Fast-forwarding molecular ground state preparation with optimal control on analog quantum simulators.

We show that optimal control of the electron dynamics is able to prepare molecular ground states, within chemical accuracy, with evolution times approaching the bounds imposed by quantum mechanics. We propose a specific parameterization of the molecular evolution only in terms of interaction already present in the molecular Hamiltonian. Thus, the proposed method solely utilizes quantum simulation routines, retaining their favorable scalings. Due to the intimate relationships between variational quantum algorithms and optimal control, we compare, when possible, our results with state-of-the-art methods in the literature. We found that the number of parameters needed to reach chemical accuracy and algorithmic scaling is in line with compact adaptive strategies to build variational Ansätze. The algorithm, which is also suitable for quantum simulators, is implemented by emulating a digital quantum processor (up to 16 qubits) and tested on different molecules and geometries spanning different degrees of electron correlation.

An open quantum system theory for polarizable continuum models.

The problem of a solute described by Quantum Chemistry within a solvent represented as a polarizable continuum model (PCM) is here reformulated in terms of the open quantum systems (OQS) theory. Using its stochastic Schrödinger equation formulation, we are able to provide a more comprehensive picture of the electronic energies and the coupling between solute and solvent electronic dynamics. In particular, the OQS-PCM proves to be a unifying theoretical framework naturally including polarization and dispersion interactions, the effect of solvent fluctuations, and the non-Markovian solvent response. As such, the OQS-PCM describes the interplay between the solute and the solvent typical electronic dynamical times and yields both the standard PCM and the so-called Born-Oppenheimer solvation regime, where the solvent electronic response is considered faster than any electronic dynamics taking place in the solute. In analyzing the OQS-PCM, we obtained an expression for the solute-solvent dispersion (van der Waals) interactions, which is very transparent in terms of a physical interpretation based on fluctuations and response functions. Finally, we present various numerical tests that support the theoretical findings.

Unraveling the molecular mechanisms of color expression in anthocyanins.

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.

Quantum optimal control theory for solvated systems.

In this work, we generalize the quantum optimal control theory (QOCT) of molecules subject to ultrashort laser pulses to the case of solvated systems, explicitly including the solvent dielectric properties in the system's quantum Hamiltonian. A reliable description of the solvent polarization is accounted for within the polarizable continuum model (PCM). The electron dynamics for the molecules in solution is coupled with the dynamics of the surrounding polarizable environment, which affects the features of the optimized laser pulse. To illustrate such effects, numerical applications of the developed method to the study of optimal population of selected excited states of two molecular solvated systems are presented and discussed.

Adsorption Mechanisms of Nucleobases on the Hydrated Au(111) Surface.

The solution environment is of fundamental importance in the adsorption of molecules on surfaces, a process that is strongly affected by the capability of the adsorbate to disrupt the hydration layer above the surface. Here we disclose how the presence of interface water influences the adsorption mechanism of DNA nucleobases on a gold surface. By means of metadynamics simulations, we describe the distinctive features of a complex free-energy landscape for each base, which manifests activation barriers for the adsorption process. We characterize the different pathways that allow each nucleobase to overcome the barriers and be adsorbed on the surface, discussing how they influence the kinetics of adsorption of single-stranded DNA oligomers with homogeneous sequences. Our findings offer a rationale as to why experimental data on the adsorption of single-stranded homo-oligonucleotides do not straightforwardly follow the thermodynamics affinity rank.

Is being overweight associated with engagement in self-injurious behaviours in adolescence, or do psychological factors have more "weight"?

INTRODUCTION: The purpose of this study was to examine the prevalence of non-suicidal self-injurious behaviours (NSSI) among healthy weight and overweight adolescents and to examine the role of age, gender, weight status, treatment condition for weight control, and psychological variables (psychopathological symptoms and emotional skills) in the prediction of NSSI. METHODS: The study had a cross-sectional design, and participants (n = 370) were aged 14-19 years and were divided in three groups: 205 adolescents with normal weight, 82 adolescents from the community with overweight/obesity, and 83 adolescents with overweight/obesity and in outpatient treatment for weight control. RESULTS: The prevalence of these behaviours in the overweight community group (25.6 %) and in the overweight clinical group (14.5 %) was similar to their healthy weight peers (19 %). Not attending an outpatient treatment for weight control, higher psychopathology and less ability to regulate emotions predict the presence of NSSI. CONCLUSION: Being overweight is not associated with NSSI, but psychosocial variables such as psychopathology, emotional deregulation and the absence of medical care predict these behaviours.

