Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 212
Filter
1.
ACS Mater Au ; 4(4): 393-402, 2024 Jul 10.
Article in English | MEDLINE | ID: mdl-39006398

ABSTRACT

High-pressure synthesis in the diamond anvil cell suffers from the lack of a general approach for the control of precursor stoichiometry and homogeneity. Here, we present results from a new method we have developed that uses magnetron cosputtering to prepare stoichiometrically precise and atomically mixed amorphous films of Cr:C. Laser-heated diamond anvil cell experiments carried out on a flake of this sample at pressures between 13.5 and 24.3 GPa lead to the observation of Cr3C (Pnma) over the entire pressure range-in good agreement with our in-house theoretical predictions-but also reveal two other metastable phases that were not expected: a novel monoclinic chromium carbide phase and the NaCl-type CrC (Fm3̅m) phase. The unexpected stability of CrC is investigated by using first-principles methods, revealing a large stabilizing effect tied to substoichiometry at the carbon site. These results offer an important case study into the current limitations of crystal structure prediction methods with regard to phase complexity and bolster the growing need for advanced theoretical approaches that can more completely survey experimentally unexplored phase space.

2.
JMIR Ment Health ; 11: e55750, 2024 May 09.
Article in English | MEDLINE | ID: mdl-38722680

ABSTRACT

BACKGROUND: Online forums are widely used for mental health peer support. However, evidence of their safety and effectiveness is mixed. Further research focused on articulating the contexts in which positive and negative impacts emerge from forum use is required to inform innovations in implementation. OBJECTIVE: This study aimed to develop a realist program theory to explain the impacts of online mental health peer support forums on users. METHODS: We conducted a realist synthesis of literature published between 2019 and 2023 and 18 stakeholder interviews with forum staff. RESULTS: Synthesis of 102 evidence sources and 18 interviews produced an overarching program theory comprising 22 context-mechanism-outcome configurations. Findings indicate that users' perceptions of psychological safety and the personal relevance of forum content are foundational to ongoing engagement. Safe and active forums that provide convenient access to information and advice can lead to improvements in mental health self-efficacy. Within the context of welcoming and nonjudgmental communities, users may benefit from the opportunity to explore personal difficulties with peers, experience reduced isolation and normalization of mental health experiences, and engage in mutual encouragement. The program theory highlights the vital role of moderators in creating facilitative online spaces, stimulating community engagement, and limiting access to distressing content. A key challenge for organizations that host mental health forums lies in balancing forum openness and anonymity with the need to enforce rules, such as restrictions on what users can discuss, to promote community safety. CONCLUSIONS: This is the first realist synthesis of online mental health peer support forums. The novel program theory highlights how successful implementation depends on establishing protocols for enhancing safety and strategies for maintaining user engagement to promote forum sustainability. TRIAL REGISTRATION: PROSPERO CRD42022352528; https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=352528.


Subject(s)
Peer Group , Humans , Social Support , Mental Health Services , Online Social Networking , Mental Disorders/psychology
3.
Chemistry ; 30(42): e202401581, 2024 Jul 25.
Article in English | MEDLINE | ID: mdl-38771299

ABSTRACT

Transition metal carbides find widespread use throughout industry due to their high strength and resilience under extreme conditions. However, they remain largely limited to compounds formed from the early d-block elements, since the mid-to-late transition metals do not form thermodynamically stable carbides. We report here the high-pressure bulk synthesis of large single crystals of a novel metastable manganese carbide compound, MnCx (P63/mmc), which adopts the anti-NiAs-type structure with significant substoichiometry at the carbon sites. We demonstrate how synthesis pressure modulates the carbon loading, with ~40 % occupancy being achieved at 9.9 GPa.

