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1.
Cortex ; 177: 194-208, 2024 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-38875734

RESUMO

Postpartum psychosis is a rare but serious condition that can affect women after childbirth. We present a case study of an individual with no comorbidities or psychiatric history who developed postpartum psychosis characterised by prominent misidentification delusions whilst admitted to hospital. The woman recovered quickly with medication and showed no evidence of relapse over the following three years. Whilst still symptomatic and after recovery, the patient was able to provide a detailed description of her experiences. Contemporaneous interviews and observations during her hospital admission and a subsequent detailed retrospective account provide a unique, comprehensive window into her experience of these time-limited delusions. Her case reveals important insights including the triggers for her misidentification delusions, the role of social and contextual influences on delusional beliefs, and her recall of active involvement in evaluating and discarding delusional hypotheses. These insights highlight the complexity of delusional beliefs, challenge existing theories of delusions, and help inform broader theories of belief formation.

2.
Aust N Z J Psychiatry ; : 48674241254213, 2024 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-38725381

RESUMO

BACKGROUND: Contact with health services prior to offences committed by people with mental illness is an opportunity for intervention and prevention. This study examines the pattern and correlates of health service contact by people with severe mental illness before a serious offence. METHOD: Linkage of a cohort of 477 Forensic Patients found not guilty due to mental illness between 1990 and 2016, and statewide databases of contact with emergency departments, hospital admission and outpatient mental health services in the state of New South Wales, Australia. RESULTS: A total of 84% of the sample had contact with any health service and 76% had contact with an outpatient mental health service prior to the index offence. About two-thirds of the sample had contact with a mental health service in the year before the offence. Factors independently associated with the absence of contact at any point prior to the index offence were non-English-speaking background, being engaged in employment or study, and an absence of childhood abuse or neglect. Although nearly every Forensic Patient had a psychotic illness at the time of the index offence, psychosis was not diagnosed at the time of 61/106 (57.5%) emergency department presentations, in 54/174 (31.0%) hospital admissions and 149/222 (67.1%) attendances at outpatient mental health services prior to the offence. CONCLUSIONS: Most Forensic Patients had contact with health services prior to their offences but many were not identified as having a psychotic illness. Although the symptoms of psychosis may have emerged in the period between contact and the offence, the findings suggest that emerging or underlying psychosis were missed or attributed to other conditions.

3.
Australas Psychiatry ; : 10398562241258764, 2024 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-38820548

RESUMO

OBJECTIVES: This paper critiques the haematological monitoring guidelines for clozapine. It describes the history of clozapine, as well as the pathophysiology and epidemiology of clozapine-induced neutropenia (CIN) and agranulocytosis (CIA). The paper appraises the extant literature on mandatory clozapine haematological monitoring. CONCLUSION: Contemporary Australian protocols for clozapine haematological monitoring are not consistent with the current evidence base. CIN and CIA are rare occurrences, and the associated risk of death is low. Potential modifications to existing guidelines include changing neutrophil thresholds for patients with benign ethnic neutropenia and reducing the frequency or removing haematological monitoring after two years of clozapine treatment.

4.
BJPsych Open ; 10(2): e59, 2024 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-38433586

RESUMO

BACKGROUND: There is uncertainty about factors associated with involuntary in-patient psychiatric care. Understanding these factors would help in reducing coercion in psychiatry. AIMS: To explore variables associated with involuntary care in the largest database of involuntary admissions published. METHOD: We identified 166 102 public mental health hospital admissions over 5 years in New South Wales, Australia. Demographic, clinical and episode-of-care variables were examined in an exploratory, multivariable logistic regression. RESULTS: A total of 54% of eligible admissions included involuntary care. The strongest associations with involuntary care were referral from the legal system (odds ratio 4.98, 95% CI 4.61-5.38), and psychosis (odds ratio 4.48, 95% CI 4.31-4.64) or organic mental disorder (odds ratio 4.40, 95% CI 3.85-5.03). There were moderately strong associations between involuntary treatment and substance use disorder (odds ratio 2.68, 95% CI 2.56-2.81) or affective disorder (odds ratio 2.06, 95% CI 1.99-2.14); comorbid cannabis and amphetamine use disorders (odds ratio 1.65, 95% CI 1.57-1.74); unmarried status (odds ratio 1.62, 95% CI 1.49-1.76) and being born in Asia (odds ratio 1.42, 95% CI 1.35-1.50), Africa or the Middle East (odds ratio 1.32, 95% CI 1.24-1.40). Involuntary care was less likely for people aged >75 years (odds ratio 0.68, 95% CI 0.62-0.74), with comorbid personality disorder (odds ratio 0.90, 95% CI 0.87-0.94) or with private health insurance (odds ratio 0.89, 95% CI 0.86-0.93). CONCLUSIONS: This research strengthens the evidence linking diagnostic, socioeconomic and cultural factors to involuntary treatment. Targeted interventions are needed to reduce involuntary admissions in disadvantaged groups.

