A rare association of serous cystadenoma of the pancreas with mediastinal lipoma: a case report

Cystic lesions of pancreas include a myriad of different conditions ranging from the common pseudocyst to unusual cystic neoplasm. With the development of better imaging modalities, cystic neoplasms are diagnosed with greater frequency and accuracy leading on to better understanding of the natural course of these lesions. Serous cystadenoma is one of the rare neoplasms of the pancreas that is unique for its benign nature. Most of the time surgery is indicated for the symptom of pain when the lesion enlarges. Surgery may also be indicated due to the fact that, it may not always be possible to dogmatically differentiate it from the potentially malignant counterpart radiologically. One of the interesting aspects about serous cystadenoma is its association with other systemic disorders like von Hippel Lindau syndrome. Herein we report a rare association of serous cystadenoma with mediastinal lipoma, which has not been reported in the literature

Parallel based support vector regression for empirical modeling of nonlinear chemical process systems

In this paper, a support vector regression (SVR) using radial basis function (RBF) kernel is proposed using an integrated parallel linear-and-nonlinear model framework for empirical modeling of nonlinear chemical process systems. Utilizing linear orthonormal basis filters (OBF) model to represent the linear structure, the developed empirical parallel model is tested for its performance under open-loop conditions in a nonlinear continuous stirred-tank reactor simulation case study as well as a highly nonlinear cascaded tank benchmark system. A comparative study between SVR and the parallel OBF-SVR models is then investigated. The results showed that the proposed parallel OBF-SVR model retained the same modelling efficiency as that of the SVR, whilst enhancing the generalization properties to out-of-sample data

Numerical simulation of general hydrodynamic dispersion in porous medium

August 1971.Includes bibliographic references (pages 84-88).A general two-dimensional equation of dispersion in a porous medium is presented. The second order linear partial differential equation describing the transient concentration distribution has mixed partial derivatives which is the result of treating the dispersion coefficients as second order symmetric tensors. Using the principles of calculus of variations a "functional" is developed for the dispersion equation that has mixed partial derivatives. The two-dimensional region is divided into triangular finite elements of arbitrary size and shape. The concentration is assumed to vary linearly over each triangular finite element. Minimization of the functional in combination with the finite element method leads to a system of simultaneous, first order, linear, ordinary differential equations. The matrix differential equation is numerically integrated using the fourth order Runge-Kutta and Adams-Moulton multistep predictor-corrector methods. Before proceeding with the use of the new functional, solutions were obtained for the dispersion equation with mixed partial derivatives in a rotated coordinate system. The numerical solutions using the new functional for one- and two-dimensional problems compared favourably with the available analytic solutions and the results obtained by finite element method that use a different functional. It was shown that the new functional can handle different ratios of lateral to longitudinal dispersion. A general stability criteria for the resulting matrix equation is developed. Stability dependent on the data is discussed in detail with examples. A brief description of the numerical instability is also given

Human Adult Stem Cells Maintain a Constant Phenotype Profile Irrespective of Their Origin, Basal Media, and Long Term Cultures

The study aims to identify the phenotypic marker expressions of different human adult stem cells derived from, namely, bone marrow, subcutaneous fat, and omentum fat, cultured in different media, namely, DMEM-Low Glucose, Alpha-MEM, DMEM-F12 and DMEM-KO and under long term culture conditions (>P20). We characterized immunophenotype by using various hematopoietic, mesenchymal, endothelial markers, and cell adhesion molecules in the long term cultures (Passages-P1, P3, P5, P9, P12, P15, and P20.) Interestingly, data revealed similar marker expression profiles irrespective of source, basal media, and extensive culturing. This demonstrates that all adult stem cell sources mentioned in this study share similar phenotypic marker and all media seem appropriate for culturing these sources. However, a disparity was observed in the markers such as CD49d, CD54, CD117, CD29, and CD106, thereby warranting further research on these markers. Besides the aforesaid objective, it is understood from the study that immunophenotyping acts as a valuable tool to identify inherent property of each cell, thereby leading to a valuable cell based therapy

Pressure modification index based on hydrodynamics and mass transfer effects for modeling of CO2 removal from natural gas via absorption at high pressures

In this paper, experimental works involving high concentration CO2 removal at elevated pressures are conducted using a high pressure CO2 pilot plant and the result is used to validate a simulation model based on established models in the literature. A rate based non-equilibrium model using 20 wt% aqueous monoethanolamine (MEA) is developed based on the work of Pandya (1983). The model considers reaction kinetics, mass transfer rate and heat transfer. Since the condition of CO2 removal at atmospheric and high pressure are different, a pressure modification index is proposed and incorporated in the mass transfer flux equation to account for the non-idealities. Comparative study involving the modified model with index-f, original rate-based non-equilibrium model, Aspen Plus equilibrium and non-equilibrium models has also been carried out for the CO2 loading at the top column exit of 1.505 m. It is found that the introduction of the proposed pressure modification index together with proper selection of mass transfer and effective interfacial area correlations results in an improvement in the average error from more than 100% to as low as 18% between the estimated and the pilot plant data