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1.
J Affect Disord ; 348: 275-282, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38163569

RESUMO

BACKGROUND: It is estimated that up to 50 % of people with bipolar disorder (BD) also have comorbid post-traumatic stress disorder (PTSD). However, little is known about the presentation and treatment of people with this comorbidity. METHODS: Data from 577 individuals diagnosed with bipolar disorder participating in the Heinz C. Prechter Longitudinal Study of BD were explored at baseline, year two and four. Three trauma groups were created: (i) one trauma (n = 75), (ii) multiple traumas (n = 417), and comorbid PTSD (n = 85). Measures of depression, mania, sleep, number of hospitalisations, suicide attempts, and medication use were analysed using regression modelling to determine differences between the three trauma groups. RESULTS: There was an increase in depression, mania, and sleep scores and a higher number of hospitalisations in participants with comorbid PTSD compared to those experiencing one trauma. Additionally, increased mania and depression scores were reported in participants experiencing multiple traumas compared to those with one trauma. There was no difference in medication use between those who experienced one trauma compared to those with comorbid PTSD. LIMITATIONS: The trauma groups may include confounding with more participants experiencing PTSD than reported in this study due to screening processes. Additionally, the severity of trauma was not recorded, therefore number of traumas was utilised as a proxy. CONCLUSION: Comorbid BD and PTSD is associated with worse symptom scores compared to participants reporting one trauma. Clinical implications include the addition of trauma-informed care to clinical settings to identify PTSD to provide appropriate treatments.


Assuntos
Transtorno Bipolar , Traumatismo Múltiplo , Transtornos de Estresse Pós-Traumáticos , Humanos , Transtornos de Estresse Pós-Traumáticos/diagnóstico , Transtorno Bipolar/epidemiologia , Transtorno Bipolar/diagnóstico , Estudos Longitudinais , Mania , Comorbidade
2.
J Am Chem Soc ; 146(5): 3270-3278, 2024 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-38275220

RESUMO

Living on an increasingly polluted planet, the removal of toxic pollutants such as sulfur dioxide (SO2) from the troposphere and power station flue gas is becoming more and more important. The CPO-27/MOF-74 family of metal-organic frameworks (MOFs) with their high densities of open metal sites is well suited for the selective adsorption of gases that, like SO2, bind well to metals and have been extensively researched both practically and through computer simulations. However, until now, focus has centered upon the binding of SO2 to the open metal sites in this MOF (called chemisorption, where the adsorbent-adsorbate interaction is through a chemical bond). The possibility of physisorption (where the adsorbent-adsorbate interaction is only through weak intermolecular forces) has not been identified experimentally. This work presents an in situ single-crystal X-ray diffraction (scXRD) study that identifies discrete adsorption sites within Ni-MOF-74/Ni-CPO-27, where SO2 is both chemisorbed and physisorbed while also probing competitive adsorption of SO2 of these sites when water is present. Further features of this site have been confirmed by variable SO2 pressure scXRD studies, DFT calculations, and IR studies.

3.
Clin Psychopharmacol Neurosci ; 21(3): 457-465, 2023 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-37424414

RESUMO

Objective: Bipolar disorder often co-occurs with post-traumatic stress disorder, yet few studies have investigated the impact of post-traumatic stress disorder in bipolar disorder on treatment outcomes. The aim of this sub-analysis was to explore symptoms and functioning outcomes between those with bipolar disorder alone and those with comorbid bipolar disorder and post-traumatic stress disorder. Methods: Participants (n = 148) with bipolar depression were randomised to: (i) N-acetylcysteine alone; (ii) a combination of nutraceuticals; (iii) or placebo (in addition to treatment as usual) for 16 weeks (+4 weeks discontinuation). Differences between bipolar disorder and comorbid bipolar disorder and post-traumatic stress disorder on symptoms and functioning at five timepoints, as well as on the rate of change from baseline to week 16 and baseline to week 20, were examined. Results: There were no baseline differences between bipolar disorder alone and comorbid bipolar disorder and post-traumatic stress disorder apart from the bipolar disorder alone group being significantly more likely to be married (p = 0.01). There were also no significant differences between bipolar disorder alone and comorbid bipolar disorder and post-traumatic stress disorder on symptoms and functioning. Conclusion: There were no differences in clinical outcomes over time within the context of an adjunctive randomised controlled trial between those with bipolar disorder alone compared to those with comorbid bipolar disorder and post-traumatic stress disorder. However, differences in psychosocial factors may provide targets for areas of specific support for people with comorbid bipolar disorder and post-traumatic stress disorder.

