• Effect of Micron-scale Photoluminescence Variation on Droop Measurements in InGaN/GaN Quantum Wells

      Barrett, R M; Ahumada-Lazo, R; Alanis, J A; Parkinson, P; Church, S A; Kappers, M J; Oliver, R A; Binks, D J; email: david.binks@manchester.ac.uk (IOP Publishing, 2021-05)
      Abstract: Micro-photoluminescence maps reveal micron-scale spatial variation in intensity, peak emission energy and bandwidth across InGaN/GaN quantum wells. To investigate the effect of this spatial variation on measurements of the dependence of emission efficiency on carrier density, excitation power-dependent emission was collected from a bright and dark region on each of blue-and green emitting samples. The onset of efficiency droop was found to occur at a greater carrier density in the dark regions than in the bright, by factors of 1.2 and 1.8 in the blue and green-emitting samples, respectively. By spatially integrating the emission from progressively larger areas, it is also shown that collection areas greater than ∼50 μm in diameter are required to reduce the intensity variation to less than 10%.
    • Effect of Micron-scale Photoluminescence Variation on Droop Measurements in InGaN/GaN Quantum Wells

      Barrett, R M; Ahumada-Lazo, R; Alanis, J A; Parkinson, P; Church, S A; Kappers, M J; Oliver, R A; Binks, D J; email: david.binks@manchester.ac.uk (IOP Publishing, 2021-05)
      Abstract: Micro-photoluminescence maps reveal micron-scale spatial variation in intensity, peak emission energy and bandwidth across InGaN/GaN quantum wells. To investigate the effect of this spatial variation on measurements of the dependence of emission efficiency on carrier density, excitation power-dependent emission was collected from a bright and dark region on each of blue-and green emitting samples. The onset of efficiency droop was found to occur at a greater carrier density in the dark regions than in the bright, by factors of 1.2 and 1.8 in the blue and green-emitting samples, respectively. By spatially integrating the emission from progressively larger areas, it is also shown that collection areas greater than ∼50 μm in diameter are required to reduce the intensity variation to less than 10%.
    • Effect of Micron-scale Photoluminescence Variation on Droop Measurements in InGaN/GaN Quantum Wells

      Barrett, R M; Ahumada-Lazo, R; Alanis, J A; Parkinson, P; Church, S A; Kappers, M J; Oliver, R A; Binks, D J; email: david.binks@manchester.ac.uk (IOP Publishing, 2021-05)
      Abstract: Micro-photoluminescence maps reveal micron-scale spatial variation in intensity, peak emission energy and bandwidth across InGaN/GaN quantum wells. To investigate the effect of this spatial variation on measurements of the dependence of emission efficiency on carrier density, excitation power-dependent emission was collected from a bright and dark region on each of blue-and green emitting samples. The onset of efficiency droop was found to occur at a greater carrier density in the dark regions than in the bright, by factors of 1.2 and 1.8 in the blue and green-emitting samples, respectively. By spatially integrating the emission from progressively larger areas, it is also shown that collection areas greater than ∼50 μm in diameter are required to reduce the intensity variation to less than 10%.
    • Effect of Micron-scale Photoluminescence Variation on Droop Measurements in InGaN/GaN Quantum Wells

      Barrett, R M; Ahumada-Lazo, R; Alanis, J A; Parkinson, P; Church, S A; Kappers, M J; Oliver, R A; Binks, D J; email: david.binks@manchester.ac.uk (IOP Publishing, 2021-05)
      Abstract: Micro-photoluminescence maps reveal micron-scale spatial variation in intensity, peak emission energy and bandwidth across InGaN/GaN quantum wells. To investigate the effect of this spatial variation on measurements of the dependence of emission efficiency on carrier density, excitation power-dependent emission was collected from a bright and dark region on each of blue-and green emitting samples. The onset of efficiency droop was found to occur at a greater carrier density in the dark regions than in the bright, by factors of 1.2 and 1.8 in the blue and green-emitting samples, respectively. By spatially integrating the emission from progressively larger areas, it is also shown that collection areas greater than ∼50 μm in diameter are required to reduce the intensity variation to less than 10%.
    • Effect of Moderate and Severe Hemophilia a on Daily Life in Children and Their Caregivers: A CHESS Paediatrics Study Analysis

