179 research outputs found

    Trapped by the Entrapment.

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    Popliteal entrapment syndrome results from extrinsic compression of the popliteal artery by the surrounding musculotendinous structures and is a rare cause of limb ischaemia. The purpose of this report is to highlight potential mistakes in the management of popliteal entrapment. In 2000, a 23 year old man underwent a popliteal to popliteal artery bypass surgery for what was initially diagnosed as a traumatic popliteal artery thrombosis. After being initially lost to follow up for 13 years, this "unspecified traumatic" thrombosis led to several inappropriate endovascular and open procedures misinterpreted as being caused by late graft failure. These included thrombectomy, aneurysmorrhaphy, polytetrafluoroethylene covered stent graft, a redo femoropopliteal bypass, and bypass thrombolysis. The diagnosis was reached 19 years after the initial surgery, when the patient underwent a redo bypass using a retrogeniculate approach. An abnormal lateral insertion of the gastrocnemius muscle medial head, and its accessory slip, constricted the artery, and also involved the popliteal vein (Type V), thus explaining previous revascularisation failures. Surgery consisted of resecting the accessory slip and the aneurysmal bypass. The artery was reconstructed with the cephalic vein. The patient was discharged on clopidogrel 75 mg, with no further complication, and a patent bypass at six months. Based on post-operative imaging (duplex ultrasound and magnetic resonance imaging), with forced plantarflexion and dorsiflexion, asymptomatic popliteal entrapment was also present on the contralateral side. The finding of an isolated popliteal artery lesion in a young individual should be considered to be caused by popliteal artery entrapment, unless proven otherwise. Definitive surgical release of the popliteal artery should be favoured over other strategies

    Serum antibody response in critically ill patients with COVID-19.

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    A Gardening Session Turns Into a Life Threatening Aortic Transection.

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    Penetrating injuries to the sub-diaphragmatic aorta are challenging, with high mortality rates. Most penetrating aortic trauma results from gunshots or stab wounds. This case reports a successful aortic bypass, following partial aortic transection caused by an accidental fall on a utility knife. A healthy 82 year old woman was admitted to the emergency department following penetrating abdominal trauma following an accidental fall on an 18 cm long utility knife. On admission, the patient was haemodynamically stable, with no neurological deficit. Computed tomography angiography revealed multiple abdominal injuries to the stomach, duodenum, L4-L5 left vertebrae, and infrarenal abdominal aorta. The patient underwent urgent midline laparotomy, followed by successful aortic repair using a 14 mm polyester graft. The gastric and duodenal lesions were repaired with an omental patch. The post-operative course was uneventful. Penetrating abdominal trauma with visceral lesions and aortic transection are high risk injuries, albeit rarely described in the literature. A low threshold for imaging, and multidisciplinary management by vascular and visceral surgeons are essential for timely recognition and successful intervention

    PID Controller Tuning Using Bode's Integrals

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    A new method for PID controller tuning based on Bode's integrals is proposed. It is shown that the derivatives of amplitude and phase of a plant model with respect to frequency can be approximated by Bode's integrals without any model of the plant. This information can be used to design a PID controller for slope adjustment of the Nyquist diagram and improve the closed-loop performance. Besides, the derivatives can be also employed to estimate the gradient and the Hessian of a frequency criterion in an iterative PID controller tuning method. The frequency criterion is defined as the sum of squared errors between the desired and measured gain margin, phase margin and crossover frequency. The method benefits from specific feedback relay tests to determine the gain margin, the phase margin and the crossover frequency of the closed-loop system. Simulation examples and experimental results illustrate the effectiveness and the simplicity of the proposed method to design and tune the PID controllers

    Characterization of tephra deposits with limited exposure: the example of the two largest explosive eruptions at Nisyros volcano (Greece)

