24 research outputs found

    The ferroelectric nematic phase: on the role of lateral alkyloxy chains.

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    The synthesis and characterisation of the 4-({[4’-nitro-(1,1'-biphenyl)−4-yl]oxy}carbonyl)phenyl 2-alkoxy-4-methoxybenzoates are reported: the 1O(m-On)PEPEBNO2 series. These materials include an additional phenyl ring compared to the extensively studied ferroelectric nematogen RM734, added to increase the liquid crystal transition temperatures. All members of the series exhibited both conventional nematic (N) phase and ferroelectric nematic (NF) phases; TNI and TNFN both decrease on increasing n, the length of the lateral alkoxy chain. The properties of this four-ring series are compared with analogous three-ring laterally substituted variants of RM734; the addition of the extra phenyl ring has a significantly more pronounced effect on the value of TNI than on TNFN. The increase in TNI may be attributed to the enhanced structural anisotropy and more favourable intermolecular interactions arising from the insertion of the phenyl ring, whereas the much weaker effect on TNFN may reflect a change in the shape of the molecule. We also report two materials with three-ring structures, the 4'-nitro-(1,1'-biphenyl)-4-yl 2-alkoxy-4-methoxybenzoates: 1O(m-On)PEBNO2 (n=1 and 2). The removal of the ester linkage between RM734 and 1O(m-O1)PEPNO2 extinguishes the NF phase and this appears to be consistent with a model in which the molecules are described in terms of a longitudinal surface charge density wave

    Ferroelectric nematogens containing a methylthio group.

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    The synthesis and characterisation of eight nematogens containing a terminal methylthio group is reported. The compounds are based on RM734 and differ in the number and position of fluorine substituents, and in the position of the lateral methoxy substituent. Seven of these compounds exhibit a monotropic ferroelectric nematic phase, NF, including examples of NF-isotropic phase transitions. Two of the compounds show the anti-ferroelectric NX phase. Their transitional behaviour is discussed in terms of molecular shape and changes in electronic properties. Their phase behaviour is similar to that of the corresponding compounds containing a terminal methoxy group, but the methoxy terminated materials consistently show the higher transition temperatures. This is accounted for by the larger reduction in molecular shape anisotropy associated with the methylthio group, and the associated change in the electronic properties. The NX phase seen for the methylthio substituted compounds are thought to reflect the suppression of the NF phase by the methylthio group rather than any specific stabilising effect. Specific interactions between methylthio groups thought to stabilise nematic behaviour do not appear to stabilise the NF phase

    The influence of molecular shape and electronic properties on the formation of the ferroelectric nematic phase.

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    The synthesis and characterisation of two series of ferroelectric nematogens based on RM734 having an additional methoxy group on the central phenyl ring are reported, the 3-methoxy-4-((4-nitrophenoxy)carbonyl)phenyl 2-alkoxy-4-alkoxybenzoates (7-m-n) and the 3-methoxy-4-((3-fluoro-4-nitro-phenoxy)carbonyl)phenyl 2-alkoxy-4-alkoxybenzoates (8-m-n). In order to compare the behaviour of these series to those of the corresponding materials that do not contain the methoxy group on the central phenyl ring, we also report the synthesis and characterisation of 4-[(4-nitrophenoxy)carbonyl] phenyl 4-methoxybenzoate (11-0-1), 4-[(3-fluoro-4-nitrophenoxy)carbonyl]phenyl 4-methoxybenzoate (12-0-1) and 4-[(3-fluoro-4-nitrophenoxy)carbonyl]phenyl 2,4-diethoxybenzoate (12-2-2). Two compounds in which a lateral ethoxy chain is attached to the central ring, 3-ethoxy-4-[(4-nitrophenoxy)carbonyl]phenyl 2,4-dimethoxybenzoate (18-2-1) and 3-ethoxy-4-[(3-fluoro-4-nitrophenoxy) carbonyl]phenyl 2,4-dimethoxybenzoate (19-2-1), are also described. The behaviour of these materials shows that the relative stabilities of the ferroelectric nematic, NF, and conventional nematic, N, phases are governed by a subtle interplay of steric and electronic factors. Furthermore, the electronic factors are better understood in terms of isolated regions of electron density rather than by a single large longitudinal dipole moment. In terms of molecular shape, to observe the NF phase it appears that the molecular structure must include one or more lateral substituents that enhance molecular biaxiality and destabilise the N phase

    Multiple polar and non‐polar nematic phases.

