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The macro-social and environmental conditions in which people live, such as the level of a country’s development or inequality, are associated with brain-related disorders. However, the relationship between these systemic environmental factors and the brain remains unclear. We aimed to determine the association between the level of development and inequality of a country and the brain structure of healthy adults.
Methods
We conducted a cross-sectional study pooling brain imaging (T1-based) data from 145 magnetic resonance imaging (MRI) studies in 7,962 healthy adults (4,110 women) in 29 different countries. We used a meta-regression approach to relate the brain structure to the country’s level of development and inequality.
Results
Higher human development was consistently associated with larger hippocampi and more expanded global cortical surface area, particularly in frontal areas. Increased inequality was most consistently associated with smaller hippocampal volume and thinner cortical thickness across the brain.
Conclusions
Our results suggest that the macro-economic conditions of a country are reflected in its inhabitants’ brains and may explain the different incidence of brain disorders across the world. The observed variability of brain structure in health across countries should be considered when developing tools in the field of personalized or precision medicine that are intended to be used across the world.
Meta-analyses of functional magnetic resonance imaging (fMRI) studies have been used to elucidate the most reliable neural features associated with various psychiatric disorders. However, it has not been well-established whether each of these neural features is linked to a specific disorder or is transdiagnostic across multiple disorders and disorder categories, including mood, anxiety, and anxiety-related disorders.
Objectives
This project aims to advance our understanding of the disorder-specific and transdiagnostic neural features associated with mood, anxiety, and anxiety-related disorders as well as to refine the methodology used to compare multiple disorders.
Methods
We conducted an exhaustive PubMed literature search followed by double-screening, double-extraction, and cross-checking to identify all whole-brain, case-control fMRI activation studies of mood, anxiety, and anxiety-related disorders in order to construct a large-scale meta-analytic database of primary studies of these disorders. We then employed multilevel kernel density analysis (MKDA) with Monte-Carlo simulations to correct for multiple comparisons as well as ensemble thresholding to reduce cluster size bias to analyze primary fMRI studies of mood, anxiety, and anxiety-related disorders followed by application of triple subtraction techniques and a second-order analysis to elucidate the disorder-specificity of the previously identified neural features.
Results
We found that participants diagnosed with mood, anxiety, and anxiety-related disorders exhibited statistically significant (p < .05 – 0.0001; FWE-corrected) differences in neural activation relative to healthy controls throughout the cerebral cortex, limbic system, and basal ganglia. In addition, each of these psychiatric disorders exhibited a particular profile of neural features that ranged from disorder-specific, to category-specific, to transdiagnostic.
Conclusions
These findings indicate that psychiatric disorders exhibit a complex profile of neural features that vary in their disorder-specificity and can be detected with large-scale fMRI meta-analytic techniques. This approach has potential to fundamentally transform neuroimaging investigations of clinical disorders by providing a novel procedure for establishing disorder-specificity of observed results, which can be then used to advance our understanding of individual disorders as well as broader nosological issues related to diagnosis and classification of psychiatric disorders.
Generalized anxiety disorder (GAD) is a highly prevalent mental illness that is associated with clinically significant distress, functional impairment, and poor emotional regulation. Primary functional magnetic resonance imaging (fMRI) studies of GAD report neural abnormalities in comparison to healthy controls. However, many of these findings in the primary literature are inconsistent, and it is unclear whether they are specific to GAD or shared transdiagnostically across related disorders.
Objectives
This meta-analysis seeks to establish the most reliable neural abnormalities observed in individuals with GAD, as reported in the primary fMRI activation literature.
Methods
We conducted an exhaustive literature search in PubMed to identify primary studies that met our pre-specified inclusion criteria and then extracted relevant data from primary, whole-brain fMRI activation studies of GAD that reported coordinates in Talairach or MNI space. We then used multilevel kernel density analysis (MKDA) with ensemble thresholding to examine the differences between adults with GAD and healthy controls in order to identify brain regions that reached statistical significance across primary studies.
Results
Patients with GAD showed statistically significant (α=0.05–0.0001; family-wise-error-rate corrected) neural activation in various regions of the cerebral cortex and basal ganglia across a variety of experimental tasks.
