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A conventional hydrocyclones is a versatile equipment with a high processing capacity and low maintenance cost. Currently, several studies aim to alter the typical structure of the conventional hydrocyclone in order to modify its performance and purpose. For this, filtering hydrocyclones have emerged, where a porous membrane replaces the conic or cylindrical wall. During the operation of this equipment, in addition to the traditionally observed streams (feed, underflow, and overflow), there is a liquid stream resulting from the filtration process, commonly referred to as filtrate. This work proposes to numerically investigate the solid particle/liquid water separation process in a filtering hydrocyclone using the commercial software Ansys CFX® 15.0. The proposed mathematical model for the study considers three-dimensional, steady state and turbulent flow, using the Eulerian-Eulerian approach and the Shear Stress Transport (SST) turbulence model. This study presents and analyzes the volume fraction, velocity, and pressure fields, along with flowlines and velocity profiles. The results indicate that the proposed model effectively captures the fluid dynamic behavior within the filtering hydrocyclone, highlighting higher pressures near the porous membrane and a higher concentration of solid particles in the conical region, with water being more concentrated in the cylindrical part of the hydrocyclone. Additionally, the findings show that the volumetric flow rate of the filtrate significantly influences the internal flow dynamics, with conventional hydrocyclones demonstrating higher pressure gradients compared to the proposed filtering hydrocyclone.
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SMA actuators are a group of lightweight actuators that offer advantages over conventional technology and allow for simple and compact solutions to the increasing demand for electrical actuation. In particular, an increasing number of SMA torsional actuator applications have been published recently due to their ability to supply rotational motion under load, resulting in advantages such as module simplification and the reduction of overall product weight. This paper presents the conceptual design, operating principle, experimental characterization and working performance of torsional actuators applicable in active rudder in aeronautics. The proposed application comprises a pair of SMA torsion springs, which bi-directionally actuate the actuator by Joule heating and natural cooling. The experimental results confirm the functionality of the torsion springs actuated device and show the rotation angle of the developed active rudder was about 30° at a heating current of 5 A. After the design and experiment, one of their chief drawbacks is their relatively slow operating speed in rudder positioning, but this can be improved by control strategy and small modifications to the actuator mechanism described in this work.
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Enfermedades del Tejido Conjuntivo , Granuloma de Células Gigantes , Mucinosis , Enfermedades de la Piel , Humanos , Granuloma de Células Gigantes/genética , Proteínas Proto-Oncogénicas p21(ras)/genética , Enfermedades de la Piel/genética , Piel , Mucinosis/diagnóstico , Mucinosis/genéticaRESUMEN
Due to the increase in the number of people affected by chronic renal failure, the demand for hemodialysis treatment has increased considerably over the years. In this sense, theoretical and experimental studies to improve the equipment (hemodialyzer) are extremely important, due to their potential impact on the patient's life quality undergoing treatment. To contribute to this research line, this work aims to study the fluid behavior inside a hollow fiber dialyzer using computational fluid dynamics. In that new approach, the blood is considered as multiphase fluid and the membrane as an extra flow resistance in the porous region (momentum sink). The numerical study of the hemodialysis process was based on the development of a mathematical model that allowed analyzing the performance of the system using Ansys® Fluent software. The predicted results were compared with results reported in the literature and a good concordance was obtained. The simulation results showed that the proposed model can predict the fluid behavior inside the hollow fiber membrane adequately. In addition, it was found that the clearance decreases with increasing radial viscous resistance, with greater permeations in the vicinity of the lumen inlet region, as well as the emergence of the retrofiltration phenomenon, characteristic of this type of process. Herein, velocity, pressure, and volumetric fraction fields are presented and analyzed.