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    Liquid-crystal materials exhibiting up to three nematic phases are reported. Dielectric response measurements show that while the lower temperature nematic phase has ferroelectric order and the highest temperature nematic phase is apolar, the intermediate phase has local antiferroelectric order. The modification of the molecular structure by increasing the number of lateral fluorine substituents leads to one of the materials showing a direct isotropic-ferronematic phase transition

    Impact of opioid-free analgesia on pain severity and patient satisfaction after discharge from surgery: multispecialty, prospective cohort study in 25 countries

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    Background: Balancing opioid stewardship and the need for adequate analgesia following discharge after surgery is challenging. This study aimed to compare the outcomes for patients discharged with opioid versus opioid-free analgesia after common surgical procedures.Methods: This international, multicentre, prospective cohort study collected data from patients undergoing common acute and elective general surgical, urological, gynaecological, and orthopaedic procedures. The primary outcomes were patient-reported time in severe pain measured on a numerical analogue scale from 0 to 100% and patient-reported satisfaction with pain relief during the first week following discharge. Data were collected by in-hospital chart review and patient telephone interview 1 week after discharge.Results: The study recruited 4273 patients from 144 centres in 25 countries; 1311 patients (30.7%) were prescribed opioid analgesia at discharge. Patients reported being in severe pain for 10 (i.q.r. 1-30)% of the first week after discharge and rated satisfaction with analgesia as 90 (i.q.r. 80-100) of 100. After adjustment for confounders, opioid analgesia on discharge was independently associated with increased pain severity (risk ratio 1.52, 95% c.i. 1.31 to 1.76; P < 0.001) and re-presentation to healthcare providers owing to side-effects of medication (OR 2.38, 95% c.i. 1.36 to 4.17; P = 0.004), but not with satisfaction with analgesia (beta coefficient 0.92, 95% c.i. -1.52 to 3.36; P = 0.468) compared with opioid-free analgesia. Although opioid prescribing varied greatly between high-income and low- and middle-income countries, patient-reported outcomes did not.Conclusion: Opioid analgesia prescription on surgical discharge is associated with a higher risk of re-presentation owing to side-effects of medication and increased patient-reported pain, but not with changes in patient-reported satisfaction. Opioid-free discharge analgesia should be adopted routinely

    Multi-disciplinary training hubs in North West England: The training hub lead perspective.

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    Introduction: Increasing the capacity of Primary Care to meet the challenge of providing future complex and multi-disciplinary care in England has led to the increasing establishment of ‘Training Hubs’ [TH]. Other terms are used interchangeably to refer to TH activity: Advanced Training Practices, Enhanced Training Practices and Community Education Providers. The aim of this study was to gather the perceptions of TH Leads in North West England on how they established their TH and lessons learned. Methods: Five semi-structured telephone interviews were undertaken with TH Leads. Thematic analysis of the transcripts was undertaken. Findings: Four themes were identified: Motivation and Expectations of Establishing THs; Benefits to Learners and Practice Staff; Implementation Challenges and Barriers to Scale-Up; Sustainability and Wider Implementation. Discussion: TH Leads highlighted that the establishment of THs enhanced the multi-disciplinary learning experience. However, several barriers for sustaining the quality of the TH learning environments were identified. Difficulties recruiting ‘Spoke Practices’ were greater than expected. Findings identified the following factors for consideration for wider implementation: the maintenance of TH Lead support networks; appropriateness of funding to encourage practices who may be reluctant to take on this additional responsibility; the importance of communication channels between THs and HEIs; careful management of students numbers.</br

    Co-producing public involvement training with members of the public and research organisations in the East Midlands: creating, delivering and evaluating the lay assessor training programme