4.
Musculoskeletal Care ; 22(2): e1885, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38682684

ABSTRACT

BACKGROUND: This study investigated the impact of Chronic Low Back Pain (CLBP) on individuals' physical activity (PA) behaviours, specifically, how they modify, cease, or continue PA when experiencing CLBP. The primary aim was to explore the relationship between CLBP and PA and how this is influenced in different contexts (e.g., necessity of a task). METHODS: A mixed-methods survey was administered to 220 participants, including self-reported outcomes, and capturing responses to three distinct questions related to PA and CLBP. The data was analysed via a content analysis. RESULTS: The findings revealed that individuals with CLBP are most likely to modify PA in work-related contexts and least likely to cease it in the same setting. Housework emerged as the most common domain for cessation of PA, while work/study activities were predominantly continued. Reasons for these trends were typically task-based rather than health or enjoyment based and influenced by the perceived necessity of the task in question. CONCLUSION: The study highlights the role of occupational and educational settings in individual responses to CLBP. The findings also highlight a gap in public awareness regarding effective CLBP management strategies, emphasising the need for increased education and awareness programs.


Subject(s)
Chronic Pain , Low Back Pain , Humans , Low Back Pain/psychology , Female , Male , Adult , Middle Aged , Chronic Pain/psychology , Exercise/psychology , Surveys and Questionnaires , Young Adult , Aged , Health Behavior
5.
J Neurosci ; 44(15)2024 Apr 10.
Article in English | MEDLINE | ID: mdl-38418220

ABSTRACT

The conformational state of DNA fine-tunes the transcriptional rate and abundance of RNA. Here, we report that G-quadruplex DNA (G4-DNA) accumulates in neurons, in an experience-dependent manner, and that this is required for the transient silencing and activation of genes that are critically involved in learning and memory in male C57/BL6 mice. In addition, site-specific resolution of G4-DNA by dCas9-mediated deposition of the helicase DHX36 impairs fear extinction memory. Dynamic DNA structure states therefore represent a key molecular mechanism underlying memory consolidation.One-Sentence Summary: G4-DNA is a molecular switch that enables the temporal regulation of the gene expression underlying the formation of fear extinction memory.


Subject(s)
G-Quadruplexes , Male , Animals , Mice , Extinction, Psychological , DEAD-box RNA Helicases/chemistry , DEAD-box RNA Helicases/genetics , DEAD-box RNA Helicases/metabolism , Fear , DNA/metabolism
6.
Injury ; 55(3): 111340, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38301490

ABSTRACT

AIMS: After hip arthroplasty surgery, hip precautions are often implemented to minimise the risk of dislocation, although existing evidence does not support their effectiveness. At our institution, we replaced post-operative precautions with a novel pose avoidance protocol in patients undergoing hip hemiarthroplasty for neck of femur fracture. The objectives of our study were to validate this new protocol by assessing the incidence of dislocation before and after its introduction and evaluating its impact on the length of hospital stay. METHODS: Between 20th September 2021 and 19th March 2023, 200 patients underwent 203 hip hemiarthroplasties. Hip precautions were replaced with the new pose avoidance protocol on 20th June 2022. Data were retrospectively collected and included patient demographics, Abbreviated Mental Test Score, American Society of Anaesthesiologists grade, surgical approach, prosthesis, dislocation, and mortality. RESULTS: The incidence of dislocation within 90 days after hip hemiarthroplasty decreased from seven out of 98 cases (7.1%) before 20th June 2022 to one out of 105 cases (1.0%), p-value 0.030. However, there was no significant difference in the length of stay, with a median (interquartile range) of 19 (10 - 29) days before 20th June 2022, and 16 (11 - 22) days thereafter, p-value 0.242. A multivariate logistic regression confirmed the pose avoidance protocol and the anterolateral approach to be independent negative predictors of dislocation, p-value 0.030 (Odds Ratio [OR] 0.077) and p-value 0.005 (OR 0.022), respectively. CONCLUSIONS: Hip precautions are unnecessary and potentially detrimental to patient outcomes following hemiarthroplasty. Replacing these precautions with our new pose avoidance protocol may have led to a significant reduction in dislocation rates and saved on the cost of adaptive equipment. We advocate for the anterolateral over the posterior approach in hip hemiarthroplasty to further mitigate the risk of dislocation. LEVEL OF EVIDENCE: IV.


