Static quantum corrections to the Schwarzschild spacetime

We study static quantum corrections of the Schwarzschild metric in the Boulware vacuum state. Due to the absence of a complete analytic expression for the full semiclassical Einstein equations we approach the problem by considering the s-wave approximation and solve numerically the associated backreaction equations. The solution, including quantum effects due to pure vacuum polarization, is similar to the classical Schwarzschild solution up to the vicinity of the classical horizon. However, the radial function has a minimum at a time-like surface close to the location of the classical event horizon. There the g_{00} component of the metric reaches a very small but non-zero value. The analysis unravels how a curvature singularity emerges beyond this bouncing point. We briefly discuss the physical consequences of these results by extrapolating them to a dynamical collapsing scenario.Comment: 10 pages; Talk given at QG05, Cala Gonone (Italy), September 200

Semiclassical zero-temperature corrections to Schwarzschild spacetime and holography

Motivated by the quest for black holes in AdS braneworlds, and in particular by the holographic conjecture relating 5D classical bulk solutions with 4D quantum corrected ones, we numerically solve the semiclassical Einstein equations (backreaction equations) with matter fields in the (zero temperature) Boulware vacuum state. In the absence of an exact analytical expression for in four dimensions we work within the s-wave approximation. Our results show that the quantum corrected solution is very similar to Schwarzschild till very close to the horizon, but then a bouncing surface for the radial function appears which prevents the formation of an event horizon. We also analyze the behavior of the geometry beyond the bounce, where a curvature singularity arises. In the dual theory, this indicates that the corresponding 5D static classical braneworld solution is not a black hole but rather a naked singularity.Comment: 26 pages, 4 figures; revised version (title changed, conclusions shortened), published as Phys. Rev. D73, 104023 (2006

Particles and energy fluxes from a CFT perspective

We analyze the creation of particles in two dimensions under the action of conformal transformations. We focus our attention on Mobius transformations and compare the usual approach, based on the Bogolubov coefficients, with an alternative but equivalent viewpoint based on correlation functions. In the latter approach the absence of particle production under full Mobius transformations is manifest. Moreover, we give examples, using the moving-mirror analogy, to illustrate the close relation between the production of quanta and energy.Comment: Revised version. To appear in Phys.Rev.

Microarray sub-grid detection: A novel algorithm

This is the post print version of the article. The official published version can be obtained from the link below - Copyright 2007 Taylor & Francis LtdA novel algorithm for detecting microarray subgrids is proposed. The only input to the algorithm is the raw microarray image, which can be of any resolution, and the subgrid detection is performed with no prior assumptions. The algorithm consists of a series of methods of spot shape detection, spot filtering, spot spacing estimation, and subgrid shape detection. It is shown to be able to divide images of varying quality into subgrid regions with no manual interaction. The algorithm is robust against high levels of noise and high percentages of poorly expressed or missing spots. In addition, it is proved to be effective in locating regular groupings of primitives in a set of non-microarray images, suggesting potential application in the general area of image processing

Workaholism, intensive smartphone use, and the sleep-wake cycle: A multiple mediation analysis

Recent contributions have reported sleep disorders as one of the health impairment outcomes of workaholism. A possible factor affecting the sleep-wake cycle might be the intensive use of smartphones. The current study aimed to explore the role of intensive smartphone use in the relationship between workaholism and the sleep-wake cycle. Two serial multiple mediation models were tested on a sample of 418 employees, who filled self-report questionnaires measuring workaholism, use of smartphones, sleep quality and daytime sleepiness, using conditional process analysis for testing direct and indirect effects. Results supported our hypotheses regarding two serial multiple mediation models-that intensive smartphone use and poor sleep quality mediated the relationship between workaholism and daytime sleepiness, and that smartphone use and daytime sleepiness mediated the relationship between workaholism and poor quality of sleep. Although the use of a cross-sectional design and the snowball technique for collecting data can be considered as possible limitations, the current study is one of the first to document the potential detrimental role of the intensive smartphone use on the workaholism-sleep disorders relationship

Engagement of the Mannose Receptor by Tumoral Mucins Activates an Immune Suppressive Phenotype in Human Tumor-Associated Macrophages

Tumor-Associated Macrophages (TAMs) are abundantly present in the stroma of solid tumors and modulate several important biological processes, such as neoangiogenesis, cancer cell proliferation and invasion, and suppression of adaptive immune responses. Myeloid C-type lectin receptors (CLRs) constitute a large family of transmembrane carbohydrate-binding receptors that recognize pathogens as well as endogenous glycoproteins. Several lines of evidence demonstrate that some CLRs can inhibit the immune response. In this study we investigated TAM-associated molecules potentially involved in their immune suppressive activity. We found that TAMs isolated from human ovarian carcinoma samples predominantly express the CLRs Dectin-1, MDL-1, MGL, DCIR, and most abundantly the Mannose Receptor (MR). Components of carcinomatous ascites and purified tumoral mucins (CA125 and TAG-72) bound the MR and induced its internalization. MR engagement by tumoral mucins and by an agonist anti-MR antibody modulated cytokine production by TAM toward an immune-suppressive profile: increase of IL-10, absence of IL-12, and decrease of the Th1-attracting chemokine CCL3. This study highlights that tumoral mucin-mediated ligation of the MR on infiltrating TAM may contribute to their immune suppressive phenotype