Conclusions
These results inform our understanding of the neural basis of GAD and are interpreted using a frontolimbic model of anxiety as well as specific clinical symptoms of this disorder and its relation to other mood and anxiety disorders. These results also suggest possible novel targets for emerging neurostimulation therapies (e.g., transcranial magnetic stimulation) and may be used to advance our understanding of the effects of current pharmaceutical treatments and ways to improve treatment selection and symptom-targeting for patients diagnosed with GAD.
Functional magnetic resonance imaging (fMRI) has been used to identify the neural activity of both youth and adults diagnosed with major depressive disorder (MDD) in comparison to healthy age-matched controls. Previously reported abnormalities in depressed youth appear to mostly align with those found in depressed adults; however, some of the reported aberrant brain activity in youth has not been consistent with what is observed in adults, and to our knowledge there has not yet been a formal, quantitative comparison of these two groups. In addition, it is not known whether these observed differences between youth and adults with depression are attributable to developmental age or length-of-illness.
Objectives
The aim of this study is to elucidate the similarities and differences in patterns of abnormal neural activity between adults and youth diagnosed with MDD and to then determine whether these observed differences are due to either developmental age or length-of-illness.
Methods
We used multilevel kernel density analysis (MKDA) with ensemble thresholding and triple subtraction to separately determine neural abnormalities throughout the whole brain in primary studies of depressed youth and depressed adults and then directly compare the observed abnormalities between each of those age groups. We then conducted further comparisons between multiple subgroups to control for age and length-of-illness and thereby determine the source of the observed differences between youth and adults with depression.
Results
Adults and youth diagnosed with MDD demonstrated reliable, differential patterns of abnormal activation in various brain regions throughout the cerebral cortex that are statistically significant (p < .05; FWE-corrected). In addition, several of these brain regions that exhibited differential patterns of neural activation between the two age groups can be reliably attributed to either developmental age or length-of-illness.
Conclusions
These findings indicate that there are common and disparate patterns of brain activity between youth and adults with MDD, several of which can be reliably attributed to developmental age or length-of-illness. These results expand our understanding of the neural basis of depression across development and course of illness and may be used to inform the development of new, age-specific clinical treatments as well as prevention strategies for this disorder.
CD is characterized by at least three features: its duration is prolonged, it does not resolve spontaneously and it is rarely completely cured. Approximately 10-15% of young people have CD. Adolescents with CD often have emotional and behavioral problems.
Objectives
To assess risk factors, derived psychiatric pathologies and coping strategies for a CD diagnosis in adolescence.
Methods
An extensive literature review was carried out on the subject in question, extracting information mainly from scientific articles, manuals and books.
Results
The main risk factors are those related with the CD in question, physical sequelae, the need for long-term hospital admissions or the use of drugs whose side effects include affective or behavioral symptoms; those related to the personality traits of the affected child or adolescent. In addition, as far as the family is concerned, the presence of a low level of education, lack of support or communication, as well as the presence of psychiatric disorders or serious medical conditions in parents. Among the most frequent psychiatric disorders associated with CD are affective and anxiety disorders, adaptive disorders, somatoform disorders, eating disorders and behavioral disorders. Whatever the CD is, it generates high levels of stress and uncertainty in the patient and family, which must be dealt together from a flexible perspective, allowing child or adolescent to adapt to the changes, reorganize and facing them with adaptive patterns of behavior. For this, it will be essential to have adequate social and family support with relational style based on communication, trust and acceptance.
Conclusions
In general, both adolescents with CD and their families have an adequate capacity to adapt to the repercussions and effects derived from the disease. Nevertheless, in case of possible emotional difficulties that may appear, a comprehensive and individualized approach to these adolescents and their families is necessary to provide them resources and coping strategies in different areas and contexts in which the disease debuts.The comprehensive therapeutic approach will consist of interventions at the individual and family level. Among the main objectives of these interventions are to achieve acceptance and adaptation to CD provinding adequate psychosocial support to enable them to cope with CD in the best possible way and to detect and address the emotional implications, even coexisting psychopathology.