4.
Clin Psychopharmacol Neurosci ; 21(2): 320-331, 2023 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-37119225

RESUMO

Objective: N-acetylcysteine (NAC) is a novel therapeutic agent with multiple mechanisms of action in the central nervous system and a favourable side effect profile. Clinical evidence indicates that adjunctive NAC may reduce the severity of depressive symptoms in individuals with major depressive disorder (MDD). Methods: A 12-week randomised controlled trial of 2,000 mg/day adjunctive NAC for MDD found no significant improvement at the primary endpoint (week 12) but did see improvements at the post-discontinuation interview (week 16). Within the context of patient-centered treatment, mixed-methods qualitative analysis was also included to explore factors that may determine individual responses to adjunctive NAC treatment. These data were drawn, under blinded conditions, from clinician notes recorded in the case report form. Using the DSM-5 symptom profile for MDD as the initial framework, themes were developed and explored. Frequencies were compared between placebo and NAC groups. Results: Per protocol analysis of individual themes across the six interviews revealed group differences in favour of NAC for overall depressive affect, optimism, relationships and reduced functional impairment. Conclusion: This study provides further evidence for the utility of the mixed methods approach complimenting the primary findings using traditional quantitative analyses, as well as being able to capture additional, often more subtle, evidence of individual symptom-level change that reflects improvement in functional abilities in response to NAC supplementation. The use of mixed methods to explore outcomes from psychiatric studies should be considered in future to work towards improved patient-centred care and both confirm quantitative findings and generate novel hypotheses.

5.
J Clin Psychiatry ; 84(3)2023 04 10.
Artigo em Inglês | MEDLINE | ID: mdl-37058607

RESUMO

Background: Experiences of interpersonal trauma, both in childhood and in adulthood, can affect the trajectory of bipolar disorder (BD). However, the degree to which childhood and/or adult trauma impacts the longitudinal trajectory of depression severity among individuals with BD actively receiving treatment remains unclear.Methods: The effects of childhood trauma (Childhood Trauma Questionnaire) and adult trauma (Life Events Checklist) on depression severity (Hamilton Depression Rating Scale) were investigated in a treatment-receiving subsample with BD (DSM-IV) of the Prechter Longitudinal Study of Bipolar Disorder (2005-present). A mixed-effects linear regression model was used to assess the trajectory of depression severity over 4 years.Results: Depression severity was evaluated in 360 participants, of whom 267 (74.8%) reported a history of interpersonal trauma. A history of childhood trauma alone (n = 110) and childhood and adult trauma combined (n = 108)-but not adult trauma alone (n = 49) -were associated with greater depression severity at the 2-year and 6-year follow-up assessments. However, the trajectory of depression severity (ie, change over time) was similar between participants with a history of childhood trauma, those with a history of adult trauma, and those with no history of interpersonal trauma. Interestingly, participants with a history of both types of trauma showed more improvement in depression severity (ie, from year 2 to year 4: ß = 1.67, P = .019).Conclusions: Despite actively receiving treatment for BD, participants with a history of interpersonal trauma-particularly childhood trauma-presented with more severe depressive symptoms at several follow-up assessments. Hence, interpersonal trauma may represent an essential treatment target.


