Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 18 de 18
Filter
1.
Bioinspir Biomim ; 18(4)2023 05 09.
Article in English | MEDLINE | ID: mdl-37158291

ABSTRACT

This paper presents the bending behaviour of the porcupine quill and bioinspired Voronoi sandwich panels, aiming to explore the effect of geometrical design on the bending performance of the inspired structures. Through the x-ray micro-computed tomography, the internal morphology of the quill is explored. The longitudinal cross-section of the porcupine quill revealed a functionally graded design in the foam structure. Based on this observation, Voronoi sandwich panels are designed by incorporating the Voronoi seed distribution strategy and gradient transition design configurations. Porcupine-inspired sandwich panels with various core designs are fabricated via material jetting technique and tested under three-point bending condition. Results show that the sample failed at the bottom face panels for uniform sandwich panels, whereas graded samples failed in the core panel. The bending behaviour developed via simulation software shows a good agreement with the experimental results. The parametric study provides insights into structural designs for engineering applications, particularly in the aerospace and automobile industries.


Subject(s)
Flexural Strength , X-Ray Microtomography
2.
Gynecol Obstet Fertil Senol ; 50(1): 75-81, 2022 Jan.
Article in French | MEDLINE | ID: mdl-34562642

ABSTRACT

The initial management of early-stage ovarian cancer consists of staging surgery including pelvic and para-aortic lymphadenectomy. The use of the sentinel lymph node (SLN) procedure in this setting may decrease the morbidity associated with this surgery. The objective of this review was to evaluate the feasibility of the SLN procedure in ovarian cancer diagnosed at an early stage by comparing the different techniques used and their accuracy. A systematic literature search was performed on PubMed and ClinicalTrials.gov for articles in English or French about the SLN technique in ovarian cancer. Ten studies were included in the analysis, with a total of 179 patients. The main tracers used were Technetium-99m, indocyanine green, and patent blue, and the most common site of injection was the proper ovarian and unfundibulopelvic ligaments. The overall detection rate was 87.7%. Of the small number of cases of lymph node metastasis reported, the SLN procedure had a sensitivity of 90.9% and a negative predictive value of 98.8%. The sentinel node procedure appears to be feasible and safe and could be reliable in determining the lymph node status of patients with early-stage ovarian cancer.


Subject(s)
Ovarian Neoplasms , Sentinel Lymph Node Biopsy , Coloring Agents , Female , Humans , Lymph Nodes/pathology , Neoplasm Staging , Ovarian Neoplasms/pathology , Ovarian Neoplasms/surgery , Sentinel Lymph Node Biopsy/methods
3.
Nanotechnology ; 33(6)2021 Nov 15.
Article in English | MEDLINE | ID: mdl-34695808

ABSTRACT

This article explores a three-dimensional solid isogeometric analysis (3D-IGA) approach based on a nonlocal elasticity theory to investigate size effects on natural frequency and critical buckling load for multi-directional functionally graded (FG) nanoshells. The multi-directional FG material uses a power law rule with three power exponent indexes concerning three parametric coordinates. Nanoshell's geometries include the square plate, cylindrical and spherical panels with the side length considered in a nanoscale with various thickness ratios. Because 3D-IGA utilizes an approximation of NURBS basic functions to integrate from geometry modeling to discretized domain, it does not require any hypotheses for deformations distribution and stress component through the plate's thickness. Therefore, the results from the 3D solution are obtained accurately with any thickness ratio of the shells. The numerical solutions are verified by those published in several pieces of literature to determine the current approach's accuracy and reliability. After a convergence solution is examined, a quartic NURBS basic function can yield ultra-converged and high-accurate results with a low computational cost. The findings show the size effect parameters which significantly impact the frequencies and the critical buckling factors of the multi-directional FG nanoshells. Generally, increases in the size effect parameters will cause declines in the frequencies and the critical buckling factors of the nanoshells.

