Scintillation Properties of CsPbBr3 Nanocrystals Prepared by Ligand-Assisted Reprecipitation and Dual Effect of Polyacrylate Encapsulation toward Scalable Ultrafast Radiation Detectors.

Lead halide perovskite nanocrystals (LHP-NCs) embedded in polymeric hosts are gaining attention as scalable and low-cost scintillation detectors for technologically relevant applications. Despite rapid progress, little is currently known about the scintillation properties and stability of LHP-NCs prepared by the ligand assisted reprecipitation (LARP) method, which allows mass scalability at room temperature unmatched by any other type of nanostructure, and the implications of incorporating LHP-NCs into polyacrylate hosts are still largely debated. Here, we show that LARP-synthesized CsPbBr3 NCs are comparable to particles from hot-injection routes and unravel the dual effect of polyacrylate incorporation, where the partial degradation of LHP-NCs luminescence is counterbalanced by the passivation of electron-poor defects by the host acrylic groups. Experiments on NCs with tailored surface defects show that the balance between such antithetical effects of polymer embedding is determined by the surface defect density of the NCs and provide guidelines for further material optimization.

Singlet Oxygen Photocatalytic Generation by Silanized TiO2 Nanoparticles.

A commercial TiO2 sample, used as received or hydrothermally treated to increase surface hydroxylation, has been functionalized by surface modification with hexadecyltrimethoxysilane. The anchoring of the silane has been characterized by FTIR and solid-state NMR spectroscopies, and the grafting density was determined by thermogravimetric and N2 physisorption analyses. The silane moieties induce a partial decrease of the shielding of the valence electrons of the Ti ions at the surface, and a local modification of their crystal field, as demonstrated by XPS and UV-vis spectroscopy, respectively. The changes in coordination and the produced oxygen vacancies result in the formation of Ti3+ defects localized in the sub-surface region, as revealed by EPR spectroscopy. These paramagnetic centers are stabilized in the silanized samples, as the electron transfer to O2 is efficiently inhibited even under UV irradiation. However, the amount of Ti3+ centers appears to be correlated with the singlet oxygen (1O2) formation rate. Accordingly, epoxidation of limonene under UV light, chosen as a model photocatalytic reaction triggered by 1O2, occurred with higher selectivity when TiO2 was silanized and upon simultaneous NIR irradiation. These evidences suggest that in the silanized sample 1O2 may be generated through Förster-type energy transfer from excited sub-surface Ti3+ centers.

Optical and Scintillation Properties of Record-Efficiency CdTe Nanoplatelets toward Radiation Detection Applications.

Colloidal CdTe nanoplatelets featuring a large absorption coefficient and ultrafast tunable luminescence coupled with heavy-metal-based composition present themselves as highly desirable candidates for radiation detection technologies. Historically, however, these nanoplatelets have suffered from poor emission efficiency, hindering progress in exploring their technological potential. Here, we report the synthesis of CdTe nanoplatelets possessing a record emission efficiency of 9%. This enables us to investigate their fundamental photophysics using ultrafast transient absorption, temperature-controlled photoluminescence, and radioluminescence measurements, elucidating the origins of exciton- and defect-related phenomena under both optical and ionizing excitation. For the first time in CdTe nanoplatelets, we report the cumulative effects of a giant oscillator strength transition and exciton fine structure. Simultaneously, thermally stimulated luminescence measurements reveal the presence of both shallow and deep trap states and allow us to disclose the trapping and detrapping dynamics and their influence on the scintillation properties.

Radiation hardness of Ce-doped sol-gel silica fibers for high energy physics applications.

The results of irradiation tests on Ce-doped sol-gel silica using x- and γ-rays up to 10 kGy are reported in order to investigate the radiation hardness of this material for high-energy physics applications. Sol-gel silica fibers with Ce concentrations of 0.0125 and 0.05 mol. % are characterized by means of optical absorption and attenuation length measurements before and after irradiation. The two different techniques give comparable results, evidencing the formation of a main broad radiation-induced absorption band, peaking at about 2.2 eV, related to radiation-induced color centers. The results are compared with those obtained on bulk silica. This study reveals that an improvement of the radiation hardness of Ce-doped silica fibers can be achieved by reducing Ce content inside the fiber core, paving the way for further material development.

