Correlation vs. exchange competition drives the singlet-triplet excited-state inversion in non-alternant hydrocarbons.

In this work, we focus on the understanding of the driving force behind the S1-T1 excited-state energy inversion (which would thus violate Hund's rule, making the S1 state lower in energy than the T1 state) of two non-benzenoid non-alternant hydrocarbons, composed of odd-membered rings. The molecules considered here have identical chemical composition but different atomic configuration in space. The delicate interplay between structural and electronic factors that might induce inversion and its energy extension, only by a few meV, is systematically investigated here by state-of-the-art calculations. Qualitative and quantitative accurate predictions are obtained employing post-HF methods, thanks to the balanced and careful inclusion of electron correlation effects. The obtained results might guide and rationalize new searches for molecules violating Hund's rule, concomitantly demonstrating the importance of key contributions from the theoretical method of choice.

Violation of Hund's rule in molecules: Predicting the excited-state energy inversion by TD-DFT with double-hybrid methods.

The energy difference (ΔEST) between the lowest singlet (S1) state and the triplet (T1) excited state of a set of azaphenalene compounds, which is theoretically and experimentally known to violate Hund's rule, giving rise to the inversion of the order of those states, is calculated here with a family of double-hybrid density functionals. That excited-state inversion is known to be very challenging to reproduce for time-dependent density functional theory employing common functionals, e.g., hybrid or range-separated expressions, but not for wavefunction methods due to the inclusion of higher-than-single excitations. Therefore, we explore here if the last developed family of density functional expressions (i.e., double-hybrid models) is able to provide not only the right excited-state energy order but also accurate ΔEST values, thanks to the approximate inclusion of double excitations within these models. We herein employ standard double-hybrid (B2-PLYP, PBE-QIDH, and PBE0-2), range-separated (ωB2-PLYP and RSX-QIDH), spin-scaled (SCS/SOS-B2PLYP21, SCS-PBE-QIDH, and SOS-PBE-QIDH), and range-separated spin-scaled (SCS/SOS-ωB2-PLYP, SCS-RSX-QIDH, and SOS-RSX-QIDH) expressions to systematically assess the influence of the ingredients entering into the formulation while concomitantly providing insights for their accuracy.

Singlet-Triplet Excited-State Inversion in Heptazine and Related Molecules: Assessment of TD-DFT and ab initio Methods.

We have investigated the origin of the S1 -T1 energy levels inversion for heptazine, and other N-doped π-conjugated hydrocarbons, leading thus to an unusually negative singlet-triplet energy gap ( ΔEST<0 ). Since this inversion might rely on substantial doubly-excited configurations to the S1 and/or T1 wavefunctions, we have systematically applied multi-configurational SA-CASSCF and SC-NEVPT2 methods, SCS-corrected CC2 and ADC(2) approaches, and linear-response TD-DFT, to analyze if the latter method could also face this challenging issue. We have also extended the study to B-doped π-conjugated systems, to see the effect of chemical composition on the results. For all the systems studied, an intricate interplay between the singlet-triplet exchange interaction, the influence of doubly-excited configurations, and the impact of dynamic correlation effects, serves to explain the ΔEST<0 values found for most of the compounds, which is not predicted by TD-DFT.

peri-Acenoacene molecules: tuning of the singlet and triplet excitation energies by modifying their radical character.

The energy difference between singlet and triplet excitons, or ΔEST, is a key parameter for novel light-emission mechanisms (i.e., TADF or thermally activated delayed fluorescence) or other photoactivated processes. We have studied a set of conjugated molecules (peri-acenoacenes and their heteroatom-doped analogues) to observe the evolution of their excited-state properties upon increasing the system size with and without substitution with a pair of N atoms. Since these molecules exhibit a (ground-state) diradicaloid character, together with marked correlation effects influencing the excited-states formed, we have applied a variety of theoretical methods (FT-DFT, TD-DFT, SF-TD-DFT, CIS, CIS(D), SCS-CC2, SA-CASSCF, and SC-NEVPT2) to bracket the accuracy of the results while concomitantly providing insights into electronic structure. The results show how this chemical strategy (N-doping) largely modifies not only the excited-state energies but also the oscillator strengths and the ΔEST values, constituting versatile platforms for fine-tuned photophysical applications.

