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1.
Ann Chir Plast Esthet ; 66(2): 126-133, 2021 Apr.
Artículo en Francés | MEDLINE | ID: mdl-33707027

RESUMEN

INTRODUCTION: The anatomical subject is still a key element to learn complex procedures in plastic surgery. We present here the evaluation of an in-training operator on a SIMLIFE® model, hyper realistic model consisting in human bodies donated to science equipped with pulsating recirculation and reventilation device. MATERIAL AND METHODS: From February 2019 to October 2019, 8 forearm flaps with radial proximal pedicle were harvested by the learner on a SIMLIFE® model. Conditions were as close as possible to the operating room : asepsy, sterile draping, assistant and instrumentation including electrocoagulation. RESULTS: The procedure was decomposed in 13 distinct steps. Mean total surgery time was 90,5±11,62minutes. There was only one case of arterial pedicle lesion resulting in major blood leak. Bleeding was measured by fake blood loss from the SIMLIFE® console. Mean intraoperatoy bleeding was 171±108 milliliters. We review pros and cons of this new technology particulary suited for complex plastic and reconstructive surgery training. CONCLUSION: Using SIMLIFE® technology we have a new mean to train for complex procedures in plastic and reconstructive surgery. This new technology could be applied to numerous other surgical procedures. Broader applications are still limited by cost and cadaver use legislation.


Asunto(s)
Procedimientos de Cirugía Plástica , Colgajos Quirúrgicos , Cadáver , Simulación por Computador , Retroalimentación , Humanos
2.
Updates Surg ; 73(1): 289-295, 2021 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-32876883

RESUMEN

To evaluate the validity and reliability of an innovative training model for endocrine surgical procedures. A simulator training model for endocrine procedures (SimLife) was developed at an academic center. The model consisted of a realistic operating environment with a coherent simulated patient dynamized by pulsatile vascularization with simulated blood warmed to 37 °C, and ventilation. Training sessions were designed for adrenal and thyroid surgery, as well as neck dissection. The primary outcome of interest was to evaluate learners' performance and satisfaction. Learners' performance was evaluated based on a scoring scale that followed the Downing method for the assessment of competency. While learners' satisfaction was evaluated using a Likert scale of 1 to 10 on four items (ease of learning, anatomic correspondence of landmarks, realism, and overall satisfaction). Participants were engaged in 32 training sessions. These included 24 adrenalectomies (conventional and laparoscopic both transabdominal and posterior), and 4 thyroid lobectomies with concomitant functional lateral compartment neck dissection. competency scores were procedure-specific addressing specific core components of a given procedure. Learners' performance scored above average in all procedures evaluated. Satisfaction scores for the specified four items ranged between 8.43 (SD 0.87) and 8.89 (SD 0.96). No major events were reported for the adrenalectomies, while only one jugular vein injury occurred during neck dissection. SimLife is a hyper-realistic training model that allows for satisfactory acquisition of skills and the evaluation of performance progression. It has the potential to become a cornerstone in specialized surgical training.


Asunto(s)
Competencia Clínica/estadística & datos numéricos , Simulación por Computador , Curriculum , Educación Médica/métodos , Procedimientos Quirúrgicos Endocrinos/educación , Modelos Educacionales , Enseñanza , Glándulas Suprarrenales/cirugía , Adrenalectomía/educación , Humanos , Disección del Cuello/educación , Reproducibilidad de los Resultados , Glándula Tiroides/cirugía , Tiroidectomía/educación
3.
Obes Surg ; 30(11): 4352-4358, 2020 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-32621055