      Khair, Kate; Nissen, Francis; Silkey, Mariabeth; Burke, Tom; Shang, Aijing; Aizenas, Martynas; Meier, Oliver; O'Hara, Jamie; Noone, Declan (American Society of Hematology, 2020-11-05)
      Introduction: Hemophilia A (HA) is a congenital bleeding disorder, caused by a deficiency in clotting factor VIII (FVIII) and characterized by uncontrolled bleeding and progressive joint damage. This analysis assesses the impact of disease burden on the daily life of children with hemophilia A (CwHA) and their caregivers, addressing a deficit of current research on this topic. Methods: The Cost of Haemophilia in Europe: a Socioeconomic Survey in a Paediatric Population (CHESS Paediatrics) is a retrospective, burden-of-illness study in children with moderate and severe HA (defined by endogenous FVIII [IU/dL] relative to normal; moderate, 1-5%; severe, <1%) across France, Germany, Italy, Spain and the UK. CwHA were recruited and stratified by both age group (0-5 years:6-11 years:12-17 years=1:1:1) and disease severity (severe:moderate=approximately 2:1, prioritizing children with severe HA [CwSHA]). Data for this analysis were captured from physicians, children, and their caregivers. Physicians completed online case report forms for treated children, and the child and/or their caregivers completed a paper-based questionnaire utilizing 5-point Likert scales. For CwHA aged 0-7, the questionnaire was completed by the caregiver, while for CwHA aged 8-17, children and caregivers completed different sections. Hours of care provided by the caregiver and work lost by the caregiver were reported as median values due to non-normal data distribution. Informed consent was obtained for all participants. Upon review, the study was approved by the University of Chester ethical committee. Results: Data from child/caregiver questionnaires were available for 196 CwHA (moderate, 25.5%; severe, 74.5%); the majority of these children, as expected, were receiving prophylaxis (72.4%), and did not have FVIII inhibitors (89.8%; Table 1). There was a direct impact of disease burden on CwHA, particularly with regard to physical and social activities (Figure 1). Overall, it was agreed or strongly agreed by the child or caregiver that 48.0% and 57.5% of children with moderate HA (CwMHA) and CwSHA respectively, have reduced physical activity due to HA, and 46.0% and 57.5%, respectively, have reduced social activity due to HA. A total of 36.0% and 61.0% of CwMHA and CwSHA, respectively, had adapted their treatment in anticipation of physical or social activity (Table 1). Furthermore, 34.0% of CwMHA and 55.4% of CwSHA were frustrated due to their disease, and many (CwMHA, 36.0%; CwSHA, 50.7%) felt that they had missed opportunities (Figure 1). For 66.0% of CwMHA and 76.0% of CwSHA, it was reported that their daily life was compromised due to their HA. Caregivers provided a median (interquartile range [IQR]) of 19.0 (10.0-59.5) and 12.0 (5.0-20.0) hours a week of care for the hemophilia-related needs of their CwMHA (n=30) or CwSHA (n=105), respectively. Of those who responded, 17.4% (n=4/23) and 25.0% (n=20/80) of caregivers to CwMHA or CwSHA, respectively, stated they have lost work due to their caregiving duty. This was more than twice as common for caregivers in families with multiple CwHA (42.9%, n=9/21 responses) compared with those in families with one CwHA (18.5%, n=15/81 responses). Median (IQR) hours of work per week estimated to be lost were 20.0 (17.0-22.0) for caregivers of CwMHA (n=4) and 12.5 (4.50-20.0) for caregivers of CwSHA (n=20). Conclusions: In conclusion, both children and caregivers make sacrifices in their daily lives due to HA; many CwHA reported reduced physical and social activities, fewer opportunities and feelings of frustration due to their HA. Caregivers reported spending a significant number of hours caring for their child and some reported losing work due to their caring responsibilities. However, some outcomes may be limited by the small number of respondents and narrow response options, particularly those regarding the caregiver burden. Responses on the hours of work lost may be subject to selection bias, as caregivers who have lost work may be more likely to respond to this question. Additionally, as this question is targeted at caregivers in employment, it is unknown if some caregivers have left employment due to their caregiving responsibilities. According to this analysis, children/caregivers are frequently required to adapt the child's treatment before the child engages in activities. Overall, the burden of disease was similar in children with moderate and severe HA. Disclosures Khair: Takeda: Honoraria, Speakers Bureau; Bayer: Consultancy, Honoraria, Speakers Bureau; Biomarin: Consultancy; HCD Economics: Consultancy; Novo Nordisk: Consultancy, Membership on an entity's Board of Directors or advisory committees; Medikhair: Membership on an entity's Board of Directors or advisory committees; Sobi: Consultancy, Honoraria, Research Funding, Speakers Bureau; CSL Behring: Honoraria, Research Funding; F. Hoffmann-La Roche Ltd: Honoraria, Research Funding; Haemnet: Membership on an entity's Board of Directors or advisory committees. Nissen:GSK: Research Funding; Novartis: Research Funding; Actelion: Consultancy; F. Hoffmann-La Roche Ltd: Current Employment. Silkey:Aerotek AG: Current Employment; F. Hoffmann-La Roche Ltd: Consultancy. Burke:HCD Economics: Current Employment; University of Chester: Current Employment; F. Hoffmann-La Roche Ltd: Consultancy. Shang:F. Hoffmann-La Roche Ltd: Current Employment, Current equity holder in publicly-traded company, Other: All authors received support for third party writing assistance, furnished by Scott Battle, PhD, provided by F. Hoffmann-La Roche, Basel, Switzerland.. Aizenas:F. Hoffmann-La Roche Ltd: Current Employment, Current equity holder in publicly-traded company. Meier:F. Hoffmann-La Roche Ltd: Current Employment, Current equity holder in publicly-traded company. O'Hara:HCD Economics: Current Employment, Current equity holder in private company; F. Hoffmann-La Roche Ltd: Consultancy. Noone:Research Investigator PROBE: Research Funding; Healthcare Decision Consultants: Membership on an entity's Board of Directors or advisory committees; European Haemophilia Consortium: Membership on an entity's Board of Directors or advisory committees.
    • Effect of Moderate and Severe Hemophilia a on Daily Life in Children and Their Caregivers: A CHESS Paediatrics Study Analysis

