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Article ; Online: Isotopic Fractionation as a Mechanistic Probe in Light-Driven C-H Bond Exchange Reactions.

Qiu, Guanqi / Ni, Chi-Li / Knowles, Robert R

Journal of the American Chemical Society

2023 Volume 145, Issue 21, Page(s) 11537–11543

Abstract: Here, we report a diagnostic framework for elucidating the mechanisms of photoredox-based hydrogen isotope exchange (HIE) reactions based on hydrogen/deuterium (H/D) fractionation. Traditional thermal HIE methods generally proceed by reversible bond ... ...

Abstract	Here, we report a diagnostic framework for elucidating the mechanisms of photoredox-based hydrogen isotope exchange (HIE) reactions based on hydrogen/deuterium (H/D) fractionation. Traditional thermal HIE methods generally proceed by reversible bond cleavage and bond reformation steps that share a common transition state. However, bond cleavage and bond reformation in light-driven HIE reactions can proceed via multiple, non-degenerate sets of elementary steps, complicating both mechanistic analysis and attendant optimization efforts. Building on classical treatments of equilibrium isotope effects, the fractionation method presented here extracts information regarding the nature of the key bond-forming and bond-breaking steps by comparing the extent of deuterium incorporation into an exchangeable C-H bond in the substrate relative to the H/D isotopic ratio of a solvent reservoir. We show that the extent of fractionation is sensitive to the mechanism of the exchange process and provides a means to distinguish between degenerate and non-degenerate mechanisms for isotopic exchange. In model systems, the mechanisms implied by the fractionation method align with those predicted by thermochemical considerations. We then employed the method to study HIE reactions whose mechanisms are ambiguous on thermodynamic grounds.
Language	English
Publishing date	2023-05-16
Publishing country	United States
Document type	Journal Article
ZDB-ID	3155-0
ISSN	1520-5126 ; 0002-7863
ISSN (online)	1520-5126
ISSN	0002-7863
DOI	10.1021/jacs.2c11212
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Article ; Online: Medication Adherence Across the Life Span in Inflammatory Bowel Disease: Implications and Recommendations for Nurses and Other Health Providers.

Knowles, Simon R / Alex, George

Gastroenterology nursing : the official journal of the Society of Gastroenterology Nurses and Associates

2020 Volume 43, Issue 1, Page(s) 76–88

Abstract: ... victimization with low social support. For adults, nonadherence is more frequently unintentional (e.g ...

Abstract	This article reviews the differences and similarities in medication adherence between adolescent and adult cohorts with inflammatory bowel disease. The review covers the rates of medication adherence, as well as predictors, consequences, and related interventions. Rates of adherence were more favorable among adolescents (65%-90%) than among adults (55%-70%). Major risk factors for poor adherence in adolescents include low medication knowledge, not establishing good medication habits initially, and peer victimization with low social support. For adults, nonadherence is more frequently unintentional (e.g., forgetting) and occurs more often in the context of a poor-quality patient-physician relationship, low medication knowledge, infrequent/missed appointments, busy lifestyle, and concurrent mental health concerns. Nonadherence to medication is associated with worsening of symptoms and risk of relapse in adults and adolescents. Nurses can play a significant role in influencing adherence to medication in patients with inflammatory bowel disease. In particular, nurses can help to impart knowledge on the importance of medication and identify factors that may help or hinder an individual in terms of adherence. Based on the current review, implications for practice and recommendations for nurses to promote medication adherence across both adolescent and adult cohorts are provided. Limitations of the currently available evidence and suggestions for future research are discussed.
MeSH term(s)	Adolescent ; Adult ; Age Factors ; Humans ; Inflammatory Bowel Diseases/drug therapy ; Inflammatory Bowel Diseases/psychology ; Medication Adherence ; Nurse's Role
Language	English
Publishing date	2020-01-25
Publishing country	United States
Document type	Journal Article ; Review
ZDB-ID	1109536-2
ISSN	1538-9766 ; 1042-895X
ISSN (online)	1538-9766
ISSN	1042-895X
DOI	10.1097/SGA.0000000000000467
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Article ; Online: Hybrid enrichment of adaptive variation revealed by genotype-environment associations in montane sedges.