RESUMEN

BACKGROUND: The demand for bariatric surgery is high and so is the need for training future bariatric surgeons. Bariatric surgery, as a technically demanding surgery, imposes a learning curve that may initially induce higher morbidity. In order to limit the clinical impact of this learning curve, a simulation preclinical training can be offered. The aim of the work was to assess the realism of a new cadaveric model for simulated bariatric surgery (sleeve and Roux in Y gastric bypass). AIM: A face validation study of SimLife, a new dynamic cadaveric model of simulated body for acquiring operative skills by simulation. The objectives of this study are first of all to measure the realism of this model, the satisfaction of learners, and finally the ability of this model to facilitate a learning process. METHODS: SimLife technology is based on a fresh body (frozen/thawed) given to science associated to a patented technical module, which can provide pulsatile vascularization with simulated blood heated to 37 °C and ventilation. RESULTS: Twenty-four residents and chief residents from 3 French University Digestive Surgery Departments were enrolled in this study. Based on their evaluation, the overall satisfaction of the cadaveric model was rated as 8.52, realism as 8.91, anatomic correspondence as 8.64, and the model's ability to be learning tool as 8.78. CONCLUSION: The use of the SimLife model allows proposing a very realistic surgical simulation model to realistically train and objectively evaluate the performance of young surgeons.


Asunto(s)
Cirugía Bariátrica , Derivación Gástrica , Laparoscopía , Obesidad Mórbida , Competencia Clínica , Humanos , Curva de Aprendizaje , Obesidad Mórbida/cirugía , Proyectos Piloto
4.
J Visc Surg ; 157(3 Suppl 2): S117-S122, 2020 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-32354683

RESUMEN

In initial surgical formation and continuing surgical education, simulation has become a compulsory technique. Just as becoming an airplane pilot requires skills, the acquisition of technical skills is essential to becoming a surgeon. The old apprenticeship model "I see, I do, and I teach" is no longer entirely compatible with the socio-economic constraints of the operating room, demands for guaranteeing patient safety, and the compulsory reduction in resident working hours. We propose a new surgical simulation model, using cadavers donated to science that are rendered dynamic with pulsatile vascularization and ventilation. Such models are available for simulation of both open surgery and laparoscopy. Surgery on a human body donated to science makes it possible to accurately reproduce the hand gestures characteristic of surgical procedures. Learning in an appropriate and realistic simulation context increases the level of skills acquired by residents and reduces stress and anxiety when they come to perform real procedures.


Asunto(s)
Competencia Clínica , Simulación por Computador , Curriculum , Educación de Postgrado en Medicina/métodos , Cirugía General/educación , Internado y Residencia/métodos , Entrenamiento Simulado/métodos , Humanos
6.
Prog Urol ; 30(2): 126-133, 2020 Feb.
Artículo en Francés | MEDLINE | ID: mdl-31932042

RESUMEN

INTRODUCTION: In 2015, we reported our experience with the learning curve in genital reassignment surgery and highlighted a four-step learning concept. CLINICAL CASE: In this article, we present our first vaginoplasty performed on a humanoid model SIMLIFE®, a human body associated with a pulsating circulation device and a ventilation device. RESULTS: The surgical technique included 14 steps. The total surgical time was 182minutes. There was no intraoperative complication, and there was no damage to the urethra or rectum. The intraoperative bleeding measured by the loss of operative fluid was 280mL. We discuss the advantages of this technology perfectly adapted to transsexual surgery. CONCLUSION: We demonstrated the feasibility of vaginoplasty performed on a humanoid model SIMLIFE® and highlighted improvement of the surgical skills with this model. This technology could find many other surgical applications. However, it faces cost constraints and legislation on corpses.


Asunto(s)
Cirugía de Reasignación de Sexo/educación , Entrenamiento Simulado/métodos , Transexualidad/cirugía , Vagina/cirugía , Pérdida de Sangre Quirúrgica , Cadáver , Femenino , Humanos , Masculino , Tempo Operativo
7.
Clin Genet ; 92(3): 281-289, 2017 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-28170084

RESUMEN

BACKGROUND: Recent clinical whole exome sequencing (WES) cohorts have identified unanticipated multiple genetic diagnoses in single patients. However, the frequency of multiple genetic diagnoses in families is largely unknown. AIMS: We set out to identify the rate of multiple genetic diagnoses in probands and their families referred for analysis in two national research programs in Canada. MATERIALS & METHODS: We retrospectively analyzed WES results for 802 undiagnosed probands referred over the past 5 years in either the FORGE or Care4Rare Canada WES initiatives. RESULTS: Of the 802 probands, 226 (28.2%) were diagnosed based on mutations in known disease genes. Eight (3.5%) had two or more genetic diagnoses explaining their clinical phenotype, a rate in keeping with the large published studies (average 4.3%; 1.4 - 7.2%). Seven of the 8 probands had family members with one or more of the molecularly diagnosed diseases. Consanguinity and multisystem disease appeared to increase the likelihood of multiple genetic diagnoses in a family. CONCLUSION: Our findings highlight the importance of comprehensive clinical phenotyping of family members to ultimately provide accurate genetic counseling.


