1,306 research outputs found

    Estimation Of Longitudinal Moment Derivatives Of Missile Configuration Using Semi Free Flying Technique

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    A Semi-Free Dynamic Flying Test Technique Has Been Used To Estimate The Pitching Moment Derivatives Of A Missile Model. Wind Tunnel Tests Were Carried Out On A 1 :8 Scale Model Of PJ08 Missile Configuration. The Pitching Moment Derivatives Were Estimated From The Angular Motion Responses Of The Model To Doublet Input Using MLE Method. The Results Of Tests On Configuration 1 For Three CG Positions Are Detailed

    Flight Data Analysis and Parameter Estimation for LCA - Phase III - Final Report

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    The Document Briefly Describes The Major Tasks Accomplished In Phase III Of The Project . Flight Test Data Were Generated From Planned Maneuvers At Various Test Points In The Flight Envelope. The Analysis Was No Longer Restricted To Small Amplitude Maneuvers ; Data From Large Amplitude Maneuvers Were Analyzed As Well To Obtain Parameter Estimates Over A Wider Range Of Angle Of Attack . Most Of The Estimates Adhered Closely To The Trends Predicted By Wind Tunnel Database And There Were No Major Surprises Except For The Reduction In Direction Stability And Aileron Control Effectiveness . Results Were Also Obtained For Coefficient Level Matching, Drag-Polar Estimation And Flight Data Analysis With Airbrakes . The Tasks Carried Out Are Discussed In Detail In The Interim Reports/Project Documents (A Complete List Is Provided At The End Of The Report).The Document Also Highlights Certain. Issues That Need To Be Investigated

    Investigation of Basic mechanical properties of Jute Reinforced polyster composites for Patellar Implant Application

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    n this study, Polyester resin matrix was reinforced with Jute fibers in different compositions and orientations. The polymer composites were prepared using Hand layup technique. Mechanical tests such as tensile test, compression test and bending test were conducted on the samples prepared to the standard dimensions. Also compared with the properties of UHMWPE, which is the presently used material.Thus it is concluded that Jute reinforced polymer composite is a low density material and the induced stresses are within the permissible range. So, existing implants can be replaced by polymer composite implants based on strength properties

    Anti-Tumor Activity of a Novel HS-Mimetic-Vascular Endothelial Growth Factor Binding Small Molecule

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    The angiogenic process is controlled by variety of factors of which the vascular endothelial growth factor (VEGF) pathway plays a major role. A series of heparan sulfate mimetic small molecules targeting VEGF/VEGFR pathway has been synthesized. Among them, compound 8 (2-butyl-5-chloro-3-(4-nitro-benzyl)-3H-imidazole-4-carbaldehyde) was identified as a significant binding molecule for the heparin-binding domain of VEGF, determined by high-throughput-surface plasmon resonance assay. The data predicted strong binding of compound 8 with VEGF which may prevent the binding of VEGF to its receptor. We compared the structure of compound 8 with heparan sulfate (HS), which have in common the functional ionic groups such as sulfate, nitro and carbaldehyde that can be located in similar positions of the disaccharide structure of HS. Molecular docking studies predicted that compound 8 binds at the heparin binding domain of VEGF through strong hydrogen bonding with Lys-30 and Gln-20 amino acid residues, and consistent with the prediction, compound 8 inhibited binding of VEGF to immobilized heparin. In vitro studies showed that compound 8 inhibits the VEGF-induced proliferation migration and tube formation of mouse vascular endothelial cells, and finally the invasion of a murine osteosarcoma cell line (LM8G7) which secrets high levels of VEGF. In vivo, these effects produce significant decrease of tumor burden in an experimental model of liver metastasis. Collectively, these data indicate that compound 8 may prevent tumor growth through a direct effect on tumor cell proliferation and by inhibition of endothelial cell migration and angiogenesis mediated by VEGF. In conclusion, compound 8 may normalize the tumor vasculature and microenvironment in tumors probably by inhibiting the binding of VEGF to its receptor

    Gastric LTi cells promote lymphoid follicle formation but are limited by IRAK-M and do not alter microbial growth.

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    Lymphoid tissue inducer (LTi) cells are activated by accessory cell IL-23, and promote lymphoid tissue genesis and antibacterial peptide production by the mucosal epithelium. We investigated the role of LTi cells in the gastric mucosa in the context of microbial infection. Mice deficient in IRAK-M, a negative regulator of TLR signaling, were investigated for increased LTi cell activity, and antibody mediated LTi cell depletion was used to analyze LTi cell dependent antimicrobial activity. H. pylori infected IRAK-M deficient mice developed increased gastric IL-17 and lymphoid follicles compared to wild type mice. LTi cells were present in naive and infected mice, with increased numbers in IRAK-M deficient mice by two weeks. Helicobacter and Candida infection of LTi cell depleted rag1(-/-) mice demonstrated LTi-dependent increases in calprotectin but not RegIII proteins. However, pathogen and commensal microbiota populations remained unchanged in the presence or absence of LTi cell function. These data demonstrate LTi cells are present in the stomach and promote lymphoid follicle formation in response to infection, but are limited by IRAK-M expression. Additionally, LTi cell mediated antimicrobial peptide production at the gastric epithelium is less efficacious at protecting against microbial pathogens than has been reported for other tissues