5.
Med Phys ; 51(6): 4489-4503, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38432192

RESUMO

BACKGROUND: The increasing use of complex and high dose-rate treatments in radiation therapy necessitates advanced detectors to provide accurate dosimetry. Rather than relying on pre-treatment quality assurance (QA) measurements alone, many countries are now mandating the use of in vivo dosimetry, whereby a dosimeter is placed on the surface of the patient during treatment. Ideally, in vivo detectors should be flexible to conform to a patient's irregular surfaces. PURPOSE: This study aims to characterize a novel hydrogenated amorphous silicon (a-Si:H) radiation detector for the dosimetry of therapeutic x-ray beams. The detectors are flexible as they are fabricated directly on a flexible polyimide (Kapton) substrate. METHODS: The potential of this technology for application as a real-time flexible detector is investigated through a combined dosimetric and flexibility study. Measurements of fundamental dosimetric quantities were obtained including output factor (OF), dose rate dependence (DPP), energy dependence, percentage depth dose (PDD), and angular dependence. The response of the a-Si:H detectors investigated in this study are benchmarked directly against commercially available ionization chambers and solid-state diodes currently employed for QA practices. RESULTS: The a-Si:H detectors exhibit remarkable dose linearities in the direct detection of kV and MV therapeutic x-rays, with calibrated sensitivities ranging from (0.580 ± 0.002) pC/cGy to (19.36 ± 0.10) pC/cGy as a function of detector thickness, area, and applied bias. Regarding dosimetry, the a-Si:H detectors accurately obtained OF measurements that parallel commercially available detector solutions. The PDD response closely matched the expected profile as predicted via Geant4 simulations, a PTW Farmer ionization chamber and a PTW ROOS chamber. The most significant variation in the PDD performance was 5.67%, observed at a depth of 3 mm for detectors operated unbiased. With an external bias, the discrepancy in PDD response from reference data was confined to ± 2.92% for all depths (surface to 250 mm) in water-equivalent plastic. Very little angular dependence is displayed between irradiations at angles of 0° and 180°, with the most significant variation being a 7.71% decrease in collected charge at a 110° relative angle of incidence. Energy dependence and dose per pulse dependence are also reported, with results in agreement with the literature. Most notably, the flexibility of a-Si:H detectors was quantified for sample bending up to a radius of curvature of 7.98 mm, where the recorded photosensitivity degraded by (-4.9 ± 0.6)% of the initial device response when flat. It is essential to mention that this small bending radius is unlikely during in vivo patient dosimetry. In a more realistic scenario, with a bending radius of 15-20 mm, the variation in detector response remained within ± 4%. After substantial bending, the detector's photosensitivity when returned to a flat condition was (99.1 ± 0.5)% of the original response. CONCLUSIONS: This work successfully characterizes a flexible detector based on thin-film a-Si:H deposited on a Kapton substrate for applications in therapeutic x-ray dosimetry. The detectors exhibit dosimetric performances that parallel commercially available dosimeters, while also demonstrating excellent flexibility results.


Assuntos
Radiometria , Silício , Radiometria/instrumentação , Hidrogênio , Dosimetria in Vivo , Terapia por Raios X/instrumentação , Humanos
7.
Nano Lett ; 24(4): 1309-1315, 2024 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-38258741

RESUMO

Electrically percolating nanowire networks are among the most promising candidates for next-generation transparent electrodes. Scientific interest in these materials stems from their intrinsic current distribution heterogeneity, leading to phenomena like percolating pathway rerouting and localized self-heating, which can cause irreversible damage. Without an experimental technique to resolve the current distribution and an underpinning nonlinear percolation model, one relies on empirical rules and safety factors to engineer materials. We introduce Bose-Einstein condensate microscopy to address the longstanding problem of imaging active current flow in 2D materials. We report on performance improvement of this technique whereby observation of dynamic redistribution of current pathways becomes feasible. We show how this, combined with existing thermal imaging methods, eliminates the need for assumptions between electrical and thermal properties. This will enable testing and modeling individual junction behavior and hot-spot formation. Investigating both reversible and irreversible mechanisms will contribute to improved performance and reliability of devices.

