Iatrogenic pneumothorax: experience of a Moroccan Emergency Center

AbstractThe incidence of iatrogenic pneumothorax (IPx) will increase with invasive procedures particularly at training hospitals, which is why we have made a retrospective study of the common diagnostic or therapeutic causes of IPx and its impact on morbidity. From January 2011 to December 2012, 36 patients developed IPx as emergencies, after an invasive procedure .Their mean age was 38 years (range: 19-69 years). Of the patients, 21 (58%) were male and 15 (42%) were female. The purpose was diagnostic in 6 cases and therapeutic in 30 cases. In 8 patients (22%) the procedure was performed due to underlying lung diseases and in 28 patients (78%) for other diseases. The procedure most frequently causing IPnx was central venous catheterization, with 20 patients (55%), other frequent causes were mechanical ventilation, 8 cases (22%) of whom we reported 3 cases of bilateral pneumothorax, 6 cases of thoracentesis (16%) and 2 patients had life-saving percutaneous tracheotomy. The majority of our patients were managed by a small chest tube placement (unilateral n=30, bilateral n=3).The average duration of drainage was 3 days (range: 1-15 days), sadly one of our patients died of ischemic brain damage 15 days after tracheotomy.At training hospitals the incidence of IPnx will increase with the increase in invasive procedures, which should only be performed by experienced personnel or under their supervision

Modélisation et étude numérique de la pollution de la nappe phréatique

Une méthode numérique pour la simulation dynamique du transfert de masse dans le sol, causant la dégradation de la qualité des eaux souterraines est développée. Pour se faire, la méthode des différences finies est utilisée pour résoudre le problème et prévoir le profil des pressions, des vitesses de filtration, des saturations en eau et de la concentration du soluté.Modelisation and numerical study of groundwater pollutionA numerical method for the dynamic simulation of mass transfert in the ground wich participate in groudwater pollution is developed. To that purpose, the finite difference method is used to solve the solution of a system and in order to know profiles of pressure, filtrate velocity, water saturation and solute concentration

Procédure numérique pour la convection naturelle bidimensionnelle: Validation sur une géométrie rectangulaire

Cet article est le premier d'une série d’applications numériques consacrées à la validation d’une procédure numérique basée sur les différences finies et mise au point pour des problèmes bidimensionnels de convection naturelle en milieu confiné (principalement cylindrique). Dans un premier temps, on considère une géométrie rectangulaire et chauffée par le bas. On s’intéresse alors aux effets du nombre de Rayleigh et à l’influence de l’inclinaison de la cavité par rapport à l’horizontale sur la structure de l’écoulement et le transfert de chaleur

Effect of the COVID-19 pandemic on surgery for indeterminate thyroid nodules (THYCOVID): a retrospective, international, multicentre, cross-sectional study

Background Since its outbreak in early 2020, the COVID-19 pandemic has diverted resources from non-urgent and elective procedures, leading to diagnosis and treatment delays, with an increased number of neoplasms at advanced stages worldwide. The aims of this study were to quantify the reduction in surgical activity for indeterminate thyroid nodules during the COVID-19 pandemic; and to evaluate whether delays in surgery led to an increased occurrence of aggressive tumours.Methods In this retrospective, international, cross-sectional study, centres were invited to participate in June 22, 2022; each centre joining the study was asked to provide data from medical records on all surgical thyroidectomies consecutively performed from Jan 1, 2019, to Dec 31, 2021. Patients with indeterminate thyroid nodules were divided into three groups according to when they underwent surgery: from Jan 1, 2019, to Feb 29, 2020 (global prepandemic phase), from March 1, 2020, to May 31, 2021 (pandemic escalation phase), and from June 1 to Dec 31, 2021 (pandemic decrease phase). The main outcomes were, for each phase, the number of surgeries for indeterminate thyroid nodules, and in patients with a postoperative diagnosis of thyroid cancers, the occurrence of tumours larger than 10 mm, extrathyroidal extension, lymph node metastases, vascular invasion, distant metastases, and tumours at high risk of structural disease recurrence. Univariate analysis was used to compare the probability of aggressive thyroid features between the first and third study phases. The study was registered on ClinicalTrials.gov, NCT05178186.Findings Data from 157 centres (n=49 countries) on 87 467 patients who underwent surgery for benign and malignant thyroid disease were collected, of whom 22 974 patients (18 052 [78 center dot 6%] female patients and 4922 [21 center dot 4%] male patients) received surgery for indeterminate thyroid nodules. We observed a significant reduction in surgery for indeterminate thyroid nodules during the pandemic escalation phase (median monthly surgeries per centre, 1 center dot 4 [IQR 0 center dot 6-3 center dot 4]) compared with the prepandemic phase (2 center dot 0 [0 center dot 9-3 center dot 7]; p<0 center dot 0001) and pandemic decrease phase (2 center dot 3 [1 center dot 0-5 center dot 0]; p<0 center dot 0001). Compared with the prepandemic phase, in the pandemic decrease phase we observed an increased occurrence of thyroid tumours larger than 10 mm (2554 [69 center dot 0%] of 3704 vs 1515 [71 center dot 5%] of 2119; OR 1 center dot 1 [95% CI 1 center dot 0-1 center dot 3]; p=0 center dot 042), lymph node metastases (343 [9 center dot 3%] vs 264 [12 center dot 5%]; OR 1 center dot 4 [1 center dot 2-1 center dot 7]; p=0 center dot 0001), and tumours at high risk of structural disease recurrence (203 [5 center dot 7%] of 3584 vs 155 [7 center dot 7%] of 2006; OR 1 center dot 4 [1 center dot 1-1 center dot 7]; p=0 center dot 0039).Interpretation Our study suggests that the reduction in surgical activity for indeterminate thyroid nodules during the COVID-19 pandemic period could have led to an increased occurrence of aggressive thyroid tumours. However, other compelling hypotheses, including increased selection of patients with aggressive malignancies during this period, should be considered. We suggest that surgery for indeterminate thyroid nodules should no longer be postponed even in future instances of pandemic escalation.Funding None.Copyright (c) 2023 Published by Elsevier Ltd. All rights reserved