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In this work, recycled poly(ethylene terephthalate) (PETR) was blended with virgin high-density polyethylene (HDPE) in an internal mixer in an attempt to obtain a material with improved properties. A compatibilizer (PE-g-MA) and a chain extender (Joncryl) were added to the PETR/HDPE blend and the rheological and thermal properties of the modified and unmodified blends as well as those of virgin PET with virgin HDPE (PETV/HDPE). All the blends were characterized by torque rheometry, differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The data obtained indicate that the incorporation of either the chain extender or the compatibilizer agent led to increases in torque (and hence in viscosity) of the blend compared to that of the neat polymers. The joint incorporation of the chain extender and compatibilizer further increased the viscosity of the systems. Their effect on the crystallinity parameters of HDPE was minimal, but they reduced the crystallinity and crystallization temperature of virgin and recycled PET in the blends. The thermal stability of the PETR/HDPE blend was similar to that of the PETV/HDPE blend, and it was not affected by the incorporation of the chain extender and/or compatibilizer.
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Wastewater from the oil industry can be considered a dangerous contaminant for the environment and needs to be treated before disposal or re-use. Currently, membrane separation is one of the most used technologies for the treatment of produced water. Therefore, the present work aims to study the process of separating oily water in a module equipped with a ceramic membrane, based on the Eulerian-Eulerian approach and the Shear-Stress Transport (SST k-ω) turbulence model, using the Ansys Fluent® 15.0. The hydrodynamic behavior of the water/oil mixture in the filtration module was evaluated under different conditions of the mass flow rate of the fluid mixture and oil concentration at the entrance, the diameter of the oil particles, and membrane permeability and porosity. It was found that an increase in the feed mass flow rate from 0.5 to 1.5 kg/s significantly influenced transmembrane pressure, that varied from 33.00 to 221.32 kPa. Besides, it was observed that the particle diameter and porosity of the membranes did not influence the performance of the filtration module; it was also verified that increasing the permeability of the membranes, from 3 × 10-15 to 3 × 10-13 m2, caused transmembrane pressure reduction of 22.77%. The greater the average oil concentration at the permeate (from 0.021 to 0.037 kg/m3) and concentrate (from 1.00 to 1.154 kg/m3) outlets, the higher the average flow rate of oil at the permeate outlets. These results showed that the filter separator has good potential for water/oil separation.
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This research aims to study the process of separating water contaminated with oil using a hydrocyclone with a porous wall (membrane), containing two tangential inlets and two concentric outlets (concentrate and permeate), at the base of the equipment. For the study, the computational fluid dynamics technique was used in a Eulerian-Eulerian approach to solve the mass and linear momentum conservation equations and the turbulence model. The effects of the concentration polarization layer thickness and membrane rejection coefficient on the permeate flow, hydrodynamic behavior of the fluids inside the hydrocyclone, and equipment performance were evaluated. Results of the velocity, transmembrane pressure and oil concentration profiles along the equipment, and hydrocyclone performance are presented and analyzed. The results confirmed the effect of the membrane rejection coefficient on the equipment performance and the high potential of the hydrocyclone with a porous wall to be used in the oil-water mixture separation.
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Petroleum has been extracted from oil reservoirs using different techniques. This activity is accompanied for a large amount of water and sometimes mixed with gas. This produced water has a high oil concentration and other toxic chemical compounds, thus, it must be treated to be reused or released to environment according to environmental protection regulations. Currently, ceramic membrane technology has been employed in the wastewater treatment, due to its high benefit-cost ratio. In this sense, this work aims to study the oil-water mixture separation process using a new configuration of tubular ceramic membrane module by computational fluid dynamic (ANSYS Fluent software). The proposed model is composed of mass and linear momentum conservation equations coupled to Darcy's law and SST k-ω turbulence model. Results of the volumetric fraction, pressure, and velocity distribution of the oil and water phases are presented and discussed. The results indicated that the proposed model and new device both have great potential to be used on the water/oil separation process and that the transmembrane pressure remains constant in the axial direction and decreases radially through the membranes, indicating an efficient system that favors the transport of clean water and oil retention.
