1,400 research outputs found

    Renormalized Electron Mass in Nonrelativistic QED

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    Within the framework of nonrelativistic QED, we prove that, for small values of the coupling constant, the energy function, E_|P|, of a dressed electron is twice differentiable in the momentum P in a neighborhood of P = 0. Furthermore, (E_|P|)" is bounded from below by a constant larger than zero. Our results are proven with the help of iterative analytic perturbation theory

    Invariant NKT cells and rheumatic disease: Focus on primary sjogren syndrome

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    Primary Sjogren syndrome (pSS) is a complex autoimmune disease mainly affecting salivary and lacrimal glands. Several factors contribute to pSS pathogenesis; in particular, innate immunity seems to play a key role in disease etiology. Invariant natural killer (NK) T cells (iNKT) are a T-cell subset able to recognize glycolipid antigens. Their function remains unclear, but studies have pointed out their ability to modulate the immune system through the promotion of specific cytokine milieu. In this review, we discussed the possible role of iNKT in pSS development, as well as their implications as future markers of disease activity

    Widening use of dexamethasone implant for the treatment of macular edema

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    Sustained-release intravitreal 0.7 mg dexamethasone (DEX) implant is approved in Europe for the treatment of macular edema related to diabetic retinopathy, branch retinal vein occlusion, central retinal vein occlusion, and non-infectious uveitis. The implant is formulated in a biodegradable copolymer to release the active ingredient within the vitreous chamber for up to 6 months after an intravitreal injection, allowing a prolonged interval of efficacy between injections with a good safety profile. Various other ocular pathologies with inflammatory etio­pathogeneses associated with macular edema have been treated by DEX implant, including neovascular age-related macular degeneration, Irvine–Gass syndrome, vasoproliferative retinal tumors, retinal telangiectasia, Coats’ disease, radiation maculopathy, retinitis pigmentosa, and macular edema secondary to scleral buckling and pars plana vitrectomy. We undertook a review to provide a comprehensive collection of all of the diseases that benefit from the use of the sustained-release DEX implant, alone or in combination with concomitant therapies. A MEDLINE search revealed lack of randomized controlled trials related to these indications. Therefore we included and analyzed all available studies (retrospective and prospective, com­parative and non-comparative, randomized and nonrandomized, single center and multicenter, and case report). There are reports in the literature of the use of DEX implant across a range of macular edema-related pathologies, with their clinical experience supporting the use of DEX implant on a case-by-case basis with the aim of improving patient outcomes in many macular pathologies. As many of the reported macular pathologies are difficult to treat, a new treat­ment option that has a beneficial influence on the clinical course of the disease may be useful in clinical practice

    Absence of Ground States for a Class of Translation Invariant Models of Non-relativistic QED

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    We consider a class of translation invariant models of non-relativistic QED with net charge. Under certain natural assumptions we prove that ground states do not exist in the Fock space

    Indagini briologiche in aree urbane: diversitĂ  briofitica dei centri abitati di Erice (Trapani) e Belmonte Mezzagno (Palermo).

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    Bryologic surveys in urban areas: bryophyte diversity of the population centers of Erice (province of Trapani) and Belmonte Mezzagno ((province of Palermo). The bryophytic flora of the towns of Erice (Trapani) and Belmonte Mezzagno (Palermo) have been studied. The first consists of 53 taxa (42 mosses and 11 liverwort), two of which are new for the province of Trapani, the second of 40 taxa (38 mosses and 2 liverworts), one of which new for the province of Palermo. A comparison between the studied bryofloras and those of other Sicilian urban areas shows that Erice’s bryophytic flora is, given its size, rich in species and families

    Evaluation of the burden of HPV-related hospitalizations as a useful tool to increase awareness: 2007–2017 data from the sicilian hospital discharge records