Asunto(s)
Secuenciación del Exoma , Familia , Estudios de Asociación Genética , Enfermedades Genéticas Congénitas/diagnóstico , Enfermedades Genéticas Congénitas/genética , Predisposición Genética a la Enfermedad , Canadá/epidemiología , Preescolar , Consanguinidad , Femenino , Enfermedades Genéticas Congénitas/epidemiología , Pruebas Genéticas , Genotipo , Humanos , Masculino , Mutación , Linaje , Fenotipo , Estudios Retrospectivos , Hermanos , Secuenciación del Exoma/métodos
8.
Surg Radiol Anat ; 39(2): 211-217, 2017 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-27315801

RESUMEN

PURPOSE: In primary and continuing medical education, simulation is becoming a mandatory technique. In surgery, simulation spreading is slowed down by the distance which exists between the devices currently available on the market and the reality, in particular anatomical, of an operating room. We propose a new model for surgical simulation with the use of cadavers in a circulation model mimicking pulse and artificial respiration available for both open and laparoscopic surgery. METHODS: The model was a task trainer designed by four experts in our simulation laboratory combining plastic, electronic, and biologic material. The cost of supplies needed for the construction was evaluated. The model was used and tested over 24 months on 35 participants, of whom 20 were surveyed regarding the realism of the model. RESULTS: The model involved a cadaver, connected to a specific device that permits beating circulation and artificial respiration. The demonstration contributed to teaching small groups of up to four participants and was reproducible over 24 months of courses. Anatomic correlation, realism, and learning experience were highly rated by users CONCLUSION: This model for surgical simulation in both open and laparoscopic surgery was found to be realistic, available to assessed objectively performance in a pedagogic program.


Asunto(s)
Educación Médica/métodos , Enseñanza Mediante Simulación de Alta Fidelidad/métodos , Procedimientos Quirúrgicos Operativos/educación , Cadáver , Humanos , Encuestas y Cuestionarios
9.
J Visc Surg ; 154(1): 15-20, 2017 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-27344609

RESUMEN

INTRODUCTION: Alike becoming a pilot requires competences, acquisition of technical skills is essential to become a surgeon. Halsted's theory on surgical education "See one, do one, and teach one" is not currently compatible with the reality of socio-economic constraints of the operating room, the patient's safety demand and the reduction of residents' work hours. MATERIEL AND METHODS: In all countries, this brings mandatory to simulation education for surgery resident's training. Many models are available: video trainers or pelvi-trainers, computed simulator, animal models or human cadaver… Human cadaveric dissection has long been used to teach surgical anatomy. RESULTS: Surgery on human cadaveric model brings greatest accuracy to the haptic characteristics of surgical procedures. Learning in an appropriate and realistic simulation context increases the level of acquisition of the residents' skills and reduces stress and anxiety when performing real procedures. CONCLUSION: We present a technique of perfusion and ventilation of a fresh human cadaver that restores pulsatile circulation and respiratory movements of the model.


Asunto(s)
Competencia Clínica , Disección/educación , Cabeza/irrigación sanguínea , Internado y Residencia , Cuello/irrigación sanguínea , Torso/irrigación sanguínea , Cadáver , Simulación por Computador , Humanos , Quirófanos
10.
Diagn Interv Imaging ; 97(12): 1297-1304, 2016 12.
Artículo en Inglés | MEDLINE | ID: mdl-27856215

RESUMEN

Pancreatic adenocarcinoma is one of the solid cancers associated with the poorest prognosis; the only curative treatment remains surgical resection but in most cases, this treatment is not possible because of distant metastasis or local extension. Irreversible electroporation is a new tumor ablation technique, which provides cellular apoptosis without any thermal coagulation effect. This technique helps preserve the ducts, vessels or nerves located in the treatment area. This article reviews the current knowledge regarding the use of electroporation for the treatment of pancreatic adenocarcinoma.