Hodel, Richard G J / Massatti, Rob / Knowles, L Lacey

Molecular ecology

2022 Volume 31, Issue 13, Page(s) 3722–3737

Abstract: The role of hybridization in diversification is complex and may result in many possible outcomes. Not only can hybridization produce new lineages, but those lineages may contain unique combinations of adaptive genetic variation derived from parental taxa ...

Abstract	The role of hybridization in diversification is complex and may result in many possible outcomes. Not only can hybridization produce new lineages, but those lineages may contain unique combinations of adaptive genetic variation derived from parental taxa that allow hybrid-origin lineages to occupy unique environmental space relative to one (or both) parent(s). We document such a case of hybridization between two sedge species, Carex nova and Carex nelsonii (Cyperaceae), that occupy partially overlapping environmental space in the southern Rocky Mountains, USA. In the region hypothesized to be the origin of the hybrid lineage, one parental taxon (C. nelsonii) is at the edge of its environmental tolerance. Hybrid-origin individuals display mixed ancestry between the parental taxa-of nearly 7000 unlinked loci sampled, almost 30% showed evidence of excess ancestry from one parental lineage-approximately half displayed a genomic background skewed towards one parent, and half skewed towards the other. To test whether excess ancestry loci may have conferred an adaptive advantage to the hybrid-origin lineage, we conducted genotype-environment association analyses on different combinations of loci-with and without excess ancestry-and with multiple contrasts between the hybrids and parental taxa. Loci with skewed ancestry showed significant environmental associations distinguishing the hybrid lineage from one parent (C. nelsonii), whereas loci with relatively equal representation of parental ancestries showed no such environmental associations. Moreover, the overwhelming majority of candidate adaptive loci with respect to environmental gradients also had excess ancestry from a parental lineage, implying these loci have facilitated the persistence of the hybrid lineage in an environment unsuitable to at least one parent.
MeSH term(s)	Carex Plant/genetics ; Genomics ; Genotype ; Humans ; Hybridization, Genetic
Language	English
Publishing date	2022-06-06
Publishing country	England
Document type	Journal Article ; Research Support, U.S. Gov't, Non-P.H.S.
ZDB-ID	1126687-9
ISSN	1365-294X ; 0962-1083
ISSN (online)	1365-294X
ISSN	0962-1083
DOI	10.1111/mec.16502
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Article ; Online: Neville Grace (1939-2022).

Knowles, Scott / Attwood, Graeme / Pacheco, David / Sanson, Robert

New Zealand veterinary journal

2022 Volume 70, Issue 5, Page(s) 245–247

MeSH term(s)	Animals ; Risk Assessment ; Risk Factors
Language	English
Publishing date	2022-07-11
Publishing country	England
Document type	Editorial
ZDB-ID	415642-0
ISSN	1176-0710 ; 0048-0169
ISSN (online)	1176-0710
ISSN	0048-0169
DOI	10.1080/00480169.2022.2094216
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Article ; Online: Broncholithiasis and Primary Ciliary Dyskinesia: An Association Not Identified in Other Chronic Airway Inflammatory Disorders.

Kennedy, Marcus P / Noone, Peadar G / Knowles, Michael R

Chest

2020 Volume 157, Issue 3, Page(s) 737

MeSH term(s)	Bronchial Diseases ; Humans ; Kartagener Syndrome ; Pulmonary Disease, Chronic Obstructive
Language	English
Publishing date	2020-02-29
Publishing country	United States
Document type	Letter ; Comment
ZDB-ID	1032552-9
ISSN	1931-3543 ; 0012-3692
ISSN (online)	1931-3543
ISSN	0012-3692
DOI	10.1016/j.chest.2019.10.055
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Article: Respiratory and low-temperature sweetening responses of fresh-cut potato (Solanum tuberosum L.) tubers to low oxygen

Ellis, G. D. / Knowles, L. O. / Knowles, N. R.

Postharvest biology and technology

2019 Volume 156, Issue -, Page(s) 110937

Document type	Article
ZDB-ID	1082798-5
ISSN	0925-5214
Database	Current Contents Nutrition, Environment, Agriculture

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Article ; Online: Implementation of a batched stepped wedge trial evaluating a quality improvement intervention for surgical teams to reduce anastomotic leak after right colectomy.