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    In light of the implementation of human papillomavirus (HPV) prevention strategies, epidemiological studies in different geographical areas are required in order to assess the impact of HPV-related diseases. The purpose of the present study was to describe the burden of HPV-related hospitalizations in Sicily. A retrospective observational study estimated 43,531 hospitalizations attributable to HPV from 2007 to 2017. During the observed period, there was a decrease for all HPV-related conditions with a higher reduction, among neoplasms, for cervical cancer (annual percent change (APC) = −9.9%, p < 0.001). The median age for cervical cancer was 45 years old, with an increasing value from 43 to 47 years (p < 0.001). The age classes with greater decreases in hospital admissions for invasive cancers were women aged 35 years or more (APC range from −5.5 to −9.86) and 25–34 years old (APC = −11.87, p < 0.001) for women with cervical carcinoma in situ. After ten years for vaccine introduction and sixteen years for cervical cancer screening availability, a relatively large decrease in hospital admissions for cervical cancer and other HPV-related diseases in Sicily was observed. Some clinical characteristics of hospitalization, such as increasing age, are suggestive clues for the impact of preventive strategies, but further research is needed to confirm this relationship

    Synthesis and Antibacterial Activity of Mono- and Bi-Cationic Pyridinium 1,2,4-Oxadiazoles and Triazoles

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    One of the main causes of mortality in humans continues to be infectious diseases. Scientists are searching for new alternatives due to the fast increase in resistance of some harmful bacteria to the frontline antibiotics. To effectively treat pathogenic infections, it is crucial to design antibiotics that can prevent the development of pathogenic resistance. For this purpose, a set of 39 quaternary pyridinium and bis-pyridinium salts with different lengths of side alkyl or fluorinated chains, heterocyclic spacers, and counter ions were tested on diverse reference bacterial ATCC (American Type Culture Collection) strains, such as S. aureus and E. coli. Subsequently, 6 out of the 39 pyridinium salts showing relevant MIC (Minimum Inhibitory Concentration) values were tested on clinically isolated, resistant strains of S. aureus, S. epidermids, S. haemolyticus, K. pneumoniae, A. baumannii, and P. aeruginosa. Additional tests have been performed to assess if the minimum concentration detected through MIC assay may limit the growth of biofilms

    Preoperative, intraoperative and postoperative corticosteroid use as an adjunctive treatment for rhegmatogenous retinal detachment

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    The treatment for rhegmatogenous retinal detachment (RRD) is surgery, including pars plana vitrectomy (PPV) and scleral buckling (SB). Despite surgical advances, degeneration of the photoreceptors and post-operative complications, such as proliferative vitreoretinopathy (PVR), often occurs as the result of inflammation, preventing complete visual recovery or causing RRD recurrence. There is increasing evidence that in the presence of RRD, the activation of inflammatory processes occurs and the surgery itself induces an inflammatory response. This comprehensive review focuses on the use of different formulations of corticosteroids (CCS), as an adjunctive treatment to surgery, either PPV or SB, for RRD repair. The purpose was to review the efficacy and safety of CCS in improving functional and anatomical outcomes and in preventing postoperative complications. This review is organized according to the timing of CCS administration: preoperative, intraoperative, and postoperative. The evidence reviewed supported the role of the pre-operative use of CCS in the treatment of combined RRD and choroidal detachment (CD), reducing CD height. No solid consensus exists on intraoperative and postoperative use of CCS to treat and prevent postoperative complications. However, a large randomized clinical trial including more than 200 eyes suggested that oral prednisone after surgery decreases the rate of postoperative grade B PVR

    Cluster magnetic fields through the study of polarized radio halos in the SKA era

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    Galaxy clusters are unique laboratories to investigate turbulent fluid motions and large scale magnetic fields. Synchrotron radio halos at the center of merging galaxy clusters provide the most spectacular and direct evidence of the presence of relativistic particles and magnetic fields associated with the intracluster medium. The study of polarized emission from radio halos is extremely important to constrain the properties of intracluster magnetic fields and the physics of the acceleration and transport of the relativistic particles. However, detecting this polarized signal is a very hard task with the current radio facilities.We use cosmological magneto-hydrodynamical simulations to predict the expected polarized surface brightness of radio halos at 1.4 GHz. We compare these expectations with the sensitivity and the resolution reachable with the SKA1. This allows us to evaluate the potential for studying intracluster magnetic fields in the surveys planned for SKA1.Comment: 11 pages, 4 figures; to appear as part of 'Cosmic Magnetism' in Proceedings 'Advancing Astrophysics with the SKA (AASKA14)', PoS(AASKA14)10
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