Assuntos
Transtorno Bipolar , Humanos , Transtorno Bipolar/diagnóstico , Depressão/diagnóstico , Depressão/etiologia , Estudos Longitudinais , Inquéritos e Questionários , Manual Diagnóstico e Estatístico de Transtornos Mentais
6.
Commun Chem ; 6(1): 44, 2023 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-36859657

RESUMO

Metal-organic frameworks (MOFs) are well known for their ability to adsorb various gases. The use of MOFs for the storage and release of biologically active gases, particularly nitric oxide (NO) and carbon monoxide (CO), has been a subject of interest. To elucidate the binding mechanisms and geometry of these gases, an in situ single crystal X-ray diffraction (scXRD) study using synchrotron radiation at Diamond Light Source has been performed on a set of MOFs that display promising gas adsorption properties. NO and CO, were introduced into activated Ni-CPO-27 and the related Co-4,6-dihydroxyisophthalate (Co-4,6-dhip). Both MOFs show strong binding affinity towards CO and NO, however CO suffers more from competitive co-adsorption of water. Additionally, we show that morphology can play an important role in the ease of dehydration for these two systems.

7.
Acta Psychiatr Scand ; 147(3): 286-300, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36645036

RESUMO

BACKGROUND: Childhood trauma is related to an increased number of depressive episodes and more severe depressive symptoms in bipolar disorder. The evaluation of the networks of depressive symptoms-or the patterns of relationships between individual symptoms-among people with bipolar disorder with and without a history of childhood trauma may assist in further clarifying this complex relationship. METHODS: Data from over 500 participants from the Heinz C. Prechter Longitudinal Study of Bipolar Disorder were used to construct a series of regularised Gaussian Graphical Models. The networks of individual depressive symptoms-self-reported (Patient Health Questionnaire-9; n = 543) and clinician-rated (Hamilton Depression Rating Scale-17; n = 529)-among participants with bipolar disorder with and without a history of childhood trauma (Childhood Trauma Questionnaire) were characterised and compared. RESULTS: Across the sets of networks, depressed mood consistently emerged as a central symptom (as indicated by strength centrality and expected influence); regardless of participants' history of childhood trauma. Additionally, feelings of worthlessness emerged as a key symptom in the network of self-reported depressive symptoms among participants with-but not without-a history of childhood trauma. CONCLUSION: The present analyses-although exploratory-provide nuanced insights into the impact of childhood trauma on the presentation of depressive symptoms in bipolar disorder, which have the potential to aid detection and inform targeted intervention development.


Assuntos
Experiências Adversas da Infância , Transtorno Bipolar , Humanos , Transtorno Bipolar/epidemiologia , Transtorno Bipolar/diagnóstico , Depressão/epidemiologia , Estudos Longitudinais , Inquéritos e Questionários
8.
Int J Neuropsychopharmacol ; 26(1): 61-69, 2023 01 19.
Artigo em Inglês | MEDLINE | ID: mdl-36037522

RESUMO

BACKGROUND: The prevalence of posttraumatic stress disorder (PTSD) co-occurring in people with bipolar disorder (BD) is high. People with BD and PTSD may experience different outcomes and quality of life after pharmacologic treatment than those with BD alone. This review systematically explores the impact of PTSD on pharmacologic treatment outcomes for adults with BD. METHODS: We conducted a systematic search up to November 25, 2021, using MEDLINE Complete, Embase, American Psychological Association PsycInfo, and the Cochrane Central Register of Controlled Trials to identify randomized and nonrandomized studies of pharmacologic interventions for adults with BD that assessed for comorbid PTSD. We used the Newcastle-Ottawa Scale and Cochrane Risk of Bias tool to assess the risk of bias. RESULTS: The search identified 5093 articles, and we reviewed 62 full-text articles. Two articles met inclusion criteria (N = 438). One article was an observational study, and the other was a randomized comparative effectiveness trial. The observational study examined lithium response rates and found higher response rates in BD alone compared with BD plus PTSD over 4 years. The randomized trial reported more severe symptoms in the BD plus PTSD group than in those with BD alone following 6 months of quetiapine treatment. There was no significant difference in the lithium treatment group at follow-up. CONCLUSIONS: Comorbid PTSD may affect quetiapine and lithium treatment response in those with BD. Because of the high risk of bias and low quality of evidence, however, these results are preliminary. Specific studies exploring comorbid BD and PTSD are required to inform pharmacotherapy selection and guidelines appropriately. (International Prospective Register of Systematic Reviews ID: CRD42020182540).


