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1.
Biomech Model Mechanobiol ; 19(5): 1925-1933, 2020 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-32125543

RESUMEN

In the present investigation, we have studied the effects of heat transfer on the peristaltic flow considering the Phan-Thien-Tanner fluid model. The fluid is flowing in a uniform circular tube in the form of wave motion. The inner walls of the tube are considered to be ciliated with small hair-like structures. Exact solutions have been derived for velocity, temperature and pressure gradient. Mechanical properties of the fluid, such as velocity, temperature, pressure rise and pressure gradient, have been discussed graphically. Trapping phenomena due to the variation of physical parameters have been deliberated. It has been observed that when the viscous forces are greater than the elastic forces, the velocity of the fluid flow significantly decreases, thermal conductivity of the fluid improves and the pressure gradient along the tube increases.


Asunto(s)
Cilios/fisiología , Calor , Modelos Biológicos , Peristaltismo , Reología , Presión
2.
Int J Exp Pathol ; 99(1): 10-14, 2018 02.
Artículo en Inglés | MEDLINE | ID: mdl-29473241

RESUMEN

Non-dysplastic Barrett's oesophagus (NDBE) occurs as a consequence of an inflammatory response triggered through prolonged gastro-oesophageal reflux and it may precede the development of oesophageal adenocarcinoma. NF-κB activation as a result of the inflammatory response has been shown in NDBE, but the possible mechanism involved in the process is unknown. The aim of this study was to assess, using immunohistochemistry, Survivin and Bcl3 expression as potential biomarkers for NF-κB activation along the oesophageal metaplasia-dysplasia-adenocarcinoma sequence. Survivin is an NF-κB-inducible anti-apoptotic protein, and Bcl3 is a negative regulator of NF-κB. There was progressive upregulation of Survivin expression along the oesophageal metaplasia-dysplasia-adenocarcinoma sequence. Bcl3 expression was upregulated in non-dysplastic Barrett's oesophagus, low-grade, high-grade dysplasia and oesophageal adenocarcinoma when compared to squamous group. The study shows the differential expression of Bcl3 between the squamous and Barrett's stage, suggesting that Bcl3 could be a surrogate marker for early event involving constitutive NF-κB activation. In addition, the study suggests that NF-κB activation may infer resistance to apoptosis through the expression of anti-apoptotic genes such as Survivin, which showed progressive increase in expression throughout the oesophageal metaplasia-dysplasia-adenocarcinoma sequence. This ability to avoid apoptosis may underlie the persistence and malignant predisposition of Barrett's metaplasia.


Asunto(s)
Adenocarcinoma/química , Esófago de Barrett/metabolismo , Biomarcadores de Tumor/análisis , Transformación Celular Neoplásica/química , Neoplasias Esofágicas/química , Esófago/química , Inmunohistoquímica , Proteínas Inhibidoras de la Apoptosis/análisis , FN-kappa B/análisis , Proteínas Proto-Oncogénicas/análisis , Factores de Transcripción/análisis , Adenocarcinoma/patología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Apoptosis , Proteínas del Linfoma 3 de Células B , Esófago de Barrett/patología , Biopsia , Transformación Celular Neoplásica/patología , Neoplasias Esofágicas/patología , Esófago/patología , Femenino , Humanos , Masculino , Metaplasia , Persona de Mediana Edad , Transducción de Señal , Survivin , Adulto Joven
3.
Comput Methods Programs Biomed ; 146: 1-9, 2017 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-28688478

RESUMEN

BACKGROUND AND OBJECTIVES: This paper aims to investigate the unsteady flow of two types of nanofluids i.e Copper water nanofluids and Silver water nanofluids) through finite length non-uniform channel driven by peristaltic sinusoidal wave propagations. METHODS: The governing equations are reduced in linear form using dimensional analysis and considering the low Reynolds number and large wavelength approximations. The time dependent temperature field, axial velocity, transverse velocity and pressure difference are obtained analytically in closed form solution. Trapping phenomenon is also discussed with the help of contour plots of stream function. A comparative study of pure water (Newtonian fluid), Copper water nanofluids and Silver water nanofluids under the influence of relevant physical parameters is made in graphical form and also discussed. The effects of absorption parameter and Grashof number on velocity profiles, temperature profiles and pressure distribution along the length of channel are examined. RESULTS CONCLUSIONS: The computational results reveal that the velocity profile is maximum for Silver water nanofluids however, it is least for Copper water nanofluids. It is also concluded the temperature profile is more for pure water in comparison to Silver water and Copper water nanofluids. This model is applicable to design, micro-peristaltic pumps which help in Nanoparticle-based targeted drug delivery and to transport the sensitive or corrosive fluids, sanitary fluids, slurries and noxious fluids in nuclear industry.


Asunto(s)
Cobre/análisis , Nanoestructuras/análisis , Reología , Plata/análisis , Agua/análisis , Presión
4.
Comput Methods Programs Biomed ; 134: 43-51, 2016 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-27480731

RESUMEN

BACKGROUND AND OBJECTIVES: The present investigation is associated with the contemporary study of viscous flow in a vertical tube with ciliary motion. METHODS/RESULTS/CONCLUSIONS: The main flow problem has been modeled using cylindrical coordinates; flow equations are simplified to ordinary differential equations using longwave length and low Reynold's number approximation; and exact solutions have been obtained for velocity, pressure gradient and temperature. Results acquired are discussed graphically for better understanding. Streamlines for the velocity profile are plotted to discuss the trapping phenomenon. It is seen that with an increment in the Grashof number, the velocity of the governing fluids starts to decrease significantly.