8.
Sensors (Basel) ; 24(2)2024 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-38276383

RESUMO

We assessed the accuracy of a prototype radiation detector with a built in CMOS amplifier for use in dosimetry for high dose rate brachytherapy. The detectors were fabricated on two substrates of epitaxial high resistivity silicon. The radiation detection performance of prototypes has been tested by ion beam induced charge (IBIC) microscopy using a 5.5 MeV alpha particle microbeam. We also carried out the HDR Ir-192 radiation source tracking at different depths and angular dose dependence in a water equivalent phantom. The detectors show sensitivities spanning from (5.8 ± 0.021) × 10-8 to (3.6 ± 0.14) × 10-8 nC Gy-1 mCi-1 mm-2. The depth variation of the dose is within 5% with that calculated by TG-43. Higher discrepancies are recorded for 2 mm and 7 mm depths due to the scattering of secondary particles and the perturbation of the radiation field induced in the ceramic/golden package. Dwell positions and dwell time are reconstructed within ±1 mm and 20 ms, respectively. The prototype detectors provide an unprecedented sensitivity thanks to its monolithic amplification stage. Future investigation of this technology will include the optimisation of the packaging technique.

10.
11.
Acta Psychiatr Scand ; 148(6): 491-524, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37904016

RESUMO

BACKGROUND: Suicidal thoughts and behaviours (STB) are a common reason for presentation to emergency departments and general hospitals. A meta-analysis of the strength of clinical risk factors for subsequent suicide might aid understanding of suicidal behaviour and help suicide prevention. METHODS: We conducted a meta-analysis of cohort and controlled studies on clinical risk factors and later suicide among people presenting to emergency departments and general hospitals with STB. Data were extracted from papers meeting inclusion criteria, published in Medline, PsycINFO, and Embase between 1 January 1960 and 10 October 2022 using papers located with the search terms ((suicide*).m_titl AND (emergency* OR accident and emergency OR casualty OR general hospital OR toxicology service).mp) or were indexed in PubMed and had titles located with the search terms (suicide* OR self-harm OR self-harm OR self-injury OR self-injury OR self-poisoning OR self-poisoning OR overdose OR para-suicide OR parasuicide [title/abstract]) AND (Emergency department OR emergency room OR Casualty OR general hospital OR toxicology OR accident and emergency [all fields]). Data about the association between clinical risk factors and suicide extracted from three or more studies were included in a random-effects meta-analysis of the odds of later death by suicide. The study was registered in PROSPERO and conducted according to MOOSE and PRISMA guidelines. RESULTS: Seventy-five studies reported on 741,624 people, of which 19,649 died by suicide (2.65%). Male sex (odds ratio (OR) = 1.99) and age (OR = 2.01) were the most consistently reported risk factors. The strongest associations with subsequent death by suicide related to violent self-harm methods at the hospital presentation, including: unspecified violent method (OR = 4.97), any violent method (OR = 4.57) and the specific violent methods of drowning (OR = 4.32), hanging (OR = 4.26), and use of firearms (OR = 10.08). Patients categorised as higher risk using suicide prediction scales or any other method that combined risk factors had moderately increased odds of suicide (OR = 2.58). Younger age, Black and Hispanic ethnicity, overdose, a diagnosis of adjustment disorder, and the absence of any psychiatric diagnosis were protective against suicide. CONCLUSIONS: Most risk factors for suicide among people who have presented with STB are not strongly associated with later suicide. The strongest risk factors relate to self-harm methods. In the absence of clear indicators of future suicide, all people presenting with suicidality warrant a thorough assessment of their needs, and further research is needed before we can meaningfully categorise people with STB according to suicide risk.