Assuntos
Transtorno Bipolar , Terapia Cognitivo-Comportamental , Transtornos de Estresse Pós-Traumáticos , Adulto , Humanos , Transtornos de Estresse Pós-Traumáticos/complicações , Transtornos de Estresse Pós-Traumáticos/tratamento farmacológico , Transtornos de Estresse Pós-Traumáticos/epidemiologia , Terapia Cognitivo-Comportamental/métodos , Transtorno Bipolar/complicações , Transtorno Bipolar/tratamento farmacológico , Transtorno Bipolar/epidemiologia , Fumarato de Quetiapina/uso terapêutico , Qualidade de Vida , Compostos de Lítio , Estudos Observacionais como Assunto
9.
Aust N Z J Psychiatry ; 57(7): 1031-1042, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35924739

RESUMO

BACKGROUND: Childhood trauma is negatively associated with depression severity in bipolar disorder; however, the underlying mechanisms remain unclear. We investigated whether personality traits (neuroticism, extraversion, openness, agreeableness, conscientiousness) mediate the relationship between childhood trauma and the severity of bipolar depression. METHODS: Data from 209 individuals with bipolar disorder recruited for the Prechter Longitudinal Study of Bipolar Disorder were analysed. Using structural equation modelling, we examined the direct and indirect associations between childhood trauma (Childhood Trauma Questionnaire) and depression severity (Hamilton Depression Rating Scale) - with the personality traits (NEO Personality Inventory-Revised) as mediators. RESULTS: The direct effect of childhood trauma on depression severity (standardised ß = 0.32, 95% bootstrap confidence interval [CI] = 0.20-0.45, p < 0.001) and the indirect effect via neuroticism (standardised ß = 0.03, 95% bootstrap CI [0.002, 0.07], p = 0.039) were significant; supporting a partial mediation model. The indirect effect accounted for 9% of the total effect of childhood trauma on depression severity (standardised ß = 0.09, 95% bootstrap CI [0.002, 0.19], p = 0.046). The final model had a good fit with the data (comparative fit index = 0.96; root mean square error of approximation = 0.05, 90% CI = [0.02, 0.07]). CONCLUSION: Personality traits may be relevant psychological mediators that link childhood trauma to a more severe clinical presentation of bipolar depression. Consequently, a person's personality structure may be a crucial operative factor to incorporate in therapeutic plans when treating individuals with bipolar disorder who report a history of childhood trauma.


Assuntos
Experiências Adversas da Infância , Transtorno Bipolar , Humanos , Transtorno Bipolar/psicologia , Estudos Longitudinais , Depressão/psicologia , Personalidade , Inventário de Personalidade
10.
Dalton Trans ; 51(47): 17947-17951, 2022 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-36416289

RESUMO

An in situ pair distribution function study assessing the reassembly of three IM-12 (UTL) intermediate materials to the corresponding fully connected materials. A greater level of atomic change is observed at higher temperatures for the reassembly of the fully disconnected intermediate, IPC-1P, compared to the two partially connected intermediates of IPC-2P and IPC-6P.

11.
Clin Psychopharmacol Neurosci ; 20(2): 300-310, 2022 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-35466101

RESUMO

Objective: There is often a shortfall in recovery following treatment for an episode of bipolar disorder (BD). Exploration of participant's experience provides vital information to enhance statistical outcomes for novel therapy trials. This study used mixed-methods to explore participants' experience of a trial testing N -acetyl cysteine (NAC) and mitochondrially active nutraceuticals for BD depression. Case: report forms from a randomised controlled trial (RCT) of BD depression (n = 148) were analysed using a pragmatic adaption of grounded theory and thematic analysis. Results: Thematic analysis of 148 study participants indicated numerous changes in participant experience over time. For example, perceived environmental stressors reported by participants decreased over the trial in both treatment groups. Quantitative analysis of the themes revealed more positive theme reports in the combination treatment arm compared to the placebo arm and there were more negative themes identified in the placebo arm, compared to the NAC arm. Conclusion: This approach revealed additional results not elucidated in the primary quantitative analysis. This emphasises the value of mixed-methods research in capturing participants' experiences in RCTs and detecting possible latent benefits and risks. Such methods can detect latent target signals in novel therapy trials conducted in BD and generate novel hypotheses.