Negative Singlet-Triplet Excitation Energy Gap in Triangle-Shaped Molecular Emitters for Efficient Triplet Harvesting.

The full harvesting of both singlet and triplet excitons can pave the way toward more efficient molecular light-emission mechanisms (i.e., TADF or thermally activated delayed fluorescence) beyond the spin statistics limit. This TADF mechanism benefits from low (but typically positive) singlet-triplet energy gaps or ΔEST. Recent research has suggested the possibility of inverting the order of the energy of lowest singlet and triplet excited states, thus opening new pathways to promote light emission without any energy barrier through triplet to singlet conversion, which is systematically investigated here by means of theoretical methods. To this end, we have selected a set of heteroatom-substituted triangle-shaped molecules (or triangulenes) for which ΔEST < 0 is predicted. We successfully rationalize the origin of that energy inversion and the reasons for which theoretical methods might produce qualitatively inconsistent predictions depending on how they treat n-tuple excitations (e.g., the large contribution of double excitations for all of the ground and excited states involved). Unfortunately, the time-dependent density functional theory method is unable to deal with the physical effects driving this behavior, which prompted us to use more sophisticated ab initio methods here such as SA-CASSCF, SC-NEVPT2, SCS-CC2, and SCS-ADC(2).

The new generation PFAS C6O4 does not produce adverse effects on thyroid cells in vitro.

PURPOSE: Per- and poly-fluoroalkyl-substances (PFASs) are synthetic compounds that raised concern due to their potential adverse effects on human health. Long-chain PFAS were banned by government rules in many states, and thus, new emerging PFAS were recently introduced as substitutes. Among these, Perfluoro{acetic acid, 2-[(5-methoxy-1,3-dioxolan-4-yl)oxy]}, ammonium salt (C6O4) was recently introduced to produce a range of food contact articles and literature data about this compound are scanty. The aim of this study was to evaluate the in vitro effects of exposure to C6O4, compared with PFOA and PFOS on thyroid cells. METHODS: FRTL5 rat-thyroid cell lines and normal human thyroid cells (NHT) were incubated with increasing concentrations of C6O4 for 24, 48, 72, and 144 h to assess cell viability by WST-1. Cell viability was confirmed by AnnexinV/PI staining. Long-chain PFAS (PFOA and PFOS) were used at same concentrations as positive controls. The proliferation of cells exposed to C6O4, PFOA, and PFOS was measured by staining with crystal violet and evaluation of optical density after incubation with SDS. Changes in ROS production by FRTL5 and NHT after exposure to C6O4 at short (10, 20, and 30 min) and long-time points (24 h) were evaluated by cytofluorimetry. RESULTS: C6O4 exposure did not modify FRTL5 and NHT cell viability at any concentration and/or time points with no induction of necrosis/apoptosis. At difference, PFOS exposure reduced cell viability of FRTL5 while and NHT, while PFOA only in FRTL5. FRTL5 and NHT cell proliferation was reduced by incubation with by PFOA and PFOS, but not with C6O4. ROS production by NHT and FRTL5 cells was not modified after C6O4 exposure, at any time/concentration tested. CONCLUSIONS: The present in vitro study constitutes the first evaluation of the potential adverse effects of the new emerging PFAS C6O4 in cultured rat and human thyroid cells, suggesting its safety for thyroid cells in vitro.

Detection of SARS-COV-2 receptor ACE-2 mRNA in thyroid cells: a clue for COVID-19-related subacute thyroiditis.

