Two-spin entanglement distribution near factorized states

We study the two-spin entanglement distribution along the infinite $S=1/2$ chain described by the XY model in a transverse field; closed analytical expressions are derived for the one-tangle and the concurrences $C_r$, $r$ being the distance between the two possibly entangled spins, for values of the Hamiltonian parameters close to those corresponding to factorized ground states. The total amount of entanglement, the fraction of such entanglement which is stored in pairwise entanglement, and the way such fraction distributes along the chain is discussed, with attention focused on the dependence on the anisotropy of the exchange interaction. Near factorization a characteristic length-scale naturally emerges in the system, which is specifically related with entanglement properties and diverges at the critical point of the fully isotropic model. In general, we find that anisotropy rule a complex behavior of the entanglement properties, which results in the fact that more isotropic models, despite being characterized by a larger amount of total entanglement, present a smaller fraction of pairwise entanglement: the latter, in turn, is more evenly distributed along the chain, to the extent that, in the fully isotropic model at the critical field, the concurrences do not depend on $r$.Comment: 14 pages, 6 figures. Final versio

Exhaustive CoMFA and CoMSIA analyses around different chemical entities: a ligand-based study exploring the affinity and selectivity profiles of 5-HT1A ligands

The 5-hydroxytryptamine (5-HT1A) receptors represent an attractive target in drug discovery. In particular, 5-HT1A agonists and partial agonists are deeply investigated for their potential role in the treatment of anxiety, depression, ischaemic brain disorder and more recently, of pain. On the other hand, 5-HT1A antagonists have been revealed promising compounds in cognition disorders and, lately, in cancer. Thus, the discovery of 5HT1A ligands is nowadays an appealing research activity in medicinal chemistry. In this work, Comparative Molecular Fields Analysis (CoMFA) and Comparative Molecular Similarity Index Analysis (CoMSIA) were applied on an in-house library of 5-HT1A ligands bearing different chemical scaffolds in order to elucidate their affinity and selectivity for the target. Following this procedure, a number of structural modifications have been drawn for the development of much more effective 5-HT1AR ligands

Obesity and Thyroid Cancer Risk: An Update

Thyroid cancer (TC) is the most common endocrine malignancy worldwide and its incidence has increased dramatically in recent years. In parallel, the prevalence of overweight and obesity has also increased, suggesting a possible link between these two diseases. Indeed, low-grade chronic inflammation, altered cytokine levels, insulin resistance, oxidative stress, and hormonal changes that occur in obese patients are all factors that contribute to the occurrence and growth of TC. In this review, the most recent evidence supporting the potential role of the mechanisms linking obesity to TC will be discusse

Association between Dietary Habits and Severity of Symptoms in Premenstrual Syndrome

Background. Premenstrual syndrome (PMS) is a set of physical, psychological, and emotional symptoms that occur during the luteal phase of the menstrual cycle. The etiopathogenesis of this condition is not fully understood, and several studies suggest a possible role of environmental factors, such as diet. The aim of this work was to investigate the relationship between dietary habits and the occurrence and severity of PMS. Methods and Results. Forty-seven women were enrolled in the study. Participants were asked to complete the Daily Record of Severity of Problems (DRSP) to diagnose PMS and to complete a three-day food record during the perimenstrual phase. Thirty women completed the study (16 with PMS and 14 controls). An analysis of the food diaries revealed no differences between the women with PMS and the control subjects in terms of total energy intake (1649 vs. 1570 kcal/day), diet composition, and the consumption of macro- or micronutrients, except for copper, whose consumption was higher in women with PMS than in the control subjects (1.27 ± 0.51 vs. 0.94 ± 0.49 mg/d, p < 0.05). Conclusions. The data presented here are very preliminary, and only a significant difference in copper intake was found when comparing women with PMS and controls. Larger studies are needed to better define how diet may contribute to the exacerbation of the psychological and somatic symptoms associated with PMS and whether PMS itself may influence macro- or micronutrient intake by changing dietary habits

Lack of cross-reactivity between anti-A IgG isoagglutinins and anti-SARS-CoV-2 IgG antibodies

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Model-Based Underwater 6D Pose Estimation from RGB

Object pose estimation underwater allows an autonomous system to perform tracking and intervention tasks. Nonetheless, underwater target pose estimation is remarkably challenging due to, among many factors, limited visibility, light scattering, cluttered environments, and constantly varying water conditions. An approach is to employ sonar or laser sensing to acquire 3D data, but besides being costly, the resulting data is normally noisy. For this reason, the community has focused on extracting pose estimates from RGB input. However, the literature is scarce and exhibits low detection accuracy. In this work, we propose an approach consisting of a 2D object detection and a 6D pose estimation that reliably obtains object poses in different underwater scenarios. To test our pipeline, we collect and make available a dataset of 4 objects in 10 different real scenes with annotations for object detection and pose estimation. We test our proposal in real and synthetic settings and compare its performance with similar end-to-end methodologies for 6D object pose estimation. Our dataset contains some challenging objects with symmetrical shapes and poor texture. Regardless of such object characteristics, our proposed method outperforms stat-of-the-art pose accuracy by ~8%. We finally demonstrate the reliability of our pose estimation pipeline by doing experiments with an underwater manipulation in a reaching task.Comment: Under RA-L Submissio