Asunto(s)
Adenocarcinoma/terapia , Electroquimioterapia/métodos , Neoplasias Pancreáticas/terapia , Adenocarcinoma/patología , Humanos , Estadificación de Neoplasias , Páncreas/patología , Neoplasias Pancreáticas/patología , Pronóstico
11.
Diagn Interv Imaging ; 97(9): 851-5, 2016 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-27132590

RESUMEN

PURPOSE: The goal of this study was to prospectively compare the sensitivity of contrast-enhanced ultrasound (CEUS) with that of multiphase multidetector-row computed tomography (MDCT) in the preoperative detection of hepatic metastases. MATERIALS AND METHOD: Forty-eight patients, with a mean age of 62years old (range: 43-85years) were prospectively included. All patients underwent CEUS following intravenous administration of 2.4mL of an ultrasound contrast agent (Sonovue(®), Bracco, Milan, Italy) and multiphase MDCT. Intraoperative ultrasound examination (IOUS) was used as the standard of reference. RESULTS: A total of 158 liver metastases were identified by IOUS, 127 by preoperative MDCT (sensitivity; 80.4%) and 102 by CEUS (sensitivity, 64.5%). The 15.9% difference in sensitivity between CEUS and MDCT was statistically significant (P=0.002). There was a disagreement between IOUS and CEUS in 23 patients (47%) and in 13 patients (27%) between IOUS and MDCT. MDCT identified one or more additional metastases in 10 patients (20%) resulting in a change in the surgical strategy. CONCLUSION: Based on an unselected patient cohort and using multiphase MDCT, CEUS is significantly inferior to MDCT for the preoperative detection of hepatic metastases of colorectal cancer.


Asunto(s)
Neoplasias Colorrectales/patología , Neoplasias Hepáticas/diagnóstico por imagen , Neoplasias Hepáticas/secundario , Tomografía Computarizada Multidetector , Adulto , Anciano , Anciano de 80 o más Años , Medios de Contraste , Femenino , Humanos , Masculino , Persona de Mediana Edad , Periodo Preoperatorio , Estudios Prospectivos , Ultrasonografía
12.
Clin Genet ; 89(3): 275-84, 2016 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-26283276

RESUMEN

An accurate diagnosis is an integral component of patient care for children with rare genetic disease. Recent advances in sequencing, in particular whole-exome sequencing (WES), are identifying the genetic basis of disease for 25-40% of patients. The diagnostic rate is probably influenced by when in the diagnostic process WES is used. The Finding Of Rare Disease GEnes (FORGE) Canada project was a nation-wide effort to identify mutations for childhood-onset disorders using WES. Most children enrolled in the FORGE project were toward the end of the diagnostic odyssey. The two primary outcomes of FORGE were novel gene discovery and the identification of mutations in genes known to cause disease. In the latter instance, WES identified mutations in known disease genes for 105 of 362 families studied (29%), thereby informing the impact of WES in the setting of the diagnostic odyssey. Our analysis of this dataset showed that these known disease genes were not identified prior to WES enrollment for two key reasons: genetic heterogeneity associated with a clinical diagnosis and atypical presentation of known, clinically recognized diseases. What is becoming increasingly clear is that WES will be paradigm altering for patients and families with rare genetic diseases.


Asunto(s)
Exoma , Genes , Enfermedades Genéticas Congénitas/diagnóstico , Mutación , Análisis de Secuencia de ADN , Canadá , Niño , Enfermedades Genéticas Congénitas/genética , Secuenciación de Nucleótidos de Alto Rendimiento , Humanos
13.
Updates Surg ; 67(3): 305-9, 2015 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-25895571

