166 research outputs found

    Numerical Solution of the Momentum and Heat Transfer Equations for a Hydromagnetic Flow Due to a Stretching Sheet of a non-uniform Property Micropolar Liquid

    Get PDF
    A study of the hydromagnetic flow due to a stretching sheet and heat transfer in an incompressible micropolar liquid is made. Temperature-dependent thermal conductivity and a non-uniform heat source/sink render the problem analytically intractable and hence a numerical study is made using the shooting method based on Runge-Kutta and Newton-Raphson methods. The two problems of horizontal and vertical stretching are considered to implement the numerical method. The former problem involves one-way coupling between linear momentum and heat transport equations and the latter involves two-way coupling. Further, both the problems involve two-way coupling between the non-linear equations of conservation of linear and angular momentums. A similarity transformation arrived at for the problem using the Lie group method facilitates the reduction of coupled, non-linear partial differential equations into coupled, non-linear ordinary differential equations. The algorithm for solving the resulting coupled, two-point, non-linear boundary value problem is presented in great detail in the paper. Extensive computation on velocity and temperature profiles is presented for a wide range of values of the parameters, for prescribed surface temperature (PST) and prescribed heat flux (PHF) boundary conditions

    Induction of calcium sensing receptor in human colon cancer cells by calcium, vitamin D and aquamin: Promotion of a more differentiated, less malignant and indolent phenotype

    Full text link
    The calcium sensing receptor (CaSR) is a robust promoter of differentiation in colonic epithelial cells and functions as a tumor suppressor. Cancer cells that do not express CaSR (termed CaSR null) are highly malignant while acquisition of CaSR expression in these cells circumvents the malignant phenotype. We hypothesize that chemopreventive agents mediate their action through the induction of CaSR. Here, we compare the effectiveness of Ca2+, vitamin D, and Aquamin (a marine algae product containing Ca2+, magnesium and detectable levels of 72 additional minerals) on the induction of CaSR in the CBS and HCT116 human colon carcinoma cell lines and the corresponding CaSR null cells isolated from these lines. All three agonists induced CaSR mRNA and protein expression and inhibited cellular proliferation in the parental and CaSR null cells. Aquamin was found to be most potent in this regard. Induction of CaSR expression by these agonists resulted in demethylation of the CaSR gene promoter with a concurrent increase in CaSR promoter reporter activity. However, demethylation per se did not induce CaSR transcription. Induction of CaSR expression resulted in a down‐regulated expression of tumor inducers and up‐regulated expression of tumor suppressors. Again, Aquamin was found to be most potent in these biologic effects. This study provides a rationale for the use of a multi‐mineral approach in the chemoprevention of colon cancer and suggests that induction of CaSR may be a measure of the effectiveness of chemopreventive agents. © 2013 Wiley Periodicals, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/111913/1/mc22123.pd

    Biases in Thorpe-scale estimates of turbulence dissipation. Part I : Assessments from large-scale overturns in oceanographic data

    Get PDF
    Author Posting. © American Meteorological Society, 2015. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Physical Oceanography 45 (2015): 2497–2521, doi:10.1175/JPO-D-14-0128.1.Oceanic density overturns are commonly used to parameterize the dissipation rate of turbulent kinetic energy. This method assumes a linear scaling between the Thorpe length scale LT and the Ozmidov length scale LO. Historic evidence supporting LT ~ LO has been shown for relatively weak shear-driven turbulence of the thermocline; however, little support for the method exists in regions of turbulence driven by the convective collapse of topographically influenced overturns that are large by open-ocean standards. This study presents a direct comparison of LT and LO, using vertical profiles of temperature and microstructure shear collected in the Luzon Strait—a site characterized by topographically influenced overturns up to O(100) m in scale. The comparison is also done for open-ocean sites in the Brazil basin and North Atlantic where overturns are generally smaller and due to different processes. A key result is that LT/LO increases with overturn size in a fashion similar to that observed in numerical studies of Kelvin–Helmholtz (K–H) instabilities for all sites but is most clear in data from the Luzon Strait. Resultant bias in parameterized dissipation is mitigated by ensemble averaging; however, a positive bias appears when instantaneous observations are depth and time integrated. For a series of profiles taken during a spring tidal period in the Luzon Strait, the integrated value is nearly an order of magnitude larger than that based on the microstructure observations. Physical arguments supporting LT ~ LO are revisited, and conceptual regimes explaining the relationship between LT/LO and a nondimensional overturn size are proposed. In a companion paper, Scotti obtains similar conclusions from energetics arguments and simulations.B.D.M. and S.K.V. gratefully acknowledge the support of the Office of Naval Research under Grants N00014-12-1-0279, N00014-12-1-0282, and N00014-12-1-0938 (Program Manager: Dr. Terri Paluszkiewicz). S.K.V. also acknowledges support of the National Science Foundation under Grant OCE-1151838. L.S.L. acknowledges support for BBTRE by the National Science Foundation by Contract OCE94-15589 and NATRE and IWISE by the Office of Naval Research by Contracts N00014-92-1323 and N00014-10-10315. J.N.M. was supported through Grant 1256620 from the National Science Foundation and the Office of Naval Research (IWISE Project).2016-04-0