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Tumour metastasis is one of the leading cause of cancer-related mortality. Circulating tumour cells (CTCs) have been implicated in loco-regional and distant metastasis and its role is being extensively studied in various malignancies, including those from the head and neck region. The main challenge in understanding their significance lies in the rarity of these cells in the blood. However, newer technologies have attempted to overcome these pitfalls. This review explores the evolution of CTC research and other related areas, including its biological significance, sustainability within the circulating vascular environment and possible clinical implications.
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Productos Biológicos , Neoplasias de Cabeza y Cuello , Células Neoplásicas Circulantes , Recuento de Células , Humanos , Metástasis de la Neoplasia , Células Neoplásicas Circulantes/patologíaRESUMEN
Electronic cigarettes (e-cigarettes) are a popular method to help quit tobacco smoking. However, there is a paucity of data in the literature on their safety and efficacy. Recently, the Indian Government has called for a ban on all e-cigarettes and taken steps to restrict access to vaping products from the market. This major decision was an attempt to safeguard the younger population from using e-cigarette and their possible longer-term addiction together with its promotions by domestic industries. In this article, we evaluate the role of e-cigarettes to help stop smoking tobacco cessation and consider the factors that have facilitated the ban on e-cigarettes in India.
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Sistemas Electrónicos de Liberación de Nicotina , Cese del Hábito de Fumar/legislación & jurisprudencia , Vapeo/legislación & jurisprudencia , India , Fumar , Vapeo/efectos adversosRESUMEN
AIMS: Oral and/or oropharyngeal acute mucositis during and after chemo-radiotherapy (chemo-RT) for head and neck squamous cell carcinoma (HNSCC) can be extremely painful, sometimes requiring nasogastric feeding to enable adequate nutrition. The MASCC/ISOO evidence-based guidelines recommend benzydamine mouthwash for mucositis prevention in RT (recently updated to include chemo-RT), and a Cochrane systematic review found other agents to be effective in prophylaxis. Diclofenac mouthwash is licensed for painful oral mucosal inflammatory conditions but to our knowledge has not been assessed in chemo-RT-associated oral mucositis. METHOD: A clinical observation and service evaluation study in 10 patients undergoing chemo-RT for HNSCC to assess the potential value of diclofenac mouthwash (0.74 mg/mL) in reducing symptoms. Patients used 20ml of mouthwash up to 4 times a day starting in week 3 (of a 6-week course of treatment), recording pain and discomfort scores using a visual analogue scale on days 0, 1,7 and 14 (until the end of week 4). As per our current clinical practice, oral mucositis was not clinically scored as an outcome. Statistical analysis was performed using a one-way ANOVA. RESULTS: Using diclofenac mouthwash, 9/10 patients experienced pain score reduction from day 0 (mean score 6.75 ± SD 1.83) to day 2 (5.05 ± SD 1.62) and day 14 (4.09 ± SD 1.96). CONCLUSIONS: Diclofenac mouthwash may be beneficial for managing chemo-RT-induced oral mucositis. While a prospective randomised clinical trial is needed, it can be prescribed for this condition within its current licence.