RESUMEN

Delayed gastric emptying (DGE) is a common complication after pancreaticoduodenectomy (PDD) significantly contributing to post-operative morbidity. Clinical risk factors for DGE occurrence after PDD remain controversial. From January 2004 to December 2011, a total of 132 patients underwent PDD for either malignancies (73.5%) or benign diseases (26.5%) in one single universitary center. Post-operative mortality and morbidity were, respectively, 3 and 44.7%. DGE has been defined in accordance with the International Study Group of Pancreatic Surgery (ISGPS) classification. DGE was distinguished in primary or secondary. Factors associated with grades B and C of DGE, based on severity and clinical impact, were assessed by means of univariate and multivariate analysis. Thirty-eight patients (28.8%) had clinical DGE grade B or C. Post-operative complications (pancreatic fistula and/or hemorrhage or anastomotic leak) were reported in 25 out of the 38 patients (65.8%, secondary DGE), while in 13 patients it was not associated to any other complication (34.2%, primary DGE). Post-operative complications (pancreatic fistula and hemorrhage) appeared to be the most important predictive factor for Grade B or C DGE.


Asunto(s)
Vaciamiento Gástrico , Pancreaticoduodenectomía/efectos adversos , Adulto , Anciano , Anciano de 80 o más Años , Fuga Anastomótica/fisiopatología , Enfermedades de los Conductos Biliares/cirugía , Pérdida de Sangre Quirúrgica/fisiopatología , Enfermedades Duodenales/cirugía , Femenino , Humanos , Masculino , Persona de Mediana Edad , Tempo Operativo , Enfermedades Pancreáticas/cirugía , Fístula Pancreática/fisiopatología , Estudios Retrospectivos , Factores de Riesgo , Factores de Tiempo , Adulto Joven
14.
Orthop Traumatol Surg Res ; 101(2): 215-9, 2015 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-25736197

RESUMEN

BACKGROUND: Lumbar spinal stenosis is a major public health issue. Interspinous devices implanted using minimally invasive techniques may constitute an alternative to the reference standard of bony decompression with or without intervertebral fusion. However, their indications remain unclear, due to a paucity of clinical and biomechanical data. Our objective was to evaluate the effects of four interspinous process devices implanted at L4-L5 on the intervertebral foramen surface areas at the treated and adjacent levels, in flexion and in extension. MATERIALS AND METHOD: Six fresh frozen human cadaver lumbar spines (L2-sacrum) were tested on a dedicated spinal loading frame, in flexion and extension, from 0 to 10 N·m, after preparation and marking of the L3-L4, L4-L5, and L5-S1 foramina. Stereoscopic 3D images were acquired at baseline then after implantation at L4-L5 of each of the four devices (Inspace(®), Synthes; X-Stop(®), Medtronic; Wallis(®), Zimmer; and Diam(®), Medtronic). The surface areas of the three foramina of interest were computed. RESULTS: All four devices significantly opened the L4-L5 foramen in extension. The effects in flexion separated the devices into two categories. With the two devices characterized by fixation in the spinous processes (Wallis(®) and Diam(®)), the L4-L5 foramen opened only in extension; whereas with the other two devices (X-Stop(®) and Inspace(®)), the L4-L5 foramen opened not only in extension, but also in flexion and in the neutral position. None of the devices implanted at L4-L5 modified the size of the L3-L4 foramen. X-Stop(®) and Diam(®) closed the L5-S1 foramen in extension, whereas the other two devices had no effect at this level. CONCLUSION: Our results demonstrate that interspinous process devices modify the surface area of the interspinous foramina in vitro. Clinical studies are needed to clarify patient selection criteria for interspinous process device implantation. LEVEL OF EVIDENCE: Level IV. Investigating an orthopaedic device.


Asunto(s)
Vértebras Lumbares/cirugía , Prótesis e Implantes , Rango del Movimiento Articular/fisiología , Sacro/cirugía , Fusión Vertebral/instrumentación , Estenosis Espinal/cirugía , Anciano , Anciano de 80 o más Años , Fenómenos Biomecánicos , Cadáver , Descompresión Quirúrgica/instrumentación , Humanos , Imagenología Tridimensional , Vértebras Lumbares/fisiopatología , Ensayo de Materiales , Periodo Posoperatorio , Diseño de Prótesis , Sacro/fisiopatología , Estenosis Espinal/diagnóstico
15.
Oncogene ; 34(28): 3676-87, 2015 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-25241899