Subject(s)
Arthroplasty, Replacement, Hip , Femoral Neck Fractures , Hemiarthroplasty , Hip Dislocation , Joint Dislocations , Humans , Hemiarthroplasty/adverse effects , Hemiarthroplasty/methods , Retrospective Studies , Femoral Neck Fractures/surgery , Femoral Neck Fractures/complications , Joint Dislocations/surgery , Arthroplasty, Replacement, Hip/adverse effects , Arthroplasty, Replacement, Hip/methods , Hip Dislocation/surgery
7.
Ecol Evol ; 14(2): e10920, 2024 Feb.
Article in English | MEDLINE | ID: mdl-38343570

ABSTRACT

Semi-enclosed seas are often associated with elevated local threats and distinct biogeographic patterns among marine fishes, but our understanding of how fish assemblage dynamics vary in relation to relatively small semi-enclosed seas (e.g., the Gulf of Aqaba) remains limited. Baited remote underwater video surveys (n = 111) were conducted across ~300 km of coral reef habitats in the Gulf of Aqaba and the northern Red Sea. A total of 55 predatory fish species were detected, with less than half of all species (n = 23) observed in both basins. Relative abundance patterns between the Gulf of Aqaba and the northern Red Sea were variable among taxa, but nearly twice as many predatory fish were observed per unit of effort in the northern Red Sea. In general, assemblages in both basins were dominated by three taxa (Epinephelinae, Carangidae, and Lethrinidae). Large-bodied and threatened species were recorded at very low abundances. Multivariate analysis revealed distinct assemblage structuring of coral reef predators between the Gulf of Aqaba and the northern Red Sea. Most of the species driving these differences were recorded in both basins, but occurred at varying levels of abundance. Environmental factors were largely unsuccessful in explaining variation in assemblage structuring. These findings indicate that biological assemblages in the Gulf of Aqaba are more distinct than previously reported and that reef fish assemblage structuring can occur even within a relatively small semi-enclosed sea. Despite inter-basin assemblage structuring, the overall low abundance of vulnerable fish species is suggestive of overexploitation in both the Gulf of Aqaba and the northern Red Sea of Saudi Arabia. As the region surveyed is currently undergoing large-scale coastal development, the results presented herein aim to guide spatial management and recovery plans for these coral reef systems in relation to this development.

8.
BMJ Open ; 14(1): e081188, 2024 01 31.
Article in English | MEDLINE | ID: mdl-38296304

ABSTRACT

OBJECTIVE: Living Library events involve people being trained as living 'Books', who then discuss aspects of their personal experiences in direct conversation with attendees, referred to as 'Readers'. This study sought to generate a realist programme theory and a theory-informed implementation guide for a Library of Lived Experience for Mental Health (LoLEM). DESIGN: Integrated realist synthesis and experience-based co-design. SETTING: Ten online workshops with participants based in the North of England. PARTICIPANTS: Thirty-one participants with a combination of personal experience of using mental health services, caring for someone with mental health difficulties and/or working in mental health support roles. RESULTS: Database searches identified 30 published and grey literature evidence sources which were integrated with data from 10 online co-design workshops conducted over 12 months. The analysis generated a programme theory comprising five context-mechanism-outcome (CMO) configurations. Findings highlight how establishing psychological safety is foundational to productive Living Library events (CMO 1). For Readers, direct conversations humanise others' experiences (CMO 2) and provide the opportunity to flexibly explore new ways of living (CMO 3). Through participation in a Living Library, Books may experience personal empowerment (CMO 4), while the process of self-authoring and co-editing their story (CMO 5) can contribute to personal development. This programme theory informed the co-design of an implementation guide highlighting the importance of tailoring event design and participant support to the contexts in which LoLEM events are held. CONCLUSIONS: The LoLEM has appeal across stakeholder groups and can be applied flexibly in a range of mental health-related settings. Implementation and evaluation are required to better understand the positive and negative impacts on Books and Readers. TRIAL REGISTRATION NUMBER: PROSPERO CRD42022312789.


