372 research outputs found

    Stagnation Point Flow of A Non-Newtonian Fluid

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    Both Hiemenz flow and Homann flow are two classical problems in the field of fluid dynamics. In this project, both the flows are re-considered and the numerical solutions are obtained. Homann flow is studied with and without the presence of partial slip. These partial differential equations are reduced to ordinary differential equations using the similarity transformations. The obtained highly nonlinear ordinary differential equations with the relevant boundary conditions are solved using 4th order Runge-kutta method. The effects of flow parameters on the momentum boundary layer are studied in detail. It is observed that slip has significant effects on the velocity profiles

    DEVELOPMENT AND OPTIMIZATION OF ENZALUTAMIDE-LOADED SOLID LIPID NANOPARTICLES USING BOX–BEHNKEN DESIGN

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    Objective: The primary motive behind this investigation is to develop and optimize the solid lipid nanoparticles formulation of enzalutamide for the effective drug delivery. Materials and Methods: The formulation variables were optimized using design of experiments. Box–Behnken design was used for the study and the results were analyzed using response surface methodology. The prepared nanoformulation was characterized for particle size, zeta potential, surface morphology, X-ray diffractometry (XRD), in vitro drug release kinetics, and stability study. Results: The influence of formulation variables, drug-to-lipid ratio, concentration of phosphatidylcholine, and concentration of poloxamer 188 were evaluated by regression analysis. The optimized formulation (F3) was found to have the minimum particle size (253 nm) with maximum entrapment efficiency (89.72%) and drug loading (23.84%). From SEM studies, the data showed a spherical shape for enzalutamide nanoparticles with uniform and relatively narrow particle distribution. From XRD examines, it is demonstrative that the drug was not in crystalline form in nanoformulation when compared with pure drug. In vitro release studies disclosed that maximum cumulative drug release was attained by F3 (99.72%) in controlled manner. The optimized formulation of enzalutamide followed zero-order release kinetics with a strong correlation coefficient (R2 = 0.9994). Conclusion: The nanoformulation prepared under optimized conditions is in concurrence with the expected results. The SLN formulation can be used as a potential carrier for the effective delivery of enzalutamide

    Design and Fabrication of Automatic Ground Clearance Adjustment System

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    Vehicle ride comfort is one of the most important performances of vehicle; the research of automotive ride comfort is getting more and more important. In this paper is to design and develop a system that is “Automatic ground clearance adjustment system” to overcome this problem by adjusting the ground clearance over this particular time period. Automatic ground clearance adjustment system mainly consists of six major parts such as Chassis, D.C motor, Embedded Development board with Radio Frequency Modules (Encoder & Decoder) and micro controller, IR sensors, alarms, indicators and batteries. The average time required by the system to vary the ground clearance of the vehicle is two seconds. The cost of implementing this system is also low. By implementing “Automatic ground clearance adjustment system”, we can vary the ground clearance of the vehicle. So there is need of developing a system which can vary the ground clearance of the vehicle

    The near infrared cavity-enhanced absorption spectrum of methyl cyanide

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    The absorption spectrum of methyl cyanide (CH3CN) has been measured in the near IR between 6000 and 8000 cm(-1) with a resolution of 0.12 cm(-1) using Fourier transform incoherent broadband cavity-enhanced absorption spectroscopy. The spectrum contains several weakly perturbed spectral regions: potential vibrational combination bands contributing to the spectrum are outlined. Line positions and cross-sections of CH3CN between 6814 and 7067 cm(-1) have been measured at high-resolution of 0.001 cm(-1) using diode laser based off-axis cavity-enhanced absorption spectroscopy. A total of 4630 new absorption lines of CH3CN are identified in this region. A value for the self-broadening coefficient has determined to be (3.3 +/- 0.2) X 10(-3) cm(-1) mbar(-1) for one isolated line at 7034.171 cm(-1). Several line series have been identified in these regions and an autocorrelation analysis performed with a view to aiding future assignments of the rotational-vibrational transitions

    Long optical cavities for open-path monitoring of atmospheric trace gases and aerosol extinction

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    An incoherent broadband cavity-enhanced absorption spectroscopy setup employing a 20 m long optical cavity is described for sensitive in situ measurements of light extinction between 630 and 690 nm. The setup was installed at the SAPHIR atmospheric simulation chamber during an intercomparison of instruments for nitrate (NO3) radical detection. The long cavity was stable for the entire duration of the two week campaign. A detection limit of similar to 2 pptv for NO3 in an acquisition time of 5 s was established during that time. In addition to monitoring NO3, nitrogen dioxide (NO2) concentrations were simultaneously retrieved and compared against concurrent measurements by a chemiluminescence detector. Some results from the campaign are presented to demonstrate the performance of the instrument in an atmosphere containing water vapor and inorganic aerosol. The spectral analysis of NO3 and NO2, the concentration dependence of the water absorption cross sections, and the retrieval of aerosol extinction are discussed. The first deployment of the setup in the field is also briefly described

