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Over the last decade, an increasing body of evidence has emerged, supporting the existence of a metastable liquid-liquid critical point in supercooled water whereby two distinct liquid phases of different densities coexist. Analyzing long molecular dynamics simulations performed using deep neural-network force fields trained to accurate quantum mechanical data, we demonstrate that the low-density liquid phase displays a strong propensity toward spontaneous polarization, as witnessed by large and long-lived collective dipole fluctuations. Our findings suggest that the dynamical stability of the low-density phase, and hence the transition from high-density to low-density liquid, is triggered by a collective process involving an accumulation of rotational angular jumps, which could ignite large dipole fluctuations. This dynamical transition involves subtle changes in the electronic polarizability of water molecules which affects their rotational mobility within the two phases. These findings hold the potential for catalyzing activity in the search for dielectric-based probes of the putative second critical point.
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The dynamics of (few) electrons dissolved in an ionic fluid-as when a small amount of metal is added to a solution while upholding its electronic insulation-manifests interesting properties that can be ascribed to nontrivial topological features of particle transport (e.g., Thouless' pumps). In the adiabatic regime, the charge distribution and the dynamics of these dissolved electrons are uniquely determined by the nuclear configuration. Yet, their localization into effective potential wells and their diffusivity are dictated by how the self-interaction is modeled. In this article, we investigate the role of self-interaction in the description of the localization and transport properties of dissolved electrons in non-stoichiometric molten salts. Although the account for the exact (Fock) exchange strongly localizes the dissolved electrons, decreasing their tunneling probability and diffusivity, we show that the dynamics of the ions and of the dissolved electrons are largely uncorrelated, irrespective of the degree to which the electron self-interaction is treated and in accordance with topological arguments.
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We present a method, based on the classical Green-Kubo theory of linear response, to compute the heat conductivity of extended systems, leveraging energy-density, rather than energy-current, fluctuations, thus avoiding the need to devise an analytical expression for the macroscopic energy flux. The implementation of this method requires the evaluation of the long-wavelength and low-frequency limits of a suitably defined correlation function, which we perform using a combination of recently-introduced cepstral-analysis and Bayesian extrapolation techniques. Our methodology is demonstrated against standard current-based Green-Kubo results for liquid argon and water, and solid amorphous Silica, and compared with a recently proposed similar technique, which utilizes mass-density, instead of energy-density, fluctuations.
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OBJECTIVE: To provide evidence to the link between serotonin (5-HT), energy metabolism, and the human obese phenotype, the present study investigated the binding and function of the platelet 5-HT transporter (SERT), in relation to circulating insulin, leptin, and glycolipid metabolic parameters. METHODS: Seventy-four drug-free subjects were recruited on the basis of divergent body mass index (BMIs) (16.5-54.8 Kg/m2). All subjects were tested for their blood glycolipid profile together with platelet [3H]-paroxetine ([3H]-Par) binding and [3H]-5-HT reuptake measurements from April 1st to June 30th, 2019. RESULTS: The [3H]-Par Bmax (fmol/mg proteins) was progressively reduced with increasing BMIs (P < .001), without changes in affinity. Moreover, Bmax was negatively correlated with BMI, waist/hip circumferences (W/HC), triglycerides (TD), glucose, insulin, and leptin, while positively with high-density lipoprotein (HDL) cholesterol (P < .01). The reduction of 5-HT uptake rate (Vmax, pmol/min/109 platelets) among BMI groups was not statistically significant, but Vmax negatively correlated with leptin and uptake affinity values (P < .05). Besides, [3H]-Par affinity values positively correlated with glycemia and TD, while [3H]-5-HT reuptake affinity with glycemia only (P < .05). Finally, these correlations were specific of obese subjects, while, from multiple linear-regression analysis conducted on all subjects, insulin (P = .006) resulting negatively related to Bmax independently from BMI. CONCLUSIONS: Present findings suggest the presence of a possible alteration of insulin/5-HT/leptin axis in obesity, differentially impinging the density, function, and/or affinity of the platelet SERT, as a result of complex appetite/reward-related interactions between the brain, gut, pancreatic islets, and adipose tissue. Furthermore, they support the foremost cooperation of peptides and 5-HT in maintaining energy homeostasis.