Subject(s)
Mental Health Services , Mental Health , Humans , Empowerment , England , Qualitative Research
9.
Phys Ther ; 104(1)2024 Jan 01.
Article in English | MEDLINE | ID: mdl-37606247

ABSTRACT

OBJECTIVE: This study aimed to estimate the proportion of exercise interventions tested in clinical trials of people with chronic low back pain (CLBP) that meet the World Health Organization's (WHO) physical activity guidelines. METHODS: A secondary analysis of the 2021 Cochrane review of exercise therapy for CLBP was performed. Data from each study were extracted by 1 reviewer and were checked by a second reviewer. Data extracted related to the frequency, duration and intensity of each exercise intervention, and the proportion of exercise interventions that met the WHO's physical activity guidelines (aerobic, muscle strengthening, or both) were determined. RESULTS: The 249 included trials comprised 426 exercise interventions. Few interventions reported an exercise type and dose consistent with the WHO guidelines (aerobic: 1.6%, muscle strengthening: 5.6%, both: 1.6%). Poor reporting of exercise intensity limited our ability to determine whether interventions met the guidelines. CONCLUSION: Few interventions tested in clinical trials for people with CLBP prescribe an exercise type and dose consistent with the WHO guidelines. Therefore, they do not appear sufficiently dosed to achieve broader health outcomes. Future trials should investigate the effect of WHO guideline-recommended exercise interventions on patient-reported outcomes (pain and disability) as well as health-related outcomes in people with CLBP. IMPACT: This exploratory analysis showed the lack of exercise interventions in the CLBP literature that meet the WHO's physical activity guidelines. With people in chronic pain groups, such as people with CLBP, being at higher risk for noncommunicable disease, it appears this is a key consideration for exercise practitioners when designing interventions for people with CLBP.


Subject(s)
Chronic Pain , Low Back Pain , Humans , Low Back Pain/therapy , Exercise , Exercise Therapy , Chronic Pain/therapy , World Health Organization
10.
Musculoskeletal Care ; 2023 Dec 06.
Article in English | MEDLINE | ID: mdl-38054520

ABSTRACT

BACKGROUND: Practitioners' attitudes and beliefs towards chronic low back pain (CLBP) influence their clinical decision making, but few studies have investigated decision making outside the context of patient vignettes for a range of first- and second-line treatment options for CLBP, or in accredited exercise physiologists (AEPs). METHODS: Using an online survey, Australian AEPs and physiotherapists rated their use of different treatments for CLBP (exercise, education, manual therapy, cognitive behavioural therapy) and their confidence in these treatments for reducing pain and disability. Their biomedical and biopsychosocial beliefs were also assessed using the Pain and Attitudes Beliefs Scale for Physiotherapists. Differences between disciplines in treatment use and confidence were analysed using Mann-Whitney U tests and independent t-tests, respectively. Multiple linear regression was used to explore factors associated with treatment choices. RESULTS: Two-hundred thirty-three practitioners (n = 143 physiotherapists, n = 90 AEPs) completed the survey. Most practitioners were confident in treating CLBP, had a moderate-high level of confidence in the different treatments, and regularly used them in practice. Practitioners with higher biomedical beliefs had greater use of, and confidence in, specific exercise, manual therapy, and combined exercise and manual therapy. Practitioners with higher biopsychosocial beliefs were more confident in general exercise, cognitive behavioural therapy, pain education and combined exercise and pain education. CONCLUSION: Practitioner beliefs influence their use of, and confidence in different treatments for CLBP. These findings suggest a need for strategies to enhance biopsychosocial beliefs/reduce biomedical beliefs in Australian exercise-based practitioners.