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    Plain english summaryMembers of the public share their views with researchers to improve health and social care research. Lay assessing is one way of doing this. This is where people, drawing upon personal and general life experience, comment on material, such as grant applications and patient information, to highlight strengths and weaknesses and to suggest improvements. This paper reports on setting up a training programme for lay assessors.Meetings were held between interested public and staff from research organisations. People discussed what lay assessing is, why they want to do it, skills and support needed and if training was wanted. They were invited to form a group to develop the training together. Training was delivered in the East Midlands. People who attended gave their thoughts about it by completing questionnaires and joining a feedback event.The group developed the structure of the training programme together and it oversaw the development of the training content by individual members. People who attended training reported feeling more confident about lay assessing. This was particularly so for those who had not done lay assessing before. They indicated how valuable it was to talk with others at the training. Our findings support the National Institute for Health Research recommendations for improving learning and development for public involvement in research.This project has created a solid base for local research organisations to work together in public involvement training. Lay assessor training is now part of a wider programme of shared resources called the Sharebank.AbstractBackground Involving members of the public in research can improve its quality and incorporate the needs and views of patients. One method for doing this is lay assessing, where members of the public are consulted to improve research materials. This paper documents the establishment of a pilot training programme for lay assessors. It describes a way of working that embodies a regional, cross-organisational approach to co-producing training with members of the public.Methods Open meetings, led by AH, were held for existing and aspiring lay assessors to define lay assessing, motivations for doing it, skills required, associated learning and development needs, and to gauge interest for training. Those who attended meetings, including members of the public and staff, were invited to form a working group to co-produce the training programme. Training was delivered in modules at two centres in the East Midlands and evaluated through participant feedback at the end of each module and at an evaluation event. Feedback was through a mix of Likert scale scoring, open text and verbal responses.Results Discussions from the open meetings informed the development of the training by the working group. Led by AH, the working group, as a whole, co-produced the structure and format of the training and oversaw training content development by individuals within the group. Training was well-received by participants. Feedback through Likert scoring (n = 14) indicated higher feelings of confidence in knowledge of relevant subject matter and in fulfilling the lay assessor role, particularly amongst those who had not done lay assessing before. Opportunities that the training afforded for interaction between participants – sharing of varied experiences and knowledge – and a ‘learn by doing’ approach was of particular value, as indicated by 10 responses to open-ended questions.Conclusions This project has created a solid foundation for collaboration between research organisations in the East Midlands in devising and delivering training in public involvement together. Our evaluation provides evidence in support of National Institute for Health Research (NIHR) recommendations on principles for learning and development for public involvement in research

    The influence of molecular shape and electronic properties on the formation of the ferroelectric nematic phase

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    The synthesis and characterisation of two series of ferroelectric nematogens based on RM734 having an additional methoxy group on the central phenyl ring are reported, the 3-methoxy-4-((4-nitrophenoxy)carbonyl)phenyl 2-alkoxy-4-alkoxybenzoates (7-m-n) and the 3-methoxy-4-((3-fluoro-4-nitrophenoxy)carbonyl)phenyl 2-alkoxy-4-alkoxybenzoates (8-m-n). In order to compare the behaviour of these series to those of the corresponding materials that do not contain the methoxy group on the central phenyl ring, we also report the synthesis and characterisation of 4-[(4-nitrophenoxy)carbonyl]phenyl 4-methoxybenzoate (11-0-1), 4-[(3-fluoro-4-nitrophenoxy)carbonyl]phenyl 4-methoxybenzoate (12-0-1) and 4-[(3-fluoro-4-nitrophenoxy)carbonyl]phenyl 2,4-diethoxybenzoate (12-2-2). Two compounds in which a lateral ethoxy chain is attached to the central ring, 3-ethoxy-4-[(4-nitrophenoxy)carbonyl]phenyl 2,4-dimethoxybenzoate (18-2-1) and 3-ethoxy-4-[(3-fluoro-4-nitrophenoxy)carbonyl]phenyl 2,4-dimethoxybenzoate (19-2-1), are also described. The behaviour of these materials shows that the relative stabilities of the ferroelectric nematic, NF, and conventional nematic, N, phases are governed by a subtle interplay of steric and electronic factors. Furthermore, the electronic factors are better understood in terms of isolated regions of electron density rather than by a single large longitudinal dipole moment. In terms of molecular shape, to observe the NF phase it appears that the molecular structure must include one or more lateral substituents that enhance molecular biaxiality and destabilise the N phase.</p
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