      Khair, Kate; Nissen, Francis; Silkey, Mariabeth; Burke, Tom; Shang, Aijing; Aizenas, Martynas; Meier, Oliver; O'Hara, Jamie; Noone, Declan (American Society of Hematology, 2020-11-05)
      Introduction: Hemophilia A (HA) is a congenital bleeding disorder, caused by a deficiency in clotting factor VIII (FVIII) and characterized by uncontrolled bleeding and progressive joint damage. This analysis assesses the impact of disease burden on the daily life of children with hemophilia A (CwHA) and their caregivers, addressing a deficit of current research on this topic. Methods: The Cost of Haemophilia in Europe: a Socioeconomic Survey in a Paediatric Population (CHESS Paediatrics) is a retrospective, burden-of-illness study in children with moderate and severe HA (defined by endogenous FVIII [IU/dL] relative to normal; moderate, 1-5%; severe, <1%) across France, Germany, Italy, Spain and the UK. CwHA were recruited and stratified by both age group (0-5 years:6-11 years:12-17 years=1:1:1) and disease severity (severe:moderate=approximately 2:1, prioritizing children with severe HA [CwSHA]). Data for this analysis were captured from physicians, children, and their caregivers. Physicians completed online case report forms for treated children, and the child and/or their caregivers completed a paper-based questionnaire utilizing 5-point Likert scales. For CwHA aged 0-7, the questionnaire was completed by the caregiver, while for CwHA aged 8-17, children and caregivers completed different sections. Hours of care provided by the caregiver and work lost by the caregiver were reported as median values due to non-normal data distribution. Informed consent was obtained for all participants. Upon review, the study was approved by the University of Chester ethical committee. Results: Data from child/caregiver questionnaires were available for 196 CwHA (moderate, 25.5%; severe, 74.5%); the majority of these children, as expected, were receiving prophylaxis (72.4%), and did not have FVIII inhibitors (89.8%; Table 1). There was a direct impact of disease burden on CwHA, particularly with regard to physical and social activities (Figure 1). Overall, it was agreed or strongly agreed by the child or caregiver that 48.0% and 57.5% of children with moderate HA (CwMHA) and CwSHA respectively, have reduced physical activity due to HA, and 46.0% and 57.5%, respectively, have reduced social activity due to HA. A total of 36.0% and 61.0% of CwMHA and CwSHA, respectively, had adapted their treatment in anticipation of physical or social activity (Table 1). Furthermore, 34.0% of CwMHA and 55.4% of CwSHA were frustrated due to their disease, and many (CwMHA, 36.0%; CwSHA, 50.7%) felt that they had missed opportunities (Figure 1). For 66.0% of CwMHA and 76.0% of CwSHA, it was reported that their daily life was compromised due to their HA. Caregivers provided a median (interquartile range [IQR]) of 19.0 (10.0-59.5) and 12.0 (5.0-20.0) hours a week of care for the hemophilia-related needs of their CwMHA (n=30) or CwSHA (n=105), respectively. Of those who responded, 17.4% (n=4/23) and 25.0% (n=20/80) of caregivers to CwMHA or CwSHA, respectively, stated they have lost work due to their caregiving duty. This was more than twice as common for caregivers in families with multiple CwHA (42.9%, n=9/21 responses) compared with those in families with one CwHA (18.5%, n=15/81 responses). Median (IQR) hours of work per week estimated to be lost were 20.0 (17.0-22.0) for caregivers of CwMHA (n=4) and 12.5 (4.50-20.0) for caregivers of CwSHA (n=20). Conclusions: In conclusion, both children and caregivers make sacrifices in their daily lives due to HA; many CwHA reported reduced physical and social activities, fewer opportunities and feelings of frustration due to their HA. Caregivers reported spending a significant number of hours caring for their child and some reported losing work due to their caring responsibilities. However, some outcomes may be limited by the small number of respondents and narrow response options, particularly those regarding the caregiver burden. Responses on the hours of work lost may be subject to selection bias, as caregivers who have lost work may be more likely to respond to this question. Additionally, as this question is targeted at caregivers in employment, it is unknown if some caregivers have left employment due to their caregiving responsibilities. According to this analysis, children/caregivers are frequently required to adapt the child's treatment before the child engages in activities. Overall, the burden of disease was similar in children with moderate and severe HA. Disclosures Khair: Takeda: Honoraria, Speakers Bureau; Bayer: Consultancy, Honoraria, Speakers Bureau; Biomarin: Consultancy; HCD Economics: Consultancy; Novo Nordisk: Consultancy, Membership on an entity's Board of Directors or advisory committees; Medikhair: Membership on an entity's Board of Directors or advisory committees; Sobi: Consultancy, Honoraria, Research Funding, Speakers Bureau; CSL Behring: Honoraria, Research Funding; F. Hoffmann-La Roche Ltd: Honoraria, Research Funding; Haemnet: Membership on an entity's Board of Directors or advisory committees. Nissen:GSK: Research Funding; Novartis: Research Funding; Actelion: Consultancy; F. Hoffmann-La Roche Ltd: Current Employment. Silkey:Aerotek AG: Current Employment; F. Hoffmann-La Roche Ltd: Consultancy. Burke:HCD Economics: Current Employment; University of Chester: Current Employment; F. Hoffmann-La Roche Ltd: Consultancy. Shang:F. Hoffmann-La Roche Ltd: Current Employment, Current equity holder in publicly-traded company, Other: All authors received support for third party writing assistance, furnished by Scott Battle, PhD, provided by F. Hoffmann-La Roche, Basel, Switzerland.. Aizenas:F. Hoffmann-La Roche Ltd: Current Employment, Current equity holder in publicly-traded company. Meier:F. Hoffmann-La Roche Ltd: Current Employment, Current equity holder in publicly-traded company. O'Hara:HCD Economics: Current Employment, Current equity holder in private company; F. Hoffmann-La Roche Ltd: Consultancy. Noone:Research Investigator PROBE: Research Funding; Healthcare Decision Consultants: Membership on an entity's Board of Directors or advisory committees; European Haemophilia Consortium: Membership on an entity's Board of Directors or advisory committees.
    • Effect of Moderate and Severe Hemophilia a on Daily Life in Children and Their Caregivers: A CHESS Paediatrics Study Analysis