11.
BMC Psychiatry ; 23(1): 873, 2023 11 24.
Article in English | MEDLINE | ID: mdl-38001403

ABSTRACT

BACKGROUND: Suicidal thoughts, acts, plans and deaths are considerably more prevalent in people with non-affective psychosis, including schizophrenia, compared to the general population. Social isolation and interpersonal difficulties have been implicated in pathways which underpin suicidal experiences in people with severe mental health problems. However, the interactions between psychotic experiences, such as hallucinations and paranoia, suicidal experiences, and the presence, and indeed, absence of interpersonal relationships is poorly understood and insufficiently explored. The current study sought to contribute to this understanding. METHODS: An inductive thematic analysis was conducted on transcripts of 22, individual, semi-structured interviews with adult participants who had both non-affective psychosis and recent suicidal experiences. A purposive sampling strategy was used. Trustworthiness of the analysis was assured with researcher triangulation. RESULTS: Participants relayed both positive and negative experiences of interpersonal relationships. A novel conceptual model is presented reflecting a highly complex interplay between a range of different suicidal experiences, psychosis, and aspects of interpersonal relationships. Three themes fed into this interplay, depicting dynamics between perceptions of i. not mattering and mattering, ii. becoming disconnected from other people, and iii. constraints versus freedom associated with sharing suicidal and psychotic experiences with others. CONCLUSION: This study revealed a detailed insight into ways in which interpersonal relationships are perceived to interact with psychotic and suicidal experiences in ways that can be both beneficial and challenging. This is important from scientific and clinical perspectives for understanding the complex pathways involved in suicidal experiences. TRIAL REGISTRATION: ClinicalTrials.gov (NCT03114917), 14th April 2017. ISRCTN (reference ISRCTN17776666 .); 5th June 2017). Registration was recorded prior to participant recruitment commencing.


Subject(s)
Psychotic Disorders , Schizophrenia , Adult , Humans , Suicidal Ideation , Psychotic Disorders/psychology , Interpersonal Relations , Hallucinations
12.
Nat Commun ; 14(1): 7616, 2023 Nov 22.
Article in English | MEDLINE | ID: mdl-37993455

ABSTRACT

Long noncoding RNAs (lncRNAs) represent a multidimensional class of regulatory molecules that are involved in many aspects of brain function. Emerging evidence indicates that lncRNAs are localized to the synapse; however, a direct role for their activity in this subcellular compartment in memory formation has yet to be demonstrated. Using lncRNA capture-seq, we identified a specific set of lncRNAs that accumulate in the synaptic compartment within the infralimbic prefrontal cortex of adult male C57/Bl6 mice. Among these was a splice variant related to the stress-associated lncRNA, Gas5. RNA immunoprecipitation followed by mass spectrometry and single-molecule imaging revealed that this Gas5 isoform, in association with the RNA binding proteins G3BP2 and CAPRIN1, regulates the activity-dependent trafficking and clustering of RNA granules. In addition, we found that cell-type-specific, activity-dependent, and synapse-specific knockdown of the Gas5 variant led to impaired fear extinction memory. These findings identify a new mechanism of fear extinction that involves the dynamic interaction between local lncRNA activity and RNA condensates in the synaptic compartment.


Subject(s)
Fear , RNA, Long Noncoding , Mice , Male , Animals , RNA, Long Noncoding/genetics , RNA, Long Noncoding/metabolism , Extinction, Psychological , Prefrontal Cortex/metabolism , Synapses/metabolism
13.
J Neurosci ; 43(43): 7084-7100, 2023 10 25.
Article in English | MEDLINE | ID: mdl-37669863