4.
Eur J Surg Oncol ; 47(11): 2900-2906, 2021 11.
Article in English | MEDLINE | ID: mdl-34274203

ABSTRACT

INTRODUCTION: Node involvement is one of the main prognostic factors for cervical cancer. Para-aortic lymph node (PALN) assessment is crucial for treating advanced cervical cancer, to define irradiation fields. Objective of this study was to develop a score predicting para-aortic lymph node involvement in patients with advanced cervical cancer. PATIENTS AND METHOD: We performed a multicenter, retrospective, study on 9 French centers from 2000 to 2015, including patients with advanced squamous cell cervix carcinoma who had PALN status assessed by imaging and/or by surgery. Factors associated with a risk of PALN involvement were determined by univariate and multivariate analysis using a logistic regression model. A score was then developed and validated. RESULTS: A total of 1446 patients treated for cervical cancer were included. Of these, 498 had an advanced squamous cell cervical cancer. Ninety-one patients (18.3%) had positive PALN. After univariate and multivariate analysis, tumor size on pelvic MRI, initial SCC, and suspected pelvic node involvement on PET-CT were included in our score. This model allowed the population to be divided into 3 risk groups. Area under the ROC curve of the score was 0.81 (95%CI = 0.72-0.90). In the low-risk group, 9% (28/287) had PALN involvement, whereas in the high-risk group, 43% (22/51) had PALN involvement. CONCLUSION: We developed a simple score predicting PALN involvement in advanced cervical cancers. Three risk groups can be defined, and patients considered to be at low risk may avoid para-aortic staging as well as extensive field irradiation.


Subject(s)
Carcinoma, Squamous Cell/pathology , Carcinoma, Squamous Cell/therapy , Lymphatic Metastasis , Uterine Cervical Neoplasms/pathology , Uterine Cervical Neoplasms/therapy , Carcinoma, Squamous Cell/diagnostic imaging , Female , France , Humans , Middle Aged , Positron Emission Tomography Computed Tomography , Predictive Value of Tests , Prognosis , Retrospective Studies , Risk Assessment , Uterine Cervical Neoplasms/diagnostic imaging
5.
Gynecol Obstet Fertil Senol ; 49(10): 736-743, 2021 10.
Article in French | MEDLINE | ID: mdl-33636412

ABSTRACT

INTRODUCTION: Advanced epithelial ovarian cancer (EOC) is associated with high mortality and often managed first with neoadjuvant chemotherapy (NACT) followed by debulking surgery. Laparoscopic surgery with or without robotic assistance (Minimally Invasive Surgery (MIS)) may represent a beneficial option for these patients. The objective of this literature review is to clarify the place of MIS in the management of advanced EOC for selected patients. METHOD: Pubmed, Cochrane and Clinicaltrials.gov online databases were used for this review, to select English or French published articles. RESULTS: We selected 11 original articles published between 2015 and 2020, 6 of which compared MIS and laparotomy. Among these 11 studies, 8 were retrospective cohorts, 2 were phase II trials, and one was a case-control study. In total, there were 3721 patients, of which 854 (23%) were treated with MIS. The robotic assistance was used with 224 patients (26%) of those MIS patients. Looking specifically at MIS patients, the laparoconversion rate was 9.5%, the rate of complete resection (CC-0) was 83.4%. Finally, the MIS complication rate was 1% intraoperatively and 12% postoperatively. The rate of complete resection, postoperative complication, as well as overall survival (OS) were comparable between patients treated with MIS or laparotomy. One study found an improved disease-free survival (DFS) in MIS versus laparotomy (18 months versus 12 months; P=0.027). CONCLUSION: MIS seems feasible, effective, and reliable in comparison to laparotomy for the completion of cytoreductive surgery after NACT without compromising oncological safety. Prospective randomized controlled trials are needed to confirm the role of MIS in advanced EOC.