      Khair, Kate; Nissen, Francis; Silkey, Mariabeth; Burke, Tom; Shang, Aijing; Aizenas, Martynas; Meier, Oliver; O'Hara, Jamie; Noone, Declan (Elsevier, 2021-08-03)
      Introduction: Hemophilia A (HA) is a congenital bleeding disorder, caused by a deficiency in clotting factor VIII (FVIII) and characterized by uncontrolled bleeding and progressive joint damage. This analysis assesses the impact of disease burden on the daily life of children with hemophilia A (CwHA) and their caregivers, addressing a deficit of current research on this topic. Methods: The Cost of Haemophilia in Europe: a Socioeconomic Survey in a Paediatric Population (CHESS Paediatrics) is a retrospective, burden-of-illness study in children with moderate and severe HA (defined by endogenous FVIII [IU/dL] relative to normal; moderate, 1-5%; severe, <1%) across France, Germany, Italy, Spain and the UK. CwHA were recruited and stratified by both age group (0-5 years:6-11 years:12-17 years=1:1:1) and disease severity (severe:moderate=approximately 2:1, prioritizing children with severe HA [CwSHA]). Data for this analysis were captured from physicians, children, and their caregivers. Physicians completed online case report forms for treated children, and the child and/or their caregivers completed a paper-based questionnaire utilizing 5-point Likert scales. For CwHA aged 0-7, the questionnaire was completed by the caregiver, while for CwHA aged 8-17, children and caregivers completed different sections. Hours of care provided by the caregiver and work lost by the caregiver were reported as median values due to non-normal data distribution. Informed consent was obtained for all participants. Upon review, the study was approved by the University of Chester ethical committee. Results: Data from child/caregiver questionnaires were available for 196 CwHA (moderate, 25.5%; severe, 74.5%); the majority of these children, as expected, were receiving prophylaxis (72.4%), and did not have FVIII inhibitors (89.8%; Table 1). There was a direct impact of disease burden on CwHA, particularly with regard to physical and social activities (Figure 1). Overall, it was agreed or strongly agreed by the child or caregiver that 48.0% and 57.5% of children with moderate HA (CwMHA) and CwSHA respectively, have reduced physical activity due to HA, and 46.0% and 57.5%, respectively, have reduced social activity due to HA. A total of 36.0% and 61.0% of CwMHA and CwSHA, respectively, had adapted their treatment in anticipation of physical or social activity (Table 1). Furthermore, 34.0% of CwMHA and 55.4% of CwSHA were frustrated due to their disease, and many (CwMHA, 36.0%; CwSHA, 50.7%) felt that they had missed opportunities (Figure 1). For 66.0% of CwMHA and 76.0% of CwSHA, it was reported that their daily life was compromised due to their HA. Caregivers provided a median (interquartile range [IQR]) of 19.0 (10.0-59.5) and 12.0 (5.0-20.0) hours a week of care for the hemophilia-related needs of their CwMHA (n=30) or CwSHA (n=105), respectively. Of those who responded, 17.4% (n=4/23) and 25.0% (n=20/80) of caregivers to CwMHA or CwSHA, respectively, stated they have lost work due to their caregiving duty. This was more than twice as common for caregivers in families with multiple CwHA (42.9%, n=9/21 responses) compared with those in families with one CwHA (18.5%, n=15/81 responses). Median (IQR) hours of work per week estimated to be lost were 20.0 (17.0-22.0) for caregivers of CwMHA (n=4) and 12.5 (4.50-20.0) for caregivers of CwSHA (n=20). Conclusions: In conclusion, both children and caregivers make sacrifices in their daily lives due to HA; many CwHA reported reduced physical and social activities, fewer opportunities and feelings of frustration due to their HA. Caregivers reported spending a significant number of hours caring for their child and some reported losing work due to their caring responsibilities. However, some outcomes may be limited by the small number of respondents and narrow response options, particularly those regarding the caregiver burden. Responses on the hours of work lost may be subject to selection bias, as caregivers who have lost work may be more likely to respond to this question. Additionally, as this question is targeted at caregivers in employment, it is unknown if some caregivers have left employment due to their caregiving responsibilities. According to this analysis, children/caregivers are frequently required to adapt the child's treatment before the child engages in activities. Overall, the burden of disease was similar in children with moderate and severe HA. Disclosures Khair: Takeda: Honoraria, Speakers Bureau; Bayer: Consultancy, Honoraria, Speakers Bureau; Biomarin: Consultancy; HCD Economics: Consultancy; Novo Nordisk: Consultancy, Membership on an entity's Board of Directors or advisory committees; Medikhair: Membership on an entity's Board of Directors or advisory committees; Sobi: Consultancy, Honoraria, Research Funding, Speakers Bureau; CSL Behring: Honoraria, Research Funding; F. Hoffmann-La Roche Ltd: Honoraria, Research Funding; Haemnet: Membership on an entity's Board of Directors or advisory committees. Nissen: GSK: Research Funding; Novartis: Research Funding; Actelion: Consultancy; F. Hoffmann-La Roche Ltd: Current Employment. Silkey: Aerotek AG: Current Employment; F. Hoffmann-La Roche Ltd: Consultancy. Burke: HCD Economics: Current Employment; University of Chester: Current Employment; F. Hoffmann-La Roche Ltd: Consultancy. Shang: F. Hoffmann-La Roche Ltd: Current Employment, Current equity holder in publicly-traded company, Other: All authors received support for third party writing assistance, furnished by Scott Battle, PhD, provided by F. Hoffmann-La Roche, Basel, Switzerland.. Aizenas: F. Hoffmann-La Roche Ltd: Current Employment, Current equity holder in publicly-traded company. Meier: F. Hoffmann-La Roche Ltd: Current Employment, Current equity holder in publicly-traded company. O'Hara: HCD Economics: Current Employment, Current equity holder in private company; F. Hoffmann-La Roche Ltd: Consultancy. Noone: Research Investigator PROBE: Research Funding; Healthcare Decision Consultants: Membership on an entity's Board of Directors or advisory committees; European Haemophilia Consortium: Membership on an entity's Board of Directors or advisory committees.
    • Effect of Si-doped InGaN underlayers on photoluminescence efficiency and recombination dynamics in InGaN/GaN quantum wells