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Leptina , Serotonina , Glucolípidos , Humanos , Insulina , Obesidad , TriglicéridosRESUMEN
The use of machine perfusion (MP) in liver transplantation (LT) is spreading worldwide. However, its efficacy has not been demonstrated, and its proper clinical use has far to go to be widely implemented. The Società Italiana Trapianti d'Organo (SITO) promoted the development of an evidence-based position paper. A 3-step approach has been adopted to develop this position paper. First, SITO appointed a chair and a cochair who then assembled a working group with specific experience of MP in LT. The Guideline Development Group framed the clinical questions into a patient, intervention, control, and outcome (PICO) format, extracted and analyzed the available literature, ranked the quality of the evidence, and prepared and graded the recommendations. Recommendations were then discussed by all the members of the SITO and were voted on via the Delphi method by an institutional review board. Finally, they were evaluated and scored by a panel of external reviewers. All available literature was analyzed, and its quality was ranked. A total of 18 recommendations regarding the use and the efficacy of ex situ hypothermic and normothermic machine perfusion and sequential normothermic regional perfusion and ex situ MP were prepared and graded according to the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) method. A critical and scientific approach is required for the safe implementation of this new technology.
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Trasplante de Hígado , Humanos , Italia , Preservación de Órganos , PerfusiónRESUMEN
Quantum ESPRESSO is an open-source distribution of computer codes for quantum-mechanical materials modeling, based on density-functional theory, pseudopotentials, and plane waves, and renowned for its performance on a wide range of hardware architectures, from laptops to massively parallel computers, as well as for the breadth of its applications. In this paper, we present a motivation and brief review of the ongoing effort to port Quantum ESPRESSO onto heterogeneous architectures based on hardware accelerators, which will overcome the energy constraints that are currently hindering the way toward exascale computing.
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BACKGROUND: Problematic Internet use (PIU), that may be defined as the inability to control one's use of Internet with negative consequences in daily life, is an emerging problem involving primarily, but not only young generations. Different studies have shown that students are particularly vulnerable to PIU. Given the paucity of information on PIU in our country, the aim of this paper was at investigating the characteristics of PIU amongst Italian University students. SUBJECTS AND METHODS: A self-assessment questionnaire, referred by the acronym QUNT ("Questionario sull'Utilizzo delle Nuove Tecnologie"), composed by 101 items grouped together to identify a series of factors, was developed and sent through e-mail invitation to several students from three Italian Universities. RESULTS: The returned questionnaires were 3324, out of a total of 51,304 sent, with no difference between the two sexes. On the contrary, the distribution of the QUNT factors was different in the two sexes, in people living alone and in overweight subjects. Men resulted to be more involved in online recreational activities, whereas women seemed more attracted to instant messaging and generally to social networks. PIU was significantly more present in men than women. The comparisons of QUNT factor scores in the four BMI categories showed that the greater the BMI the greater the score of some factors. CONCLUSIONS: The findings of the present study indicate that the use of Internet through new technologies may exceed its real utility amongst Italian university student, with some sex-related differences. Men seem more prone to use Internet for passing time and women for social relationships. Men are also at risk of developing PIU. Again, Internet use might be a basic vulnerability factor of increasing weight gain and obesity amongst young people.
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Conducta Adictiva/epidemiología , Uso de Internet/estadística & datos numéricos , Estudiantes/psicología , Estudiantes/estadística & datos numéricos , Universidades , Adolescente , Femenino , Humanos , Italia/epidemiología , Masculino , Adulto JovenRESUMEN
The thermal conductivity of classical multicomponent fluids is seemingly affected by the intrinsic arbitrariness in the definition of the atomic energies, and it is ill conditioned numerically, when evaluated from the Green-Kubo theory of linear response. To cope with these two problems, we introduce two new concepts: a convective invariance principle for transport coefficients, in the first case, and multivariate cepstral analysis, in the second. A combination of these two concepts allows one to substantially reduce the noise affecting the estimate of the thermal conductivity from equilibrium molecular dynamics, even for one-component systems.
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Anthocyanins are a broad family of natural dyes, increasingly finding application as substitutes for artificial colorants in the food industry. In spite of their importance and ubiquity, the molecular principles responsible for their extreme color variability are poorly known. We address these mechanisms by computer simulations and photoabsorption experiments of cyanidin-3-O-glucoside in water solution, as a proxy for more complex members of the family. Experimental results are presented in the range of pH 1-9, accompanied by a comprehensive systematic computational study across relevant charge states and tautomers. The computed spectra are in excellent agreement with the experiments, providing unprecedented insight into the complex behavior underlying color expression in these molecules. Besides confirming the importance of the molecule's charge state, we also unveil the hitherto unrecognized role of internal distortions in the chromophore, which affect its degree of conjugation, modulating the optical gap and in turn the color. This entanglement of structural and electronic traits is also shared by other members of the anthocyanin family (e.g. pelargonidin and delphinidin) highlighting a common mechanism for color expression across this important family of natural dyes.