Subject(s)
Neoadjuvant Therapy , Ovarian Neoplasms , Carcinoma, Ovarian Epithelial/drug therapy , Case-Control Studies , Cytoreduction Surgical Procedures , Female , Humans , Minimally Invasive Surgical Procedures , Ovarian Neoplasms/drug therapy , Ovarian Neoplasms/surgery , Prospective Studies , Retrospective Studies
8.
ISA Trans ; 103: 177-191, 2020 Aug.
Article in English | MEDLINE | ID: mdl-32303352

ABSTRACT

We investigate a novel computational approach to computational structural optimization based on deep learning. After employing algorithms to solve the stiffness formulation of structures, we used their improvement to optimize the structural computation. A standard illustration of 10 bar-truss was revisited to illustrate the mechanism of neural networks and deep learning. Several benchmark problems of 2D and 3D truss structures were used to verify the reliability of the present approach, and its extension to other engineering structures is straightforward. To enhance computational efficiency, a constant sum technique was proposed to generate data for the input of multi-similar variables. Both displacement and stress enforcements were the constraints of the optimized problem. The optimization data for cross sections with the objective function of total weight were then employed in the context of deep learning. The stochastic gradient descent (SGD) with Nesterov's accelerated gradient (NAG), root mean square propagation (RMSProp) and adaptive moment estimation (Adam) optimizers were compared in terms of convergence. In addition, this paper devised Chebyshev polynomials for a new approach to activation functions in single-layer neural networks. As expected, its convergence was quicker than the popular learning functions, especially in a short training with a small number of epochs for tested problems. Finally, a split data technique for linear regression was proposed to deal with some sensitive data.


Subject(s)
Deep Learning , Algorithms , Image Interpretation, Computer-Assisted , Least-Squares Analysis , Neural Networks, Computer , Reproducibility of Results , Stochastic Processes , Stress, Mechanical
9.
Gynecol Obstet Fertil Senol ; 47(4): 337-341, 2019 04.
Article in French | MEDLINE | ID: mdl-30769103

ABSTRACT

OBJECTIVES: There are no recommendations on the way emergency ultrasound should be performed but there are Standardized Acute Female Echography (SAFE) planes with quality criteria for ultrasound scoring. The objective of this study was to evaluate the impact of the quality of ultrasound on the diagnosis of ectopic pregnancy. METHODS: A retrospective study was conducted in 2016-2017 and included all Ectopic Pregnancies (EP). Clinical, biological and ultrasonographic characteristics were collected, in particular the analysis of ultrasound scans according to the scoring score of standardized planes (total score out of 15). EP diagnosed at first ultrasound and those from Pregnancy of unknown location (PUL) were compared. RESULTS: Hundred and seventeen patients were included: 45 (38.5%) in the group "EP from PLU" and 72 (61.5%) in the group "EP diagnosed directly". The ultrasound images were significantly better in the "directly diagnosed EP" group than in the "EP from PUL" group: 11.9/15 vs. 10.07/15 respectively (P=0.005). Moreover, in the group "EP from PUL", the images were significantly better on the final ultrasound diagnosing the EP compared to the first ultrasound performed: 11.4/15 vs. 10.07/17 (P=0.04). CONCLUSION: The evaluation of quality of ultrasound scan using a standardized scoring system shows an impact in the diagnosis of ectopic pregnancies.


Subject(s)
Endosonography , Pregnancy, Ectopic/diagnostic imaging , Ultrasonography, Prenatal , Adult , Female , Humans , Pregnancy , Pregnancy, Ectopic/therapy , Retrospective Studies
10.
Gynecol Obstet Fertil Senol ; 47(3): 265-272, 2019 03.
Article in French | MEDLINE | ID: mdl-30691974

ABSTRACT

OBJECTIVES: Surgical management of endometriosis may require different levels of surgical skill which influences the orientation of the patient. The Ultrasound-Based Endometriosis Staging System (UBESS) is a score developed in 2016 to predict the difficulty of surgery. To study the correlation between UBESS score and two main surgical classifications in the literature. METHODS: Study performed at the center of Poissy, France, between July 2016 and December 2017. Patients who underwent prospective UBESS staging then operated of their endometriosis were included. The patients were classified according to the levels of surgical difficulty of the Royal College of Obstetricians and Gynecologists (RCOG) and the classification created by Chi et al. The criterion of judgment was the correlation between the UBESS stages and RCOG and CHI levels. In a second analysis, we determined the predictive value of the operative plan for items included in the systematic sonographic evaluation described by Menakaya et al. RESULTS: Thirty-three patients were included in the study. Correlation was found to be low between UBESS and RCOG (θ=0.22) and between UBESS and CHI (θ=0.30). The prediction of the operative plan was good for endometrioma, sites specific tenderness, sliding sign, vaginal and digestive tract involvement; but modest for the anterior compartment and uterosacrals ligaments. CONCLUSION: In our study on a small number of patients, the UBESS score does not adequately predict the surgical difficulty. Taken separately, the items of systematic sonographic evaluation based on 5 domains successfully predict the operative plan.


