117 research outputs found
Calculation of transient electromagnetic forces in an axisymmetrical electromagnet with conductive solid parts
The paper describes the analysis and the calculation of transient response of a voltage fed electromagnet. This calculation is based on the simultaneous solution of the magnetic field equations and the electrical circuit equations. In the modelling of the magnetic fields, eddy currents in solid conductive parts and saturation of magnetic parts are taken into account. This modelling uses Finite Element Method for the calculation of magnetic fields and forces with special quadrilateral elements. Experimental and simulation results for an axisymmetrical electromagnet are presented and compared
Stoma-free Survival After Rectal Cancer Resection With Anastomotic Leakage: Development and Validation of a Prediction Model in a Large International Cohort
OBJECTIVE: This study aimed to develop and validate a prediction model (STOMA-score) for one-year stoma-free survival in rectal cancer (RC) patients with anastomotic leakage (AL). BACKGROUND: AL after RC resection often results in a permanent stoma. METHODS: This international retrospective cohort study (TENTACLE-Rectum) encompassed 216 participating centres, and included patients who developed AL after RC surgery between 2014-2018. Clinically relevant predictors for one-year stoma-free survival were included in uni- and multivariable logistic regression models. The STOMA-score was developed and internally validated in a cohort of patients operated between 2014-2017, with subsequent temporal validation in a 2018 cohort. The discriminative power and calibration of the models' performance were evaluated. RESULTS: This study included 2499 AL patients; 1954 in the development cohort and 545 in the validation cohort. Baseline characteristics were comparable. One-year stoma-free survival was 45.0% in the development cohort and 43.7% in the validation cohort. The following predictors were included in the STOMA-score: sex, age, ASA-classification, body mass index, clinical M-disease, neoadjuvant therapy, abdominal- and transanal approach, primary defunctioning stoma, multivisceral resection, clinical setting in which AL was diagnosed, postoperative day of AL diagnosis, abdominal contamination, anastomotic defect circumference, bowel wall ischemia, anastomotic fistula, retraction and reactivation leakage. The STOMA-score showed good discrimination and calibration (c-index 0.71, 95%CI 0.66-0.76). CONCLUSION: The STOMA-score consists of eighteen clinically relevant factors and estimates the individual risk for one-year stoma-free survival in patients with AL after RC surgery, which may improve patient counselling and give guidance when analyzing efficacy of different treatment strategies in future studies.Nynke G. Greijdanus, Kiedo Wienholts, Sander Ubels, Kevin Talboom, Gerjon Hannink, Albert Wolthuis, Francisco B. de Lacy, Jérémie H. Lefevre, Michael Solomon, Matteo Frasson, Nicolas Rotholtz, Quentin Denost, Rodrigo O. Perez, Tsuyoshi Konishi, Yves Panis, Martin Rutegård, Roel Hompes, Camiel Rosman, Frans van Workum, Pieter J. Tanis, Johannes H.W. de Wilt, and TENTACLE-Rectum Collaborative Group (Collaborators: Bremers, Andreas J.A. ... Kroon, Hidde M. ... Sammour, Tarik ... et al.
Family History, Surgery, and APC Mutation Are Risk Factors for Desmoid Tumors in Familial Adenomatous Polyposis: An International Cohort Study
BACKGROUND: Ability to identify patients with familial adenomatous polyposis who have a high risk of developing desmoid tumors may affect decisions in clinical practice. OBJECTIVES: Our aim was to assess several risk factors for desmoid tumor development in an international cohort of patients with familial adenomatous polyposis and to evaluate the clinical relevance of risk factors. DESIGN: This was a retrospective cohort study. SETTING AND PATIENTS: Polyposis registries in The Netherlands, France, Denmark, Finland, and Italy provided information on familial adenomatous polyposis patients with desmoid tumors. MAIN OUTCOME MEASURES: We used univariate and multivariable analyses of data from registries in The Netherlands, France, Denmark, and Finland to test whether gender, APC mutation site, previous colorectal surgery, colorectal cancer, and family history for desmoid tumors contribute to risk of developing desmoid tumors at any location, or specifically at an intra-abdominal location. The effect of family history was tested with a generalized linear mixed model. RESULTS: Of 2260 patients with familial adenomatous polyposis from 912 families in The Netherlands, France, Denmark, and Finland, 220 patients (10%) had desmoid tumors (101 men). In 387 patients with desmoid tumors (including 167 patients from the Italian registry), the median age at diagnosis of the first desmoid tumor was 31 years (range, 4 months-74 years). Desmoid locations were intra-abdominal (53%), abdominal wall (24%), extremities (9%), and unknown sites or combinations of sites (14%). Multivariable analysis of risk factors for desmoids at any location showed surgery (OR, 2.58; P = .0004), an APC mutation 3' of codon 1444 (OR, 3.0; P < .0001), and a positive family history (P < .0001) to be independently associated with desmoid development. When only intra-abdominal location was analyzed, APC mutation site was not associated with desmoid development. LIMITATIONS: Selection bias may have occurred. CONCLUSIONS: A positive family history for desmoid tumors, abdominal surgery, and APC mutation site are significant risk factors for development of desmoid tumors. The results may have implications for determining the optimal management of FAP patients and guide future studies.Cellular mechanisms in basic and clinical gastroenterology and hepatolog
Surgical Management and Outcomes of Rectal Cancer with Synchronous Prostate Cancer: A Multicenter Experience from the GRECCAR Group.