PURPOSE: SARS-COV-2 is a pathogenic agent belonging to the coronavirus family, responsible for the current global world pandemic. Angiotensin-converting enzyme 2 (ACE-2) is the receptor for cellular entry of SARS-CoV-2. ACE-2 is a type I transmembrane metallo-carboxypeptidase involved in the Renin-Angiotensin pathway. By analyzing two independent databases, ACE-2 was identified in several human tissues including the thyroid. Although some cases of COVID-19-related subacute thyroiditis were recently described, direct proof for the expression of the ACE-2 mRNA in thyroid cells is still lacking. Aim of the present study was to investigate by RT-PCR whether the mRNA encoding for ACE-2 is present in human thyroid cells. METHODS: RT-PCR was performed on in vitro ex vivo study on thyroid tissue samples (15 patients undergoing thyroidectomy for benign thyroid nodules) and primary thyroid cell cultures. RESULTS: The ACE-2 mRNA was detected in all surgical thyroid tissue samples (n = 15). Compared with two reporter genes (GAPDH: 0.052 ± 0.0026 Cycles-1; ß-actin: 0.044 ± 0.0025 Cycles-1; ACE-2: 0.035 ± 0.0024 Cycles-1), the mean level of transcript expression for ACE-2 mRNA was abundant. The expression of ACE-2 mRNA in follicular cells was confirmed by analyzing primary cultures of thyroid cells, which expressed the ACE-2 mRNA at levels similar to tissues. CONCLUSIONS: The results of the present study demonstrate that the mRNA encoding for the ACE-2 receptor is expressed in thyroid follicular cells, making them a potential target for SARS-COV-2 entry. Future clinical studies in patients with COVID-19 will be required for increase our understanding of the thyroid repercussions of SARS-CoV-2 infection.

A polyphasic approach to characterize Weissella cibaria and Weissella confusa strains.

AIM: To study Weissella cibaria and Weissella confusa strains, lactic acid bacteria (LAB) members naturally present in food products, but not yet included in Qualified Presumption of Safety (QPS) list of European Food Safety Authority (EFSA). METHODS AND RESULTS: We carried out a comparative genome analysis of 23 sequenced W. cibaria and 7 W. confusa genomes, in parallel with a physiological and functional characterization of several strains previously isolated from sourdough-like maize bran fermentation. The genome analysis revealed the absence of dedicated pathogenicity factors. Some putative virulence genes found in Weissella genomes were also present in other LAB strains, considered safe by EFSA and commonly used as probiotics. The physiological tests carried out on our strains corroborated the genomic results. Moreover, the following functional traits of interest to application in the food sector were identified: the majority of tested strains displayed high acidification rate, high reducing ability, production of exopolysaccharides (EPS), arabinoxylan degradation ability, growth in the presence of fructo-oligosaccharides (FOS), bile and gastric juice tolerance, and antifungal activity. CONCLUSIONS: These results provide evidence for the possible use of selected strains of W. cibaria and W. confusa in the food sector. SIGNIFICANCE AND IMPACT OF THE STUDY: This polyphasic study adds to the body of knowledge on the functional and applicable characteristics of these controversial species of LAB. This knowledge contributes to design new selected cultures included in the QPS list required for food applications.

Microbial consortia involved in fermented spelt sourdoughs: dynamics and characterization of yeasts and lactic acid bacteria.

This study aims to describe the native microbiota of fermented spelt, taking into consideration both lactic acid bacteria (LAB) and yeasts, for which little data are available. Five samples of commercial spelt flour were subjected to spontaneous fermentation to obtain a type I sourdough. A total of 186 LAB and 174 yeast isolates were selected at different refreshment steps and subjected to further analyses. Within LAB, coccal isolates constituted 78·5% of the total LAB, with the dominance of Pediococcus pentosaceus. Although documented before as a component, this is the first report of a spelt sourdough fermentation dominated by this homofermentative LAB, characterized by a high acidification rate, ability to utilize a wide range of carbon sources and to grow in high osmolarity conditions. Yeast communities resulted in four dominant species, Saccharomyces cerevisiae, Wickerhamomyces anomalus, Pichia fermentans and Clavispora lusitaniae. This study highlights for the first time the biodiversity and dynamics of yeast communities involved in sourdough fermentation of spelt. Compared to commercial baker's yeast, autochthonous W. anomalus, P. fermentans and S. cerevisiae isolates show a good performance, and their use could be an advantage for their acquired adaptation to the environment, providing stability to the fermentation process. SIGNIFICANCE AND IMPACT OF THE STUDY: Nowadays, there is a renewed interest in products based on spelt. This 'ancient grain' is a highly nutritional grain; however, its use is limited to bread-making processes, which are not standardized. The low baking and sensory quality of spelt can be overcome through fermentation processes. However, the autochthonous microbiota of spelt sourdough is poorly known. This study highlights the dynamics of microbial communities involved in sourdough fermentation of spelt and provides the basis for the selection of autochthonous cultures, with the aim of improving the nutritional potential of spelt and its rheology and bread-making properties.

Overview of procalcitonin in pregnancy and in pre-eclampsia.