Subject(s)
Endometriosis/classification , Endometriosis/surgery , Gynecologic Surgical Procedures/methods , Ultrasonography , Adult , Clinical Competence , Endometriosis/diagnostic imaging , Female , France , Humans , Retrospective Studies
11.
J Gynecol Obstet Biol Reprod (Paris) ; 45(9): 1054-1059, 2016 Nov.
Article in French | MEDLINE | ID: mdl-27114064

ABSTRACT

INTRODUCTION: Randomized controlled trials (RCT) in surgery are often subject to difficulties inherent in the study design and recruitment of patients. Women's participation rate to RCTs in surgery is relatively low and varies from 30 to 70%. These recruitment problems might induce a weak scientific value and even stop the study. Thus, optimizing recruitment is a challenge for surgical research. In contemporary literature, we lack data on motivations and profile of women who refuse to participate in a RCT in surgery. OBJECTIVE: To explore the potentially influential factors affecting women's decision to decline participation in PROSPERE trial, comparing laparoscopic sacrocolpopexy (LSCP) to vaginal mesh for cystocele repair. PATIENT AND METHOD: Retrospective, observational, qualitative, bicentric study conducted in the department of gynecology of Poissy and Lille hospitals. Patients included were those who refused to participate to PROSPERE trial in both centers. Factors of non-participation in the trial were recorded at the time of the first visit. A control group consisted of women who agreed to participate in the trial was also analyzed. RESULTS: In both centers, 139 were eligible to participate in the trial but 35 of them (25%) refused. Thirty-two women agreed to declare their refusal motivations. Vaginal mesh was finally performed in 18 (56,2%) patients and LSCP in 14 patients (43,8%). The control group consisted of 20 women, including 9 operated by vaginal mesh and 11 by LSCP. Patient's characteristics were similar in the both groups. Most influencing factor in refusal for participation was "previous choice of technique" in 50% cases (16/32), followed by "geographical remoteness and difficulties for additional visits" in 40.6% cases (13/32), and finally by "do not accept the concept of randomization" in 21.8% cases (7/32). The most influencing factor in women's acceptance was interest in helping others by "supporting medical research" in 100% cases (20/20), followed by "potential personal benefits and close follow-up" in 60% (12/20). CONCLUSION: Our study identified the most influential factors relevant to women decision-making whether or not to participate in RCT in surgery. A number of factors leading to refusal of participation are potentially correctable leading to better recruitment rates in future RCTs. Optimization of information on the principle of randomization, limiting the number of additional visits could help researchers improve participation rates.


Subject(s)
Choice Behavior , Gynecologic Surgical Procedures/psychology , Motivation , Patient Selection , Randomized Controlled Trials as Topic , Aged , Female , Humans , Middle Aged , Qualitative Research , Retrospective Studies
12.
J Clin Virol ; 72: 4-10, 2015 Nov.
Article in English | MEDLINE | ID: mdl-26356985

ABSTRACT

BACKGROUND: Varicella (VZV) infection in pregnancy can result in serious outcomes: maternal pneumoniae irrespective of the term of pregnancy, and lead to congenital varicella syndrome before 18 weeks of gestation and neonatal varicella. There are between 350 and 500 cases a year in France. Until now, there have been no scientific obstetrical guidelines for clinical practice in France for VZV infection during pregnancy. OBJECTIVES: To evaluate health care providers' knowledge and practices concerning varicella infection during pregnancy in France. STUDY DESIGN: An anonymous survey on VZV infection was sent by e-mail to gynecologists-obstetricians and midwives. We evaluated their knowledge and practices concerning VZV transmission, maternal varicella, congenital varicella syndrome, neonatal varicella and prevention. RESULTS: The survey was completed by 271 professionals: gynecologists (161/271; 60%) and midwives (110/271; 40%). Among 20 items, 5 were multiple choice questions. 29 correct answers were expected. Scores ranged from 6/29 to 28/29 (mean score: 17.44/29). CONCLUSIONS: The consequences of VZV primary infection in pregnancy are poorly known. We reveal a diversity of management among practitioners in our study population, not always in accordance with the international scientific literature or with the guidelines of other countries. Health care providers should update their knowledge of varicella infection during pregnancy. The publication of national guidelines could help to achieve this objective.