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    Explosive eruptions associated with tephra deposits that are only exposed in proximal areas are difficult to characterize. In fact, the determination of physical parameters such as column height, mass eruption rate, erupted volume, and eruption duration is mainly based on empirical models and is therefore very sensitive to the quality of the field data collected. We have applied and compared different modeling approaches for the characterization of the two main tephra deposits, the Lower Pumice (LP) and Upper Pumice (UP) of Nisyros volcano, Greece, which are exposed only within 5km of the probable vent. Isopach and isopleth maps were compiled for two possible vent locations (on the north and on the south rim of the caldera), and different models were applied to calculate the column height, the erupted volume, and the mass eruption rate. We found a column height of about 15km above sea level and a mass eruption rate of about 2 × 107kg/s for both eruptions regardless of the vent location considered. In contrast, the associated wind velocity for both UP and LP varied between 0 and 20m/s for the north and south vent, respectively. The derived erupted volume for the south vent (considered as the best vent location) ranges between 2 and 27 × 108m3 for the LP and between 1 and 5 × 108m3 for the UP based on the application of four different methods (integration of exponential fit based on one isopach line, integration of exponential and power-law fit based on two isopach lines, and an inversion technique combined with an advection-diffusion model). The eruption that produced the UP could be classified as subplinian. Discrepancies associated with different vent locations are smaller than the discrepancies associated with the use of different models for the determination of erupted mass, plume height, and mass eruption rate. Proximal outcrops are predominantly coarse grained with ≥90wt% of the clasts ranging between −6ϕ and 0ϕ. The associated total grainsize distribution is considered to result from a combination of turbulent fallout from both the plume margins and the umbrella region, and as a result, it is fines-depleted. Given that primary deposit thickness observed on Nisyros for both LP and UP is between 1 and 8m, if an event of similar scale were to happen again, it would have a significant impact on the entire island with major damage to infrastructure, agriculture, and tourism. Neighboring islands and the continent could also be significantly affecte

    De la sociologie de l'innovation à l'imagination sociologique : la théorie des champs à l'épreuve de la profession infirmière

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    Si l'on suit la perspective de Saussure pour qui le point de vue crée l'objet, la « nouveauté » d'un objet sociologique suppose au moins autant le renouvellement de son approche que la « nouveauté intrinsèque » de celui-ci. Dans cet article, nous privilégions la voie d'un tel renouvellement en mettant à l'épreuve un « vieil objet » par une « approche ancienne ». Nous inscrivant à contre-courant d'une tendance à la parcellisation de la discipline en sociologies thématiques, nous montrons la valeur heuristique qu'il y a à saisir une profession comme un espace social de positions différenciées qui ne prend sens qu'une fois réinscrit dans le champ au sein duquel il s'insère. Largement féminisée et partiellement dominée, la profession infirmière est soumise à une théorie traditionnellement mobilisée pour l'étude de groupes masculins et dominants : la théorie des champs de Pierre Bourdieu