Inequivalent Solvation Effects on the N 1s Levels of Self-Associated Melamine Molecules in Aqueous Solution.

This work shows how the N 1s photoemission (PE) spectrum of self-associated melamine molecules in aqueous solution has been successfully rationalized using an integrated computational approach encompassing classical metadynamics simulations and quantum calculations based on density functional theory (DFT). The first approach allowed us to describe interacting melamine molecules in explicit waters and to identify dimeric configurations based on π-π and/or H-bonding interactions. Then, N 1s binding energies (BEs) and PE spectra were computed at the DFT level for all structures both in the gas phase and in an implicit solvent. While pure π-stacked dimers show gas-phase PE spectra almost identical to that of the monomer, those of the H-bonded dimers are sensibly affected by NH···NH or NH···NC interactions. Interestingly, the solvation suppresses all of the non-equivalences due to the H-bonds yielding similar PE spectra for all dimers, matching very well our measurements.

Severe Covid-19 in pregnant and postpartum women admitted to an intensive care unit: A retrospective cohort study.

BACKGROUND: SARS-CoV-2 infection is associated with worse maternal and fetal outcomes. This study aims to describe the characteristics of pregnant and postpartum women with severe Covid-19 admitted to ICU. METHODS AND FINDINGS: It's a retrospective cohort study evaluating pregnant and postpartum women referenced to a specialized ICU between May 2020 and June 2022. Covid-19 was confirmed with RT-PCR or rapid antigen test on a nasopharyngeal swab. Variables were described by median and IQR when numerical, and by frequency and percentage when categorical. OR with 95% CI were calculated for the evaluation of factors related to death. P-values were calculated using Pearson's ꭓ2-test, Fisher's exact test, Wilcoxon rank sum test, and Kruskall-Wallis test, and statistical significance was established as < 0·05. Missing data were excluded. All statistical analysis were performed using R software version 4.2.2. Of the 101 admissions, 85 (84·2%) were of pregnant women. Obesity (23·0%) and systemic arterial hypertension (13·0%) were the most prevalent medical conditions. Sixty-six (65·3%) were admitted using some type of oxygen support. Forty-seven (46·5%) evolved to mechanical ventilation. There were 61 events considered obstetric complications, with 8 stillbirths/fetal losses. The overall lethality was 15·8%. Pregnancy interruption, need for non-invasive mechanical ventilation, level of oxygen support at admission, prone maneuver, hemodialysis, and healthcare-related infections were factors associated with death. Evaluating the WHO 7-category ordinary scale, there was a trend of increase in the risk of death with higher punctuation, with a statistically significant difference of women with 5 (OR = 7·27; 95% IC = 1·17-194; p = 0·031) or 6 points (OR = 12·0; 95% IC = 1·15-391; p = 0·038) when compared to the ones with 3 points, i.e., of women admitted with a high-flow non-rebreathing mask or invasive mechanical ventilation, compared with the ones admitted at room air, respectively. The main limitations of this study are the relatively small number of participants, and the use of data derived of medical records-which are susceptible to misclassification and variable amounts of missing data. CONCLUSIONS: Pregnant and postpartum women with severe Covid-19 have high lethality and a high incidence of clinical and obstetric complications. These findings support that this population should be prioritized in public health strategies that address Covid-19.

The use of TikTok among children and adolescents with Eating Disorders: experience in a third-level public Italian center during the SARS-CoV-2 pandemic.

