with renal oncocytoma on active surveillance reviewed at the Specialist Centre for Kidney Cancer at Royal Free London NHS Foundation Trust (2012 to 2019). Comparison between groups was tested using the Mann-Whitney U and the Chi-square tests. A mixed-effects model with a random intercept for patient was used to study the longitudinal association between tumour size and estimated glomerular filtration rate (eGFR).

Results: Longitudinal data from 98 patients with 101 lesions was analysed. Most patients were male (68.3%), median age was 69 years (IQR 13). The median follow-up was 29 months (IQR 26). Most lesions were small renal masses, 24% measured over 4 cm. Over half (64.4%) grew at a median rate of 2 mm per year (IQR 4). No association was observed between tumour size and eGFR over time (p=0.871). Nine lesions (8.9%) were subsequently treated. Two deaths were reported, neither were related to the diagnosis of renal oncocytoma.

Conclusion: Natural history data from the largest active surveillance cohort of renal oncocytomas to date show that renal function does not seem to be negatively impacted by growing oncocytomas, and confirms clinical outcomes are excellent after a median follow up of over 2 years. Active surveillance should be considered the gold standard management of renal oncocytomas up to 7cm.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/bju.15499DOI Listing
May 2021