Major depressive disorder (MDD) is a highly prevalent mental illness that frequently originates in early development and is pervasive during adolescence. Despite its high prevalence and early age of onset, our understanding of the potentially unique neural basis of MDD in this age group is still not well understood, and the existing primary literature on the topic includes many new and divergent results. This limited understanding of MDD in youth presents a critical need to further investigate its neural basis in youth and presents an opportunity to also improve clinical treatments that target its neural abnormalities.
Objectives
The present study aims to advance our understanding of the neural basis of MDD in youth by identifying abnormal functional activation in various brain regions compared with healthy controls.
Methods
We conducted a meta-analysis of functional magnetic resonance imaging (fMRI) studies of MDD by using a well-established method, multilevel kernel density analysis (MKDA) with ensemble thresholding, to quantitatively combine all existing whole-brain fMRI studies of MDD in youth compared with healthy controls. This method involves a voxel-wise, whole-brain approach, that compares neural activation of patients with MDD to age-matched healthy controls across variations of task-based conditions, which we subcategorize into affective processing, executive functioning, positive valence, negative valence, and symptom provocation tasks.
Results
Youth with MDD exhibited statistically significant (p<0.05; FWE-corrected) hyperactivation and hypoactivation in multiple brain regions compared with age-matched healthy controls. These results include significant effects that are stable across various tasks as well as some that appear to depend on task conditions.
Conclusions
This study strengthens our understanding of the neural basis of MDD in youth and may also be used to help identify possible similarities and differences between youth and adults with depression. It may also help inform the development of new treatment interventions and tools for predicting unique treatment responses in youth with depression.
Major depressive disorder (MDD) is a highly prevalent mental illness that often first occurs or persists into adulthood and is considered the leading cause of disability and disease burden worldwide. Unfortunately, individuals diagnosed with MDD who seek treatment often experience limited symptom relief and may not achieve long-term remission, which is due in part to our limited understanding of its underlying pathophysiology. Many studies that use task-based functional magnetic resonance imaging (fMRI) have found abnormal activation in brain regions in adults diagnosed with MDD, but those findings are often inconsistent; in addition, previous meta-analyses that quantitatively integrate this large body literature have found conflicting results.
Objectives
This meta-analysis aims to advance our understanding of the neural basis of MDD in adults, as measured by fMRI activation studies, and address inconsistencies and discrepancies in the empirical literature.
Methods
We employed multilevel kernel density analysis (MKDA) with ensemble thresholding, a well-established method for voxel-wise, whole-brain meta-analyses, to conduct a quantitative comparison of all relevant primary fMRI activation studies of adult patients with MDD compared to age-matched healthy controls.
Results
We found that adults with MDD exhibited a reliable pattern of statistically significant (p<0.05; FWE-corrected) hyperactivation and hypoactivation in several brain regions compared to age-matched healthy controls across a variety of experimental tasks.
Conclusions
This study supports previous findings that there is reliable neural basis of MDD that can be detected across heterogenous fMRI studies. These results can be used to inform development of promising treatments for MDD, including protocols for personalized interventions. They also provide the opportunity for additional studies to examine the specificity of these effects among various populations-of-interest, including youth vs. adults with depression as well as other related mood and anxiety disorders.
Neuroanatomical abnormalities are reported in psychotic disorders compared to healthy controls; nevertheless, less is known about the role of familial liability to psychosis in morphological brain changes.
Objectives
Using an exploratory voxel-based morphometry (VBM) analyses of the whole brain, we evaluated differences on GMVs across the whole brain among first-episode psychosis (FEP) patients, community-controls, and healthy siblings of patients to interrogate the role of familial liability.
Methods
Data were retrieved from a study (STREAM) conducted in Ribeirão Preto/SP Brazil. We included 71 first-episode psychosis patients (67.6% males, mean age±SD: 18.7±10.8), 24 unaffected siblings of patients (37.5% males, mean age±SD 30.8±10), and 36 controls (71.9% males, mean age±SD: 10±10.5). All magnetic resonance imaging (MRI) scans were acquired on a 3T Philips scanner. VBM data were processed using Statistical Parametric Mapping (SPM) software in MATLAB the MNI coordinate system. We performed exploratory voxel-wise comparisons of GMVs among the three groups using an analysis of covariance (ANCOVA) model in SPM. Results were considered significant if they retained significance after family-wise error (FWE) correction for multiple comparisons (p<0.05). All the analyses were adjusted for age, sex, education in years, and total brain GMV.