Procalcitonin (PCT), a precursor for calcitonin, is a prohormone involved in the inflammatory processes, which has been poorly studied in the context of pregnancy. During severe inflammation, PCT derives from almost all cell types, including monocytes and parenchymal tissues, making it a good predictive and diagnostic marker of an inflammatory state with rapidly increased serum levels in inflammation or sepsis. In normal pregnancy, PCT is basally expressed at very low level by decidual cells, even if decidual macrophages, which in normal pregnancy are skewed to M2 macrophages, are resistant to lipopolysaccharide (LPS)-induced production of PCT. As PCT increase is associated with an inflammatory state, several research groups investigated whether PCT can be considered a marker of pre-eclampsia, a pregnancy disease characterized by systemic inflammation. The first aim of this review is to summarize what is already known about the tissues synthesizing PCT, about the stimuli that cause the increase of circulating PCT levels and how PCT acts as a proinflammatory stimulus by itself. Secondly, we will describe the role of this prohormone in normal pregnancy and in pregnancies complicated by pre-eclampsia, highlighting the involvement of the decidual macrophages and the proinflammatory cytokine tumor necrosis factor-α in the modulation of PCT expression in the decidual microenvironment.

Cough and airway clearance in Duchenne muscular dystrophy.

People with Duchenne muscular dystrophy (DMD), develop a respiratory muscle weakness that results in weakened cough, airway clearance impairment and over time respiratory failure and death. Assessment of cough effectiveness through vital capacity, peak cough flow and maximal inspiratory and expiratory pressures has been used to identify the optimal timing of cough augmentation techniques initiation. The choice of therapies depends on physician knowledge, and patient/care giver abilities. The purpose of this review is to clarify mechanisms of action, benefits and disadvantages of available techniques, such as manual cough-assisting manoeuvres, glossopharyngeal breathing, air stacking by resuscitator bag or by volume-cycle ventilator, and mechanical insufflator-exsufflator. Mechanisms of mucus mobilization, like intrapulmonary percussive ventilation, may have a therapeutic role in the case of persistent atelectasis. It is also crucial to recognize the initial phase of an acute respiratory exacerbation, increase the use of these techniques which may reduce morbidity and mortality.

Current therapeutic paradigm in pediatric atopic dermatitis: Practical guidance from a national expert panel.

INTRODUCTION AND OBJECTIVES: Atopic dermatitis (AD) is the most common cutaneous inflammatory disease in both adults and children. Although emerging therapeutic approaches are being investigated for the management of pediatric AD, it still needs to be managed with conventional treatments. This consensus document is aimed at providing an update on general management and therapies of pediatric AD, defining practical recommendations for using both topical and systemic agents. MATERIAL AND METHODS: A panel of experts consisting of dermatologists and pediatricians were convened in order to define statements, through a Delphi process, standardizing the management of AD in pediatric subjects in a real-world setting. RESULTS: A set of practical recommendations obtaining an at least 75% agreement was presented. CONCLUSIONS: This set of practical recommendations represents a simple and fast snapshot on the pediatric use of common anti-AD therapeutics.

Correction to: Contribution of cryopreservation to the cumulative live birth rate: a large multicentric cycle-based data analysis from the Italian National Registry.

The original article unfortunately contained a mistake. The names of the collaborators were captured as authors of the article.

Contribution of cryopreservation to the cumulative live birth rate: a large multicentric cycle-based data analysis from the Italian National Registry.

PURPOSE: To estimate the contribution of cryopreservation to the cumulative live birth rate (CLBR) after law modification in Italy in the era of vitrification and freeze-all. METHODS: The Italian National Registry performed a cycle-based data collection. Nine Italian IVF clinics were involved incorporating a total of 10,260 fresh cycles performed between January 2015 and April 2016 resulting in 9273 oocyte retrievals and 3266 subsequent warming cycles from the same oocyte retrievals performed up to December 2016. Mean female age was 37 ± 4.3 years. Primary outcome measure was CLBR per oocyte retrieval. Confounding factors were tested in multivariate regression analysis, and the relative impact of cryopreservation to the CLBR in different patient categories was calculated. RESULTS: CLBR per oocyte retrieval was 32.6%, 26.5%, 18.7%, 13.0%, and 5.5% for women younger than 36, aged 36-39, 40-41, and older than 41 years, respectively. The total relative contribution of oocyte/embryo cryopreservation was 40.6% (95% CI 38.41-42.75). An association between maternal age, number of oocytes retrieved, fertilization rate, cryopreservation, and cumulative live birth was shown. When adjusted for confounders, a 2.3-fold increase was observed in the chance of live birth when cryopreservation was performed (OR 2.3; 95% CI 1.99-2.56). In high responder patients (> 15 oocytes retrieved) where freeze-all was applied in 67.6% of cycles to avoid the risk of hyper stimulation syndrome, the relative contribution of vitrification to the CLBR was 80.6%. CONCLUSIONS: Cryopreservation is essential in IVF and should always be available to patients to optimize success rates. Multicentric, cycle-based data analyses are crucial to provide infertile couples, clinicians, and regulatory bodies with accurate information on IVF effectiveness including fresh and cryopreserved cycles.