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BACKGROUND: Increasing evidence supports a key role of Oxytocin (OT) as a modulator of social relationships in mammals. OBJECTIVE: The aim of the present study was to investigate possible sex-related differences in plasma OT levels in human beings. METHODS: Forty-five healthy men and 45 women (mean age: 34.9 ± 6.2 years), were included in the study. Plasma preparation, peptide extraction and OT radioimmunoassay were carried out according to standardized methods. RESULTS: The results showed that OT plasma levels (pg / ml, mean ± SD) were significantly higher in women than in men (4.53 ± 1.18 vs 1.53 ± 1.19, p Ë 0.001). CONCLUSIONS: The present finding demonstrates sex-related differences in plasma OT levels in humans. It is tempting to hypothesize that such differences might be related to behaviours, attitudes, as well as susceptibility to stress response, resilience and social emotions specific of women and men.
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BACKGROUND: The aim of the present study was to appraise retrospectively the influence of valproate (VPA) and antidepressants (ADs) on the steady-state plasma concentrations of clozapine (CLZ), the prototype of various second-generation antipsychotics, norclozapine (NCLZ, its main metabolite), and their ratio (NCLZ:CLZ). METHODS: Sixty-seven psychotic patients with a prevalent diagnosis of bipolar disorder were studied. We then analyzed data altogether and subdivided them into 4 groups, according to pharmacological treatments: #1 CLZ (n = 21), #2 CLZ plus ADs (n = 13), #3 CLZ plus VPA (n = 16), and #4 CLZ plus ADs plus VPA (n = 17). RESULTS: First, significant positive between CLZ and NCLZ plasma levels (in nanograms/milliliter) and the drug daily dosages (in milligrams/kilogram of body weight) (n = 67) were observed (Spearman: rCLZ = 0.49; rNCLZ = 0.61; P < 0.001). We then normalized by given doses CLZ and NCLZ plasma levels, natural log transformed them, and performed analysis of variance factor analyses followed by pairwise comparisons, performed on the 4 groups and the 3 CLZ parameters. We identified significant drug effects on (1) CLZ plasma levels, significantly higher in group #2 versus group #1, and (2) NCLZ:CLZ ratio, lower in group #2 versus groups #1 and #3. Significant drug × gender interactions were observed in group #3, showing higher NCLZ levels and NCLZ:CLZ ratios in men compared with women. CONCLUSIONS: Despite its inherent limitations, this observational study confirms the significant increase in plasma CLZ concentrations and reduction in NCLZ:CLZ ratio when this drug was coadministered with ADs (group #2), an effect apparently counteracted by VPA (group #4). The drug × gender interactions in patients taking both CLZ and VPA (group #3) warrant further prospective study.
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Antidepresivos/farmacología , Trastorno Bipolar/sangre , Clozapina/farmacocinética , Ácido Valproico/farmacología , Adolescente , Adulto , Antimaníacos/farmacología , Antipsicóticos/sangre , Antipsicóticos/farmacocinética , Clozapina/análogos & derivados , Clozapina/sangre , Interacciones Farmacológicas , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Factores Sexuales , Adulto JovenRESUMEN
OBJECTIVE: The role of dopamine (DA) in romantic love is suggested by different evidence and is supported by the findings of some brain imaging studies. The DA transporter (DAT) is a key structure in regulating the concentration of the neurotransmitter in the synaptic cleft. Given the presence of DAT in blood cells, the present study aimed to explore it in resting lymphocytes of 30 healthy subjects of both sexes in the early stage of romantic love (no longer than 6 months), as compared with 30 subjects involved in a long-lasting relationship. METHODS: All subjects had no physical or psychiatric illness. The DAT was measured by means of the [3H]-WIN 35,428 binding and the [3H]-DA reuptake to resting lymphocytes membranes. Romantic love was assessed by a specific questionnaire developed by us. RESULTS: The results showed that the subjects in the early phase of romantic love had a global alteration of the lymphocyte DAT involving both a decreased number of proteins (Bmax) and a reduced functionality (Vmax). CONCLUSIONS: Taken together, these findings would indicate the presence of increased levels of DA in romantic love that, if paralleled by similar concentrations in the brain, would explain some peculiar features of this human feeling.