      Church, S A; Christian, G M; Barrett, R M; orcid: 0000-0001-8512-0930; Hammersley, S; Kappers, M J; Frentrup, M; Oliver, R A; Binks, D J; email: david.binks@manchester.ac.uk (IOP Publishing, 2021-09-10)
      Abstract: A series of single InGaN/GaN quantum wells (QWs) with a Si-doped InGaN underlayer were studied to investigate the impact of the underlayer on photoluminescence efficiency and recombination dynamics. The thickness of the GaN capping layer was varied between samples, which changed the electric field across the QW due to band bending near the surface. When directly exciting the wells, thermionic emission of carriers results in a rapid drop in the photoluminesence efficiency with increasing temperature such that no emission is observed above 100 K. However, exciting above the energy of the barriers caused the intensity of the QW emission to drop more slowly, with up to 12% of the 10 K emission intensity remaining at 300 K. This difference is attributed to hole transfer from the underlayer into the QW, which increases in efficiency at higher temperatures, and is enhanced by stronger electric fields present in the GaN barriers of samples with thinner GaN capping layers. Further, the sample with the narrowest cap layer of 2 nm has a different shape and characteristic time for its photoluminescence decay transient and a different emission energy temperature dependence than the other samples. This behaviour was ascribed to a change in carrier localisation for this sample due to a reversal of the net field across the well compared to the other samples.
    • Effect of Si-doped InGaN underlayers on photoluminescence efficiency and recombination dynamics in InGaN/GaN quantum wells

      Church, S A; Christian, G M; Barrett, R M; orcid: 0000-0001-8512-0930; Hammersley, S; Kappers, M J; Frentrup, M; Oliver, R A; Binks, D J; email: david.binks@manchester.ac.uk (IOP Publishing, 2021-09-10)
      Abstract: A series of single InGaN/GaN quantum wells (QWs) with a Si-doped InGaN underlayer were studied to investigate the impact of the underlayer on photoluminescence efficiency and recombination dynamics. The thickness of the GaN capping layer was varied between samples, which changed the electric field across the QW due to band bending near the surface. When directly exciting the wells, thermionic emission of carriers results in a rapid drop in the photoluminesence efficiency with increasing temperature such that no emission is observed above 100 K. However, exciting above the energy of the barriers caused the intensity of the QW emission to drop more slowly, with up to 12% of the 10 K emission intensity remaining at 300 K. This difference is attributed to hole transfer from the underlayer into the QW, which increases in efficiency at higher temperatures, and is enhanced by stronger electric fields present in the GaN barriers of samples with thinner GaN capping layers. Further, the sample with the narrowest cap layer of 2 nm has a different shape and characteristic time for its photoluminescence decay transient and a different emission energy temperature dependence than the other samples. This behaviour was ascribed to a change in carrier localisation for this sample due to a reversal of the net field across the well compared to the other samples.
    • Effect of the Molecular Structure of TPU on the Cellular Structure of Nanocellular Polymers Based on PMMA/TPU Blends

      Sánchez-Calderón, Ismael; orcid: 0000-0003-3367-8371; email: ismaelsc@fmc.uva.es; Bernardo, Victoria; email: v.bernardo@cellmattechnologies.com; Santiago-Calvo, Mercedes; orcid: 0000-0001-7678-5746; email: mercesc@fmc.uva.es; Naji, Haneen; email: haneen.naji@postgrad.manchester.ac.uk; Saiani, Alberto; email: a.saiani@manchester.ac.uk; Rodríguez-Pérez, Miguel Ángel; orcid: 0000-0002-3607-690X; email: marrod@fmc.uva.es (MDPI, 2021-09-10)
      In this work, the effects of thermoplastic polyurethane (TPU) chemistry and concentration on the cellular structure of nanocellular polymers based on poly(methyl-methacrylate) (PMMA) are presented. Three grades of TPU with different fractions of hard segments (HS) (60%, 70%, and 80%) have been synthesized by the prepolymer method. Nanocellular polymers based on PMMA have been produced by gas dissolution foaming using TPU as a nucleating agent in different contents (0.5 wt%, 2 wt%, and 5 wt%). TPU characterization shows that as the content of HS increases, the density, hardness, and molecular weight of the TPU are higher. PMMA/TPU cellular materials show a gradient cell size distribution from the edge of the sample towards the nanocellular core. In the core region, the addition of TPU has a strong nucleating effect in PMMA. Core structure depends on the HS content and the TPU content. As the HS or TPU content increases, the cell nucleation density increases, and the cell size is reduced. Then, the use of TPUs with different characteristics allows controlling the cellular structure. Nanocellular polymers have been obtained with a core relative density between 0.15 and 0.20 and cell sizes between 220 and 640 nm.
    • Effect of thermal treatments on chiral nematic cellulose nanocrystal films.