12.
Acta Psychiatr Scand ; 145(6): 591-603, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35243610

RESUMO

BACKGROUND: Childhood trauma is associated with greater depression severity among individuals with bipolar disorder. However, the mechanisms that explain the link between childhood trauma and depression severity in bipolar disorder remain poorly understood. The mediational role of attachment insecurity in childhood and adulthood was assessed in the current study. METHODS: Participants with bipolar disorder (N = 143) completed measures of childhood trauma (Childhood Trauma Questionnaire), attachment insecurity (Experiences in Close Relationships Scale) and depression severity (Hamilton Depression Rating Scale) as part of the Prechter Longitudinal Study of Bipolar Disorder. A sequential mediation model was tested using path analysis: the direct and indirect effects of childhood trauma on depression severity with attachment insecurity (attachment anxiety and avoidance) in childhood (mother and father) and adulthood (partner) as mediators were estimated. RESULTS: The final path model demonstrated an excellent fit to the data (comparative fit index = 0.996; root mean square error of approximation = 0.021 [90% confidence interval = 0.000-0.073]). Supporting the hypothesised sequential mediation model, maternal attachment anxiety in childhood and romantic attachment avoidance in adulthood partially mediated the relationship between childhood trauma and depression severity; this effect accounted for 12% of the total effect of childhood trauma on depression severity. CONCLUSION: Attachment insecurity in childhood and adulthood form part of the complex mechanism informing why people with bipolar disorder who have a history of childhood trauma experience greater depression severity. Addressing attachment insecurity represents a valuable psychotherapeutic treatment target for bipolar disorder.


Assuntos
Experiências Adversas da Infância , Transtorno Bipolar , Adulto , Ansiedade , Transtorno Bipolar/epidemiologia , Depressão/epidemiologia , Feminino , Humanos , Estudos Longitudinais , Apego ao Objeto
13.
Acta Psychiatr Scand ; 145(6): 615-627, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35243620

RESUMO

BACKGROUND: Childhood trauma affects the course of mood disorders. Researchers are now considering childhood trauma as an influential factor in the treatment of mood disorders. However, the role of childhood trauma in the treatment of bipolar disorder remains understudied. METHODS: The effect of childhood trauma on treatment outcomes was evaluated among participants randomised to treatment with lithium or quetiapine in the Clinical and Health Outcomes Initiatives in Comparative Effectiveness for Bipolar Disorder (Bipolar CHOICE) study by clinician assessment. Mixed effects linear regression models were used to analyse rates of improvement in symptom severity (assessed with the Bipolar Inventory of Symptoms Scale and the Clinical Global Impression Scale for Bipolar Disorder) and functional impairment (assessed with the Longitudinal Interval Follow-up Evaluation-Range of Impaired Functioning Tool). RESULTS: A history of any childhood trauma was reported by 52.7% of the sample (N = 476). Although participants with a history of any childhood trauma presented with greater symptom severity and functional impairment at most study visits, participants with and without a history of any childhood trauma showed similar rates of improvement in symptom severity and functional impairment over the 24 weeks of treatment. CONCLUSION: This is the first study to explore the association between childhood trauma and treatment outcomes during treatment with lithium or quetiapine in the context of a randomised trial. In Bipolar CHOICE, a history of childhood trauma did not inhibit improvement in symptom severity or functional impairment. Nevertheless, these findings need replication across different settings.


