917 research outputs found

    On the stability and deformability of top stars

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    Topological stars, or top stars for brevity, are smooth horizonless static solutions of Einstein-Maxwell theory in 5-d that reduce to spherically symmetric solutions of Einstein-Maxwell-Dilaton theory in 4-d. We study linear scalar perturbations of top stars and argue for their stability and deformability. We tackle the problem with different techniques including WKB approximation, numerical analysis, Breit-Wigner resonance method and quantum Seiberg-Witten curves. We identify three classes of quasi-normal modes corresponding to prompt-ring down modes, long-lived meta-stable modes and what we dub `blind' modes. All mode frequencies we find have negative imaginary parts, thus suggesting linear stability of top stars. Moreover we determine the tidal Love and dissipation numbers encoding the response to tidal deformations and, similarly to black holes, we find zero value in the static limit but, contrary to black holes, we find non-trivial dynamical Love numbers and vanishing dissipative effects at linear order. For the sake of illustration in a simpler context, we also consider a toy model with a piece-wise constant potential and a centrifugal barrier that captures most of the above features in a qualitative fashion

    The GEANT4 toolkit capability in the hadron therapy field: simulation of a transport beam line

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    At Laboratori Nazionali del Sud of the Instituto Nazionale di Fisica Nucleare of Catania (Sicily, Italy), the first Italian hadron therapy facility named CATANA (Centro di AdroTerapia ed Applicazioni Nucleari Avanzate) has been realized. Inside CATANA 62 MeV proton beams, accelerated by a superconducting cyclotron, are used for the radiotherapeutic treatments of some types of ocular tumours. Therapy with hadron beams still represents a pioneer technique, and only a few centers worldwide can provide this advanced specialized cancer treatment. On the basis of the experience so far gained, and considering the future hadron-therapy facilities to be developed (Rinecker, Munich Germany, Heidelberg/GSI, Darmstadt, Germany, PSI Villigen, Switzerland, CNAO, Pavia, Italy, Centro di Adroterapia, Catania, Italy) we decided to develop a Monte Carlo application based on the GEANT4 toolkit, for the design, the realization and the optimization of a proton-therapy beam line. Another feature of our project is to provide a general tool able to study the interactions of hadrons with the human tissue and to test the analytical-based treatment planning systems actually used in the routine practice. All the typical elements of a hadron-therapy line, such as diffusers, range shifters, collimators and detectors were modelled. In particular, we simulated the Markus type ionization chamber and a Gaf Chromic film as dosimeters to reconstruct the depth (Bragg peak and Spread Out Bragg Peak) and lateral dose distributions, respectively. We validated our simulated detectors comparing the results with the experimental data available in our facility

    A phase II study of induction chemotherapy followed by concurrent chemoradiotherapy in elderly patients with locally advanced non-small-cell lung cancer.

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    The optimal management of unresectable locally advanced non-small-cell lung cancer in older patients has not been defined to date. The present phase II study was planned to evaluate the activity and safety of platinum-based induction chemotherapy followed by concurrent chemoradiotherapy in elderly patients with locally advanced non-small-cell lung cancer. Patients received two cycles of paclitaxel (175 mg/m) and carboplatin (area under the curve: 5) day 1, every 3 weeks. Chemoradiotherapy (thoracic radiation therapy) was initiated on day 42 and consisted of 1.8 Gy daily, five times per week over 5 weeks (45.0 Gy target dose) followed by 10 2.0 Gy daily fractions. Concomitant chemotherapy was weekly paclitaxel 50 mg/mq followed by weekly carboplatin at an area under the curve of 2. The eligibility for patients: age 70 or older and histologically documented untreated non-small-cell lung cancer, locally advanced, unresectable, stage III A N2 bulky or III B. Thirty consecutive patients were enrolled onto the study. The median age was 73 (range 70-76). According to the intention-to-treat analysis, 1 month after the end of combined chemoradiotherapy, we observed complete and partial responses in one and 19 of the 30 patients, respectively, for an overall response rate of 66% (95% confidence interval, 45-76%). Median progression-free survival was 8.7 months (95% confidence interval, 3.4-37.8) and median survival was 15 months (95% confidence interval, 4.2-52.1). During the treatment, 12 patients (40.0%) experienced grade 3-4 neutropenia, two patients neutropenic fever, and three patients grade 3 anaemia and grade 3 thrombocytopenia, respectively. Grade 3 oesophagitis, during concomitant radiotherapy, was observed in six patients (20.0%). No treatment-related mortality was reported. The investigated sequential approach including induction chemotherapy followed by concurrent chemoradiotherapy appears safe and seems a reasonable chance for the treatment of locally advanced non-small-cell lung cancer in the elderly population