Assuntos
Overdose de Drogas , Comportamento Autodestrutivo , Suicídio , Humanos , Masculino , Ideação Suicida , Hospitais Gerais , Suicídio/psicologia , Comportamento Autodestrutivo/epidemiologia , Comportamento Autodestrutivo/psicologia , Fatores de Risco , Overdose de Drogas/epidemiologia , Serviço Hospitalar de Emergência
12.
Psychiatr Psychol Law ; 30(5): 600-617, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37744649

RESUMO

Research on the association between psychosis and criminal offending has typically focused on violent offenders with chronic psychotic illness. This stages of psychosis in prison (SOPP) study used a clinical staging approach to identify adult men referred to prison mental health services who had an at-risk mental state (ARMS), first episode of psychosis (FEP) or an established psychotic illness. Of the 105 participants included, 6% were determined to have FEP, 6% met ARMS criteria and the remainder had an established psychotic illness. Compared to a prison control sample, individuals on the psychosis spectrum were found to have higher levels of social disadvantage and other co-occurring mental health and substance use problems but were not more likely to have committed a violent offence. These findings support the notion that risk of criminal justice contact and complex illness burden exist across the full spectrum of psychotic illness.

13.
Phys Med Biol ; 68(13)2023 06 28.
Artigo em Inglês | MEDLINE | ID: mdl-37267990

RESUMO

Objective. Microbeam radiation therapy (MRT) is an alternative emerging radiotherapy treatment modality which has demonstrated effective radioresistant tumour control while sparing surrounding healthy tissue in preclinical trials. This apparent selectivity is achieved through MRT combining ultra-high dose rates with micron-scale spatial fractionation of the delivered x-ray treatment field. Quality assurance dosimetry for MRT must therefore overcome a significant challenge, as detectors require both a high dynamic range and a high spatial resolution to perform accurately.Approach. In this work, a series of radiation hard a-Si:H diodes, with different thicknesses and carrier selective contact configurations, have been characterised for x-ray dosimetry and real-time beam monitoring applications in extremely high flux beamlines utilised for MRT at the Australian Synchrotron.Results. These devices displayed superior radiation hardness under constant high dose-rate irradiations on the order of 6000 Gy s-1, with a variation in response of 10% over a delivered dose range of approximately 600 kGy. Dose linearity of each detector to x-rays with a peak energy of 117 keV is reported, with sensitivities ranging from (2.74 ± 0.02) nC/Gy to (4.96 ± 0.02) nC/Gy. For detectors with 0.8µm thick active a-Si:H layer, their operation in an edge-on orientation allows for the reconstruction of micron-size beam profiles (microbeams). The microbeams, with a nominal full-width-half-max of 50µm and a peak-to-peak separation of 400µm, were reconstructed with extreme accuracy. The full-width-half-max was observed as 55 ± 1µm. Evaluation of the peak-to-valley dose ratio and dose-rate dependence of the devices, as well as an x-ray induced charge (XBIC) map of a single pixel is also reported.Significance. These devices based on novel a-Si:H technology possess a unique combination of accurate dosimetric performance and radiation resistance, making them an ideal candidate for x-ray dosimetry in high dose-rate environments such as FLASH and MRT.


Assuntos
Silício , Síncrotrons , Raios X , Austrália , Radiometria/métodos
14.
Gen Psychiatr ; 36(2): e100921, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37144159

RESUMO

Psychiatrists and other mental health clinicians are often tasked with assessing patients' risk of violence. Approaches to this vary and include both unstructured (based on individual clinicians' judgement) and structured methods (based on formalised scoring and algorithms with varying scope for clinicians' judgement). The end result is usually a categorisation of risk, which may, in turn, reference a probability estimate of violence over a certain time period. Research over recent decades has made considerable improvements in refining structured approaches and categorising patients' risk classifications at a group level. The ability, however, to apply these findings clinically to predict the outcomes of individual patients remains contested. In this article, we review methods of assessing violence risk and empirical findings on their predictive validity. We note, in particular, limitations in calibration (accuracy at predicting absolute risk) as distinct from discrimination (accuracy at separating patients by outcome). We also consider clinical applications of these findings, including challenges applying statistics to individual patients, and broader conceptual issues in distinguishing risk and uncertainty. Based on this, we argue that there remain significant limits to assessing violence risk for individuals and that this requires careful consideration in clinical and legal contexts.

15.
ACS Appl Mater Interfaces ; 15(8): 11225-11233, 2023 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-36800377

RESUMO

Tuneable infrared properties, such as transparency and emissivity, are highly desirable for a range of applications, including thermal windows and emissive cooling. Here, we demonstrate the use of carbon nanotube networks spray-deposited onto an ionic liquid-infused membrane to fabricate devices with electrochromic modulation in the mid-infrared spectrum, facilitating control of emissivity and apparent temperature. Such modulation is enabled by intraband transitions in unsorted single-walled carbon nanotube networks, allowing the use of scalable nanotube inks for printed devices. These devices are optimized by varying film thickness and sheet resistance, demonstrating the emissivity modulation (from ∼0.5 to ∼0.2). These devices and the understanding thereof open the door to selection criteria for infrared electrochromic materials based on the relationship between band structure, electrochemistry, and optothermal properties to enable the development of solution-processable large-area coatings for widespread thermal management applications.