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Neoplasias de Cabeza y Cuello , Traumatismos por Radiación , Estomatitis , Quimioradioterapia , Diclofenaco/uso terapéutico , Neoplasias de Cabeza y Cuello/radioterapia , Humanos , Antisépticos Bucales/uso terapéutico , Dolor/tratamiento farmacológico , Estudios Prospectivos , Traumatismos por Radiación/tratamiento farmacológico , Estomatitis/tratamiento farmacológico , Estomatitis/etiología , Estomatitis/prevención & controlRESUMEN
OBJECTIVE: To assess the efficacy of scaffold-mediated localized chemotherapy in cancer. METHODS: Databases including PubMed, Cochrane Library, and SCOPUS were searched for articles reporting the use of scaffold-mediated localized drug delivery in cancer. Essential data including scaffold fabrication material and methods, drug dosage and release duration and its effect on the cancer cells were extracted. RESULTS: 15 articles out of 60 screened, fulfilled the eligibility criteria. Among the 15 studies, 5 studies included only cell lines and 2 studies were on mouse models, while 8 studies involved a combination of cell lines and mouse models. Scaffold materials included both synthetic polymers such as poly-lactide, polycaprolactone and natural materials including d-periosteum and human micro-fragmented adipose tissueA wide number of other variables included the fabrication procedure, drugs used, and the methods used to assess the effects on cancer. As a result, it was not possible to make any direct comparison of the efficacy of the therapeutic strategy used in each of these studies. CONCLUSION: Irrespective of the many variables, a common consensus in all the included studies was that scaffold mediated localized drug delivery effectively reduced cancer cell viability by increasing drug bioavailability to the target tissue, while its localized effect reduced the risk of systemic toxicity.
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Sistemas de Liberación de Medicamentos , Neoplasias/tratamiento farmacológico , Animales , Línea Celular Tumoral , Humanos , PolímerosRESUMEN
Next-generation sequencing has revealed mutations in several bone-related lesions and was recently used to uncover the genetic basis of giant cell lesions of the jaws (GCLJ). Consistent with their benign nature, GCLJ show a low tumor mutation burden. They also harbor somatic, heterozygous, mutually exclusive mutations in TRPV4, KRAS, or FGFR1. These signature mutations occur only in a subset of lesional cells, suggesting the existence of a 'landscaping effect', with mutant cells inducing abnormal accumulation of non-mutant cells that form the tumor mass. Osteoclast-rich lesions with histological similarities to GCLJ can occur in the jaws sporadically or in association with genetically inherited syndromes. Based on recent results, the pathogenesis of a subgroup of sporadic GCLJ seems closely related to non-ossifying fibroma of long bones, with both lesions sharing MAPK pathway-activating mutations. In this review, we extrapolate from these recent findings to contextualize GCLJ genetics and we highlight the therapeutic implications of this new information. © 2019 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
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Tumores de Células Gigantes/genética , Neoplasias Maxilomandibulares/genética , Tumores de Células Gigantes/patología , Tumores de Células Gigantes/terapia , Granuloma de Células Gigantes/genética , Granuloma de Células Gigantes/patología , Granuloma de Células Gigantes/terapia , Secuenciación de Nucleótidos de Alto Rendimiento/métodos , Humanos , Neoplasias Maxilomandibulares/patología , Neoplasias Maxilomandibulares/terapia , Mutación , Proteínas Proto-Oncogénicas p21(ras)/genética , Receptor Tipo 1 de Factor de Crecimiento de Fibroblastos/genética , Canales Catiónicos TRPV/genéticaRESUMEN
The current three-tier grading system (well, moderate and poorly differentiated) used to morphologically classify head and neck squamous cell carcinoma (HNSCC) is inadequate for categorisation of oropharyngeal squamous cell carcinoma (OPSCC) owing to the lack of prognostic value. The aim of this study was to assess the validity of a classification system for OPSCC based on morphology and human papilloma virus (HPV) infection status. Haematoxylin and eosin slides of 121 patients (100 M, 21 F, age range 40-89 years) with OPSCC were reviewed and categorised as histological types I, II and III. The presence of HPV was assessed by immunohistochemistry with p16 and RNAscope In situ hybridization (ISH). The follow-up period was 36 months. Ninety-six patients were p16+ and clinical stage I. Patient survival with types I, II and III was 93%, 50% and 96%, respectively. Twenty-five patients were p16-: 10 clinical stage I and 15 stage III. Amongst this group, no type I morphology was identified. At follow-up, 65% of type II and 75% of type III patients were alive. All p16+ cases were also positive for E6/E7 mRNA high-risk HPV by ISH, while 23 p16- cases were negative and two were positive. Cox regression identified three predictors of mortality: older age (HR = 1.14, 95% CI = 1.06-1.23, P = .001); female gender (HR = 0.22.95% CI 0.05-0.88, P = .033); and type II morphology (HR = 13.1, 95% CI = 1.09-157.0, P = .043). OPSCC morphological classification in three sub-types, along with HPV infection status, seems to reflect the outcome of patients with OPSCC.