Silica-Encapsulated Perovskite Nanocrystals for X-ray-Activated Singlet Oxygen Production and Radiotherapy Application.

Multicomponent systems consisting of lead halide perovskite nanocrystals (CsPbX3-NCs, X = Br, I) grown inside mesoporous silica nanospheres (NSs) with selectively sealed pores combine intense scintillation and strong interaction with ionizing radiation of CsPbX3 NCs with the chemical robustness in aqueous environment of silica particles, offering potentially promising candidates for enhanced radiotherapy and radio-imaging strategies. We demonstrate that CsPbX3 NCs boost the generation of singlet oxygen species (1O2) in water under X-ray irradiation and that the encapsulation into sealed SiO2 NSs guarantees perfect preservation of the inner NCs after prolonged storage in harsh conditions. We find that the 1O2 production is triggered by the electromagnetic shower released by the CsPbX3 NCs with a striking correlation with the halide composition (I3 > I3-x Br x > Br3). This opens the possibility of designing multifunctional radio-sensitizers able to reduce the local delivered dose and the undesired collateral effects in the surrounding healthy tissues by improving a localized cytotoxic effect of therapeutic treatments and concomitantly enabling optical diagnostics by radio imaging.

Sociodemographic and clinical factors associated with prescription of first- versus second-generation long-acting antipsychotics in incarcerated adult males.

Information on patterns of prescription of long-acting injection (LAI) antipsychotics among people who are incarcerated is lacking. Therefore, we aimed to evaluate prescribing rates for first-generation antipsychotic (FGA)-LAI versus second-generation antipsychotic (SGA)-LAI and to identify the factors associated with the prescription of one of the two classes of LAI. A cross-sectional study was conducted among incarcerated adult males hosted in Monza detention center between January 2013 and April 2023. Socio-demographic and clinical data were retrospectively collected. Descriptive and univariate statistics as well as logistic regression analyses were performed. Data were available for 135 consecutive incarcerated adult males with different mental disorders who received a LAI as part of their treatment. 75.6% of our sample was treated with FGA-LAIs, with haloperidol as the most commonly prescribed drug, followed by zuclopentixol and aripiprazole. Diagnosis of bipolar disorder and concomitant administration of antidepressants were statistically significant predictors of SGA-LAI prescription. Some patients' characteristics may influence prescription patterns in prison. Further longitudinal studies with larger samples should confirm these findings.

Energy Partitioning in Multicomponent Nanoscintillators for Enhanced Localized Radiotherapy.

Multicomponent nanomaterials consisting of dense scintillating particles functionalized by or embedding optically active conjugated photosensitizers (PSs) for cytotoxic reactive oxygen species (ROS) have been proposed in the last decade as coadjuvant agents for radiotherapy of cancer. They have been designed to make scintillation-activated sensitizers for ROS production in an aqueous environment under exposure to ionizing radiations. However, a detailed understanding of the global energy partitioning process occurring during the scintillation is still missing, in particular regarding the role of the non-radiative energy transfer between the nanoscintillator and the conjugated moieties which is usually considered crucial for the activation of PSs and therefore pivotal to enhance the therapeutic effect. We investigate this mechanism in a series of PS-functionalized scintillating nanotubes where the non-radiative energy transfer yield has been tuned by control of the intermolecular distance between the nanotube and the conjugated system. The obtained results indicate that non-radiative energy transfer has a negligible effect on the ROS sensitization efficiency, thus opening the way to the development of different architectures for breakthrough radiotherapy coadjutants to be tested in clinics.

Noninvasive Treatment of Alzheimer's Disease with Scintillating Nanotubes.