Assuntos
Experiências Adversas da Infância , Antipsicóticos , Transtorno Bipolar , Antipsicóticos/uso terapêutico , Transtorno Bipolar/tratamento farmacológico , Humanos , Lítio/uso terapêutico , Pacientes Ambulatoriais , Fumarato de Quetiapina/uso terapêutico , Resultado do Tratamento
14.
J Affect Disord ; 296: 350-362, 2022 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-34606813

RESUMO

OBJECTIVE: The influence of childhood trauma on the treatment outcomes of pharmacological and/or psychological interventions for adolescents and adults with bipolar disorder was systematically reviewed. METHODS: Randomised and non-randomised studies of interventions for bipolar disorder that included an assessment of childhood trauma were eligible. MEDLINE Complete, Embase, PsycINFO, and the Cochrane Central Register of Controlled Trials were searched. Two independent reviewers completed the screening and extraction process. Two independent reviewers assessed the risk of bias in the included studies using the Cochrane Collaboration's Risk of Bias tool and the Newcastle-Ottawa Scale. Alongside a narrative synthesis, random-effects meta-analyses were performed. RESULTS: Twelve studies (1175 participants) were included. The narrative review highlighted differential treatment outcomes among individuals with a history of childhood trauma. The meta-analyses suggested that childhood trauma was unrelated to treatment response (five studies, 426 participants; odds ratio 0.58, 95% CI 0.27-1.25, p = .164) but may be associated with greater improvement in global functioning (three studies, 210 participants; Hedge's g 0.65, 95% CI 0.04-1.26, p = .037). LIMITATIONS: The impact of childhood trauma on the effectiveness of specific pharmacological/psychological interventions could not be explored due to the small body of research identified. CONCLUSION: The overall quality of the extant evidence is low, which precludes definitive comment on the role of childhood trauma in the treatment of bipolar disorder. Additional research that uses large and representative samples is required to ascertain whether a history of childhood trauma affects the treatment outcomes of interventions for individuals with bipolar disorder.


Assuntos
Experiências Adversas da Infância , Transtorno Bipolar , Terapia Cognitivo-Comportamental , Adolescente , Adulto , Transtorno Bipolar/terapia , Humanos , Intervenção Psicossocial , Psicoterapia , Resultado do Tratamento
15.
BMJ Open ; 11(4): e044569, 2021 04 29.
Artigo em Inglês | MEDLINE | ID: mdl-33926981

RESUMO

INTRODUCTION: Despite available pharmacological and psychological treatments, remission rates for bipolar disorder remain relatively low. Current research implicates the experience of childhood trauma as a potential moderator of poor treatment outcomes among individuals with bipolar disorder. To date, the evidence reporting the influence of childhood trauma on the treatment outcomes of pharmacological and/or psychological interventions for adolescents and adults with bipolar disorder has not been systematically reviewed. METHOD AND ANALYSIS: MEDLINE Complete, Embase, PsycINFO and the Cochrane Central Register of Controlled Trials will be searched to identify randomised and nonrandomised studies of pharmacological and/or psychological interventions for bipolar disorder, which also assessed childhood trauma. To be eligible for inclusion, studies must have been conducted with adolescents or adults (≥10 years). Data will be screened and extracted by two independent reviewers. The methodological quality of the included studies will be assessed with the Cochrane Collaboration's Risk of Bias tool and the Newcastle-Ottawa Scale. If deemed viable, a meta-analysis will be conducted using a random effects model. Heterogeneity of evidence will be estimated with the I² statistics. ETHICS AND DISSEMINATION: This systematic review will use only previously published data. Therefore, ethical approval is not required. The results will be written in concordance with the Preferred Reporting Items for Systematic Review and Meta-Analysis guidelines, published in peer-reviewed journals and presented at relevant conferences. PROSPERO REGISTRATION NUMBER: CRD42020201891.


Assuntos
Transtorno Bipolar , Adolescente , Adulto , Transtorno Bipolar/terapia , Humanos , Metanálise como Assunto , Intervenção Psicossocial , Revisões Sistemáticas como Assunto , Resultado do Tratamento
16.
Chemistry ; 27(33): 8537-8546, 2021 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-33783895