Results
The whole-brain exploratory analyses revealed no significant findings at the p<0.05 level (FWE-corrected). However, pairwise comparisons revealed significant changes betweeen FEP patients and their unaffected siblings. In particular, FEP patients had decreased volumes in the right side of the following regions (FEW = 0.047): superior temporal cortex, Rolandic operculum, insula, Heschel’s gyrus, supramarginal gyrus, superior temporal pole, hippocampus, parahippocampal gyrus, fusiform gyrus, amydgala, olfactory, inferior frontal operculum, cerebellum, posterior and medial orbital frontal cortex, rectus, medial temporal, medial frontal, and putamen. FEP patients also showed decreased volumes on the left side of the following regions (FWE 0.049): frontal superior medial gyrus, superior frontal gyrus, frontal middle part, caudate, anterior cingulate cortex, thalamus, and pallidum. Patients also showed widespread reduced GMV in various GMVs regions compared to controls at FWE<0.05. However, no difference was found between siblings and controls (FWE: >0.05).
Conclusions
The study of healthy siblings of patients with heritable illnesses could help in the understanding of the contribution of genetic background and environmental factors to illness state and predisposition. Differences between patients and their siblings could be attributed to the disease state, considering that the unaffected sibling group and unrelated healthy control group did not differ. We will next evaluate biological and environmental contributors to the reported differences.
Although being an old concern, phosphate analysis is still a tremendous challenge. While many different experimental techniques are found in the literature, very few use powder X-ray diffraction (PXRD) patterns for quantitative phase analysis of different phosphate types. Our measurements performed in four commercial samples of diammonium hydrogen phosphate ((NH4)2HPO4) (DAP) show the existence of phosphate contamination mixtures, such as ammonium dihydrogen phosphate (NH4H2PO4) (ADP). The larger the amount of ADP, the larger the microstrain induced in the DAP phase, which impacts both the aggregation of the nanoparticles in solution and the final anticancer activity of the nanostructure. This study shows that PXRD is an excellent technique for quantitative phase analysis to determine the presence and amount of phosphate contamination in diammonium hydrogen phosphate samples.
Aripiprazole long-acting treatments can significantly control symptom, improve adherence and reduce the risk of relapse compared to oral drugs. An alternative start-up guideline has recently been approved in several countries that simplifies its administration.
Objectives
To present a case report of a patient with schizophrenia treated with alternative starting regimen of aripiprazole long-acting treatment.
Methods
Presentation of a clinical case supported by a non-systematic review of literature.
Results
We present the case of a 22-year-old patient diagnosed with schizophrenia, whose symptoms started after the birth of her son, 2 years ago. She has presented a poor clinical evolution, requiring several admissions to our inpatient service after discontinuation of her medication. The patient has taken different antipsychotics, including olanzapine and paliperidone long-acting treatment, which were suspended due to side effects (weight gain and increased prolactin levels). A switch to oral aripiprazole 20mg was made, which showed good response and tolerance. Given the persistence of irregular intake, it was decided to switch to aripiprazole long-acting treatment, applying an alternative initial regime consisting of two doses of aripiprazole long-acting treatments 400mg and one oral aripiprazole 20mg. The patient has since had no delusions or hallucinations and is living independently at home.
Conclusions
The administration of a simplified initial regime with aripiprazole long-acting treatments could improve therapeutic adherence while maintaining the same effectiveness and similar side effects.
Although a large number of studies have shown brain volumetric differences between men and women, only a few investigations to date have analyzed brain tissue volumes in representative samples of the general elderly population.
Objectives
We investigated differences in gray matter (GM), white matter (WM) and intracranial volumes (ICVs) between sexes in individuals above 66 years old using structural magnetic resonance imaging (MRI).