Venn, Mary L / Knowles, Charles H / Li, Elizabeth / Glasbey, James / Morton, Dion G / Hooper, Richard

Trials

2023 Volume 24, Issue 1, Page(s) 329

Abstract: Background: Large-scale quality improvement interventions demand robust trial designs with flexibility for delivery in different contexts, particularly during a pandemic. We describe innovative features of a batched stepped wedge trial, ESCP sAfe ... ...

Abstract	Background: Large-scale quality improvement interventions demand robust trial designs with flexibility for delivery in different contexts, particularly during a pandemic. We describe innovative features of a batched stepped wedge trial, ESCP sAfe Anastomosis proGramme in CoLorectal SurgEry (EAGLE), intended to reduce anastomotic leak following right colectomy, and reflect on lessons learned about the implementation of quality improvement programmes on an international scale. Methods: Surgical units were recruited and randomised in batches to receive a hospital-level education intervention designed to reduce anastomotic leak, either before, during, or following data collection. All consecutive patients undergoing right colectomy were included. Online learning, patient risk stratification and an in-theatre checklist constituted the intervention. The study was powered to detect an absolute risk reduction of anastomotic leak from 8.1 to 5.6%. Statistical efficiency was optimised using an incomplete stepped wedge trial design and study batches analysed separately then meta-analysed to calculate the intervention effect. An established collaborative group helped nurture strong working relationships between units/countries and a prospectively designed process evaluation will enable evaluation of both the intervention and its implementation. Results: The batched trial design allowed sequential entry of clusters, targeted research training and proved to be robust to pandemic interruptions. Staggered start times in the incomplete stepped wedge design with long lead-in times can reduce motivation and engagement and require careful administration. Conclusion: EAGLE's robust but flexible study design allowed completion of the study across globally distributed geographical locations in spite of the pandemic. The primary outcome analysed in conjunction with the process evaluation will ensure a rich understanding of the intervention and the effects of the study design. Trial registration: National Institute of Health Research Clinical Research Network portfolio IRAS ID: 272,250. Health Research Authority approval 18 October 2019. Clinicaltrials: gov, identifier NCT04270721, protocol ID RG_19196.
MeSH term(s)	Humans ; Anastomotic Leak ; Colectomy/adverse effects ; Quality Improvement ; Research Design
Language	English
Publishing date	2023-05-15
Publishing country	England
Document type	Journal Article ; Randomized Controlled Trial
ZDB-ID	2040523-6
ISSN	1745-6215 ; 1468-6694 ; 1745-6215
ISSN (online)	1745-6215
ISSN	1468-6694 ; 1745-6215
DOI	10.1186/s13063-023-07318-9
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Article ; Online: 1,3-Alkyl Transposition in Allylic Alcohols Enabled by Proton-Coupled Electron Transfer.

Zhao, Kuo / Seidler, Gesa / Knowles, Robert R

Angewandte Chemie (International ed. in English)

2021 Volume 60, Issue 37, Page(s) 20190–20195

Abstract: A method is described for the isomerization of acyclic allylic alcohols into β-functionalized ketones via 1,3-alkyl transposition. This reaction proceeds via light-driven proton-coupled electron transfer (PCET) activation of the O-H bond in the allylic ... ...

Abstract	A method is described for the isomerization of acyclic allylic alcohols into β-functionalized ketones via 1,3-alkyl transposition. This reaction proceeds via light-driven proton-coupled electron transfer (PCET) activation of the O-H bond in the allylic alcohol substrate, followed by C-C β-scission of the resulting alkoxy radical. The transient alkyl radical and enone acceptor generated in the scission event subsequently recombine via radical conjugate addition to deliver β-functionalized ketone products. A variety of allylic alcohol substrates bearing alkyl and acyl migratory groups were successfully accommodated. Insights from mechanistic studies led to a modified reaction protocol that improves reaction performance for challenging substrates.
MeSH term(s)	Electron Transport ; Molecular Structure ; Propanols/chemistry ; Propanols/metabolism ; Protons
Chemical Substances	Propanols ; Protons ; allyl alcohol (3W678R12M0)
Language	English
Publishing date	2021-08-03
Publishing country	Germany
Document type	Journal Article ; Research Support, N.I.H., Extramural
ZDB-ID	2011836-3
ISSN	1521-3773 ; 1433-7851
ISSN (online)	1521-3773
ISSN	1433-7851
DOI	10.1002/anie.202105285
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Article ; Online: Understanding Chemoselectivity in Proton-Coupled Electron Transfer: A Kinetic Study of Amide and Thiol Activation.

