Enhancing Dark Matter Annihilation into Neutrinos

We perform a detailed and quasi model-independent analysis of direct annihilation of Dark Matter into neutrinos. Considering different cases for scalar and fermionic Dark Matter, we identify several settings in which this annihilation is enhanced, contrary to some statements in the literature. They key point is that several restrictions of, e.g., a supersymmetric framework do not hold in general. The mass generation mechanism of the neutrinos plays an important role, too. We illustrate our considerations by two examples that are not (as usually) suppressed by the smallness of the neutrino mass, for which we also present a numerical analysis. Our results can be easily used as guidelines for model building.Comment: 33 pages, 2 figure

Statistical tests of sterile neutrinos using cosmology and short-baseline data

In this paper we revisit the question of the information which cosmology provides on the scenarios with sterile neutrinos invoked to describe the SBL anomalies using Bayesian statistical tests. We perform an analysis of the cosmological data in $\Lambda$CDM$+r+\nu_s$ cosmologies for different cosmological data combinations, and obtain the marginalized cosmological likelihood in terms of the two relevant parameters, the sterile neutrino mass $m_s$ and its contribution to the energy density of the early Universe $N_{\rm eff}$. We then present an analysis to quantify at which level a model with one sterile neutrino is (dis)favoured with respect to a model with only three active neutrinos, using results from both short-baseline experiments and cosmology. We study the dependence of the results on the cosmological data considered, in particular on the inclusion of the recent BICEP2 results and the SZ cluster data from the Planck mission. We find that only when the cluster data is included the model with one extra sterile neutrino can become more favoured that the model with only the three active ones provided the sterile neutrino contribution to radiation density is suppressed with respect to the fully thermalized scenario. We have also quantified the level of (in)compatibility between the sterile neutrino masses implied by the cosmological and SBL results.Comment: 23 pages, 4 figure

Merging Natural Products: Muraymycin-Sansanmycin Hybrid Structures as Novel Scaffolds for Potential Antibacterial Agents

To overcome bacterial resistances, the need for novel antimicrobial agents is urgent. The class of so‐called nucleoside antibiotics furnishes promising candidates for the development of new antibiotics, as these compounds block a clinically unexploited bacterial target: the integral membrane protein MraY, a key enzyme in cell wall (peptidoglycan) biosynthesis. Nucleoside antibiotics exhibit remarkable structural diversity besides their uridine‐derived core motifs. Some sub‐classes also show specific selectivities towards different Gram‐positive and Gram‐negative bacteria, which are poorly understood so far. Herein, the synthesis of a novel hybrid structure is reported, derived from the 5′‐defunctionalized uridine core moiety of muraymycins and the peptide chain of sansanmycin B, as a new scaffold for the development of antimicrobial agents. The reported muraymycin–sansanmycin hybrid scaffold showed nanomolar activity against the bacterial target enzyme MraY, but displayed no significant antibacterial activity against S. aureus, E. coli, and P. aeruginosa

Fitas comestíveis de banana como veículos para probióticos.

Orientadora Profa. Dra. Henriette Monteiro Cordeiro de Azered

Efficacy of Intravitreal dexamethasone implant in different patterns of diabetic macular edema