    Tissue engineering and regenerative medicine research - how can it contribute to fight future pandemics?

    Get PDF
    Understanding the pathogenesis of viral infection is of paramount importance for the development of better therapies. In the particular case of COVID-19, the mechanism of infection is highly complex and involves a critical cascade of events, which can lead to the death of the patient. Intense research is currently being performed to gain mechanistic insights about the virus etiology and to evaluate new therapeutic approaches. The development of point-of-care diagnostic tools, predictive drug screening platforms, and biomimetic models of the disease could play a key role in understanding the cellular and molecular mechanism of viral infection and its response to drugs. In this regard, specific tissue engineering and regenerative medicine approaches, such as microfluidics and organ-on-a-chip technologies, as well as bioprinted in vitro disease models, could be used to develop a technological platform to fight COVID-19, and other virus pandemics yet to come. Herein, we briefly discuss about how such approaches can contribute to address current and future viral pandemics by highlighting recent successful examples.D. Caballero acknowledges the financial support from the Portuguese Foundation for Science and Technology under the program CEEC Individual 2017 (CEECIND/00352/2017) and the project 2MATCH (02/SAICT/2017 - nÂș 028070) funded by the Programa Operacional Regional do Norte supported by FEDER. M. Carvalho would like to acknowledge IET Harvey Research Prize 2017. The authors also acknowledge the financial support from the EU Framework Programme for Research and Innovation Horizon 2020 on Forefront Research in 3D Disease Cancer Models as in vitro Screening Technologies (FoReCaST- no. 668983), the Portuguese Foundation for Science and Technology (FCT) distinction attributed to J. M. Oliveira (IF/00423/2012, IF/01285/2015) and FCT, Fundo Europeu de Desenvolvimento Regional (FEDER) and Programa Operacional Competitividade e Internacionalização (POCI) for funding the projects B-Liver (PTDC/EMD-EMD/29139/2017), Hierarchitech (M-ERA-NET/0001/2014) and 3BioMeD (JICAM/0001/2017)

    Can saliva offer an advantage in monitoring of diabetes mellitus?: a case control study

    Get PDF
    Objectives: Diabetes Mellitus is emerging as a major health problem over these years. Present method of blood glucose monitoring by venepuncture is invasive leading to reduced patient compliance and thereby ineffective judicious monitoring. The need of the hour is to direct research in the direction of establishing painless and more acceptable blood glucose analysis method.The objective of the study is to conduct a comparative analysis of the concentrations of salivary glucose and blood glucose in type 2 diabetes mellitus patients. Study Design: This study assessed glucose levels using the glucose oxidase method in blood and unstimulated sali - va in 90 subjects who were divided into 3 equal groups of controlled type 2 diabetes, uncontrolled type 2 diabetes and those without diabetes. Statistical analysis was carried out using one way ANOVA, Post hoc Tukeys tests and Pearson's correlation coefficient test. Results: Salivary glucose levels were significantly higher in patients with diabetes than controls. There was a signi - ficant positive correlation between salivary and plasma glucose levels in patients with diabetes. Conclusions: Glucose concentration in saliva is higher in diabetics but hyperglycemia does not influence salivary glucose levels. Further clarification is required to claim the diagnostic potentials of saliva in diabetes

    Modification of upper-ocean temperature structure by subsurface mixing in the presence of strong salinity stratification

