172 research outputs found

    Planar master integrals for the two-loop light-fermion electroweak corrections to Higgs plus jet production

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    We present the analytic calculation of the planar master integrals which contribute to compute the two-loop light-fermion electroweak corrections to the production of a Higgs boson in association with a jet in gluon-gluon fusion. The complete dependence on the electroweak-boson mass is retained. The master integrals are evaluated by means of the differential equations method and the analytic results are expressed in terms of multiple polylogarithms up to weight four.Comment: 21 pages, ancillary file

    Higgs boson decay into b-quarks at NNLO accuracy

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    We compute the fully differential decay rate of the Standard Model Higgs boson into b-quarks at next-to-next-to-leading order (NNLO) accuracy in alpha_S. We employ a general subtraction scheme developed for the calculation of higher order perturbative corrections to QCD jet cross sections, which is based on the universal infrared factorization properties of QCD squared matrix elements. We show that the subtractions render the various contributions to the NNLO correction finite. In particular, we demonstrate analytically that the sum of integrated subtraction terms correctly reproduces the infrared poles of the two-loop double virtual contribution to this process. We present illustrative differential distributions obtained by implementing the method in a parton level Monte Carlo program. The basic ingredients of our subtraction scheme, used here for the first time to compute a physical observable, are universal and can be employed for the computation of more involved processes.Comment: LaTeX, 30 pages, 3 figure

    Primary intra and extradural solitary fibrous tumor/hemangiopericytoma of thoracic spine with paravertebral intrathoracic spread: Case report and review of the literature

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    Solitary fibrous tumors/hemangiopericytomas (SFTs/HPCs), constitute 1% of all CNS tumors. Spinal SFTs/HPCs are extremely rare. To date, few retrospective studies and case reports of primary spinal SFTs/HPCs have been published in the literature. We report clinical and radiological presentation, surgical treatment, and post-operative outcome at three years follow-up of a rare case of primary spinal intra and extradural SFT/HPC of thoracic spine with dumbbell shaped paravertebral intrathoracic spread and multidirectional erosion of the bone. A 73-year-old female presented with progressive lower limbs weakness and hypoesthesia below the rib cage. MRI showed an irregular isointense T5-T7 dumbbell shaped tumor. Tumor resection was successfully carried out through posterior and antero-lateral approach. Histological examination showed a grade II SFT/HPC. No local recurrence nor systemic metastases were observed at three years follow-up. A literature review has been performed to describe epidemiology, radiographic features, treatment, recurrence rate and mean disease-free survival of primary spinal SFTs/HPCs. No radiographic pathognomonic findings have been reported for these tumors. Differential diagnosis must be made with meningioma, schwannoma, chordoma, aggressive hemangioma, metastases, angiosarcoma. Surgical resection is the first choice of treatment, and total resection should be attempted whenever possible in all cases. Postsurgical radiotherapy does not change significantly recurrence rate after GTR, nonetheless it increases mean disease-free survival, especially in patients with extradural SFTs/HPCs. After subtotal resection, adjuvant radiotherapy is necessary to reduce progression of disease. The efficacy of chemotherapy has yet to be determined. Pathological degree and total surgical resection are the most important predictive factors of recurrence

    DFT insights into the oxygen-assisted selective oxidation of benzyl alcohol on manganese dioxide catalysts

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    The reactivity pattern of the MnO2 catalyst in the selective aerobic oxidation of benzyl alcohol is assessed by density functional theory (DFT) analysis of adsorption energies and activation barriers on a model Mn4O8 cluster. DFT calculations predict high reactivity of defective Mn(IV) sites ruling a surface redox mechanism, L-H type, involving gas-phase oxygen. Bare and promoted (i.e., CeOx and FeOx) MnOx materials with high surface exposure of Mn(IV) sites were synthesized to assess kinetic and mechanistic issues of the selective aerobic oxidation of benzyl alcohol on real catalysts (T, 333- 363K). According to DFT predictions, the experimental study shows: i) comparable activity of bare and promoted catalysts due to surface Mn(IV) sites; ii) the catalytic role of oxygen-atoms in the neighboring of active Mn(IV) sites; and iii) a 0th-order dependence on alcohol concentration, diagnostic of remarkable influence of adsorption phenomena on the reactivity pattern. Evidences of catalyst deactivation due to the over-oxidation of benzyl alcohol to benzoic acid, acting as poison of the active sites, are discussed

    Modified versus standard intention-to-treat reporting: Are there differences in methodological quality, sponsorship, and findings in randomized trials? A cross-sectional study