BACKGROUND: Recent research has documented the potential associations existing between the use of social media (SM) and the occurrence/development and treatment of Eating Disorders (ED). However, the literature directly addressing the use of SM TikTok among children and adolescents with ED is still scarce. METHODS: In January-February 2021, during the second Italian national lockdown due to the SARS-CoV-2 pandemic, an anonymous paper survey was conducted in an Italian third-level center for ED in childhood and adolescence. Demographics, frequency of use of TikTok, frequently viewed topics and hashtags, experienced body-shaming, as well as the use of TikTok (active search, use of proposed contents) and perceived influences of this SM on eating attitudes and self-esteem were assessed. Groups of patients with different perceived SM-induced effects were compared to determine the frequency of their interaction with 3 specific contents (diet, Pro-Anorexia Nervosa (pro-Ana) and pro-ED recovery). RESULTS: Seventy-eight patients (93.6% females, mean age 14.5 ± 2.1 years) were enrolled in the study. For 62.8%, TikTok represented the main SM, used for 1.4 ± 1.0 h/day, with diet (21.8%) as the most frequently used topic category. Pro-Ana and pro-ED recovery contents ("#foryou" and "#edrecovery" as the most frequent, respectively) were both actively searched by patients and proposed by the SM in a significant number of cases. For 59.0%, using TikTok reduced self-esteem, while 26.9% reported TikTok-related significant changes in their daily lives, and 3.8% reported experiences of body-shaming. Patients describing a negative effect of TikTok on their self-esteem more frequently searched and browsed "diet" (p = 0.007) and pro-ED recovery (p = 0.007) contents. Positive qualitative feedback on the SM was also reported. CONCLUSIONS: This study documents the use of the SM TikTok among children and adolescents with ED. Individuals with a perceived negative effect of this SM on their self-esteem may show greater interaction with specific content. Further studies are needed to investigate the psychopathological factors influencing the relationship between ED and the use of SM.

Acidic pH Promotes Refolding and Macroscopic Assembly of Amyloid ß (16-22) Peptides at the Air-Water Interface.

Assembly by amyloid-beta (Aß) peptides is vital for various neurodegenerative diseases. The process can be accelerated by hydrophobic interfaces such as the cell membrane interface and the air-water interface. Elucidating the assembly mechanism for Aß peptides at hydrophobic interface requires knowledge of the microscopic structure of interfacial peptides. Here we combine scanning force microscopy, sum-frequency generation spectroscopy, and metadynamics simulations to probe the structure of the central fragment of Aß peptides at the air-water interface. We find that the structure of interfacial peptides depends on pH: at neutral pH, the peptides adopt a less folded, bending motif by forming intra-hydrogen bonds; at acidic pH, the peptides refold into extended ß-strand fibril conformation, which further promotes their macroscopic assembly. The conformational transition of interfacial peptides is driven by the reduced hydrogen bonds, both with water and within peptides, resulting from the protonation of acidic glutamic acid side chains.

Multicomponent Exercise Program to Improve the Immediate Sequelae of COVID-19: A Prospective Study with a Brief Report of 2-Year Follow-Up.

COVID-19 placed teams of professionals in a hostile and unfamiliar environment where the lack of knowledge of its pathology led to the adaptation of programs used so far for other conditions to try to address the immediate sequelae of COVID-19 infection. That is why the aim of this study was to assess the effects of a multicomponent exercise program (MEP) in improving cardio-respiratory performance, health status, disability due to dyspnea, aerobic capacity and endurance, and the immediate sequelae of COVID-19. Thirty-nine patients referred from different hospital services were included in this study. An intervention of seven weeks with sessions twice a week was carried out, where patients underwent intervallic training sessions followed by strengthening exercises and individualized respiratory physiotherapy exercises. The results of this study show a significant improvement in cardio-respiratory performance, health status, disability due to dyspnea, and aerobic capacity and endurance after intervention; and an increase in health status and reduction in disability due to dyspnea at the 2-year follow-up. In addition, none of the patients had any adverse effects either pre-post treatment or at the 2-year follow-up. Individualized and monitored MEP in survivors of COVID-19 showed positive effects in a pre-post evaluation and the 2-year follow up, improving the immediate sequelae of post-COVID-19 patients. This highlights the importance of the professional background of the rehabilitation teams in adapting to an unknown clinical environment.

Atomistic insight into the aggregation of [Au25(SR)18] q nanoclusters.

Atomically precise nanoclusters have been proven to give solid state aggregates with intriguing optical properties. However, the mechanism that regulates this aggregation remains unclear. Here, the aggregation of two Au25 nanoclusters in solution is investigated through enhanced sampling molecular dynamics simulations. To understand how the free energy of the systems depends on the nanocluster features, calculations were performed on three nanocluster pairs which differ in charge states and substituent nature and dimension. Our results show that the choice of the ligands heavily affects the free energy profile of the systems when the structures are nearby and, in some cases, the formation of a dimeric phase is observed. This phase is particularly stable in long-chain substituted nanoclusters, where the long alkane chains can generate bundles and the gold cores are closer compared to the short-chain ligands. We found a remarkable agreement between our calculations and the literature-available solid-state structures, especially for the orientation of the interacting nanoclusters. Moreover, some of the dimeric structures are prodromal to the formation of the aurophilic intercluster bond observed in the crystal structures, meaning that the dimer can act as a precursor and can drive the whole crystallization mechanism toward the formation of stable crystal species.