Late Epiphrenic-Retroperitoneal Fistula of an Esophageal Diverticulum Ten Years after Surgical Excision: Report of the First Case

Background: Esophageal fistula is a rare complication of an epiphrenic diverticulum and represents a difficult diagnostic challenge. In the majority of cases in the English literature, the fistula is secondary to the spontaneous perforation of the epiphrenic diverticulum and in only one case an esophagobronchial fistula occurs after resection of an epiphrenic diverticulum. No case of esophageal fistula communicating with the retroperitoneum tissues was found. Case Report: We present a case of 84 years old male admitted in 2017 in our Hospital for the appearance of epigastralgia and cough with traces of blood to sputum, asthenia and night sweats. Ten years before he underwent to a hiatal hernia plastic sec. Nissen and subsequently was reoperated for exeresis of diverticulum of the distal third of the esophagus by thoracotomy. In August 2008, because of esophageal substenosis an operation of posterior gastropexy sec. Hill with the demolition of the previous hiatoplasty was performed. In 2017, a computerized tomography shows a voluminous abscess in the right paravertebral region with development along the muscular plane of the ipsilateral psoas and a fistular path of about 4 cm between the posterior wall of the esophagus and the retroperitoneal collection of the abdomen. Conclusions: Esophageal fistula represents a complex problem of epiphrenic diverticulum and rarely a hidden complication of surgery. Surgery is the treatment of choice in suitable patients

Micro-Fragmented Adipose Tissue: A New Minimally Invasive Method for Treatment of Anal Fistula? A Pilot Study

The treatment of Anal fistula continues to be one of the most challenging clinical problems in anorectal surgery. Many sphincter-preserving procedures for the treatment of anal fistula have been recently introduced with the common goal of minimising the injury to the anal sphincters and preserving optimal function. Micro-fragmented adipose tissue injection associated closure of the internal opening with Lipogems® technique is one of them. The properties of autologous adipose-derived stem cells for regenerating tissues and suppressing inflammatory response must be better investigated on anal fistulae, and studies remain in progress. The aim of the present article is to evaluate the safety and efficacy of autologous, micro-fragmented and minimally manipulated adipose tissue injection associated with closure of the internal opening in promoting anal fistula healing

Sustainable PHBV/CuS Composite Obtained from Waste Valorization for Wastewater Purification by Visible Light-Activated Photocatalytic Activity

The persistency of antimicrobial compounds in the water cycle accelerates the issue of antimicrobial resistance. Therefore, effective wastewater remediation approaches, which can be implemented on a large scale, are urgently required. This study aims at preparing a sustainable organic/inorganic composite material that can photo-catalyze the degradation of organic pollutants in wastewater by using visible light. Specifically, films and porous composites are composed of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) as supporting material, and copper sulfide (CuS) as active photocatalyst. It is noteworthy that the proposed composite can be fully produced from waste valorization, since PHBV is a polymer, which can be obtained by fermentation of vegetable wastes, and CuS is synthesized from industrial sulfur wastes. The produced composites show remarkable capabilities in the photodegradation of tetracycline and methylene blue, selected as model organic pollutants. Moreover, the PHBV/CuS composites can be reused multiple times with minimal loss in photocatalytic efficiency. The suggested approach is not only sustainable and cost-effective, but also solves issues occurring in the application of the photodegradation techniques currently reported, such as the consumption of fossil-based chemicals and photocatalyst removal from the purified water using with expensive procedures

Cadmium Impairs p53 Activity in HepG2 Cells

Cadmium and cadmium compounds are contaminants of the environment, food, and drinking water and are important constituents of cigarette smoke. Cd exposure has also been associated with airborne particulate CdO and with Cd-containing quantum dots in medical therapy. Adverse cadmium effects reported in the literature have stimulated during recent years an ongoing discussion to better elucidate cadmium outcomes at cell and molecular level. The present work is designed to gain an insight into the mechanism of p53 impairment at gene and protein level to understand Cd-induced resistance to apoptosis. We used a hepatoma cell line (HepG2) derived from liver, known to be metal responsive. At genotoxic cadmium concentrations no cell cycle arrest was observed. The p53 at gene and protein level was not regulated. Fluorescence images showed that p53 was correctly translocated into the nucleus but that the , a downstream protein of p53 network involved in cell cycle regulation, was not activated at the highest cadmium concentrations used. The miRNAs analysis revealed an upregulation of mir-372, an miRNA able to affect expression and promote cell cycle progression and proliferation. The role of metallothioneins and possible conformational changes of p53 are discussed