RESUMO

The size of single crystals of the metal-organic framework CPO-27-Ni was incrementally increased through a series of modulated syntheses. A novel linker modulated synthesis using 2,5-dihydroxyterephthalic acid and the isomeric ligand 4,6-dihydroxyisophthalic acid yielded large single crystals of CPO-27-Ni (∼70 µm). All materials were shown to have high crystallinity and phase purity through powder X-ray diffraction, electron microscopy methods, thermogravimetry, and compositional analysis. For the first time single-crystal structure analyses were carried out on CPO-27-Ni. High BET surface areas and nitric oxide (NO) release efficiencies were recorded for all materials. Large single crystals of CPO-27-Ni showed a prolonged NO release and proved suitable for in situ single-crystal diffraction experiments to follow the NO adsorption. An efficient activation protocol was developed, leading to a dehydrated structure after just 4 h, which subsequently was NO-loaded, leading to a first NO loaded single-crystal structural model of CPO-27-Ni.

17.
Mater Adv ; 2(24): 7949-7955, 2021 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-35005625

RESUMO

The assembly-disassembly-organisation-reassembly (ADOR) process is an important tool to access zeolite structures that are otherwise unfeasible via hydrothermal methods. In situ flow pair distribution function (PDF) analysis has been used to probe the mechanism of the disassembly and organisation steps, with the disassembly a rapid step that is often difficult to capture. Zeolite UTL was hydrolysed by 6 M hydrochloric acid, with PDF measurements used to monitor framework alterations as the reaction proceeded. The resulting disassembly mechanism shows an initial rapid removal of germanium from the germanium-rich double 4 rings (d4r), followed by silicon rearrangement and gradual silanol condensation to form IPC-2P.

18.
Chem Sci ; 9(4): 850-859, 2018 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-29629152

RESUMO

17O solid-state NMR spectroscopy is employed to investigate the cation disorder in metal-organic frameworks containing two different types of metal cations. Although NMR offers exquisite sensitivity to the local, atomic-scale structure, making it an ideal tool for the characterisation of disordered materials, the low natural abundance of 17O (0.037%) necessitates expensive isotopic enrichment to acquire spectra on a reasonable timescale. Using dry gel conversion and a novel steaming method we show that cost-effective and atom-efficient enrichment of MOFs is possible, and that high-resolution 17O NMR spectra are sensitive both to the structural forms of the MOF and the presence of guest molecules. For mixed-metal forms of MIL-53, NMR can also provide information on the final composition of the materials (notably different to that of the initial starting material) and the preference for cation clustering/ordering within the MOFs. For Al, Ga MIL-53, the distribution of cations results in a mixed-pore form upon exposure to water, unlike the different structures seen for the corresponding end members. This work shows that as good levels of enrichment can be achieved at reasonable cost, 17O NMR spectroscopy should be an invaluable tool for the study of these important functional materials.

19.
Dalton Trans ; 46(12): 3915-3920, 2017 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-28265629

RESUMO

Copper-exchanged and acidic zeolites are shown to produce nitric oxide (NO) from a nitrite source in biologically active (nanomolar) concentrations. Four zeolites were studied; mordenite, ferrierite, ZSM-5 and SSZ-13, which had varying pore size, channel systems and Si/Al ratios. ZSM-5 and SSZ-13 produced the highest amounts of NO in both the copper and acid form. The high activity and regeneration of the copper active sites makes them good candidates for long-term NO production. Initial cytotoxicity tests have shown at least one of the copper zeolites (Cu-SSZ-13) to be biocompatible, highlighting the potential usage within biomedical applications.


Assuntos
Materiais Biocompatíveis/química , Cobre/química , Óxido Nítrico/química , Zeolitas/química , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Cobre/toxicidade , Células HeLa , Humanos , Concentração de Íons de Hidrogênio , Nitritos/química , Temperatura
20.
Angew Chem Int Ed Engl ; 56(15): 4324-4327, 2017 04 03.
Artigo em Inglês | MEDLINE | ID: mdl-28295998

RESUMO

The assembly-disassembly-organization-reassembly (ADOR) process has been used to disassemble a parent zeolite with the UOV structure type and then reassemble the resulting layers into a novel structure, IPC-12. The structure of the material has previously been predicted computationally and confirmed in our experiments using X-ray diffraction and atomic resolution STEM-HAADF electron microscopy. This is the first successful application of the ADOR process to a material with porous layers.

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