461 research outputs found

    Magnus and Dyson Series for Master Integrals

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    We elaborate on the method of differential equations for evaluating Feynman integrals. We focus on systems of equations for master integrals having a linear dependence on the dimensional parameter. For these systems we identify the criteria to bring them in a canonical form, recently identified by Henn, where the dependence of the dimensional parameter is disentangled from the kinematics. The determination of the transformation and the computation of the solution are obtained by using Magnus and Dyson series expansion. We apply the method to planar and non-planar two-loop QED vertex diagrams for massive fermions, and to non-planar two-loop integrals contributing to 2 -> 2 scattering of massless particles. The extension to systems which are polynomial in the dimensional parameter is discussed as well.Comment: 32 pages, 6 figures, 2 ancillary files. v2: references added, typos corrected in the text and in the ancillary file

    The activation of irrigation solutions in Endodontics: a perfected technique

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    AbstractAimIn endodontics a complete chemo mechanical cleansing of the complex root canal system is essential in order to achieve a theraupetic success.MethodologySodium hypoclorite due to its antimicrobial and proteolytic characteristic, is an efficient endodontic irrigant and it is the most commonly used.The following article introduces a refined technique in order to increase the degree of cleansing during endodontic treatment.The technique involves intracanal heating of the irrigants through a heat source.ResultsThe described technique is able to enhance simply and considerably the use of sodium hypochlorite, making it easily accessible even to generic operators.ConclusionsTo confirm the validity of this improved technique, further research and scientific studies are needed, although at the clinical level, the results by using it are very satisfactory

    Transanal minimally invasive surgery for rectal lesions

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    Background and Objectives: Transanal minimally invasive surgery (TAMIS) has emerged as an alternative to transanal endoscopic microsurgery (TEM). The authors report their experience with TAMIS for the treatment of mid and high rectal tumors. Methods: From November 2011 through May 2016, 31 patients (21 females, 68%), with a median age of 65 years who underwent single-port TAMIS were prospectively enrolled. Mean distance from the anal verge of the rectal tumors was 9.5 cm. Seventeen patients presented with T1 cancer, 10 with large adenoma, 2 with gastrointestinal stromal tumor (GIST) and 2 with carcinoid tumor. Data concerning demographics, operative procedure and pathologic results were analyzed. Results: TAMIS was successfully completed in all cases. In 4 (13%) TAMIS was converted to standard Park’s transanal technique. Median postoperative stay was 3 days. The overall complication rate was 9.6%, including 1 urinary tract infection, 1 subcutaneous emphysema, and 1 hemorrhoidal thrombosis. TAMIS allowed an R0 resection in 96.8% of cases (30/31 cases) and a single case of local recurrence after a large adenoma resection was encountered. Conclusion: TAMIS is a safe technique, with a short learning curve for laparoscopic surgeons already proficient in single-port procedures, and provides effective oncological outcomes compared to other techniques

    Predictors of use of direct oral anticoagulants in patients with venous thromboembolism : Findings from the Registro Informatizado Enfermedad Tromboembólica registry

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    Current guidelines recommend the use of direct oral anticoagulants (DOACs) for patients with venous thromboembolism (VTE). However little is known about the use of DOACs in daily practice. We used the RIETE registry to identify predictors of use of DOACs for initial and/or long-term therapy of VTE based on patient-related factors, institution-related factors or over time. Among 41,678 patients from March 2013 to September 2021, 12,286 (29%) used DOACs: for initial therapy 6,456; for long-term therapy 12,046. On multivariable analysis, independent predictors were: age 120 kg (OR: 0.64; 95% CI: 0.53-0.77), initial VTE presentation as pulmonary embolism (OR: 1.18; 95% CI: 1.13-1.25), recent bleeding (OR: 0.53; 95% CI: 0.45-0.63), renal insufficiency (OR: 0.44; 95% CI: 0.38-0.51), liver cirrhosis (OR: 0.32; 95% CI: 0.20-0.52), thrombocytopenia (OR: 0.40; 95% CI: 0.34-0.49), atrial fibrillation (OR: 1.58; 95% CI: 1.42-1.75) and prior VTE (OR: 1.14; 95% CI: 1.06-1.22). The DOACs were more likely used in other European countries (OR: 8.97; 95% CI: 8.49-9.49), America (OR: 6.35; 95% CI: 5.67-7.11) or in other countries of the world (OR: 2.99; 95% CI: 2.70-3.31) than in Spain, and progressively increased from 2013-2015 to 2016-2018 (OR: 2.78; 95% CI: 2.62-2.95) and 2019-2021 (OR: 6.36; 95% CI: 5.95-6.80). In this large multinational VTE registry, variations were observed in the use of DOACs according to patient or country factors, and over time. The safety, costs, and influence of the DOACs on VTE-related outcomes in daily practice warrant further investigation

    Contralateral risk reducing mastectomy in Non-BRCA-Mutated patients

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    The use of contralateral risk reducing mastectomy (CRRM) is indicated in women affected by breast cancer, who are at high risk of developing a contralateral breast cancer, particularly women with genetic mutation of BRCA1, BRCA2 and P53. However we should consider that the genes described above account for only 20-30% of the excess familiar risk. What is contralaterally indicated when genetic assessment results negative for mutation in a young patient with unilateral breast cancer? Is it ethically correct to remove a contralateral " healthy" breast? CRRM rates continue to rise all over the world although CRRM seems not to improve overall survival in women with unilateral sporadic breast cancer. The decision to pursue CRRM as part of treatment in women who have a low-to-moderate risk of developing a secondary cancer in the contralateral breast should consider both breast cancer individual-features and patients preferences, but should be not supported by the surgeon and avoided as first approach with the exception of women highly worried about cancer. Prospective studies are needed to identify cohorts of patients most likely to benefit from CRRM

    Is There Any Reliable Predictor of Functional Recovery Following Post-thyroidectomy Vocal Fold Paralysis?

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    Background Predicting definitive outcomes of post-thyroidectomy vocal fold paralysis (VFP) is challenging. We aimed to identify reliable predictors based on intraoperative neuromonitoring (IONM) and flexible fiberoptic laryngostroboscopy (FFL) findings. Methods Among 1172 thyroid operations performed from April to December 2021, all patients who exhibited vocal fold paralysis (VFP) at post-operative laryngoscopy were included. IONM data, including type of loss of signal (LOS), were collected. Patients underwent FFL, with arytenoid motility assessment, at 15, 45 and 120 days post-operatively. Patients were divided into two groups: those who recovered vocal fold motility (VFM) by the 120th post-operative day (recovery group) and those who did not (non-recovery group). Results Fifty-nine VFP cases (5.0% of total patients) met the inclusion criteria. Eight patients were lost at follow-up and were excluded. Overall, 9 patients were included in the non-recovery group (0.8% of total patients) and 42 in the recovery group. Among various predictive factors, only arytenoid fixation (AF) at the 15th post-operative day and Type I LOS were significant predictors for no VFM recovery (p = 0.007, RR = 9.739, CI:1.3-72.3 and p = 0.001, RR = 9.25, CI:2.2-39.3 for AF and Type I injury, respectively). The combination of type of LOS and arytenoid motility at the 15th post-op day yielded satisfactory predictive values for the progression of transient VFP to permanent. Conclusions Arytenoid motility at the 15th post-op day and type II LOS are associated with recovery of VFM. Type of LOS and FFL could be included in the follow-up protocols of patients with VFP to reliably predict clinical outcomes

    Erratum to nodal management and upstaging of disease. Initial results from the Italian VATS Lobectomy Registry

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    [This corrects the article DOI: 10.21037/jtd.2017.06.12.]
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