    Pressurized intraperitoneal aerosol chemotherapy with cisplatin and doxorubicin or oxaliplatin for peritoneal metastasis from pancreatic adenocarcinoma and cholangiocarcinoma

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    Background: Systemic chemotherapy for pancreatic adenocarcinoma (PDAC) and cholangiocarcinoma (CC) with peritoneal metastases (PM) is affected by several pharmacological shortcomings and low clinical efficacy. Pressurized intraperitoneal aerosol chemotherapy (PIPAC) is expected to maximize exposure of peritoneal nodules to antiblastic agents. This study aims to evaluate safety and efficacy of PIPAC for PM of PDAC and CC origin. Methods: This is a retrospective analysis of consecutive PDAC and CC cases with PM treated with PIPAC at two European referral centers for peritoneal disease. We prospectively recorded from August 2016 to May 2019 demographic, clinical, surgical, and oncological data. We performed a feasibility and safety assessment and an efficacy analysis based on clinical and pathological regression. Results: Twenty patients with PM from PDAC (14) and CC (six) underwent 45 PIPAC administrations. Cisplatin–doxorubicin or oxaliplatin were administered to eight and 12 patients, respectively. We experienced one intraoperative complication (small bowel perforation) and 18 grade 1–2 postoperative adverse events according to Common Terminology Criteria for Adverse Events version 4.0. A pathological regression was recorded in 50% of patients (62% in the cisplatin–doxorubicin cohort and 42% in the oxaliplatin one). Median survival from the first PIPAC was 9.7 and 10.9 months for PDAC and CC, respectively. Conclusion: PIPAC resulted feasible and safe without relevant toxicity issues, with both cisplatin–doxorubicin and oxaliplatin. The pathological response observed supports the evidence of antitumoral activity. Despite the study limitations, these outcomes are encouraging, recommending PIPAC in prospective, controlled trials in the palliative setting or the first line chemotherapy for PM from PDAC and CC

    Tissue transglutaminase is involved in the inflammatory processes of active chronic gastritis

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    Since tissue transglutaminase-2 (TG2) can represent a marker of inflammation for some gastrointestinal (GI) diseases, we aimed to evaluate TG2 and inflammatory markers? mucosal content in gastric antrum biopsies to shed light on the histological and biochemical background of chronic gastritis inflammation. Fifty-one of 78 patients who underwent upper GI endoscopy (UGIE) for dyspeptic symptoms, had a gastric biopsy. The symptom profile was assessed by a GI symptom rating scale (GSRS) score. Thirty-five patients (69%) showed chronic gastritis. TG2, interleukin-6 (IL)-6, IL-8, IL-10, tumor necrosis factor (TNF)-?, lipopolysaccharides (LPS) and toll-like receptor (TLR)-4 were evaluated in serum and the culture medium of gastric biopsies. TG2, IL-8, IL-10, TLR-4 and TNF-? were significantly higher in active chronic gastritis than in the inactive one and were linked to macrophage concentration. IL-6 was significantly lower in the active form of chronic gastritis than in the inactive one and negatively correlated with TG2. Lastly, IL-10 significantly correlated with the macrophage score. TG2 can exert an active role in chronic gastritis pathogenesis by cooperating with different markers of inflammation. It seems that TG2 can represent a possible therapeutic target for modulating inflammation and disease progression