      Guidetti, Giulia; email: giulia.guidetti@tufts.edu; Frka-Petesic, Bruno; email: bf284@cam.ac.uk; Dumanli, Ahu G; email: ahugumrah.parry@manchester.ac.uk; Hamad, Wadood Y; email: wadood.hamad@fpinnovations.ca; Vignolini, Silvia; email: sv319@cam.ac.uk (2021-07-06)
      The ability to manipulate the optical appearance of materials is essential in virtually all products and areas of technology. Structurally coloured chiral nematic cellulose nanocrystal (CNC) films proved to be an excellent platform to design optical appearance, as their response can be moulded by organising them in hierarchical architectures. Here, we study how thermal treatments influence the optical appearance of structurally coloured CNC films. We demonstrate that the CNCs helicoidal architecture and the chiral optical response can be maintained up to 250 °C after base treatment and cross-linking with glutaraldehyde, while, alternatively, an exposure to vacuum allows for the helicoidal arrangement to be further preserved up to 900 °C, thus producing aromatic chiral carbon. The ability to retain the helicoidal arrangement, and thus the visual appearance, in CNC films up to 250 °C is highly desirable for high temperature colour-based industrial applications and for passive colorimetric heat sensors. Similarly, the production of chiral carbon provides a new type of conductive carbon for electrochemical applications. [Abstract copyright: Copyright © 2021 Elsevier Ltd. All rights reserved.]
    • Effective e-moderating: Engaging your students in online discussions

      Weatherston, Debra (2007-06-01)
      This presentation discusses how to engage students in online discussions. The skills required to become an effective e-moderator and how online discussion board technology can improve engagement and focus discussion will be discussed.
    • Effectiveness of collaborative care in reducing suicidal ideation: An individual participant data meta-analysis.

      Grigoroglou, Christos; email: christos.grigoroglou@manchester.ac.uk; van der Feltz-Cornelis, Christina; Hodkinson, Alexander; Coventry, Peter A; Zghebi, Salwa S; Kontopantelis, Evangelos; Bower, Peter; Lovell, Karina; Gilbody, Simon; Waheed, Waquas; et al. (2021-04-21)
      To assess whether CC is more effective at reducing suicidal ideation in people with depression compared with usual care, and whether study and patient factors moderate treatment effects. We searched Medline, Embase, PubMed, PsycINFO, CINAHL, CENTRAL from inception to March 2020 for Randomised Controlled Trials (RCTs) that compared the effectiveness of CC with usual care in depressed adults, and reported changes in suicidal ideation at 4 to 6 months post-randomisation. Mixed-effects models accounted for clustering of participants within trials and heterogeneity across trials. This study is registered with PROSPERO, CRD42020201747. We extracted data from 28 RCTs (11,165 patients) of 83 eligible studies. We observed a small significant clinical improvement of CC on suicidal ideation, compared with usual care (SMD, -0.11 [95%CI, -0.15 to -0.08]; I , 0·47% [95%CI 0.04% to 4.90%]). CC interventions with a recognised psychological treatment were associated with small reductions in suicidal ideation (SMD, -0.15 [95%CI -0.19 to -0.11]). CC was more effective for reducing suicidal ideation among patients aged over 65 years (SMD, - 0.18 [95%CI -0.25 to -0.11]). Primary care based CC with an embedded psychological intervention is the most effective CC framework for reducing suicidal ideation and older patients may benefit the most. [Abstract copyright: Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.]
    • Effects of a disposable home electro-stimulation device (Pelviva) for the treatment of female urinary incontinence: a randomised controlled trial

      Oldham, Jackie; orcid: 0000-0001-5857-9551; email: jackie.oldham@manchester.ac.uk; Herbert, Julia; Garnett, Jane; Roberts, Stephen A. (Springer Berlin Heidelberg, 2021-08-20)
      Abstract: Aims: To compare current General Medical Practitioner treatment as usual (TAU) for the treatment of female urinary incontinence with a novel disposable home electro-stimulation device (Pelviva). Methods: Open label, Primary Care post-market evaluation. 86 women with urinary incontinence were randomly assigned to one of two 12-week treatments: TAU or Pelviva for 30 min every other day plus TAU. Outcome measures included ICIQ-UI (primary), PISQ-IR, PGI-S / PGI-I and FSFI (secondary) at recruitment and immediately after intervention, 1-h pad test at recruitment and usage diaries throughout. Results: Pelviva plus TAU produced significantly better outcome than TAU alone: 3 versus 1 point for ICIQ-UI (Difference − 1.8 95% CI: − 3.5 to − 0.1, P = 0.033). Significant differences were also observed for PGI-I at both 6 weeks (P = 0.001) and 12 weeks (P < 0.001). In the Pelviva group, 17% of women described themselves as feeling very much better and 54% a little or much better compared to 0% and 15% in the TAU. Overall PISQ-IR score reached statistical significance (P = 0.032) seemingly related to impact (P = 0.027). No other outcome measures reached statistical significance. Premature termination due to COVID-19 meant only 86 women were recruited from a sample size of 264. TAU did not reflect NICE guidelines. Conclusions: This study suggests Pelviva is more successful than TAU in treating urinary incontinence in Primary Care. The study had reduced power due to early termination due to COVID-19 and suggests TAU does not follow NICE guidelines.
    • Effects of a disposable home electro-stimulation device (Pelviva) for the treatment of female urinary incontinence: a randomised controlled trial.