16.
Psychiatry Clin Neurosci ; 77(5): 290-296, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36624927

RESUMO

AIMS: We aimed to investigate the trajectories of absolute and relative risks of cause-specific mortality among patients discharged from inpatient psychiatric services. METHODS: We conducted a national matched cohort study (2002-2013) using data from the Taiwan National Health Insurance database linked to national cause-of-death data files. Patients discharged from inpatient psychiatric care without prior psychiatric hospitalizations were individually matched to 20 comparison individuals based on sex and age. The rates, rate differences, and relative risks (hazard ratios, HRs) of cause-specific mortality were calculated at six follow-up periods post-discharge. Cumulative mortality incidence was assessed at 5 years of follow-up. RESULTS: The mortality risks of all causes were increased among patients (n = 158 065) relative to comparison individuals (n = 3 161 300). Mortality rate differences were greater for natural causes, while relative risks (HRs) were higher for unnatural causes. Suicide was the leading cause of death within the first year of discharge, while circulatory and respiratory diseases were the leading causes of death from the second year. The mortality rates and HRs for all causes of death (except homicide) were highest during the first 3 months. The elevated risk of unnatural-cause mortality declined rapidly after discharge but remained high in the long term; in contrast, risk elevation for natural-cause mortality was more stable over time. Approximately one-eighth of patients (12.9%, 95% confidence interval 12.7-13.7%) died within 5 years of follow-up. CONCLUSIONS: Integrated physical and mental health care is needed to reduce excess mortality, particularly during the first 3 months post-discharge, among psychiatric patients.


Assuntos
Serviços de Saúde Mental , Alta do Paciente , Humanos , Estudos de Coortes , Causas de Morte , Pacientes Internados , Taiwan/epidemiologia , Assistência ao Convalescente
17.
Nat Commun ; 13(1): 6872, 2022 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-36369509

RESUMO

Explosive percolation is an experimentally-elusive phenomenon where network connectivity coincides with onset of an additional modification of the system; materials with correlated localisation of percolating particles and emergent conductive paths can realise sharp transitions and high conductivities characteristic of the explosively-grown network. Nanocomposites present a structurally- and chemically-varied playground to realise explosive percolation in practically-applicable systems but this is yet to be exploited by design. Herein, we demonstrate composites of graphene oxide and synthetic polymer latex which form segregated networks, leading to low percolation threshold and localisation of conductive pathways. In situ reduction of the graphene oxide at temperatures of <150 °C drives chemical modification of the polymer matrix to produce species with phenolic groups, which are known crosslinking agents. This leads to conductivities exceeding those of dense-packed networks of reduced graphene oxide, illustrating the potential of explosive percolation by design to realise low-loading composites with dramatically-enhanced electrical transport properties.

18.
Lancet Psychiatry ; 9(12): 938-939, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36403596
20.
Nanomaterials (Basel) ; 12(19)2022 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-36234601

RESUMO

In this paper, by means of high-resolution photoemission, soft X-ray absorption and atomic force microscopy, we investigate, for the first time, the mechanisms of damaging, induced by neutron source, and recovering (after annealing) of p-i-n detector devices based on hydrogenated amorphous silicon (a-Si:H). This investigation will be performed by mean of high-resolution photoemission, soft X-Ray absorption and atomic force microscopy. Due to dangling bonds, the amorphous silicon is a highly defective material. However, by hydrogenation it is possible to reduce the density of the defect by several orders of magnitude, using hydrogenation and this will allow its usage in radiation detector devices. The investigation of the damage induced by exposure to high energy irradiation and its microscopic origin is fundamental since the amount of defects determine the electronic properties of the a-Si:H. The comparison of the spectroscopic results on bare and irradiated samples shows an increased degree of disorder and a strong reduction of the Si-H bonds after irradiation. After annealing we observe a partial recovering of the Si-H bonds, reducing the disorder in the Si (possibly due to the lowering of the radiation-induced dangling bonds). Moreover, effects in the uppermost coating are also observed by spectroscopies.

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