Methods
Using FreeSurfer version 5.3, we automatically obtained the ICVs, GM and WM volumes from MRI datasets of 84 men and 92 women. To correct for interindividual variations in ICV, GM and WM volumes were adjusted with a method using the residuals of a least-square-derived linear regression between raw volumes and ICVs. We then performed an ANCOVA comparing men and woman including age and years of schooling as confounding factors.
Results
Women had a lower socioeconomic status overall and fewer years of schooling than men. The comparison of unadjusted brain volumes showed larger GM and WM volumes in men. After the ICV correction, the adjusted volumes of GM and WM were larger in women.
Conclusions
After the ICV correction and taking into account differences in socioeconomic status and years of schooling, our results confirm previous findings of proportionally larger GM in women, as well as larger WM volumes. These results in an elderly population indicate that brain volumetric differences between sexes persist throughout the aging process. Additional studies combining MRI and other biomarkers are warranted to identify the hormonal and molecular bases influencing such differences.
In this work, Joukowski's rotor wake model is considered for a two-blade rotor of radius $R_b$ rotating at the angular velocity $\varOmega _R$ in a normal incident velocity $V_{\infty }$. This model is based on a description of the wake by a limited number of vortices of core size $a$: a tip vortex of constant circulation $\varGamma$ for each blade and a root vortex of circulation $-2\varGamma$ on the rotation axis. Using a free-vortex method, we obtain solutions matching uniform interlaced helices in the far field that are steady in the frame rotating with the rotor for a large range of tip-speed ratios $\lambda = R_b \Omega _R/V_{\infty }$ and vortex strengths $\eta = \varGamma /(R_b^{2} \Omega _R)$. Solutions are provided for a two-bladed rotor for both helicopters and wind turbines. Particular attention is brought to the study of the solutions describing steep-descent helicopter flight regimes and large tip-ratio wind turbine regimes, for which the vortex structure is strongly deformed in the near wake and crosses the rotor plane. Both the geometry of the structure and its induced velocity field are analysed in detail. The thrust and the power coefficient of the solutions are also provided and compared to the momentum theory. The stability of the solutions is studied by monitoring the linear spatio-temporal development of a localized perturbation placed at different locations. Good agreements with the theoretical predictions for uniform helices and for point vortex arrays are demonstrated for the stability properties in the far wake. However, a more complex evolution is observed for the more deformed solutions when the perturbation is placed close to the rotor.
One of the most important prognostic factors in patients diagnosed with schizophrenia is the number of hospitalizations they need during their life. In this work we describe risk factors which determinate psychotic relapse.
Methods
Retrospective review of the clinical histories of patients diagnosed with schizophrenia who needed hospitalization during the year 2008 using Hospital Ramon Cajal's history software. Data were analyzed using the SPSS software 15.0 version.
Results
- Socio-demographic: We collected a total of 57 patients, 60% were men and 77,2% were single who lived with their families. 52,8% only had Primary education and 14% had been to University. 38,6% were pensioner and 12,3% workers.
- Risk factors: 54,4% had abandoned their medication, 7% had had recent modifications in their medication, and 35,1% received long acting antipsychotic. 42,1% were identified as substance users.
- 40,4% had been diagnosed with schizophrenia more than three years ago; 57,9% had had less than 3 previous hospitalizations, and 54,4% need hospitalization the previous year.
Conslusions
Male under 30 years old have more risk of needing more hospitalizations. The main risk factor for suffering new psychotic episodes is the medication nonadherence, modifying medication only causes new episodes in few patients. Patients receiving long-acting antipsychotic agents suffer less psychotic relapse. Substance abuse among schizophrenia patients is a major complicating factor since almost half of the hospitalizations are related to it.
To describe the relation of psychosocial factors of care (phase illness, years of care, free time, extra help and symptoms of depression) influence the care burden of dementia family caregivers. To measure the relation of the level of depressive symptoms on an intense level of burden of the dementia family caregivers.
Methods
Is selected a sample of 102 primary caregivers by criteria of inclusion to which a surveys do to those that the following information gathered: sociodemographic dates of the caregivers and of the dementia patients, care burden (Zarit Interview) and depressive symptoms (Beck Depression Inventory) of the family caregivers.