    Human Cord Blood-Derived AC133+ Progenitor Cells Preserve Endothelial Progenitor Characteristics after Long Term In Vitro Expansion

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    Stem cells/progenitors are central to the development of cell therapy approaches for vascular ischemic diseases. The crucial step in rescuing tissues from ischemia is improvement of vascularization that can be achieved by promoting neovascularization. Endothelial progenitor cells (EPCs) are the best candidates for developing such an approach due to their ability to self-renew, circulate and differentiate into mature endothelial cells (ECs). Studies showed that intravenously administered progenitors isolated from bone marrow, peripheral or cord blood home to ischemic sites. However, the successful clinical application of such transplantation therapy is limited by low quantities of EPCs that can be generated from patients. Hence, the ability to amplify the numbers of autologous EPCs by long term in vitro expansion while preserving their angiogenic potential is critically important for developing EPC based therapies. Therefore, the objective of this study was to evaluate the capacity of cord blood (CB)-derived AC133+ cells to differentiate, in vitro, towards functional, mature endothelial cells (ECs) after long term in vitro expansion.We systematically characterized the properties of CB AC133+ cells over the 30 days of in vitro expansion. During 30 days of culturing, CB AC133+ cells exhibited significant growth potential that was manifested as 148-fold increase in cell numbers. Flow cytometry and immunocytochemistry demonstrated that CB AC133+ cells' expression of endothelial progenitor markers was not affected by long term in vitro culturing. After culturing under EC differentiation conditions, cells exhibited high expression of mature ECs markers, such as CD31, VEGFR-2 and von Willebrand factor, as well as the morphological changes indicative of differentiation towards mature ECs. In addition, throughout the 30 day culture cells preserved their functional capacity that was demonstrated by high uptake of DiI fluorescently conjugated-acetylated-low density lipoprotein (DiI-Ac-LDL), in vitro and in vivo migration towards chemotactic stimuli and in vitro tube formation.These studies demonstrate that primary CB AC133+ culture contained mainly EPCs and that long term in vitro conditions facilitated the maintenance of these cells in the state of commitment towards endothelial lineage

    Optimization and Validation of FePro Cell Labeling Method

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    Current method to magnetically label cells using ferumoxides (Fe)-protamine (Pro) sulfate (FePro) is based on generating FePro complexes in a serum free media that are then incubated overnight with cells for the efficient labeling. However, this labeling technique requires long (>12–16 hours) incubation time and uses relatively high dose of Pro (5–6 µg/ml) that makes large extracellular FePro complexes. These complexes can be difficult to clean with simple cell washes and may create low signal intensity on T2* weighted MRI that is not desirable. The purpose of this study was to revise the current labeling method by using low dose of Pro and adding Fe and Pro directly to the cells before generating any FePro complexes. Human tumor glioma (U251) and human monocytic leukemia cell (THP-1) lines were used as model systems for attached and suspension cell types, respectively and dose dependent (Fe 25 to 100 µg/ml and Pro 0.75 to 3 µg/ml) and time dependent (2 to 48 h) labeling experiments were performed. Labeling efficiency and cell viability of these cells were assessed. Prussian blue staining revealed that more than 95% of cells were labeled. Intracellular iron concentration in U251 cells reached ∼30–35 pg-iron/cell at 24 h when labeled with 100 µg/ml of Fe and 3 µg/ml of Pro. However, comparable labeling was observed after 4 h across the described FePro concentrations. Similarly, THP-1 cells achieved ∼10 pg-iron/cell at 48 h when labeled with 100 µg/ml of Fe and 3 µg/ml of Pro. Again, comparable labeling was observed after 4 h for the described FePro concentrations. FePro labeling did not significantly affect cell viability. There was almost no extracellular FePro complexes observed after simple cell washes. To validate and to determine the effectiveness of the revised technique, human T-cells, human hematopoietic stem cells (hHSC), human bone marrow stromal cells (hMSC) and mouse neuronal stem cells (mNSC C17.2) were labeled. Labeling for 4 hours using 100 µg/ml of Fe and 3 µg/ml of Pro resulted in very efficient labeling of these cells, without impairing their viability and functional capability. The new technique with short incubation time using 100 µg/ml of Fe and 3 µg/ml of Pro is effective in labeling cells for cellular MRI