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Proteínas de Transporte de Dopamina a través de la Membrana Plasmática/biosíntesis , Amor , Linfocitos/metabolismo , Adulto , Femenino , Humanos , Masculino , Adulto JovenAsunto(s)
Obtención de Tejidos y Órganos , Muerte Encefálica , Muerte , Humanos , Donantes de TejidosRESUMEN
This study aimed at comparing neuropsychological test scores in 83 cardiologists and nurses (exposed group, EG) working in the cardiac catheterization laboratory, and 83 control participants (non exposed group, nEG), to explore possible cognitive impairments. The neuropsychological assessment was carried out by means of a battery called "Esame Neuropsicologico Breve." EG participants showed significantly lower scores on the delayed recall, visual short-term memory, and semantic lexical access ability than the nEG ones. No dose response could be detected. EG participants showed lower memory and verbal fluency performances, as compared with nEG. These reduced skills suggest alterations of some left hemisphere structures that are more exposed to IR in interventional cardiology staff. On the basis of these findings, therefore, head protection would be a mandatory good practice to reduce effects of head exposure to ionizing radiation among invasive cardiology personnel (and among other exposed professionals).
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Servicio de Cardiología en Hospital/estadística & datos numéricos , Exposición Profesional/efectos adversos , Exposición a la Radiación/efectos adversos , Radiología Intervencionista/estadística & datos numéricos , Adulto , Encéfalo/efectos de la radiación , Relación Dosis-Respuesta en la Radiación , Femenino , Humanos , Masculino , Memoria a Corto Plazo/efectos de la radiación , Recuerdo Mental/efectos de la radiación , Persona de Mediana Edad , Pruebas Neuropsicológicas , Radiación Ionizante , Habla/efectos de la radiaciónRESUMEN
BACKGROUND AND AIM: Given the paucity of information on the possible role of oxytocin (OT) in the pathophysiology of obsessive-compulsive disorder (OCD), our study aimed at evaluating plasma OT levels in a group of 44 OCD outpatients, as compared with a similar group of healthy control subjects. At the same time, the relationships between OT and clinical features and romantic attachment characteristics were examined as well. METHODS: Diagnosis was assessed according to DSM-IV-TR criteria, while the OCD severity was measured by means of the Y-BOCS rating scale. All patients were drug free and not depressed. The romantic attachment was assessed by means of the Italian version of the 'Experiences in Close Relationships' questionnaire. Plasma OT levels were evaluated by means of a standard RIA kit. RESULTS: The main findings of our study showed that OT levels were increased in OCD patients, as compared with healthy subjects, and negatively related to symptom severity. Positive relationships were detected between OT levels and the fearful-avoidant and dismissing styles of romantic attachments, but only in male OCD patients. CONCLUSION: Taken together, these findings suggest that OT may play a role in OCD pathophysiology and also in the romantic attachment of patients with gender specificity.
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Trastorno Obsesivo Compulsivo/sangre , Oxitocina/sangre , Adulto , Femenino , Humanos , Masculino , Trastorno Obsesivo Compulsivo/diagnóstico , Escalas de Valoración Psiquiátrica , Radioinmunoensayo , Índice de Severidad de la EnfermedadRESUMEN
OBJECTIVES: The present paper aimed at reviewing literature data on the inflammatory hypothesis of mood spectrum, as well as the overlapping features with some chronic rheumatologic disorders, in particular fibromyalgia and chronic fatigue syndrome. METHODS: A literature search was carried out for English papers published in the years 2000-2014, while using the following words: mood spectrum, depression, bipolar disorders, fibromyalgia, chronic fatigue syndrome, neurotransmitters, inflammation, neuroinflammation, cytokines. RESULTS: Overlapping features were highlighted between mood spectrum, fibromyalgia and chronic fatigue syndrome suggesting common underlying mechanisms at pathophysiological level involving both central nervous and the immune systems. CONCLUSIONS: Taken together, the literature would suggest that the borders between different medical domains should be reconsidered in the light of common processes linking them.