      Oldham, Jackie; orcid: 0000-0001-5857-9551; email: jackie.oldham@manchester.ac.uk; Herbert, Julia; Garnett, Jane; Roberts, Stephen A (2021-08-20)
      <h4>Aims</h4>To compare current General Medical Practitioner treatment as usual (TAU) for the treatment of female urinary incontinence with a novel disposable home electro-stimulation device (Pelviva).<h4>Methods</h4>Open label, Primary Care post-market evaluation. 86 women with urinary incontinence were randomly assigned to one of two 12-week treatments: TAU or Pelviva for 30 min every other day plus TAU. Outcome measures included ICIQ-UI (primary), PISQ-IR, PGI-S / PGI-I and FSFI (secondary) at recruitment and immediately after intervention, 1-h pad test at recruitment and usage diaries throughout.<h4>Results</h4>Pelviva plus TAU produced significantly better outcome than TAU alone: 3 versus 1 point for ICIQ-UI (Difference - 1.8 95% CI: - 3.5 to - 0.1, P = 0.033). Significant differences were also observed for PGI-I at both 6 weeks (P = 0.001) and 12 weeks (P < 0.001). In the Pelviva group, 17% of women described themselves as feeling very much better and 54% a little or much better compared to 0% and 15% in the TAU. Overall PISQ-IR score reached statistical significance (P = 0.032) seemingly related to impact (P = 0.027). No other outcome measures reached statistical significance. Premature termination due to COVID-19 meant only 86 women were recruited from a sample size of 264. TAU did not reflect NICE guidelines.<h4>Conclusions</h4>This study suggests Pelviva is more successful than TAU in treating urinary incontinence in Primary Care. The study had reduced power due to early termination due to COVID-19 and suggests TAU does not follow NICE guidelines.
    • Effects of a disposable home electro-stimulation device (Pelviva) for the treatment of female urinary incontinence: a randomised controlled trial.

      Oldham, Jackie; orcid: 0000-0001-5857-9551; email: jackie.oldham@manchester.ac.uk; Herbert, Julia; Garnett, Jane; Roberts, Stephen A (2021-08-20)
      To compare current General Medical Practitioner treatment as usual (TAU) for the treatment of female urinary incontinence with a novel disposable home electro-stimulation device (Pelviva). Open label, Primary Care post-market evaluation. 86 women with urinary incontinence were randomly assigned to one of two 12-week treatments: TAU or Pelviva for 30 min every other day plus TAU. Outcome measures included ICIQ-UI (primary), PISQ-IR, PGI-S / PGI-I and FSFI (secondary) at recruitment and immediately after intervention, 1-h pad test at recruitment and usage diaries throughout. Pelviva plus TAU produced significantly better outcome than TAU alone: 3 versus 1 point for ICIQ-UI (Difference - 1.8 95% CI: - 3.5 to - 0.1, P = 0.033). Significant differences were also observed for PGI-I at both 6 weeks (P = 0.001) and 12 weeks (P < 0.001). In the Pelviva group, 17% of women described themselves as feeling very much better and 54% a little or much better compared to 0% and 15% in the TAU. Overall PISQ-IR score reached statistical significance (P = 0.032) seemingly related to impact (P = 0.027). No other outcome measures reached statistical significance. Premature termination due to COVID-19 meant only 86 women were recruited from a sample size of 264. TAU did not reflect NICE guidelines. This study suggests Pelviva is more successful than TAU in treating urinary incontinence in Primary Care. The study had reduced power due to early termination due to COVID-19 and suggests TAU does not follow NICE guidelines. [Abstract copyright: © 2021. Crown.]
    • Effects of Ageing on Aortic Circulation During Atrial Fibrillation; a Numerical Study on Different Aortic Morphologies

      Deyranlou, Amin; Miller, Christopher A.; Revell, Alistair; Keshmiri, Amir; orcid: 0000-0003-4747-277X; email: a.keshmiri@manchester.ac.uk (Springer International Publishing, 2021-03-02)
      Abstract: Atrial fibrillation (AF) can alter intra-cardiac flow and cardiac output that subsequently affects aortic flow circulation. These changes may become more significant where they occur concomitantly with ageing. Aortic ageing is accompanied with morphological changes such as dilation, lengthening, and arch unfolding. While the recognition of AF mechanism has been the subject of numerous studies, less focus has been devoted to the aortic circulation during the AF and there is a lack of such investigation at different ages. The current work aims to address the present gap. First, we analyse aortic flow distribution in three configurations, which attribute to young, middle and old people, using geometries constructed via clinical data. We then introduce two transient inlet flow conditions representative of key AF-associated defects. Results demonstrate that both AF and ageing negatively affect flow circulation. The main consequence of concomitant occurrence is enhancement of endothelial cell activation potential (ECAP) throughout the vascular domain, mainly at aortic arch and descending thoracic aorta, which is consistent with some clinical observations. The outcome of the current study suggests that AF exacerbates the vascular defects occurred due to the ageing, which increases the possibility of cardiovascular diseases per se.
    • Effects of long-term fasting and confinement on the cardiovascular activity.