RESUMEN

Progesterone (P4) has emerged as an important hormone-regulating mammary stem cell (MaSC) populations. In breast cancer, P4 and synthetic analogs increase the number of stem-like cells within luminal estrogen receptor (ER)- and progesterone receptor (PR)-positive breast cancers. These cells gain expression of de-differentiated cell markers CD44 and cytokeratin 5 (CK5), lose luminal markers ER and PR, and are more therapy resistant. We previously described that P4 downregulation of microRNA (miR)-29a contributes to the expansion of CD44(high) and CK5(+) cells. Here we investigated P4 downregulation of miR-141, a member of the miR-200 family of tumor suppressors, in facilitating an increase in stem-like breast cancer cells. miR-141 was the sole member of the miR-200 family P4-downregulated at the mature miRNA level in luminal breast cancer cell lines. Stable inhibition of miR-141 alone increased the CD44(high) population, and potentiated P4-mediated increases in both CD44(high) and CK5(+) cells. Loss of miR-141 enhanced both mammosphere formation and tumor initiation. miR-141 directly targeted both PR and signal transducer and activator of transcription 5A (Stat5a), transcription factors important for MaSC expansion. miR-141 depletion increased PR protein levels, even in cell lines where PR expression is estrogen dependent. Stat5a suppression via small interfering RNA or a small-molecule inhibitor reduced the P4-dependent increase in CK5(+) and CD44(high) cells. These data support a mechanism by which P4-triggered loss of miR-141 facilitates breast cancer cell de-differentiation through deregulation of PR and Stat5a, two transcription factors important for controlling mammary cell fate.


Asunto(s)
Neoplasias de la Mama/genética , MicroARNs/genética , Células Madre Neoplásicas/efectos de los fármacos , Progesterona/farmacología , Progestinas/farmacología , Factor de Transcripción STAT5/genética , Proteínas Supresoras de Tumor/genética , Animales , Neoplasias de la Mama/patología , Línea Celular Tumoral , Regulación hacia Abajo/efectos de los fármacos , Femenino , Humanos , Receptores de Hialuranos/metabolismo , Queratina-5/metabolismo , Ratones , Trasplante de Neoplasias , Células Madre Neoplásicas/patología , Receptores de Progesterona
16.
Surg Radiol Anat ; 37(4): 393-8, 2015 May.
Artículo en Inglés | MEDLINE | ID: mdl-25223848

RESUMEN

PURPOSE: With the development of laparoscopy, new surgical techniques for colon resection were required. New anatomic plans of dissection were described for laparoscopic technique (medial to lateral approach) and the surgeons had to learn a complete different anatomy known as "laparoscopic anatomy". To help the surgeon through the milestones of laparoscopic colon resection, we propose an embryological and anatomical analysis of the changes of the colon and peritoneum during the foetal period to highlight the laparoscopic approach and surgical landmarks. METHODS: Seventeen human foetuses, age ranged from 7½ to 33 weeks were studied by dissections and histology. Three adult cadavers underwent laparoscopic colon surgery. RESULTS: Photographic representations of surgical views are displayed, and detailed descriptions applicable to anatomical structures are presented. CONCLUSION: Understanding the changes in the colon and peritoneum morphology leads to a clarification of the surgical technique for laparoscopic colon surgery.


Asunto(s)
Colon/embriología , Colon/cirugía , Laparoscopía/métodos , Peritoneo/embriología , Peritoneo/cirugía , Adulto , Cadáver , Disección , Feto/embriología , Feto/cirugía , Humanos , Masculino
17.
Radiat Prot Dosimetry ; 161(1-4): 245-8, 2014 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-24594906

RESUMEN

In order to measure the energy and fluence of neutron fields, in the energy range of 8 to 1 MeV, a new primary standard is being developed at the Institute for Radioprotection and Nuclear Safety (IRSN). This project, Micro Time Projection Chamber (µ-TPC), carried out in collaboration with the Laboratoire de Physqique Subatomique et de Cosmologie (LPSC), is based on the nucleus recoil detector principle. The measurement strategy requires track reconstruction of recoiling nuclei down to a few kiloelectronvolts, which can be achieved using a micro-pattern gaseous detector. A gas mixture, mainly isobutane, is used as an n-p converter to detect neutrons within the detection volume. Then electrons, coming from the ionisation of the gas by the proton recoil, are collected by the pixelised anode (2D projection). A self-triggered electronics system is able to perform the anode readout at a 50-MHz frequency in order to give the third dimension of the track. Then, the scattering angle is deduced from this track using algorithms. The charge collection leads to the proton energy, taking into account the ionisation quenching factor. This article emphasises the neutron energy measurements of a monoenergetic neutron field produced at 127 keV. The fluence measurement is not shown in this article. The measurements are compared with Monte Carlo simulations using realistic neutron fields and simulations of the detector response. The discrepancy between experiments and simulations is 5 keV mainly due to the calibration uncertainties of 10 %.