Study of a Low-Cost PV Emulator for Testing MPPT Algorithm Under Fast Irradiation and Temperature Change

International audienceThis paper presents a study of a low-cost photovoltaic (PV) emulator to test the real implementation of maximum power point tracking (MPPT) algorithm. This PV emulator is composed of a variable DC supply in series with a variable resistor; it is based on the maximum power transfer theorem in order to provide a curve that exhibits a peak which can be tracked by an MPPT algorithm. Moreover, this emulator can be used to test the performance of the MPPT algorithm under fast variation of the solar irradiance and temperature. For this reason, the P&O MPPT algorithm with a boost DC-DC converter is used in order to validate the functionality of the PV emulator. Finally, the experimental results show that our PV emulator can provide a simple, efficient and low-cost way for users (researchers, engineers, students, etc.) to test and validate their MPPT algorithms

Real-time virtual instrumentation of Arduino and LabVIEW based PV panel characteristics

International audienceThis paper describes a virtual instrument based on a low-cost embedded board to monitor and plot the PV panel characteristics under real operation condition. The system design is based on a low-cost Arduino acquisition board in which the ATMega328 microcontroller is integrated. The acquisition is made through a low-cost current and voltage sensors and the data are transmitted in LabVIEW by using LIFA Interface for Arduino. Hence, the I-V (current-voltage) and P-V (power-voltage) characteristics for PV panel, which processed under actual conditions, can be obtained and plotted directly on a monitoring platform in LabVIEW. The proposed instrument can be used for educational or research purposes using a low-cost and easily hardware without having extensive knowledge about electronic engineering. The present instrumentation technique provides easy access to the collected data for further analysis

Surgical treatment of aspergilloma grafted in hydatid cyst cavity

Aspergilloma is a saprophytic infection that colonizes pre-existing cavities in the lung. These cavities are caused by tuberculosis, bronchiectasis, lung cancer and other pulmonary diseases. Development of aspergilloma in the residual cavities after pulmonary hydatid cyst surgery is rarely described in terms of coexistence of the two conditions. We describe 3 cases of pulmonary aspergilloma grafted in a residual cavity of cystectomy for hydatid disease. Resumo: Aspergiloma é uma infecção saprófita que coloniza cavidades pré-existentes no pulmão. Estas cavidades são causadas por tuberculose, bronquiectasias, cancro do pulmão e outras doenças pulmonares. O desenvolvimento de aspergiloma em cavidades residuais, após cirurgia pulmonar de quisto hidático, raramente é descrito em termos de coexistência das duas condições. Descrevemos 3 casos de enxerto de aspergiloma pulmonar numa cavidade residual de cistectomia para doença hidática. Keywords: Hydatid cyst, Aspergilloma, Surgery, Capitonnage, Palavras-chave: Quisto hidático, Aspergiloma, Cirurgia, Capitonage

Investigation of Partial Shading Scenarios on a Photovoltaic Array’s Characteristics

The purpose of this study is to investigate the impact of different partial shading scenarios on a PV array’s characteristics in order to develop a simple and easy-to-implement GMPP controller that tracks the PV array’s global maximum power point (GMPP). The P-V characteristic of the PV array becomes more complicated under partial shading, owing to the presence of many power peaks, as opposed to uniform irradiance conditions, when there is only one peak called the maximum power point. In fact, and according to an experiment conducted in this study, when a PV array is partially shaded, the P-V characteristic mostly presents two peaks, given the existence of only two levels of irradiance, one of which is called the global peak (i.e., the GMPP). Furthermore, the first peak is located at Vmpp1 (the PV array’s voltage corresponds to this peak), whereas the second is at Vmpp2. The proposed approach works by estimating the values of Vmpp1 and Vmpp2 using two equations in order to control the DC/DC converter of the PV system. The first equation is used when the GMPP is at the first peak, while the other is used when the GMPP is at the second peak. Several scenarios are simulated and presented in this paper to verify the accuracy of these equations. In addition, some conclusions are drawn to suggest a simple method for tracking the GMPP