Subject(s)
Chickenpox/diagnosis , Chickenpox/therapy , Herpesvirus 3, Human/isolation & purification , Pregnancy Complications/diagnosis , Pregnancy Complications/therapy , Adolescent , Adult , Attitude of Health Personnel , Female , France , Humans , Infant, Newborn , Middle Aged , Pregnancy , Pregnancy Complications/virology , Professional Competence , Surveys and Questionnaires , Young Adult
13.
Gynecol Obstet Fertil ; 42(7-8): 483-9, 2014.
Article in French | MEDLINE | ID: mdl-24927651

ABSTRACT

OBJECTIVES: Cesarean scar pregnancy is a rare entity. This situation may induce uterine rupture and/or a massive life-threatening hemorrhage. The standard treatment is laparotomy surgery, but in situ injections to replace invasive surgery. The objective of this study was to focus on the diagnosis, optimal management and long-term follow-up of the patients. PATIENTS AND METHODS: Data from 6 patients with diagnosis of cesarean scar pregnancy between 2007 and 2013 at Lariboisière hospital were retrospectively collected. RESULTS: Endovaginal ultrasound succeeded to diagnose all cases. Four patients were treated with in situ injection of methotrexate performing a vaginal way (n=2) or laparoscopy (n=2) and two others using systemic injection. One patient was complicated by hemorrhagic shock requiring iterative embolizations. Three patients achieved a new pregnancy, with one recurrent scar pregnancy complicated by massive hemorrhage. DISCUSSION AND CONCLUSION: Diagnosis and treatment of cesarean scar pregnancies must be done precociously because of high hemorrhage risks. Endovaginal ultrasound is the gold standard exam. Treatment is non-consensual, but methotrexate in situ injection is effective and safer. Monitoring the decrease of HCG levels and ultrasonography supervision of gestational sac size and its vascularization must be performed. Due to the risk of recurrence, any subsequent pregnancy shows a high risk of complications.


Subject(s)
Cesarean Section , Cicatrix , Pregnancy, Ectopic/diagnosis , Pregnancy, Ectopic/therapy , Embolization, Therapeutic , Female , Humans , Laparoscopy , Methotrexate/administration & dosage , Pregnancy , Retrospective Studies , Risk Factors , Uterine Hemorrhage , Uterine Rupture
14.
J Am Acad Dermatol ; 69(6): 909-15, 2013 Dec.
Article in English | MEDLINE | ID: mdl-24099729

ABSTRACT

BACKGROUND: Congenital erosive and vesicular dermatosis (CEVD) healing with reticulated supple scarring, a condition usually observed in premature neonates, presents at birth with vesicles and erosions. Lesions typically heal within a few months, leaving behind scarring with a distinctive supple and reticulated texture. OBJECTIVES: We sought to merge existing literature with new cases to further define CEVD. METHODS: We analyzed 19 previous reports of CEVD and added 9 additional patients; we identified unifying characteristics of this cohort. RESULTS: In 28 total cases, notable features included: preterm birth (79%), nail abnormalities (46%), hyperthermia/hypohidrosis (46%), a history of maternal chorioamnionitis (43%), alopecia (43%), neurodevelopmental and ophthalmologic abnormalities (36% each), tongue atrophy (29%), or a combination of these. Patients with CEVD may be prone to postnatal herpetic superinfections. Previously unreported findings included: erosive lichen planus, digital tip gangrene, and hydronephrosis. LIMITATIONS: The small patient sampling makes it difficult to define diagnostic criteria. As certain findings are associated with prematurity, it is unclear to what extent these features result from CEVD, premature birth, or another intrauterine pathology. CONCLUSIONS: Although rare, CEVD should be considered in the differential diagnosis of neonatal vesicles/erosions in the context of a negative infectious workup. This review strengthens the spectrum of CEVD features, thus facilitating its recognition by clinicians.