ABSTRACT

The RNA modification N6-methyladenosine (m6A) regulates the interaction between RNA and various RNA binding proteins within the nucleus and other subcellular compartments and has recently been shown to be involved in experience-dependent plasticity, learning, and memory. Using m6A RNA-sequencing, we have discovered a distinct population of learning-related m6A- modified RNAs at the synapse, which includes the long noncoding RNA metastasis-associated lung adenocarcinoma transcript 1 (Malat1). RNA immunoprecipitation and mass spectrometry revealed 12 new synapse-specific learning-induced m6A readers in the mPFC of male C57/BL6 mice, with m6A-modified Malat1 binding to a subset of these, including CYFIP2 and DPYSL2. In addition, a cell type- and synapse-specific, and state-dependent, reduction of m6A on Malat1 impairs fear-extinction memory; an effect that likely occurs through a disruption in the interaction between Malat1 and DPYSL2 and an associated decrease in dendritic spine formation. These findings highlight the critical role of m6A in regulating the functional state of RNA during the consolidation of fear-extinction memory, and expand the repertoire of experience-dependent m6A readers in the synaptic compartment.SIGNIFICANCE STATEMENT We have discovered that learning-induced m6A-modified RNA (including the long noncoding RNA, Malat1) accumulates in the synaptic compartment. We have identified several new m6A readers that are associated with fear extinction learning and demonstrate a causal relationship between m6A-modified Malat1 and the formation of fear-extinction memory. These findings highlight the role of m6A in regulating the functional state of an RNA during memory formation and expand the repertoire of experience-dependent m6A readers in the synaptic compartment.


Subject(s)
Fear , RNA, Long Noncoding , Animals , Male , Mice , Extinction, Psychological , Fear/physiology , Learning/physiology , RNA, Long Noncoding/metabolism , Synapses/metabolism
14.
BMJ Open ; 13(7): e075142, 2023 07 30.
Article in English | MEDLINE | ID: mdl-37518092

ABSTRACT

INTRODUCTION: Peer online mental health forums are commonly used and offer accessible support. Positive and negative impacts have been reported by forum members and moderators, but it is unclear why these impacts occur, for whom and in which forums. This multiple method realist study explores underlying mechanisms to understand how forums work for different people. The findings will inform codesign of best practice guidance and policy tools to enhance the uptake and effectiveness of peer online mental health forums. METHODS AND ANALYSIS: In workstream 1, we will conduct a realist synthesis, based on existing literature and interviews with approximately 20 stakeholders, to generate initial programme theories about the impacts of forums on members and moderators and mechanisms driving these. Initial theories that are relevant for forum design and implementation will be prioritised for testing in workstream 2.Workstream 2 is a multiple case study design with mixed methods with several online mental health forums differing in contextual features. Quantitative surveys of forum members, qualitative interviews and Corpus-based Discourse Analysis and Natural Language Processing of forum posts will be used to test and refine programme theories. Final programme theories will be developed through novel triangulation of the data.Workstream 3 will run alongside workstreams 1 and 2. Key stakeholders from participating forums, including members and moderators, will be recruited to a Codesign group. They will inform the study design and materials, refine and prioritise theories, and codesign best policy and practice guidance. ETHICS AND DISSEMINATION: Ethical approval was granted by Solihull Research Ethics Committee (IRAS 314029). Findings will be reported in accordance with RAMESES (Realist And MEta-narrative Evidence Syntheses: Evolving Standards) guidelines, published as open access and shared widely, along with codesigned tools. TRIAL REGISTRATION NUMBER: ISRCTN 62469166; the protocol for the realist synthesis in workstream one is prospectively registered at PROSPERO CRD42022352528.


Subject(s)
Mental Health , Publications , Humans , Research Design , Narration
15.
J Phys Chem A ; 127(31): 6521-6531, 2023 Aug 10.
Article in English | MEDLINE | ID: mdl-37499264

ABSTRACT

The reaction of N2O with O is a key step in consumption of nitrous oxide in thermal processes. It has two product channels, NO + NO (R2) and N2 + O2 (R3). The rate constant for R2 has been measured both in the forward and the reverse direction at elevated temperature and is well established. However, the rate constant for the N2 + O2 channel (R3) has been difficult to quantify and has significant error limits. The direct reaction on the triplet surface has a barrier of around 40 kcal mol-1, and it is too slow for the N2 + O2 channel to have any practical significance. Recently, Pham and Lin (2022) suggested an alternative low activation energy reaction path that involves intersystem crossing and reaction on the singlet surface. In the present work, we re-examined a wide range of experiments relevant for the N2O + O reaction through kinetic modeling, paying attention to the impact of artifacts such as impurities and surface reactions. Experimental results from shock tubes and batch reactors on the final NO yield in N2O decomposition, covering temperatures of 973-2200 K and pressures of 0.013-11.5 atm, support k3 ∼ 0, consistent with the high activation energy for reaction on the triplet surface and a low probability of ISC.