Results
Most of the sample experiences an intense burden level (74%) opposite to a light level (26%). Psychosocial characteristics are as per statistics significant in increasing the care burden there were free time, extra help and presence of symptoms of depression. Presence of serious symptoms of depression on the intense burden level are differently front or those who had a minor burden, 22% and 5% respectively.
Conclusions
There are most of the daughter-father/mother and spouse-spouse caregiver couples with a high percentage of caregivers of feminine sex (as in most of the studies realized on caregiver of dependent persons at European and international level). The need for free time and psychic self-care are cost-effective strategies to prevent the depressive disorders, as well as, to improve their caregiver's work. The psychoeducation programs that have being realized at European level directed to family caregiver are necessary in our country.
Natural polyamines (putrescine, spermidine and spermine) are low molecular weight highly protonated aliphatic molecules that physiologically modulate NMDA, AMPA/kainate glutamatergic receptors and limbic dopaminergic neurotransmission. Previous studies had demonstrated that polyamine metabolism might be disrupted in schizophrenia, what could potentially be linked to glutamatergic dysfunction. In particular, polyamine levels in blood and fibroblast cultures from patients with schizophrenia had previously been found to be higher than in healthy controls. Indeed, a significant positive correlation between blood polyamine levels and severity of illness may exist.
Methods
In order to test potential differences in blood polyamine levels between drug-free schizophrenia in-patients (n = 12), and healthy controls (n = 26, blood donors), spermidine (spd), spermine (spm), and spermidine/spermine index (spd/spm) were determined using HPLC after dansylation.
Results
No significant differences were found between groups (t = 0,974; df = 36; P = 0,337 for spd, t = l0, 52; df = 36; P = 0,959 for Spm, and, t = 0, 662; df = 36; P = 0,512 for spd/spm).
Conclusions
Though we couldn’t replicate previous findings suggesting disturbances in blood polyamine levels in schizophrenia, this issue may be a promising target. Future research should take into account possible factors such as sex, nutritional state, and stress.
Cystic echinococcosis (CE) is a zoonotic disease caused by a complex of species known as Echinococcus granulosus sensu lato. CE is endemic in Argentina, Chile, Peru, Uruguay and the South part of Brazil. In contrast, little is known regarding the presence of CE in Bolivia. In this study, 35 cysts isolated from livestock (mostly from the Department of La Paz) and 3 from humans (La Paz, Oruro and Potosi) were genetically characterized analysing the sequence of the cox1 gene (1609 bp). In total, 30 cysts (from La Paz, Cochabamba and Beni) were characterized as E. granulosus sensu stricto (3 fertile and 4 non-fertile cysts from sheep, 8 fertile and 12 non-fertile cysts from cattle and 3 fertile cysts from humans). A detailed analysis of the cox1 haplotypes of E. granulosus s.s. is included. Echinococcus ortleppi (G5) was found in 5 fertile cysts from cattle (from La Paz and Cochabamba). Echinococcus intermedius (G7) was identified in 3 fertile cysts from pigs (from Santa Cruz). Additionally, E. granulosus s.s. was detected in 4 dog faecal samples, while E. ortleppi was present in other two dog faecal samples. The implications of these preliminary results in the future implementation of control measures are discussed.
Delirium is a clinical entity consisting of acute loss of consciousness, with attention deficit and fluctuating evolution. Antidepressive medication can cause these symptoms or worsen them.
Case report
We report the case of a 84-year-old blind female who was diagnosed of delirium in relation to intoxication with sertraline. The patient was admitted into a short-stay psychiatric unit for three days. She presented behavioural disturbances consisting in auto and heteroaggressive behaviour, altered consciousness and visual hallucinations (rocks, turtles). When dosage of sertraline was doubled from 50 mg/day to 100 mg/day visual hallucinations started. There were not other medical causes found, so sertraline was suspended, achieving clinical improvement.
Discussion
This case report shows how a patient with antidepressive treatment can display delirium. The three main causes of delirium that are infections, side effects and methabolic syndrome.
