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An interosseous ganglion cyst is a very rare entity, found mostly in skeletally mature patients, particularly in long bones such as the tibia and femur. However, we are the first to report here an unusual case of interosseous ganglion cyst of the upper ribs in a young female patient, which she had an unpredicted presentation of cough and hemoptysis and a large painful lump over the anterior left upper chest. The radiological and pathological workup confirmed the presence of a benign interosseous ganglion cyst arising from the left first rib, invading the second rib and the apex of the left lung. The patient has been treated successfully by surgical resection of this rib cyst. However, we could not find any reported cases in the current literature of an interosseous ganglion cyst pathology arising in the ribs with a similar presentation of cough and hemoptysis.
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Thermal energy storage units conventionally have the drawback of slow charging response. Thus, heat transfer enhancement techniques are required to reduce charging time. Using nanoadditives is a promising approach to enhance the heat transfer and energy storage response time of materials that store heat by undergoing a reversible phase change, so-called phase change materials. In the present study, a combination of such materials enhanced with the addition of nanometer-scale graphene oxide particles (called nano-enhanced phase change materials) and a layer of a copper foam is proposed to improve the thermal performance of a shell-and-tube latent heat thermal energy storage (LHTES) unit filled with capric acid. Both graphene oxide and copper nanoparticles were tested as the nanometer-scale additives. A geometrically nonuniform layer of copper foam was placed over the hot tube inside the unit. The metal foam layer can improve heat transfer with an increase of the composite thermal conductivity. However, it suppressed the natural convection flows and could reduce heat transfer in the molten regions. Thus, a metal foam layer with a nonuniform shape can maximize thermal conductivity in conduction-dominant regions and minimize its adverse impacts on natural convection flows. The heat transfer was modeled using partial differential equations for conservations of momentum and heat. The finite element method was used to solve the partial differential equations. A backward differential formula was used to control the accuracy and convergence of the solution automatically. Mesh adaptation was applied to increase the mesh resolution at the interface between phases and improve the quality and stability of the solution. The impact of the eccentricity and porosity of the metal foam layer and the volume fraction of nanoparticles on the energy storage and the thermal performance of the LHTES unit was addressed. The layer of the metal foam notably improves the response time of the LHTES unit, and a 10% eccentricity of the porous layer toward the bottom improved the response time of the LHTES unit by 50%. The presence of nanoadditives could reduce the response time (melting time) of the LHTES unit by 12%, and copper nanoparticles were slightly better than graphene oxide particles in terms of heat transfer enhancement. The design parameters of the eccentricity, porosity, and volume fraction of nanoparticles had minimal impact on the thermal energy storage capacity of the LHTES unit, while their impact on the melting time (response time) was significant. Thus, a combination of the enhancement method could practically reduce the thermal charging time of an LHTES unit without a significant increase in its size.
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Cobre/química , Grafito/química , Conductividad Térmica , Calor , Metales , Nanopartículas , PorosidadRESUMEN
A wavy shape was used to enhance the thermal heat transfer in a shell-tube latent heat thermal energy storage (LHTES) unit. The thermal storage unit was filled with CuO-coconut oil nano-enhanced phase change material (NePCM). The enthalpy-porosity approach was employed to model the phase change heat transfer in the presence of natural convection effects in the molten NePCM. The finite element method was applied to integrate the governing equations for fluid motion and phase change heat transfer. The impact of wave amplitude and wave number of the heated tube, as well as the volume concertation of nanoparticles on the full-charging time of the LHTES unit, was addressed. The Taguchi optimization method was used to find an optimum design of the LHTES unit. The results showed that an increase in the volume fraction of nanoparticles reduces the charging time. Moreover, the waviness of the tube resists the natural convection flow circulation in the phase change domain and could increase the charging time.
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Aceite de Coco/química , Cobre/química , Convección , Calor , Modelos Teóricos , Movimiento (Física) , Nanopartículas , Porosidad , TermodinámicaRESUMEN
Thermal energy storage is a technique that has the potential to contribute to future energy grids to reduce fluctuations in supply from renewable energy sources. The principle of energy storage is to drive an endothermic phase change when excess energy is available and to allow the phase change to reverse and release heat when energy demand exceeds supply. Unwanted charge leakage and low heat transfer rates can limit the effectiveness of the units, but both of these problems can be mitigated by incorporating a metal foam into the design of the storage unit. This study demonstrates the benefits of adding copper foam into a thermal energy storage unit based on capric acid enhanced by copper nanoparticles. The volume fraction of nanoparticles and the location and porosity of the foam were optimized using the Taguchi approach to minimize the charge leakage expected from simulations. Placing the foam layer at the bottom of the unit with the maximum possible height and minimum porosity led to the lowest charge time. The optimum concentration of nanoparticles was found to be 4 vol.%, while the maximu possible concentration was 6 vol.%. The use of an optimized design of the enclosure and the optimum fraction of nanoparticles led to a predicted charging time for the unit that was approximately 58% shorter than that of the worst design. A sensitivity analysis shows that the height of the foam layer and its porosity are the dominant variables, and the location of the porous layer and volume fraction of nanoparticles are of secondary importance. Therefore, a well-designed location and size of a metal foam layer could be used to improve the charging speed of thermal energy storage units significantly. In such designs, the porosity and the placement-location of the foam should be considered more strongly than other factors.
