125 research outputs found

    Critical Issues on Diverticular Disease

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    In this session diverse critical issues in diverticular disease were considered, including 'In or outpatient management of uncomplicated diverticulitis?', 'Segmental colitis associated with diverticulosis: what is it?'and 'Diverticular inflammation is a risk factor for colorectal cancer?'. The conclusions drawn are outlined in the statements but in summary, outpatient management is safe in selected patients, as long as correct diagnosis and stage are assured, and this can allow a cost effective treatment. Non-antibiotic management is also safe but should be confined as an outpatient treatment in carefully selected patients. Segmental colitis associated with diverticulosis (SCAD) is a defined pathological entity (only diagnosed on biopsy) characterized by an inflammatory bowel disease-like pathology, occurring principally in the sigmoid colon, with rectal and right colon sparing. The pathogenesis is unclear but may include a genetic predisposition, microbiome alteration and ischaemia. Treatment can last months, and depends on severity, options include antibiotics, 5 ASA and probiotics for mild cases. Severe disease needs systemic steroids or even anti TNFα treatment. Whether diverticular inflammation is a risk factor for colorectal cancer was debated and the conclusion that within the first eighteen months of diagnosis of diverticular disease associations with cancer are found, likely due to similar symptoms and misclassification of disease. After that time, diverticular disease does not increase the risk of colorectal cancer. Therefore, this is recommended to exclude cancer with imaging and colonoscopy after healing of the first episode of diverticulitis

    Birth and Evolution of Isolated Radio Pulsars

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    We investigate the birth and evolution of Galactic isolated radio pulsars. We begin by estimating their birth space velocity distribution from proper motion measurements of Brisken et al. (2002, 2003). We find no evidence for multimodality of the distribution and favor one in which the absolute one-dimensional velocity components are exponentially distributed and with a three-dimensional mean velocity of 380^{+40}_{-60} km s^-1. We then proceed with a Monte Carlo-based population synthesis, modelling the birth properties of the pulsars, their time evolution, and their detection in the Parkes and Swinburne Multibeam surveys. We present a population model that appears generally consistent with the observations. Our results suggest that pulsars are born in the spiral arms, with a Galactocentric radial distribution that is well described by the functional form proposed by Yusifov & Kucuk (2004), in which the pulsar surface density peaks at radius ~3 kpc. The birth spin period distribution extends to several hundred milliseconds, with no evidence of multimodality. Models which assume the radio luminosities of pulsars to be independent of the spin periods and period derivatives are inadequate, as they lead to the detection of too many old simulated pulsars in our simulations. Dithered radio luminosities proportional to the square root of the spin-down luminosity accommodate the observations well and provide a natural mechanism for the pulsars to dim uniformly as they approach the death line, avoiding an observed pile-up on the latter. There is no evidence for significant torque decay (due to magnetic field decay or otherwise) over the lifetime of the pulsars as radio sources (~100 Myr). Finally, we estimate the pulsar birthrate and total number of pulsars in the Galaxy.Comment: 27 pages, including 15 figures, accepted by Ap

    G328.4+0.2 : A large and luminous Crab-like supernova remnant

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    We report on radio continuum and HI observations of the radio source G328.4+0.2 using the Australia Telescope Compact Array. Our results confirm G328.4+0.2 to be a filled-center nebula with no surrounding shell, showing significant linear polarization and an almost flat spectral index. These results lead us to conclude that G328.4+0.2 is a Crab-like, or ``plerionic'', supernova remnant (SNR), presumably powered by an unseen central pulsar. HI absorption towards G328.4+0.2 puts a lower limit on its distance of 17.4 +/- 0.9 kpc, making it the largest (D=25 pc) and most luminous (L_R = 3e35 erg/s) Crab-like SNR in the Galaxy. We infer G328.4+0.2 to be significantly older than the Crab Nebula, but powered by a pulsar which is fast spinning (P<20 ms) and which has a comparatively low magnetic field (B<1e12 G). We propose G328.4+0.2, G74.9+1.2 and N157B as a distinct group of large-diameter, high-luminosity Crab-like SNRs, all powered by fast-spinning low-field pulsars.Comment: 7 pages, 3 embedded EPS figures, uses emulateapj.sty. Accepted to ApJ. Abstract corrected so that distance is now in kpc, not pc