Subject(s)
Cicatrix/etiology , Skin Diseases, Vesiculobullous/congenital , Skin Diseases, Vesiculobullous/complications , Humans , Infant , Infant, Newborn
15.
N Engl J Med ; 367(19): 1838, 2012 Nov 08.
Article in English | MEDLINE | ID: mdl-23134384

ABSTRACT

A 42-year-old man presented with impaired nasal breathing and a slowly growing mass on the tip of the nose. Examination revealed a multilobulated sebaceous nodule protruding from the nasal tip.


Subject(s)
Nose/pathology , Rhinophyma/pathology , Adult , Electrosurgery , Humans , Male , Nose/surgery , Rhinophyma/surgery
16.
Pediatr Dermatol ; 26(5): 497-505, 2009.
Article in English | MEDLINE | ID: mdl-19840301

ABSTRACT

A growing body of literature has identified the association between neutrophilic dermatoses and multifocal, aseptic bone lesions in children, termed chronic recurrent multifocal osteomyelitis (CRMO). Classically, patients present with swelling, pain, and impaired mobility of the affected area, with skin lesions developing concurrently or in the future. Bone biopsy reveals inflammatory changes consistent with infectious osteomyelitis, but cultures and histologic staining invariably fail to identify an infectious source. Patients are refractory to antibiotic therapy, but dramatically respond to systemic steroids and may need to be maintained on low-dose steroids to prevent relapse. Numerous authors have suggested that CRMO and synovitis, acne, pustulosis, hyperostosis, osteitis (SAPHO) syndrome lie along the same clinical spectrum. In fact some believe that CRMO is the pediatric presentation of SAPHO. The two syndromes share numerous characteristics, including osteitis, a unifocal or multifocal presentation, hyperostosis, and pustulosis, which all occur in a generally healthy individual. Our seven patients, five of whom were diagnosed with CRMO, and two of whom were diagnosed with SAPHO syndrome further strengthen the idea that CRMO and SAPHO syndrome do indeed lie along the same clinical spectrum. In addition, we include two rare cases of pediatric Sweet's syndrome with evidence of pathergy.


Subject(s)
Acquired Hyperostosis Syndrome/complications , Acquired Hyperostosis Syndrome/pathology , Osteomyelitis/complications , Osteomyelitis/pathology , Skin/pathology , Acquired Hyperostosis Syndrome/drug therapy , Adolescent , Child , Child, Preschool , Chronic Disease , Female , Humans , Male , Osteomyelitis/drug therapy , Recurrence , Steroids/therapeutic use
17.
Pediatr Dermatol ; 26(5): 563-5, 2009.
Article in English | MEDLINE | ID: mdl-19840311

ABSTRACT

Sporotrichosis is caused by the dimorphic fungus, Sporothrix schenckii. Classically, infection occurs after implantation of the organism into the skin by abrasion of a puncture wound by contaminated thorns, hay, or sphagnum moss. Cats are also a commonly recognized source of sporotrichosis. In children, fixed cutaneous lesions are more common than lymphocutaneous lesions, and the face is a frequent location for infection. We present a neonate with a fixed cutaneous facial lesion and both pre-auricular and cervical lymphadenopathy who developed signs of infection at 3 weeks of age. This patient is currently the youngest reported case of sporotrichosis in the literature. The patient's family denied any trauma and denied contact with flowers, gardens, and cats; thus, the source of infection remains unknown.


Subject(s)
Amphotericin B/administration & dosage , Antifungal Agents/administration & dosage , Sporothrix/isolation & purification , Sporotrichosis/diagnosis , Sporotrichosis/drug therapy , Anti-Bacterial Agents/administration & dosage , Ceftriaxone/administration & dosage , Forehead , Humans , Infant , Male , Serratia Infections/diagnosis , Serratia Infections/drug therapy , Serratia marcescens , Sporotrichosis/microbiology , Superinfection/diagnosis , Superinfection/drug therapy , Superinfection/microbiology
SELECTION OF CITATIONS
SEARCH DETAIL
...