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Afecto , Síndrome de Fatiga Crónica/psicología , Fibromialgia/psicología , Inflamación/psicología , Animales , Citocinas , Síndrome de Fatiga Crónica/inmunología , Síndrome de Fatiga Crónica/metabolismo , Fibromialgia/inmunología , Fibromialgia/metabolismo , Humanos , Inflamación/inmunología , Inflamación/metabolismo , Mediadores de Inflamación/metabolismo , Transducción de SeñalRESUMEN
The simulation of the color optical properties of molecular dyes in liquid solution requires the calculation of time evolution of the solute absorption spectra fluctuating in the solvent at finite temperature. Time-averaged spectra can be directly evaluated by combining ab initio Car-Parrinello molecular dynamics and time-dependent density functional theory calculations. The inclusion of hybrid exchange-correlation functionals, necessary for the prediction of the correct transition frequencies, prevents one from using these techniques for the simulation of the optical properties of large realistic systems. Here we present an alternative approach for the prediction of the color of natural dyes in solution with a low computational cost. We applied this approach to representative anthocyanin dyes: the excellent agreement between the simulated and the experimental colors makes this method a straightforward and inexpensive tool for the high-throughput prediction of colors of molecules in liquid solvents.
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Social anxiety disorder (SAD) is a condition characterized by pervasiveness and impairment in social functioning, with a prevalence in the general population between 1.9% and 12.1%. The most consistent findings on its neurobiological underpinnings involve a wide range of neurotransmitters (serotonin, norepinephrine, glutamate, and GABA) and neuropeptides (oxytocin), but no comprehensive hypothesis is yet available. In particular, oxytocin is becoming increasingly established as a "prosocial neuropeptide" and, as such, is a major focus of current research, with a great range of therapeutic applications including SAD treatment. Specifically, the amygdala plays a pivotal role in conditioning and processing of fear, and exaggerated amygdala responses in SAD patients have been observed during various social-emotional stimuli. In addition to the amygdala, other brain areas of interest in SAD-related circuitry are represented by the medial prefrontal cortex, dorsal raphe, striatum, locus coeruleus, prefrontal cortex, insular cortex, and anterior cingulate cortex. The aim of this review is to provide an update on neurobiological correlates of SAD, with a special focus on neurotransmitters and brain areas possibly involved, and suggestions for future research that could lead to more specific therapeutic interventions.
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Trastornos de Ansiedad/fisiopatología , Neurotransmisores/fisiología , Trastornos de Ansiedad/metabolismo , Encéfalo/fisiopatología , Humanos , Red Nerviosa/fisiopatología , Neurotransmisores/metabolismoRESUMEN
We introduce a new method to compute the optical absorption spectra of complex molecular systems in solution, based on the Liouville approach to time-dependent density-functional perturbation theory and the revised self-consistent continuum solvation model. The former allows one to obtain the absorption spectrum over a whole wide frequency range, using a recently proposed Lanczos-based technique, or selected excitation energies, using the Casida equation, without having to ever compute any unoccupied molecular orbitals. The latter is conceptually similar to the polarizable continuum model and offers the further advantages of allowing an easy computation of atomic forces via the Hellmann-Feynman theorem and a ready implementation in periodic-boundary conditions. The new method has been implemented using pseudopotentials and plane-wave basis sets, benchmarked against polarizable continuum model calculations on 4-aminophthalimide, alizarin, and cyanin and made available through the Quantum ESPRESSO distribution of open-source codes.
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Major depression is associated with a 4-fold increased risk for premature death, largely accounted by cardiovascular disease (CVD). The relationship between depression and CVD is thought to be mediated by the so-called metabolic syndrome (MeS). Epidemiological studies have consistently demonstrated a co-occurrence of depression with MeS components, ie, visceral obesity, dyslipidemia, insulin resistance, and hypertension. Although the exact mechanisms linking MeS to depression are unclear, different hypotheses have been put forward. On the one hand, MeS could be the hallmark of the unhealthy lifestyle habits of depressed patients. On the other, MeS and depression might share common alterations of the stress system, including the hypothalamus-pituitary-adrenal (HPA) axis, the autonomic nervous system, the immune system, and platelet and endothelial function. Both the conditions induce a low grade chronic inflammatory state that, in turn, leads to increased oxidative and nitrosative (O&NS) damage of neurons, pancreatic cells, and endothelium. Recently, neurobiological research revealed that peripheral hormones, such as leptin and ghrelin, which are classically involved in homeostatic energy balance, may play a role in mood regulation. Metabolic risk should be routinely assessed in depressed patients and taken into account in therapeutic decisions. Alternative targets should be considered for innovative antidepressant agents, including cytokines and their receptors, intracellular inflammatory mediators, glucocorticoids receptors, O&NS pathways, and peripheral mediators.