Purpose: Different patterns of diabetic macular edema (DME) suggest different pathogenesis and drug response. We evaluated the outcomes after intravitreal dexamethasone (DEX) implant for DME with or without serous retinal detachment (SRD). Methods: In this retrospective study, 22 naïve patients (23 eyes) with DME who underwent a single DEX implant were evaluated. Based on the optical coherence tomographic pattern of DME, 12 eyes had a cystoid macular edema pattern (Group 1) and 11 eyes had an SRD pattern (Group 2). The best-corrected visual acuity (BCVA), central retinal thickness (R), central retinal volume (CRV), SRD height (SRDh), and intraocular pressure (IOP) were recorded before and at two and four months after the treatment. Results: There were no significant differences between the groups regarding demographic, clinical data and outcomes at baseline. In Group 1, the CRT and CRV significantly decreased at two months (P = 0.002 and P = 0.01, respectively), while the BCVA significantly improved at four months (P = 0.03). In Group 2, the CRT and CRV significantly improved (P < 0.01 and P ≤ 0.01, respectively) during the follow-up period. At four months, both groups showed a recurrence of DME, Group 1 in particular (two-month CRT reduction, -149 ± 127 μm vs four-month CRT reduction, -72 ± 174 μm; P = 0.04). The mean reduction in CRV was significantly different at four months (Group 1, -0.49 ± 1.7 mm3vs Group 2, -1.3 ± 1.3 mm3; P = 0.04). In Group 2, the SRDh significantly decreased at two (P = 0.01) and four months (P = 0.01). Four cases with elevated IOP were managed. Conclusion: DEX implants were found to be effective in different patterns of DME. The SRD pattern may predict a longer-lasting morphologic efficacy

Muraymycin Nucleoside Antibiotics: Structure-Activity Relationship for Variations in the Nucleoside Unit

Muraymycins are a subclass of naturally occurring nucleoside antibiotics with promising antibacterial activity. They inhibit the bacterial enzyme translocase I (MraY), a clinically yet unexploited target mediating an essential intracellular step of bacterial peptidoglycan biosynthesis. Several structurally simplified muraymycin analogues have already been synthesized for structure–activity relationship (SAR) studies. We now report on novel derivatives with unprecedented variations in the nucleoside unit. For the synthesis of these new muraymycin analogues, we employed a bipartite approach facilitating the introduction of different nucleosyl amino acid motifs. This also included thymidine- and 5-fluorouridine-derived nucleoside core structures. Using an in vitro assay for MraY activity, it was found that the introduction of substituents in the 5-position of the pyrimidine nucleobase led to a significant loss of inhibitory activity towards MraY. The loss of nucleobase aromaticity (by reduction of the uracil C5-C6 double bond) resulted in a ca. tenfold decrease in inhibitory potency. In contrast, removal of the 20 -hydroxy group furnished retained activity, thus demonstrating that modifications of the ribose moiety might be well-tolerated. Overall, these new SAR insights will guide the future design of novel muraymycin analogues for their potential development towards antibacterial drug candidates

Visual functional changes after ocriplasmin injection for vitreomacular traction: A microperimetric analysis

PURPOSE: The purpose is to evaluate functional changes after ocriplasmin injection to treat vitreomacular traction (VMT) by microperimetry. MATERIALS AND METHODS: Prospective interventional study on patients underwent an intravitreal ocriplasmin injection. Optical coherence tomography, best-corrected visual acuity (BCVA) test, and microperimetry were performed at baseline, 1 week, 1 and 3 months. Microperimeter recorded retinal sensitivity (RS) and central retinal sensitivity (CRS) at central 12° and 4°, respectively, and fixation as bivariate contour ellipse area (BCEA) at 68%, 95%, and 99% of fixation points. Functional parameters were analyzed in patients who had (Group A) or not (Group B) VMT release. RESULTS: Twenty-one patients including 18 with VMT and 3 with VMT plus macular hole (MH) were treated. Eleven patients achieved VMT resolution including all cases with MH that achieved hole closure. An impairment of BCVA, RS and CRS (P < 0.01; P < 0.001; P = 0.001, respectively) was reported at 1 week followed by a significant improvement (BCVA, P = 0.001; RS, CRS, P = 0.02) at 3 months. The early impairment of visual acuity and sensitivity significantly occurred in Group B (P ≤ 0.01) while their recovery significantly occurred in Group A (P < 0.01). BCEA significantly increased in dimension (68%, P = 0.01; 95%, P = 0.03) at 1 week, subsequently returning to near baseline values over follow-up. Only in Group A, fixation stability significantly improved at 3 months. CONCLUSION: Microperimetry confirms an early and reversible functional impairment after ocriplasmin injection regardless VMT resolution. If a greater decrease in function could occur in the eyes without VMT resolution, a better functional recovery could occur in the event of VMT resolution