    Get PDF
    Author Posting. © The Oceanography Society, 2016. This article is posted here by permission of The Oceanography Society for personal use, not for redistribution. The definitive version was published in Oceanography 29, no. 2 (2016): 62–71, doi:10.5670/oceanog.2016.39.The Bay of Bengal has a complex upper-ocean temperature and salinity structure that is, in places, characterized by strong salinity stratification and multiple inversions in temperature. Here, two short time series from continuously profiling floats, equipped with microstructure sensors to measure subsurface mixing, are used to highlight implications of complex hydrography on upper-ocean heat content and the evolution of sea surface temperature. Weak mixing coupled with the existence of subsurface warm layers suggest the potential for storage of heat below the surface mixed layer over relatively long time scales. On the diurnal time scale, these data demonstrate the competing effects of surface heat flux and subsurface mixing in the presence of thin salinity-stratified mixed layers with temperature inversions. Pre-existing stratification can amplify the sea surface temperature response through control on the vertical extent of heating and cooling by surface fluxes. In contrast, subsurface mixing entrains relatively cool water during the day and relatively warm water during the night, damping the response to daytime heating and nighttime cooling at the surface. These observations hint at the challenges involved in improving monsoon prediction at longer, intraseasonal time scales as models may need to resolve upper-ocean variability over short time and fine vertical scales.This work was funded by Office of Naval Research grants N00014-14-1-0236 (ELS, JNM), N00014-13-1-0483 (DLR), N00014-13-1- 0453 (JTF), and N00014-12-1-0938 (SKV, AG)

    Sinteza, antitumorsko i citostatsko djelovanje derivata 6H-indolo[2,3-b]kinoksalina

    Get PDF
    Various 6-aralkyl-9-substituted-6H-indolo[2,3-b]quinoxalines were synthesized by reaction of 1,5-disubstituted 2,3-dioxo-2,3-dihydroindole with orthophenylene diamine. Appreciable anticancer activity of compounds 5b, 5d, 5g and 5l at various cell lines among 59 human tumor cell panels was observed. All the synthesized compounds were evaluated for cytostatic activity against human Molt 4/C8 and CEM T-lymphocytes as well as for murine L1210 leukemia cells. Compound 5h exhibited an IC50 of 71 Όmol mL1 against Molt 4/C8 and 117 Όmol mL1 against CEM compared to melphalan 3.2 Όmol mL1 and 2.5 Όmol mL1, respectively. The IC50 for compound 7i against L1210 was 7.2 Όmol mL1 compared to melphalan 2.1 Όmol mL1.Reakcijom 1,5-disupstituiranih 2,3-diokso-2,3-dihidroindola s ortofenilen diaminom sintetizirani su različiti 6-aralkil-9-supstituirani-6H-indolo[2,3-b]kinoksalini. Spojevi 5b, 5d, 5g i 5l pokazali su značajno antitumorsko djelovanje na 59 humanih tumorskih stanica. Svi sintetizirani spojevi ispitani su na citostatsko djelovanje na stanične linije Molt 4/C8 i CEM T-limfocite, te na murin L1210 stanice leukemije. IC50 za spoj 5h je 71 Όmol mL1 na staničnu liniju Molt 4/C8 i 117 Όmol mL1 na CEM, dok su vrijednosti za melfalan 3,2, odnosno 2,5 Όmol mL1. IC50 spoja 7i na stanice L1210 je 7,2 Όmol mL1, dok je za melfalan 2,1 Όmol mL1

    Non-Hodgkin's lymphoma presenting as a primary bladder tumor: a case report

    Get PDF
    <p>Abstract</p> <p>Introduction</p> <p>Primary lymphoma of the bladder represents 0.2% of all bladder malignancies. Secondary involvement of the bladder by malignant lymphoma occurs in 10% to 50% of cases. Most lymphomas of the bladder are non-Hodgkin's lymphomas of the B-cell type, with preponderance among women. The impact of positron emission tomography (PET) on tumor staging has recently become very important due to its use in the study of diagnosis extension and individual therapy design.</p> <p>Case presentation</p> <p>We report the case of a 79-year-old Caucasian man with intermittent haematuria as the presenting symptom of non-Hodgkin's lymphoma of the bladder. He was first diagnosed with primary lymphoma of the bladder using the current staging method, but a positron emission tomography study subsequently revealed that he instead had a secondary involvement of the bladder.</p> <p>Conclusion</p> <p>The staging of non-Hodgkin's lymphomas, which is useful in order to plan accurate therapy, has been changing since the introduction of positron emission tomography scanning. Primary lymphomas of the bladder, although very rare, may be even more uncommon when this imaging technique is used to assess the extension of the disease. Although the interpretation of this technique has some limitations that should be taken into account, the extensive use of positron emission tomography should nonetheless help improve the diagnosis of this disease.</p
    • 

    corecore