      Liu, Yang; Li, Qince; Wang, Kuanquan; email: wangkq@hit.edu.cn; He, Runnan; Dai, Zhongquan; Zhang, Hongyu; Liu, Chengyu; Ma, Qianying; Yuan, Yongfeng; Yang, Chengjia; et al. (2021-08-09)
      Fasting has been demonstrated to improve health and slow aging in human and other species; however, its impact on the human body in the confined environment is still unclear. This work studies the effects of long-term fasting and confined environment on the cardiovascular activities of human via a 10-day fasting experiment with two groups of subjects being in confined (6 subjects) and unconfined (7 subjects) environments respectively and undergoing the same four-stage fasting/feeding process. It is found that the confinement has significant influences on the autonomic regulation to the heart rate during the fasting process by altering the activity of the parasympathetic nervous system, which is manifested by the significant higher pNN50, rMSSD, and Ln-HF of heart rate variability (HRV) (p < 0.05) and slower heart rate (p < 0.01) in the confined group than that in the unconfined group. Furthermore, the long-term fasting induces a series of changes in both groups, including reduced level of serum sodium (p < 0.01), increased the serum calcium (p < 0.05), prolonged QTc intervals (p < 0.05), and reduced systolic blood pressures (p < 0.05). These effects are potentially negative to human health and therefore need to be treated with caution. Study of the effects of fasting and confinement on the cardiovascular activities. [Abstract copyright: © 2021. International Federation for Medical and Biological Engineering.]
    • Effects of pharmacological agents for neurogenic oropharyngeal dysphagia: A systematic review and meta‐analysis

      Cheng, Ivy; orcid: 0000-0001-5853-7976; Sasegbon, Ayodele; orcid: 0000-0003-2050-0726; Hamdy, Shaheen; orcid: 0000-0001-9640-7427; email: shaheen.hamdy@manchester.ac.uk (2021-08-01)
      Abstract: Background: This systematic review and meta‐analysis aimed to evaluate the effects of pharmacological agents for neurogenic oropharyngeal dysphagia based on evidence from randomized controlled trials (RCTs). Methods: Electronic databases were systematically searched between January 1970 and March 2021. Two reviewers independently extracted and synthesized the data. The outcome measure was changed in (any) relevant clinical swallowing‐related characteristics. Key results: Data from 2186 dysphagic patients were collected from 14 RCT studies across a range of pharmacotherapies. The pooled effect size of transient receptor potential (TRP) channel agonists was large compared to placebo interventions (SMD[95%CI] =1.27[0.74,1.80], p < 0.001; I2 = 79%). Data were limited for other pharmacological agents and the overall pooled effect size of these agents was non‐significant (SMD [95% CI] =0.25 [−0.24, 0.73]; p = 0.31; I2 = 85%). When analyzed separately, large effect sizes were observed with Nifedipine (SMD[95%CI] =1.13[0.09,2.18]; p = 0.03) and Metoclopramide (SMD[95%CI] =1.68[1.08,2.27]; p < 0.001). By contrast, the effects of angiotensin‐converting enzyme (ACE) inhibitors (SMD[95%CI] = −0.67[−2.32,0.99]; p = 0.43; I2 = 61%), Physostigmine (SMD[95%CI] = −0.05[−1.03,0.93]; p = 0.92) and Glyceryl Trinitrate (GTN) (SMD [95% CI] = −0.01 [−0.11, 0.08]; p = 0.78) were non‐significant. Within stroke patients, subgroup analysis showed that TRP channel agonists had a moderate pooled effect size (SMD[95%CI] =0.74[0.10,1.39]; p = 0.02; I2 = 82%) whereas the effects of other agents were non‐significant (SMD[95%CI] =0.40[−0.04,0.84]; p = 0.07; I2 = 87%). Conclusions & Inferences: Our results showed that TRP channel agonists, Nifedipine and Metoclopromide may be beneficial for neurogenic dysphagic patients. Large scale, multicenter clinical trials are warranted to fully explore their therapeutic effects on swallowing.
    • Effects of Radiation sterilization Dose on the Molecular Weight and Gelling Properties of Commercial Alginate Samples

      Mollah, M. Z. I.; email: zahirul1973@yahoo.com; Rahaman, M S.; Faruque, M R I.; Khandaker, M U.; Osman, Hamid; Alamri, Sultan; Al-Assaf, Saphwan (Frontiers Media S.A., 2021-12-20)
      To estimate the molecular weight (Mw) and gelling properties, a total of 26 alginate samples consisting of control (n = 13) and 15 kGy γ-irradiated (n = 13) samples were characterized through viscometric and gel permeation chromatography (GPC-MALLS) methods. Based on the observations, a remarkable decrease in the intrinsic viscosity of all samples of alginates was evident due to the effects of radiation, with a linear relationship between viscosity and concentration in 0.01 M NaCl solution. The correlation among the Mw, percentage mass recovery, radii of gyration (Rz/Rg), and percentage reduction of Mw assessed by GPC was significant. The Mw decreased dramatically (from 3.1 × 105 to 0.49 × 105 mole/g in sample no. 12) by the effect of radiation with momentous relation to the % reduction of the molecular weight. The highest molecular weight reduction (84%), which is the most sensitive to γ-radiation, and the average reduction rate was ≥50%. The mass recovery was 100% obtained from samples no. 1,3,4,5,7,12, and 13, while the rest of the samples’ recovery rate was significantly higher. The reduction rate of mass molecular weight (Mw) is higher than the average molecular weight (Mv), but they showed a sensitivity towards radiation, consequently their performance are different from each other. The stability test was performed as a critical behaviour in the control, recurrently same as in the irradiated samples. Thus, the sterilization dose of 15 kGy for the Mw distribution, and subsequently for the characterization, was significantly effective.