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Cobre/química , Ácidos Decanoicos/química , Nanopartículas/química , Temperatura , Tamaño de la Partícula , Transición de Fase , Porosidad , Propiedades de SuperficieRESUMEN
In the present study, the thermal energy storage of a hot petal tube inside a shell-tube type Thermal Energy Storage (TES) unit was addressed. The shell is filled with the capric acid Phase Change Material (PCM) and absorbs the heat from a hot U-tube petal. The governing equations for the natural convection flow of molten PCM and phase change heat transfer were introduced by using the enthalpy-porosity approach. An automatic adaptive mesh scheme was used to track the melting interface. The accuracy and convergence of numerical computations were also controlled by a free step Backward Differentiation Formula. The modeling results were compared with previous experimental data. It was found that the present adaptive mesh approach can adequately the melting heat transfer, and an excellent agreement was found with available literature. The effect of geometrical designs of the petal tube was investigated on the melting response of the thermal energy storage unit. The phase change behavior was analyzed by using temperature distribution contours. The results showed that petal tubes could notably increase the melting rate in the TES unit compared to a typical circular tube. Besides, the more the petal numbers, the better the heat transfer. Using a petal tube could increase the charging power by 44% compared to a circular tube. The placement angle of the tubes is another important design factor which should be selected carefully. For instance, vertical placement of tubes could improve the charging power by 300% compared to a case with the tubes' horizontal placement.
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Temperatura de Transición , Ácidos Decanoicos/química , TermodinámicaRESUMEN
Artificial intelligence (AI) is now a trendy subject in clinical medicine and especially in gastrointestinal (GI) endoscopy. AI has the potential to improve the quality of GI endoscopy at all levels. It will compensate for humans' errors and limited capabilities by bringing more accuracy, consistency, and higher speed, making endoscopic procedures more efficient and of higher quality. AI showed great results in diagnostic and therapeutic endoscopy in all parts of the GI tract. More studies are still needed before the introduction of this new technology in our daily practice and clinical guidelines. Furthermore, ethical clearance and new legislations might be needed. In conclusion, the introduction of AI will be a big breakthrough in the field of GI endoscopy in the upcoming years. It has the potential to bring major improvements to GI endoscopy at all levels.
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Inteligencia Artificial , Diagnóstico por Computador/métodos , Endoscopía Gastrointestinal/métodos , Endoscopía Capsular , Colonoscopía/métodos , Neoplasias Colorrectales/diagnóstico , Esofagoscopía , Humanos , Neoplasias Gástricas/diagnósticoRESUMEN
INTRODUCTION: Following publication of improved patients' outcome using first line FOLFIRINOX for metastatic pancreatic adenocarcinoma, many physicians now prescribe it as neo-adjuvant or induction treatment for borderline and locally advanced pancreatic cancer. A pathologic complete response, rarely seen with previous preoperative regimens, is sometimes observed in these patients. The aim of this study was to assess long-term outcomes of patients presenting pathologic complete response after preoperative FOLFIRINOX usually followed by chemo-radiation therapy for non-metastatic pancreatic adenocarcinoma. MATERIAL AND METHODS: We retrospectively identified all resected patients with pancreatic cancer presenting pathologic complete response after FOLFIRINOX in 9 French centers from the AGEO group between November 2010 and May 2017. RESULTS: 29 patients were enrolled, 14 had borderline, 14 locally advanced and 1 oligo-metastatic pancreatic cancer. M/F ratio was 1.2 and the mean age was 57 years. All patients were treated with FOLFIRINOX (n = 29), de-escalated to gemcitabine (n = 1) and FOLFIRI (n = 2), and 24 (83 %) received radiation therapy after chemotherapy. Objective response rate to preoperative chemotherapy was 66% (RECIST V1.1). Only 8 patients received postoperative chemotherapy. After a median follow-up of 34 months from surgery, the median overall survival was not reached and the median disease free survival was 48 months. The 1-year and 2-year survival rates were 100% for OS and 96% and 72 % for DFS from surgery, 8 of the 9 observed recurrences were distant metastases. CONCLUSIONS: The promising 1 and 2-year overall survival and disease free survival rates suggest that pathologic complete response is a major prognostic factor in resected pancreatic cancer following preoperative chemo-radiotherapy. A longer follow-up and prospective series are now necessary to confirm these encouraging results and to potentially validate pathologic complete response as a relevant surrogate marker of preoperative treatment efficacy.