    PID CONTROLLER DESIGN WITH SPECIFICATIONS ON THE INFINITY-NORM OF SENSITIVITY FUNCTIONS

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    Alguns serviços da administração pública requerem uma mudança em seu modelo de funcionamento, a fim de assegurar mobilidade, agilidade, eliminação de retrabalho e melhores maneiras de disponibilização da informação. Nesse cenário, o Batalhão de Trânsito da Polícia Militar do Estado de Mato Grosso, devido ao crescimento da malha rodoviária urbana, ao excesso de imprudência dos condutores de veículos, à quantidade reduzida de policiais para atender a grande demanda do estado, buscou evoluir em seus processos de fiscalização e autuação. Um indicador importante dessa crítica situação é o fato de um percentual elevado de infrações aplicadas aos condutores de veículos não se concretizarem em efetiva cobrança devido à demora em dar entrada aos dados nos sistemas da segurança pública e do Departamento de Trânsito, e também para processar essas informações e a posterior intimação do infrator. O período legal para todo esse processo acontecer é sempre extrapolado devido à falta de recursos que possam dar agilidade a esse processo que ainda é manual, off-line e repetitivo, considerando que os dados são digitados novamente por órgãos diferentes, porém do mesmo Estado. O acesso à informação dos condutores, dos veículos e das infrações de uma forma ágil e consolidada, provê hoje uma tomada de decisão mais rápida e assertiva pelos policiais em atividade nos pontos de fiscalização. Considerando ainda que a natureza dessa atividade da Polícia Militar não é em pontos fixos na cidade e a estratégia é sempre atuar em pontos diferentes e de trânsito confuso e conflitante. Uma forma de proporcionar esse benefício foi com a disponibilização de recursos tecnológicos para o acesso móvel à base de dados do Departamento de Trânsito, tanto para as consultas quanto para a autuação e sua consequente geração de infração. A MTI viabilizou o processo de contratação do serviço em setembro/13. Foi possível iniciar o projeto em dezembro/13 com o Batalhão de Trânsito da Polícia Militar. A solução foi implantada em março/14 com a disponibilização de 100 dispositivos móveis, porém foi liberado efetivamente em produção somente em maio/14. A expansão para 300 dispositivos ocorreu em julho/2016. Em setembro/2016 já foi expandido novamente para atender aos processos de vistoria de veículos no Detran-MT.13 p.Gestão PúblicaGovernançaTecnologia da Informação e ComunicaçãoIniciativa premiada no 21º Concurso Inovação no Setor Público sob responsabilidade de Sandro Luis Brandão Campos Assessor da Presidência – analista de TI. Iniciativas premiadas no 21º Concurso Inovação no Setor Público 2016. Área temática: Processos organizacionais, serviços ou políticas públicas no Poder Executivo estadual/ distrita

    On-line arithmetic for real-time control of microsystems

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    Venous thromboembolism in critically Ill patients with COVID-19: Results of a screening study for deep vein thrombosis.

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    The rapid spread of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and coronavirus disease 2019 (COVID-19), has caused more than 3.9 million cases worldwide. Currently, there is great interest to assess venous thrombosis prevalence, diagnosis, prevention, and management in patients with COVID-19. To determine the prevalence of venous thromboembolism (VTE) in critically ill patients with COVID-19, using lower limbs venous ultrasonography screening. Beginning March 8, we enrolled 25 patients who were admitted to the intensive care unit (ICU) with confirmed SARS-CoV-2 infections. The presence of lower extremity deep vein thrombosis (DVT) was systematically assessed by ultrasonography between day 5 and 10 after admission. The data reported here are those available up to May 9, 2020. The mean (± standard deviation) age of the patients was 68 ± 11 years, and 64% were men. No patients had a history of VTE. During the ICU stay, 8 patients (32%) had a VTE; 6 (24%) a proximal DVT, and 5 (20%) a pulmonary embolism. The rate of symptomatic VTE was 24%, while 8% of patients had screen-detected DVT. Only those patients with a documented VTE received a therapeutic anticoagulant regimen. As of May 9, 2020, 5 patients had died (20%), 2 remained in the ICU (8%), and 18 were discharged (72%). In critically ill patients with SARS-CoV-2 infections, DVT screening at days 5-10 of admission yielded a 32% prevalence of VTE. Seventy-five percent of events occurred before screening. Earlier screening might be effective in optimizing care in ICU patients with COVID-19

    Low-energy electron holographic imaging of individual tobacco mosaic virions

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    Modern structural biology relies on NMR, X-ray crystallography and cryo-electron microscopy for gaining information on biomolecules at nanometer, sub-nanometer or atomic resolution. All these methods, however, require averaging over a vast ensemble of entities and hence knowledge on the conformational landscape of an individual particle is lost. Unfortunately, there are now strong indications that even X-ray free electron lasers will not be able to image individual molecules but will require nanocrystal samples. Here, we show that non-destructive structural biology of single particles has now become possible by means of low-energy electron holography. As an example, individual tobacco mosaic virions deposited on ultraclean freestanding graphene are imaged at one nanometer resolution revealing structural details arising from the helical arrangement of the outer protein shell of the virus. Since low-energy electron holography is a lens-less technique and since electrons with a deBroglie wavelength of approximately 1 Angstrom do not impose radiation damage to biomolecules, the method has the potential for Angstrom resolution imaging of single biomolecules
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