Synchronous prostate cancer (PC) and rectal cancer (RC) is a rare clinical situation. While combining curative-intent management for both cancers can be challenging, available data for guiding the multidisciplinary strategy are lacking.
Consecutive patients undergoing rectal resection for a mid-low RC with synchronous PC treated at 9 tertiary-care centers between 2008 and 2018 were included. Management strategy and data on postoperative and long-term outcomes were retrospectively analyzed.
Overall, 25 patients underwent curative-intent RC resection combined with PC management. Nine (36%), 10 (40%) and 6 (24%) patients had low-, intermediate-, and high-risk PC, respectively. Management mostly consisted of chemoradiotherapy combined in 18 patients (72%) with either TME in 12 patients or pelvic exenteration for resection of both cancers in 6 patients. Most patients underwent RC resection using a laparoscopic approach (n = 16, 64%). Anastomosis was performed in 18 patients (72%) of whom 13 received diverting ileostomy. The complete R0 resection rate was 96% (n = 24). The overall morbidity rate was 64% (n = 16) and 5 patients (20%) experienced severe surgical morbidity of which two died within 90 days of surgery after pelvic exenteration. Among patients with anastomosis, 2 patients (11%) experienced anastomotic leak requiring surgical management. After a median follow-up of 31.2 months, 3-year OS and RFS were 80.2% (CI 95% 58.8-92.2) and 68.6% (CI 95% 42.3-84.8), respectively.
This series is the largest to report that simultaneous curative-intent management of synchronous PC and RC is feasible and safe. Pelvic exenteration might be a better option when RC complete resection seems not achievable through TME
Science goals and mission concept for the future exploration of Titan and Enceladus
Abstract Saturn?s moons, Titan and Enceladus, are two of the Solar System?s most enigmatic bodies and are prime targets for future space exploration. Titan provides an analogue for many processes relevant to the Earth, more generally to outer Solar System bodies, and a growing host of newly discovered icy exoplanets. Processes represented include atmospheric dynamics, complex organic chemistry, meteorological cycles (with methane as a working fluid), astrobiology, surface liquids and lakes, geology, fluvial and aeolian erosion, and interactions with an external plasma environment. In addition, exploring Enceladus over multiple targeted flybys will give us a unique opportunity to further study the most active icy moon in our Solar System as revealed by Cassini and to analyse in situ its active plume with highly capable instrumentation addressing its complex chemistry and dynamics. Enceladus? plume likely represents the most accessible samples from an extra-terrestrial liquid water environment in the Solar system, which has far reaching implications for many areas of planetary and biological science. Titan with its massive atmosphere and Enceladus with its active plume are prime planetary objects in the Outer Solar System to perform in situ investigations. In the present paper, we describe the science goals and key measurements to be performed by a future exploration mission involving a Saturn–Titan orbiter and a Titan balloon, which was proposed to {ESA} in response to the call for definition of the science themes of the next Large-class mission in 2013. The mission scenario is built around three complementary science goals: (A) Titan as an Earth-like system; (B) Enceladus as an active cryovolcanic moon; and (C) Chemistry of Titan and Enceladus – clues for the origin of life. The proposed measurements would provide a step change in our understanding of planetary processes and evolution, with many orders of magnitude improvement in temporal, spatial, and chemical resolution over that which is possible with Cassini–Huygens. This mission concept builds upon the successes of Cassini–Huygens and takes advantage of previous mission heritage in both remote sensing and in situ measurement technologies
Management of colorectal peritoneal metastases: Expert opinion
International audienceWhen peritoneal metastases are diagnosed (strong agreement of experts): (i) seek advice from a multidisciplinary coordination meeting (MCM) with large experience in peritoneal disease (e.g. BIG RENAPE network); (ii) transfer (or not) the patient to a referral center with experience in hyperthermic intraperitoneal chemotherapy (HIPEC), according to the advice of the MCM. With regard to systemic chemotherapy (strong agreement of experts): (i) it should be performed both before and after surgery, (ii) for no longer than 6 months; (iii) without postoperative anti-angiogenetic drugs. With regard to cytoreductive surgery (strong agreement of experts): (i) Radical surgery requires a xiphopubic midline incision; (ii) no cytoreductive surgery via laparoscopy. With regard to HIPEC: HIPEC can be proposed for trials outside an HIPEC referral center (weak agreement between experts): (i) if surgery is radical; (ii) if the expected morbidity is "reasonable"; (iii) if the indication for HIPEC was suggested by a MCM, and; (iv) mitomycin is preferred to oxaliplatin (which cannot be recommended) for this indication
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