Diagnostic relevance of IgE sensitization profiles to eight recombinant Phleum pratense molecules.

BACKGROUND: Grass pollen-related seasonal allergic rhinoconjunctivitis (SARg) is clinically heterogeneous in severity, comorbidities, and response to treatment. The component-resolved diagnostics disclosed also a high heterogeneity at molecular level. Our study aimed at analyzing the characteristics of the IgE sensitization to Phleum pratense molecules and investigating the diagnostic relevance of such molecules in childhood. METHODS: We examined 1120 children (age 4-18 years) with SARg. Standardized questionnaires on atopy were acquired through informatics platform (AllergyCARD™). Skin prick tests were performed with pollen extracts. Serum IgE to airborne allergens and eight P. pratense molecules (rPhl p 1, rPhl p 2, rPhl p 4, rPhl p 5b, rPhl p 6, rPhl p 7, rPhl p 11, rPhl p 12) were tested by ImmunoCAP FEIA. RESULTS: The analysis of IgE responses against eight P. pratense molecules showed 87 profiles. According to the number of molecules recognized by IgE, the more complex profiles were characterized by higher serum total IgE, higher grass-specific serum IgE, and higher number and degree of sensitization to pollens. The most frequent IgE sensitization profile was the monomolecular Phl p 1. Sensitization to Phl p 7 was a reliable biomarker of asthma, whereas Phl p 12 of oral allergy syndrome. Sensitization to Phl p 7 was associated with a higher severity of SARg, and complex profiles were associated with longer disease duration. CONCLUSIONS: In a large pediatric population, the complexity of IgE sensitization profiles against P. pratense molecules is related to high atopic features although useless for predicting the clinical severity. The detection of serum IgE to Phl p 1, Phl p 7, and Phl p 12 can be used as clinical biomarkers of SARg and comorbidities. Further studies in different areas are required to test the impact of different IgE molecular profiles on AIT response.

Subclinical vestibular dysfunction in migraineurs without vertigo: A Clinical study.

OBJECTIVES: This observational study aimed to investigate the presence of potential vestibular system subclinical dysfunction among migraineurs without a history of vertigo and dizziness compared with healthy controls. METHODS: Patients diagnosed with episodic migraine with and without aura were enrolled. All patients and healthy controls underwent vestibular examination using the following conventional tests: sitting position, Pagnini-McClure's, Dix-Hallpike's, head hanging, video head impulse, subjective visual vertical, Romberg, Fukuda, and caloric vestibular stimulation by Fitzgerald-Hallpike's tests. Nystagmus and angular velocity of the slow phase during culmination phase was analyzed by video-nystagmography. RESULTS: Overall, 33 patients (76% female, 7 with aura and 26 without aura; mean age (mean ± SD): 29.1 ± 4.3 years) and 22 controls (33% female, mean age: 30.8 ± 9.4 years) were enrolled. There were no statistically significant differences in demographic features between patients and controls. Caloric vestibular stimulation test results were found to differ among patients and controls. In particular, right and left angular velocity (AV) were highly correlated one another (r = 0.88, P < .001). Right AV (53.0 ± 6.7 vs 44.0 ± 9.6) and left AV (54.3 ± 5.3 vs 43.3 ± 9.0) were statistically higher in migraineurs as compared to controls (P < .001). Also right V-HIT (1.1 ± 0.1 vs 0.8 ± 0.4) and left V-HIT (1.1 ± 0.1 vs 0.7 ± 0.2) were statistically higher in migraineurs compared to controls (P < .001). CONCLUSION: Our findings suggest a subclinical alteration of vestibular pathway in migraineurs who have never complained vertigo or postural imbalance. This finding supports the hypothesis of a vestibular-cerebellar dysfunction in migraineurs, particularly among those with aura.