    Structure and Rheology of the Defect-gel States of Pure and Particle-dispersed Lyotropic Lamellar Phases

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    We present important new results from light-microscopy and rheometry on a moderately concentrated lyotropic smectic, with and without particulate additives. Shear-treatment aligns the phase rapidly, except for a striking network of oily-streak defects, which anneals out much more slowly. If spherical particles several microns in diameter are dispersed in the lamellar medium, part of the defect network persists under shear-treatment, its nodes anchored on the particles. The sample as prepared has substantial storage and loss moduli, both of which decrease steadily under shear-treatment. Adding particles enhances the moduli and retards their decay under shear. The data for the frequency-dependent storage modulus after various durations of shear-treatment can be scaled to collapse onto a single curve. The elasticity and dissipation in these samples thus arises mainly from the defect network, not directly from the smectic elasticity and hydrodynamics.Comment: 19 pages inclusive of 12 PostScript figures, uses revtex, psfrag and epsfig. Revised version, accepted for publication in Euro. Phys. J. B, with improved images of defect structure and theoretical estimates of network elasticity and scalin

    Estimation methods for determination of drag characteristics of fly-by-wire aircraft

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    In this paper, several parameter/state estimation approaches for the determination of dragpolars from flight data are described and evaluated for a fly-by-wire (FBW) aircraft. Both model-based approaches (MBAs) and non-model-based approaches(NMBAs) are considered. Dynamic response data from roller coaster and wind-up-turn manoeuvres are generated in a FBW aircraft flight simulator at different flight conditions and the typical performance results are presented. A novel approach to estimate the drag polar has been evaluated. It has been found that the NMBAs perform better than the MBAs. Classically, the MBAs have been used for the determination of drag polars. The merits of an NMBA are that it does not require specification of the detailed model of the aerodynamic coefficients and it can be suitably used for online estimation of drag polars from the flight data of aerospace vehicles

    Anti-tumor and anti-angiogenic activity of novel hydantoin derivatives: Inhibition of VEGF secretion in liver metastatic osteosarcoma cells

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    A series of new azaspiro bicyclic hydantoin derivatives has been designed and synthesized. Initially, the anti-proliferative effect of the hydantoin derivatives was evaluated against human ovarian cancer cells (SKOV-3 and OVSAHO) and murine osteosarcoma cells (LM8 and LM8G7). Among the tested compounds, 8-(3-fluorobenzyl)-1′-(4-(methylsulfonyl)benzyl)-8-azaspiro[bicyclo[3.2.1]octane-3,4′-imidazolidine]-2′,5′-dione (7h) and 8-(3,4-difluorobenzyl)-1′-(4-(methylsulfonyl)benzyl)-8-azaspiro[bicyclo[3.2.1]octane-3,4′-imidazolidine]-2′,5′-dione (7i) showed a significant anti-proliferative activity against the OVSAHO and LM8G7 cells. The real-time monitoring of the effect of the compounds 7h and 7i against the proliferation of LM8G7 was revealed that resulting IC50 values were 102 μM and 13 μM, respectively. We reasoned that the presence of fluorine atom at the 3rd position of the phenyl ring of the hydantoin side chain may determine the potency of the molecule. Furthermore, the compound 7i inhibited the tube formation of the mouse endothelial cells. Finally, the treatment of the compound 7i against the proliferation of LM8G7 cells demonstrated the down regulation of the secretion of VEGF, indicate the potential angioinhibitory effects. In conclusion, our findings demonstrate the suppression of the secretion of VEGF by LM8G7 cells by the compound 7i might contribute at least in part to the antitumor action

    Synthesis and characterization of novel 1,2-oxazine-based small molecules that targets acetylcholinesterase

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    Thirteen 2-oxazine-based small molecules were synthesized targeting 5-lipoxygenase (LOX), and acetylcholinesterase (AChE). The test revealed that the newly synthesized compounds had potent inhibition towards both 5-LOX and AChE in lower micro molar concentration. Among the tested compounds, the most active compound, 2-(2-acetyl-6,6-dimethyl-4-phenyl-5,6-dihydro-2H-1,2-oxazin-3- yl)methyl-1H-isoindole-1,3(2H)-dione (2a) showed inhibitory activity towards 5-LOX and AChE with an IC50 values of 1.88, and 2.5 μM, respectively. Further, the in silico molecular docking studies revealed that the compound 2a bound to the catalytic domain of AChE strongly with a highest CDOCKER score of -1.18 kcal/mol when compared to other compounds of the same series. Additionally, 2a showed a good lipophilicity (log P = 2.66), suggesting a potential ability to penetrate the blood-brain-barrier. These initial pharmacological data revealed that the compound 2a could serve as a drug-seed in developing anti-Alzheimer's agents. © 2014 Elsevier Ltd. All rights reserved
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