Seasonal changes in immune response and reproductive investment in a biparental beetle.

Immunity and reproduction are physiologically demanding processes, therefore trade-offs are expected between these life history traits. Furthermore, investments in these traits are also known to be affected by factors such as sex, body size, individual condition, seasonal changes and parasite infection. The relationship between immunity and reproduction and the effect of other factors on this relationship were investigated in many species, but there are a small number of studies on these patterns in biparental invertebrates. Lethrus apterus is an iteroparous biparental beetle with predominant female care in respect of collecting and processing food for larvae. Males guard the nest built underground and also their mate. Here we investigate how sex, body size, time within the reproductive season and parasite load may influence the relationship between immunocompetence and reproductive investment in this species. In beetles from a natural population we quantified immune response by measuring the encapsulation response, antimicrobial activity of hemolymph, the investment into reproductive tissues by measuring the size of testis follicles in males and total egg size in females, and parasite load by counting the number of mites on the beetles. We found that the encapsulation response is condition-dependent, as large individuals showed significantly higher encapsulation ability than small ones. Antimicrobial capacity was significantly higher in females than in males. In case of antimicrobial activity there was also a seasonal change in the relationship between immunity and reproductive investment, but only under heavy mite load. Reproductive investment was influenced by the interaction between body size and season (in females) and by body size and season (in males). Furthermore in females the interaction between antimicrobial activity and season indicated that reproductive investment increased with antimicrobial activity early in the reproductive season. By investigating the relationship between immunity and reproductive investment in a natural population of a biparental beetle species, we can conclude that investments into these important life history traits are governed by complex interactions between physiological and environmental factors. Our results are discussed in the context of life history evolution, highlighting the role of the assessed factors in shaping trade-offs themselves (in invertebrates).

A classical picture of subnanometer junctions: an atomistic Drude approach to nanoplasmonics.

The description of optical properties of subnanometer junctions is particularly challenging. Purely classical approaches fail, because the quantum nature of electrons needs to be considered. Here we report on a novel classical fully atomistic approach, ωFQ, based on the Drude model for conduction in metals, classical electrostatics and quantum tunneling. We show that ωFQ is able to reproduce the plasmonic behavior of complex metal subnanometer junctions with quantitative fidelity to full ab initio calculations. Besides the practical potentialities of our approach for large scale nanoplasmonic simulations, we show that a classical approach, in which the atomistic discretization of matter is properly accounted for, can accurately describe the nanoplasmonics phenomena dominated by quantum effects.

Willingness to initiate a fight but not contest behaviour depends on intruder size in Lethrus apterus (Geotrupidae).

In resident-intruder contests, residents are expected to win more often than intruders unless the intruder has significantly higher competitive ability that is often determined by its size. Therefore, small intruders are expected to be less motivated to engage in contests than large ones and intruder size is predicted to have a positive relationship with the duration and escalation of the encounters. In a field experiment we tested these hypotheses in Lethrus apterus, a biparental beetle breeding in underground tunnels, by placing either a small or a large male in front of a tunnel occupied by a resident male. In agreement with our predictions residents won most of the encounters. Small intruders were less willing to engage in a contest and were less successful in their takeover attempts than large intruders. Contrary to many studies however, the duration and escalation (measured by the occurrence and latency of the different contest stages) of the fight in front of the burrow did not differ between the two intruder size categories. These findings suggest that in this species, small and large intruders adjust their prior decisions to their competitive abilities but once a fight started, they behave similarly during the contest.

Sampling Molecular Conformers in Solution with Quantum Mechanical Accuracy at a Nearly Molecular-Mechanics Cost.

We introduce a method to evaluate the relative populations of different conformers of molecular species in solution, aiming at quantum mechanical accuracy, while keeping the computational cost at a nearly molecular-mechanics level. This goal is achieved by combining long classical molecular-dynamics simulations to sample the free-energy landscape of the system, advanced clustering techniques to identify the most relevant conformers, and thermodynamic perturbation theory to correct the resulting populations, using quantum-mechanical energies from density functional theory. A quantitative criterion for assessing the accuracy thus achieved is proposed. The resulting methodology is demonstrated in the specific case of cyanin (cyanidin-3-glucoside) in water solution.