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    <p>Abstract</p> <p>Background</p> <p>Randomized controlled trials (RCTs) that use the modified intention-to-treat (mITT) approach are increasingly being published. Such trials have a preponderance of post-randomization exclusions, industry sponsorship, and favourable findings, and little is known whether in terms of these items mITT trials are different with respect to trials that report a standard intention-to-treat.</p> <p>Methods</p> <p>To determine differences in the methodological quality, sponsorship, authors' conflicts of interest, and findings among trials with different "types" of intention-to-treat, we undertook a cross-sectional study of RCTs published in 2006 in three general medical journals (the Journal of the American Medical Association, the New England Journal of Medicine and the Lancet) and three specialty journals (Antimicrobial Agents and Chemotherapy, the American Heart Journal and the Journal of Clinical Oncology). Trials were categorized based on the "type" of intention-to-treat reporting as follows: ITT, trials reporting the use of standard ITT approach; mITT, trials reporting the use of a "modified intention-to-treat" approach; and "no ITT", trials not reporting the use of any intention-to-treat approach. Two pairs of reviewers independently extracted the data in duplicate. The strength of the associations between the "type" of intention-to-treat reporting and the quality of reporting (sample size calculation, flow-chart, lost to follow-up), the methodological quality of the trials (sequence generation, allocation concealment, and blinding), the funding source, and the findings was determined. Odds ratios (OR) were calculated with 95% confidence intervals (CI).</p> <p>Results</p> <p>Of the 367 RCTs included, 197 were classified as ITT, 56 as mITT, and 114 as "no ITT" trials. The quality of reporting and the methodological quality of the mITT trials were similar to those of the ITT trials; however, the mITT trials were more likely to report post-randomization exclusions (adjusted OR 3.43 [95%CI, 1.70 to 6.95]; <it>P </it>< 0.001). We found a strong association between trials classified as mITT and for-profit agency sponsorship (adjusted OR 7.41 [95%CI, 3.14 to 17.48]; <it>P </it>< .001) as well as the presence of authors' conflicts of interest (adjusted OR 5.14 [95%CI, 2.12 to 12.48]; <it>P </it>< .001). There was no association between mITT reporting and favourable results; in general, however, trials with for-profit agency sponsorship were significantly associated with favourable results (adjusted OR 2.30; [95%CI, 1.28 to 4.16]; <it>P </it>= 0.006).</p> <p>Conclusion</p> <p>We found that the mITT trials were significantly more likely to perform post-randomization exclusions and were strongly associated with industry funding and authors' conflicts of interest.</p

    Cancer burden trends in Umbria region using a joinpoint regression

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    Introduction. The analysis of the epidemiological data on cancer is an important tool to control and evaluate the outcomes of primary and secondary prevention, the effectiveness of health care and, in general, all cancer control activities. Materials and methods. The aim of the this paper is to analyze the cancer mortality in the Umbria region from 1978 to 2009 and incidence from 1994-2008. Sex and sitespecific trends for standardized rates were analyzed by “joinpoint regression”, using the surveillance epidemiology and end results (SEER) software. Results. Applying the jointpoint analyses by sex and cancer site, to incidence spanning from 1994 to 2008 and mortality from 1978 to 2009 for all sites, both in males and females, a significant joinpoint for mortality was found; moreover the trend shape was similar and the joinpoint years were very close. In males standardized rate significantly increased up to 1989 by 1.23% per year and significantly decreased hereafter by -1.31%; among females the mortality rate increased in average of 0.78% (not significant) per year till 1988 and afterward significantly decreased by -0.92% per year. Incidence rate showed different trends among sexes. In males was practically constant over the period studied (not significant decrease 0.14% per year), in females significantly increased by 1.49% per year up to 2001 and afterward slowly decreased (-0.71% n.s. estimated annual percent change − EAPC). Conclusions. For all sites combined trends for mortality decreased since late ’80s, both in males and females; such behaviour is in line with national and European Union data. This work shows that, even compared to health systems that invest more resources, the Umbria public health system achieved good health outcomes

    Influence of Climate on Emergency Department Visits for Syncope: Role of Air Temperature Variability

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    BACKGROUND: Syncope is a clinical event characterized by a transient loss of consciousness, estimated to affect 6.2/1000 person-years, resulting in remarkable health care and social costs. Human pathophysiology suggests that heat may promote syncope during standing. We tested the hypothesis that the increase of air temperatures from January to July would be accompanied by an increased rate of syncope resulting in a higher frequency of Emergency Department (ED) visits. We also evaluated the role of maximal temperature variability in affecting ED visits for syncope. METHODOLOGY/PRINCIPAL FINDINGS: We included 770 of 2775 consecutive subjects who were seen for syncope at four EDs between January and July 2004. This period was subdivided into three epochs of similar length: 23 January-31 March, 1 April-31 May and 1 June-31 July. Spectral techniques were used to analyze oscillatory components of day by day maximal temperature and syncope variability and assess their linear relationship. There was no correlation between daily maximum temperatures and number of syncope. ED visits for syncope were lower in June and July when maximal temperature variability declined although the maximal temperatures themselves were higher. Frequency analysis of day by day maximal temperature variability showed a major non-random fluctuation characterized by a ∌23-day period and two minor oscillations with ∌3- and ∌7-day periods. This latter oscillation was correlated with a similar ∌7-day fluctuation in ED visits for syncope. CONCLUSIONS/SIGNIFICANCE: We conclude that ED visits for syncope were not predicted by daily maximal temperature but were associated with increased temperature variability. A ∌7-day rhythm characterized both maximal temperatures and ED visits for syncope variability suggesting that climate changes may have a significant effect on the mode of syncope occurrence
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