16.
Neurobiol Learn Mem ; 203: 107777, 2023 09.
Article in English | MEDLINE | ID: mdl-37257557

ABSTRACT

Circular RNAs (circRNAs) comprise a novel class of regulatory RNAs that are abundant in the brain, particularly within synapses. They are highly stable, dynamically regulated, and display a range of functions, including serving as decoys for microRNAs and proteins and, in some cases, circRNAs also undergo translation. Early work in animal models revealed an association between circRNAs and neurodegenerative and neuropsychiatric disorders; however, little is known about the link between circRNA function and memory. To address this, we examined circRNA in synaptosomes derived from the medial prefrontal cortex of fear extinction-trained male C57BL/6J mice and found 12,837 circRNAs that were enriched at the synapse, including cerebellar degeneration-related protein 1 antisense RNA (Cdr1as). Targeted knockdown of Cdr1as in the neural processes of the infralimbic cortex led to impaired fear extinction memory. These findings highlight the involvement of localised circRNA activity at the synapse in memory formation.


Subject(s)
MicroRNAs , RNA, Circular , Mice , Animals , Male , RNA, Circular/genetics , RNA, Circular/metabolism , RNA, Antisense , Extinction, Psychological , Fear , Mice, Inbred C57BL , MicroRNAs/metabolism
17.
J Phys Chem A ; 127(10): 2336-2350, 2023 Mar 16.
Article in English | MEDLINE | ID: mdl-36862996

ABSTRACT

The intramolecular hydrogen-shift rate coefficient of the CH3SCH2O2 (methylthiomethylperoxy, MSP) radical, a product formed in the oxidation of dimethyl sulfide (DMS), was measured using a pulsed laser photolysis flow tube reactor coupled to a high-resolution time-of-flight chemical ionization mass spectrometer that measured the formation of the DMS degradation end product HOOCH2SCHO (hydroperoxymethyl thioformate). Measurements performed over the temperature range of 314-433 K yielded a hydrogen-shift rate coefficient of k1(T) = (2.39 ± 0.7) × 109 exp(-(7278 ± 99)/T) s-1 Arrhenius expression and a value extrapolated to 298 K of 0.06 s-1. The potential energy surface and the rate coefficient have also been theoretically investigated using density functional theory at the M06-2X/aug-cc-pVTZ level combined with approximate CCSD(T)/CBS energies yielding k1(273-433 K) = 2.4 × 1011 × exp(-8782/T) s-1 and k1(298 K) = 0.037 s-1 in fair agreement with the experimental results. Present results are compared with the previously reported values of k1(293-298 K).

18.
J Phys Chem A ; 127(11): 2601-2607, 2023 Mar 23.
Article in English | MEDLINE | ID: mdl-36916833

ABSTRACT

The reaction NH3 + NH2 ⇄ N2H3 + H2 (R1) has been identified as a key step to explain experimental results for pyrolysis and oxidation of ammonia. However, no direct experimental or theoretical evidence for the reaction has been reported. In the present work, the reaction was studied by ab initio theory and by reinterpretation of experimental data. We could not locate a transition state for R1 occurring as a direct process, but alternative mechanisms yielded an upper bound to k1 of 1.5 × 1013 exp(-58.9 kcal mol-1/RT) cm3 mol-1 s-1 over 1000-2500 K, several orders of magnitude lower than values applied in modeling. Consistent with the theoretical work, re-evaluation of NH3 pyrolysis data supported a very low value of k1. However, this finding opens up a novel unresolved issue. Current kinetic models cannot capture the NH3 oxidation behavior in a number of laminar flow reactor and jet-stirred reactor experiments without adopting an improbably high value for k1. Important oxidation steps might be underestimated or missing from mechanisms.