    The Endangered Sardinian Grass Snake: Distribution Update, Bioclimatic Niche Modelling, Dorsal Pattern Characterisation, and Literature Review

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    The Sardinian grass snake, Natrix helvetica cetti, is an endangered endemic snake subspecies with a restricted and highly fragmented geographic distribution. Information on its ecology and detailed geographic distribution are scarce and may negatively impact on its conservation status. Therefore, a literature review on its taxonomy, morphology, ecology, and conservation is presented here. Moreover, field records from the authors, citizen science and the existing literature provide an updated geographic distribution highlighting its presence within 13 new and 7 historic 10 x 10 km cells. Bioclimatic niche modelling was then applied to explore patterns of habitat suitability and phenotypic variation within N. h. cetti. The geographic distribution of the species was found to be positively correlated with altitude and precipitation values, whereas temperatures howed a negative correlation. Taken together, these outcomes may explain the snake’s presence, particularly in eastern Sardinia. In addition, analysis of distribution overlap with the competing viperine snake (N. maura) and the urodeles as possible overlooked trophic resources (Speleomantes spp. and Euproctus platycephalus) showed overlaps of 66% and 79%, respectively. Finally, geographical or bioclimatic correlations did not explain phenotypic variation patterns observed in this highly polymorphic taxon. Perspectives on future research to investigate N. h. cetti’s decline and support effective conservation measures are discussed

    Nephron-sparing surgery in multiple renal cancer: a case report

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    BACKGROUND: In the last decade, nephron-sparing surgery has largely supplanted the radical approach for the treatment of small renal masses. More recently, ablative technologies have been discussed as alternative in patients that are not eligible for surgical approach.CASE SUMMARY: A 54-year-old Caucasian man was referred to our Urology Clinic for multiple renal masses. A computed tomography (CT) scan revealed three contrast-enhanced lesions located in the upper pole, middle renal, and in the lower pole of the left kidney 20 mm, 25 mm, and 45 mm long, respectively. The patient underwent laparoscopic tumorectomy of two lesions and cryoablation of the left renal mass by the transperitoneal approach, performed without clamping the renal vessels. At the end of the procedure the operator posed a reno-ureteral ipsilateral stent to tutor the urinary tract. Tumor enucleation and cryoablation were chosen to preserve renal function.CONCLUSION: This case report shows that in young patients with multiple renal tumors, cryoablation treatment is feasible and outcomes are promising as well. However, risk of complications should be considered and discussed with patients

    Comparison of quality control for trauma management between Western and Eastern European trauma center

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    <p>Abstract</p> <p>Background</p> <p>Quality control of trauma care is essential to define the effectiveness of trauma center and trauma system. To identify the troublesome issues of the system is the first step for validation of the focused customized solutions. This is a comparative study of two level I trauma centers in Italy and Romania and it has been designed to give an overview of the entire trauma care program adopted in these two countries. This study was aimed to use the results as the basis for recommending and planning changes in the two trauma systems for a better trauma care.</p> <p>Methods</p> <p>We retrospectively reviewed a total of 182 major trauma patients treated in the two hospitals included in the study, between January and June 2002. Every case was analyzed according to the recommended minimal audit filters for trauma quality assurance by The American College of Surgeons Committee on Trauma (ACSCOT).</p> <p>Results</p> <p>Satisfactory yields have been reached in both centers for the management of head and abdominal trauma, airway management, Emergency Department length of stay and early diagnosis and treatment. The main significant differences between the two centers were in the patients' transfers, the leadership of trauma team and the patients' outcome. The main concerns have been in the surgical treatment of fractures, the outcome and the lacking of documentation.</p> <p>Conclusion</p> <p>The analyzed hospitals are classified as Level I trauma center and are within the group of the highest quality level centers in their own countries. Nevertheless, both of them experience major lacks and for few audit filters do not reach the mmum standard requirements of ACS Audit Filters. The differences between the western and the eastern European center were slight. The parameters not reaching the minimum requirements are probably occurring even more often in suburban settings.</p
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