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Neoplasias Orofaríngeas , Papillomaviridae , Infecciones por Papillomavirus , Carcinoma de Células Escamosas de Cabeza y Cuello , Anciano , Anciano de 80 o más Años , Inhibidor p16 de la Quinasa Dependiente de Ciclina , Femenino , Humanos , Inmunohistoquímica , Persona de Mediana EdadRESUMEN
INTRODUCTION: Shammah is a form of smokeless tobacco commonly used in the Arabian Peninsula. The data on the harmful effects of shammah on oral health, particularly oral malignancies, are scarce. The aim of this review was to explore the association between shammah use and development of oral potentially malignant disorders (OPMD) and/or oral cancer. MATERIALS AND METHODS: PubMed, EMBASE, Scopus, Web of Science and grey literature from January 1990 up to and including April 2018 were searched. Two independent reviewers performed the study selection according to eligibility criteria. RESULTS: A total of 10 studies that met the eligibility criteria were included. The odds of developing OPMD and/or oral cancer in relation to shammah use varied, with one study reporting a 39 increased risk (39, 95% CI: 14-105). The associated increased risk was relatively low among those that have stopped using shammah and ranged from threefold (3.65; 95% CI: 1.40-9.50) to 12-fold (12.6; 95% CI: 3.3-48.2). CONCLUSION: Shammah use seems to increase the risk of development of OPMD and/or oral cancer.
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Enfermedades de la Boca/etiología , Neoplasias de la Boca/etiología , Tabaco sin Humo/efectos adversos , Humanos , Masticación , Medio Oriente , Salud BucalRESUMEN
OBJECTIVES: The establishment of animal models of xenotransplantation can contribute to the elucidation of the molecular pathogenesis of ameloblastic fibrodentinomas (AFD) and it also provides an opportunity for drug tests. We aimed to evaluate the possibility of AFD tumour growth in a patient-derived xenograft (PDX) model. In addition, we characterized the human tumour and the PDXs. MATERIALS AND METHODS: A sample of a recurrent AFD was obtained and two fragments were contralaterally implanted subcutaneously in an 8-week old female NUDE mouse. After 250 days, the PDXs were removed and submitted to histopathological and molecular analysis. Immunohistochemical reactions for Ki67 and the phosphorylated form of ERK1/2 were carried out in both, PDXs and human tumour, and the presence of BRAFV600E was assessed. RESULTS: From day 135 onwards, the PDXs presented a growth peak and remained stable until day 250. Histopathologically, the PDXs presented the same features of the patient's tumour. Tumour cells exhibited Ki67 and pERK1/2 immunoexpression in the patient's tumour and PDX. The AFD was wild-type for BRAFV600E. CONCLUSION: The PDX model recapitulated well the human tumour after a long implantation time, representing a possible model to study the AFD and other odontogenic tumours pathobiology.