Eye-related emergencies incidence at a tertiary referral center in Southern Italy during COVID-19 related lockdown

Background: In order to contain the community spread of coronavirus disease (COVID-19) in Italy, a stringent lockdown was imposed, which also impacted the healthcare services. The purpose of this study is to investigate the drop in the number of outpatients in the Ophthalmic Emergency Service (OES) in the Eye Clinic of University of Bari during the COVID-19 lockdown. Methods: A retrospective analysis of electronic medical records from a tertiary referral center in Southern Italy was performed. Demographics and medical characteristics of patients examined in the OES between March 10th, 2020 and May 3rd, 2020 were assessed and compared with records from the same period in 2019. We categorized the patients by sex, age group, and by the type of eye disease that was recorded as the principal diagnosis. The change (%) in the number of patients and diseases between the study periods was analyzed. Results: We observed a reduction in the number of OES visits during the lockdown (-63.4%) compared to the number of visits in 2019. The greatest changes were observed in the youngest (≤20 years; -76.6%) and the most elderly patients (≥81 years; -70.9%). The decrease in the number of patients presenting with each pathology ranged from -82% to -28.5%, depending on the pathology, and mainly involved the orbital and palpebral pathologies, anterior segment disorders, non-specific visual symptoms, and minor injuries. The diagnosis of chronic pathologies, rhegmatogenous retinal detachment, and vitreous haemorrhage increased by 134%, 100%, and 75%, respectively. Conclusions: Our results revealed the impact of the COVID-19 lockdown on OES activities in the Eye Clinic of University of Bari. A drop in number of visits across all age groups was observed. The number of patients presenting with minor and nonurgent conditions decreased, whereas the number of patients presenting with chronic diseases and urgent but deferrable conditions increased

Comparison of perioperative parameters in one-handed rotational phacoemulsification versus conventional phacoemulsification and femtosecond laser-assisted cataract surgery

AIM: To compare perioperative parameters of one-handed rotational phacoemulsification technique (one-handed phaco-roll) with each of other two techniques, “Divide et Conquer” and femtosecond laser-assisted cataract surgery (FLACS) METHODS: In this retrospective and comparative cohort study, eyes with uncomplicated cataract (nuclear density grade 2 to 3) treated routinely with one-handed phaco-roll (n=23; Group 1) or “Divide et Conquer” (n=23; Group 2) or FLACS (n=23; Group 3) were enrolled. Intraoperative parameters including effective phaco-time (EPt), ultrasound time (USt), aspiration time, surgical time, phacoemulsification (phaco)-power, balanced salt solution (BSS) use, cumulative dissipated energy (CDE) were recorded and compared. Clinical outcomes including best corrected visual acuity (BCVA), corneal endothelial cell density (ECD), endothelial cell loss (ECL), central corneal thickness (CCT) and central macular thickness (CMT), were assessed and compared pre-operatively and at 1mo after surgery. RESULTS: Aspiration and surgical time, and BSS used were lower in Group 1 (P<0.01) than other groups. EPt, phaco-power and CDE were lower in Group 1 (P<0.05) than Group 2 but not significantly different from Group 3. In Group 1, USt was lower (P<0.05) than Group 2 but higher (P<0.05) than Group 3. BCVA improved in all groups without significant difference between Group 1 and the other ones. No significant differences regarding all post-operative morphologic outcomes (ECD, ECL, CCT, CMT) were reported. No clinical complications occurred. CONCLUSION: One-handed phaco-roll seems to be less time-consuming than “Divide et Conquer” and FLACS and less energy-consuming than “Divide et Conquer”. Furthermore, one-handed phaco-roll seems to have an equal safety profile compared to the other two techniques