Asunto(s)
Neutrones , Protección Radiológica/instrumentación , Radiometría/instrumentación , Algoritmos , Calibración , Electrónica , Diseño de Equipo , Francia , Gases , Iones , Método de Montecarlo , Protones , Dosis de Radiación , Radiometría/métodos , Dispersión de Radiación , Rayos X
18.
Transbound Emerg Dis ; 61(2): 147-55, 2014 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-23750567

RESUMEN

Dynamic mathematical modelling and stochastic simulation of disease-host systems for the purpose of epidemiological analysis offer great opportunities for testing hypotheses, especially when field experiments are impractical or when there is a need to evaluate multiple experimental scenarios. This, combined with the ever increasing computer power available to researchers, has contributed to the development of many mathematical models for epidemic simulations, such as the individual-based model (IBM). Nevertheless, few of these models undergo extensive validation and proper assessment of intrinsic variability. The Ontario rabies model (ORM) will be used here to exemplify some advantages of appropriate model behaviour validation and to illustrate the use of a simple geometric procedure for testing directional bias in distributed stochastic dynamic model of spread of diseases. Results were obtained through the comparison of 10 000 epizootics resulting from 100 epidemic simulations started using 100 distinct base populations. The analysis results demonstrated a significant directional bias in epidemic dispersion, which prompted further verification of the model code and the identification of a coding error, which was then corrected. Subsequent testing of the corrected code showed that the directional bias could no longer be detected. These results illustrate the importance of proper validation and the importance of sufficient knowledge of the model behaviour to ensure the results will not confound the objectives of the end-users.


Asunto(s)
Transmisión de Enfermedad Infecciosa , Epidemias/veterinaria , Modelos Teóricos , Virus de la Rabia/aislamiento & purificación , Rabia/epidemiología , Animales , Epidemias/prevención & control , Ontario/epidemiología , Rabia/transmisión , Virus de la Rabia/patogenicidad , Agrupamiento Espacio-Temporal
19.
Chir Main ; 32(5): 322-8, 2013 Oct.
Artículo en Francés | MEDLINE | ID: mdl-24094570

RESUMEN

Proximal or middle lesions of median or ulnar nerves are responsible for a great loss of hand motor function. Neurotization of either deep ulnar branch of ulnar nerve (DBUN) or recurrent (thenar) branch of median nerve (RBMN) with the nerve to quadratus pronator (NPQ) from the anterior interosseous nerve (AION) could reduce length of axonal growth and therefore the reinnervation lead-time of hand intrinsic muscles. We studied the anatomy of these three nerves, to help surgeon choosing his (her) technique and approach. Twenty-three cadaver forearms were dissected. End-to-side sutures were performed to mimic these neurotizations. Distances between nerve sutures and ulnar styloid process (USP) or trapeziometacarpal joint (TM) were measured. All the sutures but one RBMN could be done. On average sutures were distant from USP by 44±17mm (neurotization of DBUN), from TM by 62±15mm (neurotization of RBMN). Knowledge of average distance to perform these neurotizations should allow choosing the best reduced approach of RBMN and DBUN. Neurotizations of DBNU and RBMN with NPQ were feasible for lesions located at 6.1cm upstream USP and 7.7cm upstream TM, respectively. End-to-side sutures remain to be clinically evaluated.


Asunto(s)
Nervio Mediano/cirugía , Transferencia de Nervios/métodos , Nervio Cubital/cirugía , Anastomosis Quirúrgica , Cadáver , Humanos , Regeneración Nerviosa , Nervios Periféricos/trasplante
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