Effective and accessible treatments for Alzheimer's disease (AD) are urgently needed. Soluble Aß oligomers are identified as neurotoxic species in AD and targeted in antibody-based drug development to mitigate cognitive decline. However, controversy exists concerning their efficacy and safety. In this study, an alternative strategy is proposed to inhibit the formation of Aß oligomers by selectively oxidizing specific amino acids in the Aß sequence, thereby preventing its aggregation. Targeted oxidation is achieved using biocompatible and blood-brain barrier-permeable multicomponent nanoscintillators that generate singlet oxygen upon X-ray interaction. Surface-modified scintillators interact selectively with Aß and, upon X-ray irradiation, inhibit the formation of neurotoxic aggregates both in vitro and in vivo. Feeding transgenic Caenorhabditis elegans expressing human Aß with the nanoscintillators and subsequent irradiation with soft X-ray reduces Aß oligomer levels, extends lifespan, and restores memory and behavioral deficits. These findings support the potential of X-ray-based therapy for AD and warrant further development.

Ultrafast and Radiation-Hard Lead Halide Perovskite Nanocomposite Scintillators.

The use of scintillators for the detection of ionizing radiation is a critical aspect in many fields, including medicine, nuclear monitoring, and homeland security. Recently, lead halide perovskite nanocrystals (LHP-NCs) have emerged as promising scintillator materials. However, the difficulty of affordably upscaling synthesis to the multigram level and embedding NCs in optical-grade nanocomposites without compromising their optical properties still limits their widespread use. In addition, fundamental aspects of the scintillation mechanisms are not fully understood, leaving the scientific community without suitable fabrication protocols and rational guidelines for the full exploitation of their potential. In this work, we realize large polyacrylate nanocomposite scintillators based on CsPbBr3 NCs, which are synthesized via a novel room temperature, low waste turbo-emulsification approach, followed by their in situ transformation during the mass polymerization process. The interaction between NCs and polymer chains strengthens the scintillator structure, homogenizes the particle size distribution and passivates NC defects, resulting in nanocomposite prototypes with luminescence efficiency >90%, exceptional radiation hardness, 4800 ph/MeV scintillation yield even at low NC loading, and ultrafast response time, with over 30% of scintillation occurring in the first 80 ps, promising for fast-time applications in precision medicine and high-energy physics. Ultrafast radioluminescence and optical spectroscopy experiments using pulsed synchrotron light further disambiguate the origin of the scintillation kinetics as the result of charged-exciton and multiexciton recombination formed under ionizing excitation. This highlights the role of nonradiative Auger decay, whose potential impact on fast timing applications we anticipate via a kinetic model.

Cu+ → Mn2+ Energy Transfer in Cu, Mn Coalloyed Cs3ZnCl5 Colloidal Nanocrystals.

In this work, we report the hot-injection synthesis of Cs3ZnCl5 colloidal nanocrystals (NCs) with tunable amounts of Cu+ and Mn2+ substituent cations. All the samples had a rodlike morphology, with a diameter of ∼14 nm and a length of ∼30-100 nm. Alloying did not alter the crystal structure of the host Cs3ZnCl5 NCs, and Cu ions were mainly introduced in the oxidation state +1 according to X-ray photoelectron and electron paramagnetic resonance spectroscopies. The spectroscopic analysis of unalloyed, Cu-alloyed, Mn-alloyed, and Cu, Mn coalloyed NCs indicated that (i) the Cs3ZnCl5 NCs have a large band gap of ∼5.35 eV; (ii) Cu(I) aliovalent alloying leads to an absorption shoulder/peak at ∼4.8 eV and cyan photoluminescence (PL) peaked at 2.50 eV; (iii) Mn(II) isovalent alloying leads to weak Mn PL, which intensifies remarkably in the coalloyed samples, prompted by an energy transfer (ET) process between the Cu and Mn centers, favored by the overlap between the lowest (6A1 → 4T1) transition for tetrahedrally coordinated Mn2+ and the PL profile from Cu(I) species in the Cs3ZnCl5 NCs. The efficiency of this ET process reaches a value of 61% for the sample with the highest extent of Mn alloying. The PL quantum yield (QY) values in these Cu, Mn coalloyed NCs are lower at higher Mn contents. The analysis of the Mn PL dynamics in these samples indicates that this PL drop stems from inter-Mn exciton migration, which increases the likelihood of trapping in defect sites, in agreement with previous studies.