19.
BMJ Open ; 13(3): e068548, 2023 03 08.
Article in English | MEDLINE | ID: mdl-36889824

ABSTRACT

INTRODUCTION: People with lived expertise in managing mental health challenges can be an important source of knowledge and support for other people facing similar challenges, and for carers to learn how best to help. However, opportunities for sharing lived expertise are limited. Living libraries support people with lived expertise to be 'living books', sharing their experiences in dialogue with 'readers' who can ask questions. Living libraries have been piloted worldwide in health-related contexts but without a clear model of how they work or rigorous evaluation of their impacts. We aim to develop a programme theory about how a living library could be used to improve mental health outcomes, using this theory to codesign an implementation guide that can be evaluated across different contexts. METHODS AND ANALYSIS: We will use a novel integration of realist synthesis and experience-based codesign (EBCD) to produce a programme theory about how living libraries work and a theory and experience informed guide to establishing a library of lived experience for mental health (LoLEM). Two workstreams will run concurrently: (1) a realist synthesis of literature on living libraries, combined with stakeholder interviews, will produce several programme theories; theories will be developed collaboratively with an expert advisory group of stakeholders who have hosted or taken part in a living library and will form our initial analysis framework; a systematic search will identify literature about living libraries; data will be coded into our analysis framework, and we will use retroductive reasoning to explain living libraries' impacts across multiple contexts. Individual stakeholder interviews will help refine and test theories; (2) data from workstream 1 will inform 10 EBCD workshops with people with experience of managing mental health difficulties and health professionals to produce a LoLEM implementation guide; data from this process will also inform the theory in workstream 1. ETHICS AND DISSEMINATION: Ethical approval was granted by Coventry and Warwick National Health Service Research Ethics Committee on 29 December 2021 (reference number 305975). The programme theory and implementation guide will be published as open access and shared widely through a knowledge exchange event, a study website, mental health provider and peer support networks, peer reviewed journals and a funders report. PROSPERO REGISTRATION DETAILS: CRD42022312789.


Subject(s)
Mental Health , State Medicine , Humans , Problem Solving , Learning
20.
Psychol Psychother ; 96(2): 426-447, 2023 06.
Article in English | MEDLINE | ID: mdl-36786386

ABSTRACT

PURPOSE: Friends and family members can be important sources of support for people who are or have been suicidal. This review aimed to synthesise qualitative evidence regarding carers' perspectives of supporting someone who has experienced suicidal behaviour. METHODS: Five electronic databases (Web of Science, CINAHL, PsychINFO, MEDLINE, and SocINDEX) were searched from inception to May 2022. Eligible qualitative studies were published in English and investigated the caring experiences of friends or family members of people who had experienced suicidal behaviour, defined as any form of suicidal ideation and/or attempts. Studies focused on non-suicidal self-injury or suicide bereavement were excluded. Data from 19 eligible studies were analysed using thematic synthesis. RESULTS: Initial carer reactions to suicidal behaviour included profound anxiety and intensive monitoring for signs of increased suicide risk amongst those they supported. Carers also reported significant challenges with understanding how to provide effective interpersonal support following suicidal crises. Professional support was perceived to be most effective when provided in a timely, interpersonally sensitive and safety-focused manner. However, several studies detailed carers' difficulties accessing appropriate support and challenges managing their own distress. CONCLUSIONS: Carers face significant challenges with knowing how to respond to suicidal behaviour, where to find appropriate help, and how to manage their own distress. Future research should seek to investigate the effectiveness of easily accessible methods of information provision and support tailored for carers of people who have experienced suicidal behaviour.


Subject(s)
Suicidal Ideation , Suicide , Humans , Family , Caregivers , Qualitative Research
SELECTION OF CITATIONS
SEARCH DETAIL
...