    Detection of Toxigenic and Atoxigenic Strains of Aspergillus flavus in Telangana and Andhra Pradesh

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    In groundnut Aspergillus flavus causes aflatoxin contamination which is a qualitative problem occurring at both pre-and post-harvest stages. These aflatoxins have carcinogenic, hepatotoxic, teratogenic and immuno-suppressive effects. The A. flavus strains which produces aflatoxins are called as toxigenic and which do not produce toxins are called as atoxigenic starins. To detect the toxigenic and atoxigenic starins of A. flavus from Telangana and Andhra Pradesh (AP), pod samples were collected from eight selected oil mills/traders’ in Mahaboobnagar, Rangareddy, Nizamabad, Karimnagar (Telangana); and Anantapur (AP) districts. A total of 24 A. flavus cultures were isolated from the collected pod samples. These isolates were identified as toxigenic/atoxigenic using cultural detection methods on Yeast extract sucrose (YES) media and coconut agar medium (CAM). Based on cultural methods, it was confirmed that there were18 toxigenic, five atoxigenic and one false positive/negative strain out of the 24 A. flavus isolates obtained from surveyed oil mills. Atoxigenic strains were obtained from Karimnagar and Nizamabad districts of Telangana

    Prevalence of Aspergillus flavus Infection and Aflatoxin Contamination of Groundnut in Telangana and Andhra Pradesh

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    Aflatoxin contamination is a qualitative problem in groundnut (Arachis hypogaea L.) occurring at both pre-and post-harvest stages. These aflatoxins are secondary metabolites produced by Aspergillus flavus and A. parasiticus and have carcinogenic, hepatotoxic, teratogenic and immuno-suppressive effects. To evaluate the prevalence of A. flavus infection and aflatoxin contamination in groundnut oil mills/traders’ of Telangana and Andhra Pradesh (AP) pod samples were collected from eight selected oil mills/traders’ in Mahaboobnagar, Rangareddy, Nizamabad, Karimnagar (Telangana); and Anantapur (AP) districts. A total of 24 pod samples were collected (Three samples from the each selected oil mill). Aflatoxin contamination in kernels was estimated by indirect competitive ELISA. In Telangana, kernel infection ranged from 42 (Mahaboobnagar) to 90.7% (Nizamabad). In AP, Tadimarri mandal recorded kernel infection up to 29.3% whereas Tadipatri recorded up to 59.3%. Aflatoxins in kernels from these mills in Telangana were highest in Rangareddy (1205.2 µg kg-1 ) followed by Karimnagar (365.5 µg kg-1 ). Oil mills of Nizamabad and Mahaboobnagar have recorded aflatoxins to a tune of 4.9 and 11.5 µg kg-1 in Telangana. In AP, aflatoxins in pod samples were 2.8 µg kg-1 (Tadipatri) and 6148.4 µg kg-1 (Tadimarri)

    Endothelial Progenitor Cells (EPCs) as Gene Carrier System for Rat Model of Human Glioma

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    Due to their unique property to migrate to pathological lesions, stem cells are used as a delivery vehicle for therapeutic genes to tumors, especially for glioma. It is critically important to track the movement, localization, engraftment efficiency and functional capability or expression of transgenes of selected cell populations following transplantation. The purposes of this study were to investigate whether 1) intravenously administered, genetically transformed cord blood derived EPCs can carry human sodium iodide symporter (hNIS) to the sites of tumors in rat orthotopic model of human glioma and express transgene products, and 2) whether accumulation of these administered EPCs can be tracked by different in vivo imaging modalities.Collected EPCs were cultured and transduced to carry hNIS. Cellular viability, differential capacity and Tc-99m uptake were determined. Five to ten million EPCs were intravenously administered and Tc-99-SPECT images were acquired on day 8, to determine the accumulation of EPCs and expression of transgenes (increase activity of Tc-99m) in the tumors. Immunohistochemistry was performed to determine endothelial cell markers and hNIS positive cells in the tumors. Transduced EPCs were also magnetically labeled and accumulation of cells was confirmed by MRI and histochemistry. SPECT analysis showed increased activity of Tc-99m in the tumors that received transduced EPCs, indicative of the expression of transgene (hNIS). Activity of Tc-99m in the tumors was also dependent on the number of administered transduced EPCs. MRI showed the accumulation of magnetically labeled EPCs. Immunohistochemical analysis showed iron and hNIS positive and, human CD31 and vWF positive cells in the tumors.EPC was able to carry and express hNIS in glioma following IV administration. SPECT detected migration of EPCs and expression of the hNIS gene. EPCs can be used as gene carrier/delivery system for glioma therapy as well as imaging probes
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