    Thin accretion disc with a corona in a central magnetic field

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    We study the steady-state structure of an accretion disc with a corona surrounding a central, rotating, magnetized star. We assume that the magneto-rotational instability is the dominant mechanism of angular momentum transport inside the disc and is responsible for producing magnetic tubes above the disc. In our model, a fraction of the dissipated energy inside the disc is transported to the corona via these magnetic tubes. This energy exchange from the disc to the corona which depends on the disc physical properties is modified because of the magnetic interaction between the stellar magnetic field and the accretion disc. According to our fully analytical solutions for such a system, the existence of a corona not only increases the surface density but reduces the temperature of the accretion disc. Also, the presence of a corona enhances the ratio of gas pressure to the total pressure. Our solutions show that when the strength of the magnetic field of the central neutron star is large or the star is rotating fast enough, profiles of the physical variables of the disc significantly modify due to the existence of a corona.Comment: Accepted for publication in Astrophysics & Space Scienc

    Controversies in the Surgical Management of Sigmoid Diverticulitis

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    The timing and appropriateness of surgical treatment of sigmoid diverticular disease remain a topic of controversy. We have reviewed the current literature on this topic, focusing on issues related to the indications and types of surgery. Current evidence would suggest that elective surgery for diverticulitis can be avoided in patients with uncomplicated disease, regardless of the number of recurrent episodes. Furthermore, the need for elective surgey should not be influenced by the age of the patient. Operation should be undertaken in patients with severe attacks, as determined by their clinical and radiological evaluation

    The DICA Endoscopic Classification for Diverticular Disease of the Colon Shows a Significant Interobserver Agreement among Community Endoscopists: an International Study

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    Background & Aims: The Diverticular Inflammation and Complication Assessment (DICA) endoscopic classification of diverticulosis and diverticular disease (DD) is currently available. It scores severity of the disease as DICA 1, DICA 2 and DICA 3. Our aim was to assess the agreement on this classification in an international endoscopists community setting. Methods: A total of 96 doctors (82.9% endoscopists) independently scored a set of DD endoscopic videos. The percentages of overall agreement on DICA score and a free-marginal multirater kappa (kappa) coefficient were reported as statistical measures of interrater agreement. Results: Overall agreement in using DICA was 91.8% with a free-marginal kappa of 88% (95% CI 80-95). The overall agreement levels were: DICA 1, 85.2%; DICA 2, 96.5%; DICA 3, 99.5%. The free marginal. was: DICA 1 = 0.753, DICA 2 = 0.958, DICA 3 = 0.919. The agreement about the main endoscopic items was 83.4% (k 67%) for diverticular extension, 62.6% (k 65%) for number of diverticula for each district, 86.8% (k 82%) for presence of inflammation, and 98.5 (k 98%) for presence of complications. Conclusions: The overall interrater agreement in this study ranges from good to very good. DICA score is a simple and reproducible endoscopic scoring system for diverticulosis and DD

    International Consensus on Diverticulosis and Diverticular Disease. Statements from the 3rd International Symposium on Diverticular Disease

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    The statements produced by the Chairmen and Speakers of the 3rd International Symposium on Diverticular Disease, held in Madrid on April 11th-13th 2019, are reported. Topics such as current and evolving concepts on the pathogenesis, the course of the disease, the news in diagnosing, hot topics in medical and surgical treatments, and finally, critical issues on the disease were reviewed by the Chairmen who proposed 39 statements graded according to level of evidence and strength of recommendation. Each topic was explored focusing on the more relevant clinical questions. The vote was conducted on a 6-point scale and consensus was defined a priori as 67% agreement of the participants. The voting group consisted of 124 physicians from 18 countries, and agreement with all statements was provided. Comments were added explaining some controversial areas

    A systematic review of high-fibre dietary therapy in diverticular disease

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    The exact pathogenesis of diverticular disease of the sigmoid colon is not well established. However, the hypothesis that a low-fibre diet may result in diverticulosis and a high-fibre diet will prevent symptoms or complications of diverticular disease is widely accepted. The aim of this review is to assess whether a high-fibre diet can improve symptoms and/or prevent complications of diverticular disease of the sigmoid colon and/or prevent recurrent diverticulitis after a primary episode. Clinical studies were eligible for inclusion if they assessed the treatment of diverticular disease or the prevention of recurrent diverticulitis with a high-fibre diet. The following exclusion criteria were used for study selection: studies without comparison of the patient group with a control group. No studies concerning prevention of recurrent diverticulitis with a high-fibre diet met our inclusion criteria. Three randomised controlled trials (RCT) and one case-control study were included in this systematic review. One RCT of moderate quality showed no difference in the primary endpoints. A second RCT of moderate quality and the case-control study found a significant difference in favour of a high-fibre diet in the treatment of symptomatic diverticular disease. The third RCT of moderate quality found a significant difference in favour of methylcellulose (fibre supplement). This study also showed a placebo effect. High-quality evidence for a high-fibre diet in the treatment of diverticular disease is lacking, and most recommendations are based on inconsistent level 2 and mostly level 3 evidence. Nevertheless, high-fibre diet is still recommended in several guideline
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