Modelling soil erosion in a Mediterranean watershed: Comparison between SWAT and AnnAGNPS models.

In this study, the simulations generated by two of the most widely used hydrological basin-scale models, the Annualized Agricultural Non-Point Source (AnnAGNPS) and the Soil and Water Assessment Tool (SWAT), were compared in a Mediterranean watershed, the Carapelle (Apulia, Southern Italy). Input data requirements, time and efforts needed for input preparation, strength and weakness points of each model, ease of use and limitations were evaluated in order to give information to users. Models were calibrated and validated at monthly time scale for hydrology and sediment load using a four year period of observations (streamflow and suspended sediment concentrations). In the driest year, the specific sediment load measured at the outlet was 0.89 t ha-1 yr-1, while the simulated values were 0.83 t ha-1 yr-1 and 1.99 t ha-1 yr-1 for SWAT and AnnAGNPS, respectively. In the wettest year, the specific measured sediment load was 7.45 t ha-1 yr-1, and the simulated values were 8.27 t ha-1 yr-1 and 6.23 t ha-1 yr-1 for SWAT and AnnAGNPS, respectively. Both models showed from fair to a very good correlation between observed and simulated streamflow and satisfactory for sediment load. Results showed that most of the basin is under moderate (1.4-10 t ha-1 yr-1) and high-risk erosion (> 10 t ha-1 yr-1). The sediment yield predicted by the SWAT and AnnAGNPS models were compared with estimates of soil erosion simulated by models for Europe (PESERA and RUSLE2015). The average gross erosion estimated by the RUSLE2015 model (12.5 t ha-1 yr-1) resulted comparable with the average specific sediment yield estimated by SWAT (8.8 t ha-1 yr-1) and AnnAGNPS (5.6 t ha-1 yr-1), while it was found that the average soil erosion estimated by PESERA is lower than the other estimates (1.2 t ha-1 yr-1).

Physical exercise and oxidative stress in muscular dystrophies: is there a good balance?

The effect of oxidative stress on muscle damage inducted by physical exercise is widely debated. It is generally agreed that endurance and intense exercise can increase oxidative stress and generate changes in antioxidant power inducing muscle damage; however, regular and moderate exercise can be beneficial for the health improving the antioxidant defense mechanisms in the majority of cases. Growing evidences suggest that an increased oxidative/nitrosative stress is involved in the pathogenesis of several muscular dystrophies (MDs). Notably, physical training has been considered useful for patients with these disorders. This review will focus on the involvement of oxidative stress in MDs and on the possible effects of physical activities to decrease oxidative damage and improve motor functions in MDs patients.

The proposal of a clinical protocol to assess central and peripheral fatigue in myotonic dystrophy type 1.

DM1 is an autosomal-dominant disorder characterized by muscle weakness, myotonia, and multisystemic involvement. According to current literature fatigue and daytime sleepiness are among the main symptoms of DM1. Oxidative stress has been proposed to be one of the pathogenic factors of fatigue consequent to DM1. In this study, we investigated the dimensions of experienced fatigue and  physiological fatigue in a sample of 26 DM1 patients (17 males, 9 females, mean age 41.6 years, SD±12.7); experienced fatigue has been studied through Fatigue Severity Scale (FSS), and physiological fatigue was measured through an intermittent incremental exercise of the forearm muscles using a myometer; oxidative stress balance markers trend during aerobic exercise test have been collected. The occurrence of central fatigue in the sample means that central activation worsens during the motor contraction; interestingly FSS score was significantly correlated to MVC (before and after the effort, r-before=-0.583, p<0.01, r-after= -0.534, p<0.05), and to motor disability measured by MRC (r=-0.496, p<0.05); moreover we found a strong tendency towards significance in the association to lactate baseline (r=0.378, p=0.057).Results are discussed to define whether or not, based on clinical and laboratory grounds, such exercise training protocol may be suitable for proper management of DM1 patients; proper assessment of fatigue should be included in algorithms for data collection in DM1 patient registries.