Qiu, Guanqi / Knowles, Robert R

Journal of the American Chemical Society

2019 Volume 141, Issue 42, Page(s) 16574–16578

Abstract: While the mechanistic understanding of proton-coupled electron transfer (PCET) has advanced significantly, few reports have sought to elucidate the factors that control chemoselectivity in these reactions. Here we present a kinetic study that provides a ... ...

Abstract	While the mechanistic understanding of proton-coupled electron transfer (PCET) has advanced significantly, few reports have sought to elucidate the factors that control chemoselectivity in these reactions. Here we present a kinetic study that provides a quantitative basis for understanding the chemoselectivity in competitive PCET activations of amides and thiols relevant to catalytic olefin hydroamidation reactions. These results demonstrate how the interplay between PCET rate constants, hydrogen-bonding equilibria, and rate-driving force relationships jointly determine PCET chemoselectivity under a given set of conditions. In turn, these findings predict reactivity trends in a model hydroamidation reaction, rationalize the selective activation of amide N-H bonds in the presence of much weaker thiol S-H bonds, and deliver strategies to improve the efficiencies of PCET reactions employing thiol co-catalysts.
MeSH term(s)	Amides/chemistry ; Electron Transport ; Hydrogen Bonding ; Kinetics ; Protons ; Sulfhydryl Compounds/chemistry ; Thermodynamics
Chemical Substances	Amides ; Protons ; Sulfhydryl Compounds
Language	English
Publishing date	2019-10-08
Publishing country	United States
Document type	Journal Article ; Research Support, N.I.H., Extramural
ZDB-ID	3155-0
ISSN	1520-5126 ; 0002-7863
ISSN (online)	1520-5126
ISSN	0002-7863
DOI	10.1021/jacs.9b08398
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Article ; Online: Rate-Driving Force Relationships in the Multisite Proton-Coupled Electron Transfer Activation of Ketones.

Qiu, Guanqi / Knowles, Robert R

Journal of the American Chemical Society

2019 Volume 141, Issue 6, Page(s) 2721–2730

Abstract: Here we present a detailed kinetic study of the multisite proton-coupled electron transfer (MS-PCET) activations of aryl ketones using a variety of Brønsted acids and excited-state Ir(III)-based electron donors. A simple method is described for ... ...

Abstract	Here we present a detailed kinetic study of the multisite proton-coupled electron transfer (MS-PCET) activations of aryl ketones using a variety of Brønsted acids and excited-state Ir(III)-based electron donors. A simple method is described for simultaneously extracting both the hydrogen-bonding equilibrium constants and the rate constants for the PCET event from deconvolution of the luminescence quenching data. These experiments confirm that these activations occur in a concerted fashion, wherein the proton and electron are transferred to the ketone substrate in a single elementary step. The rates constants for the PCET events were linearly correlated with their driving forces over a range of nearly 19 kcal/mol. However, the slope of the rate-driving force relationship deviated significantly from expectations based on Marcus theory. A rationalization for this observation is proposed based on the principle of non-perfect synchronization, wherein factors that serve to stabilize the product are only partially realized at the transition state. A discussion of the relevance of these findings to the applications of MS-PCET in organic synthesis is also presented.
MeSH term(s)	Electron Transport ; Hydrogen Bonding ; Ketones/chemistry ; Kinetics ; Protons
Chemical Substances	Ketones ; Protons
Language	English
Publishing date	2019-02-01
Publishing country	United States
Document type	Journal Article ; Research Support, N.I.H., Extramural
ZDB-ID	3155-0
ISSN	1520-5126 ; 0002-7863
ISSN (online)	1520-5126
ISSN	0002-7863
DOI	10.1021/jacs.8b13451
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