MRE11 inhibition highlights a replication stress-dependent vulnerability of MYCN-driven tumors

MRE11 is a component of the MRE11/RAD50/NBS1 (MRN) complex, whose activity is essential to control faithful DNA replication and to prevent accumulation of deleterious DNA double-strand breaks. In humans, hypomorphic mutations in these genes lead to DNA damage response (DDR)-defective and cancer-prone syndromes. Moreover, MRN complex dysfunction dramatically affects the nervous system, where MRE11 is required to restrain MYCN-dependent replication stress, during the rapid expansion of progenitor cells. MYCN activation, often due to genetic amplification, represents the driving oncogenic event for a number of human tumors, conferring bad prognosis and predicting very poor responses even to the most aggressive therapeutic protocols. This is prototypically exemplified by neuroblastoma, where MYCN amplification occurs in about 25% of the cases. Intriguingly, MRE11 is highly expressed and predicts bad prognosis in MYCN-amplified neuroblastoma. Due to the lack of direct means to target MYCN, we explored the possibility to trigger intolerable levels of replication stress-dependent DNA damage, by inhibiting MRE11 in MYCN-amplified preclinical models. Indeed, either MRE11 knockdown or its pharmacological inhibitor mirin induce accumulation of replication stress and DNA damage biomarkers in MYCN-amplified cells. The consequent DDR recruits p53 and promotes a p53-dependent cell death, as indicated by p53 loss- and gain-of-function experiments. Encapsulation of mirin in nanoparticles allowed its use on MYCN-amplified neuroblastoma xenografts in vivo, which resulted in a sharp impairment of tumor growth, associated with DDR activation, p53 accumulation, and cell death. Therefore, we propose that MRE11 inhibition might be an effective strategy to treat MYCN-amplified and p53 wild-type neuroblastoma, and suggest that targeting replication stress with appropriate tools should be further exploited to tackle MYCN-driven tumors

Fluorometric detection of protein-ligand engagement: The case of phosphodiesterase5

Phosphodiesterases (PDEs) regulate the intracellular levels of cAMP and cGMP. The great clinical success of the PDE5 inhibitors, Sildenafil (Viagra), Vardenafil (Levitra) and Tadalafil (Cialis) has led to an increasing interest for this class of enzymes. Recent studies have shown a correlation between tumor growth and PDE5 overexpression, making PDE5-selective inhibitors promising candidates for cancer treatment. The search for such inhibitors rests today on radioactive assays. In this work, we exploit the conserved catalytic domain of the enzyme and propose a faster and safer method for detecting the binding of ligands and evaluate their affinities. The new approach takes advantage of Förster Resonance Energy Transfer (FRET) between, as the donor, a fluorescein-like diarsenical probe able to covalently bind a tetracysteine motif fused to the recombinant PDE5 catalytic domain and, as the acceptor, a rhodamine probe covalently bound to the pseudosubstrate cGMPS. The FRET efficiency decreases when a competitive ligand binds the PDE5 catalytic site and displaces the cGMPS-rhodamine conjugate. We have structurally investigated the PDE5/cGMPS-rhodamine complex by molecular modelling and have used the FRET signal to quantitatively characterize its binding equilibrium. Competitive displacement experiments were carried out with tadalafil and cGMPS. An adaptation of the competitive-displacement equilibrium model yielded the affinities for PDE5 of the incoming ligands, nano- and micromolar, respectively

Human papillomavirus infection and risk factors in a cohort of Tuscan women aged 18-24: results at recruitment

<p>Abstract</p> <p>Background</p> <p>There is conclusive evidence that human papillomavirus (HPV) infections of the cervix are a necessary cause of cervical cancer. In Italy there are consistent data of HPV prevalence in women aged 25 - 64 years, but there is limited data for younger women. The objective of this on-going 3-year prospective cohort study is to investigate the prevalence, acquisition, clearance and persistence of HPV infections in young Tuscan women and the risk factors correlated with such events.</p> <p>Methods</p> <p>One thousand and sixty-six women aged between 18 and 24 years were enrolled and received an initial HPV test. They were asked to return to the clinic over the study period for further tests every 12 months, if their HPV HR result was negative, or every 6 months, if positive. Additionally, women with an HPV positive result were given a cytological examination and if the cytological diagnosis was ASC-US or more severe, only women with HPV HR, were referred for colposcopy.</p> <p>Results</p> <p>We present here data for the enrolment phase of the study. At baseline, within the study sample, just under 30% of women were infected by HPV and 19.3% of women were infected with oncogenic types. A relationship was highlighted between HPV infection, number of sexual partners (in particularly in the last 3 years) and the lifetime number of partner's partners. Condom use showed a slight protective effect in univariate analysis but these data were not statistically significant in multivariate analysis. The association between HPV infection and demographic and behavioural variables were tested by crude odds ratio (OR). Multivariate logistic regression was applied to compute the adjusted odds ratios.</p> <p>Conclusions</p> <p>The prevalence of oncogenic HPV types was high in young Tuscan women. The 3-year follow-up of this cohort may provide a better understanding of the processes of acquisition, clearance and persistence of infection and the correlated risk factors.</p