Screening for ADHD Symptoms among Criminal Offenders: Exploring the Association with Clinical Features.

BACKGROUND: Attention-deficit/hyperactivity disorder (ADHD) is a disabling disorder. High rates of ADHD have been consistently reported among prisoners. The main objectives were (1) to estimate the prevalence of ADHD symptoms in a sample of male inmates and (2) to investigate the relationship between ADHD symptoms and socio-demographic/clinical features. According to the high prevalence of childhood trauma among inmates, we assessed whether exposition to childhood trauma can be related to the presence of ADHD symptoms. METHODS: A total of 159 male prisoners admitted to Monza prison between January 2020 and June 2021 were included. Both Wender Utah ADHD rating scale and adult ADHD self-report scale were administered to assess ADHD symptoms. Moreover, inmates completed the childhood trauma questionnaire. RESULTS: Data were available for 108 inmates. Thirty-five prisoners (32.4%) were found on screening to meet the criteria for symptoms of ADHD. Cocaine use disorder, prescription of mood stabilizers and a history of emotional abuse significantly increased the likelihood of having clinically significant ADHD symptoms. Furthermore, patients who experienced physical neglect resulted in meeting the criteria for ADHD symptoms. CONCLUSIONS: ADHD symptoms are widespread among inmates and are associated with specific risk factors. Screening for ADHD should be done to provide appropriate intervention strategies.

Sb-Doped Metal Halide Nanocrystals: A 0D versus 3D Comparison.

We synthesize colloidal nanocrystals (NCs) of Rb3InCl6, composed of isolated metal halide octahedra ("0D"), and of Cs2NaInCl6 and Cs2KInCl6 double perovskites, where all octahedra share corners and are interconnected ("3D"), with the aim to elucidate and compare their optical features once doped with Sb3+ ions. Our optical and computational analyses evidence that the photoluminescence quantum yield (PLQY) of all these systems is consistently lower than that of the corresponding bulk materials due to the presence of deep surface traps from under-coordinated halide ions. Also, Sb-doped "0D" Rb3InCl6 NCs exhibit a higher PLQY than Sb-doped "3D" Cs2NaInCl6 and Cs2KInCl6 NCs, most likely because excitons responsible for the PL emission migrate to the surface faster in 3D NCs than in 0D NCs. We also observe that all these systems feature a large Stokes shift (varying from system to system), a feature that should be of interest for applications in photon management and scintillation technologies. Scintillation properties are evaluated via radioluminescence experiments, and re-absorption-free waveguiding performance in large-area plastic scintillators is assessed using Monte Carlo ray-tracing simulations.

The association between childhood trauma and lifetime suicide attempts among a sample of male prisoners: A pilot observational study.

BACKGROUND: Prisoners have higher rates of suicide attempts compared with general population. A history of childhood trauma (CT) is common among incarcerated subjects and it is a well-known risk factor for lifetime suicide attempts. Therefore, the purpose of the study was to investigate whether lifetime suicide attempts may be related to the exposition to CT among male prisoners. METHOD: We conducted a cross sectional study recruiting newly arrived inmates in an Italian jail, between January 2017 and June 2018. Prisoners were interviewed to collect socio-demographic and clinical information. Moreover, inmates completed the Childhood Trauma Questionnaire. We excluded prisoners unable to speak or read Italian, with learning disabilities or current severe psychiatric symptoms. RESULTS: A total of 215 consecutive male inmates were included. Fifty-one prisoners (23.7%) had a history of attempted suicide. The most reported CT was physical neglect. Multivariate logistic regression analysis showed that a history of childhood sexual abuse, emotional neglect and psychiatric diagnosis significantly increased the likelihood of lifetime suicide attempt. CONCLUSIONS: A previous history of suicide attempt is highly prevalent among inmates. In agreement with previous findings, lifetime suicide attempts seem to be associated with the presence of CT and psychiatric diagnosis. Therefore, CT should be considered as a relevant variable to improve the programs for the prevention of suicide in prison.