Conclusions
In the case of treating a patient with delirium, the presence of previous illness has to be investigated. It is indispensable to describe the presence of previous illness, medication and recent changes of the dosages in the medical history in a patient with Sertraline.
Disclosure of interest
The authors have not supplied their declaration of competing interest.
Single-photon emission computed tomography (SPECT) is a valid method for measuring regional cerebral blood flow (rCBF). Recent studies regarding rCBF in patients with first episode psychosis (FEP) reported heterogeneous results, but were limited with small sample size. Neuroimaging can help us in setting the diagnosis of illness, as well as in following the progress and finding more effective treatment for psychotic disorders.
Objectives
To compare, baseline alterations of the rCBF using SPECT with psychopathological status in FEP during acute phase.
Aims
To investigate the changes of rCBF in patients with FEP during acute phase.
Methods
We conducted a study on 40 drug – naïve patients with FEP at acute phase of illness during their hospitalization at Zagreb University hospital centre. The diagnosis was confirmed using diagnostic and statistical manual of mental disorders, fifth edition. rCBF was measured with SPECT and psychopathological status rated with the Positive and Negative Syndrome Scale.
Results
Our findings showed moderate to severe parieto-temporal perfusion deficits, mild to moderate parieto-fronto-temporal perfusion deficits or borderline perfusion deficits in all but one patient.
Conclusion
Our results showed alteration in rCBF at the beginning of the illness that indicate a biological market of psychotic disorder.
Disclosure of interest
The authors have not supplied their declaration of competing interest.
In this work, low-Pt content nanocatalysts (≈ 5 wt. %) supported on Hollow Carbon Spheres (HCS) were synthesized by two routes: i) colloidal conventional polyol, and ii) surfactant-free Bromide Anion Exchange (BAE). The nanocatalysts were labelled as Pt/HCS-P and Pt/HCS-B for polyol and BAE, respectively. The physicochemical characterization of the nanocatalysts showed that by following both methods, a good control of chemical composition was achieved, obtaining in addition well dispersed nanoparticles of less than 3 nm TEM average particle size (d) on the HCS. Pt/HCS-B contained more Pt0 species than Pt/HCS-P, an effect of the synthesis method. In addition, the structure of the HCS remains more ordered after BAE synthesis, compared to polyol. Regarding the catalytic activity for the Oxygen Reduction Reaction (ORR) in 0.5 M KOH, Pt/HCS-P and Pt/HCS-B showed a similar performance in terms of current density (j) at 0.9 V vs. RHE than the benchmark commercial 20 wt. % Pt/C. However, Pt/HCS-P and Pt/HCS-B demonstrated a 6 and 5-fold increase in mass catalytic activity compared to Pt/C, respectively. A positive effect of the high specific surface area of the HCS and its interactions with metal nanoparticles and electrolyte, which promoted the mass transfer, increased the performance of Pt/HCS-P and Pt/HCS-B. The high catalytic activity showed by Pt/HCS-B and Pt/HCS-P for the ORR, even with a low-Pt content, make them promising cathode nanocatalysts for Anion Exchange Membrane Fuel Cells (AEMFC).
Turbulent flows in the presence of walls may be apprehended as a collection of momentum- and energy-containing eddies (energy-eddies), whose sizes differ by many orders of magnitude. These eddies follow a self-sustaining cycle, i.e. existing eddies are seeds for the inception of new ones, and so forth. Understanding this process is critical for the modelling and control of geophysical and industrial flows, in which a non-negligible fraction of the energy is dissipated by turbulence in the immediate vicinity of walls. In this study, we examine the causal interactions of energy-eddies in wall-bounded turbulence by quantifying how the knowledge of the past states of eddies reduces the uncertainty of their future states. The analysis is performed via direct numerical simulation of turbulent channel flows in which time-resolved energy-eddies are isolated at a prescribed scale. Our approach unveils, in a simple manner, that causality of energy-eddies in the buffer and logarithmic layers is similar and independent of the eddy size. We further show an example of how novel flow control and modelling strategies can take advantage of such self-similar causality.