Asunto(s)
Cilios/fisiología , Nanopartículas del Metal/química , Modelos Teóricos , Gráficos por Computador
5.
Hepatology ; 58(1): 128-38, 2013 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-23315950

RESUMEN

UNLABELLED: The global prevalence of obesity-induced liver disease (nonalcoholic fatty liver disease; NAFLD) is rising. Suggested causes include a role for in utero influences of maternal obesity compounded by the availability of energy-dense foods throughout postnatal life. Using a physiologically relevant model, we investigated the role of the innate immune system in liver injury induced by maternal obesity followed by a postnatal obesogenic diet. Female C57BL/6J mice were fed a standard or obesogenic diet before and throughout pregnancy and during lactation. Female offspring were weaned onto a standard or obesogenic diet at 3 weeks postpartum. Biochemical and histological indicators of dysmetabolism, NAFLD and fibrosis, analysis of profibrotic pathways, liver innate immune cells, and reactive oxygen species (ROS) were investigated at 3, 6, and 12 months. Female offspring exposed to a postweaning obesogenic diet (OffCon-OD) demonstrated evidence of liver injury, which was exacerbated by previous exposure to maternal obesity (OffOb-OD), as demonstrated by raised alanine aminotransferase, hepatic triglycerides, and hepatic expression of interleukin (IL)-6, tumor necrosis factor alpha, transforming growth factor beta, alpha smooth muscle actin, and collagen (P < 0.01). Histological evidence of hepatosteatosis and a more-robust NAFLD phenotype with hepatic fibrosis was observed at 12 months in OffOb-OD. A role for the innate immune system was indicated by increased Kupffer cell numbers with impaired phagocytic function and raised ROS synthesis (P < 0.01), together with reduced natural killer T cells and raised interleukin (IL)-12 and IL-18. CONCLUSION: Maternal obesity in the context of a postnatal hypercalorific obesogenic diet aggressively programs offspring NAFLD associated with innate immune dysfunction, resulting in a comprehensive phenotype that accurately reflects the human disease.


Asunto(s)
Grasas de la Dieta/efectos adversos , Hígado Graso/etiología , Hígado Graso/inmunología , Inmunidad Innata/inmunología , Hígado/inmunología , Obesidad/etiología , Efectos Tardíos de la Exposición Prenatal , Animales , Grasas de la Dieta/metabolismo , Femenino , Hepatopatías/etiología , Hepatopatías/patología , Ratones , Ratones Endogámicos C57BL , Enfermedad del Hígado Graso no Alcohólico , Obesidad/fisiopatología , Embarazo
6.
Saudi Med J ; 25(10): 1394-9, 2004 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-15494809

RESUMEN

OBJECTIVE: To describe clinical characteristics, interventions required, and outcome of critically ill obstetric patients admitted to a general intensive care unit (ICU). METHODS: All obstetric patients admitted to ICU at Armed Forces Hospital, Riyadh, Kingdom of Saudi Arabia from 1997 to 2002 were included in the study. The data related to demographics, obstetric history, pre-existing medical problems, indications for ICU admission, intervention required, length of stay, and outcome of ICU admission were collected by retrospective review of medical records. RESULTS: The 99 obstetric admissions to ICU were represented by 0.2% of all deliveries and 1.6% of all ICU admissions. Most patients were young (median age of 30 years) with parity (median) of 3 and stayed in ICU for an average of 2 days. All except one patient were admitted during the postpartum period. The majority (76%) were admitted after cesarean section. Obstetric hemorrhage (32%) and hypertension (29%) were the 2 most common indications for admission. The majority (59/99) of patients also had pre-existing medical problem and most common (16/59) was rheumatic heart disease. Preeclampsia (23/99) and eclampsia 10/99 were the most frequent obstetric complication. Thirty-six percent of our patients required ventilatory support. In the majority of patients, direct arterial (81%) and central venous (73%) pressure monitoring was carried out. Pulmonary arterial and left atrial pressure was monitored in 4%. Almost one third of patients received antihypertensive therapy. Inotropic support was given to 9% and blood (and its products) was given to 46% of patients. Antibiotics (28%) and magnesium sulphate (25%) were the most frequently used medicines. Out of the total 99 admissions, one patient died and 16 patients developed complications. CONCLUSION: In our survey, the 2 most common indications for admitting obstetric patients to ICU were hemorrhage and hypertension. Invasive hemodynamic monitoring and ventilatory support are the 2 main interventions. Improving quality of care before and after admission to ICU may reduce maternal morbidity.


Asunto(s)
Unidades de Cuidados Intensivos/estadística & datos numéricos , Complicaciones del Trabajo de Parto/terapia , Admisión del Paciente/estadística & datos numéricos , Complicaciones del Embarazo/terapia , Resultado del Embarazo , Adolescente , Adulto , Estudios de Cohortes , Enfermedad Crítica , Países en Desarrollo , Femenino , Edad Gestacional , Humanos , Incidencia , Mortalidad Infantil/tendencias , Recién Nacido , Mortalidad Materna/tendencias , Complicaciones del Trabajo de Parto/diagnóstico , Embarazo , Complicaciones del Embarazo/diagnóstico , Complicaciones del Embarazo/mortalidad , Calidad de la Atención de Salud , Estudios Retrospectivos , Medición de Riesgo , Arabia Saudita/epidemiología , Resultado del Tratamiento
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