The Sensitization of Scintillation in Polymeric Composites Based on Fluorescent Nanocomplexes.

The sensitization of scintillation was investigated in crosslinked polymeric composite materials loaded with luminescent gold clusters aggregates acting as sensitizers, and with organic dye rhodamine 6G as the emitting species. The evolution in time of the excited states population in the systems is described by a set of coupled rate equations, in which steady state solution allowed obtainment of an expression of the sensitization efficacy as a function of the characteristic parameters of the employed luminescent systems. The results obtained indicate that the realization of sensitizer/emitter scintillating complexes is the strategy that must be pursued to maximize the sensitization effect in composite materials.

Factors associated with psychotic symptoms among a sample of male prisoners with substance use disorder: A cross-sectional study.

BACKGROUND: Prisoners have a higher prevalence of substance use disorder (SUD) than the nonincarcerated population. Many studies report that an SUD increases the likelihood of psychotic symptoms/disorders. Inmates, therefore, may be at higher risk for psychotic disorders. OBJECTIVE: The main objectives of this study were to (1) estimate the prevalence of psychotic symptoms in a sample of male inmates with high levels of SUD and (2) verify if type of abuse or other sociodemographic/clinical features are risk factors of psychotic symptoms. In light of the high prevalence of childhood trauma (CT) among inmates, a further objective was to 3) assess whether exposition to CT can predict psychotic symptoms. METHOD: We included three hundred and nineteen male prisoners, admitted to Monza prison between January 2017 and March 2019. We interviewed participants to collect sociodemographic and clinical information. We administered the Brief Psychiatric Rating Scale (BPRS) and the Drug Abuse Screening Test (DAST) to assess the presence of psychotic symptoms and SUD, respectively. Inmates also completed the Childhood Trauma Questionnaire (CTQ). RESULTS: Data were available for 141 inmates. Forty-five prisoners (31.9%) had psychotic symptoms. Multivariate logistic regression analysis showed that a history of previous incarceration (aOR = 2.98, p = 0.034), opioid abuse (aOR = 5.02, p = 0.008), suicide attempts (aOR = 5.55, p < 0.001), and childhood emotional abuse (aOR = 4.11, p = 0.027) significantly increased the likelihood of psychotic symptoms. CONCLUSIONS: Psychotic symptoms are widespread among inmates and are associated with specific risk factors. Prison and jail staff should screen for these factors at the start of an inmate's detention to identify subjects at risk of psychotic symptoms.

Factors associated with referrals to high security forensic services among people with severe mental illness and receiving inpatient care in prison.

BACKGROUND: Prison mental health care is a significant topic which has been already studied and described in literature, particularly because of important implications both in the prison and in the health care system. It's not uncommon that inmates suffering from mental disorders are referred to high security forensic services (HSFS) but, to date, studies assessing factors associated with relevant referrals to these services are missing. So, the aim of our study is to investigate socio-demographic, criminological, psychopathological and toxicological variables among those who were referred to HSFS as compared to their non-referred counterpart. METHODS: We conducted a cross-sectional study recruiting 159 subjects receiving prison inpatient care in an Italian jail, between January 2010 and August 2015. No subjects were excluded from the study. The mean age was 39. RESULTS: About half of included prisoners suffered from personality disorder while one-third from psychotic disorders. >60% of the subjects had comorbid substance use disorders. The odds of being referred to HSFS were related to previous admission (odds ratio [OR] = 5.34, 95% confidence interval [CI] 1.66-17.16), diagnosis of psychosis (OR = 2.79, 95% CI 1.11-7.04) and cannabis use disorder (OR = 2.68, 95% CI 1.14-6.28). Personality disorder was inversely associated to the referral to forensic facilities (OR = 0.37, 95% CI 0.14-0.97). CONCLUSIONS: Mental health services should improve preventive measures for vulnerable prisoners in order to reduce criminal recidivism and forensic readmission.