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Xenoinjertos , Tumores Odontogénicos , Animales , Modelos Animales de Enfermedad , Femenino , Ratones , Ratones Desnudos , Trasplante HeterólogoRESUMEN
BACKGROUND: Despite much research, there is a lack of a definite protocol or method for documenting oral submucous fibrosis (OSMF) site presentation. In this study, we propose a new potential oral mapping (OM) method and evaluated its use in recording OSMF-affected mucosal sites. METHODS: Fifty OSMF patients were evaluated by 15 primary care dental practitioners using both, a conventional subjective recording method and a new OM method, to document the degree of involvement of affected oral mucosa with a crossover study design. Mann-Whitney test (non-parametric test) was used to make comparison between groups to determine any significant differences between the two identification methods. Wilcoxon tests were used to evaluate any significant differences in the difficulty in identification of two methods. RESULTS: There was a low agreement between the two methods used to detect OSMF in affected mucosal surfaces (P-value < 0.0001). More lesions were identified using the proposed OM method, and less discrepancy was found among dental practitioners. A difference in difficulty of OSMF documentation was found (Wilcoxon z = 3.615, P-value < 0.001), with the proposed OM method found to be easier. CONCLUSION: The proposed OM method appears to be useful for documentation, can easily be adapted in clinical practice, and effectively administered in clinical research. Additionally, it could be a useful tool to helping to maintain an OSMF database.
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Mucosa Bucal/patología , Fibrosis de la Submucosa Bucal/diagnóstico , Estudios Cruzados , Humanos , Estudios ProspectivosRESUMEN
INTRODUCTION: There has been a recent rise in popularity of waterpipe smoking (WPS) among younger people. While it is a tobacco-related product, research on the possible deleterious effects on health and its relationship with cancer is sparse. In this paper, we evaluated the existing literature and association of WPS with head and neck cancer. MATERIALS AND METHODS: PubMed, EMBASE, Scopus, Web of Science and grey literature from January 1990 up to and including March 2017 were searched. Two independent reviewers performed the study selection according to eligibility criteria. RESULTS: A total of seven studies that met the eligibility criteria were included. In four studies that evaluated the associated risk of oesophageal cancer, the odds ratio (OR) ranged from 1.69 (95% CI = 0.76-3.77) to 21.4 (95% CI = 11.6-39.5). The OR for the association of WPS with nasopharyngeal cancer and oral cancer was reported to be 0.49 (95% CI = 0.20-1.43) and 4.20 (95% CI = 1.32-13.3), respectively. One study that evaluated risk in different head and neck cancers reported 2-fold OR (2.73 [95% CI = 1.65-4.41]). CONCLUSION: On the basis of our evaluation, there is an association of WPS with head and neck cancer. However, larger studies with standardized methods are needed to identify the possible detrimental health effects of WPS more fully.
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Neoplasias de Cabeza y Cuello/epidemiología , Neoplasias de la Boca/epidemiología , Neoplasias Nasofaríngeas/epidemiología , Fumar en Pipa de Agua/efectos adversos , HumanosAsunto(s)
Fibroma , Células Gigantes , Humanos , Proteínas Quinasas Activadas por Mitógenos , MutaciónRESUMEN
The aim of the present study was to integrate the available data published on odontogenic myxoma (OM) into a comprehensive analysis of its clinical/radiological features. Electronic search undertaken in January/2018, looking for publications reporting cases of OM. A total of 377 publications were included. We identified 1,692 lesions, and 695 were used for the analysis of recurrence. There is a predominance of OMs in females and in mandibles. OMs usually present with bone expansion, asymptomatic cortical perforation, and a multilocular appearance. Lesion location (maxilla/mandible), bone expansion, cortical bone perforation, locular radiological appearance, tooth resorption, odontogenic epithelial rests, or angular septa are not associated with recurrence. While curettage (31.3%) showed the highest recurrence rate, marginal resection (1.3%) and segmental resection (3.1%) showed the lowest values. Enucleation + peripheral osteotomy (6.7%) showed better results than enucleation (13.1%) or enucleation + curettage (12.7%). In comparison with unilocular lesions, multilocular ones were significantly more prevalent in mandibles, more often presented expansion and cortical bone perforation, had larger mean size, and were more often treated by segmental resection. Conservative surgical procedures are associated with higher probability of recurrence of OM. Taking into consideration the recurrence rate and morbidity associated with different surgical treatments, tumor enucleation followed by peripheral osteotomy should be considered as the first therapeutic choice.