Multimodel Approach to the Optical Properties of Molecular Dyes in Solution.

We introduce a multimodel approach to the simulation of the optical properties of molecular dyes in solution, whereby the effects of thermal fluctuations and of dielectric screening on the absorption spectra are accounted for by explicit and implicit solvation models, respectively. Thermal effects are treated by averaging the spectra of molecular configurations generated by an ab initio molecular-dynamics simulation where solvent molecules are treated explicitly. Dielectric effects are then dealt with implicitly by computing the spectra upon removal of the solvent molecules and their replacement with an effective medium, in the spirit of a continuum solvation model. Our multimodel approach is validated by comparing its predictions with those of a fully explicit-solvation simulation for cyanidin-3-glucoside (cyanin) chromophore in water. While multimodel and fully explicit-solvent spectra may differ considerably for individual configurations along the trajectory, their time averages are remarkably similar, thus providing a solid benchmark of the former and allowing us to save considerably on the computer resources needed to predict accurate absorption spectra. The power of the proposed methodology is finally demonstrated by the excellent agreement between its predictions and the absorption spectra of cyanin measured at strong and intermediate acidity conditions.

Male-biased sex ratio does not promote increased sperm competitiveness in the seed beetle, Callosobruchus maculatus.

Sperm competition risk and intensity can select for adaptations that increase male fertilisation success. Evolutionary responses are examined typically by generating increased strength of sexual selection via direct manipulation of female mating rates (by enforcing monandry or polyandry) or by alteration of adult sex ratios. Despite being a model species for sexual selection research, the effect of sexual selection intensity via adult sex-ratio manipulation on male investment strategies has not been investigated in the seed beetle, Callosobruchus maculatus. We imposed 32 generations of experimental evolution on 10 populations of beetles by manipulating adult sex ratio. Contrary to predictions, males evolving in male-biased populations did not increase their testes and accessory gland size. This absence of divergence in ejaculate investment was also reflected in the fact that males from male-biased populations were not more successful in either preventing females from remating, or in competing directly for fertilisations. These populations already demonstrate divergence in mating behaviour and immunity, suggesting sufficient generations have passed to allow divergence in physiological and behavioural traits. We propose several explanations for the absence of divergence in sperm competitiveness among our populations and the pitfalls of using sex ratio manipulation to assess evolutionary responses to sexual selection intensity.

Dysfunctional eating behaviour, psychological well-being and adaptation to pregnancy: A study with women in the third trimester of pregnancy.

This study evaluated the prevalence and predictors of dysfunctional eating. Women in the third trimester of pregnancy participated in this study (N = 105). Dysfunctional eating was associated with a higher body mass index, enhanced negative body image, more somatic symptoms, poorer marital relationships, more negative attitudes regarding pregnancy and the baby and more emotional problems. A higher body mass index prior to the pregnancy, higher weight gain during pregnancy and a more negative perception of body image predicted dysfunctional eating. Clinicians must be aware of the presence of dysfunctional eating during pregnancy to prevent relevant physiological and psychosocial consequences during this stage.

Stenotrophomonas maltophilia lipopolysaccharide (LPS) and antibiotics: "in vitro" effects on inflammatory mediators.

Stenotrophomonas maltophilia is an emerging pathogen implicated in an increasing number of severe pulmonary infections and nosocomial sepsis. We evaluated the influence of four different antibiotics on the bacterial count and LPS activity found in broth cultures of S. maltophilia. After 4 h ceftazidime (CTZ) decreased live bacteria but increased endotoxin activity, whilst isepamicin (ISE), tobramycin (TB), and polymyxin B (PB) reduced both of them. We also investigated the influence of the above mentioned antibiotics on the ability of S. maltophilia culture filtrates and S. maltophilia LPS, extracted in our laboratory, to stimulate sepsis mediators such as tumor necrosis factor a (TNF-a), interleukin 8 (IL-8), interleukin 10 (IL-10), Nitric Oxide (NO) and as bactericidal/permeability-increasing protein (BPI) in human whole blood. Our results demonstrated that both single polycationic antibiotics and the combination of two molecules are able to kill bacteria and neutralize released S. maltophilia LPS. Combination between beta-lactams and aminoglycosides is often able to reduce the pro-inflammatory effects of S. maltophilia culture filtrates.